Analysis of the reasons for uniform thinning in the condensate heat exchanger
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In the condensate heat exchanger, the condensate flows through the shell side; the inlet temperature is 140 degrees, and the temperature after cooling is 120 degrees. Upon inspection following a leak, it was found that the tubes had thinned uniformly. After the leak was repaired, the exchanger was put back into use, but it started leaking again within less than a week. Excluding material issues, what could be the cause? The material is fine
Is it confirmed that the pipe starts to corrode from the condensate side? Has the shell shown any signs of thinning? Condensate water can easily erode and thin the vapor-liquid mixture phase. In a 20-meter-long 5-bar condensate pipe, 5 leakage points were identified one after another; subsequent inspection revealed that all were caused by erosion-induced thinning, with the situation being particularly severe at the elbows. By the way, is the heat exchanger vertical or horizontal? Is there any pattern to the locations of the leaks?
Could it be that the pressure drops after the condensate enters the heat exchanger, leading to flashing? During cooling in the shell side, it exists in a gas-liquid mixture state; increasing the outlet pressure might help.