Performance testing on warming effect of heat storage-release metal film in Chinese solar greenhouse

被引：0
作者：
Fang, Hui [1 ,2 ]
Zhang, Yi [1 ,2 ]
Yang, Qichang [1 ,2 ]
Lu, Wei [1 ,2 ]
Zhou, Bo [1 ,2 ]
Zhou, Sheng [1 ,2 ]
机构：
[1] Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing
[2] Key Lab. of Energy Conservation and Waster Treatment of Agricultural Structures, Ministry of Agriculture, Beijing
来源：
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | 2015年 / 31卷 / 15期
关键词：
Chinese solar greenhouse; Energy conservation; Greenhouses; Heat release; Heat storage; Heating equipment;
D O I：
10.11975/j.issn.1002-6819.2015.15.024
中图分类号：
学科分类号：
摘要：
The Chinese Solar Greenhouse (CSG) that is widely used in North China is characterized by a lean-to south-facing roof, a removable insulating blanket and a solid north wall. The south facing roof structure and removable insulating blanket maximize the exposure to short-wave radiation during the day and minimize heat loss at night, respectively. To increase the year-round greenhouse production in North China, a sustainable heating method needs to be developed to increase the night air temperature during the winter in CSGs. Solar heating is an inexpensive and effective way to heat greenhouses, and has been investigated by several previous studies. For the present study, a heat storage-release metal film system that was attached to the north wall was developed for CSG night temperature improvement. Two experimental greenhouses were located in Beijing, China, with a floor area of 304 m2 each. Environmental parameters (temperature, humidity, heat flux) inside and outside the greenhouse were investigated, including the average solar collection efficiency of the heating system and the energy saving rates. The results showed that the average solar collection efficiency of the system was 83%, 1.6 times greater than the reported value of a heat storage-release metal film system installed in a small CSG. The energy collection efficiency during the daytime decreased sharply with declining plate-air temperature differences. To have high energy collection efficiencies, plate-air temperature differences must be kept high and this can be achieved by applying a heat pump to reduce the circulating water temperature and transfer the energy to another water tank. The effective collector absorptivity was 0.81 and heat transfer was by natural convection. During the relatively cold nights of December 23 and 24 with the lowest outdoor air temperature of approximately-18℃, the inside air temperature of the experimental CSG also was 3.7℃ higher than in the reference CSG after starting operation of the heat storage-release metal film system. The night air temperature in the experimental CSG was increased by 2.4℃ on average compared to the reference CSG. The performance of the heat storage-release metal film system can be analyzed via the collected and released heat. The variations of the total heat collected and released by the heat storage-release metal film system during the day/night periods investigated were presented together with the radiation sum at the back wall over the total area of the heat storage-release metal film system. The system collected much more energy during sunny days than during cloudy days. The utilization ratio of the collected heat of the heat storage-release metal film system was calculated and it was between 64% and 71%. So the collected heat was not utilised completely during the night as some heat was lost during transport and storage. The heat collecting efficiency for these days was calculated as 86%, 82% and 82%, respectively which was nearly constant. So the use of the heat storage-release metal film system for heating the greenhouse at night during the winter can improve the environmental conditions inside Chinese solar greenhouses for crop production, achieving high energy collection efficiency and a reduction in energy consumption. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
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页码：177 / 182
页数：5
相关论文
共 23 条
[1]  
Li T., Current situation and prospects of greenhouse industry development in China, Journal of Shenyang Agricultural University, 3, 2, pp. 123-129, (2005)
[2]  
Yang J., Zou Z., Zhang Z., Et al., Optimization of earth wall thickness and thermal insulation property of solar greenhouse in Northwest China, Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 25, 8, pp. 180-185, (2009)
[3]  
Tong G., Li B., Simulation of solar radiation on surfaces of a solar greenhouse, Journal of China Agricultural University, 11, 1, pp. 61-65, (2006)
[4]  
Guo H., Li Z., Zhang Z., Et al., The relationship between the north wall construction and interior temperature environment in solar greenhouse, Journal of Shenyang Agricultural University, 26, 2, pp. 193-199, (1995)
[5]  
Ma C., Lu H., Li R., Et al., One-dimensional finite difference model and numerical simulation for heat transfer of wall in Chinese solar greenhouse, Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 26, 6, pp. 231-237, (2010)
[6]  
Li X., Chen Q., Effects of different wall materials on the performance of heat preservation of wall of sunlight greenhouse, Chinese Journal of Eco-Agriculture, 14, 4, pp. 185-189, (2006)
[7]  
Tong G., Christopher D.M., Simulation of temperature variations for various wall materials in Chinese solar greenhouses using computational fluid dynamics, Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 25, 3, pp. 153-157, (2009)
[8]  
Zhang L., Xu G., Ma C., Et al., Application of aerated concrete in solar greenhouses, Journal of Shenyang Agricultural University, 37, 3, pp. 459-462, (2006)
[9]  
Bai Y., Chi D., Wang T., Et al., Experimental research of heating by fire-pit and underground heating exchange system in a solar greenhouse, Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 22, 10, pp. 178-181, (2006)
[10]  
Chen Z., Chen C., Ling H., Et al., Experimental study on thermal performance for the specialized multiple curved surfaces trough solar air collector dedicated to solar greenhouse, Building Science, 30, 8, pp. 58-63, (2014)
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