超临界H_2O/CO_2混合工质透平初凝区酸腐蚀过程分析

Analysis of the Acid Corrosion Process in the Initial Condensing Zone of the Supercritical H_2O/CO_2 Mixture Turbine

重点从CO_2对初凝液滴pH值的影响入手对超临界H_2O/CO_2混合工质透平初凝区腐蚀过程进行了分析,给出了H_2O/CO_2混合工质pH值的精确计算方法。并以NH_3作为碱化剂,对初凝液滴的pH值进行调节,进一步分析CO_2对初凝区的酸腐蚀过程。研究结果发现,NH_3在一定浓度范围内可以有效改善初凝区的pH值,但由于其分配系数较大,当CO_2超过一定浓度时,将不再适用,建议采用分配系数更小的碱化剂进行pH值的调节。

This paper focuses on the corrosion process of the initial condensing zone of the supercritical H2O/CO2mixture turbine starting from the effect of CO2on the pH of the initial condensate droplets,and gives an accurate calculation method for the pH value of the H2O/CO2mixed working fluid.Further analysis of the acid corrosion process of CO2in the initial condensing zone is carried out when NH3was used as alkalizer to adjust the pH value of the initial condensate droplet.The results showed that NH3could effectively improve the initial pH value within a certain concentration range.However,due to its large distribution coefficient,NH3would no longer be suitable when CO2exceeded a certain concentration.It is recommended to use a smaller distribution coefficient alkalizing agent for pH adjustment.