How to improve the heat exchange efficiency of circulating water
Thread Content
I would like to ask the experts: how do you improve the efficiency of the circulating water heat exchangers in your systems? I think the temperature difference of our circulating water is too small, being less than 5℃
The heat transfer temperature difference is a bit small; the average heat transfer temperature difference in oil refining is generally 20℃
Serial use of circulating water can be considered
On the one hand, high-efficiency heat exchangers can be used; on the other hand, the heat exchanger may suffer from severe scaling, which affects its heat exchange efficiency. Cleaning can be considered, and mechanical cleaning may be an option if the conditions permit. For a simpler solution, online chemical cleaning can be employed
Are you using cascade control? How is it best to design it? Please advise on the best course of action
If the temperature difference between the inlet and outlet of the circulating water is large at the beginning, and this difference decreases as operation time increases, it is recommended that the owner take the following actions: 1. Perform online chemical cleaning of the water cooler. 2. A simpler method involves using nitrogen for repeated backwashing. 3. If conditions permit, remove the floating head of the heat exchanger to check whether there are any debris blocking the ends of the tubes through which the circulating water flows
If the temperature difference is too small, it is possible to consider using several circulation water units in series; several of our units are operated in this manner
If you only focus on improving heat transfer efficiency, it may affect the actual heat transfer performance! The higher the temperature difference between the circulating inlet and outlet water, the greater the heat exchange efficiency of the circulating water; however, this may result in a relatively high temperature of the condensed substances!
Advocate for the cascade use of circulating water to reduce the amount of circulating water and lower power consumption!
If your heat exchange area is appropriate, it could be that the heat exchanger is blocked or that the flow rate of the cooling water is too high. If it’s feasible from a process perspective, you can reduce the cooling water flow rate; however, there shouldn’t be too many suspended particles or impurities in the water, as this could lead to sedimentation of those impurities when the flow rate decreases, thereby blocking the heat exchanger.
Prevent scaling in heat exchangers and reduce the hardness of circulating water.