Performance Of Refrigeration System Research Articles

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.

Performance analysis of a refrigeration system integrated with a thermoelectric cooler and microchannels in terms of heat transfer using a hybrid nanofluid

Advancements in chip technology increase energy consumption due to larger chip capacity, leading to intensive heat flux generation. Cooling solutions, including fan-only, fan-conventional heat sink (HS), or fan-conventional HS-heat pipe (HP) integrated systems, face penalties such as noise, dust accumulation, high electricity usage, space constraints, and thermal limitations of the working fluid. While thermoelectric coolers (TEC) have advantages like compactness and noise-free operation, they alone are insufficient for cooling sophisticated chips; combining them with microchannel heat sinks (MCHS) and superior fluid is crucial for achieving faster and more efficient cooling. Considering previous studies involving TECs used alone, with conventional fluids integrated into MCHS, and with a mono-nanofluid integrated into MCHSs, this is the first study to consider a TEC integrated with two MCHSs and to use a ZnO-TiO2/water hybrid nanofluid to maximize the performance of this miniature refrigeration system. Accordingly, an experimental study was carried out on the aforementioned refrigeration system using various concentrations (φ) of ZnO-TiO2/water hybrid nanofluid for different flow rates, utilizing both conventional heat transfer and the TEC’s mathematical operating principle. The results were interpreted via Reynolds number, Prandtl number, heat transfer rate, Nusselt number, total thermal resistance, and coefficient of performance (COP). The increase in φ from 0% to 0.03%, accompanied by a decrease in flow rate from 16 × 10−5 m3/s to 9 × 10−5 m3/s, increased the heat transfer rate for the heat-absorbing and the heat-emitting sides of the refrigeration system from 19.510 W to 45.794 W, and 13.639 W to 22.406 W, respectively. The experimental COP for pure water was 0.325 at the lowest volume flow rate, but increased to 0.934 at a φ of 0.030%. Considering the thermal characteristics, this study demonstrates that the proposed system is particularly advantageous at low flow rates and high φ, making it a potential candidate for electronic circuit cooling. Considerations such as investigating certain material properties to allow for further improvement of the proposed system were offered.

Development of Artificial Neural Network Model to Predict the Performance of R-290 Water Cooler Refrigeration System

Development of Artificial Neural Network Model to Predict the Performance of R-290 Water Cooler Refrigeration System

Experimental evaluation of a vapour compression refrigeration system using a nano-oil mixture of TiO2, Al2O3, and SiO2

Nanolubricants were used to improve the performance of refrigeration systems in a household refrigerator. In this study, a pure lubricant is used as the base compressor lubricant, and nanoparticles of TiO2, Al2O3, and SiO2 at 0.4g/L concentrations are used as nanolubricants in 50g isobutane (R600a) refrigerants. Power consumption was investigated alongside the COP. TiO2 nanolubricant has the highest COP of 2.8 and the lowest power consumption of 11.3% when compared to based lubricant. However, in terms of power consumption, SiO2 and Al2O3-nanolubricant outperformed the based lubricant by 4.5% and 7.7%, respectively. This suggests that a nanolubricant could be used in a refrigeration system to replace a based lubricant with R600a refrigerant.

An examination of the vapour compression refrigeration system performance utilizing several environmentally friendly refrigerants and the effect of nanoparticles- a review

The refrigeration system stands out as a significant contributor to the escalating trend in energy consumption. Therefore, implementing energy-saving measures is considered one of the most effective strategies for addressing this challenge. Nanofluids demonstrate remarkable promise in enhancing refrigeration systems' thermodynamic and mechanical efficiency. In contemporary times, there is a global emphasis on exploring nano refrigerants to enhance the heat transfer properties of cooling systems. Household and industrial refrigeration systems commonly utilize Hydrofluorocarbons (HFCs) because of their exceptional thermodynamic attributes. Nevertheless, the Kyoto Protocol has classified HFCs as contributors to global warming because of their high (GWP) value, which stands at 1300., their improved Coefficient of Performance (COP), and, critically, a lower GWP while having zero Ozone Depletion Potential (ODP). Integrating nanoparticles with high thermal conductivity into traditional refrigerants has revealed compelling outcomes. These include heightened heat transfer coefficients, enhanced (COP), and reduced energy consumption by compressors in household refrigerators. This article explores the use of environmentally friendly refrigerants and the impact of nanoparticles on refrigeration systems.

Experimental investigation on the influence of electronic expansion valve opening on the performance of miniature refrigeration system

In the cooling of personnel and electronic equipment under specific conditions, the miniature refrigeration system needs to provide different cooling capacity to adapt to different working conditions. At present, most scholars use capillaries as throttling components. Compared with capillaries, miniature refrigeration systems using electronic expansion valves as throttling components can provide a wider range of cooling capacity adjustment. Therefore, this study constructed a miniature vapor compression refrigeration system based on electronic expansion valves as throttling devices, with a system weight of 3.0 kg and dimensions of 380 mm × 300 mm × 200 mm. The experiment investigated the impact of electronic expansion valve opening on compressor power, cooling capacity, and COP under different refrigerant charge conditions. Results indicated that at an electronic expansion valve opening of 90, within the experimental range, there was a relative change in cooling capacity of 39.85 % and a relative change in COP of 29.11 % as the refrigerant charge increased. Refrigerant charge had a significant effect on the cooling capacity and COP of the miniature refrigeration system. Under the optimal refrigerant charge of 70 g, within the experimental range, there was a relative change in cooling capacity of 88.14 % with varying electronic expansion valve opening. The use of electronic expansion valves as throttle components in miniature refrigeration systems allows for a wider range of cooling capacity adjustments, making them suitable for more cooling conditions.

Energy, exergy, environmental and exergoeconomic (4E) analysis of an ultra-low temperature cascade refrigeration system with environmental-friendly refrigerants

To ensure the efficacy of some special vaccines, the ultra-low temperature storage below −80 °C is strictly required and the classical cascade refrigeration system has a good application prospect in the production, storage, transportation and distribution of COVID-19 vaccines. Previous investigations are mainly focused on the thermodynamic performance of cascade refrigeration cycles (CRSs) to generate low temperature, and the impact of cascade refrigeration cycles on environmental and exergoeconomic aspects is few involved. In this paper, an energy-exergy-environmental-exergoeconomic (4E) analysis model was built to investigate the comprehensive performance of an ultra-low temperature cascade refrigeration system. Eight environmental-friendly refrigerant pairs, including R290-R170, R290-R1150, R717-R170, R717-R1150, R1270-R170, R1234yf-R170 and R1234yf-R1150, were chosen and the associated refrigeration performance was compared. The results show that the optimal refrigerant pair is propane-ethane (R290-R170). Compared with HFC refrigerant pair R404A-R508B CRS, R290-R170 CRS could improve the COP by 5.94%, save 5.68% power consumption, reduce 29.67% carbon dioxide emission and decrease 5% exergy economic cost. This work is significant to select environmental-friendly nature refrigerants, enrich understanding of comprehensive performance of cascade refrigeration system and enhance depth research on ultra-low temperature refrigeration.

Assessment of booster refrigeration system with eco-friendly working fluid CO2/halogenated alkene (HA) mixture for supermarket application around the world: Energy conservation, cost saving, and emissions reduction potential

For the scope of commercial supermarkets, the demand for energy efficiency improvement and environmentally-friendly working fluid of the refrigeration system is necessary. In this study, supermarket booster refrigeration system by using eco-friendly working fluid CO2/halogenated alkene (HA) mixture is proposed, and the mixture used in systems with two evaporation temperatures and operating modes affected by ambient temperature are studied. The energy efficiency, economic performance and emission reduction potential of the whole life cycle are conducted to compare with the pure CO2 booster refrigeration system. Furthermore, the influence of climate condition is discussed when used in 40 typical cities around the world. The results show the coefficient of performance (COP) of booster refrigeration system can be significantly improved by using CO2/HA mixtures. As the ambient temperature is 33 °C, the CO2/R1234yf (93/7) operates with the maximum COP of 1.367, which is 11.59 % higher than that of pure CO2. Using CO2/HA mixtures in the booster refrigeration system can significantly improve the exergy efficiency of system. Moreover, the system using CO2/HA mixtures has higher annual performance factor and lower life cycle cost (LCC) than pure CO2. LCC of the system using CO2/R1234yf (94/6) is the lowest, and the reduction rate is 3.06–5.59 %. Meanwhile, the life cycle carbon emissions of systems in different climatic regions using CO2/R1234yf can be reduced by 2.39–5.21 %. The booster refrigeration system adopting CO2/HA mixtures is a promising alternative solution for commercial supermarket refrigeration and energy-saving.

Experimental and theoretical analysis of the solar adsorption refrigeration system under south Iraq climate condition

This study investigates the performance of a solar adsorption refrigeration system utilizing activated carbon and methanol as the adsorbent/adsorbate combination in the context of the climate conditions in southern Iraq. The primary aim is to develop an efficient and environmentally friendly refrigeration technology that can operate off-grid, particularly in regions with limited access to electricity. Through a combination of experimental trials and theoretical analysis, the research explores the impact of factors such as solar radiation intensity, collector design, and operational parameters on system efficiency. The findings reveal that the tubular form of the collector/adsorber enhances system performance by simplifying maintenance and reducing the risk of leaks. Additionally, the study demonstrates the system's capability to cool water significantly, showcasing its potential for practical applications. The key contribution of this research lies in its innovative approach to solar refrigeration technology, offering a sustainable solution for cooling needs in challenging environments. The solar-driven refrigerator achieves a COP of 0.38 (ambient 30 °C) using 5.5 kg of carbon and 0.24 kg of methanol. Collector efficiency reaches 43 % under peak sun (847 W/m2), with a theoretical maximum of 51 % (1000 W/m2). The refrigerator cools 1 L of water from 30 °C to −0.6 °C, demonstrating its potential for sustainable refrigeration and reduced reliance on fossil fuels. These findings contribute to advancing solar-driven refrigeration and reducing reliance on fossil fuels. To counteract climate change, this work lays out a practical road towards sustainable refrigeration.

Exploring refrigeration system performance with solar-powered mechanical porous sub-cooling

Exploring refrigeration system performance with solar-powered mechanical porous sub-cooling

Thermal analysis of solar energy based organic Rankine cycle cascaded with vapor compression refrigeration cycle

The air conditioning and refrigeration applications use a significant portion of the electrical energy. This research analyses a performance of refrigeration system, which comprises on different configurations of solar based organic Rankine cycle (ORC) and vapor compression refrigeration (VCR) cycles requiring low evaporation temperatures. In this research, the dry natural hydrocarbons such as n-Decane, n-Dodecane and Toluene have been chosen to serve as the working fluids in ORC. Whereas in VCR cycle natural hydrocarbons such as Ethane, Propane, isobutane, isopentane and isohexane have been used because traditional working fluids have a negative environmental impact due to high values of ozone depletion and global warming potential. The simulated results showed that the facility can be operated efficiently with the use solar thermal energy resources within the temperature range 90 to 315ºC and decreasing the need for conventional fossil fuel resources. It was also revealed that the highest efficiency was achieved by n-Dodecane in regenerative ORC, which is 35.34 % at the evaporation temperature of 315ºC and the highest overall coefficient of performance (COPoverall) in regenerative ORCCRS facility was achieved by n-Dodecane in ORC and isopentane in refrigeration cycle which is 1.017 while in case of Simple ORC–VCR facility the highest COPoverall was achieved by Toluene in ORC and isopentane in refrigeration cycle, which is 0.7174 at the evaporation temperature 315ºC.

Sustainability and operational performance assessment of supermarket air-conditioning architectures using secondary fluids and slurries

Secondary loop architectures and phase change material (PCM) slurries could reduce the environmental impact of refrigeration and air-conditioning systems by lowering significantly the amount of primary refrigerants. However, there is a barrier to their industrial development due to the lack of studies on their behaviour in operational scenarios. The present work analyses the behaviour of different secondary loop systems in an industrial context, here the air conditioning of a supermarket in France. For this purpose, a generic approach, developed in previous work, is proposed to assess their potential of adoption. This modelling approach is able to describe the sustainability and operational performance (energy, environmental, economic, social) of refrigeration systems. After validation of the model on real architecture and components, five standard or new architectures were tested: centralized direct expansion system; secondary loop system with ethylene glycol water; secondary loop system with ice slurries, TBPB hydrate slurries or CO2 hydrate slurries. The main results of this study show that new secondary systems using hydrate slurries have better cooling energy performance than direct expansion or classical brine / ice slurry secondary systems. Moreover, even including pumping power, the life cycle climate performance of secondary loop systems is much better than that of direct expansion systems. However, the total cost of ownership of direct expansion systems is lower than that of secondary systems, but with little differences for smaller pipes. Finally, trade-offs between several performances can be proposed. For example, some architectures with suitable pipe diameters could meet TCO/LCCP-based and CAPEX/pumping-based trade-offs.

Enhancing Refrigeration Efficiency through Nanoparticle-Infused Refrigerants and Phase Change Materials (PCMs) in Condenser Systems: A Comprehensive Research

Abstract: The evolution of refrigeration technology is at the forefront of scientific inquiry, with a focused exploration of innovative methodologies to elevate efficiency. This research paper embarks on a transformative journey within this landscape, specifically delving into the integration of nanoparticle-infused refrigerants and Phase Change Materials (PCMs) in condenser systems. The overarching objective is to unravel the synergistic effects of these groundbreaking innovations, shedding light on their profound impact on refrigeration system performance and their potential contributions to sustainability and energy efficiency. The study positions itself at the nexus of emerging technologies, aiming to provide not only a nuanced examination of nanoparticle-infused refrigerants and PCMs but also a holistic understanding of their combined influence on refrigeration processes. This multi-faceted exploration encompasses theoretical frameworks, empirical investigations, and the potential implications that these innovations carry for the broader realm of sustainable and energy-efficient refrigeration. As the global demand for energy-efficient solutions intensifies, the integration of nanoparticles into refrigerants stands as a promising avenue.

Investigation of an automobile air-conditioner with a liquid-suction heat exchanger using R134a and R1234yf

Air-conditioning systems (ACs) are essential in hot and humid climates to ensure acceptable ambient air quality as well as thermal comfort for buildings users. It is essential to improve refrigeration system performance without increasing the effects of global warming potential (GWP) and ozone depletion potential (ODP). The main objective of this study is to evaluate the performance of an air conditioning system that operates with a liquid suction heat exchanger (LSHX) through implementing refrigerants with zero OPD and low GWP (i.e., R134a and R1234yf). Liquid suction heat exchanger (LSHX) was added to an automobile air conditioning system (AACS).When Liquid suction heat exchanger was added to the cycle, primary results indicated that an enhancement in the cycle coefficient performance (COP) by 25.2 %and 17.3% for R134a and R1234yf respectively, and decreasing in mass flow rate of the refrigerants used (m ̇_r). Also increasing in refrigeration effect (RE) by 4.2% and 2.3% for R134a and R1234yf respectively. Presence of LSHX caused increasing in heat rejected by condenser (Qcond.) according to increasing in sub-cooling degree and decreasing in compressor work (Wcomp.), increasing in condenser exergy destruction (X. des. cond.) and thermostatic expansion device (TXV) exergy destruction, but decreasing in compressor and evaporator. Summary of previous experimental and numerical studies is presented as well.

Energetic performance of a solar driven absorption refrigeration system integrated with humidification dehumidification desalination system

Integrating cooling and desalination systems with a single heat source is a shortcut technique to meet the shortage of fresh water and energy as well as enhancing the efficiency of energy utilization. In this paper, the energetic performance of a double effect vapor absorption refrigeration system integrated with humidification-dehumidification desalination system has been optimized·H2O–LiCl achieves higher system primary energy ratio and needs lower heat source temperature by 5 °C and 11 °C at evaporation temperature of 10 °C and 4 °C, respectively as compared with H2O–LiBr. Therefore, a parametric study has been performed to get the optimum operating conditions for the integrated system using H2O–LiCl as working pair by varying generation, condensation, and evaporation temperatures. The optimum system conditions are generation, condensation, and evaporation temperatures of 103 °C, 103 °C and 7 °C, respectively. The corresponding system COP, GOR and EUF are 1.471, 2.391 and 3.863, respectively. Finally, the transient performance of the proposed integrated system assisted by solar energy has been evaluated for Marsa-Matrouh city in Egypt. The proposed integrated system could save 71.2 % of the input energy without solar assistance and 88.5 % with solar assistance as compared with separated systems.

Experimental investigation of a new CO2 refrigeration system arrangement for supermarket applications

A new position of an internal heat exchanger within the thermodynamic cycle is proposed to improve the performance of CO2 refrigeration systems in warm climates, specifically in supermarket applications. The proposed configuration uses the saturated vapor from the liquid receiver to recover the heat that is rejected by a subcooler positioned after the gas cooler. This system results in a reduced evaporator superheat. This configuration is compared with a reference system.The experimental study is conducted on a CO2 laboratory cooling system reproducing a commercial plant. The cooling capacity of the system is 30 kW. The water inlet temperature in the gas cooler (hot source) varies from 15 °C to 35 °C, while the mono-ethylene glycol outlet temperature of the evaporator (cold source) is fixed at -8 °C. The setup is validated through an energy balance.Using a subcooler in this new position improves the coefficient of performance by 10.2 % under transcritical conditions and 6.3 % under subcritical conditions when compared with the reference system.

Research on the dynamic characterization and detection of refrigerant leakage in multi-connected air-conditioning system

Microleakage, frequently arising from aging or inadequate installation, significantly affects the performance and longevity of refrigeration systems. The presence of microleakages, while not precipitating an immediate system failure, results in the gradual deterioration of components and escalates the energy consumption within buildings. Nonetheless, identifying these microleakages through conventional methodologies poses significant challenges. This study introduced a dynamic model specifically designed for detecting microleakages in multi-connected air conditioning systems, particularly in variable refrigerant volume (VRV) systems. Experiments performed under standard operating conditions were integral to enhancing the model's accuracy and furthering its validation. The model integrates the structural and thermophysical attributes of various components, thereby addressing the issues related to data acquisition in standard VRV during instances of microleakage. The analysis of dynamic parameter shifts during system microleakage led to the generation of a comprehensive dataset, which proves invaluable for machine learning and fault detection tasks. A detection and alerting protocol is written in Python presented, chiefly anchored on pressure deviations, augmented by temperature shifts and refrigeration and heating capacities, all represented as virtual volumetric alterations. The findings indicate a delayed transmission of the leakage signal from the leakage point to the system's detection points, with the maximal delay occurring at the compressor inlet under refrigeration conditions, amounting to 239 s. Evaluation under prescribed conditions indicated variances in pressure, temperature, and refrigeration and heating capacities by up to 13.2 %, thereby validating the model's precision and reliability. The program, tested with the generated dataset, accurately identifies leakage states within an average time of 20 min. This model and detection strategy provide a new perspective on microleakage in refrigeration systems, suggesting a robust strategy for their sustained and secure operation.

Analysis of the Vapor Compression Refrigeration Cycle Measures with and without Using a Heat Exchanger for Alternative Refrigerants

One of the most commonly refrigeration systems is the vapor compression refrigeration system. Since energy saving and environmental friendliness remain a challenge, researchers are working hard to find an effective solution to improve the performance of vapor compression refrigeration systems while committing to environmental standards. The main goal of this paper is to identify the best and closest alternative refrigerant to R22 among the alternative cooling fluids taken into consideration in terms of thermodynamic and mechanical properties, environmental protection, and safety of handling. This work presents an analysis and comparison of the various performance measures for a vapor compression refrigeration cycle operating without using and using a heat exchanger for environmentally friendly alternative refrigerants, namely R410A, R407A, R407C, R438, RS-44b, and R417A, and compares them with the refrigerant R22, which has direct environmental impacts on the ozone layer (ODP) and global warming (GWP). The computer simulation program Chemours Refrigerant Expert 1 was used to conduct the analyses. The performance parameters analyzed are coefficient of performance, compressor work, cooling capacity, temperature of condensation, intake and exhaust pressure, volumetric capacity, theoretical displacement, intake, exhaust, condensation and evaporation temperature without and with a heat exchanger, and super heating temperature with a heat exchanger. It was concluded from this study that the best alternative to R22 refrigerant among the alternative refrigerants taken into consideration in the study is the RS-44b refrigerant in terms of all performance measures and environmentally friendly. Keywords: Refrigerant; Vapor compression; Performance measures; Evaporation; Heat exchanger.

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.

Experimental study of compact room temperature magnetic cooling system based on different flow time ratios

Magnetic refrigeration has become a promising new technology to replace conventional vapor-compression refrigeration technology, for it has excellent application characteristics such as the high efficiency, environmental friendliness and structural simplicity. Many studies have been carried out to analyze the various subsystems, but the interaction laws between the systems are not yet clear, and the optimization of each subsystem is still an area of research worth exploring. This work is based on a compact room temperature magnetic refrigeration system developed before, and carries out experimental research on the different flow time ratio to explore the correlation among refrigeration temperature span, cooling capacity, pressure drop, coefficient of performance (COP) and blow fraction under a fixed magnetic field timing. Especially, the effects of different flow time ratios (100%, 80%, 60%) on the system performance are studied under magnetic field timing of 1∶4∶1∶4 and a frequency of 0.45 Hz. The experimental results reveal that a low utilization factor combined with a high flow time ratio can achieve a greater temperature spread, whereas a high utilization factor combined with a high flow time ratio can accomplish a bigger cooling capacity. When the utilization factor is 0.42 and the flow time ratio is 100%, the maximum unloaded cooling temperature span is 26.2 K. Meanwhile, the effects of the utilization factor and flow time ratio on the pressure drop and COP of the regenerator are studied in detail. It is discovered that raising the flow time ratio and reducing the utilization factor both result in a fall in fluid velocity, which leads the pressure to further decrease and the COP to rise. In a word, this research investigates the relationship among cooling temperature span, cooling capacity, pressure drop, COP, and flow time ratio in a fixed magnetic field timing, thus providing the groundwork for future improving the performances of room temperature magnetic refrigeration systems.