Against the partial HP preheater bypass technology(PHPHBT) used in high pressure low temperature economizer(HPLTE) system of double-reheat units

the dynamic characteristics of the HPLTE system were numerically studied. The results show that

the outlet water temperature variation of the HPLTE was small

when the unit load was changed by 1%

2% and 3% of the rated load rapidly under different working conditions with the adoption of PHPHBT. With the same load step

as the unit's initial load increased

the response speed of the water temperature at the HPLTE outlet slowed down

and the transition time it reached stable state prolonged. The variation of water temperature at the HPLTE outlet increased with the load adjustment value

but it rarely affected the water temperature at the economizer inlet. The above research fully demonstrated that the safety and stability of the relevant systems and equipment can be ensured after adopting the PHPHBT.