US3774396A - Method and apparatus for controlling a heat exchanger - Google Patents

Method and apparatus for controlling a heat exchanger Download PDF

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US3774396A
US3774396A US00244151A US3774396DA US3774396A US 3774396 A US3774396 A US 3774396A US 00244151 A US00244151 A US 00244151A US 3774396D A US3774396D A US 3774396DA US 3774396 A US3774396 A US 3774396A
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temperature
heat exchanger
enthalpy
pressure
superheated steam
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L Borsi
H Dingler
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Siemens AG
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Siemens AG
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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

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  • the apparatus for Performing 1the method the 122/448, 451; 236/11, 14 invention includes sensing devices for sensmg the 2 pressure and temperature of the slightly superheated 5 References Cited steam.
  • a computation circuit of the apparatus UNITED STATES PATENTS determines the specific actual enthalpy as an electrical quantity to control an adjusting device for controlling 2222222 2/2222 1:222:22 we 3,253,994 5/1966 Kagi 60/107 x 22 Claims, 8 Drawing Figures Patented Nov. 27, 1973 b Sheets-Sheet 1 /%l l I Patented Nov. 27, 1973 3,774,396
  • the invention relates to a method and apparatus for Controlling a steam-generating heat exchanger such as a forced-flow boiler or thelike. More particularly, the invention relates to a method and apparatus for con-' trolling at least one of the operating mediums such as feedwater and fuel, supplied to the heat exchanger.
  • a forced-flow boiler such as a Benson boiler
  • a number of primary control loops for controlling, for example, the feedwater throughput, the output pressure of the steam delivered, the temperature of the steam generated and the pressure in the combustion chamber. It has now been found advisable for the control of forced-flow boilers to provide, additionally, a control loop which serves for the rapid detection and compensation of heating disturbances.
  • a supplementary control loop of this type is'known, in which the actual temperature T, of the steam in the boiler is measured at a point where the steam is in a slightly superheated state.
  • the term slightly superheated state refer here and in the following to steam at temperature T in the range of 370C 40C, at a pressure p in the range of 180 atm 100 atm and having a specific enthalpy i in the range of 640 kcal/kg i 60kcal/kg.
  • the measurement point for the actual temperature T is at theof the energy carrier is noted most quickly at the output of the evaporator, the energy carrier being, for example, oil, gas or coal.
  • the actual temperature T,- determined here is compared with a predetermined reference temperature T,,, and the temperature difference (AT T, -'T,,) obtained, is used as the correction quantity for a subordinated control circuit, for example, for controlling the feedwater throughput. Because of this known measure, a certain degree of control of the slightly superheated steam has been previously possible in ,a once-through forced-flow boiler when heating disturbances occur.
  • Example 1 7 From an inspection of the enthalpy-temperature Example 1 7 Assume that the slightly superheated steam is in a first state a defined by the temperature T, 370C and the pressure p 200 atm. From the i-T diagram, the steam has an enthalpy of i, 610 kcal/kg. An increase of the enthalpy Ai 30 kcal/kg (for example, because of a heating disturbance) results ina temperature change AT 10C for a fixed pressure p A calculation shows that this temperature change AT can be com'pensatedby a relative change A M /M of the feedwater throughput'M of 8 percent. I
  • This relative change AM /M is brought about by a changed adjustment of the positioning valve. Furthermore, it follows from the i-T diagram that the temperaheating disturbances, are also picked up as being such a heating disturbance and are erroneously compensated for by a change of the adjustment of the positioning member, for example, for thefeedwater throughput.
  • a temperature change AT in the slightly superheated steam in a heat exchanger can be caused not only by a heating disturbance; it can also be caused by a pressure change Ap that is produced by a change in the steam consumption. Another example will serve to illustrate this.
  • Example 3 The slightly superheated steam is assumed to be in the state c defined by the temperature T 370C, pressure p 180 atm, and specific enthalpy i 650 kcal/kg.
  • a pressure change of Ap 15 atm which may be caused, for example, by a change in steam withdrawal, leads with no change in the heating, that is, with constant enthalpy i to a temperature change AT 10C which, although not caused by a heating disturbance, automatically results in an unnecessary control action in the known control loop.
  • Pressure changes of this kind occur very frequently, especially when the steam generator is operated at varying pressure, that is, if the pressure p, changes with a change in load, or if its storage capacity is heavily drawn upon or more specifically, if the steam output delivered is predetermined over a large pressure range, for example, by a superordinated control of the electric power output of a connected turbogenerator.
  • the foregoing method objects are realized bycontinuously determining the specific actual'enthalpy (i of the slightly superheated steam in the heat exchanger and using this quantity as an auxiliary control quantity.
  • a preferred embodiment of the invention includes continuously measuring the pressure (p,) and temperature (T,) of the slightly superheated steam at a location of the heat exchanger.
  • the measured actual values of pressure (P,) and temperature (T,) are supplied to a computation circuit for determining .the control deviation (x,,,,) of the specific actual enthalpy (i from the reference value of the enthalpy (i and the control deviation (x 0f the specific enthalpy is used as a correction quantity for the input quantity of an adjusting means.
  • the adjusting means can include a controller to which the inpu'tquantity is supplied.
  • the adjusting means further can include positioning equipment connected to the controller.
  • the positioning equipment can, for example, in turn include a valve for adjusting the supply of feedwater to' the'heat exchanger as well as a positioning device connected to the valve for adjusting the position of the valve. It is also possible to of fuel to the heat exchanger.
  • the relative loop gain is constant at any operating point T which is considered as a special advantage. If, for instance, a feedwater positioning valve is used as the positioning member, the quantity (Ai/( AM /M is constant for any temperature T Expressed otherwise, an enthalpy change Ai is directly proportional to the change AM /AM of the feedwater flow. In contrast to the known control method, in which only the actual temperature T, of the slightly superheated steam is measured, there occurs therefore no nonlinearity in the gain of the temperature control loop (operating point and drive dependence).
  • control deviation x of the specific enthalpy is determined from the measured actual values p, and T, and from predetermined reference values for the pressure p,, and for the temperature T,,.
  • the specific enthalpy i is the determiningfactor for the equilibrium between the heat supply and the feedwater flow and is an unambiguous function of the temperature T and the pressure p:
  • a further embodiment of themethod for control on a heat exchanger according to the invention is therefore given by providing that the control deviation X,,,, of the specific enthalpy is calculated according to equation (5) above, wherein X, and K, are predetermined values and wherein x,,,,,, denotes the control deviation (p p of the pressure and x, the control deviation (T,- T )'of the temperature.
  • the parameters K,, and K can no longer be considered as constants.
  • a further embodiment of the method according to the invention consequently provides for this case and the values K and K are controlled as functions of the load, particularly in dependence on the reference value P, of the electric power of a turbogenerator connected to the heat exchanger. correspondingly, the reference value p of the pressure and the reference value T, of the temperature can also be controlled. In this manner, control in the varying pressure mode can also be realized.
  • all four values K K p and T are simultaneously controlled as functions of the load, for
  • the enthalpy deviation x,,, can therefore be determined for this special case according toequation (6).
  • Example 4 i Let the slightly superheated steam be in a state d defined by the pressure p,, 220 atm and by the specific enthalpy i 630 kcal/kg.
  • the steam is subjected 1 to a negative temperature change of A T,, -7C with the pressure held constant, it is accompanied by an enthalpy change A i -20 kcal/ kg. in this way, the
  • Thefir'st of these embodiments comprises the moregeneral case and is provided for :the sliding pressure mode of operation (p, variable) of the heat exchanger and for constant reference enthalpy i,, of the slightly superheated steam.
  • an auxiliary quantity, designated at a pres-' sure-dependent reference temperature T is formed as a function of the measured actual pressure p,-.
  • a temperature deviation (T, T is determined by subtracting this reference temperature T,- from the measured actual temperature T,-, and the control deviation x of the specific enthalpy is determined as a function of the temperature deviation (T,- T)
  • each of the quantities T, and A i/ A T), are most advantageously formed in respective function generators.
  • the second embodiment is suited particularly for fix ed-pressure operation (p,, approximately constant) of the heat exchanger and for constant reference enthalpy i of the slightly superheated steam.
  • the control deviation x of the specific enthalpy is calculated according to equa- 6. .9.1 2).
  • the reference enthalpy i of the slightly superheated steam is assumed not to be constant.
  • the reference enthalpy i is assumed as fluctuating about a mean refer'ence value T
  • a change Ai i i from the mean reference enthalpy i can be brought about intentionally in the operation of a heat exchanger.
  • Such an intentional change Ai can occur, for example, through control, if thereference enthalpy i,, is controlled in dependence on the load; however, it can also be caused by the action of a superordinated control if, for example, after a soot blowing operation, the distribution of the heat flow over the individual heating surfaces of the heat exchanger has changed.
  • a still further embodiment of the invention for the case where the heat exchanger is operated with a reference enthalpy i, which varies about a mean reference value T
  • a pressure dependent reference temperature T is formed as a function of the measured actual pressure p,- and a temperature deviation (T T is determined by subtracting the pressuredependent reference temperature T, from the measured actual temperature T,-.
  • an enthalpy deviation x5 is determined as a function of this temperature deviation (T, T,,), and, for the purpose offorming an effective deviation 'x for use as an auxiliary control quantity, the'intended enthalpy deviation Ai i i is subtracted from the enthalpy .deviation x determined in the above manner.
  • the intended en'- thalpy change Ai can here be controlled as a function of the'load, for example, 'as'afunction of thereference value P of the electric power of a turbogenerator connected' to the heat exchanger.
  • FIG. 1 is a signal flow diagram for controlling the feedwater in a Benson boiler according to the method and apparatus of the invention.
  • FIG. 2 illustrates a computing circuitfor determining the control deviation x 'of the specific enthalpy for a fixed operating point P T of the slightly superheatedsteam
  • FIG. 3 is a computing circuit for determining the con- I trol deviation x,,,, for constant reference enthalpy i and fixed pressure p for fixed-pressure operation.
  • FIG. 7 illustrates a'computing circuit for determining the effective control deviation x,,,, in view of an intended change AL, of the mean reference enthalpy t
  • FIG. 8 is a signal flow diagram for the feedwater control in a Benson boiler which includes superimposing the effective specific enthalpy deviation obtained according to FIG. 7.
  • a Benson boiler l is supplied with thermal energy bymeans of an energy carrier 2 for evaporating the inflowing feedwater 3.
  • the energy carrier for example, can be oil, gas or coal.
  • an injection water stream 6 is diverted away from the feedwater 3.
  • the feedwater flow less the injection water 6 Ma flow meter 8, and converted into an electrically measuredquantity M by a measuring transducer 9.
  • the flow meter 8 can be in the form of a measuring orifice.
  • the feedwater throughput 7 is preheated in' apreheater 10 of the Benson-boiler 1 and is vaporized in an evaporation 11;
  • the steam leaving the evaporator 11 is slightly superheated.
  • .It is then conducted to a first steam superheater 12.
  • From there thesteam is fed to an injection cooler 13, into which the diverted injection water 6 is fed through an injection water valve. l4.' The steam then flows to a .further steam superheater 15.
  • the steam 16 leaving the Benson boiler l is subsequently fed to a turbogenerator (not shown).
  • a temperature transmitter 17 is placed between the evaporator 11 and the first steam superheater 12 for continuously measuring the actual value of the temperature of the slightly superheated steam.
  • a temperature transducer 18 connected to the transmitter 17 converts this value into an electrical quantity T,-.
  • a pressure transmitter 19 for continuously measuring-the actual pressure value.
  • a pressure transducer 20 is connected to the pressure transmitter 19 that converts the pressure into a corresponding electrical quantity p electrical output quantity x using these quantities.
  • the quantity x is a measure of the deviation of the specific actual enthalpy i,- fromthe specific reference enthalpy i f ln the basic flow diagram shown in FIG. 1, the formation of. the output quantity x takes place with the aid oftwo fixed, predetermined electrical quantities T and p,,, which are generated in respective reference value transmitters 22 and 23 according to the desired temperature and pressure of the slightly superheated steam.
  • Embodiments of the computing circuit 21 which are adapted to a given requirement are described below with reference to the following FIGS.
  • the output quantity x,,,, of the I set as a fixed value by a reference setting device (not shown) or is controlled as aifunction of the load.
  • the input quantity (2 of the regulator 25 is a measure of the deviation of the measured throughput from the adjusted reference throughput.
  • the positioning quantity y delivered by the regulator 25 acts on the feedwater equation (5 valve 4 in a direction minimizing the deviation "of the feedwater throughput from its reference value.
  • FIG. 2 illustrates a computing circuit designated 21a which can be used with a heat exchanger or oncethrough, forced-flow boiler in which the operating point of the slightly superheated steam is determined by pressure and temperature and is essentially fixed, that is, not controlled.
  • the electrical quantities of current and voltage oc-' curring in the electrical circuits which are proportional or. correspond to the physically measured values of pressure, temperature or quantities of specific enthalpy are designated here and with reference to the remaining FIGS. asthe physically measured values andquantities to which they refer.
  • the control deviationx of thespecific enthalpy is determined in the computing circuit 21a of FIG. 2 by
  • the values K, and K are here constants adapted to the operating point.
  • the preset reference value p of the pressure is subtracted from the continuously measured actual value p of the pressure at the subtraction circuit 26.
  • the difference x p, p is multiplied by the constant K, at the multiplier 27.
  • the product K x is fed to the first input of an adder 28.
  • the reference value T is subtracted from the continuously measured actual value T, of the temperature at the subtraction circuit 29; and the difference x, T,' T is multiplied by the constant K, at another multiplier 30.
  • the product K Jr is fed to the other input of the Y adder 28.
  • the control deviation x of the specific enthalpy determined according to equation Example 4 below will illustrate howthe constant K and K are determined for a fixed operatingpoint.
  • Example 4 The operating point A of the slightly superheated steam will be assumed as given by the temperature T,.
  • FIG. 3 shows a computing circuit designated 21b for determining the control deviation x in which the pressure reference value and the temperature reference value T are no longer fixed, preset constants of the slightly superheated steam; they are rather controlled via respective function generators 31 and32 as functions of the electric power P, which'a turbogenerator connected to the heat exchanger is to deliver.
  • FIG. 4 a computing circuit designated 21c. with this circuit, the enthalpy deviation x (P according to equation (6) given above is determined.
  • the values K, and K are now also controlled as functions of the desired electric power P, via respective function generators 33 and 34.
  • the computing circuit is of particular importance for the case that the control deviation x is to be determined for anextended range of. operation, where the values of K,, and K can no longerv be considered as constant. I.
  • FIG. 5 shows acomputing circuit designated 21d, in which the control deviation x,,,,- of the specificenthalpy is determined on the basis of equation (12) for varying pressure operation 1,, variable) and constant reference enthalpy i,, of the heat exchanger.
  • a reference temperai ture T which is a function of the actual pressure p is determined as an auxiliary quantity withthe aid of the function generator 35.
  • This pressure-dependent reference temperature T is subsequently subtracted in a subtraction circuit 36 from the measured actual temfers from the foregoing embodiments only with respect to the realization of the pressure-dependent reference temperature T,,.. It is applicable forfixed-p'ress'ure oper ation (p const), specifically, if the heat content of the slightly superheated steam is to be kept constant,
  • the steam at the output of the evaporator 11 in FIG. l.-Thepressure is switched in here linearly without the use of the function generator 35 shown in FIG. 5.
  • the measured actual pressure p is first multiplied by a constant a o inalmultiplier 38.
  • the summation a1... .,p1-+T aT,,, p0 according to equation (9) is subsequently made.
  • the sum formed in this manner is equal to the pressure-dependent reference temperature T, and is fed to the subtraction circuit 36 as shown in FIG. 5.
  • the circuit configuration shown in FIG. 7 and designated 21f is provided.
  • An enthalpy deviation designated by the symbolf is determined in the computing circuit 21f, which corresponds to the computing circuit 21d shown in FIG. 5.
  • the control deviation x is effective as an auxiliary control quantity and is generated in a subtraction circuit 40 by subtracting an intended en-' thalpy change Ai, from the enthalpy deviation x determined by electronic circuits from the values of p, and T1.
  • the intended enthalpy change AL is formed inturn in an adder 41 from a first'enthalpy value Ai, and a second enthalpy value Ai
  • the first enthalpy value Ai is delivered tothe adder 41 by a control 42 according to an enthalpy deviation x which is' formed in the circuit 44 from values of P,- and T measured, for example, at the output of the steam superheater 12 following the evaporator 11 of FIG. 1.
  • the second enthalpy quantity Ai is determined, for example, by a function generator 43 as a function of the desired value of the power P, of the turbogenerator connected to the heat exchanger.
  • FIG. 8 shows a control circuit in a heat exchanger; this configuration constitutes a variant of the usual feedwater controlsystem in a Benson boiler 1 and uses the specific enthalpy for control purposes.
  • an enthalpy quantity AL is provided at the output of the Pl (proportional-integrating) control 42.
  • the enthalpy quantity Ai is formed with the Pl control 42 from the deviation x',,, A T of the temperature difference (T T,,) from its reference value, the temperature pertaining to the intensely superheated steam and being measured at the injection cooler 13.
  • the effective enthalpy deviation x determined in the circuit configuration of FIG. 7 is linked at a multiplier 44 with a reference value P, to the reference value M W of the feedwater throughput.
  • the value P is equal, for example, to the desired value of the power output of the turbogenerator following the Benson boiler 1.
  • the measured feedwater flow M is compared in a subtraction circuit 45 with this reference value M and the difference (M M formed there is fed to a PI control 46.
  • the positioning drive of the feedwater valve 4 is controlled in accordance with the positioning quantity y delivered by the Pl control 46.
  • Method of controlling a heat exchanger such as a forced-flow boiler or the like wherein slightly superheated steam is generated, comprising continuously determining the specific actual enthalpy (i,-) of the slightly superheated steam, and utilizing the specific actual en-. thalpy as an auxiliary control quantity.
  • the heat exchanger is supplied with the operating mediums of fuel and feedwater and is equipped with adjusting means for adjusting the flow of at least one of the operating mediums to the heat exchanger, comprising continuously measuring the actual pressure (p,) and actual temperature (T,-) of the slightly superheated steam in the heat exchanger, supplying the measured actual values of pressure (p,) and temperature (T to a computation circuit for determining the control deviation (x,,,,) of the specific actual enthalpy (i,) from the reference value of the enthalpy (i and supplying the control deviation (x,,,,,) of the specific enthalpy as a correction quantity for the input quantity of the adjusting-means.
  • the adjusting means includes a controller connected to a positioning device for adjusting the flow of one of the operating mediums to the heat exchanger, comprising supplying the control deviation (x,,,,) of the specific enthalpy as a correction quantity for the input quantity (e) of the controller.
  • the method of claim 2 comprising supplying respective predetermined reference values of pressure (p,,) and temperature (T,,) for the slightly superheated steam to the computation circuit, and determining the control deviation (x,,,,-) of the specific enthalpy from the measured actual values of the pressure (p,-) and temperature (T,-) and the predetermined refemce values of pressure (p,,) and temperature (T i 5.
  • the method of claim 4 comprising determining the specific enthalpy (.xwi) according to the equation:
  • turbogenerator for supplying the same, the turbogenerator having a reference value (P of electric capacity, and wherein the values of pressure (p0) and temperature(T,,) and values of (K,-,) and (K,) are all functions of (P,,).
  • the heat ex- 5 changer operates under the condition that the reference value of the pressure (p,,) is variable and the reference value of the enthalpy (i of the slightly superheated steam is constant, and wherein the method comprises forming a pressure dependent auxiliary quantity as a function of the measured actual pressure (p,-), said quantity being in the form of reference temperature (T subtracting the reference temperature (71,) from the measured actual temperature (T,-) to determine a temperature deviation (T 1.), and determining the control deviation (x,,,,-) of the specific enthalpy as a function of the temperature deviation (T,- T
  • T pendent reference temperature
  • ence temperature from the measured actual temperature (7 ⁇ ) to determine the temperature deviation (T, T determining a control deviation quantity (f asa function of the temperature deviation (T, 7),), and subtracting an intended enthalpy change (Ai i, i,,) from the quantity (f to formthe control deviation (x,,,,).
  • the method of claim 15 wherein the heat exchanger is connectable to a turbogenerator for supplying the" same, the turbogenerator having a specified value (P of electric capacity, and wherein the intended enthalpy change (Ai is a function of (P 17.
  • the heat exchanger is equipped with an injection cooler supplied with intensely heated steam and a superordinated controller, comprising detecting the temperature difference (T', T',,) of the intensely superheated steam at the injection cooler and forming therewith the deviation quantity (x' A and supplying the deviation quantity (x',,, A to the superordinated controller to form the quantity (Ai' for correcting the enthalpy deviation (Ai 18.
  • a heat exchanger such as a forced-flow boiler or the like supplied with the operating mediums of fuel and feedwater and having an evaporator wherein slightly superheated steam is generated
  • the heat exchanger being equipped with an apparatus for controlling the heat exchanger, the apparatus comprising pressure detection means and temperature detection means for continuously measuring the pressure and temperature respectively of the slightly superheated steam at the output of the evaporator, computation means connected to said detection means for continuously determining the specific actual enthalpy of the slightly superheated steam, and means connected to said computation means for controlling the heat exchanger in response to said specific actual enthalpy.
  • the heat exchanger is equipped with a conduit to supply the feedwater tothe heat exchanger proper, said adjustment means comprising positioning equipment, said equipment including a valve for controlling the supply of feedwater to the heat exchanger, and a positioning device connected to said valve for adjusting the position i of said valve,
  • the heat ex- 1 changer is equipped with a conduit to supply the fuel to the heat exchanger proper, said adjustment means comprising positioning equipment said equipment ineluding a valve for controlling the supply of fuel to the connected to said pressure transmitter for converting said pressure to a corresponding electrical quantity; said temperature detection means comprising a temperature transmitter placed at the output of the evaporator, and a temperature transducer connected to said temperature transmitter for converting said temperature to a corresponding electrical quantity; said computation means comprising respective reference transmitters for providing respective predetermined electrical reference quantities of pressure and temperature for the slightly superheated steam, and further computation circuit means connected to said reference transmitters and said transducers for forming a control deviation signal corresponding to the deviation of the specific actual enthalpy from the reference value of the enthalpy; and said adjustment means comprising means responsive to the control deviation signal for adjusting the flow of at least one of the operating mediums to the heat exchanger.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Steam Boilers And Waste-Gas Boilers (AREA)
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EP0079598A2 (en) * 1981-11-13 1983-05-25 Westinghouse Electric Corporation Steam turbine bypass system
US4451003A (en) * 1983-06-09 1984-05-29 Exxon Research And Engineering Co. Control scheme and apparatus for a cogeneration boiler
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US4557686A (en) * 1984-07-16 1985-12-10 Phillips Petroleum Company Control of the flow of fuel to multiple burners
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US5676713A (en) * 1993-09-28 1997-10-14 Hitachi, Ltd. Method of fuel gasification and an apparatus for performing such a method
EP1614962A1 (de) * 2004-07-09 2006-01-11 Siemens Aktiengesellschaft Verfahren zum Betrieb eines Durchlaufdampferzeugers
US7504260B1 (en) * 2000-05-16 2009-03-17 Lang Fred D Method and apparatus for controlling gas temperatures associated with pollution reduction processes
US20100288210A1 (en) * 2007-11-28 2010-11-18 Brueckner Jan Method for operating a once-through steam generator and forced-flow steam generator
US20110139094A1 (en) * 2008-06-12 2011-06-16 Brueckner Jan Method for operating a continuous flow steam generator
CN103080648A (zh) * 2010-09-03 2013-05-01 西门子公司 太阳能加热的直流式蒸汽发生器的运行方法以及太阳能直流式蒸汽发生器
US20130319403A1 (en) * 2011-02-17 2013-12-05 Jan Brückner Method for operating a solar-thermal parabolic trough power plant
US20170234528A1 (en) * 2016-02-17 2017-08-17 Netzsch Trockenmahltechnik Gmbh Method And Device For Generating Superheated Steam From A Working Medium

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DE3243578C3 (de) * 1982-11-25 1998-10-22 Babcock Energie Umwelt Verfahren zum Betreiben eines Zwangsdurchlaufdampferzeugers
DE3303548C3 (de) * 1983-02-03 1995-05-18 Babcock Energie Umwelt Verfahren zum Betreiben eines Zwangdurchlauf-Dampferzeugers
US4776301A (en) * 1987-03-12 1988-10-11 The Babcock & Wilcox Company Advanced steam temperature control
JP2563099B2 (ja) * 1992-05-04 1996-12-11 シーメンス アクチエンゲゼルシヤフト 強制貫流蒸気発生器
US5307766A (en) * 1993-03-12 1994-05-03 Westinghouse Electric Corp. Temperature control of steam for boilers
WO2000031469A1 (fr) * 1998-11-25 2000-06-02 Masnoi, Sergei Sergeevich Procede d'exploitation d'une installation a turbine a vapeur

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US3877636A (en) * 1973-01-16 1975-04-15 Hitachi Ltd Automatic starting device for plant
US4005581A (en) * 1975-01-24 1977-02-01 Westinghouse Electric Corporation Method and apparatus for controlling a steam turbine
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US4471622A (en) * 1981-07-22 1984-09-18 Tokyo Shibaura Denki Kabushiki Kaisha Rankine cycle apparatus
EP0079598A2 (en) * 1981-11-13 1983-05-25 Westinghouse Electric Corporation Steam turbine bypass system
US4471620A (en) * 1981-11-13 1984-09-18 Westinghouse Electric Corp. Turbine low pressure bypass spray valve control system and method
EP0079598A3 (en) * 1981-11-13 1985-01-23 Westinghouse Electric Corporation Steam turbine bypass system
US4451003A (en) * 1983-06-09 1984-05-29 Exxon Research And Engineering Co. Control scheme and apparatus for a cogeneration boiler
US4489679A (en) * 1983-12-12 1984-12-25 Combustion Engineering, Inc. Control system for economic operation of a steam generator
US4557686A (en) * 1984-07-16 1985-12-10 Phillips Petroleum Company Control of the flow of fuel to multiple burners
US4589255A (en) * 1984-10-25 1986-05-20 Westinghouse Electric Corp. Adaptive temperature control system for the supply of steam to a steam turbine
US4574746A (en) * 1984-11-14 1986-03-11 The Babcock & Wilcox Company Process heater control
US5676713A (en) * 1993-09-28 1997-10-14 Hitachi, Ltd. Method of fuel gasification and an apparatus for performing such a method
US7504260B1 (en) * 2000-05-16 2009-03-17 Lang Fred D Method and apparatus for controlling gas temperatures associated with pollution reduction processes
EP1614962A1 (de) * 2004-07-09 2006-01-11 Siemens Aktiengesellschaft Verfahren zum Betrieb eines Durchlaufdampferzeugers
WO2006005708A1 (de) * 2004-07-09 2006-01-19 Siemens Aktiengesellschaft Verfahren zum betrieb eines durchlaufdampferzeugers
US20080066695A1 (en) * 2004-07-09 2008-03-20 Axel Butterlin Process for Operating a Continuous Steam Generator
US7624708B2 (en) 2004-07-09 2009-12-01 Siemens Aktiengesellschaft Process for operating a continuous steam generator
AU2005261689B2 (en) * 2004-07-09 2010-02-04 Siemens Aktiengesellschaft Process for operating a continuous steam generator
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
US20110139094A1 (en) * 2008-06-12 2011-06-16 Brueckner Jan Method for operating a continuous flow steam generator
US9291345B2 (en) * 2008-06-12 2016-03-22 Siemens Aktiengesellschaft Method for operating a continuous flow steam generator
CN103080648A (zh) * 2010-09-03 2013-05-01 西门子公司 太阳能加热的直流式蒸汽发生器的运行方法以及太阳能直流式蒸汽发生器
US20130319403A1 (en) * 2011-02-17 2013-12-05 Jan Brückner Method for operating a solar-thermal parabolic trough power plant
US20170234528A1 (en) * 2016-02-17 2017-08-17 Netzsch Trockenmahltechnik Gmbh Method And Device For Generating Superheated Steam From A Working Medium
US10451270B2 (en) * 2016-02-17 2019-10-22 Netzsch Trockenmahltechnik Gmbh Method and device for generating superheated steam from a working medium

Also Published As

Publication number Publication date
FI52398B (fi) 1977-05-02
FR2133672B1 (fi) 1981-04-10
BE782175A (fr) 1972-10-16
SE7204787L (fi) 1972-10-16
ZA722332B (en) 1972-12-27
GB1387716A (en) 1975-03-19
CA959562A (en) 1974-12-17
DE2118028A1 (de) 1973-03-15
FI52398C (fi) 1977-08-10
IT957176B (it) 1973-10-10
AT317929B (de) 1974-09-25
FR2133672A1 (fi) 1972-12-01

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