Hongfei Zheng
Beijing Institute of Technology
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Featured researches published by Hongfei Zheng.
International Journal of Photoenergy | 2015
Hongfei Zheng; Gang Wu; Jing Dai; Yanyan Ma
This paper presents design and testing of a shell-encapsulated solar collector which can be used in north area of China for wall-amounting installation. The designed solar collector is based on the combination of a novel compound curved surface concentrator and an aluminum concentric solar receiver, which is contained in a glass evacuated-tube. As there is no perforative joint between the double-skin glass evacuated-tube and the aluminum concentric solar receiver, the difficulty of vacuum keeping for a glass-metal joint is avoided. The cavity shell provides an additional thermal insulation to reduce heat loss of the designed solar collector. The working principle of the compound curved surface concentrator is described. The ray-tracing results are given to show the effect of deviation angle of the concentrator on its optical efficiency, hence determining its maximum acceptance angle. A prototype of the designed solar collector has been constructed and tested under the sunny winter weather condition. The experimental results indicate that the hot water temperature higher than 80°C with a daily average efficiency of about 45~50% has been achieved at the average ambient temperature below 0°C, so the designed solar collector can produce hot water at a useful temperature in winter.
International Journal of Photoenergy | 2015
Zhengliang Li; Mingxian Chen; Husheng Meng; Zehui Chang; Hongfei Zheng
A new trough solar concentrator which is composed of multiple reflection surfaces is developed in this paper. The concentrator was analyzed firstly by using optical software. The variation curves of the collecting efficiency affected by tracking error and the deviation angle were given out. It is found that the deviation tolerance for the collector tracking system is about 8 degrees when the receiver is a 90 mm flat. The trough solar concentrators were tested under real weather conditions. The experiment results indicate that, the new solar concentrator was validated to have relative good collecting efficiency, which can be more than 45 percent when it operated in more 145°C. It also has the characteristics of rdust, wind, and snow resistance and low tracking precision requirements.
Entropy | 2018
Yanjie Zheng; Yunsheng Zhao; Shen Liang; Hongfei Zheng
Based on the reversible heat engine model, theoretical analysis is carried out for economic performance of a solar tower power plant (STPP) combined with multi-effect desalination (MED). Taking total revenue of the output power and the fresh water yield per unit investment cost as the economic objective function, the most economical working condition of the system is given by analyzing the influence of the system investment composition, the receiver operating temperature, the concentration ratio, the efficiency of the endoreversible heat engine, and the relative water price on the economic parameters of the system. The variation curves of the economic objective function are given out when the main parameter is changed. The results show that the ratio of water price to electricity price, or relative price index, has a significant impact on system economy. When the water price is relatively low, with the effect numbers of the desalination system increasing, and the economic efficiency of the overall system worsens. Only when the price of fresh water rises to a certain value does it make sense to increase the effect. Additionally, the threshold of the fresh water price to the electricity price ratio is 0.22. Under the conditions of the current price index and the heliostat (or reflector), the cost ratio and the system economy can be maximized by selecting the optimum receiver temperature, the endoreversible heat engine efficiency, and the optimum concentration ratio. Given the receiver surface temperature and the endoreversible heat engine efficiency, increasing the system concentration ratio of the heliostat will be in favor of the system economy.
International Journal of Photoenergy | 2015
Gang Pei; Yuehong Su; Sauro Filippeschi; Hongfei Zheng
1Department ofThermal Science and Energy Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China 2Department of Architecture and Built Environment, The University of Nottingham, Nottingham NG7 2RD, UK 3Department of Energy, System, Territory and Constructions Engineering, University of Pisa, 55126 Pisa, Italy 4School of Mechanical and Vehicle Engineering, Beijing Institute of Technology, Beijing 100081, China
Journal of Renewable and Sustainable Energy | 2014
Guiqiang Li; Gang Pei; Yuehong Su; Yunyun Wang; Xu Yu; Jie Ji; Hongfei Zheng
Low-concentration photovoltaic compound parabolic concentrators (PV-CPC) are a significant addition of solar cell application, especially in Building Integrated Photovoltaics, because it does not need a tracking system and can be installed in a stationary condition. However, higher concentrations correspond with the smaller half acceptance angle, which is a limitation but can be improved by a lens-walled structure. In this paper, to validate the rationale of this structure, a low-concentration PV-CPC using an acrylic lens-walled structure module was designed and fabricated with low-cost materials. The corresponding simulation was also performed with different materials to determine whether the factor that the truncation had a significant effect. The observed outcome implied that the low-concentration PV-CPC using an acrylic lens-walled structure has a larger half acceptance angle than the mirror CPC, and that a maximum optical efficiency of more than 80% can be achieved using Schott BK glass as the lens w...
Energy Conversion and Management | 2013
Jianyin Xiong; Guo Xie; Hongfei Zheng
Energies | 2012
Gang Pei; Guiqiang Li; Yuehong Su; Jie Ji; Saffa Riffat; Hongfei Zheng
Renewable Energy | 2014
Zehui Chang; Hongfei Zheng; Yingjun Yang; Yuehong Su; Zhanchun Duan
Desalination | 2014
Huifang Kang; Yingjun Yang; Zehui Chang; Hongfei Zheng; Zhanchun Duan
Energy Conversion and Management | 2011
Hongfei Zheng; Tao Tao; Jing Dai; Huifang Kang