Jiangyong Bao¹, Jianjun He^1,*, Biao Chen², Kaijun Yang¹, Jun Jie², Ruifeng Wang¹, Shihao Zhang²

Energy Engineering, Vol.118, No.4, pp. 947-959, 2021, DOI:10.32604/EE.2021.014535

Abstract As a surface functional material, super-hydrophobic coating has great application potential in wind turbine blade anti-icing, self-cleaning and drag reduction. In this study, ZnO and SiO₂ multi-scale superhydrophobic coatings with mechanical flexibility were prepared by embedding modified ZnO and SiO₂ nanoparticles in PDMS. The prepared coating has a higher static water contact angle (CA is 153°) and a lower rolling angle (SA is 3.3°), showing excellent super-hydrophobicity. Because of its excellent superhydrophobic ability and micro-nano structure, the coating has good anti-icing ability. Under the conditions of −10°C and 60% relative humidity, the coating can delay the freezing time by 1511S,… More >

Duojin Fan¹, Chengji Shi², Kai Sun², Xiaojuan Lu^2,*

Energy Engineering, Vol.118, No.4, pp. 1197-1221, 2021, DOI:10.32604/EE.2021.014532

Abstract This paper proposed a new type of combined cooling heating and power (CCHP) system, including the parabolic trough solar thermal (PTST) power generation and gas turbine power generation. The thermal energy storage subsystem in the PTST unit provides both thermal energy and electrical energy. Based on the life cycle method, the configuration optimization under eight operation strategies is studied with the economy, energy, and environment indicators. The eight operation strategies include FEL, FEL-EC, FEL-TES, FEL-TES&EC, FTL, FTL-EC, FTL-TES, and FTL-TES&EC. The feasibility of each strategy is verified by taking a residential building cluster as an example. The indicators under the… More >

Quan Min¹, Min Deng¹, Zichen Zheng^2,*, Shu Wang², Xianyong Gui³, Haichuan Zhang²

Energy Engineering, Vol.118, No.4, pp. 853-874, 2021, DOI:10.32604/EE.2021.014515

Abstract Combined with the characteristics of the distributed-drive electric vehicle and direct yaw moment control, a double-layer structure direct yaw moment controller is designed. The upper additional yaw moment controller is constructed based on model predictive control. Aiming at minimizing the utilization rate of tire adhesion and constrained by the working characteristics of motor system and brake system, a quadratic programming active set was designed to optimize the distribution of additional yaw moments. The road surface adhesion coefficient has a great impact on the reliability of direct yaw moment control, for which joint observer of vehicle state parameters and road surface… More >

Jin Zhang¹, Youliang Tang¹, Feng Yu^2,*

Energy Engineering, Vol.118, No.4, pp. 1083-1094, 2021, DOI:10.32604/EE.2021.014482

Abstract In this paper, position sensorless control system of permanent magnet synchronous linear motor (PMSLM) based on sliding mode observer (SMO) with an improved phase-locked loop (PLL) is studied. Firstly, according to the mathematical model, a SMO is designed for sensorless control PMSLM drive. Thereafter, an improved PLL is proposed to tackle the imperfection of data overflow existed in the traditional PLL. The designed SMO incorporating with the improved PLL can be effectively suppress the pulsation of the estimated position and hence the chattering of the derived electrical angular velocity. At last, simulated and experimental results are presented to verify the… More >

Yiya Wang, Hailong Yu^*, Shucheng Wu, Li Liu, Liuyang Huang, Baozhong Zhu, Yunlan Sun, Enhai Liu

Energy Engineering, Vol.118, No.4, pp. 797-823, 2021, DOI:10.32604/EE.2021.014467

Abstract Hot Dry Rock (HDR) is the most potential renewable geothermal energy in the future. Enhanced Geothermal System (EGS) is the most effective method for the development and utilization of HDR resources, and fractures are the main flow channels and one of the most important conditions for studying heat transfer process of EGS. Therefore, the heat transfer process and the heat transfer mechanism in fractures of EGS have been the hot spots of research. Due to the particularity of the mathematical models of heat transfer, research in this field has been at an exploratory stage, and its methods are mainly experimental… More >

Feiyang Li, Jianfeng Pan^*, Chenxin Zhang, Evans K. Quaye, Xia Shao

Energy Engineering, Vol.118, No.4, pp. 1135-1154, 2021, DOI:10.32604/EE.2021.014366

Abstract In order to obtain the combustion characteristics of the CH₄/Air premixed flame under the action of the wall interaction, a study on the impact of the jet flame on the wall at different separation distances was carried out. The separation distance from the burner outlet to the lower surface of the wall is changed and the flame structure is obtained through experiments. The temperature, velocity and reaction rate are obtained through numerical simulation, and the law of flame characteristics change is obtained through analysis. The results show that as the separation distance increases, the premixing cone inside the flame gradually… More >

Dequn Zhou, Xinyi Gu, Hao Ding^*

Energy Engineering, Vol.118, No.4, pp. 961-979, 2021, DOI:10.32604/EE.2021.014101

Abstract Understanding how aging population and low fertility affect household energy consumption is important for optimizing household energy consumption and reaching effective policies. This paper studies the impacts of demographic transition on household energy consumption based on panel data of 30 provinces in China from 2005 to 2016. Child-age dependency rate (CDR) and old-age dependency rate (ODR) are selected to track the shifts in age structure. They are introduced into a STIRPAT model to measure their impacts on household energy consumption. Besides, 8 representative regions are additionally chosen and investigated to find some regional characteristics. The results show that current demographic… More >

Peng Qi^1,*, Yu Shang^2,*

Energy Engineering, Vol.118, No.3, pp. 727-736, 2021, DOI:10.32604/EE.2021.014203

Abstract With the increasingly prominent environmental problems of abandoned coal mines, this paper discussed the significance of environmental vulnerability assessment of abandoned coal mines. Environmental vulnerability assessment is essentially an assessment of environmental quality. At present, the research object of environmental impact assessment method and program of mine is mostly single factor. However, the impact of abandoned coal mine on the environment is multifaceted, which was summarized into nine prominent common problems. Based on these nine factors, the environmental vulnerability assessment model of abandoned coal mine based on multifactor evaluation was established by using the analytic hierarchy process (AHP) method, the… More >

Haibo Liu^1,*, Yujie Dong², Fuzhong Wang¹

Energy Engineering, Vol.118, No.3, pp. 679-689, 2021, DOI: 10.32604/EE.2021.014630

Abstract For the problems of nonlinearity, uncertainty and low prediction accuracy in the gas outburst prediction of coal mining face, the least squares support vector machine (LSSVM) is proposed to establish the prediction model. Firstly, considering the inertia coefficients as global parameters lacks the ability to improve the solution for the traditional particle swarm optimization (PSO), an improved PSO (IPSO) algorithm is introduced to adjust different inertia weights in updating the particle swarm and solve the fitness to stagnate. Secondly, the penalty factor and kernel function parameter of LSSVM are searched automatically, and the regression accuracy and generalization performance is enhanced… More >

Chunxue Gao^1,*, Yu Hao¹, Qiuxin Liu^1,2

Energy Engineering, Vol.118, No.3, pp. 667-678, 2021, DOI:10.32604/EE.2021.014703

Abstract Based on the characteristics of sewage from beauty salons, a simulation model of a small sewage source heat pump triple supply system that can be applied to such places is established to optimize the operating conditions of the system. The results show that with the increase of sewage temperature and flow, the performance of the system also increases. In summer conditions, the system provides cooling, recovers waste heat and condensed heat from sewage, with a COP value of 8.97; in winter conditions, the system heats and produces hot water, with a COP value of 2.44; in transitional seasons, only hot… More >