CN102979628B - A kind of method realizing gas-steam combined cycle set frequency modulation function - Google Patents

Abstract

The invention belongs to machine unit automatic generation control technique field, provide a kind of method realizing gas-steam combined cycle set frequency modulation function, the frequency modulation implementation of gas turbine control system is moved forward, by the outside spare interface of lifting/lowering load, frequency modulation control logic is increased in steam turbine control system, control the frequency modulation load of gas turbine, frequency modulation function is increased in steam turbine control system, realize gas-steam combined cycle set frequency modulation function and meet relevant criterion requirement, for similar unit provides valuable Technical Reference foundation, optimize the frequency modulation performance of gas-steam combined cycle set, there is stronger propagation and employment be worth.

Description

A Method for Realizing the Frequency Regulation Function of Gas-Steam Combined Cycle Unit

technical field

The invention belongs to the technical field of unit automatic power generation control, and in particular relates to a method for realizing the frequency regulation function of a gas-steam combined cycle unit.

Background technique

Faced with the pressure of increasingly tense energy and environmental protection, my country has gradually restricted the construction of traditional coal-fired power generation units, replacing them with clean and efficient power generation methods such as gas, wind energy and solar energy, among which gas-steam combined cycle units are vigorously constructed main types of units. Compared with traditional coal-fired power generation units, gas-steam combined cycle units have the advantages of fast speed and environmental protection. Nowadays, the proportion of power generation is increasing, and the frequency regulation performance of gas-steam combined cycle units plays an increasingly important role in grid frequency regulation. bigger and bigger.

With the popularization and wide application of the domestic control system, the realization method of the frequency modulation function of the traditional coal-fired unit has been very mature. The frequency regulation function of the gas-steam combined cycle generator set mainly depends on the gas turbine. Since the control system and control method of the gas turbine are blocked by foreign technology, it is difficult for technicians to understand its characteristics in depth, and the modification of its internal control logic configuration is also restricted by many conditions. Therefore, it is difficult to add a frequency modulation function to the gas turbine control system.

Contents of the invention

The invention provides a method for realizing the frequency regulation function of gas-steam combined cycle unit, aiming at solving the problem that the frequency regulation function of the current gas-steam combined cycle generator set mainly depends on the gas turbine. Since the gas turbine control system and control method are blocked by foreign technology, technicians are more difficult. It is difficult to understand its characteristics in depth, and the modification of its internal control logic configuration is also restricted by many conditions. It is difficult to add a frequency modulation function to the gas turbine control system.

The purpose of the present invention is to provide a method for realizing the frequency modulation function of the gas-steam combined cycle unit. In this method, the frequency modulation implementation mode of the gas turbine control system is moved forward. The frequency modulation control logic controls the frequency modulation load of the gas turbine, adds the frequency modulation function to the steam turbine control system, and realizes the frequency modulation function of the gas-steam combined cycle unit.

Further, the realization conditions of the method for realizing the frequency regulation function of the gas-steam combined cycle unit are:

(1) The gas turbine control system and the steam turbine control system have a clock synchronization function;

(2) The gas-steam combined cycle unit is in a normal shutdown state;

(3) The steam turbine control system includes at least three accurate unit speed signals;

(4) The gas turbine has an external reserved interface for raising/lowering load.

Further, the specific steps of the method for realizing the frequency regulation function of the gas-steam combined cycle unit are:

Step 1, select three unit speed analog signals in the steam turbine control system, and make a judgment among the three;

Step 2, comparing the determined actual speed signal of the steam turbine unit with the rated speed signal of the steam turbine unit, and converting the compared speed difference signal into a frequency modulation load;

Step 3: Transmit the converted frequency modulation load trigger load up/down pulse to the gas turbine control system, and linearly output the length of the pulse according to the size of the frequency modulation load;

Step 4, connect the steam turbine control system to two sets of hard-wired pulse outputs for load increase/decrease, and the gas turbine control system to connect two sets of hard-wired pulse inputs for load increase/decrease;

Step 5, the gas turbine control system automatically adjusts the opening degree signal based on the original gas control valve opening degree according to the received rising/falling load pulses.

Further, in step 3, when the converted frequency modulation load triggers the up/down pulse to the gas turbine control system, if the frequency modulation load is positive, it means that the grid frequency is low and the unit needs to increase the load, so the load up pulse is triggered; if the frequency modulation load If it is negative, it means that the network frequency is high, and the unit needs to reduce the load, so the load reduction pulse is triggered.

Further, in step five, when the gas turbine control system receives the load-up pulse, it automatically increases the opening signal on the basis of the original gas control valve opening;

When the gas turbine control system receives the load reduction pulse, it automatically reduces the opening signal based on the original gas control valve opening.

Further, the steam turbine control system is provided with:

The speed difference and frequency modulation load conversion function module is used to convert the speed difference signal between the rated speed of the steam turbine unit and the actual speed of the steam turbine unit into a frequency modulation load signal, and output the frequency modulation load signal;

The steam machine pulse generating module is connected with the said rotational speed difference and frequency modulation load conversion functional module, and is used to receive the frequency modulation load signal output by the said rotational speed difference and frequency modulation load conversion functional module, trigger the generation of raising/lowering load pulses, and /Drop load pulses are passed to the gas turbine control system.

Further, the gas turbine control system is provided with:

External reserved interface for increasing/decreasing load, which is used to connect two sets of hard wiring for increasing/decreasing load connected to the steam turbine control system, and input the increasing/decreasing load pulse to the gas turbine control system;

The gas regulating valve lifting module is used to automatically adjust the opening degree signal based on the original gas regulating valve opening degree according to the received rising/falling load pulse.

Further, the rated speed of the steam turbine unit is 3000rpm.

The method for realizing the frequency modulation function of the gas-steam combined cycle unit provided by the present invention moves the frequency modulation realization mode of the gas turbine control system forward, and adds the frequency modulation control logic in the steam turbine control system to control the gas turbine through the interface reserved externally for the increase/decrease load The frequency modulation load is added to the steam turbine control system to realize the frequency modulation function of the gas-steam combined cycle unit and meet the requirements of relevant standards. It provides a valuable technical reference for similar units and optimizes the frequency modulation of the gas-steam combined cycle unit. Performance, with strong promotion and application value.

Description of drawings

Fig. 1 is an implementation flowchart of a method for realizing the frequency regulation function of a gas-steam combined cycle unit provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a method for realizing the frequency regulation function of a gas-steam combined cycle unit provided by an embodiment of the present invention.

In the figure: 21. Steam turbine control system; 211. Speed difference and frequency modulation load conversion function module; 212. Steam engine pulse generation module; 22. Gas turbine control system; 221. External reserved interface for raising/lowering load; 222. Gas regulation Valve lift module.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the invention.

The purpose of the present invention is to provide a method for realizing the frequency modulation function of the gas-steam combined cycle unit. This method moves the frequency modulation implementation mode of the gas turbine control system 22 forward, and through the external reserved interface 221 for raising/lowering load, the steam turbine control system In 21, the frequency modulation control logic is added to control the frequency modulation load of the gas turbine, and the frequency modulation function is added to the steam turbine control system 21, thereby realizing the frequency modulation function of the gas-steam combined cycle unit.

In the embodiment of the present invention, the realization conditions of the method for realizing the frequency regulation function of the gas-steam combined cycle unit are:

(1) The gas turbine control system 22 and the steam turbine control system 21 have a clock synchronization function;

(2) The gas-steam combined cycle unit is in a normal shutdown state;

(3) The steam turbine control system 21 includes at least three accurate unit speed signals;

(4) The gas turbine has an external reserved interface 221 for raising/lowering load.

Fig. 1 shows the implementation process of the method for realizing the frequency regulation function of the gas-steam combined cycle unit provided by the embodiment of the present invention.

The specific steps are:

Step S101, select three unit rotational speed analog signals in the steam turbine control system 21, and make a judgment among the three;

Step S102, comparing the determined actual speed signal of the steam turbine unit with the rated speed signal of the steam turbine unit, and converting the compared speed difference signal into a frequency modulation load;

Step S103, transmitting the converted frequency modulation load trigger load up/down pulse to the gas turbine control system 22, and linearly output the length of the pulse according to the size of the frequency modulation load;

Step S104, the steam turbine control system 21 is connected to two sets of hard-wired pulse outputs for raising/lowering load, and the gas turbine control system 22 is connected to two sets of hard-wired pulse inputs for raising/lowering load;

In step S105, the gas turbine control system 22 automatically adjusts the opening degree signal based on the original gas control valve opening degree according to the received load raising/lowering pulse.

In the embodiment of the present invention, in step S103, when the converted frequency modulation load trigger up/down pulse is transmitted to the gas turbine control system 22, if the frequency modulation load is positive, it means that the grid frequency is low and the unit needs to increase the load, so the trigger up/down pulse is triggered. Load pulse; if the frequency modulation load is negative, it means that the network frequency is high, and the unit needs to reduce the load, so the load reduction pulse is triggered.

In the embodiment of the present invention, in step S105, when the gas turbine control system 22 receives the load-up pulse, it automatically increases the opening degree signal on the basis of the opening degree of the original gas regulating valve;

When the gas turbine control system 22 receives the load reduction pulse, it automatically reduces the opening degree signal based on the original gas control valve opening degree.

Fig. 2 shows the implementation structure of the method for realizing the frequency regulation function of the gas-steam combined cycle unit provided by the embodiment of the present invention. For ease of illustration, only the parts relevant to the present invention are shown.

In the embodiment of the present invention, the steam turbine control system 21 is provided with:

Speed difference and frequency modulation load conversion function module 211, used to convert the speed difference signal between the rated speed of the steam turbine unit and the actual speed of the steam turbine unit after comparison into a frequency modulation load signal, and output the frequency modulation load signal;

The steamer pulse generation module 212 is connected with the speed difference and frequency modulation load conversion function module 211, and is used to receive the frequency modulation load signal output by the speed difference and frequency modulation load conversion function module 211, trigger the generation of the up/down load pulse, and increase/decrease the load pulse. The load shedding pulse is delivered to the gas turbine control system 22 .

In the embodiment of the present invention, the gas turbine control system 22 is provided with:

The external reserved interface 221 for increasing/decreasing load is used to connect two sets of hard wiring for increasing/decreasing load connected to the steam turbine control system 21, and input the increasing/decreasing load pulses to the gas turbine control system 22;

The gas regulating valve lifting module 222 is used to automatically adjust the opening degree signal based on the original gas regulating valve opening degree according to the received pulse of raising/decreasing load.

In the embodiment of the present invention, the rated speed of the steam turbine unit is 3000 rpm.

The application principle of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The present invention proposes a method for realizing the frequency modulation function of the gas-steam combined cycle unit, which moves the frequency modulation implementation mode in the gas turbine forward, adds the frequency modulation function to the steam turbine control system 21, and realizes the control of the frequency modulation load of the gas turbine through the reserved interface of the gas turbine.

The present invention adds frequency modulation control logic to the steam turbine control system 21 through the interface 221 reserved externally for load increase/decrease, realizes the frequency modulation function of the gas-steam combined cycle unit and meets the requirements of relevant standards, and provides technical reference for similar units.

Realization conditions:

(1) The gas turbine control system 22 and the steam turbine control system 21 have a clock synchronization function;

(2) The gas-steam combined cycle unit is in a normal shutdown state;

(3) The steam turbine control system 21 includes at least three accurate unit speed signals;

(4) The gas turbine has an external reserved interface 221 for raising/lowering load.

Implementation steps:

The steam turbine control system 21 includes:

(1) Select three unit speed analog signals in the steam turbine control system 21, and make a judgment among the three;

(2) Compare the judged unit actual speed signal with the unit rated speed (3000rpm) signal (rated speed - unit actual speed);

(3) The compared speed difference signal is converted into a frequency modulation load through the speed difference and frequency modulation load conversion function module 211;

(4) Trigger the up/down pulse of the converted frequency modulation load to the gas turbine control system 22 through the pulse generation module 21 of the steam turbine control system (the frequency modulation load is positive, indicating that the network frequency is low, and the unit needs to increase the load, so trigger the load up pulse, and vice versa as well);

(5) The steam turbine control system 21 can linearly output the length of the pulse according to the size of the frequency modulation load;

The connection between the steam turbine and the gas turbine control system 22 includes:

(6) The steam turbine control system 21 needs to be connected to two sets of hard-wired pulse outputs for raising/lowering load;

(7) The gas turbine control system 22 needs to be connected to two sets of hard-wired pulse inputs for load raising/lowering;

The gas turbine control system 22 includes:

(8) After receiving the load-up pulse, the gas turbine control system 22 automatically increases the opening degree signal on the basis of the original gas control valve opening degree, and vice versa;

The method for realizing the frequency modulation function of the gas-steam combined cycle unit provided by the embodiment of the present invention moves the frequency modulation implementation mode of the gas turbine control system 22 forward, and increases the frequency modulation in the steam turbine control system 21 through the external reserved interface 221 for increasing/decreasing the load Control logic, control the frequency modulation load of the gas turbine, add the frequency modulation function to the steam turbine control system 21, realize the frequency modulation function of the gas-steam combined cycle unit and meet the requirements of relevant standards, provide a valuable technical reference for similar units, and optimize the gas-steam combined cycle unit. The frequency modulation performance of the steam combined cycle unit has strong promotion and application value.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention. Inside.

Claims (2)

1. one kind realizes the method for gas-steam combined cycle set frequency modulation function, it is characterized in that, the frequency modulation implementation of gas turbine control system moves forward by the method, by the outside spare interface of lifting/lowering load, frequency modulation control logic is increased in steam turbine control system, control the frequency modulation load of gas turbine, increase frequency modulation function in steam turbine control system, realize gas-steam combined cycle set frequency modulation function;

This specific implementation step realizing the method for gas-steam combined cycle set frequency modulation function is:

Step one, chooses three generating unit speed analog signalses in steam turbine control system, carries out three and gets middle judgement;

Step 2, compares the steam turbine unit actual speed signal after judgement and steam turbine unit rated speed signal, converts the speed discrepancy signal relatively to frequency modulation load;

Step 3, triggers the pulse of lifting/lowering load by the frequency modulation load after conversion and is passed to gas turbine control system, and the length of size linear convergent rate pulse according to frequency modulation load;

Step 4, steam turbine control system is connected the two groups of hardwire pulses of lifting/lowering load and export, gas turbine control system connects lifting/lowering load two groups of hardwire Puled input;

Step 5, gas turbine control system affectionately rushes according to the lifting/lowering load received, automatically at the enterprising Row sum-equal matrix opening amount signal in former gas control valve aperture basis;

In step 3, when the frequency modulation load triggering lifting/lowering pulse after conversion is passed to gas turbine control system, if frequency modulation load is just, then illustrates that net is frequently low, need unit to increase load, therefore the pulse of triggering load up; If frequency modulation load is negative, then illustrates that net is frequently high, need unit to reduce load, therefore trigger load down pulse;

In step 5, after gas turbine control system receives load up pulse, automatically on former gas control valve aperture basis, increase opening amount signal;

After gas turbine control system receives load down pulse, automatically on former gas control valve aperture basis, reduce opening amount signal;

Be provided with in steam turbine control system: speed discrepancy and frequency modulation load transition function module, for converting the speed discrepancy signal of the steam turbine unit rated speed after relatively and steam turbine unit actual speed to frequency modulation load signal, and frequency modulation load signal is exported; Steam turbine pulse generating module, be connected with frequency modulation load transition function module with described speed discrepancy, ground frequency modulation load signal is exported for receiving described speed discrepancy and frequency modulation load transition function module, trigger and generate the pulse of lifting/lowering load, and the pulse of lifting/lowering load is passed to gas turbine control system;

Be provided with in gas turbine control system: the outside spare interface of lifting/lowering load, for accessing lifting/lowering load two groups of hardwires that steam turbine control system picks out, to the pulse of gas turbine control system input lifting/lowering load;

Gas control valve lifting module, for affectionately rushing according to the lifting/lowering load received, automatically at the enterprising Row sum-equal matrix opening amount signal in former gas control valve aperture basis;

Described steam turbine unit rated speed is 3000rpm.

2. the method for claim 1, is characterized in that, this realization condition realizing the method for gas-steam combined cycle set frequency modulation function is:

(1) gas turbine control system and steam turbine control system have clock synchronous function;

(2) gas-steam combined cycle set is in normal shut down condition;

(3) steam turbine control system at least comprises three accurate generating unit speed signals;

(4) gas turbine has the outside spare interface of lifting/lowering load.