The difference between closed cooling tower and open cooling tower
Date:Jul 09, 2020
The cooling principle of the open cooling tower is that the circulating water is sprayed on the filler of glass fiber in a spray way, and the heat exchange is achieved through the contact between water and air. Then, a fan drives the air flow in the tower to circulate, bringing out the hot air flow after heat exchange with water, thus achieving cooling. In this cooling mode, the initial investment is relatively small, but the operating cost is relatively high (water consumption and power consumption).
The cooling principle of the closed cooling tower is, simply speaking, two cycles: one inner cycle and one outer cycle. There is no packing, and the main core part is copper tube surface cooler.
① Internal circulation: connect with the target equipment to form a closed circulation system (the circulating medium is soft water). Cool the target equipment and bring the heat from the target equipment to the cooling unit.
② External circulation: in the cooling tower, cool the cooling tower itself. It is not in contact with the internal circulating water phase, but only through the copper tube surface cooler in the cooling tower for heat exchange and heat dissipation. In this cooling mode, the operation of the motor is set according to the water temperature through automatic control.
Two cycles, when the ambient temperature is high in spring and summer, need to run simultaneously. In autumn and winter, the ambient temperature is not high, and in most cases only one internal circulation is needed. In the closed cooling tower, the hot water from the heat source exchanges heat with the air and spray water through the coil wall in a closed circulating device, and is continuously sent to the heat source for recycling after being cooled. As the cooling water is placed in a closed device, it will not be lost and can save water. There are three types of closed cooling towers: counter-current closed cooling towers, cross-flow closed cooling towers and mixed-flow closed cooling towers.