Патент USA US2126248код для вставки
Aug. 9, 1938. M. EULE 2,126,248 STEAM GENERATOR WITH FORCED PASSAGE OF THE OPERATING MEDIUM - Filed March 12, 1937 0f . Wafer of Wafer* v ` I F» 2 sheets-sheet 1 ‘ wafer *deo/77 I' ` | cab/aci’ fr@ 'f2' ¿LI C j i ATTORNEY. Aug. 9, 1938. M, EULEA “ 2,126,248 STEAM GENERATOR WITH FORCED PASSAGE OF THE OPERATING MEDIUM Filed March 12, 1957 42 sheets-sheet 2 F1a. 6. -1 FUEL und Ffm MJ» FUR. ,3) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _, _ _ _ F _ _ _ _ _ _ _ INVENTOR Mam-:N EULE .1 BY . a» . ß @www ATTORNEY Patented Àug. 9, 193s »i wie@ UNITED NsrATes PATENT orsi-cs- ' ‘ - Y» ’ 2,126,248.’j v « ` I ' f v . STEAM GENERATOR wrm Foiaoni)` pas'-` SAGE THE OPERATING MEDIUM Y Martin Eule, Berlin-Spandau, Germany, assigner to Siemens-Schuckertwerke Aktiengesellschaft, , Berlin-Siemensstadt, Germany, a corporation of Germany Application March 12, 1937,` Serial No. 130,477 In Germany November 23, 1934 “ ` 3 claims. (ci. 1272-443) My invention relates to steam generators of the superheater arrives, as a rule, too late. The the forced-flow tubular type and it has for an regulation effected by this impulse, consequently, object to provide a control system therefor -lagsï considerably, whereas the derivation of the , wherein elTec'ts of lag, so far as the temperature 5 impulse `is concerned, are substantially avoided. This application is a continuation in part of application> Serial No. 50,860, ñled by me on November 21, 1935 for Steam generators with forced passage of the operating medium. A further and more particular object of my invention is to modify the steam-producing con ditions of one ofthe tubes of a plurality of parallel-connected tubes so that said tube will `have a region of variable temperature over lapping a portion of the evaporation zone of the remaining tubes, or within the physical limits of the latter, whereby there is provided a tube region of Variable temperature within the main evaporation zone and which region may be used to provide a temperature impulse for the con trolling apparatus. » In steam. generators of the above character, the supply of the operating medium and the . fuel must be varied in such a manner as to ap 25 `proximately maintain a. predetermined ratio of both operating mediaif in the case of variations of load the condition of the steam produced is tolremain unchanged. This may be also ac complished by the two regulating methods which, as a rule, have hitherto been employed. >By one of the regulating methods the operating medium `and the fuel is simultaneously supplied Ain a> greater or smaller amount depending upon the desired output, in which case a Correction im 35 pulse is caused to be transmitted in response to the steam temperature for ensuring a reliable regulation thereof, which impulse in addition acts upon the supply of fuel. According to the other method >the supply of the operating me V40 dium and the fuel is not varied simultaneously, l 30 impulse at the preheater is effected so prema turely that considerable variations of the oper- v Ul yating conditions may again occur at the end of the -generator.` No temperature impulse may be derived from the‘part of the heating surface lying between the preheater and the superheater‘; i. e., from the evaporatingfheating surface of the 10 generator, since the temperature of the operat ing medium during the evaporation remains un altered. ~ ` The -`object of the-present invention is, there fore, to-utilize the part~of the heating surface lying betweenfthe preheater and the‘superheater for the‘transmissionof the impulse. ~ ‘ The "essence of the invention consists in gen eral inthe fact that the supply of heat or `of the' operating medium to one of the tubes con '.20 vne'cted'in parallel and forming the heating sur >4`face is so regulated with respect to the-other Ttubes that in this partièulartube the preheating »terminates later ‘or the superheating begins earï lier than in the other tubes and that the tem perature impulseis derived frcmthis tube from a `point wherethe preheating terminates or the 'superheating begins. NvIf the impuls-e in response to the temperature fof the superheated‘steam is to be transmitted, in due time, ther-tube destined for the supply'of `the impulse must experience with respect to the `other tubes a decreased supply of the operating f medium or an increased supply of heat. Depend ingiupon the extent, `to which the decrease or p increase of thefsupply of beth mentioned oper `ating vmedia isbrought about, the superheating Vin the tube supplying‘the impulse, measured ,ac :cording to the length of ‘the tube, will commence correspondinglyïearlier ¿than in the other tubes. but in succession; that is tosay, the» supply of . It is thus possible to` derive `the `temperature »im the operating medium is at ñrst adjusted to the ‘pulses to a'sufñcient extent from a heating sur vdesired new value and then the supply of fuel face part which normally forms the evaporating is regulated by an impulse,Ã derived in response `heating surface. In practice, this `may be ac to a variation of the temperature of the steam „complished in the simplest manner by reducing 45 produced. In both regulating methods, the deri the supply of operating medium tothe measuring vation of an impulse in response to the tempera » tube with‘frespect to the other tubes. In 'this' tureof the steam produced plays an important i case, it is only necessary to insert in this tube part. For the transmission ofthis temperature in the path of flow at a suitable point, preferably i150 impulse only two'points of the heating surface inthe zone in which the operating medium is» 50 of the steam generator had hitherto been taken still liquid, a resistance correspondingly rated. into consideration; viz. the superheater and the Dependent upon the magnitude of this resist-V preheater. The derivation of the impulse from » ance, theppoint at which the superheating begins, these parts of the heating >surface is, however, ,willydisplace itself in the measuring tube more not fully satisfactory. An impulse derived. from’ i or :less opposite‘to the` direction of flow of the! 55 2 2,126,248 It has hitherto been customary in steam gen erators with forced passage of the operating me ture impulse necessary for the regulation of the generator may be then derived from this heating surface point, at which the superheating begins. It suffices if the supply of the operating medium dium to arrange at least one part of the heating surface, in which under normal operation the or the supply of heat for this measuring tube is la so regulated that the steam flowing from this conversion of liquid into steam is effected, as con tact heating surface in the path of the fuel in vtube into the salt separating drum is only slight order to prevent a burning out of the tubes due ’ Thus, it will be seen that, in all applications of the invention, a plurality of parallel tubes are operating medium with respect to the other tubes. ' principally in this phase of production of steam to salts depositing from the operating medium. Since, with a measuring tube having means pro viding for its superheating Zone being displaced forwardly relatively to the superheating zone of the other‘tubes, the other phases or zones of steam production of the measuring tube are also displaced to» more or less extent in the direc tion opposite to flow of working fluid, with vthe result that the salt deposit zone of the measuring tube may not remain Within the contact or con vection heating region of the generator Ybut be shifted into the radiant heat zones; and, in con sequence, it may happen that the measuring tube, because of the wandering of the phases of steam production and creeping of the salt deposit zone into the radiant heat zone, -or zone of high heat intensity, may have salt deposited in portions of the surface thereof subject to such high tem peratures and give rise to burning out of the measuring tube, this objection having already been lavoided by the intentional displacement of the salt‘deposit zone of the remaining tubes into the contact or convection heating surface where >such a »relatively low temperature normally ob tains as to avoid burning out of tubes, even though depositsrof salt should occur. The other solution, as above _generally stated, of the probleml upon which the invention is based prescribes that at least' one of the parallel con nected tubes should experience an increased sup Vply of operating medium or decreased supply of heat with respect to the other tubes and Vthat ly superheated. arran'ged'to have at least one thereof serve as a measuring tube in order to provide a controlling temperature impulse so that lag may be mini mized. Any suitable means may be employed to secure offsetting of the zones of steam pro duction of the measuring tube with respect to such zones of the Vremaining tubes, the essential feature being to provide for the temperature im pulse being taken at a point of variable tempera ture along the measuring tube and falling Within the physical limits of the evaporation zone of the remaining tubes. In the drawings, Figs. 1 to 5, inclusive, are dia grammatic views` illustrating the essential feature orcharacteristic of the present invention; Fig. 6 is 'a diagrammatic view showing the ap plication of the principle of Figs. l, 3, and 5; Fig. '7 is a diagrammatic view showing the ap plication of the principle of Figs. 2 and 4. Y _ Figs. 8 and 9 are diagrammatical sectional views :30 of ilow control or throttling devices for the tubes. The present invention is illustrated in diagram matic form in Figs. 1 to 5. VThe tubes forming the heating surfaces are diagrammatically repre sented in the form of heavy lines. The ends of the tubes enter collecting or distributing vessels. The direction of flow of the operating medium is indicated by the arrows as shown. Flow control or throttle points in the tubes are indicated by cross lines intersecting the tubes, whereas the temperature points are indicated by small Ycircles drawn on the tube lines. Insofar as the flowfcon the temperature impulse should be derived from ' trol or throttle points are cut oft" or the tempera this particular tube at the point, at which the ture measuring points are not used for the regu preheating ends. » It may be further stated that the invention has a particular importance for such steam gen erators which are fed with an excess of operating Y to medium, and in which the steam before the be ginning of its superheating hows into a drum, in which the excess of water is separated from the steam produced up to that moment and is car ried off from the generator. For such steam generators it was hitherto not possible rto de rive for the boiler a temperature impulse suit able for regulating purposes before the separat ing drum.Y If the invention is to be 'applied for these steam generators two methods are possible according to the invention. In accordance with one method, the preheating zone is displaced, as lation the corresponding symbols are shown in all . figures in dashes. In all figures the lowest of the three tubes serves for the reception of the impulse which as above described may alternately be derived from the one or the `other of the tubes shown by the use of change-over 'devices not shown. The diagrammatical representation which shows only three tubes is to be considered only ‘as an example; the number of the tubes -may vary at will. Figs. l and 3 show the conditions for the case, 55 in which the impulse is transmitted in response `to the temperature of the superheated steam, the time at which the superheating begins being displaced towards the operating medium inlet point. In these views, short lines intersecting 60 above described, toward the boiler outlet, that vthe tubes indicate flow control or throttling de is, in this case, toward the separating drum, and vices, the heavy short lines, at t, indicating a the temperature impulse is taken at a point along throttling or resistance setting of the devices and the measuring tube within 'the ñnal region of the light lines, at o, an open or non-throttling -65 the preheating Zone of -the measuring'tube which setting thereof. overlaps the initial portion ofthe evaporation Figs'. 2 and 4 show the derivation of the im Zone of the remaining tubes. In the other meth od, the measuring tubeis soV arranged and Vsteam producing media are so supplied thereto that the initial portion of the superheating zone -thereof overlaps a portion of the evaporation »Zone ofthe ‘remaining tubes; and, as before, the initial over lapping portion of the superheating zone of the measuring tube is used to give 'la temperature impulse for controlling purposes. The tempera ‘ pulse from a point lying at the end 'or near the ond of the preheating, the end of the preheating being displaced with ‘respect to the other tubes towards the generator outlet. Fig. 5 vshows 'the 70 derivation of the impulse in the case of a steam generator which 'is fed with an lexcess of water and in which the excess of water is separated from the steam in a drum as shown in the draw ings. As beforefthe resistance or throiítling'setß 75 2, 126,248 ting of the flow control devices is indicated in each instance by a heavy> cross-line and by the reference character t and the non-throttling set tings thereof are indicated by the light cross lines and the reference character o. In Figs. 6 and 7, there are shown diagrammatic ` arrangements employing the principle of control already described; and, in each of these views there are shown parallel connected tubes I0 and 10 II supplied with feedwater by a pump I2 and with heat by means of any suitable combustion apparatus connected generally at I3. Super heated steam is supplied from the tubes to the prime mover I5. The tubes I0 are so arranged and steam-pro ducing media are so supplied, thereto that the heating surface is divided into a preheating zone A, an evaporating zone B, and a superheating zone C; however, the measuring tube II is ar ranged, by any suitable means, to have its corre sponding Zones offset so as to provide regions of 3 in the measuring tube with respect to the re maining tubes, any suitable flow control or throt tling devices being associated with the tubes for this purpose. In Figs. 1 to '7, inclusive, the throt tling or resistance setting of these devices is indi 5 cated in each instance by a heavy cross-line and the reference character t and the non-throttling setting is indicated by a light cross-line o. Figs. 8 andV 9 show, by wayy of example, iiow control or throttling devices capable of being placed in the throttling position, t, or in the non-throttling or open position o. In these views, the resistance or throttling condition, t, is secured by adjusting the valve 22 so that ñow occurs through the upper branch of the passage having the orifice 23 While the open or non-throttling condition is secured by adjustment of the valve so that ñow occurs through the lower branch of the passage. As hereinbefore described, the load effect of the prime mover may be used to supply a controlling 20 impulse to either or both of the steam-producing the heating surface thereof, preheatingor super media, feedwater and heat, supplied to the boiler. heating, overlapping or falling within the physi In Figs. 6 and 7, `this impulse is indicated dia `cal limits of the evaporation zone B, whereby such grammatically as originating with the prime 25 overlapping portion of the measuring tube pro- . mover governor and going to motors I9 and 20, vides a region of variable temperature within the whichdetermine or control the operation of the limits of the evaporation Zone B and which may feed pump and of the fuel and air supply. In _be used to give a temperature controlling im addition, the temperature impulse coming from pulse. l the device I8 in Fig. 6 is shown as being super 30 In Fig. 6, by restricting the flow, for example, imposed upon the main impulse in order to exer 30 in the measuring tube II relatively to the flow cise a corrective effect, whereby a desired out in each of the remaining tubes II), it will be seen going superheated steam temperature may be that the superheating zone C’ extends further maintained. Inv Fig. 7, instead of the governor back so that the initial portion b-cV falls within impulse being used to control both the feedwaterA 35 the physical limits of the main evaporation Zone and the heat supply means, this impulse is B of the tubes III, and this initial or overlapping exerted only on the feed water supply means, portion of the measuring tube is, therefore, sub ject to rise and fall of temperature dependent on operating conditions and may be used- to provide 40 a temperature impulse for the controlling appa ratus. Any suitable means may be used to secure dif ferential throttling of flow in the measuring tube with respect to the remaining tubes. Accord 45 ingly, in Fig. 6, the heavy cross-line I Ii at the left hand end of the measuring `tube indicates a greater resistance to fiow therein than through the remaining tubes I0, the resistance of the latter being indicated by the relatively light cross lines I1. In this view, a temperature responsive device I8 is shown associated with the overlap ping portion b--c of the measuring tube and pro vides an impulse for the control system, as will the temperature responsive device I8’ operating to control the fuel and air supply means. Ac cordingly, therefore, so far as the present inven tion is concerned, it is only essential that the con 40 trol system shall use a temperature impulse and it is immaterial speciñcally how this impulse is utilized. While I have shown my invention in several forms, it will be obvious to those skilled in the 45 art that it is not so limited, but is susceptible of Vvarious other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are speciñcally set forth in the appended claims. f What I claim is: - be immediately pointed out. 1. In a steam generator, a plurality of parallel 55 >Fig. '7 shows a diagrammatic arrangement connected tubes, means for supplying feedwater 55 which is similar to Fig. 6 except that the resist as working medium and heat to the tubes so that ances are reversed, greater flow occurring the Working medium is preheated, vaporized and through the measuring tube I I than through the superheated in successive Zones; means providing .remaining tubes II), with the result that the pre for offsetting of said zones in one tube with re heating, evaporation, and superheating zones A2, spect to the zones of the remaining tubes, so that B2, and C2 are displaced toward the outlet, where-- said first tube constitutes a measuring tube, by there is provided a final portion a--b of the whereby the measuring tube has a region of preheating Zone A2 which overlaps the initial variable temperature which partially overlaps the portion ofthe main evaporation zone B, this over evaporation Zone of said remaining tubes; and lapping portion a-b of the measuring tube pro means for deriving a temperature impulse fromv 65 viding a region of heating surface whose tem said overlapping region of the measuring tube perature varies dependent upon operating con and for utilizing the impulse to control said sup ditions and which falls Within the physical limits ply means. of the main evaporation zone. ` Accordingly, the 70 temperature responsive device IB’ is associated 2. The combination as claimed in claim 1 wherein the means providing for oifsetting of the with the overlapping portion a-b and provides zones in the tubes are adjusted so that the initial 70 a temperature impulse for the controlling system. portion of the superheating Zone of the measur As hereinbefore pointed out, resistance or flow ing tube is overlapped by the ñnal portion of the control devices are associated withthe various >evaporation Zone of the remaining tubes and 75 tubes soY as to secure a differential ñow effect wherein the means for deriving a temperature 75 4 2,126,248 impulse -from the measuring tube is associated with said overlapped portion thereof. ' 3. The combination as claimed ‘inV claim 1 wherein the means providing for oiïsetting the zones of the tubes are adjusted so that the final portion of the preheating zone'of the measuring tube is overlapped by the initial portion of the evaporation zone of the remaining tubes and wherein the means for deriving the temperature impulse from the measuring tube is associated with said lñnal overlapped preheating portion thereof. Y Y MARTIN EULE.