Everyone has many dreams in life, but if one of them keeps bothering you, the rest is action. In the process of air conditioning system design or management often encounter such a problem: Several refrigerators were selected, so that to control the number of open refrigerator according to the change of cooling load. Cooling tower in number and refrigerator is a one-to-one matching relationship, and open cooling towers generally are selected more. The cooling tower is usually set on the top of the building, and the refrigerator is usually located in the basement. The pipeline between the refrigerator and the cooling tower should be as short as possible, and the cooling tower needs to be designed and installed in parallel.
1. Problems when using open cooling towers in parallel
Water distribution in cooling tower is not balanced and multiple cooling towers are used in parallel. Some tower water level rising and overflows from the top water pan is constantly. In some towers, the water level is lowered until all the water in the catchment pan is sucked out. When filling water can compensate for the overflow, as continue time makes an insufficient cooling water system can not work normally, the cooling effect is not good.
2. Solutions to problems that open cooling towers are used in parallel
Control problem of water level of cooling tower. When multiple parallel cooling towers are operated by automatic control, electric valves are installed in the inlet pipe of the open cooling tower, while the outlet pipe of the tower is not installed. Under the condition of low load, the water level of the catchment pan of a single cooling tower will rise and cause overflow, while the catchment pan of other towers that are not in operation will need water refill.
The cooling tower of water strike phenomenon and the unit are set in parallel operation. The sound of water strike is serious, the pipeline vibrates, and even the surrounding equipment moves. Multiple cooling towers operate in parallel, and the number of running towers decreases under the condition of low load. The electric butterfly valve on the water inlet pipe of the cooling tower that is not in operation should be closed to ensure the water temperature when cooling water enters the chiller. When the height difference between the cooling tower and the backwater main pipe is low, the water level of the collecting pan of the out-of-service cooling tower far away from the cooling tower in operation will gradually decrease through the parallel backwater main pipe. When the water level drops to the main water pipe of the cooling tower or even lower, air will enter the system through the cooling tower out of use, forming the phenomenon of "pumping", seriously affecting the pump performance.
There is no separate regulating valve installed on the water supply and return pipe of each cooling tower products, which is not conducive to water balance adjustment. The resistance between the parallel cooling tower and the water pump pipe is not balanced. The backwater pipe section of cooling tower is not properly installed, such as the inverted slope of the horizontal pipe, the branch pipe and the main pipe are connected with the "T" shape, resulting in unsmooth water flow.
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