大型联合循环机组化学水工况的控制与监督

针对大型联合循环余热锅炉(HRSG)的水汽质量标准、给水炉水处理方式、水汽取样及仪表设置、凝结水处理等方面进行了论述。对于三压再热HRSG,给水推荐采用高pH处理,炉水推荐采用平衡磷酸盐/低磷酸盐+NaOH处理,为了与给水高pH处理相适应,热力系统应采用无铜系统。基于我国燃机启动频繁的特点及机组本身快速启动的要求,大型联合循环机组宜设置凝结水除铁设施。综合考虑投资、占地面积及环保等因素,不建议设置凝结水除盐设施。建议相关部门加强HRSG水汽质量标准及停炉保护方法的研究以保证我国大型联合循环机组的安全经济运行。

Control and Supervision of Chemical Water Treatment Regime for Large-scale Combined Cycle Units

Aiming at HRSG for large-scale combined cycle units,quality criterion of water and steam,feed water and boiler water treatment mode,water and steam sampling,chemical analysis instruments and condensate treatment are discussed.It's suggested for three-pressure HRSG with reheating system that feed water is treated in high PH mode and boiler water is treated using equilibrium phosphate or low concentration phosphate and NaOH.In order to suit with the high PH mode,the thermodynamic system should have no copper.Based on the characteristic of Chinese gas turbines' frequent startup and the need for quick startup,the iron removing equipment should be used in large-scale combined cycle units.Taking into account the factors including investment,site area and environment protection and so on,it's not suggested to adopt condensate demineralization system.To guarantee the safe and economical operation of large-scale combined cycle units,the relevant departments should strengthen the research for quality criterion of water and steam in HRSG and the maintenance method of boilers during outage.