Dual Evaporator Research Articles

Comparative analysis of a modified cascade refrigeration cycle including an auto-cascade refrigeration cycle using different zeotropic refrigerant mixtures for reducing the environmental impact

The two primary challenges in auto-cascade refrigeration (ACR) cycles are high compressor discharge temperatures and low efficiency at ultra-low temperatures. This study proposes a modified cascade refrigeration cycle (MCR) combined with an ACR cycle for cooling to –60 ℃. The innovative aspect of this work is to improve the ACR performance with simpler designs without increasing the system complexity, contrary to the common trend. For the high-temperature cycle (HTC), a dual evaporator refrigeration cycle with R1234yf is used while an ACR cycle is used for the low-temperature cycle (LTC). Environmentally friendly refrigerant mixtures, such as R170/R290, R170/R600a, and R170/R600, were analyzed using energy, exergy, and exergoeconomic methods. The results show that compared to R23/R134a, the R170/R600 significantly improves the performance of the MCR by increasing the COP and exergy efficiency by 24.0 %, and reducing the exergy destruction by 26 %, unit cooling cost by 11.2 %, and total investment cost by 9.7 %. Moreover, when compared with theoretical studies COP improvements range from 38.7 % to 94.1 %, demonstrating the importance and superiority of the system proposed in this study.

Investigating dehumidification and heating performance in a dual evaporator heat pump system for electric vehicles

In cold, moisture-rich winter environments, window fogging represents a substantial safety hazard for drivers. Electric vehicles often incorporate heat pump systems to address challenges such as dehumidification and heating specific to cold weather. Therefore, it is essential to evaluate the dehumidification and heating efficiency of these systems through focused research. This study presents a dual-evaporator heat pump system designed specifically for electric vehicles, equipped with two distinct modes for dehumidification and heating. The research examines how factors such as inlet air volume and the degree of opening of the electronic expansion valve affect the system's dehumidification and heating performance. Experimental analyses were conducted to explore the system's response under various conditions of inlet air humidity and compressor speed in both modes. Results suggest that increasing inlet air volume improves dehumidification effectiveness but may reduce heating performance. Likewise, a wider opening of the electronic expansion valve enhances heating but could decrease dehumidification efficiency. Importantly, the study indicates that when the relative humidity of the inlet air exceeds 70 %, a single evaporator mode is more effective for dehumidification. However, when the relative humidity is below 70 %, the dual evaporator mode is more advantageous, showing better heating performance.

Thermodynamic and economic analysis of a solar-assisted ejector-enhanced flash tank vapor injection heat pump cycle with dual evaporators

This paper proposes a solar-assisted ejector-enhanced flash tank vapor injection heat pump cycle with dual evaporators (SEFVIC), designed for heat pump drying application. Compared to the standard flash tank vapor injection heat pump cycle (FVIC), the SEFVIC uses an additional high-temperature evaporator to further minimize irreversible losses during the heat transfer process. Moreover, it integrates solar energy to improve the drying quality and heating capacity of the cycle. Meanwhile, the introduction of an ejector improves the system's performance by reducing throttling loss. The advantages of SEFVIC over FVIC are evaluated using theoretical models based on the first and second laws of thermodynamics. Results show that SEFVIC reveals a 34.1 % improvement in the heating coefficient of performance and a 192.8 % enhancement in volumetric heating capacity compared to FVIC under typical operating condition. Notably, SEFVIC maintains superior performance even at lower evaporating temperatures. Moreover, exergy research indicates that 77.1 % of the total exergy destruction in SEFVIC is attributed to the solar collector. Economic analysis indicates that the integration of solar energy into the SEFVIC is economically beneficial. These findings highlight the prospective application of SEFVIC and guide combining the multi-temperature heat pump drying system and auxiliary solar source.

Comparative Analysis of Ventilation Systems for Aging Salami

The aim of this study was to evaluate the influence of different ventilation systems in two aging cells. One cell featured transverse airflow starting from the top, while the other had a dual-flow system with vertical air motion from top to bottom and vice versa. In addition to monitoring weight loss during aging, chemical and physical analyses were conducted on various salamis to assess the influence of ventilation both between the two aging cells and among different positions of the salamis within the same cell. It was found that the dual-evaporator (DEV) cell behaved better than transverse flow (TFL) cell.

Instability characteristics and heat transfer of a separator assisted dual-evaporators loop thermosyphon under heating power maldistribution condition

Thermosyphon loop with multiple evaporators has been widely used in the data centers thanks to its compact structure and local hot spot avoiding. However, under the heating power maldistribution condition, on account of the separation and convergence of flow steams from different evaporators, the instability of the system can be exacerbated which leads to premature failure and damage of servers. Thus, a separator assisted loop thermosyphon with dual evaporators had been proposed to improve its heat transfer performances and stability. An experimental study of the instability characteristics and heat transfer of the system are carried out under different filling ratios, cooling water temperatures and heating powers in this paper. To fully understand the interaction mechanism of two evaporators behind the oscillation, the visualization of flow patterns in the liquid tube and two-phase tube are observed as well. Results showed that during the oscillatory operation, since the evaporator2 (high heat load) circuit will circulate first, the variation of fluid temperature at evaporator1(low heat load) outlet lags others. Besides, when the inlet water temperature increases, the operating states of the system transfer from oscillatory operation to stable operation. When the filling ratio varies from 50 %-70 %, instability occurs in the system, the oscillation period increases from 115 s to 911 s and amplitude increases from 2.5 °C to 11.1 °C with an increase of the filling ratio. It should be noted that in our new system, it still can operate stably even when the heating power difference between two evaporators are as large as 350 W. In addition, alternatively oscillation in the two evaporators, maximum heat transfer coefficient of evaporator2 and minimum heat transfer coefficient of evaporator1 can be found when the heat load varies due to the mass competition between two circuits. According to above results, it is expected that the system could be beneficial to the application in the data center cooling.

First Results of Nb3Sn Coated Cavity by Vapor Diffusion Method at SARI

Nb3Sn is emerging as one of the focal points in superconducting radio frequency (SRF) research, owing to its excellent superconducting properties. These properties hold significant possibilities for cost reduction and the miniaturization of accelerators. In this paper, we report the recent efforts of the Shanghai Advanced Research Institute (SARI) in fabricating high-performance Nb3Sn superconducting cavities using the vapor diffusion method. This includes the construction of a Nb3Sn coating system with dual evaporators and the test results of 1.3 GHz single-cell coated cavities. The coated samples were characterized, and the growth state of the Nb3Sn films was analyzed. The first coated superconducting cavity was tested at both 4.4 K and 2 K, with different cooldown rates passing through the Nb3Sn critical temperatures. The causes of Sn droplet spot defect formation on the surface of the first cavity were analyzed, and such defects were eliminated in the coating of the second cavity by controlling the evaporation rate. This study provides a reference for the preparation of high-performance Nb3Sn-coated cavities using the vapor diffusion method, including the setup of the coating system, the comprehension of the vapor diffusion process, and the test conditions.

A parametric study on energy, exergy and exergoeconomic assessments of a modified auto-cascade refrigeration cycle supported by a dual evaporator refrigerator

This paper presents an evaluation of the energetic, exergetic, and exergoeconomic performances of a modified auto-cascade refrigeration (MACR) cycle integrated with a dual evaporator refrigerator (DER) to determine optimum operating conditions. DER facilitates a reduction in the compression ratio, allowing the low-boiling-point component to release more heat before entering the evaporator. In this study, the R170/R290 refrigerant mixture, which has a low global warming potential but an explosion risk, was used. The main purpose of this study is to eliminate the risk of explosion by reducing the compressor discharge temperature and at the same time to enhance the overall cycle performance. To achieve this, DER is used instead of air-cooled coils, which have limited cooling performance. Despite an ambient temperature of 35°C, the MACR cycle achieved a remarkable 51.29 % reduction in compressor discharge temperature when the separator inlet temperature was reduced to 10°C by the DER. It also results in a 72.73% reduction in compression work rate and a significant 137.02% increase in cooling effect compared to the conventional auto-cascade refrigeration cycle. Furthermore, the MACR cycle exhibits notable improvements in total exergy destruction rate and exergy destruction cost rate with a 75.23% and a 76.07% reduction, respectively. Simultaneously, the exergy efficiency and the exergoeconomic factor increased by 266.67% and 179.15%, respectively. The MACR cycle achieves optimum energy and exergy performance with a 60% R170 mass fraction and 0.50 vapor quality, resulting in 1.429kW compression work rate, a COP of 0.70, and an exergy efficiency of 26.66 %. The optimum exergoeconomic performance is achieved with a 40% R170 mass fraction and 0.50 vapor quality.

Analysis and multi-objective evolutionary optimization of Solar-Biogas hybrid system operated cascade Kalina organic Rankine cycle for sustainable cooling and green hydrogen production

A novel cascade system of Kalina and Organic Rankine cycle for cooling and green hydrogen production was proposed. The cascade system is designed to utilizes the heat effectively with heat recovery components for sustainable cooling and green hydrogen. The proposed system consists of a solar-biogas hybrid heat source, Kalina and ORC power generation system, dual evaporator vapor compression cooling system and solid oxide electrolyser. The system's performance is evaluated based on the availability of low-temperature heat sources (90 to 150 °C) and medium-grade heat sources (190–280 °C). It is assessed for its capability to provide cooling only or in combination with hydrogen production, and their efficient utilization is compared from energetic, exergetic, environmental, and economic perspectives. To optimize this innovative system, a multi-objective evolutionary approach is employed, considering operating conditions as constraints and incorporating performance metrics for all criteria as objectives. Utilizing multi-objective decision-making techniques, diverse optimal points are pinpointed within the trade-off space, enabling real-time adaptive responses to changes in weather, energy demands, and biogas availability. The net present value analysis demonstrates that, assuming a hydrogen selling price of $6 per kilogram and cooling costs of $4 per KW the payback periods are calculated to be 2 years for the ORC-VCRS cycle and 3 years for the integrated Kalina topping with bottoming ORC cycle. The multi-objective optimization results indicate that the optimum operating conditions for the cascade system involve boiler, absorber, and condenser temperatures set at 196 °C, 110 °C, and 25 °C, respectively. Under these conditions, the system achieves an energy utilization ratio of 0.76, an exergy efficiency of 21.56 %, and a total cost of $58,677.

Energetic performance and life cycle carbon emission of CO2 automotive air conditioning system with an evaporative gas cooler and a dual-evaporator configuration in China

Enhanced actions on climate change have led CO2 air conditioner to take center stage in automotive field. However, its inefficient performance in hot climates limits its further application. A dual-evaporator (D-E) configuration, an evaporative gas cooler (EGC), and their combination (D-E + EGC) were first integrated with the system and experimentally studied in this paper in an attempt to alleviate this problem. Annual energy consumption and life cycle climate performance (LCCP) under four modes (baseline, D-E, EGC, and D-E + EGC) in China were estimated. Results show D-E increases evaporation pressure and EGC is able to decrease discharge pressure. D-E + EGC combines the advantages of both. Thus, improvement percentage in coefficient of performance (COP) brought by D-E + EGC is the highest, followed by those of EGC and D-E. This percentage is more significant at higher ambient temperatures, and even reaches 67.4 % at 45°C outdoor condition. In any mode, annual energy consumption and LCCP in southeast China are double or triple of those in other regions, which shows this system is of high energy consumption and high emission in southeast China. Compared with baseline mode, annual energy consumption and LCCP can be reduced by 3 ∼ 7 % for D-E, 14 ∼ 16 % for EGC, and 18 ∼ 22 % for D-E + EGC. Specifically, D-E + EGC could save up to 890 kWh of electricity and reduce carbon emission by up to 440kgCO2 per vehicle, indicating this technique is a promising way to reduce energy consumption and carbon emission for vehicles equipped with CO2 air conditioners.

Analysis of an ejector-assisted flash tank vapor injection heat pump cycle with dual evaporators for dryer application

In this paper, an ejector-assisted flash tank vapor injection heat pump cycle with dual evaporators (EFVIC) for heat pump dryer applications is proposed based on a basic flash tank vapor injection heat pump cycle (FVIC). An ejector is introduced to recover the expansion work of the system, and a high temperature evaporator is added to utilize the ejector's entrainment ability to reduce the irreversible loss caused by lower temperature difference. The performance improvements of EFVIC are evaluated through energy analysis, exergy analysis and comparisons with FVIC. The results indicate that the volumetric heating capacity and heating coefficient of performance of EFVIC with R1234yf are improved by 66.99 % and 18.88 % compared with those of FVIC using R1234yf, respectively. In addition, the presented cycle achieves better exergy efficiency because the exergy destruction proportion of expansion valves in EFVIC is 75.98 % lower than that in FVIC. Furthermore, the compressor has the highest exergy destruction among all components for EFVIC, accounting for 33.22 % of the total exergy destruction, hence it has the greatest optimization potential. The advantages of the presented cycle performance reveal its energy saving characteristics and application potential in heat pump dryer.

Novel integration of dual evaporator loop heat pipe for improved electric vehicle battery thermal regulation

The Battery Thermal Management System (BTMS) plays a crucial role in ensuring the efficient and safe operation of Hybrid Electric Vehicles (HEVs) and/or Electric Vehicles (EVs). Among various heat transfer techniques, Loop Heat Pipes (LHPs) have demonstrated their potential for effective heat transfer from Li-ion batteries due to their high heat transfer rates over a longer distance. The conventional design of LHPs poses challenges for constructing robust battery pack modules, particularly in electric vehicles (EVs). This complexity arises from the separation of liquid and vapor lines at either the top or bottom of the evaporator, along with the inclusion of a compensation chamber. Furthermore, the evolving requirements of BTMS highlight the necessity for efficient heat removal from multiple locations. To address these requirements, a novel Dual Evaporator Loop Heat Pipe (DE-LHP) has been developed as a BTMS solution featuring separate vapor and two liquid lines positioned at the uppermost section of each cylindrical evaporator. The developed DE-LHP is tested as a BTMS solution with a 3S4P battery module (10Ah capacity) at different charging and discharging rates (1C, 1.5C, and 2C) in surrounding temperatures ranging from 30 °C to 45 °C. When the thermal performance of the DE-LHP-equipped BTMS was compared to a module without BTMS, a drop in maximum cell temperature was noted. At an ambient temperature of 35 °C, the DE-LHP BTMS achieved temperature reductions of 22.8 %, 22.6 %, and 18.8 % at charging rates of 1C, 1.5C, and 2C, respectively. In addition, at a threshold temperature of 60 °C, the module with DE-LHP BTMS demonstrated enhanced discharging capability from 41 % State of Charge (SOC) to 0 % SOC for a 1.5C discharging rate and from 59 % SOC to 0 % SOC for a 2C discharging rate compared to the module without BTMS. Furthermore, when the module was exposed to ambient temperatures ranging from 30 °C to 45 °C, the DE-LHP BTMS maintained a temperature difference across the battery module of less than 3.5 °C for all charging rates and 1C and 1.5C discharging rates.

Performance analysis of dual-evaporator ejector refrigeration system in different configurations: Experimental investigation

This study aimed to assess the effectiveness of an ejector refrigeration cycle, using a laboratory-scale experimental system operating in different configurations. The investigated configurations consisted of a conventional vapour compression refrigeration (CVCR) system and a dual evaporator ejector system (DEES) operated in two modes: DEES with a single thermal expansion valve (DEESA) and DEES with dual thermal expansion valves (DEESB). The findings revealed that the utilization of the ejector enhanced the refrigerant's mass flow rate. Additionally, the DEESA configuration achieved higher cooling capacities compared to the CVCR. Moreover, the DEESA configuration achieved up to 21% higher coefficient of performance (COP) values. On the other hand, when the system was operated in the DEESB configuration, it yielded lower evaporation temperatures and higher superheating degrees in comparison to DEESA. Based on the evaluations, it can be concluded that the ejector operates more efficiently in systems with dual evaporators, thereby making positive contributions to overall system performance.

Performance analysis of a separator assisted dual-evaporators two-phase thermosyphon loop under heating power maldistribution condition based on an experimentally validated model

Multiple evaporators two-phase thermosyphon loop is typical pattern which is utilized in the data centers. Under heating power maldistribution condition, the system could suffer in the temperature oscillation and performance degradation which limit its application. To solve this problem, a separator assisted dual-evaporators thermosyphon loop (SDTPTL) is evaluated and compared with traditional dual-evaporators thermosyphon loop (DTPTL) by using experimentally validated model. The simulation results show that the SDTPTL can always achieve better performances than the DTPTL at any operating conditions. Evaporator outer wall temperatures of two evaporators in the SDTPTL are lower than that in the DTPTL about 2.2––5.9 °C and 3.8–8.2 °C when heat load of evaporator2 (high heating power) ranges from 0.8 kW to 1.4 kW, and lower about 1.6–4 °C and 1.7–4 °C when heat load of evaporator1 (low heating power) ranges from 0.1 kW to 0.5 kW, respectively. Besides, compared with the DTPTL, the SDTPTL has a better benefit in evaporator outer wall temperatures at higher heat load and working fluid charge. In addition, to further improve the performances of the SDTPTL, the sensitivity analyses about structure configurations of the system are conducted as well. Results show that the system can achieve better performances at lower separator height. The evaporator outer wall temperatures of two evaporators can be decreased about 57.4 °C and 3.6 °C when separator height reduces from 0.8 m to 0.2 m. It is expected that this new cycle will be beneficial to develop dual evaporators thermosyphon loop under heating power maldistribution condition.

Comparative performance investigation of a dual evaporator cycle using an ejector with the conventional cycle using a pressure reducing valve

The performance of a dual evaporator cycle using ejector is compared with a conventional cycle employing pressure reducing valve. In both the systems, high temperature evaporator is considered as a flooded evaporator, thus a separator is employed after the high temperature evaporator. However, low temperature evaporator is a kind of conventional dry evaporator. The comparison of both systems, i.e., conventional and ejector assisted, is done for the same cooling capacities and same dryness fraction at the exit of high temperature evaporator with R134a, R152a, and R1234yf refrigerants. The effects of varying the states of refrigerant at the exit of flooded evaporator, and temperatures of both the evaporators and the condenser are analyzed using Engineering Equation Solver. It is found that the compressor work is reduced in both the cycles with the rise in low temperature evaporator temperature; however, a little variation is observed in the total cooling effect. The cooling effect in high temperature evaporator is increased with the increase in dryness fraction at the exit of the high temperature flooded evaporator, but it is decreased in low temperature evaporator.

Parametric study on the exergy analysis of a dual evaporator cooling cy-cle powered by the organic Rankine cycle

This study conducts a parametric study based on the energy and exergy analysis of a combined cycle composed of an organic Rankine and dual evaporator cooling cycles. The mechanical power supplied provides the mechanical compression refrigeration cycle with two evaporators. The influence of operating temperature, including the impact of the evaporator temperature of the organic Rankine cycle and the effect of dual evaporator cooling cycle evaporator temperature, were investigated; in this case, three organic fluids were employed such as R134a, R290, and R600. The results indicate that using R600 as the working fluid for both cycles enhance the system performance, and the energy efficiency of the combined system grows from 27.10 % to 40.22 %.The performance factor of the dual evaporator cooling cycle increases from 3.25 to 3.29 for the evaporating temperature of the first evaporator and from 2.07 to 4.28 for the second evaporator. Moreover, it is also noted that the exergy efficiency of the dual evaporator cooling cycle decreased from 40.03 % to 30.18 % for the first evaporator and increased by 32.47 % to 38.82 % for the second evaporator.

A refrigerant-injection heat pump-based efficient integrated thermal management system for electric vehicles approaching the wide temperature range in China

The integrated thermal management system of electric vehicles is responsible for the temperature regulation of the cabin and electrical system. The wide temperature range of vehicles specifies the operating conditions required for different regions, which is −33 – 39 °C in China. Through experimental studies conducted on heat pump systems and thermal analyses of electrical systems, this study innovatively developed an efficient integrated thermal management system based on a refrigerant-injection heat pump. In addition, a simulation platform for the system was established using the advanced modeling environment for performing simulation of engineering systems (AMESim) software to evaluate the system performance. The results showed that the stability and efficiency of battery cooling based on the intermediate heat exchanger were better than those obtained with a dual evaporator setup. The proposed solution could reduce energy consumption by 30% at an ambient temperature of 35 ℃. The thermal management system with the heat recovery for the motor and electric control at high temperatures could reduce the energy consumption by 11.98% – 56.69% and meet the heating condition of −22.04 ℃. The integrated thermal management system based on a refrigerant injection heat pump widened the operating range during the highway fuel economy test (EPA-420-B-12-001). Aided by electric heating, the simulation system developed in this study could satisfy the load requirements for the wide temperature range in China.

Energetic performance evaluation of an automotive CO2 air conditioning system with a dual-evaporator configuration

Inefficient performance of CO2 refrigerant in hot climates has become a major obstacle to its wide application in electric vehicles. In this paper, the vacant heating core in cooling mode was exploited to increase the heat transfer area of evaporator and improve system performance. With the aid of a validated evaporator model and an experimental test rig, performance improvements brought by this added area were evaluated. Results indicated that this area is not suggested to be directly added to cooling core. This necessitates a dual-evaporator (D-E) configuration. For case I (small CO2 pressure drop), the growth rate in heat transfer rate brought by D-E configuration is 19∼20% and less sensitive to parallel or series operation. Nevertheless, this growth rate for case II (large CO2 pressure drop) is greatly affected, 30.6∼32.6% for parallel operation and 7.5∼17.6% for series operation. Specifically, it is around 17.5% and 7.5∼13.6% for series cross-parallel and cross-counter arrangements, respectively. By comprehensive consideration, the cross-parallel arrangement is recommended to be adopted. Experimental results indicated that the cross-parallel D-E configuration greatly increases the evaporation temperature and exhibits a slight impact on optimum high pressure within the transcritical cycle. The enhancement in COP brought by this configuration is around 6∼12% without additional cost, and it rises with the decreased air flowrate through evaporator and air velocity through gas cooler and the increased ambient temperature. This indicates that this configuration is an effective and economical technology to alleviate the efficiency degradation issue of transcritical CO2 automotive air-conditioners.

Feasibility assessment of a CO2 based power, cooling, and heating system driven by exhaust gas from ocean-going fishing vessel

The research presents a novel CO2 transcritical trigeneration system for ocean-going fishing vessel. Cascade ejectors are employed to decrease the exergy destruction caused by the dual evaporators, enhancing the cooling capacity of the system. By recovering the waste heat of exhaust, the system is designed to cover refrigeration demand of a refrigerated sea water (RSW) tank, the domestic hot water demand at different temperature levels onboard, as well as the power for sailing. The performance of the system is investigated from both thermodynamic and economic perspectives. The feasibility of applying the proposed system to replace the original refrigeration system of a RSW tank is evaluated in different periods, including prechilling, chilling, and chilling maintenance. Analysis show that sufficient cooling can be provided to a RSW tank under most typical engine operation modes, which is significantly influenced by the split ratio and refrigeration capacity ratio. Constraint multi-objective genetic algorithm under engine load of 100% is conducted to determine the maximum potential of the system under the optimum working condition and ensure the smooth operation of the system under all typical engine load. It is estimated that a cooling capacity of 619.9 kW can be offered to the RSW, and the cooling provided to the cold room (502.8 kW) can realize the freezing of 25018 kg fish. After covering the power consumed by compressor and pump, the system still can reach a net power output of 97.32 kW. The thermal efficiency of the engine integrated with the proposed system is improved by 2.89%, and the brake specific fuel consumption is reduced by 5.88%. And the heat rejected by the system can be used to heat water from 25 °C to 45 °C (11.93 kg/s) and 90 °C (2.18 kg/s), respectively. The proposed system shows better overall performance compared to the basic system without ejectors.

Analysis of modified CO2 based combined power and ejector-expansion refrigeration cycle with dual evaporators activated by engine exhaust

ABSTRACT In this research, a combined system consisting of a supercritical CO2 Brayton cycle and an ejector-expansion refrigeration cycle with dual evaporators is presented with the aim to harness the engine exhaust heat effectively. Cascade ejectors are adopted to further reduce the destruction caused by the isenthalpic expansion process, which also can be considered as pressure recovery process. Comparative analysis in terms of thermodynamic and economic is performed between the previously reported system and the modified system under the combined power, refrigeration, and freezing mode (mode 1) and combined refrigeration and freezing mode (mode 2). It is found that improvements of 0.57% and 10.22% in exergy efficiency under mode 1 and mode 2 were achieved by the modified system, respectively, and the sum unit cost of product is reduced by 7.72% compared to the basic system. In the optimized condition, cooling capacities of 18.79 kW and 33.80 kW can be provided for refrigerated zone and freezing zone, respectively. And the exergy efficiency and sum unit cost of product of the system are 16.95% and 108.64 $/GJ, respectively, with a dynamic payback period of 4.994 years.

Advanced exergy, economic, and environmental evaluation of an Organic Rankine Cycle driven dual evaporators vapour-compression refrigeration system using organic fluids

The current research combines a dual evaporator vapour-compression refrigeration system with an organic Rankine cycle. The integrated system is a renewable energy-based technology that can provide refrigeration at different refrigeration temperatures and capacities. The system's performance is compared using five different organic working fluids: butane, pentane, isopentane, hexane, and R245fa, to recommend the most suitable fluid for the system. Coefficient of performance (COP), exergy efficiency (ηex), total cost (Ctot), and payback period (PB) are taken as the performance parameters. Moreover, the system's exergy performance is analysed using advanced exergy analysis (AEA), and sensitivity analysis to determine the optimal operating condition for system components. The result indicates that butane is the optimal fluid for improving energy, exergy, economical, and environmental performance. The system has a COP of 0.377, an exergy efficiency of 10.91%, a total cost of $33,091, and a payback period of 5.8 years. Boiler, compressor, condenser, and EPG make up 31% of the total exergy destruction that can be avoided by adequately selecting their operating condition. The optimal condition for boiler temperature, condenser temperature, the pinch-point temperature difference in condenser and boiler, and compressor efficiency is 120 °C, 40 °C, 3 °C, 10 °C, and 0.7, respectively.