300MW热电联产机组热经济性研究

Study on Thermal Economic Performance for 300 MW Heat and Power Cogeneration Unit

300 MW热电联产机组是未来发展的重点。对某300 MW供热机组进行变工况计算,分析供热抽汽量、抽汽压力、抽汽回水份额对机组热经济性的影响。结果表明,机组对外抽汽供热可以提高机组的热经济性;相同抽汽量的条件下,抽汽压力越低,热经济性越好;对外抽汽回水率降低,机组的热经性降低。研究还表明,在供热抽汽量为300 t/h、抽汽压力为0.5 MPa时,与600 MW级凝汽式机组和分散锅炉的分产供能相比,2台300 MW热电联产机组集中供热采暖期可节标煤17.66×104t。

The 300 MW heat and power cogeneration unit is a key development in the future. This paper makes a computation of the 300 MW heating unit under off-design condition to analyze the influence of steam extraction rate, steam extraction pressure, and the extraction steam backwater rate on the thermal economic performance. The results indicate that steam extraction from unit for heat supply can improve the unit＇s thermal economic performance; With same steam extraction, the lower the extraction pressure is, the higher the thermal economic performance becomes; and the thermal economic performance decreases with the decrease of the extraction steam backwater flow rate. Compared withl× 600 MW unit and distributive boiler, the 2 ×300 MW heating unit during centered heating period can save 17.66×10^4 t of standard coal under the steam extraction rate of 300 t/h and extraction pressure of 0.5 MPa.