考虑壁温特性的高温再热器减温水投运方式优化

Optimization of high temperature reheater desuperheating water spraying method considering wall temperature characteristics

过热器和再热器的减温水是保证其受热面安全运行的重要手段,但减温水的投入会严重影响机组的经济性。通过屏式过热器、高温过热器和高温再热器的壁温特性试验,结合受热面管道的安全性,提出提高减温水投入的触发温度,降低减温水量;同时试验测量喷水减温的延迟时间,认为喷水减温的投入时间在考虑再热蒸汽温度变化趋势的同时,需要兼顾喷水减温的延迟时间,精准控制减温水投入。提高减温水触发温度和优化喷水减温投入时间均可减少减温水量,大幅提高锅炉运行经济性,也可防止减温器管道受到频繁热冲击,保证受热面管道安全,该方法实际应用效果良好。

The desuperheater is an important means to ensure the safety of superheater and reheater heating surface,but the input of desuperheater will seriously affect the economy of the unit. Through wall temperature characteristic test of screen superheater, high temperature superheater and high temperature reheater, and on the premise of ensuring the safety of heating surface pipes, several suggestions were proposed, such as rising the the trigger temperature of desuperheating water and decreasing the water quantity of desuperheating water. At the same time,the delay time of desuperheating water spraying was observed, and it was considered that the service time of desuperheating water spraying should take into account the delay time of desuperheating water spraying and pay close attention to the variation trend of reheat steam temperature. It found out that, increasing the temperature of water spraying and optimizing the service time of water spraying can both reduce the amount of desuperheating water, greatly improve the economy of boiler operation, prevent the desuperheater pipeline from being subjected to frequent thermal shock, and ensure the safety of heating surface pipes. This method has good application effect.