Journal articles: 'Thermodynamic power cycles'

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Rivera, Wilfrido, Karen Sánchez-Sánchez, J. Alejandro Hernández-Magallanes, J. Camilo Jiménez-García, and Alejandro Pacheco. "Modeling of Novel Thermodynamic Cycles to Produce Power and Cooling Simultaneously." Processes 8, no. 3 (March 9, 2020): 320. http://dx.doi.org/10.3390/pr8030320.

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Thermodynamic cycles to produce power and cooling simultaneously have been proposed for many years. The Goswami cycle is probably the most known cycle for this purpose; however, its use is still very limited. In the present study, two novel thermodynamic cycles based on the Goswami cycle are presented. The proposed cycles use an additional component to condense a fraction of the working fluid produced in the generator. Three cycles are modeled based on the first and second laws of thermodynamics: Two new cycles and the original Goswami cycle. The results showed that in comparison with the original Goswami cycle, the two proposed models are capable of increasing the cooling effect, but the cycle with flow extraction after the rectifier presented higher irreversibilities decreasing its exergy efficiency. However, the proposed cycle with flow extraction into the turbine was the most efficient, achieving the highest values of the energy utilization factor and the exergy efficiency. It was found that for an intermediate split ratio value of 0.5, the power produced in the turbine with the flow extraction decreased 23% but the cooling power was 6 times higher than that obtained with the Goswami Cycle.

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Ibrahim, O. M., and S. A. Klein. "High-Power Multi-Stage Rankine Cycles." Journal of Energy Resources Technology 117, no. 3 (September 1, 1995): 192–96. http://dx.doi.org/10.1115/1.2835340.

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This paper presents an analysis of the multi-stage Rankine cycle aiming at optimizing the power output from low-temperature heat sources such as geothermal or waste heat. A design methodology based on finite-time thermodynamics and the maximum power concept is used in which the shape and the power output of the maximum power cycle are identified and utilized to compare and evaluate different Rankine cycle configurations. The maximum power cycle provides the upper-limit power obtained from any thermodynamic cycle for specified boundary conditions and heat exchanger characteristics. It also provides a useful tool for studying power cycles and forms the basis for making design improvements.

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Yuan, Z., and E. E. Michaelides. "Binary-Flashing Geothermal Power Plants." Journal of Energy Resources Technology 115, no. 3 (September 1, 1993): 232–36. http://dx.doi.org/10.1115/1.2905999.

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Binary-flashing units utilize new types of geothermal power cycles, which may be used with resources of relatively low temperatures (less than 150°C) where other cycles result in very low efficiencies. The thermodynamic cycles for the binary flashing units are combinations of the geothermal binary and flashing cycles. They have most of the advantages of these two conventionally used cycles, but avoid the high irreversibilities associated with some of their processes. Any fluid with suitable thermodynamic properties may be used in the secondary Rankine cycle. At the optimum design conditions binary-flashing geothermal power plants may provide up to 25 percent more power than the conventional geothermal units.

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Inozemtsev, N. N. "Thermodynamic cycles for spacecraft power plants." Russian Aeronautics (Iz VUZ) 53, no. 4 (December 2010): 443–49. http://dx.doi.org/10.3103/s1068799810040112.

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Tozer, R. M., and R. W. James. "Cold Generation Systems: A Theoretical Approach." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 209, no. 4 (November 1995): 287–96. http://dx.doi.org/10.1243/pime_proc_1995_209_008_01.

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The objective of this study was to derive the thermodynamic formulae for ideal combined driving and cooling cycles when the objective of the overall cycle is to produce cooling by using a high-temperature heat source. For this it has been necessary to investigate absorption cooling thermodynamics and to focus on the analysis of one-, two- and three-stage cycles and multi-stage cycles in general. This paper has investigated the absorption thermodynamic principles involved to obtain simple formulae, in a similar way to the Carnot cycle. The first driving cycle considered has a high-temperature source such as a combustion process. From this driving cycle the heat dissipated at the lower temperature is used to drive the next consecutive driving and/or absorption cooling cycles. All the work produced in the driving cycles is used for the cooling cycles with mechanical compressors, whereas the dissipated heat of the last driving cycle is used to drive the absorption cycles. A simple universal law for driving and cooling cycles has been derived, which is applicable to combined heat and power (cogeneration) systems.

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Kosowski, Krzysztof, and Marian Piwowarski. "Subcritical Thermodynamic Cycles with Organic Medium and Isothermal Expansion." Energies 13, no. 17 (August 21, 2020): 4340. http://dx.doi.org/10.3390/en13174340.

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The efficiencies of the Organic Rankine Cycle (ORC) are not very high and only very seldom do they exceed 20%. The increase and optimization of initial parameters and certain modifications of the thermodynamic cycle make it possible to overcome these drawbacks. A new modified cycle has been described and analyzed in detail in the paper. Similarly to the Ericsson cycle for gas turbines, isothermal expansion in the turbine is suggested for the power plant with organic media. The new cycle and the typical ORC power plants have the same block diagram. The only difference is that expansion in the proposed cycle occurs not adiabatically but as an isothermal process. The thermodynamic calculations have been carried out for 11 various fluids and 4 different cycles. The obtained results have clearly shown that cycles with isothermal expansion (isothermal turbines) are characterized by remarkably higher efficiency than typical power plants with adiabatic turbines. The increase in efficiency varies from 6 to 12 percent points for cycles with saturated live vapor and from 4 to 7 percent points for cycles with superheated live vapor. The performed analyses have shown that it is possible to achieve a very high efficiency (over 45%) of organic cycle, which is a very competitive value. In such cases the proposed power plants can achieve an efficiency which is higher than that of modern steam turbine plants with supercritical parameters.

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Layton, Astrid, John Reap, Bert Bras, and Marc Weissburg. "Correlation between Thermodynamic Efficiency and Ecological Cyclicity for Thermodynamic Power Cycles." PLoS ONE 7, no. 12 (December 14, 2012): e51841. http://dx.doi.org/10.1371/journal.pone.0051841.

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Dunham, Marc T., and Brian D. Iverson. "High-efficiency thermodynamic power cycles for concentrated solar power systems." Renewable and Sustainable Energy Reviews 30 (February 2014): 758–70. http://dx.doi.org/10.1016/j.rser.2013.11.010.

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Piwowarski, Marian, and Krzysztof Kosowski. "Advanced Turbine Cycles with Organic Media." Energies 13, no. 6 (March 12, 2020): 1327. http://dx.doi.org/10.3390/en13061327.

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Organic Rankine Cycle (ORC) power plants have become very popular and have found their applications in systems with renewable sources of energy. So far their overall efficiencies are not very impressive and only for the upper temperature of about 300 °C do they exceed 20%. A drawback of these cycles is the limitation of the cycle upper temperature due to the heat exchanger technology and the materials used. However, it is possible to overcome these difficulties by certain modifications of the thermodynamic cycles, a proper choice of the working medium and the optimization of cycle parameters. In the paper the problems of choosing the working medium and the question of higher temperature at the turbine inlet have been discussed. Different modifications of the schemas of the thermodynamic cycles have also been taken into account. The variants of power plants with regenerators, reheaters and heat exchangers have been considered. The proposed increase in temperature (in some cases up to 600 °C or higher) and innovative modifications of the thermodynamic cycles allow to obtain the power plant efficiency of above 50%. The modified cycles have been described in detail in the paper. The proposed cycles equipped with regenerators and reheaters can have the efficiency even slightly higher than classical steam turbine plants with a reheater and regenerators. Appropriate cycle and turbine calculations have been performed for the micro power plants of turbine output in the range of 10 kW–300 kW (up to several MW in some cases). The best arrangements achieved very high values of the overall cycle efficiency.

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Kosowski, Krzysztof, Karol Tucki, Marian Piwowarski, Robert Stępień, Olga Orynycz, Wojciech Włodarski, and Anna Bączyk. "Thermodynamic Cycle Concepts for High-Efficiency Power Plans. Part A: Public Power Plants 60+." Sustainability 11, no. 2 (January 21, 2019): 554. http://dx.doi.org/10.3390/su11020554.

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An analysis was carried out for different thermodynamic cycles of power plants with air turbines. Variants with regeneration and different cogeneration systems were considered. In the paper, we propose a new modification of a gas turbine cycle with the combustion chamber at the turbine outlet. A special air by-pass system of the combustor was applied and, in this way, the efficiency of the turbine cycle was increased by a few points. The proposed cycle equipped with a regenerator can provide higher efficiency than a classical gas turbine cycle with a regenerator. The best arrangements of combined air–steam cycles achieved very high values for overall cycle efficiency—that is, higher than 60%. An increase in efficiency to such degree would decrease fuel consumption, contribute to the mitigation of carbon dioxide emissions, and strengthen the sustainability of the region served by the power plant. This increase in efficiency might also contribute to the economic resilience of the area.

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Vijayaraghavan, Sanjay, and D. Y. Goswami. "Organic Working Fluids for a Combined Power and Cooling Cycle." Journal of Energy Resources Technology 127, no. 2 (February 6, 2005): 125–30. http://dx.doi.org/10.1115/1.1885039.

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A new thermodynamic cycle has been developed for the simultaneous production of power and cooling from low-temperature heat sources. The proposed cycle combines the Rankine and absorption refrigeration cycles, providing power and cooling as useful outputs. Initial studies were performed with an ammonia-water mixture as the working fluid in the cycle. This work extends the application of the cycle to working fluids consisting of organic fluid mixtures. Organic working fluids have been used successfully in geothermal power plants, as working fluids in Rankine cycles. An advantage of using organic working fluids is that the industry has experience with building turbines for these fluids. A commercially available optimization program has been used to maximize the thermodynamic performance of the cycle. The advantages and disadvantages of using organic fluid mixtures as opposed to an ammonia-water mixture are discussed. It is found that thermodynamic efficiencies achievable with organic fluid mixtures, under optimum conditions, are lower than those obtained with ammonia-water mixtures. Further, the refrigeration temperatures achievable using organic fluid mixtures are higher than those using ammonia-water mixtures.

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Lyngfelt, A., and P. Stenberg. "Wet Peat Power Processes: A Thermodynamic Study." Journal of Engineering for Gas Turbines and Power 110, no. 2 (April 1, 1988): 155–60. http://dx.doi.org/10.1115/1.3240094.

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The efficiencies of four power processes for wet peat have been studied. These include gas turbine cycles, steam power cycles, and combinations thereof. It is concluded that wet peat can be used in power processes with reasonable efficiency. The paper suggests that wet peat power processes could be cost competitive relative to conventional power production.

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Ayub, Abubakr, Costante M. Invernizzi, Gioele Di Marcoberardino, Paolo Iora, and Giampaolo Manzolini. "Carbon Dioxide Mixtures as Working Fluid for High-Temperature Heat Recovery: A Thermodynamic Comparison with Transcritical Organic Rankine Cycles." Energies 13, no. 15 (August 4, 2020): 4014. http://dx.doi.org/10.3390/en13154014.

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This study aims to provide a thermodynamic comparison between supercritical CO2 cycles and ORC cycles utilizing flue gases as waste heat source. Moreover, the possibility of using CO2 mixtures as working fluids in transcritical cycles to enhance the performance of the thermodynamic cycle is explored. ORCs operating with pure working fluids show higher cyclic thermal and total efficiencies compared to supercritical CO2 cycles; thus, they represent a better option for high-temperature waste heat recovery provided that the thermal stability at a higher temperature has been assessed. Based on the improved global thermodynamic performance and good thermal stability of R134a, CO2-R134a is investigated as an illustrative, promising working fluid mixture for transcritical power cycles. The results show that a total efficiency of 0.1476 is obtained for the CO2-R134a mixture (0.3 mole fraction of R134a) at a maximum cycle pressure of 200 bars, which is 15.86% higher than the supercritical carbon dioxide cycle efficiency of 0.1274, obtained at the comparatively high maximum pressure of 300 bars. Steam cycles, owing to their larger number of required turbine stages and lower power output, did not prove to be a suitable option in this application.

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McMahan, A., S. A. Klein, and D. T. Reindl. "A Finite-Time Thermodynamic Framework for Optimizing Solar-Thermal Power Plants." Journal of Solar Energy Engineering 129, no. 4 (January 22, 2007): 355–62. http://dx.doi.org/10.1115/1.2769689.

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Fundamental differences between the optimization strategies for power cycles used in “traditional” and solar-thermal power plants are identified using principles of finite-time thermodynamics. Optimal operating efficiencies for the power cycles in traditional and solar-thermal power plants are derived. In solar-thermal power plants, the added capital cost of a collector field shifts the optimum power cycle operating point to a higher-cycle efficiency when compared to a traditional plant. A model and method for optimizing the thermoeconomic performance of solar-thermal power plants based on the finite-time analysis is presented. The method is demonstrated by optimizing an existing organic Rankine cycle design for use with solar-thermal input. The net investment ratio (capital cost to net power) is improved by 17%, indicating the presence of opportunities for further optimization in some current solar-thermal designs.

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15

Cole, G. H. A. "Multicycle Approach to Power Cycle Studies." International Journal of Mechanical Engineering Education 23, no. 2 (April 1995): 129–41. http://dx.doi.org/10.1177/030641909502300207.

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The thermodynamic behaviour of the Rankine cycle for steam and the Joule cycle for gases, together with the various modifications, are derived from a single approach based on that of the combined cycle. The possible modifications of the cycles are identified for steam and for gas, together with the relationships between the two cases. The arguments allow the input data for the steam cycle to involve conditions at the turbine exit.

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Sun, Chen, Xue-Tao Cheng, and Xin-Gang Liang. "Output power analyses for the thermodynamic cycles of thermal power plants." Chinese Physics B 23, no. 5 (May 2014): 050513. http://dx.doi.org/10.1088/1674-1056/23/5/050513.

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Chen, Lingen, Huijun Feng, and Yanlin Ge. "Power and Efficiency Optimization for Open Combined Regenerative Brayton and Inverse Brayton Cycles with Regeneration before the Inverse Cycle." Entropy 22, no. 6 (June 17, 2020): 677. http://dx.doi.org/10.3390/e22060677.

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A theoretical model of an open combined cycle is researched in this paper. In this combined cycle, an inverse Brayton cycle is introduced into regenerative Brayton cycle by resorting to finite-time thermodynamics. The constraints of flow pressure drop and plant size are taken into account. Thirteen kinds of flow resistances in the cycle are calculated. On the one hand, four isentropic efficiencies are used to evaluate the friction losses in the blades and vanes. On the other hand, nine kinds of flow resistances are caused by the cross-section variances of flowing channels, which exist at the entrance of top cycle compressor (TCC), the entrance and exit of regenerator, the entrance and exit of combustion chamber, the exit of top cycle turbine, the exit of bottom cycle turbine, the entrance of heat exchanger, as well as the entrance of bottom cycle compressor (BCC). To analyze the thermodynamic indexes of power output, efficiency along with other coefficients, the analytical formulae of these indexes related to thirteen kinds of pressure drop losses are yielded. The thermodynamic performances are optimized by varying the cycle parameters. The numerical results reveal that the power output presents a maximal value when the air flow rate and entrance pressure of BCC change. In addition, the power output gets its double maximal value when the pressure ratio of TCC further changes. In the premise of constant flow rate of working fuel and invariant power plant size, the thermodynamic indexes can be optimized further when the flow areas of the components change. The effect of regenerator on thermal efficiency is further analyzed in detail. It is reported that better thermal efficiency can be procured by introducing the regenerator into the combined cycle in contrast with the counterpart without the regenerator as the cycle parameters change in the critical ranges.

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Açikkalp, Emin. "Models for optimum thermo-ecological criteria of actual thermal cycles." Thermal Science 17, no. 3 (2013): 915–30. http://dx.doi.org/10.2298/tsci110918095a.

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In this study, the ecological optimization point of irreversible thermal cycles (refrigerator, heat pump and power cycles) was investigated. The importance of ecological optimization is to propose a way to use fuels and energy source more efficiently because of an increasing energy need and environmental pollution. It provides this by maximizing obtained (or minimizing supplied) work and minimizing entropy generation for irreversible (actual) thermal cycles. In this research, ecological optimization was defined for all basic irreversible thermal cycles, by using the first and second laws of thermodynamics. Finally, the ecological optimization was defined in thermodynamic cycles and results were given to show the effects of the cycles? ecological optimization point, efficiency, COP and power output (or input), and exergy destruction.

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Grkovic, Vojin, Dragoljub Zivkovic, and Milana Gutesa. "A new approach in CHP steam turbines thermodynamic cycles computations." Thermal Science 16, suppl. 2 (2012): 399–407. http://dx.doi.org/10.2298/tsci120503178g.

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This paper presents a new approach in mathematical modeling of thermodynamic cycles and electric power of utility district-heating and cogeneration steam turbines. The approach is based on the application of the dimensionless mass flows, which describe the thermodynamic cycle of a combined heat and power steam turbine. The mass flows are calculated relative to the mass flow to low pressure turbine. The procedure introduces the extraction mass flow load parameter ?h which clearly indicates the energy transformation process, as well as the cogeneration turbine design features, but also its fitness for the electrical energy system requirements. The presented approach allows fast computations, as well as direct calculation of the selected energy efficiency indicators. The approach is exemplified with the calculation results of the district heat power to electric power ratio, as well as the cycle efficiency, versus ?h. The influence of ?h on the conformity of a combined heat and power turbine to the grid requirements is also analyzed and discussed.

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Heikal, H. A., and M. G. Higazy. "On the Thermodynamic Cycles of Gas Turbine Power Plants." International Journal of Mechanical Engineering Education 29, no. 4 (October 2001): 321–43. http://dx.doi.org/10.7227/ijmee.29.4.3.

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F. Arce, Pedro, and Nian F. Vieira. "Thermodynamic Simulation of Steam Power Cycles using GUIMatLab Interfaces." International Journal of Engineering Research and Applications 7, no. 1 (January 2017): 88–93. http://dx.doi.org/10.9790/9622-0701038893.

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Kolios, A. J., S. Paganini, and S. Proia. "Development of thermodynamic cycles for concentrated solar power plants." International Journal of Sustainable Energy 32, no. 5 (October 2013): 296–314. http://dx.doi.org/10.1080/14786451.2012.663758.

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Ibrahim, O. M., S. A. Klein, and J. W. Mitchell. "Optimum Heat Power Cycles for Specified Boundary Conditions." Journal of Engineering for Gas Turbines and Power 113, no. 4 (October 1, 1991): 514–21. http://dx.doi.org/10.1115/1.2906271.

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Optimization of the power output of Carnot and closed Brayton cycles is considered for both finite and infinite thermal capacitance rates of the external fluid streams. The method of Lagrange multipliers is used to solve for working fluid temperatures that yield maximum power. Analytical expressions for the maximum power and the cycle efficiency at maximum power are obtained. A comparison of the maximum power from the two cycles for the same boundary conditions, i.e., the same heat source/sink inlet temperatures, thermal capacitance rates, and heat exchanger conductances, shows that the Brayton cycle can produce more power than the Carnot cycle. This comparison illustrates that cycles exist that can produce more power than the Carnot cycle. The optimum heat power cycle, which will provide the upper limit of power obtained from any thermodynamic cycle for specified boundary conditions and heat exchanger conductances is considered. The optimum heat power cycle is identified by optimizing the sum of the power output from a sequence of Carnot cycles. The shape of the optimum heat power cycle, the power output, and corresponding efficiency are presented. The efficiency at maximum power of all cycles investigated in this study is found to be equal to (or well approximated by) η=1−TL,in/φTH,in where φ is a factor relating the entropy changes during heat rejection and heat addition.

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Morehouse, J. H. "Thermally Regenerative Hydrogen/Oxygen Fuel Cell Power Cycles." Journal of Solar Energy Engineering 110, no. 2 (May 1, 1988): 107–12. http://dx.doi.org/10.1115/1.3268239.

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Two thermodynamic power cycles are analytically examined for future engineering feasibility. These power cycles use a hydrogen-oxygen fuel cell for electrical energy production and use the thermal dissociation of water for regeneration of the hydrogen and oxygen. The first cycle uses a thermal energy input at over 2000K to thermally dissociate the water. The second cycle dissociates the water using an electrolyzer operating at high temperature (1300K) which receives both thermal and electrical energy as inputs. The results show that while the processes and devices of the 2000K thermal system exceed current technology limits, the high temperature electrolyzer system appears to be a state-of-the-art technology development, with the requirements for very high electrolyzer and fuel cell efficiencies seen as determining the feasibility of this system.

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Sinkevich, Mikhail, Anatoliy Kosoy, and Oleg Popel. "Comparative analysis of the Allam cycle and the cycle of compressorless combined cycle gas turbine unit." E3S Web of Conferences 209 (2020): 03023. http://dx.doi.org/10.1051/e3sconf/202020903023.

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Nowadays, alternative thermodynamic cycles are actively studied. They allow to remove CO2, formed as a result of fuel combustion, from a cycle without significant energy costs. Calculations have shown that such cycles may meet or exceed the most advanced power plants in terms of heat efficiency. The Allam cycle is recognized as one of the best alternative cycles for the production of electricity. Nevertheless, a cycle of compressorless combined cycle gas turbine (CCGT) unit is seemed more promising for cogeneration of electricity and heat. A comparative analysis of the thermal efficiency of these two cycles was performed. Particular attention was paid to ensuring equal conditions for comparison. The cycle of compressorless CCGT unit was as close as possible to the Allam cycle due to the choice of parameters. The processes, in which the difference remained, were analysed. Thereafter, an analysis of how close the parameters, adopted for comparison, to optimal for the compressorless CCGT unit cycle was made. This analysis showed that these two cycles are quite close only for the production of electricity. The Allam cycle has some superiority but not indisputable. However, if cogeneration of electricity and heat is considered, the thermal efficiency of the cycle of compressorless CCGT unit will be significantly higher. Since it allows to independently regulate a number of parameters, on which the electric power, the ratio of electric and thermal power, the temperature of a working fluid at the turbine inlet depend. Thus, the optimal parameters of the thermodynamic cycle can be obtained in a wide range of operating modes of the unit with different ratios of thermal and eclectic powers. Therefore, the compressorless CCGT unit can significantly surpass the best steam turbine and combined cycle gas turbine plants in district heating system in terms of thermal efficiency.

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Gawthrop, Peter J., and Edmund J. Crampin. "Energy-based analysis of biochemical cycles using bond graphs." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 470, no. 2171 (November 8, 2014): 20140459. http://dx.doi.org/10.1098/rspa.2014.0459.

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Thermodynamic aspects of chemical reactions have a long history in the physical chemistry literature. In particular, biochemical cycles require a source of energy to function. However, although fundamental, the role of chemical potential and Gibb's free energy in the analysis of biochemical systems is often overlooked leading to models which are physically impossible. The bond graph approach was developed for modelling engineering systems, where energy generation, storage and transmission are fundamental. The method focuses on how power flows between components and how energy is stored, transmitted or dissipated within components. Based on the early ideas of network thermodynamics, we have applied this approach to biochemical systems to generate models which automatically obey the laws of thermodynamics. We illustrate the method with examples of biochemical cycles. We have found that thermodynamically compliant models of simple biochemical cycles can easily be developed using this approach. In particular, both stoichiometric information and simulation models can be developed directly from the bond graph. Furthermore, model reduction and approximation while retaining structural and thermodynamic properties is facilitated. Because the bond graph approach is also modular and scaleable, we believe that it provides a secure foundation for building thermodynamically compliant models of large biochemical networks.

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Perz, E. "A Computer Method for Thermal Power Cycle Calculation." Journal of Engineering for Gas Turbines and Power 113, no. 2 (April 1, 1991): 184–89. http://dx.doi.org/10.1115/1.2906543.

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This paper describes a highly flexible computer method for thermodynamic power cycle calculations (PCC). With this method the user can model any cycle scheme by selecting components from a library and connecting them in an appropriate way. The flexibility is not restricted by any predefined cycle schemes. A power cycle is mathematically represented by a system of algebraic equations. The structure of mathematical cycle models as well as different approaches to set up and solve the resulting equations with computer programs are discussed in the first section. The second section describes the developed method. The mass and energy balance equations are set up and solved with a semiparallel algorithm. As input only the cycle’s topology and component parameters must be entered. Information about the calculation sequence and the convergence method can be omitted completely. The example of two simple steam cycles demonstrates the applied technique. The method requires only a few, if any, iterations. Calculation time and storage requirements can be kept low enough to calculate even very complex cycles on personal computers. At the end of the paper input data and results for a complex cycle scheme as it may occur in reality are given to demonstrate the performance finally.

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Kapooria, R. K., S. Kumar, and K. S. Kasana. "An analysis of a thermal power plant working on a Rankine cycle: A theoretical investigation." Journal of Energy in Southern Africa 19, no. 1 (February 1, 2008): 77–83. http://dx.doi.org/10.17159/2413-3051/2008/v19i1a3314.

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Today, most of the electricity produced throughout the world is from steam power plants. However, electricity is being produced by some other power generation sources such as hydropower, gas power, bio-gas power, solar cells, etc. One newly devel-oped method of electricity generation is the Magneto hydro dynamic power plant. This paper deals with steam cycles used in power plants. Thermodynamic analysis of the Rankine cycle has been undertaken to enhance the efficiency and reli-ability of steam power plants. The thermodynamic deviations resulting in non-ideal or irreversible func-tioning of various steam power plant components have been identified. A comparative study between the Carnot cycle and Rankine cycle efficiency has been analyzed resulting in the introduction of regen-eration in the Rankine cycle. Factors affecting effi-ciency of the Rankine cycle have been identified and analyzed for improved working of thermal power plants.

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Bahrampoury, Rasool, and Ali Behbahaninia. "Thermodynamic investigation of dual-separator Kalina cycle system: Comparative study." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 232, no. 3 (July 11, 2017): 282–92. http://dx.doi.org/10.1177/0957650917720288.

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In this study, an arrangement of Kalina cycle is proposed in which it is intended to implement weak solution of Kalina cycle system 11 (KCS 11) for more power production. In this cycle, which is a version of KCS11 (KCS111), the weak solution of the traditional separator is heated in hot section of the evaporator. The stream that now includes vapor is separated in high-temperature separator that brings about an extra potential to produce work. In order to set pinch temperature in each of the heat exchangers included in the cycles an iterative method is used. The two cycles are compared for the same conditions as the base case, which is followed by a comprehensive sensitivity analysis. The consequences of streams’ curves in the heat exchangers are considered to present analytical justification for the improvements. Comparing the cycles at the base condition, it is observed that the presented cycle improves the exergy efficiency by nearly 18% while more than 17% improvement at the optimum ammonia mass fraction is achievable. Results show that, the proposed cycle produces larger mass flow rate of vapor passing through the turbines and is more efficient than KCS 11 for varying ammonia mass fractions. Results indicate that the trend of thermal efficiency versus ammonia mass fraction is descending for the both cycles.

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Thorbergsson, Egill, and Tomas Grönstedt. "A Thermodynamic Analysis of Two Competing Mid-Sized Oxyfuel Combustion Combined Cycles." Journal of Energy 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/2438431.

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A comparative analysis of two mid-sized oxyfuel combustion combined cycles is performed. The two cycles are the semiclosed oxyfuel combustion combined cycle (SCOC-CC) and the Graz cycle. In addition, a reference cycle was established as the basis for the analysis of the oxyfuel combustion cycles. A parametric study was conducted where the pressure ratio and the turbine entry temperature were varied. The layout and the design of the SCOC-CC are considerably simpler than the Graz cycle while it achieves the same net efficiency as the Graz cycle. The fact that the efficiencies for the two cycles are close to identical differs from previously reported work. Earlier studies have reported around a 3% points advantage in efficiency for the Graz cycle, which is attributed to the use of a second bottoming cycle. This additional feature is omitted to make the two cycles more comparable in terms of complexity. The Graz cycle has substantially lower pressure ratio at the optimum efficiency and has much higher power density for the gas turbine than both the reference cycle and the SCOC-CC.

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Kaufman, Richard, Thomas V. Marcella, and Eric Sheldon. "Reflections on the pedagogic motive power of unconventional thermodynamic cycles." American Journal of Physics 64, no. 12 (December 1996): 1507–17. http://dx.doi.org/10.1119/1.18414.

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Liu, Yunxia, Yuanyang Zhao, Qichao Yang, Guangbin Liu, and Liansheng Li. "Thermodynamic comparison of CO2 power cycles and their compression processes." Case Studies in Thermal Engineering 21 (October 2020): 100712. http://dx.doi.org/10.1016/j.csite.2020.100712.

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Segantin, Stefano, Andrea Bersano, Nicolò Falcone, and Raffaella Testoni. "Exploration of power conversion thermodynamic cycles for ARC fusion reactor." Fusion Engineering and Design 155 (June 2020): 111645. http://dx.doi.org/10.1016/j.fusengdes.2020.111645.

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González-Portillo, Luis F., Javier Muñoz-Antón, and José M. Martínez-Val. "Thermodynamic mapping of power cycles working around the critical point." Energy Conversion and Management 192 (July 2019): 359–73. http://dx.doi.org/10.1016/j.enconman.2019.04.022.

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Rogalev, Andrey, Nikolay Rogalev, Vladimir Kindra, Ivan Komarov, and Olga Zlyvko. "Research and Development of the Oxy-Fuel Combustion Power Cycles with CO2 Recirculation." Energies 14, no. 10 (May 18, 2021): 2927. http://dx.doi.org/10.3390/en14102927.

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The transition to oxy-fuel combustion power cycles is a prospective way to decrease carbon dioxide emissions into the atmosphere from the energy sector. To identify which technology has the highest efficiency and the lowest emission level, a thermodynamic analysis of the semiclosed oxy-fuel combustion combined cycle (SCOC-CC), the E-MATIANT cycle, and the Allam cycle was carried out. The modeling methodology has been described in detail, including the approaches to defining the working fluid properties, the mathematical models of the air separation unit, and the cooled gas turbine cycles’ calculation algorithms. The gas turbine inlet parameters were optimized using the developed modeling methodology for the three oxy-fuel combustion power cycles with CO2 recirculation in the inlet temperature at a range of 1000 to 1700 °C. The effect of the coolant flow precooling was evaluated. It was found that a decrease in the coolant temperature could lead to an increase of the net efficiency up to 3.2% for the SCOC-CC cycle and up to 0.8% for the E-MATIANT cycle. The final comparison showed that the Allam cycle’s net efficiency is 5.6% higher compared to the SCOC-CC cycle, and 11.5% higher compared with the E-MATIANT cycle.

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Liu, Liuchen, Qiguo Yang, and Guomin Cui. "Supercritical Carbon Dioxide(s-CO2) Power Cycle for Waste Heat Recovery: A Review from Thermodynamic Perspective." Processes 8, no. 11 (November 15, 2020): 1461. http://dx.doi.org/10.3390/pr8111461.

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Supercritical CO2 power cycles have been deeply investigated in recent years. However, their potential in waste heat recovery is still largely unexplored. This paper presents a critical review of engineering background, technical challenges, and current advances of the s-CO2 cycle for waste heat recovery. Firstly, common barriers for the further promotion of waste heat recovery technology are discussed. Afterwards, the technical advantages of the s-CO2 cycle in solving the abovementioned problems are outlined by comparing several state-of-the-art thermodynamic cycles. On this basis, current research results in this field are reviewed for three main applications, namely the fuel cell, internal combustion engine, and gas turbine. For low temperature applications, the transcritical CO2 cycles can compete with other existing technologies, while supercritical CO2 cycles are more attractive for medium- and high temperature sources to replace steam Rankine cycles. Moreover, simple and regenerative configurations are more suitable for transcritical cycles, whereas various complex configurations have advantages for medium- and high temperature heat sources to form cogeneration system. Finally, from the viewpoints of in-depth research and engineering applications, several future development directions are put forward. This review hopes to promote the development of s-CO2 cycles for waste heat recovery.

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Öztürk, A., A. Şenel, and S. U. Onbaşıo??lu. "Thermodynamic optimization of combined cycles." International Journal of Energy Research 29, no. 7 (2005): 657–70. http://dx.doi.org/10.1002/er.1098.

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Kosoy, Boris, Larisa Morozyuk, Sergii Psarov, and Artem Kukoliev. "Synthesis of scheme-cycle designs of absorption water-ammonia thermotransformers with extended degazation zone." Eastern-European Journal of Enterprise Technologies 4, no. 8(112) (August 31, 2021): 23–33. http://dx.doi.org/10.15587/1729-4061.2021.238203.

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The search for new and improvement of existing technical design of energy converter systems for specific consumers requires a reasonable choice of the most rational design for these objects. Thermotransformers that operate on the reverse and mixed thermodynamic cycles, in combination with power plants utilizing renewable and non-traditional primary energy (fuel), are considered to be of interest for small-scale power generation (trigeneration systems), which is consistent with the concept of distributed energy generation. Cold in trigeneration systems is provided by heat-using thermotransformers. This paper reports a method for synthesizing a scheme-cycle designs of absorption water-ammonia thermotransformers that utilize renewable heat sources with a low-temperature potential of 90–250 °С. A "cycle method" was applied to perform the thermodynamic analysis of the cycle of simple absorption thermotransformers with the expansion of the degazation zone with an increase in the temperature of the heating source; the technological schemes for the corresponding cycles have been substantiated. The influence of changing the degazation zone on the energy efficiency of the machine has been established. A scheme-cycle designs of the thermochemical compressor for a thermotransformer with a return supply of solutions to the generator and absorber at " excess temperatures" has been proposed, as a way to improve the cycle energy efficiency. A comparative analysis of the degree of thermodynamic perfection of the considered cycles has been performed using a specific example. The thermodynamic analysis demonstrated that the practical implementation of the scheme-cycle designs "with excess temperatures" could provide energy-saving conditions in small-scale trigeneration systems.

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Macchi, E., S. Consonni, G. Lozza, and P. Chiesa. "An Assessment of the Thermodynamic Performance of Mixed Gas–Steam Cycles: Part A—Intercooled and Steam-Injected Cycles." Journal of Engineering for Gas Turbines and Power 117, no. 3 (July 1, 1995): 489–98. http://dx.doi.org/10.1115/1.2814122.

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This paper discusses the thermodynamics of power cycles where steam or water are mixed with air (or combustion gases) to improve the performance of stationary gas turbine cycles fired on clean fuels. In particular, we consider cycles based on modified versions of modern, high-performance, high-efficiency aeroderivative engines. The paper is divided into two parts. After a brief description of the calculation method, in Part A we review the implications of intercooling and analyze cycles with steam injection (STIG and ISTIG). In Part B we examine cycles with water injection (RWI and HAT). Due to lower coolant temperatures, intercooling enables us to reduce turbine cooling flows and/or to increase the turbine inlet temperature. Results show that this can provide significant power and efficiency improvements for both simple cycle and combined cycle systems based on aero-engines; systems based on heavy-duty machines also experience power output augmentation, but almost no efficiency improvement. Mainly due to the irreversibilities of steam/air mixing, intercooled steam injected cycles cannot achieve efficiencies beyond the 52–53 percent range even at turbine inlet temperatures of 1500°C. On the other hand, by accomplishing more reversible water–air mixing, the cycles analyzed in Part B can reach efficiencies comparable (RWI cycles) or even superior (HAT cycles) to those of conventional “unmixed” combined cycles.

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Yu, Wan, Qichao Gong, Dan Gao, Gang Wang, Huashan Su, and Xiang Li. "Thermodynamic Analysis of Supercritical Carbon Dioxide Cycle for Internal Combustion Engine Waste Heat Recovery." Processes 8, no. 2 (February 12, 2020): 216. http://dx.doi.org/10.3390/pr8020216.

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Waste heat recovery of the internal combustion engine (ICE) has attracted much attention, and the supercritical carbon dioxide (S-CO2) cycle was considered as a promising technology. In this paper, a comparison of four S-CO2 cycles for waste heat recovery from the ICE was presented. Improving the exhaust heat recovery ratio and cycle thermal efficiency were significant to the net output power. A discussion about four different cycles with different design parameters was conducted, along with a thermodynamic performance. The results showed that choosing an appropriate inlet pressure of the compressor could achieve the maximum exhaust heat recovery ratio, and the pressure increased with the rising of the turbine inlet pressure and compressor inlet temperature. The maximum exhaust heat recovery ratio for recuperation and pre-compression of the S-CO2 cycle were achieved at 7.65 Mpa and 5.8 MPa, respectively. For the split-flow recompression cycle, thermal efficiency first increased with the increasing of the split ratio (SR), then decreased with a further increase of the SR, but the exhaust heat recovery ratio showed a sustained downward trend with the increase of the SR. For the split-flow expansion cycle, the optimal SR was 0.43 when the thermal efficiency and exhaust heat recovery ratio achieved the maximum. The highest recovery ratio was 24.75% for the split-flow expansion cycle when the total output power, which is the sum of the ICE power output and turbine mechanical power output, increased 15.3%. The thermal performance of the split-flow expansion cycle was the best compared to the other three cycles.

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El-Masri, M. A. "On Thermodynamics of Gas-Turbine Cycles: Part 3—Thermodynamic Potential and Limitations of Cooled Reheat-Gas-Turbine Combined Cycles." Journal of Engineering for Gas Turbines and Power 108, no. 1 (January 1, 1986): 160–68. http://dx.doi.org/10.1115/1.3239864.

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Reheat gas turbines have fundamental thermodynamic advantages in combined cycles. However, a larger proportion of the turbine expansion path is exposed to elevated temperatures, leading to increased cooling losses. Identifying cooling technologies which minimize those losses is crucial to realizing the full potential of reheat cycles. The strong role played by cooling losses in reheat cycles necessitates their inclusion in cycle optimization. To this end, the models for the thermodynamics of combined cycles and cooled turbines presented in Parts 1 and 2 of this paper have been extended where needed and applied to the analysis of a wide variety of cycles. The cooling methods considered range from established air-cooling technology to methods under current research and development such as air-transpiration, open-loop, and closed-loop water cooling. Two schemes thought worthy of longer-term consideration are also assessed. These are two-phase transpiration cooling and the regenerative thermosyphon. A variety of configurations are examined, ranging from Brayton-cycles to one or two-turbine reheats, with or without compressor intercooling. Both surface intercoolers and evaporative water-spray types are considered. The most attractive cycle configurations as well as the optimum pressure ratio and peak temperature are found to vary significantly with types of cooling technology. Based upon the results of the model, it appears that internal closed-loop liquid cooling offers the greatest potential for midterm development. Hybrid systems with internally liquid-cooled nozzles and traditional air-cooled rotors seem most attractive for the near term. These could be further improved by using steam rather than air for cooling the rotor.

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Kosowski, Krzysztof, Karol Tucki, Marian Piwowarski, Robert Stępień, Olga Orynycz, and Wojciech Włodarski. "Thermodynamic Cycle Concepts for High-Efficiency Power Plants. Part B: Prosumer and Distributed Power Industry." Sustainability 11, no. 9 (May 9, 2019): 2647. http://dx.doi.org/10.3390/su11092647.

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An analysis was carried out for different thermodynamic cycles of power plants with air turbines. A new modification of a gas turbine cycle with the combustion chamber at the turbine outlet has been described in the paper. A special air by-pass system of the combustor was applied, and in this way, the efficiency of the turbine cycle was increased by a few points. The proposed cycle equipped with an effective heat exchanger could have an efficiency higher than a classical gas turbine cycle with a regenerator. Appropriate cycle and turbine calculations were performed for micro power plants with turbine output in the range of 10–50 kW. The best arrangements achieved very high values of overall cycle efficiency, 35%–39%. Such turbines could also work in cogeneration and trigeneration arrangements, using various fuels such as liquids, gaseous fuels, wastes, coal, or biogas. Innovative technology in connection with ecology and the failure-free operation of the power plant strongly suggests the application of such devices at relatively small generating units (e.g., “prosumers” such as home farms and individual enterprises), assuring their independence from the main energy providers. Such solutions are in agreement with the politics of sustainable development.

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Hung, Tzu-Chen, and Yong-Qiang Feng. "Innovative Research in the Organic Rankine Cycle." Impact 2020, no. 6 (November 16, 2020): 76–78. http://dx.doi.org/10.21820/23987073.2020.6.76.

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Thermodynamic cycles consist of a sequence of thermodynamic processes involving the transfer of heat and work into and then out of a system. Variables, such as pressure and temperature, eventually return the system to its initial state. During the process of passing through the system, the working fluid converts heat and disposes of any remaining heat, making the cycle act as a heat engine, where heat or thermal energy is converted into mechanical energy. Thermodynamic cycles are an efficient means of producing energy and one of the most well-known examples is a Rankine cycle. From there, scientists have developed the organic Rankine cycle (ORC), which uses fluid with a liquid to vapour phase change that occurs at a lower temperature than the water to steam phase change. Dr Tzu-Chen Hung and Dr Yong-Qiang Feng, who are based at both the Department of Mechanical Engineering, National Taipei University in Taiwan, and the School of Energy and Power Engineering, Jiangsu University in China, are carrying out work that seeks to design and build improved ORC systems which can be used for low-grade heat to power conversion.

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Campanari, S., P. Iora, P. Silva, and E. Macchi. "Thermodynamic Analysis of Integrated Molten Carbon Fuel Cell–Gas Turbine Cycles for Sub-MW and Multi-MW Scale Power Generation." Journal of Fuel Cell Science and Technology 4, no. 3 (November 2, 2006): 308–16. http://dx.doi.org/10.1115/1.2744051.

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This paper investigates the thermodynamic potential of the integration of molten carbon fuel cell (MCFC) technology with gas turbine systems for small-scale (sub-megawatt or sub-MW) as well as large-scale (multi-MW) hybrid cycles. Following the proposals of two important MCFC manufacturers, two plant layouts are discussed, the first based on a pressurized, externally reformed MCFC and a recuperated gas turbine cycle and the second based on an atmospheric MCFC, with internal reforming integrated within an externally fired gas turbine cycle. Different levels of components quality are considered, with an analysis of the effects of variable pressure ratios, different fuel mixture compositions (variable steam-to-carbon ratio) and turbine inlet temperature levels, together with potential advantages brought about by an intercooled compression process. The analysis shows interesting effects due to the peculiarity of the mutual interactions between gas turbine cycle and fuel cells, evidencing the importance of a careful thermodynamic optimization of such cycles. Results show the possibility to achieve a net electrical efficiency of about 57–58% for a small plant size (with a difference of 1.5–2 percentage points between the two layouts), with the potential to reach a 65% net electrical efficiency when integrated in advanced cycles featuring high-efficiency, large-scale equipment (multi-MW scale cycles).

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Angelino, G., and C. Invernizzi. "Cyclic Methylsiloxanes as Working Fluids for Space Power Cycles." Journal of Solar Energy Engineering 115, no. 3 (August 1, 1993): 130–37. http://dx.doi.org/10.1115/1.2930039.

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The potential merits of cyclic polymethylsiloxanes, particularly those conventionally denominated D4 and D5, as working fluids for space power cycles are discussed. The attractive technical characteristics of these substances which are fully nontoxic, moderately flammable, and stable at high temperature are presented. Some experimental results on vapor pressure and on thermal stability are reported. A maximum operating temperature of about 400°C appears achievable. A comprehensive thermodynamic analysis comparing siloxanes with other classes of high temperature fluids is performed. The peculiar characters of siloxane cycles are found to be: a good overall efficiency achieved through a massive regeneration, a moderate expansion work, and an abundant volume flow at turbine exhaust. A number of two-stage turbines for two power levels (i.e., 30 and 5 kW) were designed using an appropriate optimization program. The resulting main features of such expanders were a satisfactory efficiency, a low rotating and peripheral speed, and a comparatively large wheel diameter. These characteristics seem of particular interest for low capacity systems where, with other fluids, turbines tend to be impractically small and fast rotating and where a high level of regeneration becomes more acceptable. In considering for the sake of comparison the thermodynamic performance of many classes of organic fluids, it becomes apparent that the full potential of organic power cycles in view of the variety of future needs has not yet been thoroughly investigated.

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Oreijah, Mowffaq, Abhijit Date, and Aliakbar Akbarzadaha. "Comparison between Rankine Cycle and Trilateral Cycle in Binary System for Power Generation." Applied Mechanics and Materials 464 (November 2013): 151–55. http://dx.doi.org/10.4028/www.scientific.net/amm.464.151.

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An experimental validation on laboratory scale has been conducted to investigate and to compare two thermodynamic cycles, Trilateral Flash Cycle (TFC) and Organic Rankine Cycle (ORC). The research covers the heat engine utilizing a hydrothermal resource to compare the performance of TFC and ORC. This research would help to analysis the thermal efficiency and power efficiency for both cycles. TFC shows a higher power production than in ORC for the same applied parameters. ORC, however, can be operated at lower rotational speed than for TFC. This project could help, also, to evaluate the current two phase screw expander for both cycles. It is concluded to propose a larger heat exchanger for TFC as the heat recovery can be more reliable in this cycle than in ORC. This research can be applied to generate electrical power from hydrothermal resources such as geothermal energy and solar thermal.

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Ahmed, Aram Mohammed, László Kondor, and Attila R. Imre. "Thermodynamic Efficiency Maximum of Simple Organic Rankine Cycles." Energies 14, no. 2 (January 8, 2021): 307. http://dx.doi.org/10.3390/en14020307.

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The increase of the maximal cycle temperature is considered as one of the best tools to increase cycle efficiency for all thermodynamic cycles, including Organic Rankine Cycles (ORC). Technically, this can be done in various ways, but probably the best solution is the use of hybrid systems, i.e., using an added high-temperature heat source to the existing low-temperature heat source. Obviously, this kind of improvement has technical difficulties and added costs; therefore, the increase of efficiency by increasing the maximal temperature sometimes has technical and/or financial limits. In this paper, we would like to show that for an ideal, simple-layout ORC system, a thermodynamic efficiency-maximum can also exist. It means that for several working fluids, the thermodynamic efficiency vs. maximal cycle temperature function has a maximum, located in the sub-critical temperature range. A proof will be given by comparing ORC efficiencies with TFC (Trilateral Flash Cycle) efficiencies; for wet working fluids, further theoretical evidence can be given. The group of working fluids with this kind of maximum will be defined. Generalization for normal (steam) Rankine cycles and CO2 subcritical Rankine cycles will also be shown. Based on these results, one can conclude that the increase of the maximal cycle temperature is not always a useful tool for efficiency-increase; this result can be especially important for hybrid systems.

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Chauhan, Vijay, P. Anil Kishan, and Sateesh Gedupudi. "Combined Cycle for Power Generation and Refrigeration Using Low Temperature Heat Sources." International Journal of Energy Optimization and Engineering 3, no. 3 (July 2014): 34–56. http://dx.doi.org/10.4018/ijeoe.2014070103.

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A combined refrigeration and power cycle, which uses ammonia-water as the working fluid, is proposed by combining Rankine and vapour absorption cycles with an advantage of varying refrigeration capacity to power output ratio. The study investigates the usage of low temperature heat sources for the cycle operation. Results of parametric analysis are presented, which show the scope for optimization. Results of thermodynamic optimization of the cycle for second law efficiency performed using genetic algorithm for different ambient temperatures are also presented. The cycle shows good potential for obtaining refrigeration and power generation.

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Angelino, G., and C. Invernizzi. "Real gas Brayton cycles for organic working fluids." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 215, no. 1 (February 1, 2001): 27–38. http://dx.doi.org/10.1243/0957650011536543.

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Organizing a closed Brayton cycle in such a way that the compression process is performed in the vicinity of the critical point where specific volumes are a fraction of those of an ideal gas yields performance indices particularly attractive, mainly at moderate top temperatures. Cycle thermodynamic analysis requires the development of adequate methods for the computation of thermodynamic properties above the vapour saturation curve about the critical point. Working fluids suitable for the proposed cycle can be found in the class of organics, in particular among the newly developed, zero ozone depletion potential, chlorine-free compounds. The numerous technical and environmental requirements which a fluid must meet for practical use combined with the peculiar thermodynamic restraints limit the number of suitable fluids. Mixing two substances of different critical temperatures yields an indefinite number of fluids with tailor-made thermodynamic properties. One such mixture 0.93 HFC23 + 0.07 HFC125 (molar fraction), having tcr = 30°C, at tmax = 400°C, pmax = 150 bar, gives an efficiency above 27 per cent with heat rejection temperatures between 89 and 33°C. With a different mixture composition with a 50°C critical temperature, at the same tmax and pmax, an efficiency of 25.1 per cent is attained in a combined heat and power generation cycle with heat available in the range 53-103°C. An experimental programme to test the thermal stability of organic fluids showed that top temperatures of 380-450°C are achievable with some commercially available fluoro-substituted hydrocarbons. In view of practical applications a conversion unit based on a reciprocating engine could handle without problems the pressures and temperatures involved. The use of turbomachinery would lead to power plant of large capacity for the usual rotor dimensions or to micro-turbines at high rotating speed in the low power range.

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Boydak, Ozlem, Ismail Ekmekci, Mustafa Yilmaz, and Hasan Koten. "Thermodynamic investigation of organic Rankine cycle energy recovery system and recent studies." Thermal Science 22, no. 6 Part A (2018): 2679–90. http://dx.doi.org/10.2298/tsci170720103b.

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Recently, new environment-friendly energy conversion technologies are required for using energy resources valid to power generation. Accordingly, low-grade heat sources as solar heat, geothermal energy, and waste heat, which have available temperatures ranging between 60 and 200?C, are supposed as applicants for recent new generation energy resources. As an alternative energy source, such low-grade heat sources usage generating electricity with the help of power turbine cycles was examined through this study. Such systems have existing technologies applicable at low temperatures and a compact structure at low cost, however, these systems have a low thermal efficiency of the Rankine cycles operated at low temperatures. An organic Rankine cycle is alike to a conventional steam power plant, except the working fluid, which is an organic, high molecular mass fluid with a liquid-vapor phase change, or boiling point, at a lower temperature than the water-steam phase change. The efficiency of an organic Rankine cycle is about between 10% and 20%, depending on temperature levels and availability of a valid fluid.

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Journal articles on the topic 'Thermodynamic power cycles'

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