Case Studies in Thermal Engineering最新文献

Thermal performance of shell-and-tube polymeric hollow fiber heat exchangers as oil coolers 壳管式聚合物中空纤维热交换器作为油冷却器的热性能

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-10-22 DOI: 10.1016/j.csite.2024.105329

{"title":"Thermal performance of shell-and-tube polymeric hollow fiber heat exchangers as oil coolers","authors":"","doi":"10.1016/j.csite.2024.105329","DOIUrl":"10.1016/j.csite.2024.105329","url":null,"abstract":"<div><div>Motor oil must be appropriately treated in motors, and aluminum plate heat exchangers are used to cool it. An aluminum heat exchanger is an additional part of the oil treatment module, which increases its size and weight. Two compact plastic shell-and-tube heat exchangers were tested alongside with aluminum heat exchanger to evaluate the efficiency of the plastic cooling core inside the oil module. A total of 63 experimental points were tested on three heat exchangers with good thermal balance (discrepancy of about 1,8 %), and the data were used to evaluate the heat transfer coefficients. While plastic unit PA11 showed the heat outputs exceeding the heat output of the aluminum plate unit by about 7 %, the pressure drops were about ten times higher. The unit PEEK showed good performance and pressure drops on the oil side, but the heat transfer was limited by a small heat transfer surface. Analysis of thermal resistances confirmed that the thermal resistance between the wall and the oil is dominant due to the oil's low thermal conductivity and high viscosity. The results showed that optimization of the fiber structures is needed, aiming to increase the oil flow around the fiber structures.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529201","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

Thermal runaway evolution of a 4S4P lithium-ion battery pack induced by both overcharging and unilateral preheating 过充电和单侧预热诱发 4S4P 锂离子电池组的热失控演化

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-10-22 DOI: 10.1016/j.csite.2024.105324

{"title":"Thermal runaway evolution of a 4S4P lithium-ion battery pack induced by both overcharging and unilateral preheating","authors":"","doi":"10.1016/j.csite.2024.105324","DOIUrl":"10.1016/j.csite.2024.105324","url":null,"abstract":"<div><div>To clarify the thermal runaway characteristics of lithium-ion battery pack, this study has established a thermal runaway experimental platform based on actual power battery pack. A 4 in series and 4 in parallel battery pack was assembled using 86 Ah lithium iron phosphate batteries, and the experiment of thermal runaway induced by overcharging and unilateral preheating was carried out. The behavior and characteristics including the temperature change characteristics of each cell, the heat generated and transfer paths during thermal runaway propagation, the voltage changes of each serial module and the total voltage, flame evolution behavior, gas generation characteristics, debris, and mass loss were investigated. The research results show that module 1 was the first to experience thermal runaway due to preheating. The redistributed current caused the batteries in the remaining modules to rapidly generate heat. Subsequently, the heat transfer from module 1 triggered thermal runaway in modules 2, 3, and 4 in sequence. The entire flame combustion process lasted for 38 min, with the maximum temperature reaching 937.1 °C, resulting in thermal runaway in all batteries. The sequence of thermal runaway has been clarified, with the flame generated by the ignition of the battery casing, connecting tabs, and combustible gases emitted from the batteries serving as the primary paths for heat transfer and thermal radiation. The experimental results provide valuable insights into the thermal engineering issues of large-scale lithium-ion battery pack.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529202","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

Multi-criteria study and machine learning optimization of a novel heat integration for combined electricity, heat, and hydrogen production: Application of biogas-fueled S-Graz plant and biogas steam reforming 多标准研究和机器学习优化新型热能集成系统，实现电力、热能和氢气的联合生产：以沼气为燃料的 S-Graz 工厂和沼气蒸汽转化的应用

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-10-22 DOI: 10.1016/j.csite.2024.105323

{"title":"Multi-criteria study and machine learning optimization of a novel heat integration for combined electricity, heat, and hydrogen production: Application of biogas-fueled S-Graz plant and biogas steam reforming","authors":"","doi":"10.1016/j.csite.2024.105323","DOIUrl":"10.1016/j.csite.2024.105323","url":null,"abstract":"<div><div>The current research introduces an environmentally friendly heat design method by employing biogas fuel, aiming to yield electricity, hydrogen, and heating load simultaneously. The proposed arrangement consists of a biogas-powered S-Graz plant and a biogas steam reforming cycle. Although methane-fueled S-Graz plants for multigeneration purposes have been studied in previous studies, research on employing biogas fuel to launch a S-Graz plant and integrating a biogas steam reforming cycle with such a plant has yet to be examined. The model is simulated using the engineering equation solver software, and the study includes thermodynamic, exergoeconomic, and sustainability assessments to show the potential of the suggested configuration. By conducting a sensitivity study, a machine learning optimization method within MATLAB is implemented to exhibit the final optimal solution for the proposed arrangement. This optimization uses artificial neural networks and a non-dominated sorting genetic algorithm-II algorithm in a triple-objective framework based on energy efficiency, sustainability index, and products’ specific cost. The optimization demonstrates that the mentioned objectives reach optimal values of 58.26 %, 4.56, and 15.56 $/GJ, respectively. Also, the optimal net output power and hydrogen production rate equal 5746 kW and 1.45 m<sup>3</sup>/s, respectively. Besides, the process determines the optimal exergy efficiency, total net present value, and payback period as 52.70 %, 50.3 M$, and 8.96 years, respectively. The total investment cost rate for this system also is found to be 219.8 $/h.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529767","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

Impact of collector aspect ratio on the energy and exergy efficiency of a louvered fin solar air heater 集热器长宽比对百叶窗翅片太阳能空气加热器能效和放能效的影响

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-10-22 DOI: 10.1016/j.csite.2024.105312

引用次数: 0

Thermodynamic evaluation of a Ca-Cu looping post-combustion CO2 capture system integrated with thermochemical recuperation based on steam methane reforming 基于蒸汽甲烷重整的钙-铜循环燃烧后二氧化碳捕集系统与热化学回收的热力学评估

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-10-22 DOI: 10.1016/j.csite.2024.105327

{"title":"Thermodynamic evaluation of a Ca-Cu looping post-combustion CO2 capture system integrated with thermochemical recuperation based on steam methane reforming","authors":"","doi":"10.1016/j.csite.2024.105327","DOIUrl":"10.1016/j.csite.2024.105327","url":null,"abstract":"<div><div>The calcium looping integrated with the chemical looping combustion (CaL-CLC) process is an efficient and cost-effective CO<sub>2</sub> capture technology that avoids the energy-intensive air separation unit in the calcium looping (CaL) process. However, in these CaL-CLC and CaL system integration schemes, the carbonation heat is utilized for steam generation, resulting a significant temperature difference and considerable irreversible loss. To prevent temperature mismatch, this paper proposes a novel Ca-Cu looping post-combustion CO<sub>2</sub> capture method with thermochemical recuperation based on steam methane reforming. Additionally, a novel system integrated with turbine exhaust heat recovery is introduced to effectively reduce carbon emissions from flue gas. Results show that the proposed system has superior performance compared to the reference system based on the Ca-Cu looping method. The specific primary energy consumption for CO<sub>2</sub> avoidance decreased from 2.40 MJ<sub>LHV</sub>/kg CO<sub>2</sub> in the reference system to 2.02 MJ<sub>LHV</sub>/kg CO<sub>2</sub>. Exergy analysis indicates that a total of 3.0 % reduction in exergy destruction can be achieved in chemical reaction processes and heat recovery processes, contributing to the superior performance of the proposed system. Furthermore, the effects of key operating parameters indicate that cascaded turbine exhaust recovery is essential for improving the thermodynamic efficiency of the proposed system. Overall, recovering the mid-temperature carbonation heat via thermochemical regeneration and integrating with exhaust heat recovery contribute to reducing SPECCA, thus providing a promising low-energy-consumption alternative for CO<sub>2</sub> capture.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529198","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

A high-performance all-day vertical thermoelectric generator based on a double-sided reflective structure 基于双面反射结构的高性能全天候垂直热电发生器

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-10-22 DOI: 10.1016/j.csite.2024.105333

{"title":"A high-performance all-day vertical thermoelectric generator based on a double-sided reflective structure","authors":"","doi":"10.1016/j.csite.2024.105333","DOIUrl":"10.1016/j.csite.2024.105333","url":null,"abstract":"<div><div>Harvesting environmental energy sources is crucial for achieving renewable energy generation and net-zero emissions. However, ensuring uninterrupted electricity generation from environmental energy sources remains challenging. In this study, we present a simple, compact, and expandable all-day vertical passive thermoelectric generator (V-TEG) with a double-sided reflective structure that simultaneously harnesses solar and space cold energy. Outdoor experimental measurements, combined with finite element simulation analysis, revealed that the optimal angles of the solar reflector relative to the TEG range from 30° to 50°. Additionally, the TEG placed in the north–south orientation was found to enhance its daytime performance. The use of low-cost black paint combined with the solar reflector achieved equivalent spectral selectivity, effectively minimizing the infrared heat loss of the hot end of the TEG. During a 48-h outdoor test, the V-TEG achieved an average daytime power of 112.00 mW/m<sup>2</sup> and a peak of 363.42 mW/m<sup>2</sup>. Comparative experiments demonstrated that the V-TEG outperformed horizontally placed TEG during the daytime. Furthermore, scaling the system by connecting three TEGs in series significantly increased the daily power output. This compact V- TEG system offers a promising solution for long-term power generation in low-power sensors and off-grid communities, supporting renewable energy and carbon neutrality goals.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529292","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

Research on the process of heat transfer between mobile variable temperature heat source and thermoacoustic plate 移动变温热源与热声板之间的传热过程研究

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-10-22 DOI: 10.1016/j.csite.2024.105311

{"title":"Research on the process of heat transfer between mobile variable temperature heat source and thermoacoustic plate","authors":"","doi":"10.1016/j.csite.2024.105311","DOIUrl":"10.1016/j.csite.2024.105311","url":null,"abstract":"<div><div>The purpose of this paper is to analyze the effects of several easy-to-operate parameters (operating frequency, plate stack length, plate stack position, and amplitude) on the refrigeration performance, to explore the optimization path of thermoacoustic refrigerator, and to provide a design basis for further cost reductions. The heat transfer process between the air mass and the plate was investigated as an object, and the physical and mathematical models of the heat transfer process were established. The gas microcluster moving heat and plate stack temperature difference were taken as the response. Operating frequency, plate position, plate length and gas vibration displacement amplitude were the design factors. The change relationship of the system response under the interaction of factors was analyzed by using the central composite experimental design and the response surface method, and experimental verification was carried out. The results show that the deviation of the predicted model from the experimental data is less than 5.9 % when the operating frequency is in the range of 0 Hz–12 Hz, and that the location of the plate stack is 0.45 from the pressure belly point of the sound field, where the heat of the air mass transfer is the largest.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529203","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

Thermal resistance capacity model for transient simulation of capillary-box heat exchangers 用于毛细管箱式热交换器瞬态模拟的热阻容量模型

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-10-21 DOI: 10.1016/j.csite.2024.105321

{"title":"Thermal resistance capacity model for transient simulation of capillary-box heat exchangers","authors":"","doi":"10.1016/j.csite.2024.105321","DOIUrl":"10.1016/j.csite.2024.105321","url":null,"abstract":"<div><div>In this paper, a novel simplified hybrid model is developed to simulate the transient thermal behaviors of capillary-box heat exchangers (CBHEs) buried in the seabed, serving as the front-end heat exchangers in seawater source heat pump system (SWHPs). The thermal resistance and capacity (TRC) approach is applied for derivation of the governing equations inside and outside the heat exchangers. Also, an analytical solution is integrated to model heat transfer in the seabed base. The effects of seawater seepage on the thermal performance of CBHEs are taken into account in the present model. The state-space representation is used to solve the governing equations. The model is verified against experimental data, achieving very good agreement with the mean bias error (<em>MBE</em>) of 7.2 %. A comparison with a three-dimensional computational fluid dynamic (CFD) model indicates that the TRC model's maximum relative error and <em>MBE</em> are 0.7 % and 2.0 % lower than those of the CFD model. Additionally, the ratio of the time required by the CFD and TRC models for a 31-day run was 138. These results demonstrate that the TRC model is sufficiently accurate and fast in the thermal simulation of CBHEs. Furthermore, the thermal properties of CBHEs are examined using the present model. The model in this study provides practical implications for heat transfer analysis and design improvement of CBHEs utilized in SWHPs.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529200","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 analysis of the influence of PCM on the thermal behavior of lightweight buildings in different natural environments 不同自然环境下 PCM 对轻质建筑热行为影响的实验分析

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-10-21 DOI: 10.1016/j.csite.2024.105320

{"title":"Experimental analysis of the influence of PCM on the thermal behavior of lightweight buildings in different natural environments","authors":"","doi":"10.1016/j.csite.2024.105320","DOIUrl":"10.1016/j.csite.2024.105320","url":null,"abstract":"<div><div>Phase-change materials (PCM) can effectively improve the thermal performance of lightweight buildings, but their heat storage and release capacity are highly dependent on the heat exchange between the wall surface and the ambient environments. However, the current research mostly focuses on numerical simulation in a specific climate environment, and the effectiveness of PCM on the thermal regulation of lightweight buildings under a long-period natural environment is insufficient. Therefore, two experimental rooms (with and without PCM) of the same size were built and conducted in this paper to compare the changing rules of wall surface temperature, heat flux, and indoor temperature in different seasons without mechanical equipment. The results show that: (1) The effect of PCM on the thermal performance of lightweight buildings is highly correlated with seasons, and its contribution efficiency varies in different seasons; (2) The attenuation rate of the internal surface temperature in different seasons can be reduced by 18.08%–42.90 %, the delay time can be improved to 2.67–4 h compared with the reference wall; (3) PCM can effectively inhibit the fluctuation and rise of indoor temperature, which can reduce the maximum indoor temperature by 4.9–12.0 °C, increase the minimum temperature by 1.1–2.8 °C, and the thermal comfort hours added by 2–5 h; (4) Lightweight buildings incorporating PCM can saves 18.69 % and 49.63 % for the peak cooling in summer and transition seasons, and 15.9 % for the heating in winter. The research results can provide the theoretical basis and experimental support for the efficient application of PCM in lightweight buildings.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529284","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

Numerical investigation on thermal performance of three configurations of solar thermal collector integrated with metal hydride 对集成了金属氢化物的三种太阳能集热器配置的热性能进行数值研究

IF 6.4 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-10-21 DOI: 10.1016/j.csite.2024.105314

{"title":"Numerical investigation on thermal performance of three configurations of solar thermal collector integrated with metal hydride","authors":"","doi":"10.1016/j.csite.2024.105314","DOIUrl":"10.1016/j.csite.2024.105314","url":null,"abstract":"<div><div>This study investigates the optimal configuration of a Metal Hydride-based Solar Thermal Collector (MH-STC) by developing a transient 3D mathematical model to simulate three distinct configurations: C1, C2, and C3. These configurations differ in the placement of water pipes within the metal hydride bed C1 features pipes in the top region, C2 in the core zone, and C3 at the bottom. The performance of these configurations was rigorously compared based on hydrogen charge state, outlet water temperature, useful energy output, and thermal efficiency across varying water flow rates. Results reveal that configuration C1 achieves superior thermal performance during daytime operation, producing outlet temperatures up to 10 °C higher than the other configurations. Conversely, configuration C3 excels at nighttime heating, delivering water temperatures approximately 11.5 °C higher than C1. Furthermore, the analysis indicates that hydrogen desorption pressure significantly impacts outlet water temperature; for instance, increasing the pressure from 2.41 bar to 6 bar enhances the average outlet temperature of the C3 design by about 20 °C during the day and reduces it by approximately 15 °C at night. These findings highlight the critical need for optimizing solar collector designs to effectively meet the thermal demands of both daytime and nighttime applications.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529196","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