Working Principle of Cooling Water Tower
Principle: A cooling tower is a device that uses water and air contact to dissipate waste heat generated in an industrial or refrigeration air conditioner by evaporation. The basic principle is: after drying the air with low enthalpy value, it enters the cooling tower from the air inlet net after the convection of the fan; the high temperature water molecules with large pressure of saturated steam flow to the air with low pressure, and the water with high humidity and high value The water system is spilled into the tower. When the water droplets come into contact with the air, on the one hand, due to the direct heat transfer between the air and the water, on the other hand, due to the pressure difference between the surface of the water vapor and the air, the evaporation phenomenon is generated under the action of the pressure, and the latent heat is taken away for evaporation. The heat in the water is taken away to evaporate heat and heat, so as to achieve the purpose of cooling. The working process of the cooling tower: the working process of the circular counterflow cooling tower is as an example: the hot water is pumped from the main room through the water pump to the watering system of the cooling tower through the pipeline, the throat, the throat and the central throat with a certain pressure. Inside, the cleaning workbench spreads the water evenly on the packing through small holes in the water pipe; the dry low-value air enters the tower from the bottom into the tower under the action of the fan, and the hot water flows through the surface of the packing. When the water film and the air are formed for heat exchange, the hot air with high humidity and high enthalpy value is extracted from the top, and the water is cooled into the bottom basin and flows into the host through the outlet pipe. Under normal circumstances, the air entering the tower is the air that dries the low-humidity temperature. There is obviously a difference in concentration of water molecules and a difference in kinetic energy between the water and the air. When the fan is running, under the action of static pressure inside the tower, The water molecules continuously evaporate into the air and become water vapor molecules, and the average kinetic energy of the remaining water molecules is lowered, so that the temperature of the circulating water is lowered. It can be seen from the above analysis that the evaporative cooling and the temperature of the air (generally the dry bulb temperature) are lower or higher than the water temperature, and as long as the water molecules can continuously evaporate into the air, the water temperature is lowered. However, the evaporation of water into the air does not continue indefinitely. When the air in contact with water is not saturated, the water molecules continuously evaporate into the air, but when the air on the contact surface of the water vapor reaches saturation, the water molecules will not evaporate, but in a state of dynamic equilibrium, low temperature constant temperature. groove. The amount of water molecules that evaporate is equal to the amount of water molecules that return from the air to the water, and the water temperature remains the same. It can be seen that the drier the air in contact with water, the lower the temperature of the thermostat, the easier it is to evaporate, and the water temperature is easily lowered.