CN115306496A - Cold-state pre-warming starting control method for steam turbine of gas-steam combined cycle unit - Google Patents

Abstract

The application provides a gas steam combined cycle unit steam turbine cold state warms up start control method in advance, is applied to coaxial gas steam combined cycle unit, includes: issuing an action instruction to each valve of the steam turbine; confirming the steam quality, and shielding a Z2 criterion in the confirming process; determining the state of the heating pipe, and shielding the verification of the Z4 standard and the full-open state of the ESV valve; checking the steam inlet quantity of the steam turbine; checking the shaft temperature, the steam flow, the superheat degree and an X1 criterion; controlling a front drain valve of the high-pressure regulating valve and a front drain valve of the medium-pressure regulating valve to be opened; releasing a steam quality confirmation button, verifying various parameters of the steam turbine, and shielding the verification of a Z2 standard, an X6 standard and the full-open state of an ESV valve; setting a set rotating speed value in a steam turbine controller as a warming rotating speed; starting to calculate the warm-up time, and reaching a preset rotating speed value in a water washing mode; the SSS clutch is engaged until the sequence control start is completed.

Description

Cold-state pre-warming starting control method for steam turbine of gas-steam combined cycle unit

Technical Field

The application relates to the field of intelligent control of a gas and steam combined cycle unit, in particular to a cold pre-warming starting control method for a steam turbine of the gas and steam combined cycle unit.

Background

The coaxial gas-steam combined cycle unit firstly applies a cold pre-warming technology, two pre-warming steam pipelines are additionally arranged on the side of a steam turbine, and the pre-warming steam pipelines respectively act on a high-pressure main steam pipeline of a high-pressure cylinder of the steam turbine and the side of a medium-pressure cylinder. When the steam turbine is started to carry out the impulse to the grid connection, the starting time of the unit can be effectively reduced, and the aims of energy conservation and efficiency improvement are achieved.

However, how to realize the automatic starting of the steam turbine of the gas-steam combined cycle unit based on the cold-state pre-warming technology becomes a problem which needs to be solved urgently at present.

Disclosure of Invention

In order to solve the problems, the application provides a cold-state pre-warming starting control method for a steam turbine of a gas-steam combined cycle unit.

According to one aspect of the application, a cold-state pre-warming starting control method for a steam turbine of a gas-steam combined cycle unit is provided. The method is applied to a coaxial gas-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-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 method comprises the following steps:

issuing an action instruction to each valve of the steam turbine;

confirming the steam quality, and shielding a Z2 criterion in the confirming process;

determining the state of the heating pipe, and shielding the verification of the Z4 standard and the full-open state of the ESV valve;

checking the steam inlet quantity of the steam turbine;

checking the shaft temperature, the steam flow, the superheat degree and an X1 criterion;

controlling a front drain valve of the high-pressure regulating valve and a front drain valve of the medium-pressure regulating valve to be opened;

releasing a steam quality confirmation button, verifying various parameters of the steam turbine, and shielding the verification of a Z2 standard, an X6 standard and the full-open state of an ESV valve;

setting a set rotating speed value in a steam turbine controller as a warming rotating speed;

starting to calculate the time for putting into the warming-up device, and reaching a preset rotating speed value in a washing mode;

the SSS clutch is engaged until the sequence control start is completed.

In some embodiments of the present application, said commanding the operation of each valve of the steam turbine comprises:

giving closing instructions to a high-pressure main steam valve, a medium-pressure main steam valve, a low-pressure main steam valve, a high-pressure regulating valve, a medium-pressure regulating valve, a low-pressure regulating valve and a high-exhaust check valve;

issuing an instruction of putting into a pressure controller of the steam turbine;

issuing an instruction of putting in the hydrophobic subring;

issuing opening instructions to a front drain valve of the high-pressure regulating valve, a front drain valve of the medium-pressure regulating valve and a water spray isolation valve of the low-pressure cylinder;

and issuing an opening instruction to a front drain valve of the intermediate-pressure main steam valve.

Wherein, the checking the steam inlet quantity of the steam turbine comprises the following steps:

comparing the steam inlet set value of the steam turbine with a preset steam inlet threshold value, and comparing the TAB value of the steam turbine with a preset first TAB threshold value;

and responding to the fact that the steam inlet set value of the steam turbine is larger than the steam inlet threshold value and the TAB value of the steam turbine is larger than the first TAB threshold value, and executing the step of verifying the shaft temperature, the steam flow and the superheat degree.

In some embodiments of the present application, the verifying the shaft temperature, the steam flow, the superheat degree, and the X1 criterion includes:

comparing the high-pressure rotor shaft temperature with a preset shaft temperature threshold;

comparing the steam flow with a preset flow threshold;

comparing the main steam superheat degree with a preset superheat degree threshold value;

checking the X1 criterion;

and responding to the fact that the shaft temperature of the high-pressure rotor is larger than the shaft temperature threshold value, the steam flow is larger than the flow threshold value, the superheat degree is larger than the superheat degree threshold value, meanwhile, the X1 criterion is met, the step of controlling the opening of the front drain valve of the high-pressure regulating valve and the front drain valve of the medium-pressure regulating valve is directly executed without waiting for the ESV valve to be in a fully-open state.

In some embodiments of the present application, controlling the opening of the pre-high pressure trim trap and the pre-medium pressure trim trap comprises:

and starting the static variable frequency starting device of the gas turbine, and issuing an instruction for opening the front drain valve of the high-pressure regulating valve and the front drain valve of the medium-pressure regulating valve when the rotating speed of the gas turbine is greater than the preset rotating speed of the gas turbine.

As a possible implementation manner, the setting the set value of the rotation speed in the steam turbine controller to the warming-up rotation speed includes:

setting a set rotating speed value in the steam turbine controller as the warming rotating speed, increasing the rotating speed of the steam turbine according to a first rising rate until the rotating speed of the steam turbine reaches the warming rotating speed, and resetting the steam quality confirming button; wherein the first rising rate is smaller than the rising rate of the rotating speed in the cold starting process of the steam turbine.

In some embodiments of the present application, the calculating of the starting warm-up time and reaching the preset rotation speed value in the water washing mode includes:

and starting to invest the warm-up time calculation, wherein the rotating speed of the steam turbine meets a preset rotating speed value in a water washing mode, and shielding the verification of the Z2 criterion, the Z4 criterion, the X6 criterion and the full opening of the ESV valve.

In some embodiments of the present application, the SSS clutch is engaged until a compliant launch is completed, including:

the SSS clutch is engaged, the pre-warming medium-pressure stop valve and the pre-warming high-pressure stop valve are controlled to be closed, the high-exhaust ventilation valve is controlled to be closed, and the rotating speed of the steam turbine is increased to a preset rotating speed threshold value at a second rising rate; wherein the second rising rate is less than the rising rate of the rotating speed in the cold starting process of the steam turbine;

resetting a rated rotation speed release button of the picture;

comparing the turbine TAB value with a preset second TAB threshold value;

continuing to engage the SSS clutch in response to the turbine TAB value being greater than the second TAB threshold;

and controlling a starting initial pressure controller for the steam turbine so as to complete the starting sequential control of the steam turbine.

In other embodiments of the present application, the method further comprises:

and prolonging the holding time of the combustion engine after the combustion engine reaches the preset rotating speed value in the water washing mode.

According to the technical scheme, the cold-state pre-warming starting of the steam turbine of the gas-steam combined cycle unit is automatically carried out by shielding the Z2 criterion, the Z4 criterion and the X6 criterion and checking the full opening of the ESV valve in the sequential control starting process of the steam turbine, so that the starting time of the unit can be effectively reduced, the aims of saving energy and improving efficiency can be fulfilled, and the problems of starting failure and the like caused by the problems of protection logic triggering and the like in the starting process can be solved.

Additional aspects and advantages of the present 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 present application.

Drawings

The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a flowchart of a cold pre-warm start control method for a steam turbine of a gas-steam combined cycle unit according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of cold pre-warming of a turbine of the coaxial gas-steam combined cycle unit in the embodiment of the application;

FIG. 3 is a schematic diagram of a cold pre-warming starting process of a steam turbine of a gas-steam combined cycle unit according to an embodiment of the present application;

FIG. 4 is a schematic diagram of another cold pre-warm start-up process of a steam turbine of a gas steam combined cycle unit according to an embodiment of the present application;

fig. 5 is a schematic diagram of a cold pre-warming starting process of a steam turbine of a gas steam combined cycle unit according to another embodiment of the present application.

Detailed Description

Reference will now be made in detail to the embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application and should not be construed as limiting the present application.

It should be noted that, the coaxial gas-steam combined cycle unit firstly applies the cold pre-warming technology, and two pre-warming steam pipelines are added at the side of the steam turbine, and the pre-warming steam pipelines respectively act on the high-pressure main steam pipeline of the high-pressure cylinder of the steam turbine and the side of the medium-pressure cylinder. When the steam turbine is started to carry out the impulse to the grid connection, the starting time of the unit can be effectively reduced, and the aims of energy conservation and efficiency improvement are achieved.

However, how to realize the automatic starting of the steam turbine of the gas-steam combined cycle unit based on the cold-state pre-warming technology becomes a problem which needs to be solved urgently at present.

In order to solve the problems, the application provides a cold-state pre-warming starting control method for a steam turbine of a gas-steam combined cycle unit.

Fig. 1 is a flowchart of a cold pre-warm start control method for a steam turbine of a gas-steam combined cycle unit according to an embodiment of the present application. It should be noted that the cold pre-warming start control method for the steam turbine of the gas and steam combined cycle unit in the embodiment of the present application is applied to a coaxial gas and steam combined cycle unit, and a high-pressure pre-warming steam pipeline and a medium-pressure pre-warming steam pipeline are added to the steam turbine side of the coaxial gas and steam combined cycle unit, wherein the high-pressure pre-warming steam pipeline is connected to a main steam pipeline of a high-pressure cylinder, the medium-pressure pre-warming steam pipeline is directly communicated with the medium-pressure cylinder side, and pre-warming valve groups are installed on both the high-pressure pre-warming steam pipeline and the medium-pressure pre-warming steam pipeline. As shown in FIG. 2, a high-pressure pre-warming steam pipeline 201 and an intermediate-pressure pre-warming steam pipeline 202 are added to the steam turbine side of the coaxial gas-steam combined cycle unit. Wherein, the high pressure steam pipe 201 that warms up in advance is connected with the main steam pipe of high-pressure jar, and the intermediate pressure steam pipe 202 that warms up in advance is direct to be linked together with the intermediate pressure jar side, and the warm valve group of warming up in advance is all installed to high pressure steam pipe 201 that warms up in advance and intermediate pressure steam pipe 202. The high-pressure pre-warming steam pipeline 201 is provided with 2 pneumatic shutoff valves, and the medium-pressure pre-warming steam pipeline 202 is provided with 1 pneumatic shutoff valve and 1 starting shutoff regulating valve. As shown in fig. 1, the test method comprises the following steps:

step 101, issuing action instructions to each valve of the steam turbine.

In some embodiments of the application, in the process of the turbine starting sequence control, a starting load limiting input instruction does not need to be issued, and the step of issuing an action instruction to each valve of the turbine is executed only after the rotating speed is greater than a preset value. For example, the step of giving action instructions to each valve of the steam turbine is executed only after the rotating speed is more than 858 r/min.

The process of giving an action command to each valve of the steam turbine may include the steps of:

and 101-1, issuing closing instructions to a high-pressure main steam valve, a medium-pressure main steam valve, a low-pressure main steam valve, a high-pressure regulating valve, a medium-pressure regulating valve, a low-pressure regulating valve and a high-exhaust check valve.

In the embodiment of the application, a closing instruction is issued to the high-pressure main steam valve, the medium-pressure main steam valve, the low-pressure main steam valve, the high-pressure regulating valve, the medium-pressure regulating valve, the low-pressure regulating valve and the high-exhaust check valve, and after the high-pressure main steam valve, the medium-pressure main steam valve, the low-pressure main steam valve, the high-pressure regulating valve, the medium-pressure regulating valve, the low-pressure regulating valve and the high-exhaust check valve are all put into a preparation state, step 101-2 is executed.

And 101-2, issuing an instruction for putting into a pressure controller of the steam turbine.

In some embodiments of the subject application, a command is issued to the turbine pressure controller and step 101-3 is performed after each turbine parameter is put into its respective pressure and temperature mode and the speed is greater than 858 r/min.

And 101-3, issuing an instruction of putting into the hydrophobic sub-ring.

That is, after the hydrophobic sub-rings are all put into the ready state, the step 101-4 is performed.

And 101-4, issuing opening instructions to a drain valve before the high-pressure regulating valve, a drain valve before the medium-pressure regulating valve and a water spraying isolation valve of the low-pressure cylinder.

In some embodiments of the present application, step 101-5 is performed after issuing an opening command to the high pressure and medium pressure before-governor trap and the low pressure cylinder before-governor trap are all in a fully open state. For example, after the opening instruction is given, the front drain valve of the high-pressure regulating valve, the front drain valve of the medium-pressure regulating valve and the water-spraying isolation valve of the low-pressure cylinder all reach the full-open state within 90s, and then the step 101-5 is executed.

And 101-5, issuing an opening instruction to a front drain valve of the medium-pressure main steam valve.

In some embodiments of the present application, an open command is issued to the medium-pressure main steam valve front steam trap, and the subsequent steps are executed after waiting for 90s and the medium-pressure main steam valve front steam trap is in a fully open state, or if the turbine starting device control task TAB meets more than 62%.

Step 102, steam quality is confirmed, and a Z2 criterion is shielded in the confirmation process.

Based on the sample discovery before the start-up sequence control, as the medium-pressure pre-warming steam pipeline directly acts on the intermediate pressure cylinder, the corresponding thermal stress X and Z criteria cannot be triggered in the start-up process, otherwise, the test can be directly waited for and the start-up test cannot be continued, and therefore the thermal stress Z2 criteria needs to be shielded in the process of determining the steam quality.

It can be understood that the steam turbine can be operated stably and safely only if the steam quality is qualified, and all stages of blades of the steam turbine can be protected, so that the linear change of the blades of the steam turbine is avoided, and the problems of the reduction of the efficiency of the steam turbine, the increase of the axial thrust and the increase of the vibration can also be avoided.

In some embodiments of the present application, the process of confirming the steam quality may include: checking a thermal stress Z1 criterion and a thermal stress X1 criterion, or checking the opening degree of the high-pressure regulating valve; the wall temperature is verified, and the thermal stress Z2 criterion, the X2 criterion and the full open state of the ESV valve are not required to be verified. As an example, if the thermal stress Z1 criterion and the thermal stress X1 criterion are both satisfied, or the opening of the high pressure regulator valve is more than 50%, and the wall temperature is less than 150 ℃, the step 103 is directly executed without confirming whether the thermal stress Z2 criterion and the thermal stress X2 criterion are satisfied, or waiting for the fully opened state of the ESV valve.

Step 103, determining the warm pipe state and shielding the verification of the Z4 criterion and the full open state of the ESV valve.

It can be understood that the warm pipe temperature and pressure are normal, and the problems of large vibration of the steam turbine, pipeline fracture and the like can be prevented. The determination of the heating pipe state is equivalent to the verification of the temperature and the pressure of the heating pipe, and if the temperature and the pressure of the heating pipe both meet the regulation, the heating pipe state is normal. That is, if the warm pipe state is normal, the step 104 is directly continued without confirming whether the thermal stress Z4 criterion is satisfied or whether the ESV valve is in the fully open state.

And 104, checking the steam inlet quantity of the steam turbine.

It can be understood that the size of the air input of the steam turbine has direct relation with the stable start of the steam turbine, and the air input of the steam turbine is verified to ensure the stable start of the steam turbine and lay a foundation for the rotating speed rise of the steam turbine and the constant-speed running of the steam turbine.

In some embodiments of the present application, the process of verifying the steam inlet amount of the steam turbine may include: comparing the steam inlet set value of the steam turbine with a preset steam inlet threshold value, and comparing the TAB value of the steam turbine with a preset first TAB threshold value; and responding to the fact that the steam inlet set value of the steam turbine is larger than the steam inlet threshold value and the TAB value of the steam turbine is larger than the first TAB threshold value, and executing a step 105 of verifying the shaft temperature, the steam flow and the superheat degree. For example, if the turbine approximate setting is greater than 98% and the turbine TAB is greater than 62%, then step 105 may be continued.

That is, if the steam inlet set value of the steam turbine is greater than the steam inlet threshold and the TAB value of the steam turbine is greater than the first TAB threshold, step 105 is directly executed without waiting for all the ESV valves to be in the fully open state within the preset time.

And 105, checking the shaft temperature, the steam flow, the superheat degree and an X1 criterion.

In some embodiments of the present application, the step may comprise: comparing the high-pressure rotor shaft temperature with a preset shaft temperature threshold value; comparing the steam flow with a preset flow threshold; comparing the main steam superheat degree with a preset superheat degree threshold value; checking the X1 criterion; and responding to the fact that the shaft temperature of the high-pressure rotor is larger than a shaft temperature threshold value, the steam flow is larger than a flow threshold value, the superheat degree is larger than a superheat degree threshold value, and meanwhile the X1 criterion is met, and the step of controlling the front steam trap of the high-pressure regulating valve and the front steam trap of the medium-pressure regulating valve to be opened is directly executed without waiting for the ESV valve to be in a fully-opened state. For example, if the preset shaft temperature threshold is 200 ℃ for comparison and the preset flow threshold is 15%, step 106 is directly executed in response to that the high-pressure rotor shaft temperature is greater than 200 ℃ and the steam flow is greater than 15%, and the superheat degree X1 criterion is met, without waiting for the ESV valve to be in the fully open state.

And 106, controlling the steam trap before the high-pressure regulating valve and the steam trap before the medium-pressure regulating valve to be opened.

In order to avoid the problem that the temperature of the high-pressure regulating valve and the medium-pressure regulating valve rises during starting, the front drain valve of the high-pressure regulating valve and the front drain valve of the medium-pressure regulating valve can be opened in time to cool the temperature around the high-pressure regulating valve and the medium-pressure regulating valve.

In some embodiments of the present application, the static variable frequency starting apparatus of the combustion engine is started, wherein the combustion engine starting mode is a water washing mode, and when the rotation speed of the combustion engine reaches a preset rotation speed of the combustion engine, the command for opening the front drain valve of the high pressure regulating valve and the front drain valve of the middle pressure regulating valve is given. Namely, the static frequency conversion device of the combustion engine is started, and when the rotation speed of the combustion engine is greater than 780r/min, the steam trap before the high-pressure regulating valve and the steam trap before the medium-pressure regulating valve are opened.

And step 107, releasing the steam quality confirmation button, checking various parameters of the steam turbine, and shielding the checking of the Z2 standard, the X6 standard and the full-open state of the ESV valve.

And 108, setting the set rotating speed value in the steam turbine controller as the warming rotating speed.

In some embodiments of the present application, the step comprises: and setting a set rotating speed value in the steam turbine controller as a warming rotating speed, increasing the rotating speed of the steam turbine according to a first rising rate until the rotating speed of the steam turbine reaches the warming rotating speed, and resetting a steam quality confirming button. Wherein the first rising rate is less than the rising rate of the rotating speed in the cold starting process of the steam turbine. That is, by reducing the rate of rise of the rotation speed, the stability of the starting process can be further improved.

And step 109, starting to calculate the heating time, and reaching a preset rotating speed value in the water washing mode.

In some embodiments of the present application, the process of starting the on-stream warm-up time calculation includes: whether the rotating speed of the steam turbine meets the check of a preset rotating speed value in a washing mode or not is judged; checking the valve limits of the high-pressure regulating valve, the medium-pressure regulating valve and the low-pressure regulating valve; checking related thermal stress X criteria and Z criteria; checking the flow of the high-pressure main steam; checking the cultural mining of the high-pressure cylinder; and meanwhile, the verification of the thermal stress Z2 criterion, the thermal stress Z4 criterion and the thermal stress X6 criterion are shielded, and the verification of full opening of all ESV valves is also shielded.

As an example, if the rotation speed value of the steam turbine reaches 780r/min, the valve limits of the high-pressure governor valve, the medium-pressure governor valve and the low-pressure governor valve are all larger than 105% in the corresponding time range, the related thermal stress X criterion and the related thermal stress Z criterion are all satisfied, the verification of the thermal stress Z2 criterion, the thermal stress Z4 criterion and the thermal stress X6 criterion is shielded, the flow rate of the high-pressure main steam is larger than 15%, and the temperature difference of the high-pressure cylinder reaches the requirement, the index step 110 is directly continued without waiting for the fully opened state of all the ESV valves.

And 110, engaging the SSS clutch until the sequential control starting is finished.

In some embodiments of the present application, step 110 may include the steps of:

110-1, engaging an SSS clutch, controlling a pre-heating medium-pressure stop valve and a pre-heating high-pressure stop valve to be closed, controlling a high-exhaust ventilation valve to be closed, and increasing the rotating speed of the steam turbine to a preset rotating speed threshold value at a second rising rate; and the second rising rate is smaller than the rising rate of the rotating speed in the cold starting process of the steam turbine.

As an example, if the pre-warming middle pressure stop valve and the pre-warming high pressure stop valve are both closed, the high discharge vent valve is also closed, and the rotation speed of the turbine is increased to 2850r/min or more at the second increase rate, the step 110-2 is continuously performed.

And step 110-2, resetting a rated rotating speed release button of the picture.

In the embodiment of the application, the screen rated speed release button is reset, and step 110-3 is executed after the drain valves before the high pressure regulating valve, the medium pressure main steam valve and the medium pressure regulating valve are all closed.

And step 110-3, comparing the turbine TAB value with a preset second TAB threshold value.

For example, the second TAB threshold may be 99%, i.e., the turbine TAB value is compared to 99%.

And step 110-4, responding to the condition that the TAB value of the steam turbine is larger than a second TAB threshold value, and continuing to engage the SSS clutch.

In some embodiments of the present application, the SSS clutch engagement continues if the turbine TAB value is greater than the second TAB threshold. And if the rotating speed of the steam turbine reaches more than 2850r/min, the high bypass valve is less than 5%, the high-pressure main steam flow is more than 20%, and the pressure of the high-pressure steam inlet blade is more than 2.5MPa, continuing to execute the step 110-5.

And step 110-5, starting the initial pressure controller for the control of the steam turbine so as to complete the starting sequence control of the steam turbine.

In some embodiments of the present application, the method further includes: and prolonging the time for keeping the combustion engine after the preset rotating speed in the water washing mode is reached. Therefore, the meshing can be successfully carried out after the turbine reaches the preset rotating speed.

Next, the cold-state pre-warming starting control method of the steam turbine of the gas and steam combined cycle unit according to the embodiment of the present application will be verified through a schematic diagram in the starting process.

Fig. 3 is a schematic diagram of a cold pre-warming starting process of a steam turbine of a gas steam combined cycle unit in an embodiment of the application. As shown in fig. 3, in the cold pre-warming starting process of the whole unit, the signals of the thermal stress Z2 criterion, the thermal stress Z4 criterion and the thermal stress X6 criterion are not triggered, the switching value signals are all 0, and the rotating speed of the steam turbine remains the same, so that the fact that the Z2 criterion, the Z4 criterion and the X6 criterion are successfully shielded in the starting process is proved, and the normal starting of the steam turbine is ensured.

FIG. 4 is a schematic diagram of a cold pre-warm start-up process for a steam turbine of another gas steam combined cycle plant in an embodiment of the present application. As shown in fig. 4, in the whole unit cold-state pre-warming starting process, all the signals that the ESV valves are in the fully open state are not triggered, the switching value signal is 0, and the rotating speed of the steam turbine still rises, so that the process successfully shields the verification that all the ESVs are in the fully open state, and the normal starting of the steam turbine is ensured.

FIG. 5 is a schematic diagram of a cold pre-warm start-up process of a steam turbine of a gas and steam combined cycle plant according to yet another embodiment of the present application. As shown in FIG. 5, in the cold pre-warming starting process of the whole unit, after the rotating speed of the gas turbine reaches the preset value 780r/min, the SFC signal of the static variable frequency starting device successfully enables the rotating speed of the gas turbine to reach the preset value 780r/min within 30min to be successfully engaged with the gas turbine. That is, by prolonging the time of the fifth step of the start-up sequence control of the combustion engine in the pre-warming mode, the SFC can smoothly drag the rotating speed of the steam turbine to the preset value and successfully engage with the combustion engine.

According to the cold-state pre-warming starting control method for the steam turbine of the gas and steam combined cycle unit, the Z2 criterion, the Z4 criterion, the X6 criterion and the full-open check of the ESV valve are shielded in the sequential control starting process of the steam turbine, so that the cold-state pre-warming starting of the steam turbine of the gas and steam combined cycle unit is automatically carried out, the starting time of the unit can be effectively shortened, the energy-saving and efficiency-increasing targets can be achieved, and the problems of starting failure and the like caused by the problems of protection logic triggering and the like in the starting process can be avoided.

In the description of the present specification, reference to the description of "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and combined by one skilled in the art without being mutually inconsistent.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless explicitly specified otherwise.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing steps of a custom logic function or process, and alternate implementations are included within the scope of the preferred embodiment of the present application in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present application.

The logic and/or steps represented in the flowcharts or otherwise described herein, e.g., an ordered listing of executable instructions that can be considered to implement logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Further, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.

It should be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and when the program is executed, the program includes one or a combination of the steps of the method embodiments.

In addition, functional units in the embodiments of the present application may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc. Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

Claims (9)

1. A cold pre-warming starting control method for a steam turbine of a gas-steam combined cycle unit is characterized in that the method is applied to a coaxial gas-steam combined cycle unit, a high-pressure pre-warming steam pipeline and a medium-pressure pre-warming steam pipeline are additionally arranged on the steam turbine side of the coaxial gas-steam combined cycle unit, wherein 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 medium-pressure cylinder side, and pre-warming valve groups are installed on the high-pressure pre-warming steam pipeline and the medium-pressure pre-warming steam pipeline; the method comprises the following steps:

issuing an action instruction to each valve of the steam turbine;

confirming the steam quality, and shielding a Z2 criterion in the confirming process;

determining the state of the heating pipe, and shielding the verification of the Z4 standard and the full-open state of the ESV valve;

checking the steam inlet quantity of the steam turbine;

checking the shaft temperature, the steam flow, the superheat degree and an X1 criterion;

controlling a front drain valve of the high-pressure regulating valve and a front drain valve of the medium-pressure regulating valve to be opened;

releasing a steam quality confirmation button, checking various parameters of the steam turbine, and shielding the checking of a Z2 standard, an X6 standard and the full-open state of an ESV valve;

setting a set rotating speed value in a steam turbine controller as a warming rotating speed;

starting to calculate the time for putting into the warming-up device, and reaching a preset rotating speed value in a washing mode;

the SSS clutch is engaged until the sequential start is complete.

2. The method of claim 1, wherein said commanding the operation of each valve of said turbine comprises:

giving closing instructions to a high-pressure main steam valve, a medium-pressure main steam valve, a low-pressure main steam valve, a high-pressure regulating valve, a medium-pressure regulating valve, a low-pressure regulating valve and a high-exhaust check valve;

issuing an instruction of putting into a pressure controller of the steam turbine;

issuing an instruction of putting in the hydrophobic subring;

issuing opening instructions to a front drain valve of the high-pressure regulating valve, a front drain valve of the medium-pressure regulating valve and a water spray isolation valve of the low-pressure cylinder;

and issuing an opening instruction to the front drain valve of the medium-pressure main steam valve.

3. The method of claim 1, wherein said verifying an amount of steam admission to said turbine comprises:

comparing the steam inlet set value of the steam turbine with a preset steam inlet threshold value, and comparing the TAB value of the steam turbine with a preset first TAB threshold value;

and responding to the fact that the steam inlet set value of the steam turbine is larger than the steam inlet threshold value and the TAB value of the steam turbine is larger than the first TAB threshold value, and executing the step of verifying the shaft temperature, the steam flow and the superheat degree.

4. The method of claim 1, wherein the verifying the shaft temperature, the steam flow, the superheat, and the X1 criterion comprises:

comparing the high-pressure rotor shaft temperature with a preset shaft temperature threshold value;

comparing the steam flow with a preset flow threshold;

comparing the superheat degree of the main steam with a preset superheat degree threshold value;

checking the X1 criterion;

and responding to the fact that the shaft temperature of the high-pressure rotor is larger than the shaft temperature threshold value, the steam flow is larger than the flow threshold value, the superheat degree is larger than the superheat degree threshold value, meanwhile, the X1 criterion is met, the step of controlling the opening of the front drain valve of the high-pressure regulating valve and the front drain valve of the medium-pressure regulating valve is directly executed without waiting for the ESV valve to be in a fully-opened state.

5. The method of claim 1, wherein controlling the opening of the pre-high and pre-medium pressure trim trap comprises:

and starting the static variable frequency starting device of the gas turbine, and issuing an instruction for opening the front drain valve of the high-pressure regulating valve and the front drain valve of the medium-pressure regulating valve when the rotating speed of the gas turbine is greater than the preset rotating speed of the gas turbine.

6. The method of claim 1, wherein setting the speed set point in the steam turbine controller to the warm-up speed comprises:

setting a set rotating speed value in the steam turbine controller as the warming rotating speed, increasing the rotating speed of the steam turbine according to a first rising rate until the rotating speed of the steam turbine reaches the warming rotating speed, and resetting the steam quality confirming button; wherein the first rising rate is less than the rising rate of the rotating speed in the cold starting process of the steam turbine.

7. The method of claim 1, wherein the beginning of the warm-up time to start calculation and reaching a predetermined speed value in the water wash mode comprises:

and starting to invest the warm-up time calculation, wherein the rotating speed of the steam turbine meets a preset rotating speed value in a water washing mode, and shielding the verification of the Z2 criterion, the Z4 criterion, the X6 criterion and the full opening of the ESV valve.

8. The method of claim 1, wherein the SSS clutch is engaged until a compliant launch is complete, comprising:

the SSS clutch is engaged, the pre-warming medium-pressure stop valve and the pre-warming high-pressure stop valve are controlled to be closed, the high-exhaust ventilation valve is controlled to be closed, and the rotating speed of the steam turbine is increased to a preset rotating speed threshold value at a second rising rate; wherein the second rising rate is less than the rising rate of the rotating speed in the cold starting process of the steam turbine;

resetting a rated rotation speed release button of the picture;

comparing the turbine TAB value with a preset second TAB threshold value;

continuing to engage the SSS clutch in response to the turbine TAB value being greater than the second TAB threshold;

and controlling a starting initial pressure controller for the steam turbine so as to complete the starting sequential control of the steam turbine.

9. The method according to any one of claims 1-8, further comprising:

and prolonging the holding time of the combustion engine after the combustion engine reaches the preset rotating speed value in the water washing mode.

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