Johannes D. Pelda^*, Sebastian Aichele, Dmitry Romanov, Stefan Holler

Energy Engineering, Vol.123, No.8, 2026, DOI:10.32604/ee.2026.079450 - 12 July 2026

Abstract The transformation of district heating systems in Germany is a central topic in energy and climate policy, given the 2045 climate neutrality targets. This study focuses on the main district heating system in the city of Göttingen in Germany, whose heat generation currently relies primarily on three Combined Heat and Power (CHP) plants subsidized under the German CHP Act, one wood chip boiler and two gas boilers. In 2025, the network’s heating demand amounted to 89 GWh, which was mainly covered by wood chips or biogas (41%) and natural gas (21%). This paper examines an… More > Graphic Abstract

Bingchao Zhao^1,*, Jiahao Yu¹, Zhen Zhang¹, Jinduo Wang¹, Dan Zhang², Wenbo Zhou²

Frontiers in Heat and Mass Transfer, Vol.24, No.3, 2026, DOI:10.32604/fhmt.2026.079362 - 29 June 2026

Abstract To achieve the goal of deep desalination of saline wastewater driven by solar energy, the evaporation experiments of Na₂SO₄ aqueous solution droplets under thermal radiation heating condition have been carried out with the working conditions of 1450 and 1930 nm, heat flux varied from 1.1 × 10⁵ to 2.5 × 10⁵ W·m⁻², initial mass fraction in the range of 0.01~0.16 and droplet initial volume of 2.0~8.0 μL, respectively. The results indicate that absorption coefficient, initial mass fraction, heat flux and initial droplet volume have significantly influences on the evaporation characteristics. The main evaporation time can be shortened… More >

Berry Lamy^*, Romaine Byfield, Yiding Cao

Frontiers in Heat and Mass Transfer, Vol.24, No.3, 2026, DOI:10.32604/fhmt.2026.079339 - 29 June 2026

Abstract Climate change and the ongoing dependence on fossil fuels present major challenges for global agriculture, with fossil fuel use in the agrifood sector accounting for a substantial and growing share of greenhouse gas (GHG) emissions. Agrifood systems currently contribute approximately one-third of total anthropogenic GHG emissions. Integrating renewable energy solutions for heating and power can help offset a significant fraction of these emissions. In this study, an analytical heat transfer and thermodynamic model is developed to evaluate the performance, energy balance, and thermal losses of the proposed system under realistic operating conditions. The model enables… More >

Yingjie Su¹, Yubin Qiu², Zhuojun Dong¹, Jiying Liu^2,*, Bo Gao^1,3,*

Energy Engineering, Vol.123, No.7, 2026, DOI:10.32604/ee.2025.074454 - 18 June 2026

Abstract In response to the high energy consumption, large load fluctuations, and insufficient adaptability associated with conventional control strategies in industrial park heating and hot water systems, this paper studies a 15,000 m² factory office building in Jinan as its object of study. A photovoltaic-thermal integrated air-source heat pump system (PVT-ASHP) is developed. This system leverages its hardware parameter co-optimization and intelligent operational strategy control to perform cost reduction and efficiency increase, while focusing on the novel innovative high effectiveness of its operational strategies. The study first employs the Hooke-Jeeves algorithm to optimize key hardware parameters so… More > Graphic Abstract

Zebing Chen¹, Yang Wang¹, Hong Wu¹, Wenbin Zhao¹, Jinjun Yan¹, Luyao Peng², Yugang Zhao², Zilong Wang², Kang Li^2,*, Saleh S. Meibodi³, Mohammad Moosazadeh⁴, Soheil Mohtaram^2,*

Frontiers in Heat and Mass Transfer, Vol.24, No.2, 2026, DOI:10.32604/fhmt.2026.077274 - 30 April 2026

Abstract Energy storage batteries require strict thermal management due to temperature sensitivity, operating optimally within a narrow thermal range. Simultaneously, control rooms demand stable and comfortable ambient conditions for staff staying long-term. Conventional temperature control systems typically employ isolated solutions, resulting in functional fragmentation and inefficient resource utilization. To address these challenges, this study proposes and implements an integrated R290 secondary loop heat pump air-conditioning system designed to simultaneously manage the thermal environments of both energy storage batteries and control rooms. By adopting a secondary-loop coupling architecture, all thermal regulation is achieved indirectly via indirect heat… More > Graphic Abstract

Xiufeng Fei¹, Jian Liu^1,2, Dianhang Wei^1,*, Xiaosong Zhang^1,2,*

Frontiers in Heat and Mass Transfer, Vol.24, No.2, 2026, DOI:10.32604/fhmt.2026.076167 - 30 April 2026

Abstract Thermal-transfer printing technology has gained widespread adoption in small-format printing devices owing to its fast printing speed, good image quality, and environmental sustainability. However, scaling this technology to large-format printing equipment remains challenging, primarily because the internal heat transfer mechanisms in the large-scale thermal-transfer printing head (TPH) are not yet fully understood. This knowledge gap limits further optimization of device design. A two-dimensional model was established to numerically investigate the internal heat transfer within the thermal-transfer printing head under pulse heating conditions. The simulations reveal that the internal temperature distribution adopts a star-like pattern, driven More >

Polina A. Tretyakova^*, Alexey P. Belkin, Alexander A. Rumyantsev, Anna A. Menshikova

Energy Engineering, Vol.123, No.4, 2026, DOI:10.32604/ee.2025.075393 - 27 March 2026

Abstract Limited adoption of solar energy in the Northwestern region of Russia is associated with insufficient data on annual solar radiation indicators and on the potential of solar collectors for water heating. The study aims to evaluate the potential of solar water heating for domestic use in Northwestern Russia, using Tyumen city as the case. In this region, the number of cloudy days ranges from 5% to 50%, with cloud cover increasing in winter. New data on the total solar radiation, availability duration, and cloud cover have been collected. Solar irradiance could reach 900 MJ/m² during summer… More >

Adebowale Martins Obalalu^1,*, Abdulazeez Adebayo Usman², Umair Khan³

FDMP-Fluid Dynamics & Materials Processing, Vol.22, No.2, 2026, DOI:10.32604/fdmp.2026.076959 - 04 March 2026

Abstract Efficient thermal management in porous media is essential for advanced engineering applications, including solar energy systems, electronic cooling, and aerospace thermal control. This study presents a comprehensive analysis of ternary hybrid nanofluids, TiO₂–CdTe–MoS₂ dispersed in water, flowing over a vertical stretching or shrinking surface in a Darcy–Brinkman porous medium. The investigation accounts for the combined effects of magnetohydrodynamics, thermal radiation, viscous dissipation, and internal heat generation. In contrast to previous studies that predominantly focused on single or binary nanofluids, the present work systematically examines the thermal and hydrodynamic performance of ternary hybrid nanofluids, highlighting their enhanced… More >

Yumeng Li, Fuyong Su^*

Frontiers in Heat and Mass Transfer, Vol.24, No.1, 2026, DOI:10.32604/fhmt.2026.076007 - 28 February 2026

Abstract Based on the Fluent numerical simulation method, this study systematically analyzed the structural parameters of the spiral tube heat exchanger and the influence of the external baffle on its heat transfer performance. The results show that when the equivalent diameter of the spiral tube increased from 16.68 to 21.23 mm, its surface heat transfer coefficient decreased from 22,040 to 17,230 W/m²·K, and the outlet air temperature dropped from 822.3 to 807.3 K. However, the pressure loss decreased from 2.692 to 0.958 kPa. which reveals the contradiction between the heat transfer efficiency and the flow resistance. By More > Graphic Abstract

Song Zhang, Yang Yu^*, Shuguang Li, Xue Li

Energy Engineering, Vol.123, No.3, 2026, DOI:10.32604/ee.2025.072333 - 27 February 2026

Abstract Thermal storage electric heating (TSEH), as a prevalent variable load resource, offers significant potential for enhancing system flexibility when aggregated into a cluster. To address the uncertainties of renewable energy and load forecasting in active distribution networks (ADN), this paper proposes a multi-timescale coordinated optimal dispatch strategy that incorporates TSEH clusters. It utilizes the thermal storage characteristics and short-term regulation capabilities of TSEH, along with the rapid and gradual response characteristics of resources in active distribution grids, to develop a coordinated optimization dispatch mechanism for day-ahead, intraday, and real-time stages. It provides a coordinated optimized… More > Graphic Abstract