Closed circulation system for directly cooling mine through surface cooler and working method

The invention discloses a closed circulation system for directly cooling a mine through a surface cooler and a working method. The closed circulation system comprises a ground part and an downhole part, wherein the ground part comprises the surface cooler, a high-pressure circulating pump, a high-pressure water inlet pipe, a high-pressure water return pipe, an ethylene glycol water supply pipe, anethylene glycol water supply tank, a charging pump and a surface cooler fan; the downhole part comprises a high-pressure water return pipe, a high-low pressure heat exchanger, a downhole circulatingwater inlet pipe, a downhole circulating water return pipe, a downhole circulating water pump, an air cooler and an air cooler local fan blower. According to the closed circulation system, the coolingcapacity of an outdoor natural cold source is utilized to achieve the mine cooling, and the automatic adjustment can be realized by adjusting the flow of the circulating pump according to the changein the outdoor temperature;