Yan Li , Guixiang Lu , Huijuan Su , Mingxin Lyu , Yanhua Lai , Zhen Dong
{"title":"Experimental investigation on flow characteristics of regenerators considering variable fluid properties","authors":"Yan Li , Guixiang Lu , Huijuan Su , Mingxin Lyu , Yanhua Lai , Zhen Dong","doi":"10.1016/j.ijrefrig.2024.11.002","DOIUrl":"10.1016/j.ijrefrig.2024.11.002","url":null,"abstract":"<div><div>A method was proposed to improve the accuracy of permeability and inertial resistance coefficient measurements for the flow characteristics of a regenerator, considering density and dynamic viscosity. Given the thickness of the porous medium at only 2 mm, and to simplify gradient data processing, the harmonic mean of the fluid density and dynamic viscosity was utilized. Various mesh counts of wire mesh and sintered powder filler were tested. The results showed that permeability decreased for both types of fillers as mesh count increased. Due to the high randomness inherent in the sintered powder, repeated tests were conducted, with errors being within 17 %. The inertial resistance coefficient fluctuated between 300 and 600 mesh counts, with a significant increase at 700 mesh. In contrast, the inertial resistance coefficient of the wire mesh increased consistently with the mesh count. The significant inertial resistance within the sintered powder was due to its irregularity, and a high positive correlation was observed between the regularity of the filler microstructure and the pressure drop across the regenerator. The flow characteristic correlations for two types of fillers were derived, applicable within the Reynolds number ranges of 6.54 to 99.17 for the wire mesh filler and 0.86 to 15.91 for the powder filler, with both exhibiting a goodness of fit exceeding 95 % being achieved.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 362-371"},"PeriodicalIF":3.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662869","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 growth characteristics of TBAB clathrate hydrate from flowing TBAB solution in a rectangular channel","authors":"Takashi Morimoto , Ryo Sasaki , Yoshikazu Teraoka , Hiroyuki Kumano","doi":"10.1016/j.ijrefrig.2024.11.004","DOIUrl":"10.1016/j.ijrefrig.2024.11.004","url":null,"abstract":"<div><div>Tetra-<em>n</em>‑butyl ammonium bromide (TBAB) is a quaternary ammonium salt, and its hydrate has been identified as a potential phase-change material possessing an appropriate phase-change temperature for air-conditioning systems. Moreover, depending on the hydrate formation conditions, TBAB hydrate can form a slurry that is promising as a secondary refrigerant. In a harvest-type TBAB hydrate slurry generation system, the hydrate crystals formed on the cooling surface are scraped with a scraper. The amount of the TBAB hydrate formed on the surface then needs to be predicted. In this study, the growth of TBAB clathrate hydrate in a flowing TBAB solution in a rectangular acrylic channel was experimentally investigated. The dependence of the thickness of the layered hydrate on the flow rate, concentration of the solution, and temperature difference between the TBAB solution and brine was investigated. Moreover, numerical analysis of the layered hydrate formation was performed using the measured values, such as the inlet-solution temperature and cooling-plate temperature. A comparison between the experimental and numerical results was performed. It was found that the growth rate of the hydrate layer was lower than that of the ice layer regardless of the concentration of the solution. Moreover, the experimental thickness of the TBAB hydrate layer was smaller than that obtained by numerical analysis regardless of the temperature difference, although good agreement was obtained in the case of ice.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"170 ","pages":"Pages 19-30"},"PeriodicalIF":3.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723427","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}
Chuancong Wan , Chaoyue Shi , Shaolong Zhu , Song Fang , Limin Qiu , Guoyou Shi , Dingfu Li , Shouqiang Shao , Kai Wang
{"title":"Comprehensive design and preliminary experiments of liquid hydrogen storage tank for trucks","authors":"Chuancong Wan , Chaoyue Shi , Shaolong Zhu , Song Fang , Limin Qiu , Guoyou Shi , Dingfu Li , Shouqiang Shao , Kai Wang","doi":"10.1016/j.ijrefrig.2024.10.037","DOIUrl":"10.1016/j.ijrefrig.2024.10.037","url":null,"abstract":"<div><div>As the global demand for lower carbon emissions intensifies, the deployment of medium and small-scale liquid hydrogen (LH2) storage tanks in heavy-duty trucking and aviation is expected to increase. However, heat leakage into these cryogenic vessels leads to a continuous increase in tank pressure, potentially resulting in sudden hydrogen release and other safety concerns. While horizontal LH2 tanks demonstrate greater suitability in the transportation sector compared to vertical tanks, investigations in this domain remain scarce. Research on horizontal tanks is crucial for safe and efficient storage. Understanding these dynamics is essential for predicting temperature and pressure changes during self-pressurization, ensuring safe liquid hydrogen storage. This study designed and built a 500-liter horizontal liquid hydrogen tank for vehicle fuel storage, following ISO 13985 standards to ensure practical applicability. The project encompassed material selection, structural design, and both stress and thermodynamic analyses. Preliminary experiments were conducted using liquid nitrogen as a substitute for liquid hydrogen. Experiments assessed tank heat leakage, vapor-cooled shield insulation performance, thermal stratification, lossless storage time, and pressure changes during self-pressurization and steady-state evaporation. Results validate the efficiency of our pressure vessel design method for complex conditions, enhancing understanding of self-pressurization and thermal stratification in horizontal tanks. The vapor-cooled shield reduced heat leakage into the tank by 22.7%, decreasing the daily evaporation rate under liquid nitrogen conditions from 1.87 wt% to 1.5 wt%. and maintaining an initial liquid level of 50% extended the lossless storage time to 50 h in the LN2 scenario. These findings offer valuable insights for assessing the performance of subsequent liquid hydrogen experiments.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 279-293"},"PeriodicalIF":3.5,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662957","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}
Hammad Ur Rahman, Mussawir Ul Mehmood, Ismail Lazoglu
{"title":"A centralized frost detection and estimation scheme for Internet-connected domestic refrigerators","authors":"Hammad Ur Rahman, Mussawir Ul Mehmood, Ismail Lazoglu","doi":"10.1016/j.ijrefrig.2024.10.032","DOIUrl":"10.1016/j.ijrefrig.2024.10.032","url":null,"abstract":"<div><div>Frost accumulation on heat exchange units is a significant problem in refrigeration systems, adversely affecting their operating performance and thereby leading to increased power consumption. Therefore, timely detection and accurate quantification of frost are crucial for effective defrosting strategies. This study presents a novel centralized cloud-based IoT scheme for frost detection and thickness estimation. The image processing is performed on the cloud server to process evaporator coil images for frost thickness quantification. Experiments were conducted on a domestic refrigerator to assess the effectiveness of the proposed image-processing approach and determine latency and processing time. The presented scheme effectively quantifies frost thickness on the evaporator in the 1–5 mm range with a 10.8% error margin. The total inference time, which includes image acquisition, pre-processing, transmission latency, and frost thickness estimation, is approximately 5.15 seconds. The results demonstrate that the proposed image processing method performs comparably to conventional sensors and similar image processing techniques. Moreover, the centralized cloud-based IoT architecture presented effectively meets the scalability demands of consumer refrigerators.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 194-203"},"PeriodicalIF":3.5,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593313","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":"A novel characterization methodology for vapor-injected compressors: A comparative analysis with existing black-box models","authors":"Amjid Khan, Craig R. Bradshaw","doi":"10.1016/j.ijrefrig.2024.10.036","DOIUrl":"10.1016/j.ijrefrig.2024.10.036","url":null,"abstract":"<div><div>In regions characterized by high temperature gradients, vapor compression systems often necessitate operation at very high pressure ratios resulting in a reduction in system capacity. Economized vapor injection compressors are used to avoid these issues, yet a precise predictive map for various compressor technologies with minimal data and relatively better performance remains unclear. This paper establishes a black-box compressor model to accurately predict compressor power, injection mass ratio, and evaporator mass flow rate in compressors with a single vapor injection port. This model is compared against three legacy models from literature and the ANN model, for reference. All five models are evaluated based on their ability to predict the aforementioned metrics. The proposed black-box model can predict the relevant metrics all within 5 % Mean Absolute Percentage Error (MAPE). Additionally, a refrigerant sensitivity analysis is performed with the black-box models. The model is trained using data from R410A and then used the coefficients to predict the performance of the same compressor when using R454B, and vice versa. It can estimate the evaporator mass flow rate with an accuracy within 3 %, the power within 2 %, and the injection mass ratio with MAPE less than 3 %.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 254-266"},"PeriodicalIF":3.5,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662955","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}
Qingpu Li , Yaqi Ding , Xiangqi Meng , Rui Qiu , Neng Gao
{"title":"Experimental investigation on R134a free convection condensation outside the enhanced tubes with different structural micro-fins","authors":"Qingpu Li , Yaqi Ding , Xiangqi Meng , Rui Qiu , Neng Gao","doi":"10.1016/j.ijrefrig.2024.10.033","DOIUrl":"10.1016/j.ijrefrig.2024.10.033","url":null,"abstract":"<div><div>The free convection condensation heat transfer of R134a outside the horizontal copper tubes with micro-fin under heat fluxes varying between 4.2 and 60.2 kW m<sup>2</sup> and saturation temperatures of 35 °C, 40 °C and 45 °C was investigated experimentally in the paper. The difference in four micro-fin tube structure is mainly outer diameter, fin structure, fin number, fin height, etc. The experimental result shows an increase in the heat transfer coefficient is observed with a decrease in the heat transfer temperature difference and saturation temperature, under the same application requirement, the heat transfer temperature difference of smooth tube is close to 3.68∼10.83 times that of enhanced tubes. Meanwhile, refrigerant thermal resistance ratio surpassing 0.5 implies that, in the specific experimental conditions, refrigerant thermal resistance consistently serves as the predominant resistance. Most correlations always underestimate the heat transfer characteristics with a deviation of greater than 26.8 % through the comparative analysis between experimental data and theoretical calculation. Apart from Sreepathi et al. and Kumar et al. correlations, moreover, the prediction effect of three-dimensional micro-fin enhanced tube is inferior to that of two-dimensional micro-fin enhanced tube for the selected correlations. Therefore, a fresh correlation is introduced, incorporating insights from the comparison results presented and the relevant experimental data, it can predict R134a heat transfer coefficient with ±1.0 % mean deviation.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"170 ","pages":"Pages 31-43"},"PeriodicalIF":3.5,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723428","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":"Monitoring the heating energy performance of a heat wheel in a direct expansion air handling unit","authors":"Miklos Kassai , Laith Al-Hyari","doi":"10.1016/j.ijrefrig.2024.10.035","DOIUrl":"10.1016/j.ijrefrig.2024.10.035","url":null,"abstract":"<div><div>This study presents an on-site examination of the heating energy performance of a real ventilation system, running on the flat roof of a shopping complex building in Hungary. The main focus of this study is to delve into the heating energy efficiency of specific air handling elements, such as the air-to-air rotary heat wheel and the direct expansion heating coil supplied by a variable refrigerant volume outdoor unit under real operation conditions. Additionally, an investigation was carried out during the heating season to scrutinize the potential occurrence of CO<sub>2</sub> transfer from the exhaust airflow to the supply airflow within the heat wheel, which issue highlights a notable limitation of the heat recovery system. Based on the monitored and measured data, the energy saving impact of the heat wheel was 20.5 % on the electric power consumption of the variable refrigerant volume outdoor unit throughout the entire heating period, compared to operation without heat wheel. Furthermore, the relative average of CO<sub>2</sub> cross-contamination is recorded as 3.8 % in the investigated heating season.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 115-123"},"PeriodicalIF":3.5,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587467","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":"Achieving off-grid refrigeration in remote areas: A solar-powered vapor compression refrigerator prototype with PCM integration","authors":"Angelo Maiorino , Fabio Petruzziello , Arcangelo Grilletto , Claudio Cilenti , Ciro Aprea","doi":"10.1016/j.ijrefrig.2024.10.028","DOIUrl":"10.1016/j.ijrefrig.2024.10.028","url":null,"abstract":"<div><div>The availability of vaccines, medicines, and perishable goods in remote or off-grid areas remains a formidable challenge. Integrating solar photovoltaic (PV) systems with refrigeration technology has emerged as a promising solution to address this critical need. This paper presents an autonomous solar-powered refrigerator prototype for off-grid refrigeration in remote areas utilising renewable energy. The system comprises a 160 W photovoltaic module, a 12/24 V DC compressor refrigerator, a lead-acid battery, and a Maximum Power Point Tracking (MPPT) controller. Its main feature is complete autonomy from the electricity grid, thanks to its standalone configuration. An experimental campaign evaluated the system's behaviour in the laboratory for 24 h at different set-point temperatures. A water-based Phase Change Material (PCM) was implemented to improve its autonomy in severe outdoor conditions. A further experimental campaign emulated the functioning of the prototype while managing the temperature of a sample solution whose melting temperature was equal to – 21 °C to ensure its liquid state during the tests. The target range for preserving the sample was defined at ± 1 °C. Several real conditions have been considered, such as higher cooling loads realised through 21 litres of additional thermal mass in the refrigerator and pick and place conditions for simulating the opening and closing of the door. The results demonstrate that the solar refrigerator prototype achieves complete autonomy from the electricity grid, paving the way for solutions for preserving perishable goods such as medicines and food in unelectrified areas.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 267-278"},"PeriodicalIF":3.5,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662956","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}
Xujing Lou , Quan Zhang , Sikai Zou , Fanxi Meng , Chang Yue , Hao Zhou , Lixing Wen , Gang Long
{"title":"Field study on the temperature uniformity of containerized batteries using a two-phase liquid cooling system under mismatched conditions","authors":"Xujing Lou , Quan Zhang , Sikai Zou , Fanxi Meng , Chang Yue , Hao Zhou , Lixing Wen , Gang Long","doi":"10.1016/j.ijrefrig.2024.10.023","DOIUrl":"10.1016/j.ijrefrig.2024.10.023","url":null,"abstract":"<div><div>The conventional liquid cooling system carries the risk of dew condensation and air cooling has poor thermal management performance for battery energy storage systems. To address these issues, a novel two-phase liquid cooling system was developed for containerized battery energy storage systems and tested in the field under mismatched conditions. The thermal management performance and safety during the charging and discharging processes were analyzed by investigating the main influencing factors, including battery temperature and cooling system characteristics (battery temperature variation, temperature uniformity, supply liquid temperature, cold plate temperature distribution, and compressor status). The results showed that the novel system can maintain a maximum cell temperature difference of less than 3 °C at the rack level and less than 2 °C at the pack level, resulting in a 60% reduction compared to the traditional air cooling system. Relative to a supply liquid temperature of 15∼25 °C, a relatively high supply temperature of 20∼30 °C for two-phase liquid cooling can not only reduce the running time of the compressor but also enhance its start-stop consistency. Compared to other studies, this novel system is reliable and safe for containerized energy storage batteries, even in capacity mismatch and direct return pipeline conditions.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"170 ","pages":"Pages 85-97"},"PeriodicalIF":3.5,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723424","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}
Eva Kudrnáčová , Tersia Kokošková , Nicole Lebedová , Daniel Bureš
{"title":"Effect of different freezing temperatures on the physical, technological, and organoleptic properties of aged semimembranosus muscles from farmed fallow deer (Dama dama)","authors":"Eva Kudrnáčová , Tersia Kokošková , Nicole Lebedová , Daniel Bureš","doi":"10.1016/j.ijrefrig.2024.10.029","DOIUrl":"10.1016/j.ijrefrig.2024.10.029","url":null,"abstract":"<div><div>Although venison could play an important role in human nutrition, this meat remains undervalued and still contributes very little to the formal meat industry. Moreover, information on processing methods of fallow deer meat and overall quality is still very limited. The objective of this study was to determine how physical, technological, and organoleptic properties differ between 14-day-aged vacuum-packaged fallow deer meat stored either chilled or frozen at different temperatures (-10 °C, -18 °C, -40 °C and -80 °C) for six months. Physical, technological, and organoleptic analyses were conducted on <em>semimembranosus</em> muscles (SM) obtained from farmed fallow deer bucks (<em>n</em>= 10). Freezing significantly increased meat redness, yellowness, chroma values, cooking loss and tenderness compared to fresh meat but did not affect pH values, lightness, thawing, or grilling loss. Mean pH readings were 5.5–5.6, being highest in the samples measured one day after slaughter. Freezing at -80 °C had the most pronounced effect on some sensory attributes, namely, the highest game meat aroma intensity, sour odour, sour flavour and the lowest chewiness. The findings indicate that a freezing temperature of -18 °C and subsequent slow thawing might be preferential in terms of maintaining fallow deer meat quality.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 323-333"},"PeriodicalIF":3.5,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662866","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}