US3262431A - Economic combination and operation of boiler throttle valves - Google Patents

Economic combination and operation of boiler throttle valves Download PDF

Info

Publication number
US3262431A
US3262431A US267512A US26751263A US3262431A US 3262431 A US3262431 A US 3262431A US 267512 A US267512 A US 267512A US 26751263 A US26751263 A US 26751263A US 3262431 A US3262431 A US 3262431A
Authority
US
United States
Prior art keywords
pressure
flow
valve
superheater
section
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
US267512A
Other languages
English (en)
Inventor
Frederick J Hanzalek
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
Original Assignee
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
Priority to GB1052417D priority Critical patent/GB1052417A/en
Priority to NL133605D priority patent/NL133605C/xx
Application filed by Combustion Engineering Inc filed Critical Combustion Engineering Inc
Priority to US267512A priority patent/US3262431A/en
Priority to NL6402810A priority patent/NL6402810A/xx
Priority to CH373664A priority patent/CH457505A/de
Priority to DE19641426684 priority patent/DE1426684A1/de
Priority to FR968499A priority patent/FR1391296A/fr
Priority to ES0297958A priority patent/ES297958A1/es
Priority to BE645707A priority patent/BE645707A/xx
Priority to ES0302109A priority patent/ES302109A1/es
Application granted granted Critical
Publication of US3262431A publication Critical patent/US3262431A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • F22B35/14—Control systems for steam boilers for steam boilers of forced-flow type during the starting-up periods, i.e. during the periods between the lighting of the furnaces and the attainment of the normal operating temperature of the steam boilers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
    • F01K3/00—Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein
    • F01K3/18—Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein having heaters
    • F01K3/20—Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein having heaters with heating by combustion gases of main boiler
    • F01K3/22—Controlling, e.g. starting, stopping
    • 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

Definitions

  • An object of this invention is an economic combination of elements facilitating starting up of the vapor generator.
  • Another object is an improved method of starting the generator and warming the turbine connected therewith.
  • a still further object is a combination of turbine controls and vapor control valves for said vapor generator and a method for utilizing them to provide an economical utilization of said valves.
  • FIG. l is a schematic showing of the combination of elements, and a ow and control diagram, incorporating the invention.
  • FIG. 2 is a graph showing the relation between flow and superheater pressure during startup.
  • the arrangement of the vapor generator which is preferably a steam generator, and associated sub-systems within the plant cycle is shown in a simplied manner in FIG. 1.
  • Modern steam generators regardless of pressure level, have by their very nature, (1) a water heating section or economizer, (2) an evaporator or at supercritical pressures an intermediate section, which by convention is commonly termed furnace walls or a vapor generator section, and finally (3) a superheater.
  • the pressure level at which the steam generator operates influences particularly the relative size of these sections and their temperature level.
  • the circulation of water in the evaporator or furnace walls may be produced by the feedwater pump assisted by a recirculating pump and system for recirculating fluid through the furnace Walls.
  • Steam from the turbine section 42 may be fed through a second reheater section 44 subjected to furnace heat and then passed through a section 46 of the turbine and then conducted to a condenser 48.
  • the condensate passes 3,262,431 Patented July 26, 1966 ICC through a filter demineralizer 50 and low pressure heaters 52 to a de-aerator 54 and intermediate pressure heaters S5.
  • the feed pumps 1l) and 12 then return the feedwater through high pressure heaters 56 to the feedwater valves.
  • Components of particular utility in the startup system include the B.T. and the B.T.B. valves mentioned above. Upstream of these valves, piping 58 connects the furnace wall system with the boiler extraction valve B.E. and the water separator or flash tank 6l). The steam side of the separator 60 is connected to the superheater system 30 and 32 through piping 62 and a steam admission valve S.A. and to the condenser 48 through a spill-over valve S.P. Water from the separator is dischargedto the condenser through the water drain valve W.D.
  • a steam discharge valve S.D connected to the line 34 between the superheater 32 and the turbine throttle valve 36 may be used to discharge steam used for superheater cooling and heating of steam leads to the condenser.
  • An injection valve LC. controls desuperheating water flow for condenser protection.
  • the LS. valve is a superheater injection valve for controlling superheater output temperature and the LR. valves are reheater injection valves for controlling the reheater output temperatures.
  • the furnace Walls or vapor'generator 28 dene a furnace Within which fuel, supplied by any suitable and wellknown means such as pipe 63, may be burned to supply heated gases and a source of heat for heating the iiuid contained in the several sections 16, 26, 28, 30, 32, 40 and 44 exposed to the hot gases.
  • a bypass 64 across the furnace and steam cooled walls provides a path for returnof recirculated fluid forced through these walls by the recirculating pump 18 which acts as a mixed ow pump, pumping both feedwater and reci-rculating fluid.
  • the recirculating Huid is mixed with the incoming feedwater in a mixing chamber 66. Reference may be made to application Serial No. 127,395 of W. W. Schroedter led July 27, 1961, now Patent No.
  • B.T., B.T.B., and B.E. valves all of which are in the connections between the furnace Walls and the superheaters and serve to block the passage of water from one section to the other.
  • the B.T. valves are large, throttling, poppettype valves designed for low pressure drop which at design load or full load conditions will pass the major part of the vapor ow from the furnace walls to the superheater with a minimum of pressure drop through the valves.
  • the B.T.B. valves act as a bypass around the B.T. valves during startup conditions but remain Wide open under full flow conditions when they will transmit a minor part of the full flow from the furnace walls to the superheaters.
  • the B.T.B. valves are heavy duty, relatively expensive valves designed for severe throttling service to control vapor flow at temperatures in the neighborhood of 800 F. and at pressure differences on the opposite sides of the valve equal to and greater than the critical pressure drop.
  • the B.T.B. valve is also a poppet-type valve but designed for much more severe service than the B.T. valve which is not adapted to operate at a critical pressure drop but only at flows having less than sonic velocity. Because of the nature of the valve and the service required of it it is desirable to keep the B.T.B. valves as small as possible consistent with the requirements of the remainder of the system and this is one of the objects of the invention.
  • the B.E. valves which are also throttling poppet valves designed to operate at a critcial pressure drop but differ from the B.T.B. valves in that they are designed to handle water flow at the critical pressure drop as well as vapor flow. These B.E. valves are also expensive and their service is severe so that they should be kept as small as is consistent with the requirements of the remainder of the system.
  • the relatively small quantities of feedwater flow during all startup operations are regulated by the feedwater bypass valves F.W.B. Their operation is coordinated to proportion feedwater flow to firing rate.
  • the boiler throttling valves B.T. and B.T.B. are bypassed by way of a low pressure system including the B.E. valves and the flash tank 60. This boiler throttling valve arrangement keeps the furnace wall operating at its proper pressure under all conditions while allowing the superheater to operate at a lower pressure level.
  • the pressure in the superheater system rises proportionally with load and may reach full operating pressure at about 30% load, point 100 in FIG. 2.
  • the boiler throttling valves are then fully open and loading proceeds under control of the turbine control valves at essentially constant turbine throttle pressure.
  • the liquid compartment including the economizer and the center, outer and steam cooled furnace walls are filled and vented up to the B.T. and B.T.B. valves separating the superheater system from the furnace wall system 'which valves at this time are closed. These valves are blocked against opening until the temperature at the steam cooled water outlet reaches some preselected temperature, such as 800 F. by known mechanism indicated schematically at 67, such as a temperature actuated switch or valve, blocking valve actuating servo mechanism.
  • the B.E. valve is closed and set for automatic pressure control at some selected vapor generator pressure, for example 1000 p.s.i.
  • the feedwater pumps are started and establish a minimum feedwater flow of say 5% of full load flow and the feed water flow as controlled by the feedwater bypass valve F.W.B. passes through the economizer and the furnace wall system and is discharged through the boiler extraction valve B.E. to the separator.
  • the water returns to the condenser through the water drain valve W.D. Pressure in the furnace wall lsystem is maintained by the B.E. valve at the selected setting value.
  • the steam admission stop check valve S.A. connecting the separator .with the superheater system is open and the recirculating pump 18 is started.
  • Firing is initiated and maintained at a rate to bring the steam cooled wall outlet steam temperature up at a preselected rate consistent with gas temperature limitations
  • the furnace wall outlet temperature rises above the saturation temperature equivalent to the pressure in the separator the fluid begins to flash into steam in the flask tank with the steam portion passing into the superheater at saturated temperature.
  • the steam flow cools the gas touched superheater tubing and heats the headers and interconnecting piping.
  • the rate of flow through the steam piping and its rate of temperature rise is controlled by the manually actuated steam drain valve S.D. through which the low pressure steam is permitted to proceed to the condenser.
  • pressure control is reset to maintain the pressure in the furnace wall system at higher pressure than the saturation pressure equivalent to the highest fluid temperature in the walls.
  • preselected temperature say 550
  • the pressure will be maintained, in the example chosen for illustrative purposes which is a supercritical system, at 3500 p.s.i.
  • the steam cooled wall outlet temperature is held at 600 to 650 F. until the solids concentration of the water 'being circulated reaches acceptable limits.
  • the flow sweeping the furnace wall system during this time is maintained by the recirculating system at a preselected rate which may 'be at an equivalent level of about 60% of full load flow.
  • the lowpressure steam from the superheater outlet may be fed through the turbine to heat and roll the turbine.
  • the throttle valve system as described above has another advantage in that low pressure high temperature steam can be made available to the turbine on hot re-starts.
  • the throttle valve combination described above is capable of low flows at critical throttling pressure drop and high ows at low pressure drop both with a high degree of control at different points in the loading sequence.
  • a hot start follows the principal actions of a cold start by again using the low pressure separator-superheater system in order to provide low pressure, high enthalpy steam to the turbine valve chest.
  • the boiler throttling valves are closed, the upstream boiler sections are pressurized to full operating pressure i.e. 3500 p.s.i.
  • Firing may be re-established and about 5% feedwater ow admitted With the higher temperature level in the furnace and furnace wall sections sufficient separator steam for turbine rolling is available immediately. Furnace wall outlet temperature quickly reaches the 800 F. limit, if not there already, and steam to the turbine will be in the order of 850 F. Boiler input is increased to the initial loading level and the turbine synchronized.
  • the most desirable enthalpy performance of steam delivered to the turbine is that which on the critical turbine part produces the lowest possible cumulative thermal fatigue damage under any operating condition.
  • the turbine is synchronized at some combination of superheater pressure and flow indicated at point '70 in FG. 2 which assures that the generator will be driven .by the turbine and not motorized. It lis desirable to have a minimum flow through the turbine when it is synchronized and initially loaded of about 7% ofthe total full :load ow. It is also desirable, from a control simplicity standpoint, to
  • the position of the turbine control valve is fixed to provide a fixed opening which will provide the desired minimum flow ⁇ through the turbine under the synchronizing steam pressure of about 800 p.s.i.g. maintained by v :the spill-over valve S.P.
  • the steam required to operate the turbine after transferring from the startup system to the main system, i.e. from the B.E. valve to the B.T.B. valve, passes through the B.T.B. valve with a critical throttling pressure drop.
  • This superheater pressure is indicated by SCXR which indicates supercritical pressure, which is 3500 p.s.i. in the example used for illustration, multiplied by the critical throttling drop ratio which is approximately .545.
  • This pressure is indicated by 30 in FIG. 2 and by the line 82.
  • the B.T. valves may ibe opened.
  • the B.T. valve is pressure operated or controlled by two different pressures.
  • both the superheater pressure and the flow would increase along the line marked 90 until the full superheater pressure were reached at point 1100.
  • the B T. valves would be automatically opened to maintain the 3500 p.s.i. in the water Wall section.
  • valves would be wide open to pass full flow and the pressure in the entire system would be maintained by operation of the turbine throttle valves and the flow control mechanism. In all cases maximum turbine efficiency is obtained when turbine throttle valves are throttled the minimum amount and in the above case maximum turbine efficiency would be obtained from synchronizing all the way to full superheater pressure. From the point to the full load point 8S, normal sequencing of the turbine control valves for the remaining admission arcs is used since this again is the path of maximum turbine efficiency.
  • the fiow and superheater pressure rise would be along the line 86 from point 70 to 84 as in the special case.
  • the B.T. valve would open and the increased flow produced by the feedwater pumps would be used to maintain the superheater pressure substantially constant and the same as that at point 80.
  • the turbine would then be controlled by the first admission arc which would be wide open at point 92 and the turbine would operate at its maximum efiiciency for those pressure conditions.
  • a third example of turbine control would be the so-I called single point or full admission turbine control valve or arrangement.
  • the turbine operates at its best efiiciency with the turbine throttle valves wide open but this is the valve condition designed for full load flow to the turbine and is the valve condition utilized when the turbine and generator are delivering essentially their full rated load.
  • the turbine control valves would be fixed at a limited open position to provide the conditions indicated by point 70 givin-g the turbine a fixed predetermined throttle opening. As before the increasing feedwater flow through the system will open the B.T.B.
  • valves which would handle a flow indicated by the point 94 which obviously would require much more expensive equipment than B.T.B. valves only large enough to handle the flow at point 84.
  • B.T.B. valves having a fiow capacity not substantially greater than the flow capacity required for synchronizing may be utilized.
  • the turbine throttle valves could then be left in the position which produced the desired superheater pressure and the through flow increased to increase the superheater pressure or they could be manipulated to maintain the superheater pressure substantially constant until the turbine control valves reached an opening position, i.e.
  • a vapor generator system for supplying vaporto a load having a selected minimum flow requirement and having first and second heating sections and first and second valve means in parallel connecting said sections in series and an adjustable restriction at the outlet of said second section, in combination, means forcing a flow of Huid through said first section, said valve means said second section and said restriction in series, said first valve means being adjustable to impede said flow and maintain a predetermined working pressure in said first section, said restriction having a preselected opening position at which said selected minimum flow will produce a preselected pressure in said second section and a greater than critical pressure drop across said first valve means, said first valve means having a maximum fiow capacity at r l said working pressure only sufficient to raise the pressure in said second section to a raised pressure only slightly above that which will eliminate the critical pressure drop across said first valve means with said restriction in said preselected opening position, said second valve means being adjustable to maintain said working pressure in said first section at increased ows.
  • a combination as claimed in claim 1 having a third valve means in parallel with said first and second valve means and said third valve means having a maximum capacity less than 30 percent of full load flow and being adjustable to impede iiow and maintain a predetermined working pressure in said iirst section, a separator receiving the output of said third valve means and delivering vapor to said second section, means limiting the pressure in said separator and second section to said preselected pressure, means blocking said separator and limiting means from-said second section including means transferring control from said third valve means to said iirst valve means for maintaining said working pressure.
  • a combination as claimed in claim 1 including means responsive to the pressure in said rst section adjusting both said valve means.
  • a combination as claimed in claim 3 including means responsive to the pressure downstream of said second valve means preventing lsaid second valve means from opening until the critical pressure drop across said second valve has been eliminated.
  • a system as claimed in claim 1 in which said maximum ilow capacity is less than 30 percent of full load iiow and said irst section has a minimum iiow requirement greater than said load minimum flow requirement, and including a recirculation system in said irst section augmenting the through iiow in said iirst section.
  • a combination as claimed in claim 1 including means responsive to the temperature at the outlet of said iirst section preventing both said valve means from opening until a preselected temperature is attained in said rst section.
  • a vapor generator system for supplying vapor to a load having a selected minimum iiow requirement and having first and second heating sections and iirst and second valve means in parallel connectingl said sections in series and an adjustable restriction at the outlet of said second section, in combination, means forcing a flow of fluid through said iirst section said valve means said second section and said restriction in series, said first valve means being adjustable to impede said flow and maintain a predetermined working pressure in said iirst section, said restriction having a preselected opening position at which said selected iiow will produce a preselected pressure in said second section and a greater than critical pressure drop across said first valve means, said iirst valve means having a maximum iiow capacity at said working pressure substantially equal to said selected fiow, said second valve means being adjustable to maintain said working pressure iu said first section at increased flows.
  • a forced ow once-through vapor generator system having an initial startup iiow requirement comprising a superheater section connection in series with and receiving vapor from a vapor generator section, throttle valve means in parallel connecting said sections and including pressure responsive valve means for maintaining the pressure in said generator section at a preselected pressure and constructed and arranged to accommodate critical pressure drop and having a limited tiow area insufficient to supply said initial startup iiow at pressure differences across said valve materially less than said critical pressure drop and said throttle valve means also including a second throttle valve means unsuited for use with critical pressure drop, said second valve being pressure responsive and throttling to maintain said preselected pressure in said generator section, and having a flow area suiiicient to pass the full load iiow of said vapor generator system.
  • pressure responsive main valve means in the connection between said sections for maintaining a preselected pressure in said generator section, pressure responsive means preventing opening said valve until the downstream pressure increases to a value slightly above that required to eliminate a critical pressure drop across said valve, an adjustable throttle valve in said superheater outlet and said path having a preselected limited opening position which will produce a pressure in said superheater less than said downstream pressure with a preselected minimum through flow and increasing the superheater pressure to said downstream pressure with increased through iiow, a bypass around said main valve having a maximum through ow capacity at least as great as said minimum through iiow and not substantially greater than said increased through iiow, and means effective to open said main valve upon further increase in flow.
  • a pressure responsive main valve in the connection between said sections for maintaining a preselected pressure in said generator section, pressure responsive means preventing opening of said valve until al preselected downstream pressure substantially equal to the product of said preselected generator pressure and the critical pressure ratio is attained, adjustable throttle means in said superheater outlet and flow path having a preselected limited opening position, a bypass around said main valve including means maintaining said preselected pressure in said generator section, a separator and means limiting the pressure in said separator and superheater to a pressure producing greater than critical pressure drop across said bypass, means for blocking said bypass, a second bypass around said main valve including a pressure responsive valve for maintaining said preselected pressure in said generator section with critical pressure drop conditions across said bypass and having a maximum flow capacity at least as great as the flow capacity of said throttle valve in its limited opening position at said limited pressure but not
  • a forced iiow once-through vapor generator for supplying vapor to a device having a minimum startup flow requirement, comprising, a vapor generator section, a superheater section and. valve means in parallel connecting said sections for series iiow through said sections, a iirst one of said valve means constructed to etiiciently pass liquid and vapor at substantially sonic velocity, connected to the outlet of said vapor generator section, a separator receiving the liquid and vapor through i'low from said first valve means and passing only vapor to said superheater section and throttle, means limiting the pressure in said separator and superheater to a selected limited pressure, said first valve means having a maximum tlow capacity at sonic velocity and the normal working pressure of said generator section substantially equal to sai-d minimum iiow requirement, a throttle at the outlet of said superheater section having a selected position for, and producing said limited pressure at, said minimum ilow requirement, a second one of said valve means for
  • a vapor generator section, and a superheater section means for forcing fluid through said sections in series, means in parallel connecting said sections and including a iirst means impeding iiow to less than 30 percent full load flow to maintain said generator section at a preselected pressure, a separator tank receiving i'low from said generator section and said iirst means and means for delivering vapor from said tank to said superheater section and means limiting the pressure in said tank to a limited pressure and providing a greater than critical pressure drop across said connecting means, means for blocking flow through said separator and first means, a second means connecting said sections and including a pressure reducing valve connecting said sections when said separator and rst means are blocked, and impeding ow to maintain said generator section at said preselected pressure, an adjustable outlet opening for said superheater section having a preselected limited opening position producing said limited pressure at a selected flow rate less than 30 percent of full load
  • an improved operating method comprising the steps of maintaining the pressure upstream of said valve means at a predetermined value, restricting said through-flow downstream of said second heating section while maintaining critical pressure drop across said valve means, substantially completely opening said one valve means and raising the pressure in said second heating section to a pressure only slightly above that which will give critical pressure drop and thereafter manipulating said second valve means to' further increase the pressure in said second heating section.
  • valve means in parallel connecting said sections in series including one valve means constructed for operation with critical pressure drop and a second valve means of substantially larger flow area unsuited for such operation, means forcing flow through said sections in series and a throttle between said superheater section and a load having a minimum initial loading uid ow requirement less than 30 percent of full load ow, the method of operating comprising the steps of forcing substantially the same through ow of vaporizable uid through said sections and said throttle in series while maintaining the pressure in said generator section at a preselected value by actuating said one valve rneans in response to generator section pressure, restricting said through ilow downstream of said superheater section to said minimum flow and establishing a preselected superheater pressure substantially less than that required to produce critical pressure drop across said valvemeans, then decreasing said pressure drop -to slightly less than said critical pressure drop but materially less than said generator pressure and substantially completely opening said one valve and
  • valve means in parallel connecting said sections in series including one valve means suitable for operation with critical pressure drop and a second valve means of substantially larger ow area unsuited for such operation, means forcing flow through said sections in series land a throttle between said superheater section and a load having a minimum initial loading uid flow requirement, an improved operating method comprising the steps of forcng substantally the same through flow of vaporizable Huid through said sections and said throttle in series While maintaining the pressure in said generator section at a preselected value, setting said throttle in a preselected opening position and adjusting said through ow to provide said minimum initial flow and a superheater pressure substantially less than that required for critical pressure drop across said valve means, maintaining said through flow at said minimum initial ow and reducing said throttle opening to increase said superheater pressure to a higher pressure substantially less than the pressure in said generator section and slightly above that which will give critical pressure drop across said valve means and substantially completely opening said
  • a method as claimed in claim including the step of maintaining said superheater pressure substantially constant at said higher pressure and increasing said through flow and opening said throttle to a second preselected position.
  • a vapor generator system supplying a vapor to a load having a minimum initial loading iluid flow requirement materially less than 30 percent of full load ow, and having a vapor generator section having a predetermined minimum ow requirement of approximately 30 percent of full load flow and substantially greater than the minimum ow requirement of said load, a superheater section, valve means in parallel connecting said sections in series, including one valve means suitable for operation with critical pressure drop in a second valve means of substantially larger flow area unsuited for such operation, means forcing flow through said sections in series and a throttle between said superheater section and said load, an improved operating method comprising the steps -of forcing substantially the same through flow of Vaporizable fluid through said sections and said throttle in series while maintaining the pressure in said generator section at a preselected value, setting said throttle in a preselected opening position and Aadjusting said lthrough flow to provide said minimum initial load ow and a superheater pressure substantially yless than that required for critical pressure drop across said valve means, increasing said superheater pressure
  • valve means in parallel connecting said sections in series including one valve means suitable for operation with critical pressure drop and a second valve means of .substantially larger How area unsuited for such operation, means forcing flow through said sections in series yand a throttle between said superheater section and a load having Ia minimum initial loading uid ow requirement materially less than 30 percent of full load flow
  • an improved operating method comprising the steps of forcing substantially the same through ow of vaporizable uid through said sections and said throttle in series while maintaining the pressure in said generator section at a preselected value, setting said throttle in a preselected opening position and adjusting said through flow to provide said minimum initial flow and a superheater pressure substantially less than that required for critical pressure drop across said valve means, increasing said superheater pressure to a higher pressure substantially less than the pressure in said generator section to eliminate said critical pressure drop and substantially completely open said one valve means while maintaining at least said minimum through flow but less

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Control Of Steam Boilers And Waste-Gas Boilers (AREA)
  • Engine Equipment That Uses Special Cycles (AREA)
  • Control Of Turbines (AREA)
US267512A 1963-03-25 1963-03-25 Economic combination and operation of boiler throttle valves Expired - Lifetime US3262431A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
GB1052417D GB1052417A (fr) 1963-03-25
NL133605D NL133605C (fr) 1963-03-25
US267512A US3262431A (en) 1963-03-25 1963-03-25 Economic combination and operation of boiler throttle valves
NL6402810A NL6402810A (fr) 1963-03-25 1964-03-17
CH373664A CH457505A (de) 1963-03-25 1964-03-23 Dampferzeuger zur Speisung einer Turbine und Verfahren zu dessen Betrieb
DE19641426684 DE1426684A1 (de) 1963-03-25 1964-03-23 Betriebsverfahren fuer ein Dampferzeugungssystem mit UEberhitzern
FR968499A FR1391296A (fr) 1963-03-25 1964-03-24 Procédé et dispositif pour faire fonctionner une installation génératrice de vapeur
ES0297958A ES297958A1 (es) 1963-03-25 1964-03-24 Un metodo de hacer funcionar un sistema generador de vapor
BE645707A BE645707A (fr) 1963-03-25 1964-03-25
ES0302109A ES302109A1 (es) 1963-03-25 1964-07-15 Un sistema generador de vapor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US267512A US3262431A (en) 1963-03-25 1963-03-25 Economic combination and operation of boiler throttle valves

Publications (1)

Publication Number Publication Date
US3262431A true US3262431A (en) 1966-07-26

Family

ID=23019096

Family Applications (1)

Application Number Title Priority Date Filing Date
US267512A Expired - Lifetime US3262431A (en) 1963-03-25 1963-03-25 Economic combination and operation of boiler throttle valves

Country Status (7)

Country Link
US (1) US3262431A (fr)
BE (1) BE645707A (fr)
CH (1) CH457505A (fr)
DE (1) DE1426684A1 (fr)
ES (2) ES297958A1 (fr)
GB (1) GB1052417A (fr)
NL (2) NL6402810A (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3411300A (en) * 1967-05-31 1968-11-19 Combustion Eng Method and apparatus for sliding pressure operation of a vapor generator at subcritical and supercritical pressure
US4019467A (en) * 1976-04-20 1977-04-26 Westinghouse Electric Corporation Valve sequencing startup control system for once-through boiler
US4099384A (en) * 1975-01-02 1978-07-11 Foster Wheeler Energy Corporation Integral separator start-up system for a vapor generator with constant pressure furnace circuitry
US4241585A (en) * 1978-04-14 1980-12-30 Foster Wheeler Energy Corporation Method of operating a vapor generating system having integral separators and a constant pressure furnace circuitry
US4338789A (en) * 1980-02-01 1982-07-13 Dolan John E Method of varying turbine output of a supercritical-pressure steam generator-turbine installation
WO1983003635A1 (fr) * 1982-04-19 1983-10-27 John Edward Dolan Procede de variation de la puissance de sortie d'une turbine d'une installation de turbine-generateur de vapeur a pression surcritique
US5390631A (en) * 1994-05-25 1995-02-21 The Babcock & Wilcox Company Use of single-lead and multi-lead ribbed tubing for sliding pressure once-through boilers
US20130047938A1 (en) * 2010-05-07 2013-02-28 Joachim Brodeßer Method for operating a steam generator
CN110382842A (zh) * 2017-04-10 2019-10-25 三菱日立电力系统株式会社 燃气轮机联合循环设备以及燃气轮机联合循环设备的控制方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102192819B (zh) * 2010-03-11 2013-03-20 中国核动力研究设计院 蒸汽发生器二次侧役前水压试验快速升温工艺

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3038453A (en) * 1957-02-07 1962-06-12 Combustion Eng Apparatus and method for controlling a forced flow once-through steam generator

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3038453A (en) * 1957-02-07 1962-06-12 Combustion Eng Apparatus and method for controlling a forced flow once-through steam generator

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3411300A (en) * 1967-05-31 1968-11-19 Combustion Eng Method and apparatus for sliding pressure operation of a vapor generator at subcritical and supercritical pressure
US4099384A (en) * 1975-01-02 1978-07-11 Foster Wheeler Energy Corporation Integral separator start-up system for a vapor generator with constant pressure furnace circuitry
US4019467A (en) * 1976-04-20 1977-04-26 Westinghouse Electric Corporation Valve sequencing startup control system for once-through boiler
US4241585A (en) * 1978-04-14 1980-12-30 Foster Wheeler Energy Corporation Method of operating a vapor generating system having integral separators and a constant pressure furnace circuitry
US4338789A (en) * 1980-02-01 1982-07-13 Dolan John E Method of varying turbine output of a supercritical-pressure steam generator-turbine installation
WO1983003635A1 (fr) * 1982-04-19 1983-10-27 John Edward Dolan Procede de variation de la puissance de sortie d'une turbine d'une installation de turbine-generateur de vapeur a pression surcritique
US5390631A (en) * 1994-05-25 1995-02-21 The Babcock & Wilcox Company Use of single-lead and multi-lead ribbed tubing for sliding pressure once-through boilers
US20130047938A1 (en) * 2010-05-07 2013-02-28 Joachim Brodeßer Method for operating a steam generator
US9683733B2 (en) * 2010-05-07 2017-06-20 Siemens Aktiengesellschaft Method for operating a steam generator
CN110382842A (zh) * 2017-04-10 2019-10-25 三菱日立电力系统株式会社 燃气轮机联合循环设备以及燃气轮机联合循环设备的控制方法

Also Published As

Publication number Publication date
ES302109A1 (es) 1965-12-01
CH457505A (de) 1968-06-15
GB1052417A (fr)
NL133605C (fr)
NL6402810A (fr) 1964-09-28
DE1426684A1 (de) 1970-02-12
ES297958A1 (es) 1964-12-01
BE645707A (fr) 1964-09-25

Similar Documents

Publication Publication Date Title
US3220193A (en) Devices for improving operating flexibility of steam-electric generating plants
US3286466A (en) Once-through vapor generator variable pressure start-up system
US3338053A (en) Once-through vapor generator start-up system
US3358450A (en) Method and apparatus for steam turbine startup
US3262431A (en) Economic combination and operation of boiler throttle valves
US3529580A (en) Start-up system
US3009325A (en) Once-through vapor generating and superheating unit
US2900792A (en) Steam power plant having a forced flow steam generator
US4487166A (en) Start-up system for once-through boilers
US2921441A (en) Feed water preheating system for steam power plants
US3374621A (en) Gas turbine auxiliary for steam power plants
US3019774A (en) Once-through vapor generator
US3135096A (en) Method of and apparatus for operating at startup and low load a oncethrough vapor generating system
US3243961A (en) Apparatus and method of operating a forced flow once-through vapor generating power plant
US3259111A (en) Start-up system for forced flow vapor generator
US3213835A (en) Recirculating system having partial bypass around the center wall
US3362164A (en) Start-up system for forced flow vapor generator
US3055181A (en) Method of operating a power plant system
US3120839A (en) Device for low load operation of once-through boilers
US3313111A (en) Startup system for a once through steam generator including a startup balancing heatexchanger
US3271961A (en) Start-up system for forced flow vapor generator
US3612005A (en) Once-through steam generator recirculating startup system
US3003479A (en) Steam and air boiler with heating surface of smallest load
US3304716A (en) Start-up system for forced flow vapor generator
US3225748A (en) Common startup system