Research On Heating System Of Solar Energy Inter Seasonal Heat Storage Composite Ground Source Heat Pump For Agricultural Greenhouse

Solar energy inter seasonal heat storage（SEISHS）composite ground source heat pump（GSHP）is a clean,efficient and multi-complementary clean heating mode.In this study,in order to explore a stable and efficient new way of clean heating for agricultural greenhouse in cold areas of China,the research on clean heating for glass greenhouse was carried out.A compound heating system composed of SEISHS and GSHP was designed and constructed.The relevant experimental researches on the heating characteristics of GSHP,the operation characteristics of SECSHS based on the soil,and the heating characteristics of the composite system of solar energy and GSHP were carried out respectively.First of all,the experimental research on the heating characteristics of GSHP for agricultural greenhouse was carried out.The quantitative relationship between the return water temperature on the load side of the heat pump unit and the heating system coefficient of performance(COP_sy)is obtained.The regularity of the diurnal periodic change of the soil temperature in the heat exchange well has been found out.After heating,the soil temperature in the well cluster area decreased about 1℃.In addition,the average temperature rise of soil self-recovery in the transitional season is less than 0.1℃,which fully shows that it is necessary to take soil heat supplement measures.Secondly,the experimental study of SEISHS based on soil was carried out.The effects of solar irradiation and thermal storage operation parameters on the solar collection and thermal storage performance are analyzed.The results show that the average ratio of heat storage and power consumption is 20.02.Through SEISHS,the soil temperature in the well cluster area is 0.3℃higher than that in the non-heat extraction area.These results verify that it is feasible to increase soil temperature in the well cluster area by solar energy inter seasonal heat storage in this area.Finally,the experimental research on the operation characteristics of the solar energy heating compound GSHP heating is carried out.The COP_syof GSHP is 3.11,which is 18.7%higher than that of last heating season.The overall analysis shows that the proportion of direct solar heating in the whole heating season is 10.70%.The COP_sy of compound heating mode is3.32,which is 6.8%higher than that of only GSHP heating mode.Compared with electric heating and GSHP heating mode,The operation power consumption of compound heating mode is reduced by 70.74%and12.17%respectively,which has better environmental protection benefits.The results of this study can provide data support and guidance for related research and application promotion.