6 00 MW电站锅炉过热器减温水治理策略及效果

大唐国际托克托发电有限责任公司三、四期4×600 MW机组自投运以来,锅炉过热器减温水量大大超出设计值,满负荷时达到330~350 t/h,远超过77.8 t/h(100%THA)的设计值。虽经燃烧器改造、燃烧调整诸措施均不能有效降低减温水量,这直接影响到机组的安全及经济运行。通过数值模拟和热力计算分析,提出了燃烧器调整和尾部受热面改造以降低过热器减温水量的治理方案,首先在5号炉上实施了尾部受热面改造。改造后的锅炉效率测试表明,在不同负荷下过热器减温水量和排烟温度明显降低,锅炉效率明显提高,综合发电煤耗下降约3 g/kW h。

Desuperheater Spray Reduction Strategies for 600 MW Power Station Boiler and Result

After 4 x 600 MW units of phase III and IV of Datang International Power Generation Co.Ltd.were put into operation,the desuperheater spray amount(DSA) for each boiler exceeds its designed value.The DSA reaches to 330~350 t/h at full load(100%THA) which is much larger than the designated value of 77.8 t/h.Although some measures,such as combustor improvement and combustion tuning,had been adopted to these units,the DSA can not be effectively reduced,so this influences directly the safe and economic operation of units.Based on the numerical simulation and heat balance analysis,the suggestions for improving desuperheater spray,such as the combustor tuning and the tail thermal surface improving,were presented to decrease the desuperheater spray amount of superheater.The tail thermal surface improvement was first done for boiler 5.The boiler performance test after improvement indicates that the DSA and exit flue gas temperature decrease markedly at the diverse loads,and the boiler efficiency increases obviously,the synthetical coal rate decreases approximately of 3 g/kWh.