Thermal Science and Engineering Progress最新文献

{"title":"Sustainable combustion and pollution cost analysis of diesel engine fueled with waste plastics pyrolysis oil and advanced additives: An experimental investigation on emission reduction potential","authors":"Amar Kumar Das ,&nbsp;Aswani Kumar Acharya ,&nbsp;Biswaranjan Parida ,&nbsp;Achyut K Panda ,&nbsp;Zhitong Yao ,&nbsp;Sachin Kumar","doi":"10.1016/j.tsep.2025.104136","DOIUrl":"10.1016/j.tsep.2025.104136","url":null,"abstract":"<div><div>Plastics are essential to modern life, consisting primarily of non-biodegradable polymers made from carbon, hydrogen, and occasionally elements like chlorine and nitrogen. The rapid growth of the global population has increased the demand for commodity plastics, due to its diverse applications. The world is now grappling with the challenge of effectively managing and recovering resources from the vast amount of plastic wastes. To prevent environmental pollution from plastic wastes, recycling and recovery are essential. The depletion of fossil fuels and rising energy demand has driven research into alternative energy sources. Plastics, due to their petrochemical origin and high calorific value, are well-suited for energy recovery. The fuels extracted from waste plastics by pyrolysis with regard to various inclusions of fuel additives have a significant effect on mitigating the pollutants from engine emissions. This study combines waste plastic fuel production with ethanol, nanographene, and biogas additives, optimizing engine performance and emissions. An environmental pollution cost analysis was conducted for WPO blended with ethanol, nanographene, and biogas under optimized engine conditions. The study showed notable reductions of CO by 0.06 % for 20WPO, 11.53 % for 20W20E as compared to diesel and other fuel mixtures. Similarly, HC and NOx were found reduced by 2.5 % for 20W20E as compared to diesel. The concentration of CO₂ for 20W20E was also reduced by 1.9 % as compared to diesel. 20W20E has lowest environmental cost (2.7305 × 10⁻⁴ kg/kJ), shortest payback (0.6665 yr), and highest energy payback (9.1713 yr), showing the best environmental and economic balance. The 20W20E blend showed the best overall performance across all load conditions.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104136"},"PeriodicalIF":5.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 kinetics and products of co-pyrolysis of polyvinyl chloride and polyethylene terephthalate","authors":"Yiyuan Wang ,&nbsp;Ziqiang Ding ,&nbsp;Daming Chai ,&nbsp;Wenwen Han ,&nbsp;Chuansheng Wang ,&nbsp;Fengfu Yin ,&nbsp;Hongbo Chen","doi":"10.1016/j.tsep.2025.104126","DOIUrl":"10.1016/j.tsep.2025.104126","url":null,"abstract":"<div><div>The production of plastic waste is increasing rapidly. Landfilling and incineration, as common recycling methods, are no longer sufficient to meet environmental protection requirements. Therefore, plastic pyrolysis has attracted widespread attention. Polyvinyl chloride (PVC) and polyethylene terephthalate (PET) are both typical components of waste plastics. Due to the overlap in their application fields, they often coexist in the collected waste plastics. Therefore, co-pyrolysis of PVC and PET plastics appears to be more valuable for research. This study was conducted based on thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC–MS), and their combined techniques. It was found that when PVC and PET are mixed, the stage II of the pyrolysis reaction of PVC plastic is enhanced, and the yield of aromatic organic substances in stage II of the co-pyrolysis reaction of the mixed plastic significantly decreases. Due to the insufficient ability of the traditional KAS method in analyzing the kinetics of complex multi-step reactions, this study combines the mathematical method of Gaussian peak fitting with the KAS method, and fits the TG curve of plastic pyrolysis into a multi-stage reaction curve with peaks, and conducts independent analysis. Compared with single-component plastics, the average apparent activation energy of PVC-PET mixed plastics is lower, and there is a synergistic effect between the pyrolysis reactions of the two plastics. The energy demand of the mixed plastics co-pyrolysis reaction is more stable, which is conducive to the stable operation of the equipment in industrial production and reduces energy loss. And the solid product of PVC-PET co-pyrolysis has a loose texture that is not easily adhered to the surface of the pyrolysis reactor, effectively reducing the risk of equipment scorching.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104126"},"PeriodicalIF":5.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 of hemispherical solar still using sodium sulfate decahydrate and sodium carbonate decahydrate as energy storage materials: An enviro and economic analysis","authors":"S. Mohamed Illyas ,&nbsp;A. MuthuManokar ,&nbsp;A.E. Kabeel ,&nbsp;V. Selvakumar","doi":"10.1016/j.tsep.2025.104139","DOIUrl":"10.1016/j.tsep.2025.104139","url":null,"abstract":"<div><div>The present study focuses on improving the performance of hemi spherical solar still (HSS) using hydrated salts – Sodium Sulfate Decahydrate (SSD), Sodium Carbonate Decahydrate (SCD) as energy storage materials and graphite plates. The performance of the modified solar still (MSS) is compared with the conventional solar still (CSS) in terms of clean water production, economics and environmental impact. The DSC curve shows a higher latent heat and broader melting-solidification range for SSD compared with SCD providing longer heat retention. The latent heat released by the salts in the MSS maintains a higher water temperature and vapor pressure than the CSS, creating a larger vapor pressure gradient that drives evaporation and results in 83.20 % increase in the evaporative heat transfer coefficient during 17.00–20.00 hrs. While the day time and night time distillate productivity of MSS-SSD is 15.20 % and 154.40 % respectively higher than CSS, the productivity of MSS-SCD is 12.80 % and 133.30 % higher when compared to CSS. The cost per liter for MSS-SSD is 19 % lower than CSS and it is 17 % cheaper for MSS-SCD. Enviro economic analysis shows that the net CO₂ emitted for CSS, MSS-SSD and MSS-SCD were estimated as 188.42, 313.54 and 311.16 kg respectively. The CO₂ mitigation potential is relatively higher for MSS-SSD and MSS-SCD which are mitigated 24 tons and 22.6 tons with over their life time compared with 16.8 tons from CSS. The carbon credit earned during the 5th year is $79.3 and an average value of $109.5 for the CSS and MSS respectively. The MSS accounts for an increase in carbon credit earning to 38 % in the 10th year and it is 39 % in 15th year when compared to CSS.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104139"},"PeriodicalIF":5.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 numerical study on heat and mass transfer of Zanthoxylum bungeanum microwave drying","authors":"Yao Zhang ,&nbsp;Yuhong Du ,&nbsp;Yuanyuan Li ,&nbsp;Tao He ,&nbsp;Tao Hong ,&nbsp;Dezhi Gou ,&nbsp;Nouman Rasool ,&nbsp;Shunmin Zhu ,&nbsp;Zhengming Tang","doi":"10.1016/j.tsep.2025.104137","DOIUrl":"10.1016/j.tsep.2025.104137","url":null,"abstract":"<div><div>Microwave-assisted dehydration has gained many applications in agricultural processing, yet its application to Zanthoxylum bungeanum remains underexplored. Besides, the heat and mass transfer process of the Zanthoxylum bungeanum sample during the microwave drying process, remains poorly understood. To fill this research gap, this work investigates the drying characteristics of Zanthoxylum bungeanum in microwave ovens under different conditions through a combined approach of numerical simulation and experimental validation. We first developed a multiphysics coupled numerical model for the microwave drying of Zanthoxylum bungeanum in COMSOL Multiphysics, with the measured dielectric properties of Zanthoxylum bungeanum. Then, the numerical model was validated with experiments. Subsequently, with the aid of the validated numerical model, we investigated the effects of microwave power and sample layer thickness on the drying process. Parametric analysis revealed non-uniform moisture distribution characterized by central accumulation and edge dehydration under microwave drying conditions. Its moisture gradient ranges from 3.32 % to 7.38 %. Meanwhile, both power and thickness significantly affect the moisture variation coefficient, with ranges of 0.31–0.89 and 0.55–0.90, respectively. In addition, the layer thickness optimisation shows that the temperature variation coefficient is less than 0.15 at 9 mm, and the heating efficiency is higher than 80 %. These findings provide valuable insight into the heat and mass transfer process of Zanthoxylum bungeanum during microwave driving and the application of microwave-assisted dehydration in Zanthoxylum bungeanum, but also guide the microwave drying of other food crops.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104137"},"PeriodicalIF":5.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dry-out vapor quality incipience in flow boiling: Empirical correlation development with particle Swarm algorithm","authors":"Nima Irannezhad,&nbsp;Luisa Rossetto,&nbsp;Andrea Diani","doi":"10.1016/j.tsep.2025.104142","DOIUrl":"10.1016/j.tsep.2025.104142","url":null,"abstract":"<div><div>With the growing demand for electronic cooling, flow boiling has emerged as a critical mechanism in modern thermal systems. Considering the complexity of flow boiling mechanism, which is influenced by many parameters such as operating conditions, tube geometry, type of refrigerant and other factors, predicting parameters such as critical heat flux and vapor quality at the incipience of dry-out is rather challenging and often requires high computational effort. Concluding a comprehensive review of studies on flow boiling dry-out, the current article garners 418 data points regarding vapor quality at the incipience of dry-out in flow boiling of refrigerants inside tubes, with diameters from 0.6 to 6 mm. Heat fluxes, mass fluxes and reduced pressures in the database ranged from 5 to 400 kW m⁻², 150 to 1500 kg m⁻² s⁻¹ and 0.1 to 0.9 respectively. Utilizing the Particle Swarm Algorithm and seven dimensionless numbers which influence the flow boiling mechanism, a new empirical correlation is proposed which can achieve an accuracy of 15.9 % mean average error. A secondary database comprised of 133 data points is also collected for validation of the model. The proposed model of vapor quality at the incipience of dry-out is considerably accurate and facilitates the predictions of dry-out for tubes with inner diameter between 0.6 mm and 3 mm.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104142"},"PeriodicalIF":5.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation of wall geometry effects on thermal performance of CuO-enhanced phase change materials for latent heat storage","authors":"Naresh Kumar Goud Ranga ,&nbsp;S.K. Gugulothu ,&nbsp;P. Gandhi ,&nbsp;Raju Muthyala ,&nbsp;G. Sailaja","doi":"10.1016/j.tsep.2025.104138","DOIUrl":"10.1016/j.tsep.2025.104138","url":null,"abstract":"<div><div>The need for compact, fast-charging thermal energy storage (TES) systems is critical for applications such as solar collectors, battery cooling, and electronic thermal regulation. However, conventional phase change materials (PCMs) suffer from low thermal conductivity and non-uniform melting, which limit their efficiency and response time. To address these limitations, this study numerically investigates the synergistic effect of wall geometry modification and nanoparticle enhancement on the melting performance of RT42 paraffin PCM embedded with 4 wt% CuO nanoparticles. A two-dimensional rectangular enclosure (50 mm × 100 mm) with constant cross-sectional area (5000 mm²) is subjected to lateral heat flux (1000 W/m²) across five optimized wall profiles and a reference geometry. Using the enthalpy-porosity method, the melting dynamics and thermal energy storage performance are evaluated. CuO addition enhances thermal conductivity from 0.15 to 0.45 W/m·K. Model validation shows &lt;2 % deviation in liquid fraction, confirming accuracy. Among all designs, Cases IV and V (inclined and extended walls) demonstrate superior performance: 98–100 % liquid fraction at 7000 s, 25 % higher energy storage (25 kJ), and average temperature elevation to 305.1 K compared to 303.8 K in the reference case. The novelty of this work lies in the integrated evaluation of thermal boundary design and nanoparticle-enhanced PCM under identical heat flux and volume constraints—a rarely explored combination in literature. This study motivates the adoption of dual enhancement strategies to overcome PCM limitations and informs the development of next-generation TES modules with improved efficiency, thermal uniformity, and melting rate.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104138"},"PeriodicalIF":5.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of chamber cross section variation on a highly diluted and preheated combustion chamber characteristic","authors":"Raouf Dastanian ,&nbsp;Kiumars Mazaheri ,&nbsp;Amir Mardani","doi":"10.1016/j.tsep.2025.104141","DOIUrl":"10.1016/j.tsep.2025.104141","url":null,"abstract":"<div><div>Increased temperature homogeneity, reduced pollutant emissions, and combustion stability are key features expected from industrial furnaces employing flameless combustion. This study systematically examines the effects of furnace geometry, specifically convergent versus divergent axial cross-sectional profiles, and wall temperature on flameless combustion characteristics within a laboratory-scale fixed-volume chamber. Utilizing two-dimensional axisymmetric simulations with detailed chemical kinetics coupled to the (EDC) turbulence–chemistry interaction model, the investigation explores variations in height-to-average diameter ratios (<span><math><mrow><mi>H</mi><mo>/</mo><msub><mi>D</mi><mrow><mi>ave</mi></mrow></msub></mrow></math></span>), through comprehensive parametric analysis supported by model validation and grid independence tests. Findings indicate that divergent furnace geometries promote enhanced internal gas recirculation and flame stability at lower <span><math><mrow><mi>H</mi><mo>/</mo><msub><mi>D</mi><mrow><mi>ave</mi></mrow></msub></mrow></math></span>, whereas convergent geometries yield superior performance at higher ratios. The stable reaction zone volume is strongly influenced by wall temperature and geometry. Reaction zone volume depends on wall temperature, furnace geometry, and <span><math><mrow><mi>H</mi><mo>/</mo><msub><mi>D</mi><mrow><mi>ave</mi></mrow></msub></mrow></math></span>. In divergent geometry at 1200 K with <span><math><mrow><mi>H</mi><mo>/</mo><msub><mi>D</mi><mrow><mi>ave</mi></mrow></msub><mo>=</mo><mn>2.6</mn></mrow></math></span>, the reaction zone occupies over 80 % of the furnace volume. Increasing the <span><math><mrow><mi>H</mi><mo>/</mo><msub><mi>D</mi><mrow><mi>ave</mi></mrow></msub></mrow></math></span> to 5 at the same wall temperature reduces the reaction zone volume to less than 10 %. As wall temperature increases, the contribution of radiant heat transfer becomes more significant. Specifically, divergent geometries with low <span><math><mrow><mi>H</mi><mo>/</mo><msub><mi>D</mi><mrow><mi>ave</mi></mrow></msub></mrow></math></span> ratios and convergent geometries with high <span><math><mrow><mi>H</mi><mo>/</mo><msub><mi>D</mi><mrow><mi>ave</mi></mrow></msub></mrow></math></span> ratios exhibit greater radiative heat transfer contributions. Carbon monoxide emissions are influenced by the ignition delay and the rate of CO₂ decomposition. At wall temperatures around 1200 K, carbon monoxide levels are more affected by ignition delay, whereas at temperatures exceeding 1400 K, CO emissions are predominantly governed by the rate of CO₂ breakdown.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104141"},"PeriodicalIF":5.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 flexural strength and combustion characteristics of noise reduction materials for ultra-high voltage large oil filling equipment","authors":"Fengju Shang ,&nbsp;Xinyang Fan ,&nbsp;Shixiang Liu ,&nbsp;Jiaqing Zhang ,&nbsp;Guocheng Ding ,&nbsp;Xiepeng Sun ,&nbsp;Fei Tang ,&nbsp;Xiaolei Zhang","doi":"10.1016/j.tsep.2025.104132","DOIUrl":"10.1016/j.tsep.2025.104132","url":null,"abstract":"<div><div>This paper investigates the pyrolytic properties, combustion behaviors, thermal stability and mechanical properties of noise reduction materials for use in ultra-high voltage large oil filling equipment. Thermogravimetric analysis (TGA) and flexural strength tests were performed on each material to assess thermal decomposition and structural integrity. Experiments were also carried out using a Cone Calorimeter to assess ignition behaviors, heat release rate (HRR), mass loss rate (MLR), carbon monoxide (CO) generation and smoke generation at different external radiant heat flows (ERHF: 10, 25 and 45 kW/m²). Thermogravimetric analyses revealed significant differences in thermal stability: material #4 had the highest onset decomposition temperature (<em>T_onset</em> = 274 and 288 °C), while material #7 had the lowest onset decomposition temperature (<em>T_onset</em> = 207 and 251 °C) at 10K/min and 20K/min heating rate, respectively. Compressive strength analyses showed that #2 (12.1 MPa) and #6 (10.7 MPa) were the strongest materials, and their stability was affected by compositional homogeneity. The results of combustion behaviors showed that materials #1 and #3 ignited under high ERHF (45 kW/m²) conditions at 208 and 141 s respectively, while the other materials did not catch fire. The HRR curves indicated that materials ignited under high ERHF conditions exhibited a sharp increase in HRR, which then decreased when combustion could no longer be sustained. The MLR of the materials increased with ERHF but remained relatively stable across materials, suggesting a comparable fire hazard. Considering the above performances, it concludes that materials #4, #5 and #7 are the relatively potential choices to be employed. This study may provide important insights into the selection of noise reduction materials to ensure the operational safety and fire performance of ultra-high voltage large oil filling equipment.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104132"},"PeriodicalIF":5.4,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of flow and thermal performance of water-based nanofluid in gravity heat pipe","authors":"Yuguo Gao ,&nbsp;Tianle Niu ,&nbsp;Yilin Ning ,&nbsp;Kim L. Liaw ,&nbsp;Arun S. Mujumdar ,&nbsp;Agus P. Sasmito","doi":"10.1016/j.tsep.2025.104131","DOIUrl":"10.1016/j.tsep.2025.104131","url":null,"abstract":"<div><div>This study presents a numerical investigation into the flow and thermal performance of gravity heat pipes, employing the Volume of Fluid (VOF) multiphase flow model in conjunction with a User-Defined Function (UDF) to simulate evaporation and condensation processes. The results demonstrate that the graphene oxide nanofluid heat pipe achieves a 33 % faster startup, forming a stable condensate film in 2 s compared to 3 s for pure water, and exhibits superior thermal performance. When the heating power increases from 10 W to 40 W, the total thermal resistance decreases by<!--> <!-->approximately 42 %<!--> <!-->for the pure water heat pipe, but only by<!--> <!-->5.2 %<!--> <!-->for the graphene oxide (GO) nanofluid pipe, indicating its more stable performance across a power range. At 40 W, the GO nanofluid (0.2 wt%)<!--> <!-->enhances the equivalent convective heat transfer coefficient by 5 %<!--> <!-->and reduces the total thermal resistance by<!--> <!-->up to 5.2 %<!--> <!-->compared to pure water. Most notably, at the optimal power of 50 W, the GO nanofluid achieves a<!--> <!-->maximum reduction in thermal resistance of 7.8 %<!--> <!-->and an<!--> <!-->enhancement in the convective heat transfer coefficient of 4.5 %, while maintaining a more stable flow field, thereby extending the operational limit beyond 50 W.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104131"},"PeriodicalIF":5.4,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 desirable control for non-inverter HVAC systems by dynamic set-temperature approach","authors":"Mohammad Foruzan Nia,&nbsp;Eric Hu,&nbsp;Mergen H. Ghayesh","doi":"10.1016/j.tsep.2025.104135","DOIUrl":"10.1016/j.tsep.2025.104135","url":null,"abstract":"<div><div>The conventional control of non-inverter HVAC systems, which operate using an ON/OFF mechanism, is typically based on comparing the sensor-measured temperature with a fixed setpoint. However, this approach is often inaccurate because these sensors cannot precisely measure the target variable (e.g., the room’s mean temperature). To overcome this limitation without physically modifying the sensor’s location or type, this study developed a neural network model for a benchmark test room, equipped with an AC operating in ON/OFF mode. This model captures the dynamic correlation between the hydrodynamic and thermal characteristics of the room and the sensor temperature readings. It predicts a suitable range for the sensor set temperature (<em>T_dset</em>_- and <em>T_dset+</em>) at each time step, based on the desired target temperature range and boundary conditions. The effectiveness of the proposed dynamic control strategy was compared with both the classical and ideal control strategies for six cases featuring randomly distributed boundary conditions. The comparison considered energy consumption as well as the percentage of time the target variable remained within the desired range (i.e., <em>T_set- &lt; T_average &lt; T_set</em>₊). Results showed that the dynamic control strategy improved regulation of the target variable by 50–100 % and reduced energy consumption by approximately 3–10 % compared to the classical method, while closely approximating the performance of the ideal control. Notably, the strategy remained effective even when varying target setpoints and fluctuating boundary conditions were applied. This performance was achieved even though the input data used to train the models were based on a fixed set temperature of 25 ± 0.5 °C.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"67 ","pages":"Article 104135"},"PeriodicalIF":5.4,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}