| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a geothermal utilization system that performs control so that circulation liquid is not frozen even under a cold point.SOLUTION: A geothermal utilization system 1, when circulation liquid reaches or approaches its freezing temperature, starts freezing prevention operation. In the freezing prevention operation, a heat source side circulation pump 7 is operated, and heat source side circulation liquid is circulated. Consequently, the circulation liquid becomes high temperature by heat exchange with underground heat, and the heat source side circulation liquid or load side circulation liquid is prevented from being frozen. Also, when the load side circulation liquid approaches the freezing temperature, in the freezing prevention operation, the heat source side circulation pump 7, a heat pump device 4, and a load side circulation pump 12 are operated.</p> |
