The DISPATCHES Ultra-Supercritical Power Plant model is an example flowsheet for a pulverized coal-fired ultra-supercritical power plant. This model simulates a plant producing 436 MW of gross power and it is based on the flowsheet presented in 1999 USDOE Report #DOE/FE-0400. A flowsheet of the power plant is shown in the figure below:
Acronym | Name |
---|---|
RH | Reheater (RH_1 and RH_2) |
T | Turbine (T_1 to T_{11}) |
BFPT | Boiler Feed Water Pump Turbine |
FWH | Feed Water Heaters (FWH_1 to FWH_9) |
CM | Condensate Mixer |
CP | Condenser Pump |
BP | Booster Pump |
BFWP | Boiler Feed Water Pump |
DA | Deaerator |
BFW | Boiler Feed Water |
F^{cond} | Condenser Flow Outlet (mol/s) |
F^{boiler} | Boiler Flow Inlet (mol/s) |
The ultra-supercritical power plant model considers the following assumptions: (i) the heater unit models are used to model main steam boiler, reheater 1 and 2, and condenser, and (ii) the multi-stage turbines are modeled as multiple lumped single stage turbines. Some of the parameters in the model, such as the area of feed water heaters, the overall heat transfer coefficient of heat exchangers, and the efficiency of the turbines at multiple stages have been estimated for a total power out of 436 MW, while the main steam conditions, i. e. pressure and temperature, are adopted from the aforementioned DOE report. The ultra-supercritical power plant model is constructed using some units from the IDAES power generation unit model library and the IAPWS property package for steam and water. The unit models used in this model are shown in the table below:
Unit Model | Units in the flowsheet |
---|---|
HelmTurbineStage | Turbines (T_1 to T_{11}) and BFPT |
HelmSplitter | Turbine Splitters |
Heater | Boiler components, i.e., Boiler, RH_1, and RH_2 |
HelmMixer | Mixers (including CM and DA) |
HelmIsentropicCompresssor | Pumps (including CP, BP, and BFWP) |
HeatExchanger | Condenser and Feed Water Heaters (FWH_1 to FWH_9) |
The ultra-supercritical Power Plant model has 2 degrees of freedom:
- Boiler feed water flow (boiler.inlet.flow_-mol)
- Boiler feed water pressure (boiler.outlet.pressure)
Variable Name | Description |
---|---|
PlantPowerOut | Net power out from the plant in MW |
PlantHeatDuty | Total boiler heat duty (i.e., Boiler, RH_1, and RH_2) in MWth |
- The outlet temperature of the boiler components is set to be 866 K, as shown in the following equation, where Unit represents Boiler, RH_1, and RH_2:
Unit.outlet.temperature = 866
- PlantPowerOut is given by the total turbine mechanical work, as shown in the following equation:
PlantPowerOut = \sum^{11}_{i=1}{T_i.mechanical_-work}
- PlantHeatDuty is given as the summation of the heat duties of boiler components as shown in the following equation, where Unit is in [Boiler, RH_1, RH_2]:
PlantHeatDuty = \sum_{Unit}{Unit.heat_-duty}