.TransiEnt.Components.Heat.HeatRecoverySteamGenerator.HeatRecoverySteamGenerator_L1

Information

1. Purpose of model

Model for heat recovery steam generator based on pinch point analysis.

The model has been developed to account for the load dependend effect of the water-steam side on the gas outlet temperature without the necessity to use dynamic balance equations for the water/steam side.

It is thus a compromise of numerical robustness and calucations speed as well as physical insight.

2. Level of detail, physical effects considered, and physical insight

• The outlet temperatures of air and steam are determined from pinch-point analysis.
• No detailled design information, such as surface areas have to be known.
• Air side outlet temperature dynamics is artificially corrected with PT1, according to thermal energy storage in internal steel mass.

3. Limits of validity

• This model is only valid for once through/benson type heat recovery steam generator with a single pressure level. For these, the pinch point is at the evaporator outlet (in gas flow direction).
• The air flow direction is assumed as vertical.
• A constant pinch point and approach point temperature difference is used.
• At very low loads, such as during start up and cool down, a minimum water flow rate is assured in the evaporator by means of a blow down flow.

4. Interfaces

1. Air Inlet
2. Air Outlet
3. Water inlet
4. Steam Outlet

5. Nomenclature

(no remarks)

6. Governing Equations

The air temperature at the pinch point is determined from the water saturation temperature at the steam outlet pressure, as set by steam turbine or bypass.

The heat available from the gas flow upstream of this point is used for steam generation and superheating and determines the steam and feedwater massflow.

7. Remarks for Usage

(no remarks)

8. Validation

The model has been validated with the heat recovery steam generator of the Electric Thermal Energy Storage demonstration plant of Siemens Gamesa Renewable Energy in Hamburg-Bergedorf, Germany.

9. References

[1] V.L. Eriksen (Ed.), Heat recovery steam generator technology, Woodhead Publishing, an imprint of Elsevier, Duxford, United Kingdom, 2017.

[2] V. Ganapathy, Waste heat boiler deskbook, Fairmont Press, Lilburn, GA, 1991.

[3] M. von der Heyde, Abschlussbericht zum Teilprojekt der TUHH im Verbundforschungsprojekt Future Energy Solution (FES), BMWI 03ET6072C, 2021

[4] M. von der Heyde, Electric Thermal Energy Storage based on Packed Beds for Renewable Energy Integration, Dissertation, Hamburg University of Technology, 2021

10. Version History

First Version in 04.2020 for the research project Future Energy Solution (FES) by Michael von der Heyde (heyde@tuhh.de)

Contents

Name	Description
Outline
Summary
PressureLoss	Pressure loss model on gas side
HeatTransferExternal	Heat transfer model gas to inner insulation surface
Insulation