Two-stage heating geothermal system using geothermal energy

A two-stage heating geothermal system using geothermal energy, comprising:

• a geothermal heat exchanger able to perform heat exchange with an underground heat source;
• a geothermal heat pump able to perform a cooling and heating operation for a first user side using heat transferred from the geothermal heat exchanger;
• a booster heat pump able to perform at least one of a cooling and heating operation and a hot water supply operation for a second user side using a heat source, separately from the geothermal heat pump, the heat source being waste heat that has been generated due to the cooling and heating operation of the geothermal heat pump and has been transferred toward the geothermal heat exchanger;
• a bypass line connecting a pipe, by which the booster heat pump is connected to the second user side, and a pipe, by which the geothermal heat pump is connected to the first user side, such that heat generated by the booster heat pump is transferred to the first user side by bypassing the geothermal heat pump;
• and
• a bypass line opening and closing valve comprising a three-way valve disposed on a branch point between a pipe, by which the booster heat pump is connected to the second user side, and the bypass line to control a flow rate of refrigerant through the bypass line.