SU848710A1 - Automatic regulating system for steam-gas unit - Google Patents

Description

(54) SYSTEM OF AUTOMATIC REGULATION OF STEAM AND GAS INSTALLATION

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The invention relates to thermal, energy and can be used in the automation of steam and gas plants with a high-pressure steam generator and an additional combustion chamber.

Closest to the present invention is a system for automatic regulation of a combined-cycle plant, which contains a fuel regulator for a high-pressure steam generator, connected by its input to a puff pressure and fuel consumption sensor, and by an output to a fuel valve of the steam generator, a fuel-air ratio controller connected by its input to a fuel and air consumption sensor, and with an outlet to a steam generator air valve, a gas turbine temperature controller that is connected to the gas sensor c, and an outlet with a fuel valve; a combustion chamber; a gas turbine speed controller connected via its output through a first non-linear unit to the same fuel valve; and a steam turbine speed controller (I.

The disadvantage of this system is reduced reliability of the plant. When operating in the power system, a drop in the mains frequency and, accordingly, a decrease in the rotor speed of the KCHvinpeccopa rotor can cause a sharp decrease in air flow to the steam generator and an increase in the gas temperature before the gas turbine. As a result, it becomes necessary to shut down the installation due to compressor surging and exceeding the limit temperature of the gases in front of the gas turbine.

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- The purpose of the invention is to increase the reliability of the installation.

In order to achieve this goal, a chain of successively connected

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 a nonlinear unit, a normally open contact that is connected to the gas temperature sensor, and a differentiator, and the output of the gas turbine speed controller is additionally connected to the fuel and air valves of the steam generator through the specified circuit ..

The drawing shows the scheme of the system, we automatically adjust

Claims (1)

, 30 combined-cycle plant. The installation includes a high-pressure steam generator 1, a combustion chamber 2, a steam turbine 3 with a condenser 4, a generator 5 is located on the shaft, a gas turbine b with a compressor 7 and a generator 8 located on its shaft. The control system includes a steam generator control circuit that includes a regulator 9 fuel, steam pressure sensor 10, fuel consumption sensor 11, adder 12 and steam generator fuel valve 13; circuit, adjusting the fuel-air ratio of the steam generator of the rator, including fuel-air ratio regulator 14, fuel consumption sensor 11, air consumption sensor 15, adder 16 and air valve 17; gas temperature control circuit in front of the gas turbine / gas temperature control regulator 18 in front of the gas turbine gas temperature sensor 19 in front of the gas turbine, adder 20, fuel valve 21; a gas turbine rotor speed control loop, consisting of a speed controller 22 for the first and second non-linear units 23 and 24, a differentiator 25; a speed controller 22 is connected to the non-linear blocks 23 and 24. A temperature sensor 19 is connected to the controller 18, which together with the first non-linear unit 23 is connected to the adder 20 connected to valve 2 Sensors 10 and 11 are connected to the controller 9, the output of which is connected to the adder 12, to the other output is connected through the differentiator 25 and the normally open contact 26 of the sensor 19 gas temperatures in front of the gas turbine, the second nonlinear block 24. The adder 12 is connected to the valve 13. Sensors 11 and 15 are connected to the controller 14, which, together with the differentiator 25, is connected to the sum matrix 16. The last one is connected to the valve 17. The second nonlinear block contact 26 and differentiator 25 form a circuit 27 through which regulator 22 is connected with valves 13 and 17. Regulator 28 of the speed of the steam turbine 3 is connected to control valve 2 9. The system works as follows. I With an increase in the frequency of rotation of the rotor of the steam turbine 3, the controller 28 acts on the valve cover by 29. With a pre-emergency increase in the frequency of rotation of the gas rotor of the gas tank, the regulator 22 acts through a nonlinear unit 23 having a characteristic of the insensitivity zone type or 20 which covers the valve 21, while the flow of fuel to the combustion chamber 2 is reduced, which, in turn, leads to a decrease in the power of the gas turbine 6 and, consequently, to the restoration of the frequency of rotation of the rotor of the gas turbine. In case of a pre-emergency reduction of the rotational speed of the rotor of the gas turbine 6, the regulator 22 acts through a non-linear unit 24 having a characteristic of the dead zone type and the differentiator 25 on the adders 12 and 16, which cover the valves 13 and 17. At the same time, the fuel and air consumption are not sufficient. the steam generator 1 is reduced, which leads to a decrease in the temperature of the gases in front of the gas turbine to a predetermined value and, therefore, prevents a pre-emergency stop due to temperature increase and surge of the compressor. When the gas temperature in front of the gas turbine drops to a predetermined value (plant unloading), a normally open contact 26 of the temperature sensor 19 trips the action of the controller 22 to reduce the fuel supply and unload the plant to the set value, rather than stopping it. Thus, the proposed system allows to increase the reliability of the installation, reduces the number of emergency shutdowns, which increases the technical and economic indicators of its operation. The invention of the automatic control system of the gas-vapor plant, containing a fuel regulator for a high-pressure steam generator connected by its input to steam pressure and fuel consumption sensors, and an outlet to the steam generator fuel valve, a fuel-air ratio controller connected by its input to a fuel consumption sensor and air, and an outlet with a steam generator air valve, a gas temperature regulator in front of a gas turbine, connected by its input with a gas temperature sensor, and an outlet with a fuel an inlet valve of the combustion chamber, a gas turbine speed controller connected by its output through the first non-linear unit to the same fuel valve, and a steam turbine speed controller, which, in order to increase the reliability of the installation, an additional circuit is introduced into the system of the second nonlinear unit in series, a normally open contact that is connected to the gas temperature sensor and a differentiator, and the output of the gas turbine speed controller is additionally connected to the fuel and zdushnym valves of the steam generator through said circuit. Sources of information taken into account n & and expertise 1, B.C. jeep and others. Dynamic testing of the automatic control system of a CCGT with HSV-120-540. Maintenance, modernization and repair of equipment, Moscow, TsNIITE Neftekhim, 1977, No. 9, p. 3-5