시설원예용 복합열원 축열식 히트펌프시스템의 실증연구

Abstract

In this study, to develop a regenerative heat pump system using surplus heat over the production temperature of garden crops for the heating of winter green house, a storage single heat source heat pump system was installed in a university. The average COPs of the heat pump thermal storage mode was 3.0 and the thermal storage capacity was 75.0kWh under the condition that the average outdoor temperature was 11.1℃ per day. The COPh of the thermal storage heat source heating mode was 1.4, and the heating capacity was 173.6kWh. In the case of a single heat source heat pump system, it is judged that the heating capacity is insufficient as compared with the heat quantity of heat storage, so that a direct heating mode in which the high temperature water stored in the heat storage tank is directly heat exchanged and the outdoor heat source heating mode And a solar collector is installed independently to increase the heating capacity of the heat pump system. The blueberry farmhouse where the actual green house warming occurred was selected as the experimental site and the thermal environment was measured. The design index of the system was set to maintain the internal temperature of the greenhouse at 15 ℃, which is the optimal temperature for blueberry cultivation. As a result, in order to utilize the surplus heat of the green house, it was concluded that the outside temperature should be 15℃ and amount of insolation should be 220W/㎡ or more. Based on the results of the preliminary experiments, we designed and installed a 3RT(10.5kW) capacity of hybrid heat pump system. From October 30, 2015 to February 15, 2016, we conducted an empirical test. This system includes a heat pump thermal storage mode for storing surplus heat at the upper end of the green house in a heat storage tank, a hot water heating mode for directly heating the high temperature water stored in the heat storage tank, a outdoor heat source heating mode for the outdoor heat source , A solar collector is installed at the top of the system independently from the heat pump system, and the solar heat is directly stored and stored in the heat storage tank. At the average outside temperature of 11.4℃, the COPs are 2.3 and the thermal storage capacity is 64.2kWh. In the case of hot water heating mode, the heating capacity is 88.8 kWh. In outdoor heat source heating mode, the COPh is 7.5 and the heating capacity is 249.6kWh. In the case of the thermal storage heat source heating mode, the average COPh is 6.8 and the heating capacity is 44.2kWh. In the case of Solar collector storage mode, the average of insolation per day is 462.0W/㎡ and thermal storage capacity is 11.2kWh. Under the condition that the average outside temperature is 5.6℃, the COPs of heat pump thermal storage mode is 4.7 and the thermal storage capacity is 24.8kWh. In case of hot water heating mode, it did not work because of the water temperature stored in the storage tank did not exceed 30℃. In the case of outdoor heat source heating mode, the COPh is 7.6 on average and the heating capacity is 316.2kWh. In the case of the heat pump thermal storage mode in the storage tank, the COPh is 7.1 on average and the heating capacity is 100.5kWh. In the case of the Solar collector thermal storage mode, the average of insolation per day is 277.5W/㎡ and thermal storage capacity is 2.4kWh.