A research on utilization of geothermal energy sources for greenhouse heating in Aydin province

In this study; utilization of geothermal energy sources for greenhouse heatingin Aydın province has been investigated. Plastic and steel pipe heating installationsin plastic greenhouses were evaluated in some respects: design parameters, influenceon greenhouse climate and technical and economical feasibility. Calculation of therequired length of the heating pipes used as a heat exchanger was described. Physicaland chemical properties of the geothermal sources that affect the greenhouse heatingwere investigated.This study presents the determination of design parameters of geothermalheating systems in plastic greenhouses. The greenhouse, 19.2 m wide and 52 m long,is made of two adjacent 9.6 m wide span covered with polyethylene (PE) plastic. Thedesign parameters of hot water heating systems were determined for three differentplastic greenhouses: PE plastic greenhouse without thermal screen, PE plastic+PEthermal screen, and PE plastic+ polyester thermal screen. Heating requirements ofthe plastic greenhouses were calculated for 0 °C and ?5 °C of outside temperaturesand 5 °C, 10 °C, 15 °C, and 18 °C of inside temperatures. It was considered that theplastic (diameter= 25 mm and 32 mm) and steel pipes (diameter= 51 and 57 mm)were used as the heat exchanger in the plastic greenhouses. The length of the heatpipes, heat transfer from the heating pipes to the inside air, and volumetric flow rateof the circulating pump were calculated for the plastic greenhouses (1000 m2 of floorarea). When the outside temperature is ?5 °C, fort the 15 °C internal air temperatureheating requirement is 169.2 W/m2, 126.9 W/m2 and 98.7 W/m2 in PE plasticgreenhouse, PE screened greenhouse and polyester screened greenhouse,respectively. The total length of 40 mm diameter of plastic pipes as heat exchanger is1539.3 m, 1154.4 m and 897.9 m for the PE plastic greenhouse, PE screenedgreenhouse and polyester screened greenhouse, respectively.