CN115263447A - Cold-state pre-warming control system of gas-steam combined cycle unit - Google Patents

Abstract

The application provides a gas steam combined cycle unit's cold state warms up control system in advance includes: the first pre-warming unit is used for determining whether the first pre-warming stage is finished or not according to the switching conditions of the warm cylinder drain valve, the high-discharge check valve and the high-discharge ventilation valve; the second pre-warming unit is used for determining whether the second pre-warming stage is finished or not according to the switching conditions of the low side valve, the high side valve, the middle side valve and the steam turbine electric isolation valve; the third pre-heating unit is used for determining whether the third pre-heating stage is finished or not according to the superheat degree of the main steam, the temperature and the pressure of a steam pipeline of the cylinder heater and the switching condition of a drain valve of the cylinder heater; the fourth pre-warming unit is used for determining whether a fourth pre-warming stage is finished or not according to the switching conditions of the pre-warming medium-pressure butterfly valve, the medium-pressure regulating valve and the high-pressure gate valve, the temperature and the pressure of the steam pipeline of the warming cylinder, the rotating speed of the gas turbine and the rotating speed of the steam turbine; and the fifth pre-warming unit is used for determining whether the fifth pre-warming stage is finished or not according to the state of the steam turbine.

Description

Cold state preheating control system of gas-steam combined cycle unit

technical field

The application relates to the field of intelligent control of a gas-steam combined cycle unit, in particular to a cold-state preheating control system of a gas-steam combined cycle unit.

Background technique

During the cold start-up stage of the gas-steam combined cycle unit, it usually takes a lot of time to make the unit smoothly generate electricity and connect to the grid. The reason is that the cylinder block of the steam turbine starts to warm up until the speed of the steam turbine rises to 3000r/min, so that the subsequent combined cycle mode can be carried out.

By adding a cold-state pre-heating pipeline to the steam turbine side, the goal of cold-state pre-heating is realized by using the temporary steam. The pre-heating steam pipeline acts on the high-pressure cylinder and the medium-pressure cylinder of the steam turbine respectively. This allows the steam turbine to be warmed up in advance before the unit is ready to start. However, the relevant technology has not proposed how to control the cold-state warm-up stage of the unit to ensure the smooth start-up of the unit.

Contents of the invention

In order to solve the above problems, the present application provides a cold state preheating control system of a gas-steam combined cycle unit.

According to one aspect of the present application, a cold-state preheating control system of a gas-steam combined cycle unit is provided, which is applied to a coaxial gas-steam combined cycle unit, and a high-pressure preheating is added to the turbine side of the coaxial gas-steam combined cycle unit The steam pipeline and the medium-pressure preheating steam pipeline, wherein, the high-pressure preheating steam pipeline is connected with the main steam pipeline of the high-pressure cylinder, the medium-pressure preheating steam pipeline is directly connected with the medium-pressure cylinder side, and the high-pressure preheating steam pipeline and the The medium-pressure preheating steam pipelines are all equipped with preheating valve groups; the system includes:

The first pre-heating unit is used to determine whether the first pre-heating stage is completed according to the switching conditions of the warming cylinder trap, the high-row check valve and the high-row ventilation valve;

The second preheating unit is used to determine whether the second preheating stage is completed according to the switching conditions of the low bypass valve, high bypass valve, middle bypass valve, and steam turbine electric isolation valve after the first preheating stage is completed;

The third pre-heating unit is used to determine whether the third pre-heating stage is based on the degree of superheat of the main steam, the temperature and pressure of the warming cylinder steam pipe, and the opening and closing of the warming cylinder steam trap after the second pre-warming stage is completed. Finish;

The fourth pre-heating unit is used to, after the completion of the third pre-warming stage, according to the switching conditions of the pre-heating medium-pressure butterfly valve, medium-pressure regulating valve and high-pressure gate valve, as well as the temperature and pressure of the steam pipeline of the warming cylinder, the fuel The engine speed and the steam turbine speed are used to determine whether the fourth warm-up stage is completed;

The fifth preheating unit is configured to determine whether the fifth preheating stage is completed according to the state of the steam turbine after the fourth preheating stage is completed.

In some embodiments of the present application, the first pre-heating unit includes: a switching signal input module for fully opening the warming cylinder drain valve, a switching signal input module for fully closing the high-row check valve, and a fully closed high-row ventilation valve. The switch signal input module that is closed, the switch signal output module and the first AND module that are completed in the first warm-up stage; where:

The switch signal input module for fully opening the heating cylinder drain valve, the switch signal input module for fully closing the high row check valve, and the fully close switch signal input module for the high row ventilation valve are all connected to the first One is connected to the input end of the module; the output end of the first and module is connected to the switching signal output module completed in the first warm-up stage.

In some embodiments of the present application, the second preheating unit includes: a switch signal input module for fully closing the low bypass valve, a switch signal input module for fully closing the high bypass valve, and a switch signal input module for fully closing the middle bypass valve. The signal input module, the digital signal input module for the fully closed electric isolation valve of the steam turbine, the digital signal output module and the second AND module for the completion of the second warm-up stage; where:

The switch signal input module for the full close of the low bypass valve, the switch signal input module for the full close of the high bypass valve, the switch signal input module for the full close of the middle bypass valve and the full close of the electric isolation valve of the steam turbine The switching signal input modules of the second AND module are all connected to the input terminals of the second AND module; the switching signal output modules completed in the second warm-up stage are connected to the output terminals of the second AND module.

As a possible implementation, the third preheating unit includes: a switch signal input module whose main steam superheat degree is less than the superheat degree threshold, and a switch signal input module whose temperature and pressure of the warming cylinder steam pipeline meet preset conditions , switch signal input module for warm cylinder steam trap closed state, switch signal input module for warm cylinder trap open state, switch signal output module for completion of the third warm-up stage, first non-module, second non-module and The third AND module; where:

The switch signal input module whose superheat degree of the main steam is less than the superheat threshold is connected to the input terminal of the first non-module; the switch signal input module of the warm cylinder drain valve closed state is connected to the second non-module ; The output end of the first non-module, the output end of the second non-module, the temperature and pressure of the warming cylinder steam pipeline all meet the preset conditions of the switching signal input module and the open state of the warming cylinder steam trap The switch signal input modules of the switches are all connected to the input terminals of the third AND module; the output terminals of the third AND module are connected to the switch signal output modules completed in the third warm-up stage.

As another possible implementation, the third pre-heating unit further includes: a switch signal input module for the fifth stage command of pre-heating, a switch signal input module for the temperature of the warming cylinder steam pipeline, and a switch signal input module for the temperature of the warm cylinder steam pipeline. Switch signal input module, the fourth AND module, the fifth AND module and the first OR module; wherein:

The switching value signal input module of the fifth stage command of pre-warming and the switching signal input module of the steam pipeline temperature of the heating cylinder are connected to the input end of the fourth AND module; the switch of the fifth phase of pre-warming command The digital signal input module and the switching signal input module of the heating cylinder steam pipeline pressure are connected to the input end of the fifth AND module; the output end of the fourth AND module, the output end of the fifth AND module and The switching signal input modules whose superheat degree of the main steam is less than the superheat degree threshold are all connected to the input terminals of the first OR module; the output terminals of the first OR module are connected to the input terminals of the first non-module.

In some embodiments of the present application, the fourth preheating unit includes: a switch signal input module for fully opening the preheating medium pressure butterfly valve, a switch signal input module for fully opening the medium pressure regulating valve, and a switch for fully opening the high pressure gate valve. Quantity signal input module, switch signal input module with the temperature and pressure of the warming cylinder steam pipeline meeting the preset conditions, analog signal input module of gas turbine speed, analog signal input module of steam turbine speed, switch for the completion of the fourth stage preheating Quantity signal output module, the sixth AND module, the seventh AND module, the eighth AND module, the first comparison is greater than the module, and the second comparison is greater than the module; wherein:

The switch signal input module for fully opening the preheating medium pressure butterfly valve, the switch signal input module for fully opening the medium pressure regulating valve, and the fully open switch signal input module for the high pressure gate valve are all connected to the sixth and module connected to the input terminal of the gas turbine speed; the analog signal input module of the gas turbine speed is connected to the input terminal of the first relatively large module; the analog signal input module of the steam turbine speed is connected to the input terminal of the second relatively large module The first comparison module and the second comparison module are both connected to the input end of the seventh AND module; the output end of the sixth AND module, and the temperature and pressure of the heating cylinder steam pipeline are all satisfied The preset switching value signal input module and the output terminal of the seventh AND module are connected to the input terminal of the eighth AND module; the output terminal of the eighth AND module is connected to the fourth stage preheating is completed connected to the switch signal output module.

In other embodiments of the present application, the fourth pre-warming unit further includes: a switching signal input module of the manual confirmation button of the fourth pre-warming stage, and the switching signal of the manual confirmation button of the fourth pre-warming stage The input module is also connected to the input end of the eighth AND module.

As a possible implementation, the fifth preheating unit includes: a digital signal input module ready for sequential start of the steam turbine and a digital signal output module completed in the fifth preheating stage, and the sequential start of the steam turbine The ready switch signal input module is connected with the switch signal output module completed in the fifth warm-up stage.

According to the technical solution of the application, the steam turbine is preheated in advance through the cold state preheating control system of the gas-steam combined cycle unit, and the time for conventional preheating of the unit is reduced, so that the goal of energy saving and efficiency increase can be achieved. The system uses multiple pre-heating units to fully automatic and intelligently control the entire pre-heating process, which can not only avoid system failures and signal jumps and changes, but also ensure the smooth start-up of the unit.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Description of drawings

The above and/or additional aspects and advantages of the present application will become apparent and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, wherein:

Fig. 1 is a structural block diagram of a cold state preheating control system of a gas-steam combined cycle unit provided in an embodiment of the present application;

Fig. 2 is the structural representation of the preheating of the steam turbine in the cold state of the coaxial gas-steam combined cycle unit in the embodiment of the present application;

Fig. 3 is a schematic structural view of a first pre-heating unit in the embodiment of the present application;

Fig. 4 is a schematic structural diagram of a second pre-heating unit in the embodiment of the present application;

Fig. 5 is a schematic structural diagram of a third pre-heating unit in the embodiment of the present application;

Fig. 6 is a schematic structural view of a fourth pre-heating unit in the embodiment of the present application;

Fig. 7 is a schematic structural diagram of another fourth pre-heating unit in the embodiment of the present application;

Fig. 8 is a schematic structural view of a fifth pre-heating unit in the embodiment of the present application;

Fig. 9 is a schematic structural diagram of another third pre-heating unit in the embodiment of the present application;

Detailed ways

Embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary, and are intended to explain the present application, and should not be construed as limiting the present application.

It should be noted that in the cold start-up stage of the gas-steam combined cycle unit, it usually takes a lot of time to make the unit smoothly generate electricity and connect to the grid. The reason is that the cylinder block of the steam turbine starts to warm up until the speed of the steam turbine rises to 3000r/min, so that the subsequent combined cycle mode can be carried out.

By adding a cold-state pre-heating pipeline to the steam turbine side, the goal of cold-state pre-heating is realized by using the temporary steam. The pre-heating steam pipeline acts on the high-pressure cylinder and the medium-pressure cylinder of the steam turbine respectively. This allows the steam turbine to be warmed up in advance before the unit is ready to start. However, the relevant technology has not proposed how to control the cold-state warm-up stage of the unit to ensure the smooth start-up of the unit.

In order to solve the above problems, the present application provides a cold state preheating control system of a gas-steam combined cycle unit.

Fig. 1 is a structural block diagram of a cold state preheating control system of a gas-steam combined cycle unit provided by an embodiment of the present application. It should be noted that the cold state preheating control system of the gas-steam combined cycle unit in the embodiment of the present application is applied to the coaxial gas-steam combined cycle unit, and the high-pressure pre-heating steam pipeline and Medium-pressure pre-heating steam pipeline, wherein, the high-pressure pre-heating steam pipeline is connected with the main steam pipeline of the high-pressure cylinder, the medium-pressure pre-heating steam pipeline is directly connected with the medium-pressure cylinder side, and the high-pressure pre-heating steam pipeline and the medium-pressure pre-heating steam pipeline All are equipped with preheating valve group. As shown in FIG. 2 , a high-pressure preheating steam pipeline 201 and a medium-pressure preheating steam pipeline 202 are added to the steam turbine side of the coaxial gas-steam combined cycle unit. Among them, the high-pressure pre-heating steam pipeline 201 is connected with the main steam pipeline of the high-pressure cylinder, and the medium-pressure pre-heating steam pipeline 202 is directly connected with the medium-pressure cylinder side, and the high-pressure pre-heating steam pipeline 201 and the medium-pressure pre-heating steam pipeline 202 are installed with Preheat valve group. Two pneumatic shut-off valves are installed on the high-pressure pre-heating steam pipeline 201, and one pneumatic shut-off valve and one start-up and shut-off regulating valve are installed on the medium-pressure pre-heating steam pipeline 202.

As shown in Figure 1, the cold state preheating control system of the gas-steam combined cycle unit in the embodiment of the present application includes: a first preheating unit 101, a second preheating unit 102, a third preheating unit 103, a fourth preheating unit Unit 104, fifth preheating unit 105.

Wherein, the first pre-heating unit 101 is used to determine whether the first pre-heating stage is completed according to the switching conditions of the warming cylinder trap, the high-row check valve and the high-row ventilation valve. The second preheating unit 102 is used to determine whether the second preheating stage is completed according to the switching conditions of the low bypass valve, high bypass valve, middle bypass valve, and steam turbine electric isolation valve after the first preheating stage is completed. The third preheating unit 103 is used to determine whether the third preheating stage is completed after the second preheating stage is completed, according to the superheat degree of the main steam, the temperature and pressure of the warming cylinder steam pipeline, and the opening and closing of the warming cylinder steam trap . The fourth pre-heating unit 104 is used to, after the completion of the third pre-warming stage, according to the switching conditions of the pre-heating medium-pressure butterfly valve, medium-pressure regulating valve and high-pressure gate valve, as well as the temperature and pressure of the warming cylinder steam pipeline, the speed of the gas turbine and Turbine speed to determine whether the fourth warm-up stage is complete. The fifth preheating unit 105 is configured to determine whether the fifth preheating stage is completed according to the state of the steam turbine after the fourth preheating stage is completed.

In some embodiments of the application, after the cold state pre-heating of the unit is started, the instruction signals for controlling the full opening of the trap valve of the warming cylinder, the full closing of the high-row check valve and the full opening of the high-row ventilation valve are issued first, and after receiving the respective After the corresponding feedback signal, it is determined that the first warm-up stage is completed.

Fig. 3 is a schematic structural diagram of the first pre-heating unit in the embodiment of the present application. As shown in Figure 3, the first pre-heating unit includes: a switch signal input module 301 for fully opening the warm cylinder drain valve, a switch signal input module 302 for fully closing the high-row check valve, and a switch for fully opening the high-row ventilation valve. Quantity signal input module 303, switch quantity signal output module 304 and first AND module 305 completed in the first warm-up stage. Among them, the digital signal input module 301 for the full opening of the warm cylinder drain valve, the digital signal input module 302 for the full close of the high row check valve and the digital signal input module 303 for the full open of the high row ventilation valve are all connected with the first and module The input terminal of 305 is connected; the output terminal of the first AND module 305 is connected with the switch signal output module 304 completed in the first warm-up stage.

That is to say, when the warm cylinder steam trap is fully open, the output signal of the switching signal input module 301 of the warm cylinder steam trap fully open is 1; when the high row check valve is fully closed, the high row check valve is fully closed. The output signal of the switching value signal input module 302 is 1. When the high row ventilation valve is fully open, the output signal of the switching value signal input module 303 of the high row ventilation valve is fully open is 1. At this time, the first AND module 305 The switching signal output module 304 that outputs the signal 1 to the completion of the first pre-warming stage indicates that the first pre-warming stage has been completed. If the switching signal output by any of the above modules is 0, the conditions for the completion of the first warm-up stage are not met, and the relevant equipment and equipment need to be checked and processed until the conditions for the completion of the first warm-up stage are met.

In some embodiments of the present application, after the first pre-warming stage is completed, the first pre-heating unit transmits a completion signal to the second pre-heating unit, and the second pre-heating unit initiates a control low Bypass valve fully open, high bypass valve fully closed, middle bypass valve fully closed, steam turbine electric isolation valve fully closed command signal, and wait for the feedback signal corresponding to each valve, after receiving the corresponding feedback signal, determine the second preset The warm phase is complete.

As an implementation, as shown in Fig. 4, the second preheating unit may include: a switch signal input module 401 for the low bypass valve fully closed, a switch signal input module 402 for the high bypass valve fully closed, a medium bypass valve fully closed The digital signal input module 403 for closing, the digital signal input module 404 for the electric isolation valve of the steam turbine fully closed, the digital signal output module 405 for the completion of the second warm-up stage, and the second AND module 406. Among them, the switch signal input module 401 for the low bypass valve fully closed, the switch signal input module 402 for the high bypass valve fully closed, the switch signal input module 403 for the medium bypass valve fully closed, and the switch signal input module for the fully closed steam turbine electric isolation valve The signal input modules 404 are all connected to the input end of the second AND module 406 , and the switch signal output module 405 completed in the second warm-up stage is connected to the output end of the second AND module 406 .

That is to say, when the low side valve is fully closed, the switching signal input module 401 outputs a switching signal of 1, and when the high side valve is fully closed, the switching value of the high side valve is fully closed. The switching value signal output by the signal input module 402 is 1, and when the middle side valve is fully closed, the switching value signal output by the middle side valve is fully closed. The switch signal input module 404 outputs a switch signal of 1 when the electric isolation valve of the steam turbine is fully closed. After passing through the second AND module 406, when the input signals are all 1, the switch signal output module that completes the second warm-up stage outputs 1. . In this way, when the low bypass valve, high bypass valve, middle bypass valve and steam turbine electric isolation valve are all closed, it means that the second preheating stage has been completed. If the switching value signal output by any of the above modules is 0, the conditions for the completion of the second pre-warming stage are not met, and the related equipment and equipment need to be checked and processed until the conditions for the completion of the second pre-warming stage are met.

In some embodiments of the present application, after the second pre-heating stage is completed, the third pre-heating unit determines the third Whether the warm-up phase is complete. For example, if the superheat of the main steam is greater than 56°C, and the temperature and pressure of the warming cylinder steam pipe meet the preset conditions, and the warming cylinder steam trap has been opened, it can be explained that the parameters of the preheating steam have met the conditions of cold preheating. The design requirements, that is, the third warm-up stage has been completed.

As a possible implementation, as shown in Fig. 5, the third preheating unit may include: a switching signal input module 501 whose main steam superheat degree is less than the superheat degree threshold, and the temperature and pressure of the warming cylinder steam pipeline satisfy preset conditions The digital signal input module 502 of the warm cylinder steam trap closed state, the digital signal input module 503 of the closed state of the warm cylinder steam trap, the digital signal input module 504 of the open state of the warm cylinder steam trap, the digital signal output module 505 of the completion of the third warm-up stage, The first NOT module 506 , the second NOT module 507 and the third AND module 508 . Wherein, the switch signal input module 501 whose superheat degree of the main steam is less than the superheat degree threshold is connected to the input terminal of the first non-module 506 . The switching value signal input module 503 of the closed state of the hot cylinder drain valve is connected to the second non-module 507 . The output terminal of the first non-module 506, the output terminal of the second non-module 507, the switch signal input module 502 of which the temperature and pressure of the warming cylinder steam pipeline meet the preset conditions, and the switch signal input module of the open state of the warm cylinder steam trap 504 are all connected to the input end of the third AND module 508, and the output end of the third AND module 508 is connected to the switch signal output module 505 completed in the third warm-up stage.

Among them, the switch signal input module 502 whose temperature and pressure of the heating cylinder steam pipeline meet the preset conditions is to monitor the temperature and pressure of the high-pressure pre-heating steam pipeline 201 and the medium-pressure pre-heating steam pipeline 202 in FIG. If the temperature and pressure of each pipeline meet the preset conditions, then the switching signal input module 502 whose temperature and pressure of the warming cylinder steam pipeline meet the preset conditions outputs a high level.

That is to say, when the superheat degree of the main steam is greater than or equal to the preset superheat degree threshold, the output signal of the first non-module 506 is 1. When the warm cylinder steam trap is in the open state, the switch signal input module 503 of the warm cylinder steam trap closed state is 0, the output signal of the second non-module 507 is 1, and the switch of the warm cylinder steam trap open state The switch signal of the quantity signal input module 504 is 1. If the temperature and pressure of the warming cylinder steam pipeline meet the preset conditions, the switching signal input module 502 , whose temperature and pressure both meet the preset conditions, outputs a switching signal of 1. In this way, when the superheat degree of the main steam is greater than or equal to the preset threshold value of the superheat degree, and the temperature and pressure of the warming cylinder steam pipeline meet the preset conditions, and the warming cylinder steam trap has been opened, it can be explained that the parameters of the preheating steam Bacteria meet the design requirements for cold pre-warming to complete the third pre-warming stage. If the switching value signal output by any one of the modules connected to the input terminal of the third module 508 is 0, then the conditions for completing the third warm-up stage are not satisfied, and the relevant equipment and its equipment need to be checked and processed until the condition is met. The conditions for the completion of the third warm-up stage.

In some embodiments of the present application, after the completion of the third pre-heating stage, the fourth pre-heating unit will pre-heat according to the switching conditions of the medium-pressure butterfly valve, medium-pressure regulating valve and high-pressure gate valve, as well as the temperature and Pressure, gas turbine speed and steam turbine speed to determine whether the fourth preheating stage is completed. Specifically, the fourth pre-heating unit will pre-heat the medium-pressure butterfly valve, medium-pressure regulating valve, and high-pressure gate valve, and the temperature and pressure of the steam pipeline of the warming cylinder meet the preset conditions, and at the same time, the speed of the gas turbine and the speed of the steam turbine are both When the respective setpoints are met, it is determined that the fourth warm-up phase is complete.

As a possible implementation, as shown in Figure 6, the fourth pre-heating unit may include: a switching signal input module 601 for fully opening the pre-heating medium pressure butterfly valve, a switching value input module 602 for fully opening the medium pressure regulating valve, Switching signal input module 603 for full opening of high-pressure gate valve, switching signal input module 604 for warming cylinder steam pipeline temperature and pressure meeting preset conditions, analog signal input module for gas turbine speed 605, analog signal input module for steam turbine speed 606 , the switching value signal output module 607 of the completion of the fourth stage preheating, the sixth AND module 608 , the seventh AND module 609 , the eighth AND module 610 , the first comparison module 611 and the second comparison module 612 .

Among them, the switching value signal input module 601 for fully opening the preheating medium pressure butterfly valve, the switching value input module 602 for fully opening the medium pressure regulating valve, and the switching value signal input module 603 for fully opening the high pressure gate valve are all connected with the input of the sixth AND module 608. end connection. The analog signal input module 605 of the gas turbine speed is connected to the input terminal of the first comparison module 611 . The analog signal input module 606 of the steam turbine speed is connected to the input terminal of the second comparison module 612 . Both the first comparison greater than module 611 and the second comparison greater than module 612 are connected to the input terminal of the seventh AND module 609 . The output end of the sixth AND module 608 , the switching signal input module 604 whose temperature and pressure of the warming cylinder steam pipe meet the preset conditions, and the output end of the seventh AND module 609 are connected to the input end of the eighth AND module 610 . The output end of the eighth AND module 610 is connected to the switching signal output module 607 of the completion of the fourth stage preheating.

That is to say, when the pre-heating medium-pressure butterfly valve is fully open, the switching signal input module 601 outputs a switching signal of 1. When the medium pressure control valve is fully open, the switch signal output by the medium pressure control valve fully open switch input module 602 is 1. When the high pressure gate valve is in the fully open state, the switch signal input module 603 for fully opening the high pressure gate valve outputs a switch signal of 1, and in this case the output signal of the sixth AND module 608 is 1.

The first comparison is greater than the preset gas turbine speed threshold in module 611. For example, the gas turbine speed threshold is 600r/min, and when the output value of the analog signal input module 605 of the gas turbine speed is greater than 600r/min, the first comparison is greater than that of module 611 The output signal is 1. The second comparison is greater than the preset steam turbine speed threshold in module 612, such as the steam turbine speed threshold is 15r/min, then when the output value of the analog signal input module 606 of the steam turbine speed is greater than 15r/min, the second comparison is greater than the output signal of module 612 is 1. In this way, the preheating medium pressure butterfly valve, medium pressure regulating valve, and high pressure gate valve can be opened in the fourth preheating unit, and the temperature and pressure of the steam pipeline of the warming cylinder all meet the preset conditions, and the speed of the gas turbine and the speed of the steam turbine are both When the respective setpoints have been met, it is determined that the fourth warm-up phase is complete. If the output signal of any module connected to the input end of the eighth and module 610 is 0, then the completion condition of the fourth warm-up stage is not satisfied, and relevant signals and equipment thereof need to be checked and processed until the fourth pre-heating stage is satisfied. until the completion condition of the warm phase.

As another possible implementation, as shown in FIG. 7 , the fourth pre-warming unit may also include: a switching signal input module 701 of the manual confirmation button of the fourth pre-warming stage, and the manual confirmation button of the fourth pre-warming stage The switch signal input module 701 is also connected to the input terminal of the eighth AND module 610, and the connection mode of other modules is consistent with that in FIG. 6 , and will not be repeated here. By introducing the switching value signal input module 701 of the manual confirmation button of the fourth warm-up stage, it is equivalent to adding the manual confirmation link of the fourth warm-up stage, so that the inspection and confirmation of relevant staff can avoid the occurrence of equipment abnormalities, etc. Further ensure the smooth start of the unit.

In some embodiments of the present application, after the fourth pre-heating stage is completed, the fifth pre-heating unit will determine whether the fifth pre-heating stage is completed according to the state of the steam turbine. Wherein, the fifth preheating unit determines that the fifth preheating stage has been completed when the steam turbine startup sequence control is ready, which is equivalent to reaching the goal of cold state preheating.

As a possible implementation, as shown in FIG. 8 , the fifth preheating unit may include: a switch signal input module 801 ready for sequential start of the steam turbine and a switch signal output module 802 completed in the fifth preheating stage, And the digital signal input module 801 ready for sequential start of the steam turbine is connected to the digital signal output module 802 completed in the fifth warm-up stage.

That is to say, when the sequential start of the steam turbine is ready, the digital signal output by the digital signal input module 801 for the ready start of the steam turbine is 1, which proves that the preheating steam has fully warmed the pipes at this time, and the steam turbine has Start the warm-up, and the cold-state pre-heating control process ends smoothly.

In some other embodiments of the present application, combined with the fifth pre-heating unit, in an actual power plant application, in order to avoid the fifth pre-heating stage being falsely triggered, the third pre-heating unit is based on the structure shown in Figure 5, It is also possible to add logic to exclude false triggering of the fifth warm-up stage. As shown in Fig. 9, on the basis of Fig. 5, the third pre-heating unit may further include: a switching signal input module 901 for pre-warming the fifth stage command, a switching signal input module 902 for the temperature of the steam pipeline of the warming cylinder, a warm-up The switch signal of cylinder steam pipeline pressure is input to module 903 , fourth AND module 904 , fifth AND module 905 and first OR module 906 .

Wherein, the digital signal input module 901 for the command of the fifth stage of pre-heating and the digital signal input module 902 for the steam pipe temperature of the heating cylinder are connected to the input end of the fourth AND module 904 . The digital signal input module 901 for the command of the fifth phase of pre-heating and the digital signal input module 903 for the steam pipeline pressure of the heating cylinder are connected to the input end of the fifth AND module 905 . The output terminal of the fourth AND module 904 , the output terminal of the fifth AND module 905 , and the switch signal input module 501 whose superheat degree of the main steam is less than the superheat degree threshold are all connected to the input terminal of the first OR module 906 . The output of the first OR module 906 is connected to the input of the first NOT module 506 . When the fifth stage of pre-warming is completed, the digital signal input module 901 of the fifth stage of pre-warming command outputs a digital signal of 1. When the temperature of the warming cylinder steam pipeline reaches the preset condition corresponding to the temperature, the output switching signal of the switching signal input module 902 of the warming cylinder steam pipeline temperature is 1; when the pressure of the warming cylinder steam pipeline reaches the preset condition corresponding to the pressure, The digital signal input module 903 for warming cylinder steam pipeline pressure outputs a digital signal of 1, and the temperature and The preset condition of the pressure is consistent with the preset condition of the switch signal input module 502 whose temperature and pressure of the warming cylinder steam pipeline meet the preset conditions.

That is to say, the third preheating unit is not completed until the fifth preheating stage, the main steam superheat is greater than or equal to the preset superheat threshold, and the temperature and pressure of the warming cylinder steam pipeline meet the preset conditions. The completion of the third warm-up phase is not confirmed until the trap has been opened.

According to the cold state preheating control system of the gas-steam combined cycle unit of the embodiment of the present application, the steam turbine is preheated in advance through the cold state preheating control system of the gas-steam combined cycle unit, and the duration of the conventional preheating of the unit is reduced, so that it can Achieve the goal of energy saving and efficiency enhancement. The system uses multiple pre-heating units to fully automatic and intelligently control the entire pre-heating process, which can not only avoid system failures and signal jumps and changes, but also ensure the smooth start-up of the unit.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

It should be understood that each part of the present application may be realized by hardware, software, firmware or a combination thereof. In the embodiments described above, various steps or methods may be implemented by software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware as in another embodiment, it can be implemented by any one or a combination of the following techniques known in the art: Discrete logic circuits with logic gates for implementing logic functions on data signals , ASICs with suitable combinational logic gates, Programmable Gate Arrays (PGA), Field Programmable Gate Arrays (FPGA), etc.

Those of ordinary skill in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. During execution, one or a combination of the steps of the method embodiments is included.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing module, each unit may exist separately physically, or two or more units may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. If the integrated modules are realized in the form of software function modules and sold or used as independent products, they can also be stored in a computer-readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, and the like. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present application, and those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

Claims (8)

1. A cold state pre-warming control system of a gas and steam combined cycle unit is characterized by being applied to a coaxial gas and steam combined cycle unit, wherein a high-pressure pre-warming steam pipeline and a medium-pressure pre-warming steam pipeline are additionally arranged on the side of a steam turbine of the coaxial gas and steam combined cycle unit, the high-pressure pre-warming steam pipeline is connected with a main steam pipeline of a high-pressure cylinder, the medium-pressure pre-warming steam pipeline is directly communicated with the side of a medium-pressure cylinder, and pre-warming valve groups are respectively arranged on the high-pressure pre-warming steam pipeline and the medium-pressure pre-warming steam pipeline; the system comprises:

the first pre-warming unit is used for determining whether the first pre-warming stage is finished or not according to the switching conditions of the warm cylinder drain valve, the high-discharge check valve and the high-discharge ventilation valve;

the second pre-warming unit is used for determining whether the second pre-warming stage is finished or not according to the switching conditions of the low side valve, the high side valve, the middle side valve and the steam turbine electric isolation valve after the first pre-warming stage is finished;

the third pre-heating unit is used for determining whether the third pre-heating stage is finished or not according to the superheat degree of the main steam, the temperature and the pressure of the steam pipeline of the cylinder heater and the switching condition of the drain valve of the cylinder heater after the second pre-heating stage is finished;

the fourth pre-warming unit is used for determining whether the fourth pre-warming stage is finished or not according to the switching conditions of a pre-warming medium-pressure butterfly valve, a medium-pressure regulating valve and a high-pressure gate valve, the temperature and the pressure of the steam pipeline of the warming cylinder, the rotating speed of the gas turbine and the rotating speed of the steam turbine after the third pre-warming stage is finished;

and the fifth pre-warming unit is used for determining whether the fifth pre-warming stage is finished or not according to the state of the steam turbine after the fourth pre-warming stage is finished.

2. The system of claim 1, wherein the first pre-warming unit comprises: the system comprises a switching value signal input module for fully opening a drain valve of a warm cylinder, a switching value signal input module for fully closing a high-discharge check valve, a switching value signal input module for fully opening a high-discharge ventilation valve, a switching value signal output module for completing a first pre-warming stage and a first AND module; wherein:

the switching value signal input module of the fully-opened cylinder warming drain valve, the switching value signal input module of the fully-closed high-discharge check valve and the switching value signal input module of the fully-opened high-discharge ventilation valve are connected with the input end of the first and module; and the output end of the first and module is connected with the switching value signal output module which finishes the first pre-warming stage.

3. The system of claim 1, wherein the second pre-warming unit comprises: the system comprises a low bypass valve full-closed switching value signal input module, a high bypass valve full-closed switching value signal input module, a middle bypass valve full-closed switching value signal input module, a steam turbine electric isolation valve full-closed switching value signal input module, a switching value signal output module finished in a second pre-warming stage and a second AND module; wherein:

the switching value signal input module of the low side valve full-close, the switching value signal input module of the high side valve full-close, the switching value signal input module of the middle side valve full-close and the switching value signal input module of the steam turbine electric isolation valve full-close are connected with the input ends of the second and module; and the switching value signal output module finished in the second pre-warming stage is connected with the output end of the second and module.

4. The system of claim 1, wherein the third pre-warming unit comprises: the system comprises a switching value signal input module, a switching value signal output module, a first non-module, a second non-module and a third and module, wherein the superheat degree of main steam is smaller than a superheat degree threshold value, and the temperature and the pressure of a steam pipeline of a warm cylinder meet preset conditions; wherein:

the switching value signal input module with the main steam superheat degree smaller than the superheat degree threshold value is connected with the input end of the first non-module; the switching value signal input module of the closed state of the warm cylinder drain valve is connected with the second non-module; the output end of the first non-module, the output end of the second non-module, the switching value signal input module with the temperature and the pressure of the cylinder warming steam pipeline meeting preset conditions and the switching value signal input module with the open state of the cylinder warming drain valve are connected with the input end of the third and module; and the output end of the third and module is connected with the switching value signal output module which completes the third pre-warming stage.

5. The system of claim 4, the third pre-warming unit further comprising: a switching value signal input module for pre-warming a fifth stage instruction, a switching value signal input module for warming the temperature of a cylinder steam pipeline, a switching value signal input module for warming the pressure of the cylinder steam pipeline, a fourth AND module, a fifth AND module and a first OR module; wherein:

the switching value signal input module of the pre-warming fifth stage instruction and the switching value signal input module of the warming cylinder steam pipeline temperature are connected with the input ends of the fourth and the fourth modules; the switching value signal input module of the pre-warming fifth stage instruction and the switching value signal input module of the warming cylinder steam pipeline pressure are connected with the input ends of the fifth and the module; the output end of the fourth and module, the output end of the fifth and module and the switching value signal input module of which the main steam superheat degree is less than the superheat degree threshold are connected with the input end of the first or module; and the output end of the first OR module is connected with the input end of the first non-module.

6. The system of claim 1, wherein the fourth pre-warming unit comprises: the system comprises a pre-warming medium-pressure butterfly valve fully-opened switching value signal input module, a medium-pressure regulating valve fully-opened switching value input module, a high-pressure gate valve fully-opened switching value signal input module, a warming cylinder steam pipeline switching value signal input module with temperature and pressure meeting preset conditions, a gas turbine rotating speed analog signal input module, a steam turbine rotating speed analog signal input module, a fourth stage pre-warming completed switching value signal output module, a sixth AND module, a seventh AND module, an eighth AND module, a first comparison larger module and a second comparison larger module; wherein:

the pre-warming medium-pressure butterfly valve fully-opened switching value signal input module, the medium-pressure regulating valve fully-opened switching value signal input module and the high-pressure gate valve fully-opened switching value signal input module are connected with the input end of the sixth and module; the analog signal input module of the rotating speed of the gas turbine is connected with the input end of the first larger module; the analog quantity signal input module of the rotating speed of the steam turbine is connected with the input end of the second comparison larger module; the first comparison larger module and the second comparison larger module are both connected with the input end of the seventh comparison module; the output end of the sixth and module, the output end of the switching value signal input module and the output end of the seventh and module, which meet the preset conditions for the temperature and the pressure of the cylinder warming steam pipeline, are connected with the input end of the eighth and module; and the output end of the eighth and module is connected with the switching value signal output module which finishes the fourth-stage pre-warming.

7. The system of claim 6, wherein the fourth pre-warming unit further comprises: and the switching value signal input module of the fourth pre-warming stage manual confirmation button is also connected with the input end of the eighth and module.

8. The system of claim 1, wherein the fifth pre-warming unit comprises: the system comprises a switching value signal input module for ready sequential control starting of the steam turbine and a switching value signal output module for finishing a fifth pre-warming stage, wherein the switching value signal input module for ready sequential control starting of the steam turbine is connected with the switching value signal output module for finishing the fifth pre-warming stage.

Images