Journal articles: 'Turbo expanders'

1

Adams, Jacob, Nathaniel O’Connor, Matthew Jones, and John Brisson. "Experimental improvements to the acoustic expander with applications to cryogenic refrigeration." IOP Conference Series: Materials Science and Engineering 1327, no. 1 (2025): 012146. https://doi.org/10.1088/1757-899x/1327/1/012146.

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Abstract The acoustic expander is an innovative cryogenic component that uses pressure waves for work transfer as part of a continuous flow, recuperative cycle refrigerator. This expander uses passive reed-valves coupled to an acoustic resonator to produce refrigeration. The passive reed-valves are pressure-controlled by the imposed, static pressure difference across the expander and the natural oscillating pressure in the resonator. The resonator is a series of tubes and cones. The practical implications of these simple components are that the acoustic expander does not require controlled valving or close-tolerance sliding seals at low-temperature, unlike existing piston- or turbo-expanders. This work compares two resonator designs, a harmonic resonator and a non-harmonic resonator. The non-harmonic resonator is excited by a single-frequency allowing for operation at an expansion pressure-ratio of 2.4. These expanders are expected to be useful in medium-scale refrigeration applications that are not well served by current small-scale Stirling cryocoolers or large-scale turbo-expander refrigerators.

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Fermoselli, N. E. G. "PREDICTING THE IMPACT OF A FCC TURBO EXPANDER ON PETROLEUM REFINERIES." Revista de Engenharia Térmica 9, no. 1-2 (2010): 40. http://dx.doi.org/10.5380/reterm.v9i1-2.61929.

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Implementing a turbo expander connected to a fluid catalytic cracking (FCC) unit in order to produce power from flue gas has already become a common practice in oil refineries worldwide. Despite of recovering energy which used to be wasted in an orifice chamber, the implementation of expander and its skids still requires high investment, which often begins with a third-stage cyclones installation to enhance flue gas cleanness. Moreover, machine and also pipes need to be made with special materials in order to resist high temperatures and erosion. Hence, there are some items to be checked before start up a turbo expander to ensure the return on investment will reach expectations, keeping in mind that its ability to extract energy from flue gas changes widely depending on FCC operational conditions. Then, the aim of this paper is to provide the analysis of one stage turbo expander which is fed with flue gas from partial combustion FCC unit and installed with isolation valves, highlighting some points which deserve special attention before start up this type of machine. It brings together some approaches to provide valuable information about a turbo expander, particularly when it is not running yet, including the results to a hypothetical case and the sequence of calculus that can be done without using any special software applied for: • To estimate real energy generation through the turbo expander as a function of FCC feed; • To check the leaks effect; • To predict the impact of turbo expander on carbon monoxide boiler, due to a fall in temperature of the expanded flue gas; • To calculate the appropriate amount of extra supplementary gas required to be burned in the flue gas boiler in order to keep the production of steam stable; • To analyze the moisture of the flue gas so that it may predicts condensation when hot gas comes into contact with the cold duct, after opening isolation valves; • And finally, how turbo expanders fit in cleaning development mechanism to get certified carbon credits.

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Antipenkov, B. A., A. B. Davydov, A. Sh Kobulashvili, G. A. Perestoronin, and A. A. Fal'chenko. "Turbo-expanders for mobile air separation equipment." Chemical and Petroleum Engineering 21, no. 3 (1985): 125–27. http://dx.doi.org/10.1007/bf01154881.

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Adams, Jacob L., and J. G. Brisson. "Acoustic expanders for use in recuperative cryocoolers." IOP Conference Series: Materials Science and Engineering 1301, no. 1 (2024): 012134. http://dx.doi.org/10.1088/1757-899x/1301/1/012134.

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Abstract An acoustic expander has been developed for use in recuperative cryocoolers. The acoustic expander uses reed-valves to generate a standing acoustic wave from a continuously expanding flow. The mechanical energy from the wave is passively dissipated to the ambient environment. The acoustic expander does not require complex moving parts or control mechanisms at low-temperature; in contrast to piston- or turbo-expanders that require moving displacers or spinning shafts. This expander has demonstrated isentropic expansion efficiencies of 50% for a pressure ratio of 1.4 and expansion efficiencies of 40% for a pressure ratio of 1.9 with air as the working fluid.

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Martyanov, O. A., and V. I. Merkulov. "Overview of the problem of moist air flow in turbo-expanders." Izvestiya MGTU MAMI 8, no. 4-1 (2014): 51–55. http://dx.doi.org/10.17816/2074-0530-67673.

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Ke, Changlei, Lianyou Xiong, Nan Peng, et al. "Efficiency Improvement of Small Cryogenic Helium Turbo-expanders in TIPC." IOP Conference Series: Materials Science and Engineering 1301, no. 1 (2024): 012028. http://dx.doi.org/10.1088/1757-899x/1301/1/012028.

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Abstract An experimental helium liquefier/refrigerator, using ultra high speed cryogenic turbo-expanders is designed and developed in Technical Institute of Physics and Chemistry (TIPC), and liquefaction rate of around 42 L/hr and refrigeration capacity of around 130 W @ 4.5 K is achieved. The turbo-expander constitutes the most critical component of a helium liquefier/refrigerator causing that the turbine efficiency has a great influence on the performance of the whole cryogenic process plant. Inlet Flow Radial (IFR) turbine design is dictated by criteria like velocity ratios. For small flow rate plants the size of the turbine impeller needs to be reduced. In order to reach a high efficiency, the rotational speed must be increased to complete a large specific enthalpy drop. The present article describes the latest technical developments at TIPC, including results obtained during field trials with the TIPC helium liquefier and refrigerator. The motivation of these developments is to improve the efficiency of the machines, and also to widen the range of operation.

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NAKAYAMA, Yoshihiro, Tetsuro MATSUMOTO, and Sadao SATO. "Cool-down characteristics of helium liquefier with turbo-expanders." TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan) 23, no. 1 (1988): 23–29. http://dx.doi.org/10.2221/jcsj.23.23.

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Barmby, T. H., and A. Cleveland. "Control Systems for Turbo Expanders in Pressure Reduction Service." Journal of Engineering for Gas Turbines and Power 113, no. 2 (1991): 296–99. http://dx.doi.org/10.1115/1.2906562.

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Kitt, S. R., and B. D. Rose. "Foothills Decompression/Recompression Facilities—Unique Power Recovery Application in Gas Pipelines." Journal of Engineering for Gas Turbines and Power 116, no. 1 (1994): 143–51. http://dx.doi.org/10.1115/1.2906783.

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Foothills Pipe Lines Ltd. is the Canadian sponsor of the Alaska Natural Gas Transportation System (ANGTS), a pipeline project selected in Canada and the United States as the means for transporting Alaskan gas reserves to the lower 48 United States. Currently, certain Prebuild portions of the ANGTS are in operation delivering Canadian gas to U. S. markets. A recent system expansion of the Eastern Leg Prebuild to accommodate increased Canadian gas exports entailed the construction of Decompression/Recompression facilities at Empress, Alberta to enable high-pressure operation of the Foothills pipeline while maintaining gas stripping at existing lowpressure extraction plants. The general process of the Decompression/Recompression facilities involves the expansion of high-pressure pipeline gas to conditions acceptable to the low-pressure extraction plants, then the recompression of the residue gas for return to the pipeline at original pressure. By directing the inlet gas through turbo expanders coupled to brake compressors, a substantial portion of the expansion energy is captured and used in providing the first stage of gas recompression. Including supplemental conventional compression, the Decompression/Recompression facilities are capable of providing approximately 37MW (50,000 HP) for continuous gas recompression. Although power recovery with turbo expanders is relatively common in the gas processing industry, such an application for gas recompression in large gas pipelines is unique. This technical paper describes the Foothills Decompression/Recompression facilities with their utilization of turbo expanders for pipeline recompression service, emphasizing the process design as well as the characteristics of the rotating equipment.

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Renuke, Avinash, Alberto Traverso, and Matteo Pascenti. "Experimental Campaign Tests on a Tesla Micro-Expanders." E3S Web of Conferences 113 (2019): 03015. http://dx.doi.org/10.1051/e3sconf/201911303015.

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This paper presents the experimental campaign on Tesla turbo expanders carried out at Thermo-chemical Power group (TPG) of University of Genoa, Italy. An experiment system is established using compressed air as a working fluid. A 200 W turbine is tested with rotational speed up to 40000 rpm. Experimental analysis focused mainly on the efficiency features of this expander, showing the impact on performance of different disk gaps, disk thickness, discharge holes, exhaust geometry, as a function of speed and mass flow. An improved version of 3 kW air Tesla turboexpander is built. Preliminary experimental results are discussed along with the effect of number of nozzles on the performance of the turbine.

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Pietro, Bartocci, Abad Alberto, MAttisson Tobias, et al. "Bioenergy with Carbon Capture and Storage (BECCS) developed by coupling a Pressurised Chemical Looping combustor with a turbo expander: How to optimize plant efficiency." Renewable and Sustainable Energy Reviews 169 (September 25, 2022): 112851. https://doi.org/10.5281/zenodo.7317240.

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Carbon Capture and Storage is a technology of paramount importance for the fulfillment of the Sustainable Development Goal 7 (Affordable and Clean Energy) and the Sustainable Development Goal 5 (Climate Action). The European Union is moving rapidly towards low carbon technologies, for instance via the Energy Union Strategy. Coupling biofuels and carbon capture and storage to decarbonize the power and the industrial sector can be done through the development of BECCS (Bioenergy with Carbon Capture and Storage). Chemical Looping combustion is one of the cheapest way to capture CO2. A Chemical Looping Combustion (CLC) plant can be coupled with a turbo expander to convert energy to power, but it has to work in pressurised conditions. The effect of pressure on the chemical reactions and on fluidised bed hydrodynamics, at the moment, is not completely clear. The aim of this review is to summarize the most important highlights in this field and also provide an original method to optimize power plant efficiency. The main objective of our research is that to design a pressurised Chemical Looping Combustion plant which can be coupled to a turbo expander. To achieve this we need to start from the characteristics of the turbo expander itself (eg. the Turbine Inlet Temperature and the compression ratio) and then design the chemical looping combustor with a top down approach. Once the air and the fuel reactor have been dimensioned and the oxygen carrier inventory and circulation rate have been iden- tified, the paper proposes a final optimization procedure based on two energy balances applied to the two re- actors. The results of this work propose an optimization methodology and guidelines to be used for the design of pressurised chemical looping reactors to be coupled with turbo expanders for the production of power with carbon negative emissions.

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Arifin, M., and A. D. Pasek. "Design of Radial Turbo-Expanders for Small Organic Rankine Cycle System." IOP Conference Series: Materials Science and Engineering 88 (September 23, 2015): 012037. http://dx.doi.org/10.1088/1757-899x/88/1/012037.

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Fiaschi, Daniele, Giampaolo Manfrida, and Francesco Maraschiello. "Thermo-fluid dynamics preliminary design of turbo-expanders for ORC cycles." Applied Energy 97 (September 2012): 601–8. http://dx.doi.org/10.1016/j.apenergy.2012.02.033.

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Spale, Jan, Guk Chol Jun, Vaclav Novotny, Philipp Streit, Andreas P. Weiß, and Michal Kolovratnik. "Development of a 10 kW class axial impulse single stage turboexpander for a micro-CHP ORC unit." EPJ Web of Conferences 264 (2022): 01044. http://dx.doi.org/10.1051/epjconf/202226401044.

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Development of micro ORC systems with 1-15 kW power output for micro-cogeneration and waste heat recovery at the Czech Technical University in Prague, University Centre for Energy Efficient Buildings (CTU UCEEB) has over ten years of history with many successes. These include 6 different ORC units, all with in-house designed rotary vane expanders (RVE) of many versions throughout this development. Among main advantages of the RVE belong relatively simple and robust design at low cost even at very small series of single-unit production and all that with acceptable efficiency. The ORC units operate with hexamethyldisiloxane (MM) working fluid at high pressure ratios and expansion ratios and the isentropic efficiency of RVE has a limit at these conditions around 60%, often however only at values around 50%. While this might be enough on a cost side for commercialization of this technology, in pursuit of higher efficiency solutions, different expander technology needs to be selected. A turbo-expander is a logical choice with prospect of higher efficiency. At the same time, a literature review has found a lack of reported detailed experimental data for micro (5-50 kW) turbo-expanders, possibly hindering global development towards economically feasible solutions. A project named Dexpand, “Optimised expanders for small-scale distributed energy systems” aims at these issues by objectives in designing, optimizing, manufacturing and testing several ORC expanders with MM and isobutane and their subsequent performance mapping and comparison. One major task is a design of a turboexpander for a 120 kWth biomass fired microcogeneration ORC unit currently operated at the CTU UCEEB. An axial impulse single stage turboexpander was selected as a suitable choice, providing a prospect of a decent efficiency at technically manageable rotational speed and size. This paper provides a detail of currently performed design activities, starting from boundary conditions specification, over development and optimization of a 1D model, preliminary 2D CFD calculations and finishing in a state of a robust and detailed 3D CFD model with a real gas model. Note that the working fluid, high molar mass organic vapour, is highly non-ideal in its behaviour and the flow conditions with pressure design ratio around 13 is highly supersonic (nozzle outlet isentropic Mach number exceeds 2). The current results based on 3D CFD indicate a prospect of an isentropic efficiency 71% at mechanical power output of 11 kW. Lastly, ongoing and future work is outlined, which includes aerodynamic optimization based on the developed 3D CFD model and construction design of the entire turbine assembly.

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YOSHIDA, Jun, Eito MATSUO, Yasuyuki TAKATA, and Masanori MONDE. "Thermodynamic analysis of high pressure hydrogen gas refueling system with turbo-expanders." Mechanical Engineering Journal 6, no. 3 (2019): 18–00388. http://dx.doi.org/10.1299/mej.18-00388.

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Costall, A. W., A. Gonzalez Hernandez, P. J. Newton, and R. F. Martinez-Botas. "Design methodology for radial turbo expanders in mobile organic Rankine cycle applications." Applied Energy 157 (November 2015): 729–43. http://dx.doi.org/10.1016/j.apenergy.2015.02.072.

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Zhou, Kaimiao, Liang Chen, Haodong Wang, et al. "Comparison of mean-line methods for hydrogen turbo-expanders in hydrogen liquefiers." Case Studies in Thermal Engineering 60 (August 2024): 104632. http://dx.doi.org/10.1016/j.csite.2024.104632.

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Taleshian, Mehdi, Hasan Rastegar, and Hossein Askarian Abyaneh. "Modeling and Power Quality Improvement of Grid Connected Induction Generators Driven by Turbo-Expanders." International Journal of Energy Engineering 2, no. 4 (2012): 131–37. http://dx.doi.org/10.5923/j.ijee.20120204.04.

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Rahman, Mohammed Mahbubur. "POWER GENERATION FROM PRESSURE REDUCTION IN THE NATURAL." Journal of Mechanical Engineering 41, no. 2 (2011): 89–95. http://dx.doi.org/10.3329/jme.v41i2.7472.

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Power can be generated from the pressure energy of natural gas along its supply chain at various pressure reduction points by using turbo-expanders. This technology is being applied in different countries around the world. This paper attempts to asses the potential of using this technology for Bangladesh. A number of producing wells and pressure reduction stations are investigated. It is found that pre-heating before expansion is almost always necessary to avoid hydrate formation. The power obtainable at the wellheads range from 150-500 kW, and that from pressure reduction stations range from 200 kW to 5 MW.DOI: http://dx.doi.org/10.3329/jme.v41i2.7472

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Qiu, Shun, Changlei Ke, Kongrong Li, Xiaohua Zhang, Nan Peng, and Liqiang Liu. "Investigation on the dynamic response of aerostatic bearing-rotor system with different bearing gases." IOP Conference Series: Materials Science and Engineering 1327, no. 1 (2025): 012069. https://doi.org/10.1088/1757-899x/1327/1/012069.

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Abstract Due to their low friction and long lifespan, aerostatic bearings are widely used in high-speed cryogenic turbo expanders. Variations in bearing gas viscosity and density lead to differences in the static and dynamic characteristics of these bearings. In this study, a fluid-structure coupled model of the bearing-rotor system is established. The bearing lubricant equation and rotor motion equation are solved simultaneously to obtain the nonlinear dynamic response of the system. The findings reveal that the system exhibits rich nonlinear phenomena, indicating that the load capacity of helium bearings is greater than that of hydrogen and air bearings, while the stability of air bearings is superior to that of hydrogen and helium bearings.

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Faddeev, I. P. "Turbo expanders to utilize the pressure of natural gas delivered to Saint Petersburg and industrial centers." Chemical and Petroleum Engineering 34, no. 11 (1998): 704–11. http://dx.doi.org/10.1007/bf02418862.

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Liu, Hongmin, Jiansheng Zuo, Shun Qiu, et al. "Simulative and experimental analysis of high-speed helium turbo-expanders in a 5t/day hydrogen liquefier." International Journal of Hydrogen Energy 133 (June 2025): 152–64. https://doi.org/10.1016/j.ijhydene.2025.04.403.

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Haselbacher, Hermann. "Performance of water/steam injected gas turbine power plants consisting of standard gas turbines and turbo expanders." International Journal of Energy Technology and Policy 3, no. 1/2 (2005): 12. http://dx.doi.org/10.1504/ijetp.2005.006737.

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Weiß, Andreas P., Václav Novotný, Tobias Popp, et al. "Customized ORC micro turbo-expanders - From 1D design to modular construction kit and prospects of additive manufacturing." Energy 209 (October 2020): 118407. http://dx.doi.org/10.1016/j.energy.2020.118407.

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Osborne, Deborah A., and Luis San Andre´s. "Experimental Response of Simple Gas Hybrid Bearings for Oil-Free Turbomachinery." Journal of Engineering for Gas Turbines and Power 128, no. 3 (2006): 626–33. http://dx.doi.org/10.1115/1.1839922.

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Gas film bearings offer unique advantages enabling successful deployment of high-speed microturbomachinery (<0.4 MW). Current applications encompass micropower generators, air cycle machines and turbo expanders. Mechanically complex gas foil bearings are in use; however, their excessive cost and lack of calibrated predictive tools deters their application to mass-produced systems. The present investigation provides experimental results for the rotordynamic performance of a small rotor supported on simple and inexpensive hybrid gas bearings with static and dynamic force characteristics desirable in high-speed turbomachinery. These characteristics are adequate load support, stiffness and damping coefficients, low friction and wear during rotor startup and shutdown, and most importantly, enhanced rotordynamic stability. The test results evidence the paramount effect of feed pressure on early rotor lift-off and substantially higher threshold speeds of rotordynamic instability. Higher supply pressures also determine larger bearing direct stiffnesses, and thus bring an increase in the rotor-bearing system critical speed albeit with a reduction in damping ratio.

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Haghjoo, Hossein, Emad Aram, Gholamreza Ahmadi, and Davood Toghraie. "Energy, exergy, economic, and environmental analyses and multi-objective optimisation of using turbo-expanders in natural gas pressure reduction stations." International Journal of Exergy 38, no. 2 (2022): 238. http://dx.doi.org/10.1504/ijex.2022.123607.

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Haghjoo, Hossein, Emad Aram, Gholamreza Ahmadi, and Davood Toghraie. "Energy, exergy, economic, and environmental analyses and multi-objective optimisation of using turbo-expanders in natural gas pressure reduction stations." International Journal of Exergy 38, no. 2 (2022): 238. http://dx.doi.org/10.1504/ijex.2022.10048293.

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Cappiello, Alessandro, and Raffaele Tuccillo. "Design and CFD Analysis of a Radial-Inflow Turbine for Small Scale ORC Applications." E3S Web of Conferences 197 (2020): 11005. http://dx.doi.org/10.1051/e3sconf/202019711005.

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In recent years, Organic Rankine Cycle (ORC) technology has received growing interests, thanks to its high flexibility and to the capability to exploit energy sources at temperature levels difficult to be approached with conventional power cycles. These features allow exploiting renewable and renewable-equivalent energy sources, by either improving the energy conversion efficiency of existing plants or using waste heat from industrial process. As far as the expander is concerned, a high potential solution is represented by turbo-expanders, which allow reduction of plant clutter and complexity, so enhancing the potential impact on the diffusion of small power ORC-based plants. The present work concerns the design of a RadialInflow Turbine for a bottoming Organic Rankine Cycle in the tens of kW scale. Design boundary conditions are retrieved by a zero-dimensional model of a solar-assisted micro gas turbine in cogenerating mode. The design process is started by means of an in-house mean-line design code accounting for real gas properties. The code is used to carry out parametric analyses to investigate the design space for several working fluids encompassing different classes, namely refrigerants and siloxanes. The program is used to assess the effect of design variables and working fluid on the turbine performance and turbine design characteristics. Subsequently, the most promising design candidates are selected and three-dimensional first guess stator and rotor geometries are built on these preliminary designs. Stationary and rotating passages are then meshed and analyzed by means of RANS CFD based solution of the stator – rotor interaction.

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Fedorova, M. A. "I. Ivkovic-Kihic, M. Read, Sh. Rane, A. Kovacevic. «Compressors and their systems». Post conference report / trans. from Engl. M. A. Fedorova." Omsk Scientific Bulletin. Series Aviation-Rocket and Power Engineering 6, no. 1 (2022): 86–91. http://dx.doi.org/10.25206/2588-0373-2022-6-1-86-91.

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The article presents an overview report of the 12th International Conference on Compressors and their systems which was held in a hybrid format from September 6 to 8, 2022 in the City, University of London, UK. At this prestigious scientific and educational forum, within the framework of the plenary session, world experts made reports in the field of compressor technology and de-carbonization, as well as presentations at several technical and panel sessions on such topics as screw, scroll, vane and piston compressors; compressor systems and their diagnostic and control systems; turbo-machines; mathematical modeling and optimization of compressors, expanders and their systems. In addition, within the framework of the conference, a traditional short training course and a Forum on CFD (gas dynamic calculations) in rotary positive displacement machines were held. The introductory session was devoted to the basics of CFD implementation using the finite volume method. New studies in the field of CFD in rotary volumetric machines were presented, including those based on such programmes as ANSYS Forte and OpenFOAM. Complex modeling approaches, such as SCORG and GT-Suite, also attracted the attention of participants. Information about the next conference on Compressors and their systems, which will be held in 2023, is presented.

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Abdul, Mannan Ansari* Vinod Sehrawat Tarun Gupta. "OPERATING PARAMETERS ACCUMULATION OF HELIUM LIQUEFICATION SYSTEM: (H.E & TURBINE)." INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY 5, no. 8 (2016): 554–58. https://doi.org/10.5281/zenodo.60098.

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Present work involves analysis and optimization of the process parameters (like helium flow rate, pressure and temp.) for main components as (eight different heat exchangers as well as three different turbo-expanders) of helium liquefaction plant of refrigeration capacity 1 kW at 4.5 K. Nevertheless, this plant can be operated in mixed mode also as helium refrigerator-cum-liquefier, although it is optimized for refrigeration load. To optimize process of any helium refrigeration/liquefaction system, this is important to consider one independent variable at a time and under valid assumptions, and its effect on the various process. From the analysis, the optimized value of the concerned and considered process variables is taken. The main components of system that affect process parameters are compressor, heat exchangers ,expansion devices or expansion valve besides this basically concerned with the parameters of the heat exchangers as well as expansion engines.  Current calculation work mainly total compressor mass flow rate, fraction of total compressor flow of mass diverted towards engines, inlet temperature to many expansion engine and heat exchangers are calculated and accumulated using steady state condition. Present study, analysis and optimization of the important operating parameters is done considering logical assumptions and fulfilling important practical constraints that are explained in this report.

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San Andrés, Luis. "Hybrid Flexure Pivot-Tilting Pad Gas Bearings: Analysis and Experimental Validation." Journal of Tribology 128, no. 3 (2006): 551–58. http://dx.doi.org/10.1115/1.2194918.

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Gas film bearings offer unique advantages enabling successful deployment of high-speed microturbomachinery. Current applications encompass micro power generators, air cycle machines, and turbo expanders. Mechanically complex gas foil bearings are in use; however, their excessive cost and lack of calibrated predictive tools deter their application to mass-produced oil-free turbochargers, for example. The present investigation advances the analysis and experimental validation of hybrid gas bearings with static and dynamic force characteristics desirable in high-speed turbomachinery. These characteristics are adequate load support, good stiffness and damping coefficients, low friction and wear during rotor startup and shutdown, and most importantly, enhanced rotordynamic stability at the operating speed. Hybrid (hydrostatic/hydrodynamic) flexure pivot-tilting pad bearings demonstrate superior static and dynamic forced performance than other geometries as evidenced in a high-speed rotor-bearing test rig. A computational model including the effects of external pressurization predicts the rotordynamic coefficients of the test bearings and shows good correlation with measured force coefficients, thus lending credence to the predictive model. In general, direct stiffnesses increase with operating speed and external pressurization, whereas damping coefficients show an opposite behavior. Predicted mass flow rates validate the inherent restrictor-type orifice flow model for external pressurization. Measured coast-down rotor speeds demonstrate very low-friction operation with large system time constants. Estimated drag torques from the gas bearings indirectly validate the recorded system time constant.

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Liu, Hongmin, Jiansheng Zuo, Shun Qiu, et al. "Corrigendum to “Simulative and experimental analysis of high-speed helium turbo-expanders in a 5t/day hydrogen liquefier” [Int J Hydrog Energy, 133 (2025) 152-164]." International Journal of Hydrogen Energy 145 (July 2025): 841. https://doi.org/10.1016/j.ijhydene.2025.05.325.

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Sahu, A. K., O. Chandratre, H. Kavad, et al. "Development of Cold Box for Upgradable Helium Refrigerator Plant of 200 W at 4.5 K." IOP Conference Series: Materials Science and Engineering 1327, no. 1 (2025): 012033. https://doi.org/10.1088/1757-899x/1327/1/012033.

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Abstract The cold box for helium refrigerator plant of cooling power ~200 W at 4.5 K has been developed at IPR, Gandhinagar, India. Helium compressor system, which gives helium flow ~60 g/s at 14 bar, has been used for this plant. The cold box of the plant is made using a vertical vacuum chamber, within which all cold components are assembled. The thermodynamic process used is a modified Claude Cycle. This cold box has 7 plate-fin heat exchangers, 3 turbo-expanders, an 80 K helium purifier and a JT valve. LN2 pre-cooling is used in the cold box to ensure 80 K before the helium purifier. Turbine-1 and 2 are warmer ones and are connected hydraulically in series. The 3rd turbine is colder one and is in series with JT valve. This plant, due to certain reasons, has been developed using components made for other purposes. Later, based on the detailed process analysis and optimization, it was found that if only 7th heat exchanger, the coldest one, is replaced by a higher capacity, cooling power of the plant can be improved significantly. Similarly, there are other possibilities to upgrade it up to cooling power ~1 kW at 4.5 K. Hence, provision was kept for up-gradation to a plant of higher capacity with different modes of cooling. The architecture of this layout has been developed and implemented indigenously. Details of the design concept of the cold box and experiences of initial operations will be discussed in this paper.

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Zafar, S., and T. K. Nandi. "Numerical investigations on pressure wave refrigerators for sizing the dump tank and studying its effect on the operating frequency at first peak efficiency." IOP Conference Series: Materials Science and Engineering 1327, no. 1 (2025): 012180. https://doi.org/10.1088/1757-899x/1327/1/012180.

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Abstract Pressure Wave Refrigerators (PWRs), in principle, work with thermal separation through shock waves. A PWR typically comprises a rotating gas distributor that periodically injects high-pressure gas into one or more stationary receiving tubes. The sudden release of high-pressure gas in a tube or channel produces shock waves that heat up the residual gas towards the dead end, while the rarefied waves produce refrigeration in the driver gas at the nozzle end. Upon connection to the outlet port, the refrigerated gas flows out of the receiving tube into a receiver. PWRs have several advantages, such as simple design, low cost, high reliability, low rotational speed, and high efficiency comparable to conventional turbo-expanders. Reflected shock waves from the dead end of the receiving tube of a PWR seriously affect the performance through heating of the fluid inside the tube. A dump tank, is usually fitted at the end of the receiving tube so that the reflected shock waves are attenuated. The effects of the size of the dump tank in terms of the volume of the stationary receiving tube are studied for different tube lengths and pressure ratios. The isentropic efficiency of a 2m tube increases from 54% to 78 % by using a dump tank having volume ten times that of the receiving tube. During the operation of a PWR, there are peaks in isentropic efficiency at certain operating cycle frequencies. In this work, appearance of the first peak efficiency is also investigated for different sizes of the dump tank.

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Dalesandro, A., A. Weiner, J. P. Kelley, et al. "The SPARC cryogenic system." IOP Conference Series: Materials Science and Engineering 1301, no. 1 (2024): 012107. http://dx.doi.org/10.1088/1757-899x/1301/1/012107.

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Abstract The SPARC project at Commonwealth Fusion Systems (CFS) is a tokamak system designed to demonstrate commercially relevant fusion energy and achieve net fusion power output during the first operating campaign, with eventual fusion pulse energies exceeding 1 GJ. The SPARC tokamak includes eight magnet systems, three that use high-temperature superconducting (HTS) tapes. The SPARC cryogenic system (CRYO) consists of three supercritical helium cryogenic loops at nominal temperatures of 8 K, 15 K, and 80 K. CRYO 8 K and 15 K loops cool the HTS magnets to maintain thermal stability and prevent quench, while magnets cooled to 80 K are normally conductive. CRYO provides cold helium using a hybrid system that includes a Brayton-cycle-based cryoplant supporting all CRYO temperature loops, and a fixed volume 8 K blowdown system to remove heat and maintain temperature stability of the toroidal field (TF) magnets during and immediately following fusion pulses. CRYO 4.5 K equivalent peak cooling power is 17 kW for the cryoplant and 2.9 MW for the blowdown system during a 10-second fusion pulse. Primary cryoplant mechanical equipment includes screw compressors, turbo-expanders, heat exchangers, and circulation pumps, while the blowdown system consists of a series of warm and cold helium storage tanks operating at independent temperatures and pressures, with make-up compressors to reset the blowdown system between pulses. CRYO also includes a distribution valve box and multiple vacuum-jacketed (VJ) process lines ranging in nominal diameter from 20 to 600 mm. This paper investigates the various sub-elements which in combination represent SPARC CRYO, and attempts to address some of the technical challenges identified by the team.

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Hasan, N., V. Ganni, P. Knudsen, F. Casagrande, and J. Howard. "Process design for FRIB’s experimental refrigeration system." IOP Conference Series: Materials Science and Engineering 1301, no. 1 (2024): 012130. http://dx.doi.org/10.1088/1757-899x/1301/1/012130.

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Abstract The experimental system (ES) for the Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) has several segments. Following the acceleration through the three superconducting LINAC segments, the heavy ion beam is guided through the target, a fragment pre-separator and (the A1900) separator segments. There are many beam lines and then it can be split and sent to various experimental vaults and instrumentation, e.g. S800 spectrograph, and the newly proposed High Rigidity Spectrometer (HRS). Presently, superconducting magnets at the target and fragment pre-separator segments, along with the LINAC superconducting cryo-modules, are supported by FRIB’s main central helium liquefier/refrigerator (CHL). The remainder of the cryogenic loads are supported by the legacy NSCL Cryogenic Refrigerator (a re-commissioned Bureau of Mines helium liquefier from the mid 1970’s) and has many obsolete components for reliable operation. Considering the operational reliability of the accelerator, maintainability of the entire cryogenic system at FRIB and ever-growing experimental beam lines – it is logical to segregate the experimental system loads from the accelerator system loads. A new 4.5 K refrigerator along with a thermal shield (55 K) refrigerator are planned to support the operation of these experimental system (ES) loads and make plans for the CHL maintenance. These refrigerators will be able to support a combination of 4.5 K isothermal refrigeration, 4.5 K liquefaction (for magnet lead cooling and transients) and thermal radiation shield loads. The design loads, modes of operation and the planned operation of the FRIB cryogenic system with these refrigeration systems are discussed. This paper outlines the key selection parameters and design modes for the major components, such as the warm compressors, turbo-expanders and heat exchangers.

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Olumide, Akindele Owulade, Raymond Isi Lawani, Amos Essien Nkese, Isaac Tokunbo Olugbemi Gilbert, and Ogu Elemele. "Comprehensive Review of Climate Change Mitigation through Cutting-edge LNG Technologies." Engineering and Technology Journal 10, no. 05 (2025): 4789–96. https://doi.org/10.5281/zenodo.15342393.

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This paper comprehensively reviews the potential of cutting-edge LNG technologies to mitigate climate change .We explore advancements in liquefaction processes, focusing on cryogenic heat exchangers, mixed refrigerant cycles, and turbo molecular expanders, aiming to improve efficiency and reduce energy consumption. Carbon capture and storage (CCS) technologies are examined as a strategy to capture and store CO2 emissions generated during LNG production. Novel approaches to methane emissions reduction, such as advanced leak detection and repair, membrane-based technologies, and utilization of boil-off gas, are also discussed. Liquefied natural gas (LNG) plays a significant role in the global energy landscape, but its life cycle raises concerns about greenhouse gas emissions, particularly methane leakage. Furthermore, the paper analyzes the efficient transportation and distribution of LNG, including LNG shipping technologies, cryogenic insulation, boil-off gas management, and supply chain optimization strategies for emissions reduction. Safe and responsible storage and handling practices are explored, encompassing onshore and offshore facilities, innovative storage solutions, and robust safety measures. The paper delves into the utilization of LNG in various end-use applications, including power generation, transportation (trucks, marine vessels), and industrial processes. While acknowledging the challenges of infrastructure development and cost considerations, the potential for emissions reduction across diverse sectors is highlighted. Finally, the paper emphasizes the importance of life cycle assessments to comprehensively evaluate the environmental impact of LNG. Collaborative efforts among industry stakeholders, governments, and research institutions are identified as crucial for accelerating the transition to cleaner LNG technologies. Continued research on leak mitigation, carbon capture, and life cycle optimization, alongside supportive policies and public awareness, are emphasized as essential for harnessing the potential of LNG for a sustainable future while mitigating climate change. This review provides valuable insights for policymakers, industry leaders, and researchers seeking to navigate the complex landscape of LNG and its role in a climate-conscious energy future.  

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Moiseiev, Sergiy, Maksym Novikov, Arkadii Burniashev, et al. "DEVELOPMENT OF BREAKTHROUGH TECHNOLOGIES FOR STRENGTHENING OF TURBO-EXPANSION INSTALLATIONS ELEMENTS." Bulletin of the National Technical University «KhPI» Series: Engineering and CAD, no. 1 (June 7, 2023): 53–67. http://dx.doi.org/10.20998/2079-0775.2023.1.06.

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The paper is aimed at the development of breakthrough technologies for the strengthening of turbo-expander installations. For this purpose, new ways proposed for ensuring the strength of the most hardly loaded elements of turbo-expander installations. They involve a combination of known methods of discrete and continuous strengthening. However, at the same time, the problem of justification of rational parameters and modes of technological operations arises. This problem is caused by the fact that such complex strengthening methods are characterized by a significantly expanded set of varied parameters. In this wide parametric space, their optimal set differs from the optimal sets in narrower subspaces. To determine the influence of varied parameters on the characteristics of the stress-strain state of contacting discretely-continuously strengthened bodies, a number of studies were carried out. The shape of the strengthening area and the material properties of the strengthened zones are varied. A significant influence of varied parameters on the distribution and level of contact pressure and equivalent stresses in the system of contacting bodies has been established. Based on the analysis of the results of these and a number of other studies, recommendations have been developed regarding the design and technological solutions of elements of turbo-expander installations. On this base, a number of turbo-expander units with improved technical characteristics have been developed. In particular, the growth of their resource and efficiency have been ensured. Keywords: turbo-expander, discrete and continuous strengthening, contact interaction, stress-strain state, technical characteristics

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Jelodar, Mehdi Taleshian, Hasan Rastegar, and Hossein Askarian Abyaneh. "Modeling turbo-expander systems." SIMULATION 89, no. 2 (2013): 234–48. http://dx.doi.org/10.1177/0037549712469661.

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Chuang, P. S., H. H. Tsai, H. W. Chiang, et al. "Design and analysis of the helium purification system for the NSRRC cryogenic system." IOP Conference Series: Materials Science and Engineering 1240, no. 1 (2022): 012090. http://dx.doi.org/10.1088/1757-899x/1240/1/012090.

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Abstract Helium is an expensive consumable in cryogenic facilities and is used widely in space, medical and energy research. At NSRRC, liquid helium is used as a coolant for superconducting magnets and SRF cavities . Minor contaminants such as nitrogen, oxygen, moisture and oil will be picked up when liquid helium circulates in large scale cryogenic systems and such contaminants can crystalize and cause damage to the cold box turbo expanders resulting in system damage and failure . Therefore, a helium purification system is designed as an integral part of the cryogenic system to conserve helium by providing 99.9995% pure helium to the liquefier after eliminating contaminants. The NSRRC helium purification process is based on two principles, the first one being a cryo-sorption device using activated charcoal and a molecular sieve and the other being a cryo-condensation unit using a tubular heat exchanger. The purifier has been designed to purify impure helium with overestimated contaminants of as much as 2.5% nitrogen and 2.5% oxygen with a mass flow rate of 475 nm3/hr and delivering a pressure of 17 bar(a) of impure helium to the purifier, the actual impurity will be much lower than the actual design contaminants. In this paper, calculation and design of the helium purification system and components composed of one double pipe counter flow heat exchanger, one vessel and tube heat exchanger, one pre-cooler and one charcoal vessel will be discussed together with charcoal mass requirement calculations and design of other components. In NSRRC, helium is liquefied and is used as a coolant for the SRF system and for cryogenic undulators. During a cryogenic cycle in the cryogenic system, helium may pick up contaminants such as moisture, oxygen, oil, and nitrogen, which have a higher freezing point than liquid helium and will crystalize. These frozen impurities will then affect plant capacity and operation such as alternating flow characteristics, damaging moving parts like turbines in the cold box causing the overall cooling efficiency to drop. Eliminating the contaminants is therefore very important for the cryogenic system.

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Ovsyannik, A. V., and V. P. Kliuchinski. "Turbo-Expander Units on Low Boiling Working Fluids." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 64, no. 1 (2021): 65–77. http://dx.doi.org/10.21122/1029-7448-2021-64-1-65-77.

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The article examines the possibility of increasing the efficiency of the turbo-expander cycles on low-boiling working fluids using those methods that are used for steam turbines, viz. increasing the parameters of the working fluid before the turbo-expander and using secondary overheating. Thus, four schemes of the turbo-expander cycle are considered: the one without overheating of the low-boiling working fluid, the one with single overheating of low-boiling fluid, the one with double overheating and the one with double overheating at supercritical parameters. All the studied cycles were considered with a heat exchanger at the outlet of the turbo expander, designed to heat the condensate of a low-boiling working fluid formed in the condenser of the turbo expander unit. Cycles inP–hcoordinates were built for the studied schemes. The method of thermodynamic analysis of the studied cycles based on the exergetic efficiency has been developed. The results of the research are presented in the form of Grassman-Shargut diagrams, which show exergy losses in the elements of the studied cycles on a scale, and also show the positive effect of the operation of the turbo-expander cycle in the form of electrical power. The analysis of the obtained results showed that the main losses that have a significant impact on the exergy efficiency are the losses of exergy in the recovery boiler. The increase of parameters of low-boiling working body, and the use of intermediate superheating reduce losses in the waste heat boiler and, consequently, increases exergetic efficiency of turbo-expander cycle. The turbo-expander cycle with double overheating at supercritical parameters of the low-boiling fluid is of the largest exergetic efficiency out of the schemes that have been examined.

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Majer, Matteo, and Matteo Pini. "Design guidelines for high-pressure ratio supersonic radial-inflow turbines of organic rankine cycle systems." Journal of the Global Power and Propulsion Society 9 (April 11, 2025): 19–46. https://doi.org/10.33737/jgpps/195437.

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The radial-inflow turbine (RIT) is a widely adopted turbo-expander in power and propulsion systems of low-to-medium power capacity due to its high efficiency and compactness. Compared to conventional radial turbines for gas turbines and air cycle machines, the design of expanders for high-temperature organic Rankine cycle power systems involves additional challenges, as these machines operate with very high expansion or volumetric flow ratio and partly or entirely in the nonideal compressible fluid dynamic regime. This study examines the impact of the working fluid, of the volumetric flow ratio, and of the nonideal thermodynamic effects on the design guidelines for RIT. To this purpose, a reduced-order modeling framework for turbine fluid-dynamic design encompassing a loss model based on first principles is developed and verified against results from uRANS. Results highlighted that at the geometrical scale of interest the impact of the working fluid molecular complexity on the efficiency is marginal. Moreover, it is shown that the average isentropic pressure-volume exponent <inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mrow><mml:mover><mml:mi>γ</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover></mml:mrow></mml:mrow><mml:mrow><mml:mi>P</mml:mi><mml:mi>v</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> can be used to predict the magnitude of nonideal thermodynamic effects on the stage efficiency, whose variation depends on the value of the volumetric flow ratio and of the work and flow coefficients. Design guidelines that can be used for preliminary turbine design in system-level calculations are presented in graphical form, and illustrate the relation between the optimal set of stage duty coefficients, i.e., the work and flow coefficients that maximize the efficiency, the stage efficiency, the volumetric flow ratio, and the similarity parameter <inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:msub><mml:mrow><mml:mover><mml:mi>γ</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover></mml:mrow><mml:mrow><mml:mi>P</mml:mi><mml:mi>v</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula>.

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Tkachuk, Mykola, Gennadiy Lvov, Sergey Kravchenko, et al. "Substantiating promising technical solutions for turbo- expander power plants based on the research into working processes and states." Eastern-European Journal of Enterprise Technologies 4, no. 7 (124) (2023): 98–105. http://dx.doi.org/10.15587/1729-4061.2023.285865.

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One of the most rational methods of energy utilization of compressed gas in pipelines is to use turbo-expander installations. In particular, these are autonomous turbo-expander power stations. A fundamentally new concept has been devised to improve the technical and economic performance of this type of machines. This concept is not focused on a separate aspect of the plant's operation but on their entire set. In particular, physical principles, structures, and technologies were considered as an object of research. First, effective parameters of gas-dynamic flows and heat-mass transfer were determined based on the modeling of work processes. Secondly, progressive designs of turbo-expander units have been created. Thirdly, technologies for the production of parts and assemblies of turbo-expander units have been developed, which combine, unlike the traditional ones, different types of strengthening for contacting parts in their pair. A method of parametric modeling was used to substantiate the technical solutions of the elements of turbo-expander power plants. This makes it possible to determine the technical characteristics of these installations under a certain set of parameters. By purposeful variation, a recommended set of their parameters was determined, which ensure the improvement of the most important technical characteristics. A specialized database was built, which contains an array of information about the regularities of the influence of variation of significant parameters on various characteristics of turbo-expander power plants. Already on this basis, the problems of synthesis of successful technical solutions of turbo-expander power plants are solved. As a result, their high energy efficiency is ensured. Thus, the efficiency of the expander was achieved at the level of 86 % while the resource increased by 20–25 %. All these solutions were implemented in a number of unique turbo-expander units. Their effectiveness has been demonstrated during operation

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Lee, Jonghoon, Sungryeol Kim, Dabin Son, and Sangwook Han. "A Study on the Replacement of Self-starting Generators using Turbo Expander Generator." TRANSACTION OF THE KOREAN INSTITUTE OF ELECTRICAL ENGINEERS P 71, no. 4 (2022): 281–86. http://dx.doi.org/10.5370/kieep.2022.71.4.281.

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Tkachuk, Mykola А., Maksym Novikov, Mykola M. Tkachuk, et al. "AREAS AND STAGES OF DESIGN AND TECHNOLOGICAL SUPPORT FOR ENHANCED PERFORMANCE OF TURBO-EXPANDER POWER PLANTS." Bulletin of the National Technical University «KhPI» Series: Engineering and CAD, no. 2 (December 18, 2023): 106–12. http://dx.doi.org/10.20998/2079-0775.2023.2.11.

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The paper describes an integrated approach to the design and technological support of enhanced performance of turbo-expander power plants. An analysis of the current state of development of turboexpander power plants has made it possible to establish that traditional approaches have largely exhausted the possibilities of improving their technical characteristics. Moreover, a situation is emerging where, in order to ensure the improvement of such characteristics, it is necessary to involve not isolated design or technological measures, but joint design and technological measures. To implement this approach, the method of generalized parametric modeling is used. At the same time, by combining design and technological parameters, the parametric space in which to search for rational technical solutions for turbo-expander power plants is expanded. This expansion of the parametric space makes it possible to increase the efficiency of the final solution. Such a solution cannot be achieved through design or technological measures alone. The developed approach is implemented in the form of a sequence of solved stages. First, it is a study of the working processes of gas dynamics, heat and mass transfer, and power generation in turboexpander power plants. Secondly, it is the optimization of technological operations for strengthening the elements of these plants. Thirdly, it is the development of real samples of turbo-expander power plants with improved technical characteristics. In general, these stages, which are carried out in a coordinated manner on the basis of the developed generalized parametric approach, made it possible to increase the durability of turboexpander elements by 25-40 % and ensure the efficiency of the detander at the level of 86 %. Keywords: turbo-expander power plant; turbine installation; discrete-continuous strengthening, generalized parameter, design and technological support; technical characteristics

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Ovsyannik, A. V., and V. P. Kliuchinski. "Thermodynamic Analysis and Optimization of Secondary Overheating Parameters in Turbo-Expander Plants on Low Boiling Working Fluids." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 64, no. 2 (2021): 164–77. http://dx.doi.org/10.21122/1029-7448-2021-64-2-164-177.

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The paper presents a thermodynamic analysis of secondary overheating in turbo-expander plants on low-boiling working fluids. The possibility of optimizing the parameters of the working fluid in a secondary stem superheater has been studied. The research was carried out for two typical turbo-expander cycles: with a heat exchanger at the outlet of the turbo-expander, intended for cooling an overheated low-boiling working fluid, and without a heat exchanger. Cycles in T–s coordinates were constructed for the studied schemes. The influence of pressure and temperature in the intermediate superheater on the exergetic efficiency of the turbo-expander unit was studied. Thus, the dependences of the exergetic efficiency and losses on the elements of the turbo-expander cycle are obtained when the temperature of the working fluid changes and pressure of the working fluid not changes in the intermediate superheater, and when the pressure changes and the temperature does not change. As a low-boiling working fluid, the ozone-safe freon R236EA is considered, which has a “dry” saturation line characteristic, zero ozone layer destruction potential, and a global warming potential equal to 1370. It has been determined that increasing the parameters of the low-boiling working fluid in front of the low-pressure turbo expander (regardless of the scheme of the turbo expander cycle) does not always cause an increase in the exergetic efficiency. Thus, overheating of the working fluid at a pressure exceeding the critical pressure causes a positive exergetic effect, but for each temperature there is an optimal pressure at which the efficiency will be maximum. At a pressure below the critical pressure, overheating leads to a decrease in the exergetic efficiency, and the maximum exergetic effect is achieved in the absence of a secondary steam superheater. All other things being equal, a turbo-expander cycle with a heat exchanger is more efficient than without it over the entire temperature range and pressure of the low-boiling working fluid under study.

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Li, Chaojie, Yanqin Mao, Xiaoyue Wang, Zhixing Zhan, and Liang Cai. "Numerical Simulation of Internal Flow Field in Turbo-Expander." Journal of Physics: Conference Series 2137, no. 1 (2021): 012073. http://dx.doi.org/10.1088/1742-6596/2137/1/012073.

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Abstract As everyone pays more attention to energy consumption, it is very meaningful to use natural gas pressure energy for power generation and turbo-expander is an important part of power generation devices. In this paper, the turbo-expander model for pressure energy generation is meshed and numerically simulated based on fluent, and the pressure distribution and velocity distribution in the turbo-expander are obtained. The volute profile is Archimedes spiral, and the impeller is modeled by cfturbo. The main conclusions are as follows: when the number of grids is more than 2.2 million, the simulation results are less affected by the number of grids. The internal basin of the turbo-expander has obvious pressure gradient and velocity gradient. Due to the negative pressure at the elbow of the inlet pipe of the centrifugal effect, the existence of the blade leads to the change of the flow direction. Different watershed planes have different pressure and velocity distributions. The velocity and pressure of the watershed plane near the impeller outlet and the volute outlet are often smaller, but the flow vortex is more intense.

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Li, Yao, Jin Tang Yang, Xiao Liang Zhang, Gong Fa Li, and Jin Hui Wang. "Intelligent Control of Turbo-Expander System." Advanced Materials Research 129-131 (August 2010): 400–405. http://dx.doi.org/10.4028/www.scientific.net/amr.129-131.400.

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Expander is undertaking the important task to offer essential cold to the air separation course, that the cold produced to make air liquefy, compensate cold loss of the whole separation process. In order to guarantee the operation of the expander system safe and reliable, through analyzing to this system, adopting DCS system to configuration control, make the control of expander system simpler and more convenient, more ocular, and effective, it has certain reference function to other equipment’s control of the air separation.

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Zellner, B., W. Sterr, and O. Herrmann. "Integration of Turbo-Expander and Turbo-Ramjet Engines in Hypersonic Vehicles." Journal of Engineering for Gas Turbines and Power 116, no. 1 (1994): 90–97. http://dx.doi.org/10.1115/1.2906815.

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Turbo-expander-ramjet and turbo-ramjet are two engine concepts considered for hypersonic aircraft designs with a flight regime between Mach 0 and 7. To establish any performance or integration aspects for these two combined-cycle engine types, an extended study of a variety of influence parameters is necessary, because the interaction between aircraft and propulsion system is even stronger than on conventional aircraft. In fact, the propulsion system is very sensitive to intake and nozzle/afterbody design at these high speeds. This paper presents the engine configurations chosen for comparison and describes the computer program used for the propulsion system performance simulation, including all relevant integration aspects. Furthermore, some results of propulsion system performance for a generic hypersonic aircraft and a typical ascent profile will be compared to indicate the special characteristics of the engines. Finally, some thoughts concerning the suitability and relevant technological requirements of the two engine types—seen from an aircraft manufacturer’s view—are included. The paper includes the results of two diploma theses, written by W. Sterr [1] and B. Zellner [2] at the Technical University of Munich, supervised by Prof. H. Rick (LFA) and O. Herrmann (MBB).

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Galerkin, Y. B., A. F. Rekstin, O. A. Solovyeva, A. A. Drozdov, and V. B. Semenovskiy. "Statistical Mathematical Model for Calculating the Efficiency of Turbo-Expander Compressors: Improvement and Identification." Proceedings of Higher Educational Institutions. Маchine Building, no. 7 (748) (July 2022): 68–81. http://dx.doi.org/10.18698/0536-1044-2022-7-68-81.

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Despite their small size turbo expander units used for transportation and processing oil and gas have a capacity of up to 5.5 MW. Designing new turbo-expander units includes several stages, one of which is the variant calculation of the compressor for the given parameters. For calculating the efficiency of the compressor by its main parameters a specialized statistical model is used. The efficiency of stages designed according to a single unambiguous methodology depends on the design parameters and similarity criteria. The generalization of experience in designing turbo-expander units allowed improving the statistical mathematical model used in the Universal Modeling Method, taking into account the specifics of compressors. The new version of the mathematical model correctly takes account of losses in the inlet nozzle, the method of manufacturing the impeller, the diffuser type, etc. The resulting mathematical model includes 22 empirical coefficients. To select the correct values of the coefficients, the results of 26 acceptance tests of turbo-expander compressors were used. The error of the new statistical model with the selected of empirical coefficient values was 1.8%, which is sufficient for its practical application in project activities.

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Journal articles on the topic 'Turbo expanders'

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