排气热电偶在控制系统国产化改造中的变化

The Change of Exhaust Thermocouple in the Localization Transformation of Control System

燃气轮机的发电原理是利用燃料与空气在一定压力下燃烧产生的高温燃气进入透平膨胀做功、将热能转换为机械能带动发电机发电的热力学过程。为了追求高发电效率,透平前的进气初温可达1400℃左右,导致测温原件难以长时间持续有效地对进气温度进行监控,进气温度是表征燃料燃烧是否稳定的重要判别依据。以TCS国产化改造后的某电厂9FA机组为研究对象,首先从燃烧监测保护的原理出发,由排气温度计算得到允许的排气分散度区间,进而间接映射出透平进气温度场的均匀程度,制定控制及保护策略,分析改造前后控制逻辑的差异性,进一步提高鉴别燃烧工况正常与否的精度与准度。

The power generation principle of gas turbine is a thermodynamic process that uses the high-temperature gas generated by the combustion of fuel and air under a certain pressure to enter the turbine to expand and do work,converting heat energy into mechanical energy to drive the generator to generate electricity.In order to pursue high power generation efficiency,the initial temperature of intake air in front of the turbine can reach about 1400℃,which makes it difficult for the temperature measuring element to continuously and effectively monitor the intake air temperature for a long time,and the intake air temperature is an important criterion to characterize whether the fuel combustion is stable.Taking the 9FA unit of a power plant after turbine control system(TCS)localization transformation as the research object,starting from the principle of combustion monitoring and protection,the allowable exhaust dispersion range was calculated from the exhaust temperature,and then the uniformity of the turbine inlet temperature field is indirectly mapped,the control and protection strategy was formulated,the difference of control logic before and after the transformation was analyzed,and the accuracy and accuracy of distinguishing whether the combustion condition is normal or not are further improved.