Countercurrent tower
1. The water is in the filling of the tower, the water is from top to bottom, and the air is from bottom to top, the two flow in opposite directions to a cooling tower.
2. The counterflow cooling tower has good thermal performance and is divided into three cooling sections: the space from the water distributor to the top of the filler. The water temperature in this section is relatively high, so heat can still be transferred to the air; the heat exchange section between filler water and air; filler To the water spraying section of the sump space, the water is cooled in this section, which is called "tail effect". In northern my country, the water temperature can drop by 1-2°C. In summary, under the same circumstances, the counter-current tower has a smaller packing volume by about 20% than the cross-flow tower, and the heat exchange process of the counter-current tower is more reasonable and has high cooling efficiency.
3. The water distribution system is not easy to be blocked, the water filling is kept clean and not easy to age, the moisture backflow is small, and the antifreeze and deicing measures are easier. Multiple units can be designed in combination. In winter, the required water temperature and quantity can be combined for single operation or all fans can be shut down.
4. Easy construction, installation and maintenance, low cost, commonly used in air conditioning and industrial large and medium cooling circulating water.
Cross flow tower
l. Water is in the filling in the tower, the water flows from top to bottom, and the air flows horizontally from the outside of the tower to the inside of the tower. The two flow directions are perpendicular to the cooling tower. Commonly used in residential areas with strict noise requirements, it is the cooling cycle tower that is used more in the air-conditioning industry. Advantages: energy saving, low water pressure, low wind resistance, low-speed motor is also equipped, no dripping noise and wind noise, easy maintenance of filling and water distribution system.
2. Multiple foundations can be constructed and placed at will according to the shape of the building, and single or multiple cooling towers can be activated according to the required water temperature.
3. It should be noted that: the frame should be 40% more heat exchange, there should be more filler volume, the filler is easy to age, the water distribution hole is easy to be blocked, the anti-icing is not good, and the moisture backflow is large. The advantage of the cross-flow tower is exactly the disadvantage of the counter-flow tower.
Closed cooling tower
1. Closed cooling tower, also known as closed cooling tower, evaporative cooler. It is a modification and development of the traditional cooling tower. It is actually a combination of an evaporative cooling tower, a cooler and a wet cooling tower. It is a horizontal evaporative cooling tower. The process fluid flows inside the tube and the air flows outside the tube. The two do not touch each other. After the water in the reservoir at the bottom of the tower is pumped by the circulating pump, it is sent to the outside of the pipe and sprayed down evenly. It is not in contact with the hot water or refrigerant of the process fluid and the air outside the pipe, and becomes a closed cooling tower. The effect of heat and mass transfer is enhanced by spraying water.
2. The closed cooling tower is suitable for various cooling systems that require high circulating water quality, and has application prospects in electric power, chemical industry, steel, food and many industrial sectors. On the other hand, compared with air-cooled heat exchangers, evaporative cooling towers use the latent heat of evaporation of the water on the lower side of the tube to significantly enhance heat and mass transfer on the air side, which also has obvious advantages.
The winter temperature in the northern region is usually below zero, and the problem of frost prevention in the operation of closed cooling towers has become increasingly prominent. If it is not solved well, the heat exchange tubes or other parts of the cooling tower may be damaged by freezing. According to different process characteristics, some closed cooling towers run all day in winter, some run for part of the time, and some are almost not used. But all need to consider the issue of antifreeze.