Xin Xu^*, Lian Zhang^*

Energy Engineering, Vol.118, No.6, pp. 1905-1920, 2021, DOI:10.32604/EE.2021.016738

Abstract This paper briefly summarizes the current status of typical solar thermal power plant system, including system composition, thermal energy storage medium and performance. The thermo-physical properties of the storage medium are some of the most important factors that affect overall efficiency of the system, because some renewable energy sources such as solar and wind are unpredictable. A thermal storage system is therefore necessary to store energy for continuous usage. Based on the form of storage or the mode of system connection, heat exchangers of a thermal storage system can produce different temperature ranges of heat transfer fluid to realize energy… More >

Zhen Liu^1,3, Jianwen Wang^1,2,*, Fuzhong Bai³, Caifeng Wen^1,2, Yunchao Du¹

Energy Engineering, Vol.118, No.6, pp. 1627-1640, 2021, DOI:10.32604/EE.2021.016357

Abstract The yaw of the horizontal axis wind turbine results in the deflection of the wake flow field of the tower. The reasonable layout of wind farm can reduce the power loss of the downstream wind turbine generators due to the blocking effect of the upstream wake flow and increase the output power of the whole wind farm. However, there is still much space for further research. In this paper, experimental research is conducted on the near-wake deflection characteristics of wind turbine tower under yaw state, expecting the effect of throwing away a brick in order to get a gem. In… More >

Ahmed Abubakar Elwan^*, Mohammed Hafiz Habibuddin

Energy Engineering, Vol.118, No.6, pp. 1681-1701, 2021, DOI:10.32604/EE.2021.016291

Abstract With population growth around the world, municipal waste disposal and continued energy demand becomes some of the major challenges to deal with. In order to address these, an approach is required for an optimal waste management system that offers the population benefit with a lower environmental impact. This study evaluates the technical-economic and environmental impact analysis of a grid-connected waste to energy (WtE) plant to power a Univerisiti Teknologi Malaysia (UTM) community. The energy recovery potential of the waste stream was assessed using the life cycle assessment (LCA) method with GaBi^TM software (version 4). A technical, economic and environmental analysis… More >

Lei Wang¹, Zekun Wang^2,3,4,*, Yingjian Yang², Shuni Zhou⁵, Yehong Dong⁵, Fanghong Zhang⁵

Energy Engineering, Vol.118, No.6, pp. 1611-1626, 2021, DOI:10.32604/EE.2021.016010

Abstract China has abundant wind energy resources and huge development potential among developing countries. Japan is a developed country that planned to increase the use of renewable energy, especially wind energy. This research is aimed at reviewing the development of wind power and relevant policies between China and Japan. Firstly, we introduced the current status of global wind power development, such as the global installed capacity of wind power. The annual development of wind power generation in China and Japan is compared, and the distribution characteristics of wind resources are compared. Furthermore, the market share in China and Japan is introduced.… More >

Jianfeng Yang^*, Yu Ding

Energy Engineering, Vol.118, No.6, pp. 1839-1853, 2021, DOI:10.32604/EE.2021.015930

Abstract With the widespread application of power electronic equipment in the power grid, the harmonic problem of the power grid becomes more pronounced, reducing the efficiency of power production, transmission, and utilization, and interfering with the normal operation of the power grid. Based on the requirements of harmonic suppression and power system protection, a shunt active power filter (SAPF) is proposed as an effective harmonic suppression method. However, there are problems with impulse current and impulse voltage in the starting process of SAPF. Impulse current and impulse voltage cause the power grid and switchgear to bear greater current stress and voltage… More >

Xiyuan Li¹, Peng Chu^2,3,*, Zhuang Lu^2,3, Yuanyuan Liu^2,3, Zibin Zhu^2,3, Jin Gao^2,3, Xiaoxue Liao^2,3, Tao Yang^2,3

Energy Engineering, Vol.118, No.6, pp. 1811-1825, 2021, DOI:10.32604/EE.2021.015751

Abstract The permeability is a key factor to determine the efficiency of coalbed methane (CBM) production. The borehole enlargement technology using hydraulic and mechanical measures to cut coal is an effective method to increase the coal seam permeability and improve the efficiency of gas drainage. Reasonable design of the layout of boreholes is the prerequisite for efficient and economical gas drainage. In this paper, based on the strain-softening model, the stress and permeability model of the coal seam around the enlarged borehole was built, and based on the dual-medium model, the gas migration model in the coal seam was established. Then… More >

Fuyun Zhu, Guoqing Wu^*

Energy Engineering, Vol.118, No.6, pp. 1703-1712, 2021, DOI:10.32604/EE.2021.015602

Abstract Accurate power load forecasting plays an important role in the power dispatching and security of grid. In this paper, a mathematical model for power load forecasting based on the random forest regression (RFR) was established. The input parameters of RFR model were determined by means of the grid search algorithm. The prediction results for this model were compared with those for several other common machine learning methods. It was found that the coefficient of determination (R²) of test set based on the RFR model was the highest, reaching 0.514 while the corresponding mean absolute error (MAE) and the mean squared… More >

Xiyang Li^1,2, Bin Cheng^1,2, Hui Zhang^1,2,*, Xianghan Zhang¹, Zhi Yun¹

Energy Engineering, Vol.118, No.6, pp. 1869-1886, 2021, DOI:10.32604/EE.2021.015542

Abstract With the continuous increase in the proportional use of wind energy across the globe, the reduction of power generation efficiency and safety hazards caused by the icing on wind turbine blades have attracted more consideration for research. Therefore, it is crucial to accurately analyze the thickness of icing on wind turbine blades, which can serve as a basis for formulating corresponding control measures and ensure a safe and stable operation of wind turbines in winter times and/or in high altitude areas. This paper fully utilized the advantages of the support vector machine (SVM) and back-propagation neural network (BPNN), with the… More >

Wei Zhao¹, Miao Jiang², Jun Dong¹, Lee Li^2,*

Energy Engineering, Vol.118, No.6, pp. 1755-1766, 2021, DOI:10.32604/EE.2021.015467

Abstract In recent years, more and more high-voltage overhead transmission lines were built passing through the karst regions in southwestern China. This type of special landform seems to have an adverse effect on the aging of the sheds of the line suspension composite insulators, which may lead to unexpected flashover and line tripping. In order to find out the particularity of the aging characteristics of insulators operating in the karst regions, samples in operation were selected from both the karst regions and the flatlands. Hydrophobicity, amount of surface contamination, and contaminant composition of the sheds were studied, then a comparison of… More >

Yukun Lv, Zhuang Wei^*, Quanzhi Ge, Fan Yang, Shuang Yang

Energy Engineering, Vol.118, No.6, pp. 1855-1867, 2021, DOI:10.32604/EE.2021.015248

Abstract The water-cooling heat dissipation technology can solve the heat dissipation and noise problems of the calculation plate. Therefore, the structural design of the water-cooling plate directly affects its flow and heat transfer characteristics, which restricts the promotion and application of the technology. To this end, the water-cooling plate of a heat dissipation system was taken as the research object, and its flow and heat transfer characteristics were numerical simulated and experimental studied. Through comparative analysis, the rationality of the numerical simulation method was verified. Based on this, three improved schemes of water-cooling plate structure were proposed and numerical simulation was… More >