In recent years, with the development and maturity of the technology of thin-walled coiled welded small tubes, welded stainless steel tubes have been widely used in domestic condensers. Especially in recent years, a large number of welded stainless steel pipes have been used in the condenser renovation of new power plants and condensers of old power plants in China, and successful experience and good results have been achieved.
Condenser tube replace retrofitting scheme:
1. Replace cooling pipe (stainless steel pipe instead of copper tube) and install spray system at throat
2. Replace the condenser support plate, tube plate and cooling tube retrofitting of condenser tube replacement: before overhaul, prepare all the software and hardware, only replace the condenser tube bundle and related parts, and the condenser shell will not move, so the construction will be completed by using the overhaul time of the power plant.
Copper tube and welded stainless steel tube
Summarizing the design and operation experience at home and abroad, compared with brass tubes, welded stainless steel tubes have the following advantag
1. Ammonia corrosion resistance, impact resistance;
2. It is not easy to stain and scale, and the service life can reach 30 to 40 years;
3. The tube wall thermal resistance only accounts for 3% ~ 5% of the total thermal resistance. The water velocity in the tube increases, the cleaning coefficient increases and the wall thickness decreases, which makes the heat transfer performance of stainless steel better than that of copper alloy when stainless steel tubes are selected for condenes:
ser cooling tubes, special attention should be paid to the Cl-ion content in cooling water. TP304,304L can be used when cl-ion content is less than 200mg/kg, TP316,316L should be used when cl-ion content is less than 1000mg/k, and TP317.317L should be used when cl-ion content is less than 5000mg/kg.
