Improving the efficiency of cooling towers in the water cycle

Abstract

Cooling towers are the main equipment of the water cycle. Cooling is carried out by the circulating water of heat exchange devices. The heated water is cooled in cooling towers by mixing with the air flow and again directed to use as a cooling agent. Cooling is carried out as a result of heat exchange. The driving force necessary to overcome the friction force of the flows, which interferes with the flow of air, is provided by injection or exhaust fans. The total driving force can be expressed as the sum of the individual driving forces in the air and water flows. The work with air mixing of the liquid phase is carried out due to the energy of compressed air and can be calculated as the work of isothermal compression according to the equations given in the work. Cooling towers of various types are known. Fan cooling towers are the most advanced type of water coolers, since they provide practically stable cooling of water by changing the fan speed or their periodic shutdown, they allow higher thermal loads and deep cooling of water, that is, a greater approximation of the temperature of the cooled water to the theoretical cooling limit due to the increased relative air flow passing through the cooling tower. The main characteristics of cooling towers in terms of irrigation area, hydraulic load, etc. are given. A diagram of a fan cooling tower is presented, its main advantages are listed, such as cooling capacity, intensification of mass transfer (water) to another (air), that is, a typical process of coupled heat and mass transfer. The main elements of the cooling tower are considered. The sprinkler, as the main element of the cooling tower, is necessary to increase the contact surface between water and air, accelerate the cooling process. The ways of increasing the efficiency of their operation are shown. Water traps minimize drip entrainment – up to 100%. Water distribution systems should evenly distribute the cooled water over the surface area of the sprinkler. The energy consumption coming through the nozzles is presented. The role of entrance windows as elements of a cooling tower is highlighted, the main directions for further improving the efficiency of modern cooling towers.