Compressor Power Consumption Research Articles

Modeling of Proton Exchange Membrane Fuel Cell Stack and Start Strategy Optimization with a Multi-Objective Genetic Algorithm

This paper proposes a non-dominated ranking genetic algorithm (NSGA-II) method for fast optimizing the loading strategy at the start of a proton exchange membrane fuel cell (PEMFC) stack to optimize the dynamic response capability, power density and system efficiency. First, a Simulink model of the PEMFC stack including anode module, cathode module, water transfer module and output voltage module is established as the base model for optimization, and the accuracy of the stack model is verified through experiments. The power consumption of the air compressor is the main parasitic power considered, and it is modelled using the air compressor map by taking a table look-up method directly. The three performance indicators of dynamic response capability, power density and system efficiency are then optimized simultaneously based on NSGA-II. The results show that the optimized start-up loading strategy results in a PEMFC stack that outperforms the base model in all three indicators, demonstrating the success of the method in solving time-consuming multiple optimization problems. This study presents an effective and rapid approach for the multi-objective optimization of PEMFC stack, which is of guidance for engineering practice.

Experimental Analysis of the Dual Source Heat Pump with Varying Water Temperature

Purpose: The aim is to examine how water temperature influence the coefficient of performance (COP) of a dual-source heat pump (DSHP) and to show how water temperature influence the relationship between heating capacity and power consumption of the DSHP. Methods: An experimental method to examine an installed 5kW DSHP system with an attached converters and other connected components, which arrangement properly controls for the indoor temperature and relative humidity of the laboratory. Results and Conclusions: The findings reflects that the COP of the DSHP pumps increases at low water temperature. As water temperature increases, the heat loss to water and compressor power consumption decreases, and in turn reduce the COP. The average temperature increases from 36.55oC to 59.15oC and COP reduces, by 40%, from 2.83–1.12. Implications: The implication is that the DSHP which is shown to be energy efficient is environmentally friendly, and as a result, would remain very useful in the fifth generation of heating systems with the use of smart technology in future. Originality/Value: The value of the article lies in its focus on the performance of the DSHP as an energy and efficiency device for in heating and cooling in buildings.

Multi-objective optimization of supercritical CO2 Brayton cycles for coal-fired power generation with two waste heat recovery schemes

The efficiency of supercritical CO2 (sCO2) Brayton cycle (SCBC) based coal-fired power generation can be enhanced by harnessing the waste heat from sCO2 cooling and flue gas, which currently remains largely untapped. In this paper, we propose two types of design roadmap for utilizing this waste heat. The first method involves using an organic Rankine cycle (ORC) to generate additional power, while the second method utilizes LiBr/H2O absorption refrigeration cycle (ARC) to further cool down compressor inlet sCO2, and thereby reduces its compression power consumption. An energy-economic-environmental multi-criteria models are formulated to access performance of the aforementioned designs and compare them with a standalone sCO2 Brayton recompression cycle system (Standalone). The non-dominated sorting genetic algorithm II is applied to carry out the multi-objective optimization of the three systems. The results show that the SCBC-ARC system achieves the maximum thermal efficiency (ηth) and minimum environmental impact load (EIL), while SCBC-ORC system achieves the minimum levelized cost of electricity (LCOE). We also find that minimizing LCOE conflicts with maximizing ηth and minimizing EIL, respectively. The relationship between maximizing ηth and minimizing EIL is consistent, suggesting that increasing efficiency will alleviate environmental impact of the systems. We also identify and discuss balanced designs for the systems, and our results show that the ηth of SCBC-ORC and SCBC-ARC is 1.40% and 1.70% higher than the Standalone, respectively, the LCOE is 0.56% lower and 3.66% higher than Standalone, respectively, and EIL is 1.16% and 1.59% lower than the Standalone, respectively.

Experimental analysis of an ejector assisted dual-evaporator vapor compression system

Condenser split dual-evaporator vapor compression systems (C-DEVCS) have been used to maintain the two evaporators of a single refrigeration system at different temperatures for long. The throttling process occurring in the expansion valve of these systems is irreversible in nature and thus responsible for a part of energy loss. It has been found that the isenthalpic expansion loss can be reduced using ejector as a throttling device which provides isentropic expansion. Moreover, it recovers some of the energy lost in expansion and reduces compressor work. In the current work, an experimental test facility of ejector assisted dual-evaporator vapor compression system (EA-DEVCS) is developed for R-134a working fluid and analyzed for different condenser temperature. The overall COP of EA-DEVCS is found to increase from 1.982 to 2.925 and 9.8 % decrease in compressor power consumption when the water temperature at the inlet of condenser is decreased from 35 °C to 27 °C. The entrainment ratio of the ejector gets increased from 0.396 to 0.701 with the decrease in condenser temperature.

Experimental Study on the Flow Characteristics of Two-Stage Variable Turbines in a Twin-VGT System

The twin variable geometry turbocharger (VGT) System, through efficient use of exhaust energy, maximizes internal combustion engine (ICE) power, reduces exhaust emissions and improves reliability. However, the internal flow characteristics of the twin-VGT system are greatly affected by the environment. To ensure that the two-stage adjustable supercharged internal combustion engine is efficient in all geographical environments and under all operating conditions, it is necessary to conduct in-depth research on the internal flow characteristics of high- and low-pressure turbines. In this paper, an experimental system of the flow characteristics of a double variable-geometry turbocharging (twin-VGT) system is designed and developed. A two-stage variable turbine flow characteristic test was carried out, focusing on the relationship between the initial rotational velocity of high variable-geometry turbocharging (HVGT) and blade opening in low variable-geometry turbocharging (LVGT). The effects of high- and low-pressure variable-geometry turbocharger (VGT) blade opening on available exhaust energy, expansion ratio distribution, blade velocity ratio, compressor power consumption and isentropic efficiency were studied. The results show that when the available energy of exhaust gas is constant, with the increase in HVGT turbine speed, when the LVGT blade opening decreases by 10%, the low-pressure turbine expansion ratio increases by about 0.23.

Thermodynamic feasibility and multiobjective optimization of a closed Brayton cycle-based clean cogeneration system

The present research has analyzed the energy and exergy of a combined system of simultaneous power generation and cooling. To provide a comprehensive data sheet of this system, the system has been investigated in the temperature range of 300–800 °C, and 6 working fluids, including air, carbon dioxide, nitrogen, argon, xenon, and helium, have been investigated. The parameters affecting the performance of the system, namely the compressor inlet pressure, the compressor pressure ratio, and the intermediation pressure ratio were investigated. The power produced by the Brayton cycle at a pressure ratio of 5.2 is the highest due to the increase in compressor power consumption and turbine power generation. The results of the parametric study showed that the exergy efficiency of the system has the maximum value at the pressure ratio of 4.73. The results of the parametric study showed that increasing the pressure of the compressor does not have a significant effect on the electricity consumption and the temperature of the working fluid due to the constant pressure ratio. The input energy to the heat exchanger of the absorption chiller decreases with the increase in the Brayton cycle pressure ratio, and as a result, the cooling created by the chiller also decreases. In this method, three objective functions of exergy efficiency, energy efficiency, and total production power are considered as objective functions. The most optimal value of intermediation pressure ratio was obtained after the optimization process of 1.389. Also, the most optimal value of the pressure ratio of high-pressure and low-pressure turbines was reported as 2.563 and 1.845, respectively.

STUDY THERMAL OF COMPRESSOR POWER REDUCTION ON USING SOLID DRY PAD PRE-AIR COOLING SYSTEM

AbstractThe uses of compressor based air conditioning system has rapidly increased the consumption of fossil fuel energy resources and the degradation of environment quality. Massive study has been done worldwide to reduce energy consumption for compressor based air conditioning (AC) system. This study is subjected to investigate the use of solid dry pad as pre-air cooling for AC system. In this study, solid dry pad would be placed in the evaporator and condenser inlet air side. This placement was objected to give a pre-cooling effect for evaporator and condenser inlet air, so then the compressor could be operated with a lower power consumption. The experiment would be carried out within three level air mass flowrate of 0.293 kg/s; 0.319 kg/s; and 0.359 kg/s, for air velocity of 2.2; 2.4; and 2.7 m/s respectively, the cooling cabin is set into 30oC using a heater as a cooling load. As a results, it could be revealed that at the highest air mass flowrate of 0.359 kg/s, it could achieved the lowest compressor power consumption of 0.44 kW, within a higher cooling capacity of 2.625 kW, a higher condenser heat rejection of 3.622 kW and also higher COP of 5.9. Referring to those results, it can be concluded that when employing solid dry pad pre-air cooling for evaporator and condenser AC system, it could reduced compressor power consumption by 12.2%; 21.9% and 20% for air velocity of 2.2; 2.4; and 2.7 m/s respectively.Keywords : solid dry pad, pre-air cooling, compressor power reduction.

Experimental Research on the Output Performance of Scroll Compressor for Micro Scale Compressed Air Energy Storage System

Micro compressed air energy storage systems are a research hotspot in the field of compressed air energy storage technology. Compressors and expanders are the core equipment for energy conversion, and their performance has a significant impact on the performance of the entire compressed air energy storage system. Scroll compressors have the advantages of small size, low noise, light weight, low vibration, long service life, continuous and stable gas transmission, and reliable operation. This article builds a micro compressed air energy storage system based on a scroll compressor and studies the effects of key parameters such as speed, torque, current, and storage tank pressure on the temperature difference, pressure ratio, energy consumption, and efficiency of the scroll compressor. The experimental results indicate that the power consumption of the scroll compressor shows an increasing trend with the increase in current, torque, and gas storage tank pressure. The isentropic efficiency of a scroll compressor shows a decreasing trend with increasing current, torque, and storage tank pressure. The maximum values of power consumption and isentropic efficiency of the scroll compressor are 3427 W and 90.8%, respectively.

Performance of hybrid electric vehicle air-conditioning using SiO2/POE nanolubricant

The automobile air-conditioning (AAC) system uses the most energy among all auxiliary components in hybrid electric vehicles (HEV) with an electrically-driven compressor (AAC-EDC). Incorporating nanolubricant improves AAC-EDC performance and reduces battery and AAC component size. This study aims to assess the performance of an AAC-EDC system by employing SiO2/POE nanolubricants. The performance of the AAC-EDC was examined using SiO2/POE with a volume concentration of up to 0.01 %, a refrigerant charge of 120–160 g, and a compressor speed of 1200–3840 rpm. The performance of the AAC system was measured by its heat absorption, compressor work, coefficient of performance (COP), and EDC power consumption. The SiO2/POE was stable for 30 days with a zeta potential of 102.5 mV. The SiO2/POE demonstrated superior performance over the pure POE lubricants. The compressor work and power consumption were reduced to 26.17 % and 11.97 %, respectively. The lowest expansion valve discharge temperature of 9.6 °C was achieved at 160 g refrigerant charge and compressor speed of 3840 rpm. The nanolubricant attained the highest COP of 3.36 at 1860 rpm speed and 160 g charge. The SiO2/POE nanolubricant with a volume concentration of 0.01 % is highly recommended for optimal performance in the AAC-EDC system.

Accelerated Degradation Test on Electric Scroll Compressor Using Controlled Continuous Liquid Slugging

Refrigerant-based electric scroll compressors are known for their reliability, efficiency, and quiet operation. They are often used in heat pump systems due to their ability to efficiently handle varying levels of load conditions, both for heating and cooling modes of operation. As electric compressors are considered the heart of the heat pump system, being able to determine degradation of compressors prior to failure is of paramount importance for the health of this system. Typical failures for electric scroll compressors range from electrical faults, refrigerant leaks, to mechanical failures and overheating. Specifically, one of the primary failure modes for an electric scroll compressor is mechanical damage due to the high stress effects of refrigerant liquid slugging. These stresses are due to excessively high internal pressures exhibited on the compressor scrolls, which are generated by compressing liquid refrigerant at the suction side of the compressor. This paper provides a new testing methodology that introduces liquid slugging at various degrees of refrigerant quality to degrade a compressor to near the end of useful life. Furthermore, this test aims to determine specific operating conditions and signals that can indicate early compressor degradation. This fault injection configuration consists of a modified heat pump system with the addition of two low pressure heat exchangers added in parallel (with respective electronically controlled expansion valve for each heat exchanger) used to control the refrigerant quality during compressor operations. For a given refrigerant quality, the heat pump system was operated at a fixed compressor performance conditions to sustain liquid slugging for a fixed duration. Afterwards, refrigerant was controlled to be pure vapor at the compressor suction side and the compressor was controlled at several different performance conditions (i.e., fixed compressor suction superheat temperature and compressor pressure ratios, at various compressor speeds), so as to duplicate conditions known to us from the compressor component data sheet for an ideal electric scroll compressor. Through these tests, the results show that the severity of scroll failures depend heavily on the refrigerant quality and the amount of liquid slugging exposure time. Furthermore, symptoms of compressor degradation are detected using the following signals: i) temperature and pressure at the compressor suction side, ii) temperature and pressure at the compressor discharge side, and iii) electric compressor speed and power consumption. To further aid in determining the compressor degradation ground truth, complete compressor teardown was performed to identify sections within the compressor that exhibited significant amounts of wear as compared to a stock compressor.

Self-optimized efficient operation of trans-critical CO2 ejector-expansion heat pump water heater system with two-stage evaporation

In application scenarios with lower ambient temperatures and higher sink temperatures, the trans-critical CO2 heat pump water heater system using an ejector instead of a conventional expansion device offers better performance, and the higher pressure differential allows for partial pressure loss recovery through the ejector. However, the complexity of discharge pressure and ejector matching affects the further application of the system. Therefore an optimization method called Extremum seeking control method is proposed to achieve the lowest power consumption implementation under off-design conditions. The ESC controller applied to the system uses the compressor power consumption as the feedback signal and the discharge pressure is used as operating input set-point. The dynamical model of a trans-critical CO2 heat pump water heater built on Modelica/Dymola is used as the study object and optimized for three scenarios: fixed, sloped step profile, and actual ambient temperature. The simulation results show that the ESC applicable to the proposed system can optimize the matching of discharge pressure and ejector driving nozzle throat area to obtain the best performance. Compared with the benchmark system, the extremum seeking control for actual ambient temperature conditions results in a 5.7% increase in system efficiency.

Design of the cryogenic loop for the superconducting toroidal-field magnets of the Divertor Tokamak Test

The design of the cryogenic circuit for the toroidal field magnets has a relevant role in the overall costs of the DTT cryogenic plant (or cryoplant), hence numerical tools can be useful to investigate and to compare different configurations for the TF cooling circuit in support of the selection of the most suitable one. The system-level cryogenic circuit module of the validated thermal–hydraulic 4C code is adopted in this work to model the DTT TF cooling system. At first, the model of the reference circuit layout is implemented and simulated during the plasma pulsed operation of the DTT machine, highlighting the necessity to reduce the heat load transferred to the refrigerator due to the large power consumption of the cold compressor. In view of the above, different TF circuit layouts and optimization strategies are presented, including mitigation strategies for the smoothing of the peak heat load to the refrigerator, leading to a reduction of the cold compressor power up to the 66% with respect to that computed for the reference TF cryogenic circuit layout.

Experimental Investigation of Coefficient of Performance Enhancement (COP) in Ice Plant Using Brine-Based Metal Oxide Nanofluids

The research investigates brine-based metal oxide nanofluids to improve heat transfer and ice plant COP. The novelty of the study is in the use of stable nanofluids of ZnO, CuO, and Al2O3 prepared using surfactants and ultra-sonication to improve the performance of an ice plant working on the vapor compression refrigeration cycle. The study found that the COP of the ice plant was significantly enhanced using these nanofluids, with the greatest improvement of 27% observed for Al2O3 nanofluids at a particle volume concentration of 0.3%. The experiment also showed a reduction in compressor power consumption by 22% at the same concentration and temperature, indicating the potential use of these nanofluids in ice plant applications. The study further demonstrated that the COP improvement was more significant at a controlled temperature of 20 °C than at 25 °C.

Energy, exergy, economic and environmental (4E) evaluation of a solar-integrated energy system at medium–high temperature using CO2 as the parabolic trough collector (PTC) working medium

This paper proposes a solar-integrated energy system at medium–high temperature (i.e., working temperature >300 °C) for power generation, desalination, and sodium hydroxide (NaOH) production. The system consists of four subsystems, including parabolic trough collector (PTC), organic Rankine cycle (ORC), multi-effect distillation (MED), and electrodialysis. The PTC system uses CO2 gas as the working medium to obtain medium–high temperature heat sources. The electrodialysis system electrolyzes the brine to obtain NaOH and HCl, thus avoiding environmental pollution. Energy, exergy, economic and environmental analysis were adopted to evaluate the system's performance, and six critical parameters were investigated. The results showed that the system production of desalinated water, NaOH, and HCl was 106.75 kg/h, 10.61 kg/h, and 48.46 kg/h, respectively, when the direct normal irradiance was 500 W/m2. The net output power of the ORC and the power consumption of the electroanalysis system reached 23.07 kW and 5.00 kW, respectively. The power consumption of the PTC compressor was 8.01 kW. The exergy destruction of solar collector accounted for the most significant proportion, reaching 76.98%. The exergy efficiency of the system reached 12.42%. Among the six different ORC working mediums (R134a, R152a, R600, R600a, R717, and Pentane), Pentane performed the best in the integrated system, while R134a performed the worst. The annual income of the system could reach 27,645 $, with a simple payback period and payback period of 8.62 years and 10.12 years, respectively. The net present value could reach 1,103,722 $. The system could reduce CO2 emissions by 5.64 tons per year. The research in this paper contributes to understanding the overall characteristics of solar-integrated energy systems when using gaseous working mediums to achieve medium and high-temperature thermal storage. It provides a reference for the development of more efficient solar-integrated energy systems.

Study on the working medium of high temperature heat pump suitable for industrial waste heat recovery

In order to find a high-temperature heat pump (HTHP) working medium suitable for industrial waste heat recovery, this paper theoretically analyzes the thermodynamic properties of six refrigerants, including the coefficient of performance (COP), condensation pressure, compression ratio, heating capacity, exhaust temperature, and compressor power consumption. Based on the theoretical analysis results, environmental effects and the temperature range of industrial waste heat, MC-1 can be considered as a suitable working medium for high-temperature water source heat pump. The thermodynamic performance of MC-1 was experimentally studied and compared with that of HFC245fa and F-1 refrigerants. The results show that when the outlet water temperature of the condenser changes from 65 to 110 ℃ and the temperature lift is 35 ℃, the coefficient of performance of MC-1 varies from 4.24 to 5.05, which is much higher than that of both HCFC245fa and F-1. When the outlet water temperature of the condenser varies from 95 to 100 ℃, the average coefficient of performance of MC-1 is 16.2% higher than F-1 and 18.0% higher than HCFC245fa. The relative deviation between the theoretical calculation results and the experimental results of the main thermodynamic performance parameters does not exceed 10%, indicating that the theoretical results are reliable. Therefore, MC-1 can be recommended as the working medium for high-temperature heat pump with a single-stage cycle.

Method for turbocharging and supercharging 2-stroke engines, applied to an opposed-piston new concept for hybrid powertrains

The internal combustion engine's (ICE) electrification calls to question ICE concepts nowadays, leading to new engine architectures conceived to operate as series hybrids. This is the case of the unit analyzed in this work; a 2-stroke, spark-ignited, rod-less opposed-piston engine (2S-ROPE). Previous results revealed some efficiency and maximum power drawbacks, which motivated the development of the supercharged or turbocharged engine version. Supercharging the engine results in a straightforward task; however, turbocharging the engine reveals serious stability problems due to the thermo-fluid-dynamic coupling between the intake and exhaust lines.This work presents a method to study and identify the exhaust line geometry since the impact of pressure pulse propagation on the scavenging process is one of the most critical points to be considered from the very first steps. Finally, despite the difficulties of turbocharging the presented 2S engine, the parametric study revealed a suitable geometrical configuration and the engine operative range. Compared to the supercharged engine version, the turbocharged one presents more difficulties but diminishes the mechanical compressor power consumption, implying an advantage in efficiency terms.

Enhancement of electric vehicle air-conditioning system with dual condensers

Air-conditioning systems of electric vehicles (EV) not only cool the cabin space but also remove the heat generated by the battery during rapid charging or driving. These two cooling functions consume electric energy, affecting electric vehicle competitiveness in fuel efficiency and mileage. Therefore, improving the system performance and efficiency of EV air-conditioning systems is essential. Previous studies have mainly focused on improving the system performance and efficiency by optimizing the main design parameters of the air-cooled condenser or by comparing the performance and efficiency of water- or air-cooled condensers. This study proposed a novel architecture, and conducted experimental and numerical research on the effects of combined condensers that use both water and air to condense refrigerant on the performance and efficiency of the EV air-conditioning system. The simulation results of the developed numerical model were compared with the bench test results. The compressor power consumption and system efficiency under the maximum capacity conditions were selected for comparison. The results show that the air-conditioning system with the combined condenser reduced the compressor power consumption by 13.1% to 14% and improved the system efficiency by 14.6% to 15.7% compared with the air-conditioning system using a single air-cooled condenser.

Real-time power optimization based on PSO feedforward and perturbation & observation of fuel cell system for high altitude

The control technology of the air supply system is key to the performance and reliability of the fuel cell system (FCS). However, due to the low oxygen pressure in high altitude environment, the power consumption of the air compressor is large, and the output power of FCS is seriously degraded. To effectively increase the output power of the FCS under changeable altitude conditions, this article introduces a real-time power optimization strategy based on the particle swarm optimization (PSO) feedforward and perturbation and observation (P&O) algorithm. Considering the change of total entropy and loss of centrifugal air compressor with altitude, the working characteristics of centrifugal compressors at different altitudes are studied. Aiming at the long optimization time of the traditional P&O method and the misjudgment problem when the external conditions change drastically, the PSO feedforward-based P&O method is designed to adjust the air compressor voltage. The results show that the proposed strategy has real-time power optimization capability and can adapt to altitude change. The average setting time is 1.8 s when the operating condition changes and the power decreases to 9.1% at 3000 m altitude under a higher load (300 A).

Investigation on energy-saving potential from heat rejection pressure management in a CO2 transcritical vapor compression system

Heat rejection pressure is an important factor influencing the performance of a CO2 (R-744) transcritical vapor compression system. Previous relevant studies have investigated the optimum heat rejection pressure ensuring the maximum coefficient of performance (COP) and operating parameters affecting the optimum pressure value. However, studies presenting quantitatively how much energy can save when an R-744 transcritical system operates in the optimum heat rejection pressure are still rather limited. This work aims to investigate an energy-saving potential gain achieved by managing heat rejection pressure in an R-744 transcritical system and provides quantitatively how much energy can save with that. In that way, this work tries to fill out the research gap. Simulations were carried out employing prevalidated model, the system COP was investigated in various operating conditions, and the optimum heat rejection pressure securing the maximum COP was found. The optimum heat rejection pressure found in this work was compared to the existing correlations, thereby the comparison results are provided in this paper. The system's dynamic performance was also investigated in two different cases: when the expansion valve opening was regulated for the optimum heat rejection pressure, and when the valve opening was adjusted with a thermostatic expansion valve conventionally. In this study, it is observed the given system reduces the compressor power consumption by 62% when the refrigerant temperature at the main gas cooler outlet varies within a range of 33 ℃ to 45 ℃ and the evaporator temperature of 1 ℃. Consequently, in terms of energy-saving potential, this paper highlights the importance of heat rejection pressure management in an R-744 transcritical system and the significance of proper selection for the control target of an expansion valve depending on the system's operating regime.

Performance of a computerized refrigeration cycle test rig for varying concentrations of (CuO-Al2O3/MO) hybrid nano-lubricants and R600a refrigerant charges: an energetic and exergetic approach

ABSTRACT This article examined the energetic and exergetic performance evaluations of a computerized refrigeration cycle test rig for different concentrations of (CuO-Al2O3/MO) hybrid nano-lubricants and R600a refrigerant mass charges. In this particular investigation, three different refrigerant mass charges of 80 g, 100 g, and 120 g were employed, together with four different hybrid nano-lubricant concentrations of 0.1 g/L, 0.2 g/L, 0.3 g/L, and 0.4 g/L. A number of significant parameters, including COP, compressor power consumption (W), refrigerator pull-down time (minutes), second law efficiency (%), and total exergy destruction (W) of mineral oil without nanoparticles and nano-doped mineral oil using (CuO/Al2O3) hybrid nanoparticles as the lubricant, were examined in the course of this investigation. The optimum condition is achieved at 0.2 g/L of (CuO-Al2O3/MO) with 100 g mass of R600a refrigerant. At optimal conditions (0.2 g/L concentration of hybrid nano-lubricant and 80 g refrigerant mass charge), compressor work and total exergy destruction are lowered by (2.20–23.53%) and (4.51–49.00%), respectively. It is also observed that at optimum condition COP and second law efficiency grew within the range of (0.93–28.97%) and (3.38 to 25.42%), respectively. In conclusion, the performance of the computerized refrigeration cycle test rig altered with (CuO-Al2O3/MO) hybrid nano-lubricant concentrations and R600a refrigerant charges.