US3175541A - Automatic feedwater control system and method of operating same - Google Patents

Automatic feedwater control system and method of operating same Download PDF

Info

Publication number
US3175541A
US3175541A US267507A US26750763A US3175541A US 3175541 A US3175541 A US 3175541A US 267507 A US267507 A US 267507A US 26750763 A US26750763 A US 26750763A US 3175541 A US3175541 A US 3175541A
Authority
US
United States
Prior art keywords
flow
feedwater
response
vapor generator
signal
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
US267507A
Other languages
English (en)
Inventor
Richard D Hottenstine
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 NL132446D priority Critical patent/NL132446C/xx
Application filed by Combustion Engineering Inc filed Critical Combustion Engineering Inc
Priority to US267507A priority patent/US3175541A/en
Priority to GB6692/64A priority patent/GB998651A/en
Priority to NL6401459A priority patent/NL6401459A/xx
Priority to ES0297036A priority patent/ES297036A1/es
Priority to FR965791A priority patent/FR1389147A/fr
Priority to BE644874A priority patent/BE644874A/xx
Priority to CH305064A priority patent/CH440322A/de
Priority to DEC32366A priority patent/DE1278447B/de
Application granted granted Critical
Publication of US3175541A publication Critical patent/US3175541A/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
    • F22D—PREHEATING, OR ACCUMULATING PREHEATED, FEED-WATER FOR STEAM GENERATION; FEED-WATER SUPPLY FOR STEAM GENERATION; CONTROLLING WATER LEVEL FOR STEAM GENERATION; AUXILIARY DEVICES FOR PROMOTING WATER CIRCULATION WITHIN STEAM BOILERS
    • F22D5/00—Controlling water feed or water level; Automatic water feeding or water-level regulators
    • 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
    • F22—STEAM GENERATION
    • F22D—PREHEATING, OR ACCUMULATING PREHEATED, FEED-WATER FOR STEAM GENERATION; FEED-WATER SUPPLY FOR STEAM GENERATION; CONTROLLING WATER LEVEL FOR STEAM GENERATION; AUXILIARY DEVICES FOR PROMOTING WATER CIRCULATION WITHIN STEAM BOILERS
    • F22D11/00—Feed-water supply not provided for in other main groups

Definitions

  • This invention relates generally to the control of flow of a vaporizable fluid to a vapor generator. More particularly, it relates to an improved control system for supplying a vapor generator with accurate amounts of feedwater to achieve the desired vapor characteristics over the full range of generator operation and the method of operating the same.
  • One method of controlling feedwater supply commonly employed in present-day practice involves the use of flow meters which automatically adjust the feedwater supply valve in response to a signal emitted by a load demand sensing device such that an accurate supply of feedwater to the heating surface of the generator is obtained.
  • Such a control system is limited in that conventional flow meters are not accurate over the full load range of high capacity vapor generators to the extent necessary to insure the generation of vapor having close tolerance temperature and pressure characteristics.
  • Plow meters which are accurate within low flow ranges are not accurate within the high flow-high load ranges required by such generators and conversely, flow meters accurate at high flow rates are inaccurate within low flow-low load ranges. To provide flow meters which are accurate within both high and low load-flow ranges is tremendously expensive therefore rendering their use undesirable.
  • the invention contemplates the use of individual flow meters, one of which is accurate for low flow rates and employed when the generator is operating at low loads where the amount of feedwater supplied to the fluid system is low and the other, which is accurate at high flow rates and is employed when the generator is operating at high loads where the amount of feedwater supplied is high.
  • This system is so designed that the ranges of the two flow meters overlap such that the feedwater supply is always under control and the system further provides a means for controlling the operation of the flow meters that permits a smooth operational transition from one flow meter to the 3,175,541 Patented Mar. 30, 19d? other as the load on the vapor generator increases from startup to full operating capacity.
  • control system is so designed that the flow meter employed at low generator loads can be utilized for metering the flow of operating fluid supplied to desuperheating apparatus where this fluid is obtained from the same source as is the generator feedwater.
  • This additional function for the low flow meter is desirable since it eliminates a period of inoperation for the meter thereby rendering this system more efficient.
  • the added function is permitted due to the fact that desuperheating of vapor is not normally undertaken until the generator load eX- ceeds 25 percent of rated capacity during which time this meter would normally be inoperative, the control of feedwater having been undertaken by the other flow meter in the system.
  • Another object of the invention is to provide an improved control system for metering vaporizable fluid to a vapor generator in which one of the flow meters employed for metering feedwater to the vapor generator at low loads can be employed for metering operating fluid to the desuperheater at high generator loads.
  • FIG. 1 is a schematic representation of one form of feedwater control system for a vapor generator contemplated by the instant invention
  • FIG. 2 is a graphic representation of the signal response of the flow meters over the generator load range.
  • FIG. 3 is a partial schematic representation of a slightly modified form of feedwater control system.
  • FIGURE 1 a schematic representation of the fluid system 10 of a vapor generator which may be operated at supercritical or subcritical pressures. While the system depicted in the drawing and described herein is of the once-through type, it is to be understood that the present invention is equally adaptable to vapor generators of the recirculation type.
  • the fluid system comprises a feed pump 12 which forces the vaporizable working fluid or feedwater through a flow measuring device 14 and a flow control valve 16 into the economizer 18. From the economizer 18 the vaporizable working fluid flows through a heating surface 20 and from here through a connecting conduit 22 to the final or finishing heating surface 24. While flowing through the economizer 18 and heating surface 20 the working fluid extracts heat from combustion gases generated in the furnace of the vapor generator by burners (not shown) whereby it is transformed into vapor, either saturated or containing an amount of superheat.
  • an attemporator or desuperheater 26 is positioned in the connecting conduit 22 to reduce the amount of superheat contained in the vapor leaving the heating surface 20 before it enters the finishing heating surface 24.
  • the desuperheater 26 is of the spray or direct contact type wherein relatively cool water, which may be obtained from the same source as is the feedwater employed in the generator, is sprayed into the superheated Vapor flowing through the conduit 22. The superheater provides a transient control for the final temperature of the vapor which emerges from the vapor generator.
  • the vapor after it leaves the vapor generator at the desired temperature and pressure, is delivered to a vapor operated prime mover which may be a turbine or the like, passing through the valve 28 and then to the prime mover (not shown).
  • the prime mover in conventional systems drives an electricgenerator.
  • the vapor upon leaving the prime mover is condensed, heated by suitable preheaters, deaerated and returned to the through-flow circuit, being again forced therethrough by means of the pump 12.
  • the supply of vapor to prime movers from once-through or high capacity recirculating types of vapor generators can be controlled by controlling the amount of feedwater or vaporizable working medium delivered to the fluid circuit. This can be accomplished by changing the setting of the flow control valve 16 or by altering the speed of the feed pump 12 in response to the load demand on the vapor generator.
  • the accuracy of control in such systems is enhanced by adjusting the valve setting or pump speed in response to the amount of fluid flow as determined by a flow measuring device, such as that designated as 14, and which may be any suitable means, such as a venturi meter or flow nozzle.
  • Control is effected by means of a flow transducer which imparts a signal representing the actual flow experienced by the flow measuring device to asurnmation point where it is compared with a desired set point signal corresponding to the load demand on the generator. This comparison provides an error signal if the feedwater flow is not at the desired value and this error signal is transmitted to a controller which adjusts the setting of the flow control valve until the desired rate of flow is obtained.
  • a means obviating the need for a single flow measuring means accurate over the entire range of vapor generator operation comprising a bypass line 30 around the flow control valve 16 which contains a bypass flow measuring device 32 and a bypass flow control valve 34.
  • This line comprises part of the vapor generator fluid system and is adapted to conduct feedwater from the feed pump 12 to the economizer 18 when the vapor generator is operating at low loads, for example from O to 25 of rated capacity.
  • the bypass flow measuring device 32 because it is required to measure only low flows, may be a conventional flow measuring device which is accurate over this limited range of flow. Feedwater passes through the bypass line 36 until the vapor generator reaches 25% of its rated capacity when the bypass flow control valve 34 is closed and the main flow control valve 16 is opened.
  • the control system employed for controlling the flow of fluid through the fluid system comprises flow transducers 36 and 38 which emit signals corresponding to the rates of flow measured by the main flow measuring device 14 and bypass flow measuring device 32. These signals are transmitted through a signal ratioing device comprising contacts 40 and 4t) and an adjustable switch operated by a servo motor 41 to a summation point 42 Where the signal is compared with a desired set point signal designated as 43 corresponding to the load demand on the vapor generator.
  • the set point signal 43 may be derived from any conventional load measuring means, such as means measuring megawatt output of the power plant, outlet pressure of the vapor generator, or the like.
  • This comparison provides an error signal which 1s transmitted to a controller 44, which in turn transm ts the signal to whichever of the flow control valves, 16 or 34, is in operation through a switching device comprising contacts 46 and 46' and an adjustable switching arm operated by a servo motor 48 to adjust the valve being operated to deliver the desired feedwater flow to the vapor generator.
  • the servo motor 41 is driven in response to the load on the vapor generator as determined by the rate of feedwater flow flowing through the main flow measuring device 14 by means of a controller 56.
  • the arrangement is such that at generator loads of from 0 to 20% the adjustable switching arm of the ratioing device closes contact 40 thereby elfecting control of feedwater flow by means of the signal emitted by the bypass flow measuring device 32 to the bypass flow control Valve 34.
  • the servo motor 41 When the load on the vapor generator exceeds 20% of rated generator capacity the servo motor 41 is actuated by the controller 50 and the switching arm begins its movement from contact 40 to contact 40' thereby splitting the signal to the summation point 42 and controller 44 thus eifecting adjustment of the bypass flow control valve 34 by means of the signals emitted by both the bypass flow measuring device 32 and the main flow measuring device 14.
  • the arm When the arm reaches contact 40, which occurs when the generator load reaches 25 of rated capacity, servo motor 48 is actuated to move the adjustable switching arm of the switching device from Contact 46 to contact 46 thereby gradually closing the bypass flow control valve 34 and opening the main flow control valve 16 to thus transfer control of feedwater from the former to the latter.
  • control of feedwater is effected by the main flow control valve 16 solely in response to the signal emitted by the main flow measuring device 14.
  • This transfer is graphically represented in FIGURE 2 where the solid line indicates control of feedwater in response to the signal emitted by the bypass flow measuring device 32 which is accurate at low flow rates and the dotted line indicates control in response to the signal emited by the main flow measuring device 14 which is accurate at high flow rates.
  • the operation of the system is as follows: When feed water flow to the vapor generator is initiated, as at start up, the adjustable switching arm of the ratioing device is positioned so as to close the contact 413 and that of the switching device is positioned to close the contact 46; therefore main flow control valve 16 is closed and bypass flow control valve 34 is open and control of the latter is efiected by means of the signal emitted by the bypass flow measuring device 32.
  • the adjustable switching arm of the ratioing device is at contact 46, closing the same thereby effecting control of feedwater flow solely by means of the signal transmitted by the flow transducer 36 associated with the main flow measuring device 14.
  • servo motor 48 is actuated to gradually effect movement of the switching arm from contact 46 to contact 46' thereby closing the bypass flow control valve 34 and opening the main flow control valve 16'which now assumes feedwater flow control in response to the signal emitted by the flow transducer 36 associated with the main fiowmeasuring device 14.
  • a line 52 for delivering working fiuid to the desuperheater 26 Associated with the present control system is a line 52 for delivering working fiuid to the desuperheater 26.
  • This line connects with the bypass line between the bypass flow measuring device 32 and bypass flow control valve 34 to deliver working fluid in the form of generator feedwater to the desuperheater 26 for the purpose of lowering the amount of superheat in the vapor flowing through connection conduit 22.
  • a control valve 54 is positioned in the line 52 for controlling the amount of working fluid delivered to the desuperheater in order to control the temperature of the vapor emerging from the generator in response to a signal emitted from a temperature sensing device 56 positioned at the vapor generator outlet.
  • the means for controlling the amount of working fiuid delivered to the desuperheater 26 comprises a switching device 58, summation points 60 and 62 and three-action type controllers 64 and 66 which serve to transmit a signal to the control valve 54 for adjusting the amount of working fluid delivered to the superheater.
  • the switch 58 closes contact 68 thereby establishing a signal circuit from the temperature sensing device 56 to the control valve 54.
  • desuperheating can occur in response to the signal emitted by the temperature sensing device 56 which is transmitted to a summation point 60 where it is compared with a set point signal indicated as 70, the difference emerging as an error signal transmitted through a controller 64 directly to the control valve 54 which is thereby adjusted to admit the required amount of working fluid to the desuperheater 26 in order to obtain the desired temperature of vapor flowing in connecting conduit 22.
  • desuperheat control is efiected in response to the signal emitted by the flow transducer 38 associated with the bypass flow measuring device 32.
  • the switching device 58 is moved from the contact 68 to the contact 72 and control is maintained by a comparison at the summation point 62 of a set point signal which comprises the error signal transmitted from the summation point 60 through the controller 64 where it is compared with the flow signal transmitted from the flow transducer 38 associated with the bypass flow measuring device 32 and the difference transmitted as an error signal through the controller 66 to control the valve 54.
  • the bypass flow measuring device 32 and flow transducer 38 are made to operate as a portion of the desuperheat control thereby increasing the over-all efiiciency of the control circuit.
  • FIGURE 3 depicts a slightly modified version of the present invention wherein feedwater control, rather than being effected by adjustment of the main flow control valve 16, is accomplished by varying the speed of the feed pump 12.
  • the system shown in FIGURE 3 is the same as that shown in FIGURE 1 except that the signal transmitted by the controller 44 when the adjustable switching arm of the switching device closes contact 46 is transmited to a means 74 for adjusting the speed of the feed pump 12 rather than to a means for adjusting the setting of the main flow control valve 16.
  • the control system of the invention may be hydraulic or may employ air pressure.
  • An electrical system is preferred because of its convenience and the controllers 44, 64 and 66 indicated may be any of the three-action type, i.e., those providing proportional action, integrating action and differential action, such as the three-action controllers manufactured by Leeds & Northrup Company or the Hagan Company, or the like.
  • the controller indicated at 50 need not provide or use either the ditierential action or the integrating action since such actions are of no particular advantage.
  • the summation points 42, 60 and 62 indicated need no controlling hardware if an electrical system is used since they are merely Wiring points where DC. voltage systems are combined or compared.
  • a vapor generator having a feedwater supply system comprising a feedwater inlet line; first flow regulating means for regulating the flow of feedwater through said inlet line; first flow metering means for measuring the flow of feedwater through said inlet line and for emitting a signal in response to said flow; second fiow regulating means, independent of said first flow regulating means, having its outlet connected to said feedwater inlet line downstream of said first flow regulating means; second flow metering means for measuring the flow of fcedwater through said second flow regulating means and for emitting a signal in response to said fiow; vapor generator load sensing means adapted to emit a signal in response to the load demand on said vapor generator; control means including means for actuating each of said flow regulating means in response to said load demand signals and for regulating their operation in response to the signals emitted by said first and second flow metering means, and means for eiiecting regulation of feedwater flow at low flow rates in response to the signal emitted by said second fiow metering means and
  • a vapor generator having a feedwater supply sys tem comprising a feedwater inlet line; a first valve interposed in said feedwater valve inlet line for regulating the flow of feedwater therethrough; first flow metering means for measuring the flow of feedwater through said inlet line and for emitting a signal in a response to said flow; a second valve, independent of said first valve, having its outlet connected to said feedwater inlet line downstream of said first valve; second flow metering means for measuring the flow of feedwater through said second valve and for emitting a signal in response to said flow; vapor generator load sensing means adapted to emit a signal in response to the load demand on said vapor generator; control means including means for actuating said valves in response to said load demand signal and for regulating their operation in response to the signal emitted by said first and second flow metering means, and means for efiiecting regulation of feedwater flow at low flow rates in response to the signal emitted by said second flow metering means and for transferring regulation of feed
  • a vapor generator feedwater supply system comprising feedwater inlet line; a first valve interposed in said feedwater inlet line for regulating the flow of feedwater therethrough; first fiow metering means accurate over a range of high flow rates for measuring the flow of feedwater through said inlet line and for emitting a signal in response to said flow to regulate the flow to said vapor generator; a second valve, independent of said first valve, having its outlet connected to said feedwater inlet line downstream of said first valve; second flow metering means accurate over a range of loW flow rates for measuring the flow of feedWater through said second valve and for emitting a signal in response to said flow to regulate the flow to said vapor generator; vapor generator load sensing means adapted to emit a signal in response to the load demand on said vapor generator; control means including means for actuating said second valve in response to a low load demand signal and said first valve in response to a high load demand signal and for regulating their operation in response to the signals emitted by said first and second flow metering means, and signal
  • a feedwater supply system comprising a feedwater inlet line; a first valve interposed in said feedwater inlet line for regulating the flow of feedwater therethrough; first flow metering means actuate over a range of high flow rates positioned in said feedwater line upstream of said first valve for measuring the flow of feedWater through said inlet line and for emitting a signal in response to said flow to elfect regulation of said flow; a second valve, independent of said first valve, located in bypass relation therewith, and adapted to regulate the flow of feedwater to said vapor generator; second flow metering means accurate over a range of low flow rates for measuring the flow of feed- Water through said second valve and for emitting a signal in response to said flow to effect regulation thereof; vapor generator load sensing means adapted to emit a signal in response to the load demand on said vapor generator; control means including valve actuating means for rendering said second valve operative over low range of load demand in response to said load demand signal and said first valve over a high range
  • a vapor generator including a desuperheater having a feedwater and desuperheater supply system comprising an inlet line; first flow regulating means for regulating the flow through said inlet line; first flow metering means for measuring the fiow through said inlet line and for emitting a signal in response thereto; second flow regulating means, independent of said first flow regulating means, having its outlet connected to said inlet line downstream of said first flow regulating means; second flow metering means for measuring the flow through said secflow regulating means in response to the signal'emitted by said second flow metering means.
  • a method for regulating feedWater flow to a vapor generator having first flow regulator means, second flow regulator means in bypass relation with said first regulator means, first flow metering means accurate over a range of high vapor generator load requirements associated with said first flow regulator means, second flow metering means accurate over a range of low vapor generator load requirements associated With said second flow regulating means, means for operating said flow regulator means in response to said flow metering means and means for actuating said flow regulator means in response to vapor generator load requirements comprising the steps of regulating the admission of feedwater to said vapor genera-tor over a range of low vapor generator load requirements by operating said second flow regulator means and controlling its operation by said second flow metering means; regulating the admission of feedwater to said vapor generator over a range of intermediate vapor generator load 7 requirements by said second flow regulator means but transferring control of its'operation to both flow metering means; and regulating the admission of feedwater to said vapor generator over a range of high vapor generator load requirements by transferring the operation from said second flow regulator means to said
  • a method for regulating feedwater flow to a vapor generator having first flow regulator means, second flow regulator means in bypass relation with said first flow regulator means, first signal emitting flow metering means accurate over a range of high vapor generator load requirements associated with said first flow regulator means,
  • I second signal emitting flow metering means accurate over ond flow means and for emitting a signal in response thereto; third flow regulating means connected in parallel relation with said second flow regulating means for regulating the flow of Water to said desuperheater; vapor generator load sensing means adapted to emit a signal in response to the load demand on said vapor generator; control means including means for actuating said first and second flow regulating means in response to said load demand signals and for regulating their operation in response to the signals emitted by said first and second flow metering means; means for elfecting regulation of feedwater flow at low flow rates in response to the signal emitted by said second flow metering means and for transferring regula- I a range of low vapor generator load requirements associated with said second flow regulator means, signal responsive means to operate said flow regulator means in response to said flow metering means including means associated with said'second flow regulator means for operating the same by the combined operation of both flow metering means and means for actuating said How regulator means in response to vapor generator load requirements comprising the
  • a method for regulating feedwater and desuperheater Water flow to a vapor generator having a desuperheater, first flow regulator means, second flow regulator means in bypass relation with said first flow regulator means, third flow regulator means for regulating flow to said desuperheater in parallel with said second flow regulator means, first flow metering means associated with said first flow regulator means, second flow metering means associated with said second and third flow regulator means, means for operating said flow regulator means in response to said flow metering means and means for actuating said flow regulator means in response to vapor generator load requirements comprising the steps of regulating the admission of feedwater to said vapor generator over a range of low vapor generator load requirements by operating said second flow regulator means and controlling its operation by said second flow metering means; regulating the admission of feedwater to said vapor generator over a range of intermediate vapor generator load requirements by the continued operation of said second flow regulator means but transferring the control thereof to both flow metering means; and regulating the admission of feedwater to said vapor generator over a range of high vapor generator

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Water Supply & Treatment (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Control Of Steam Boilers And Waste-Gas Boilers (AREA)
US267507A 1963-03-25 1963-03-25 Automatic feedwater control system and method of operating same Expired - Lifetime US3175541A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
NL132446D NL132446C (de) 1963-03-25
US267507A US3175541A (en) 1963-03-25 1963-03-25 Automatic feedwater control system and method of operating same
NL6401459A NL6401459A (de) 1963-03-25 1964-02-18
GB6692/64A GB998651A (en) 1963-03-25 1964-02-18 Automatic feedwater control system and method of operating same
ES0297036A ES297036A1 (es) 1963-03-25 1964-02-29 Un metodo de controlar el flujo en el sistema de agua de alimentaciën de un generador de vapor
FR965791A FR1389147A (fr) 1963-03-25 1964-03-02 Perfectionnements apportés à la commande automatique de l'alimentation pour générateurs de vapeur
BE644874A BE644874A (de) 1963-03-25 1964-03-06
CH305064A CH440322A (de) 1963-03-25 1964-03-10 Verfahren zur Regelung des Flusses im Speisewassersystem eines Dampferzeugers und Einrichtung zur Durchführung des Verfahrens
DEC32366A DE1278447B (de) 1963-03-25 1964-03-10 Speisewasseranlage fuer den Anfahrbetrieb von Dampferzeugern

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US267507A US3175541A (en) 1963-03-25 1963-03-25 Automatic feedwater control system and method of operating same
BE644874A BE644874A (de) 1963-03-25 1964-03-06

Publications (1)

Publication Number Publication Date
US3175541A true US3175541A (en) 1965-03-30

Family

ID=25655746

Family Applications (1)

Application Number Title Priority Date Filing Date
US267507A Expired - Lifetime US3175541A (en) 1963-03-25 1963-03-25 Automatic feedwater control system and method of operating same

Country Status (6)

Country Link
US (1) US3175541A (de)
BE (1) BE644874A (de)
CH (1) CH440322A (de)
DE (1) DE1278447B (de)
GB (1) GB998651A (de)
NL (2) NL6401459A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3850148A (en) * 1972-06-12 1974-11-26 Sulzer Ag Forced through-flow steam generator having a superimposed forced circulation
US4031863A (en) * 1974-09-17 1977-06-28 Sulzer Brothers Limited Process and a control system for controlling the exit temperature of vapor flowing through a contact heating surface of a vapor generator
US4541365A (en) * 1984-10-15 1985-09-17 Clayton Manufacturing Company Method and apparatus for supplying feedwater to a forced flow boiler
US5809943A (en) * 1997-05-14 1998-09-22 Asea Brown Boveri Ag Device for precontrolling the feedwater of a cooling-air temperature controller for a cooling-air cooler

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB884132A (en) * 1957-03-20 1961-12-06 Duerrwerke Ag Improvements in or relating to the control of forced-flow, once-through boilers
US3096744A (en) * 1958-12-23 1963-07-09 Sulzer Ag Method of and apparatus for regulating the steam temperature in a steam generator

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1006643B (de) * 1953-08-31 1957-04-18 Martinus Van Damme Motorschlepper mit Tiefpflug

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB884132A (en) * 1957-03-20 1961-12-06 Duerrwerke Ag Improvements in or relating to the control of forced-flow, once-through boilers
US3096744A (en) * 1958-12-23 1963-07-09 Sulzer Ag Method of and apparatus for regulating the steam temperature in a steam generator

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3850148A (en) * 1972-06-12 1974-11-26 Sulzer Ag Forced through-flow steam generator having a superimposed forced circulation
US4031863A (en) * 1974-09-17 1977-06-28 Sulzer Brothers Limited Process and a control system for controlling the exit temperature of vapor flowing through a contact heating surface of a vapor generator
US4541365A (en) * 1984-10-15 1985-09-17 Clayton Manufacturing Company Method and apparatus for supplying feedwater to a forced flow boiler
US5809943A (en) * 1997-05-14 1998-09-22 Asea Brown Boveri Ag Device for precontrolling the feedwater of a cooling-air temperature controller for a cooling-air cooler

Also Published As

Publication number Publication date
BE644874A (de) 1964-09-07
NL6401459A (de) 1964-09-28
CH440322A (de) 1967-07-31
NL132446C (de)
DE1278447B (de) 1968-09-26
GB998651A (en) 1965-07-21

Similar Documents

Publication Publication Date Title
US3244898A (en) Power plant system and control therefor
US3038453A (en) Apparatus and method for controlling a forced flow once-through steam generator
JPH0227122Y2 (de)
ES350139A1 (es) Procedimiento para la regulacion de una instalacion genera-dora de potencia y calor por vapor.
US3908897A (en) Off-line integration of bridge and boiler controls
US3802189A (en) Boiler-turbine control system
US3175541A (en) Automatic feedwater control system and method of operating same
US2526898A (en) Vapor temperature control
US4080789A (en) Steam generator
US3271960A (en) Method and apparatus for supply of steam to an auxiliary turbine in a steam power plant
US3134367A (en) Regulating system for once-through boilers
US3202136A (en) Control system for once-through flow vapor generator
US3089308A (en) Regulating system for steam power plants with forced-flow boilers
US3971219A (en) Turbine control system
US3096744A (en) Method of and apparatus for regulating the steam temperature in a steam generator
US3260246A (en) Regulating arrangement for forced flow type boiler
US2962865A (en) Control of forced flow steam generators
US3205869A (en) Cooling parts of a steam generator by feedwater
US2259417A (en) Control system
US2170348A (en) Control system
US2297203A (en) Means for controlling the operation of vapor generators
US2672732A (en) Feedwater control means for steam power plants
SU767453A1 (ru) Устройство дл регулировани температуры перегретого пара
US4271673A (en) Steam turbine plant
GB845013A (en) Regulation of thermal power plants