Is it better to have a large or small temperature difference in the return water of circulating water?
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Last time, was it better to have a larger or smaller temperature difference in the water?
It’s best if it meets the requirements exactly. Excessive temperature differences also constitute a waste of energy. For reference.
The temperature difference in the circulating water is generally set between 25–35 degrees Celsius or 30–38 degrees Celsius. It is recommended that the return water temperature not exceed 40 degrees Celsius; above this temperature, the rate of scale formation increases, which leads to a rapid decline in the efficiency of the heat exchanger. Additionally, if the return water temperature is too high, it will increase the load on the subsequent air coolers, and some air coolers are unable to handle large temperature differences. Therefore, the return water temperature should not be set too high. Based on your process load, select the appropriate pump and air cooler capacity, leaving a margin of more than 20% in general
From a process perspective, if it’s too large, adjustments can be made as there is some margin; but if it’s too small, production is limited and no adjustments are possible
As long as the design requirements are met, a larger size is better
Generally, a temperature range of 5 to 12°C is considered reasonable. If the temperature is too low, it indicates that too much circulating water is being used or that the temperature of the medium is low; if it’s too high, it means the flow rate of the circulating water is slow. In such cases, scaling can occur on the side involving the circulating water, which in turn leads to corrosion beneath the scale. I’m not sure if this understanding is correct – just my humble opinion
Generally speaking, a larger temperature difference has an impact on those affected by it, and choosing a heat exchange device that is more economical is advisable in such cases. However, the operational conditions at the site must be taken into consideration, and a comprehensive evaluation is required.