Compressor Input Power Research Articles

EXPERIMENTAL INVESTIGATION OF EFFECTS OF NANOREFRIGERANTS ON VAPOR COMPRESSION REFRIGERATION SYSTEM USING R1234yf INSTEAD OF R134a

In this study, the usage of refrigerant R1234yf was experimentally investigated with the addition of various nanoparticles instead of R134a as a working fluid in a VCRS. Firstly, the usage of pure R1234yf instead of R134a was experimentally investigated with energy and exergy approaches without any modification in the VCRS. As a result of pure refrigerant experiments, it was determined that the compressor power input increased by around 9%, cooling capacity decreased by around 8% and EER decreased by around 17% in the system using R1234yf compared to the system using R134a. Additionally, it was determined that the second law efficiency of the VCRS reduced by around 8% in the system using R1234yf compared to the system using R134a. Then, Al2O3, graphene or CNT nanoparticles were added for compensate for performance drops to the VCRS using R1234yf via compressor oil at various mass fractions. Thus, the best enhancement in the system performance parameters was obtained with the usage of R1234yf including 0.250% graphene by mass. Accordingly, it was observed that the cooling capacity of the system with R1234yf including 0.250% graphene by mass was improved up to 24% and 14% compared to the VCRS with pure R1234yf and R134a, respectively. Consequently, the EER value of the VCRS with R1234yf including 0.250% graphene by mass was enhanced up to 32% and 13% compared to the system using pure R1234yf and R134a, respectively. Additionally, the second law efficiency of the system slightly increased with the usage of R1234yf including 0.250% graphene by mass.

Numerical analysis of scroll compressor performance with pre-discharge valve for low-temperature heat pumps

Scroll compressors are a crucial component of automotive air conditioning systems. When operating at off-designed working conditions, over-compression can occur in the scroll compressor. A pre-discharge valve (PDV) is proposed to enhance the performance of the scroll compressor under off-design working conditions. The performance of the scroll compressor with a PDV for a low-temperature heat pump system is simulated. The results show that the scroll compressor with the PDV structure has lower pressure in the compression chambers and improved over-compression compared to conventional scroll compressors. The use of the PDV also leads to a reduction in the temperature of the refrigerant gas in the compression chambers and a decrease in the leakage between the compression chambers. As the evaporating temperature increases from −25 °C to −5 °C, the mass flow rate and volumetric efficiency increase, and the discharge temperature decreases. At an evaporating temperature of −5 °C, the discharge temperature at the center discharge port of the scroll compressor with the PDV is reduced by 2.4 °C compared to the conventional scroll compressor. The input power of the scroll compressor is reduced by 165.4 W–897.7 W. The volumetric efficiency and the isentropic efficiency are improved by 0.13 % and 6.63 % respectively.

Assessment of using different ozone-friendly R22 alternative refrigerants in residential air conditioners in a high-ambient temperature country

The performance of a vapor compression refrigeration system (VCRS)-based residential air conditioner operating in a high-ambient temperature (HAT) country was investigated using six zero-ODP (ozone depletion potential) refrigerants as replacements to R22. The non-flammable alternative refrigerants considered in the present research were R134a, R404A, R407C, R410A, R448A, and R507A. Using the basic conservation laws, the VCRS was modeled during steady-state operation and solved using engineering equation solver (EES) software. Coefficient of performance (COP), pressures and temperatures at compressor suction and discharge, Global Warming Potential (GWP), critical pressure and temperature, compressor pressure ratio, volumetric cooling capacity (VCC) specific cooling capacity (SCC), and refrigeration effect were utilized as assessment criteria for the alternative refrigerants considered. From these refrigerants, the highest values of suction pressure, discharge temperature, and condenser pressure were attained by R410A. In addition, the discharge temperatures for all refrigerants, except R134a, were all higher than their corresponding critical values, causing a quicker drop in the VCRS’s performance. As an alternative refrigerant, R407C showed the highest SCC of 141.0 kJ/kg followed directly by 139.2 and 138.0 kJ/kg for R410A and R448A, respectively. A reverse trend was found for VCC with respective values of 4722 and 3775 kJ/m3 for R410A and R448A. Lower volume flow rates and smaller-sized compressors are expected for higher VCC refrigerants. The same trend was found for the compressor’s specific work input and condenser’s specific heat transfer with values of (51.14, 46.82, and 45.38 kJ/kg) and (190.3, 187.8, and 183.4 kJ/kg) for R410A, R407C, and R448A, respectively. For applications in HAT countries, larger condenser’s specific heat transfer makes the refrigerant more applicable. Conversely, with respect to COP, refrigerant R134a with a value of 3.075 was the superior alternative followed by R448A and R407C with respective COPs of 3.042 and 3.011. Based on the overall assessment in terms of environmental obligation, COP, compressor input power, refrigerant flow rate required, and all the evaluations made in this research, refrigerant R448A was recommended as the most appropriate substitute to R22 which can effectively be used in residential air conditioners in a HAT country.

Parametric analysis and performance prediction of an ultra-low temperature cascade refrigeration freezer based on an artificial neural network

A thermodynamic analysis is proposed to improve the designing and operating parameters in an ultra-low temperature cascade refrigeration system (CRS). The expressions for predicted parameters of the CRS are obtained based on an artificial neural network (ANN) method. In the first part, a parametric analysis is carried out to analyze the influences of seven variables on the COP, total compressor input power, discharge temperature of two compressors, total exergy destruction, and exergy efficiency. The results show that the condensation temperature of the low-temperature circuit has an optimal value, which maximizes COP and exergy efficiency but minimizes the total compressor input power and exergy destruction. In the second part, the performance of CRS is predicted by the ANN model. Eighty sets of input-output parameters are applied as both the training and testing data. It is found that the correlation coefficients for training-testing data in the range of 0.9886–0.9994 are estimated. The mean absolute errors obtained in the prediction for COP, total compressor power, total exergy destruction, exergy efficiency, and discharge temperature of high and low-temperature cycles with the testing set are 0.0027, 0.9090, 1.0314, 0.1691, 1.1438, and 1.0230, respectively. The outcome indicates that the ANN model has good advantages in predicting the cascade refrigeration system's performance.

Effect of system configuration on the performance of a hybrid air conditioning system based on R-1234yf

The study presents theoretical results on a hybrid air conditioning system in which the sensible and latent loads are separately managed. The problem studied is significant in view of the growing demand for air conditioning systems globally, and also due to the adverse impact of these systems on global warming. In order to reduce the environmental impact of the air conditioning systems, this study proposes a hybrid system comprised of a vapour compression heat pump and a desiccant wheel. Due to restrictions on high global warming potential (GWP) refrigerants, R-1234yf, a low GWP refrigerant is considered as the working fluid for the heat pump. An enthalpy wheel is included to reduce the ventilation load on the system. The proposed hybrid system’s performance is evaluated using the first and second laws of thermodynamics and psychrometric principles. Results are compared with that of a conventional air conditioning system. Based on the calculated values of component and process wise irreversibility, further modifications to the hybrid system are proposed. These modifications consist of addition of a liquid-to-suction heat exchanger and use of a split condenser. Results show that depending upon the latent load on the conditioned space, the compressor power input can be reduced by as much as 47% using the proposed hybrid system. Compared to the conventional system, the modified hybrid system shows excellent performance under both high as well as low latent loads, whereas the simple hybrid system performs very well in applications involving high latent loads. The work presented is novel as it considers both first and second laws of thermodynamics to arrive at an optimum hybrid system configuration using an environment friendly refrigerant. It is expected that the study will be useful in the development of energy efficient and environment friendly air conditioning systems that operate equally well under low and high latent loads.

Experimental study of compressor electric current detection for a split-type air conditioner affects energy savings

The paper presents an experimental study that aims to measure the compressor electric current of a split-type air conditioner for analyzing the various abnormal condition of the R-32 refrigerant pressure, especially for detecting compressor electric current while occurring dirt in the evaporator coil and condenser coil. The method was to install sensor devices to measure the temperature and humidity of inlet air and outlet air, and the velocity of the air outlet of the evaporator unit. In condenser unit was to measure the electric current compressor and electric power input. All data from sensors send to the Arduino board and using Parallax Data Acquisition (PLX-DAQ) Excel Macro for the record. The results show physical behavior and the changing of compressor electric current according to the abnormal condition of the refrigerant system, blocking of condenser and evaporator coil.

Effect of reject temperature on aerospace pulse tube refrigerator

Pulse tube refrigerators (PTRs) have significant potential application prospects for space infrared detection. Currently, the third-generation detection technology is a developing trend in the large array focal plane field, which requires the PTR to provide higher cooling capacity for the infrared detector by increasing the input power and heat dissipation. Owing to the vacuum environment present in orbit, the temperature of the working environment becomes more extreme, particularly for coaxial PTRs. In this study, the effect of reject temperature on the cooling performance of a coaxial PTR was systematically investigated, and some parameters are analyzed, such as compressor impedance, phase shifts, main losses, enthalpy flow, mass flow, and input power with reject temperature. As the reject temperature increases, the phase at each position in the PTR will exhibit different degrees of hysteresis, and there will be less loss of major components and decreased enthalpy flow at the cold end of the pulse tube. In addition, an experimental study on the adaptability of the PTR with different cooling temperatures to the reject temperature was performed. In the experiment, when the reject temperature increases from −40 °C to 40 °C, the input electrical power required for PTR with a cooling capacity of 4 W@60 K increases from 106 W to 193 W. The experimental results are consistent with the simulated values.

Moving magnet linear compressor: Operating characteristics under resonance and off-resonance frequencies

ObjectivesThis study compared the accuracy of a Linear Equivalent model and a Fourier Transform model in approximating the resonant frequency of a moving magnet oil-free linear compressor. Furthermore, moving magnet linear compressor performance under resonance and off-resonance frequencies was also examined via an experimental approach. MethodsA Linear Equivalent model and a Fourier Transform model were developed and compared with experimental results at low-pressure ratios of 2–2.5. By varying the operating frequency and compressor piston stroke, the power consumption, compressor losses, efficiency, and cooling capacity are assessed experimentally. ResultsThis study showed that the disparities between resonance frequencies estimated by theoretical models and experimental data were below 10 %. However, the Linear Equivalent model was more accurate than the Fourier Transform model in forecasting the resonance frequency of the linear compressor at a low-pressure ratio of 2–2.5. Both experimental and modelling results showed that the resonance frequency of a linear compressor declined with the increasing compressor stroke but increased with increasing pressure ratio. Experiments were also carried out to compare the performance of linear compressors in resonance and off-resonance frequencies. Results showed that the lowest compressor input power of 91.96 W and the highest motor efficiency of 81.98 % was achieved when the linear compressor was operated at 38 Hz resonance frequency. Moreover, the cooling capacity has been found to increase by 270 W approximately when the linear compressor piston operating stoke extends from 10 mm to 13 mm. ConclusionsIn all, this study showed that the linear compressor motor efficiency is the highest when operating at resonance frequency. However, the cooling capacity of the linear compressor system does not vary significantly with operating frequency. A higher cooling capacity can be achieved by increasing compressor piston stroke.

Thermodynamics of integrated energy supply for small-scale production and living condition in rural areas

Combining fresh material drying/cooling and environment regulation of residential buildings, a new integrated energy supply (IES) system based on heat pump is proposed to improve the energy efficiency, comfort of living condition and retention rate of agricultural products in rural areas. To balance supply and demand, the IES system, based on the characteristics of energy utilization in rural areas, is able to operate among four basic modes: Building Heating (BH), Building Cooling (BC), Material Drying (MD), Material Cooling (MC), and two integrated modes: BHMC and BCMD. Under typical working conditions, thermal performances including cooling capacity, heating capacity, compressor input power and coefficient of performance (COP) are compared among different operation modes when refrigerants are R32, R152a, R22 and R1234yf, respectively. It can be found that integrated energy supply system have lower cooling and heating capacity, and higher compressor power, but its COP is also the biggest. Comparison results also show that the time ratio of integrated operation mode (tr) and time ratio of one operation mode (ts) are important factors effecting the entire energy efficiency.

Effect of Compressor-Discharge-Cooler Heat-Exchanger Length Using Condensate Water on the Performance of a Split-Type Air Conditioner Using R32 as Working Fluid

The utilization of condensate water as a compressor-discharge cooler results in subcooling on the condenser outlet. On the other hand, a split-type air conditioner (A/C) with R32 as working fluid can provide higher compressor-discharge temperatures than other refrigerants used in the same A/C. Therefore, A/C working with R32, equipped with a heat exchanger by utilizing waste-condensate water as the compressor-discharge cooler, has promising potential to produce the largest subcooling effect in air-conditioning systems. The aim of this study is to investigate the effect of condensate water as the compressor-discharge cooler on the performance of an A/C using R32 as the working fluid with different sizes of heat exchanger. The experimental study was carried out on the A/C with a compressor capacity of 1.1 kW, using three different heat-exchanger lengths, i.e., 18, 20 and 22 cm. The results indicated that longer heat exchangers produced higher degrees of subcooling; the heat exchangers with lengths of 18, 20 and 22 cm produced average degrees of subcooling of 0.9, 1.5 and 4.5 K, respectively. Therefore, increments in the degree of subcooling generate improvements in cooling capacity, lowering the compressor-input power, and enhance the COP of the A/C. The average COP improvement of the A/C with heat-exchanger lengths of 18, 20 and 22 cm were 9.1, 14.4 and 27.3%, respectively.

Comprehensive performance analysis of cascade refrigeration system with two-stage compression for industrial refrigeration

The cascade refrigeration system with two-stage compression (CRST) with R1150/R717 as the refrigerant group was studied to replace the three-stage cascade refrigeration system (TCRS) with R1150/R41/R717 as the refrigerant group, aiming to improve the operational efficiency of the industrial refrigeration system in the temperature range of −120°C to −80°C. This paper selected typical cities in five major climatic zones in China to analyze the coefficient of performance (COP), annual total power consumption, and seasonal energy efficiency ratio (SEER) of CRST and TCRS under different climatic conditions based on compressor discharge temperature, compressor input power, COP, and thermodynamic perfectibility. According to the results, the compressor input power of CRST is 1.45–1.61 kW lower than that of TCRS. CRST improved by 7.0%–11.7% in terms of COP and thermodynamic perfectibility. The seasonal performance analysis compared the CRST and TCRS operating in five different climate zones; the SEER of CRST increased by 26.3%–29.2%. CRST has a significant energy-saving effect, with an annual total power consumption of 8.6%–10.2% lower than that of TCRS. Finally, in the evaporation temperature range of −120°C to −80°C, the technical scheme of using CRST to replace TCRS in different climate zones is entirely feasible.

A Comparative Performance Study of an Ejector-Expansion Refrigeration Cycle Using R134a and its Alternatives: Application of Automobile Air Conditioning

In this study, the performance of ejector-expansion refrigeration cycle (EERC) with R134a alternative refrigerants (R152a, R1234yf, R404A, R407C, R507A and R600a) for automobile air-conditioning application is investigated numerically. The ejector is modeled with a constant mixing-pressure assumption taking into consideration the friction effect in the ejector mixing section. The studied refrigerants are compared based on the optimum area ratio, discharge temperature, compressor input power, volumetric cooling capacity, exergy destruction, COP, exergy efficiency and COP improvement. The results show that R152a and R1234yf have the closest performance to R134a and can be considered the most suitable alternative refrigerants for R134a. The COP and exergy efficiency are improved by 2.26% and 2.27%, respectively, using R152a compared to the use of R134a, whereas they are reduced by 2.89% and 2.88% using R1234yf. The volumetric cooling capacity is reduced for both R152a and R1234yf by 6.14% and 6.8%, respectively. In addition, the effect of compressor rotational speed on the performances is reported.

A review of stability, thermophysical properties and impact of using nanofluids on the performance of refrigeration systems

• Reviewed the experimental studies on nanoparticles-doped refrigeration systems. • Noticed many limitations for using nanoparticles in today's technology. • Observed the enhanced heat transfer mechanism with smaller particle sizes of nanoparticles. • Achieved long-term stability by moving away from the isoelectric point. • Reported a deterioration in the stability with longer sonication time. The popularity of the studies on improving the thermal properties of base fluids in thermal engineering applications is considerably increasing day by day. Recently, many researchers have proved that the use of nanoparticles along with the base fluids exhibits better thermal properties as well as better system performance. In line with this, it is noticed a respectful increase in the number of studies regarding nanoparticle use in refrigeration systems. Accordingly, the present paper aims to summarize the preparation of nanofluids, the variation of thermophysical properties, the stability of nanofluids, impacts on the system performances of nanofluid usage, limitations, and challenges of nanoparticle usage, particularly in the refrigeration systems. Previous studies revealed that the heat transfer mechanism of the lubricants and refrigerants is highly improved with nanoparticle addition. It is observed that the increase in thermal properties becomes more visible as nanoparticle fractions increase, but this case may worsen the viscosity of nanofluids. The enhanced thermal properties contribute to improving refrigeration system performance. Many papers emphasize that nanoparticle-doping triggers an increase in system performance by both reducing the compressor power input and increasing the cooling capacity of the refrigeration systems. However, some critical points such as stability, homogeneous distribution, agglomeration, and sedimentation considerably influence the sustainability of performance improvement. In conclusion, nanoparticle-doping for refrigeration systems can be accepted as a very promising way of improving the performance, nevertheless, some questions such as high cost, toxic effect, poor stabilization, erosion effect, high viscosity, clogging issues should be more addressed in the future.

Experimental investigation and comparison on heating performance characteristics of two transcritical CO2 heat pump systems

An experimental investigation and comparison of the heating performance of the transcritical CO2 single-stage and vapor injection cycles were conducted. The effects of operating parameters on the heating performance of the two cycles were investigated. The experimental results showed that the heating capacity of the vapor injection cycle was 7.0% higher and the discharge temperature of the refrigerant was 7.7–11.8 ℃ lower than that of the single-stage cycle under the same condition. Besides, both the compressor input power and heating capacity were increased with the increasing temperature of the glycol aqueous solution. However, the growth rate of heating capacity was greater than that of the compressor input power. Therefore, the coefficient of performance of the vapor injection cycle was 4.4% greater than that of the single-stage cycle. So the vapor injection cycle has a wider range of applications in cold conditions. When the vapor injection pressure increased, the coefficient of performance of the vapor injection cycle increased then decreased, so there was a peak of the coefficient of performance. Therefore, a new correlation of the optimal vapor injection pressure was proposed. The new correlation has a significant meaning for designing a transcritical CO2 vapor injection cycle.

Energy and exergy analysis of a Linde-Hampson refrigeration system using R170, R41 and R1132a as low-GWP refrigerant blend components to replace R23

This study presents a comprehensive comparative analysis of the thermodynamic performance of a single-stage Linde-Hampson refrigerator (LHR) for refrigerant couples, namely R1234yf + R170, R1234yf + R23, R1234yf + R41 and R1234yf + R1132a, to seek the most suitable substitute for R23 at the temperatures down to −60 °C. The compressor input power, cooling capacity, coefficient of performance, exergy loss and exergy efficiency are selected as the objective functions. The operating parameters include the evaporation temperature, suction pressure, and condenser outlet temperature. The compositions of each binary mixture were obtained from the vapor-liquid equilibrium behavior according to the suction pressure and target evaporation temperature. Simulation and comparative study show that better energy and exergy performance are obtained with all the replacements under all studied conditions compared to R23. Further results show that the R1234yf + R41 mixture performs better, and hence is suggested as the most promising alternative couple for the single-stage LHR at −60 °C. By properly increasing the suction pressure and decreasing the condensation temperature, the system performance can be enhanced. This indicates that a multi-objective scheme has the potential to significantly improve the performance of low-temperature applications.

An experimental study on the starting characteristics of an improved radiant-convective air source heat pump system

The application of air source heat pump (ASHP), a kind of environmental-friendly energy-saver used for space heating, can help to slow down energy crisis and global warming problems. Recently, to improve the indoor thermal environment, several studies on investigating novel indoor heating terminals of ASHP have been carried out. In this paper, a novel radiant-convective heating terminal was designed and coupled into an ASHP, and its starting characteristics were experimentally investigated. The experimental results showed that both compressor frequency and indoor air fan opening criteria significantly impacted the starting characteristics of the improved ASHP. With an increase in compressor frequency, the values of radiant-convective panel surface temperatures, discharge temperature and pressure, and compressor input power at the end of the starting stages increased, but the suction pressure decreased. Besides, the time point for turning on indoor air fan was prolonged from 100 to 680 s when the temperature of air fan opening criteria increased from 28.0 to 43.0 °C, and the shortest starting time of the improved ASHP occurred when employing the indoor air fan opening criteria of 38.0 °C. Furthermore, an optimized control strategy for the improved ASHP was presented. Compared to a conventional control strategy, the optimized control strategy can significantly shorten the starting time of improved ASHP from 29 to 11 min.

Theoretical analysis on a novel two-stage compression transcritical CO2 dual-evaporator refrigeration cycle with an ejector

This paper proposes a novel two-stage compression transcritical CO2 dual-evaporator refrigeration cycle with an ejector. The ejector and flash tank introduced in the novel system is used to reduce the flashed vapor flowing through the low-temperature evaporator and thus reduce the input power of the low-temperature compressor, rather than traditionally reducing the compressor input power by lifting the compressor suction pressure. Thermodynamic analysis results indicate that under all given operating conditions, the performances of novel system are better than those of conventional system. Compared with the conventional system, the COP and exergy efficiency of the novel system under a typical operating condition is increased by 19.6% and 15.9% respectively, and the discharge temperature of high-temperature compressor in the novel system is reduced by 10.5 °C. In addition, the optimum gas cooler pressure of the novel system is 10.3 MPa, which is lower than that of the conventional system. Moreover, exergy analysis results display that the overall exergy destruction in all expansion devices for both systems accounts for the largest part of the total exergy destruction, but its proportion of the novel system is smaller than that of the conventional system.

Thermodynamic comparison of CO2 power cycles and their compression processes

The power system using carbon dioxide (CO2) as the working fluid has been the research hotspot due to its high performance and potential for use in many energy fields. In this paper, the difference of compression processes between supercritical CO2 (S–CO2) and transcritical CO2 (T-CO2) power cycles is researched, and their effects on the thermodynamic performances of power cycles and equipment are discussed. The results show that the thermal efficiency and net output power increase with the decreasing of the compressor/pump inlet temperature, and there is a big jump near the critical temperature. The condensation margin is more sensitive to the temperature than the pressure near the critical point. To minimize the compressor input power and to guarantee the reliability of equipment, the inlet parameters of compressors should be designed and operated carefully. And the inlet velocity of compressors should be set below the usually recommend value.

Second law analysis on performance of double stage reciprocating air compressor with inter cooler

Nowadays compressors are playing a major role in many processing industries, manufacturing industries and power sector. At many cases, the compressors are the ultimate comprehensive one on energy consumption in industries. The major grievance of the compression process is heating effect of air compression process which leads to ineffective compression and constant air supply. Many researchers are showing interest to increase the performance of air compressors. Optimizing the suitable designs, working parameters and fluid properties are the three main ways for improving the performance of air compressors. Energy and second law efficiency analysis are the necessary one to recognize the important of energy consumption and conservation. For analysing the performance of the air compressor it is mandatory to measure the working parameters such as pressure, temperature, mass flow rate of air, speed of the compressor and electrical input power. Since the measurementation and instrumentation is playing a vital influence on the performance of air compressor. Therefore investigating the error on instrumentation and its influence on performance of air compressor is compulsory to regulate the eminence of experimental set-up. And these error factors will designate the effect of the uncertainty cause on the performance of air compressor. Uncertainties are significant in all experimental dealings and must be measured throughout the various points of an experimental analysis. In this research work, a study on energy, second law uncertainty efficiency and analysis were done in a double stage reciprocating air compressor with inter cooler setup which is located in Sathyamangalam, Tamilnadu, India. Based on the local ambient conditions and required output for various applications were taken for this performance analysis of double stage reciprocating air compressor with inter cooler. The discharge pressure from the double stage compression is varied from 3 bar to 7 bar. For the corresponding output pressure, first law and second law efficiency of the system was calculated. For the fixed mass flow rate of air the calculated first law efficiency of the system varies from 38% to 64% and second law efficiency of the system varies from 57% to 67%. For the corresponding pressure ratios the uncertainty on the performance of air compressor based on the first law and second law analysis were mathematically modelled. Based on the model the uncertainty on the performance of compressor were found for the error of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1%, 2% in all the instruments and it was discussed in the result.

Performance evaluation of ice plant operating on R134a blended with varied concentration of Al2O3SiO2/PAG composite nanolubricant by experimental approach

Abstract Performance of an ice plant test rig is investigated experimentally for composite nanoparticles (Al2O3 SiO2) at different volume concentration ranging from 0.02% to 0.1% dispersed in Polyalkylene Glycol (PAG46) lubricating oil utilising R134a as working refrigerant. Performance of the test rig is evaluated on the basis of parameters including: temperature of brine solution in the brine tank (pull-down time), compressor power input, freezing capacity and COP. Temperature and pressure readings acquired using suitable thermocouples and gauges fitted on the test rig is used for the analysis. Refrigerant properties are obtained using REFPROP 9.1 software developed by NIST. Concentration of composite nanolubricant (Al2O3 SiO2/PAG) at 0.08% is found to be optimum owing to lowest compressor power input and highest COP achieved at this concentration. Result shows that the mixture of R134a/composite nanolubricant (Al2O3 SiO2/PAG) worked efficiently in the rig, and performance is found better than operated with either of the nanoparticles dispersed alone in PAG. It is observed that power consumption in the compressor working with composite nanolubricant is found 6.8% and 3.5% less than Al2O3 and SiO2 nanoparticle respectively dispersed alone, whereas COP is found 10.89% and 5.3% more than Al2O3 and SiO2 nanoparticle respectively dispersed alone at 0.08% volume concentration. Total exergy destruction for system working with composite nanolubricant is lowest among all the combinations with value of 0.60 kW.