DE1933473A1 - Device to improve the shutdown safety when operating turbo systems - Google Patents

Description

SIEMENS AKTIENGESELLSCHAFT Erlangen, - JULY 1, 1969

Werner-von-Siemens-Str. 50

Our reference: PLA 68/0728 Bu / Fl

Device to improve the peeling safety during operation of turbo sets

The main application P 17 51 631.3 relates to a method for improvement the shutdown safety when operating turbo sets, which regulate and shut off the flow of propellant to the turbine parts (HP, MD and / or LP parts) with control and Tight-closing valves are provided, preferably from saturated steam turbo sets, Their housings, lines, superheaters, cyclones and the like form considerable storage volumes for the steam. According to this Registration has already solved the problem of the quick release speed in turbo sets of the type mentioned in the event of a load cut-off and hanging or jamming control valves without that expensive rotary flaps in front of the low-pressure parts or other, large storage volumes having facilities of the turbo sets should be used. This is achieved by the fact that, depending on whether the setpoint of the control valve position for a maximum permissible speed of the proportional range (closed position and / or position shortly before closing) or is not reached due to malfunctions (e.g. valve jams), the actual value The yes or no signal corresponding to the valve position is derived and the signals obtained for several monitored control valves when one or more of the control valves do not assume their desired position, a resultant signal results, which In the sense of an AND condition, it is related to a value corresponding to the overspeed actual value of the turbine (s) Signal, and in this malfunction case, a command derived from the resulting signal and the speed-proportional signal as Trigger command of the safety device, especially the quick-release device (the quick-closing valves) and, if necessary, blow-off devices is forwarded.

The main application is also a device for Implementation of the aforementioned method, which is mainly characterized in that as the yes or no signals

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Valve position supplying query organs, limit switches provided which can be actuated depending on the stroke of the control valves. The signals are generated electrically. the The present invention assumes that there are many hydraulic and electrohydraulic turbine control devices It is desirable if the signals generated according to the method of the parent application for reducing the quick-closing speed already exist are available as hydraulic signals, d. H. to use these signals directly without switching on auxiliary electrical power, electro-hydraulic forming is not required. It is therefore based on the task of a device to implement the method according to the main application, with which hydraulic signals obtained in a simple way can be.

The subject of the invention is now a device for implementation the procedure to improve the safety of shutdown in the operation of turbo sets, which are used for regulation and shut-off the propellant flow to the turbine parts (HP, MD and / or HP parts) are provided with control and quick-closing valves, preferably of saturated steam turbo sets, their housings, lines, Superheaters, cyclones and the like. Considerable storage volumes for the Form steam, depending on whether the setpoint of the control valve position for a maximum permissible speed of the proportional range (closed position and / or position shortly before closing) or due to malfunctions (e.g. valve jams) is not reached, a yes or an on signal corresponding to the actual value of the valve position is derived and the for several monitored control valves then obtained signals when one or more of the control valves do not assume their desired position, result in a signal which in the sense an and-condition is related to an over actual speed value of the turbine (s) corresponding to the signal, and in this malfunction case, one from the resulting and the speed-proportional one Command derived from the signal as a release command to the safety devices, such as

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direction (the Schnellsehlußventllen) mad if necessary blow-off devices will sow. Batest ... (Patsntaasieldimg P 17 51 631. 3), in use on hydraulic © the electro-hydraulic control e devices _t at desQB © In v © s controller three-phase or load-dependent controlled oil säsiaek eiaes regular oil ice via hydraulic Steliao gates »d® a öffmragagrad d © 2? Regalian tile determined and in buckets SehnellaehliaBölkreis AE®% öldnaek by the safety device (eg, B "Dretoahlwäeht © ^ Bnsklagersicherung, manual release ₉ capacitor aelratieiarieliirtisg o. SGI ₀₎ Ia disturbance case iat be changed such that the SehnellsshlußveBtile be closed _β The invention consists in that sot acquisition of the actual value of the rule investment division © ntepraetesdea Yes «bsw Neinaignale with dea Regelveiatilkegela hub & pendently coupled query organs are used, which each dta Kaualqusrsehaitt between the ad- waä expiry since © eis © s Hilfeu.lstreigee at®u © ETa, and that this auxiliary 81sw © ig about Eis irehsahlsbhäisgig feetätigbarSeut a @a Schnellschlussölkreis aageiefeloae® !! is, where the Scteltgliei in the event of an overspeed connects the Setegllse & lußölkreis with the auxiliary oil branch and the latter gea © is @ a © elt ü®m Setaelliehlußölreia with a disturbed control valve (© ώ) 5ife @ r di @ Abfsageorgane the triggering of the Schnellcfelueses ^ SBd experiences a change in pressure that may cause the blow-off ice directions.

The advantages that can be achieved by the invention are above all therein to see that electrical auxiliary power for the protective circuit can be dispensed with and aaS conventional and proven mechanical-hydraulic Converter and hydraulic slide valve used can be, which latter act on the quick release device, so that it is a simple and safe circuit results.

It is particularly advantageous if, as is known per se, the Pressure in the Regelölreia is a so-called secondary oil pressure, which Via a signal change stage from the with increasing turbine speed or decreasing load, increasing primary oil pressure of a control gyro is obtained and accordingly with increasing load

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load or falling speed increases, with an increasing Secondary oil pressure on the servomotors of the control valves in the valve opening direction acts, and that the quick-acting oil circuit supplied by a pressure oil pump through the safety devices can be connected to a drain, the pressure reduction in the quick-closing oil circuit acting in the direction of closing of the quick-closing valves. A Such a system has the advantage that in the event of oil leaks in the oil supply system or the system is automatically shut down if the oil pumps fail.

According to a further development of the invention, the query organs are designed as a reset spring-loaded slide switch, which Are mechanically coupled to the tappets of the respective control valves via a coupling arm or the like and for the purpose of checking the A port set protrudes from the slide valve housing and which have a closure piece for controlling the passage cross section between their inlet and outlet side, the Switch slide with intact, in or shortly before the closed position located control valves, from the coupling arm in their closing direction released, resetting spring-loaded with a locking piece close their drainage opening, however, with the control valve hanging be held by the coupling arm while keeping the drain opening free,

The surveillance system can still be perfected by that the switching element is known rotating, resetting spring-loaded Slide switch is formed, which on the one hand can be acted upon by the secondary oil of the control oil circuit, and on the other on the one hand with control edges the connection between the quick-acting oil circuit and auxiliary oil branch establishes or interrupts. The rotation pressed by the pressure oil on the slide has - as is known per se - a The result is elimination of the exercise at rest and thus a faster one Speak to. ....- ■ '

Further features and details of the invention are set out below based on the illustrative embodiments only Drawing explains in which show:

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Pig. 1 is a diagram in which the proportional ^{degree X = p} "*" ff is plotted as a function of the load P? ^η Ν the curve thus represents the usual characteristic for proportional control;

Flg. 2 schematiaeh as a circuit diagram, partly with constructive Representation, the device according to the inventionj

3 shows a section from S ¹ Ig. 2 rentable with the rule open,

Pig. 4 a simplified circuit diagram of a turbine system between Boilers and condensers to which the invention is applicable.

The control range of a steam turbine system (not shown in more detail), which can operate with hydraulic or electro-hydraullach control, is assumed to be 5 _{according to Pig a 1.} This area is between JJL ,. - 0 $> (üTennlast) and X "= 5 % (idle). P means the load, Dtt the idle speed, n- ^ the nominal load speed and d. the release speed, corresponding to a degree of proportionality X «+ 1 # = 6 # · Naturally, the invention is not limited to control ranges up to 5 ^ or release speeds of 6 # above the rated speed. It is essential, however, that this triggering speed value is below that speed value which is provided for the response of the quick-release device. The latter speed value is generally set between 10 to 13% above the nominal speed. As is well known, this setting is necessary so that a turbine can be safely intercepted when the shut-off device responds without aie reaching the critical overspeed value of $ 25.

The one in the Pig. The device shown in FIGS. 2, 3 now implements a method for improving the shutdown reliability during operation of turbo sets, which are used to regulate and shut off the Medium flow to the turbine parts T, which HD-, MD- and / or LP parts with control valves V1, V2 and quick release valves SS are provided. This method is preferred

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wise suitable for saturated steam turbo sets, the housing, lines, ÜlDerhitzer, cyclones and the like. Form considerable storage volumes for the steam. With such saturated steam turbo sets, it is important that if a control or control valve is not hung or jammed, the quick-closing device is not only activated at 10 to% overspeed, but rather the quick-closing speed is reduced for the special case of strong load reduction in the case of hanging control valves, so that a Overspeed of $ 25 is certainly not reached, without additional intercepting devices, such. B. large rotary flaps would have to be used in front of the low-pressure parts. In this case, the interception process can be safely controlled even without the use of large rotary flaps. The device according to the invention is in the Pig. 2 and 3 shown in application to a hydraulic control device in detail. In FIG. 2, an oil pressure p1 proportional or load-dependent to the speed ώ of the shaft of the turbine T indicated at 1 is generated by a controller (not shown in more detail) via a control gyro Kr. This speed-dependent or load-dependent primary oil pressure p1 is converted via a signal reversing stage S into a secondary oil pressure p2 that increases with increasing load or decreasing speed. In the illustrated embodiment, a follower piston system F1 is used for this purpose, which has a resetting spring-loaded follower piston f1 and a slotted sleeve f2, the oil pressure in piston chamber f3 being greater the further the follower piston f1 is temporarily due to the downward moving cross-section and the drainage cross-section concealing slot sleeve is also moved downwards. Follower piston f1 and slotted socket f2 can be moved relative to each other, whereby the primary oil pressure acts on arm f21 via a hydraulic-mechanical converter (not shown) and, with increasing values, pushes the slotted socket on follower piston f1 temporarily upwards, whereby the outlet cross-section f10 to f20 is briefly increased and the pressure in the follower piston f drops. As a result, the tension spring holding the follower piston loses its counterforce and pulls the follower piston upwards with it until the normal drainage cross-section and thus the oil pressure corresponding to the new spring preload are established. That

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The oil located in the piston chamber f3, which is therefore dependent on the size of the primary oil pressure P1, thus assumes pressure values p2 which are essentially inversely proportional to the primary oil pressure p1. Its main oil pump 2 conveys pressure oil from an outlet with an increase in the pressure level via line 11 and the channels k1, k2 of the slide switch S1 of the quick release device into the line 12 of the quick release oil circuit and thus under the piston m1 de; - quick release valve SS. This quick release valve is through in the closing direction the spring 3 is spring-loaded and closes or opens with its closure piece 4 the cross-section qi of the steam line ID. In the exemplary embodiment shown, when the oil pressure drops in the Schnellschluiilkreis 1 2, the -SchnellschlussvantiX SS as well as other SchnellschluSventile not shown eimehren its closed position. Connected to the Druekölleitwng 1 1 is the auxiliary oil branch 1 3? to this in turn the sdsmatiseti indicated are known per se- ¹ :} SchalteinriehtöBgea for dea £ ond @ Ds © torsehuts KS ₉ the speed monitor DW and the BmeteiagerieheruBg BLS respectively connected, in such a way that they are connected as paew®atlgeb. = b.järauliache Converter (Kond.ensatorsefoutg KS) or meehaalssh-kjärauliBche converter (speed monitor DW, thrust bearing & eraag DIS) äea auxiliary branch in each case with the process A in the event of an inadmissible condenser pressure, an inadmissibly high speed displacement or an inadmissible axial displacement of the shaft . In this case, the Schnellachliissö ^ circle 1 2 ariickloa _{9 and the} sonic closing valves will close. Via the switch lever S1, the lever 5 is used to manually trigger the SofeDellsclilti direction. The slide switch S1 has a »in the housing 6 läagsverschieblich and spring-loaded on äureti the spring 7 supported switch plunger 8, which is provided at entspreefeeBden piston parts with control edges 9, 10 and 11 _e toaw The control edges. the piston 9 serve to bring the stop slide S1 ia the Betriebsstelluag ^ u by giving starting aid 81 under the piston 9 via the inlet channel 12 and the plunger 8 is thereby shifted into the operating position shown, in which position the plunger 8 with its differential piston system designed piston 10,

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11 goes into self-holding. For this purpose, the piston chamber 10a is via a line 10b connected to the drainage space 13; that of line 1 1 below the piston 10 reaching via channel k1 pressure oil can thus the Hold piston 10 in the operating position shown. Via the channel k1 and the channel of smaller cross-section k2 thus passes Trip oil in the trip oil circuit 1 2. Also gets the pressure oil from line 1 1 and the channel k3 in the auxiliary oil branch 1 3, so that the monitoring devices K1, DW and DLS in their Be held in the open position. Would by the hand lever 5 of the The plunger 8 is moved into its lower position, and the three-way piston 11 would establish a connection between line 1 and 2 via the space 10a and line 10b to the drainage chamber 13 and the pressure in the quick-acting oil line 1 2 is lowered, so that the quick-acting valves SS would go into their closed position. The speed or load-dependent secondary oil pressure p2 prevails in the line 14, to which the hydraulic piston systems via the power amplifier K or servomotors M1, M2 of the control or Hegel valves V1 or V2 are connected. The valve tappets 14 with locking pieces 14a these valves are spring-loaded by the return springs 15 in such a way that that when the secondary oil pressure drops, the valves Vl, V2 go to the closed position. For the sake of simplicity, recirculations which are known per se are in Pig. 2 not shown. By one rise the secondary oil pressure, amplified by the boosters K, are the tappets 14 of the valves V1, V2 by applying force to the power piston 16 in the corresponding, the respective secondary oil pressure proportional opening position shifted, the valve seats of the Valves V1, V2 are indicated schematically at 17, guides for the tappets 14 at 18. While in Pig. Pig shows the closed position of the valves V1, V2. 2a shows a layer of the locking device 14a in the opening position. The control valve shown in Pig »2a can be the control valve V1 or the control valve V2 or another of the still existing control valves (not shown). '.' ■ - ..

Invention are now used to obtain the actual value of the Position of the control valves V1, V2 corresponding yes or no signals with the control valves V1, V2 coupled query-

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organs 19, 19 '. The latter each control the channel cross-section between the inlet side of an auxiliary oil branch 1 5 and the outlet A. The query elements 19, 19 'are spring-loaded as a return. (Helical compression springs 20) formed switch slides, which are each mechanically coupled via a coupling arm 21, 21 'with the tappets 18 of the respective control valves V1, V2. The interrogation organs 19 »19 'have actuating plungers 22, 22' with a closure st tick 23, which each control a drain opening 24. To check the ease of movement, the tappets 22 protrude through the slide valve housing 25 with an extension 22a. Thus, the. When the control valves V1, V2 are intact, in or just before the closed position, the tappets 22, 22 'of the interrogation organs 19, 19 * are released by the coupling arms 21, ^21f in their closing direction (arrows 26), so that they are loaded by the respective return spring 20 close the drain opening 24 with their locking pieces 23. If, on the other hand, a malfunction occurs in the control valves V1, V2, ie the valve tappets 14 hang or jam, the respective valve tappet 14 with its coupling arm 21 and its coupling sleeve 21a holds the tappet 22 of the interrogation organs 19, 19 'in its open position , so that there is a connection from the inlet side 1 5 of the help olive branch to the drain.

To realize the as a criterion for the presence of a disturbance Serving and condition, the arrangement is still made in such a way that that the auxiliary oil weighing 1 5 via a speed-dependent actuatable, an oil flow cross-section controlling switching element S2 is connected to the quick-acting oil circuit 1 2, namely how can be seen - via the auxiliary oil branch 1 3. The switching element S2 is known as a rotating, resetting spring-loaded one (Helical spring 27) formed switch slide, which on the one hand can be acted upon by the secondary oil of the control oil circuit 1 4 via line 1 4 ' is and on the other hand with control edges 28a of the slide piston 28 connects the quick-closing oil circuit 1 2 or the associated quick-closing auxiliary oil circuit 13-auxiliary oil branch 1 5

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or interrupts. Specifically, the slide switch S2 has a housing 29 with a slide body 30 mounted in it in a longitudinally movable manner, the latter being provided with the piston parts 31, 32 and the said piston part 28. A small amount of leakage oil flows from the piston chamber 28 to the piston chamber 31a, 32a and from here via the connecting channel 33 to the drain space 34 and from here to the drain. This achieves lubrication of the rotating slide and prevents the line 1 5 from running empty. If the secondary oil pressure p2 in line 1 4 * falls below a minimum value, ie the speed has reached its highest permissible Vert n _A »which corresponds to the degree of proportionality X ^ + 1 # (see Pig * 1), the slide 30 of the switch slide S2 are no longer held in the position provided is, and the restoring spring 27 pushes the slide 30 so far down that a connection between the olive branch 1 3, channel k6, channel k7 to the auxiliary olive branch 1 5 is made. If one or more of the control valves VI, V2 are suspended at the same time, the interrogation organs 19 and 19 'have connected the auxiliary oil branch 15 to the outlet A. The TJnd condition is thus established, that is, the quick-closing auxiliary oil branch 1 3 is depressurized and the quick-closing valves SS respond. Between auxiliary oil branch 1 5 and switching element S2, a manually or remotely actuated locking element S3 is also switched on, which prevents a pressure reduction via the interrogation organs 19, 19 * in the locked position when checking the safety devices KS, DW, DLS or S1. In detail, the locking member S3, as shown, has a slide switch 35, which is mounted with two piston parts 35a, 35b and a return spring 36 within a slide housing 37, the control channels 38 separated from one another by the piston part 35a or - as shown - released can be and wherein the slide part 35 »with a port set 39 provided for manual operation protrudes outward through the housing 37. With d 42 a throttle element, switched on between lines 1 2 and 1 4, is referred to.

The secondary oil pressure p2 is also expedient for test purposes of the control oil circuit 1 4 can be switched off via a valve 40 from the switching element S2, whereby an overspeed can be simulated, and the locking member S3 is a manometer 41 with valve 42 un-

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indirectly upstream. Ae pressure gauge 41 can thus be controlled via the switching element when the locking element S3 is in the locking position S2 read off the pressure that is building up from the quick-acting oil valve 1 3.

FIG. 4 shows, for example, with the aid of a simplified circuit diagram for a turbine system, how the control valves V1 _f V2 etc. and quick-closing valves can be switched in terms of steam. It is a single-shaft turbo set old the high-pressure turbine part HD and the low-pressure turbine parts ND1 and ND2, with the low-pressure parts being double-flow. The turbo generator G is coupled to the shaft 1, which spsiet three-phase flow into the network * The steam passes from the boiler P Slber the superheater Ü, the Sehgelleehlußventil SS1 and the control valve V1 in the high pressure turbine part HD; after flowing through the latter over the ZwiseheniTberhitzer TO into the LP TeIIe ND1 usä ND2 or -. conducted falla rope amounts of steam bypassing OCE high pressure UUD Niederdrücktet © HD ₃ ID directly into the condenser, fl blown h * werdeis eollen, via the blow-off -Quick-closing style SS2 and the «« associated control valve V2 in the above-mentioned Kotsdea uter K © _o K means the In fig. 2 shown in more detail DrehzaM. regulator whereby the "Wlrlrangsllnien 43 is expressed" that Bin® Wlrkvesblscirag between the regulator R, the control valves V1 _S ¥ 2 and the Sctaellachlußventilen SS1, SS2 is produced «As already indicated, the device according to the invention can also serve this purpose If the failure condition is met, not only close the shell-closing valve SS1, but also by opening the quick-closing blow-off valve SS2 and the discharge control valve 2, a quantity of steam can be blown off directly into the condenser, bypassing the high-pressure and low-pressure turbine parts. This blow-off process can be staggered The quick release vector SS1 must be carried out before the response, which is done before the release speed of 6% is reached.

6 claims
4 figures

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Claims (1)

PLA 68/0728 - 12 - ■ Claims 6.) Device for carrying out the method for improvement the shutdown safety device when operating turbo sets, which regulate and shut off the flow of propellant to the turbine parts (HP, MD and / or LP parts) with standard and Quick-closing valves are provided, preferably from saturated steam turbo set zen, their housing, lines, superheaters, cyclones and the like. Form considerable storage volumes for the steam, in which depending on whether the setpoint of the control valve position for a maximum permissible speed of the proportional range (Closed position and / or position shortly before closing) reached or due to malfunctions (e.g. valve sticking) is not reached, a yes or no signal corresponding to the actual value of the valve position is derived and the for signals obtained from several monitored control valves when one or more of the control valves do not reach their desired position take, result in a resulting signal, which is related in the sense of an AND condition with a the actual overspeed value of the turbine (s) corresponding to the signal, and in this case of failure, a signal from the resulting and the command derived from the speed-proportional signal as a trigger command for the safety devices, such as the Quick-closing device (the quick-closing valves) and, if necessary, blow-off devices is supplied, according to patent .... (patent application P 17 51 631.3) »in application to hydraulic or electro-hydraulic control devices in which an oil pressure of a control oil circuit controlled by the controller as a function of speed or load is via hydraulic Servomotors determine the degree of opening of the control valves and in a «rapid-closing oil circuit the oil pressure is passed through the safety devices (e.g. speed monitor, thrust bearing safety device, manual release, capacitor protection device, etc.) in the event of a fault can be changed in such a way that the SehneilSchlußνentile are closed, characterized in that to obtain the corresponding to the actual value of the control valve position Yes or no signals with the control valve cones, stroke-dependent S / 1019 - 13 - PM 68/0728 ■ - 15 - Gigantic coupled query organs are used, which control the channel cross-section between the inlet and outlet side of an auxiliary oil tank, and that this auxiliary circuit is connected to the quick-release oil circuit via a switching element that can be actuated depending on the rotation and that controls an oil flow cross-section, the switching element connecting the Sehne11 -schlussölkreis with the auxiliary oil branch and the latter in the event of overspeed together with the Sehnellsehlußölkreis in the event of a faulty control valve (s), however, the interrogation organs trigger the Rapid closure and, if necessary, the blow-off devices Experience change in pressure. 2. Apparatus according to claim 1, characterized in that - as known per se - the pressure in the control oil circuit is a so-called Secondary oil pressure is, but which is a signal reversing stage the primary oil pressure of a control gyro, which increases with increasing turbine speed or decreasing load, is obtained and accordingly increases with increasing load or decreasing speed, with an increasing secondary oil pressure the servomotors of the control valves acts in the valve opening direction, and that the Sehnellschlussölkreis supplied by a pressure oil pump through the safety devices with a Drain can be connected, the pressure reduction in the tendon closing oil circuit acting in the closing direction of the quick-closing valves. 3. Apparatus according to claim 2, characterized in that the Query organs are designed as rttokstell-spring-loaded slide switches, which via a coupling arm o. The like. With the The tappets of the respective control valves are mechanically coupled and, for the purpose of checking the ease of movement, it is a port set from the Slide switch housings protrude and which have a closure piece to control the passage cross-section between their inlet and outlet side, the slide switch when intact, Control valves located in or shortly before the closed position are released by the coupling arm in their closing direction and spring-loaded with a spring-loaded locking device Close the drain opening, but if the control valve is hanging 009886/1019 -14- PLA 68/0728 - 14 - the coupling arm under Treihaltang of the drainage opening. 4. Apparatus according to claim. 2, marked by the fact that the Switching element is designed as a rotating, resetting spring-loaded slide valve known to me, which on the one hand can be acted upon by the secondary oil of the control oil circuit " and on the other hand, with control edges, the connection between Schnellsohlußölkreis and HilfsSlsweig is established or interrupted. 5. Device according to one of claims 2 to 4 »characterized in that« wipe the auxiliary oil branch and switching element a hand- or remotely operated locking element is switched on, which is in the locked position when testing the safety devices Prevents pressure reduction via the interrogation organs. 6. Apparatus according to claim 4 and 5, characterized in that the secondary oil pressure of the control oil ice for testing purposes but a valve Tom switching element can be switched off (pretense an overspeed) and that a pressure gauge is connected directly upstream of the locking member, on which the over the switching member is located when the locking member is in the locking position Read the developing pressure from the tendon closing oil circle leaves. 009885/1019