US2998227A

US2998227A - Single-pass counterflow condenser

Info

Publication number: US2998227A
Application number: US676526A
Authority: US
Inventors: Ernest C Gaston
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-08-06
Filing date: 1957-08-06
Publication date: 1961-08-29
Anticipated expiration: 1978-08-29

Description

ug- 29, 1961 E. c. GASTON 2,998,227

SINGLE-PASS couNTERFLow coNDENsER Filed Aug. 6, 1957 5 Sheets-Sheet 1 Il l Il 24 rroR/vfy Aug 29 1961 E. c. GASTON 2,998,227

SINGLE-PASS coUNTERFLoW CONDENSER Filed Aug. e, 1957 s sheets-sheet 2 /Nl/E/vra ERA/57* C GA sro/v ATTORNEY Aug. 29, 1961 E. c. GASTON SINGLE-PASS couNTERFLow coNDENsER 5 Sheets-Sheet' 5 Filed Aug. 6, 1957 VvE/vra@ ERA/57' C. GASTo/V United States Patent Olice 2,998,227 Patented Aug. 29, 1961 2,998,227 SINGLE-PASS COUNTERFLOW CONDENSER Ernest C. Gaston, Birmingham, Ala. Filed Aug. 6, 1957, Ser. No. 676,526 Claims. (Cl. 257-44) This invention relates to turbine generator installations and more particularly to condensers for turbines of such installations.

An object of the present invention is to p-rovide a novel condenser for large size turbine generators having two turbines arranged in tandem or parallel with two separate exhausts. 1

The present invention contempla-tes a novel singlepass counterilow condenser which comprises a pair of shells connected to receive exhaust steam from two separated exhausts of two turbines arranged in tandem or parallel for ilow transversely of the shells. Two groups of tubular members are provided for said shells to effect ow of cooling medium in indirect heat exchange relationship with the steam. An intermediate water box is provided for each group of tubular members and is disposed between the shells. Each of the groups of tubular members has associated therewith an inlet and outlet terminal water box located at remote ends of the shells and is in communication with the intermediate water box. Means are provided for eifecting ow of cooling medium in the two groups of tubular members in opposite directions and, under certain conditions of operation, for flow in the tubular members in the same direction.

The above and other objects and advantages of the present invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings wherein one embodiment of the present invention is illustrated.

In the drawings:

FIG. l is a side elevational View of the novel condenser of the present invention;

FIG. 2 is a front elevational and enlarged view of the condenser of FIG. 1;

FIG. 3 is a partly diagrammatic and isometric illustration of the condenser of FIG. 1 to more clearly illustrate the relative arrangement of parts;

FIG. 4 is a diagrammatic representation of the condenser of FIG. 1 and illustrates the valve arrangement for effecting counterlow and unidirectional flow of the cooling medium through the condenser.

Referring now to the drawings and more particularly to FIG. l hereof, the novel condenser of the present invention is generally designated by the reference character 11. Condenser 11 comprises a pair of horizontally disposed

shells

12 and 14 which are substantially rectangular shaped in cross section and the

shells

12 and 14 are provided with upper casings 15 and 16, respectively, and lower casings 17 and 18, respectively. Upper casings 15 and 16 are surmounted by coupling flanges 19 and 20, respectively, which are adapted for connection to two separated exhausts of two turbines (not shown) arranged in tandem or parallel, whereby steam from the turbine exhausts tlows downwardly through

shells

12 and 14 and transversely thereof. The lower casings 17 and 18 collect condensed steam and are provided with

drain outlets

22 and 23, respectively, at the bottoms of the casings to discharge condensate from the condenser. Upper casings 15 and 16 and lower casings 17 and 18 are provided with conventional equalizer lines or

conduits

24 and 25, respectively.

Referring now to FIG. 3, two groups 28 and 29 of tubular members 30 are provided for condenser 11 to conduct a cooling medium therethrough in indirect heat exchange relationship with the steam owing through

shells

12 and 14. Group 28 includes a pair of

tube bundles

32 and 33 arranged in

shells

12 and 14, respectively, and group 29 includes a pair of tube bundles 35 and 36 arranged in

shells

12 and 14, respectively. Adjacent terminal portions of tubes 30 of

tube bundles

32 and 33 are mounted on

tube sheets

37 and 33, respectively, associated with an intermediate water box 40 disposed between

adjacent ends

41 and 42 of

shells

12 and 14, respectively. The opposite and remote terminal portions of tubes 30 of

tube bundles

32 and 33 are mounted in

tube sheet

43 and 44, respectively, associated with

terminal water boxes

45 and 46, disposed at remote ends 47 and 48 of

shells

12 and 14, respectively. The adjacent terminal portions of tubes 30 of tube bundles 35 and 36 are mounted in

tube sheets

49 and 50, respectively, associated with an intermediate water box 51 disposed between

ends

41 and 42 of

shells

12 and 14. The opposite and remote terminal portions of tubes 3G of tube bundles 3'5 and 36 are mounted in

tube sheets

53 and 54, respectively, associated with

terminal water boxes

55 and 56 on remote ends 47 and 48 of

shells

12 and 14. As seen in FIG. 3, tubes 30 of

tube bundles

32 and 33 are in communication with each other by way of intermediate water box 40 and the tubes 30 of tube bundles 35 and 36 communicate with each other through intermediate water box '51. Furthermore,

terminal water boxes

45 and 46 communicate with each other through tubes 30 of group 28 and intermediate water box 4t), while

terminal water boxes

55 and 56 are in communication through the tubes of group 29 and intermediate water box 51. A crossover or bypass conduit 60 connects

terminal water boxes

45 and 55 and a similar conduit 61 connects

terminal water boxes

46 and 56. The

terminal water boxes

45, 46, 55 and 56 are provided with conduits 62, 63 (shown in FIGS. 1 and 2 but not in FIG. 3), 64 and 65, respectively.

In FIG. 4 of the drawings', there is illustrated a diagrammatic representation of condenser 11 to more clearly show and describe the llow of a cooling medium through the condenser under certain conditions of operation.

Conduits

62, 63, 64 and 65 are provided with Valves 67,

68, 69 and 70, respectively, shown in FIG. 4 but not in FIGS. 1 to 3 for the sake of clearness. Also,

crossover conduits

60 and 61 include

valves

71 and 72, respectively. Conduit y64 of terminal water box 55 is connected to the discharge of a pump 73, which in turn, is connected at its suction side to a source (not shown) of cooling medium, as -for example water. Similarly, conduit 63 of terminal water box 46 is connected to the discharge of a pump 74, which in turn is connected at its suction side to a source (not shown) of water. It will be understood that

pumps

73 and 74 may be connected to the same or different sources of cooling medium.

In normal operation of the condenser 11,

valves

71 and 72 are closed while

valves

67, 68, 69 and 70 are opened to provide a ow as indicated by the arrows in FIG. 4. Water is drawn by pump 73 and delivered through conduit 64 to terminal water box 55 whence it flows through tubes 30 of tube bundle 35 into intermediate water box 51. From water box 51, the water ows through tubes of tube bundle 36 and into terminal water box 56 whence it is discharged through conduit 65 to waste. Pump 74 delivers water through conduit 63 into terminal water box 46, whence the water flows through the tubes 30 of

tube bundle

33 and 32 of group 28 countercurrent with respect to the ow of water through the tubes of group 29. The water from tube bundle 32 enters terminal water box 45 and is discharged through conduit 62 to waste. The

steam entering shells

12 and 14 flows downwardly therein and substantially normal to the tubes 30 where it passes in heat exchange relationship with the water iiowing through the tubes, The condensed steam collects in lower casings 17 and 18 and is discharged through

outlets

22 and 23 for use in a boiler or the like (not shown). It will be readily understood by those skilled in the art that by reason o f the counterflow of circulating water in condenser 11, shells 12l and 14 have equal condensing capacity whereby identical back pressures may be maintained at each turbine exhaust nozzle during normal operation.

The subject condenser may maintain equal condensing capacities during one pump operation, as for example for cold water operation, light load operation or operation during a period of maintenance Work on one of the two circulating

water pumps

73 and 74. For example, if pump 74 were inoperative, the subject condenser is operated by

closing valves

68, 70 and 71 and

opening valves

67, 72 and 69. In such event, water iiows through the following circuit: Conduit 64, terminal water box S, tubes 30 of group 29 and intermediate water box 51, terminal water box 56, conduit 61, terminal water box 46, tubes 30 of group 28 and intermediate water box 40, terminal water box 4S, and out to waste through conduit 62. If pump 73 were inoperative, then

valves

67, 69` and 72 are closed and

valves

70, 71 and 68 are opened. Accordingly, the flow of Water would be traced as follows: Conduit 63, terminal water box 46, tubes 30 of group 28 and intermediate water box 40, terminal water Vbox 45, crossover conduit 60, terminal water box 55, tubes 30 of group 29 and intermediate water box 51, terminal water box 56, and conduit 65 to waste.

In the operation of condensers of the described type, the circulating water is drawn by the pumps from rivers or the like which contain leaves, twigs and other foreign matter or debris. After certain periods of operation of such condensers, the same become fouled `whereby the ow of circulating water is reduced to a rate at which backwashing of the condenser becomes necessary. Such a fouling condition in the subject condenser would occur in

terminal water boxes

55 and 46 and on the sides of

tube sheets

53 and 44 facing the interior of such boxes. When, for example, it is discovered that terminal water box 55 is fouled and it is desired to backwashthe associated portion of the condenser, valves 69 and 70-are closed and

valves

67, 68, 71 and 72 are opened whereby the water ows through the following circuits: Conduit 63, terminal water box .46, part through conduit61, terminal water box 56-tubes 30` of group 29 and intermediate water box SI-terminal water box SS--conduit 60 into terminal water box 45; the remainder of the water from terminalwater box 46 flows through tubes 30 of group 28 and intermediate water box 40 into terminal water box 45, whence the water from both circuits and the debris from tube sheet 53 is discharged to waste through conduit 62. When it is desired to backwash the portion of the condenser associated with `the tube sheet 44 of terminal water box 46 because of fouling of the last-mentioned tube sheet,

valves

67 and 68 are closed and

valves

69, 70, 71 and 72 are opened whereby the water flows through the following circuit: yConduit `64, terminal water box 55, Vpart through conduit 60-terminal water box 45---tubes 30 lof group 28 kand intermediate water box 40- terminal Water box 46-.conduit 61 and into terminal water box 56; the remainder of the water from terminal water box 55 ows through tubes 30 of group 29` and intermediate water. box 51terminal water box 56, whence the water vfrom both circuits .and the debris from tube sheet 44 are discharged through conduit 65. By providing simple shut-olf Valves in the circulating

water discharge lines

62 and 63, a simple and inexpensive arrangement for backwashing is obtained without the necessity for installing the costly and space consuming 3-way valves which are `generally vinstalled for this purpose.

It will be apparent from the foregoing that the present kinvention provides a single-pass condenser with two-pass v 4 condenser performance characteristics in that the subject condenser has straight-through water passages having counteriiow performance, whereby water ows in opposite directions through two parallel water passageways. Though a twin shell condenser has been described hereinbefore, it will be appreciated by those skilled in the art that a single shell without intermediate water boxes may be employed to accomplishthe single-pass counterflow principle. In such event, the advantages obtained with the use of two shells and intermediate water boxes would not be available but the condenser still has the desirable feature of single-pass counter-flow operation. It may be well to point out that the use of a condenser with two shells and intermediate water boxes has the advantage of reduction in length of condenser tubes, thereby eliminating the premium cost on tubes which otherwise would of necessity be of excessive length. Furthermore, there is provided a positive, simple and relatively inexpensive solution to the problems associated with thermal expansion and the differentials in expansion between the tubes and the shell.

The present invention also contemplates within the spirit and scope thereof a condenser wherein each pair of water boxes is not separated but is of single and unitary construction and have internal partitions with valves in such partitions.

Although one embodiment of the invention has been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes can be made in the design and arrangement of the parts without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

What is claimed is:

l. A surface condenser adapted for connection to the two separated exhausts of two turbines arranged in tandem or parallel, comprising a pair of coplanar and horizontally disposed shells connected to the turbine exhausts for receiving steam for flow transversely of the shells, two groups of tubular members in said shells arranged parallel .to each other and normal to the ow of steam through said shells, an intermediate water box for each group of tubular members disposed between adjacent ends of said shells, an inlet and an outlet terminal water box for each group of tubular members and disposed at each remote end of the shells, means communicating an inlet terminal water box at each remote end of the shells with a source of cooling water to provide ow of the water through the associated group of tubular members in opposite directions and in indirect heat exchange with the steam in said shells, said outlet terminal water boxes effecting discharge of the cooling water flowing through the groups of tubular members from the condenser, bypass means at each remote end of the shells for communicating the inlet and outlet terminal water boxes with each other at said remote ends, means for stopping ow of cooling water to an inlet terminal water box at one remote end, andk means for causing all of the Water entering the outlet terminal water box at said one remote end from its associated group of tubular members to flow through the bypass means into the inlet water terminal box at said one remote end, to thereby effect a series (flow of cooling water from one group of tubular members' into the other group of tubular members.

2. A surface condenser adapted to receive steam from two :separated exhausts of two turbines arranged in tandem or parallel, comprising shell means connected to the turbine exhausts for receiving steam therefrom for ilow transversely o-f the shell means, two groups of tubular members in said shell means arranged parallel to each other and normal to the flow of steam through said shell means, an intermediate water box for each group of tubular members disposed between adjacent ends of said shell means, terminal water box means `disposed `at either end of the tube groups of tubular membersand serving at each end as inlets and outlets for the tubular members, means communicating one of the terminal water box means with a source of cooling water to pro-vide the end of one of said groups of tubular members with cooling water and the corresponding end of said other group of tubular members with a discharge outlet, means communicating the other of said terminal water box means with a source of cooling Water to provide the opposite end of the other of said group of tubular members with cooling medium for rflow in a direction opposite to that in said one group yof tubular members and to provide the opposite and corresponding end of said one group of tubular members with a discharge outlet, bypass means for each terminal water box means and operable for communicating the corresponding ends of .the two groups of tubular members with each other, and means operable for cutting ol communication of the source of cooling water with the end of said one group of tubular members when the bypass means is operated to communicate said last-mentioned end of said one group of tubular members with the corresponding end of the other of said group of tubular members, and operable for communicating the opposite end of said other group of tubular members with a source of cooling water when the bypass means is operated to cut oi communication between said last-mentioned opposite end of the other group of tubular members with the corresponding end of said one group of tubular members, whereby the cooling Water flows from said one group of tubular members into said other group of tubular members in series flow relationship.

3. A surface condenser adapted for connection to the two separated exhausts of two turbines arranged in tandem or parallel, comprising -a pair of coplanar and horizontally disposed shells connected to the turbine exhausts for receiving steam Afor oW transversely of the shells, two groups of tubular members in said shells arranged parallel to each other and normal to the How of steam through said shells, an intermediate water box for each group of tubular members disposed between adjacent ends of said shells, an inlet and an outlet terminal water box for each group of tubular members and disposed at each remote end of the shells, means communicating an inlet terminal w-ater box at each remote end of the shells with a source of cooling water to provide tlow of the Water through the associated group of tubular members in opposite directions and in indirect heat exchange with the steam in said shells, said outlet terminal water boxes eifecting discharge of the cooling water flowing through the groups of tubular members from the condenser, bypass conduits for the inlet and outlet terminal water boxes at each remote end of said shells IJror communicating the inlet and outlet terminal water boxes -at said end, valve means for each bypass conduit and for an inlet and an adjoining outlet terminal water box at one remote end, said valve means being operable for causing all of the cooling water entering the outlet terminal Water box at said remote end from its associated group of tubular members to ow through said bypass conduit at said remote end into the adjoining inlet water terminal water box, to thereby effect a series ow of cooling Water from one group of tubular members into the other group of tubular members.

4. A surface condenser adapted for connection to the two separated exhausts of two turbines arranged in tandem or parallel, comprising a pair of coplanar and horizontally disposed shells connected to the turbine exhausts for receiving steam for flow transversely of the shells,

two groups of tubular members in said shells arranged parallel to each other and normal to the flow of steam through said shells, an intermediate water box for each group of ytubular members `disposed between adjacent ends of said shells, an inlet and an outlet terminal water box for each group of tubular members land disposed at each remote end of the shells, means communicating an inlet terminal water box at each remote end of the shells with -a source of cooling water to provide flow of the water through the associated group of tubular members in opposite directions and in indirect heat exchange with the steam in said shells, said outlet terminal water boxes effecting discharge of the cooling water flowing through the groups of tubular members from the condenser, bypass means at each remote end of the shells for communicating the inlet `and outlet terminal water boxes with each other at said remote ends, means for stopping the flow of cooling water into the inlet terminal water box at one of said remote ends and stopping the rllow of water discharged Ifrom the outlet terminal water box at the other of said remote ends, and means for causing the cooling water entering the inlet terminal water box at said other remote end to ow through both of said groups of tubular members in the same direction to be discharged from the condenser through the outlet terminal water box at said one remote end.

5. A surface condenser adapted for connection to the two separated exhausts of two turbines arranged in tandem or parallel, comprising a pair of coplanar and horizontally disposed shells connected to the turbine exhausts for receiving steam for flow transversely of the shells, two groups o-f tubular members in said shells arranged parallel to each other and normal to the ow of steam through said shells, an intermediate water box :for each group of tubular members disposed between adjacent ends of said shells, an inlet and an outlet terminal water box for each group of tubular members and disposed at each remote end of the shells, means communicating an inlet terminal water box at each remote end of the shells with a source of cooling Water to provide flow of the water through the associated group of tubular members in opposite directions and in indirect heat exchange with the steam in said shells, said outlet terminal water boxes eiecting discharge of the cooling Water owing through the groups of tubular members from the condenser, bypass conduits for the inlet and outlet terminal Water boxes at each remote end of said shells for communicating the inlet and outlet terminal water boxes at said end, valve means for each bypass conduit and for the inlet terminal water box at said one remote end and the outlet terminal water box at said other remote end, said valve means being operable for causing the cooling water entering the inlet terminal water box at said other remote end to ow through both of said groups otE tubular members in the same direction to be discharged from the condenser through the outlet terminal water box at said one remote end.

References Cited in the le of this patent UNITED STATES PATENTS 1,729,309 Frey Sept. 24, 1929 1,753,955 Tuley Apr. 8, 1930 1,837,860 Grace Dec. 22, 1931 FOREIGN PATENTS 18,037 Great Britain July 30, 1914