Self-starting control method for ultra-supercritical double-reheat unit

Abstract

The application relates to a self-starting control method of an ultra-supercritical double-reheat unit. The specific scheme is as follows: a first group of target systems and a first group of target devices are started in turn according to a preset first order; a BEST small steam turbine is controlled to drive a small generator to perform self-starting according to a preset starting mode; a second group of target systems and a second group of target devices are started in turn according to a preset second order, so that a coal feeder in a coal pulverizing system and a first target coal mill in a coal mill group are started; a corresponding steam turbine of the BEST small steam turbine is controlled to perform a rush start, and a corresponding thermal power generating unit of the BEST small steam turbine is controlled to be connected to a power grid; other target coal mills in the coal mill group except the first target coal mill are started in turn according to a preset third order, so that a load value of the generating unit is increased to a target load value. The application can realize optimized self-starting process control strategy of the BEST small steam turbine with the small generator, and the starting time of the ultra-supercritical double-reheat coal-fired unit is shortened.

Description

Technical Field

[0001] This application relates to the field of control technology for ultra-supercritical double reheat coal-fired power units, and in particular to a self-starting control method for ultra-supercritical double reheat power units. Background Technology

[0002] In related technologies, in power plants using BEST small steam turbines with small generators in ultra-supercritical double reheat coal-fired units, operators typically have to start each system piece by piece to complete the overall startup. Each system has a startup sequence control program, making it difficult to achieve coordinated control across systems. Operators need to confirm the successful startup of each system before starting the next, consuming significant time. Furthermore, due to the initial application of BEST small steam turbines with small generators, operators must choose between BEST small steam turbine startup and electric motor startup each time, increasing their workload. Unlike conventional thermal power plant units, it is crucial to confirm the successful startup of the BEST small steam turbine with small generator each time before proceeding with subsequent startups. Summary of the Invention

[0003] Therefore, this application provides a self-starting control method for ultra-supercritical double reheat units. The technical solution of this application is as follows:

[0004] This application provides an embodiment of a self-starting control method for an ultra-supercritical double reheat unit, the method comprising:

[0005] The first group of target systems and the first group of target devices are started sequentially according to a preset first order; the first group of target systems includes multiple target systems; the first group of target devices includes multiple target devices;

[0006] The BEST small steam turbine is controlled to drive the small generator to start automatically according to the preset starting method;

[0007] The second group of target systems and the second group of target equipment are started sequentially according to a preset second order, so as to start the coal feeder in the pulverizing system and the first target coal mill in the coal mill unit; the second group of target systems includes multiple target systems; the second group of target equipment includes multiple target equipment.

[0008] Control the turbine corresponding to the BEST small steam turbine to start running, and control the thermal power generating unit corresponding to the BEST small steam turbine to connect to the grid;

[0009] The target coal mills in the coal mill unit, except for the first target coal mill, are started in the third preset order to increase the load value of the generator unit to the target load value.

[0010] According to one embodiment of this application, the step of sequentially activating the first group of target systems and the first group of target devices in a preset first order includes:

[0011] The closed cooling water system, condensate system, deaerator water supply system, and open water system are started sequentially.

[0012] The oil station system of the boiler coal mill unit and the oil station system of the blower are controlled separately.

[0013] The air preheater, BEST small steam turbine lubrication oil station system, steam turbine lubrication oil start function group, and generator sealing oil start function group are started in sequence.

[0014] The control unit starts the turning gear and issues a hydrogen charging / purging warning signal;

[0015] The turbine EH oil system, constant cooling water system, and bypass oil station system are started sequentially.

[0016] According to one embodiment of this application, controlling the BEST small steam turbine to drive the small generator to start automatically according to a preset starting mode includes:

[0017] Control the water source to statically inject water into the pipeline;

[0018] Control the water supply pump to engage the rotating gear;

[0019] Start the auxiliary steam start function group of the steam turbine;

[0020] The shaft sealing system and vacuum system of the thermal power generating unit are started separately;

[0021] The system sequentially controls the start-up of the feedwater pump, deaerator, and boiler condensate system.

[0022] In response to the cold start of a thermal power generating unit, control the opening of the boiler drain valve and exhaust valve;

[0023] The boiler water supply function group and the boiler cold flushing function group are started sequentially.

[0024] Control the feedwater pump to inject water into the boiler via pipeline;

[0025] The water supply function group of the adjacent boiler, the feed water pump, and the BEST small steam turbine warm-up system are started in sequence.

[0026] Adjust the speed of the BEST small steam turbine to be greater than the first speed;

[0027] The inner cylinder metal temperature is controlled to be below a first temperature for a first duration, or the inner cylinder metal temperature is controlled to be above a first temperature for a second duration.

[0028] The current starting mode of the BEST small steam turbine is determined to be the BEST small steam turbine independent starting mode; the BEST small steam turbine independent starting mode is the starting mode in which the BEST small steam turbine starts independently without relying on the electric motor;

[0029] The speed of the control converter is increased to the second speed, and the BEST small steam turbine is controlled to complete the steam source switching;

[0030] Control the No. 7 and No. 8 low-pressure heaters to be engaged respectively, control the overflow valve to be in automatic mode, and control the converter to be in master control mode.

[0031] According to one embodiment of this application, the method of controlling the BEST small steam turbine to drive the small generator to start automatically according to a preset starting mode further includes:

[0032] Control the water source to statically inject water into the pipeline;

[0033] Control the water supply pump to engage the rotating gear;

[0034] The turbine auxiliary steam start function group, shaft seal and vacuum system, feedwater pump start function group, deaerator, and boiler start-up condensate system are started sequentially.

[0035] In response to the cold start of a thermal power generating unit, control the opening of the boiler drain valve and exhaust valve;

[0036] The boiler water supply function group and the boiler cold flushing function group are started sequentially.

[0037] Control the feedwater pump to inject water into the boiler via pipeline;

[0038] The water supply function group of the adjacent boiler, the feed water pump, and the BEST small steam turbine warm-up system are started in sequence.

[0039] Adjust the speed of the BEST small steam turbine to be greater than the first speed;

[0040] The inner cylinder metal temperature is controlled to be below a first temperature for a first duration, or the inner cylinder metal temperature is controlled to be above a first temperature for a second duration.

[0041] The current starting mode of the BEST small steam turbine is determined to be the electric motor starting mode; the electric motor starting mode is the starting mode in which the BEST small steam turbine relies on an electric motor to complete the start-up.

[0042] Controls the converter to start up and controls the converter to be in master control mode;

[0043] Control the BEST small steam turbine to fully open the regulating valve or control the BEST small steam turbine primary low-temperature reheat steam inlet electric valve to fully close;

[0044] The speed of the control converter is increased to the second speed, and the BEST small steam turbine is controlled to complete the steam source switching;

[0045] Control the No. 7 and No. 8 low-pressure heaters to be engaged respectively, control the overflow valve to be in automatic mode, and control the converter to be in master control mode.

[0046] According to one embodiment of this application, the step of sequentially starting the second group of target systems and the second group of target equipment in a preset second order to start the coal feeder in the pulverizing system and the first target coal mill in the coal mill unit includes:

[0047] The start-up function groups of the desulfurization slurry pump, dry slag discharge system, and flue gas system are started in sequence.

[0048] Control the thermal power generating unit to perform an oil leakage detection experiment in the boiler pulverizing system;

[0049] Control the boiler to perform furnace purging operations;

[0050] Control the activation of denitrification acoustic soot blowing program for thermal power generating units;

[0051] Control the turbine oil circulation system to circulate oil;

[0052] The boiler plasma ignition system preparation function group and the pulverizing system function group are started sequentially.

[0053] Control the start-up of the primary air heater and the secondary air heater respectively;

[0054] Control the air preheater to perform continuous soot blowing operation, and control the flue gas damper of the heat exchanger to be adjusted to the middle position;

[0055] The system controls the feedwater system and turbine bypass system to enter automatic mode, and controls the start-up of the water supply function group of the adjacent boiler.

[0056] Engage the interlock status of the turbine drain valve;

[0057] Control the start-up of the first-layer plasma system or fuel system;

[0058] Control the startup of the first module;

[0059] Control the boiler temperature to rise to the first target value, and control the boiler pressure to rise to the second target value;

[0060] Control the operation of the first target coal mill, and control the operation of the hot air damper of the first target coal mill;

[0061] Control the boiler to perform hot cleaning;

[0062] Control the input of the extrusion head of the slag removal system and control the slag removal system to perform slag discharge operations at regular intervals;

[0063] The operating status of the fan is determined, and in response to the fact that one fan of the flue gas system is in operation and the other fan of the flue gas system is in a stopped state, the fan on the other side of the flue gas system is controlled to start operation.

[0064] According to one embodiment of this application, controlling the turbine corresponding to the BEST small steam turbine to start and controlling the thermal power generating unit corresponding to the BEST small steam turbine to connect to the grid includes:

[0065] Control the turbine to start running and control the thermal power generator unit to connect to the grid;

[0066] The system sequentially controls the start-up of the low-temperature heater steam side and the generator grid connection function group;

[0067] Control the boiler to increase the amount of fuel so that the load value of the thermal power generating unit rises to the first load value;

[0068] Control the activation of all extrusion heads in the slag removal system;

[0069] The denitrification system of the decoupling stock has been put into operation.

[0070] According to one embodiment of this application, the step of sequentially starting other target coal mills in the coal mill unit, excluding the first target coal mill, in a preset third order to increase the load value of the generator unit to the target load value includes:

[0071] Control the boiler to increase the amount of fuel so that the load value of the thermal power generating unit rises to the second load value;

[0072] The slag discharge system and the second target coal mill are started sequentially.

[0073] Switch the steam source of the control steam pump to the cooling and reheat system;

[0074] Control the steam-side operation of the high-temperature heater;

[0075] Control the deaerator steam source to switch to the sixth-stage extraction steam pipeline;

[0076] Control the boiler to increase the amount of fuel so that the thermal power generating unit can increase the load value to the third load value;

[0077] The auxiliary steam source is switched to the secondary recooling section;

[0078] The load value of the thermal power generating unit is increased to the fourth load value so that the thermal power generating unit enters a dry state;

[0079] Control the activation of the flue gas recirculation system;

[0080] The primary air fan and the third target coal mill are started sequentially.

[0081] Control the thermal power generating unit to increase the load value to the fourth load value, and control the thermal power generating unit to switch to the coordinated control system (CCS);

[0082] Control the water supply system to switch to the main water supply valve;

[0083] The first circulating pump, the second circulating pump, and the fourth target coal mill are started sequentially.

[0084] Control the fuel system and plasma ignition system to stop operating;

[0085] Control the load value of thermal power generating units to rise to the fifth load value of 500MW;

[0086] Control the start-up of the fifth target coal mill;

[0087] Stop the operation of the auxiliary steam source for the low-temperature economizer;

[0088] Control the activation of the air preheater bypass economizer system;

[0089] Start the sixth target coal mill.

[0090] According to one embodiment of this application, the first rotational speed is 999 rpm; the first duration is 30 min; the second duration is 10 min; and the second rotational speed is 2440 r / min.

[0091] According to one embodiment of this application, the first load value is 50MW.

[0092] According to one embodiment of this application, the second load value is 150MW, the third load value is 200MW, the fourth load value is 300MW, and the fifth load value is 550MW.

[0093] The technical solutions provided by the embodiments of this application bring at least the following beneficial effects:

[0094] By comprehensively monitoring the operating conditions of the thermal power generating units, and issuing control commands to various functional groups, sub-functional groups, equipment drive levels, and other related systems according to the needs of different stages during the start-up process of the thermal power generating units, the start-up control strategy of the BEST small steam turbine with small generator of the ultra-supercritical double reheat coal-fired power unit was optimized, shortening the start-up time of the ultra-supercritical double reheat coal-fired power unit. Furthermore, based on the working status of each control system, the control of the boiler, turbine, electrical system, and various auxiliary systems was coordinated, realizing the automatic start-up process of the entire unit.

[0095] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0096] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application, and do not constitute an undue limitation of this application.

[0097] Figure 1 This is a flowchart of an automatic start-up control method for an ultra-supercritical double reheat unit according to an embodiment of this application;

[0098] Figure 2 This is a structural block diagram of a self-starting control device for an ultra-supercritical double reheat unit according to an embodiment of this application. Detailed Implementation

[0099] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0100] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0101] It should be noted that in power plants using BEST small turbines with small generators in ultra-supercritical double reheat coal-fired units, operators typically have to start each system piece by piece to complete the overall startup. Each system has a startup sequence control program, making it difficult to achieve coordinated control across systems. Operators need to confirm the successful startup of each system before starting the next, consuming significant time. Furthermore, due to the initial application of BEST small turbines with small generators, operators must choose between BEST turbine startup and electric motor startup each time, increasing their workload. Unlike conventional thermal power plants, it is crucial to confirm the successful startup of the BEST small turbine with small generator each time before proceeding with subsequent startups.

[0102] To address the aforementioned issues, this application proposes a self-starting control method for ultra-supercritical double reheat units. Figure 1 This is a flowchart of a self-starting control method for an ultra-supercritical double reheat unit according to an embodiment of this application.

[0103] like Figure 1 As shown, the self-starting control method of this ultra-supercritical double reheat unit includes:

[0104] Step 110: Start the first group of target systems and the first group of target devices in the preset first order.

[0105] In the embodiments of this application, the first group of target systems includes multiple target systems.

[0106] In this application embodiment, the first group of target devices includes multiple target devices.

[0107] As a possible example, the first group of target systems and the first group of target equipment are started sequentially according to a preset first order, and the start-up of each system in the first group of target systems and the start-up of all water systems of the first group of target equipment units, the start-up of the BEST small steam turbine and the steam turbine oil system, the start-up of the coal mill, the start-up of the oil system, the start-up of the air preheater, etc. are confirmed.

[0108] Checking whether each piece of equipment in the preparation is operating normally lays the foundation for the subsequent startup of various systems in the thermal power generating unit. In some embodiments of this application, step 110 includes:

[0109] Step 111: Sequentially control the start-up of the closed cooling water system, condensate system, deaerator water supply system, and open water system;

[0110] Step 112: Control the start-up of the oil station system of the boiler coal mill unit and the oil station system of the blower respectively;

[0111] Step 113: Sequentially control the start-up of the air preheater, the BEST small steam turbine lubrication oil station system, the steam turbine lubrication oil start-up function group, and the generator sealing oil start-up function group;

[0112] Step 114: Control the turning gear to start and issue a hydrogen charging and replacement prompt signal;

[0113] Step 115: Sequentially control the start-up of the turbine EH oil system, the constant cooling water system, and the bypass oil station system.

[0114] Step 120: Control the BEST small steam turbine to drive the small generator to start automatically according to the preset starting mode.

[0115] In some embodiments of this application, step 120 includes:

[0116] Step a1: Control the water source to statically inject water into the pipeline;

[0117] Step a2: Control the water supply pump to engage the rotating gear;

[0118] Step a3: Control the turbine auxiliary steam start function group to start;

[0119] Step a4: Control the start-up of the shaft sealing system and vacuum system of the thermal power generator set respectively;

[0120] Step a5: Sequentially control the start-up of the feedwater pump, deaerator, and boiler condensate system.

[0121] In this embodiment of the application, the deaerator may be a thermal deaerator.

[0122] Step a6: In response to the cold start of the thermal power generating unit, control the opening of the boiler drain valve and exhaust valve;

[0123] Step a7: Sequentially control the boiler water supply function group and the boiler cold flushing function group to start;

[0124] Step a8: Control the feedwater pump to inject water into the boiler via pipeline;

[0125] In this embodiment of the application, pipeline pre-boiler water injection refers to the water injection into the motor chamber of the boiler water circulation pump that must be completed before the boiler is filled with water.

[0126] Step a9: Sequentially control the start-up of the adjacent boiler water supply function group, feedwater pump, and BEST small steam turbine warm-up system;

[0127] It should be noted that before filling the boiler with water, the status of all valves in the boiler start-up system and the steam-water system should be checked. Thermal power plants generally have standard valve operation cards for the steam-water system before startup. Boiler water filling can only begin after the boiler water circulation pump motor chamber has been filled with water.

[0128] Step a10: Adjust the speed of the BEST small steam turbine to be greater than the first speed;

[0129] Step a11: Control the inner cylinder metal temperature to be below the first temperature for a first duration, or control the inner cylinder metal temperature to be above the first temperature for a second duration.

[0130] Step a12: Determine the current starting mode of the BEST small steam turbine as the BEST small steam turbine independent starting mode; the BEST small steam turbine independent starting mode is the starting mode of the BEST small steam turbine that starts independently without relying on the electric motor.

[0131] Step a13: Control the converter speed to increase to the second speed, and control the BEST small steam turbine to complete the steam source switching;

[0132] Step a14: Control the No. 7 and No. 8 low-pressure heaters to be engaged, control the overflow valve to be in automatic mode, and control the converter to be in master control mode.

[0133] In some embodiments of this application, step 120 further includes:

[0134] Step b1: Control the water source to statically inject water into the pipeline;

[0135] Step b2: Control the water supply pump to engage the rotating gear;

[0136] Step b3: Sequentially control the start-up of the turbine auxiliary steam starting function group, shaft seal and vacuum system, feedwater pump starting function group, deaerator, and boiler start-up condensate system.

[0137] Step b4: In response to the cold start of the thermal power generating unit, control the opening of the boiler drain valve and exhaust valve;

[0138] Step b5: Sequentially control the boiler water supply function group and the boiler cold flushing function group to start;

[0139] Step b6: Control the feedwater pump to inject water into the boiler via pipeline;

[0140] Step b7: Sequentially control the start-up of the adjacent boiler water supply function group, feedwater pump, and BEST small steam turbine warm-up system;

[0141] Step b8: Adjust the speed of the BEST small steam turbine to be greater than the first speed;

[0142] Step b9: Control the inner cylinder metal temperature to be below the first temperature for a first duration, or control the inner cylinder metal temperature to be above the first temperature for a second duration.

[0143] Step b10: Determine that the current starting mode of the BEST small steam turbine is electric motor starting mode; the electric motor starting mode is the starting mode in which the BEST small steam turbine relies on an electric motor to complete the start-up.

[0144] Step b11: Control the converter to start, and control the converter to be in master control mode;

[0145] Step b12: Control the BEST small steam turbine regulating valve to be fully open or control the BEST small steam turbine primary low-temperature reheat steam inlet electric valve to be fully closed;

[0146] Step b13: Control the converter speed to increase to the second speed, and control the BEST small steam turbine to complete the steam source switching;

[0147] Step b14: Control the No. 7 and No. 8 low-pressure heaters to be engaged, control the overflow valve to be in automatic mode, and control the converter to be in master control mode.

[0148] Optionally, the first rotational speed can be 999 rpm; the first duration can be 30 min; the second duration can be 10 min; and the second rotational speed can be 2440 r / min.

[0149] As a possible example, if the BEST small steam turbine with a small generator is successfully started using the electric motor starting method, first start the converter and put the converter in converter master control mode. Then, after the converter master control is raised to 100%, the converter can smoothly drive the BEST small steam turbine to run. At this time, the speed rises to above 2440 r / min and is in converter master control mode, which means that the BEST small steam turbine with the small generator has started successfully, and finally meets the process requirements of boiler water flushing. At the same time, it is necessary to establish a vacuum system at this time to lay the foundation for the next step of boiler and turbine start-up.

[0150] Step 130: Start the second group of target systems and the second group of target equipment in the preset second order so that the coal feeder in the pulverizing system and the first target coal mill in the coal mill unit are started; the second group of target systems includes multiple target systems; the second group of target equipment includes multiple target equipment.

[0151] In some embodiments of this application, step 130 includes:

[0152] Step c1: Sequentially control the start-up function groups of the desulfurization slurry pump, dry slag discharge system, and flue gas system;

[0153] Step c2: Control the thermal power generating unit to perform an oil leakage detection experiment of the boiler pulverizing system;

[0154] Step c3: Control the boiler to perform furnace purging operation;

[0155] Step c4: Control the thermal power generating unit to engage the denitrification soot blowing program.

[0156] Step c5: Control the turbine oil circulation system to circulate oil;

[0157] Step c6: Sequentially control the start-up of the boiler plasma ignition system preparation function group and the pulverizing system function group;

[0158] Step c7: Control the primary air heater and the secondary air heater to start respectively;

[0159] Step c8: Control the air preheater to perform continuous soot blowing operation and control the flue gas damper of the heat exchanger to be adjusted to the middle position;

[0160] Step c9: Control the feedwater system and turbine bypass system to enter automatic mode respectively, and control the adjacent boiler water supply function group to start.

[0161] Step c10: Engage the interlock status of the turbine drain valve;

[0162] Step c11: Control the start of the first-layer plasma system or fuel system;

[0163] Step c12: Control the first module to start;

[0164] Step c13: Control the boiler temperature to rise to the first target value, and control the boiler pressure to rise to the second target value;

[0165] Step c14: Control the operation of the first target coal mill and control the operation of the hot air damper of the first target coal mill;

[0166] Step c15: Control the boiler to perform hot cleaning;

[0167] Step c16: Control the extrusion head of the slag removal system to be engaged, and control the slag removal system to perform slag discharge operations at regular intervals;

[0168] Step c17: Determine the operating status of the fan. In response to the fact that one fan of the flue gas system is in operation and the other fan of the flue gas system is in a stopped state, control the other fan of the flue gas system to start operation.

[0169] As a possible implementation example, the desulfurization slurry pump, dry slag discharge system, flue gas system, oil leak test, furnace purging, denitrification acoustic soot blowing, oil circulation, and plasma system are started sequentially. This ultimately leads to the successful startup of the first coal mill and coal feeder in the pulverizing system. At this point, various pressures and temperatures gradually increase, eventually meeting the preset target requirements.

[0170] Step 140: Control the turbine corresponding to the BEST small steam turbine to start running, and control the thermal power generator unit corresponding to the BEST small steam turbine to connect to the grid.

[0171] It should be noted that the act of an independent power plant or small power system connecting with an adjacent power system to exchange power is called grid connection.

[0172] In some embodiments of this application, step 140 includes:

[0173] Step 141: Control the turbine to start running and control the thermal power generating unit to connect to the grid;

[0174] Step 142: Sequentially control the start-up of the low-temperature heater steam side and the generator grid connection function group;

[0175] Step 143: Control the boiler to increase the amount of fuel so that the load value of the thermal power generating unit rises to the first load value;

[0176] In this embodiment of the application, the load value of the thermal power generator set is increased to the first load value to meet the initial load warm-up conditions.

[0177] Step 144: Control all extrusion heads of the slag removal system to be engaged;

[0178] Step 145: Denitrification system of decoupled strand put into operation.

[0179] As a possible example, the aforementioned first load value could be a pre-set load value, such as 50MW.

[0180] Step 150: Start the other target coal mills in the coal mill unit in the preset third order, except for the first target coal mill, so that the load value of the generator unit can be increased to the target load value.

[0181] In some embodiments of this application, step 150 includes:

[0182] Step d1: Control the boiler to increase the amount of fuel so that the load value of the thermal power generating unit rises to the second load value;

[0183] Step d2: Sequentially control the start-up of the slag discharge system and the second target coal mill;

[0184] Step d3: Control the steam pump to switch the steam source to the cooling and reheating system;

[0185] Step d4: Control the steam side of the high-temperature heater to be activated;

[0186] Step d5: Control the deaerator steam source to switch to the sixth-stage extraction steam pipeline;

[0187] Step d6: Control the boiler to increase the amount of fuel so that the thermal power generator unit can increase the load value to the third load value;

[0188] Step d7: Control the auxiliary steam source to switch to the secondary recooling section;

[0189] Step d8: Control the load value of the thermal power generating unit to increase to the fourth load value, so that the thermal power generating unit enters a dry state; 300MW

[0190] Step d9: Activate the flue gas recirculation system;

[0191] Step d10: Sequentially control the primary air fan and the third target coal mill to start;

[0192] Step d11: Control the thermal power generator set to increase the load value to the fourth load value, and control the thermal power generator set to switch to the coordinated control system (CCS).

[0193] It should be noted that CCS (Coordination Control System) refers to a system that coordinates the operating states of the steam turbine and boiler through a control loop, while simultaneously issuing commands to the boiler automatic control system and the steam turbine automatic control system to achieve rapid response to load changes, maximize the unit's frequency regulation and peak shaving capabilities, and stabilize operating parameters.

[0194] Step d12: Control the water supply system to switch to the main water supply valve;

[0195] Step d13: Sequentially control the start-up of the first circulating pump, the second circulating pump, and the fourth target coal mill;

[0196] Step d14: Control the fuel system and plasma ignition system to stop operating;

[0197] Step d15: Control the load value of the thermal power generating unit to rise to the fifth load value of 500MW;

[0198] Step d16: Control the fifth target coal mill to start;

[0199] Step d17: Stop the operation of the auxiliary steam source for the low-temperature economizer;

[0200] Step d18: Control the activation of the air preheater bypass economizer system;

[0201] Step d19: Control the start of the sixth target coal mill.

[0202] As a possible example, the second, third, fourth, and fifth load values ​​mentioned above can all be preset load values. The second load value is 150MW, the third load value is 200MW, the fourth load value is 300MW, and the fifth load value is 550MW.

[0203] The self-starting control method for ultra-supercritical double reheat units according to embodiments of this application leverages the advantages of the BEST small turbine having multiple starting modes, achieving a flexible and energy-efficient control strategy. Combined with the self-starting control strategy for thermal power generating units, it realizes self-starting control strategies for ultra-supercritical double reheat units under both electric motor starting and BEST small turbine independent starting modes. This method comprehensively monitors the unit's operating conditions and, based on the needs of different stages during the thermal power generating unit's startup process, issues control commands to various functional groups, sub-functional groups, equipment drive stages, and other related systems. It optimizes the startup control strategy for the BEST small turbine-driven small generator in ultra-supercritical double reheat coal-fired units, shortening the startup time. Furthermore, based on the operating status of each control system, it coordinates the control of the boiler, turbine, electrical, and auxiliary systems, automatically completing the entire unit's startup process.

[0204] Figure 2 This is a structural block diagram of a self-starting control device for an ultra-supercritical double reheat unit according to an embodiment of this application.

[0205] like Figure 2 As shown, the self-starting control device of the ultra-supercritical double reheat unit includes:

[0206] The first startup module 201 is used to sequentially start the first group of target systems and the first group of target devices according to a preset first order; the first group of target systems includes multiple target systems; the first group of target devices includes multiple target devices;

[0207] The second starting module 202 is used to control the BEST small steam turbine to drive the small generator to start automatically according to the preset starting method;

[0208] The third startup module 203 is used to start the second group of target systems and the second group of target equipment in a preset second order, so as to start the coal feeder in the pulverizing system and the first target coal mill in the coal mill unit; the second group of target systems includes multiple target systems; the second group of target equipment includes multiple target equipment.

[0209] Control module 204 is used to control the turbine start-up of the BEST small steam turbine and to control the thermal power generating unit corresponding to the BEST small steam turbine to connect to the grid.

[0210] The fourth start-up module 205 is used to start the other target coal mills in the coal mill unit in a preset third order, except for the first target coal mill, so as to increase the load value of the generator unit to the target load value.

[0211] The self-starting control device for ultra-supercritical double reheat units according to embodiments of this application leverages the advantages of the BEST small turbine having multiple starting modes, realizing a flexible and energy-efficient control strategy. Combined with the self-starting control strategy for thermal power generating units, it achieves self-starting control strategies for ultra-supercritical double reheat units under both electric motor starting and BEST small turbine independent starting modes. This device comprehensively monitors the operating conditions of thermal power generating units. Based on the needs of different stages during the start-up process, it issues control commands to various functional groups, sub-functional groups, equipment drive stages, and other related systems. It optimizes the start-up control strategy for the BEST small turbine-driven small generator in ultra-supercritical double reheat coal-fired units, shortening the start-up time. Furthermore, based on the operating status of each control system, it coordinates the control of the boiler, turbine, electrical system, and auxiliary equipment, achieving automatic start-up of the entire unit.

[0212] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0213] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0214] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0215] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0216] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0217] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A self-starting control method for an ultra-supercritical double reheat unit, characterized in that, The method includes: The first group of target systems and the first group of target devices are started sequentially according to a preset first order; the first group of target systems includes multiple target systems; the first group of target devices includes multiple target devices; The BEST small steam turbine is controlled to drive the small generator to start automatically according to a preset starting mode; the preset starting mode includes the BEST small steam turbine independent starting mode and the electric motor starting mode. The second group of target systems and the second group of target equipment are started sequentially according to a preset second order, so as to start the coal feeder in the pulverizing system and the first target coal mill in the coal mill unit; the second group of target systems includes multiple target systems; the second group of target equipment includes multiple target equipment. Control the turbine corresponding to the BEST small steam turbine to start running, and control the thermal power generating unit corresponding to the BEST small steam turbine to connect to the grid; The other target coal mills in the coal mill unit, except for the first target coal mill, are started in the preset third order to increase the load value of the generator unit to the target load value. The step of sequentially activating the first group of target systems and the first group of target devices in a preset first order includes: The closed cooling water system, condensate system, deaerator water supply system, and open water system are started sequentially. The oil station system of the boiler coal mill unit and the oil station system of the blower are controlled separately. The air preheater, BEST small steam turbine lubrication oil station system, steam turbine lubrication oil start function group, and generator sealing oil start function group are started in sequence. The control unit starts the turning gear and issues a hydrogen charging / purging warning signal; The turbine EH oil system, constant cooling water system, and bypass oil station system are started sequentially. The step of sequentially activating the second group of target systems and the second group of target equipment in a preset second order to start the coal feeder in the pulverizing system and the first target coal mill in the coal mill unit includes: The start-up function groups of the desulfurization slurry pump, dry slag discharge system, and flue gas system are started in sequence. Control the thermal power generating unit to perform an oil leakage detection experiment in the boiler pulverizing system; Control the boiler to perform furnace purging operations; Control the activation of denitrification acoustic soot blowing program for thermal power generating units; Control the turbine oil circulation system to circulate oil; The boiler plasma ignition system preparation function group and the pulverizing system function group are started sequentially. Control the start-up of the primary air heater and the secondary air heater respectively; Control the air preheater to perform continuous soot blowing operation, and control the flue gas damper of the heat exchanger to be adjusted to the middle position; The system controls the feedwater system and turbine bypass system to enter automatic mode, and controls the start-up of the water supply function group of the adjacent boiler. Engage the interlock status of the steam turbine drain valve; Control the start-up of the first-layer plasma system or fuel system; Control the startup of the first module; Control the boiler temperature to rise to the first target value, and control the boiler pressure to rise to the second target value; Control the operation of the first target coal mill, and control the operation of the hot air damper of the first target coal mill; Control the boiler to perform hot cleaning; Control the input of the extrusion head of the slag removal system and control the slag removal system to perform slag discharge operations at regular intervals; The operating status of the fan is determined, and in response to the fact that one fan on one side of the flue gas system is in operation and the other fan on the other side of the flue gas system is in a stopped state, the fan on the other side of the flue gas system is controlled to start operation. The step of sequentially starting the other target coal mills in the coal mill unit, excluding the first target coal mill, in a preset third order to increase the load value of the generator unit to the target load value includes: Control the boiler to increase the amount of fuel so that the load value of the thermal power generating unit rises to the second load value; The slag discharge system and the second target coal mill are started sequentially. Switch the steam source of the control steam pump to the cooling recirculation system; Control the steam-side operation of the high-temperature heater; Control the deaerator steam source to switch to the sixth-stage extraction steam pipeline; Control the boiler to increase the amount of fuel so that the thermal power generating unit can increase the load value to the third load value; The auxiliary steam source is switched to the secondary recooling section; The load value of the thermal power generating unit is increased to the fourth load value so that the thermal power generating unit enters a dry state; Control the activation of the flue gas recirculation system; The primary air fan and the third target coal mill are started sequentially. Control the thermal power generating unit to increase the load value to the fourth load value, and control the thermal power generating unit to switch to the coordinated control system (CCS); Switch the water supply system to the main water supply valve; The first circulating pump, the second circulating pump, and the fourth target coal mill are started sequentially. Control the fuel system and plasma ignition system to stop operating; Control the load value of the thermal power generating unit to rise to the fifth load value; Control the start-up of the fifth target coal mill; Stop the operation of the auxiliary steam source for the low-temperature economizer; Control the activation of the air preheater bypass economizer system; Start the sixth target coal mill.

2. The method according to claim 1, characterized in that, The control of the BEST small steam turbine to drive the small generator to start automatically according to the preset starting mode includes: Control the water source to statically inject water into the pipeline; Control the water supply pump to engage the rotating gear; Start the auxiliary steam start function group of the steam turbine; The shaft sealing system and vacuum system of the thermal power generating unit are started separately; The system sequentially controls the start-up of the feedwater pump, deaerator, and boiler condensate system. In response to the cold start of a thermal power generating unit, control the opening of the boiler drain valve and exhaust valve; The boiler water supply function group and the boiler cold flushing function group are started sequentially. Control the feedwater pump to inject water into the boiler via pipeline; The water supply function group of the adjacent boiler, the feed water pump, and the BEST small steam turbine warm-up system are started in sequence. Adjust the speed of the BEST small steam turbine to be greater than the first speed; The inner cylinder metal temperature is controlled to be below a first temperature for a first duration, or the inner cylinder metal temperature is controlled to be above a first temperature for a second duration. The current starting mode of the BEST small steam turbine is determined to be the BEST small steam turbine independent starting mode; the BEST small steam turbine independent starting mode is the starting mode in which the BEST small steam turbine starts independently without relying on the electric motor; The speed of the control converter is increased to the second speed, and the BEST small steam turbine is controlled to complete the steam source switching; Control the No. 7 and No. 8 low-pressure heaters to be engaged respectively, control the overflow valve to be in automatic mode, and control the converter to be in master control mode.

3. The method according to claim 1, characterized in that, The method for controlling the BEST small steam turbine to drive the small generator to start automatically according to a preset starting mode also includes: Control the water source to statically inject water into the pipeline; Control the water supply pump to engage the rotating gear; The turbine auxiliary steam start function group, shaft seal and vacuum system, feedwater pump start function group, deaerator, and boiler start-up condensate system are started in sequence. In response to the cold start of a thermal power generating unit, control the opening of the boiler drain valve and exhaust valve; The boiler water supply function group and the boiler cold flushing function group are started sequentially. Control the feedwater pump to inject water into the boiler via pipeline; The water supply function group of the adjacent boiler, the feed water pump, and the BEST small steam turbine warm-up system are started in sequence. Adjust the speed of the BEST small steam turbine to be greater than the first speed; The inner cylinder metal temperature is controlled to be below a first temperature for a first duration, or the inner cylinder metal temperature is controlled to be above a first temperature for a second duration. The current starting mode of the BEST small steam turbine is determined to be the electric motor starting mode; the electric motor starting mode is the starting mode in which the BEST small steam turbine relies on an electric motor to complete the start-up. Control the converter to start up, and control the converter to be in master control mode; Control the BEST small steam turbine to fully open the regulating valve or control the BEST small steam turbine primary low-temperature reheat steam inlet electric valve to fully close; The speed of the control converter is increased to the second speed, and the BEST small steam turbine is controlled to complete the steam source switching; Control the No. 7 and No. 8 low-pressure heaters to be engaged respectively, control the overflow valve to be in automatic mode, and control the converter to be in master control mode.

4. The method according to claim 1, characterized in that, The control of the turbine corresponding to the BEST small steam turbine to start up, and the control of the thermal power generating unit corresponding to the BEST small steam turbine to connect to the grid, include: Control the turbine to start running and control the thermal power generator unit to connect to the grid; The system sequentially controls the start-up of the low-temperature heater steam side and the generator grid connection function group; Control the boiler to increase the amount of fuel so that the load value of the thermal power generating unit rises to the first load value; Control the engagement of all extrusion heads in the slag removal system; The denitrification system of the decoupling stock has been put into operation.

5. The method according to claim 2 or claim 3, characterized in that, The first rotational speed is 999 rpm; the first duration is 30 min; the second duration is 10 min; and the second rotational speed is 2440 r / min.

6. The method according to claim 4, characterized in that, The first load value is 50MW.

7. The method according to claim 1, characterized in that, The second load value is 150MW, the third load value is 200MW, the fourth load value is 300MW, and the fifth load value is 550MW.

Images