Xinwei Wang^1,2,*, Ming Li¹, Hankun Bing¹, Dongxing Zhang¹, Yuanshu Zhang¹

Energy Engineering, Vol.121, No.12, pp. 3875-3898, 2024, DOI:10.32604/ee.2024.056237 - 22 November 2024

Abstract After long-term operation, the performance of components in the GTCC system deteriorates and requires timely maintenance. Due to the inability to directly measure the degree of component malfunction, it is necessary to use advanced exergy analysis diagnosis methods to characterize the components’ health condition (degree of malfunction) through operation data of the GTCC system. The dissipative temperature is used to describe the degree of malfunction of different components in the GTCC system, and an advanced exergy analysis diagnostic method is used to establish a database of overall operating condition component malfunctions in the GTCC system.… More >

Zakaria Triki¹, Ahmed Selloum¹, Younes Chiba¹, Hichem Tahraoui^1,2, Dorsaf Mansour³, Abdeltif Amrane^4,*, Meriem Zamouche⁵, Mohammed Kebir⁶, Jie Zhang⁷

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1107-1128, 2024, DOI:10.32604/fhmt.2024.052223 - 30 August 2024

Abstract Refrigeration plays a significant role across various aspects of human life and consumes substantial amounts of electrical energy. The rapid advancement of green cooling technology presents numerous solar-powered refrigeration systems as viable alternatives to traditional refrigeration equipment. Exergy analysis is a key in identifying actual thermodynamic losses and improving the environmental and economic efficiency of refrigeration systems. In this study exergy analyze has been conducted for a solar-powered vapor compression refrigeration (SP-VCR) system in the region of Ghardaïa (Southern Algeria) utilizing R1234ze(E) fluid as an eco-friendly substitute for R134a refrigerant. A MATLAB-based numerical model was… More >

Abdul Sattar Laghari¹, Mohammad Waqas Chandio¹, Laveet Kumar^2,*, Mamdouh El Haj Assad³

Energy Engineering, Vol.121, No.8, pp. 2023-2038, 2024, DOI:10.32604/ee.2024.051082 - 19 July 2024

Abstract The selection of working fluid significantly impacts the geothermal ORC’s Efficiency. Using a mixture as a working fluid is a strategy to improve the output of geothermal ORC. In the current study, modelling and thermodynamic analysis of ORC, using geothermal as a heat source, is carried out at fixed operating conditions. The model is simulated in the Engineering Equation Solver (EES). An environment-friendly mixture of fluids, i.e., R245fa/R600a, with a suitable mole fraction, is used as the operating fluid. The mixture provided the most convenient results compared to the pure working fluid under fixed operating More >

Yi Tu^1,*, Yuan Wu², Yu Zeng³

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 989-1014, 2024, DOI:10.32604/fdmp.2024.045624 - 07 June 2024

Abstract The formation of ice on the leading edge of aircraft engines is a serious issue, as it can have catastrophic consequences. The Swirl Anti-Icing (SAI) system, driven by ejection, circulates hot fluid within a 360° annular chamber to heat the engine inlet lip surface and prevent icing. This study employs a validated Computational Fluid Dynamics (CFD) approach to study the impact of key geometric parameters of this system on flow and heat transfer characteristics within the anti-icing chamber. Additionally, the entropy generation rate and exergy efficiency are analyzed to assess the energy utilization in the… More >

Karrar A. Hammoodi^1,*, Hayder A. Dhahad², Wissam H. Alawee³, Z. M. Omara⁴

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 217-262, 2024, DOI:10.32604/fhmt.2024.047329 - 21 March 2024

Abstract In the face of an escalating global water crisis, countries worldwide grapple with the crippling effects of scarcity, jeopardizing economic progress and hindering societal advancement. Solar energy emerges as a beacon of hope, offering a sustainable and environmentally friendly solution to desalination. Solar distillation technology, harnessing the power of the sun, transforms seawater into freshwater, expanding the availability of this precious resource. Optimizing solar still performance under specific climatic conditions and evaluating different configurations is crucial for practical implementation and widespread adoption of solar energy. In this study, we conducted theoretical investigations on three distinct… More > Graphic Abstract

Fawziea M. Hussien¹, Atheer S. Hassoon^2,*, Ghaidaa M. Ahmed¹

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 175-191, 2024, DOI:10.32604/fhmt.2023.047177 - 21 March 2024

Abstract A heat exchanger’s performance depends heavily on the operating fluid’s transfer of heat capacity and thermal conductivity. Adding nanoparticles of high thermal conductivity materials is a significant way to enhance the heat transfer fluid's thermal conductivity. This research used engine oil containing alumina (Al₂O₃) nanoparticles and copper oxide (CuO) to test whether or not the heat exchanger’s efficiency could be improved. To establish the most effective elements for heat transfer enhancement, the heat exchangers thermal performance was tested at 0.05% and 0.1% concentrations for Al₂O₃ and CuO nanoparticles. The simulation results showed that the percentage increase… More >

Caifeng Wen^1,2, Qiang Wang^1,*, Yang Cao¹, Liru Zhang^1,2, Wenxin Wang³, Boxin Zhang¹, Qian Du¹

Energy Engineering, Vol.120, No.7, pp. 1603-1619, 2023, DOI:10.32604/ee.2023.027074 - 04 May 2023

Abstract To solve the problems of large losses and low productivity of permanent magnet synchronous generators used in wind power systems, the field-circuit coupling method is used to accurately solve the electromagnetic field and temperature field of the generator. The loss distribution of the motor is accurately obtained by considering the influence of external circuit characteristics on its internal physical field. By mapping the losses to the corresponding part of the three-dimensional finite element model of the motor, the temperature field is solved, and the global temperature distribution of the generator, considering the influence of end More >

Tieming Wang^a , Fuyong Su^b,*

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-4, 2023, DOI:10.5098/hmt.20.12

Abstract This paper analyzes the power generation technology of coke dry quenching (CDQ) waste heat boiler, and compares the exergy efficiency of medium temperature medium pressure boiler and high temperature high pressure boiler. The scheme of high temperature ultrahigh pressure primary intermediate reheat boiler to further improve the power generation efficiency of CDQ waste heat is put forward, and the exergy efficiency is analyzed. The bottleneck problem of further improving power generation efficiency by CDQ waste heat power generation and the exergy efficiency limit under the current process conditions are obtained. More >

Yashar Aryanfar^1,*, Jorge Luis García Alcaraz²

Energy Engineering, Vol.120, No.2, pp. 263-275, 2023, DOI:10.32604/ee.2023.022587 - 29 November 2022

Abstract The usage of renewable energies, including geothermal energy, is expanding rapidly worldwide. The low efficiency of geothermal cycles has consistently highlighted the importance of recovering heat loss for these cycles. This paper proposes a combined power generation cycle (single flash geothermal cycle with trans-critical CO₂ cycle) and simulates in the EES (Engineering Equation Solver) software. The results show that the design parameters of the proposed system are significantly improved compared to the BASIC single flash cycle. Then, the proposed approach is optimized using the genetic algorithm and the Nelder-Mead Simplex method. Separator pressure, steam turbine output More > Graphic Abstract

Rabeb Toujani, Nahla Bouaziz^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.4, pp. 991-1001, 2023, DOI:10.32604/fdmp.2022.022239 - 02 November 2022

Abstract A hybrid heat pump (compression/absorption) with an integrated thermal photovoltaic unit is studied. The considered working fluids are organic mixtures: R245fa/DMAC and R236fa/DMAC, chosen for their low Global Warming Potential. The main objective is the optimization of energy efficiency in order to minimize the environmental impact through the implementation of a sustainable strategy. It is shown that Exergy Analysis itself is a valuable tool in energy integration. Within the imposed framework of minimizing total annual costs, entropy analysis can be instrumental in determining the optimal plant concept, optimizing energy conversion and use, and improving profitability. More >