Circulating water regulation
Thread Content
When the temperature of a certain process medium is too high, the inlet and outlet of the circulating water cooler are in the fully open position, and all other control methods have been employed yet the temperature of that material remains high – can the temperature be adjusted by changing the opening degree of the inlet and outlet of the cooler under such circumstances? How should it be adjusted?
Since the outlet and inlet of the circulating water are already fully open, how can the opening degrees of these outlets and inlets be used to regulate the temperature? ? There are four means of temperature control: heat carrier flow rate, heat carrier inlet temperature, material flow rate, and heat exchange area. The heat carrier flow rate is usually used for adjustment ； The heat carrier inlet temperature actually serves to adjust the temperature difference for heat exchange, but it is difficult to control the heat carrier inlet temperature ； Generally, the material flow rate is not used to adjust the material outlet temperature; as a result, changes in the main material lead to changes in the production load, which in turn causes changes upstream and downstream ； Adjusting the heat exchange area is also difficult; in the submerged heat exchange mode, the level of the immersion liquid can be adjusted.
It can’t be adjusted anymore; the heat exchanger is too small
The temperature at full opening is still high; if I lower the temperature further, won’t it be even higher? Is the heat exchanger designed to be too small? Is it still the high load on the process side? ? One can try to reduce the load on the process side, or lower the temperature of the circulating water.
Imports and exports are already fully open; there is no point in adjusting their levels any further. Either increase the heat exchange area or lower the temperature of the cooling medium.
It can be assumed that if the exhaust from the pipelines/equipment is poor, it results in low heat transfer efficiency... so trying to improve the exhaust system might help. But if this assumption is not correct, then the basic methods of improvement are as mentioned above
The valve is already fully open; how can it be adjusted anymore? Check whether the heat exchanger is clogged Communicate with the upstream party to see if there are any measures to lower the water temperature Or can it be adjusted by reducing the load on other water coolers in order to increase the water consumption of that particular water cooler?
From the perspective of control principles, if (Tcws – Tcwr) / (Tc – Tcws) < 0.3, using a control system for circulating water is not appropriate. Options such as gas-phase bottlenecks or liquid-phase bottlenecks can be considered.
Having the inlet and outlet of the heat exchanger fully open is already the limit; exhaust gas can be used to ensure that the heat exchanger operates at full capacity. It is also possible to contact the circulating water system to lower the temperature of the circulating water and increase its pressure, thereby improving the heat exchange efficiency. If the efficiency of the heat exchanger decreases after long-term use, it is also possible to reduce its thermal resistance by flushing it, thereby improving the heat exchange performance.
The inlet and outlet valves for the circulating water are fully open. If the temperature of the material being cooled is still high, the simplest solution is to lower the temperature of the incoming circulating water. Another option is to perform backwashing on the circulating water pipes, and the effect of backwashing should be quite noticeable