S. Srinivasa senthil, K. Vijayakumar^*

Energy Engineering, Vol.122, No.12, pp. 5149-5173, 2025, DOI:10.32604/ee.2025.070889 - 27 November 2025

Abstract Heating, ventilation, and air conditioning (HVAC) systems contribute substantially to global energy consumption, while rejecting significant amounts of low-grade heat into the environment. This paper presents a non-intrusive spiral-coil heat exchanger designed to recover waste heat from the outdoor condenser of a split-type air conditioner. The system operates externally without altering the existing HVAC configuration, thereby rendering it suitable for retrofitting. Water was circulated as the working fluid at flow rates of 0.028–0.052 kg/s to assess thermal performance. Performance indicators, including the outlet water temperature, heat transfer rate, convective coefficient, and efficiency, were systematically evaluated.… More >

Hamed Yousefzadeh Eini, Mohammad Hossein Sabouri, Mojtaba Babaelahi^*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.7, pp. 1771-1788, 2025, DOI:10.32604/fdmp.2025.066747 - 31 July 2025

Abstract Heat Recovery Ventilators (HRVs) are essential for improving indoor air quality (IAQ) and reducing energy consumption in residential buildings situated in cold climates. This study considers the efficiency and performance optimization of HRVs under cold climatic conditions, where conventional ventilation systems increase heat loss. A comprehensive numerical model was developed using COMSOL Multiphysics, integrating fluid dynamics, heat transfer, and solid mechanics to evaluate the thermal efficiency and structural integrity of an HRV system. The methodology employed a detailed geometry with tetrahedral elements, temperature-dependent material properties, and coupled governing equations solved under Tehran-specific boundary conditions. A More >

Linwei Yao^1,*, Xiangning Lin^1,2, Huashen He¹, Jiahui Yang¹

Energy Engineering, Vol.122, No.8, pp. 3285-3308, 2025, DOI:10.32604/ee.2025.066628 - 24 July 2025

Abstract In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant (WIPP) and renewable energy accommodation, an electricity-hydrogen-waste multi-energy system integrated with phase change material (PCM) thermal storage is proposed. First, a thermal energy management framework is constructed, combining PCM thermal storage with the alkaline electrolyzer (AE) waste heat recovery and the heat pump (HP), while establishing a PCM-driven waste drying system to enhance the efficiency of waste incineration power generation. Next, a flue gas treatment method based on purification-separation-storage coordination is adopted, achieving spatiotemporal decoupling between waste incineration… More >

Ziyi Wang^1,2, Sen Li^1,2,*, Xiaolin Wei^1,2, Jing Zhao¹, Bo Li¹, Yuan Yao¹

Frontiers in Heat and Mass Transfer, Vol.23, No.1, pp. 163-184, 2025, DOI:10.32604/fhmt.2024.059740 - 26 February 2025

Abstract In the novel fully dry converter gas recovery process, a novel circumfluent cyclone separator with an evaporation heating surface can simultaneously realize the dust removal and sensible heat recovery of converter gas. For this equipment, the distributions of internal flow and wall heat transfer affect the efficiency of dust removal and sensible heat recovery. In this study, based on on-site operation tests, the distributions of internal flow and wall heat transfer in the circumfluent cyclone separator are studied by numerical simulation. The results indicate that the flow rate proportions in different regions of the circumfluent More >

Guowei Li^1,*, Shujuan Bu², Xinle Yang², Kaijie Liang¹, Zhengri Shao¹, Xiaobei Song¹, Yitian Tang³, Dejing Zong⁴

Energy Engineering, Vol.121, No.12, pp. 3843-3874, 2024, DOI:10.32604/ee.2024.056195 - 22 November 2024

Abstract A novel dual-pressure organic Rankine cycle system (DPORC) with a dual-stage ejector (DE-DPORC) is proposed. The system incorporates a dual-stage ejector that utilizes a small amount of extraction steam from the high-pressure expander to pressurize a large quantity of exhaust gas to perform work for the low-pressure expander. This innovative approach addresses condensing pressure limitations, reduces power consumption during pressurization, minimizes heat loss, and enhances the utilization efficiency of waste heat steam. A thermodynamic model is developed with net output work, thermal efficiency, and exergy efficiency (W_net, η_t, η_ex) as evaluation criteria, an economic model is established… More >

Yuming Zhao¹, Jing Wang¹, Bin Sun², Zhenshang Wang¹, Huashan Li², Jiongcong Chen^2,*

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1171-1188, 2024, DOI:10.32604/fhmt.2024.054594 - 30 August 2024

Abstract Data centers (DCs) are highly energy-intensive facilities, where about 30%–50% of the power consumed is attributable to the cooling of information technology equipment. This makes liquid cooling, especially in two-phase mode, as an alternative to air cooling for the microprocessors in servers of interest. The need to meet the increased power density of server racks in high-performance DCs, along with the push towards lower global warming potential (GWP) refrigerants due to environmental concerns, has motivated research on the selection of two-phase heat transfer fluids for cooling servers while simultaneously recovering waste heat. With this regard,… More >

Bin Xiao^*

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 35-48, 2024, DOI:10.32604/fhmt.2024.048039 - 21 March 2024

Abstract Experiments were conducted in this study to examine the thermal performance of a thermosyphon, made from Inconel alloy 625, could recover waste heat from automobile exhaust using a limited amount of fluid. The thermosyphon has an outer diameter of 27 mm, a thickness of 2.6 mm, and an overall length of 483 mm. The study involved directing exhaust gas onto the evaporator. This length includes a 180-mm evaporator, a 70-mm adiabatic section, a 223-mm condenser, and a 97-mm finned exchanger. The study examined the thermal performance of the thermosyphon under exhaust flow rates ranging from… More >

T. E. Boukelia^1,2,*, A. Bourouis¹, M. E. Abdesselem³, M. S. Mecibah³

Energy Engineering, Vol.120, No.11, pp. 2449-2467, 2023, DOI:10.32604/ee.2023.030183 - 31 October 2023

Abstract Concentrating Solar Power (CSP) plants offer a promising way to generate low-emission energy. However, these plants face challenges such as reduced sunlight during winter and cloudy days, despite being located in high solar radiation areas. Furthermore, their dispatch capacities and yields can be affected by high electricity consumption, particularly at night. The present work aims to develop an off-design model that evaluates the hourly and annual performances of a parabolic trough power plant (PTPP) equipped with a waste heat recovery system. The study aims to compare the performances of this new layout with those of… More >

Ali Jaber Abdulhamed^1,*, Aws Al-Akam¹, Ahmed A. Abduljabbar², Mohammed H. Alkhafaji³

Energy Engineering, Vol.120, No.8, pp. 1729-1746, 2023, DOI:10.32604/ee.2023.029069 - 05 June 2023

Abstract Thermoelectric generators (TEGs) are considered promising devices for waste heat recovery from various systems. The Seebeck effect can be utilized to generate power using the residual heat emitted by the filter dryer receiver (FDR) of an air conditioning (A/C) system, which would otherwise go to waste. The study aims to build a set of thermoelectric generators (TEG) to collect the waste heat of the FDR and generate low-power electricity. A novel electrical circuit with two transformers is designed and fabricated to produce a more stable voltage for operation and charging. The thermoelectric generator (TEGs) was… More >

Liqing Yan¹, Jiang Liu^1,2,*, Guangwei Ying³, Ning Zhang⁴

Energy Engineering, Vol.120, No.8, pp. 1919-1938, 2023, DOI:10.32604/ee.2023.027546 - 05 June 2023

Abstract Recovery of waste heat from boiler flue gas is an effective way to improve energy utilization efficiency. Taking a heating station heating project as an example, the existing heating system of this heating station was analyzed for its underutilized flue gas waste heat and low energy utilization rate. Rankine cycle is an effective waste heat recovery method, and a steam boiler organic Rankine cycle (ORC) cogeneration waste heat utilization method is proposed. The system model simulation is constructed and verified. First, a thermodynamic model was constructed in MATLAB and five suitable work gases were selected More > Graphic Abstract