The invention relates to a novel comparative open-type water circulation system comprising a water tank and power supply cabinets. Connection pipelines are arranged between the water tank and the power supply cabinets. Control valves are arranged on the connection pipelines. The control valves are ball valves. A sealing plate is arranged on the water tank. An absorption part is arranged under the sealing plate. The connection pipelines are arranged in connection holes. Pressure control cabinets are arranged below the power supply cabinets, and are connected with the power supply cabinets. Pipelines are arranged between the pressure control cabinets and the power supply cabinets. Control parts are arranged on the pipelines. A descaling part is controlled through a solenoid valve, and descaling of the water tank can be carried out at any time. Manual descaling agent spreading is not needed, such that the work load of operators is reduced. With the sealing plate arranged on the water tank, the water in the water tank is prevented from being evaporated too fast, and pollutant is prevented from entering the water tank. Therefore, a circulation pipe network is prevented from being blocked by the pollutants in the water tank.