Research On Improving Operation Mode Of Circulating Cooling Water System In Thermal Power Plant

Our country is increasingly short of water resource, so more and more thermal power plants use weak acid cation resin exchanger to treat makeup water of circulating cooling water system for the purpose of increasing concentration multiple and saving water. And Shanxi Hepo Power Co., Ltd is one of them. Because of strong corrosion of treated water by this technique and insufficient experience, the power plant uses the mixed water composed of 50 percent of the treated water by weak acid ion exchanger and 50 percent of raw water as makeup water to prevent copper tubes of condenser from corrosion. But after several years' running, calcium carbonate scale thick of 1mm appeared on copper tubes of condenser along with a lot of corrosion pits, and some places of the tubes even broke.To solve the problem above, we studied the operation mode of the system which uses treated water by weak acid cation resin exchanger as the makeup water of circulating cooling water system. In the initial experiment, we researched its original water stabilizer and improved the water stabilizer, compared their effects of scale and corrosion inhibition and decided the method of both raising the weak acid water quota and improving water stabilizer to resolve the problem.Through further experiment, we studied the effects of different water stabilizers commonly used in circulating cooling water system after increasing the quota of weak acid water, and made the new composite water stabilizer which can adapt to new situation and improved the water stabilizer the power plant used before. Then we made simulation experiment to investigate their actual effects in new situation. Finally, we choosed one operation mode of circulating cooling water system of the Power Plant and evaluated the economic efficiency of the improved system.From the experimental results, we came to the conclusion that it is feasible to use 100 percent of treated water by weak acid cation resin exchanger as the makeup water of circulating cooling water system by improving water stabilizer composite. With this method we successfully resolved the problem of coexistence of scaling and corrosion in Shanxi Hepo Power Co., Ltd, at the same time, increased concentration multiple, saved water, reduced metallic corrosion rate, effectively protected equipments, therefore, great economic benefit has been achieved.