US3050042A

US3050042A - Steam generator organization

Info

Publication number: US3050042A
Application number: US727824A
Authority: US
Inventors: Edward L Kochey
Original assignee: Combustion Engineering Inc
Current assignee: Combustion Engineering Inc
Priority date: 1958-04-11
Filing date: 1958-04-11
Publication date: 1962-08-21
Anticipated expiration: 1979-08-21

Description

Aug. 21, 1962 E. L. KOCHEY STEAM GENERATOR ORGANIZATION Filed April 11. 1958 8 SheetsSheet 1 INVENTOR.

Edward L. Kochey ATTORNEY Aug. 21, 1962 E. 1.. KOCHEY 3,050,042

STEAM GENERATOR ORGANIZATION Filed April 11. 1958 a Sheets-Sheet 2 INVENTOR Edward L. Kochey BY ATTORNEY Fig. 2.

/n O////u/// 1962 E. L. KOCHEY 3,050,042

' STEAM GENERATOR ORGANIZATION Filed April 11. 1958 a Sheets-Sheet 3 I INVENTOR 36 Z I 1 Edward L. Kochey 50/ Fig. 3. U L' &

ATTORNEY Aug. 21, 1962 E. KOCHEY STEAM GENERATOR ORGANIZATION FiledApril 11. 1958 8 Sheets-Sheet 4 lNvENToR Edwu rd L. Kochey ATTORNEY Aug. 21, 1962 E. KOCHEY 3,050,042

STEAM GENERATOR ORGANIZATION Filed April 11. 1958 8 Sheets-Sheet 5 INVENTOR EDWARD L. KOCHEY EW M f w ATTORNEY 21, 1962 E. 1.. KOCHEY 3,050,042

STEAM GENERATOR ORGANIZATION Filed April 11. 1958 8 Sheets-Sheet 6 u u b FIG. 6 FIG. 7

r INVENTOR EDWARD L. KOCHEY 4o 2% A4 fm ATTORN EY Aug. 21, 1962 Filed April 11. 1958 E. L. KOCHEY 3,050,042

STEAM GENERATOR ORGANIZATION 8 Sheets-Sheet 7 um mull um 1M1] um IIIHL 5 IHII III]

INVENTOR EDWARD L. KOCHEY ATTORNEY 8 Sheets-Sheet 8 Filed April 11. 1958 INVENTOR EDWARD L.KOGHEY (w A oizxa ATTORNEY United States Patent 3,050,042 STEAM GENERATOR ORGANIZATION Edward L. Koehey, Princeton Junction, N.J., assignor to Combustion Engineering, Inc., New York, N.Y., a corporation of Delaware Filed Apr. 11, 1958, Ser. No. 727,824 7 Claims. (Cl. 122-406) This invention relates to high capacity vapor generators and particularly to such generators employing vapor heating elements which extend into and across a stream of hot gases which are generated in a furnace.

In modern high capacity steam generators it is neces sary to employ a large amount of steam heating surface, either superheater or reheater surface, in the form of tubular panels, elements or bundles which are subjected to and traverse the stream of hot gases generated in the furnace of the unit and which gases pass through the various passages of the unit on their way to being exhausted through a suitable stack. This gas stream passing through the unit does not have a uniform heat distribution across it. Traversely of the stream, either from front to rear or side to side, a varying amount of heat will be imparted to heat exchange surface contacted by the stream with this resulting from several factors that include variation across the gas stream of flow velocity, mass flow and/ or temperature. Throughout this application the term heating characteristics is employed to generically designate the many factors that attribute to this variation in heat transfer across the gas stream. This variation causes the steam heating surface over which these gases flow to be subjected to absorb more heat in one location than in another and accordingly may result in overheating the heat exchange elements in the zone of high heat absorption.

In order to offset this effect of the transverse variation of heat absorption the present invention provides for substantially reversing the flow pattern or location of the steam from one side of the gas stream to the other during the serial flow of the steam through the steam heating surface. With the invention this result is accomphshed in a simple and expeditious manner and in accordance therewith the steam heater is formed of two sections which are in serial flow relation and which are spaced from each other in the direction of the gas flow. The downstream section relative to the gas flow is disposed in the vertical gas pass of a conventionally shaped steam generator organization which has a configuration generally in the form of an inverted U. This section is comprised of numerous sinuously bent tubular elements which are disposed in vertical planes spaced across the width of the gas pass. The inlets of these tubes are connected with suitable inlet header while the outlets are connected with a header that is located between this gas pass and the furnace. Located vertically above this outlet header is another header that supplies the other section of the steam heater which is formed of tubular panels that extend down into the furnace and which are spaced across the width of the furnace. The inlets of these panels communicate with this other header and the two headers are connected together by vertically extending conduits which straddle the horizontal gas pass that extends from the upper end of the furnace with these conduits interconnecting the corresponding ends of these headers. Within the header to which the outlets of the tubes of the first-mentioned section of the steam heater are connected is a bafiie or partition which is constructed in such a manner as to divide the interior of the header into two separate chambers with these chambers being so arranged that the steam which enters the header from the tubes connected to one longitudinal half of the header leaves the header through the vertically extending conduit at ice the far end of the other half and the steam entering the header through the tubes connect to said other half leaves through the vertically extending conduit connected with the far end of said one half. Through this organization the respective transverse location of the steam flowing through the two sections of the steam heater is reversed with this reversal offsetting to a substantial extent the effect of the transverse variation in heating characteristics of the gas stream upon the steam heater. In a modified construction instead of having two vertically spaced headers a single header is employed. This header is positioned above the vertical gas pass and has the baffle disposed within it and the tubes of the two sections of the steam heater communicate with it in a manner so this same reversal of steam flow is had.

It is the object of this invention to provide an improved vapor generator organization which is effective to diminish the effect that transverse variations in heating characteristics of the combustion gas has on the steam heating surface over which it flows.

Other and further objects of the invention will become apparent to those skilled in the art as the description proceeds.

With the aforementioned objects in view, the invention comprises an arrangement, construction and combination of the elements of the inventive organization in such a manner as to attain the results desired as hereinafter more particularly set forth in the following detailed description of an illustrative embodiment, said embodiment being shown by the accompanying drawing wherein:

FIG. 1 is a vertical sectional view of a high capacity vapor generator that embodies the present invention with the lower portion of the furnace being eliminated for the sake of simplicity;

FIG. 2 is a sectional view taken from line 22 of FIG. 1 and shows the disposition of the low temperature section of the steam heater with the front wall of the gas pass within which this steam heater section is disposed being removed in order to show the elements of the heater;

FIG. 3 is a sectional view taken along line 33 of FIG. 1 and shows the relative positioning of the panels of the high temperature section of the steam heater and the connection of these panels with the inlet header;

FIG. 4 is a detailed perspective view partially broken away showing the interior construction of the outlet header of the low temperature section of the steam heater;

FIG. 5 is a vertical sectional view in the nature of that of FIG. 1 showing the upper portion of a. high capacity vapor generator and showing a modified form of the invention relative to that of FIG. 1 with this FIG. 5 embodiment employing only a single header intermediate the two sections of the heat exchanger rather tha two headers;

FIG. 6 is a sectional view taken from line 66 of FIG. 5 and is fragmentary in nature showing the spacing of the tube members across the vertical gas: pass and the connection of these tubes with the header as well as the connection of the supply tubes of the other steam heater section with this header;

FIG. 7 is a sectional view taken from line 77 of FIG. 5 and is also fragmentary in nature showing the spacing of the tube panels of the high temperature section of the steam heater across the horizontal gas pass and the disposition of and interconnection of the supply tubes for these panels;

FIGURE 8 is a sectional view taken along line 88 of FIGURE 5 showing in detail the tube connections to the headers;

FIG. 9 is a sectional view taken along line 99 of FIG. 8 showing in detail the tube connections with the common head-er;

- 3 7 FIG. 10 is a perspective view of the single header of the FIG. embodiment showing the tube connections and indicating in dotted lines the disposition of the bathe therewithin.

now to the drawings, wherein like reference characters are used throughout to'designatelike elements, and particularly to FIGS. 1-4 the illustrative embodiment of the invention depicted therein comprises-furnace in the lower portion of which fuel is introduced and with the combustion gases passing upwardly through the furnace and out the lateral outlet 12. This outlet is formed in the upper end of the rearwall 14 of the furnace and opposite front wall 116, with the horiontal gas pass 18 extending from this outlet and leading to the upper end of the gas pass 29 which extends downwardly alongside of the furnace in spaced relation with the furnace. The combustion gases leaving outlet 12 pass through a gas pass 18 and down gas pass 2%? with the gases being discharged from the bottom of this gas pass and then being directed to a suitable air heater (not shown) from which they are conveyed to a stack or other point of discharge. The flow of the combustion gases is indicated by arrows 22.

At the lower endof vertical gas pass 20 is economizer 2 4 and extending through the upper end of furnace 10 are superheater elements 26 with these elements being connected with additional superheater elements 28 in gas pass 18 andwith these elements 18 being connected with header 2.9 which conveys the superheated steam o. a. des r d, Poi t f u After a portion of the energy of the superheated steam has been utilized it is brought back to the team generator to have its energy level raised with the steam being reheated to a desired temperature by passing it through a reheater heat exchanger. This reheater is formed of a lowtemperature section 30 and a high temperature section 32 with these sections being in serial flow relation. The steam to be reheated enters header 34, passes through the tubular elements. of low temperature section 32 and. into outlet header 36. From this outlet header the steam passes upwardly to header 28 which serves as the inlet to high temperature reheater section 32. The steam is heated to its final desired temperature in this high temperature reheater section and is then conveyed to the desired point of use.

Lowtemperature reheater section 30 is in the form. of a tube bundle that is made up of a large number of tubes 35 that arein parallel flow relation and that are sinuously bent as shown in FIG. 1. A number of individual tubes 35 are disposed in successive common planes across gas pass 20 and internested, with there being four such tubesinternested in each such plane in thje FIG. 1. organization, The internested tubes may be said to define an element, identified as in FIG. 2, with this element being disposed in vertical planes that are spaced across the gas pass 20 from side wall 42 to side wall 44. The tubes of these spaced elements 40 have. their outlets connected with outlet header 36 as shown in FIGS. 1 and 2. with the tubes as connected to this header occupying the same relative position that they occupy within gas pass 20 and with the tube connections being in the lower portion of the drum.

Drums

36 and 38 are interconnected by the rather

large conduits

46 and 47 which connect the corresponding ends of the headers and which straddle horizontal gas p ass'lfl with the headers being sufficiently long for this purpose.

The high temperature reheater section 32 is comprised of a number of tubular panels 48 that extend downwardly into the upper end of furnace 10 and which are spaced as shown in FIG. 3 across the width of the furnace from sidewall 50 to side wall 52; The tubes of panels 48 have their inlets connected to one of the stub headers 54 and th e outlets to one of the headers 56. Steam is supplied to inlet headers 54 through the connecting or supply tubes 58 that extend from header 38 to the headers 54 as shown in FIG. 1 and with there being six such supply tubes 58 for each of the headers 54. These several supply tubes '58 for each of the headers 54 are circumferentially spaced in their connection with drum 38 and are disposed in a common transverse plane and the connection of these groups of supply tubes is such that the groups have the same relative position as the panels 49 which they supply. In other words, supply tubes 50 which supply the outermost panels 48 are connected at the outermost portion of the header 38 while those that are connected with progressively inwardly positioned panels are connected at progressively inward locations on header 38.

With this reheater construction, if there were no means to prevent it, the steam which passes through the elements 40 of low temperature section 30 would pass through panels 48 of high temperature section 32 which are in the same general location transversely of the stream of hot gases, i.e., the steam passing through the elements 40 at the left of gas pass 2! as viewed in FIG. 2 would pass through the panels 48 at the left of furnace 10 is viewed in FIG. 3 while the steam passing through the right hand element 40 would pass through the righthand panels 48. If this were the case the same steam would be passing through the elements in the high and low temperature sections of the reheater which were located in the high heat absorption Zone or region of the combustion gas stream that results from this stream of gases having nonuniform transverse heating characteristics as explained hereinbefore. This would cause the metal temperature in the high temperature section 32 to become substantially higher in these locations of high heat absorption than in other locations which may result in overheating and damaging these elements. In order to oifset to a substantial extent the etfect of thisvariation in heat absorption transversely of the combustion gas stream, outlet header 36 is provided with an internal construction which is effective to generally reverse the steam flow fromone side ofthe unit to the other in passing from the low temperature section 30 to the high temperature section 32 of the reheater so, that the steam flowing through low temperature section 30 will have an opposite transverse location upon its passage through high temperature section 32.

This internal comprises a plate 56 which has a width. only slightly smaller than the diameter. of header 36 and which extends between the. vertically extending

conduits

46 and 47. This plate has a helix or half twist at its center portion and transverse semicircular plates 61 are provided at each end to efiectively divide the header interior into two separate passages or

chambers

60 and 62. The steam from the tubes of elements 40 that are located left of the center of gas pass 261 (FIG. 2) and are accordingly connected with header 36 to the left of the center (FIG. 4)enters chamber 62 and passes to the right as indicated by the arrows and out conduit 47,while the steam from the remaining elements 40 the tubes of which are connected to the right of the center of header 36 as viewedin FIG. 4 enters chamber 60 and passes as indicated by the arrows to the left through header 36 and out conduit 46. The engagement of plate 56 with the inner wall surface of header 36 as well as the engagement of end plates 12 with this header need not be a perfect fluid tight juncture since a limited steam flow from either of the

chambers

60 or 62 to the other chamber will have no effect upon the overall effective operation of the invention. However, if it is desired, a tight wal-l juncture.

may be provided although tack welding to hold the bafiie plate and end plates in the proper position will be sufiicient.

Itwill be appreciated that in FIG. 3 only a few of the elements 40 have been shown with this being desirable in order that an uncomplicated illustration and showing may be had and that a better understanding of the invention produced.

The embodiment of FIGS. 5 through difiers from the embodiment of FIGS. 1 through 4 just described in that a single header identified as 70 is employed rather than two vertically spaced headers with this single header being disposed above vertical gas pass and transversely of this gas pass. The tubes that make up both the high temperature and low temperature reheater sections communicating with this header with the header having the spiral bafile therewithin so that a cross over of the steam flow is efiected as in the previously described embodiment.

In the embodiment of FIGS. 5 through 10 the low temperature reheater section is of a construction generally similar to the low temperature reheater section shown in FIGS. 1 and 2 except that reheater section 30" is located generally at the top of the vertical gas pass 29 with the tubes of this reheater section extending upwardly through the roof of the steam generator and being connected with header 70. This reheater section 30 is comprised of a large number of individual tubes with a number of these tubes being positioned in a common plane and internested as shown to form what may be termed an element 4% and with there being a large number of these elements spaced across the width of the gas pass 20 as indicated in FIG. 6. As illustratively disclosed each of the elements is comprised of four internested tubes. The tubes of the elements 40' are connected generally with the lower portion of header 70 as shown, with FIG. 10 illustrating the disposition of the elements 40 with relation to this header.

Within header 70 is positioned baffle 56 in the same manner as the previously described embodiment with this 'baiile having end plates 61 and being efiective to divide header 70 into the two

chambers

60 and 62. The group of elements 40' that are connected with header 70 at the left of the center as viewed in FIG. 10, with this group being identified as 72, communicate with chamber 62. This group is the group of elements 40' that make up approximately half of'steam super heater section 30' and with the location of the element 40 that make up this group 70 being located in gas pass 2! in a relation that correspond with their interconnection with header 70, or, in other words, as disposed in FIG. 10 they make up the left half of the low temperature section 30". The other half of the elements 40', identified in FIG. 10 as group 74, connect with chamber 60.

Extending from chamber 60 at the left of header 70 (FIG. 10) and connected with the upper region of header 70 are the supply tubes 58 which supply steam to the high temperature reheater section with this group of supply tubes being identified as 76. At the right of the center of header 70 is another group of supply tubes 58' with this group being identified as 78 and with this group communicating with chamber 62. Thus the steam entering header 70 through the group of element 72 leaves the header through the group of tubes 78 while the steam entering header 70 through the group of elements 74 leaves the header through groups of tubes 76 so that a lateral cross over of the steam flow is had.

The high temperature reheater section 48' is comprised of a plurality of tubular panels 86 that are spaced across the horizontal gas pass 18. Adjacent pairs of panels are connected with a common inlet header 82 and a common outlet header 84. The inlet headers 82 are supplied with steam from header 70 through the supply tubes 58' with the connection of these tubes to the header being in the same relative location as the panels to which they supply steam. This is best shown in FIGS. 7 and 8. Thus the steam from the left half of header 70 is supplied to the left half of high temperature reheater 48 as related to the header 70 in FIG. 10. This is so because panels 80 and groups 40 are in planes that are parallel to each other and header is normal to these planes.

It will be noted that in the modification of FIGS. 5 through 10 high temperature reheater section 48' is not positioned in the upper portion of furnace 10 but is positioned in horizontal gas pass 18 with the upper portion of the furnace having superheater 26' disposed therewithin.

While the invention has been described as applied to a reheater of a steam generator, since the problem is more acute in a reheater as a result of the lower heat transfer rate as compared with a superheater resulting from the lower steam pressure in the reheater, it will be understood that the invention is also applicable to superheaters or other vapor heaters to eliminate the deleterious efiect of unequal heat absorption transversely across the gas stream caused by the heating characteristics of the combustion gas.

While I have illustrated and described a preferred embodiment of my invention it is to be understood that such is merely illustrative and not restrictive and that variations and modifications may be made therein without departing from the spirit and scope of the invention. I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes as fall within the purview of my invention.

What I claim is:

1. A vapor generator including means for burning a fuel and forming a stream of hot combustion gases, a pair of substantially coextensive headers disposed with their longitudinal axes in spaced generally parallel relation, and disposed transversely of said gas stream, said headers being interconnected at their ends by a pair of parallel conduits, one of said headers having plate means therein including a portion extending longitudinally thereof and dividing it into a first chamber and a second chamber separate from said first and each of which extends longitudinally of the header with said first chamber communicating with one of said conduits at one end of the header and with a substantial circumferential and longitudinal portion of the header Wall on the opposite half of the header from said one end, and with the second chamber being oppositely arranged communicating with the other conduit at the other end of the header and with a substantial circumferential and longitudinal portion of the header wall at the opposite end, a number of steam heater elements spaced across said gas stream being effectively connected to said one header in spaced relation therealong in the same relative positions they occupy in gas stream, those connected with the longitudinal half of the header including said one end communicating with said second chamber and being out of communication with said first chamber and the remaining elements communicating with said first chamber and being out of communication with said second chamber, other steam heater elements in series flow relation with the first mentioned elements and similarly spaced across said stream and connected with the other header in spaced relation therealong in the same relative positions they occupy in the gas stream. I

2. A vapor generator including means for burning a fuel and forming a stream of hot combustion gases, said generator including means for heating vapor generated by the generator with this means including a first group of tubes disposed in said stream in planes parallel with the direction of the gas flow and comprising a first vapor heating section, a header generally normal to said planes,

outlets of said tubes communicating with said header at locations spaced along the length of the header and in the same general relative locations with respect to each other that the tubes occupy in said gas stream with those communicating with the header on one side of the longitudinal center communicating with one chamber and those communicating with the other side communicating with the other chamber, a second group of tubes displaced from said first with relation to the direction of gas flow but similarly oriented with relation to the gas flow, the second group of tubes having inlets with the inlet of these tubes corresponding with the tubes of the first group that communicate with the header at said one side of the longitudinal center also communicating with said header at said one side but with said other chamber, and the inlets of the remaining tubes in said second group communicating with the other side of the header but with said one chamber.

3. In a vapor generator wherein two groups of parallel flow vapor heating tubes are positioned in a stream of hot combustion gases with the tubes of each group being positioned in spaced parallel planes across the gas stream and the two groups being spaced in the direction of the gas flow, the tubes of the two groups being similarly oriented with relation to the stream of combustion gases, means interconnecting the two groups for. serial vapor flow and in such a manner that the vapor passes through tubes of the two groups located in different relative positions in the gas stream, said means including a pair of parallel, laterally spaced headers to one of which is connected the tubes of one group and to the other of which is connected the tubes of the other group with the tubes being connected to the headers in spaced relation therealong and in their same relative positions theyv occupy in the gas stream, a pair of spaced parallel conduits interconnecting the ends of one of said headers with the corresponding ends of the other, plate means disposed within one of said headers including a portion extending longitudinally thereof and cooperating with the walls of the header to form a first chamber thatprevents communication of the conduit and the tubes connected to the same longitudinal half of the header as the conduit while permitting communication with the other tubes and a second chamber which has the sameeffect with regard to the conduit connected with their other half of the header.

4. The organization of claim 3 wherein the plate means includes aplate longitudinally disposed in the header and the longitudinal edges of which engage-the header wall with the plate being provided with a generally half twist generally centrally intermediate its ends. a

5. A vapor generator comprising an upright elongated furnace having a front and rear wall interconnected by a pair of spaced side walls with the furnace having a lateral outlet at its upper end in the rear wall for egress of combustion gases,'a gas passageway communicating with said outlet and extending down alongside said-furnace, a first vapor heater comprised of tubes in parallel flow relation disposed in the upper portion of the furnace'in vertically disposed and horizontally spaced planes which planes extend from front to rear of the furnace, a header at the upper end of the generator and generally normal to said planes, said tubes communicating with said header at a location corresponding with their relative location in the furnace and in longitudinal rows along the header, a second vapor heater positioned in said passageway and also comprised of tubes in parallel flow relation and in spaced planes disposed similarly to those of the first heater, a second header laterally adjacent said passageway and normal to said planes, the tubes of said second vapor heater communicating with said second header at a location corresponding with their relative location in the passage and in longitudinal rows along the header, a pair of parallel conduits interconnecting the corresponding ends of the two headers, and plate means disposed longitudinally within one of said headers and effective to divide the same into two chambers such that the tubes communicating with the header at locations generally on each side of the center are prevented from communicating with said conduit connected with said header on the same side of the center but permitted to communicate with the conduit on the opposite side of the center.

6. The organization of claim 5 wherein said plate means includes an elongated plate extending across the header and being helical generally at its center.

7. A vapor generator comprising an upright elongated furnace having a front and rear wall interconnected by a pair of spaced side walls with the furnace having a lateral outlet at its upper end in the rear wall for egress of combustion gases, a lateral oiftake extending from said outlet and a gas passageway extending down from the end of said offtake and alongside said furnace in spaced relation therewith, vapor heating tubular panels extending down into the furnace and disposed in vertical planes extending from front to rear of the furnace and spaced across the furnace, a vaporheater in the gas passageway in the form of a tube bundle comprised of numerous sinuously bent tubes in parallel flow relation and in spaced planes disposed similar to those of said panels, a header for these latter tubes, said header being normal to said planes and positioned below said ofitake and intermediate said gas passageways and said furnace with the header extending beyond the sides of said otftake, the tubes of said bundle .being connected with their relative location in the passageway, another header parallel with the first mentioned header and positioned above said offtake, this latter header also extending beyond the sides of said olftake, said panels communicating with this latter header in spaced relation therealong and in thesame relative relation they occupy in the furnace, generally vertical conduits interconnecting the corresponding ends of said header and disposed on opposite sides of the ofitake, plate means in one of said headers having a portion extending longitudinally thereof-and effective to prevent communication of the conduit and the tubes communicating with the same longitudinal half of the header while permitting communication of the conduit and the tubes communicating with opposite longitudinal halves of the header whereby a reversal of steam flow is effected across the unit.

References Cited in the file of this patent UNITED STATES PATENTS Robinson Mar. 31, 1936 Wood Aug. 10, 1943