Green Corrosion Inhibitor in Central Air-conditioning Cooling Water

Abstract

The occurrence of metal corrosion can greatly reduce the air-conditioning efficiency, and even affect the safe and stable operation of equipment in central air-conditioning cooling water circulation system. Adding corrosion inhibitor to cooling water system is currently the most commonly and effective method. Electrochemical impedance method is used to evaluate the corrosion performance of single sodium tungstate, sodium molybdate, and sodium gluconate, while polarization curve method is used to evaluate the corrosion performance of two compound agent. Results show that corrosion performance of sodium tungstate, sodium molybdate, and sodium gluconate is ranged as follows: sodium tungstate > sodium gluconate > sodium molybdate. There has synergistic effect between sodium tungstate and sodium gluconate, as well as between sodium tungstate and sodium molybdate, and mixed use can improve corrosion effect. The optimized prescription is that, the sodium tungstate is 65 mg/L, sodium molybdate is 35 mg/L, by this way, the corrosion rate can reach 98.31%.