US3251408A

US3251408A - Cooling systems

Info

Publication number: US3251408A
Application number: US460021A
Authority: US
Inventors: Watson Henry; Daltry John Harold
Original assignee: English Electric Co Ltd
Current assignee: English Electric Co Ltd
Priority date: 1960-03-02
Filing date: 1965-06-01
Publication date: 1966-05-17
Anticipated expiration: 1983-05-17
Also published as: GB905924A

Description

May 17, 1966 H. WATSON ETAL 3,251,4081

COOLING SYSTEMS Filed June 1, 1965 5 Sheets-Sheet 1 DRAIN TANK May 17, 1966 H. WATSON ETAL COOLING SYSTEMS 3 Sheets-Sheet 2 Filed June 1, 1965 A May 17, 1966 H. wATsoN ETAL 3,251,403

COOLING SYSTEMS Filed June l, 1965 3 Sheets-Sheet 5 United States Patent O 3,251,408 COOLING SYSTEMS v Henry Watson and John Harold Daltry, both of Rugby, England, assignors to The English Electric Company Limited, London, England, a British company Filed June 1, 1965, Ser. No. 460,021 Claims priority, application Great Britain, Mar. 2, 1960,

7,467/ 60 4 Claims. (Cl. 165-71) This application is a ,continuation-impart of application Serial No. 335,791, filed Januaryr, 1964, now abandoned, which is a continuation-in-part of application Serial No. 81,030, filed January 6, 1961, now abandoned.

This invention relates to water cooling lsystems for steam -turbine plants.

According to the invention, such a water cooling system comprises a direct contact steam condenser, a heat exchanger element for cooling, by indirect heat exchange with air, condensatefrom said condenser, warm water inlet means and cold water outlet means on said heat exchanger element, a warm water pipe connected to the condenser for carrying condensate therefrom, a pump in said warm water pipe for circulating water through the system, a cold water pipe connected to the condenser so as to carry cold water thereto, first con-. duit means connected to the warm water pipe for leading water therefrom to the said element, second conduit means connected between said first conduit means and the warm water inlet means of the said element, third conduit means connected to the cold water pipe for leading waterthereto from the said element, fourth conduit means connected between the cold water outlet means of said element and said -third conduit means, a sector valve, adjustable to a plurality of positions and connected to said first, second, third and fourth conduit means so as, when in a first said position, to allow Water to flow from said first to said second and from fourth to said third conduit means, and drain means connected to each said sector valve for draining the heat exchanger element when sa-id sector valve is in a second said position.

According to a preferred feature of the invention, the heat exchanger element comprises a first water-containing portion connected at one end thereof to warm water inlet means, a second water-containing portion connected at one end thereof in 4series with the first watercontaining portion and at the other end thereof to said cold water outlet means, so that when the sector valve is in said first position water can flow through the heat exchanger element in double-pass operation, and the sector valve comprises a body, a plug rotatable in said body between said positions, means defining a first passage and means defining a second passage in said plug, which passages bring said second and fourth conduit means respectively into communication with said drain means when the sector valve is in said second position, so that both said water-containing portions of the heat exchanger element may be drained simultaneously. Y

According to another'preferred feature of the invention, the system also comprises means defining a third passage and means defining a fourth passage in said plug for bringing said first conduit means into communication with said second and fourth conduit means respectively when the sector valve is in'a third said position,

so that both said water-containing portions of the heat exchanger element may be filled simultaneously.

A Water cooling system for a steam turbine plant will now be described by way of example and with reference to the accompanying drawings, 4in which:

FIG. l is a diagram showing the principal components of the system;

FIG. 2 is a1 sectional elevation of a sector valve forming part of the system, taken on the line II-II of FIG. 3;

FIG. 3 is a sectional plan view of the same sector valve, taken on the line III-III of FIG. 2;

FIGS. 4, 5 and 6 are three diagrammatic views showing the sector Valve in three different operating positions; and

FIG. 7 is a diagrammatic view corresponding to FIG. 5 but showing a modified form of sector valve according to the invention.

With reference firstly to FIG. l, a steam turbine exhausts into a direct-contact steam condenser '30, whence a warm water pipe 35 for condensed steam leads in succession through `a stop valve 36, pump 37, nonreturn valve 38 and Iisolating valve 39. A cold water pipe 40 leads through an isolating valve 34, a hydraulic turbine- 33 (which is coupled to an electricimotor 43 and which is also 4coupled to the pump 37), and a stop valve 31, to the cold water jets 101 of the condenser 30. Connected in parallel with each other between the Warm water pipe 35 and cold water pipe 40 are a number of sector or plug valves 3, each having an outlet port 5 connected to the cold water pipe 40 by a pipe 60 and an inlet port 8 connected to the warm water` pipe 35 by a pipe 61. In addition each sector valve 3 has a warm water outlet port 9 connected through a pipe 49 to the inlet end of a fheat exchanger' element 42, for cooling water by indirect contact with air. The heat exchanger elements are associated with a dry cooling tower (not shown). 42 has two water-containing portions 102 which are connected together at one end by a header 103, and at their other ends to the pipe 49 and pipe 46 respectively. Pipe 46 leads to an inlet/outlet port 6 of the sector valve 3.

Each header 103 is provided with two

automatic vent valves

71 and 105. The

valves

71 and 105 may be of any well-known type.

Each sector valve 3 has two drain ports 4 and 7, both of 'which are connected through a pipe 47 to a drain tank 48. A pipe 45, in which there is an isolating valve 50, leads to the drain tank 40 from the warm water pipe the drain tank 48 through: a stop valve 51; a transfer pump 52 capable of discharging through a non-return valve 53;the valve 53; an isolating valve 54; and an adjustable valve 55 to a point on the cold Water pipe 40 upstream of the valve 34.

With reference now to FIGS. 2 and 3, which show the sector valve 3 in greater detail, lthe ports 5 and 8 are arranged diametrically 'opposite each other in a valve casing 104. The ports 6 and 9 are also arranged diamet- Irically opposite each other in the casing 104, as are the two drain ports 4 and 7. All six ports are rectangular, but the drain ports 4 and 7 are narrower and shorter Ithan the remaining ports. Concentric with the valve casing 104 is a rotatable plug 10, having two diametrically-opposite lands 11 and vtwo diametrically opposite concave portions 12. An internal duct 23 connects one Each heat exchanger element The pipe 35 is connected to the cold water pipe 40 Athrough a by-pass valve 41. A return pipe leads from concave portion 12 to a point on the land 11 adjacent a chamfered edge 22 of the `other concave portion 12. The plug carries a bearing journal 13, engaging a com- -bined plain and thrust bearing sleeve 16 in the bottom of the casing 104; and the plug 10 also carries an operating shaft 14, journalled in a plain bearing 17 in the cover 19 of the casing, through which the shaft 14 penetrates for loperation from outside by suitable means. Longitudinal and

circular sealing strips

20 and 21 respectively are provided in the casing 104 to seal the plug 10 therein; and

seals

24, 25 are provided between the plug 10 and the cover 19 and bottom 15 of the casing 3 respectively, to seal the

bearings

17, 16 from ythe water space in the casing 104.

With reference now to FIGS. 1 to 6, when the turbine 100 is operating, exhaust steam from the turbine is condensed in the condenser by direct contact with cold water from the jets 101. The condensate is circulated as warm water by pump 37, successively through pipe 35, ports 8 and 9 of sector valves 3, pipes 49, the heat exchanger elements 42 (in which the water is cooled), pipes 46,

ports

6, 5 of sector valves 3, and pipe 40, to the turbine 33, where the Water loses some of its kinetic energy in driving the turbine: and so to the condenser jets 101.

The direction of water flow during the process described above, with the heat exchanger elements 42 in double-pass operation, is shown by arrows in FIG. l.

To drain the heat exchanger elements 42, the sector valves 3 are first adjusted to the position shown in FIG. 5. Water now fiows downwards under gravity through `the pipes 46 and 49 simultaneously, and thence through the ports 6, 7 and 9, 4 respectively to the pipe 47 and drain tank 48. At the same time the vent valves 105 open to allow air to fill the heat exchanger elements.

To fill the heat exchanger elements 42, the sector valves 3 are first adjusted to the position shown in FIG. 6. In this position, port 8 is in communication with port 9 through the chamfered edge 22 of one concave portion of the plug 10; and with port 6 through the duct 23. Water is pumped by pump 37 through pipe 35 and port 8 to ports 6 and 9 as just described, and so to the elements 42. It can be seen that both water-containing portions 102` of each heat exchange element 42 can thus be filled simultaneously. The

valves

71 and 105 open automatically to allow air, displaced by water entering the heat exchanger element to escape to atmosphere.

The 'bypass valve 41 in FIG. 1 provides a means of bypassing all the sectors 42 should this be necessary. It is however also necessary to be able to bypass any yone of the sectors 42 when that particular element is out of service for example for repairs or maintenance, in order to maintain the Water fiow in the other heat exchange sectors 42 within predetermined limits. In one example this has been done by the use of three separate valves, one in the cooling tower and two close to the condenser, with associated pipework to provide a suitable individual bypass for each sector 42.

Such extra pipework is expensive, as is the provision of a separate bypass valve for each sector 42, and can be avoid by the use of sector valves modified as shown in FIG. 7.

The valve shown in FIG. 7 has a diametral passage 70 through the plug 10 of the valve, arranged so that when the plug is in the position shown in FIGS. 5 and 7, i.e. for draining the associated heat exchange sector 42, water can ow directly from port 8 to port 5 through the passage 70.

It will be seen that when the sector valve is in the positions shown in FIGS. 4 and 6, i.e. when the associated heat-exchanger sector 42 is in normal operation or when it is being filled, the bypass passage 70 is inoperative.

The passage 70 may be of any convenient size, depending on what proportion of the normal water flow through the sectors 42 it is desired to maintain flowing Ithrough the system. This will usually be the amount necessary to maintain the efficiency of the water turbine 33 at or above a desired minimum value. In a typical example, the iow yof water through the bypass passage 70 when the associated sector 42 is out of service is one-half of the flow `through the sector when the latter is in normal operation.

What we claim as our invention and desire to secure by Letters Patent is:

1. A water-cooling system for a steam turbine plant, comprising `a direct-contact steam condenser, a heat exchanger element for cooling, by indirect heat exchange with air, condensate from said condenser, warm water inlet means and cold water youtlet means on said heat exchanger element, a warm water pipe connected to the condenser for carrying condensate therefrom, a pump in said warm water pipe for circulating water through the system, a cold water pipe connected to the condenser so as to carry cold water thereto, first conduit means connected to the warm water pipe for leading water therefrom to the said element, second conduit means connected 'between said first conduit means and the warm water inlet means of the said element, third conduit means connected to the cold water pipe for leading water thereto from the said element, fourth conduit means connected between the cold water outlet means of said element and said third conduit means, a sector valve comprising a generally-cylindrical hollow body, means defining first and second ports in said body communicating with said first and second conduit means respectively, means defining third and fourth ports in said body communicating with said third and fourth conduit means respectively, means defining fifth and sixth por-ts in said body, said first and third ports being diametrically opposite each other as are respectively said second and fourth ports and said fifth and sixth ports, and all the ports -being angularly offset from each other, a cylindrical plug rotatable in said body, means defining a first passage and means defining a second passage in said plug, said first passage being arranged to bring said first and second ports into communication with each other when the plug -is in a first position relative to the 'body 'and said second passage being arranged to bring said third and fourth ports into communication with each other when the plug is in said first position, so as to allow water to flow from said first to Said second and from said fourth to said third conduit means, respectively, and drain means connected to said fifth and sixth ports for draining the heat exchange element when said plug is in a second said position relative to the body.

2. A water cooling system according to claim 1, in which the heat exchanger element comprises a first watercontaining portion connected at one end thereof to said warm water inlet means, a second water-containing portion connected at one end thereof in series with said first water-containing portion and at the other end thereof to said cold water outlet means, so that when the sector valve is in said first position water can flow through the heat exchanger element in double-pass operation, and in which the angle Iby which said fifth and sixth ports are offset in said body relative -to said second and said fourth ports in such that when the plug is in said second position, the said passages therein bring said fifth and sixth ports into communication respectively with said second and fourth ports whereby to bring said second and fourth conduit means into communication with said drain means, so tha-t both of said water-containing portions of the heat exchanger element may be drained simultaneously through said drain means.

3. A water cooling system according to claim 2, and comprising means defining a third passage and means defining a fourth passage in said plug for bringing said first port into communication with said second and fourth ports respectively when the plug is in a third positionvrelative to said body, so that both said watercontaining portions of the heat exchanger element may be filled through said warm water pipe, said sector valve, and thence through said wann water inlet means andsaid cold water outlet means simultaneous-1y.

4. A water cooling system according to claim 2, comprising means defining a diametral passage in said plug arranged so that when said plug is in said second position said diametral passage communicates with said lirst and third ports so as to allow water to 110W from said iirst port through said diametral passage -to saidthird port.

References Cited by the Examiner UNITED STATES PATENTS 2,414,062 1/ 1942 Richter 165-61 X 2,891,773 6/ 1959 Heller 165-71 X ROBERT A. OLEARY, Primary Examiner.

Claims

1. A WATER-COOLING SYSTEM FOR A STEAM TURBINE PLANE, COMPRISING A DIRECT-CONTACT STEAM CONDENSER, A HEAT EXCHANGER ELEMENT FOR COOLING, BY INDIRECT HEAT EXCHANGE WITH AIR, CONDENSATE FROM SAID CONDENSER, WARM WATER INLET MEANS AND COLD WATER OUTLET MEANS ON SAID HEAT EXCHANGER ELEMENT, A WARM WATER PIPE CONNECTED TO THE CONDENSER FOR CARRYING CONDENSATE THEREFROM, A PUMP IN SAID WARM WATER PIPE FOR CIRCULATING WATER THROUGH THE SYSTEM, A COLD WATER PIPE CONNECTED TO THE CONDENSER SO AS TO CARRY COLD WATER THERETO, FIRST CONDUIT MEANS CONNECTED TO THE WARM WATER PIPE FOR LEADING WATER THEREFROM TO THE SAID ELEMENT, SECOND CONDUIT MEANS CONNECTED BETWEEN SAID FIRST CONDUIT MEANS AND THE WARM WATER INLET MEANS OF SAID ELEMENT, THIRD CONDUIT MEANS CONNECTED TO THE COLD WATER PIPE FOR LEADING WATER THERETO FROM THE SAID ELEMENT, FOURTH CONDUIT MEANS CONNECTED BETWEEN THE COLD WATER OUTLET MEANS OF SAID ELEMENT AND SAID THIRD CONDUIT MEANS, A SECTOR VALVE COMPRISING A GENERALLY-CYLINDRICAL HOLLOW BODY, MEANS DEFINING FIRST AND SECOND PORTS IN SAID BODY COMMUNICATING WITH SAID FIRST AND SECOND CONDUIT MEANS RESPECTIVELY, MEANS DEFINING THIRD AND FOURTH PORTS IN SAID BODY COMMUNICATING WITH SAID THIRD AND FOURTH CONDUIT MEANS RESPECTIVELY, MEANS DEFINING FIFTH AND SIXTH PORTS IN SAID BODY, SAID FIRST AND THIRD PORTS BEING DIAMETRICALLY OPPOSITE EACH OTHER AS ARE RESPECTIVELY SAID SECOND AND FOURTH PORTS AND SAID FIFTH AND SIXTH PORTS, AND ALL THE PORTS