CN113586184B - Deep peak shaving method based on main reheat steam communication of thermal power plant - Google Patents
Deep peak shaving method based on main reheat steam communication of thermal power plant Download PDFInfo
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- CN113586184B CN113586184B CN202111019212.0A CN202111019212A CN113586184B CN 113586184 B CN113586184 B CN 113586184B CN 202111019212 A CN202111019212 A CN 202111019212A CN 113586184 B CN113586184 B CN 113586184B
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- 238000000034 method Methods 0.000 title claims abstract description 67
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 57
- 238000003303 reheating Methods 0.000 claims description 51
- 230000001105 regulatory effect Effects 0.000 claims description 23
- 239000003245 coal Substances 0.000 claims description 20
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- 238000010438 heat treatment Methods 0.000 claims description 13
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- 238000012544 monitoring process Methods 0.000 claims description 12
- 238000010298 pulverizing process Methods 0.000 claims description 12
- 239000000446 fuel Substances 0.000 claims description 11
- 238000009833 condensation Methods 0.000 claims description 10
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- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 8
- 239000003546 flue gas Substances 0.000 claims description 8
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- 238000001816 cooling Methods 0.000 claims description 5
- 238000001704 evaporation Methods 0.000 claims description 5
- 230000008020 evaporation Effects 0.000 claims description 5
- 238000010248 power generation Methods 0.000 claims description 5
- 238000007664 blowing Methods 0.000 claims description 4
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- 239000003921 oil Substances 0.000 abstract description 18
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- 239000002699 waste material Substances 0.000 description 1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K11/00—Plants characterised by the engines being structurally combined with boilers or condensers
- F01K11/02—Plants characterised by the engines being structurally combined with boilers or condensers the engines being turbines
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D15/00—Adaptations of machines or engines for special use; Combinations of engines with devices driven thereby
- F01D15/10—Adaptations for driving, or combinations with, electric generators
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K13/00—General layout or general methods of operation of complete plants
- F01K13/003—Arrangements for measuring or testing
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K13/00—General layout or general methods of operation of complete plants
- F01K13/02—Controlling, e.g. stopping or starting
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B33/00—Steam-generation plants, e.g. comprising steam boilers of different types in mutual association
- F22B33/18—Combinations of steam boilers with other apparatus
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B35/00—Control systems for steam boilers
- F22B35/18—Applications of computers to steam boiler control
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22G—SUPERHEATING OF STEAM
- F22G5/00—Controlling superheat temperature
- F22G5/20—Controlling superheat temperature by combined controlling procedures
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P80/00—Climate change mitigation technologies for sector-wide applications
- Y02P80/10—Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
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- General Engineering & Computer Science (AREA)
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Abstract
The invention discloses a deep peak shaving method based on main reheat steam communication of a thermal power plant, which comprises two units for configuring main and auxiliary machines and an auxiliary thermodynamic system of the thermal power plant, and is characterized in that: the method uses common pipelines and valves of a power station to implement communication transformation on the existing main steam, reheat cold section and hot section steam systems, adopts a method that one unit boiler is stopped and the other boiler operates by 40% -50% of MCR so as to provide steam required by two steam turbine generators with 20% of ECR electric load operation, and realizes deep peak regulation without oil feeding of a thermal power unit; the deep peak regulation and the power response of the thermal power generating unit are better, and compared with the conventional load reduction peak regulation mode, the fuel oil and plant power consumption and heat loss are reduced.
Description
Technical Field
The invention belongs to the technical field of operation of thermal power plants, and particularly relates to a deep peak shaving method based on main reheat steam communication of a thermal power plant.
Background
The large thermal power generating unit is in normal state when participating in power grid peak regulation, and the trend of matching new energy is more obvious along with the large-scale access of new energy to the power grid, so that the thermal power generating unit is required to have enough peak regulation depth and the power response rate is required to adapt to the characteristics of new energy gap power generation such as wind power. The minimum non-oil-feeding stable combustion load of a large-sized pure condensing generator set boiler is designed to be 40% -50% BMCR (maximum evaporation capacity), when the load of the generator set must be reduced to below 40% ECR (rated electric power) according to a conventional peak regulation method of a thermal power unit, the boiler must be fed with oil for stable combustion, and because the price of fuel is high, a power plant can also operate in a mode of maintaining the boiler above 40% BMCR and starting a high-low pressure bypass, and the generated heat losses of the fuel and working medium are huge waste of primary energy, which is the root of the phenomena of large wind abandon, light abandon and water abandon in China.
In order to solve the contradiction between full new energy consumption and primary energy loss, the thermal power generating unit is flexibly operated and modified to adapt to the influence caused by the structural change of the energy, and after implementation, the best index of the thermal power generating unit reaches the level of 15% -20% ECR (minimum steady burning load without oil) with minimum technical output and 2.5% -3.0% P e/min of 'climbing rate'. The flexible operation transformation of the domestic thermal power generating unit is only implemented in the northern area at present, and due to large investment amount, heat supply conditions and energy storage condition differences, the adopted technologies of thermoelectric decoupling, large-scale heat storage and electricity storage, large-capacity electric boilers and the like are not suitable for power plants without large-scale heat supply requirements, and meanwhile, the unit is far lower than the design working condition operation, and main and auxiliary equipment adaptability, safety, economy and the like are still required to be further researched and evaluated.
The invention provides a method different from the current flexible operation transformation technology, which can realize stable operation of a boiler without adding oil and achieve the aim of better peak regulation capacity and power response of a unit under the condition that large-scale heat storage and electricity storage equipment cannot be additionally arranged in a plurality of thermal power plants and no energy consumption background of heat and electricity users is caused by peak staggering.
Disclosure of Invention
The invention aims to solve the technical problems: the deep peak shaving method based on the main reheat steam communication of the thermal power plant is provided to solve the technical problems that the existing technologies of thermal decoupling, large-scale heat storage and electricity storage, large-capacity electric boilers and the like are not suitable for power plants without large-scale heat supply requirements.
The technical scheme of the invention is as follows:
A deep peak regulation method based on main reheat steam communication of a thermal power plant comprises the steps of configuring main and auxiliary machines and an auxiliary thermodynamic system of the thermal power plant by two units, carrying out communication transformation on the existing main steam, reheat cold section and hot section steam systems by using common pipelines and valves of the power plant, and adopting a method that one unit boiler is stopped and the other boiler operates by 40% -50% of MCR so as to provide steam required by the operation of two turbine generators with 20% ECR electric loads, thereby realizing deep peak regulation without oil throwing of the thermal power plant.
The method specifically comprises the following steps:
Step 1, a thermal power plant operation mode and a working medium flow; setting a steam and condensed water flow path;
Step 2, steam-water system configuration selection and technical transformation are carried out;
step 3, determining the thermal measurement and control requirements;
and 4, determining the operation modes of two units of the thermal power plant.
The setting of the steam and condensate flows in step 1 comprises: the method aims at the shutdown of the No.1 unit and the peak load regulation operation of the turbine generator with 20% ECR, and the flow of steam and condensate water is as follows: the method comprises the steps of enabling a boiler to be saturated with steam, enabling a boiler superheater No. 2 to be connected with a first electric blocking valve on the side of an outlet B of the boiler superheater No. 2, enabling a boiler superheater No. 2 to be connected with a first outlet branch pipe of the boiler superheater No.1, enabling a first electric door to be connected with a main steam communication pipe, enabling a second electric door to be connected with a boiler superheater outlet branch pipe of the boiler superheater No.1, enabling a boiler high-pressure cylinder No.1 to be connected with a high-row check valve, enabling a boiler reheat cold section No.1, enabling a third electric door to be connected with a reheat cold section communication pipe, enabling a fourth electric door to be connected with a boiler reheat cold section No. 2, enabling a boiler reheater inlet first electric blocking valve and a second electric blocking valve to be connected with a boiler reheater outlet of the boiler No. 2, enabling a fifth electric door to be connected with a reheat hot section communication pipe, enabling a sixth electric door to be connected with a boiler reheater outlet branch pipe of the boiler No.1, enabling a boiler reheat hot section master pipe of the boiler to be connected with a boiler No.1, enabling a boiler high-pressure cylinder of the boiler No.1 to be connected with a boiler high-row check valve 1, enabling a boiler condensate water pump to be connected with a boiler condensate water to be the boiler No.1, enabling a boiler condensate water to be recycled through a seventh electric door, enabling electric door to be connected with a boiler reheater 2, enabling electric heater, enabling a boiler to be connected with a boiler, and a boiler to be connected with a controller.
The setting of the steam and condensate flows in step 1 comprises: the boiler of the No. 2 unit operates with 40-50% of MCR and the No. 2 turbo generator operates with 20% of ECR load peak regulation, and the flow of steam and condensate water is as follows: the method comprises the steps of (1) saturating steam of a No. 2 furnace, a No. 2 furnace superheater, a second electric blocking valve on the B side of an outlet of the No. 2 furnace superheater, a second outlet branch pipe of the No. 2 furnace superheater, a main steam main pipe of the No. 2 machine, a high-pressure cylinder of the No. 2 machine, a high-discharge check valve of the No. 2 machine, a reheating cold section of the No. 2 machine, a first electric blocking valve and a second electric blocking valve at an inlet of the No. 2 furnace reheater, a first electric blocking valve at an outlet of the No. 2 furnace reheater, a first branch pipe of the No. 2 furnace reheater, a reheat heat section main pipe of the No. 2 machine, a medium-pressure cylinder of the No. 2 machine and a condenser of the No. 2 machine.
The method for carrying out steam-water system configuration selection and technical transformation in the step 2 comprises the following steps:
step A: the outlet branch pipe of the No. 1 boiler superheater is communicated with the outlet branch pipe of the No. 2 boiler superheater through a second electric door, a main steam communication pipe and a first electric door, the pipe diameter ID of the communication pipe is 330.2 multiplied by 35.2mm, the second electric door and the first electric door are respectively provided with a DN550 gate valve, and DN45 drain valves are arranged at the front and rear positions of the valves and the lower positions of the communication pipes;
B, a reheating cold section of the No. 1 machine is communicated with a re-cooling section of a No. 2 boiler through a reheating cold section connecting pipe, a third electric door and a fourth electric door, the diameter of the connecting pipe is phi 863.6X119.05 mm, the third electric door and the fourth electric door are DN850 gate valves, and DN50 drain valves are arranged at the front and rear positions of the valves and the lower positions of the connecting pipe;
Step C, a No. 1 boiler reheater outlet branch pipe is communicated with a No. 2 boiler reheater outlet branch pipe through a connecting pipe, a sixth electric door and a fifth electric door, the diameter ID of the connecting pipe is 679.5 multiplied by 34mm, the sixth electric door and the fifth electric door are respectively provided with DN750 gate valves, and DN50 drain valves are arranged at the front and rear positions of the valves and the lower positions of the connecting pipe;
and D, communicating the No. 1 machine condensate water recycling electric door with the No. 1 machine condensate water recycling regulating door through a connecting pipe, a seventh electric door, an electric regulating door and an eighth electric door, wherein the connecting pipe is phi 273 multiplied by 8.5mm, and DN250 valves are selected for the seventh electric door, the electric regulating door and the eighth electric door.
And 3, determining the thermal measurement and control requirements as follows: the electric blocking valve of the boiler superheater, the electric blocking valve of the reheater inlet, the electric blocking valve of the reheater outlet and the electric door are remotely operated and can be in stop, a pressure temperature measuring point is arranged on a steam connecting pipe, and a thermal monitoring control signal is connected to a unit DCS (distributed control system) to realize remote monitoring and operation; the seventh electric door, the eighth electric door and the electric regulating door of the condensation water system are remote operation valves, and a thermal control signal is connected to a DCS (distributed control system) of the unit to realize remote monitoring and operation.
The operation modes of the two units of the thermal power plant comprise:
Step 1, when two units of a thermal power plant are configured to be reduced from 50% ECR load to 20% ECR load and participate in deep peak regulation of a power grid, maintaining pressure and stopping a furnace by a boiler No.1, and carrying out operation adjustment by a boiler No.2 with two steam turbine generators;
Step 2, checking and confirming that the load of the two units and the pressure and the temperature of the superheated steam are consistent, slightly opening the first electric door and the second electric door of the main steam connecting pipe of the two boilers, slightly opening the fifth electric door and the sixth electric door of the reheating hot section connecting pipe, slightly opening the third electric door and the fourth electric door of the reheating cold section connecting pipe, and opening the related drain valve to connect the steam pipeline heating pipe; the opening degree of the micro-opening is not more than 20-30% of the full-opening;
Step 3, when the temperature of the connecting pipe is close to the steam temperature of corresponding pipelines of the two units, gradually opening the first electric door, the second electric door, the fifth electric door, the sixth electric door, the third electric door and the fourth electric door until the connecting pipe is fully opened, and closing all the hydrophobic doors of the reheating steam connecting pipe; the temperature approach means that the temperature difference is not more than 5%;
Step 4, keeping 50% MCR working condition of the No. 2 boiler unchanged, reducing coal feeding amount of a No. 1 boiler coal mill, starting to stop the No. 1 boiler operation, adjusting and controlling power generation, main steam pressure and reheat steam pressure balance of two units by using two high-pressure regulating gates of the two steam turbines, when the load of the two units is reduced to 40% ECR, putting the No. 1 boiler oil gun into combustion supporting, stopping the powder making system one by one, monitoring metal temperature change conditions of heating surfaces of the No. 1 boiler and the reheater in the load reducing process, and if temperature rise occurs, regulating and closing corresponding flue gas baffles and accelerating the speed of the powder making system in stop operation;
Step5, controlling the load reduction rate of the two units to be 2 MW/min-12 MW/min;
Step 6, after the whole pulverizing system of the boiler No.1 is stopped, stopping all oil guns, stopping delivering induced draft fans after a hearth is purged, closing all air door baffles of an air-smoke system of the boiler No.1, keeping the air preheater of the boiler No.2 to operate, and keeping the pressure of the boiler No.1 and stopping the boiler;
Step 7, after the boiler No. 1 completely stops fuel, adjusting and closing a first electric blocking valve (1) and a second electric blocking valve of a superheater of the boiler No. 1, a first electric blocking valve and a second electric blocking valve (13) of a reheater outlet, a first electric blocking valve of a reheater inlet and a second electric blocking valve of an inlet, and stopping a steam-driven water supply pump of the machine No. 1;
step 8, adjusting the load of the No. 2 boiler to 40% -50% MCR, maintaining the load of 20% ECR of the two units, and adapting to the dispatching command;
step 9, the operation of 50% ECR unit production modes of the two steam turbine generator units is restored to be controlled by using 40% -50% MCR of the No. 2 boiler load and 20% ECR load of the two steam turbine generator units and the No. 1 boiler pressure maintaining and furnace stopping state;
Step 10, starting a boiler induced draft fan No. 1 and a blower, starting a steam feed pump of a unit No. 1, feeding water to a boiler, blowing a hearth, then putting into an oil gun for ignition, checking and starting all drain valves of a reheat steam system at the side of the boiler No. 1, starting a pulverizing system, and improving main reheat steam parameters;
Step 11, adjusting and opening a first electric blocking valve and a second electric blocking valve at an inlet of a No. 1 boiler reheater, and adjusting flue gas baffles at two sides of the reheater according to the temperature rising conditions of main steam and reheat steam to control the temperature rising rate of the main steam and reheat steam to rise at 2 ℃/min;
Step 12, when the steam pressure and the steam temperature of the outlet header of the No. 1 boiler reheater are consistent with those of the reheating heat section connecting pipe, opening a first outlet electric blocking valve and a second outlet electric blocking valve of the reheater; when the steam pressure and the steam temperature of the outlet header of the No. 1 boiler superheater are consistent with those of the main steam communication pipe, a first electric blocking valve and a second electric blocking valve of the No. 1 boiler superheater are opened, and the No.2 boiler is kept stable in running when the two unit steam systems are operated in parallel;
Step 13, adjusting the combustion of a No. 1 boiler, adding coal into a pulverizing system one by one to increase the amount of coal, adjusting two units in a matching way, increasing the total power according to a 30MW/min liter load rate, and checking that a drainage valve of the superheated steam system should be closed in an interlocking way when the load of the two units reaches 30% ECR;
And 14, when the loads of the two units reach 40% ECR, adjusting the load balance of the two boilers, closing the first electric door, the second electric door, the fifth electric door, the sixth electric door, the third electric door and the fourth electric door according to the pressure and the temperature of the cold section and the hot section of the main steam and the reheat steam, completely stopping the No. 1 boiler fuel, converting the two units into unit operation, and gradually recovering the load to 50% ECR operation.
When the load of the No. 1 boiler is reduced, the fuel quantity is reduced, the coal mill is stopped, the evaporation quantity of the boiler is reduced along with the reduction, and when the pressure of an outlet header of the No. 1 boiler superheater is lower than the pressure of a main steam communication pipe, a first electric blocking valve and a second electric blocking valve of the No. 1 boiler superheater are adjusted to be closed, and the pressure difference is kept to be 0.1-0.2 MPa; when the pressure of the outlet header of the reheater is lower than the pressure of a connecting pipe of a reheating heat section, regulating and closing a first outlet electric blocking valve and a second outlet electric blocking valve of the reheater of the No. 1 boiler, keeping the pressure difference between 0.1 and 0.2MPa, maintaining the steam flow of each heating surface of the boiler, and controlling the metal temperature of each part of the over-reheater not to exceed the temperature by using the cooperation of the superheater of the boiler and a baffle of the reheater.
In the process of adjusting the loads of the two machines, the water level of the condenser of the No.1 machine set is monitored, and when the water level is ultrahigh, the condensate is conveyed back to the condenser of the No. 2 machine according to the recirculation electric door of the No.1 machine, the seventh electric door, the electric adjusting door, the eighth electric door, the condensate recirculation adjusting door of the No. 2 machine and the condenser of the No. 2 machine.
The invention has the beneficial effects that:
the invention furthest utilizes the existing conditions of the thermal power plant, implements the communication transformation of the main reheat steam system and the condensate system, has less investment, and simultaneously realizes the average 20% ECR deep peak regulation of two units of the thermal power plant by a method of operating 2 steam turbines with 1 boiler.
The thermal power plant configured by the two units is manufactured by using common pipelines and valves of a power station only to implement the existing thermodynamic system, 1 unit boiler is stopped, the other boiler operates and provides steam required by average load of the two turbo generators, if the minimum non-oil-throwing stable combustion load of the boiler is 40% MCR (rated evaporation capacity), the two turbo generators can operate with 20% ECR electric load on average, the deep peak regulation and the power response of the thermal power unit are better, and compared with a conventional load reduction peak regulation mode, the fuel oil consumption, the station power consumption and the heat loss are reduced.
Drawings
FIG. 1 is a schematic diagram of a steam system of a No. 1 unit of the present invention;
FIG. 2 is a schematic diagram of a steam system of a No. 2 unit according to the present invention
FIG. 3 is a schematic view of a condensate system according to the present invention.
Detailed Description
A deep peak shaving method based on main reheat steam communication of a thermal power plant comprises the following steps:
Step 1, assuming that the 2X 600MW units of the thermal power plant can be stably operated with 50% -100% ECR without oil, the lowest non-oil stable combustion load of the boiler is 40% MCR, when receiving an operation instruction of the whole plant according to 240MW (average load rate 20% ECR) total load, stopping the boiler with the No.1 unit, operating the steam turbine generator with 120MW load, operating the No. 2 unit with 40% -50% MCR, and operating the steam turbine generator with 120MW load, and performing subsequent description.
Step 2, the method takes the shutdown of the No. 1 unit and the 20% ECR load peak regulation operation of the turbogenerator as the target, and the steam and condensed water flows are shown in the figures 1 and 3: the method comprises the steps of (1) saturating steam of a No. 2 furnace superheater, (2) a first electric blocking valve 2' at the outlet B side of the No. 2 furnace superheater, (4 ') a first electric blocking valve 19 ' & gt a main steam connecting pipe 18 ' & gt a second electric door 17 ' & gt a No. 1 furnace superheater outlet branch pipe 4- & gt a No. 1 machine main steam main pipe 5- & gt a No. 1 machine high-pressure cylinder- & gt a No. 1 machine high-row check valve 7- & gt a No. 1 machine reheating cold section 9- & gt a third electric door 23- & gt a reheating cold section connecting pipe 24- & gt a fourth electric door 25- & gt a No. 2 machine reheating cold section 9' & gt a No. 2 furnace reheater inlet first electric blocking valve 10' and a second electric blocking valve 11' & gt No. 2 furnace reheater outlet second electric blocking valve 13' & gt No. 2 furnace reheater outlet second branch pipe 15' & gt a fifth electric connecting pipe 22- & gt a No. 1 machine reheating main pipe 21- & gt a sixth electric door 20- & gt a No. 1 furnace reheater outlet branch pipe 15- & gt a No. 1 machine reheating main pipe 16- & gt a No. 1 machine reheating heat section 16- & gt a No. 1 machine reheating heat pipe 2, a No. 2 electric machine reheating cold section 9' & gt a condenser 2 condenser, a No. 2 electric water pump, a No. 2 electric blocking valve, a No. 2 electric water pump, a No. 2 electric condenser, and a No. 2 electric condenser, a No. 2 condenser, and a No. 2 electric condenser, and a No. 2, and a condenser, and a No. 2 electric compressor, and a condenser, and a No. 2, and a valve 2, respectively, and, respectively.
Step 3, the method runs with 40% -50% of MCR of a No. 2 unit boiler and 20% of ECR load peak regulation of a No. 2 turbo generator, and steam and condensate flows are shown in the figures 1 and 3: the boiler No. 2 saturated steam- & gt boiler superheater No. 2, the second electric blocking valve 1 'at the outlet B side of the boiler superheater No. 2- & gt boiler superheater, the second outlet branch pipe 3' of the boiler superheater No. 2, the main steam main pipe 5 'of the boiler No. 2- & gt boiler high pressure cylinder No. 2 high-row check valve 7'), the reheating cold section 9 'of the boiler No. 2, the first electric blocking valve 10' at the inlet of the boiler reheater No. 2 and the second electric blocking valve 11 '& gt boiler reheater No. 2- & gt boiler reheater, the first electric blocking valve 12' at the outlet of the boiler reheater No. 2, the first branch pipe 14 'of the boiler reheater No. 2, the main pipe 16' of the reheating hot section of the boiler No. 2, the medium pressure cylinder (FIG. 3) & gt boiler condenser No. 2.
Step 4, as shown in fig. 1, the outlet branch pipe 4 of the boiler No.1 is communicated with the outlet branch pipe 4' of the boiler No.2 through a second electric door 17, a main steam communication pipe 18 and a first electric door 19, the pipe diameter ID of the communication pipe is 330.2 multiplied by 35.2mm, the second electric door 17 and the first electric door 19 are respectively provided with DN550 gate valves, and DN45 drain valves are arranged at the front and rear positions of the valves and the lower positions of the communication pipes; the reheating cooling section (9) of the No.1 machine is communicated with the re-cooling section (9') of the No.2 boiler through a reheating cooling section connecting pipe 24, a third electric door 23 and a fourth electric door 25, the diameter of the connecting pipe phi 863.6X119.05 mm, the third electric door 23 and the fourth electric door 25 are respectively provided with DN850 gate valves, and DN50 drain valves are arranged at the front and back of the valves and at the low positions of the connecting pipes; the outlet branch pipe 15 of the No.1 boiler reheater is communicated with the outlet branch pipe (15') of the No.2 boiler reheater through a connecting pipe 21, a sixth electric door 20 and a fifth electric door 22, the diameter ID of the connecting pipe is 679.5 multiplied by 34mm, the sixth electric door 20 and the fifth electric door 22 adopt DN750 gate valves, and DN50 drain valves are arranged at the front and rear positions of the valves and the lower positions of the connecting pipes; as shown in fig. 3, the electric recirculation door 27 of the condensation water of the machine No.1 and the electric recirculation door 28 of the condensation water of the machine No.1 are communicated with the electric recirculation door 2 'of the condensation water of the machine No.2 and the electric recirculation door 28' of the condensation water of the machine No.2 through a connecting pipe 29, a seventh electric door 30, an electric adjustment door 31 and an eighth electric door 32, wherein the diameter of the connecting pipe is phi 273 multiplied by 8.5mm, and the seventh electric door 30, the electric adjustment door 31 and the eighth electric door 32 are DN250 valves.
Step 5, the electric blocking valve of the boiler superheater, the electric blocking valve of the reheater inlet, the electric blocking valve of the reheater outlet and the electric valve are remotely operated and can be stopped, a pressure temperature measuring point is arranged on a steam connecting pipe, and a thermal monitoring control signal is connected to a unit DCS; the seventh electric door, the eighth electric door and the electric regulating door 31 of the condensate water system shown in fig. 3 are remote operation valves, and a thermal control signal is connected to the set DCS system.
And step 5, through the technical improvement, the method can realize the deep peak shaving operation based on the main reheat steam of the thermal power plant. The implementation process of the method is as follows:
When two units of the 2X 600MW thermal power plant are required to be reduced from 50% ECR load to 20% ECR load to participate in deep peak regulation of the power grid, the boiler is further described by maintaining pressure and stopping the boiler of No. 1.
Checking and confirming that the load of the two units and the pressure and the temperature of the over-reheat steam are basically consistent, slightly opening the first electric door 19 and the second electric door 17 of the main steam connecting pipe of the two boilers, slightly opening the fifth electric door 22 and the sixth electric door 20 of the reheat hot section connecting pipe, slightly opening the third electric door 23 and the fourth electric door 25 of the reheat cold section connecting pipe, and opening the related drain valve to connect the steam pipeline heating pipe;
when the temperature of the connecting pipe is close to the steam temperature of corresponding pipelines of the two units, the first electric door 19, the second electric door 17, the fifth electric door 22, the sixth electric door 20, the third electric door 23 and the fourth electric door 25 are gradually opened until the connecting pipe is fully opened, and all the drain doors of the reheat steam connecting pipe are closed;
The method comprises the steps of keeping 50% of MCR working conditions of a No. 2 boiler unchanged, reducing coal feeding quantity of a No. 1 boiler coal mill, starting to stop the No. 1 boiler, adjusting and controlling the power generation power, main steam pressure and reheat steam pressure of two units by using two steam turbine high-pressure regulating gates to be basically balanced, when the load of the two units is reduced to 40% ECR (240 MW), feeding the No. 1 boiler oil gun for supporting combustion in a short time, stopping the operation of the pulverizing system one by one, and strictly monitoring metal temperature change conditions of heating surfaces of the No. 1 boiler and a reheater in the load reducing process, and if the temperature rises, adjusting and closing corresponding flue gas baffles and accelerating the speed of the shutdown pulverizing system;
Under normal conditions, controlling the load reduction rate of two units to be 2MW/min, if a power grid is needed, controlling the load reduction rate to 12MW/min, and checking that a drain valve of a related steam system is required to be interlocked and opened according to a rule when the unit load is reduced to 30% ECR and 20% ECR;
The load reducing process of the No.1 boiler reduces the fuel quantity and stops operating the coal mill, the evaporation quantity of the boiler is reduced along with the load reducing process, when the pressure of the outlet header of the No.1 boiler superheater is lower than that of the main steam connecting pipe 18, the first electric blocking valve 1 and the second electric blocking valve 2 of the No.1 boiler superheater are adjusted to be closed, and the pressure difference is kept between 0.1 and 0.2MPa; when the pressure of the outlet header of the reheater is lower than the pressure of a reheating heat section connecting pipe 21, regulating and closing a second outlet electric blocking valve 13 of a first outlet electric blocking valve 12 of a reheater of a No.1 boiler, maintaining the pressure difference between 0.1 and 0.2MPa, maintaining the steam flow of each heating surface of the boiler, and controlling the metal temperature of each part of the reheater not to exceed the temperature by using the cooperation of the superheater of the boiler and a reheater baffle;
When the boiler No.1 is shut down, all oil guns are shut down, a draught fan is shut down after a hearth is purged, all air door baffles of the boiler No.1 air smoke system are closed, the operation of a boiler No.2 air preheater is reserved, and the boiler No.1 is shut down under pressure;
After the boiler No.1 is completely stopped, adjusting and closing a first electric blocking valve 1 and a second electric blocking valve 2 of a boiler superheater No.1, a first electric blocking valve 12 and a second electric blocking valve 13 of a reheater outlet, a first electric blocking valve 10 and a second electric blocking valve 11 of a reheater inlet, and stopping a steam-water feeding pump of a machine No.1, wherein the steam-water flow of two units is described in the step 2;
In the load adjustment process of the two machines, the water level of the condenser of the No. 1 machine set is monitored, and when the water level is high, the condensed water is conveyed back to the condenser of the No. 2 machine according to the procedures of the condensed water recycling electric door of the No. 1 machine, the seventh electric door, the electric adjustment door, the eighth electric door, the condensed water recycling adjustment door of the No. 2 machine and the condenser of the No. 2 machine;
and adjusting the load of the No. 2 boiler to 40-50% of MCR, maintaining the load of 20% of ECR of the two units, and adapting to the dispatching command.
Taking the boiler load of No. 2 of 40-50% of MCR, the two units with 20% of ECR load, the boiler pressure maintaining and furnace stopping state of No.1 as an example, and recovering 50% of ECR unit manufacturing modes of the two units respectively for further explanation;
Starting a No. 1 boiler induced draft fan and a blower, starting a No. 1 unit steam feed pump, feeding water to a boiler, blowing a hearth, then putting an oil gun into the hearth for ignition, checking and starting all drain valves of a No. 1 boiler side over-reheat steam system, starting a powder making system, and improving main reheat steam parameters;
adjusting and opening a first electric blocking valve at an inlet of a No.1 boiler reheater and a second electric blocking valve at an inlet, adjusting flue gas baffles at two sides of the reheater according to the temperature rise conditions of main steam and reheat steam, and controlling the temperature rise rate of the main steam and reheat steam to rise steadily at 2 ℃/min;
When the steam pressure and the steam temperature of the header at the outlet of the No.1 boiler reheater 1 are consistent with those of the reheating heat section connecting pipe, opening a first outlet electric blocking valve and a second outlet electric blocking valve of the reheater; when the steam pressure and the steam temperature of the outlet header of the No.1 boiler superheater are consistent with those of the main steam communication pipe, a first electric blocking valve and a second electric blocking valve of the No.1 boiler superheater are opened, and the No. 2 boiler is kept stable in running when the two unit steam systems are operated in parallel;
The method comprises the steps of adjusting the combustion of a No. 1 boiler, adding coal into a pulverizing system one by one to increase the amount of coal, adjusting two units in a matching way, increasing the total power according to a load rate of 30MW/min, and checking that the related drain valve of the superheated steam system is closed in an interlocking way when the load of the two units reaches 30% ECR;
When the loads of the two units reach 40% ECR, the load balance of the two boilers is adjusted, the first electric door and the second electric door, the fifth electric door and the sixth electric door and the third electric door are closed according to the pressure and the temperature of the cold section and the hot section of the main steam and the reheat steam are basically consistent, the No. 1 boiler fuel is completely stopped, the two units are converted into unit operation, and the load is gradually restored to 50% ECR operation.
A deep peak shaving method based on main reheat steam communication of a thermal power plant comprises the following steps: for a 2X 600MW thermal power plant, the on-site thermodynamic system is fully utilized, and the main steam, the reheating cold section, the reheating hot section steam system and the condensate system are transformed, when two units are required to be reduced in load to 20% ECR operation, the boiler belt of 1 unit can be adopted to operate without adding oil by 40% -50% of MCR, the boiler and related auxiliary machines of the other unit are stopped, the two turbo generators are both provided with 20% ECR modes, so that the deep peak regulation is realized, and the minimum peak regulation depth can reach the domestic better level.
The method is further described below with reference to the drawings and specific examples.
Example 1:
A depth peak regulation method based on main reheat steam communication of a thermal power plant comprises two main auxiliary machines and auxiliary systems of the thermal power plant, wherein as shown in figure 1, a No. 1 boiler superheater outlet branch pipe 4 is communicated with a No. 2 boiler superheater outlet branch pipe 4' through a second electric door 17 main steam connecting pipe 18 and a first electric door 19, the pipe diameter ID of the connecting pipe is 330.2 multiplied by 35.2mm, the material is A335P91, the second electric door 17 and the first electric door 19 are DN550 gate valves, the model is Z9R66H-P55190V, DN45 drain valves are arranged at the front and rear positions of the valves and the low positions of the connecting pipes, and the model is J61Y-P55190V; the reheating cold section (9) of the No. 1 machine is communicated with the re-cold section 9' of the No. 2 boiler through a reheating cold section connecting pipe 24, a third electric door 23 and a fourth electric door 25, the diameter of the connecting pipe phi 863.6X119.05 mm is A672B70CL32, the third electric door 23 and the fourth electric door 25 are DN850 gate valves, the model number is Z966H-P4150V, DN50 drain valves are arranged at the front and back of the valves and at the low point of the connecting pipe, and the model number is J61Y-50; the No. 1 boiler reheater outlet branch pipe 15 is communicated with the No. 2 boiler reheater outlet branch pipe 15' through a connecting pipe 21, a sixth electric door 20 and a fifth electric door 22, the pipe diameter ID of the connecting pipe is 679.5 multiplied by 34mm, the material is A335P91, DN750 gate valves are selected for the sixth electric door 20 and the fifth electric door 22, the model Z9R66H-P5550V is adopted, DN50 drain valves are arranged at the front and back of the valves and at the low point of the connecting pipe, and the model J61Y-P5550V is adopted; as shown in fig. 3, the electric door 27 for recycling condensation water of the machine No. 1 and the electric door 28 for recycling condensation water of the machine No. 1 are communicated with a pipeline between the electric door 27 'for recycling condensation water of the machine No. 2 and the electric door 28' for recycling condensation water of the machine No. 2 through a connecting pipe 29, a seventh electric door 30 and an eighth electric door 32, and an electric door 31, wherein the connecting pipe has a pipe diameter of phi 273 x 8.5mm, is made of 20 carbon steel, and the electric door 30, the eighth electric door 32 and the electric door 31 are DN250 valves, and the models are Z962N-P35C and Z962N-P35C; the electric blocking valve type Z960Y-3000Lbc9II of the boiler superheater, the electric blocking valve type Z966H-P4150V of the reheater inlet and the electric blocking valve type Z9R66H-P5550V of the reheater outlet shown in the figure 1 are all remotely operated and can be stopped valves, a pressure temperature measuring point is arranged on a steam connecting pipe, and a thermal monitoring control signal is connected to a unit DCS system; the seventh electric door, the eighth electric door and the electric regulating door 31) of the condensate water system shown in fig. 3) are used for remotely operating valves, and a thermal control signal is connected to a set DCS system. The method is implemented by a steam and condensate flow path: the method comprises the steps of saturating steam of a No. 2 furnace, a No. 2 furnace superheater outlet B side first electric blocking valve 2 '& gt, a No. 2 furnace superheater first outlet branch pipe 4' & gt, a first electric door 19 & gt, a main steam connecting pipe 18 & gt, a second electric door 17 & gt, a No. 1 furnace superheater outlet branch pipe 4 & gt, a No. 1 machine main steam main pipe 5 & gt, a No. 1 machine high pressure cylinder & gt, a No. 1 machine high-row check door 7 & gt, a No. 1 machine reheating cold section 9 & gt, a third electric door 23 & gt, a reheating cold section connecting pipe 24 & gt, a fourth electric door 25 & gt, a No. 2 machine reheating cold section 9 & gt, a No. 2 furnace reheater inlet first electric blocking valve 10 'and a second electric door. The blocking valve 11' →the furnace reheater No. 2→the second electric blocking valve 13 'at the outlet of the furnace reheater No. 2→the second branch pipe 15' at the outlet of the furnace reheater No. 2→the fifth electric door 22→the reheat heat section connecting pipe 21→the sixth electric door 20→the outlet branch pipe of the furnace reheater No. 1→the main pipe of the reheat heat section of the machine No. 1→the middle pressure cylinder of the machine No. 1→the low pressure cylinder of the machine No. 1 (fig. 3) →the condenser of the machine No. 1→the condensate pump of the machine No. 1→the condensate recycling electric door of the machine No. 1→the seventh electric door→the electric regulating door→the eighth electric door→the condensate recycling regulating door of the machine No. 2; the operation modes of the two units are interchangeable; the method can enable the peak regulation adaptability and the peak regulation depth of the thermal power plant to reach a better level, and can reduce the consumption of fuel oil and plant power consumption compared with load peak regulation.
The initial working conditions of the two units of the 2X 600MW thermal power plant are as follows: the unit manufacturing modes of the two units are respectively operated with 50% ECR load, the load of the units is required to be reduced to 20% ECR according to the command, the unit is involved in deep peak regulation of a power grid, and the boiler No.1 is arranged to maintain pressure and stop when the unit manufacturing mode is executed;
Checking and confirming that the load of the two units and the pressure and temperature of the over-reheat steam are basically consistent, slightly opening the first electric door and the second electric door of the main steam connecting pipe of the two boilers, slightly opening the fifth electric door and the sixth electric door of the reheat hot section connecting pipe, slightly opening the third electric door and the fourth electric door of the reheat cold section connecting pipe, and opening the related drain valve to connect the steam pipeline heating pipe;
when the temperature of the connecting pipe is close to the steam temperature of corresponding pipelines of the two units, the first electric door, the second electric door, the fifth electric door, the sixth electric door, the third electric door and the fourth electric door are gradually opened until the connecting pipe is fully opened, and all the drain doors of the reheat steam connecting pipe are closed;
The method comprises the steps of keeping 50% of MCR working conditions of a No. 2 boiler unchanged, reducing coal feeding quantity of a No. 1 boiler coal mill, starting to stop the No. 1 boiler, adjusting and controlling the power generation power, main steam pressure and reheat steam pressure of two units by using two steam turbine high-pressure regulating gates to be basically balanced, when the load of the two units is reduced to 40% ECR (240 MW), feeding the No. 1 boiler oil gun for supporting combustion in a short time, stopping the operation of the pulverizing system one by one, and strictly monitoring metal temperature change conditions of heating surfaces of the No. 1 boiler and a reheater in the load reducing process, and if the temperature rises, adjusting and closing corresponding flue gas baffles and accelerating the speed of the shutdown pulverizing system;
Controlling the load reduction rate of the two units to be 2-12 MW/min according to the requirement, and checking that the drain valve of the related steam system should be interlocked and opened according to the regulation when the load of the units is reduced to 30% ECR and 20% ECR;
The load reducing process of the No. 1 boiler reduces the fuel quantity and stops the coal mill, when the pressure of an outlet header of the No. 1 boiler superheater is lower than that of a main steam communication pipe, a first electric blocking valve and a second electric blocking valve of the No. 1 boiler superheater are adjusted to be closed, and the pressure difference is kept to be 0.1-0.2 MPa; when the pressure of the outlet header of the reheater is lower than the pressure of a connecting pipe of a reheating heat section, regulating and closing a first outlet electric blocking valve and a second outlet electric blocking valve of a No. 1 boiler reheater, keeping the pressure difference between 0.1 and 0.2MPa, maintaining the steam flow of each heating surface of the boiler, and controlling the metal temperature of each part of the reheater not to exceed the temperature by using the cooperation of the superheater of the boiler and a baffle of the reheater;
When the boiler No.1 is shut down, all oil guns are shut down, a draught fan is shut down after a hearth is purged, all air door baffles of the boiler No.1 air smoke system are closed, the operation of a boiler No.2 air preheater is reserved, and the boiler No.1 is shut down under pressure;
After the boiler No. 1 is completely stopped from fuel, adjusting and closing a first electric blocking valve and a second electric blocking valve of a boiler No. 1 superheater, a first outlet electric blocking valve and a second outlet electric blocking valve of a reheater, a first electric blocking valve of a reheater inlet and a second electric blocking valve of the inlet, and stopping a steam feed pump of the boiler No. 1;
In the load adjustment process of the two machines, the water level of the condenser of the No. 1 machine set is monitored, and when the water level is high, the condensed water is conveyed back to the condenser of the No. 2 machine according to the procedures of the condensed water recycling electric door of the No. 1 machine, the seventh electric door, the electric adjustment door, the eighth electric door, the condensed water recycling adjustment door of the No. 2 machine and the condenser of the No. 2 machine;
and adjusting the load of the No. 2 boiler to 40-50% of MCR, maintaining the load of 20% of ECR of the two units, and adapting to the dispatching command.
Example 2:
The current working condition of the thermal power plant is that the No. 2 boiler load is 40% -50% of MCR, the two units are respectively provided with 20% of ECR load, the No. 1 boiler pressure maintaining and furnace stopping state is taken as an example, and the 50% ECR unit manufacturing modes of the two units are required to be recovered;
Starting a No. 1 boiler induced draft fan and a blower, starting a No. 1 unit steam feed pump, feeding water to a boiler, blowing a hearth, then putting an oil gun into the hearth for ignition, checking and starting all drain valves of a No. 1 boiler side over-reheat steam system, starting a powder making system, and improving main reheat steam parameters;
The first electric blocking valve 10 and the second electric blocking valve 11 at the inlet of the No. 1 boiler reheater are adjusted and opened, the flue gas baffles at two sides of the reheater are adjusted according to the temperature rising conditions of the main steam and the reheat steam, and the temperature rising rate of the main steam and the reheat steam is controlled to be 2 ℃/min to be steadily increased;
When the steam pressure and the steam temperature of the outlet header of the No. 1 boiler reheater are consistent with those of the connecting pipe of the reheating heat section 21, opening a first outlet electric blocking valve 12 and a second outlet electric blocking valve 13 of the reheater; when the steam pressure and the steam temperature of the outlet header of the No. 1 boiler superheater are consistent with those of the main steam communication pipe 18, a first electric blocking valve 1 and a second electric blocking valve 2 of the No. 1 boiler superheater are opened, and when two unit steam systems are operated in parallel, the No. 2 boiler is kept to operate stably;
The method comprises the steps of adjusting the combustion of a No. 1 boiler, adding coal into a pulverizing system one by one to increase the amount of coal, adjusting two units in a matching way, increasing the total power according to a load rate of 30MW/min, and checking that the related drain valve of the superheated steam system is closed in an interlocking way when the load of the two units reaches 30% ECR;
When the loads of the two units reach 40% ECR, the load balance of the two boilers is adjusted, the pressures and the temperatures of the cold and hot sections of the main steam and the reheat steam are basically consistent, the first electric door and the second electric door, the fifth electric door and the sixth electric door, the third electric door and the fourth electric door are closed, the No. 1 boiler fuel is completely stopped, the two units are converted into unit operation, and the load is gradually restored to 50% ECR operation.
The running boiler is provided with 40% -50% of MCR, the two turbo generators are operated with 20% of ECR electric power, and as the two turbo generators have certain idle load and power consumption and are not completely the same, the actual load of the running boiler is higher than the minimum steady combustion working condition designed by 40% of MCR, thereby being beneficial to the safe running of the boiler.
The pressure and the temperature of the cold and hot sections of the main steam and the reheat steam are basically consistent, when in practical application, the steam pressure deviation is about 0.2MPa, and the temperature deviation is 20-30 ℃ and can be regarded as consistent, and the steam merging operation is carried out.
The investment of the technical improvement funds is less, the method is embodied in that the method only uses the common pipelines and valves of the power station to carry out transformation, the large-scale heat storage and electricity storage equipment is not required to be added, the transformation of low-load operation of the burner is not required, and the like, and meanwhile, the degree of long-time deviation of the main machine and the auxiliary machine from the design operation can be improved.
The invention can save a great amount of peak-shaving fuel oil and station service electricity, and is characterized in that the oil feeding time is reduced by more than 4 hours in the process of reducing load and recovering the boiler by 8 hours in the peak-shaving time of each day compared with the conventional peak-shaving mode, the ignition, heating and boosting time of the hot furnace can be shortened when the boiler is stopped during pressure maintaining, the steam turbine is in the state of running with load, the complex operation of the steam turbine is avoided, and the time consumption of the recovery process is reduced.
Claims (6)
1. The deep peak shaving method based on the main reheat steam communication of the thermal power plant comprises two units for configuring main and auxiliary machines and an auxiliary thermodynamic system of the thermal power plant, and is characterized in that: the method uses common pipelines and valves of a power station to implement communication transformation on the existing main steam, reheat cold section and hot section steam systems, adopts a method that one unit boiler is stopped and the other boiler operates by 40% -50% of MCR so as to provide steam required by two steam turbine generators with 20% of ECR electric load operation, and realizes deep peak regulation without oil feeding of a thermal power unit;
The method specifically comprises the following steps:
Step 1, a thermal power plant operation mode and a working medium flow; setting a steam and condensed water flow path;
Step 2, steam-water system configuration selection and technical transformation are carried out;
the method for carrying out steam-water system configuration selection and technical transformation in the step 2 comprises the following steps:
Step A: the outlet branch pipe (4) of the No. 1 boiler superheater is communicated with the outlet branch pipe (4') of the No. 2 boiler superheater through a second electric door (17), a main steam connecting pipe (18) and a first electric door (19), the pipe diameter ID of the main steam connecting pipe (18) is 330.2 multiplied by 35.2mm, DN550 gate valves are selected for the second electric door (17) and the first electric door (19), and DN45 drain valves are arranged at the front and back of the valves and at the low point of the main steam connecting pipe (18);
B, a reheating cold section (9) of a No. 1 machine is communicated with a No. 2 boiler re-cold section (9') through a reheating cold section connecting pipe (24), a third electric door (23) and a fourth electric door (25), the diameter phi of the reheating cold section connecting pipe (24) is 863.6X19.05 mm, DN850 gate valves are selected for the third electric door (23) and the fourth electric door (25), and DN50 drain valves are arranged at the front and back of the valves and at the low point of the reheating cold section connecting pipe (24);
Step C, a No. 1 boiler reheater outlet branch pipe (15) is communicated with a No. 2 boiler reheater outlet branch pipe (15') through a reheating heat section connecting pipe (21), a sixth electric door (20) and a fifth electric door (22), the diameter ID of the reheating heat section connecting pipe (21) is 679.5 multiplied by 34mm, DN50 drain valves are arranged at the front and rear positions of the valves and the lower position of the reheating heat section connecting pipe (21) by selecting DN750 gate valves for the sixth electric door (20) and the fifth electric door (22);
D, a communication pipe (29), a seventh electric door (30), an electric regulating door (31) and an eighth electric door (32) are communicated with the No. 2 machine condensate water recycling electric door (27 ') and the No. 2 machine condensate water recycling regulating door (28') through pipelines, the pipe diameter of the communication pipe is phi 273 multiplied by 8.5mm, and DN250 valves are selected for the seventh electric door (30), the electric regulating door (31) and the eighth electric door (32);
step 3, determining the thermal measurement and control requirements;
Step4, determining the operation modes of two units of the thermal power plant;
the operation modes of the two units of the thermal power plant comprise:
Step 1, when two units of a thermal power plant are configured to be reduced from 50% ECR load to 20% ECR load and participate in deep peak regulation of a power grid, maintaining pressure and stopping a furnace by a boiler No.1, and carrying out operation adjustment by a boiler No.2 with two steam turbine generators;
Step 2, checking and confirming that the load, the pressure and the temperature of the excess and the reheat steam of the two units are consistent, slightly opening a first electric door (19) and a second electric door (17) of a main steam connecting pipe of the two boilers, slightly opening a fifth electric door (22) and a sixth electric door (20) of a reheat hot section connecting pipe, slightly opening a third electric door (23) and a fourth electric door (25) of a reheat cold section connecting pipe, and opening a related drain valve to connect a steam pipeline heating pipe; the opening degree of the micro-opening is not more than 20-30% of the full-opening;
Step 3, when the temperatures of the main steam connecting pipe (18), the reheating hot section connecting pipe (21) and the reheating cold section connecting pipe (24) are close to the temperatures of corresponding pipelines of the two units, the first electric door (19) and the second electric door (17), the fifth electric door (22) and the sixth electric door (20), the third electric door (23) and the fourth electric door (25) are gradually opened until the main steam connecting pipe, the reheating hot section connecting pipe and the reheating cold section connecting pipe are fully opened, and the drain doors at all positions of the reheating steam connecting pipe are closed; the temperature approach means that the temperature difference is not more than 5%;
Step 4, keeping 50% MCR working condition of the No. 2 boiler unchanged, reducing coal feeding amount of a No. 1 boiler coal mill, starting to stop the No. 1 boiler operation, adjusting and controlling power generation, main steam pressure and reheat steam pressure balance of two units by using two steam turbine high-pressure regulating gates, when the load of the two units is reduced to 40% ECR, putting the No. 1 boiler oil gun into combustion supporting, stopping the powder making system one by one, monitoring metal temperature change conditions of heating surfaces of each part of the No. 1 boiler and the reheater in the load reducing process, and adjusting and closing corresponding flue gas baffles and accelerating the speed of the powder making system in a stop mode when the temperature rises;
step 5, controlling the load reduction rate of the two units to be 2MW/min to 12MW/min;
Step 6, after the whole pulverizing system of the boiler No. 1 is stopped, stopping all oil guns, stopping delivering induced draft fans after a hearth is purged, closing all air door baffles of an air smoke system of the boiler No. 1, keeping the air preheater of the boiler No. 1 to operate, and keeping the pressure of the boiler No. 1 and stopping the boiler;
Step 7, after the boiler No.1 is completely stopped, adjusting and closing a first electric blocking valve (1) and a second electric blocking valve (2) of a boiler superheater No.1, a first electric blocking valve (12) and a second electric blocking valve (13) of a reheater outlet, a first electric blocking valve (10) and a second electric blocking valve (11) of a reheater inlet, and stopping a steam feed pump of the machine No. 1;
step 8, adjusting the load of the No. 2 boiler to 40% -50% MCR, maintaining the load of 20% ECR of the two units, and adapting to the dispatching command;
Step 9, the operation of 50% ECR unit production modes of the two steam turbine generator units is restored to be controlled by using 40% -50% of MCR of the No.2 boiler load and 20% of ECR load of the two steam turbine generator units in a boiler pressure maintaining and stopping state of the No. 1 boiler;
Step 10, starting a boiler induced draft fan No. 1 and a blower, starting a steam feed pump of a unit No. 1, feeding water to a boiler, blowing a hearth, then putting into an oil gun for ignition, checking and starting all drain valves of a boiler side passing and reheating steam system No. 1, starting a pulverizing system, and improving main reheating steam parameters;
Step 11, adjusting and opening a first electric blocking valve (10) and a second electric blocking valve (11) at an inlet of a No. 1 boiler reheater, and adjusting flue gas baffles at two sides of the reheater according to the temperature rising conditions of main steam and reheat steam to control the temperature rising rate of the main steam and reheat steam to rise at 2 ℃/min;
Step 12, when the steam pressure and the steam temperature of the outlet header of the No. 1 boiler reheater are consistent with those of the reheating heat section connecting pipe (21), opening a first outlet electric blocking valve (12) and a second outlet electric blocking valve (13) of the reheater; when the steam pressure and the steam temperature of the outlet header of the No. 1 boiler superheater are consistent with those of the main steam communication pipe (18), a first electric blocking valve (1) and a second electric blocking valve (2) of the No. 1 boiler superheater are opened, and when two unit steam systems are operated in parallel, the No. 2 boiler is kept stable in operation;
Step 13, adjusting the combustion of a No.1 boiler, adding coal into a pulverizing system one by one to increase the amount of coal, adjusting two units in a matched manner, increasing the total power according to the load rate of 30MW/min, and when the load of the two units reaches 30% ECR, checking that the drain valve of the steam system after inspection and reheating should be closed in an interlocking manner;
And 14, when the loads of the two units reach 40% ECR, adjusting the load balance of the two boilers, closing the first electric door (19), the second electric door (17), the fifth electric door (22), the sixth electric door (20), the third electric door (23) and the fourth electric door (25) according to the pressure and the temperature of the cold section and the hot section of the main steam and the reheat steam, turning the two units into unit operation, and gradually recovering the load to 50% ECR operation.
2. The deep peak shaving method based on main reheat steam communication of thermal power plants according to claim 1, wherein the method is characterized in that: the setting of the steam and condensate flows in step 1 comprises: the method aims at the shutdown of the No. 1 unit and the peak load regulation operation of the turbine generator with 20% ECR, and the flow of steam and condensate water is as follows: furnace No. 2 saturated steam, furnace No. 2 superheater outlet B side first electric block valve (2 '), furnace No. 2 superheater outlet branch pipe (4 '), first electric door (19), main steam connecting pipe (18), second electric door (17), furnace No. 1 superheater outlet branch pipe (4), machine No. 1 main steam main pipe (5), machine No. 1 high pressure cylinder, machine No. 1 high-row check valve (7), machine No. 1 reheat cold section (9), third electric door (23), reheat cold section connecting pipe (24), fourth electric door (25), boiler No. 2 reheat cold section (9 '), furnace No. 2 reheater inlet first electric block valve (10 ') and second electric block valve 11 '), a No. 2 furnace reheater outlet second electric blocking valve (13 '), a No. 2 boiler reheater outlet branch pipe (15 '), a fifth electric door (22), a reheat hot section connecting pipe (21), a sixth electric door (20), a No. 1 boiler reheater outlet branch pipe (15), a No. 1 machine reheat hot section main pipe (16), a No. 1 machine middle pressure cylinder, a No. 1 machine low pressure cylinder, a No. 1 machine condenser, a No. 1 machine condensate pump (26), a No. 1 machine condensate recycling electric door (27), a seventh electric door (30), an electric regulating door (31), an eighth electric door (32), a No. 2 machine condensate recycling regulating door (28) and a No. 2 machine condenser.
3. The deep peak shaving method based on main reheat steam communication of thermal power plants according to claim 1, wherein the method is characterized in that: the setting of the steam and condensate flows in step 1 comprises: the boiler of the No. 2 unit operates with 40-50% of MCR and the No. 2 turbo generator operates with 20% of ECR load peak regulation, and the flow of steam and condensate water is as follows: the method comprises the steps of (1 ') of a No. 2 furnace saturated steam, (2) a No. 2 furnace superheater, (1 ') of a second electric blocking valve on the B side of an outlet of the No. 2 furnace superheater, (3 ') of a second outlet branch pipe of the No. 2 furnace superheater, (5 ') of a main steam main pipe of the No. 2 machine, (2) a high-pressure cylinder of the No. 2 machine, (7 ') of a high-row check valve of the No. 2 boiler, (9 ') of a cooling section, (10 ') of an inlet of a No. 2 furnace reheater, (11 ') of a first electric blocking valve, (12 ') of an outlet of the No. 2 furnace reheater, (14 ') of an outlet of the No. 2 furnace reheater, (16 ') of a main pipe of a reheating heat section of the No. 2 machine, (2) of a condenser of the No. 2 machine.
4. The deep peak shaving method based on main reheat steam communication of thermal power plants according to claim 1, wherein the method is characterized in that: and 3, determining the thermal measurement and control requirements as follows: the electric blocking valve of the boiler superheater, the electric blocking valve of the reheater inlet, the electric blocking valve of the reheater outlet and the electric door are remotely operated and can be stopped, pressure and temperature measuring points are arranged on a main steam connecting pipe (18), a reheating hot section connecting pipe (21) and a reheating cold section connecting pipe (24), and a thermal monitoring control signal is connected to a unit DCS (distributed control system) to realize remote monitoring and operation; the seventh electric door, the eighth electric door and the electric regulating door (31) of the condensation water system are remote operation valves, and a thermal control signal is connected to a DCS (distributed control system) of the unit to realize remote monitoring and operation.
5. The deep peak shaving method based on main reheat steam communication of thermal power plants according to claim 1, wherein the method is characterized in that: during the load reduction process of the No. 1 boiler, the fuel amount is reduced, the coal mill is stopped, the boiler evaporation amount is reduced along with the reduction, and when the pressure of the outlet header of the No. 1 boiler superheater is lower than that of a main steam connecting pipe (18), the first electric blocking valve (1) and the second electric blocking valve (2) of the No. 1 boiler superheater are adjusted to be closed, and the pressure difference is kept between 0.1 MPa and 0.2MPa; when the pressure of the outlet header of the reheater is lower than the pressure of a reheating heat section connecting pipe (21), regulating and closing a first outlet electric blocking valve (12) and a second outlet electric blocking valve (13) of the reheater of the No. 1 boiler, maintaining the pressure difference between 0.1 and 0.2MPa, maintaining the steam flow of each heating surface of the boiler, and controlling the metal temperature of each part of the reheater and the passing boiler not to exceed the temperature by matching regulation of the superheater and the reheater baffle of the boiler.
6. The deep peak shaving method based on main reheat steam communication of thermal power plants according to claim 1, wherein the method is characterized in that: in the load adjustment process of the two units, the water level of the No. 1 unit condenser is monitored, and when the water level is ultrahigh, the condensed water is conveyed back to the No.2 unit condenser according to the condensed water recycling electric door (27), the seventh electric door (30), the electric adjustment door (31), the eighth electric door (32), the condensed water recycling adjustment door (28') of the No.2 unit and the No.2 unit condenser.
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| CN113175363A (en) * | 2021-04-25 | 2021-07-27 | 西安热工研究院有限公司 | Master pipe connection system for adjusting high-pressure cylinder to do work and operation method |
| CN113175362A (en) * | 2021-04-25 | 2021-07-27 | 西安热工研究院有限公司 | Bus pipe connection system for realizing zero output of low-pressure cylinder and operation method |
| CN113175360A (en) * | 2021-04-25 | 2021-07-27 | 西安热工研究院有限公司 | Bus pipe connection system for improving deep peak shaving low-pressure cylinder efficiency and operation method |
| CN113250767A (en) * | 2021-04-25 | 2021-08-13 | 西安热工研究院有限公司 | Four-pipeline main pipe connection system for deep peak shaving and operation method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113175363A (en) * | 2021-04-25 | 2021-07-27 | 西安热工研究院有限公司 | Master pipe connection system for adjusting high-pressure cylinder to do work and operation method |
| CN113175362A (en) * | 2021-04-25 | 2021-07-27 | 西安热工研究院有限公司 | Bus pipe connection system for realizing zero output of low-pressure cylinder and operation method |
| CN113175360A (en) * | 2021-04-25 | 2021-07-27 | 西安热工研究院有限公司 | Bus pipe connection system for improving deep peak shaving low-pressure cylinder efficiency and operation method |
| CN113250767A (en) * | 2021-04-25 | 2021-08-13 | 西安热工研究院有限公司 | Four-pipeline main pipe connection system for deep peak shaving and operation method |
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