1000MW火电机组深度调峰下供热能力提升改造及应用

Retrofit and Application of Heating Capacity Improvement in a 1000 MW Thermal Power Unit Under Deep Peak Regulation

某1 000 MW火电机组深度调峰时,背压式汽轮机排汽压力降低,排汽无法进入供热联箱。对背压式汽轮机进行排汽改造,增加高温再热器抽汽管道,并且分析计算不同中压调节阀开度下的机组供热能力。结果表明:通过关小中压调节阀开度来提高高温再热器压力,可以确保背压式汽轮机在机组调峰阶段安全连续运行;通过高温再热器抽汽提升了单台机组的供热能力,机组负荷降低至350 MW时,实现供热抽汽质量流量达到115 t/h,供热抽汽压力不低于1 MPa,温度维持在320℃左右。

To solve the problem that the exhaust steam from the back pressure steam turbine(BPT)can not enter into the heating header with the decreased pressure in a 1000 MW thermal power unit under deep peak regulation condition,a retrofit was conducted on the exhaust steam of the BPT by adding the extraction pipeline from the high temperature reheater steam tube,while the heating capacity of the unit was analyzed and calculated with different opening degrees of the intermediate pressure(IP)control valve.Results show that,with the improved pressure of the high temperature reheater by decreasing the opening degree of the IP control valve,the BPT can operate safely and continuously under deep peal regulation condition.Additionally,the heating capacity is improved by extracting steam from the high temperature reheater.When the unit load reduces to 350 MW,the mass flow of the heating extraction steam can reach at 115 t/h with the heating steam pressure of over 1 MPa and the heating steam temperature at around 320℃.