Experimental investigation and performance analysis on ground source heat pump system for greenhouse cooling

For the purpose of exploring the way and exploiting the potential of ground source heat pump(GSHP) cooling technology for the facility agriculture and solving the problem of high humidity in greenhouse horticulture after using the deeply conventional evaporative cooling method, the authors have carried out the experiment on ground source heat pump system for solar greenhouse cooling in Beijing region was carried out, and put forward some related calculating models of energy transfer and performance analysis for the in summer system was put forward. Analysis results based on the measurements made during Aug.17-19, 2007 shown that the coefficient of performance(COP) of the greenhouse cooling system(COPsyscg) reached 3.01 on average. The day of Aug.17 was the hottest one among three days, the analytical result shown that the average air temperature in and outside of greenhouse from 10:00 to 14:00 were 31.3℃ and 34.1℃, respectively, and average temperature had reached 2.8℃. Meanwhile, air relative humidity was 60.7% on average in greenhouse, which meand that the GSHP system played an important role in cooling and dehumidifying. Besides, the outside sun shading ratio of PE sunshade screen was 70% .