Mary Ann Yi Ying Chua , Perumal Kumar , Milinkumar T. Shah , Jundika C. Kurnia , Siaw Khur Wee
{"title":"Computational study of helical coil heat exchanger: Energy, entropy, exergy, entransy (4E) analysis and application of field synergy principle","authors":"Mary Ann Yi Ying Chua , Perumal Kumar , Milinkumar T. Shah , Jundika C. Kurnia , Siaw Khur Wee","doi":"10.1016/j.ijrefrig.2025.01.026","DOIUrl":"10.1016/j.ijrefrig.2025.01.026","url":null,"abstract":"<div><div>The current global energy crisis requires high-efficiency energy conversion and management systems. Besides maximising heat transfer, reducing energy loss is also an effective method for energy resource sustainability. Helical coil heat exchangers have a compact design and superior heat transfer capacity compared to conventional shell-and-tube heat exchangers. However, the designing process often relies on the first law of thermodynamics without an in-depth understanding of the interplay between local flow conditions and energy destruction, leading to efficiency loss. Therefore, the current study investigates turbulent heat transfer in helical coil tubes to analyse local flow conditions using energy, entransy, entropy, and exergy principles with supercritical carbon dioxide. The perspective concerning the synergy between velocity vectors and temperature gradients is also included. Under the combined effects of centrifugal and buoyancy forces, local flow features are revealed, and heat transfer improves up to 58 % principally due to thermophysical properties variations of bulk fluid. The most efficient energy utilisation leads to 60 % reduction in entransy dissipation, which coincides with the maximum heat transfer performance. Sources and locations with inefficient energy utilisation serve as guidelines for designing more effective heat transfer systems. Entropy and exergy analyses are also consistent to heat transfer, and entropy generation paradox is not observed in local thermodynamic analysis. However, synergy angle and field synergy number are not suitable to analyse supercritical flows.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"172 ","pages":"Pages 41-63"},"PeriodicalIF":3.5,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Neeraj Kumar Vidhyarthi , Ankit Srivastava , Sandipan Deb , Sagnik Pal , Ajoy Kumar Das
{"title":"Experimental investigation and physics-informed neural network based modelling of heat transfer coefficient and pressure drop in R513A flow boiling through micro-fin tube","authors":"Neeraj Kumar Vidhyarthi , Ankit Srivastava , Sandipan Deb , Sagnik Pal , Ajoy Kumar Das","doi":"10.1016/j.ijrefrig.2025.01.025","DOIUrl":"10.1016/j.ijrefrig.2025.01.025","url":null,"abstract":"<div><div>This research investigates the heat transfer coefficient (HTC) and frictional pressure drop (FPD) during flow boiling of refrigerant R513A in a micro-fin tube under varying operational conditions. The primary goal is to enhance understanding of flow boiling characteristics to improve heat exchanger designs for environmentally friendly refrigerants. Experimental analysis was conducted using a 1000 mm-long tube with an outer diameter of 9.52 mm, considering heat flux (12–36 kW·m⁻²), vapor quality (0.02–0.96), mass flux (50–300 kg·m⁻²·s⁻¹), and saturation temperature (290.15–300.15 K). A Physics-Informed Neural Network (PINN) model was developed to predict HTC and FPD using these operational parameters as inputs, integrating experimental data with physical constraints for enhanced prediction accuracy. The PINN architecture, comprising 4-64-128-64-2 neurons, was optimized through systematic hyperparameter tuning, achieving well-converged training and validation losses. Key findings reveal the significant impact of heat flux, mass flux, and vapor quality on HTC and FPD, with micro-fin geometries enhancing heat transfer efficiency. This study bridges experimental data with advanced predictive modeling, offering a novel framework for optimizing thermal systems using sustainable refrigerants. The results provide valuable insights for designing high-efficiency, environmentally sustainable cooling systems.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"172 ","pages":"Pages 94-107"},"PeriodicalIF":3.5,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experimental campaign on non-fluorinated refrigerant mixtures in a low-charge heat pump","authors":"Matteo Caramaschi , Jonas Kjær Jensen , Kasper Korsholm Østergaard , Stefano Poppi , Laure Meljac , Ted Holmberg , Brian Elmegaard","doi":"10.1016/j.ijrefrig.2025.01.008","DOIUrl":"10.1016/j.ijrefrig.2025.01.008","url":null,"abstract":"<div><div>This work experimentally investigated the energy performance of several non-fluorinated refrigerant mixtures and their pure components on a prototype of a low-refrigerant charge single-stage water-to-water heat pump. The pure refrigerants tested in the unit were Propane (R-290), Propylene (R-1270) and Dimethyl Ether (DME, R-E170). In addition, the tested mixtures were Propane-CO<sub>2</sub>, Propylene-CO<sub>2</sub>, DME-CO<sub>2</sub>, Propylene-DME at different compositions and temperatures. Total refrigerant charge amounts, including auxiliary pipes and valves, ranged between 190 g and 290 g. Heating capacities ranged between 3.7 kW and 12.2 kW. The highest capacities were obtained by Propylene-CO<sub>2</sub> [0.93–0.07]. At high source and sink glide conditions, mixing low amounts of CO<sub>2</sub> showed performance enhancements, especially on Propylene and DME. Compared to Propane, DME mixed with 5 % CO<sub>2</sub>, resulted in up to 12 % COP enhancement, 16 % lower capacity, and 50 % higher limit heating capacity (LHC). Propylene and the low-glide mixture Propylene-DME performed well at low source and sink glides compared to Propane. Measurements on the refrigerant cycle also suggest that the circulating composition of the mixture slightly shifted toward the most volatile component. The results suggest that well-designed refrigerant mixtures containing Propylene, DME and CO<sub>2</sub> may enhance efficiency, heating capacity, and the heating capacity at maximum charge while maintaining conventional operating pressures and discharge temperatures.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"172 ","pages":"Pages 120-133"},"PeriodicalIF":3.5,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Davide Menegazzo , Aaron J. Rowane , Giulia Lombardo , Sergio Bobbo , Laura Fedele , Mark O. McLinden
{"title":"Compressed liquid density and speed of sound measurements and correlation of the binary mixture {carbon dioxide (CO2) + 1,1-difluoroethene (R1132a)} at temperatures from 220 K to 350 K","authors":"Davide Menegazzo , Aaron J. Rowane , Giulia Lombardo , Sergio Bobbo , Laura Fedele , Mark O. McLinden","doi":"10.1016/j.ijrefrig.2025.01.014","DOIUrl":"10.1016/j.ijrefrig.2025.01.014","url":null,"abstract":"<div><div>The blend of carbon dioxide (CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>) and R1132a has been proposed as low-GWP refrigerant for low temperature refrigeration down to −60 °C, as an alternative to R23. This study provides new experimental data on the compressed-liquid density, vapour density, and compressed-liquid speed of sound for the CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> + R1132a binary system. These measurements were obtained using a two-sinker densimeter and a pulse-echo-type speed-of-sound instrument. The density measurements span a temperature range of 220 K to 350 K and pressures up to 30 MPa with an expanded uncertainty ranging from 0.031% to 0.132%, while the speed of sound measurements cover temperatures from 230 K to 350 K and pressures up to 65 MPa with an expanded uncertainty of 0.031% to 1%. For both properties, two different mixture compositions were tested corresponding to mole fractions of CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> equal to 0.5942 and 0.7926. Due to the strong absorption of the sound pulse by the mixture, the standard dual-path analysis could not be employed. Therefore, a method utilizing only the short-path signal was developed. Additionally, we present a mixture model based on the experimental data, derived from a Helmholtz energy model, which demonstrates a good fit with the measurements. Finally, we applied this model to compare CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/R1132a mixtures with R23 and other alternatives. This preliminary analysis revealed the potential of CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/R1132a as possible low-GWP and near-azeotropic refrigerants, less flammable than hydrocarbon-based mixtures and capable of providing cold at −60 °C.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"172 ","pages":"Pages 1-16"},"PeriodicalIF":3.5,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Davide Menegazzo , Giulia Lombardo , Laura Vallese , Mauro Scattolini , Sergio Bobbo , Laura Fedele
{"title":"Experimental compressed liquid density measurements and correlation of the binary mixture {3,3,3-trifuoropropene (R1243zf) + isobutane (R600a)}","authors":"Davide Menegazzo , Giulia Lombardo , Laura Vallese , Mauro Scattolini , Sergio Bobbo , Laura Fedele","doi":"10.1016/j.ijrefrig.2025.01.013","DOIUrl":"10.1016/j.ijrefrig.2025.01.013","url":null,"abstract":"<div><div>In the context of evolving regulations such as the F-gas Regulation and the Kigali Amendment to the Montreal Protocol, the exploration of alternatives to fluorinated greenhouse gases in air conditioning and refrigeration has garnered significant attention. Essential attributes sought in viable refrigerants encompass low Global Warming Potential (GWP), thermodynamic cycle efficiency, non-flammability, non-toxicity, material compatibility, and cost-effectiveness. Hydrofluoroolefins (HFOs) have emerged as promising replacements for hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) in HVAC and refrigeration systems. Simultaneously, the quest for low GWP refrigerants has prompted a revaluation of hydrocarbons (HCs) like propane (R290) and isobutane (R600a), renowned for their efficiency, minimal charge requirements, and affordability despite their flammability. While extensive data and reliable Equations of State (EoS) are available for HCs, HFOs lack comprehensive information. This study contributes empirical measurements on the compressed liquid density of the 3,3,3-trifluoropropene (R1243zf) + isobutane (R600a) binary system. Utilizing a vibrating tube densimeter, measurements were conducted on three mixture compositions within the temperature range of 283.15 K to 353.15 K and at pressures ranging from near saturation to 35 MPa. The obtained dataset, combined with existing literature, served as the basis for a new mixture model developed using the Helmholtz-energy-explicit EoS. This model accurately represents the behaviour of the binary mixture, enhancing the available understanding of its thermodynamic properties.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"172 ","pages":"Pages 64-74"},"PeriodicalIF":3.5,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xinyue Hao , Dejiang Liu , Neng Gao , Guangming Chen , Lina Zhang , Qiu Tu
{"title":"Performance investigation of a novel multi-parameter adjustable ejector with a broad operating range","authors":"Xinyue Hao , Dejiang Liu , Neng Gao , Guangming Chen , Lina Zhang , Qiu Tu","doi":"10.1016/j.ijrefrig.2025.01.020","DOIUrl":"10.1016/j.ijrefrig.2025.01.020","url":null,"abstract":"<div><div>Ejectors can be extensively used in industry and other fields, such as fuel cells, etc., to reduce pressure energy loss or recover low-pressure fluids. However, constant-dimension ejectors are difficult to meet with high efficiency under different operating conditions. This paper investigates the dimensional adjustment strategy of adjustable ejectors under varying fluid flow rates and working pressures, analyzing performance before and after adjustment. Computational Fluid Dynamics (CFD) simulations and experiments were conducted for performance testing and verification. The performance advantages of adjustable ejectors under varying operating conditions are highlighted in a new study, which offers both theoretical and experimental backing for broader implementation. The actual working region is innovatively divided according to the working performance of the ejector. The findings reveal that maintaining optimal dimensions is crucial for high performance, especially under fluctuating primary fluid pressures, where nozzle and mixing chamber dimensional adjustments are essential to maintaining efficiency. Experimental results show that adjusting the ejector dimensions (B2) in response to primary fluid pressure increases (1000 kPa to 1300 kPa) maintains the entrainment ratio and improves performance by up to 28.5 %, preventing significant efficiency drops. This research offers significant insights into the practical application and tuning of ejectors in dynamic systems.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"173 ","pages":"Pages 139-152"},"PeriodicalIF":3.5,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuande Dai , Huiyang Zhu , Giuseppe Bianchi , Sham Rane , Fanghua Ye
{"title":"Numerical investigation on flow characteristics and working performance in oil-injected sliding vane rotary compressors","authors":"Yuande Dai , Huiyang Zhu , Giuseppe Bianchi , Sham Rane , Fanghua Ye","doi":"10.1016/j.ijrefrig.2025.01.018","DOIUrl":"10.1016/j.ijrefrig.2025.01.018","url":null,"abstract":"<div><div>Oil is injected into Sliding Vane Rotary Compressors (SVRCs) for cooling, sealing and lubrication purposes. This paper presents numerical investigations on the oil-gas two-phase flow characteristics of the SVRC followed by studying the effects of the oil injection parameters on the compressor performance. The analytical grid generation methodology was employed to discretise the rotating and deforming rotor fluid domain. The Computational Fluid Dynamics (CFD) model of the SVRC was developed and validated with experimental test data. The flow topology was analyzed to illustrate the flow and oil distribution features within the compressor. Moreover, the influence of the oil injection parameters (oil to gas ratio, oil injection angle, oil injection temperature and rotational speed) on the compressor performance were explored. The results show that the oil accumulates at the leading sides of the blades and then flows into the blade tip region, which helps to reduce the internal leakage. In the reference case, the compressor achieves the volumetric efficiency of 95.1 %, the adiabatic efficiency of 60.3 %, the exhaust temperature of 337.4 K and the specific power of 9.86 kW/(m<sup>3</sup> min<sup>-1</sup>). Furthermore, increasing oil to gas ratio leads to better cooling and sealing performance, but also results in higher specific power. Oil to gas mass ratio has higher sensitivity than oil injection temperature or angle. About 8° shift in oil injection angle results in 4.2 % decrease in specific power. The lubricating oil capacity should be increased accordingly to the increasing rotational speed.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"171 ","pages":"Pages 202-216"},"PeriodicalIF":3.5,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huiyuan Jin , Yajin Zhang , Miao Shi , Tao Yin , Ru Liu , Youming Liu , Juan You
{"title":"Impact of freezing technologies on the quality of catfish (Ictalurus punctatus) fillets: Insights from protein properties and ice crystal analysis","authors":"Huiyuan Jin , Yajin Zhang , Miao Shi , Tao Yin , Ru Liu , Youming Liu , Juan You","doi":"10.1016/j.ijrefrig.2025.01.009","DOIUrl":"10.1016/j.ijrefrig.2025.01.009","url":null,"abstract":"<div><div>The effects of air freezing (AF), saline immersion freezing (SIF), composite immersion freezing (CIF), and liquid nitrogen spray freezing (LNSF) on the muscle quality, protein properties, and microstructure of catfish fillets were investigated. The results indicated that LNSF improved water retention of frozen catfish fillets, maintained hardness, reduced water migration, and exhibited lower fat oxidation and protein denaturation levels compared to other freezing methods. Ice crystals observations through polarizing light microscopy revealed that dendritic ice crystals between muscle fascicles grew vertically to the direction of the muscle fascicles. In contrast, ice crystals within the muscle fascicles grew parallel to them. The LNSF effectively reduced pore and ice crystal sizes, resulting in a denser muscle fiber structure. These findings suggested that LNSF effectively preserved the moisture and freshness of the samples and was the most energy-efficient method for maintaining the quality of catfish fillets compared to the other treatments.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"173 ","pages":"Pages 44-54"},"PeriodicalIF":3.5,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Numerical study on effects of wettability on performances of CO2 ejector","authors":"Fang Liu , Wei Yang , Shuai Jia , Pengfei Li","doi":"10.1016/j.ijrefrig.2025.01.015","DOIUrl":"10.1016/j.ijrefrig.2025.01.015","url":null,"abstract":"<div><div>Inner wall surface wettability could affect ejector performances, however, no-slip wall boundary conditions were mostly assumed in CO<sub>2</sub> ejector simulation studies. In this study, we introduced velocity slip boundary condition into the 3D heterogeneous mixture model for a two-phase CO<sub>2</sub> ejector, by using different apparent contact angle at the inner wall of mixing chamber, motive nozzle or diffuser. Numerical simulation results show that the inner wall wettability of mixing chamber and diffuser affects flow and mass transfer in a CO<sub>2</sub> ejector significantly, while the inner wall wettability of motive nozzle affects ejector performances very slightly. As apparent contact angle increases from 5° to 175°, resulting in the change of slip condition from negative slip to no-slip then to positive slip, velocity in mixing chamber increases, pressure in mixing chamber decreases, expansion angle after motive nozzle outlet decreases, thus backflow vortices become smaller then disappear. This leads to an increase in suction mass flow rate, and entrainment ratio can be enhanced over 15 %. Correlations between entrainment ratio and apparent contact angle at the wall of different parts in ejector were developed. As the wall wettability changes from hydrophilic to superhydrophobic, the variation trends of ejector performances are similar under different operating conditions with motive nozzle inlet in the supercritical, near-critical, and subcritical regions. This study is helpful to understand flow mechanisms inside the CO<sub>2</sub> ejector with different wall wettability, and provides a new approach to improve the performances of a two-phase CO<sub>2</sub> ejector by changing wall surface wettability.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"171 ","pages":"Pages 267-283"},"PeriodicalIF":3.5,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experimental retrofit of an R404A/R23 ultra-low temperature freezer using R448A and electronic expansion valves","authors":"Pau Giménez-Prades, Joaquín Navarro-Esbrí, Cosmin-Mihai Udroiu, Adrián Mota-Babiloni","doi":"10.1016/j.ijrefrig.2025.01.017","DOIUrl":"10.1016/j.ijrefrig.2025.01.017","url":null,"abstract":"<div><div>The lack of regulations that limit the GWP of refrigerants operating in vapour compression systems with a target temperature below –50°C has caused slower market development. Therefore, limited refrigerants and technologies for ultra-low temperature (ULT) refrigeration have been studied. In this work, an experimental assessment of R448A as a lower-GWP alternative to R404A in the high-temperature stage of a ULT two-stage cascade refrigeration system is done using R23 as the low-temperature stage refrigerant. Furthermore, capillary tubes and electronic expansion valves are compared as expansion devices. First, the pull-down performance starting from three room temperatures (15, 20, and 25°C) down to –80°C is analysed. Then, the hysteresis operation with those ambient temperatures and set freezer temperatures of –80, –70, –60, and –50°C is studied. The pull-down time was higher (38 to 55 min slower) using the capillary tubes compared to the electronic expansion valves. Also, the energy consumption of the hysteresis operation was higher (up to 32.3% higher) using the capillary tubes. The electronic expansion valves obtained comparable energy consumption and cooling capacity with R404A/R23 and R448A/R23. The highest COP is achieved by R448A/R23 (up to 10.2% higher than R404A/R23). Therefore, the suitability of R448A as a replacement for R404A in ULT refrigeration is confirmed.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"171 ","pages":"Pages 217-227"},"PeriodicalIF":3.5,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}