日光温室空气-土壤源双效热泵系统设计与性能测试

Design and Performance Test of Air-Soil Dual-source Heat Pump System for Solar Greenhouse

为探索一种节能高效的日光温室热环境调控模式,基于热泵技术,设计搭建了一种空气-土壤源双效热泵系统,并对系统性能进行了测试分析。该系统将空气、土壤2种不同热源热泵有效复合,采用串联板式换热模式,通过温控器和电磁阀可实现4种供热模式:空气源热泵单板换热模式、空气源热泵双板换热模式、土壤源热泵单板换热模式和土壤源热泵双板换热模式。通过日光温室供暖水箱加温测试,分析双效热泵系统在不同模式下的性能系数(COP)和节能效果。春季测试期间,空气源单板换热模式下热泵COP平均值为2.1,双板换热模式下热泵COP平均值为3.1,与温室燃煤加温锅炉相比平均节能50.4%;土壤源单板换热模式下平均性能系数为2.2,双板换热模式下平均性能系数为2.3。冬季测试期间,典型晴天里空气源热泵双板换热模式可有效提升温室模型内气温,与室外气温相比平均提升15.7℃。测试结果显示,相同热源条件下,冷凝端采用双板换热模式时机组COP高于单板换热模式,双板换热模式可提高机组整体换热效率和节能效果。空气-土壤源双效热泵系统可以有效利用空气能和地热能,在日光温室热环境调控方面具有较好的应用前景。

In order to explore an energy-efficient thermal environment control model in greenhouse,based on heat pump technology,a new type of air-soil dual-source heat pump system matched with the greenhouse model was designed and built,and the system performance was also tested. This system was compounded of air source heat pump and soil source heat pump,and adopted the plate heat exchanger in series form. The air-soil dual-source heat pump system had four kinds of heating modes,including air source mode with single plate heat exchanger,air source mode with double plates heat exchanger,soil source mode with single plate heat exchanger and soil source mode with double plates heat exchanger.These working modes can be converted by controlling the on-off of the electromagnetic valve. The soil source heat pump mode can solve the adaptability problem of air source heat pump under low temperature condition,while the air source heat pump mode can alleviate the problem of imbalance of the acquisition and release of the soil source heat pump. In the winter and spring test period,the COP（ coefficient of performance） and temperature rise rate of the heat pump system in air source mode with single and double plates heat exchanger were tested by heating the water in the heat insulating water tank. The operation results in spring were better than that in winter. In spring,the COPof the heat pump system in single and double plates air source mode were 2. 1 and 3. 1,respectively,and the COPof the heat pump system in single and double plate soil source mode were 2. 2 and 2. 3,respectively. The energy-saving effect of air source mode with double plates heat exchanger was the most significant,the energy-saving rate was up to 50. 4%. During the winter test period,the air source mode with double plates heat exchanger could raise the temperature in the greenhouse model in the typical sunny days. The indoor temperature was higher than the outdoor temperature about 15. 7℃ on average. According to the results,the performance of the double plate heat exchanger was both better than that of the single plate heat exchanger during the winter and spring. The results also showed that both the amount of heating medium and system pressure can affect the effect of the dual-source heat pump system. In conclusion,this air-soil dual-source heat pump system can make use of air energy and geothermal energy efficiently to realize the energy conservation of solar greenhouse in winter.