Mitsubishi Heavy Industries Technical Review
    Vol. 50 No. 1 (2013)   New Products & Technologies
    Technical Papers

    Improved Reliability of High-AVT (High-pH Water Treatment) Application to Combined Cycle Plants

    Senichi Tsubakizaki,
    Hirofumi Ando,
    Yasuhiro Takei,
    Takashi Naganuma,
    Yasunori Sakamoto,
    Taichi Nishi

    Generally in the water treatment of combined cycle plants, ammonia and hydrazine are used in the feedwater system and phosphates are used in the boiler system. However, in Mexico, the Tuxpan No. 2 and No. 5 power plants have adopted "High‐AVT (high‐pH water treatment)," in which ammonia is used to set the pH of feedwater higher than the conventional level, requiring no phosphates in the boiler system. Tuxpan No. 2 power plant started commercial operations in 2001. Since then, more than 10 years have passed with no problems having been found during equipment inspections. In response to such good operational results, we will introduce high‐AVT as an option for the water treatment of combined cycle plants.