IF 9.4 1区工程技术

Energy Pub Date : 2025-09-23 DOI: 10.1016/j.energy.2025.138576

Ramazan Macit , Hanife Apaydın Özkan , Tolga Baklacioglu

{"title":"Machine learning-based fuel flow rate prediction for Boeing 737-800 aircraft: A comprehensive approach across climb, cruise and descent flight phases","authors":"Ramazan Macit , Hanife Apaydın Özkan , Tolga Baklacioglu","doi":"10.1016/j.energy.2025.138576","DOIUrl":"10.1016/j.energy.2025.138576","url":null,"abstract":"<div><div>This study presents a novel approach for unified Fuel Flow Rate (FFR) prediction across climb, cruise, and descent phases of a Boeing 737-800, using real flight data records, which is proven to provide superior accuracy compared to the existing models in the literature using the flight phase-limited approach. Unlike traditional mathematical models, the proposed framework employs machine learning techniques to accurately capture fuel consumption patterns. FFR is predicted based on 11 input features: altitude, Mach number, total air temperature, wind speed, rate of climb/descent, exhaust gas temperatures for engines 1 and 2, and engine power settings (N11C, N21C, N12C, N22C). Four models are implemented and compared: a two-layer Feed-Forward Network (FFN), a Nonlinear Autoregressive Exogenous (NARX), a Long-Short Term Memory (LSTM) model, and a Layer Recurrent Network (LRN). Performance is evaluated using mean absolute error, mean absolute percentage error, root mean square error, and R metrics, while generalizability is tested on eight completely unseen flight data. Among the tested models, the LRN delivers the most accurate results, proving to be highly effective for predicting fuel flow rate. Additionally, a comparative analysis with previous studies reveals that the proposed model achieves superior performance compared to existing methods across the considered flight phases.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"337 ","pages":"Article 138576"},"PeriodicalIF":9.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cooperative energy management and fuel cell thermal management of fuel cell hybrid electric buses via multi-agent reinforcement learning 基于多智能体强化学习的燃料电池混合动力客车协同能量管理和燃料电池热管理

IF 9.4 1区工程技术

Energy Pub Date : 2025-09-23 DOI: 10.1016/j.energy.2025.138534

Sichen Gao , Fei Ju , Weichao Zhuang , Qun Wang , Yuhua Zong , Liangmo Wang

{"title":"Cooperative energy management and fuel cell thermal management of fuel cell hybrid electric buses via multi-agent reinforcement learning","authors":"Sichen Gao , Fei Ju , Weichao Zhuang , Qun Wang , Yuhua Zong , Liangmo Wang","doi":"10.1016/j.energy.2025.138534","DOIUrl":"10.1016/j.energy.2025.138534","url":null,"abstract":"<div><div>This study proposes a collaborative control strategy based on multi-agent reinforcement learning (MARL) to tackle the dynamic coupling optimization challenge between the energy management strategy (EMS) and the fuel cell thermal management strategy (FCTMS) in hydrogen fuel cell hybrid electric buses. Specifically, the EMS adopts a multi-objective equivalent consumption minimization strategy (ECMS), incorporating penalty terms for powertrain state-of-health (SOH) degradation and temperature violations. To maintain battery state-of-charge (SOC), this multi-objective ECMS employs the twin delayed deep deterministic policy gradient (TD3) algorithm to dynamically adjust its equivalent factor (EF). Meanwhile, the FCTMS utilizes fuel cell power as one of the state information to guide another TD3 agent in synchronously optimizing coolant flow rate and radiator air flow rate, ensuring optimal operating temperature. Results show that, compared with a hierarchical control strategy integrating ECMS (neglecting powertrain durability and thermal characteristics) and PID-based FCTMS, the proposed strategy significantly reduces driving cost, fuel cell SOH degradation, battery SOH degradation, fuel cell temperature violations, fuel cell outlet–inlet temperature difference violations and battery temperature violations by 5.30%, 3.86%, 10.62%, 99.02%, 47.68% and 29.33%, respectively. Moreover, further investigation demonstrates that the proposed strategy exhibits superior adaptability to unknown driving scenarios.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"337 ","pages":"Article 138534"},"PeriodicalIF":9.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145120388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on enhanced heat transfer mechanism for crossflow-counterflow combined mechanical draft cooling tower 横流-逆流联合机械通风冷却塔强化传热机理研究

IF 9.4 1区工程技术

Energy Pub Date : 2025-09-23 DOI: 10.1016/j.energy.2025.138656

Hongming Chen, Youhao Wang, Xiaojing Yuan, Suoying He, Ming Gao

{"title":"Study on enhanced heat transfer mechanism for crossflow-counterflow combined mechanical draft cooling tower","authors":"Hongming Chen, Youhao Wang, Xiaojing Yuan, Suoying He, Ming Gao","doi":"10.1016/j.energy.2025.138656","DOIUrl":"10.1016/j.energy.2025.138656","url":null,"abstract":"<div><div>This paper proposes a crossflow-counterflow combined mechanical draft cooling tower structure, aiming to reconstruct the flow field within the tower and enhance air-water heat transfer. Through numerical simulation, the study deeply investigates the influence mechanisms of five key parameters (middle zone water-spraying density <em>q</em><sub>2</sub>, outer zone water-spraying density <em>q</em><sub>3</sub>, middle zone water-spraying width <em>L</em>, crossflow filling height <em>H</em>, and crossflow filling width <em>D</em>) on the aerodynamic field and air-water temperature field within the tower, identifying an optimal parameter combination within the study scope. The results showed these parameters significantly affected the aerodynamic field distribution by regulating the balance between ventilation resistance and water-spraying density, thereby optimizing airflow organization. Concurrently, adjustments in the flow field led to adjustments in ventilation rate, which combined with the water-spraying density to reconfigure the air-water temperature field and in turn influenced heat and mass transfer efficiency. Orthogonal analysis obtained the optimized parameter combination: <em>D</em> = 2 m, <em>H</em> = 1 m, <em>L</em> = 1.5 m, <em>q</em><sub>2</sub> = 3 kg/(m<sup>2</sup>·s), <em>q</em><sub>3</sub> = 3 kg/(m<sup>2</sup>·s). Under this configuration, the circulating water temperature drop reached 12.12 °C, showing a 3.5 % improvement compared to the original counterflow mechanical draft cooling tower, significantly enhancing the thermal performance of the cooling tower. This research provides crucial theoretical foundations and engineering application references for optimizing cooling tower designs.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"337 ","pages":"Article 138656"},"PeriodicalIF":9.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

City low-carbon transition efficacy evaluation and prediction based on game combination empowerment and Stacking integration model —An example of 296 cities in China 基于博弈组合赋能与堆叠整合模型的城市低碳转型效能评价与预测——以中国296个城市为例

IF 9.4 1区工程技术

Energy Pub Date : 2025-09-23 DOI: 10.1016/j.energy.2025.138612

Dongxiao Niu , Ruoyun Du , Xiaomin Xu , Yanpei Zhao

{"title":"City low-carbon transition efficacy evaluation and prediction based on game combination empowerment and Stacking integration model —An example of 296 cities in China","authors":"Dongxiao Niu , Ruoyun Du , Xiaomin Xu , Yanpei Zhao","doi":"10.1016/j.energy.2025.138612","DOIUrl":"10.1016/j.energy.2025.138612","url":null,"abstract":"<div><div>The low-carbon transition is imperative for addressing global climate change and advancing sustainable development. In response to China's “3060” strategy, Chinese provinces and cities have implemented measures to ensure sustainable development. This study constructs a low-carbon transition efficacy (LCTE) assessment system covering energy consumption and carbon emissions, energy structure and efficiency, green economy and innovation, and the urban environment and ecology. By adopting the game empowerment method, combining the BBWM and IDOCRIW methods, the approach proposed in this paper mitigates the limitations of single-method weighting. Furthermore, a Stacking model is used to predict Chinese cities' LCTE trends from 2024 to 2030. The results demonstrate an overall upward trend in LCTE across 292 Chinese cities from 2006 to 2022, with significant regional disparities. The eastern region maintains multidimensional leadership, bolstered by robust economic foundations and policy incentives; the central region exhibits steady yet gradual progress; and the western and northeastern regions encounter heightened transition pressures. The LCTE is forecast to increase modestly nationwide from 2024 to 2030. By systematically evaluating and forecasting the trend of Chinese LCTE, this study comprehensively explores the diversity and specificity of Chinese cities in the low-carbon economic transition and proposes targeted recommendations, providing an important theoretical basis for urban planning and coordinated regional development.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"337 ","pages":"Article 138612"},"PeriodicalIF":9.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of blade-to-blade wake interference on aerodynamic performance of darrieus vertical axis wind turbines 叶片尾迹干扰对达瑞氏垂直轴风力机气动性能的影响

IF 9.4 1区工程技术

Energy Pub Date : 2025-09-23 DOI: 10.1016/j.energy.2025.138646

Kai Zhang, Peiyu Cao, Yuming Liang, Zilong Wang, Qingqing Gu

{"title":"Effect of blade-to-blade wake interference on aerodynamic performance of darrieus vertical axis wind turbines","authors":"Kai Zhang, Peiyu Cao, Yuming Liang, Zilong Wang, Qingqing Gu","doi":"10.1016/j.energy.2025.138646","DOIUrl":"10.1016/j.energy.2025.138646","url":null,"abstract":"<div><div>This study employs two-dimensional numerical simulations to systematically evaluate the effects of blade number and solidity on the power coefficient and unsteady flow characteristics of H-type Darrieus vertical axis wind turbines (VAWTs). Although conventional VAWTs designs typically adopt three or more blades, the results indicate that even under optimal tip-speed ratio conditions, such multi-blade configurations exhibit relatively low power coefficients. Through detailed analysis of velocity, vorticity, and turbulence intensity fields, the mechanisms underlying torque fluctuations, wake interactions, and blade load distributions are elucidated. The findings reveal that although the single-blade configuration achieves the highest power coefficient, exceeding the two-blade design by 3.6 %, it suffers from significant torque fluctuations that impair operational stability. In contrast, the two-blade VAWT offers an optimal balance, delivering a power coefficient 1.6 % higher than conventional three-blade designs, along with lower peak turbulence intensity and faster flow recovery within the rotor. Crucially, multi-blade configurations (3–5 blades) experience severe wake interference. As the number of blades increases, the vortex shedding frequency rises markedly, and cumulative wake effects lead to delayed flow recovery, resulting in a 7.2 % reduction in power coefficient. Furthermore, each blade number corresponds to a distinct optimal solidity value. While reducing the number of blades enhances instantaneous energy capture efficiency, increasing the blade count improves torque stability at the cost of greater wake losses. These insights provide new perspectives on rotor optimization for VAWTs and offer valuable guidance for the future design of vertical axis wind turbines.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"337 ","pages":"Article 138646"},"PeriodicalIF":9.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Novel numerical method for simultaneous design and control optimization of seasonal thermal energy storage systems 季节性蓄热系统同步设计与控制优化的新数值方法

IF 9.4 1区工程技术

Energy Pub Date : 2025-09-23 DOI: 10.1016/j.energy.2025.138580

Wonsun Song , Jakob Harzer , Christopher Jung , Leon Sander , Moritz Diehl

{"title":"Novel numerical method for simultaneous design and control optimization of seasonal thermal energy storage systems","authors":"Wonsun Song , Jakob Harzer , Christopher Jung , Leon Sander , Moritz Diehl","doi":"10.1016/j.energy.2025.138580","DOIUrl":"10.1016/j.energy.2025.138580","url":null,"abstract":"<div><div>The transition to a carbon-neutral energy system requires widespread deployment of renewable energy sources and economically feasible energy storage solutions. This study presents a comprehensive optimization framework that jointly addresses the design and control of a nonlinear energy system supplying both heat and electricity to the Dietenbach district in Freiburg, Germany. The proposed system integrates solar and wind power with battery storage and seasonal thermal energy storage coupled via a heat pump, enhancing self-sufficiency and mitigating seasonal supply–demand mismatches. A multi-node lumped-parameter model captures heat transfer within the pit thermal energy storage, forming the basis of a periodic optimal control problem solved numerically. An averaging method reduces computation time by 80.5% while preserving fidelity for year-long optimization. A case study shows a projected total yearly energy cost of 5.93€/m<sup>2</sup> for combined heat and electricity, which is 73% lower than the German average. This study underscores the feasibility of designing economically viable, autonomous energy communities in real-world scenarios and provides an efficient, robust optimization framework for designing system components and operational control strategies.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"337 ","pages":"Article 138580"},"PeriodicalIF":9.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Three-dimensional thermodynamic analysis of hydrogen-enriched methanol combustion enabled by integrated steam reforming 一体化蒸汽重整实现富氢甲醇燃烧的三维热力学分析

IF 9.4 1区工程技术

Energy Pub Date : 2025-09-23 DOI: 10.1016/j.energy.2025.138625

Ruizhao Gao , Kunteng Huang , Ruihua Chen , Ruikai Zhao , Jian Li , Jun Shen , Li Zhao

{"title":"Three-dimensional thermodynamic analysis of hydrogen-enriched methanol combustion enabled by integrated steam reforming","authors":"Ruizhao Gao , Kunteng Huang , Ruihua Chen , Ruikai Zhao , Jian Li , Jun Shen , Li Zhao","doi":"10.1016/j.energy.2025.138625","DOIUrl":"10.1016/j.energy.2025.138625","url":null,"abstract":"<div><div>Due to growing concerns over carbon emissions and the need for cleaner alternative fuels, methanol has emerged as a promising candidate for internal combustion engines owing to its high hydrogen content, low carbon intensity, and ease of storage. However, methanol encounters considerable difficulties during cold start conditions, mainly attributed to its low volatility and high latent heat of vaporization. To address this challenge, this study proposes an integrated approach combining in-cylinder steam reforming and hydrogen-enriched combustion of methanol. A comprehensive equilibrium-based thermodynamic model is developed to simulate the combustion–reforming coupling process, accounting for key parameters such as pressure ratio, air fuel ratio, and ambient conditions. The results demonstrate that methanol steam reforming significantly enhances hydrogen yield, with the content of combustible gaseous components in the fuel increasing by 70 % compared to non-reformed conditions. A high pressure ratio in compression stroke is beneficial for improving internal combustion engine performance and methanol steam reforming, whereas the air fuel ratio exhibits the opposite effect on internal combustion engine performance. Following dual-objective optimization of an Otto cycle incorporating methanol steam reforming, the optimal operating conditions were determined to be a pressure ratio no lower than 17 and an air-fuel ratio of approximately 14, yielding a thermal efficiency of 34.11 % and a hydrogen conversion of 33.67 %. This study aims to establish a foundational theoretical framework to guide the future design and optimization of methanol-fueled internal combustion engines.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"337 ","pages":"Article 138625"},"PeriodicalIF":9.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Progress in innovative technologies in thermal insulation for cryogenic applications 低温应用隔热创新技术的进展

IF 9.4 1区工程技术

Energy Pub Date : 2025-09-23 DOI: 10.1016/j.energy.2025.138658

Parul Soni , Nainsi Srivastava , Rahul Kumar , Amit Kumar Thakur , Rajesh Singh , Praveen Barmavatu , Vineet Singh Sikarwar

{"title":"Progress in innovative technologies in thermal insulation for cryogenic applications","authors":"Parul Soni , Nainsi Srivastava , Rahul Kumar , Amit Kumar Thakur , Rajesh Singh , Praveen Barmavatu , Vineet Singh Sikarwar","doi":"10.1016/j.energy.2025.138658","DOIUrl":"10.1016/j.energy.2025.138658","url":null,"abstract":"<div><div>Technological developments for thermal insulation in cryogenic materials are crucial for electronic cooling. This review paper compiles advancements in cryogenic thermal insulation technologies for electronic cooling, including multilayer insulation (MLI), vacuum insulation panels (VIPs), vapor compression systems (VCS) and aerosols, in order to demonstrate the superiority of MLI and to establish the groundwork for future high-efficiency insulation research. These developments guarantee less heat transmission and enhance the control of overheating. The research of thermal insulation, which can be further effective with its application, is the main subject of this review paper. The paper compiles important developments in thermal insulation methods and offers a thorough analysis. It primarily replaces the use of electronic cooling, which reduces electrical resistance in high-performance computing and quantum electronics by chilling electronic components to extremely low temperatures using liquid nitrogen or helium. The MLI offers the most effective thermal insulation. The goal of the review paper is to lay the groundwork for future research on thermal insulation, with an emphasis on its performance and requirements at cryogenic temperatures. It is recognized that different applications have different needs for each methodology; thus, there is room to develop a more effective insulating method.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"337 ","pages":"Article 138658"},"PeriodicalIF":9.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced data-driven method for design cooling load calculation averting the overestimation due to design weather data 改进的数据驱动的设计冷负荷计算方法，避免了由于设计天气数据造成的高估

IF 9.4 1区工程技术

Energy Pub Date : 2025-09-23 DOI: 10.1016/j.energy.2025.138655

Qiyan Li , Youming Chen , Kaijun Dong , Qin Sun

{"title":"Enhanced data-driven method for design cooling load calculation averting the overestimation due to design weather data","authors":"Qiyan Li , Youming Chen , Kaijun Dong , Qin Sun","doi":"10.1016/j.energy.2025.138655","DOIUrl":"10.1016/j.energy.2025.138655","url":null,"abstract":"<div><div>Design cooling load is always overestimated when using design weather data (DWD), resulting in oversized air-conditioning (AC) system, low operating energy efficiency and highly initial investment. In this study, a data-driven model is developed based on explainable feature selection (EFS) and multi-task learning (MTL), termed as the EFS-MTL model, for averting the overestimation. Design cooling loads under various non-guarantee rates (such as 0.4 %, 1 %, 2 % and 50 h) were calculated using heat balance method for a large number of sample rooms combined by building/room parameters with multi-year hourly-recorded weather data (HWD) of a city. The EFS-MTL model was then trained by the dataset of the sample rooms with the room parameters (as inputs) and the corresponding design cooling loads (as outputs). To illustrate the EFS-MTL model's capacity in eliminating the overestimation, the EFS-MTL model was trained with the datasets created by HWD of Beijing, Changsha and Guangzhou. The design cooling loads calculated by the EFS-MTL model and DWD were compared. Results show that the median relative deviations of the EFS-MTL model range from −1.44 % to 0.27 %. These results demonstrate that the EFS-MTL model provides an effective approach to correctly and fast calculate design cooling load of AC systems without DWD.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"337 ","pages":"Article 138655"},"PeriodicalIF":9.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploring Temperature Reduction Factor (TRF) in a small-scale heat recovery steam generator under shutdown conditions 小型热回收蒸汽发生器在停机条件下的温度降低系数（TRF）研究

IF 9.4 1区工程技术

Energy Pub Date : 2025-09-23 DOI: 10.1016/j.energy.2025.138445

Saman Alizadeh Berduki, Ali Jafarian

{"title":"Exploring Temperature Reduction Factor (TRF) in a small-scale heat recovery steam generator under shutdown conditions","authors":"Saman Alizadeh Berduki, Ali Jafarian","doi":"10.1016/j.energy.2025.138445","DOIUrl":"10.1016/j.energy.2025.138445","url":null,"abstract":"<div><div>Investigating the minimization of HRSG temperature drop during its temporary shutdown is crucial for the purpose of its prompt restart. To achieve this goal, the relative Temperature Reduction Factor (TRF) was introduced and explored at each hour of the shutdown process. Therefore, in this paper, a numerical simulation of the HRSG shutdown process, extending to 118800 s, was performed under two distinct scenarios: the first incorporating a stack damper, and the second excluding it. By regulating the stack damper, the exhaust gas flow, and consequently the heat transfer rate and HRSG cool-down, can be controlled, thereby preventing the occurrence of undesirable thermal stresses. This paper investigates the effect of the stack damper on the critical TRF index, employed as a decision-making and comparative criterion, in order to determine the extent of its contribution to reducing the restart time. The results indicated that the maximum increase in TRF after 33 h of HRSG shutdown, under Scenario 2, is approximately 10 % (55 K) higher than that of Scenario 1. Therefore, under Scenario 2, the restart time increases by approximately 30 min (25 %). Additionally, the results indicate that the use of the Damper Open strategy is permissible if the restart occurs before the 20-h critical time. However, should the system restart process extend to 33 h, the use of the Damper Closed strategy is recommended.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"337 ","pages":"Article 138445"},"PeriodicalIF":9.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145120279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

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