Is the heat exchanger not performing well in terms of heat transfer?
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Ammonia condensation cooler: I measured the temperatures of the cold and hot fluids entering and leaving it today. Guys, could you please check whether there is scaling or blockage in the cold water pipeline? Please give me some advice. Thank you all. Cold water inlet temperature: 28.5°C; Ammonia inlet temperature: 82°C. Cold water outlet temperature: 35°C; Ammonia outlet temperature: 57.5°C℃
Status of the request processing? Medium flow rate?
15 cubic meters of ammonia water remaining from coking process; it passes through the ammonia vaporization tower and then a heat pump before entering the cooler, with no flow rate
You need prior data for comparison in order to determine whether the heat exchange efficiency has declined. Additionally, you need to consider the process requirements: if the data required to meet those requirements could not be achieved before but now cannot be met either, then it is possible to conclude that the heat exchange efficiency has decreased. After that, you can investigate the reasons for this decline, such as checking whether the temperature of the cooling water inlet remains the same as before. If there is no change in the process parameters, then disassemble the cooler to check for any blockages in the tubes, clean them, and then test the performance again. The above suggestions are for reference only
Check whether pressure gauges are installed at the inlet and outlet of the cooling water to see if there is a particularly large pressure difference. Compare with those in the same position if available.
Just from the data I’ve measured, can’t it be analyzed?
I’m consulting the experts here: just based on the data, can we tell anything from the temperature changes in the cold water circuit and the hot medium circuit? The cooling water circuit has always been left on. It’s been several years
Referring to the attached calculation sheet, the ammonia flow rate is taken as 4.5 tons/h, which is 30% of the ammonia water flow rate; phase change heat is not considered. 8.5 tons of cooling water are required to lower the temperature from 82 degrees to 57.5 degrees. Through heat exchange at temperatures ranging from 28.5 degrees to 35 degrees, the actual flow rate of cooling water can be estimated based on a pipe diameter of 1.5 meters and a flow velocity of 1.5 m/s; in this case, DN50 is used as the standard. However, if calculated based on a heat exchange area of 70 m2, the heat transfer coefficient of the heat exchanger is only around 25, whereas that of typical plate heat exchangers is between 2500 and 6000. It can be seen that the heat exchanger is fouled. Based on the plate heat exchanger design considerations, the ammonia flow rate is too low and the temperature difference is not significant; therefore, there is no need for such a large heat exchange area.
It can’t be determined just from the inlet and outlet temperature data, what about the previous data?