Cooling water temperature
Thread Content
How is the return water temperature of a cooling water heat exchanger usually controlled? What problems can arise from an increase in return water temperature if flow rate is not taken into account?
The designed temperature rise is usually 8 degrees; too high a value can lead to scaling.
Isn’t the normal circulating water designed to have a return temperature of 42°C? The return temperature is controlled by the fan in the cooling tower at the circulating water station
We usually keep the return water temperature at 35°; if it exceeds this value, we turn on the fan
We control the temperature difference of the water last time to be 8°C. If the return water temperature is above 35°C, start the fan or add an additional circulation pump.
The supply temperature of the circulating water we use is 31 degrees, while the return water temperature is 8 degrees higher. The temperature may fluctuate slightly with changes in season and ambient temperature, and this is adjusted using variable-frequency fans.
It is sufficient to control the water supply temperature according to the process requirements; there are many methods for heat dissipation.
The internal control parameters vary among different plants; energy conservation must be taken into account. At high temperatures, circulating water tends to form scale, which affects heat exchange efficiency and can also cause corrosion of the tube bundles.
Is what the poster is asking about the control method for the return temperature of circulating water? What we should pay more attention to is whether the cooling load on the medium is insufficient. Generally, while ensuring an effective cooling effect on the medium, it is necessary to make the most of the circulating water by maintaining a temperature difference of 6 to 8 degrees between it.
I’m mainly concerned about the consequences of an increase in cooling water temperature when the flow rate of the cooling water is reduced What is the maximum acceptable temperature?
Is the poster considering that the load on the hot side has decreased, which is why they want to reduce the flow rate of the cooling water as well, resulting in an increase in the return water temperature?