Conventional Refrigeration System Research Articles

Solar photovoltaic refrigeration system coupled with a flexible, cost-effective and high-energy-density chemisorption cold energy storage module

Owing to the environmental pollution and high costs associated with lead-acid batteries, this paper proposes a solar photovoltaic (PV) refrigeration system coupled with a flexible, cost-effective and high-energy-density chemisorption cold energy storage module. Its operation mode includes daytime solar PV refrigeration/cold energy charging mode and nighttime cold energy discharging mode. A novel composite sorbent SrCl2 is developed using expanded natural graphite as matrix and carbon coated aluminum as additive, exhibiting superior heat and mass transfer performance. A sorbent performance test bench is constructed, demonstrating that the cold energy storage density reaches 503.6 kJ/kg at an evaporating temperature of −15 °C, 1.5 times of ice storage. Compression-assisted desorption is adopted to regulate desorption temperature, so that 75–90 °C solar hot water from low-cost non-concentrating solar collectors can be utilized as the driving heat source. For an evaporating temperature of −10 °C and a solar hot water temperature of 90 °C, the electrical coefficient of performance for cold energy storage unit reaches 3.72, representing a 33 % improvement compared to conventional solar PV refrigeration systems. This novel system features characteristics such as low cost, high efficiency and eco-friendliness, offering a promising solution for solar refrigeration.

Simulation Study on Performance of Solar-Powered Desiccant Wheel and Ground Source Heat Pump Air Conditioning in Qingdao

In China, a large amount of the total energy consumption is made up of building energy, particularly in humid regions. The conventional vapor compression refrigeration systems cannot effectively control the indoor humid and thermal environment. Therefore, this article proposes a solar-powered desiccant wheel and ground-source heat pump (SDW-GSHP) air conditioning system. The energy consumption of the system is mainly from sustainable sources of solar and geothermal energy, showcasing excellent energy efficiency and environmental friendliness. The desiccant wheel (DW) processes latent heat loads, and the GSHP processes the sensible heat load. The regeneration air of the DW is heated by a solar collector. The operational performance of the system was simulated by using TRNSYS during the typical summer week (15 July to 22 July) in Qingdao. The simulation results indicated that indoor temperature was maintained within 25.8–26.2 °C and the relative humidity was maintained in the range of 57–61%. The COP of the SDW-GSHP air conditioning system was 42.1% higher than that of the DW air conditioning system with electric heating regeneration, and electricity saved 43.7%.

Research on performance of jet refrigeration cycle driven by waste heat of refrigerated vehicle

Nowadays, refrigerated food storage and transport vehicles are very common. However, with regard to the engine of vehicles, a significant amount of heat is discharged into the environment in the form of exhaust gas and jacket water. If the cooling system is used to convert this waste heat into cooling capacity, the thermal efficiency of the engine will be improved to a certain extent. Therefore, this paper uses two waste heat recovery jet refrigeration systems to recover heat from the exhaust gas and jacket water of the refrigerated vehicle. One is a conventional jet refrigeration system that uses only engine exhaust as the heat source, and the other is a system that adds a preheater upstream of the generator based on the conventional system, using engine jacket water to preheat the working fluid. This paper presents the results of comparing the impact of R141b/R123, R141b/R245fa, R142b/R134a, and R142b/R152a working fluids on system performance, and considers the effects of operating temperature and secondary flow pressure drop in the ejector receiving chamber on the system performance. The research results indicate that of the four selected working fluids, the R141b/R245fa (0.4/0.6) blend has the best overall performance. After the addition of a preheater, the system using R142b/R134a (0.6/0.4) hybrid working fluid achieves the maximum cooling capacity of 16.0994 kW and the maximum thermal efficiency of 5.45%, and the exergy loss in the generator is 1 kW lower than without the preheater.

Experimental and numerical study on a heat-driven direct-coupled Stirling refrigerator

As an environmentally friendly refrigeration system, the heat-driven Stirling refrigerator, which has demonstrated high efficiency and promising application prospects, is receiving significant attention for utilizing the waste heat to generate the cooling capacity. In this study, a heat-driven direct-coupled Stirling refrigerator, featuring an engine unit and a refrigeration unit directly coupled through a thermal buffer tube rather than utilizing a piston-based mechanism, is designed and tested. In comparison to the conventional heat-driven Stirling refrigeration systems, the proposed system exhibits the potential for significantly increased reliability and simplicity. Simulations and experiments were carried out to investigate the output characteristics of the system under different heating temperatures and mean pressures. The results show that higher heating temperature is beneficial for producing the acoustic power, thereby increasing the cooling capacity, with the mean pressure among 2.7–3.2 MPa. In the experiments, the system can provide a cooling capacity of 363W with a coefficient of performance of 0.17 when the heating, ambient, and cooling temperatures are 250, 35, and 7 °C, respectively. The results have validated the feasibility of the heat-driven direct-coupled Stirling refrigerator, which is a potential alternative for air-conditioning through waste-heat recovery.

Conceptual design and analysis of a tricycle mounted solar-powered photovoltaic cold room system

Energy crisis in developing countries is worrisome, and this has made the preservation and transportation of medical and perishable food items a common problem. Most conventional refrigeration systems operate with electricity; however, there are regions where it is difficult or not cost efficient to provide electric service. Therefore, this research seeks to solve the problems of inconsistent, irregular and complete non availability of power supply required to keep food products and drugs refrigerated over a long period of time by designing a tricycle mounted solar-powered cold room. The tricycle mounted solar-powered cold room designed consists of a refrigeration system having a compressor, a condenser, an expansion valve and an evaporator; a solar system having a photovoltaic (PV) module, charge regulator, storage battery and DC to AC inverter; and a tricycle for easy distribution and safe delivery of refrigerated items. A comprehensive analytical design was performed on each of the systems and the design results showed that the solar-powered cold room has refrigerating cooling load, PV array size, battery cap, and inverter power of 986 W, 275 W, 94 kWh, and 8000 W respectively. A structural analysis was also carried out on the tricycle chassis using the finite element method on Autodesk Inventor software. The results showed that the maximum von misses stress experienced by tricycle chassis was 56.96 MPa which is significantly lower than the yield strength of the chassis material used in the design, indicating a robust structural integrity and can therefore be used to carry the loads that it will be subjected to without deformation.

Performance analysis and optimization of a solar assisted heat pump-driven vacuum membrane distillation system for liquid desiccant regeneration

Liquid desiccant air-conditioning (LDAC) system is one of the excellent alternatives to conventional vapor compression refrigeration system due to its great energy-saving potential. However, regeneration of diluted liquid desiccant is the main energy-consuming process, and its performance plays a significant role in LDAC system. Recently vacuum membrane distillation (VMD) is becoming an emerging and promising separation process rely on the advantage of high permeate flux and low energy losses. The interest of usage solar energy techniques for feed solution heating in VMD systems is regarded as a sustainable path for membrane distillation process. In this work, a solar-driven VMD system incorporating a vapor-compression heat pump for liquid desiccant regeneration is introduced. An adapted solar/heat pump hybrid heating strategy has been devised to establish a connection between the heat-demanding process and the solar thermal supply. A comprehensive multicriteria assessment of energy, exergy, and environmental evaluation is conducted, and the influences of crucial parameters on both key components and system performance are evaluated to ensure a systematic examination. Results show that both the COP and STEC decrease obviously with the growth of the inlet solution temperature, whereas SEEC is improved abviously from 410.6 kW·h/m3 to 566.1 kW·h/m3 due to the effect of heat pump. The exergy analysis indicates that exergy losses in solar collector and stratified heat storage tank accounted for over 80 % of the total exergy losses. Additionally, single-objective optimization and multi-objective optimization are employed to explore the optimum operating conditions of key componets and whole system. Results show the ideal optimal solution can be obtained with a COP of 19.92 and a SEEC of 142.89 kW·h/m3 when the weights of COP and SEEC are taken as [0.5, 0.5].

Investigation of Solar Powered Single Effect Absorption System

Cooling processes like refrigeration and air conditioning are known for their high energy consumption. Since most Indian states experience abundant sunshine year-round, solar refrigeration is a suitable technology for the country. Solar-powered absorption refrigeration systems offer a viable alternative to traditional refrigeration, providing not only cooling and ice-making capabilities but also energy savings and environmental benefits. However, further research is necessary to enable widespread industrial adoption and the replacement of conventional refrigeration systems with solar powered absorption system. Using solar energy for an air-conditioning system is typically more cost-effective, when it can fulfil both heating and cooling needs. This research focuses on the thermodynamic modelling of a system, specifically the effect of various temperature on COP. Thermodynamic modelling was done with the help of first law of thermodynamics. Using engineering equation solver software, study simulated the cycle and equations were developed for energy and mass flow for each component. Further, before proceeding to analysis some assumptions were also made. We then analysed how the Coefficient of Performance (COP) changed when varying the temperatures across each component. Our findings show that COP increases with increase in condenser, evaporator, and absorber temperatures, but it is declined with decrease in generator temperature.

EFFECT OF SiO2 AND ZnO NANOPARTICLES TO INCREASE REFRIGERATION MACHINE PERFORMANCE

In this investigation, the impact of silicon dioxide (SiO2) and zinc oxide (ZnO) nanoparticles on the performance of a refrigeration machine system was systematically examined. The focus was on evaluating the coefficient of performance (COP) concerning the utilization of a polyolester (POE) lubricant, R600a refrigerant, and distinct nanoparticles (SiO2 and ZnO) within the refrigeration system. The nanoparticles were individually introduced into the R600a refrigerant in masses of 0.5 g, 1.0 g, and 1.5 g. The experimental outcomes demonstrated a noteworthy enhancement in COP with the addition of nanoparticles. Specifically, the introduction of 1.5 g of SiO2 resulted in a substantial increase of 25.88% in COP, marking it as the most influential dosage. Similarly, the addition of 1.0 g of ZnO led to a significant COP increase of 13.6%, representing the optimal quantity for ZnO. Furthermore, the inclusion of 1.5 g of SiO2 brought about a remarkable reduction in energy consumption, with a decrease of 25.58%, while 1.5 g of ZnO resulted in a notable 16.28% decrease in energy consumption. The experimental configuration involved the use of 20 g of refrigerant and 500 ml of POE lubricant. Comparative analysis demonstrated that the refrigeration system incorporating nanoparticles outperformed the conventional R600a refrigeration system devoid of nanoparticles. This study contributes valuable insights into the potential enhancements in refrigeration system efficiency through the strategic incorporation of SiO2 and ZnO nanoparticles, offering a promising avenue for optimizing the performance of refrigeration technology.

Performance improvement potential of ejector-based dual-evaporator refrigeration system using photovoltaic modules and nano-refrigerant

This paper presents a novel system for resolving the high energy consumption of conventional vapor compression refrigeration systems. An ejector-based dual-evaporator refrigeration system (EDERS) is developed utilizing photovoltaic (PV) modules and a nano-refrigerant (NR) with 0.5 wt% of Al2O3. This novel arrangement combines four promising environmentally friendly technologies: dual-temperature cycle, ejector, PV panel, and NR. The comprehensive thermodynamic analysis and optimization of the proposed system, energetic and exergetic analysis methods are incorporated to evaluate the performance of nanoparticle (NP)-doped EDERS in this study. The results demonstrate that the use of Al2O3 NP compared with utilizing pure R134a EDERS notably improves performance under typical operating conditions. Specifically, the coefficient of performance (COP), volumetric cooling capacity, and exergy efficiency (ηex) are 7.14 %, 4.33 %, and 8.91 % higher, respectively. Moreover, the compressor power and total exergy destruction are 6.76 % and 9.94 % lower, respectively. Additionally, under the operating conditions considered in this study, the required PV area is reduced by 5.31 %–8.07 %, whereas the COP and ηex values improve by 5.64 %–8.39 % and 5.38 %–10.06 %, respectively. The study also finds that the COP and ηex values of (R600a + Al2O3) surpass those of (R134 + Al2O3), whereas the COP and ηex values of (R1234ze(E) + Al2O3) and (R1234yf + Al2O3) are smaller than those of (R134 + Al2O3). This suggests that the performance benefits of NPs may vary depending on the specific refrigerant used in the system. The results can be employed as a useful guide for the application of NRs to multi-evaporator refrigeration systems before setting up an experimental system.

Ultra-Low-Temperature Refrigeration Systems: A Review and Performance Comparison of Refrigerants and Configurations

During the last decade, many industrial and medical applications have shown a requirement for low-temperature-cooling usage (from −40 to −80 °C), which cannot be efficiently obtained via the conventional refrigeration systems usually employed for medium-temperature applications (from 0 to −40 °C). A proper ultra-low-temperature (ULT) refrigeration system design is essential to achieve the desired output. The performance can be maximised via the suitable selection of the configuration and refrigerant for a specific temperature range. This work contributes a detailed overview of the different systems and refrigerants used in ultra-low-temperature applications. Different systems, such as single-stage vapour compression, multi-stage, cascade, auto-cascade, and air refrigeration cycles, are presented and discussed. An energy analysis is then carried out for these systems identifying the optimal system design and refrigerant selection to achieve the highest performance. This paper aims to provide the reader with a comprehensive background through an exhaustive review of refrigeration systems suitable for ultra-low-temperature applications. The effectiveness of these systems is proven numerically, mainly based on the temperature level and purpose of the application.

EN Energy efficiency improvement for the older reefer vessel by the combined compression-ejector refrigeration machine

A marine combined compression-ejector refrigeration machine that comprises conventional refrigeration and air-conditioning system using single-stage refrigeration machine and an ejector refrigeration machine is proposed and studied. The ejector refrigeration machine is driven by the waste heat from the single-stage refrigeration machine and acts as the bottom cycle of the single-stage refrigeration machine. A system analysis shows that the COP of a compression-ejector refrigeration machine is significantly higher than a one-stage refrigeration system. Improvement in COP can be as high as 19.3% for evaporating temperature of the single-stage refrigeration machine Tc at -40°C. Influence of flowing part of ejector profile, operating parameters, scheme and cycle of the marine combined compression-ejector refrigeration machine on its performance characteristics is shown. Rational methods to increase efficiency of marine combined compression-ejector refrigeration machine, operating with environmentally friendly low-boiling refrigerant R245fa, are offered and investigated. The present study shows that the combined compression-ejector refrigeration machine using the ejector refrigeration machine as the bottom cycle of the one-stage refrigeration machine is viable. The opportunities of implementing solar panels, raised challenges for older reefer vessels (20-40years) force to analyse situation. While opportunities exist for efficiency improvement and environmental alignment, challenges in retrofitting older vessels, especially those nearing the end of their operational life, make economic viability a critical consideration. The analysis of the possible solar panel application estimates a cost range of 398,269.20 to 426,717.00 euros, emphasizing the need for careful evaluation. The conclusion advocates against implementing solar panels on the researched vessel, highlighting the lack of justification in both economic and operational efficiency aspects

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

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

Thermodynamic and economic evaluation of a non-cascaded dual-temperature compression–absorption–resorption refrigeration system

Thermal processes in many industries require simultaneous cooling at multiple temperatures, highlighting the need for an efficient and cost-effective dual-temperature refrigeration system. This study proposes two novel non-cascaded dual-temperature ejector-assisted compression–absorption–resorption refrigeration cycles (ECARC) to deliver simultaneous refrigeration effects at -5°C and 7°C. These cycles are classified based on the compressor staging with an ejector as ECARC-1 and ECARC-2. The performance simulations of the proposed cycles were carried out at the design conditions and a detailed parametric study was performed to determine the influence of the key operating parameters on the first and the second law coefficients of performance. The proposed novel cycles are more efficient and utilise heat more effectively by consuming up to 60 % less electricity than the conventional multi-evaporator compression refrigeration system, for the same operating conditions and refrigeration capacity. These cycles are also more cost effective with a reduction in their unit production cooling cost by up to 50 % and 25.5% as compared with the state-of-the-art double-effect absorption refrigeration system and the multi-evaporator compression refrigeration system, respectively. Thus, the proposed cycles show excellent thermal and economic advantages for a potential dual-temperature refrigeration system, and the development of these systems contribute towards the decarbonisation of the industrial cooling and heating sector.

Optimization and thermo-economic performance of a solar-powered vapor absorption cooling system integrated with sensible thermal energy storage

Higher demand for refrigeration systems adversely affects power grids, causing blackouts, increased electricity expenses, and carbon emissions. However, using renewable energy thermally driven refrigeration absorption systems is a promising alternative. The higher initial cost and dependency on local weather, large space area for installation, and complex design are hurdles for the widespread of these systems compared to the conventional vapor compression refrigeration systems. This study uses response surface methodology to model a real vapor absorption machine (VAM) incorporated with the measured data. This VAM is the refrigeration machine of a solar-powered absorption cooling system (SPACS) integrated with thermal energy storage for milk chilling installed and operated in Jaipur (India). The weather data for 2022 is used in performance and productivity analysis in this study. The results show that most of the summer months, the system can produce desired cooling to take down the 1000 l of milk within 3 h as per standards ISO 5708 – 2 II. Moreover, the solar loop still has sufficient driving heat to charge the 1000 l cold storage tank/another milk tank. During winter days, it takes a significant system response time (SRT) to reach the thermal energy storage (TES) up to 95 °C; after that, VAM operates significantly underperforming due to weak solar insolation; even the system cannot provide cooling to the first milking. The system produces monthly cooling energy of up to 2356 kWh in summer and is reduced to 620 kWh during monsoon and winter. The maximum value of the coefficient of performance (COPVAM) is achieved as 0.55 with an average of 0.41–0.46 during summer months whereas 0.34–0.39 during monsoon and winter days. The system's energy efficiency ratio (EER) ranges from 2.5 to 6.5, with an overall average of 4.55, which is far better than the conventional vapor compression refrigeration systems. The LCOE for the SPACS has been estimated to be 0.177 $/kWh, whereas the simple payback period is 12.4 years, and the discounted payback period is 19.7 years.

Performance Evaluation of LiBr-H2O and LiCl-H2O Working Pairs in Compression-Assisted Double-Effect Absorption Refrigeration Systems for Utilization of Low-Temperature Heat Sources

To improve the performance of conventional double-effect absorption refrigeration systems (DEARS), new series parallel (SP) and reverse parallel (RP) configurations using LiCl-H2O and LiBr-H2O as working fluids, combined with two vapor compressors (VC), are proposed and thermodynamically evaluated. The effects of the distribution ratio (D) and compression ratio (CR) on the system performance are discussed. The results reveal that both configurations can extend the operation ranges of DEARS effectively at a higher distribution ratio, and the performance for low-grade heat source utilization is improved substantially by the use of VC. The compressor positioned between the evaporator and absorber is superior to that between the high-pressure generator and low-pressure generator because of the better performance improvement and larger operating ranges. In all the examined cases, LiCl-H2O systems perform better than LiBr-H2O systems in terms of the coefficient of performance (COP) and exergetic efficiency. At the higher CR of approximately 2, the compression-assisted DEARS can be driven by heat sources below 100 °C with high levels of COPs above 1.16 for the LiBr-H2O working pair and 1.29 for the LiCl-H2O working pair. The system can operate at the optimum condition by adjusting the CR values according to the characteristics of the heat sources.

Comparison of an absorption-compression hybrid refrigeration system and the conventional absorption refrigeration system: Exergy analysis

This paper presents an exergy analysis considering different operating conditions of an alternative configuration of an ammonia-water hybrid absorption refrigeration system, where part of condensation heat is recovered and supplied to generator (RCHG-ARS). In order to identify and quantify the irreversibilities in each component of the cycle and its variations, the exergy efficiency and the relative exergy loss of the system were evaluated. Moreover, the results obtained were compared with those obtained by the conventional ARS cycle. Furthermore, the effect of the internal heat exchanger effectiveness on the exergy efficiency and relative exergy loss was analyzed. The results indicate that the generation temperature and the exergy efficiency of the RCHG-ARS cycle decrease in 24 °C and 30%, respectively, it in comparison to ARS cycle at the conventional generation pressure (11.67 bar). However, to decrease the generator pressure at 5.94 bar, the evaporation temperature for the RCHG-ARS decreases in 19.3 °C and the exergy efficiency can be 0.20% higher than the obtained with the ARS cycle. It is also revealed that the exergy efficiency for the RCHG-ARS cycle become more significant at lower condensing and evaporating temperatures as well as lower generator pressures and higher internal heat exchanger effectiveness respect to ARS cycle. Moreover, the minimum values of relative exergy losses are obtained at higher generator temperatures or lower evaporating and condensing temperatures in the RCHG-ARS cycle. Finally, it can be concluded that the main components that increase the relative exergy destruction in the RCHG-ARS cycle are the generator, absorber and the compressors.

Performance enhancement of absorption refrigeration systems: An overview

The introduction of absorption refrigeration technology addressed several significant con-cerns in the domain of energy crisis, rising cost of fossil fuel, and ecological challenges aris-ing due to the excess use of traditional compression refrigeration systems. ARS (absorption refrigeration system) is gaining popularity as a result of benefits such as the use of low-grade heat sources and environmentally acceptable low-cost working fluid pairs. However, two sig-nificant hurdles to commercial success for this technology are the often too big size of the refrigeration system and the poor performance of the system. Numerous studies have been conducted in an attempt to discover methods for improving the COP (coefficient of perfor-mance) of ARS in order to get these systems more competitive in comparison to the conven-tional compression refrigeration systems. The goal of this article is to perform a review of the literature on different methods used to enhance the COP of ARSs based on cycle layout mod-ification and working pair selection as they are the promising solutions for the enhancement of the performance of ARSs. The futuristic aspect of this technology includes the introduction of new working pairs with no corrosion to the system components, including nanoparticles to increase heat transfer rate while reducing the cost of the system. Heat recovery methods should be introduced and the efficient design of various components especially the generator and absorber are to be addressed. This technology could be combined with other refrigeration technologies while utilizing the waste heat to further improve the efficiency of ARSs.

Investigative comparison of R134a, R290, R600a and R152a refrigerants in conventional vapor compression refrigeration system

This work represents the performance comparison of conventional vapour compression refrigeration system (VCRS) using various refrigerants such as R134a, R152a, R600a and R290. The theoretical model has been utilized for computing work input to the compressor, refrigerating effect and coefficient of performance (COP) for R134a, R290, R600a and R152a refrigerants. This investigation has been done for the evaporator temperature range of -30 °C to 10 °C and the condenser temperature range of 40 °C to 45 °C. In this performance analysis it is seen that R290 shows favourable properties and can serve as best refrigerant among all in the group. R290 shows almost equal COP to R600a in large operating temperature range and it has very high refrigerating capacity comparatively to R134a together with its low global warming potential and ozone depletion potential. R152a and R600a also show some satisfying properties.

Theoretical analysis of three CO2/C3H8 (R744-R290) cascade refrigeration systems with precooling processes in low-temperature circuits

In a cascade refrigeration system (CRS), the superheat of the vapour discharged from a low-temperature compressor is large for refrigerants with significant adiabatic exponents, and part of the cooling heat in the fluid can be removed using precooling technology. In this study, three CO2/C3H8 cascade refrigeration systems with precooling processes, namely a CRS with an air precooler (CRSA), CRS with a mechanical precooler (CRSM) and CRS with both an air precooler and a mechanical precooler (CRSAM), are proposed. The performances of the proposed systems are compared studied that of a conventional cascade refrigeration system (CCRS) in terms of energy and exergy. The results indicate that a design that arrange precoolers and precooling refrigerant circuits in low-temperature circuits is beneficial, directly reducing the work input of C3H8 compressors and improving refrigeration performance. When the condensing temperature rises from 12 °C to 48 °C, the coefficient of performance (COP) of the CRSA, CRSM and CRSAM enhances by 2.73% to 5.19%, 1.82% to 4.90% and 3.71% to 7.86% compared with the CCRS, and the exergy efficiency averagely improves by 4.01%, 3.41%, and 8.48%, respectively. In addition, the applicable conditions of the different systems are discussed, and the component cost is evaluated in terms of component capacity. The research results may provide guidelines for the practical application of CO2/C3H8 CRS with precooling processes.

Performance of Solar Hybrid Cooling Operated by Solar Compound Parabolic Collectors under Weather Conditions in Riyadh, Kingdom of Saudi Arabia

The scientific aim of this work is to encourage energy conservation. This article offers a fresh perspective on renewable energy in the air conditioning sector, the country’s economic growth, and environment-friendly techniques to overcome global warming challenges. In this research, a solar vapor absorption refrigeration (SVAR) system was combined with a conventional vapor compression refrigeration (VCR) system to analyze their combined performance, employing a compound parabolic collector (CPC). The goal was to assess the performance of a solar hybrid cooling system using this non-tracking solar collector. CPC was validated for heat output with 2.9% uncertainty by utilizing an engineering equation solver (EES). Other system components were also validated with EES and then extended to a larger-capacity solar hybrid cooling system. The results of this research indicate that CPC is effective in providing the required heat to SVAR throughout the year without any tracking, and the integration of SVAR in series with the VCR condenser produces 83% higher COP than the system that integrates VCR with the condenser of the SVAR system for Riyadh. The configuration results in high values of exergy COP and an efficiency of 88% and 84%, respectively, increases the cooling capacity of the VCR by 68%, and decreases the carbon emission by 166.4%.