CN117231975A - Control method for water supply temperature of high-temperature gas cooled reactor - Google Patents

Abstract

The invention provides a control method for the water supply temperature of a high-temperature gas cooled reactor, and belongs to the technical field of nuclear power. The control method comprises the following steps: steam generated by an auxiliary electric boiler is respectively fed into a deaerator and a feed water heater through an auxiliary steam header, the feed water heater is drained to the deaerator, and the rotating speed of a main helium fan is adjusted to enable the temperature of a reactor core to be raised to 200-230 ℃; stopping dewatering the feed water heater to the deaerator, and after the steam generator stably outputs the main steam, cooling and decompressing the main steam, and then heating the main steam to the deaerator to supply water; when the steam extraction of the steam turbine meets the requirement of water supply heating, the primary steam extraction and the secondary steam extraction are utilized to heat the water supply heater and the deaerator respectively, the auxiliary electric boiler is stopped, and the main steam is used as a standby heating steam source after temperature and pressure reduction. The invention meets the requirement of water supply heating through auxiliary electric boilers, main steam temperature and pressure reduction and steam extraction heating of the steam turbine, and realizes the stability of water supply temperature through the cooperation between different steam sources, so that the temperature of a reactor core before the high-temperature reactor is started reaches more than 200 ℃.

Description

Control method for water supply temperature of high-temperature gas cooled reactor

Technical Field

The invention belongs to the technical field of nuclear power, and particularly relates to a control method of water supply temperature of a high-temperature gas cooled reactor.

Background

The process of establishing the balance core of the high-temperature reactor gas cooled reactor needs to go through the primary reactor core and the transition core. The primary installed core is formed by mixing 7 parts of low-enrichment fuel elements and 8 parts of graphite elements, and the enrichment degree of the low-enrichment fuel elements is 4.2%. The transition process is from the initial reactor core to all fuel balls with low enrichment degree, to the fuel balls with low enrichment degree and the fuel balls with high enrichment degree, and finally to all fuel elements with high enrichment degree.

The transition reactor core stage needs 2-3 years, and in the operation process of the primary reactor core and the transition reactor core, the power distribution distortion can be caused due to the difference of the distribution of the fuel elements, graphite nodules and the fuel elements with different enrichment degrees in the reactor core, so that the power peak factor is larger than that of the balance reactor core, and the temperature of the fuel elements is higher than the design value. The increased core temperature consumes some of the remaining reactivity, resulting in the need to add more fuel spheres to maintain the reactor operating at higher power, which has the effect of post-emergency shutdown supplemental fuel sphere increased remaining reactivity such that the reactor needs to raise the core temperature above 200 ℃ before critical to introduce negative reactivity for safe and stable start-up.

According to the current design, the water supply flow entering the steam generator before critical is 36kg/s, the steam generated by the auxiliary electric boiler heats the water supply of the deaerator, the maximum temperature can reach 160 ℃, the reactor core temperature can not be ensured to be raised to more than 200 ℃ by the operation of the main helium fan before critical of the reactor, and the safe and stable starting after emergency shutdown is ensured.

Disclosure of Invention

The invention aims to at least solve one of the technical problems in the prior art and provides a control method for the water supply temperature of a high-temperature gas cooled reactor.

The invention provides a control method of the water supply temperature of a high-temperature gas cooled reactor, wherein the water supply temperature control system of the high-temperature gas cooled reactor comprises a reactor, a steam generator, a main helium fan, an auxiliary electric boiler, an auxiliary steam header, a water supply heater and a deaerator; wherein;

the reactor is connected with the steam generator, the main helium fan is arranged on the steam generator, the steam generator is connected with a steam turbine steam extraction pipeline through a main steam pipeline, the auxiliary steam header is sequentially communicated with the main steam pipeline of the steam generator, the auxiliary electric boiler, the deaeration steam pipeline and the feed water heater through a main steam supply pipeline, an auxiliary electric boiler steam supply pipeline and a feed water heater steam inlet pipeline respectively, the feed water heater is communicated with the deaerator through a drain pipeline, and the main steam supply pipeline is provided with a temperature and pressure reducing valve group; the control method comprises the following steps:

before a unit is started, steam generated by the auxiliary electric boiler is respectively fed into the deaerator and the feed water heater through the auxiliary steam header, the feed water heater is drained to the deaerator so as to control the feed water temperature to be 190 ℃, and then the temperature of the reactor core is raised to 200-230 ℃ by adjusting the main helium fan to a preset rotating speed;

after the reactor power reaches the preset power, the feed water heater stops draining water to the deaerator so as to maintain the feed water temperature at 140 ℃, after the steam generator stably outputs main steam, the main steam is subjected to temperature and pressure reduction and then enters the deaerator through the auxiliary steam header to heat the feed water, and the auxiliary electric boiler is used as a standby heating steam source;

when the steam extraction of the steam turbine meets the requirement of water supply heating, the steam extraction pipeline of the steam turbine is utilized to heat the water supply heater and the deaerator respectively, the auxiliary electric boiler is stopped, and the main steam generated by the steam generator is used as a standby heating steam source after temperature and pressure reduction.

Optionally, an oxygen removal steam regulating valve is arranged on the oxygen removal steam pipeline, and a heating steam regulating valve is arranged on the steam inlet pipeline of the feed water heater; wherein,

the opening degree of the deoxidizing steam regulating valve is regulated to control the steam quantity entering the deoxidizer;

and controlling the steam quantity entering the feedwater heater by adjusting the opening of the heating steam regulating valve.

Optionally, the preset rotating speed range of the main helium fan is 75kg/s-100kg/s.

Optionally, the feed water flow is maintained at 15-20kg/s before the unit is started.

Optionally, the main steam pipeline is also communicated with a bypass steam pipeline, and a bypass valve is arranged on the bypass steam pipeline;

after the steam generator stably outputs main steam, maintaining the outlet pressure of the steam generator to be a preset pressure value through the side discharge valve.

Optionally, a primary steam extraction pipeline is connected between the main steam pipeline and the steam inlet pipeline of the feedwater heater, and a steam turbine steam inlet valve group is arranged on the primary steam extraction pipeline; wherein,

after the temperature and pressure of the main steam output by the steam generator meet the turbine turning requirement, slowly closing the side exhaust valve, and opening the turbine steam inlet valve group to control the outlet pressure of the steam generator to be a preset pressure value, and enabling the main steam to enter the turbine to generate electricity.

Optionally, a first-stage steam extraction isolation valve is arranged on the first-stage steam extraction pipeline, a second-stage steam extraction pipeline is connected between the low-pressure cylinder steam inlet pipeline and the deaerator, and a second-stage steam extraction isolation valve is arranged on the second-stage steam extraction pipeline;

the heating of the feedwater heater and the deaerator respectively by utilizing the steam extraction pipeline of the steam turbine comprises the following steps:

opening the primary steam extraction isolation valve, heating steam to a feed water heater through the primary steam extraction pipeline, closing the deoxidized steam regulating valve, and maintaining the outlet temperature of the feed water heater at 140 ℃;

after the feed water heater is put into use, the deoxidizing steam regulating valve is closed, the secondary steam extraction isolation valve is opened, and steam is heated to the deoxidizer through the secondary steam extraction pipeline so as to maintain the temperature of the deoxidizer stable.

Optionally, the control method further includes:

when the steam turbine trips or gets rid of load, the primary steam extraction isolation valve and the secondary steam extraction isolation valve are closed in an interlocking way, and the deoxidizing steam regulating valve and the heating steam regulating valve are opened to the opening corresponding to the preset temperature;

the temperature and pressure reducing valve group is automatically adjusted to maintain the pressure and the temperature of the auxiliary steam header stable, so that partial main steam is reduced in temperature and pressure and then supplied to the deaerator and the feed water heater, and the temperature of the feed water is maintained stable.

Optionally, the bypass steam pipeline is also connected with a condenser, and the control party

The method further comprises the steps of:

when the turbine jumps or gets rid of load, the side discharge valve is quickly opened, main steam is discharged into the condenser, and the outlet pressure of the steam generator is maintained to be a preset pressure value.

The invention provides a control method of water supply temperature of a high-temperature gas cooled reactor, which comprises the following steps: before a unit is started, steam generated by the auxiliary electric boiler is respectively fed into the deaerator and the feed water heater through the auxiliary steam header, the feed water heater is drained to the deaerator so as to control the feed water temperature to be 190 ℃, and then the temperature of the reactor core is raised to 200-230 ℃ by adjusting the rotating speed of the main helium fan to a preset rotating speed; after the reactor power reaches the preset power, the feed water heater stops draining water to the deaerator so as to maintain the feed water temperature at 140 ℃, after the steam generator stably outputs main steam, the main steam is subjected to temperature and pressure reduction and then enters the deaerator through the auxiliary steam header to heat the feed water, and the auxiliary electric boiler is used as a standby heating steam source; when the steam turbine extraction meets the requirement of water supply heating, the primary extraction steam and the secondary extraction steam are utilized to heat the water supply heater and the deaerator respectively, the auxiliary electric boiler is stopped, the main steam generated by the steam generator is used as a standby heating steam source after being subjected to temperature and pressure reduction, the water supply heating requirement is met through the auxiliary electric boiler, the main steam is subjected to temperature and pressure reduction and the steam turbine extraction steam heating in the unit operation process, the water supply temperature is stable through the cooperation between different steam sources, and the core temperature reaches more than 200 ℃ before the high-temperature reactor is started.

Drawings

FIG. 1 is a schematic diagram of a feedwater temperature control system for a high temperature gas cooled reactor according to an embodiment of the present invention;

FIG. 2 is a flow chart of a method for controlling the feed water temperature of a high temperature gas cooled reactor according to another embodiment of the invention;

Detailed Description

The present invention will be described in further detail below with reference to the drawings and detailed description for the purpose of better understanding of the technical solution of the present invention to those skilled in the art. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by a person skilled in the art without creative efforts, based on the described embodiments of the present invention belong to the protection scope of the present invention.

It should be noted that, based on the conventional water supply control method at present, the requirement of higher water supply temperature when the high-temperature stack is started and stable water supply temperature in transient state cannot be met; because the modularized high-temperature gas cooled reactor is provided with two or more reactors, the auxiliary electric boiler has limited heating and water feeding capacity based on the conventional control method at present, and can only be started to full power when a single reactor is started, and the steam turbine can provide steam extraction and heating water feeding when being provided with a certain load, so that the whole machine set needs longer time and has poorer economic benefit; in addition, as the high-temperature gas cooled reactor steam generator is a direct current heat exchanger, the internal water storage is about 10t, the heat storage quantity is small, the temperature of an outlet tube plate reaches 520 ℃ when the rated power is in operation, cold and hot impact can be caused on the steam generator when the water supply temperature greatly fluctuates, the requirement on the stability of the water supply temperature is higher, at present, a steam turbine is used for extracting steam to heat the water supply in the normal operation process of a unit, the temperature of the water supply is rapidly reduced from 200 ℃ to 30 ℃ when the steam turbine is in transient working conditions such as load shedding or tripping, and the like, and exceeds the temperature rising and falling rate (10 ℃/h) of the design of the steam generator, the cold impact is caused on the steam generator, and the service life of the steam generator is reduced.

In view of this, the invention improves the connection relationship among deaerators, feedwater heaters, auxiliary steam headers and steam generators. The connection relation of the high temperature gas cooled reactor water supply temperature control system is as shown in fig. 1, the reactor 4 is connected with the steam generator 3, the main helium fan 5 is arranged on the steam generator 3, the steam generator 3 is communicated with all structures through a main steam pipeline 21, for example, a main steam supply pipeline 29 is connected on the main steam pipeline 21, an auxiliary steam header 12 is communicated with the steam generator 3 through the main steam supply pipeline 29, in addition, the auxiliary steam header 12 is also communicated with the auxiliary electric boiler 13 through an auxiliary electric boiler steam supply pipeline 27, the auxiliary steam header 12 is also communicated with the deaerator 1 through a deaeration steam pipeline 28, and the auxiliary steam header 12 is also communicated with the feed water heater 2 through a feed water heater steam inlet pipeline 30; the feedwater heater 2 communicates with the deaerator 1 via a water drain line 20, and the feedwater heater 2 communicates with the steam generator 3 via a main feedwater line 19.

Further, referring to fig. 1, an oxygen removal steam valve 14 is disposed on an oxygen removal steam pipe 28, a heating steam valve 15 is disposed on a feedwater heater steam inlet pipe 30, and a temperature and pressure reducing valve set 11 is disposed on a main steam supply pipe 29.

Still further, referring to fig. 1, a steam turbine inlet pipe 23 and a bypass steam pipe 22 are further connected to the main steam pipe 21; the steam turbine inlet valve group 6 and the high-pressure cylinder 7 are connected to the steam turbine inlet pipeline 23, the high-pressure cylinder 7 is also communicated with the feed water heater inlet pipeline 30 through the primary steam extraction pipeline 25, and the primary steam extraction pipeline 25 is provided with the primary steam extraction isolation valve 16. Secondly, a bypass valve 10 and a condenser 9 are connected to a bypass steam pipe 22, the condenser 9 is further connected to a low-pressure cylinder 8, the condenser 9 is communicated with the deaerator 1 through a condensed water pipe 18, the low-pressure cylinder 8 is connected to a high-pressure cylinder 7 through a low-pressure cylinder steam inlet pipe 24, the other end of the high-pressure cylinder 7 is further communicated with the deaerator 1 through a secondary steam extraction pipe 26, and a secondary steam extraction isolation valve 17 is arranged on the secondary steam extraction pipe 26.

According to the connection relation of all the devices in the system, water in the feed water heater and the feed water deaerator enters the steam generator, the hot steam of the reactor is utilized to heat the water in the steam generator, the generated main steam enters the high-pressure cylinder and the low-pressure cylinder to generate power, and based on the connection relation and the specific action process, the detailed process of the feed water temperature control method of the high-temperature gas cooled reactor is given below.

As shown in fig. 2, the present invention provides a control method S100 for water supply temperature of a high temperature gas cooled reactor, which includes steps S110 to S130:

s110, before the unit is started, steam generated by an auxiliary electric boiler is respectively fed into a deaerator and a feed water heater through an auxiliary steam header, and the feed water heater is drained to the deaerator to control the feed water temperature to be 190 ℃; and then, the temperature of the reactor core is raised to 200-230 ℃ by adjusting the rotating speed of the main helium fan to a preset rotating speed.

Specifically, in combination with the illustration of fig. 1, before the unit starts, the water supply flow is maintained at 15-20kg/s, steam generated by the auxiliary electric boiler 13 enters the auxiliary steam header 12, the outlet of the auxiliary steam header 12 is divided into two paths, one path is led into the deaerator 1 to heat water supply, and the other path is led into the water supply heater 2 to raise the water supply temperature. Afterwards, the drain water of the feed water heater 2 is recycled to the deaerator 1 through the drain pipeline 20 to further heat the feed water of the deaerator 1, wherein the deaeration steam regulating valve 14 controls the steam quantity entering the deaerator 1 so as to control the feed water temperature of the deaerator 1 to 160 ℃, the heating steam regulating valve 15 controls the steam quantity entering the feed water heater 2, controls the water temperature at the outlet of the feed water heater 2, controls the water temperature at the inlet of the steam generator 3 to 190 ℃, and reduces the heat of the primary loop taken away by the secondary loop so as to facilitate the primary helium fan 5 to raise the core temperature of the reactor 4.

Further, in the embodiment, the temperature of the reactor core can be raised by adjusting the rotating speed of the main helium fan, wherein the rotating speed of the main helium fan is controlled to be 75kg/s-100kg/s, so that the temperature of the reactor core can be raised to 200-230 ℃ for compensating the backup reactivity, and the safe and stable starting of the unit after the emergency shutdown is ensured.

In the embodiment, the deaerator water supply and the water supply in the water supply heater are heated by auxiliary steam generated by the electric boiler, the water drain in the water supply heater is further recycled to heat the deaerator water supply, the inlet water supply temperature of the steam generator can reach 190 ℃, and the reactor core temperature can be further controlled at 200-230 ℃ by adjusting the flow of the main helium fan so as to solve the problem that the conventional control method cannot meet the higher water supply temperature when the high-temperature gas cooled reactor is started.

And S120, after the reactor power reaches the preset power, the feed water heater stops draining water to the deaerator so as to maintain the deaerator feed water temperature at 140 ℃, and after the steam generator stably outputs main steam, the main steam is subjected to temperature and pressure reduction and then enters the deaerator through the auxiliary steam header to heat the feed water, and the auxiliary electric boiler is used as a standby heating steam source.

Specifically, as shown in fig. 1, after the control process S110 in the first stage is completed, the water supply temperature is raised to above 200 ℃, the power is gradually raised after the reactor 4 is started, the water supply flow is gradually raised along with the power, after the power of the reactor 4 reaches 10MW, the water supply heater 2 is gradually withdrawn to heat the steam, that is, after the power of the reactor reaches the preset power, the water supply heater 2 stops dewatering to the deaerator 1, at this time, only the steam generated by the auxiliary electric boiler 13 enters the deaerator 1, the steam entering the deaerator 1 is reduced, and the water supply temperature is controlled at 140 ℃.

It should be understood that, since only the auxiliary electric boiler provides the water heating steam source at this time, if the electric boiler fails and stops running, the water temperature cannot be maintained, the manual emergency stop is performed, the two-loop isolation is triggered, the water does not enter the steam generator any more, and the cold impact of the steam generator is avoided.

Further, please continue to refer to fig. 1, after the steam generator 3 stably outputs steam, the main steam is reduced in pressure and temperature to 1.25mpa and 210 ℃ by the temperature and pressure reducing valve set 11, and the reduced temperature and pressure steam is introduced into the auxiliary steam header 12, and the auxiliary electric boiler 13 operates with low power as a standby heating steam source to maintain the water supply temperature stable. Meanwhile, in this process, the outlet pressure of the steam generator 3 is maintained at a preset pressure value (11 MPa) by the side-discharge valve 10.

In this embodiment, the auxiliary electric boiler is used as a backup heating steam source after the main steam is fed, so that the energy consumption of the electric boiler in the unit starting process is greatly reduced, and meanwhile, the auxiliary steam can be fed to another reactor through the auxiliary steam header for starting the other reactor.

It should be further noted that when the auxiliary electric boiler is used as a standby heating steam source, only the deaerator is used in the stage, 130t of water is supplied when the deaerator is in normal operation, a certain heat capacity is provided, the electric boiler is used as a standby, if the failure of the temperature-reducing pressure-reducing valve bank loses the main steam supply, the electric boiler can be started quickly to maintain the stable water supply temperature, and the cold impact of the steam generator in the starting stage is avoided.

In the embodiment, after the main steam is supplied and put into operation, only the deaerator is put into operation, and the auxiliary electric boiler is used as a standby heating steam source, so that the energy consumption of the electric boiler in the starting process of the unit is greatly reduced, and the cost is saved. And after the steam generator corresponding to the first reactor generates steam, the second reactor can be started synchronously, the time required for the whole start of the unit is shortened, the single reactor is not required to be started to full power, and the steam turbine can provide steam extraction and heating water supply when a certain load is carried out, so that the second reactor is started.

S130, when the steam extraction of the steam turbine meets the requirement of water supply heating, the primary steam extraction and the secondary steam extraction are utilized to heat the water supply heater and the deaerator respectively, the auxiliary electric boiler is stopped, and the main steam generated by the steam generator is used as a standby heating steam source after temperature and pressure reduction.

Specifically, as shown in fig. 1, when the temperature and pressure of the main steam generated by the steam generator 3 meet the turbine turning requirement, the steam inlet valve group 6 of the turbine is opened to enable the main steam to enter the turbine for power generation, the side exhaust valve 10 is gradually closed, and at the moment, the outlet pressure of the steam generator is controlled to be 11MPa by the steam inlet valve group 6 of the turbine. When the unit load reaches 20%, the primary extraction steam and the secondary extraction steam of the steam turbine meet the requirement of water supply heating.

Further, when the steam turbine extraction meets the requirement of water supply heating, the primary extraction steam and the secondary extraction steam are utilized to heat the water supply heater and the deaerator respectively, and the auxiliary electric boiler is stopped, at the moment, the main steam generated by the steam generator is used as a standby heating steam source. That is, the primary steam extraction pipeline of the steam turbine supplies steam to the water heater for heating, and the secondary steam extraction pipeline supplies steam to the deaerator for heating.

Specifically, as shown in fig. 1, the primary steam extraction isolation valve 16 is slowly opened, steam is heated to the feedwater heater 2 through the primary steam extraction pipeline 25, and meanwhile, the deaeration steam regulating valve 14 is slowly closed to reduce the temperature of the deaerator 1, and the outlet temperature of the feedwater heater 2 is kept stable at 140 ℃ in the process. After the feedwater heater 2 is put into use, the deaeration steam regulating valve 14 is continuously and slowly closed, the secondary steam extraction isolation valve 17 is slowly opened, the heating steam source of the deaerator 1 is switched from the main steam supply to the secondary steam extraction supply, and the heating steam supply of the deaerator 1 is carried out through the secondary steam extraction pipeline 26 so as to maintain the temperature stability of the deaerator 1.

In the embodiment, after the steam turbine is put into operation, the auxiliary electric boiler is out of operation and is in a hot standby operation state, and the main steam supply is used as a standby heating steam source to maintain the stability of the water supply temperature.

Furthermore, in order to avoid that the temperature of the outlet tube plate of the steam generator is rapidly reduced from 520 ℃, the embodiment sets different valve positions of the deoxidizing steam valve adjusting and the heating steam valve adjusting according to different temperature platforms, so that different opening degrees are required to be opened according to different temperatures, and a preset amount of steam matched with the temperature is introduced into the deoxidizer and the feedwater heater. For example, the temperature platform comprises 140-150 ℃, 150-160 ℃, 160-170 ℃, 170-180 ℃, 180-190 ℃ and 190-200 ℃, and at the temperature, according to valve opening data obtained through the test, when the turbine jumps or gets rid of load, the deoxidizing steam valve and the heating steam valve are quickly opened to preset opening for recovering the water supply temperature.

Specifically, the control method of the present embodiment further includes: as shown in fig. 1, when the steam turbine trips or throws load, the primary steam extraction isolation valve 16 and the secondary steam extraction isolation valve 17 are closed in an interlocking manner, and the deoxidizing steam regulating valve 14 and the heating steam regulating valve 15 are opened to the opening degrees corresponding to the preset temperature; after the pressure of the auxiliary steam header 13 is reduced, part of the main steam is subjected to temperature and pressure reduction through the temperature and pressure reduction valve bank 11 and then is respectively supplied to the deaerator 1 and the feedwater heater 2.

Further, as shown in fig. 1, when the turbine jumps or gets rid of load, the bypass valve 10 is opened rapidly, and the main steam is discharged into the condenser 9, so as to maintain the outlet pressure of the steam generator 3 at a preset pressure value of 11MPa.

As shown in fig. 1, when the water supply temperature is 180-190 ℃, the primary steam extraction isolation valve 16 and the secondary steam extraction isolation valve 17 are closed in an interlocking way when the turbine jumps or gets rid of load, the deoxidizing steam valve 14 and the heating steam valve 15 are quickly opened to preset opening corresponding to the 180-190 ℃ platform, after the pressure of the auxiliary steam header 12 is reduced, the temperature and pressure reducing valve group 11 automatically tracks the pressure and temperature (1.25 mpa,210 ℃) in the auxiliary steam header 12, and partial main steam is extracted to be reduced in temperature and pressure and then supplied to the deoxidizer and the water supply heater, so that the inlet water temperature of the steam generator is ensured to be stabilized within +/-10 ℃, and cold impact of the steam generator is avoided. In the process, the bypass valve maintains the outlet pressure of the steam generator to be 11MPa, and the unit operation is maintained stable.

Further, in this embodiment, the steam supply parameters (1.25 mpa,210 ℃) of the main steam after temperature and pressure reduction are close to those of the deaerator and the feedwater heater (wherein the deaerator steam supply parameters are 0.8mpa,200 ℃ and the feedwater heater steam supply parameters are 1.5mpa,230 ℃), so that the main steam can simultaneously supply heating steam for the deaerator and the feedwater heater for quickly recovering the feedwater temperature.

In this embodiment, the main steam generated by the steam generator is used as a standby heating steam source after temperature and pressure reduction, when the steam turbine is subjected to load shedding or tripping, the main steam can be reduced in temperature and pressure and then supplied more quickly, and meanwhile, the temperature drop of the water supply after the water supply heater can be prevented, so that the problems that when the steam turbine is subjected to load shedding and the water supply temperature drops quickly, the main steam temperature also drops quickly (for example, the main steam drops by 50 ℃ within 10 minutes), the complex processes such as steam supply and load lifting of the electric boiler are required to be started, the steam turbine has water inlet risks, and meanwhile, the steam turbine also needs to be shut down by switching on and off are solved.

In addition, in the embodiment, the control method can maintain the temperature of the main steam stable, the steam turbine can maintain 3000 turns, and after the state of the standby group is stable, the load is increased by re-grid connection, so that the recovery time of the unit is shortened.

The invention provides a control method for the water supply temperature of a high-temperature gas cooled reactor, which comprises the following steps of

The beneficial effects are that:

firstly, auxiliary steam generated by an electric boiler heats deaerator water supply and water supply in a feed water heater, water drain in the feed water heater is further recovered to heat deaerator water supply, the inlet water supply temperature of a steam generator can reach 190 ℃, the reactor core temperature can be further controlled at 200-230 ℃ through flow adjustment of a main helium fan, the backup reactivity is compensated, and safe and stable starting of a unit after emergency shutdown is ensured.

And secondly, after the steam generator corresponding to the first reactor generates steam, the second reactor can be synchronously started, so that the starting time of the unit is shortened.

Thirdly, in the starting stage of the unit, the main steam is cooled and depressurized and then is fed into the deaerator to heat the water supply, the low-power operation of the auxiliary electric boiler is used as a standby, the deaerator has large heat capacity, the electric boiler is rapidly started to maintain the water supply temperature when the temperature and pressure reducing valve group fails, and the cold impact risk of the steam generator in the starting stage is reduced.

Fourth, in the normal operation stage of the unit, steam turbine is used for extracting steam to heat water supply, main steam is cooled and depressurized and then is introduced into an auxiliary steam header for standby, when the steam turbine jumps or gets rid of load, steam is rapidly supplied to a deaerator and a feed water heater, the temperature of the water supply is maintained to be stable, and the cold impact risk of a steam generator in the normal operation stage is reduced.

It is to be understood that the above embodiments are merely illustrative of the application of the principles of the present invention, but not in limitation thereof. Various modifications and improvements may be made by those skilled in the art without departing from the spirit and substance of the invention, and are also considered to be within the scope of the invention.

Claims (10)

1. A control method of the water supply temperature of a high-temperature gas cooled reactor is characterized in that the water supply temperature control system of the high-temperature gas cooled reactor comprises a reactor, a steam generator, a main helium blower, an auxiliary electric boiler, an auxiliary steam header, a water supply heater and a deaerator; wherein;

the reactor is connected with the steam generator, the main helium fan is arranged on the steam generator, the steam generator is connected with a steam turbine steam extraction pipeline through a main steam pipeline, the auxiliary steam header is sequentially communicated with the main steam pipeline of the steam generator, the auxiliary electric boiler, the deaeration steam pipeline and the feed water heater through a main steam supply pipeline, an auxiliary electric boiler steam supply pipeline and a feed water heater steam inlet pipeline respectively, the feed water heater is communicated with the deaerator through a drain pipeline, and the main steam supply pipeline is provided with a temperature and pressure reducing valve group; the control method comprises the following steps:

before a unit is started, steam generated by the auxiliary electric boiler is respectively fed into the deaerator and the feed water heater through the auxiliary steam header, the feed water heater is drained to the deaerator so as to control the feed water temperature to be 190 ℃, and then the temperature of the reactor core is raised to 200-230 ℃ by adjusting the main helium fan to a preset rotating speed;

after the reactor power reaches the preset power, the feed water heater stops draining water to the deaerator so as to maintain the feed water temperature at 140 ℃, after the steam generator stably outputs main steam, the main steam is subjected to temperature and pressure reduction and then enters the deaerator through the auxiliary steam header to heat the feed water, and the auxiliary electric boiler is used as a standby heating steam source;

when the steam extraction of the steam turbine meets the requirement of water supply heating, the steam extraction pipeline of the steam turbine is utilized to heat the water supply heater and the deaerator respectively, the auxiliary electric boiler is stopped, and the main steam generated by the steam generator is used as a standby heating steam source after temperature and pressure reduction.

2. The control method according to claim 1, wherein the deoxidizing steam pipeline is provided with a deoxidizing steam regulating valve, and the feedwater heater inlet steam pipeline is provided with a heating steam regulating valve; wherein,

the opening degree of the deoxidizing steam regulating valve is regulated to control the steam quantity entering the deoxidizer;

and controlling the steam quantity entering the feedwater heater by adjusting the opening of the heating steam regulating valve.

3. The control method according to claim 1, wherein the preset rotational speed of the main helium blower is in the range of 75kg/s to 100kg/s.

4. The control method according to claim 1, wherein the feed water flow rate is maintained at 15-20kg/s before the start-up of the unit.

5. The control method according to any one of claims 1 to 4, characterized in that the main steam line is also in communication with a bypass steam line on which a bypass valve is provided;

after the steam generator stably outputs main steam, maintaining the outlet pressure of the steam generator to be a preset pressure value through the side discharge valve.

6. The control method according to claim 5, wherein the preset pressure value of the steam generator outlet is 11MPa.

7. The control method according to claim 6, wherein a primary steam extraction pipeline is connected between the main steam pipeline and the feedwater heater steam inlet pipeline, and a steam turbine steam inlet valve group is arranged on the primary steam extraction pipeline; wherein,

after the temperature and pressure of the main steam output by the steam generator meet the turbine turning requirement, slowly closing the side exhaust valve, and opening the turbine steam inlet valve group to control the outlet pressure of the steam generator to be a preset pressure value, and enabling the main steam to enter the turbine to generate electricity.

8. The control method according to claim 7, wherein a primary extraction isolation valve is arranged on the primary extraction pipeline, a secondary extraction pipeline is connected between the low-pressure cylinder steam inlet pipeline and the deaerator, and a secondary extraction isolation valve is arranged on the secondary extraction pipeline;

the heating of the feedwater heater and the deaerator respectively by utilizing the steam extraction pipeline of the steam turbine comprises the following steps:

opening the primary steam extraction isolation valve, heating steam to a feed water heater through the primary steam extraction pipeline, closing the deoxidized steam regulating valve, and maintaining the outlet temperature of the feed water heater at 140 ℃;

after the feed water heater is put into use, the deoxidizing steam regulating valve is closed, the secondary steam extraction isolation valve is opened, and steam is heated to the deoxidizer through the secondary steam extraction pipeline so as to maintain the temperature of the deoxidizer stable.

9. The control method according to claim 8, characterized in that the control method further comprises:

when the steam turbine trips or gets rid of load, the primary steam extraction isolation valve and the secondary steam extraction isolation valve are closed in an interlocking way, and the deoxidizing steam regulating valve and the heating steam regulating valve are opened to the opening corresponding to the preset temperature;

the temperature and pressure reducing valve group is automatically adjusted to maintain the pressure and the temperature of the auxiliary steam header stable so as to supply steam to the deaerator and the feed water heater after partial main steam is subjected to temperature and pressure reduction and maintain the temperature of the feed water stable.

10. The control method according to claim 9, wherein a condenser is further connected to the bypass steam pipe, the control method further comprising:

when the turbine jumps or gets rid of load, the side discharge valve is quickly opened, main steam is discharged into the condenser, and the outlet pressure of the steam generator is maintained to be a preset pressure value.