阅读说明：本技术 F级燃气-蒸汽联合循环机组快速启动至额定负荷的方法 (Method for quickly starting F-grade gas-steam combined cycle unit to rated load ) 是由 王梓越 张长志 倪玮晨 李浩然 王坤 赵毅 王建 王建军 甘智勇 于 2021-08-05 设计创作，主要内容包括：本发明涉及一种F级燃气-蒸汽联合循环机组快速启动至额定负荷的方法,燃气轮机点火,燃气轮机带动其发电机至额定负荷发电并网；在高压调门开度达15％时,汽轮机进入压力控制；汽轮机在进口压力控制模式下运行且高压调门开度大于20％超过60秒,中压蒸汽压力大于1.3MPa时,进行中压蒸汽并汽；低压主蒸汽压力大于0.3MPa,低压旁路开度大于20％时,并入低压主蒸汽。本发明通过汽轮机提早进入压力控制(IPC),使汽轮机中压并汽和低压并汽的时间节点提前,进而缩短了F级燃气-蒸汽联合循环机组冷态快速启动至带额定负荷的时间,减少了联合循环机组在低负荷时燃机非预混模式工况的时间。(The invention relates to a method for quickly starting an F-grade gas-steam combined cycle unit to a rated load, wherein a gas turbine is ignited, and the gas turbine drives a generator of the gas turbine to generate power at the rated load and is connected to the grid; when the opening degree of the high-pressure regulating valve reaches 15%, the steam turbine enters pressure control; the steam turbine operates in an inlet pressure control mode, when the opening of the high-pressure regulating valve is more than 20% and more than 60 seconds and the pressure of the medium-pressure steam is more than 1.3MPa, the medium-pressure steam is combined with the steam; when the low-pressure main steam pressure is greater than 0.3MPa and the opening of the low-pressure bypass is greater than 20%, the low-pressure main steam is merged into the low-pressure main steam. According to the invention, the pressure control (IPC) is entered in advance by the steam turbine, so that the time nodes of medium-pressure steam mixing and low-pressure steam mixing of the steam turbine are advanced, the time from the cold state quick start of the F-stage gas-steam combined cycle unit to the rated load is shortened, and the time of the non-premixed mode working condition of the combustion engine of the combined cycle unit at low load is reduced.)

1. A method for quickly starting a F-grade gas-steam combined cycle unit to a rated load comprises the following steps:

(1) igniting the gas turbine, and driving the generator of the gas turbine to a rated load to generate and grid-connect;

(2) when the opening degree of the high-pressure regulating valve reaches 15%, the steam turbine enters pressure control;

(3) the steam turbine operates in an inlet pressure control mode, when the opening of the high-pressure regulating valve is more than 20% and more than 60 seconds and the pressure of the medium-pressure steam is more than 1.3MPa, the medium-pressure steam is combined with the steam;

(4) when the low-pressure main steam pressure is greater than 0.3MPa and the opening of the low-pressure bypass is greater than 20%, the low-pressure main steam is merged into the low-pressure main steam;

(5) when the unit starting state picture shows that the high-pressure steam inlet condition is met, the DCS sends an instruction to allow the high-pressure cylinder of the steam turbine to enter steam, and when the temperature of the high-pressure steam is between 296 and 565 ℃ and a Releaseload button appears on an MKVI picture, the high-pressure cylinder of the steam turbine is allowed to enter steam;

(6) exit temperature matching loading: and when the temperature matching value reaches 566 ℃ and the stress and differential expansion parameters are normal, the temperature matching is quitted to load, the input of the desuperheating water and the input of AVC are controlled, and the turbine is brought to the rated load.

2. The method for rapidly starting a class F gas-steam combined cycle unit to rated load according to claim 1, wherein: the condition for grid connection of the generator of the gas turbine in the step (1) specifically comprises the following steps:

firstly, the voltage of a generator of a gas turbine is approximate to or equal to the system voltage;

the frequency of the generator of the gas turbine is approximately equal to the system frequency;

and the voltage phase of the generator of the gas turbine to be tested is the same as the voltage phase of the system.

3. The method for rapidly starting a class F gas-steam combined cycle unit to rated load according to claim 1, wherein: the inlet pressure control of the steam turbine in the step (2) should meet the following specific conditions:

firstly, in a stable state, the pressure before adjusting the door is put into the range of 600 plus 605psi as much as possible;

② the opening degree of the high-pressure bypass is less than 20 percent as much as possible.

4. The method for rapidly starting a class F gas-steam combined cycle unit to rated load according to claim 1, wherein: the specific conditions of medium-pressure steam combination in the step (3) comprise:

firstly, the steam turbine operates in an inlet pressure control mode, and the opening degree of a high-pressure regulating valve is more than 20% and exceeds 60 seconds;

the opening of the medium-pressure bypass is more than 20%, and the time is delayed for 60 seconds;

thirdly, the pressure of the medium-pressure steam is more than 1.3 MPa;

and fourthly, the output of the unit is more than 17 MW.

5. The method for rapidly starting a class F gas-steam combined cycle unit to rated load according to claim 1, wherein: the conditions for merging the low-pressure main steam in the step (4) specifically comprise the following steps:

firstly, the superheat degree of low-pressure main steam is more than 20 ℃;

the low-pressure main steam pressure is more than 0.3 MPa;

③ the low side opening degree is more than 20 percent, and the time is at least 60 seconds;

fourthly, the opening degree of the high-pressure regulating valve is more than 20 percent, and the time is at least 60 seconds;

the load of the unit is greater than 17 MW.

6. The method for rapidly starting a class F gas-steam combined cycle unit to rated load according to claim 1, wherein: on the basis of meeting the operating conditions, the step (3) and the step (4) can be interchanged in sequence.

7. The method for rapidly starting a class F gas-steam combined cycle unit to rated load according to claim 1, wherein: the steam inlet condition of the high-pressure cylinder of the steam turbine in the step (5) specifically comprises the following steps:

firstly, when the metal temperature of an upper cylinder in the first stage of a high-pressure cylinder of a steam turbine is lower than 182 ℃, the temperature of high-pressure steam is lower than or equal to 376 ℃;

the metal temperature of the first-stage inner upper cylinder of the high-pressure cylinder of the steam turbine is higher than 182 ℃ and lower than 510 ℃, namely the temperature of high-pressure steam is higher than the metal temperature;

and thirdly, when the metal temperature of the first-stage inner upper cylinder of the high-pressure cylinder of the steam turbine is higher than 510 ℃, the temperature of the high-pressure steam is higher than or equal to 510 ℃.

Technical Field

The invention belongs to the technical field of thermal power generation safety, relates to a starting technology of an F-level gas-steam combined cycle unit, and particularly relates to a method for quickly starting the F-level gas-steam combined cycle unit to a rated load.

Background

The gas-steam combined cycle is used as an advanced power generation technology, and the position of the gas-steam combined cycle in the power production industry of China is increasingly improved. The unit has the advantages of high efficiency, low consumption, quick start, flexible adjustment, high availability ratio, investment saving, short construction period, small environmental pollution and the like, and is increasingly valued and developed in foreign power industries.

Research shows that the whole starting process is as fast as possible from the ignition and grid connection of a combustion engine to the steam inlet of a steam turbine to the rated load of the gas-steam combined cycle generator set. However, the current starting method is slow in speed and large in gas consumption.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and provides a method for quickly starting an F-level gas-steam combined cycle unit to a rated load, so that the gas consumption is reduced, and necessary technical support is provided for safe, environment-friendly and economic operation of the gas-steam combined cycle unit.

The technical scheme adopted by the invention for solving the technical problem is as follows:

a method for quickly starting a F-grade gas-steam combined cycle unit to a rated load comprises the following steps:

(1) igniting the gas turbine, and driving the generator of the gas turbine to a rated load to generate and grid-connect;

(2) when the opening degree of the high-pressure regulating valve reaches 15%, the steam turbine enters pressure control;

(3) the steam turbine operates in an inlet pressure control mode, when the opening of the high-pressure regulating valve is more than 20% and more than 60 seconds and the pressure of the medium-pressure steam is more than 1.3MPa, the medium-pressure steam is combined with the steam;

(4) when the low-pressure main steam pressure is greater than 0.3MPa and the opening of the low-pressure bypass is greater than 20%, the low-pressure main steam is merged into the low-pressure main steam;

(5) when the unit starting state picture shows that the high-pressure steam inlet condition is met, the DCS sends an instruction to allow the high-pressure cylinder of the steam turbine to enter steam, and when the temperature of the high-pressure steam is between 296 and 565 ℃ and a Release load button appears on an MKVI picture, the high-pressure cylinder of the steam turbine is allowed to enter steam;

(6) exit temperature matching loading: and when the temperature matching value reaches 566 ℃ and the stress and differential expansion parameters are normal, the temperature matching is quitted to load, the input of the desuperheating water and the input of AVC are controlled, and the turbine is brought to the rated load.

Further, the condition for grid connection of the generator of the gas turbine in the step (1) specifically includes:

firstly, the voltage of a generator of a gas turbine is approximate to or equal to the system voltage;

the frequency of the generator of the gas turbine is approximately equal to the system frequency;

and the voltage phase of the generator of the gas turbine to be tested is the same as the voltage phase of the system.

Further, the entering pressure control of the steam turbine in the step (2) should meet the following specific conditions:

firstly, in a stable state, the pressure before adjusting the door is put into the range of 600 plus 605psi as much as possible;

② the opening degree of the high-pressure bypass is less than 20 percent as much as possible.

Further, the specific conditions of the medium-pressure steam combination in the step (3) comprise:

firstly, the steam turbine operates in an inlet pressure control mode, and the opening degree of a high-pressure regulating valve is more than 20% and exceeds 60 seconds;

the opening of the medium-pressure bypass is more than 20%, and the time is delayed for 60 seconds;

thirdly, the pressure of the medium-pressure steam is more than 1.3 MPa;

and fourthly, the output of the unit is more than 17 MW.

Further, the condition for merging the low-pressure main steam in the step (4) specifically comprises the following steps:

firstly, the superheat degree of low-pressure main steam is more than 20 ℃;

the low-pressure main steam pressure is more than 0.3 MPa;

③ the low side opening degree is more than 20 percent, and the time is at least 60 seconds;

fourthly, the opening degree of the high-pressure regulating valve is more than 20 percent, and the time is at least 60 seconds;

the load of the unit is greater than 17 MW.

Further, the step (3) and the step (4) can be interchanged in sequence on the basis of meeting the operation condition.

Further, the steam inlet condition of the high-pressure cylinder of the steam turbine in the step (5) specifically includes:

firstly, when the metal temperature of an upper cylinder in the first stage of a high-pressure cylinder of a steam turbine is lower than 182 ℃, the temperature of high-pressure steam is lower than or equal to 376 ℃;

the metal temperature of the first-stage inner upper cylinder of the high-pressure cylinder of the steam turbine is higher than 182 ℃ and lower than 510 ℃, namely the temperature of high-pressure steam is higher than the metal temperature;

and thirdly, when the metal temperature of the first-stage inner upper cylinder of the high-pressure cylinder of the steam turbine is higher than 510 ℃, the temperature of the high-pressure steam is higher than or equal to 510 ℃.

The invention has the advantages and positive effects that:

according to the invention, the time nodes of medium-pressure steam mixing and low-pressure steam mixing of the steam turbine are advanced by the early entry of the steam turbine Into Pressure Control (IPC), so that the time from the cold state quick start of the F-stage gas-steam combined cycle unit to the rated load is shortened, the time of the non-premixed working condition of the gas turbine of the combined cycle unit at low load is reduced (nitrogen and oxide harmful to the environment are generated under the working condition), the gas consumption is reduced, and necessary technical support is provided for the safe, environment-friendly and economic operation of the gas-steam combined cycle unit.

Drawings

FIG. 1 is a schematic system flow diagram of the method of the present invention.

Detailed Description

The present invention is further illustrated by the following specific examples, which are intended to be illustrative, not limiting and are not intended to limit the scope of the invention.

A method for quickly starting a F-class gas-steam combined cycle unit to a rated load comprises the following specific steps as shown in figure 1:

(1) igniting the gas turbine, and driving the generator of the gas turbine to a rated load to generate and grid-connect;

(2) when the high pressure steam pressure slightly exceeds the IPC set value, the Inlet Pressure Control (IPC) can be put into use, namely, the steam turbine enters the pressure control (IPC) in advance, the high side is gradually closed, and the high side pressure set value tracks the actual pressure. The IPC is important to be put into as early as possible, all high-pressure steam can be smoothly switched to enter a steam turbine from entering a bypass after the IPC is put into, the temperature matching can be switched to DCS for automatic temperature rise, and the merging of medium-pressure main steam is completed as early as possible;

(3) the method comprises the following steps that a steam turbine runs IN an inlet pressure control mode (IPCIN), when the opening of a high-pressure regulating valve is more than 20% and more than 60 seconds and the pressure of medium-pressure steam is more than 1.3MPa, medium-pressure steam is mixed with steam;

(4) when the low-pressure main steam pressure is greater than 0.3MPa and the opening of the low-pressure bypass is greater than 20%, the low-pressure main steam can be merged into the low-pressure main steam as early as possible;

(5) when the DCS displays the high-pressure steam inlet condition that the starting state of the unit is met, the DCS sends an instruction to allow the high-pressure cylinder of the steam turbine to enter steam. When the high pressure steam temperature is between 296 ℃ (565 ° f) and 565 ℃ (1050 ° f), a "Release load" button appears on the MKVI screen, allowing the turbine high pressure cylinder to enter steam.

(6) Exit temperature matching loading: when the temperature matching value reaches 566 ℃ and the parameters of stress, differential expansion and the like are normal, the temperature matching can be quitted for loading. And controlling the input of the temperature-reducing water, and timely inputting AVC. Bringing the turbine to rated load. At this time, the gas-steam combined cycle unit reaches the rated load (or the highest load required by dispatching)

In addition, the conditions for the parallel connection of the internal combustion engine and the generator in the step (1) specifically include:

the voltage of the generator to be connected to the grid is approximate to or equal to the system voltage.

And the frequency of the generator to be connected to the grid is approximately equal to the system frequency.

And the voltage phase of the generator to be connected to the grid is the same as the voltage phase of the system.

Moreover, in the step (2), the steam turbine early enters the pressure control (IPC), the IPC can be put in early when the opening of the high-pressure throttle reaches about 15%, but the following conditions are met:

under a stable state, the pressure before the valve adjustment is put into the range of 600-605psi as much as possible (the load ratio loadcmd of the steam turbine is about more than 60 percent and the opening degree of the valve adjustment is about 15 percent when the hot state is started);

secondly, in order to stabilize the water level of the steam drum, the opening degree of the high-pressure bypass is as small as 20 percent as possible;

moreover, the conditions for incorporating the medium-pressure main steam in the step (3) specifically include:

operating a steam turbine IN an inlet pressure control mode (IPC IN) and enabling the opening of a high-pressure regulating valve to be more than 20% and more than 60 seconds;

the opening of the medium-pressure bypass is more than 20%, and the time is delayed for 60 seconds;

thirdly, the pressure of the medium-pressure steam is more than 1.3 MPa;

and fourthly, the output of the unit is more than 17 MW.

Moreover, the conditions for the step (4) of merging the low-pressure main steam specifically include:

firstly, the superheat degree of low-pressure main steam is more than 20 ℃;

the low-pressure main steam pressure is more than 0.3 MPa;

③ the low side opening is more than 20 percent (time is at least 60 seconds);

opening degree of the high-pressure regulating valve is more than 20% (time is at least 60 seconds);

the load of the unit is greater than 17 MW.

Moreover, the step (3) and the step (4) can be interchanged in order on the basis of satisfying the operating conditions.

Moreover, the steam inlet conditions of the high-pressure cylinder of the steam turbine in the step (5) specifically include:

when the metal temperature of the upper cylinder in the first stage of the high pressure cylinder is less than 182 deg.C (360 deg.C), the high pressure steam temperature is not greater than 376 deg.C (710 deg.C);

the upper cylinder metal temperature in the first stage of the high pressure cylinder is greater than 182 ℃ (360 ° f) and less than 510 ℃ (950 ° f), i.e. the high pressure steam temperature is greater than the metal temperature;

and thirdly, when the metal temperature of the upper cylinder in the first stage of the high-pressure cylinder is more than 510 ℃ (950 DEG F), the temperature of the high-pressure steam is not less than 510 ℃ (950 DEG F).

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept, and these changes and modifications are all within the scope of the present invention.