Journal articles: 'Refrigeration and refrigerating machinery'

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Lebedev, B., L. Knaub, E. Lebedeva, and E. Pavlishko. "AN EXPERIMENTAL STUDY OF THE AMMONIA HERMETIC SMALL REFRIGERATION MACHINE." Аграрний вісник Причорномор'я, no. 94 (December 25, 2019): 139–54. http://dx.doi.org/10.37000/abbsl.2019.94.20.

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The article focuses on the study of the design parameters of small refrigerating machines. This article shows practical studies of the dependence of the energy parameters of the refrigerating machine on its design features.In particular, the dependence of the coefficient of performance upon the superheating of steam at the suction in the compressor was studied, and preventing method of such overheating for small refrigerating machines was proposed. At the second stage the possibility of using a regenerative heat exchanger in an ammonia refrigerating machine was examined. The advantages of its use are shown. In general, the possibility of increasing the refrigeration efficiency by changing design parameters of the refrigerating machine is shown.

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Krivtsov, D. V., and A. F. Porutchikov. "Development and investigation of refrigerating machine with dosage filling ammonia." Izvestiya MGTU MAMI 8, no. 1-3 (May 10, 2014): 88–91. http://dx.doi.org/10.17816/2074-0530-67596.

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The paper considers the low refrigeration capacity ammonia refrigerating machine. New technical solutions are proposed to decrease ammonia capacity, to scale-up the operating safety and to provide self-acting unsupervised automatic mode. The method of constructing a mathematical model and analysis of the refrigeration machine operation is described.

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Kirillov, N. G. "Stirling Refrigerating Machines — Promising Equipement for Moderate Refrigeration." Chemical and Petroleum Engineering 41, no. 7-8 (July 2005): 372–76. http://dx.doi.org/10.1007/s10556-005-0123-5.

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Fot, A. N., and D. K. Melnikov. "Features of calculation of refrigerating machines with combined cooling of condensers taking into account climatic and economic factors." Omsk Scientific Bulletin. Series Aviation-Rocket and Power Engineering 5, no. 4 (2021): 17–23. http://dx.doi.org/10.25206/2588-0373-2021-5-4-17-23.

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A method for calculating refrigerating machines with a condensation unit implementing water and air cooling methods is proposed taking into account the economic and climatic features of the calculated region. Since economic and climatic factors have different degrees of influence on the energy efficiency and efficiency of refrigerating machines over the entire range of changing temperatures of cooling media, the results of calculating refrigerating machines according to the proposed methodology allow making informed decisions about the layout of the condensation unit both at the design stage and at the stage of developing a program for managing the refrigeration unit throughout the year. A comparative analysis of refrigerating machines with combined cooling of condensers for the regions of Omsk and Berlin is carried out. The most significant influence of the climatic factor at low temperatures of the cooling air and the influence of the cost of cooling water at high air temperatures were revealed.

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Danilishin, A. M., and Y. V. Kozhukhov. "Centrifugal Compressors Gas-Dynamic Characteristics Influence on the Refrigerating Machines Efficiency." Problems of the Regional Energetics, no. 2(58) (May 2023): 72–80. http://dx.doi.org/10.52254/1857-0070.2023.2-58-07.

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The article is devoted to the study R134a refrigerating machine efficiency and consisting of a centrifugal compressor, a condenser, a temperature-regulating valve and an evaporator. The main purpose of the work is to analyze the centrifugal compressor gas dynamic characteristics effect on the refrigeration machine vapor-compression cycle efficiency. This goal is achieved through the study by actual working process numerical experiment in the refrigeration machine centrifugal compressor with an idealized process for other elements. The object of the study are the refrigeration machine characteristics, expressed by the theoretical refrigeration coefficient COPRt. Single-stage centrifugal compressors with the design conditional flow coefficient in the range from 0.035 to 0.12 are considered. The design of centrifugal compressors was carried out according to a new calculation method to the flow part efficiency increase. The method comprehensively combines the inviscid and viscous flow calculations with the use of the single-criteria and multiparametric optimization. Previously, the method was tested and compared with experimental data. The most important result is the results of the refrigeration cycle efficiency evaluating through the centrifugal compressors highly efficient flow parts design methodology application. An increase in COPRt was obtained taking into account the centrifugal compressor actual process in the range from 2.6% to 7.2%. The significance of the results obtained lies in the possibility of using high-efficiency centrifugal compressors gas dynamic characteristics for the chillers refrigeration cycles analysis and calculation. The level of the compressors isentropic efficiency ranges from 0.80 to 0.85, depending on the design conditional flow coefficient.

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KHOROLSKY, Valentyn, Yurii KORENETS, Oleksandr OMELCHENKO, and Volodymyr HONCHARENKO. "REFRIGERATION MACHINES IN THE SYSTEM OF CONSISTENT MANAGEMENT OF ELECTRIC ENERGY CONSUMPTION OF THE COMPLEX ENTERPRISE-INDUSTRIAL REFRIGERATOR." Herald of Khmelnytskyi National University. Technical sciences 313, no. 5 (October 27, 2022): 200–212. http://dx.doi.org/10.31891/2307-5732-2022-313-5-200-212.

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The strategy of the coordinated management of electric consumption of the industrial refrigerator of the enterprise of a food complex on production of foodstuff is offered. The structure of the integrated intelligent power management system of the refrigerator enterprise has been developed, in which the systems of automated control of electricity metering and control of the refrigeration trajectory of refrigeration chambers are built-in. The system uses a situation center, industrial Internet of Things (IIoT), digital platform “FOOD” with software (freezing of food products). According to the ASUE-ACS command, the upper level of the industrial refrigerator and its software fulfill the set parameters of the portfolio of orders for active and reactive capacities of the food complex enterprises. An algorithm for controlling an industrial refrigerator during periods of power system power limitations has been developed. It is proved that the reduction of specific energy consumption for the production of one ton of frozen food during the period of power system power limitations and fan outages is possible only by optimizing the technological and energy parameters of refrigeration machines. Technologies for reducing energy consumption by controlling the reactive and active power of synchronous motors of reciprocating compressors and frequency control of asynchronous motors of screw compressors and asynchronous motors of evaporating condensers are presented. Simulation of the geometry of the in-chamber loading of the refrigerating chambers of an industrial refrigerator is performed. New approaches to the choice of adaptive regulators of synchronous motor exciters have been developed, which are coordinated in real time with the energy modes of operation of refrigeration machines and the geometry of refrigeration chamber loading. The possibility of improving the efficiency of power management regimes of food industry enterprises through coordinated automated control of cooling and freezing of meat products, poultry, fish, dairy products, fruits and the use of automated power management systems by building expert and human-machine decision making systems. The developed systems will allow to meet the requirements of energy generating companies for active and reactive loads, reduce costs in the power grid and maintain the voltage in the nodes of electrical receivers within the established norms.

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Bogatyreva, E. V. "Systems approach to modeling recycling refrigeration machines." Transactions of the Krylov State Research Centre S-I, no. 1 (December 8, 2021): 130–31. http://dx.doi.org/10.24937/2542-2324-2021-1-s-i-130-131.

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Refrigeration equipment is not provided on many small fishing vessel projects. It is proposed to install absorption refrigerating machines (ABRM) as refrigeration units for small vessels of the fishing fleet, the working medium of which is a water ammonia mixture. Such machines can operate by using the heat of exhaust gases, that is, receive energy from internal combustion engines. Ship power plants, unlike stationary ones, have characteristics and properties inherent only to them. In modeling, it is proposed to use a systematic approach to optimize the parameters. The principle of a systematic approach is considered. An example of dividing ABRM into subsystems is given. The graph of the simplified thermal circuit of ABRM is presented. Recommendations are given for optimizing the operating parameters.

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Dobre, Cătălina, Lavinia Grosu, Alexandru Dobrovicescu, Georgiana Chişiu, and Mihaela Constantin. "Stirling Refrigerating Machine Modeling Using Schmidt and Finite Physical Dimensions Thermodynamic Models: A Comparison with Experiments." Entropy 23, no. 3 (March 19, 2021): 368. http://dx.doi.org/10.3390/e23030368.

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The purpose of the study is to show that two simple models that take into account only the irreversibility due to temperature difference in the heat exchangers and imperfect regeneration are able to indicate refrigerating machine behavior. In the present paper, the finite physical dimensions thermodynamics (FPDT) method and 0-D modeling using the Schmidt model with imperfect regeneration were applied in the study of a β type Stirling refrigeration machine.The 0-D modeling is improved by including the irreversibility caused by imperfect regeneration and the finite temperature difference between the gas and the heat exchangers wall. A flowchart of the Stirling refrigerator exergy balance is presented to show the internal and external irreversibilities. It is found that the irreversibility at the regenerator level is more important than that at the heat exchangers level. The energies exchanged by the working gas are expressed according to the practical parameters, necessary for the engineer during the entire project. The results of the two thermodynamic models are presented in comparison with the experimental results, which leads to validation of the proposed FPDT model for the functional and constructive parameters of the studied refrigerating machine.

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Tsoy, Alexandr, Oleksandr Titlov, Alexandr Granovskiy, Dmitriy Koretskiy, Olga Vorobyova, Diana Tsoy, and Rita Jamasheva. "Improvement of refrigerating machine energy efficiency through radiative removal of condensation heat." Eastern-European Journal of Enterprise Technologies 1, no. 8(115) (February 25, 2022): 35–45. http://dx.doi.org/10.15587/1729-4061.2022.251834.

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In regions with a continental climate, refrigerators with air-cooled condensers operate at high condensation pressures during the summer season which reduces their efficiency and accelerates the wear of compressors. To reduce condensation pressure, it was proposed to use radiative cooling which is a way of heat removal through the planet's atmosphere to outer space in a form of infrared radiation. A refrigerating machine with an assembly of condensation heat removal including air and liquid cooling condensers connected in series has been developed. To reduce the condensation temperature, a pre-cooled heat-transfer agent is fed to the liquid cooling condenser during the day hours at high atmospheric temperatures. At night, the heat-transfer agent is cooled by radiative cooling. An experimental study of the operation of a 600 W refrigerating machine including a sealed piston compressor was conducted. R134a refrigerant was used. Supply of pre-cooled heat-transfer agent at +33.1 °С has provided a reduction of condensation temperature from +47.0 to +39.1 °С. The study was conducted at an atmospheric air temperature of +38.0 °С. The degree of pressure growth was decreased by 30 %. The refrigeration coefficient was increased by 11 %. In comparison with the conventional scheme with an air-cooled condenser, energy consumption by the system did not change in the daytime. The offered scheme of condensation heat removal reduces the pressure of condensation and provides stability for refrigerating machine operation. It can be used in stationary refrigerating machines at high daytime temperatures.

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Bukin, Vladimir Grigorievich, Alexey Vasilievich Ezhov, and Aleksander Ivanovich Andreev. "Temperature-entropy diagrams for calculating cycles of refrigerating machines using refrigerant mixtures." Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies 2020, no. 4 (November 18, 2020): 79–86. http://dx.doi.org/10.24143/2073-1574-2020-4-79-86.

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The article represents the advantages and disadvantages of refrigeration machines operating on non-azeotropic refrigerant mixtures. There has been illustrated their specific feature in comparison with pure substances: they are non-isothermal during phase transitions. It can be effective when cooling or heating flows that significantly change the temperature, and ineffective when working with volumes, where it is necessary to maintain a constant temperature. In the first case there takes place a decrease in the internal irreversibility of heat transfer processes in evaporators and condensers; in the second case - an increase. When using mixed refrigerants, it is possible to simultaneously obtain several temperature levels in a single-stage machine at the same pressure in the evaporators, they can obtain low boiling points of the refrigerant without vacuum in the evaporator and regulate the refrigeration capacity of the machine by changing the composition of the mixture. The prospects of using mixtures of working bodies of refrigerating machines have been proved. The diagrams T-S, T-ξ, i-ξ are presented allowing to calculate the cycle of the machine, to determine its operating parameters and to calculate the technical and energy characteristics. The developed thermal diagrams make it possible to accurately examine the dynamics of the boiling and condensation processes of a binary mixture, show the change in the concentration of the mixture in the vapor and liquid phases and make it possible to construct and calculate the cycle of a refrigeration machine operating on a mixed refrigerant. Examples of constructing cycles of two schemes of refrigeration machines operating on a mixed refrigerant are considered: with separation of the working substance flow and without separation. Methods for calculating the cycle are provided

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Pronin, V. A., A. V. Kovanov, V. A. Tsvetkov, E. N. Mikhailova, and P. A. Belov. "To the issue of optimising the performance of a scroll compressor as part of a CO2 booster refrigerating machine in order to increase its efficiency." Herald of Dagestan State Technical University. Technical Sciences 50, no. 1 (May 8, 2023): 42–52. http://dx.doi.org/10.21822/2073-6185-2023-50-1-42-52.

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Objective. With the decreasing use of refrigerants with a high global warming potential, increasing the efficiency of refrigeration machines using natural working fluids is a very urgent task. The CO2 booster refrigerant cycle may be optimal for the fields of commercial refrigeration, climate engineering and heat pumps, but needs to be adapted to regions with hot climates. The purpose of the study is also to systematize possible ways to improve the spiral technology, as a guarantee of increasing the efficiency of booster refrigeration machines.Method. Such solutions have already been tested by increasing the transcritical cycle efficiency through the use of an ejector and parallel compression. However, the use of a scroll compressor in the transcritical cycle may be a good alternative to these methods. This solution, a little bit improves technical and economic indexes of the refrigerating machine, in the most part reducing capital and operational costs. When considering the prospect of improving the efficiency of a booster system with scroll compressor, it is necessary to address the issue of compressor performance optimisation. An issue of this kind can be referred to improving the efficiency of the booster system, at the expense of the internal characteristics of the refrigeration machine.Result. Thus, in this paper, a conceptual approach is considered to solve this problem based on a system analysis of the interconnection of the compressor as the main energy-intensive element of a refrigeration machine.Conclusion. Development of conceptual model, allows to identify influence of various factors on scroll compressor operation and to build adequate mathematical model, to choose or develop necessary calculation methods.

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Wall, Göran. "Optimization of refrigeration machinery." International Journal of Refrigeration 14, no. 6 (November 1991): 336–40. http://dx.doi.org/10.1016/0140-7007(91)90029-g.

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Babenkov, Yu I., V. V. Romanov, G. A. Galka, N. A. Bazhutkina, and A. A. Yuritsyn. "Calculation of dynamic operating modes refrigeration machines with electric energy sources." E3S Web of Conferences 431 (2023): 02006. http://dx.doi.org/10.1051/e3sconf/202343102006.

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The method of calculating the dynamic operating modes of refrigerating machines with electric power sources is described. As an example, the results of the calculation and data of experimental studies of the processes of starting a refrigerating machine with an electric asynchronous motor are given.

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Titlov, Alexandr, Eugeniy Osadchuk, Alexandr Tsoy, Assel Alimkeshova, and Rita Jamasheva. "Development of cooling systems on the basis of absorption water-ammonia refrigerating machines of low refrigeration capacity." Eastern-European Journal of Enterprise Technologies 2, no. 8 (98) (April 16, 2019): 57–67. http://dx.doi.org/10.15587/1729-4061.2019.164301.

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Bukin, Vladimir Grigorievich, Aleksander Ivanovich Andreev, and Roman Romanovich Minofyev. "Pressure losses investigation at boiling two-phase flow movement in inclined pipes of a marine refrigeration machine evaporator." Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies 2023, no. 4 (November 27, 2023): 40–45. http://dx.doi.org/10.24143/2073-1574-2023-4-40-45.

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The study of pressure losses at boiling two-phase flow movement in vertical and inclined pipes of evaporators of ship refrigeration units is carried out. The study of the ascending two-phase flow is promising from the point of view of practical application. Such a movement is typical for various types of industrial heat exchange equipment, including for the development of promising types of evaporators, for example, vertical apparatuses for ships in which internal boiling of the refrigerant occurs. A methodology has been developed and an experiment has been set up to study the processes in the steam generating channels of refrigeration units at various angles of inclination with a fixed height. At the same time, the length of the channel changed, it became possible to analyze friction losses. A new approach has been applied that brings the model as close as possible to the actual boiling process, taking into account the constant increase of steam in the channel. Experimental studies have been carried out and data on pressure losses have been revealed when the angle of inclination of the steam generating channel changes. The main dependences and various components of hydraulic resistances during the movement of a boiling two-phase flow are presented. Based on the data obtained, the justification of ship evaporators transition of refrigeration units to the vertical arrangement of the heat exchange steam generating beam is proved. The results obtained indicate that an increase in the slope of the pipe, provided that the height is maintained, leads to an increase in pressure losses. Applicability to marine refrigerating machines has been determined – the transition to vertical apparatuses has advantages, primarily in reducing pressure losses. The obtained set of data allows to recommend the design of vertical evaporators for auxiliary ship installations.

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Lavrenchenko, G. K., J. V. Zmitrochenko, S. M. Nesterenko, and M. G. Khmelnuk. "Characteristics of Voorhees refrigerating machine with hermetic piston compressor producing refrigeration at one or two temperature levels." International Journal of Refrigeration 20, no. 7 (January 1997): 517–27. http://dx.doi.org/10.1016/s0140-7007(97)00034-0.

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Yang, Wen-Jei, Shin Fann, and John H. Kim. "Heat and Fluid Flow Inside Rotating Channels." Applied Mechanics Reviews 47, no. 8 (August 1, 1994): 367–96. http://dx.doi.org/10.1115/1.3111084.

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Power generation and refrigeration accomplished by means of rotating or reciprocating machinery. One of the basic elements of rotating machinery is the rotating channel system. With the desire for ever increasing efficiency in power generation and refrigeration, higher or lower operating temperatures are achieved. It has provided motivation for the pursuit of knowledge on heat transfer and fluid flow characteristics. This paper reviews the literature pertinent to studies of fluid flow and/or heat transfer in channel flows subjected to radial rotation, parallel rotation, and coaxial revolution. Special problems unique to rotating systems are discussed and future study areas are suggested.

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Pronin, V. A., A. V. Kovanov, V. A. Tsvetkov, E. N. Mikhailova, and E. A. Kalashnikova. "Assessment of the influence of gap wall mobility factor at calculation of leakage in working section of a scroll compressor. Part 1." Omsk Scientific Bulletin. Series Aviation-Rocket and Power Engineering 7, no. 1 (2023): 9–17. http://dx.doi.org/10.25206/2588-0373-2023-7-1-9-17.

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The scroll type compressor is widely used in the medium capacity segment of refrigeration and air conditioning technology including heat pumps. Today there is an active process of changing from hydrofluorocarbons to natural refrigerants with low global warming potential. CO2, with its low critical point and correspondingly high operating pressures, is gaining in importance. For operation with new refrigerants, the scroll compressor has to be adapted to take account of all its design features, the most important of which are the clearances in the machine's flow area. It has to be considered that the thermodynamic properties of carbon dioxide, different from hydrofluorocarbons, have a significant influence on the volume and energy values of the compressor. In this case relevance consists in increase of accuracy of compressor losses calculation and prediction of refrigeration machine characteristics. As the basic volumetric losses in the scroll compressor are leakages of working substance in its working part, and the process of flow of medium is unsteady, their quantitative component causes interest. The purpose of this work is to clarify the physical basis of the leakage process in the radial clearance and the degree of influence of various factors on it. Such analysis gives further opportunity to refine the methodology of calculation of leakages of compressed medium, taking into account the mobility factor of gap walls. It will raise accuracy of the received results which can serve as a base to prognosis of optimum characteristics of the compressor, due to their approximation and will allow to optimize designing of refrigerating machines at the chosen modes of work.

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Labay, Volodymyr, and Kyrylo Andreiko. "Influence of transformation coefficient of refrigerating machine on exergetic efficiency of air conditioning system of operating clean rooms." Energy engineering and control systems 9, no. 1 (2023): 9–16. http://dx.doi.org/10.23939/jeecs2023.01.009.

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Exergetic method is a universal way of thermodynamic research of various processes of energy transformation in energy technological systems, to which air conditioning system for clean room belongs. Implementation of exergetic analysis for energy technological system makes it possible to determine the influence of various elements of its system on its work and because of this to increase the effectiveness of work of energy technological system in general. Performance of any air conditioning system depends on energy effectiveness of refrigeration machine, which serves it and consumes electricity to reduce the heat of supply air which enters the room. And it means that the main purpose of selection of certain refrigeration machine for air conditioning system is to reach the maximum cooling capacity with minimum energy consumption. Innovative mathematical research model of the implemented central straight flow air conditioning system for operating clean rooms was used in this article. The aim of the model is to make computer estimation of exergetic efficiency of existing air conditioning system depending on different factors which have influence on its work, in particular the coefficient of transformation (or energy efficiency rate, EER) of its refrigeration machine. The dependence of the exergetic output-input ratio of implemented air conditioning system for operating clean rooms on coefficient of transformation of its refrigeration machine by different parameters of outdoor and indoor air and the temperature difference between the indoor and supply air were presented. It is shown that the implemented air conditioning system should be preferably used with higher coefficient of transformation of its refrigeration machine and higher difference between temperatures of indoor and supply air by various temperatures of outdoor air that will give the opportunity to gain the highest exergetic output-input ratio, which means gaining the most cost effective option for the exploitation of implemented air conditioning system.

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Belyanovskaya, E. A., G. M. Pustovoy, A. I. Sklyarenko, M. P. Sukhyy, K. M. Sukhyy, О. О. Yeromin, and O. M. Prokopenko. "Calculation algorithm for operating parameters of steam-compressive chilling machine with adsorptive chillling unit." Computer Modeling: Analysis, Control, Optimization 8, no. 2 (December 2020): 3–9. http://dx.doi.org/10.32434/2521-6406-2020-8-2-3-9.

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The work is focused on the development of an effective algorithm for calculating the operational characteristics of a steamcompressive chilling machine with an adsorptive chilling unit, which involves a cold box, an adsorber, an evaporator and a condenser, water being used as a refrigerant. An algorithm for calculating the operating parameters of the adsorptive chilling unit has been developed, which includes the determination of the cooling capacity of the steam compressor refrigeration unit, the heat load on the condenser, the power consumed by the compressor, the coefficient of performance of the steam compressor refrigeration unit, as well as the calculation of the mass of water, the mass of the adsorbent, the refrigerating capacity, the coefficient of performance of the adsorptive chilling unit and the coefficient of useful energy utilization of a steam compressive chilling machine with an adsorption chilling unit. The chilling capacity and the coefficient of performance of the adsorption chilling unit are estimated under the operating conditions of a typical steam compression chilling machine. The crucial factors affecting the efficiency of the adsorptive chilling unit are analyzed. It has been established that the chilling capacity, the coefficient of performance of the adsorption refrigeration module and the energy efficiency of the installation are determined by the thermal load on the condenser, and, therefore, by the mass of water that is desorbed and evaporated. The coefficient of performance of the adsorption chilling unit and the efficiency of the steam compressor chilling machine with the adsorptive chilling unit are estimated to be 0.878 and 4.64. The criteria for the selection of adsorbents for the adsorption module are analyzed. The temperature of regeneration is determined by the temperatures in the condenser, and the limit adsorption affects the mass of the adsorbent and the size of the adsorber. A comparison of the efficiency of adsorptive chi l l ing uni t based on silicoaluminophosphates and composite adsorbents «silica gel – sodium acetate» is carried out. The prospects of using composites «silica gel – СН3СООNa» are shown. The optimal composition of the composite was established, which corresponds to the minimal size of the adsorber, (80% sodium acetate and 20% silica gel). The prospects of using adsorptive conversion of thermal energy for utilization of low-potential thermal energy during the operation of steam compressive chilling machine are shown. Keywords: adsorptive conversion of heat energy, composite adsorbent, steam compressive chilling unit, adsorption, adsorptive capacity.

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Olimpos, Paul T. "Effect of Computer-Based Training Materials Using Flat Diagrams and Graphics Animations on Students’ Familiarization of Marine Auxiliary Machinery." European Journal of Education and Pedagogy 5, no. 3 (June 11, 2024): 55–62. http://dx.doi.org/10.24018/ejedu.2024.5.3.821.

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The technological advances that have occurred in recent years have inspired maritime institutions to look for more advanced and efficient teaching strategies. This quasi-experimental study aims to determine the effect of the 2D flat diagrams and 3D graphic animations as instructional materials on Marine Engineering students’ familiarization with auxiliary engine machinery. The participants were second-year students taking up BS Marine Engineering for the second semester of the school year 2021–2022. Two instruments were used. The first was a 30-item multiple-choice questionnaire focusing on Marine Refrigeration systems and Air Conditioning systems. The questions relate to the components of each system, its functions, and its operation. The second instrument was the assessments at the end of the CBTs. Mean, Standard Deviation, Paired t-test, and T-test for independent samples were used to analyze the data. The finding showed that using 2D flat diagrams and 3D graphic animations is essential for the Marine Engineering students’ familiarization with auxiliary engine machinery. Students exposed to the Refrigeration System and Air Conditioning System CBTs with 3D graphic animation have a higher level of familiarization than students exposed to the use of a 2D flat diagram. Moreover, simultaneously, students’ performance increases when they are exposed to the Refrigeration System and Air Conditioning System CBTs with 3D graphic animation. This study recommends upgrading the CBTs used by the school from 2D or flat diagrams to more sophisticated CBTs with 3D graphic animations.

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Morosuk, Tatiana, Ruslan Nikulshin, and Larisa Morosuk. "Entropy-cycle method for analysis of refrigeration machine and heat pump cycles." Thermal Science 10, no. 1 (2006): 111–24. http://dx.doi.org/10.2298/tsci0601111m.

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Real and ideal cycles of any complexity can be compared through the definition of the irreversibility's and ways of their minimization in the thermodynamic analysis. The paper considers the use of entropy-cycle method for thermodynamic analysis of refrigerating machines and heat pumps. Using this method preconditions of practical use for analysis, synthesis, and optimization have been created. The methodology of the entropy-cycle method can be use in many areas of the scientific work and educational process.

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Sun, Ying. "Intelligent Operation and Control of Refrigeration Craft in Cold Storage." Advanced Materials Research 468-471 (February 2012): 1827–30. http://dx.doi.org/10.4028/www.scientific.net/amr.468-471.1827.

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In this paper, we discuss the difference between intelligent and non-intelligent system, and analyze some problems in the development and research of auto-control system in the cold storage. These problems involve engineering survey, predictive control of technical parameters, control reliability of machinery equipment, local control and global control. And the methods of artificial neural networks, genetic algorithm and least square are put forward to resolve them.

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Kaewvaen, Manah. "Explore the Safety of Electrical Systems in Factories that are Related to Cooling System that uses Ammonia as a Refrigerant." Journal Of Technical Education Development 35, no. 124 (December 1, 2022): 102–9. http://dx.doi.org/10.14416/j.ted.2022.08.012.

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Electrical safety research in industrial chiller plants using ammonia as a refrigerant. To analyze the safety of the plant's electrical system and evaluating the safety of the electrical systems of factories in the business group Cold storage factory, Ice plant, Frozen food factory the use of ammonia as a refrigerant in the production and storage activities by performing data analysis with the general status of the machinery. And factory personnel who surveyed the safety of the electrical system in the factory related to the refrigeration system using ammonia as the refrigerant of satisfaction in various areas using percentage and standard deviation. Including opinions related to factors contributing to the research. The results of data analysis showed that the satisfaction of the electrical system operators to the factory electrical system safety. Environment, engine room, cooling system and the surrounding area has a high level of safety the electrical system in the control room and the refrigeration system is of a very safe level. Personnel and electrical hazard prevention of all types of plants are of a very high level of safety. And the satisfaction of the frozen food factory group was in the highest criteria in all aspects when compared between the cold storage factory. And an icehouse at a high level but with a lower average Depending on the electrical design Factory condition Service life and personnel, which results in satisfaction the main factor contributing to the safety of electrical systems in the refrigeration industry is more efficient. Depending on legal operations Control of machinery, equipment and protection in various areas to ensure adequate safety.

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Zhang, Li, Yuan Yuan Zhang, and Yan Miao Ma. "Numerical Simulation of Noise Radiation from Semi-Hermetic Reciprocating Food Refrigeration Compressors." Applied Mechanics and Materials 248 (December 2012): 85–90. http://dx.doi.org/10.4028/www.scientific.net/amm.248.85.

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The semi-hermetic reciprocating compressor is the dominant noise source of food refrigeration unit. Excessive noise and vibration have a negative impact on both people's health and work efficiency；moreover, it causes fatigue damage to machinery thus reducing its working life. In this paper, numerical simulation of noise radiation from semi-hermetic reciprocating food refrigeration was carried out by successful combination of Pro/E, Hypermesh, Nastran and Virtual Lab Acoustics software. The simulation results show that the low-frequency noise radiation near the end of the piston-cylinder is directional and stronger than that of the other side, which offers a valuable reference for noise reduction. In addition, the sound pressure dB curve of any field point can be obtained through the numerical simulation, and it clearly shows that sound pressure values away from the piston end are significantly lower than those at the piston side; and noise radiation energy of compressor concentrates at 500Hz and 1000Hz. This paper provides an effective research method for the semi-hermetic reciprocating compressor’s noise reduction

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Rao T, Rama, and Ranjan Ojha P. "Modification of Design of Cryo-Oxygen Plant for Improved Performance." SOJ Materials Science & Engineering 6, no. 1 (May 7, 2018): 1–11. http://dx.doi.org/10.15226/sojmse.2018.00152.

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Development of an industry is very important for the nation and so is its economical functioning. Cryogenics, being versatile in its application needs proper nourishment and care, which is done by periodic improvements in its systems. Specifically liquid Oxygen is a very important item for high level research and applications. The possibility of launching space vehicle has also come due to the development of liquid oxygen. This also finds its use as a lifesaving item for doctors and many more. The necessity for the economic development of these plants will benefit mankind in many fields. There are many researches which has been done starting from reducing the cost of Oxygen Liquefaction and ultimately its production for cryogenics. The only expenditure for production of liquid Oxygen is electricity. Out of the total electricity consumed, compressor consumes 90% and the remaining 10% is used in running other machinery and lighting of the plants. Studies have also led to the fact that the temperature also plays a great role in consumption of electricity. So in this paper, an attempt has been done to reduce this temperature also. We have incorporated a solar refrigeration system and Freon cooler. Booster compressor is also introduced and modification in it has led to the work saving up to 4.30%. Keywords: Cryogenics; Liquefaction; Solar Refrigeration System; Freon cooler; Booster Compressor;

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Semenov, A. E., A. I. Andreev, and A. A. Tsyplakov. "Simulation of operating modes of the refrigerating machine and the heat pump when drying fish." IOP Conference Series: Earth and Environmental Science 866, no. 1 (October 1, 2021): 012031. http://dx.doi.org/10.1088/1755-1315/866/1/012031.

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Abstract Saving energy resources in the fishing industry is an important task. The purpose of the study is to determine rational schemes and operating modes of air conditioning systems for drying fish. The methodology for calculating the air conditioning system for drying fish and on its basis a computer program in the mathematical package MathCAD is developed. Two air conditioning schemes are considered: a scheme using an air heater and a chiller and a scheme using a chiller and a heat pump. The schemes were analyzed from the standpoint of energy indicators. The parameters of the air supplied to the drying chamber were taken for calculations on the basis of the need to maintain the parameters set by the fish processing technology. In this paper, air conditioning schemes for drying fish are considered, an analysis of the main energy costs during the operation of equipment is carried out. On the basis of calculations, the advantages and disadvantages of the systems, their energy costs for maintaining the specified technological modes are shown. The influence of temperature and flow rate of cold outdoor air and the use of heat recovery units for the exhaust air are shown. It was established that when using outside air with heat exchangers, it is possible to significantly reduce the consumption of heat energy for the technological mode in the cold season. In the absence of heat sources, the scheme with a refrigeration machine and a heat pump has an advantage. The research results were introduced at the fish enterprise of the Astrakhan region by the LLC “Technology of comfort”.

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Johnson, V. W., J. Pearson, and T. A. Jackson. "Formulation of Serratia entomophila for biological control of grass grub." New Zealand Plant Protection 54 (August 1, 2001): 125–27. http://dx.doi.org/10.30843/nzpp.2001.54.3752.

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Cultures of the bacterium Serratia entomophila (Enterobacteriaceae) have been applied as the biological control product Invade for the control of grass grub for more than a decade However the use of the bacterium is limited by the specific requirements of the live microbial cultures for distribution and delivery The cultures must be maintained under refrigeration and applied through a modified seed drill To overcome these problems we have developed a system for stabilising the bacterium in a biopolymer matrix which can then be incorporated into claybased granules The resulting formulation can be stored at ambient temperatures for extended periods and applied to the soil through conventional farm machinery Such thermostable formulations of sensitive microorganisms are likely to have a wide application in the biological control of pests and diseases

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Qiang, Mingchen, Qi Zhao, Shaohang Yan, Xue Liu, Yu Hou, and Tianwei Lai. "Performance Prediction of High-Speed Hydrogen Gas-Lubricated Herringbone Grooved Journal Bearing." Applied Sciences 12, no. 13 (June 24, 2022): 6432. http://dx.doi.org/10.3390/app12136432.

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The liquefaction of hydrogen is considered to be a crucial process in the large-scale utilization of hydrogen energy. In hydrogen liquefaction, hydrogen turbo-expander is a key refrigerating machine for high liquefaction efficiency. Performance of the turbo-expander is directly affected by the hydrogen gas bearings. To obtain a deep understanding of the performance characteristics of hydrogen gas bearings, the static and dynamic characteristics of herringbone grooved journal bearings under hydrogen and other lubricating gases were numerically calculated and compared. The bearing load capacity and critical mass of hydrogen gas bearings were slightly lower than those of helium-, air- and nitrogen-lubricated bearings. To improve the performance of the hydrogen gas bearings used in high-speed turbo-machinery, the influence of working conditions was analyzed. It is found that the load capacity of hydrogen gas bearings can be improved by increasing the ambient pressure, reducing the gas film clearance, and raising the bearing eccentricity ratio. Meanwhile, the critical mass increases, and the bearing dynamic stability is enhanced.

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Guojie, Zhang, Li Yunpeng, Ye Jianming, Jin Zunlong, and Sławomir Dykas. "Performance prediction and loss evaluation of the carbon dioxide supersonic nozzle considering the non-equilibrium condensation." Journal of Physics: Conference Series 2707, no. 1 (February 1, 2024): 012009. http://dx.doi.org/10.1088/1742-6596/2707/1/012009.

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Abstract Carbon dioxide (CO2) is being considered as a promising working medium in energy conversion and refrigeration cycles due to its unique properties. When carbon dioxide flows with supersonic in turbo machinery (compressor), the non-equilibrium effect is enhanced due to the large change of fluid velocity, resulting in non-equilibrium condensation of the blade, which will seriously affect the performance of the compressor. Considering the similarities in flow characteristics between the nozzle and the compressor blade, the condensing flow of the blade can be predicted by simulating in a nozzle. The real gas model is used. The pressure and the nucleation rate are predicted based on the modified model, and the flow losses and thermal efficiency are analyzed in different states. The results show that the pressure variation in the nozzle aligns well with the experimental data. When the fluid transitions from subcritical to supercritical, the condensation interval decreases and the peak of the nucleation rate increases. The maximum supercooling decreases gradually. The flow losses are relatively large, and the thermal efficiency is low.

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Baragunov, A. B. "Adapted Machinery and Technology for Alpine Pasture Dairy Farming." Agricultural Machinery and Technologies 18, no. 1 (March 24, 2024): 108–14. http://dx.doi.org/10.22314/2073-7599-2024-18-1-108-114.

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The paper highlights that grazing a dairy herd on ecologically pristine mountain pastures facilitates the production of raw milk at reduced costs. Preserving the native properties of milk and achieving superior product quality necessitates prompt milk processing, particularly through eﬃcient cooling and storage at low temperatures. (Research purpose) The primary objective of this research is to substantiate the methodology for dairy cattle management and to develop technological solutions for milking and primary milk processing in mountainous pastures. (Materials and methods) Prototypes of milking machines and cooling equipment utilizing natural cold sources were developed and produced. Trials were conducted on farms in the Kabardino-Balkarian Republic. A methodology to produce consumable milk has been developed considering the natural and climatic conditions inherent in grazing dairy cattle on mountain pastures and existing machinery for milking and primary processing of raw materials. The technology includes the basic operations such as dairy herd feeding and management, milking, primary milk processing and storage of drinking cow’s milk. (Results and discussion) The technology is poised to enhance milk production by 10 percent, elevate the fat content by 3 percent, and decrease the incidence of mastitis in cows attributed to conventional machine milking tailored for lowland conditions by 40 percent. Moreover, it promises a 15 percent reduction in energy consumption for operating milking and refrigeration equipment as well as an increase in labor productivity. These technical and technological advancements are fortified with patent protection. (Conclusions) The development of dairy farming in mountainous regions, rich in naturally growing, ecologically pristine pasture lands, is an economically attractive direction to produce premium domestic dairy products. Comparative analyses conducted through laboratory assessments and field trials substantiate the viability of employing the proposed technological methodologies and machinery.

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Khan, Shoukat, Muataz Atieh, and Muammer Koç. "Micro-Nano Scale Surface Coating for Nucleate Boiling Heat Transfer: A Critical Review." Energies 11, no. 11 (November 16, 2018): 3189. http://dx.doi.org/10.3390/en11113189.

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Nucleate boiling is a phase change heat transfer process with a wide range of applications i.e., steam power plants, thermal desalination, heat pipes, domestic heating and cooling, refrigeration and air-conditioning, electronic cooling, cooling of turbo-machinery, waste heat recovery and much more. Due to its quite broad range of applications, any improvement in this area leads to significant economic, environmental and energy efficiency outcomes. This paper presents a comprehensive review and critical analysis on the recent developments in the area of micro-nano scale coating technologies, materials, and their applications for modification of surface geometry and chemistry, which play an important role in the enhancement of nucleate boiling heat transfer. In many industrial applications boiling is a surface phenomenon, which depends upon its variables such as surface area, thermal conductivity, wettability, porosity, and roughness. Compared to subtractive methods, the surface coating is more versatile in material selection, simple, quick, robust in implementation and is quite functional to apply to already installed systems. The present status of these techniques for boiling heat transfer enhancement, along with their future challenges, enhancement potentials, limitations, and their possible industrial implementation are also discussed in this paper.

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Liu, Dongliang, Liang Wang, Tong Wang, Yan Liu, and Ya Chen. "Optimization of Ventilation and Alarm Setting During the Process of Ammonia Leak in Refrigeration Machinery Room Based on Numerical Simulation." Journal of Risk Analysis and Crisis Response 7, no. 1 (2017): 37. http://dx.doi.org/10.2991/jrarc.2017.7.1.5.

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Vicatos, George, and E. Krafft. "Comparison between two different solution-pumping methods in absorption refrigeration machines." Journal of Energy in Southern Africa 21, no. 3 (August 1, 2010): 16–22. http://dx.doi.org/10.17159/2413-3051/2010/v21i3a3257.

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This paper presents a pumping method in absorp-tion refrigeration where a vapour-driven pump is to replace the electricity-driven pump. The vapour pump is driven by a fraction of the generator’s hot, high-pressure, vapour mixture. The refrigerator is thus exclusively heat-powered and rendered inde-pendent of the availability of electricity as the main energy source. The design and operation of the vapour pump is presented. The results obtained by a computer simulation program show a decrease in performance (COP), which is confirmed by the data obtained from a 1 kW cooling capacity refrigerator. Peak performances occur at higher generator tem-peratures when compared to a cycle using an elec-tricity-driven pump

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Eltawil, Mohamed A., Maged Mohammed, and Nayef M. Alqahtani. "Developing Machine Learning-Based Intelligent Control System for Performance Optimization of Solar PV-Powered Refrigerators." Sustainability 15, no. 8 (April 19, 2023): 6911. http://dx.doi.org/10.3390/su15086911.

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Display refrigerators consume significantly high energy, and improving their efficiency is essential to minimize energy consumption and greenhouse gas emissions. Therefore, providing the refrigeration system with a reliable and energy-efficient mechanism is a real challenge. This study aims to design and evaluate an intelligent control system (ICS) using artificial neural networks (ANN) for the performance optimization of solar-powered display refrigerators (SPDRs). The SPDR was operated using the traditional control system at a fixed frequency of 60 Hz and then operated based on variable frequencies ranging from 40 to 60 Hz using the designed ANN-based ICS combined with a variable speed drive. A stand-alone PV system provided the refrigerator with the required energy at the two control options. For the performance evaluation, the operating conditions of the SPDR after the modification of its control system were compared with its performance with a traditional control system (TCS) at target refrigeration temperatures of 1, 3, and 5 °C and ambient temperatures of 23, 29, and 35 °C. Based on the controlled variable frequency speed by the modified control system (MCS), the power, energy consumption, and coefficient of performance (COP) of the SPDR are improved. The results show that both refrigeration control mechanisms maintain the same cooling temperature, but the traditional refrigerator significantly consumes more energy (p < 0.05). At the same target cooling temperature, increasing the ambient temperature decreased the COP for the SPDR with both the TCS and MCS. The average daily COP of the SPDR varied from 2.8 to 3.83 and from 1.91 to 2.82 for the SPDR with the TCS and MCS, respectively. The comparison results of the two refrigerators’ conditions indicated that the developed ICS for the SPDR saved about 35.5% of the energy at the 5 °C target cooling temperature and worked with smoother power when the ambient temperature was high. The COP of the SPDR with the MCS was higher than the TCS by 26.37%, 26.59%, and 24.22% at the average daily ambient temperature of 23 °C, 29 °C, and 35 °C, respectively. The developed ANN-based control system optimized the SPDR and proved to be a suitable tool for the refrigeration industry.

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Ялама, В. В., and М. Г. Хмельнюк. "EN Energy efficiency improvement for the older reefer vessel by the combined compression-ejector refrigeration machine." Refrigeration Engineering and Technology 59, no. 3 (September 30, 2023): 146–58. http://dx.doi.org/10.15673/ret.v59i3.2664.

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A marine combined compression-ejector refrigeration machine that comprises conventional refrigeration and air-conditioning system using single-stage refrigeration machine and an ejector refrigeration machine is proposed and studied. The ejector refrigeration machine is driven by the waste heat from the single-stage refrigeration machine and acts as the bottom cycle of the single-stage refrigeration machine. A system analysis shows that the COP of a compression-ejector refrigeration machine is significantly higher than a one-stage refrigeration system. Improvement in COP can be as high as 19.3% for evaporating temperature of the single-stage refrigeration machine Tc at -40°C. Influence of flowing part of ejector profile, operating parameters, scheme and cycle of the marine combined compression-ejector refrigeration machine on its performance characteristics is shown. Rational methods to increase efficiency of marine combined compression-ejector refrigeration machine, operating with environmentally friendly low-boiling refrigerant R245fa, are offered and investigated. The present study shows that the combined compression-ejector refrigeration machine using the ejector refrigeration machine as the bottom cycle of the one-stage refrigeration machine is viable. The opportunities of implementing solar panels, raised challenges for older reefer vessels (20-40years) force to analyse situation. While opportunities exist for efficiency improvement and environmental alignment, challenges in retrofitting older vessels, especially those nearing the end of their operational life, make economic viability a critical consideration. The analysis of the possible solar panel application estimates a cost range of 398,269.20 to 426,717.00 euros, emphasizing the need for careful evaluation. The conclusion advocates against implementing solar panels on the researched vessel, highlighting the lack of justification in both economic and operational efficiency aspects

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KHOROLSKY, Valentyn, Yurii KORENETS, and Yulіya PETRUSHYNA. "THEORETICAL FOUNDATIONS FOR ASSESSING THE RELIABILITY OF REFRIGERATION MACHINE EQUIPMENT ON THE BASIS OF THE NEURO-FUZZY METHOD FOR IDENTIFYING THEIR STATE." Herald of Khmelnytskyi National University. Technical sciences 307, no. 2 (May 2, 2022): 103–9. http://dx.doi.org/10.31891/2307-5732-2022-307-2-103-109.

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In order to design modern smart enterprises such as industrial refrigerators with a high level of reliability of their operation while maintaining the proper quality of cooling, freezing and storage of various types of products, the article analyzes the current level of safety and time to failure of equipment for refrigeration equipment for refrigeration of industrial refrigerators and system analysis of the technical system of equipment of refrigeration machines to determine the requirements for the system for assessing the level of safety of equipment of enterprises – industrial refrigerators. A methodology has been developed for analyzing the state of the equipment of refrigeration machines of industrial refrigerators, as an object of malfunctions. Models of possible malfunctions are constructed with the identification of relationships between technological parameters of operability, reliability and emergency situations. A situational model of the state of the refrigeration machine as a source of malfunctions has been developed, which is distinguished by the ability to identify relationships between parameters, events – the causes of emergencies and the state of refrigeration supply of refrigeration chambers. Knowledge about fuzzy situations is structured and fuzzy reliability models are constructed that characterize the state of the equipment. The practical value of the study lies in the development of a methodology for assessing the reliability and durability of refrigeration equipment based on a neuron-fuzzy identification method, creating a knowledge base and a system for managing the refrigeration plant performance process. Thus, it is possible to manage systems for predicting and monitoring emergency situations in systems for operational monitoring of technological processes for freezing the results of eating.

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DeBaufre, Wm L. "The Williams Refrigerating Machine." Journal of the American Society for Naval Engineers 31, no. 2 (March 18, 2009): 454–69. http://dx.doi.org/10.1111/j.1559-3584.1919.tb00794.x.

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Vitale, Salvatore, Tim A. Albring, Matteo Pini, Nicolas R. Gauger, and Piero Colonna. "Fully turbulent discrete adjoint solver for non-ideal compressible flow applications." Journal of the Global Power and Propulsion Society 1 (November 22, 2017): Z1FVOI. http://dx.doi.org/10.22261/jgpps.z1fvoi.

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Abstract Non-Ideal Compressible Fluid-Dynamics (NICFD) has recently been established as a sector of fluid mechanics dealing with the flows of dense vapors, supercritical fluids, and two-phase fluids, whose properties significantly depart from those of the ideal gas. The flow through an Organic Rankine Cycle (ORC) turbine is an exemplary application, as stators often operate in the supersonic and transonic regime, and are affected by NICFD effects. Other applications are turbomachinery using supercritical CO2 as working fluid or other fluids typical of the oil and gas industry, and components of air conditioning and refrigeration systems. Due to the comparably lower level of experience in the design of this fluid machinery, and the lack of experimental information on NICFD flows, the design of the main components of these processes (i.e., turbomachinery and nozzles) may benefit from adjoint-based automated fluid-dynamic shape optimization. Hence, this work is related to the development and testing of a fully-turbulent adjoint method capable of treating NICFD flows. The method was implemented within the SU2 open-source software infrastructure. The adjoint solver was obtained by linearizing the discretized flow equations and the fluid thermodynamic models by means of advanced Automatic Differentiation (AD) techniques. The new adjoint solver was tested on exemplary turbomachinery cases. Results demonstrate the method effectiveness in improving simulated fluid-dynamic performance, and underline the importance of accurately modeling non-ideal thermodynamic and viscous effects when optimizing internal flows influenced by NICFD phenomena.

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Mutaufiq, Hendri Sulistyo, Kamin Sumardi, Ega Taqwali Berman, and Apri Wiyono. "Performance Investigation of Cooling Machine Practice Props After Retrofitted by Natural Refrigerants." Jurnal Teknik: Media Pengembangan Ilmu dan Aplikasi Teknik 20, no. 2 (December 30, 2021): 136–45. http://dx.doi.org/10.26874/jt.vol20no2.419.

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Penyesuaian komponen utama mesin pendingin perlu dilakukan setelah di-retrofit/diganti dengan refrigeran baru yang ramah lingkungan. Ini dilakukan untuk mendapatkan kinerja mesin pendingin yang baik. Penelitian ini bertujuan untuk menyelidiki pengaruh penyesuaian komponen utama mesin pendingin dalam meningkatkan kinerja mesin pendingin setelah menggunakan refrigeran baru yang ramah lingkungan. Penelitian dirancang secara eksperimen pada mesin pendingin jenis refrigerator yang menggunakan refrigeran R-134a sebagai fluida kerja. Jenis refrigeran hidrokarbon yang digunakan untuk menyubtitusi R-134a adalah Musicool-22 (MC-22). Beban pendinginan dalam kabin evaporator adalah larutan garam. Pengujian dilakukan dalam dua tahap. Pada tahap pertama refrigerator beroperasi dengan kondisi asalnya (R-134a dan CT1/variasi 1) dan pada tahap kedua fluida kerja R-134a di-retrofit dengan MC-22 dengan penyesuaian komponen utamanya. Selanjutnya kinerja refrigerator dianalisis menggunakan software CoolPack 1.5 dengan membandingkan nilai Refrigerating Effect (RE), kalor kerja kompresor, dan angka kinerja (COP) refrigerator sebelum di-retrofit dan setelah di-retrofit. Hasil analisis menunjukkan bahwa angka kinerja refrigerator terbaik adalah saat refrigerator beroperasi dengan variasi 3 (refrigeran MC-22, alat ekspansi CT2) dengan kenaikan nilai COP berkisar 0,62% sampai 2,12% dari kondisi asalnya.

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Mohammed, Mena Safaa, and Nibal Fadel Farman. "Solar adsorption cooling system operating by activated–carbon–ethanol bed." International Journal of Renewable Energy Development 13, no. 3 (March 28, 2024): 430–47. http://dx.doi.org/10.61435/ijred.2024.60170.

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One efficient way to convert small thermally energized into effective cooling is through adsorption cooling technology, which increases energy efficiency and reduces environmental pollution. This study's primary goal is to hypothetically examine the thermal coefficient of performing the solar adsorptive refrigerator machine operated with an activating carbon/Ethanol operating dual. The impact of different operating situations and design factors on the machine's performance is inspected and evaluated. The present double-bed solar energy adsorptive-cooler unit is modeled by thermodynamic methodology. Then, it was analyzed to evaluate its effectiveness work under Baghdad climate conditions. For the current study, the two-bed solar adsorption cooling unit with 0.5 kW capacity input heat 11893 that operates at 5 °C for the evaporator and 45 °C for the condenser is presented. The Engineering-Equation-Solver (EES) simulation program was created and used to solve the modeling equations that predict the optimal cycle performance and evaluate the optimum reasonable values of the operation parameters of the proposed system. The pressure range for the refrigeration cycle is 2.408 kPa for the evaporation state and 23.14 kPa for the condensation state. The findings demonstrate that an optimum coefficient of performance (COP) is 0.702 at 95 °C, a 20% performance increase, which generates 39.4 of cooling water. It produced 1 kg of chilled water for 2.463 kg of activated carbon at a temperature of 5°C. The improved solar-powered adsorption systems and refrigeration technologies are appealing substitutes that can satisfy energy demands in addition to meeting needs for cooling, ice production, air conditioning, and refrigeration preservation and safeguarding of the environment with Iraq's climate conditions.

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Kothny., G. L. "AUXILIARIES: NEW MARINE REFRIGERATING MACHINE." Journal of the American Society for Naval Engineers 28, no. 1 (March 18, 2009): 238–47. http://dx.doi.org/10.1111/j.1559-3584.1916.tb00614.x.

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Irwansyah, Dandi, Rita Sundari, Rini Anggraini, and Khuzaimah Arifin. "EFFECT OF SiO2 AND ZnO NANOPARTICLES TO INCREASE REFRIGERATION MACHINE PERFORMANCE." International Journal of Innovation in Mechanical Engineering and Advanced Materials 5, no. 2 (December 27, 2023): 63. http://dx.doi.org/10.22441/ijimeam.v5i2.21859.

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In this investigation, the impact of silicon dioxide (SiO2) and zinc oxide (ZnO) nanoparticles on the performance of a refrigeration machine system was systematically examined. The focus was on evaluating the coefficient of performance (COP) concerning the utilization of a polyolester (POE) lubricant, R600a refrigerant, and distinct nanoparticles (SiO2 and ZnO) within the refrigeration system. The nanoparticles were individually introduced into the R600a refrigerant in masses of 0.5 g, 1.0 g, and 1.5 g. The experimental outcomes demonstrated a noteworthy enhancement in COP with the addition of nanoparticles. Specifically, the introduction of 1.5 g of SiO2 resulted in a substantial increase of 25.88% in COP, marking it as the most influential dosage. Similarly, the addition of 1.0 g of ZnO led to a significant COP increase of 13.6%, representing the optimal quantity for ZnO. Furthermore, the inclusion of 1.5 g of SiO2 brought about a remarkable reduction in energy consumption, with a decrease of 25.58%, while 1.5 g of ZnO resulted in a notable 16.28% decrease in energy consumption. The experimental configuration involved the use of 20 g of refrigerant and 500 ml of POE lubricant. Comparative analysis demonstrated that the refrigeration system incorporating nanoparticles outperformed the conventional R600a refrigeration system devoid of nanoparticles. This study contributes valuable insights into the potential enhancements in refrigeration system efficiency through the strategic incorporation of SiO2 and ZnO nanoparticles, offering a promising avenue for optimizing the performance of refrigeration technology.

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KHOROLSKY, Valentyn, Oleksandr OMELCHENKO, Yurii KORENETS, Volodymyr HONCHARENKO, and Yulіya PETRUSHYNA. "REFRIGERATION SUPPLY OF REFRIGERATION CHAMBERS OF SMART INDUSTRIAL REFRIGERATORS WITH NEURON-FUZZY CONTROL SYSTEMS OF FOOD FREEZING PROCESSES." Herald of Khmelnytskyi National University 303, no. 6 (December 2021): 264–71. http://dx.doi.org/10.31891/2307-5732-2021-303-6-264-271.

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A set of theoretical, methodological and practical problems associated with the creation of an intelligent complex for adaptive control of microclimate parameters, the processes of freezing food products in the refrigerating chambers of an industrial refrigerator has been studied. Accordingly, for this task, the structure of the neural network controller of the refrigeration capacity of refrigeration machines of the process control system of an industrial refrigerator was developed, in which information enters the database, a neural network with a learning module and turns into decision-making modules into management actions on the executive intelligent mechanisms of compressors, condensers, evaporators, minimizing CO2 emissions. A model of refrigeration supply for refrigerating chambers of an industrial refrigerator has been developed, in which the parameters of loading geometry and freezing speed, refrigerant pressure in the evaporator in real time determine the parameters of refrigeration supply for refrigerating chambers. The microclimate of the refrigerating chamber is estimated using a multi-parameter model of a neuron-odd decision tree with two integrated output nodes for classifying the state of refrigeration supply of refrigerating chambers. For the decision maker, an intelligent decision support system has been developed for the main block of the upper level of the process control system for an industrial refrigerator, which differs from analogues in the accuracy of predicting the quality of the frozen product by training the neural network using the backpropagation method. Simulation studies of the neural network control system for the refrigeration supply of refrigerating chambers and the process of freezing products with interchangeable structures proved that the system provides the specified control quality parameters, minimizes CO2 emissions and prevents the loss of taste properties of the frozen product.

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Dardouch, J., M. Charia, and A. Bernatchou. "Numerical study of a Solar Absorption Refrigeration Machine." E3S Web of Conferences 150 (2020): 01009. http://dx.doi.org/10.1051/e3sconf/202015001009.

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In this paper, we present a numerical study of a single-stage absorption refrigeration machine, operating with a couple of water-ammonia fluids, equipped with a distillation column and associated with a solar heating system using solar collectors. The study has showed the benefit of using the distillation column which is manifested by: The decrease of the operating temperature, The improvement of the coefficient of performance, Surface reduction of the solar collectors, The improvement of the solar coefficient of performance. The solar study shows that the absorption refrigeration machine equipped with a distillation column is better suited to solar energy with significantly better performance compared to the simple absorption refrigeration machine.

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Kasi, Parthiban, and M. Cheralathan. "Review of cascade refrigeration systems for vaccine storage." Journal of Physics: Conference Series 2054, no. 1 (October 1, 2021): 012041. http://dx.doi.org/10.1088/1742-6596/2054/1/012041.

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Abstract Various models are already developed to achieve the refrigerating effect. Each refrigeration system has its own set of benefits and drawbacks, as well as a unique application. The vapor compression refrigeration system and the sorption refrigeration system are the two most prominent refrigeration technologies that may be utilized for a variety of purposes. In the medical profession, cascade refrigeration will be established in the storage of blood banks, plasma, vaccines, bone banks, biological fluids storage, etc. Storing heat-sensitive vaccines at the right temperature is crucial yet often difficult by the availability of ultralow temperature cold storage. This paper has reviewed that the different types of cascade refrigeration systems for a better refrigerating effect on vaccine storage.

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Siahaan, Juniawan Preston, Rizqi Ilmal Yaqin, Bobby Demeianto, Mula Tumpu, Muhammad Zaki Latif Abrori, Yuniar Endri Priharanto, and Syahrul Pradana. "Performance test of small fishing vessel refrigeration machine for fish storage." Jurnal Polimesin 21, no. 6 (December 31, 2023): 613. http://dx.doi.org/10.30811/jpl.v21i6.4165.

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The refrigeration system in the fishing process is important for maintaining the quality of the catch. However, the design of small-scale refrigeration machines is still not common, so it is an interesting study. Therefore, this study aimed to evaluate the design of small-scale fishing vessel refrigeration machines. Field studies are needed in machine manufacturing to observe the components required to match the refrigeration machine components onboard fishing vessels. This uses a direct observation method to determine the components of the refrigeration machine on the ship. Furthermore, the performance of the machines produced will be tested through the load cooling process. Parameters determined in the performance test include monitoring temperature (suction and discharge), pressure (suction and discharge), evaporator temperature, load temperature, COP (Coefficient of Performance), and compressor power. Refrigerant temperature measurement uses an insulative principle so that ambient temperature does not affect it. The result is that the machine produced has a capacity of 35 l or 15 kg of load. Meanwhile, in the performance test, the COP and electrical power generated while cooling the load for approximately 4 hours were 2,42 and 507 W, respectively. The results of this design were successful and did not experience failure. The significanceof this study can be used as a reference source for making cooling machines for storing the catch of small-scale fishermen.

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Kumbhar, Anil, Viveka Kaur, and Dr Sunil S. Bhagwat. "Analysis of Vapor Absorption Refrigeration Machine Performance with Different Configuration of Water Supply." International Journal of Trend in Scientific Research and Development Volume-3, Issue-2 (February 28, 2019): 76–79. http://dx.doi.org/10.31142/ijtsrd20275.

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Sharapov, Irek, Sergey Vizgalov, Timur Mustafin, and Ibragim Khisameev. "A turbocompressor refrigeration machine characteristics’ calculation." IOP Conference Series: Materials Science and Engineering 604 (September 3, 2019): 012047. http://dx.doi.org/10.1088/1757-899x/604/1/012047.

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Yang, Juan Juan, Ke Li, and Xin Yang Cui. "Experimental Study on Miniature-Refrigeration System." Key Engineering Materials 531-532 (December 2012): 584–87. http://dx.doi.org/10.4028/www.scientific.net/kem.531-532.584.

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Abstract:

A prototype of miniature cooling system was developed, which mainly consists of the miniature compressor from DONG YUAN and a spiral-tube evaporator designed by ourselves. The performances of the prototype with different parameters were tested. The influence of ambient temperature, chilled water temperature on the performance of the cooling system were analyzed. The best operating conditions and the optimum amount of refrigerant were obtained. Conclusions were gotten as follows:1) With environment temperature rising, compression ratio increases, system power consumption increases and refrigerating capacity COP decreases. 2) With chilled water temperature rising, compression ratio and power consumption decrease, refrigerating capacity increases, and COP increases rapidly.3) Paper gets system performance: refrigerating capacity is 63 W, compressor power consumption is 24.5 W, COP value is 2.57. in operation condition: refrigerant amount is 40g, environment temperature is 30°C, chilled water temperature is 40 °C, chilled water mass flow is 45 kg/h.

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Journal articles on the topic 'Refrigeration and refrigerating machinery'

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