Dry-wet Combined Cooling Tower

Dry-wet combined cooling tower is an application form of tubular indirect evaporative cooler. Its working principle is divided into three parts:

(1) Primary side heat exchange cycle: When the hot water on the primary side flows through the coil of the closed cooling tower, it is divided into four stages for heat transfer:

a. The heat I of the hot solution is transferred to the inner surface of the coil by convection heat transfer;

b. Heat conduction through the tube wall to the outer surface of the coil;

c. Heat is transferred from the outer surface of the coil to the water film flowing outside the tube, and the water film is transferred to the air by evaporation and convection heat exchange

2) Secondary side pre-cooling cycle: The tertiary side spray water is pumped from the lower water pan of the cooling tower to the water distribution system by the spray pump. After the radiating head is sprayed on the heat-dissipating material, it exchanges latent heat and sensible heat with the air, and after pre-cooling, it flows to the coil group, forming a stable water film on the outer wall of the pipe, absorbing the heat transmitted by the medium in the pipe, and then recirculating it again. Go back to the water tray, and so on.

(3) Air circulation: the fan draws the unsaturated air outside the cooling tower into the tower, and the airflow passes through the coil, the heat sink and the spray water on the secondary side to exchange latent heat and sensible heat to absorb heat, and then pass through the water blocker. The gas and water are separated, and the nearly saturated moist air is discharged out of the tower.

Through the above three cycles and four-stage heat exchange, the cooling tower cools the secondary heat carrier solution to the required temperature to return it to the system to maintain its normal operation.