What is the optimal temperature difference between the inlet and outlet water in the circulating water of the device?
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Our plant manager has recently issued an instruction requiring that for the coolers in all units of the plant, the temperature difference between the inlet and outlet of the circulating water must be kept above 8 degrees. However, the unit I work in has limited heat sources; most of the materials used have a low temperature of around 40 degrees, resulting in a total temperature difference of only 3–4 degrees in the circulating water. Some colleagues from other units have also complained that when the pressure of the circulating water is reduced, the temperature after cooling doesn’t drop enough, which leads to a decrease in the yield of liquid products. Yet despite this, the manager insisted on this requirement, and the technical department ordered that it be followed without considering whether it’s feasible or not; otherwise, penalties would be imposed. If anyone has relevant design specifications on this topic, please share them for reference. Everyone can also share their opinions on whether such a measure is necessary
General design guidelines state that in areas in the south where water resources are abundant, the temperature difference in the cooling water cycle (which generally refers to the difference between the inlet and outlet temperatures, or in other words, the temperature difference at the inlet and outlet of the heat exchanger) should be between 5–10°C. In areas in the north where water resources are scarce, this value is usually set between 10–15°C. These are general guidelines rather than mandatory requirements; each design firm and company has its own specific circumstances. It is advisable for the return temperature of cooling water not to exceed 40°C, as too high a return temperature can lead to severe scaling.
More or less reflects the capacity of the fan; generally, around 10 degrees is sufficient
We require that the temperature difference in the circulation water not be less than 7 degrees
For circulating water, it is generally required that the temperature of the water leaving the circulating water system does not exceed 35°C. Of course, the greater the temperature difference between the inlet and outlet water, the better; however, this difference is usually around 10 degrees. This is applicable to water treatment systems; if it is required that the temperature difference between the inlet and outlet water of each cooler remain within a certain range, then this can only be achieved by adjusting the water flow rate. I assume your factory also sets such requirements in order to save energy and reduce consumption.
It is generally 8 to 10 degrees, with an outlet water temperature of 32 and a return water temperature of 40.
Our company’s requirement is a temperature of not less than 7°C, and generally we manage to meet this target quite well.
The control parameter for the circulating water in our system is also the return temperature of this water; it is generally kept at or below 35 degrees. However, in some heat exchangers, due to process requirements, the temperature is limited to at most 40 degrees, as exceeding this temperature can lead to scaling in the heat exchangers! !
We generally require that the return water temperature not exceed 40 degrees, in order to prevent the growth of microorganisms in the circulating water, which could lead to scaling and reduce the cooling efficiency. The inlet and outlet temperatures of the circulating water are controlled at around 10 degrees.
We control the inlet water temperature between 5-30 degrees, and ensure the outlet water temperature does not exceed 50 degrees!
In the north, the temperature of our incoming water varies significantly throughout different seasons, but the difference is generally within 10 degrees
In our factory, under normal conditions, the temperature of the recycled water is above 30 degrees and does not exceed 40 degrees. The temperature difference between the inlet and outlet of the recycled water is generally above 10 degrees and does not exceed 15 degrees.
We control it at 8 degrees here, internal control
In our factory, the circulating water is processed by the power units before returning to various equipment. In summer, due to the high temperatures, the temperature of the return water in the circulating water system cannot be reduced, and as a result, the circulating water enters the device, which significantly reduces the heat exchange efficiency – a problem that gives the managers a lot of headaches!