Dry cooling system for powerplants

Patent metadata

Field	Value
Publication number	US-10161683-B2
Application number	US-201615271818-A
Country	US
Kind code	B2
Filing date	Sep 21, 2016
Priority date	Aug 20, 2015
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

An indirect dry cooling system suitable for steam condensing applications in a power plant Rankine cycle in one embodiment includes an air cooled condenser having a plurality of interconnected modular cooling cells. Each cell comprises a blower and tube bundle assemblies each including inlet headers, outlet headers, and plurality of tubes extending between the headers. In one embodiment, the tube bundle assemblies may be shop fabricated as a unit to form an A-frame or V-frame cell construction The tubes may be finned. Steam circulating in a closed flow loop on the tube side from a steam turbine is cooled in each cell by ambient air blown through the tube bundles, thereby forming liquid condensate. The condensate is collected and returned to the Rankine cycle for reheating to form steam to drive the turbine.

First claim

What is claimed is:

1. A dry cooling system for condensing steam comprising:
a steam turbine fluidly coupled to a Rankine cycle flow loop circulating a heat transfer medium;
an air cooled heat exchanger fluidly coupled to the Rankine cycle flow loop and arranged to receive exhaust steam from a steam turbine;
the air cooled heat exchanger comprising a plurality of fluidly interconnected cooling cells each comprising:
a pair of first and second inlet headers fluidly coupled to the Rankine cycle flow loop;
a pair of first and second outlet headers fluidly coupled to the Rankine cycle flow loop;
a first tube bundle comprising a plurality of tubes fluidly coupled between the first inlet and outlet headers;
a second tube bundle angularly oriented to the first tube bundle and comprising a plurality of tubes fluidly coupled between the second inlet and outlet headers; and
an air blower arranged to direct ambient cooling air through the first and second tube bundles;

wherein the plurality of cooling cells are arranged in a horizontally extending row in which each of the first and second inlet headers are axially aligned and connected in a contiguous series to other respective first and second inlet headers, and each of the first and second outlet headers are connected in a contiguous series to other respective first and second headers respectively;
wherein at least some of the cooling cells are arranged in an adjoining pair in which the inlet headers of a first and second cooling cell are mechanically coupled together via joints which includes a flow partition plate configured to prevent steam from flowing directly from the inlet headers of the first cooling cell into corresponding inlet headers of the second cooling cell;
wherein exhaust steam from the steam turbine is bifurcated and flows to each of the first and second inlet headers, through the first and second tube bundles wherein the steam is condensed forming condensate, the condensate being collected in the first and second outlet headers and then flows back to the Rankine cycle flow loop.

2. The system according to claim 1 , wherein the first and second tube bundles are arranged in a vertically-oriented triangular shape and converge towards a top of the cooling cell.

3. The system according to claim 1 , wherein the first and second outlet headers are supported by a horizontal mounting surface, and the first and second inlet headers are mechanically coupled together to form a self-supporting A-frame construction.

4. The system according to claim 1 , wherein the first inlet header, first tube bundle, and first outlet header form a first cooling flow path, and the second inlet bundle, second tube bundle, and second outlet header form a second cooling flow path fluidly isolated from the first flow path.

5. The system according to claim 1 , wherein the first and second inlet headers are connected together via mating bolted flanges to adjoining first and second inlet headers respectively, and first and second outlet headers are connected together via mating bolted flanges to adjoining first and second outlet headers respectively.

6. The system according to claim 1 , wherein in the steam flows downwards in the first and second tube bundles of each cooling cell from the first and second inlet headers to the first and second outlet headers.

7. The system according to claim 1 , wherein the tubes have an oblong cross sectional shape and include a plurality heat transfer fins disposed on opposing sides of the tubes which extending towards adjoining tubes in the first and second tube bundles.

8. The system according to claim 1 , further comprising a steam inlet manifold fluidly coupled to the first and second inlet headers that bifurcates the steam flow, and a condensate outlet manifold which combines condensate from the first and second outlet headers.

9. The system according to claim 1 , wherein:
the first inlet header, first outlet header, and first tube bundle are shop fabricated defining a first half section including comprising a plurality of linearly spaced apart finned tubes fluidly coupled between the first inlet and outlet headers; and
the second inlet header, second outlet header, and second tube bundle are shop fabricated defining a second half section including a comprising a plurality of linearly spaced apart finned tubes fluidly coupled between the second inlet and outlet headers;
the first and second half sections arranged proximate to each other at an installation site at an acute angle wherein the first and second inlet headers are disposed proximately to each other, and the first and second outlet headers are disposed distally to each other forming a triangular configuration.

10. The system of claim 1 , wherein terminal ends of the tubes of the first and second tube bundles are each fluidly connected to a flat tubesheet attached to a box-shaped header manifold attached to each of the first and second inlet and outlet headers.

11. The system according to claim 10 , wherein each header manifold has a bell shape with a narrow end attached to the first and second inlet and outlet headers and a broader end that supports the tubesheets.

12. The system according to claim 1 , wherein the blower is disposed below the first and second inlet headers and blows cooling air upwards and outwards through the first and second tube bundles for condensing the steam.

13. A modular air cooled heat exchanger for cooling a heat transfer medium, the heat exchanger comprising:
a plurality of fluidly coupled cooling cells arranged in a contiguous row of adjoining fluidly interconnected cooling cells, each cooling cell comprising:
a shop fabricated first half section including a first inlet header, a first outlet header, and a first tube bundle comprising a plurality of linearly spaced apart finned tubes fluidly coupled between the first inlet and outlet headers; and
a shop fabricated second half section including a second inlet header, a second outlet header, and a second tube bundle comprising a plurality of linearly spaced apart finned tubes fluidly coupled between the second inlet and outlet headers;

the first and second half sections arranged proximate to each other at an installation site at an acute angle wherein the first and second inlet headers are disposed proximately to each other, and the first and second outlet headers are disposed distally to each other forming a triangular configuration;
the first and second inlet headers and the first and second outlet headers of each cooling cell being axially aligned with each other respectively;
wherein at least some of the cooling cells being arranged in adjoining pairs in which the first and second inlet headers of a first cooling cell are fluidly isolated from the first and second inlet headers of an adjoining second cooling cell respectively, and the first and second outlet headers of the first cooling cell are in fluidly coupled to the first and second outlet headers of the adjoining second cooling cell respectively thereby forming a direct flow path therebetween;
wherein the heat transfer medium flows in the first cooling cell from the first and second inlet headers through the first and second tube bundles into the first and second outlet headers, and axially into the first and second outlet headers of the second cooling cell; and the heat transfer medium then flows in the second cell from the first and second outlet headers through the first and second tube bundles into the first and second inlet headers;
a blower arranged and operable to flow ambient cooling air through the first and second tube bundles;
wherein heated heat transfer medium flows thr

Assignees

• Holtec International

Inventors

• Singh Krishna P
• Maciunas Vytautas Vincas
• Rampall Indresh

Classifications

• F28B1/06 Primary

  using air or other gas as the cooling medium · CPC title

• F28B9/06

  with provision for re-cooling the cooling water or other cooling liquid · CPC title

• F28B1/02

  using water or other liquid as the cooling medium · CPC title

• F01K9/003

  condenser cooling circuits · CPC title