Calculations on the energy-saving efficiency of replacing heat exchangers

First of all, what does the sentence \"The current values are a temperature difference of around 10°C and a pressure difference of 15 KPA; the manufacturer states that after replacement the temperature difference should be 5°C and the pressure difference 6.5 KPA\" mean? Since the pressure drop provided by the backend has decreased from 15 to 6.5 KPA, what you are referring to is a reduction in energy consumption due to the pressure drop on the gas side; but what do you mean by this temperature difference? Because you have already provided that the air temperature range is 111 to 33 degrees later on. Does it refer to the difference between the exhaust temperature of the original equipment and the return water temperature? Secondly, the energy-saving calculation on the water side involves an analysis of the benefits resulting from reduced circulation volume, while the gas side focuses on an analysis of the benefits associated with lower pressure drop energy consumption for the operation of air compressors, in order to meet the process requirements. Furthermore, at the moment you are providing a temperature difference of only 6 degrees as designed by the manufacturer; therefore, the amount of water used will naturally be large, and energy savings are not significant ； Moreover, a gas pressure drop of 6.5 KPA is already quite significant. Finally, I have handled many similar cases; if you are interested, I can discuss the details over the phone and provide you with a proposal – the energy-saving benefits will be considerable compared to current methods.

The temperature difference we are referring to is the difference between the exhaust temperature of the equipment and the temperature of the water entering the circulation system. Our equipment has been in use for about 8 years; it seems there is a problem with the secondary heat exchanger, as the temperature difference and pressure difference keep increasing. Cleaning it didn’t have any effect either. So this time we want to replace it with a new one. 5℃ and 6.5 KPA are the effects that the manufacturer claims can be achieved after the replacement. We want to calculate the return on investment to see how long it will take to recoup the costs, and to determine whether the replacement is worthwhile.

Well, the guess I gave above matches that \"difference\" you mentioned. If the original poster intends to calculate the return on investment based on this factor, I would suggest making the temperature range more energy-efficient. For example, the exhaust temperature is close to 30 degrees, and the outlet water temperature is also around 30 degrees. Additionally, there is still room for the pressure drop to decrease. Furthermore, based on your description of the conditions of the equipment on site, if there is no increase in production, if no changes are required in the upstream processes, and if there are no issues caused by debris or dirt clogging the pipes, then it would be advisable to check whether the inlet water temperature, volume, and quality meet the required standards. If there are no problems at all, the equipment must be replaced. There must be a problem with the equipment, such as the outer fins coming loose and resulting in reduced efficiency, etc. . . . If I were to submit a proposal, some additional parameters would be needed; the signature includes contact information.