US3429371A - Surface condenser - Google Patents

Description

Feb. 25, 1969 w. E. PALMER ET AL 3,42%,371

SURFACE CONDENSER Filed Oct. 10, 1967 AGENT INVENTORS WILLIAM E. PALMER LESLIE L. FORSTER fizw/r FIG. 2

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3,429,371 SURFACE CONDENSER William E. Palmer and Leslie L. Forster, Easton, Pa., as-

signors to Ingersoll-Rand Company, New York, N.Y., a corporation of New Jersey Filed Oct. 10, 1967, Ser. No. 674,221 US. Cl. 165-112 9 Claims Int. Cl. F28b 9/10 ABSTRACT OF THE DISCLOSURE This invention relates to surface condensers, and more particularly to a surface condenser having an inlet for an auxiliary steam supply for reheating of the condensate.

In the prior art there are surface condensers which utilize a portion of the primary steam supply for reheating and deaerating the condensate. However, what has been needed is a condenser which permits the use of steam at higher temperatures, and also during start-up, to perform a superior reheating and deaerating function.

To achieve the foregoing improvements, it is the teaching of US. Patent No. 2,542,873 to A. D. Karr for Multistage Deaerating and Reheating Hot Well for Steam Condensers, issued Feb. 20, 1951, to add an auxiliary and constant input from some related source. In accordance with the Karr patent, a heating fluid or vapor, from some constant source is introduced to reheat the condensate. Now, most industrial installations will have a plurality of possible secondary sources, operating under variable loads, which are steam driven and which expel the spent steam and heat to some other condensing medium, or as waste.

Steam from such secondary sources (for instance, a turbine which drives a boiler feed pump) requires condensation, and might well serve the purpose of reheating the condensate. Yet, contemporary plant installation designs suggest that these auxiliary sources be exhausted into the main condenser which serves the generating turbine. But here, the pressure and heat of the secondary steam sources are lost in the main condensing cycle. As the secondary steam sources proceed from equipments which exhibit greatly varying loading, the steam flow therefrom will vary greatly. Heretofore, then, it has not been known how to use such sources as a means in the reheating of the condensate, how to salvage and make use of the otherwise wasted heat, steam, and temperature there available, and how to profit from these two fuelsaving benefits while also condensing the steam from such sources without providing a separate condenser and without using the condenser tubes of the main condenser.

The Karr patent advanced a means of reheating the condensate, by using hot spillage from some associated equpiment. Clearly, the auxiliary supply, according to the Karr teaching, must be from a constant supply source, as the patented structure has no means to accommodate for pressure fluctuations arising from variances in steam flow from a greatly varying auxiliary supply and demand. This is evident from the fact that the condenser structure has but a simple orifice means, or fixed internal diameter, through-connecting the condensing chamber with the reheating deaeration chamber.

It is an object of this invention, then, to set forth a 3,429,371 Patented Feb. 25, 1969 condenser, in which means are provided for reheating the condensate and comprising use of an auxiliary and variable-flow steam source to that end. Another object of this invention is to provide means to accommodate the reheating chamber automatically for fluctuations in pressure developed therein 'which arise from the variances in the steam flow from the auxiliary steam source and the condenser pressure.

A feature of this invention is the introduction of steam from one of such auxiliaries, albeit a variable-source auxiliary, to the condenser housing in the immediate vicinity of the reheatting-deaeration equipment.

Another feature of this invention is in the deployment of a trough between the main condenser section and the reheating section to collect fill water to provide sealing between the sections and to discharge the fill water therefrom to provide communication between the sections therethrough so as to accommodate, for pressure fluctuations arising from variances in steam flow from a greatly varying, auxiliary supply and condenser pressure.

The foregoing and further objects and features of this invention will become more apparent by reference to the following discussion taken in conjunction with the accompanying figures in which:

FIGURE 1 is an elevational view in cross-section of the condenser according to the invention;

FIGURE 2 is a partial cross-sectional view of the pressure accommodating means of the condenser in FIG- URE l; and

FIGURE 3 is a partial cross-sectional view of another embodiment of a pressure accommodating means for the condenser of FIGURE 1, wherein:

In FIGURE 1 the condenser according to the invention is shown having a housing 1 with a primary steam inlet 2 which conducts the primary steam over the condenser tube bundles 3 which are supported centrally in the condenser. Disposed beneath the bundles is a hotwell 4 having spillways 5 which pass the condensate to a lower weir 6. The lower weir has spillways 7 which further conduct the condensate to a lower reservoir 8 disposed in the bottom of the condenser. The hotwell 4 and lower weir 6 divide the condenser into two compartments, a reheatingdeaerating compartment 9,, and a primary condensing compartment 10. Formed in the wall of the condenser housing 1 is an auxiliary steam inlet 11. This is the inlet from the variable steam source which, according to the invention, is used to re-heat condensate as it flows from :spillways 7. An outlet 12 provides means for passing the condensate out of the condenser for re-use. Pressure accommodating means 13 is disposed in one or more sides of the condenser and comprises a series of surmounting troughs. The first, second and third trough members 14, 15, and 16, respectively, form troughs 14, 15', 16', which are best illustrated in FIGURE 2. Each of the troughs has associated therewith automatic fill valves, these being fill valves 17, 18, and 19. The troughs also have associated therewith automatic drain valves 20, 21, and 22. The pressure accommodating means 13 comprises the arrangement of valves and a pressure sensor and control device 23. The control device has a high pressure line 24 and a low pressure line 25 by means of which it is joined to the two compartments 9 and 10. In FIGURE 2, it is seen there are coupling means 26 proceeding from the control device 23 to valves 17, 18 and 19. Further there are couplin means 27 joining valves 20, 21, and 22 to the control device 23. A water fill line 28, communicating the condensate in the hotwell 4 with the troughs 14, 15, and 16, passes through valves 17, 18, and 19, or any one thereof, depending upon the actuation of the control device 23. Divider wall 29 separates trough 16 into a low pressure water level 30 and a high pressure water level 31. The two levels are derived from pressure differentials in the two compartments. Further, trough member 16 divides trough 15' into high and low pressure levels 32 and 33 respectively. Trough 14' is also dividable into high and low pressure levels by means of trough member 15. However, in the condenser mode of operation illustrated, trough 14' is used as a means of providing communication between the two compartments.

FIGURE 3 shows another embodiment of a pressure accommodating means 13' which may be practiced with the novel condenser. In this a pressure differential control device 34 is used to correct the pressure differential between the two compartments. High pressure line 35 and low pressure line 36 are joined to the control device 34. Fill valve 38 receives condensate from fill line 39 or from some separate source. In this embodiment only one trough member 40 is used to form a single trough 40'. Valve 41 discharges water from trough member 40, and appropriate coupling means 42 and 43 provide device 34 with means for operating valves 38 and 41. Again, as in the prior embodiment, the trough is dividable into high and low levels by means of the divider wall 29. However, the existing pressure differential can be computed as a function of the aperture of passageway 44 defined by the terminal end of the divider wall 29 and the level of water in trough 40'. As the pressure differential varies from the optimum range, the pressure accommodating means 13' senses this and opens or closes valves 38 and 41 to maintain the correct aperture 44 for optimum pressure differential. The operation, through which this function is performed, is detailed in the following discussion.

The primary steam inlet 2 exhausts its steam into compartment 10 where tube bundles 3 are located in a horizontal attitude in the condenser housing 1. The primary steam introduced into compartment 10 will be condensed upon these tubes and fall by gravity to the hotwell 4. The condensate thus formed will pass therefrom to the lower weir 6. The condensate divides into a multiplicity of falling streams from spillways and 7 to reheat and deaerate the condensate, this in a manner practiced in prior art.

In accordance with the invention, steam from an auxiliary source of variable flow is introduced through inlet 11. The auxiliary inlet 11 is so situated that steam enters the condenser in the immediate vicinity of the reheating and deaerating equipment. This steam is directed to flow through the falling condensate streams. By contact of the steam with the streams, reheating of the condensate is accomplished together with deaeration thereof. Pressure accommodating means 13 are so arranged as to permit any excess steam to flow therethrough and eventually up into the bottoms of the tube bundles 3. In the tube bundles, the excess steam and noncondensibles are handled in a conventional manner.

The pressure accommodating means 13, disposed between compartments 9 and 10, is further designed to allow the pressure in compartment 9 to be greater than the pressure in compartment and to maintain an optimum pressure differential therebetween, regardless of fluctuations in pressure and steam flow from inlet 11 or variations in condensing pressure in compartment 10. The condensate leaving chamber 10 will pass through the steam atmosphere in compartment 9. Due to the steam flow from inlet 11, compartment 9 is at a relatively greater temperature level, and thereby a transfer of heat from the additional steam flow to the falling condensate will occur. Further, there will be direct condensing action, in compartment 9 where, in the heat transfer, the additional steam flow is condensed by the cooler, falling condensate.

The novel pressure accommodating means 13, as more fully illustrated in FIGURE 2, automatically maintains an optimum pressure differential between compartments 10 and 9. Such an optimum condition is presumed to exist, in the condenser, for the status of the components as shown. Thus, trough 14' provides for some communication between the two compartments, and troughs and 16' provide a partial water seal, Device 23 senses a pressure differential which occurs between adjustable limits and, by way of coupling means 26, holds valves 17, 18, and 19 in a closed position, and valve 20 in an open condition. Device 23, accordingly, holds valves 21 and 22 closed, and at some prior moment had opened valves 17 and 18 to fill troughs 15' and 16.

In the event of excess steam and pressure from the auxiliary inlet 11 (FIG. 1), device 23 will respond to provide broader through connecting means between the compartments through which the excess may pass to the upper compartment 10. Under such conditions, device 23 will open valve 21, to discharge the water seal in trough 15'. Should this not bring the condenser to the optimum pressure differential, device 23 will open valve 22 also, to discharge the water seal in trough 16'. As the pressure differential proceeds to achieve the optimum again, or as the steam and pressure in flowing from the auxiliary inlet slackens, device 23 will accommodate for the changes. Thus, device 23 will close either one or both valves 21 and 22 and open one or both valves 17 and 18. When sufficient water seal has been achieved, as reflected in the pressure differential, device 23 recloses valves 17 and 18.

It is a teaching of our disclosure to propound several embodiments, any of which are within the spirit of our invention. Thus, the valving shown in FIGS. 1 and 2 might be manually operated, and the effects thereof monitored by sight-level gauges. Further, the fill water might be derived from sources external to the condenser and, on discharging the fill water-50 as to open the water sealthe discharge valves can be vented external to the condenser. Embodiments drawn from the teachings of our invention, according to FIGS. 1 and 2, can use any plurality of surmounting troughs; three troughs are illustrated, but this is arbitrary.

Only by way of example, our disclosure teaches a further embodiment of the invention. As shown in FIGURE 3, the pressure accommodating means 13' can be such as responds to the fill water level. In this embodiment, the fill water level either constricts or widens the passageway 44 which communicates compartments 10 and 9. The water level will be a function representative of the interface, between the high-pressure compartment 9 and the lower-pressure compartment 10, occurring at the passageway 4-4. If excess steam from inlet connection 11 causes the differential pressure between compartments 9 and 10 to increase beyond the optimum, the pressure differential control device 34 will sense this and will close valve 38 and open drain valve 41 until equilibrium of optimum pressure differential is reached. Similarly, if the pressure differential between compartments 9 and 10 falls below the optimum, the pressure differential control device 34 will cause [fill valve 38 to open and drain valve 41 to close. At normal steady conditions in the optimum pressure differential range, both the fill valve 68 and drain valve 41 will be closed. In this embodiment, a closer, and less grossly-graduated control can be maintained over the pressure differential. Obviously, the devices 23 and 34 might be supplanted by electrical or fiuidic control devices or a float operated valve actuated by the water level. Still further alternate embodiments of the teachings of our invention will occur to those skilled in the art.

This invention, then, teaches a condenser structure which conserves heat energy, in a power plant cycle, by returning a greater amount of heat to the condensate, heat which would otherwise be lost as vented waste, or lost through condensing action on the condenser tubes of the primary condenser compartment.

This invention teaches condenser structures which derive the foregoing benefits from otherwise heretofore lost energy, and further advances the efiiciency of power plant start-up. Auxiliary steam sources, such as are used to supply steam, heat, and pressure to the auxiliary inlet of the novel condenser structure, are generally in operation before the primary turbine-generator set is started. Thus, by means of the auxiliary inlet, the reheating-deaerating cycle for the condensate of the primary steam will be initiated before the major portion of the plant cycle is in operation.

While we have described our invention in connection with specific apparatus, it is to be clearly understood that this is done only by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof and in the accompanying claims.

We claim:

1. A condenser, comprising:

a condenser housing;

said housing having first input means for a first source of steam flow, second input means for a second source of variable steam flow, means forming first and second compartments in said housing, means disposed within said compartments for condensing steam from said first and second sources, means disposed in at least one of said compartments for deaerating the condensate, means disposed in at least one of said compartments for reheating the condensate, and means disposed between said compartments to seal therebetween, automatically, and to provide variable degrees of communication therebetween, automatically. 2. A condenser according to claim 1, further comprising:

a reservoir disposed within said housing; and

wherein said compartment-forming means comprise a hotwell disposed across said housing and supported by walls of said housing to collect condensate and to permit flow therefrom to said reservoir.

3. A condenser, according to claim 1, wherein:

said first input means addresses steam to said first compartment, and said second input means addresses steam to said second compartment.

4. A condenser, according to claim 1, wherein:

said condensing means comprise first and second means for condensing said steam, said first condensing means being disposed in said first compartment and said second condensing means being disposed in said second compartment.

5. A condenser, according to claim 1, wherein:

said seal and communication means comprises means which automatically sense a pressure differential existing between said first and second compartments, and control means automatically responsive to said sense means for providing greater water sealing between said compartments, and less water sealing therebetween.

6. A condenser, according to claim 5, wherein:

said control means further provide for greater and less communication between said compartments.

7. A condenser, according to claim 1, wherein:

said seal and communication means comprise trough means carried by said walls and disposed between said compartments, water input means disposed adjacent to said trough means, water discharging means coupled to said trough means, pressure sensing and control means coupled to said first and second compartments and coupled to both said water input and discharging means to admit water via said Water input means to said trough means and to discharge Water from said trough means via said water discharging means, automatically.

8. A condenser, according to claim 7, wherein:

said trough means comprise a plurality of surmounting and spaced troughs.

9. A condenser, according to claim 1, wherein: said seal and communication means comprise a trough UNITED STATES PATENTS 2,542,873 2/1951 Karr 165113 3,194,021 7/1965 Peake et a1 6095 3,204,692 9/1965 Smith 60-95 X 3,363,678 1/1968 Forster et a1 165-112 LLOYD L. KING, Primary Examiner.

ALBERT W. DAVIS, Assistant Examiner.

US. Cl. X.R.

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