Higher COP Research Articles

A double-effect/two-stage absorption refrigeration and thermal energy storage hybrid cycle using dual working fluids

• The hybrid cycle can get a generation temperature of 385 K and a COP of 2.37. • This cycle can work below 273.15 K with a high ESD over 300 kJ·kg −1 . • It realized combined cooling and heating for 24 h using dual working fluids. To improve the flexibility of absorption thermal energy storage (ATES) cycle, including lower the generation temperature, larger the operating temperature region and combined cooling and heating for 24 h, a double-effect/two-stage absorption refrigeration and thermal energy storage hybrid cycle using LiBr/H 2 O and LiBr-[BMIM]Br/C 2 H 5 OH working fluids is proposed in this paper. The cycle includes an absorption heat pump (AHP) sub cycle and an ATES sub cycle. Based on the measured thermophysical properties, the thermodynamic performance of this new cycle under different working conditions was calculated by MATLAB. According to the results, the hybrid cycle obtained a low generation temperature of 385 K, attributed to the utilization of the low-temperature working fluid LiBr-[BMIM]Br/C 2 H 5 OH. Moreover, the evaporation temperature of 268.15 K expanded the operating region of the hybrid cycle, and the highest COP and ESD of 2.37 and 394 kJ·kg −1 were obtained at that temperature, respectively. More importantly, the cycle realized combined cooling and heating all day long, with a cooling output temperature range of 268.15–278.15 K and a heating output temperature range of 321–344 K, which can fully meet the demands of commercial and civilian applications. To further verify the feasibility of the cycle, the model sensitivity and chemical potential achieved in the hybrid cycle were analyzed.

Isotherms and kinetics of water sorption onto MOFs for adsorption cooling applications

• Three adsorbents: MOF 801, aluminum fumarate, and MIL 100 (Fe), were synthesized. • Water sorption isotherms onto the MOFs were thermogravimetrically measured. • The diffusion coefficients were determined using the TALDF sorption kinetics model. • COP th and SCE were computed for the studied pairs. • MIL 100 (Fe)/water had the fastest kinetics, highest net uptake with a high COP of 0.8. MOFs (metal organic frameworks), a new type of porous coordination polymers (PCPs), has emerged as a novel class of adsorbent material that has piqued the interest of academics working on a variety of sorption-related applications all over the world. Adsorption heat pump research is no exception, and it has accelerated since the MOF adsorbents were introduced. In this study, water adsorption isotherms onto three distinct synthesized MOFs, MOF 801, aluminum fumarate, and MIL 100 (Fe), were experimentally obtained at three different temperatures (30, 50, and 70 °C) with varying evaporating pressures using the thermogravimetric technique. The S-shaped adsorption isotherms were correlated with the well-known Sun-Chakraborty model. P- T -W diagrams were generated using the adsorption isotherms data to determine the net adsorption uptake within a certain adsorption heat pump working condition. Water sorption kinetics were also analyzed using the time-adapted linear driving force model. Adsorption enthalpy, specific cooling effect, and coefficient of performance of the studied pairs were calculated and compared with the results of the PS-I/water pair. Results suggested that, for a water-based adsorption cooling system, the studied MOF adsorbents significantly outperform the traditional polymer-based adsorbent PS-I. Among the MOF/water pairs, MIL 100 (Fe)/water pair showed the fastest sorption kinetics with a diffusion time constant of 5.4 × 10 −4 s −1 . This pair also exhibited the highest specific cooling effect of 569.42 kJ kg −1 and a coefficient of performance of 0.80, which was rather impressive. These results will be valuable in determining suitable adsorbent-adsorbate pairs for next-generation adsorption cooling systems.

Study on Thermal Performance of the Small-Scale Air Conditioning with Thermoelectric Cooling Module

This work presents the COP and EER of the combined air conditioning and thermoelectric cooling systems. The small-scale air conditioning (8000 BTU/hr) with thermoelectric cooling systems is set up in the closed room (2.0*2.0*2.0 m), and free energy from the photovoltaic cell is used for the thermoelectric cooling module. The COP and EER with the thermoelectric cooling module are higher than those without the thermoelectric cooling module. It is observed that the COP and EER increase as the axial fan speeds increase. In addition, there is good agreement from the comparison, giving an average error of 3.77%. The highest COP and EER for the system with the thermoelectric cooling module are 1.71 and 5.85 for an airflow rate of 4.7 m3/s, respectively. The results can be used as guidelines for developing the thermal performance of air conditioning by combining it with the thermoelectric cooling module.

Optimization of A Solar Ejector Refrigeration System in the Region of Adrar, Algeria

This study aims to simulate a solar ejector refrigeration system in the region of Adrar (27.82 N, 0.18 W). It is the first investigation of such refrigeration system in this region, the importance of this study is to benefit from the free intense solar energy for cooling and air conditioning and reduce using electrical energy produced by thermal power station which is harmful to the environment and causing warming global. It is a theoretical study using real gas equation (REFPROP database). The system is inspected for various evaporator temperatures from 0 to 30 °C and for various condenser temperatures from 25 to 50 °C. For each situation, the system is optimized by choosing the best ejector parameters and the ideal generator temperature. Different refrigerants are used as R11, R134a and R717 (ammonia). The last one is observed to be the best fluid in all the working conditions. More explicitly, the highest COPs is 0.28 when the system produces refrigeration at 30 °C and the boiler temperature is 90 °C. The COPs values are acceptable and very interesting, and it’s higher than other cities in the world like Athens, this study can be generalized in other hot regions. The examination is performed with a code written in Fortran.
 HIGHLIGHTS
 
 The importance of this study is to benefit from the free intense solar energy for cooling and air conditioning and reduce using electrical energy
 For each situation, the system is optimized by choosing the best ejector parameters and the ideal generator temperature. Different refrigerants are used as R11, R134a and R717 (ammonia). The last one is observed to be the best fluid in all the working conditions
 More explicitly, the highest COPs is 0.28 when the system produces refrigeration at 30 °C and the boiler temperature is 90 °C
 This study can be generalized in other hot regions
 
 GRAPHICAL ABSTRACT

A comprehensive review and analysis on CO2 heat pump water heaters

• Existing CO 2 HPWHs in industrial and residential sectors are reviewed. • Performance restricted by the pinch point effect is analyzed. • Limitations in CO 2 compressors and lubrication are revealed for the first time. • Current enhancements to overcome the limitations are summarized. In the context of the Montreal Protocol, CO 2 is considered as an appropriate natural refrigerant with an Ozone Depletion Potential (ODP) of zero and a Global Warming Potential (GWP) of one. A CO 2 heat pump water heater (HPWH) can provide hot water with a relatively high COP and consume significantly less energy than all electric or gas water heaters. This study reviews and analyses the existing CO 2 HPWHs both in industrial and residential sectors, where the low-temperature and high-temperature systems are classified by the heat delivery temperature of below and above 80 °C, respectively. The significance and features of existing CO 2 HPWHs are also summarised in this study. Moreover, the performance limitations of current CO 2 HPWHs are discussed considering the temperature gliding matching, and the technical constraints in both CO 2 compressors and heat exchangers. Due to the drastic variation of CO 2 heat capacity with temperature and pressure, the heat exchange process between sCO 2 and water is affected by the pinch point. The temperature gliding matching can be enhanced by optimising the parameters in both the CO 2 and water sides, using zeotropic refrigerant mixtures, or adding new devices or cycles to the existing CO 2 system. Another way to improve the system performance is increasing the discharge pressure or discharge temperature, while current CO 2 reciprocating compressors have an upper-temperature limit of 140 °C and upper-pressure limit of 140 bar, as well as some constraints in the heat exchangers. Due to the decomposition risk of lubricant in the compressor, two types of oil-free compressors (turbo and scroll) have been described. But it is found that the turbo-compressor is hard to provide a competitive efficiency when the pressure is high, and there is a significant leakage flow in a scroll compressor.

Drop-in assessment of plug-in R404A refrigeration equipment using low-global warming potential mixtures

Abstract This study analyses the performance of plug-in refrigeration equipment, which has the condenser on the system and delivers heat to the indoor medium, using mixtures with low-global warming potential (GWP). The theoretical drop-in replacement of R404A that is widely used in the plug-in refrigeration equipment, is investigated utilizing refrigerants with GWP<150 such as R454C, R455A, R457A and R465A. In the study, four cases of evaporation temperatures (-25°C, -15°C, -5°C and 0°C) and two cases of condenser temperatures (30°C and 40°C) were considered for freezer and chiller modes of the equipment. According to the obtained results, the power consumption of R404A is determined to be higher than other refrigerants for both studied condenser temperatures. The mass flow rate circulating in the system decreases using R404A’s alternatives. Furthermore, the highest COP is reached with R457A which has a greater COP than R404A about by 8.5%. The compressor discharge pressures of alternative refrigerants are smaller compared to R404A as well. The reduction in CO2 emission is also presented in terms of total equivalent warming impact (TEWI) computations. The conducted analysis points out that it will be possible to use directly the investigated mixtures (especially R457A and R455A are most promising ones) in plug-in refrigeration devices as alternatives to R404A without performing any constructional modification in the system.

Study on the performance of an energy-efficient three-stage auto-cascade refrigeration system enhanced with a pressure regulator

This paper proposed a modified three-stage auto-cascade refrigeration cycle (MTARC) associated with an intermediate pressure regulator. The energy and exergy analyses indicate that the MTARC can acquire lower evaporating temperature, greater cooling capacity and higher COP. Under a typical operating condition, the MTARC using the alternative ternary zeotropic mixture of R1234yf/R41/R14(0.66/0.17/0.17) has an evaporator inlet temperature of −90.90 °C, COP of 0.4509 and exergy efficiency of 40.67%, which are 4.63 °C lower, 32.93% and 15.38% higher than those of the conventional three-stage ARC, respectively. Further research shows that with the decreasing intermediate pressure, the thermodynamic performance of the MARC can be improved significantly, but the compressor exhaust temperature also increases. When the intermediate pressure decreases from 1.8 MPa to 1 MPa, the cooling capacity, COP and exergy efficiency of the MTARC increase by 30.34%, 22.10% and 13.79% respectively, while the exhaust temperature increases 18.59 °C from 116.66 °C to 135.25 °C, which indicates that the selection of intermediate pressure needs to be comprehensively considered. The proposed new approach is valuable for optimizing the design and application of the refrigerator at an ultra-low temperature level of −80 °C.

A mechanical vapor compression regeneration system of potassium formate solution: Model development, experimental verification and performance prediction

Low energy consumption is the regeneration goal of high concentration potassium formate (KCOOH) solution, which can reduce freezing point while improve moisture absorption when being used as the antifreeze or liquid desiccant. This paper proposed a mechanical vapor compression (MVC) regeneration system, which can greatly reduce energy consumption when dealing with high concentration solution. The developed models of MVC regeneration system were in good agreement with the experiments, whose relative deviation between the model and experimental values is from −13.49 to 10.18 %, to predict and analyze the regeneration performance of KCOOH solution. Experimental results shows that the MVC regeneration system had still a high COP (12.22–16.30) when dealing with the high concentration solution. Performance prediction displays that the optimal heat transfer temperature difference was from 7 to 11 °C. Research of this paper provides the technical support for the design optimization and engineering application of MVC regeneration system.

Thermodynamic performance’s analysis of a cold production by hybrid compressor-based thermochemical sorption processes using ammoniated salts

Many developments in recent years concern the hybridization of sorption systems with a mechanical compressor. This paper presents an assessment study of different hybrid thermochemical systems used to ensure a cold production. A screening over more than 100 ammonia salts have been done to investigate the different compressor configurations. The compressor can be used to assist the decomposition phase, the synthesis phase or both phases. Two major points are tackled: the modification of the operating range and of the performances of such hybrid systems. This article is intended to be a thermodynamic tool for selecting the most suitable ammoniated salt and compressor operating configuration for a targeted cooling application. Compression-assisted decomposition has already been studied in the scientific literature for thermochemical systems, but not the compression-assisted synthesis for a low-temperature cold production. This latter hybridization extends the operating range of the thermochemical process quite the same way as the assisted decomposition but brings better average performances over the operating range compared to a fully thermally driven system, with higher COP (+8%), exergetic efficiency (+2%) and primary energy efficiency (+4%). The possibility to use a compressor in both phases leads to very interesting performances over a largely extended operating range. In this case, the average exergetic efficiency can be 32% higher than the average exergetic efficiency of a fully thermally driven system.

Thermodynamic and economic analysis of two-stage CO2 Heat Pump with reverse Brayton cycle

At present, the output water temperature of most CO2 heat pumps is below 95°C. Herein, the reverse-Brayton cycle is innovatively applied to the CO2 heat pump to increase its output water temperature. A numerical model of a two-stage reverse-Brayton cycle with refrigerant injection and internal heat exchanger is proposed. The effects of discharge pressure, suction temperature, injection mass ratio, and pressure of refrigerant injection on COP of this system at different heat source temperatures are analyzed. Simulation results show that the highest COP can reach 3.05 with a discharge temperature of 129.1°C. The highest discharge temperature is 157.1°C and the temperature lift is 87.1°C with a COP of 2.85 correspondingly. High temperature hot water or steam is supplied by the proposed cycle with a respectable COP, which will broaden the application scope of CO2 heat pumps in industries. Moreover, relationship between COP and the payback period is revealed under typical conditions to evaluate the benefit of the proposed system.

A Comprehensive Thermodynamic Assessment of Cascade Refrigeration System Utilizing Low GWP Hydrocarbon Refrigerants

The thermodynamic performance of a two-stage vapor compression cascade refrigeration system using hydrocarbon refrigerants is studied extensively in this study. The selection of hydrocarbon refrigerants for the cascade refrigeration system is conducted based on the molecular weight, freezing point, vaporization, density, global warming potential and ozone depletion potential. In the lower temperature circuit, Trans-2-butane (T2BUTENE) is utilized while Toluene (toluene), Cyclopentane (CYCLOPEN) and Cis-2-butane (C2BUTENE) are used on the higher temperature circuit. The performance of the system is evaluated considering three major operating temperature such as evaporator temperature, condensation temperature of lower temperature circuit (LTC), and condensation temperature of higher temperature circuit (HTC). Furthermore, comparisons between the presented work and the previous established work are conducted to show the improved performance of cascade refrigeration utilizing the hydrocarbon refrigerants. The results from the simulations suggest that highest COP and exergy efficiency is achieved when Trans-2-butane is employed in lower temperature circuit while Toluene is implemented on the higher temperature circuit. The results also suggest that the highest exergy destruction occurs at the condenser and the lowest can occur either at the lower circuit expansion valve or the evaporator for different refrigerant pairs. In addition, utilizing hydrocarbon refrigerants on cascade refrigeration systems can achieve a minimum 7.21 % higher COP than the recently employed refrigerants in previously established published works.

Thermodynamic assessment of a triple cascade refrigeration system utilizing hydrocarbon refrigerants for ultra-low temperature applications

• Triple cascade refrigeration system is implemented for ultra-low temperature applications. • System performance analyzed for hydrocarbon-based environment friendly refrigerants. • Temperatures of MTC and LTC condenser are evaluated for maximum COP values. • At different evaporator temperatures, better performance is gained by different pairs. • Heptane and Toluene are recommended in MTC for −120 °C to −110 °C, and −100 °C to −90 °C, respectively. This work presents a detailed thermodynamic analysis of a triple cascade vapor refrigeration system (TCRS) utilizing hydrocarbon refrigerants for ultra-low temperature application. Different hydrocarbon refrigerants pairs are used in different circuits (High temperature circuit HTC, Mid temperature circuit MTC, and Low temperature circuit LTC) to obtain the most suitable refrigerant combination by mathematical modeling of the system. The design and operating parameters considered in this study include (1) evaporator temperature (2) LTC condensation temperature (3) MTC condensation temperature. A thermodynamic analysis consisting of energy and exergy analysis were employed in terms of operating conditions to obtain COP, total compressor work, exergy efficiency, total exergy destruction, mass flow rate and discharge temperatures of compressors. Furthermore, an analysis on component exergy destruction was conducted to show the possibilities of improvement of TCRS utilizing the hydrocarbon refrigerants. The results suggest that at different evaporator temperatures different hydrocarbon refrigerants on TCRS give higher COP and exergy efficiency. The highest COP and exergy efficiency at −100 °C evaporator temperature was calculated to be 0.5931 and 54.446 %, respectively. This study also suggests that hydrocarbon refrigerants can be used in ultra-low temperature applications without compromising the thermodynamic performance of the refrigeration system.

Thermodynamic analysis of compressor operated resorption thermochemical energy storage system for heat storage, combined cooling and heat upgradation

A novel compressor operated resorption thermochemical energy storage system (CRTES) is proposed for heat storage, combined cooling and heat upgradation. The system uses halide salt-ammonia working pairs due to their wide working temperatures, high sorption capacity, and low cost. The CRTES system works on a simple resorption system during energy storage process and with a compressor during energy recovery process. The thermodynamic performance of the CRTES system is analyzed and compared for several halide salt pairs by considering the cooling temperatures of 5, 10, and 15 °C. The effect of variation in compression ratio and cooling temperature on heat up gradation, energy storage efficiency and COP of the CRTES system is studied. The highest degree of heat up gradation and energy storage efficiency are obtained using FeCl2-NaBr and SrCl2-KI, respectively. The higher COPs are obtained using KI as regenerating salt. The CRTES system based on FeCl2 and MnCl2 can be used for medium temperature energy storage (>100 °C) as the heat storage temperature is in the range of 153 to 176 °C. while the system based on SrCl2 and CaCl2 can be used for low temperature energy storage (≤100 °C) as the heat storage temperature is in the range of 84 to 93 °C.

Reasonable performance comparison for a refrigeration system using different refrigerants: Case with propane and isobutane mixtures with several compositions

Traditional refrigerants such as HCFC and HFC have a great influence on global warming. On the other hand, natural refrigerants have little impact on the environment, and low global warming potential (GWP) and zero ozone depletion potential (ODP) are key-characteristics of natural refrigerants. Hydrocarbon refrigerant is one of the natural refrigerants with higher COP than other natural refrigerants. Furthermore, performance improvement is promoted by mixing hydrocarbon refrigerants. Due to their characteristics, refrigerant mixtures have an advantageous heat exchange performance over a single refrigerant. Generally, refrigerant mixtures have temperature glide during phase change. Because of this, temperature difference can be maintained uniform during the heat exchange with secondary fluid. In this study, cooling cycle using isobutane/propane mixtures is researched to maximize the performance when changing mixing ratio by simulation. However, refrigerants with different isobutane ratios can be considered completely different refrigerants. Therefore, a good methodology is needed to compare performances of cycle. In this study, unlike previous studies, various methodologies are used to compare the performance of refrigerant mixtures. Also experiments for isobutane/propane mixtures were conducted. Various temperature conditions are used in the simulation study, and outdoor temperature of 35 °C and indoor temperature of 27 °C were used in the experiment to validate the simulation results.

New environment friendly working pairs of dimethyl ether and ionic liquids for absorption refrigeration with high COP

To overcome the limitations of absorption refrigeration system brought by commercial working pairs of NH3/H2O and H2O/LiBr for the utilization of low-grade heat, a new class of working pairs consisting of dimethyl ether (DME) and ionic liquids (ILs) are developed. The solubilities of DME in three ILs [BMIM][BF4], [BMIM][PF6] and [BMIM][Tf2N] were firstly measured and correlated. Then, COPs of the single-effect absorption refrigeration system (ARS) and absorption-compression hybrid refrigeration system (ACRS) using DME/IL were calculated under different conditions. The maximum COP of ARS using the three DME/IL working pairs can be up to 32.0% larger than that using NH3/H2O, while the maximum COP of ACRS using the three DME/IL working pairs can be up to 38.3% larger than that using NH3/H2O under studied conditions. The three DME/IL working pairs also show much better cooling performance than HFC/IL and HFO/IL working pairs which are R152a/[HMIM][Tf2N] and R1234ze(E)/[HMIM][Tf2N]. In ACRS, DME/ILs can drop the optimal generation temperature in ARS by more than 10 K. DME/ILs are very promising alternative absorption refrigeration working pairs due to the high COP, wide applicability and environmental friendliness.

Energy and exergy analysis of an absorption system with working pairs LiBr-H2O and Carrol-H2O at applications of cooling and heating

In this work, an air-cooled, single effect solar-driven absorption system is being evaluated from the point of view of 1st and 2nd thermodynamic principles for two different applications: absorption chiller and heat pump. One of the most widely used working pairs, LiBr-H2O, is applied in this study due to its high performance in the absorption cycle. Their performance is compared with another working pair Carrol-H2O (Carrol contains LiBr and EG -Ethylene glycol- with a mass ratio of 4.5:1). The Carrol solution has the advantage of reducing the crystallization risk at the high concentration solution that enters the absorber. The numerical modelling was implemented on a modular object-oriented simulation platform (NEST platform tool), which allows linking different components, considered objects. In the simulations performed, the heat source temperature in the system is in the range of 70–90 ∘C, and the inlet temperature at evaporator secondary circuit at chiller application is fixed in two values, 9∘C and 14∘C, and for heat pump application in 0∘C and -5∘C. Moreover, EG is added to the evaporator at heat pump application to prevent the refrigerant water from freezing below zero. The studied mass concentration range of EG of 10–40%. The result shows the COP of an absorption chiller and heat pump are around 0.7 and 1.6, respectively, and the COPEX values are 0.2-0.6 at chiller application and 0.5-1.5 at heat pump application. When compared with LiBr system, Carrol system has about 6.4% higher COP, about 6.3% higher COPEX, and a decrease of about 19% of cooling capacity. In the heat pump application, the heat source temperature should be lower than 90∘C, and EG concentration at evaporator has been chosen as 30% as an optimal value. According to the operation condition, this EG concentration has been determined to avoid freezing in the evaporator in the studied working range. However, too much EG significantly decreases the pressure in the evaporator and increases the viscosity, hence will increase the maintenance of equipment as more vacuum tightness is required.

Experimental Performance Analysis of R1234yf in an Air-Conditioning System as Substitute of R134a

In this work, R1234yf is tested in an air-conditioning system as a proposed alternative to R134a. The system is tested at 30, 35, 40, 45 and 50[Formula: see text]Hz evaporator fan frequency to cool the air entering into the evaporator section at a fixed temperature of 35∘C. The system is charged with 600, 700, 800, 1000 and 1200[Formula: see text]g of each refrigerant. The charge mass of 800 grams gives the best performance for both refrigerants. Also, R1234yf has higher COP, exergetic efficiency, second law efficiency, and lower compressor power consumption. Both refrigerants operate at a moderate range of compressor discharge temperature of 85∘C.

TRNSYS 16: A veritable solar modelling and programming simulation tool used in the design of a continuous solar powered adsorption refrigeration system

Project feasibility gave rise to the need for simulation. Simulation of a project leads to reduction in production cost, which ensures the success of the proposed project. Also, it provides initial design data for the experimental project. Thus, the design analysis and variables used for project simulation must be designed properly, revised, tested, and re-tested to guarantee how accurate the experimental design is. Hence, solar adsorption refrigeration system was designed, simulated and constructed using zeolite 4A/13X blend and water. The models were simulated using TRNSYS 16.0 simulation tool. From the result, it was observed that the collector area increases with increase in the system COP from month to month. The highest system COP of 1.53 was obtained in the month of April while the least was 0.4 for July due to frequent rainfall. Also, a much high COP was obtained for dry season while lower COP was gotten for harmattan season. Key words: TRNSYS, adsorption refrigeration, solar cooling, solar adsorption, adsorbent, solar concentrating collectors.

Thermal Performance Evaluation of the Variation of Condenser Dimensions for Foodstuffs Transportation Cooling Systems

The process of sending food using transportation requires a refrigeration system to keep the product fresh. Unsuitable temperatures will cause the transported products to often experience damage so that they are rejected in the mark. To achieve this, it is done through testing using a condenser with several variations of dimensions for a room temperature of 5oC. The dimensions of condenser-1 are (W 23 x H 14) inch2 x 19 mm, condenser-2 is (W 23 x H 14) inch2 x 26 mm, and condenser-3 is (W 23 x H 14) inch2 x 44 mm. The test results show that condenser-3 produces a faster cooling time compared to condenser-2 and condenser-1. Cooling time for condenser-3 is 1160 minutes, while condenser-2 and condenser-1 are 1560 minutes and 1860 minutes, respectively. Condenser-3 provides the lowest compression work of 42.131 kJ/kg compared to condensers 2 and 1, respectively 42.931 kJ/kg, and 46.147 kJ/kg. This has an impact on the COP value, namely condenser-3, condenser-2, and condenser-1 each of 3.437, 3.233, and 2.845. COP at condenser-3 occurs the highest. These results indicate that the largest condenser dimension gives the most optimum thermal performance results. An efficient refrigeration system has low compression work and high COP.

Experimental Analysis of the Vapour Compression Refrigeration System with Microchannel Condenser using R134a and R1234yf Refrigerant

Vapour Compression Refrigeration (VCR) system with high COP, low input power consumption and minimal exergy losses are of great research hotspot. The current research focuses on analysis of exergy and performance of vapour compression refrigeration (VCR) cycle is in a real-world application. Experiments were carried out in the VCR system using round tube condenser and microchannel condenser along with different refrigerants R134a, and R1234yf. Temperatures were varied from +20°C to 5°C for the evaporator and 40°C to 50°C for the condenser. Among the two refrigerants, experimental results show that refrigerants operating in micro-channel condensers have COP of 6% and 4%greater higher with5% and 3% lower exergy loss compared to the round tube condenser for R134a and R1234yf respectively.R1234yf appears to be a better equivalent for R134a, according to the findings. The efficiency defect in the condenser is the greatest and least in the evaporator for the coolants examined.