Selection of circulating water pumps for winter and summer

Most air conditioning systems operate year-round, with hot water in winter and cold water in summer.

Some projects in the design process are only blindly pursuing the reduction of initial investment or for other reasons. Instead of setting up the winter and summer circulating water pumps separately, they share the circulating water pump. However, the actual thermal load of most buildings in winter is smaller than that in summer, and the temperature difference between the supply and return of air conditioning water system is generally 5 °C in summer and 10 °C in winter. The pipelines are double-controlled.

Therefore, the circulating water flow rate of air conditioning in winter will be 1/3-1/2 of that in summer. In theory, the lift of winter water pump is 1/9-1/4 of summer. If the same set of fixed speed pump is used in winter, it can only pass through The small valve method increases the resistance of the pipeline to make the system operate normally, so that the characteristic curve of the pipeline changes from the summer I to the winter II, which inevitably wastes a large amount of electrical energy. In order to save energy, consider designing two sets of pumps for winter and summer use, using valve switching.

In the winter, a small-flow, low-lift circulating water pump can be used to save operating costs, and the speed control pump can also be use