Journal articles: 'Vapor ejector refrigeration'

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Sumeru, Kasni, Luga Martin, Farid Nasir Ani, Henry Nasution, and Farid Nasir Ani. "Energy Savings in Air Conditioning System Using Ejector: An Overview." Applied Mechanics and Materials 493 (January 2014): 93–98. http://dx.doi.org/10.4028/www.scientific.net/amm.493.93.

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There are two ejector configurations described in the present study: ejector refrigeration cycle and the ejector as an expansion device. The use of waste heat from the car engine and industry as a heat-driven energy for air conditioning system in automobile and building can save energy. Although the ejector refrigeration cycle has a low COP, the use of waste heat as a heat-driven energy incurs a lower operational cost compared with vapor compression refrigeration system. In addition, an ejector as an expansion device can be applied in the vapor compression refrigeration cycle to improve the performance system.

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Yosaf, Salem, and Hasan Ozcan. "Effect of Ejector Location in Absorption Refrigeration Cycles Using Different Binary Working Fluids." International Journal of Air-Conditioning and Refrigeration 27, no. 01 (March 2019): 1950003. http://dx.doi.org/10.1142/s2010132519500032.

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In this study, three novel modifications of ejector-absorption refrigeration cycles (E-ARC) are investigated to evaluate the effect of ejector location on cycle performances. In the first modification (triple pressure level absorption refrigeration cycle TPL-ARC), the ejector is located at the evaporator inlet. In the second modification (double ejector absorption refrigeration cycle DE-ARC), two ejectors are used; one is located at the evaporator inlet and the other at the absorber inlet, which are coupled to each other. In the third modification (low pressure condenser absorption refrigeration cycle LPC-ARC), the steam ejector is installed at the downstream of the vapor generator discharging line. An additional flow splitter is integrated to the steam ejector outlet and part of the vapor is extracted and returned to the absorber at a pressure equal to the diffuser pressure. Effect of ejector location on thermodynamic performances are evaluated considering three different working fluids, namely ammonia–water solution (NH3–H2O), lithium bromide-water solution (H2O–LiBr), and lithium chloride–water solution (H2O–LiCl). Even though all three configurations enhance the conventional absorption refrigeration cycle (C-ARC) performances, the LPC-ARCs work at high temperature and improve the cycle performance. The TPL-ARC proves to improve the COP and exergy efficiency up to 9.14% and 7.61%, respectively, presenting the highest thermodynamic performance enhancement and lowest operating temperature.

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Ouelhazi, I., Y. Ezzaalouni, and L. Kairouani. "Parametric analysis of a combined ejector-vapor compression refrigeration cycle." International Journal of Low-Carbon Technologies 15, no. 3 (June 15, 2020): 398–408. http://dx.doi.org/10.1093/ijlct/ctaa011.

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Abstract From the last few years, the use of efficient ejector in refrigeration systems has been paid a lot of attention. In this article a description of a refrigeration system that combines a basic vapor compression refrigeration cycle with an ejector cooling cycle is presented. A one-dimensional mathematical model is developed using the flow governing thermodynamic equations based on a constant area ejector flow model. The model includes effects of friction at the constant-area mixing chamber. The current model is based on the NIST-REFPROP database for refrigerant property calculations. The model has basically been used to determine the effect of the ejector geometry and operating conditions on the performance of the whole refrigeration system. The results show that the proposed model predicts ejector performance, entrainment ratio and the coefficient of performance of the system and their sensitivity to evaporating and generating temperature of the cascade refrigeration cycle. The simulated performance has been then compared with the available experimental data from the literature for validation.

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Huang, B. J., C. B. Jiang, and F. L. Hu. "Ejector Performance Characteristics and Design Analysis of Jet Refrigeration System." Journal of Engineering for Gas Turbines and Power 107, no. 3 (July 1, 1985): 792–802. http://dx.doi.org/10.1115/1.3239802.

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Ejector performance characteristics and design analysis of jet refrigeration systems were studied. It was shown that choking phenomena in the secondary vapor play a very important role in ejector performance. Ejector choking, which is usually associated with a hypothesized effective area for the secondary vapor in the mixing zone, takes place when the ejector is operating at a back pressure below the critical value. The effective areas analyzed from the experiment were shown not to be constant but to vary with operating conditions. A performance map was constructed from the experimental results to show the ejector performance characteristics and from which the design analysis of jet refrigeration systems was carried out. Several important features of jet refrigeration system design are summarized in the present paper. Further analyses were also made to show the performance characteristics of jet refrigeration systems operating at off-design conditions.

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Raza, Waseem, Gwang Soo Ko, and Youn Cheol Park. "A Study on the Combined Driven Refrigeration Cycle Using Ejector." International Journal of Air-Conditioning and Refrigeration 29, no. 01 (January 25, 2021): 2150004. http://dx.doi.org/10.1142/s2010132521500048.

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The rising need for thermal comfort has resulted in a rapid increase in refrigeration systems’ usage and, subsequently, the need for electricity for air-conditioning systems. The ejector system can be driven by a free or affordable low-temperature heat source such as waste heat as the primary source of energy instead of electricity. Heat-driven ejector refrigeration systems become a promising solution for reducing energy consumption to conventional compressor-based refrigeration technologies. An air-conditioning system that uses the ejector achieves better performance in terms of energy-saving. This paper presents a study on the combined driven refrigeration cycle based on ejectors to maximize cycle performance. The experimental setup is designed to determine the coefficient of performance (COP) with ejector nozzle sizes 1.8, 3.6, and 5.4[Formula: see text]mm, respectively. In this system, the R-134a refrigerant is considered as a working fluid. The results depict that the efficiency is higher than that of the conventional refrigeration method due to comparing the performance of the conventional refrigeration cycle and the combined driven refrigeration cycle. The modified cycle efficiency is better than the vapor compression cycle below 0∘C, which implies sustainability at low temperatures by using low-grade thermal energy. For the improvement of mechanical efficiency, proposed cycle can be easily used.

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Mukhtar, Hamza K., and Saud Ghani. "Hybrid Ejector-Absorption Refrigeration Systems: A Review." Energies 14, no. 20 (October 13, 2021): 6576. http://dx.doi.org/10.3390/en14206576.

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Absorption Refrigeration Systems (ARS) are potential alternatives to direct expansion (DX) refrigeration systems. This review focused on the incorporation of an ejector into absorption refrigeration cycles to constitute Hybrid Ejector-Absorption Refrigeration Systems (HEARS). The ejector adds several advantages to the absorption refrigeration systems depending on its location in the cycle. The two prevalent configurations of HEARS are Triple pressure level (TPL-HEARS), and Low Pressure Condenser (LPC-HEARS). Previous studies revealed the preference of the latter configuration as it allows lower circulation ratios, enhances the refrigeration effect, and could achieve a COP up to 1. Moreover, LPC configuration is suitable with single, double, and variable-effect absorption systems with a COP of above unity. In turn, the TPL-HEARS notably enhances the absorption process, particularly when a variable geometry ejector is utilized. This configuration could obtain a COP around 1.1, but only with high-density refrigerant vapor. Lately, to attain the advantages of both configurations, some studies investigated the viability of adding two ejectors to the cycle. This paper meticulously reviews investigations conducted on the emerging dual ejectors-absorption refrigeration technology. This paper reveals the general performance trend and the maximum attainable COP by each type of hybrid ejector-absorption refrigeration system. DEARS and Ejector-driven absorption refrigeration systems (ED-ARS) could achieve COP that ranges between 1.2 and 1.46. The use of a flash tank and a RHE is essential in NH3/H2O HEARS. At high generator temperatures (of 120–170 °C), DEARS was found to be the system with less complexity and best performance. Nevertheless, the performance of the DEARS might drop significantly if the heat source temperature is fluctuating. Thence, the variable-effect HEARS is considered the best alternative. The capability of HEARS to be integrated with different power generation cycles is also highlighted. Finally, the review presents possible future research opportunities to improve the absorption refrigeration technology.

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Mukhtar, Hamza K., and Saud Ghani. "Hybrid Ejector-Absorption Refrigeration Systems: A Review." Energies 14, no. 20 (October 13, 2021): 6576. http://dx.doi.org/10.3390/en14206576.

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Absorption Refrigeration Systems (ARS) are potential alternatives to direct expansion (DX) refrigeration systems. This review focused on the incorporation of an ejector into absorption refrigeration cycles to constitute Hybrid Ejector-Absorption Refrigeration Systems (HEARS). The ejector adds several advantages to the absorption refrigeration systems depending on its location in the cycle. The two prevalent configurations of HEARS are Triple pressure level (TPL-HEARS), and Low Pressure Condenser (LPC-HEARS). Previous studies revealed the preference of the latter configuration as it allows lower circulation ratios, enhances the refrigeration effect, and could achieve a COP up to 1. Moreover, LPC configuration is suitable with single, double, and variable-effect absorption systems with a COP of above unity. In turn, the TPL-HEARS notably enhances the absorption process, particularly when a variable geometry ejector is utilized. This configuration could obtain a COP around 1.1, but only with high-density refrigerant vapor. Lately, to attain the advantages of both configurations, some studies investigated the viability of adding two ejectors to the cycle. This paper meticulously reviews investigations conducted on the emerging dual ejectors-absorption refrigeration technology. This paper reveals the general performance trend and the maximum attainable COP by each type of hybrid ejector-absorption refrigeration system. DEARS and Ejector-driven absorption refrigeration systems (ED-ARS) could achieve COP that ranges between 1.2 and 1.46. The use of a flash tank and a RHE is essential in NH3/H2O HEARS. At high generator temperatures (of 120–170 °C), DEARS was found to be the system with less complexity and best performance. Nevertheless, the performance of the DEARS might drop significantly if the heat source temperature is fluctuating. Thence, the variable-effect HEARS is considered the best alternative. The capability of HEARS to be integrated with different power generation cycles is also highlighted. Finally, the review presents possible future research opportunities to improve the absorption refrigeration technology.

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LITTLE, ADRIENNE B., and SRINIVAS GARIMELLA. "A REVIEW OF EJECTOR TECHNOLOGY FOR REFRIGERATION APPLICATIONS." International Journal of Air-Conditioning and Refrigeration 19, no. 01 (March 2011): 1–15. http://dx.doi.org/10.1142/s2010132511000351.

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This paper provides a comprehensive review of ejector technology for refrigeration applications, combining an understanding of basic fluid flow fundamentals within the ejector with application in cycle-level development. An ejector is a passive device that requires no external mechanical input or moving parts. A high-velocity motive stream produces a low-pressure region into which a suction flow is entrained, resulting in a pressure rise of the suction flow and mixing between the two streams to provide a pumping effect. The first part of this review addresses the progression from experiment-based analytical models to computational modeling of the ejector itself from the early 1950s to 2009. Included is an assessment of the most recent work in CFD modeling, and an exploration into what is needed to develop these models further. Suggestions for future research include better modeling of shock phenomena and the effects of two-phase flow in ejectors. The second part of this review focuses on ejector applications in refrigeration cycles with special emphasis on the vapor-jet refrigeration cycle. Important connections are made between ejector component and system level studies, an understanding of which would enable improvement of system level performance to the extent where they could be used in some niche applications instead of conventional refrigeration systems.

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Коновалов, Дмитро Вікторович, Роман Миколайович Радченко, Сергій Георгійович Фордуй, Фелікс Володимирович Царан, Віктор Павлович Халдобін, and Артем Вікторович Грич. "Моделювання та програмний комплекс для дослідження функціонування ежектора в змінних режимах." RADIOELECTRONIC AND COMPUTER SYSTEMS, no. 3 (October 5, 2021): 37–47. http://dx.doi.org/10.32620/reks.2021.3.04.

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One of the current directions of development of modern energy-saving and energy-efficient technologies for ship and stationery (including municipal) energy is the use of ejector refrigeration machines, which can be used for air conditioning systems together with an absorption refrigeration machine (cascade cycle) or vapor compressor refrigeration machine as part of cogeneration or trigeneration units. Such circuit solutions can be used together with ensuring the rational organization of work processes in the main elements of the refrigeration machine, in particular in the jet device - ejector, the appropriate design of which, in turn, will further increase the thermal coefficient. Improving the design of the ejector is a rather complex and long process and does not always give positive results. It is primarily because many tests are required on full-scale models. Therefore, computer simulation of the ejector operation at different variable input parameters, considering the geometric characteristics of the flow part and variable mode characteristics during operation is more attractive in terms of finding options for rational (optimal) design. The paper presents the results of software development for modeling hydrodynamic processes in the flowing part of the ejector, considering the variable operating modes of the ejector refrigeration machine. The existing method for calculating the pressure and circulation characteristics of jet devices is used. The developed software complex "RefJet" in the design mode defines the maximum achievable coefficients of ejection of a jet ejector. In the simulation mode - provides determination of the ejection coefficients of the already designed (certain sizes) ejector at variable values of pressure at the inlet and outlet in specific operating conditions, considering its operation at the limit and partial modes. The work of the software package was tested in the development and analysis of circuit solutions of ejector refrigeration machines as part of the heat recovery circuits of three-generation units based on internal combustion engines and gas turbine engines.

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JIAUTHEEN, PARVEEN BANU, and MANI ANNAMALAI. "REVIEW ON EJECTOR OF VAPOR JET REFRIGERATION SYSTEM." International Journal of Air-Conditioning and Refrigeration 22, no. 03 (September 2014): 1430003. http://dx.doi.org/10.1142/s2010132514300031.

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Vapor Jet Refrigeration (VJR) system is attractive among various heat operated refrigeration systems, because it has the potential of utilizing low grade thermal energy with source temperature as low as 60°C, which could be harnessed from renewable energy, waste heat, automobile-exhaust, etc. Also absence of moving parts in this system resulted in lesser maintenance costs. In addition to that this system causes very low environmental pollution due to almost negligible consumption of high grade energy from fossil fuels for running a small liquid pump of the system. Although VJR was invented very long back, still performance improvement to compete with vapor compression refrigeration system is in progress. Plenty of research has been carried out in different aspects for enhancing the efficiency of this technology. The present work/paper gives an overview of VJR system and its progression in the aspect of performance improvement. The developmental progress of the VJR technology presented in this paper has been categorized into the following groups, namely (a) general performance of an ejector, (b) numerical analysis, viz., classical one-dimensional analysis and Computational Fluid Dynamics (CFD) analysis, (c) experimental studies, (d) flow visualization studies, (e) performance enhancement techniques, and (f) two-phase ejector. And also presented a glimpse of some of the review papers from literature on VJR system.

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Boumaraf, Latra, and Rachedi Khadraoui. "Investigation on the Performance of a Solar Hybrid Refrigeration System Using Environmentally Friendly Fluids." International Journal of Heat and Technology 38, no. 4 (December 31, 2020): 960–66. http://dx.doi.org/10.18280/ijht.380423.

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In order to evaluate the performance of a hybrid compression / ejection refrigeration system using solar energy at low or medium temperature, a simulation model of its behavior based on those of its various components has been developed. It includes in particular for the ejector, a 1-D model of the "constant section mixing" type developed in optimal transition regime. The refrigerants tested are steam for the ejector loop and the R1234yf (replacing the R134a) for the mechanical compression loop. The behavior of the H2O vapor flowing in the ejector is considered that of the perfect gas. The properties of refrigerants are calculated using REFPROP® software, everywhere else. For a cooling capacity of 10 kW and air conditioning operating conditions, the model allows to determine the main parameters of the ejector and its entrainment ratio, the thermal and mechanical COP of the whole refrigeration system as well as the necessary surface of the solar collector. Furthermore, the influence of the temperature of the boiler, the condenser, the intercooler as well as that of the evaporator on the mechanical COP of the hybrid system and the solar collection surface in particular, were examined. The results highlight that the solar refrigeration system with hybrid cycle compression/ejection using the refrigerants H2O/R1234yf allows an increase of the mechanical COP higher than 50% compared to that of the conventional refrigeration system and thus constitutes an acceptable ecologically system that can compete with the latter.

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KUMAR, RAJ, and ANIL KUMAR. "ENERGY AND EXERGY ANALYSIS OF COMPACT POWER GENERATION AND HYBRID SOLAR ENERGY-WASTE HEAT-BASED TRIPLE EFFECT EJECTOR-VAPOR ABSORPTION REFRIGERATION CYCLE." International Journal of Air-Conditioning and Refrigeration 21, no. 04 (December 2013): 1350023. http://dx.doi.org/10.1142/s2010132513500235.

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An NH 3– H 2 O ejector-absorption refrigeration cycle, and an R-152a ejector refrigeration cycle are employed with a renewable energy power generator to make a proposed compact power generation and triple effect ejector-absorption refrigeration cycle. The exergy analysis of the cycle leads to a possible performance improvement. Approximately 71.69% of the input exergy is destructed due to irreversibilities in different components. Around 7.976% is available as the useful exergy output. The exhaust exergy lost to the environment is 20.33%, which is lower than the exhaust energy loss of 47.95%, while the useful energy output is 27.88%. The refrigerants used are of zero ODP and negligible GWP, and the CO 2 emission of the exhaust gases is very small as compared to that of the fossil fuel run engine, hence, this cycle is favorable to the global environment. The results also show that the proposed cycle has significant higher energy and exergy efficiency than the earlier investigated 'triple effect refrigeration cycle' and 'the combined power and ejector-refrigeration cycle'.

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Lei, Yu, Shengyu Li, Jun Lu, Ye Xu, Yong Yong, and Dingding Xing. "Numerical Analysis of Steam Ejector Performance with Non-Equilibrium Condensation for Refrigeration Applications." Buildings 13, no. 7 (June 29, 2023): 1672. http://dx.doi.org/10.3390/buildings13071672.

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In recent years, there has been great interest in developing cooling systems with humidity- and temperature-independent control capabilities that can operate efficiently at varying temperatures. This paper proposes a bi-loop double-evaporator ejection–compression cycle, which utilizes low-grade heat and is suitable for the construction industry. The proposed cycle involves the concurrent operation of a vapor compression cycle and an ejector refrigeration cycle that enables it to handle altered pressure levels and operate with varying compression ratios all the way to a common condenser pressure. Conventional computational fluid dynamics (CFD) approaches often model steam as an ideal gas with single-phase flow. In contrast, this research employs the wet steam model to optimize ejector geometry. The wet steam model takes into account non-equilibrium water vapor condensation, thus providing a more precise assessment of spontaneous condensation behavior and its impact on ejector performance. When compared to the conventional dry gas model, the use of the wet steam model dramatically decreases the entrainment ratio error from 16.24% for single-phase steam to 3.92% when compared to experimental data. This study concentrates on four critical attributes of wet steam, including Mach number, droplet nucleation rate, average droplet radius, and liquid mass fraction, to develop a strategy for enhancing ejector performance and efficiency. The study demonstrates that optimal area and primary nozzle diameter ratios for the steam ejector are 5 and 2.4, respectively. Increasing the area ratio mitigates condensation intensity, thereby reducing the liquid mass fraction in the diffuser. Overall, this paper provides valuable insights into improving and optimizing ejector performance, thus highlighting the importance of considering the behavior of spontaneous condensation in ejector design and modeling.

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Chen, Jin Zeng, Yan Fei Li, and G. H. Li. "A New Method for Desalination of Seawater With Steam-Ejector Refrigeration Plant." Applied Mechanics and Materials 94-96 (September 2011): 273–79. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.273.

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Desalination of seawater has played an important role in many arid regions in the world. There are many methods for desalination of seawater, such as MED, MSF, RO, ED, TVC, and MVC, etc. Different methods have different advantages and disadvantages. In the present work, a new method for desalination of seawater with steam-ejector refrigeration plant was introduced. The main purpose of the new method is a hybrid plant of TVC and steam-ejector refrigeration. In the hybrid circle, no other energy was need. When the steam-ejector refrigeration plant is working, the seawater as cooling water is introduced into evaporator of TVC and evaporates. The vapor getting in TVC is extracted by a second steam-ejector, together with the active steam, is used as source of heat for desalination. The main advantage of this hybrid plant is that part of the heat energy of cooling water in refrigeration is reused. Comparing with other distillation method desalination of seawater, the energy consumption is much less. Especially on marine usage, the advantage is clear.

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Poirier, Michel, Daniel Giguère, and Hristo Sapoundjiev. "Experimental parametric investigation of vapor ejector for refrigeration applications." Energy 162 (November 2018): 1287–300. http://dx.doi.org/10.1016/j.energy.2018.08.034.

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Коновалов, Дмитро Вікторович, Роман Миколайович Радченко, Сергій Георгійович Фордуй, Віктор Павлович Халдобін, Олексій Олегович Зєліков, and Олександр Анатолійович Різун. "ВДОСКОНАЛЕННЯ ТЕПЛОВИКОРИСТОВУЮЧИХ ЕЖЕКТОРНИХ ХОЛОДИЛЬНИХ МАШИН ЗАСТОСУВАННЯМ АЕРОТЕРМОПРЕСОРНИХ ТЕХНОЛОГІЙ." Aerospace technic and technology, no. 1 (February 26, 2021): 60–66. http://dx.doi.org/10.32620/aktt.2021.1.06.

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The paper shows and analyzes circuit solutions for improving the existing schemes of ejector heat-using refrigeration machines, which are used as part of cogeneration plants. One of the promising areas is the use of an aerothermopressor, which implements the effect of thermogasdynamic compression, which is to increase the pressure while reducing the temperature in the evaporation of liquid, which injected into the flow of vapor moving at speed near the sound. To analyze the efficiency of ejector refrigeration machines, the developed calculation model was used, which takes into account the use of an aerothermopressor in the cycles of refrigeration machines with the features of the calculations of cycles and circuits. To select and determine possible circuit solutions, the efficiency of an aerothermopressor for different refrigerants was evaluated and a comparative analysis of the characteristic parameters of the efficiency of an aerothermopressor in the range of cooling temperature differences is 20–100 oC was made. It is possible to increase the efficiency of ejector heat-using refrigeration machines when using an aerothermopressor by providing a temperature difference of 60–100 oC. The analysis showed that the most important are: R717, R134a, R227ea, R1234ze (E), R1234yf (2–4%). It is possible to provide a higher thermal coefficient for ejector heat-using refrigeration machines by using an aerothermopressor in the circuit using the circulation of liquid refrigerant. The corresponding increase in the thermal coefficient is 1.5–2.0%. The use of an aerothermopressor in the scheme with heat recovery allows removing additional overheating of vapor before suctioning into the ejector with a corresponding increase in the thermal coefficient by 4-8%. The analysis shows that the total increase in the thermal coefficient due to the combined use of an aerothermopressor, heat recovery, and recirculation is 10–15% at a base value of 0.30–0.40.

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Yadav, Ajay Kumar, and Neeraj. "Performance Analysis of Refrigerants R1234yf, R1234ze and R134a in Ejector-Based Refrigeration Cycle." International Journal of Air-Conditioning and Refrigeration 26, no. 03 (September 2018): 1850026. http://dx.doi.org/10.1142/s2010132518500268.

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Performance enhancement of refrigeration and heat pump systems by cycle modification is an emerging research topic now-a-days to reduce the electricity consumption leading to mitigate the problems related to the environmental pollution by utility power plants. Due to no moving parts, low cost, simple structure and low maintenance requirements, the use of two-phase ejector has become a promising cycle modification recently. Use of ejector as an expansion device by replacing the throttle valve in the vapor compression refrigeration cycle seems to be one of the efficient ways to reduce the throttling losses or the expansion irreversibility in the refrigeration/heat pump cycle. Ejector also reduces the compressor work by raising the suction pressure to a level higher than that in the evaporator leading to the improvement of COP. The present work aims to evaluate the performance of an ejector based vapor compression refrigeration cycle under a wide range of operating conditions. Two newly proposed refrigerants i.e., R1234yf and R1234ze, and commonly used refrigerant R134a are considered for simulation and a comparative study has been carried out. A numerical model is developed and a parametric study of important parameters such as entrainment ratio, high side pressure (condenser pressure) and evaporator temperature are analyzed for the improvement of COP of the system. Results show that the COP of the R1234ze is highest compared to R1234yf and R134a for the given evaporating and condensing temperature.

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Pardiñas, Ángel Á., Michael Jokiel, Christian Schlemminger, Håkon Selvnes, and Armin Hafner. "Modeling of a CO2-Based Integrated Refrigeration System for Supermarkets." Energies 14, no. 21 (October 21, 2021): 6926. http://dx.doi.org/10.3390/en14216926.

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An integrated energy system that consists of a centralized refrigeration unit can deliver the entire HVAC&R (heating, ventilation, air conditioning, and refrigeration) demand for a supermarket. CO2 (R744) is a natural refrigerant that is becoming increasingly popular for these centralized units due to significant energy and cost savings, while also being sustainable, safe, and non-toxic. This study focuses on the fully integrated CO2 refrigeration system configuration for a supermarket in Porto de Mos, Portugal, which was equipped and fully monitored through the EU-funded project MultiPACK. A dynamic system model was developed in Modelica and validated against measurement data from the site recorded for one week. The model is used to provide additional ejector performance data supporting the obtained measurement data and to evaluate the system configuration at equivalent boundary conditions. The simulation results show that the installation of a vapor ejector (high-pressure lift) is sufficient to improve the efficiency of the unit compared to an ejector-less (high-pressure valve) system. However, more notable enhancements are achieved by including additional flooded evaporation with liquid ejectors and smart regulation of the receiver pressure, adding up to a global efficiency increase of 15% if compared to the high-pressure valve system during the validation week.

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Aidoun, Zine, Khaled Ameur, Mehdi Falsafioon, and Messaoud Badache. "Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 2: Two-Phase Ejectors." Inventions 4, no. 1 (March 6, 2019): 16. http://dx.doi.org/10.3390/inventions4010016.

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Two-phase ejectors play a major role as refrigerant expansion devices in vapor compression systems and can find potential applications in many other industrial processes. As a result, they have become a focus of attention for the last few decades from the scientific community, not only for the expansion work recovery in a wide range of refrigeration and heat pump cycles but also in industrial processes as entrainment and mixing enhancement agents. This review provides relevant findings and trends, characterizing the design, operation and performance of the two-phase ejector as a component. Effects of geometry, operating conditions and the main developments in terms of theoretical and experimental approaches, rating methods and applications are discussed in detail. Ejector expansion refrigeration cycles (EERC) as well as the related theoretical and experimental research are reported. New and other relevant cycle combinations proposed in the recent literature are organized under theoretical and experimental headings by refrigerant types and/or by chronology whenever appropriate and systematically commented. This review brings out the fact that theoretical ejector and cycle studies outnumber experimental investigations and data generation. More emerging numerical studies of two-phase ejectors are a positive step, which has to be further supported by more validation work.

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Wang, Rui, and Hong Tao Gao. "Experimental Analysis of Effects of Non-Structural Factors on Performance of Liquid-Gas Ejector Driven by Aqueous LiBr Solution." Advanced Materials Research 732-733 (August 2013): 472–75. http://dx.doi.org/10.4028/www.scientific.net/amr.732-733.472.

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Miniaturization and high-efficiency plays an important role in the further development of absorption refrigeration. In order to improve the mass transfer efficiency, liquid-gas ejector is intended to be used in refrigeration system. Experimental analysis of effects of non-structural factors on Liquid-Gas Ejector driven by aqueous LiBr solution is presented. Solution concentration, solution temperature, evaporator temperature and back pressure are varied to analyze the ejector performance. The results show that the large difference between refrigerant vapor pressure and partial pressure of solution enhances absorption of water into aqueous lithium bromide solution. The optimal solution concentration range is 56.61wt%~57.61wt% when the throat diameter of convergent-divergent nozzle is 1.5mm. Cooling capacity increases with the decreasing of back pressure.

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Gjerasimovski, Aleksandar, Maja Sharevska, Natasha Gjerasimovska, Monika Sharevska, and Risto Filkoski. "Thermal characteristics of combined compressor - ejector refrigeration/heat pump systems for HVAC&R." Thermal Science, no. 00 (2023): 182. http://dx.doi.org/10.2298/tsci230513182g.

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Thermal characteristics of combined compressor - ejector refrigeration/heat pump systems applied in heating, ventilation, air conditioning and refrigeration (HVAC&R) of buildings are investigated. An original model for estimation of the thermal characteristics of the combined cycles is developed, to determine the influence of the evaporation, interstage, condensation, and generating temperature conditions on mechanical and thermal COPs of the combined system, and to optimize the thermal parameters of the cycle. Results are presented for different temperature conditions, with R134a as a suitable refrigerant. A comparison between the thermal characteristics of the simple mechanical vapor compression cycle, the simple ejector thermocompression cycle, and the combined compressor - ejector refrigeration / heat pump cycle is given. The benefits of implementation of combined compressor - ejector refrigeration/heat pump cycles in HVAC&R systems are discussed. The temperature lift or temperature difference between condensing temperature and interstage temperature significantly influences the thermal (ejector) coefficient of performance. If temperature lift is between 10 K and 20 K, high values of thermal COPs can be achieved (0.5?1.0, for generating temperature equal to 80?C; 1.0?1.8, for generating temperature equal to 120?C); If temperature lift is between 30 K and 40 K, very low values of COPth can be obtained (0.05?0.3). High values of mechanical COPs can be achieved (24.8?6.9), for compressor stage temperature lift 10?30 K.

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Xing, Meibo, Gang Yan, and Jianlin Yu. "Performance evaluation of an ejector subcooled vapor-compression refrigeration cycle." Energy Conversion and Management 92 (March 2015): 431–36. http://dx.doi.org/10.1016/j.enconman.2014.12.091.

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Kumar, Kundan, Hitesh Kumar Gupta, and Pramod Kumar. "Analysis of a hybrid transcritical CO2 vapor compression and vapor ejector refrigeration system." Applied Thermal Engineering 181 (November 2020): 115945. http://dx.doi.org/10.1016/j.applthermaleng.2020.115945.

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Riani, Novi Indah, Syamsuri Syamsuri, and Rungky Rianata Pratama. "Simulasi Numerik Aliran Melewati Nozzle Pada Ejector Converging – Diverging Dengan Variasi Diameter Exit Nozzle." R.E.M. (Rekayasa Energi Manufaktur) Jurnal 2, no. 1 (August 14, 2017): 19. http://dx.doi.org/10.21070/r.e.m.v2i1.796.

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In the process of cooling or refrigeration, are required components where capable to flow the fluid to create a cycle of the cooling process. Among some of the vapor compression systems, the usage of ejector is the simplest system. Ejector has three main parts: primary nozzle, mixing chamber and diffuser. Various experiments of steam ejectors developed to increase the value of the COP. Entrainment ratio directly affects to the COP value generated by the system, where the geometric shapes and operating conditions in the steam ejector will affect to the value entrainment ratio. This research was carried out numerical simulations using CFD commercial software with k-epsilon to predict flow phenomena which passes through the ejector nozzle in the ejector converging-diverging which varying exit diameters 3.5 mm; 4mm; 5 mm; and 5.5 mm. Respectively the simulation results showed exit nozzle steam ejector that the smallest diameter of 3.5 mm give the optimum performance because it provide the highest speed of fluidity. While the state of vacuum in mixing chamber increase, it cause the secondary mass flow higher as well as the value of the entrainment ratio.

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Wang, Xiao, Jianlin Yu, Mengliu Zhou, and Xiaolong Lv. "Comparative studies of ejector-expansion vapor compression refrigeration cycles for applications in domestic refrigerator-freezers." Energy 70 (June 2014): 635–42. http://dx.doi.org/10.1016/j.energy.2014.04.076.

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Sarkar, Jahar. "Ejector enhanced vapor compression refrigeration and heat pump systems—A review." Renewable and Sustainable Energy Reviews 16, no. 9 (December 2012): 6647–59. http://dx.doi.org/10.1016/j.rser.2012.08.007.

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Zhu, Yinhai, and Peixue Jiang. "Hybrid vapor compression refrigeration system with an integrated ejector cooling cycle." International Journal of Refrigeration 35, no. 1 (January 2012): 68–78. http://dx.doi.org/10.1016/j.ijrefrig.2011.09.003.

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Zhang, Zhenying, Xu Feng, Dingzhu Tian, Jianjun Yang, and Li Chang. "Progress in ejector-expansion vapor compression refrigeration and heat pump systems." Energy Conversion and Management 207 (March 2020): 112529. http://dx.doi.org/10.1016/j.enconman.2020.112529.

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Sharma, Dishant, Gulshan Sachdeva, and Dinesh Kumar Saini. "Optimized Refrigerant Flow Rate and Dimensions of the Ejector Employed in a Modified Ejector Vapor Compression System." International Journal of Air-Conditioning and Refrigeration 28, no. 04 (December 2020): 2050038. http://dx.doi.org/10.1142/s2010132520500388.

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This paper presents the analysis of a modified vapor compression cooling system which uses an ejector as an expansion device. Expanding refrigerant in an ejector enhances the refrigeration effect and reduces compressor work. Therefore, it yields a better coefficient of performance. Thermodynamic analysis of a constant area ejector model has been done to obtain primary dimensions of the ejector for given condenser and evaporator temperature and cooling capacity. The proposed model has been used to design the ejector for three refrigerants; R134a, R152a and R1234yf. The refrigerant flow rate and the diameters at various sections of the ejector have been obtained by doing numerical modeling in Engineering Equation Solver (EES). Refrigerant R1234yf demanded the highest diameter requirements at a fixed 5∘C evaporator temperature and 40∘C condenser temperature for a given range of cooling load. Both primary and secondary refrigerants flow rates are higher for R1234yf followed by R134a and then R152a.

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Mishra, Shubham, and Jahar Sarkar. "Performance characteristics of low global warming potential R134a alternative refrigerants in ejector-expansion refrigeration system." Archives of Thermodynamics 37, no. 4 (December 1, 2016): 55–72. http://dx.doi.org/10.1515/aoter-2016-0027.

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AbstractPerformance assessment of ejector-expansion vapor compression refrigeration system with eco-friendly R134a alternative refrigerants (R152a, R1234yf, R600a, R600, R290, R161, R32, and propylene) is presented for air-conditioning application. Ejector has been modeled by considering experimental data based correlations of component efficiencies to take care of all irreversibilities. Ejector area ratio has been optimized based on maximum coefficient of performance (COP) for typical air-conditioner operating temperatures. Selected refrigerants have been compared based on area ratio, pressure lift ratio, entrainment ratio, COP, COP improvement and volumetric cooling capacity. Effects of normal boiling point and critical point on the performances have been studied as well. Using ejector as an expansion device, maximum improvement in COP is noted in R1234yf (10.1%), which reduces the COP deviation with R134a (4.5% less in basic cycle and 2.5% less in ejector cycle). Hence, R1234yf seems to be best alternative for ejector expansion system due to its mild flammability and comparable volumetric capacity and cooling COP. refrigerant R161 is superior to R134a in terms of both COP and volumetric cooling capacity, although may be restricted for low capacity application due to its flammability.

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Yoon, Jung-In, Chung-Lae Kim, and Chang-Hyo Son. "Performance comparison of refrigeration cycle using R134a with the vapor-liquid ejector." Journal of the Korean Society of Marine Engineering 39, no. 9 (November 30, 2015): 890–94. http://dx.doi.org/10.5916/jkosme.2015.39.9.890.

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Elakhdar, M., B. M. Tashtoush, E. Nehdi, and L. Kairouani. "Thermodynamic analysis of a novel Ejector Enhanced Vapor Compression Refrigeration (EEVCR) cycle." Energy 163 (November 2018): 1217–30. http://dx.doi.org/10.1016/j.energy.2018.09.050.

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Yapıcı, Rafet. "Experimental investigation of performance of vapor ejector refrigeration system using refrigerant R123." Energy Conversion and Management 49, no. 5 (May 2008): 953–61. http://dx.doi.org/10.1016/j.enconman.2007.10.006.

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Gullo, Paride, Armin Hafner, Krzysztof Banasiak, Silvia Minetto, and Ekaterini Kriezi. "Multi-Ejector Concept: A Comprehensive Review on its Latest Technological Developments." Energies 12, no. 3 (January 28, 2019): 406. http://dx.doi.org/10.3390/en12030406.

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The adoption of the EU F-Gas Regulation 517/2014 and the resulting development of the multi-ejector concept have led carbon dioxide to take center stage as the sole refrigerant (R744) in several applications. Therefore, a knock-on effect on the number of supermarkets relying on “CO2 only” refrigeration systems has been experienced. Additionally, a global consensus of commercial multi-ejector based R744 units is also intensifying as a consequence of both the promising results obtained and the other measures in force for environment preservation. Furthermore, the multi-ejector concept is expected to offer significant energy savings in other high energy-demanding buildings (e.g., hotels, gyms, spas) as well, even in warm climates. In this investigation, the evolution of R744 ejector supported parallel vapor compression system layouts for food retail applications was summed up. Furthermore, their technological aspects, the results related to the main theoretical assessments and some relevant field/laboratory measurements were summarized. Also, the experience gained in the adoption of the multi-ejector concept in transcritical R744 vapor-compression units aimed at other energy intensive applications was presented. Finally, the persistent barriers needing to be overcome as well as the required future work were brought to light.

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Wang, F., D. Y. Li, and Y. Zhou. "Analysis for the ejector used as expansion valve in vapor compression refrigeration cycle." Applied Thermal Engineering 96 (March 2016): 576–82. http://dx.doi.org/10.1016/j.applthermaleng.2015.11.095.

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Li, Yunxiang, and Jianlin Yu. "Thermodynamic Analysis of a Modified Ejector-Expansion Refrigeration Cycle with Hot Vapor Bypass." Journal of Thermal Science 28, no. 4 (July 3, 2019): 695–704. http://dx.doi.org/10.1007/s11630-019-1124-6.

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Al-Dabbas, Mohammad Awwad Ali. "The Availability of Hybrid Nano Adsorption-Multi Stage Ejector Cooling Cycle with a Different Type of Steam Generator." Mathematical Modelling of Engineering Problems 8, no. 5 (October 31, 2021): 826–36. http://dx.doi.org/10.18280/mmep.080520.

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Ejectors are a kind of pump that does not have any moving components. In certain cases, the motor fluid may be a liquid, steam, or another gas. The research focuses on using nano adsorption combined with a multi ejector to fuel a sophisticated nano adsorption power plant, which is equipped with three shapes of steam boiler generators. The simulation was accomplished by implementing it with the cooperation of the two programs MATLAB A and MATLAB B, together with a solid flow. To raise the temperature of the working fluid before it enters the generator, a jet pump is positioned before the generator. To enhance the mass flow rate of vapor going into the ejector, a two-stage adjustable booster was added after the evaporator, which gives low evaporator temperature. A further experiment in which the two-stage adjustable booster was used before the generator to reduce the amount of work done by the generator. The ejector's cooling unit is powered by steam created from many energy sources powered by advanced hybrid heat and power systems, including solar energy and steam produced by the electric steam generator. The different devices are either directly triggered by a thermal source to achieve heating, cooling, or refrigeration. The steam boiler generator is the core of the cooling unit; in this research, various types of steam boiler generators are linked with adsorption units, such as steam-powered solar boilers, gas boilers, solid fuel steam boilers, and electric boilers. Heat exchangers were utilized to transfer heat from the solar chimney to the ejector cooling unit. The impact of various ejector geometries on the advanced cooling unit was studied and simulated for the single, double, and triple nozzle ejector. There were no issues with the more effective cooling unit. This unit performed better than traditional adsorption cooling units, having a greater efficiency.

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Han, Yu, Xiaodong Wang, Wei Wang, Yuan Xien Lee, and Ao Li. "Numerical Investigation of Transonic Flow-Induced Spontaneous Condensation in Micro-Ejector Nozzles." Micromachines 14, no. 6 (June 16, 2023): 1260. http://dx.doi.org/10.3390/mi14061260.

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Micro-cooling systems are compact refrigeration systems widely applicable in microchemical analysis, biomedicine, and microelectromechanical systems (MEMS). These systems rely on the use of micro-ejectors to achieve precise, fast, and reliable flow and temperature control. However, the efficiency of micro-cooling systems is hindered by spontaneous condensation occurring downstream of the nozzle throat and within the nozzle itself, impacting the performance of the micro-ejector. A micro-scale ejector mathematical model describing wet steam flow was simulated to investigate the steam condensation phenomenon and its influence on flow, incorporating equations for liquid phase mass fraction and droplet number density transfer. The simulation results of wet vapor flow and ideal gas flow were compared and analyzed. The findings revealed that the pressure at the micro-nozzle outlet exceeded predictions based on the ideal gas assumption, while the velocity fell below it. These discrepancies indicated that condensation of the working fluid reduces the pumping capacity and the efficiency of the micro-cooling system. Furthermore, simulations explored the impact of inlet pressure and temperature conditions on spontaneous condensation within the nozzle. The results demonstrated that the properties of the working fluid directly influence transonic flow condensation, underscoring the importance of selecting appropriate working fluid parameters for nozzle design to ensure nozzle stability and optimal micro-ejector operation.

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Megdouli, K., B. M. Tashtoush, E. Nahdi, M. Elakhdar, A. Mhimid, and L. Kairouani. "Performance analysis of a combined vapor compression cycle and ejector cycle for refrigeration cogeneration." International Journal of Refrigeration 74 (February 2017): 517–27. http://dx.doi.org/10.1016/j.ijrefrig.2016.12.003.

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40

Sumeru, K., H. Nasution, and F. N. Ani. "A review on two-phase ejector as an expansion device in vapor compression refrigeration cycle." Renewable and Sustainable Energy Reviews 16, no. 7 (September 2012): 4927–37. http://dx.doi.org/10.1016/j.rser.2012.04.058.

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Tan, Yingying, Youming Chen, and Lin Wang. "Thermodynamic Analysis of a Mixed Refrigerant Ejector Refrigeration Cycle Operating with Two Vapor-liquid Separators." Journal of Thermal Science 27, no. 3 (May 18, 2018): 230–40. http://dx.doi.org/10.1007/s11630-018-1004-5.

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Shen, Anxiang, Keli Guan, Xingyang Yang, Sumin Jin, and Le Yang. "Theoretical analysis of a novel liquid-vapor separation condensation ejector refrigeration cycle with zeotropic mixtures." Energy Conversion and Management 223 (November 2020): 113322. http://dx.doi.org/10.1016/j.enconman.2020.113322.

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Gil, Bartosz, and Jacek Kasperski. "Efficiency Evaluation of the Ejector Cooling Cycle using a New Generation of HFO/HCFO Refrigerant as a R134a Replacement." Energies 11, no. 8 (August 16, 2018): 2136. http://dx.doi.org/10.3390/en11082136.

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Theoretical investigations of the ejector refrigeration system using hydrofluoroolefins (HFOs) and hydrochlorofluoroolefin (HCFO) refrigerants are presented and discussed. A comparative study for eight olefins and R134a as the reference fluid was made on the basis of a one-dimensional model. To facilitate and extend the possibility of comparing our results, three different levels of evaporation and condensation temperature were adopted. The generator temperature for each refrigerant was changed in the range from 60 °C to the critical temperature for a given substance. The performed analysis shown that hydrofluoroolefins obtain a high efficiency of the ejector system at low primary vapor temperatures. For the three analyzed sets of evaporation and condensation temperatures (te and tc equal to 0 °C/25 °C, 6 °C/30 °C, and 9 °C/40 °C) the maximum Coefficient of Performance (COP) was 0.35, 0.365, and 0.22, respectively. The best performance was received for HFO-1243zf and HFO-1234ze(E). However, they do not allow operation in a wide range of generator temperatures, and, therefore, it is necessary to correctly select and control the operating parameters of the ejector.

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Радченко, Роман Миколайович, Богдан Сергійович Портной, Сергій Анатолійович Кантор, Веніамін Сергійович Ткаченко, and Анатолій Анатолійович Зубарєв. "ОТРИМАННЯ І ВИКОРИСТАННЯ КОНДЕНСАТУ ПРИ ОХОЛОДЖЕННІ ПОВІТРЯ НА ВХОДІ ЕНЕРГОУСТАНОВКИ ТА ПРОБЛЕМА СЕПАРАЦІЇ КРАПЕЛЬНОЇ ВОЛОГИ З АЕРОЗОЛЬНОЇ СУМІШІ В ГРАДИРНЯХ." Aerospace technic and technology, no. 5 (November 8, 2018): 23–27. http://dx.doi.org/10.32620/aktt.2018.5.04.

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The processes of heat-humidity treatment (cooling with dehumidification) of air in a two-stage air cooling system at the inlet of a gas turbine unit applying a combined type heat-energized refrigeration mechanism, which consists of an absorption lithium-bromide high-temperature refrigeration mechanism to approximately 15 °C and a refrigerant ejector low-temperature refrigeration mechanism to 10 °С and below, which transform the heat of exhaust gases from gas turbine unit to the cold with the production of condensate in air cooling system as a by-product of air cooling has been analyzed. The analysis was carried out for the climatic conditions of the south of Ukraine. The heat removal from the condensers and the absorber of the heat-energized refrigeration mechanism are carried out with open wet cooling towers. Based on the distribution of the heat load on the steps of the two-stage air cooling system and the heat coefficients of the heat-energized refrigeration mechanisms, the project load on the cooling towers was determined and their number was selected. Based on the results of modeling of the operation of the air cooling system at the inlet of the gas turbine unit, were obtained data from the current and total amount of condensate that falls in the air cooling system during the condensation of water vapor, which is always contained in moist air, as well as the amount of water needed to feed an open cooling tower. In this case, only water losses due to mechanical removal (without taking into account its evaporation in cooling towers) were considered, which poses the problem of separation of droplet moisture from the aerosol mixture. As a result of comparing the amount of water needed to feed the cooling towers, on the one hand, and the amount of condensate obtained in the process of air cooling at the inlet of the gas turbine unit, on the other hand, was demonstrated that it is possible to partially satisfy the necessary water needs for cooling towers. A scheme of two-stage air cooling system at the inlet of a gas turbine unit with absorption lithium-bromide and refrigerant ejector refrigeration mechanism and wet cooling towers is proposed, to discharge heat from heat-energized refrigeration mechanisms, to produce condensate as a by-product of air cooling, and apply it to feed cooling towers

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Zeng, Min-Qiang, Qiu-Yun Zheng, Xue-Lai Zhang, Fan-Yang Mo, and Xin-Rong Zhang. "Thermodynamic analysis of a novel multi-target temperature transcritical CO2 ejector-expansion refrigeration cycle with vapor-injection." Energy 259 (November 2022): 125016. http://dx.doi.org/10.1016/j.energy.2022.125016.

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Khan, Yasin, Md Walid Faruque, Mahdi Hafiz Nabil, and M. Monjurul Ehsan. "Ejector and Vapor Injection Enhanced Novel Compression-Absorption Cascade Refrigeration Systems: A Thermodynamic Parametric and Refrigerant Analysis." Energy Conversion and Management 289 (August 2023): 117190. http://dx.doi.org/10.1016/j.enconman.2023.117190.

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Rostamzadeh, Hadi, Towhid Gholizadeh, Sajjad Rostamzadeh, Shahram Vosoughi, and Ali Asghar Farshad. "Role of ejector expander in optimal inherently safety design of cascade NH3/Propane/CO2 vapor compression refrigeration systems." Process Safety and Environmental Protection 146 (February 2021): 745–62. http://dx.doi.org/10.1016/j.psep.2020.12.009.

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Lillo, Gianluca, Rita Mastrullo, Alfonso William Mauro, Raniero Trinchieri, and Luca Viscito. "Thermo-Economic Analysis of a Hybrid Ejector Refrigerating System Based on a Low Grade Heat Source." Energies 13, no. 3 (January 23, 2020): 562. http://dx.doi.org/10.3390/en13030562.

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The rising of the global energy demand requires the use of alternative energy conversion systems employing renewable sources. In the refrigeration and air conditioning fields, heat driven ejector systems represent a promising way to produce the cooling effect by using available low-grade temperature sources. In this paper, a thermo-economic analysis of a waste heat recovery hybrid ejector cycle (WHRHEC) was carried out. A thermodynamic model was firstly developed to simulate a WHRHEC able to obtain chilled water with a cooling load of 20 kW, by varying the working fluids and the pinch point values in the heat exchangers. Specific single- and two-phase heat transfer correlations were used to estimate the heat transfer surface and therefore the investment costs. The operative ranges that provide a reasonable compromise between the set-up costs and the cycle performances were then defined and compared to the current waste heat-driven technologies, such as absorption chillers and organic Rankine cycles (ORCs) coupled with vapor compression cycles (VCCs). The last part of the paper presents an economic analysis providing the map of the design (plant size) and contingent (specific cost of energy, waste heat availability) variables that lead to the economic convenience of a WHRHEC system when integrated to a conventional VCC plant.

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Direk, Mehmet, Ümit İşkan, Cüneyt Tunçkal, Mehmet Selçuk Mert, and Fikret Yüksel. "An experimental investigation of ejector employed a dual-evaporator vapor compression refrigeration system under various entrainment ratios using R134a as the refrigerant." Sustainable Energy Technologies and Assessments 52 (August 2022): 102293. http://dx.doi.org/10.1016/j.seta.2022.102293.

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Riaz, Fahid, Kah Hoe Tan, Muhammad Farooq, Muhammad Imran, and Poh Seng Lee. "Energy Analysis of a Novel Ejector-Compressor Cooling Cycle Driven by Electricity and Heat (Waste Heat or Solar Energy)." Sustainability 12, no. 19 (October 4, 2020): 8178. http://dx.doi.org/10.3390/su12198178.

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Low-grade heat is abundantly available as solar thermal energy and as industrial waste heat. Non concentrating solar collectors can provide heat with temperatures 75–100 °C. In this paper, a new system is proposed and analyzed which enhances the electrical coefficient of performance (COP) of vapour compression cycle (VCC) by incorporating low-temperature heat-driven ejectors. This novel system, ejector enhanced vapour compression refrigeration cycle (EEVCRC), significantly increases the electrical COP of the system while utilizing abundantly available low-temperature solar or waste heat (below 100 °C). This system uses two ejectors in an innovative way such that the higher-pressure ejector is used at the downstream of the electrically driven compressor to help reduce the delivery pressure for the electrical compressor. The lower pressure ejector is used to reduce the quality of wet vapour at the entrance of the evaporator. This system has been modelled in Engineering Equation Solver (EES) and its performance is theoretically compared with conventional VCC, enhanced ejector refrigeration system (EERS), and ejection-compression system (ECS). The proposed EEVCRC gives better electrical COP as compared to all the three systems. The parametric study has been conducted and it is found that the COP of the proposed system increases exponentially at lower condensation temperature and higher evaporator temperature. At 50 °C condenser temperature, the electrical COP of EEVCRC is 50% higher than conventional VCC while at 35 °C, the electrical COP of EEVCRC is 90% higher than conventional VCC. For the higher temperature heat source, and hence the higher generator temperatures, the electrical COP of EEVCRC increases linearly while there is no increase in the electrical COP for ECS. The better global COP indicates that a small solar collector will be needed if this system is driven by solar thermal energy. It is found that by using the second ejector at the upstream of the electrical compressor, the electrical COP is increased by 49.2% as compared to a single ejector system.

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Journal articles on the topic 'Vapor ejector refrigeration'

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