International Journal of Refrigeration-revue Internationale Du Froid最新文献

{"title":"Experimental study on hydraulic performance and cavitation characteristics of a R134a refrigerant self-lubricating centrifugal pump","authors":"Ze Zhang ,&nbsp;Song Yang ,&nbsp;Beile Zhang ,&nbsp;Xufeng Fang ,&nbsp;Rong Xue ,&nbsp;Shuangtao Chen ,&nbsp;Yu Hou","doi":"10.1016/j.ijrefrig.2024.10.027","DOIUrl":"10.1016/j.ijrefrig.2024.10.027","url":null,"abstract":"<div><div>As the primary power equipment in pump flooding cooling systems, the efficiency and performance of mechanical pumps play a crucial role in two-phase cooling systems. A high-speed centrifugal pump with self-lubricating working fluid was designed with a speed of 7500 rpm and a flow coefficient of 0.0506. The hydraulic and cavitation performance of the pump were tested with R134a as the working fluid. The results show that the working fluid pump is capable of efficiently pumping R134a with an efficiency of 40.3 % and a head coefficient of 0.988 under the design condition. Within the tested range of inlet temperature from 5°C to 15°C, the flow coefficient from 0.01 to 0.105, and the height of the refrigerant tank from 1.4 m to 5 m, lower net positive suction heads available at the same flow rate will reduce the pump head, increase power consumption, and decrease efficiency. Increasing the pump speed from 3000 rpm to 7500 rpm can improve the pump's performance. At 6000 rpm, the critical cavitation number of the working fluid pump increases with the increase in flow coefficient. At 7500 rpm, the critical cavitation number has a minimum value when the flow coefficient φ = 0.0434. At the design speed and flow rate, both the critical cavitation coefficient and fracture cavitation number increase as the inlet temperature decreases. The inducer can significantly reduce the critical cavitation number of the pump. Finally, an empirical correlation considering the thermodynamic effects is proposed to predict the increase in the critical cavitation number.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 204-213"},"PeriodicalIF":3.5,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662951","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":"Advanced model for a non-adiabatic capillary tube considering both subcooled liquid and non-equilibrium two-phase states of R-600a","authors":"Seongjun Jeon ,&nbsp;Jaedeok Ko ,&nbsp;Hyoin Lee ,&nbsp;Ji Hwan Jeong","doi":"10.1016/j.ijrefrig.2024.10.031","DOIUrl":"10.1016/j.ijrefrig.2024.10.031","url":null,"abstract":"<div><div>Previous empirical correlations have largely failed to predict the mass flow rate variations of R-600a during the transient pull-down operation of household refrigerators. This shortcoming is attributed to the fact that these correlations were developed for specific thermodynamic states of the refrigerant at the capillary inlet, whereas the thermodynamic state varies during transient operations, particularly involving non-equilibrium two-phase states. To address these limitations, a novel model has been developed. This model comprises two distinct sub-models corresponding to the refrigerant state at the capillary tube inlet: one for the subcooled liquid state and the other for the non-equilibrium two-phase state. These sub-models are integrated to account for the transitions in the thermodynamic state of R-600a at the capillary inlet. The integrated model demonstrates excellent agreement with observed variations in the R-600a mass flow rate during the pull-down operation of actual refrigerators. The mean absolute percentage error between the measured and estimated mass flow rates is approximately 10 % over the entire period of pull-down operations tested under various environmental conditions.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 140-151"},"PeriodicalIF":3.5,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593235","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":"Research and thermal comfort analysis of the air conditioning system of the Ferris wheel car based on thermoelectric cooling","authors":"Huizhi Li ,&nbsp;Kuansheng Huang ,&nbsp;Jiahui Liu ,&nbsp;Mingjing Zhu ,&nbsp;Jinchao Xing","doi":"10.1016/j.ijrefrig.2024.10.030","DOIUrl":"10.1016/j.ijrefrig.2024.10.030","url":null,"abstract":"<div><div>To solve the problem of thermal discomfort caused by the lack of cooling facilities on the Ferris wheel and to investigate the effect of the coupling effect of thermoelectric modules on the thermoelectric cooling (TEC) system, this paper proposes a two-module thermoelectric cooling and air-conditioning system that can be applied to the Ferris wheel. Firstly, the experimental platform was established to test the performance parameters of the TEC system and reveal the influence of the thermoelectric module (TEM) coupling effect on the system performance. Then, the thermal environment inside the Ferris wheel was simulated using the CFD method and human thermal comfort was evaluated. The results show that when the voltage of TEM1 and TEM2 is 10 V and 6 V respectively, the thermoelectric cooling and air-conditioning system has the best working performance, and the coefficient of performance (COP) is 0.43. And the human thermal comfort deviation A_EQT is 0.29, which is in a comfortable state under the action of the air-conditioning system.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 80-88"},"PeriodicalIF":3.5,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571571","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":"Quantitative detection of refrigerant charge faults in multi-unit air conditioning systems based on machine learning algorithms","authors":"Tong Zhao,&nbsp;Junhong Yang,&nbsp;Junda Zhu,&nbsp;Mengbo Peng,&nbsp;Can Lu,&nbsp;Zekun Shi","doi":"10.1016/j.ijrefrig.2024.10.026","DOIUrl":"10.1016/j.ijrefrig.2024.10.026","url":null,"abstract":"<div><div>Refrigerant charging discrepancies constitute the predominant malfunctions in air conditioning systems. Achieving the optimal charging level is crucial for system performance, underscoring the importance of precise refrigerant level prediction. This study introduces an algorithm designed for the quantitative detection of refrigerant charging errors by integrating the Markov Transition Field (MTF), Convolutional Neural Networks (CNN), and Multi-head Self-Attention (MSA) mechanisms. A high-precision enthalpy difference chamber was employed to establish a Variable Refrigerant Flow (VRF) refrigerant charging test bench. This setup facilitated the analysis of system parameter sensitivity to charging faults and aided in the creation of a training dataset for the algorithm. Comparative analysis was conducted against Support Vector Machines (SVM), Random Forests (RF), CNN with Self-Attention (AT), and MTF-CNN-MSA. The findings reveal that our method adeptly captures temporal dependencies and dynamic shifts in time series as visual representations, offering novel insights for discerning fault patterns within such data. Notably, the maximum pressure variations at high-pressure and low-pressure points were 0.25 MPa and 0.07 MPa, respectively, with temperature shifts of 12 °C and 3.5 °C at the high and low-temperature points. The high-pressure and high-temperature points are particularly sensitive to changes in refrigerant charging, and parameters from these sections were utilized to construct the dataset. The CNN-MSA algorithm demonstrates consistent performance across various fault types, effectively delineating fault characteristics. The accuracies achieved by SVM, RF, CNN-AT, and MTF-CNN-MSA were 84.38 %, 73.75 %, 88.13 %, and 93.75 %, respectively. In comparison, the CNN-MSA algorithm was able to more accurately detect refrigerant charge faults at different levels.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 184-193"},"PeriodicalIF":3.5,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593308","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":"Simulation and experimental study on splitting performance of Rectifier Nozzle Type Critical Distributor for multi-parallel evaporators","authors":"Xiaofeng Li,&nbsp;Wenfu Zhang,&nbsp;Zhili Sun,&nbsp;Di Liang,&nbsp;Lei Yan,&nbsp;Haiwang Zhao,&nbsp;Jiale Chen,&nbsp;Fumin Hou,&nbsp;Xian Lv,&nbsp;Dandan Wang,&nbsp;Jiangman Yan","doi":"10.1016/j.ijrefrig.2024.10.022","DOIUrl":"10.1016/j.ijrefrig.2024.10.022","url":null,"abstract":"<div><div>To solve the problem of performance degradation of multi-parallel evaporator due to inhomogeneous refrigerant distribution, a Rectifier Nozzle-Type Critical Distributor (RNCD) was developed. The multi-parallel evaporator test bench with RNCD and Centrifugal Distributor (CD) was built and the four parameters of cooling rate, outlet degree of overheat, pressure drop and cooling capacity of multi-parallel evaporator with RNCD were analyzed. Research shows that: The application of RNCD can improve the uniformity of superheat and cooling capacity while increasing the cooling rate of the system. When evaporator temperature is -28 °C, the ratio of overheat inhomogeneity of RNCD than CD was reduced by 0.58, and the ratio of cooling capacity inhomogeneity of branches was reduced by 0.45. The total pressure drop of the three components is roughly the same as that of the evaporator. RNCD can bear more pressure drop of the throttle valve. Combined with the simulation of experimental conditions, the study shows that RNCD has better distribution ability and can play the role of secondary throttle pressure drop. The RNCD proposes a novel approach to addressing the issue of inhomogeneous refrigerant distribution in refrigeration system as well as the optimization of the refrigeration system.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 101-114"},"PeriodicalIF":3.5,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571573","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":"Study on the friction characteristics of a self-lubricating linear compressor using vapor injection","authors":"Shuo Zhang ,&nbsp;Huiming Zou ,&nbsp;Mingsheng Tang ,&nbsp;Fanchen Kong ,&nbsp;Wencong Shao ,&nbsp;Zhouhang Hu","doi":"10.1016/j.ijrefrig.2024.10.014","DOIUrl":"10.1016/j.ijrefrig.2024.10.014","url":null,"abstract":"<div><div>The self-lubricating linear compressor with aerostatic bearings has good prospect for the scenario which has difficulties of oil returning. This study presents a novel oil-free linear compressor and establishes a frictional damping model by using equivalent circuit approach to evaluate the mechanical performance of the compressor. The changes in friction damping characteristics of VISLLC under different piston strokes and injection pressure are analyzed. The flow resistance coefficients within the porous medium and gas gap are obtained by experimental tests and modeling analysis. Simulation results indicate that the equivalent frictional damping coefficient can be reduced by 36.1 % comparing with that of the non-injection and the efficiency can improved the by 17.2 %. The frictional damping coefficient in the porous bearing thickness of 0.9 mm at 600 kPa injection pressure is 3.64 N·s·m⁻¹.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 294-307"},"PeriodicalIF":3.5,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662958","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":"High-fidelity model development of CO2 booster refrigeration systems in supermarkets using field measurements","authors":"Wenzhuo Li,&nbsp;Ivan Korolija,&nbsp;Rui Tang,&nbsp;Dejan Mumovic","doi":"10.1016/j.ijrefrig.2024.10.025","DOIUrl":"10.1016/j.ijrefrig.2024.10.025","url":null,"abstract":"<div><div>Supermarket refrigeration systems adopting traditional refrigerants with high global warming potential (GWP) have impacts on global warming for indirect and direct greenhouse gases (GHG) emissions. CO₂ is a popular low-GWP alternative. The transcritical operation of CO₂ systems worsens their energy performance, but provides recoverable heat as a heat source to reduce gas consumption. To evaluate operation performance, data-driven models, trained by historical data, are weak in implementation with datasets outside the scope of training data; in contrast, theoretical models have better extrapolation ability to calculate all operation conditions of CO₂ systems at supermarket. Existing theoretical modeling approaches often lack validation against the limited public-access data, which reduces model reliability for further applications, and adopt oversimplified inference methods for unmeasured variables, which increases the risks of breaking thermodynamic laws and lowering model accuracy. This study therefore develops a steady-state theoretical model for CO₂ booster refrigeration systems validated against field measurements from three UK supermarkets. The available measurements are utilized to the best level to ensure model accuracy and physical interpretability. Proposed methods to infer missing variables in CO₂ systems include condenser outlet temperature, evaporating temperature, compressor isentropic efficiency and compressor mass flow rate. Results show that proposed inference methods enhance the abilities of the proposed modeling approach to ensure data integrity, avoid breaking thermodynamic laws, and improve model accuracy by reflecting real-time actual values of unmeasured variables rather than rough assumptions. The proposed modeling approach provides satisfactory accuracy validated using high-resolution measurements across the whole year from three real supermarkets.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 152-165"},"PeriodicalIF":3.5,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593306","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}

{"title":"Characteristic analysis and diagnosis method optimization of scroll compressor pressure pulsation signal under voltage fluctuation","authors":"Yanjie Zhao ,&nbsp;Tonghe Zhang ,&nbsp;Yongxing Song ,&nbsp;Qiang Liu ,&nbsp;Lin Liu ,&nbsp;Ming Yu ,&nbsp;Yi Ge","doi":"10.1016/j.ijrefrig.2024.10.024","DOIUrl":"10.1016/j.ijrefrig.2024.10.024","url":null,"abstract":"<div><div>Under off-design conditions, scroll compressors can lead to reduced efficiency, motor damage, and even cause safety problems such as leaks or explosions. To solve the above problems, this paper analyzes the influence mechanism of different voltages on the spectrum of pressure pulsation signal and modulation signal and provides theoretical support for fault diagnosis and enhances the interpretability of the model. A voltage fault diagnosis method of scroll compressor based on Time-frequency Principal component Convolutional Network (TPCN) model is proposed. By demodulation analysis of the pressure pulsation signal of the low-pressure inlet and high-pressure outlet of the refrigerant in the scroll compressor, the spectrum information of the principal component modulation signal under different voltages is obtained. The pooling strategy is used to accurately identify and extract the fault information in the modulated signal spectrum as the input data of the model. The input data is divided into the training set and the test set according to the ratio of 8:2 to complete the training and testing of the fault diagnosis model. The experimental results show that the accuracy of TPCN model for the diagnosis of 5 types of faults reaches 100 %. The average accuracy of the model is 100 %, which indicates that the model has good stability.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 89-100"},"PeriodicalIF":3.5,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571572","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":"Investigation of discharge valve in ultra-high-speed rotary compressors: An experimental and FSI simulation-based study","authors":"Hua Zhong ,&nbsp;Wei Zhao ,&nbsp;Zhaodong Zhang ,&nbsp;Che Wang ,&nbsp;Keke Gao ,&nbsp;Jianhua Wu","doi":"10.1016/j.ijrefrig.2024.10.017","DOIUrl":"10.1016/j.ijrefrig.2024.10.017","url":null,"abstract":"<div><div>The rotary compressors are currently witnessing a trend towards high-speed operation, resulting in an increased frequency of valve motion and a higher mass flow rate through the discharge valve. Consequently, high-speed operation leads to intensified impact between the valve and both the valve stopper and valve seat, thereby posing challenges to the reliability of the valve. Simultaneously, the dynamic characteristics of the valve at high operating speeds exert a significant influence on the compressor's performance. This paper develops a three-dimensional fluid-structure interaction (FSI) model to investigate the dynamic characteristics and reliability of the valve in a high-speed rotary compressor while considering heat transfer during the flow process within the cylinder. The proposed model shows better agreement with the experiment. The study revealed that as the rotational speed increases, there is an obvious rise in over-compression loss and a pronounced valve closure delay, which increases the impact velocity of the valve. The valve experiences two peaks of equivalent stress within one cycle, rendering it susceptible to fail at high speeds. The adoption of a double-valve structure at a rotational speed of 12,000 rpm leads to a significant reduction in over-compression loss by 62.9 %, an increase in volumetric efficiency by 6.7 %, a maximum decrease in impact velocity by 54.5 %, and a maximum decrease in equivalent stress by 25.6 %. The reliability of the double-valve structure under 12,000 rpm was proved by an endurance experiment. Besides, the asymmetry in the opening process of the two valves has been unveiled for the first time.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"168 ","pages":"Pages 730-741"},"PeriodicalIF":3.5,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528179","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":"Enhanced characteristic equation method for single-stage absorption heat pumps","authors":"Jan Albers","doi":"10.1016/j.ijrefrig.2024.09.028","DOIUrl":"10.1016/j.ijrefrig.2024.09.028","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The method of characteristic equations aims to describe the part-load behavior of sorption heat pumps and chillers as well as heat transformers as simply as possible but yet still accurately. Based on an approach by T. Furukawa for heat transformers, the method was further developed by F. Ziegler and others for absorption heat pumps and generalized for application in multistage processes. Clever simplifications were made, to represent the cooling capacity &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mover&gt;&lt;mi&gt;Q&lt;/mi&gt;&lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; of absorption chillers with a characteristic temperature difference &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; as a simple linear equation &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mover&gt;&lt;mi&gt;Q&lt;/mi&gt;&lt;mo&gt;˙&lt;/mo&gt;&lt;/mover&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;·&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;msub&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;min&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. In &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, the average hot, cooling, and chilled water temperatures are combined, and the slope and loss parameters, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;msub&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;min&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; are constant. However, in practical applications of this established method, inconsistencies arise. For example, the calculated slope parameter &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; does not match the slope when plotting simulated or measured cooling capacities against &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. Furthermore, the loss parameter &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;mstyle&gt;&lt;mi&gt;Δ&lt;/mi&gt;&lt;/mstyle&gt;&lt;msub&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;min&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; is actually not constant.&lt;/div&gt;&lt;div&gt;In this work a more precise formulation of the characteristic equation is derived which takes into account that the solution entering the absorber and desorber is generally superheated or subcooled. By means of a domain-wise heat transfer calculation, these effects can be implemented into the method and explain the above mentioned inconsistencies. The new formulation allows for explicit consideration of different heat exchanger designs and cooling water configurations. No iterations or regression analyses are required. Thus, the calculation method can be easily implemented into industrial controlle","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 124-139"},"PeriodicalIF":3.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593234","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}