Simulation Study On Dynamic Characteristic Of HRSG

As the middle heat-exchange equipment between the gas turbine (or gas internalcombustion engine) and steam turbine,the heat recovery steam generator(or HRSG forshort) plays an important role to match into a rational and efficient combined cyclesystem.In the past,people have a lot of study for the front device-the gas turbine (orgas internal combustion engines) and the post device-the steam turbine beside theHRSG.However, the factors such as the load change,environment temperature andstart-stop characteristics of unit often cause the units run under off-designcondition.Therefore,it is very important to analyze the dynamic characteristics of theHRSG.The single-pressure and non-additionally heat recovery steam generator is regardedas the main research object.Based on the thermodynamics theories and conservationequations of working process of HRSG in steady and dynamic state,this paper getsgas side and steam-water side dynamic mathematical models of each part by adoptingthe idea of lumped parameter model.Then it analyzes the integral dynamiccharacteristics and static characteristics of HRSG by uniting these mathematicalmodels.With single-pressure and non-additionally heat recovery steam generator of oneindustrial park combined cycle system, for example,EES is applied to calculate theequations of HRSG in steady and dynamic state.Then export parameters and theirchange characteristics corresponding to different inlet parameters are analyzed,thusthe variation range of input parameters and scope of gas internal combustion enginework load rate which can guarantee the normal work of HRSG are determined.What’smore,the regularity of variations of export parameters with time varying for stepchanges in the inlet parameters under varying operating conditions are alsoanalyzed.The results would be instructive to keep the HRSG in normal operation andto design of control system of the whole system.