Abstract:

In order to expand the heat supply capacity of 600MW supercritical condensing turbine-generator unit and meet the requirements of combined heat and power production, several technical measures to improve the external heat supply capacity of the unit have been studied. A new pattern on heat supply retrofit was put forward, which is to stop #1 & #2 HP heater, and extract the original #1 & #2 section steam from cold reheater to increase the quantity of external heating supply. The influences on selective catalytic reduction (SCR), the safety of the last stage blades of the steam turbine, the axial thrust of the steam turbine and the economy were analyzed. It is proved that the method is feasible, worthy for reference when the condensing turbine-generator unit implements large flow low pressure heat supply retrofit.

Key words: condensing turbine-generator unit, heat supply, retrofit, HP heater