Article
Thermodynamics
Rui Yang, Nathan Blanc, Guy Z. Ramon
Summary: This article presents a theoretical investigation on phase-change thermoacoustic heat pumping. The results show that phase change can significantly increase the cooling power and coefficient of performance (COP), but the enhancement in COP only occurs under small temperature differences. The gap in observed performance between the ideal model and the full system is due to the deviation of the acoustic field from the requirements for effective enhancement under large temperature differences.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Thermodynamics
Nico Haggqvist, Tor-Martin Tveit, Ron Zevenhoven
Summary: For industrial applications, accurately monitoring the condition of critical equipment and maximizing performance under varying operating conditions is crucial. However, it is often difficult to directly measure important parameters for monitoring and optimization, requiring estimation. This study presents and validates a model that simulates cyclic temperature variations in an industrial Stirling cycle-based high temperature heat pump, using measured cylinder pressures and slow-changing temperature data. This model will be used for online monitoring and system performance optimization.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Riying Wang, Jianying Hu, Zilong Jia, Depeng Chang, Limin Zhang, Ercang Luo, Yanlei Sun, Zhanghua Wu, Yanyan Chen
Summary: Heat pump technology, especially Stirling heat pumps, has gained attention due to their high efficiency, environmental friendliness, and ability to operate at various temperatures. This paper presents a novel heat-driven double-acting free-piston Stirling heat pump system with multiple units, simplifying the design complexity and improving system reliability and efficiency.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Thermodynamics
Tianjiao Bi, Zhanghua Wu, Wei Chen, Limin Zhang, Ercang Luo, Bin Zhang
Summary: This study investigates a 4-stage LTTAEG through numerical simulation and experiment, finding the highest electric power and thermal-to-electric efficiency under certain parameters. However, nonlinear phenomena caused by high pressure oscillations in the system have led to deviations between simulation and experimental results, highlighting the need for further investigation in future studies.
Article
Thermodynamics
Jiaxin Chi, Lei Xiao, Zhanghua Wu, Jingyuan Xu, Yupeng Yang, Yiwei Hu, Liming Zhang, Jianying Hu, Ercang Luo
Summary: This research proposes a novel heat-driven thermoacoustic heat pump with a gas-liquid coupled resonator that exhibits high efficiency, compact structure and easy fabrication. The experimental results show that the heat pump performs well and can be used for low-grade thermal energy utilization and indoor heating.
INTERNATIONAL JOURNAL OF REFRIGERATION
(2023)
Article
Thermodynamics
Mohammad Ja'fari, Artur J. Jaworski
Summary: This article focuses on the numerical study of nonlinear features in oscillatory flow of a high pressure amplitude standing wave thermoacoustic heat engine. The performance of thermoacoustic devices can be negatively affected by nonlinearities arising from high pressure amplitudes. Acoustic mass streaming is one such nonlinearity that can influence the system performance through undesired convective heat transfer. Hence, it is important to understand these nonlinear phenomena in thermoacoustic devices both theoretically and practically.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Geng Chen, Lihua Tang, Zhibin Yu
Summary: This paper investigates the dual-acoustic-driver concept for thermoacoustic heat pumps (TAHPs), which can significantly increase the system's compactness. The authors conducted theoretical analyses and parametric studies to examine the effects of acoustic drivers on the acoustic and thermal characteristics of the TAHP. The results show that the temperature difference is non-zero only when the acoustic field contains a traveling-wave component, and driving the acoustic drivers near resonance frequencies can achieve a large temperature difference. This study provides new insights for developing compact, efficient, and high-power-density TAHPs for industrial waste heat recovery.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2022)
Article
Thermodynamics
Elias Vieren, Toon Demeester, Wim Beyne, Alessia Arteconi, Michel De Paepe, Steven Lecompte
Summary: Industrial heat pumps are an emerging technology that has the potential to revolutionize industrial heating. By using an optimization model, it is possible to identify the best operating conditions and working fluids for maximum performance. Transcritical cycles have been shown to be more efficient than subcritical cycles, especially for applications with large temperature glides.
APPLIED THERMAL ENGINEERING
(2023)
Article
Green & Sustainable Science & Technology
Keri-Marie Adamson, Timothy Gordon Walmsley, James K. Carson, Qun Chen, Florian Schlosser, Lana Kong, Donald John Cleland
Summary: This article examines the development of high-temperature transcritical heat pump technology and proposes solutions to key technical challenges, including a new cascade cycle innovation. The article also proposes a new candidate cycle for high-temperature transcritical heat pump cycle that requires further investigation.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Thermodynamics
Wigdan Kisha, Paul Riley, Jon McKechnie, David Hann
Summary: Recent developments in thermoacoustic engines have shown that thermoacoustic technology is a viable option for waste heat recovery and low-cost electricity generation. By using the asymmetric heat method, the unbalanced acoustic impedance within the cores can be effectively matched, leading to an increase in thermoacoustic efficiency. Both numerical calculations and laboratory measurements confirm that this new technique can increase loop acoustic power and electrical power output in thermoacoustic engines.
Article
Acoustics
Geng Chen, Jingyuan Xu
Summary: This study focuses on the acoustic characteristics of looped-tube TARs integrated with single or dual external or in-built acoustic drivers. The positioning of the acoustic drivers affects the eigenmodes of the TAR, especially in asymmetric configurations. Looped-tube TARs with dual acoustic drivers exhibit standing-wave acoustic field only in-phase and anti-phase modes, while hybrid wave components are present at other phase differences.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2021)
Article
Thermodynamics
Hamed Abedini, Elias Vieren, Toon Demeester, Wim Beyne, Steven Lecompte, Sylvain Quoilin, Alessia Arteconi
Summary: This study analyzes the performance of binary mixtures as working fluid in high-temperature heat pumps. An optimization framework is developed to determine the best working fluid and cycle configuration for different heat sources and sinks. The best performing mixtures are near-azeotropic and offer advantages such as reduced compression ratio and compressor outlet temperature compared to pure fluids.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Thermodynamics
Baomin Dai, Qi Wang, Shengchun Liu, Dabiao Wang, Liqi Yu, Xinhai Li, Yuanyuan Wang
Summary: The concept of dual-temperature condensation and dual-temperature evaporation is proposed for achieving carbon neutrality in industrial heating. Two new high-temperature heat pump systems are developed and optimized, showing better performance than existing heat pumps and traditional boilers in terms of energy consumption, CO2 emissions, and cost. Compared to boilers, high-temperature heat pumps have lower emissions and Ej-DCDE-2 is recommended as a replacement for industrial heating.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Thermodynamics
George Kosmadakis, Panagiotis Neofytou
Summary: This article examines an alternative waste heat recovery solution for ships, which relies on a reversible unit that switches between electricity production and steam generation. By utilizing the waste heat from the engine's cooling water, the reversible unit is able to increase the capacity factor. The study shows that the reversible unit outperforms individual solutions and achieves significant fuel savings.
Review
Chemistry, Multidisciplinary
Marcel Ulrich Ahrens, Maximilian Loth, Ignat Tolstorebrov, Armin Hafner, Stephan Kabelac, Ruzhu Wang, Trygve Magne Eikevik
Summary: Decarbonization of the industrial sector is crucial for reducing global warming. Utilizing high temperature heat pumps with natural fluids, such as ammonia-water absorption-compression heat pumps, shows great potential for increasing energy efficiency and reducing emissions in industrial processes. This study reviews the state of technology, identifies existing challenges, and highlights recent developments and promising solutions for ammonia-water ACHP systems at high temperature operation.
APPLIED SCIENCES-BASEL
(2021)
Article
Thermodynamics
Yong Cheng, Fukai Song, Lei Fu, Saishuai Dai, Zhiming Yuan, Atilla Incecik
Summary: This paper investigates the accessibility of wave energy absorption by a dual-pontoon floating breakwater integrated with hybrid-type wave energy converters (WECs) and proposes a hydraulic-pneumatic complementary energy extraction method. The performance of the system is validated through experiments and comparative analysis.
Article
Thermodynamics
Jing Gao, Chao Wang, Zhanwu Wang, Jin Lin, Runkai Zhang, Xin Wu, Guangyin Xu, Zhenfeng Wang
Summary: This study aims to establish a new integrated method for biomass cogeneration project site selection, with a focus on the application of the model in Henan Province. By integrating Geographic Information System and Multiple Criterion Decision Making methods, the study conducts site selection in two stages, providing a theoretical reference for the construction of biomass cogeneration projects.
Article
Thermodynamics
Mert Temiz, Ibrahim Dincer
Summary: The current study presents a hybrid small modular nuclear reactor and solar-based system for sustainable communities, integrating floating and bifacial photovoltaic arrays with a small modular reactor. The system efficiently generates power, hydrogen, ammonia, freshwater, and heat for residential, agricultural, and aquaculture facilities. Thermodynamic analysis shows high energy and exergy efficiencies, as well as large-scale ammonia production meeting the needs of metropolitan areas. The hybridization of nuclear and solar technologies offers advantages of reliability, environmental friendliness, and cost efficiency compared to renewable-alone and fossil-based systems.
Editorial Material
Thermodynamics
Wojciech Stanek, Wojciech Adamczyk
Article
Thermodynamics
Desheng Xu, Yanfeng Li, Tianmei Du, Hua Zhong, Youbo Huang, Lei Li, Xiangling Duanmu
Summary: This study investigates the optimization of hybrid mechanical-natural ventilation for smoke control in complex metro stations. The results show that atrium fires are more significantly impacted by outdoor temperature variations compared to concourse/platform fires. The gathered high-temperature smoke inside the atrium can reach up to 900 K under a 5 MW train fire energy release. The findings provide crucial engineering insights into integrating weather data and adaptable ventilation protocols for smoke prevention/mitigation.
Article
Thermodynamics
Da Guo, Heping Xie, Mingzhong Gao, Jianan Li, Zhiqiang He, Ling Chen, Cong Li, Le Zhao, Dingming Wang, Yiwei Zhang, Xin Fang, Guikang Liu, Zhongya Zhou, Lin Dai
Summary: This study proposes a new in-situ pressure-preserved coring tool and elaborates its pressure-preserving mechanism. The experimental and field test results demonstrate that this tool has a high pressure-preservation capability and can maintain a stable pressure in deep wells. This study provides a theoretical framework and design standards for the development of similar technologies.
Article
Thermodynamics
Aolin Lai, Qunwei Wang
Summary: This study assesses the impact of China's de-capacity policy on renewable energy development efficiency (REDE) using the Global-MSBM model and the difference-in-differences method. The findings indicate that the policy significantly enhances REDE, promoting technological advancements and marketization. Moreover, regions with stricter environmental regulations experience a higher impact.
Article
Thermodynamics
Mostafa Ghasemi, Hegazy Rezk
Summary: This study utilizes fuzzy modeling and optimization to enhance the performance of microbial fuel cells (MFCs). By simulating and analyzing experimental data sets, the ideal parameter values for increasing power density, COD elimination, and coulombic efficiency were determined. The results demonstrate that the fuzzy model and optimization methods can significantly improve the performance of MFCs.
Article
Thermodynamics
Zhang Ruan, Lianzhong Huang, Kai Wang, Ranqi Ma, Zhongyi Wang, Rui Zhang, Haoyang Zhao, Cong Wang
Summary: This paper proposes a grey box model for fuel consumption prediction of wing-diesel hybrid vessels based on feature construction. By using both parallel and series grey box modeling methods and six machine learning algorithms, twelve combinations of prediction models are established. A feature construction method based on the aerodynamic performance of the wing and the energy relationship of the hybrid system is introduced. The best combination is obtained by considering the root mean square error, and it shows improved accuracy compared to the white box model. The proposed grey box model can accurately predict the daily fuel consumption of wing-diesel hybrid vessels, contributing to operational optimization and the greenization and decarbonization of the shipping industry.
Article
Thermodynamics
Huayi Chang, Nico Heerink, Junbiao Zhang, Ke He
Summary: This study examines the interaction between off-farm employment decisions between couples and household clean energy consumption in rural China, and finds that two-paycheck households are more likely to consume clean energy. The off-farm employment of women is a key factor driving household clean energy consumption to a higher level, with wage-employed wives having a stronger influence on these decisions than self-employed ones.
Article
Thermodynamics
Hanguan Wen, Xiufeng Liu, Ming Yang, Bo Lei, Xu Cheng, Zhe Chen
Summary: Demand-side management is crucial to smart energy systems. This paper proposes a data-driven approach to understand the relationship between energy consumption patterns and household characteristics for better DSM services. The proposed method uses a clustering algorithm to generate optimal customer groups for DSM and a deep learning model for training. The model can predict the possibility of DSM membership for a given household. The results demonstrate the usefulness of weekly energy consumption data and household socio-demographic information for distinguishing consumer groups and the potential for targeted DSM strategies.
Article
Thermodynamics
Xinglan Hou, Xiuping Zhong, Shuaishuai Nie, Yafei Wang, Guigang Tu, Yingrui Ma, Kunyan Liu, Chen Chen
Summary: This study explores the feasibility of utilizing a multi-level horizontal branch well heat recovery system in the Qiabuqia geothermal field. The research systematically investigates the effects of various engineering parameters on production temperature, establishes mathematical models to describe their relationships, and evaluates the economic viability of the system. The findings demonstrate the significant economic feasibility of the multi-level branch well system.
Article
Thermodynamics
Longxin Zhang, Songtao Wang, Site Hu
Summary: This investigation reveals the influence of tip leakage flow on the modern transonic rotor and finds that the increase of tip clearance size leads to a decline in rotor performance. However, an optimal tip clearance size can extend the rotor's stall margin.
Article
Thermodynamics
Kristian Gjoka, Behzad Rismanchi, Robert H. Crawford
Summary: This paper proposes a framework for assessing the performance of 5GDHC systems and demonstrates it through a case study in a university campus in Melbourne, Australia. The results show that 5GDHC systems are a cost-effective and environmentally viable solution in mild climates, and their successful implementation in Australia can create new market opportunities and potential adoption in other countries with similar climatic conditions.
Article
Thermodynamics
Jianwei Li, Guotai Wang, Panpan Yang, Yongshuang Wen, Leian Zhang, Rujun Song, Chengwei Hou
Summary: This study proposes an orientation-adaptive electromagnetic energy harvester by introducing a rotatable bluff body, which allows for self-regulation to cater for changing wind flow direction. Experimental results show that the output power of the energy harvester can be greatly enhanced with increased rotatory inertia of the rotating bluff body, providing a promising solution for harnessing wind-induced vibration energy.