The dynamic characteristics of the bottoming cycle of a gas turbine combined cycle have a significant influence on the load variation characteristics of the unit. Partially recuperation is a new method which can be used to improve the performance of combined cycle at partial load

it is an important part of system feasibility evaluation to study the effect of partially recuperation on the dynamic characteristics of the bottoming cycle. In this paper

a dynamic simulation model of the bottoming cycle system of a partially recuperative combined cycle unit is established by using modular modeling method

and the dynamic characteristics of inlet parameter disturbance and load shedding process are studied. The results show that

the dynamic model can accurately reflect the dynamic characteristics of the bottoming cycle

and the simulation results show that the dynamic response of partially recuperative units facing the disturbance of exhaust parameters is consistent with that of conventional units. The disturbance of exhaust temperature T4 mainly affects the high-pressure superheated steam and reheated steam

and the influence range is larger. The disturbance of T_4 with 5% can reduce the bottoming cycle power by 16.32%. The response speed of the unit is slower

and the time constant of the steam turbine power is about 400. The disturbance of exhaust flow affects the steam of each stage

and the influence range is relatively small

the disturbance of 10%reduces the bottoming cycle power by 9.49%

the response speed of the unit is faster

the time constant of the steam turbine power is about 60. When the recuperative ratio is disturbed

the dynamic response of the unit is similar to that of the T4 disturbance

and the operation strategy of recuperative regulation results in the load variation of the combined cycle being borne entirely by the bottoming cycle

the time needed for partially recuperative units to reach steady state is 1 100 s later than that of conventional units

and the recuperative regulation mode is suitable for use in the load interval below 51.4%.