SU553345A1 - Steam Turbine Control System - Google Patents

Description

I

The invention relates to a power system and can be used in the automation of heating turbines.

Systems are known for automatically controlling a steam turbine with a steam extraction drive of an electrical geierator. The systems contain sensors of rotational speed and vapor pressure in the selection, connected to the servos of the regulators of the high pressure and low pressure parts of the turbium, and a check valve on the steam line of selection 1. When the rotational frequency is changed, the servomotors of the regulators of the high and low pressure parts receive the same signs when the pressure of iara is changed in the selection - signals of different signs. A non-return valve installed on the extraction steam line closes the steam access from the steam line to the turbine when it is discharged, in this case duplicating the functions of the regulators of the low pressure part.

The disadvantage of such systems is the reliability of the turbine operation.

A turbine control system with steam extraction is also known, containing sensors for rotational speed and pressure of steam in the selection, connected to the sulfur motors of the regulators of the high and low pressure parts of the turbium, and mounted on the extraction steam line a check valve and valve

with actuators 2. In this system, steam access from the extraction steam line to the turbine is blocked when the load is reset and the check valve, and, if necessary, a shut-off valve, which increases the reliability of the system.

This system is closest to the proposed by technology and achieved result.

The disadvantage of such a system is unreliable operation of the turbine in a number of modes, for example, after the discharge of electrical load in the operation with steam extraction, since after covering the regulating opra i part of the inverse pressure, the temperature of the steam rises due to throttling; pressure, which can cause rapid heating of the rotor and the growth of its relative rasipfeip.

Pelting is an increase in reliability in a wide range of modes.

In order to reach the target, the servomotors of the regulators of the high and low pressure parts of the line with the limit switches connected to the return valve i: the gate valve and the mode switch are installed. The servomotor of the regulator of the high pressure part is additionally connected with the control of the valve driven actuator.

The drawing is a schematic diagram of the control system.

Steam expenses are regulated by regulator 1 with servo motor 2 high pressure parts 3 and regulator 4 with servo motor 5 parts of low pressure 6. Rotation speed sensor 7 and pressure sensor 8 are connected to both servomotors 2 and 5. In addition, servo motor 2 is connected by a line 9 with the actuator 10 of the valve 11 on the steam line selection line 12 through the limit switch 13 of the check valve 14, the limit switch 15 of the valve And and the mode switch 16 with the servo motor 5 of the regulator 4 low pressure parts.

Automatic regsilirovaniya after an instantaneous discharge of electrical load works as follows.

A rotational speed sensor 7, having received a signal for an increase in the rotor rotational frequency, sends a command to servomotors 2 and 5 to close the regulators 1 and 4, and the latter are closed. After the load is released, the regulator 1 passes the steam flow, the minimum allowed to start the selection, the servo motor 2 commands the valve 11 to close and open the low pressure part of the regulator. The last command goes to the servomotor 5 via mode selector 16, provided the limit switches 13 or 15 operate. As a result, the regulator of the low pressure part opens and the turbine is automatically converted to condensation mode.

Thus, the controlling effect on the opening of the regulators of the low pressure part comes only in the event of a complete closure of the check valve or valve in the extraction steam line.

By introducing an additional link from the servomotor of the regulator to the high pressure part to the servomotor of the regulator, to the low pressure part

5, it is excluded the possibility, upon discharge, of an electric load, of prolonged exposure of the high-temperature steam to the flow part of the low pressure cylinder. The reliability of the system is further enhanced because the effects on low pressure regulators and the switch are automated and, therefore, personnel erroneous actions are excluded.

Claims (2)

1. Turbine control system with steam extraction, containing sensors for rotational speed and pressure of steam in the selection, connected to servomotors of regulators 0 parts of high and low pressure turbines, and a check valve and a valve with actuators installed on the steam extraction line, characterized in that, in order to increase the reliability of operation in a wide range 5 modes, the servomotors of the regulators of the high and low pressure parts are connected by a line in which limit switches are connected, connected to a check valve and a gate valve, and a switch of the pressures. 2. A system according to claim 1, characterized in that the servomotor of the regulator of the high-pressure part is additionally connected by a control line with a slide actuator. Sources of information taken into account in the examination: 1. Khilchenko L.N. Regulation of steam turbines, M., “Maschgiz, 1960, p. 179-181. 0 2. Copyright certificate № 2160Р F 01 D 17/20, 1965. 12 "-V