JPH057942U - Turbine inlet temperature limit control circuit - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the gas turbine inlet temperature limit control circuit. [Composition] A thermometer 11 for measuring the exhaust gas temperature of the gas turbine 10, a pressure gauge 12 for measuring the combustor pressure, a steam input meter 14 for measuring the amount of steam supplied to the combustor, and an output of the pressure gauge 12 are set in advance. First function generator 1 for generating a turbine outlet temperature limit signal corresponding to the turbine inlet temperature
3, a second function generator 15 which receives the output of the steam input meter 14 and outputs a temperature bias, a thermometer 11, a pressure gauge 12,
And a control means for receiving the output of the function generator 13 and outputting the turbine temperature limit control signal 18s is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a turbine inlet temperature limit control circuit applied to control a fuel flow rate of a gas turbine.

[0002]

[Prior Art]

 Control of a gas turbine needs to satisfy different characteristic requirements of each of the components of the gas turbine, that is, the compressor, the combustor, the turbine, and the generator. Therefore, as shown in FIG. 2, the following control circuits are operated in parallel, and the method of selecting the minimum signal among the outputs of these control circuits controls the protection of each state variable that is mutually related. The requirements are satisfied at the same time, and the most effective operation is possible.

(A) Speed governor control circuit 1 (b) Load limit control circuit 2 (c) Turbine temperature limit control circuit 3 (d) Fuel limit control circuit 4 Of the outputs of these control circuits, the minimum signal is the minimum signal. It is selected by the selector circuit 5 and used as a control output CSO (Control Signal Output), and the fuel supply amount is controlled based on this.

The turbine temperature limit control circuit 3 controls the exhaust gas temperature to keep the turbine inlet temperature within the design value. The NO _X reduction, as the output reduction response at high temperatures, water, steam or the like is injected into the gas turbine, water turbine inlet temperature by introduction of steam is reduced slightly. Taking advantage of the fact that there is a margin in the turbine inlet temperature, more fuel is added (up to the design temperature) to increase the output.

[0005]

[Problems to be Solved by the Invention] Conventionally, this temperature setting was determined assuming that a specified amount of water or steam was contained, but in this case, if the temperature control operation is performed without water or steam, the turbine is set. It is not preferable because the inlet temperature will exceed the set value.

An object of the present invention is to provide a turbine inlet temperature control circuit for a gas turbine that solves this problem.

[0007]

[Means for Solving the Problems]

 The present invention takes the following means to solve the above problems.

That is, as a turbine inlet temperature limit control circuit, a first measuring unit that measures the exhaust gas temperature of the gas turbine, a second measuring unit that measures the combustor pressure, and the amount of water or steam supplied to the combustor. And a third function generating means for receiving the output of the second measuring means and generating a turbine outlet temperature limit signal corresponding to a preset turbine inlet temperature, Second function generating means for receiving the output of the measuring means and outputting a temperature bias; and control means for receiving the outputs of the first measuring means and the first and second function generating means and outputting a turbine temperature limit control signal. To provide.

[0009]

[Action]

 By the above means, the first function generating means receives the combustor pressure signal and generates the turbine outlet temperature limit signal corresponding to the preset tabine inlet temperature. The second function generating means receives the input amount of water or steam and outputs a temperature bias. Furthermore, the control means receives an exhaust gas temperature signal, a turbine outlet temperature limit signal, and a temperature bias, and outputs a turbine inlet temperature limit control signal.

As described above, according to the input amount of water or steam, that is, the turbine inlet temperature limit control signal is output so that the turbine inlet temperature always maintains the set value even if the input is zero, and the control is performed. To be done.

[0011]

【Example】

 An embodiment of the present invention will be described with reference to FIG. The parts described in the conventional example are assigned the same numbers to avoid redundancy, and therefore a description thereof will be omitted. The parts related to the present invention will be mainly described.

An exhaust gas thermometer 11 for measuring the exhaust gas temperature of the gas turbine 10 is provided. A combustor pressure gauge 12 for measuring the combustor pressure is also provided.

The output of the thermometer 11 is sent to the subtractor 17. The output of the pressure gauge 12 is sent to the adder 16 via the first function generator 13. Further, the output of the steam input meter 14 for measuring the amount of steam input to the combustor of the gas turbine 10 is sent to the adder 16 via the second function generator 15. The output of the adder 16 is sent to the P1 controller 18 via the subtractor 17, and the output of the P1 controller 18 is sent to the minimum selector circuit 5.

These are the turbine temperature limit control circuit 3. In the above, the first function generator 13 previously calculates the relationship between the turbine outlet temperature corresponding to the allowable turbine inlet temperature for each combustor pressure at the time of start-up and at the time of load, and calculates it for the turbine pressure with respect to the combustor pressure. Output as an outlet temperature limit signal. This turbine outlet temperature limit signal is switched between output for start-up and load operation depending on the operating state of the gas turbine and is output.

The set value for load operation is a value obtained by adding a bias during load to the set value for start-up, so that switching from start-up to load operation can be performed smoothly.

Further, the second function generator 15 outputs a temperature bias signal preset according to the amount of steam input.

The outputs of the first and second function generators 13 and 15 are added by the adder 16 to be a corrected turbine outlet temperature limit signal, which is sent to the subtractor 17. Here, the temperature of the exhaust gas is compared, and the temperature limit control output signal (BPC SO) 18s is sent via the P1 controller 18 to the minimum selector 5.

As described above, the turbine inlet temperature is controlled so as to always maintain the set value (allowable value) according to the amount of steam input. Therefore, even if the amount of steam input is zero, the turbine inlet temperature will not exceed the set value (permissible value) as in the past.

[0019]

[Effect of the device]

 As described above, according to the present invention, the turbine inlet temperature is controlled so as to always maintain the set value in accordance with the input amount of water or steam. Therefore, even if the amount of water or steam input is zero, the turbine inlet temperature will not exceed the set value. That is, the reliability is greatly improved.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is an overall configuration block diagram of a conventional example.

[Explanation of symbols]

 10 Gas Turbine 11 Thermometer 12 Pressure Gauge 13,15 Function Generator 16 Adder 17 Subtractor 18 P1 Controller

Claims (1)

[Claims for utility model registration] Claims: 1. A first measuring means for measuring the exhaust gas temperature of the gas turbine, a second measuring means for measuring the combustor pressure, and an amount of water or steam supplied to the combustor. A third measuring means for measuring,
A first function generating means for receiving an output of the second measuring means and generating a turbine outlet temperature limit signal corresponding to a preset turbine inlet temperature, and an output of the third measuring means for outputting a temperature bias. And a control means for receiving the outputs of the first measuring means and the first and second function generating means and outputting a turbine temperature limit control signal. −
Bin inlet temperature limit control circuit.