Weak current College】 【Tower of some relevant knowledge.

<br> <br> Cooling tower is a widely used in thermal equipment, its role is through heat and mass Exchange will high-temperature cooling water heat disperses into the atmosphere, thereby lowering the temperature of the cooling water, its role is mainly cold .water cooling, two fluid mixing in the Tower, with two contact fluid partial pressure of water vapor between wires thermal fluid part of evaporation and its cooling. <br> <br> For cooling tower selection, specifically what to do? just a flow into .and out of the water temperature difference can? <br> <br> Currently, the public aware of cooling tower-water-and air cooled two main forms. The two towers and a natural draft cooling tower and mechanical draft cooling tower. <br .> <br> Due to the cooling tower is mainly affected by air wet-bulb temperature impact on water evaporation and conduction to the heat, so its water consumption is very large. <br> <br> While air conduction cooling tower is the use .of the air receiver for heat, mainly affected by air dry-bulb temperature. <br> Due to air dry-bulb temperature is higher, specific heat, heat absorption capacity is limited, and cooling efficiency low, therefore, requires air cooler has a .large surface area, the high cost of air coolers. <br> <br> Cooling tower service of process equipment for various industries, now the difference from the process equipment to look reasonable change in cooling towers. The civil service of object for cooling towers .are refrigerator, it requires cooling tower water temperature is the same, namely: 37 ° c water temperature into the Tower, Tower water temperature of 32 ° c. The difference is: refrigerator with different capacities, the different capacity with different sizes of water cooling .towers, water cooling of the civil Tower and other industrial cooling water phase. This determines the civil Tower can be made standard Tower, to improve efficiency, and the applicable civil Tower temperature is divided into two grades, ie: Southern design temperature by wet- .bulb temperature is 28 ° c; the North by wet-bulb temperature is 27 degrees centigrade. <br> <br> Power industry of process equipment are steam turbine, water temperature on cooling tower requested by 90% guarantee rate in summer, the water .temperature does not exceed from Tower 33 ° c water temperature difference due to different due to the unit. Compared with civil tower to its cooling water much more, this determines different generator supporting different sizes of cooling tower, the same unit in different geographic locations with .the size of the cooling tower should also be different. To common 200MW machine, for example, the cooling water is 36000t / h, in Beijing (wet bulb temperature: 24.4 ° c) with 4500 square meters natural draft cooling tower. The same unit .in Shanxi Datong (wet bulb temperature: 19.0?) need to be completed with Tower of tricking water area just 3000 square meters. Shanxi and Beijing is located in the North, if only by the Civil Division of the Tower, Cosmos is more standard input .-cooling tower investment of 1500 square meters. <br> <br> Cooling tower common parameters: <br> <br> 1) evaporation (WE) kg / h, air conditioner, Tw1-Tw2 = 5 ° c, WE = 0.0083 .× L, that is circulating water 0.83% evaporation. <br> <br> 2) bleach water (WD) kg / h <br> <br> According to the construction of the cooling and ventilation rate vary, the general drift rate as .follows: <br> <br> Open water, cycle 0.3% <br> <br> Closed loop water 0.15% <br> <br> 3) sewage water (WB) kg / h <br> <br> Sewage water is .based on water quality and concentration. General air conditioning, open and closed loop water for 0.3%. <br> <br> Water-water Supplement 4) (Δ L) kg / h <br> <br> Water-water supplement is .included in item 3 on aggregate. (ΔL = WE + WD + WB) <br> <br> Air conditioner open application: circulation water 1.43% <br> <br> Closed water circulation of occasions: 1.28%. <br> <br> 5) .cooling water flow Q (m3 / h) <br> This needless to say, remember the time when the selected column will work out of cooling water to take the coefficient on 1.15. <br> <br> 6) and Tower temperature difference < .br> Cooling tower selection of important parameters, the civil standard Tower-type cooling tower design conditions for temperature 35 ℃, inlet water temperature 37 ° c, 32 ° c, into and out of the water tower is 5 ° c temperature difference; industrial .cooling tower design conditions generally divided into 65 ° -45 ° c to 43 ° c-33 ° c and 40 ° c-32 ° c, and several stalls, and out of the Tower up to 8 ° c temperature difference of-20 degrees .centigrade. <br> <br> 7) wet bulb temperature (℃) τ <br> Cooling tower water and water temperature difference generally known as cooling range it mainly depends on the ambient wet-bulb temperature. The efficacy of cold water for cooling .tower with a water temperature and the difference between Rheumatoid bulb temperature or known as the value of almost glossed over. Therefore local wet-bulb temperature changes directly affect the cooling towers of cooling effect. <br> <br> 8) dry-bulb temperature .(° c) 0 <br> Air conduction cooling tower is the use of the air receiver for heat, mainly affected by air dry-bulb temperature. Due to air dry-bulb temperature is higher, specific heat, heat absorption capacity is limited, .and cooling efficiency low, therefore, requires air cooler has a large surface area, the high cost of air coolers. <br> <br> <br> <br> <br> <br> <br>.