International Journal of Refrigeration-revue Internationale Du Froid最新文献_第6页

Study on the moisture adsorption characteristics of AlPO4-LTA and its dehumidification performance in desiccant coated dehumidifier

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid

Pub Date : 2025-01-27 DOI: 10.1016/j.ijrefrig.2025.01.029

Yaofeng Zhang , Lin Liu , Peng Liu , Lisheng Deng , Jun Li , Xiaofeng Guo , Yugo Osaka , Hongyu Huang

Zeolite-like molecular sieves show high potential in solid desiccant dehumidification cooling systems. They are recognized for remarkable moisture adsorption capacity and regeneration performance, characterized by their S-shaped adsorption isotherms. As a new type of zeolite-like molecular sieves, AlPO₄-LTA has been reported with superior equilibrium moisture uptake, but its dynamic dehumidification characteristics in practical dehumidification systems still lack. In this study, to explore the application potential of AlPO₄-LTA, the material was synthesized through ionothermal method, followed by an examination of its features and moisture adsorption characteristics, focusing extensively on the dynamics of moisture adsorption and desorption. Moreover, the practical dehumidification characteristics of AlPO₄-LTA coated dehumidifier were investigated by a validated mathematical model. Observations confirmed that the AlPO₄-LTA possessed a uniform structure, a high specific surface area, and a narrow pore size distribution. The equilibrium moisture adsorption uptake can reach 0.42 kg·kg⁻¹ in adsorption isotherm of 30°C. The adsorption/desorption kinetics coefficients

k_{a d s}

/

k_{d e s}

of the AlPO₄-LTA coatings determined by the linear driving force (LDF) model were on the magnitude of 0.001–0.01 s^-1. Numerical results revealed the moisture removal capacity (MRC) and dehumidification coefficient of performance (DCOP) of AlPO₄-LTA coated dehumidifier can reach 8.58 g·kg⁻¹ and 0.17 at regeneration temperature of 75°C, respectively, which were 1.8 and 1.1 times over those conventional AlPOs (including FAM-Z01 and EMM-8) coated dehumidifiers.

{"title":"Study on the moisture adsorption characteristics of AlPO4-LTA and its dehumidification performance in desiccant coated dehumidifier","authors":"Yaofeng Zhang , Lin Liu , Peng Liu , Lisheng Deng , Jun Li , Xiaofeng Guo , Yugo Osaka , Hongyu Huang","doi":"10.1016/j.ijrefrig.2025.01.029","DOIUrl":"10.1016/j.ijrefrig.2025.01.029","url":null,"abstract":"<div><div>Zeolite-like molecular sieves show high potential in solid desiccant dehumidification cooling systems. They are recognized for remarkable moisture adsorption capacity and regeneration performance, characterized by their S-shaped adsorption isotherms. As a new type of zeolite-like molecular sieves, AlPO<sub>4</sub>-LTA has been reported with superior equilibrium moisture uptake, but its dynamic dehumidification characteristics in practical dehumidification systems still lack. In this study, to explore the application potential of AlPO<sub>4</sub>-LTA, the material was synthesized through ionothermal method, followed by an examination of its features and moisture adsorption characteristics, focusing extensively on the dynamics of moisture adsorption and desorption. Moreover, the practical dehumidification characteristics of AlPO<sub>4</sub>-LTA coated dehumidifier were investigated by a validated mathematical model. Observations confirmed that the AlPO<sub>4</sub>-LTA possessed a uniform structure, a high specific surface area, and a narrow pore size distribution. The equilibrium moisture adsorption uptake can reach 0.42 kg·kg⁻¹ in adsorption isotherm of 30°C. The adsorption/desorption kinetics coefficients <span><math><msub><mi>k</mi><mrow><mi>a</mi><mi>d</mi><mi>s</mi></mrow></msub></math></span>/<span><math><msub><mi>k</mi><mrow><mi>d</mi><mi>e</mi><mi>s</mi></mrow></msub></math></span> of the AlPO<sub>4</sub>-LTA coatings determined by the linear driving force (LDF) model were on the magnitude of 0.001–0.01 s<sup>-1</sup>. Numerical results revealed the moisture removal capacity (<em>MRC</em>) and dehumidification coefficient of performance (<em>DCOP</em>) of AlPO<sub>4</sub>-LTA coated dehumidifier can reach 8.58 g·kg⁻¹ and 0.17 at regeneration temperature of 75°C, respectively, which were 1.8 and 1.1 times over those conventional AlPOs (including FAM-Z01 and EMM-8) coated dehumidifiers.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"172 ","pages":"Pages 158-169"},"PeriodicalIF":3.5,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349284","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}

引用次数: 0

A cascade control strategy for electromagnetic capacity control system of reciprocating compressor

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid

Pub Date : 2025-01-26 DOI: 10.1016/j.ijrefrig.2025.01.019

Rui Zhang , Yao Wang , Yidan Zhang , Degeng Zhao , Jinjie Zhang , Zhinong Jiang , Ting Lei , Mingze Zhou

Reciprocating compressor is the key equipment in refrigeration system. The electromagnetic capacity control system plays an important role in energy conservation of the reciprocating compressor. The objective of this study is to design a control strategy that addresses several challenges, including large seating impacts, mismatch between load variations and actuator response capabilities, and insufficient robustness within the electromagnetic capacity control system. Firstly, a nonlinear model of the reciprocating compressor with stepless capacity control system is established. Secondly, an Integral Model Predictive Control-Adaptive Backstepping Integral Sliding Mode Control (IMPC-ABISMC) cascade controller is designed via three steps. Finally, the controller is comparatively tested. The results demonstrate that the control strategy can ensure that the reciprocating compressor buffer tank pressure is timely and accurately tracked the set value, reducing the steady-state error to a range of 0–0.13% and the expected load generated exhibits greater smoothness than that of Adaptive Fuzzy Sliding Mode Control (AFSMC). Additionally, the control strategy can control the actuator to track the target trajectory under different working loads with tracking accuracies of less than 0.09mm and maintains a low average seating velocity of 0.016m s^-1, demonstrating strong robustness against the pressure disturbance and the load force disturbance. The innovation of this study lies in the design of the IMPC and ABISMC controllers, as well as the cascading of two controllers via intermediate transformation, forming a cascade control strategy that ensures precise load response while accommodating dynamic performance of the actuator. This control strategy is applicable to compressor experiencing frequent load variation, facilitating stepless capacity control and effectively addressing challenges such as excessive energy consumption.

{"title":"A cascade control strategy for electromagnetic capacity control system of reciprocating compressor","authors":"Rui Zhang , Yao Wang , Yidan Zhang , Degeng Zhao , Jinjie Zhang , Zhinong Jiang , Ting Lei , Mingze Zhou","doi":"10.1016/j.ijrefrig.2025.01.019","DOIUrl":"10.1016/j.ijrefrig.2025.01.019","url":null,"abstract":"<div><div>Reciprocating compressor is the key equipment in refrigeration system. The electromagnetic capacity control system plays an important role in energy conservation of the reciprocating compressor. The objective of this study is to design a control strategy that addresses several challenges, including large seating impacts, mismatch between load variations and actuator response capabilities, and insufficient robustness within the electromagnetic capacity control system. Firstly, a nonlinear model of the reciprocating compressor with stepless capacity control system is established. Secondly, an Integral Model Predictive Control-Adaptive Backstepping Integral Sliding Mode Control (IMPC-ABISMC) cascade controller is designed via three steps. Finally, the controller is comparatively tested. The results demonstrate that the control strategy can ensure that the reciprocating compressor buffer tank pressure is timely and accurately tracked the set value, reducing the steady-state error to a range of 0–0.13% and the expected load generated exhibits greater smoothness than that of Adaptive Fuzzy Sliding Mode Control (AFSMC). Additionally, the control strategy can control the actuator to track the target trajectory under different working loads with tracking accuracies of less than 0.09mm and maintains a low average seating velocity of 0.016m s<sup>-1</sup>, demonstrating strong robustness against the pressure disturbance and the load force disturbance. The innovation of this study lies in the design of the IMPC and ABISMC controllers, as well as the cascading of two controllers via intermediate transformation, forming a cascade control strategy that ensures precise load response while accommodating dynamic performance of the actuator. This control strategy is applicable to compressor experiencing frequent load variation, facilitating stepless capacity control and effectively addressing challenges such as excessive energy consumption.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"172 ","pages":"Pages 200-213"},"PeriodicalIF":3.5,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372652","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}

引用次数: 0

Thermodynamic and economic analysis of a novel dual-pressure organic rankine cycle coupled two-stage vapor compression heat pump system

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid

Pub Date : 2025-01-26 DOI: 10.1016/j.ijrefrig.2025.01.024

Zhikang Wang , Yimin Li , Zhijie Qiu , Dongjiang Han , Jun Sui

Based on the demand for waste heat recovery and steam heating in the medicine, steel and textile fields, a novel series double-pressure organic Rankine cycle coupled two-stage vapor compression heat pump system driven by low temperature waste heat is proposed. The economic feasibility and thermodynamic superiority of the system are demonstrated by contrasting its thermodynamic and economic performance with that of the conventional single-stage organic Rankine cycle-vapor compression heat pump system. Then, a sensitivity analysis is conducted to assess the impact of temperature parameters on the system performance. Finally, the comprehensive performance of six candidate working mediums is evaluated using the grey relational analysis and entropy weight method. The findings indicate that the system coefficient of performance (COP_s), exergy efficiency and net present value of the two-stage composite system are increased by 9.3 %, 5 % and 9.6 % respectively compared to the single-stage composite system, and the investment payback period is shortened by 8.3 %. Sensitivity analyses show that the thermodynamic and economic indicators exhibit contrasting trends in response to changes in temperature parameters. Under all evaluated heat source temperatures, Hydrocarbons (HCs) exhibit elevated gray relational degrees, indicating superior overall performance.

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引用次数: 0

Insight into the flammability limit and combustion reactions behaviors of R1233zd(E)/R1270 mixtures refrigerants

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid

Pub Date : 2025-01-25 DOI: 10.1016/j.ijrefrig.2025.01.023

Xueyan Wang , Hua Tian , Gequn Shu , Zhao Yang

The R1233zd(E)/R1270 mixture is a potential alternative refrigerant. However, its flammability must be considered. The effect of R1233zd(E) on the flammability limit and combustion mechanism of R1270 was investigated through both experiments and the ReaxFF MD method. Firstly, the flammability limit of the R1233zd(E)/R1270 mixture was determined at 298.15 K dry air using a high-precision experimental setup. The flammable zones of R1270 range from 2.51 % to 10.75 % at y = 0. As the R1233zd(E) ratio increases, the flammable zone of the refrigerant mixture initially increases and then decreases. When y = 0.9, there is a limit point where the lean and rich limits merge, and the volume fraction of R1270 is 1.32 %. Beyond this point, flame propagation becomes impossible. Then, this study analyzed the effect of R1233zd(E) on the combustion mechanism of R1270 at the atomic level using the ReaxFF MD method. The results showed that R1233zd(E) had an inhibitory effect on the consumption rate of R1270. The maximum reduction rates of R1270 consumption were 15.91 %, 5.73 %, 60.26 %, 14.81 %, and 23.17 % for five simulated temperatures. The F and Cl radicals compete with H, OH, and O radicals for binding sites on molecular fragments, thereby delaying the oxidation process. The reaction pathways and rate constants were also significantly inhibited. This study provides valuable guidance for the safe application of R1233zd(E)/R1270 mixture.

{"title":"Insight into the flammability limit and combustion reactions behaviors of R1233zd(E)/R1270 mixtures refrigerants","authors":"Xueyan Wang , Hua Tian , Gequn Shu , Zhao Yang","doi":"10.1016/j.ijrefrig.2025.01.023","DOIUrl":"10.1016/j.ijrefrig.2025.01.023","url":null,"abstract":"<div><div>The R1233zd(E)/R1270 mixture is a potential alternative refrigerant. However, its flammability must be considered. The effect of R1233zd(E) on the flammability limit and combustion mechanism of R1270 was investigated through both experiments and the ReaxFF MD method. Firstly, the flammability limit of the R1233zd(E)/R1270 mixture was determined at 298.15 K dry air using a high-precision experimental setup. The flammable zones of R1270 range from 2.51 % to 10.75 % at <em>y</em> = 0. As the R1233zd(E) ratio increases, the flammable zone of the refrigerant mixture initially increases and then decreases. When <em>y</em> = 0.9, there is a limit point where the lean and rich limits merge, and the volume fraction of R1270 is 1.32 %. Beyond this point, flame propagation becomes impossible. Then, this study analyzed the effect of R1233zd(E) on the combustion mechanism of R1270 at the atomic level using the ReaxFF MD method. The results showed that R1233zd(E) had an inhibitory effect on the consumption rate of R1270. The maximum reduction rates of R1270 consumption were 15.91 %, 5.73 %, 60.26 %, 14.81 %, and 23.17 % for five simulated temperatures. The F and Cl radicals compete with H, OH, and O radicals for binding sites on molecular fragments, thereby delaying the oxidation process. The reaction pathways and rate constants were also significantly inhibited. This study provides valuable guidance for the safe application of R1233zd(E)/R1270 mixture.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"172 ","pages":"Pages 183-199"},"PeriodicalIF":3.5,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349282","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}

引用次数: 0

Computational study of helical coil heat exchanger: Energy, entropy, exergy, entransy (4E) analysis and application of field synergy principle

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid

Pub Date : 2025-01-25 DOI: 10.1016/j.ijrefrig.2025.01.026

Mary Ann Yi Ying Chua , Perumal Kumar , Milinkumar T. Shah , Jundika C. Kurnia , Siaw Khur Wee

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.

{"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}

引用次数: 0

Experimental investigation and physics-informed neural network based modelling of heat transfer coefficient and pressure drop in R513A flow boiling through micro-fin tube

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid

Pub Date : 2025-01-25 DOI: 10.1016/j.ijrefrig.2025.01.025

Neeraj Kumar Vidhyarthi , Ankit Srivastava , Sandipan Deb , Sagnik Pal , Ajoy Kumar Das

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.

{"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}

引用次数: 0

Experimental campaign on non-fluorinated refrigerant mixtures in a low-charge heat pump

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid

Pub Date : 2025-01-23 DOI: 10.1016/j.ijrefrig.2025.01.008

Matteo Caramaschi , Jonas Kjær Jensen , Kasper Korsholm Østergaard , Stefano Poppi , Laure Meljac , Ted Holmberg , Brian Elmegaard

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-CO₂, Propylene-CO₂, DME-CO₂, 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-CO₂ [0.93–0.07]. At high source and sink glide conditions, mixing low amounts of CO₂ showed performance enhancements, especially on Propylene and DME. Compared to Propane, DME mixed with 5 % CO₂, 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 CO₂ may enhance efficiency, heating capacity, and the heating capacity at maximum charge while maintaining conventional operating pressures and discharge temperatures.

{"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}

引用次数: 0

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

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid

Pub Date : 2025-01-22 DOI: 10.1016/j.ijrefrig.2025.01.014

Davide Menegazzo , Aaron J. Rowane , Giulia Lombardo , Sergio Bobbo , Laura Fedele , Mark O. McLinden

The blend of carbon dioxide (CO

_{2}

) 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

_{2}

+ 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

_{2}

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

_{2}

/R1132a mixtures with R23 and other alternatives. This preliminary analysis revealed the potential of CO

_{2}

/R1132a as possible low-GWP and near-azeotropic refrigerants, less flammable than hydrocarbon-based mixtures and capable of providing cold at −60 °C.

{"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}

引用次数: 0

Experimental compressed liquid density measurements and correlation of the binary mixture {3,3,3-trifuoropropene (R1243zf) + isobutane (R600a)}

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid

Pub Date : 2025-01-21 DOI: 10.1016/j.ijrefrig.2025.01.013

Davide Menegazzo , Giulia Lombardo , Laura Vallese , Mauro Scattolini , Sergio Bobbo , Laura Fedele

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.

{"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}

引用次数: 0

Performance investigation of a novel multi-parameter adjustable ejector with a broad operating range

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid

Pub Date : 2025-01-20 DOI: 10.1016/j.ijrefrig.2025.01.020

Xinyue Hao , Dejiang Liu , Neng Gao , Guangming Chen , Lina Zhang , Qiu Tu

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.

{"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}

引用次数: 0