DD288196A5 - METHOD AND CIRCUIT ARRANGEMENT FOR THE AUTOMATIC RUNNING OF LARGE TURBO SETS - Google Patents

Abstract

The invention relates to a method for automatic start-up of large turbosets with mechanical-hydraulic speed regulators, in which a speed gradient gradient ascertained in a processing unit as a function of the heat state of the turbine is set as desired value and the actual gradient of the turbine speed as control variable is assigned to a speed gradient controller which is superior to the speed controller, using the Speed adjustment motor of the speed controller as an actuator of the speed gradient controller. There is a constant comparison of the setpoint (s) with the Drehzahlsteigergradienten (nGr) made, which is achievable with the effective basic speed (I) of Drehzahlverstellmotors (8). At a greater setpoint value, a signal for switching to an increased base speed (II, III) of the speed adjustment motor (8) is formed and applied to its control circuit (7), which also receives the control deviation of the speed characteristic controller (4) having PI characteristics. In critical speed ranges of the turbo set, the calculated setpoint is first compared with speed increase gradients set for those ranges and the higher value used as the optimum setpoint. A circuit arrangement for implementing the method is described. Fig. 1 {Startup; Turbo set; Speed controller, mechanical-hydraulic; Drehzahlverstellmotor; Actuator; Drehzahlgradientenregler; Fuehrungsregler; Drehzahlsteigerungsgradient; Rating; Attitude, level; Basic speed}

Description

For this 2 pages drawings

Field of application of the invention

The invention relates to a method and a circuit arrangement for the automatic up process of large turbo sets with mechanical-hydraulic speed controllers from the rotor rotating device operation up to the synchronization speed.

-2- 288 196 Characteristic of the known state of the art

High-speed automatic transmission systems for turbo sets usually have an electro-hydraulic turbine power controller, which also includes the Approaching from the P.otordrehvorrichtungsbetrieb up to the synchronization speed with variable Speed increase gradient allowed.

[BBC Turbotrol Steam Turbine Control System] Actuator is in any case an electro-hydraulic actuator

Converter (hereinafter EHW) acting on the control oil circuit on the turbine. The positioning speed of the EHW is generally so great that the restriction of desired Speed increase gradients, at a corresponding to the heat state of the turbine realized optimum Speed increase, by no means located in the actuator EHW. Rather, by electronic circuits, the desired Speed increase gradient realized. The determination of the optimal speed increase gradients, depending on the heat state of the turbo set, takes place either

using special probes or selected measuring points according to specific criteria, one in one

Processing unit as a function of the heat state of the turbine determined speed increase gradient as the setpoint

andthe actual gradient of the turbine speed is applied to a speed gradient controller which is superordinate to the speed controller

(DD, WP F 01 D / 320656).

For starting steam turbines, a device is also known, in the speed controller one to the lowest Anwärmdrehzahl descending speed adjustment has by his speed adjustment already during

of the high process is set by a Zeitberberber on the respective target speed.

The Zeitberber is designed as a cam, which is driven by a motor (Drehzahlverstellmotor),

whose speed is adjusted to the planned timetable (DD 47 386).

With this device, however, only a once predetermined selected approach curve can be realized. A realization

from the heat state optimal starting curves Is not possible. At realization of the startup process

Turbosets with mechanical-hydraulic speed controllers by acting on the Drehzahlverstellmotor is due to

the predetermined by the Drehzahlverstellmotor fixed basic speed, only a speed increase with constant

Speed possible. A heat state corresponding, ie process-dependent speed increase is thus without

additional measures can not be realized.

Object of the invention

The aim of the invention is the automatic process-dependent startup of turbo sets, which have no electro-hydraulic turbine power control with EHW as an actuator, but are equipped with conventional mechanical-hydraulic speed controllers.

Explanation of the essence of the invention The invention has for its object to provide a method for meeting the objective, with which the speed of the Drehzahlverstellmotors process dependent can be influenced so that optimal Drehzahlsteigergradienten effective

are, at the same time a circuit arrangement for the realization of the method to create.

It is assumed that a determined in a processing unit depending on the heat state of the turbine Drehzahlsteigerungsgradient as setpoint and the actual gradient of the turbine speed as a controlled variable a the speed controller Superordinate speed gradient can be switched, the Drehzahlverstellmotor the Drehzahreglers the Represents actuator of the speed gradient controller. In accordance with the invention, a comparison of the setpoint value for the speed characteristic controller having the Pl characteristic is always used

with the speed increase 'rungsradionten made achievable with the effective basic speed of Drehzahlverstellmotors, with a larger setpoint signal to generate a relation to the normal range set

Basic speed increased basic speed of the Drehzahlverstellmotors formed and placed on its control circuit. This

Furthermore, the control deviation of the speed gradient controller is supplied.

In a further refinement, the nominal value is initially determined in critical rotational speed ranges for those ranges Speed increase gradient compared and the eich each resulting from the comparison greater gradient than the setpoint

used. The Dreruahlsteigergradienten the critical speed ranges are expedient from the discharge curve of the

Turbosatzes determined and provided by means of adjusters. To implement the method, a circuit arrangement with a between the processing unit and Speed gradient controller lying setpoint guide means for delivering the setpoint guide speed gradient as Setpoint provided. According to the invention is between the output of the setpoint luhrungseinrichtung and the setpoint input of the Pl characteristic

having a maximum speed selection circuit arranged speed gradient controller. In this will be the

Sollwerlführungsdrehzahlgradie "t in critical speed ranges with specified for these areas Speed increase gradient compared, the higher one is switched through. The speed increase gradients

The critical speed ranges are - specified by adjuster - Torschaltungen in each critical

Speed range in the maximum selection circuit is effective. Parallel to the setpoint input of the speed gradient controller is a comparator, in which the of the Maximalauswahlschaltung output Sollzahlführungsführungsgradgradgradt compared with the speed increase gradient

is, with the effective, z. B. set in normal operation, basic speed of the Drehzahlverstellmotors is reached. The

Output of the comparator is guided to the control circuit of the Drehzahlverstellmotors. If the comparison shows that the desired value of the guide speed gradient is greater than the other i3t, in the control circuit Grunddrohzahl switched to a higher speed. Suitably, the solution is designed so that successively more stepped on the output of the comparator Basic speeds for the engine are adjustable. For the coupling of the drive circuit with the speed gradient controller, a three-point member is suitable. It is also

possible to provide for a pulse width modulator, whereby an increase in the control quality can be achieved.

To implement the method, the circuit arrangement can be configured with a microcomputer controller into which some Function modules of the circuit arrangement are integrated. Then the microcomputer controller fulfills the following tasks:

1. Speed gradient controller in start-up mode, d. H. Calculation of the optimal speed gradient and output of a

Actuator signals to the speed control motor according to given criteria (eg according to DD / WP F 01 D / 320656).

Setpoint-actual comparison of the speed gradients and influencing the speed adjustment motor in the sense of the actual-setpoint adjustment according to the Pl-control algorithm.

2. Selection of the most favorable starting curve based on the calculated optimum speed increase gradient.

3. Definition of the speed hold time depending on the heat state.

4. Comparison of the calculated optimal speed increase gradient h with the speed increase gradient n _Or attainable with the basic speed of the speed adjustment motor with continuous control.

With ή> no, the next higher basic speed is set by means of circuitry measures.

5. Automatic correction of the set optimal speed increase gradient when passing through the critical speed ranges, if the set, calculated optimal speed increase gradient is below the permissible.

embodiment The detailed explanation is based on the drawing. Fig. 1: shows the circuit arrangement for carrying out the method.

About the current values of selected measuring points, such as the n-turbo set, which are received in the measured value acquisition unit 1; p, θ live steam; p, θ hot rail steam; Metal θ HD and MD turbine u. v. a., Are to be approached in the preprocessing unit 2 dia target speed nsoii, the optimal Drehzahlsteigerungsgradient h and the holding or dwell τ determined according to predetermined criteria.

The calculated values are applied to the setpoint value guiding device 3, which outputs the optimum speed increase gradient ή in accordance with the course shown to the speed gradient controller 4 via the maximum selection circuit 11. The output of this controller 4, which operates according to the Pl algorithm, acts via a three-point link 5 and a relay module 6 on the control circuit 7 of the Drehzahlverstellmotors (DZVM) 8, via the intermediate slide block of the mechanical-hydraulic speed control 9, the speed of the turbo set 10 im influenced desired sense. Instead of the three-point member 5, the control of the DZVM can also be done via a pulse width modulator, whereby a better adaptation of Istdrehzahldientenkurve to the target speed gradient curve is reached, in block 12 is the realized effective Drehzahlsteigerungsgradient (actual value) according to the relationship

Δ;

determined, given as a control variable to the controller 4 and compared with the predetermined by the maximum selector 11 optimal Drehzahlsteig gradients ή.

Since the DZVM has a constant base speed, it is tested in the comparator 13 whether the determined optimum The speed increase gradient ή can be reached with the set effective basic speed of the DZVM. It makes sense

the speed gradient signal from the output of the maximum selection circuit 11 is used for the comparison, as thus also the critical speed ranges are taken into account.

If the predetermined speed increase gradient is greater than that achievable with the effective base speed Drehzahlsteigerungsgradient (n> n _Gl ), so is by circuit engineering measures, eg. B. switching on resistors

set the exciter circuit of the DZVM, in the control circuit 7 for the DZVM 8 a larger base speed, the

Speed increase gradient greater than n can realize. To ensure that the critical speed ranges are traversed as safely as possible during startup, is

the setpoint command signal ή (setpoint command speed gradient) in the maximum selection circuit 11 in the illustrated

Example three speed increase gradient ήκι compared to n «. If the nominal value guidance rotational speed gradient ή is smaller than the rotational speed gradient permissible in the critical rotational speed range Δηκ, then

for the wirkon speed range, the predetermined divided speed increase gradient ή instead of the

Söllwertführungsdrehzahlgradienten as optimal Drehzahlsteigerui. j ^ yradiant (setpoint) switched through. Contrary to known methods which, in the critical rotational speed, involve a simple multiplication of the predetermined nominal gradient,

z. B. with the factor 10, realize the necessary h from the outlet curve of the turbo set, as by

Multiplication with 10 preset target gradients due to the limited maximum speed of the DZVM anyway not

would be feasible.

The speed increase gradients to be realized in the critical speed ranges are transmitted to the adjusters 14; 15;

specified. Through the gates 17; 18; 19 takes place in the critical speed ranges Δη _Κ) to Δη «switching on or offνοηίΐκι to nx ₃ to the maximum selection;

In Fig. 2 is the supplement of the existing control circuit 7 (Fig. 1) for switching stepped basic speeds of the DZVM

shown. It is assumed that in addition to the effective for normal operation basic speed I of the DZVM, z. B.

η = 250min ' ¹ , for realizing the speed increase gradients with two further base speeds II required in synchronization with the synchronization speed in consideration of the ή _κ ; III, ζ. Β. 500; 1000min "', got along

Setting the additional higher basic speeds is done in a conventional manner by field weakening means Additional resistors. The additional resistances are dependent on the result of the comparison in the comparator 13 by means of Relay d1 or d 2 switched on. If two additional basic speeds are selected, the comparison must be made twice. The first comparison tests whether

ή is adjustable with the basic speed I (normal gear). In case of non-compliance, the relay d 1 is activated and the

Basic speed II, eg η = 600min " ¹ ) In case of non-compliance, the relay d 2 is activated and the next higher basic speed III

η = 1000min " ¹ set (switching R2 on in addition to R1 in the exciter circuit).

By an additional signal must be ensured that durcn on reaching the synchronization speed or shortly before Switching off d1 and d2 the basic speed I (normal gear) is set again.

Claims (8)

1. A method for the automatic high-speed large turbo sets with mechanical-hy Iraulischan speed regulators, sin in a processing unit depending on the heat state of the turbine determined Drehzahlsteigerungsgradient and the actual gradient of the turbine speed as a controlled variable speed governor superordinate speed gradient are switched using the ürehzahlgradientenreglers , characterized in that a constant comparison of the setpoint (nor) is made, which is achievable with the effective base speed (I) of Drehzahlverstellmotors (8), wherein at a larger setpoint (ή> ήο _Γ ) a signal to switch to an increased base speed (II, III) of the speed adjustment motor (8) is formed and applied to its control circuit (7), which also receives the control deviation of the Pl characteristic having speed gradient controller (4). 2. The method according to claim 1, characterized in that in critical rotational speed ranges (Δη _Κ ι; Δη «2 to Δη« η) of the turbo set of the setpoint (ή) initially determined for these areas speed increase gradient (ήχη ή _Κ 2 to ή *, ,) and the higher value is used as the optimum setpoint (ή). 3. The method according to claim 1 and 2, characterized in that the Speed increase gradient (ήχη n _K2 to fi ^) for the critical speed ranges (Δη _Κ ι, Δη _Κ2 to Δηχη) are determined from the outlet curve of the turbo _set . 4. Circuit arrangement for the automatic start-up of large turbo sets with mechanical hydraulic speed regulators, in which a processing unit is provided in which a speed increase gradient and speed hold times determined and supplied to the speed governor speed governor as a setpoint, wherein between the processing unit and the Drehzahlgradientenregler a setpoint guide means for outputting the Sollwerteführungsdrehzahlgradienten as a setpoint, using the Drehzahlverstellmotors the speed controller as an actuator for the Drehzahlgradientenregler, characterized in that between the output of the setpoint guide means (3) and the setpoint input of the Pl characteristic having Drehzahlgradientreglers (4) a maximum selection circuit (11) is arranged in the the setpoint guide speed gradient in critical speed ranges with speed limits set for these ranges compared to the setpoint input of the Drehzahlgradientreglers (4) is a comparator (13) in which the setpoint guide speed gradient is compared with the speed increase gradient, which is achievable with the effective basic speed of the Drehzahlverstellmotors, and the output of Comparator (13) to the control circuit (7) of the Drehzahlverstellmotors (8) is guided. 5. Circuit arrangement according to claim 4, characterized in that via the output of the comparator (13) successively a plurality of stepped basic speeds (II; Nl) for the Drehzahlverstellmotor (8) in the control circuit (7) are adjustable. 6. Circuit arrangement according to claim 4, characterized in that the control circuit (7) of the Drehzahlverstellmotors (8) is further coupled via a three-point link (5) to the output of the Drehzahlgradientreglers (4). 7. Circuit arrangement according to claim 4, characterized in that the control circuit (7) of the Drehzahlverstellmotors (8) is further coupled via a pulse width modulator to the output of the Drehzahlgradientreglers (4). 8. Circuit arrangement according to claim 4, characterized in that the Drehzahlsteigerungsgradienten (ήκιί ήκ2 to n _K n) of the critical speed ranges (Δηκι; Δηκ2 to Δηκη) by means of adjusters (14; 15; 16) in each case via gate circuits (17; 19) are applied to the maximum selection circuit (11).