What are the causes of leakage in condenser heat exchangers, and how can leakage be detected?

Common causes of heat exchanger leakage include: 1. Incorrect selection of material for the heat exchange tubes, resulting in insufficient corrosion resistance under the operating conditions. 2. Quality issues in heat exchanger manufacturing, such as those related to welding techniques and materials. The competition among equipment manufacturers is extremely fierce these days, with prices kept very low; in order to make a profit, cutting corners becomes the main method used to control costs. 3. The issue of corrosion of the heat exchange medium in heat exchangers: The required water quality for circulating water is that the chloride content should not exceed 50 mg/L for stainless steel equipment, and not more than 100 mg/L for carbon steel equipment. For example, if the chloride content is too high, chlorides penetrate into austenitic stainless steel, leading to intergranular corrosion. The most characteristic feature of intergranular stress corrosion is that the stainless steel pipes or sheets crack in areas under stress. To prevent corrosion of stainless steel caused by chloride ions, chemical agents such as sodium silicate or sodium borate can be added. Next, other factors affecting the corrosion rate include dissolved oxygen and hardness in the heat transfer medium, with dissolved oxygen having the greatest impact.

I agree with the person above; we have a real-life example in our factory. We have a fixed-tube-sheet type water cooler; since it was put into operation in 2003, the fourth unit of this type has been installed. The situation was as follows: shortly after it started operating in 2003, leaks began to occur. An endoscopic inspection revealed a hole of 1 square centimeter in the middle of one of the tubes, with a pressure difference of 4 MPa on either side, which caused a large amount of fluid to leak into the circulating water. The judgment at the time was a manufacturing defect. Take tube plugging measures. From then on, new leaks appeared after running for not long, and the pipe was blocked by stopping the machine more than a dozen times. There was once suspicion that overheating occurred during operation, causing equipment problems. A new unit was installed in 2005, while the original design remained unchanged. Overheating was avoided through operational improvements. But again, tube perforation occurred after not running for long, in a situation similar to that of the first unit. It was only at this point that the technicians suspected that the material grade of the equipment was insufficient, leading to corrosion! So in 2006, another unit was updated; this time, the redesign improved the corrosion resistance of the materials used. After the equipment was installed in 2007, a major overhaul conducted after one year of operation revealed severe corrosion in areas such as the spacing tube sheet end caps. Investigations showed that during the renovation, the equipment manufacturer had still used carbon steel for these components. Updated again in 09! ! ! Dizzy!

Agree with the opinion from the second floor. Our company’s heat exchangers have been leaking continuously; material and manufacturing defects have been ruled out – the problem lies with the circulating water

Seeking help regarding leaks between the tube sheet and tube ends in the condenser caused by large temperature differences in water during winter! ! ? ? ? ? Adding sawdust every day will help alleviate the situation. What should I do? ? ?

Reply to 1# Wu Zhijun: It’s useful; I searched for it for a long time