Applied Thermal Engineering最新文献

{"title":"Power generation from self-adsorption and evaporation in Janus hydrovoltaics","authors":"Zheng Liu ,&nbsp;Keyuan Yang ,&nbsp;Guohua Liu","doi":"10.1016/j.applthermaleng.2025.127255","DOIUrl":"10.1016/j.applthermaleng.2025.127255","url":null,"abstract":"<div><div>Adsorption and evaporation is widely available in nature that attracts increasing interests in environmental energy harvesting. Here, we propose self-adsorption and evaporation Janus generator to induce the continuous electricity (ambient humidity of 30 ∼ 85 %), solving the issue of continuous water supply and effective water gradient. The hydrophilic region modified with Calcium chloride (CaCl₂) solution forms self-adsorption functional layer to achieve continuous water supply and the hydrophobic region forms evaporation functional layer. The Janus structure creates a distinct wet/dry interface to maintain effect water gradient. At wetting region, the more positive ions are attracted to carbon surface ascribed to electric double layer (EDL) effect. Through adsorption and evaporation cycles, it generates continuous water flow and ions migration that induces significant potential difference between wetting and drying regions. A centimetre-sized device can generate a continuous voltage of 0.67 V when exposing to the environment. The proposed self-adsorption and evaporation Janus generator provides new insight in environmental energy harvesting, showing great potential in wearable electronic device.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127255"},"PeriodicalIF":6.1,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144320881","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":"Box-Behnken design and artificial neural network guided insights on viscosity reduction and maximum swollen volume of heat-treated sugarcane bagasse based kraft black liquor","authors":"Kumar Anupam ,&nbsp;Anshu ,&nbsp;Shrutikona Das ,&nbsp;Pankaj Kumar Goley ,&nbsp;Ashwani Kumar Dixit","doi":"10.1016/j.applthermaleng.2025.127244","DOIUrl":"10.1016/j.applthermaleng.2025.127244","url":null,"abstract":"<div><div>Heat treatment is an efficient technology for reducing the viscosity and improving the combustion behaviour of non-wood black liquors for chemical recovery in pulp mills. However, the interactive effects of process parameters and predictive modelling of this technology are little reported in the literature. This research presents Box-Behnken Design (BBD) and Artificial Neural Network (ANN) guided insights on a heat treatment process used for addressing the high viscosity and lower swelling problems associated with kraft black liquor of sugarcane bagasse. Here, the heat treatment of sugarcane bagasse based semi-concentrated kraft black liquor (SB_SCKBL) was performed considering the temperature (175–185 °C), time (10–20 min), and residual active alkali (RAA) as Na₂O (4.5–6.5 %) as the process inputs while the viscosity reduction and maximum swollen volume (MSV) as the outputs. The viscosity reduction and MSV quadratic models revealed <em>R²</em> of 1.0 and 0.9869, respectively, with <em>p</em>_value &lt; 0.05, signal: noise &gt;4.0 and non-significant lack of fits. A significant interaction between temperature–time, temperature-RAA, and RAA-time was noted towards viscosity reduction and MSV. A viscosity reduction of 75.24–76.96 % and MSV of 10.3-11.0 ml/g have been obtained at the optimum process conditions with an overall desirability of 0.66. ANN models developed for viscosity reduction and MSV using a back-propagation algorithm gave the overall R-values of 0.999 and 0.832, respectively. The original and optimally heat-treated SB_SCKBL was studied for physicochemical characteristics, SEM, FTIR, XRD, TGA and DSC. This study might be beneficial for designing black liquor heat treatment plants in pulp mills operating on agro-residues.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127244"},"PeriodicalIF":6.1,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144320886","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":"Performance assessment and emission implications of an ammonia co-combustion power system with various coal ranks","authors":"Jester Lih Jie Ling ,&nbsp;Ha Eun Lee ,&nbsp;Hyun Jun Park ,&nbsp;See Hoon Lee","doi":"10.1016/j.applthermaleng.2025.127177","DOIUrl":"10.1016/j.applthermaleng.2025.127177","url":null,"abstract":"<div><div>Ammonia (NH₃)-coal co-combustion has been identified as a key strategy for decarbonizing coal-fired power generation. Large-scale implementation requires a comprehensive investigation into co-combustion behaviour, considering the influence of coal properties on system performance. The variability in coal composition and the resulting flue-gas characteristics necessitate detailed analysis, as their direct effect on system efficiency and emissions is significant. This study presents a simulation of NH₃ co-combustion in a 1 GW ultra-supercritical power cycle, evaluating five different coals (bituminous, sub-bituminous, and three lignite coals) with co-combustion ratios ranging from 0 to 0.5. The findings of this study demonstrated a decline in net efficiency, concomitant with a decrease in calorific values of coal and an increase in co-combustion ratios. The variation in coal compositions also significantly influenced the combustion-temperature trends and thereby the flue-gas composition (especially the NO_x emission). In addition, the properties of the flue-gas had a discernible impact on boiler efficiency and heat-exchange performance. A distinct correlation was observed between boiler efficiency and the primary flue-gas constituents, H₂O, CO₂, and N₂ across different coal ranks, both in terms of molar-flow rate and concentration. A general decrease in the log mean temperature difference (LMTD) was observed as the coal rank shifted from bituminous to lignite. However, with rising co-combustion ratios, a trend reversal was observed in all the lignite coals, with LMTD profiles transitioning from decreasing to increasing, in contrast to the behaviour seen with higher-rank coals. This study provides a comprehensive analysis of NH₃ co-combustion with various coal ranks—offering insights that lay the foundation for the widespread large-scale adoption of relevant technologies.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127177"},"PeriodicalIF":6.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144314484","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":"Geometric optimization for low-degradation film-cooling holes at the leading edge of turbine blades","authors":"Zequn Du,&nbsp;Ruquan You,&nbsp;Haiwang Li,&nbsp;Chenggong Tian,&nbsp;Sheng Quan","doi":"10.1016/j.applthermaleng.2025.127222","DOIUrl":"10.1016/j.applthermaleng.2025.127222","url":null,"abstract":"<div><div>Existing designs for film cooling of turbine blades mainly focus on higher cooling effectiveness, ignoring the performance degradation during actual operation. This oversight can reduce the lifespan and lead to insufficient design reliability. To handle this issue, the conjugate heat transfer method was employed to investigate the impact of geometric deviations of film holes on cooling effectiveness at the leading edge. An optimized design method for the geometric parameters of film holes, aimed at minimizing cooling effectiveness degradation, has been developed. Using Sobol sensitivity analysis, the study revealed that the upper deviation in the hole diameter had a dominant effect on both cooling effectiveness and its degradation, accounting for 57.1 % and 70.2 %, respectively. The deviation in flow direction angle and spanwise angle, when acute, significantly simplified the optimization process. After attenuation, the diameter of the original blade decreased, and the film experienced reverse flow. This led to a sharp reduction in cooling effectiveness, with the area-averaged temperature increasing by 20.2 K. Following optimization, the design diameter of the film holes was reduced in advance, leading to minimal changes in the diameter after attenuation. By optimizing the angles, the film coverage was improved, achieving a compensation effect on the cooling performance. During the optimization process, the total pressure of internal cooling chamber was monitored, and the absolute value was always less than 2 %. As a result of the optimization, the sensitivity of the leading-edge cooling performance to the geometric deviations was reduced, and the overall cooling effectiveness decay rate was lowered by 44 %. The optimization approach enables the fine-tuning of blade design, ensuring long-term reliable operation.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127222"},"PeriodicalIF":6.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144330367","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 method to predict a local Nusselt number profile on the hemispherical surface under air jet impingement cooling","authors":"Suraj Kumar ,&nbsp;Veerendra Kumar ,&nbsp;B. Premachandran","doi":"10.1016/j.applthermaleng.2025.127158","DOIUrl":"10.1016/j.applthermaleng.2025.127158","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This research focuses on accurately estimating the local Nusselt number profile (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) on the hot surface of a convex hemispherical block under air jet impingement cooling using the inverse technique such as Bayesian inverse approach with the Metropolis Hastings–Markov Chain Monte Carlo (MH-MCMC) algorithm, which is critical for applications like thermal treatment of materials, electronics cooling, cooling of turbine blade leading-edge, rocket launcher cooling, rotary cement kiln shell cooling, casting industry processes, etc. To accurately evaluate the local Nusselt number profile on the hot hemispherical surface, the unknown parameters &lt;span&gt;&lt;math&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;, and &lt;span&gt;&lt;math&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; of the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; profile were predicted using the proposed inverse technique combined with artificial neural networks and steady-state temperatures measured on the bottom surface of the hemispherical block. The local Nusselt number profile was predicted as &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;0703&lt;/mn&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;78&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;[&lt;/mo&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;1747&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;001&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;]&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; for the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;L&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; ratio of 6 and Reynolds numbers ranging from 23&lt;!--&gt; &lt;!--&gt;000 to 50&lt;!--&gt; &lt;!--&gt;000. Surrogate and synthetic temperature data were initially employed to assess the effectiveness of the inverse method. The estimated parameters closely matched the target values with low percentage deviations, proving the robustness of the inverse method. The local Nusselt number predicted was then compared against local Nusselt number obtained from experiments and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; turbulence model simulations, showing strong agreement with the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; profile estimated using the Bayesian with MH-MCMC approach. Simulated temperature distributions were also analyzed to understand the thermal behavior on the hemispherical surface under various Reynolds numbers. The findings highlight that the proposed inverse methodology accurately predicts the local Nusselt number profile on the hot hemispherical surface under air jet impingement conditions, with potential applications in optimizing cooling processes in various ","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127158"},"PeriodicalIF":6.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144320885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and theoretical research on evaluation criterion for defrosting initiation time accuracy of air source heat pump","authors":"Yang Tan ,&nbsp;Wenzhe Wei ,&nbsp;Wei Wang ,&nbsp;Yuying Sun ,&nbsp;Shiquan Wang ,&nbsp;Zikun Li ,&nbsp;Zhaoyang Li ,&nbsp;Rui Tang ,&nbsp;Chunxiao Zhang ,&nbsp;Shen Wei","doi":"10.1016/j.applthermaleng.2025.127235","DOIUrl":"10.1016/j.applthermaleng.2025.127235","url":null,"abstract":"<div><div>The defrosting control strategy plays a critical role in influencing the heating performance and reliability of air source heat pump (ASHP). However, there is still a lack of a practical criterion to evaluate the defrosting initiation time accuracy. To solve this problem, an experimental bench was built, and the frosting-defrosting experiments using twenty-one ASHPs from nine manufacturers were conducted. Based on the variation characteristics of energy loss caused by frosting-defrosting, a new testing method, double-cycle method, was developed, which can determine the optimal defrosting initiation time by only two frosting-defrosting processes. Then, utilizing this method, the operation performance distribution at the optimal defrosting initiation time was analyzed, and an evaluation criterion for defrosting initiation time accuracy based on the attenuation rate of heating capacity was proposed. Results showed that the proposed double-cycle method can determine the optimal defrosting initiation time quickly and accurately. It can reduce the experimental duration for determining the optimal defrosting initiation time by 47.56 –56.64 %, and the relative errors in 90% of the experiments were within 5%. Then, by analyzing the operation parameters using this method, a new evaluation criterion, the attenuation rate of 5–20% in heating capacity, was proposed for defrosting initiation time accuracy.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127235"},"PeriodicalIF":6.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on the effect of longitudinal ventilation on the ignition characteristics of fires with multiple ignition sources in tunnels","authors":"Qiuju Ma ,&nbsp;Jianhua Chen ,&nbsp;Zhennan Chen","doi":"10.1016/j.applthermaleng.2025.127201","DOIUrl":"10.1016/j.applthermaleng.2025.127201","url":null,"abstract":"<div><div>Tunnels are long, narrow and confined spaces, and in the event of a fire, multiple sources of ignition are usually involved under the action of flames and hot smoke. However, unlike the common assumption of simultaneous ignition in many existing studies, real tunnel fires typically feature sequential ignition, where a primary fire source ignites surrounding combustibles over time.</div><div>Moreover, longitudinal ventilation, as the most common ventilation method in tunnels, has many complex and contradictory effects on the ignition characteristics of tunnel fires. Therefore, this study addresses this critical by investigating the sequential ignition behavior of multiple oil pool fires under longitudinal ventilation conditions. Data on temperature, gas concentration and radiant heat flux were obtained. The results show that there are two typical ignition conditions for multi-source fires in tunnels under longitudinal ventilation conditions. The ignition time intervals of adjacent oil pans show different patterns with the change of wind speed, but in general, the ignition time intervals of the third oil pan are shorter than those of the second oil pan; and the combustion durations of adjacent oil pans become shorter and shorter with the sequence of oil pan ignition. In addition, when <em>v</em> = 0 m/s, the peak temperature of the ceiling flue gas is symmetrically distributed, and the concentration of the upstream ceiling gas varies with the ignition process of the oil pan. When <em>v &gt;</em> 0 m/s, the peak temperature near the upstream ceiling remains close to ambient levels, and the gas concentration of the upstream ceiling basically has no obvious change. Considering the multiple ignition sources as a whole, it can be found that the temperature rise of the ceiling gas downstream of the multiple ignition sources is exponentially decaying. Therefore, for each critical ignition state, a prediction formula for the temperature rise of the smoke gas downstream of the tunnel multi-fire source is proposed. The results of this study help people to have a comprehensive understanding of the ignition process of tunnel multi-source fires.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127201"},"PeriodicalIF":6.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144339010","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":"Exploring the application of solar irradiation in driving a stand-alone membrane distillation unit","authors":"Ndamulelo N. Phosha ,&nbsp;Xolile G. Fuku ,&nbsp;Leonard Tijing ,&nbsp;Machawe M. Motsa","doi":"10.1016/j.applthermaleng.2025.127169","DOIUrl":"10.1016/j.applthermaleng.2025.127169","url":null,"abstract":"<div><div>This work presents the evaluation of a solar energy-driven membrane distillation process with significant promise for generating high-quality water from seawater, brackish water, and hard groundwater. In addition, PVDF/EPS blended membranes were developed through the addition of triacetin, silicone oil, and polydimethyl siloxane (PDMS). Scanning electron microscopy revealed that with immersion in an ethanol–water coagulation bath, the porosity of the membranes increases with the triacetin membrane exhibiting the highest porosity as seen on the SEM and supported by the permeate fluxes. The addition of the PDMS and silicone oil led to an increase in contact angle with the membrane modified with PDMS having a contact angle of 109 ± 3.5 and 108 ± 2.63 and the silicone oil membrane had a contact angle of 101.39 ± 1.73 and 101.1 ± 1.28. The triacetin membrane had better permeate flux of 9.19 kg/m²h compared to PDMS and silicone which had 4.53 and 5.52 kg/m²h respectively at the highest operational temperature of 65 °C. The developed solar irradiation device was able to double the ambient air temperature during the MD process and the highest recorded temperature was 62 °C. Heat generation was dependent of environment temperatures; however, the peak temperature was maintained for a period of 3 h after the environmental temperature had started declining. The salt rejection for synthetic NaCl solution, hard groundwater and seawater was 99 %. The findings of this study demonstrated that the readily available solar energy can be directly incorporated to heat feedwater in a scalable stand-alone setup and subsequently be deployed in highly irradiated regions.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127169"},"PeriodicalIF":6.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144314485","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":"Set-point temperature representation in a resistance–capacitance network model to predict both heating rates and room temperatures","authors":"Seon-In Kim ,&nbsp;Ju-Hong Oh ,&nbsp;Eui-Jong Kim","doi":"10.1016/j.applthermaleng.2025.127228","DOIUrl":"10.1016/j.applthermaleng.2025.127228","url":null,"abstract":"<div><div>This study proposes a novel control-oriented Resistance–Capacitance (RC) model that incorporates a set-point temperature representation to enhance compatibility with real Heating, Ventilation, and Air-Conditioning (HVAC) systems and to improve predictive control accuracy. Model Predictive Control (MPC) is increasingly adopted in HVAC applications, where the effectiveness of control relies on accurate physical modeling. Conventional RC models typically calculate the required heating rate by controlling the room temperature, whereas actual HVAC systems operate based on set-point temperatures. This mismatch between the control input in the model and actual system behavior can lead to prediction and control errors. The proposed model introduces a time-variable thermal resistance between the set-point and room temperatures and calculates the heating rate based on the temperature difference. This structure enables the direct use of the set-point as the control input and allows the simultaneous prediction of both the room temperature and heating rate while preserving physical interpretability. Because the set-point temperature is the target in actual Air Handling Unit (AHU) operations, the model improves both the stability and accuracy. Validation using real building data showed that the proposed model achieved a 3.6% improvement in room temperature prediction over the reference model. For the AHU heating rate prediction, which conventional RC models do not explicitly address, the model demonstrated acceptable performance. The proposed RC model provides a practical and accurate framework for MPC-based HVAC control implementation by capturing the natural convergence of room temperature towards the set point and explicitly modeling its influence.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127228"},"PeriodicalIF":6.1,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144306704","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":"Computational generation of energy-efficient rural residential floor plans under hot summer and cold winter climates based on segmentation algorithm model","authors":"Fang’ai Chi,&nbsp;Guoqing Zhu","doi":"10.1016/j.applthermaleng.2025.127227","DOIUrl":"10.1016/j.applthermaleng.2025.127227","url":null,"abstract":"<div><div>Building sector accounts for a large energy consumption, while the “Digital Intelligence” technology has a promising perspective in the energy-efficient building design. The functional layout and the spatial geometry have significant impacts on the building energy consumption. Compared to the current research status, the novelty of this work is that a segmentation algorithm model with capacities of generative design and energy consumption optimization was proposed to the rural residential buildings. The segmentation algorithm model was used to obtain the design building parameters, optimize the functional space layout and generate the design schemes. Among the design schemes of floor plans generated from the proposed algorithm model, the most energy-efficient one was exported, by assigning the large energy demand rooms to the low energy consumption intensity locations, and selecting the minimum sum of the ratios of room perimeter to the total area of floor plan. A comparison study between the base case and the generated scheme was conducted, under the Hangzhou’s climate, and a difference of 792 kW·h between the two buildings was realized, with energy saving rate of 6.4 %. Therefore, through the proposed segmentation algorithm model, the design schemes of the rural residential buildings could be automatically optimized and generated.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"278 ","pages":"Article 127227"},"PeriodicalIF":6.1,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144330228","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}