Coil And Filler In Composite Cross Flow Cooling Tower Structure Design And Performance Analysis

With the rapid development of China’s economy, environment and energy have become increasingly prominent, all sectors of society to energy conservation, reducing energy consumption standard proposed new requirements. Uneven distribution of water resources in the north and south, low per capita water, industrial water consumption and other issues gradually manifested.Not a long ago, Industrial equipment using water-cooled, water cooled heat absorption temperature, and then directly into the rivers. This not only makes a lot of water draining away, but also caused water pollution. Subsequent cooling tower to some extent solves the problem of cooling water is directly discharged, the air surrounding the cooling tower is the use of unsaturation, when the ambient air in contact with water, because water-saturated air layer present on the surface layer, the layer of water vapor with respect to the partial pressure of water vapor in the ambient air pressure, so that the saturated air layer of water molecules surrounding continuous jumping into the air layer, the process is evaporated. Contact with air and water evaporation mechanism is very complicated, it is coupled heat and mass values, the driving force is the difference between evaporation process enthalpy of saturated air layer and the surrounding air. The air and the water evaporative cooling process, water cooling for the goal of the surrounding air temperature limit.At present, the cooling tower is not only applied in industrial production, in the civil air conditioning, metallurgy, textile, etc used widely. In such aspects as the structure, material, technology development is very rapid, all kinds of products, can meet various technological requirements. Such as glass fiber reinforced plastic cooling tower series, household air-conditioning fans, closed cooling tower free cooling system applied directly to the room, etc. The classification of cooling tower are open and closed, cross-flow and counter flow, natural ventilation and mechanical ventilation. Open type cooling tower process water directly exposed to air, heat transfer efficiency of favor is relatively closed higher, but easy to cause process cooling water pollution, and affect the internal scale problems such as process equipment, closed cooling tower process water does not directly with the surrounding air and avoids the problem of pollution, but it is in thermal efficiency is low, the dosage of metal coil, higher cost disadvantages. Cross flow cooling tower water spray and air cross flow, relative to the counter flow, its heat and mass transfer efficiency is low, but the flow resistance is small, the cooling water.Coil composite filler and full use of the cooling tower fill full advantage of a large majority of heat exchange, the temperature of the shower water in the appropriate direction to reduce the height and increase the temperature difference inside and outside the tube, a lower cooling load, save the coil area. Further, the shower water temperature is also reduced so that the water in the outer surface of the possibility of fouling of the coil is reduced, increasing the heat transfer coefficient, so that operation of the cooling tower is more convenient for maintenance.This topic based on a common plate of the heat transfer model of district and packing area, the heat flux density for solving the related parameters. Type the parameters according to the empirical data commonly used directly, and then use formula for solving the cross-flow packing is obtained and the coil composite structure and the performance parameters of the cooling tower. Calculating the spray density of spray water in the spray density per unit area is the range of15～20m3/(m2·h), the velocity of cooling water inside the comprehensive considering the heat transfer and resistance, generally by1.5～2.5m/s, the intake air flow velocity V=2.5m/s.Design conditions for the standard working conditions, atmospheric pressure of9.94x104pa, dry bulb temperature of31.5℃, the sheet temperature28℃. Cooling water pipe of the cooling tower is100m3/h, the tube inlet temperature of37℃and cooling water outlet temperature is32℃, accordingly we can draw the cooling load of the cooling tower and calculation, the district and packing area of the heat flux density, heat and mass transfer coefficient, then calculate the packing volume and volume coil, coil height and coil save quantity and packing area spray water temperature drop. To calculate the cooling tower section size and disk district of tube row number and the number of passes on each floor. Finally illustrates the packing can’t unlimited increase instead of a coil.In general, packing and coil complex cross flow cooling tower, coil can save about50%.Then, the performance parameters of the tower were analyzed, the influence of wind and spray density, the flow rate of the cooling water inside the tube of the heat exchanger effectiveness. Coil air-side area makes the heat increases air velocity strengthening filler area with water spray density increases, the range of filler in the calculation of volumetric mass transfer coefficient increases, the packing area air velocity increases, the packing volume mass transfer coefficient increases, which is approximately linear. Finally, the influence of wind resistance of the coil area, the greater the wind speed, the greater the resistance to increase fan energy consumption, heat strengthened presence in this antagonistic relationship with the wind speed increases, so keep up, according to the actual situation, choose a more economical wind speed.