US3312198A - Steam generator having improved steam heating sections arranged for parallel flow - Google Patents

Steam generator having improved steam heating sections arranged for parallel flow Download PDF

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Publication number
US3312198A
US3312198A US515880A US51588065A US3312198A US 3312198 A US3312198 A US 3312198A US 515880 A US515880 A US 515880A US 51588065 A US51588065 A US 51588065A US 3312198 A US3312198 A US 3312198A
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US
United States
Prior art keywords
tubes
flow
section
steam
reheater
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US515880A
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English (en)
Inventor
Herbert M Eckerlin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Combustion Engineering Inc
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Combustion Engineering Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Combustion Engineering Inc filed Critical Combustion Engineering Inc
Priority to US515880A priority Critical patent/US3312198A/en
Priority to GB53228/66A priority patent/GB1152066A/en
Priority to ES0333978A priority patent/ES333978A1/es
Priority to NL6617190A priority patent/NL6617190A/xx
Priority to FR87089A priority patent/FR1503491A/fr
Priority to BE691062D priority patent/BE691062A/xx
Application granted granted Critical
Publication of US3312198A publication Critical patent/US3312198A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B35/00—Control systems for steam boilers
    • F22B35/06—Control systems for steam boilers for steam boilers of forced-flow type
    • F22B35/10—Control systems for steam boilers for steam boilers of forced-flow type of once-through type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B29/00—Steam boilers of forced-flow type
    • F22B29/06—Steam boilers of forced-flow type of once-through type, i.e. built-up from tubes receiving water at one end and delivering superheated steam at the other end of the tubes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22G—SUPERHEATING OF STEAM
    • F22G1/00—Steam superheating characterised by heating method
    • F22G1/06—Steam superheating characterised by heating method with heat supply predominantly by radiation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22G—SUPERHEATING OF STEAM
    • F22G7/00—Steam superheaters characterised by location, arrangement, or disposition
    • F22G7/14—Steam superheaters characterised by location, arrangement, or disposition in water-tube boilers, e.g. between banks of water tubes

Definitions

  • the invention relates in general to large steam generators equipped with steam superheater and/or steam superheater and steam reheater.
  • the invention is more specifically concerned with a steam generating furnace chamber having walls lined with upright fluid cooled tubes, and in which a portion of the tubular wall lining is sup plemented by superheater or reheater radiant wall heating surfaces.
  • the terminal temperature difference i.e., the difference between the temperature of the combustion gases at the gas pass terminal end and the temperature of the fluid flowing through heat absorbing surfaces that are the last ones touched by these gases, approaches a level which violates good, economic design.
  • the present invention overcomes the above difficulties by dividing the steam heater such as superheater or reheater into two sections which are arranged for parallel flow, with one section constituting the radiant heat absorbing part lining a portion of the furnace wall, and the other section constituting a convection heat absorbing part located in the rear gas pass of the boiler.
  • the physical characteristics of the radiant section such as tube diameter, tube spacing and number of tubes can be selected so as to conveniently accommodate the tube diameter and spacing of the waterwall tubes lining other parts of the furnace walls, without excessive and costly offsetting of tubes.
  • these dimensions can now be chosen freely so as to limit the pressure drop through the reheater to an optimum and economic value.
  • the temperature of the fluid leaving each parallel steam heater section can now be held within allowable limits by the proper selection of tube diameter and steam flow to avoid overheating of the radiant tube wall.
  • FIG. 1 is a schematic representation of a steam generator equipped with a radiant wall reheater section and .a reheater low temperature convection section, and showing means for controlling the steam temperature by regulation of the respective steam flow through these sections;
  • FIG. 2 is an elevational view of the tubes lining the front furnace wall, and including the tubes of a radiant wall reheater section;
  • FIG. 3 is an elevational view of a radiant wall section of the reheater showing the tube and tube bends as repre sented by centerlines;
  • FIG. 4 is an elevational section through the front furnace wall when taken on line 44 of FIG. 2;
  • FIG. 5 is a plan section through the furnace wall when taken on line 55 of FIG. 4;
  • FIG. 6 is a plan section through the furnace wall similar to that shown in FIG. 5, however, showing the reheater radiant wall tubes in staggered rows.
  • a steam generator 10 comprising a furnace chamber 12 having walls lined with closely spaced water carrying tubes 14.
  • the furnace 12 received fuel and air 'by way of burners 16 for burning and production of combustion gases. These hot gases rise in the furnace and are partially cooled by the furnace wall tubes including the tubes 18 of the radiant reheater wall section 19 which line the upper part of the front wall 20 of the furnace. These gases then sweep over the tubular heating surfaces of the final or finishing section 22 of the reheater, pass into a horizontal gas offtake duct 24 and flow downwardly through a rear gas pass 26.
  • Gas duct 24 contains a high temperature superheater section 28, and rear pass 26 has located therein a low temperature superheater section 29 followed by a low temperature reheater convection section 30. After transferring heat to these heating surfaces the gases may pass over additional conventional heat exchangers such as an economizer and an air heater (not shown) and are then discharged into the atmosphere by a stack, not shown.
  • additional conventional heat exchangers such as an economizer and an air heater (not shown) and are then discharged into the atmosphere by a stack, not shown.
  • the working fluid cycle comprises a feedwater source from which feedwater is conducted to the steam evaporating surfaces of the steam generator such as waterwall tubes 14.
  • the evaporated steam then passes to a superheater such as low temperature superheater 29 and high temperature or finishing superheater 28, from whence the steam is conducted to a point of use such as the high pressure stage of a steam turbine, not shown.
  • the steam is returned at lower pressure and temperature to a reheater for reheating, such as to low temperature reheater sections 19 and 3t and high temperature reheater section 22, and thence may be conducted to the low pressure stage of the turbine for final conversion of the thermal energy thereof Into mechanical and electrical energy.
  • a reheater for reheating such as to low temperature reheater sections 19 and 3t and high temperature reheater section 22, and thence may be conducted to the low pressure stage of the turbine for final conversion of the thermal energy thereof Into mechanical and electrical energy.
  • the front wall 20 of the furnace 12 is lined with waterwall tubes 14.
  • the upper part of the front wall 20 is, in addition, lined with the tubes 18 of the radiant wall reheater section 19.
  • These tubes 18 originate in inlet header 32 which receives steam from the high pressure turbine stage by way of conduit 33, with these tubes passing through the furnace wall as shown in FIG. 4.
  • the waterwall tubes 14 which are closely spaced in the lower portion of the furnace chamber 12, as shown in FIG. 2, are bifurcated at 34 to facilitate passage therebetween of tubes 18 which are then bent upwardly as shown in FIG. 4 and are suitably offset as shown in FIG. 3 to form a wall panel of closely spaced tubes located directly in front of the now widely spaced waterwall tubes 36 that have issued from bifurcates 34.
  • the diameter and spacing of the waterwall tubes 14 and those of the radiant reheater wall tubes 18 are substantially the same.
  • only every other tube 18 passing between tubes 36 must be offset, however, with the offset dimensions of each tube being identical.
  • a similar simplified tube arrangement is possible according to the invention at the points where the reheater tubes 18 pass through the tubes 38 forming the roof of the furnace chamber as shown in FIGS. 3 and 4. These tubes instead are being bifurcated as are tubes 14, are offset as shown at 39 to provide a space for two reheater tubes 18 to pass therethrough. Again, only one of a pair of tubes 18 must be offset with the offsets being identical.
  • This steam after being reheated to a moderate extent by passing through reheater convection section 30, is thereafter conducted to a point 41 in the link 42 connecting the outlet of reheater radiant section 19 with the inlet of the finishing reheater 22.
  • the relatively low temperature reheated steam flowing from convection reheater section 30 is intermixed with the relatively high temperature reheated steam flowing from radiant wall reheater section 19.
  • the steam mixture then passes through finishing reheater 22 for heating to a final predetermined temperature before being conducted by way of conduit 44 to a point of use such as the low pressure stage of the steam turbine.
  • flow controlling devices are provided in conduits 33 and 40 such as valves 46 and 48, respectively.
  • a temperature indicating device 50 is installed to obtain indications of the temperature of the steam leaving radiant section 19 such as at point 51 in link 42.
  • a temperature indicating device 52 is installed to obtain indications of the temperature of the reheated steam leaving finishing reheater section 22, such as at a point 53 in outlet conduit 44.
  • These temperature indicating devices 50 and 52 are operationally connected by well known electrical, hydraulic, or other means to actuators 54 and 55 of valves 46 and 48, respectively.
  • These connecting means are organized for transmission of control signals originating in temperature indicating devices 50 and/ or 52 to valve actuators 54 and 56 for regulating the flow of steam to reheater radiant section 19 and reheater convection section 30 in response to temperature variations of the reheated steam at the temperature measuring points 51 and/or 53.
  • valve 46 is actuated to permit an increased flow through reheater radiant section 19, and valve 48 is actuated to correspondingly reduce the flow through reheater convection section 30.
  • valve actuators 54 and 5s upon exceeding this limit impulses are transmitted from temperature recorder 52 to valve actuators 54 and 5s, respectively, to decrease the steam flow through reheater radiant section 19 and to increase the flow through reheater convection section 30.
  • impulses are transmitted from temperature recorder 52 to valve actuators 54 and 56, respectively, to increase the steam flow through reheater radiant section 19 and to decrease the flow through reheater convection section 36.
  • FIG. 6 there is shown an arrangement of radiant reheater tubes wherein the tubes are disposed in two staggered rows 58, instead of one solid row as shown in FIG. 5.
  • the arrangement shown in FIG. 6 permits a more uniform heat absorption by both waterwall tubes 36 and radiant reheater tubes 58.
  • a vapor generator having an elongated furnace chamber defined by fluid cooled tube-lined walls, the combination of one section of said walls being lined with a plurality of upright tubes parallelly spaced, with said first tubes being cooled by the flow therethrough of a relatively low enthalpy fluid; another section of said walls adjoining said first section being lined with a plurality of upright second tubes parallelly spaced, with said second tubes being cooled by the flow therethrough of a first quantity of relatively high enthalpy fluid; means for producing a stream of hot gases for flowing over said tube-lined walls in heat exchange relation therewith and for partially cooling said gases; a gas offtake duct adjoining one end of said furnace chamber for receiving said partially cooled gases; first tubular heat absorbing surfaces provided in said duct for additional cooling of said gases; means for flowing a second quantity of high enthalpy fluid through said first tubular heating surfaces in parallel flow relation with the flow of said high enthalpy fluid through said second tubes; second heat absorbing surfaces provided in said gas stream in heat
  • a vapor generator having an elongated furnace chamber defined by fluid cooled tube-lined walls, the combination of one section of said walls being lined with a plurality of upright tubes parallelly spaced, with said first tubes being cooled by the flow therethrough of a relatively low enthalpy fluid; another section of said walls adjoining said first section being lined with a plurality of upright second tubes parallelly spaced, with said second tubes being cooled by the flow therethrough of a first quantity of relatively high enthalpy fluid; means for producing a stream of hot gases for flowing over said tube-lined walls in heat exchange relation therewith and for partially cooling said gases; a gas ofltake duct adjoining one end of said furnace chamber for receiving said partially cooled gases; first tubular heat absorbing surfaces provided in said duct for additional cooling of said gases; means for flowing a second quantity of high enthalpy fluid through said first tubular heating surfaces in parallel flow relation with the flow of said high enthalpy fluid through said second tubes; second heat absorbing surfaces provided in said gas stream in heat

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Control Of Steam Boilers And Waste-Gas Boilers (AREA)
US515880A 1965-12-23 1965-12-23 Steam generator having improved steam heating sections arranged for parallel flow Expired - Lifetime US3312198A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US515880A US3312198A (en) 1965-12-23 1965-12-23 Steam generator having improved steam heating sections arranged for parallel flow
GB53228/66A GB1152066A (en) 1965-12-23 1966-11-28 Steam Generator
ES0333978A ES333978A1 (es) 1965-12-23 1966-11-30 Un generador de vapor.
NL6617190A NL6617190A (fr) 1965-12-23 1966-12-07
FR87089A FR1503491A (fr) 1965-12-23 1966-12-12 Générateur de vapeur
BE691062D BE691062A (fr) 1965-12-23 1966-12-12

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US515880A US3312198A (en) 1965-12-23 1965-12-23 Steam generator having improved steam heating sections arranged for parallel flow

Publications (1)

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US3312198A true US3312198A (en) 1967-04-04

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US515880A Expired - Lifetime US3312198A (en) 1965-12-23 1965-12-23 Steam generator having improved steam heating sections arranged for parallel flow

Country Status (6)

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US (1) US3312198A (fr)
BE (1) BE691062A (fr)
ES (1) ES333978A1 (fr)
FR (1) FR1503491A (fr)
GB (1) GB1152066A (fr)
NL (1) NL6617190A (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4398504A (en) * 1980-01-23 1983-08-16 Combustion Engineering, Inc. Steam generating heat exchanger
US20100288210A1 (en) * 2007-11-28 2010-11-18 Brueckner Jan Method for operating a once-through steam generator and forced-flow steam generator
US20110162592A1 (en) * 2008-09-09 2011-07-07 Martin Effert Continuous steam generator

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0075041B1 (fr) * 1981-09-15 1986-03-05 GebràœDer Sulzer Aktiengesellschaft Générateur de vapeur avec une paroi tubulaire de surchauffe
FR2800440B1 (fr) * 1999-10-28 2001-11-30 Alstom Energy Sys Sa Echangeur mural, pour foyer de chaudiere, constitue de tubes dont l'entree et la sortie sont situees dans la partie basse de l'echangeur

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2834326A (en) * 1952-08-26 1958-05-13 Babcock & Wilcox Co Vapor generating and superheating unit, and method effected thereby
US2869521A (en) * 1955-03-16 1959-01-20 Babcock & Wilcox Co Apparatus for generating and superheating steam
US2902982A (en) * 1953-06-26 1959-09-08 Babcock & Wilcox Co Forced circulation vapor generating units

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2834326A (en) * 1952-08-26 1958-05-13 Babcock & Wilcox Co Vapor generating and superheating unit, and method effected thereby
US2902982A (en) * 1953-06-26 1959-09-08 Babcock & Wilcox Co Forced circulation vapor generating units
US2869521A (en) * 1955-03-16 1959-01-20 Babcock & Wilcox Co Apparatus for generating and superheating steam

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4398504A (en) * 1980-01-23 1983-08-16 Combustion Engineering, Inc. Steam generating heat exchanger
US20100288210A1 (en) * 2007-11-28 2010-11-18 Brueckner Jan Method for operating a once-through steam generator and forced-flow steam generator
US9482427B2 (en) * 2007-11-28 2016-11-01 Siemens Aktiengesellschaft Method for operating a once-through steam generator and forced-flow steam generator
US20110162592A1 (en) * 2008-09-09 2011-07-07 Martin Effert Continuous steam generator

Also Published As

Publication number Publication date
GB1152066A (en) 1969-05-14
FR1503491A (fr) 1967-11-24
ES333978A1 (es) 1967-10-16
BE691062A (fr) 1967-06-12
NL6617190A (fr) 1967-06-26

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