SU969918A1 - Automatic control system for hydrostatic lift of tyrrbomachine rotor - Google Patents

Description

The invention relates to a power system and can be used in hydrostatic rotor lifting systems in segmental sliding bearings, primarily ms steam turbines.

The closest in technical essence and the achieved result to the proposed is a dual-control system of hygrostatic lifting of the rotor of the turbomachine, containing valves on the lines of supplying oil to the chambers of the hydraulic lift of each supporting segment of the soleplate, starting devices of electric drives of these gates and temperature sensors of each of the segments, temperature shaft and oil temperature l.

A disadvantage of the known system is the reduced reliability, due to the use of a displacement sensor with complex measuring equipment on the housing segment.

The purpose of the invention is to increase reliability.

In order to achieve this goal, comparison units, auto-uter blocks, delay blocks, switches, and travel stops were introduced into the system by the number of non-suction segments, as well. The temperature sensor of each segment is connected to the input of the cocfr- corresponding comparison unit and to the input of the corresponding switch, the shaft temperature sensor is connected to the inputs of all switches, and the oil temperature sensor is connected to the inputs of all comparison units, the output of each of which is through the corresponding unit

10, the automatic control and the travel stop are connected to the input of the actuator of the electric drive of the corresponding valve, and the output of each switch is connected to the inputs of the respective automatic control unit and travel limiter, and the output of each of their travel stops is also connected via the delay unit to the inputs of the automatic control unit and start-up device for another carrier segment.

The drawing shows a system diagram of the automatic control of the hydrostatic lifting of the rotor of a turbo25 machine.

In the bearing insert 1, self-aligning bearing segments 2 and 3 bearings are located, covering the shaft neck 4. On a surface

3d friction segments camera located

5 hydraulic lifts. In the body of the segments, sensors b and 7 of the temperature of the segments are installed, which are connected to amplifiers 8 and 9 of the signals, and the shaft temperature sensor 10, which is connected to the signal amplifier 11, contacts the surface of the shaft neck. The hydraulic lift chambers 5 are connected via lines 12 and 13 to the oil supply valves 14 and 15, the opening degree of which is controlled by the electric drives 16 and 17. The lines 12 and 13 after the valves 14 and 15 are connected in parallel to the oil line 18, which is connected to the oil tank through oiltiacoc 19 20. In the oil line 18, after the pump 19, an oil temperature sensor 21 is installed, which is connected to the signal amplifier 22 and functions as a setpoint device. The output of the amplifier 22 is connected to the first input of the signal comparison units 23 and 24, each of which relates to the corresponding segment 2 and 3. The outputs of the comparison units 23 and 24 are connected respectively to the first inputs of the automatic control units 25 and 26, and the outputs of the latter through the first outputs limiters 27 and 28 of the stroke are connected to blocks 29 and 30 of the delay, and the inputs with reversing starting devices 31 and 32, the outputs of which are connected to electric drives 16 and 17 of the respective gates 14 and 15, the outputs of amplifiers 8 and 9 are connected to the second inputs of the blocks s 23 and 24 and pergvymn input switches 33 and 34, and vyhody.usilitel 11 connected to second inputs of the switches 33 and 34,

The system works as follows. .

In the normal operating position, there is a gap between the segments 2,3 and shaft neck 4, through which oil flows from pump 19 from the oil tank. in this position, as shown by tests, the temperature of the supplied oil and the friction surfaces of the segments 2 and 3 are one: 1 and the temperature of the neck 4 differs from the tag of the oil. Therefore, the equality between the temperatures of the oil and the segments 2 and 3 is equal to zero, and between the temperatures of the oil and the neck 4 is not equal to zero. In this case, the output signal of the amplifier 11 from the sensor 10 is fed to the second inputs of the switches 33 and 34 and the output signals of the amplifiers 8 and 9 from the temperature sensors 6 and 7, respectively, to the second inputs of the comparison units 23 and 24 and to the first inputs of the switches 33 and 34 With an equal value of the signals arriving at the first and second inputs of the switches 33 and 34, the signals of the last at the output will be absent, and the equal signals arriving

the first, second, and third inputs of the comparison units 23 and 24 from the amplifier 22, the respective amplifiers 8 and 9, and the feedbacks of the electric drives 16 and 17 form the output inhibit

signals of blocks 23 and 24 of the comparison. As a result of this mode, the control system of the hydrostatic lift of the rotor will be balanced, and between the segments 2,3 and shaft neck 4

a gap is established through which the oil supplied to the hydraulic lift chambers 5 by the pump 19 flows. If the temperature of one of the segments (for example, segment 2) increases by the value of At from the predetermined oil temperature, an increment signal from the sensor is sent to the second input of the comparator unit 23 b temperature. As a result

mismatch of signals from the sensor, {a b (segment 2 temperature) and d: gtchik 21 (oil temperature), the comparison unit 23 generates and outputs a signal from the output to

first input of unit 25 automatic

management The latter forms and generates a signal as the first input of the stroke limiter 27. If the valve 14 is not fully opened, then the output signal from the first output of the limiter 27 is fed to the first input of the reversing starter 31.-, The signal from the second output of the limiter 27 to the delay block-29 comes only::. .

When a signal arrives at the first start of the device 31, the latter, with its output signal, turns on the electric actuator 16 to open the valve 14, thereby increasing the oil supply to the chambers 5 of the hydraulic lift of segment 2. As a result, segment 2 will begin to move away from the shaft 4 of the shaft, increasing the lubricating gap, and

the temperature will begin to decrease. During the process of opening the valve 14, through a feedback of the actuator 16, a signal is sent to the third input of the comparator unit 23. As soon as the signal at the third input of block 23 is compared with the signal size, the pulse with

the output of the .23 block is reduced, and the actuator 16 is turned off.

If a further increase in temperature of segment 2 stops, then

In this process, the control of the hydrostatic lift of the rotor in the bearing due to an increase in the flow of oil into the chambers of the hydraulic lift also stops;

If the temperature of segment 2 increases, the process of opening the valve 14 will continue until it is fully opened. With a fully open valve 14, stroke limiter 27 removes the signal to

the first output from the reverse device 31 and outputs a signal from its second output to the block 29 of the delay. After the time delay has expired, if the temperature increment of the segment does not stop, a signal is sent from the output of the delay unit 29 to the third input of the automatic control unit 26 and the latter is turned off. At the same time, the signal from the output of the delay unit 29 is fed to the second input of the reversing starter 32. The latter actuates and turns on the electric actuator 17 to close the valve 15 of the bearing 3 segment 1. As a result of the reduction in the flow area of the valve 15, the oil flows will be redistributed between segments 2 and 3, which will result to adjust the temperature of the segment 2 and the oil supplied. As soon as the temperature of the latter is compared, the adjustment process in the hydrostatic lift of the rotor will stop.

If, in the hydrostatic lifting of the rotor, the temperature of segment 3 is not equal to the oil temperature, then the automatic control of the oil supply to X1 Measures of the hydraulic lift will be carried out similarly to the elements described above, 24,26,28, 30 and 32. A second case of system malfunction is possible. Because of the redistribution of loads one of. segments, e.g. segment 2, are pressed against the shaft neck 4. In this case, his teyuretura becomes equal to the temperature of the shaft. Tog, and from the outputs of amplifiers 8 and 11, temperature sensors 6 and 10 are supplied with equal largest signals to the first and second inputs of the switch 33. The latter generates and issues a signal to the second inputs of the automatic control unit 25 and the limiter 27 of the stroke. In this case, the automatic control unit 25 will be locked for the period of the presence of a signal at its second input. As a result of receiving the signal from the switch 33, the stroke limiter 27 generates and outputs a signal to the reversing starting device 31, which turns on the electric actuator 16 until the valve 14 is opened.

As a result of an increase in the supply of oil to the hydraulic lift chambers and the establishment of a gap between the friction surfaces: the temperatures of segment 2 and neck 4 will begin to differ from each other. Due to the mismatch of the signals at the input of the switch 33, the latter removes the output signal from the automatic control unit 25 and the limiter 27 of the stroke.

The further maintenance of the set temperature at all points will be carried out by blocks 23 and 24 from amplifier 22.

The proposed system makes it possible to abandon the installation of additional sensors on the turbomachine bearings: a displacement cop with its own measuring system, and also excludes wear of the surface of the friction segments. That caNHM increases reliability.

Claims (1)

1. Koval G.S. and others. Testing and operating experience of radial segment bearings and system of hydraulic lifting of rotors K-500-240-2 XTGZ. In the book. Boiler and turbine installations of power units with a capacity of 500800 MW. Ed. Doroschuk V.E., and Ruein V.B. M., Energie, 1979, pp. 371-380.