System and method for heat recovery steam generators

Patent metadata

Field	Value
Publication number	US-9739478-B2
Application number	US-201313759985-A
Country	US
Kind code	B2
Filing date	Feb 5, 2013
Priority date	Feb 5, 2013
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

A system includes a heat recovery steam generator (HRSG) having a plurality of evaporator sections. At least one evaporator section includes a forced circulation evaporator configured to generate a saturated steam, a once-through evaporator configured to generate a first superheated steam, and a first superheater configured to receive the saturated steam and the first superheated steam.

First claim

The invention claimed is:

1. A system, comprising:
a heat recovery steam generator (HRSG), comprising:
a plurality of different pressure evaporator sections, wherein at least one of the plurality of different pressure evaporator sections is a low-, intermediate-, or high-pressure evaporator section that comprises:
a first evaporator configured to generate a saturated steam;
a second evaporator configured to generate a first superheated steam;
a first superheater configured to receive the saturated steam from the first evaporator and generate a second superheated steam; a second superheater configured to receive the first superheated steam from the second evaporator and generate a third superheated steam; and a downstream system configured to receive the second superheated steam from the first superheater and the third superheated steam from the second superheater, wherein the downstream system comprises an attemperator configured to receive the second superheated steam from the first superheater and the third superheated steam from the second superheater.

2. The system of claim 1 , wherein the HRSG comprises the high-pressure evaporator section, the intermediate-pressure evaporator section, and the low-pressure evaporator section.

3. The system of claim 1 , wherein the second evaporator comprises a once-through evaporator disposed upstream of the first evaporator comprising a forced circulation evaporator.

4. The system of claim 1 , wherein the second superheater is disposed upstream of the first superheater.

5. The system of claim 1 , wherein each of the first and second superheaters is disposed upstream of both the first evaporator and the second evaporator.

6. The system of claim 1 , comprising a first control valve configured to adjust a flowrate of water entering the first evaporator, and a second control valve configured to adjust a flowrate of water entering the second evaporator.

7. The system of claim 1 , comprising a controller configured to independently control a first flow through the first evaporator and the first superheater and a second flow through the second evaporator and the second superheater.

8. The system of claim 1 , comprising an integrated gasification combined cycle (IGCC) power plant having the HRSG.

9. The system of claim 1 , wherein the second evaporator comprises a once-through evaporator disposed upstream of the first evaporator comprising a forced circulation evaporator, the second superheater is disposed upstream of the first superheater, and each of the first and second superheaters is disposed upstream of both the first evaporator and the second evaporator.

10. The system of claim 1 , comprising a third superheater configured to receive a flow from the attemperator.

11. The system of claim 1 , wherein the first evaporator comprises a forced circulation evaporator configured to generate approximately 20 to 40 percent of the steam produced in at least one of the plurality of evaporator sections, and the second evaporator comprises a once-through evaporator configured to generate approximately 60 to 80 percent of the steam produced in the at least one of the plurality of evaporator sections.

12. The system of claim 1 , wherein the first evaporator comprises a forced circulation evaporator having horizontal piping.

13. The system of claim 1 , wherein the first evaporator comprises a forced circulation evaporator.

14. The system of claim 1 , wherein the second evaporator comprises a once-through evaporator.

15. A method of operation of a heat recovery steam generator (HRSG), comprising:
generating a saturated steam using a first evaporator disposed in an evaporator section of the heat recovery steam generator (HRSG)
generating a first superheated steam using a second evaporator disposed in the evaporator section of the HRSG;
generating, via a first superheater, a second superheated steam by superheating the saturated steam from the first evaporator;
generating, via a second superheater, a third superheated steam by superheating the first superheated steam from the second evaporator; and routing the second superheated steam from the first superheater and the third superheated steam from the second superheater to a downstream system, wherein routing comprises attemperating the third superheated steam with the second superheated steam in an attemperator of the downstream system to generate a fourth superheated steam.

16. The method of claim 15 , comprising independently controlling, via a controller, a first flow through the first evaporator and the first superheater and a second flow through the second evaporator and the second superheater.

17. The method of claim 15 , wherein the second evaporator comprises a once-through evaporator located upstream of the first evaporator comprising a forced circulation evaporator.

18. The method of claim 15 , wherein the second superheater is disposed upstream of the first superheater.

19. The method of claim 15 , comprising receiving a heated flow through first regions having the first and second superheaters upstream of second regions having the first evaporator and the second evaporator.

20. The method of claim 15 , comprising superheating, via a third superheater, the fourth superheated steam from the attemperator.

21. The method of claim 15 , wherein the evaporation section is a low-, intermediate, or high-pressure evaporator section that comprises the first evaporator, the second evaporator, the first superheater, and the second superheater.

22. The method of claim 15 , wherein the saturated steam is approximately 20 to 40 percent of a total steam in the evaporator section, and the first superheated steam is approximately 60 to 80 percent of the total steam in the evaporator section.

23. The system of claim 15 , wherein the first evaporator comprises a forced circulation evaporator and the second evaporator comprises a once-through evaporator.

24. A system, comprising:
a heat recovery steam generator (HRSG) comprising:
a plurality of evaporator sections, wherein at least one of the plurality of evaporator sections comprises:
a first flow path having a forced circulation evaporator configured to generate a saturated steam and a first superheater configured to receive the saturated steam from the forced circulation evaporator and generate a second superheated steam;
a second flow path having a once-through evaporator configured to generate a first superheated steam and a second superheater configured to receive the first superheated steam from the once-through evaporator and generate a third superheated steam, wherein the first and second flow paths are in a parallel configuration;
an attemperator configured to receive flows from the first and second flow paths, wherein the attemperator is configured to attemperate the third superheated steam with the second superheated steam to generate a fourth superheated steam.

25. The system of claim 24 , wherein the once-through evaporator is disposed upstream of the forced circulation evaporator.

26. The system of claim 24 , wherein the second superheater is disposed upstream of the first superheater.

27. The system of claim 24 , comprising a controller having instructions disposed on a non-transitory, machine readable medium, wherein the instructions are configured to independently control a first flow through the first flow path to the attemperator and a s

Assignees

• Gen Electric

Inventors

• Rancruel Diego Fernando
• Viscome Drake Joseph
• Fadde Elizabeth Angelyn
• Atwell Ashlee Nicole
• Conger Kyle Joseph

Classifications

• F22G5/00

  Controlling superheat temperature · CPC title

• Y02E20/16

  Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT] · CPC title

• Y10T137/0324

  With control of flow by a condition or characteristic of a fluid · CPC title

• Y02E20/18

  Integrated gasification combined cycle [IGCC], e.g. combined with carbon capture and storage [CCS] · CPC title

• F22G3/00 Primary

  Steam superheaters characterised by constructional features; Details or component parts thereof · CPC title