Method and device for controlling the steam pressure in front of a multi-module high-temperature reactor turbine

Abstract

This application discloses a method and apparatus for controlling the steam pressure before the turbine of a multi-module high-temperature reactor. The method includes: when an RB (Reactive Bore) condition occurs, adjusting the opening of the turbine's regulating valve to correspond to the turbine's current output power; adjusting the opening of the regulating valve according to a pressure control mode, and determining whether the deviation between the measured value of the steam pressure before the turbine and the pressure setpoint exceeds a deviation limit; if not, switching to a valve control mode and adjusting the opening of the regulating valve according to the valve control mode; and reverting to pressure control mode and adjusting the opening of the regulating valve according to the pressure control mode. Through this technical solution, when one or more modules of the multi-module high-temperature reactor experience a shutdown, the steam pressure before the turbine can be controlled, avoiding excessive fluctuations in the steam pressure before the turbine. Furthermore, it can reduce the number of reactor module shutdowns and lower safety risks.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nuclear power, and particularly relates to a control method and device for front steam pressure of a multi-module high-temperature reactor turbine. BACKGROUND

[0002] In a multi-module high-temperature gas-cooled reactor, in order to make the evaporator operate in a working condition with relatively stable pressure, the control strategy for the front steam pressure of the turbine is to use pressure control in a normal working condition, and to use DEH (turbine control system) logic to control in an RB working condition (one or more modules of the multi-module high-temperature reactor are shut down in an emergency), so as to ensure the front steam pressure of the turbine to be stable, thereby realizing the stability of the evaporator outlet pressure. However, the DEH logic mainly adjusts the regulating valve at a certain rate until the regulating valve is adjusted to a fixed valve opening. In order to reduce the fluctuation of the steam pressure in the steam header, the rate generally needs to be adjusted according to the actual situation on site, and in order to adjust the rate, the working condition needs to be reproduced constantly, which may need to shut down the reactor multiple times, and multiple shutdowns of the reactor will pose a great challenge to the safety of the nuclear power plant. SUMMARY

[0003] The application aims to at least solve one of the technical problems in the prior art, and provides a control method and device for front steam pressure of a multi-module high-temperature reactor turbine.

[0004] According to a first aspect of an embodiment of the application, a control method for front steam pressure of a multi-module high-temperature reactor turbine is provided, comprising:

[0005] Step S1, adjusting the opening of a regulating valve of a turbine to an opening corresponding to a current output power of the turbine when an RB working condition occurs;

[0006] Step S2, adjusting the opening of the regulating valve according to a pressure control mode, so that the front steam pressure of the turbine is stabilized around a pressure set value, and determining whether a deviation between a measured value of the front steam pressure of the turbine and the pressure set value exceeds a deviation limit value, if yes, completing the control, otherwise, entering step S3;

[0007] Step S3, switching to a valve control mode, and adjusting the opening of the regulating valve according to the valve control mode until the front steam pressure of the turbine tends to be stable;

[0008] Step S4, resuming the pressure control mode, adjusting the opening of the regulating valve according to the pressure control mode, so that the front steam pressure of the turbine is stabilized around the pressure set value, if the deviation between the measured value of the front steam pressure of the turbine and the pressure set value does not exceed the deviation limit value, completing the control, otherwise, returning to step S1.

[0009] Optionally, in step S2, the adjusting the opening of the regulating valve according to the pressure control mode specifically comprises:

[0010] obtaining a measured value of the steam pressure before the steam turbine;

[0011] determining a first target opening according to the obtained measured value and the pressure set value;

[0012] adjusting the opening of the regulating valve according to the determined first target opening.

[0013] Optionally, in step S3, the adjusting the opening of the regulating valve according to the valve control mode specifically comprises:

[0014] obtaining a steam flow of the steam turbine;

[0015] determining a second target opening according to the obtained steam flow;

[0016] adjusting the opening of the regulating valve according to the determined second target opening.

[0017] Optionally, the steam flow is represented by the sum of the percentages of the steam turbine feed water flow.

[0018] Optionally, in step S3, in the process of adjusting the opening of the regulating valve according to the valve control mode, the pressure set value of the controller tracks the actual measured value of the steam pressure before the steam turbine.

[0019] Optionally, in step S4, in the process of adjusting the opening of the regulating valve according to the pressure control mode, the pressure set value is slowly switched from the actual measured value of the steam pressure before the steam turbine to a rated value.

[0020] Optionally, after the pressure set value is slowly switched from the actual measured value of the steam pressure before the steam turbine to the rated value, the pressure set value is not allowed to be modified within a preset time, and the preset time is the shortest time required to stabilize the steam pressure before the steam turbine.

[0021] According to a second aspect of the embodiments of the present application, a device for controlling the steam pressure before the steam turbine of a multi-module high-temperature reactor is provided, comprising a control module configured to perform the following steps:

[0022] Step S1, adjusting the opening of the regulating valve of the steam turbine to an opening corresponding to the current output power of the steam turbine when the RB condition occurs;

[0023] Step S2, adjusting the opening of the regulating valve according to the pressure control mode to stabilize the steam pressure before the steam turbine around a pressure set value, and determining whether the deviation between the measured value of the steam pressure before the steam turbine and the pressure set value exceeds a deviation limit value, if yes, completing the control, otherwise entering step S3.

[0024] Step S3, switching to the valve control mode, and adjusting the opening of the regulating valve according to the valve control mode until the steam pressure before the steam turbine tends to be stable;

[0025] Step S4, resuming the pressure control mode, adjusting the opening of the regulating valve according to the pressure control mode to stabilize the steam pressure before the steam turbine around the pressure set value, if the deviation of the measured value of the steam pressure before the steam turbine from the pressure set value does not exceed the deviation limit value, the control is completed, otherwise, returning to step S1.

[0026] According to a third aspect of the embodiments of the present application, an electronic device is provided, comprising a memory, a processor, and a program stored in the memory and executable on the processor, the program being configured to implement the steps of the control method of the steam pressure before the steam turbine of the multi-module high-temperature reactor as described above.

[0027] According to a fourth aspect of the embodiments of the present application, a medium is provided, the medium storing a program, the program being executable by a processor to implement the steps of the control method of the steam pressure before the steam turbine of the multi-module high-temperature reactor as described above.

[0028] The above technical solutions of the present application have the following beneficial technical effects:

[0029] Through the above technical solutions, when one or more modules of the multi-module high-temperature reactor are shut down, the control of the steam pressure before the steam turbine can be realized, and the excessive fluctuation of the steam pressure before the steam turbine can be avoided. In addition, the number of shutdowns of the reactor modules can be reduced, and the safety risk can be reduced. Furthermore, the human intervention can be avoided, the amount of manual intervention can be reduced, and the probability of human operation errors can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a flow chart of a control method of the steam pressure before the steam turbine of the multi-module high-temperature reactor in an exemplary embodiment of the present application;

[0031] Figure 2 is a schematic diagram of the control principle of the steam pressure before the steam turbine under normal conditions in an exemplary embodiment of the present application;

[0032] Figure 3 is a schematic diagram of the control principle of the steam pressure before the steam turbine under RB conditions in an exemplary embodiment of the present application;

[0033] Figure 4 is a block diagram of an electronic device for implementing the control method of the steam pressure before the steam turbine of the multi-module high-temperature reactor according to the embodiments of the present application. DETAILED DESCRIPTION

[0034] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application, so that those skilled in the art can better understand the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0035] The present application provides a kind of multi-module high temperature reactor steam turbine front steam pressure control method, Figure 1 A flow of a multi-module high temperature reactor steam turbine front steam pressure control method is shown, which includes the following steps:

[0036] Step S1, when RB condition occurs, the opening of the regulating valve of the steam turbine is adjusted to the opening corresponding to the current output power of the steam turbine.

[0037] In this embodiment, the opening of the regulating valve of the steam turbine is adjusted to the opening corresponding to the current output power of the steam turbine as the first adjustment under RB condition, which can be realized by the feedforward value of the reactor power. For example, during normal operation, the steam turbine regulating valve controls the steam turbine front steam pressure around the rated value through PID output, and the pressure regulating algorithm of the PID has a feedforward, which can send the current reactor power value to the steam turbine control system as the feedforward control value of the steam turbine front pressure. When a reactor trip occurs, the corresponding target load becomes zero, and the PID can control the opening of the steam turbine regulating valve to quickly adjust to the valve position corresponding to the target load of the remaining operating reactor.

[0038] Step S2, adjust the opening of the regulating valve according to the pressure control mode, so that the steam turbine front steam pressure is stabilized around the pressure set value, and determine whether the deviation of the measured value of the steam turbine front steam pressure from the pressure set value exceeds the deviation limit value, if yes, the control is completed, otherwise, go to step S3.

[0039] In this embodiment, the opening of the regulating valve is adjusted according to the pressure control mode, so that the steam turbine front steam pressure is stabilized around the pressure set value, as the second adjustment under RB condition, which specifically includes: obtaining the measured value of the steam turbine front steam pressure. Determine the first target opening according to the measured value and the pressure set value. Adjust the opening of the regulating valve according to the determined first target opening.

[0040] It should be noted that after the second adjustment, since the pressure drop trend of the steam pipe is not clear, there may be a case that the regulating valve does not stabilize the pressure within the predetermined range after adjustment, therefore, the opening of the regulating valve is further adjusted in this embodiment.

[0041] Step S3, switch to the valve control mode, and adjust the opening of the regulating valve according to the valve control mode until the steam pressure before the steam turbine tends to be stable.

[0042] In this embodiment, the opening of the regulating valve is adjusted according to the valve control mode as the third adjustment under the RB working condition, and the process specifically includes: obtaining the steam flow of the steam turbine. The second target opening is determined according to the obtained steam flow. The opening of the regulating valve is adjusted according to the determined second target opening.

[0043] In the process of adjusting the opening of the regulating valve according to the valve control mode, the pressure set value of the controller tracks the actual measured value of the steam pressure before the steam turbine. The purpose of this is to make the calculation output of the controller 0 under the valve control mode, so that the output of the controller tracks the current regulating valve opening, thereby realizing the non-disturbance switching of the two control modes.

[0044] In the process of adjusting the opening of the regulating valve according to the valve control mode, the pressure set value of the controller tracks the actual measured value of the steam pressure before the steam turbine. The purpose of this is to make the calculation output of the controller 0 under the valve control mode, so that the output of the controller tracks the current regulating valve opening, thereby realizing the non-disturbance switching of the two control modes.

[0045] It should be noted that in order to ensure that the valve has enough time to act, it is necessary to maintain a certain time of valve control mode control. In addition, since the valve action is faster than the steam pressure change, a certain stabilization time is left for the steam pressure to preliminarily reach a balanced and stable state in the steam pipeline, and the maintenance of a certain time of valve control mode control can meet the above working condition requirements.

[0046] Step S4, restore to the pressure control mode, and adjust the opening of the regulating valve according to the pressure control mode to make the steam pressure before the steam turbine stable around the pressure set value. If the deviation of the measured value of the steam pressure before the steam turbine from the pressure set value does not exceed the deviation limit value, the control is completed, otherwise, return to step S1.

[0047] In this embodiment, the opening of the regulating valve is adjusted according to the valve control mode as the third adjustment under the RB working condition, and the process specifically includes: obtaining the steam flow of the steam turbine. The second target opening is determined according to the obtained steam flow. The opening of the regulating valve is adjusted according to the determined second target opening.

[0048] The preset time can be 60 seconds or other time length.

[0049] After the above process ends, if the deviation of the measured value of the steam pressure before the steam turbine from the pressure set value does not exceed the deviation limit value, the steam pressure before the steam turbine has been stabilized, otherwise, the above steps S1-S4 need to be repeated.

[0050] Through the above technical solution, when one or more modules of the multi-module high-temperature reactor are shut down, the control of the steam pressure before the steam turbine can be realized, and the excessive fluctuation of the steam pressure before the steam turbine can be avoided. Moreover, the number of shutdowns of the reactor modules can be reduced, and the safety risk can be reduced. In addition, the human intervention of the operator can be avoided, the operation amount of the manual intervention can be reduced, and the probability of the human operation error can be reduced.

[0051] For the convenience of understanding, the following examples introduce the process of controlling the steam turbine by using the control method of the steam pressure before the steam turbine according to the embodiments of the present application.

[0052] (I) Control in normal operation condition

[0053] In the normal operation process, the steam turbine regulating valve controls the steam pressure before the steam turbine near the rated value through the PID output. The pressure regulation algorithm of the PID has a feedforward, and the value of the feedforward control is derived from the RB target load value generated by the power control module of the two reactors. The current reactor power value can be sent to the steam turbine control system as the feedforward control value of the steam pressure before the steam turbine. The control principle is as shown in Figure 2

[0054] In order to ensure the accuracy of the feedforward, the corresponding relationship between the reactor power target load value and the opening of the steam turbine regulating valve can be checked, so as to keep the corresponding relationship between the two accurate at all times.

[0055] Through the above control mode, the stability of the steam pressure before the steam turbine in the normal operation condition can be ensured.

[0056] (II) Control in the condition that one or more reactors are shut down

[0057] When one reactor is shut down, the corresponding evaporator is isolated, and the steam pressure before the main steam header and the steam turbine will fluctuate greatly. At the same time, the shutdown signal triggered by the reactor protection system will trigger the RB signal, and the generation of the signal indicates that the unit enters the RB condition. In this condition, the steam pressure control strategy in the RB condition is needed to realize the control of the steam pressure, which specifically includes:

[0058] ​1、In the case of RB, the target load corresponding to the RB is zero. In order to maintain the stability of the steam pressure before the steam turbine, the PID controls the opening of the regulating valve according to the feedforward value (and the measured value of the steam pressure before the steam turbine) so as to quickly adjust the valve position corresponding to the target load of the remaining operating reactor.

[0059] 2、After the above adjustment, the PID controls the steam pressure by the pressure control mode, and the steam pressure before the steam turbine is stabilized near the pressure set value. The deviation between the measured value of the steam pressure before the steam turbine and the pressure set value is calculated, and it is judged whether the deviation is less than or equal to 7.5%. If yes, it indicates that the control is completed.

[0060] 3、Since the pressure drop trend of the steam pipeline is not clear, there may be a case that the steam pressure before the steam turbine cannot be stabilized in the rated range, i.e. the deviation between the pressure set value and the measured value is greater than 7.5%. At this time, the control logic in the RB case is triggered, and the steam turbine control system is converted to the valve control mode, and the opening of the regulating valve is adjusted according to the valve control mode until the steam pressure before the steam turbine tends to be stable. The valve position instruction is derived from the sum of the feedwater flow percentage, because the feedwater flow can represent the steam flow, and the steam flow has a clear corresponding relationship with the opening of the regulating valve, so the feedwater flow percentage can be directly used as the given value.

[0061] The time limit for conversion to the valve control mode is set, and after the time limit, the pressure control mode can be automatically switched. The setting of the time limit needs to ensure that the valve has enough time to act, and since the valve action is faster than the steam pressure change, a certain stabilization time is left for the steam pressure to preliminarily reach a balanced and stable state.

[0062] During this process, the PID is in a manual state, the pressure set value of the PID tracks the actual pressure measured value, the calculation output of the PID is 0, and the AV output of the PID tracks the actual valve opening. The purpose of this is to keep the PID output during the manual-automatic switching process, i.e. the switching process between the pressure control mode and the valve control mode of the steam turbine, to realize the non-disturbance switching.

[0063] At the same time, the operator is not allowed to modify the pressure set value during the working time. The purpose of this is to stabilize the steam pressure before the steam turbine by automatic means and reduce the control fluctuations introduced by human operation.

[0064] 4、After the time limit of the valve control mode ends, the control mode is automatically switched to the pressure control mode. The PID controls the steam pressure by the pressure control mode again, and after the steam pressure before the steam turbine is stabilized near the pressure set value, the deviation between the measured value of the steam pressure before the steam turbine and the pressure set value is calculated again, and it is judged whether the deviation is less than or equal to 7.5%. If yes, it indicates that the control is completed.

[0065] During the process, the pressure set value is switched slowly from the actual measured value of the steam pressure before the steam turbine to the rated value. After the pressure set value is switched slowly from the actual measured value of the steam pressure before the steam turbine to the rated value, the operator is not allowed to modify the pressure set value within a preset time (for example, 60s) to avoid control fluctuation caused by artificial operation. After the steam pressure before the steam turbine is stabilized, the control of the steam pressure before the steam turbine is restored to the normal pressure control mode, and the operator can modify the pressure set value according to the working condition of the unit.

[0066] After the above operation is completed, if the steam pressure before the steam turbine cannot be stabilized, the above steps 1-4 can be repeated until the steam pressure before the steam turbine can be stabilized in the rated range.

[0067] The embodiment of the present application further provides a multi-module high-temperature reactor steam turbine front steam pressure control device for implementing the multi-module high-temperature reactor steam turbine front steam pressure control method provided by the above embodiment.

[0068] The specific implementation method of the multi-module high-temperature reactor steam turbine front steam pressure control device provided by the embodiment of the present application can be referred to the multi-module high-temperature reactor steam turbine front steam pressure control method provided by the embodiment of the present application, which will not be repeated here.

[0069] It should be noted that the steam turbine front steam pressure control device provided by the embodiment of the present application and the method embodiment in the above embodiment belong to the same concept. Any method provided in the method embodiment can be run on the steam turbine front steam pressure control device. The specific implementation process is described in the method embodiment, which will not be repeated here.

[0070] The embodiment of the present application further provides an electronic device for executing the control method described above. Figure 4 The composition block diagram of the electronic device for executing the multi-module high-temperature reactor steam turbine front steam pressure control method of the embodiment of the present application is shown.

[0071] Figure 4 As shown, an electronic device 400 includes a processor 410 and a memory 420. The processor 410 is communicatively connected to the memory 420. The memory 420 stores instructions executable by the processor 410. The instructions executed by the processor 410 can enable the processor 410 to implement the method described in the above embodiment.

[0072] The memory 420 and the processor 410 are connected by a bus, which can connect the processor 410 and the memory 420 together, and can also connect various other circuits such as peripheral devices, voltage stabilizers and power management circuits, which are well known in the art, and thus will not be further described herein.

[0073] The processor 410 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interface, voltage regulation, power management and other control functions. The memory 420 can be used to store data used by the processor 410 in performing operations. For example, the memory 420 can include any one or a combination of any type of RAM (Random Access Memory), any type of ROM (Read-Only Memory), flash memory devices, hard disks, optical disks, etc. More generally, any memory can use any technology to store information. Further, any memory can provide volatile or non-volatile retention of information.

[0074] It should be noted that the electronic device provided by the embodiments of the present application and the method embodiments in the above embodiments belong to the same concept, and any method provided in the method embodiments can be run on the electronic device, and the specific implementation process is detailed in the method embodiments, which will not be described here.

[0075] The embodiments of the present application also provide a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the method provided by the above method embodiments.

[0076] The computer readable storage medium can be any tangible medium containing or storing a program, which can be electrical, magnetic, optical, electromagnetic, infrared, semiconductor system, device, equipment, and more specific examples include but are not limited to: electrical connection with one or more wires, portable computer disk, hard disk, optical fiber, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0077] It should be noted that the medium provided by the embodiments of the present application and the method embodiments in the above embodiments belong to the same concept, and any method provided in the method embodiments can be stored on the medium, and the specific implementation process is detailed in the method embodiments, which will not be described here.

[0078] It should be noted that the terms "target", "current" and the like in the description and in the claims of the present application and in the above description of the drawings are used to distinguish similar objects and are not necessarily intended to describe a specific order or sequence. It should be understood that the data thus used can be interchanged, where appropriate, so that the embodiments of the present application described herein can be carried out in orders other than those illustrated or described herein. Furthermore, the terms "comprise" and "comprising" and any variations thereof, are intended to cover not exclusively containing, for example, a process, method, system, product or apparatus comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to such processes, methods, products or apparatuses.

[0079] It should be understood that the above is only illustrative, and the technical solutions of the present application are not limited in any way. In specific applications, those skilled in the art can make settings according to needs, and the present application does not limit this.

Claims

1. A method of control of the steam pressure before the turbine in a multi-module high-temperature reactor, characterized by, Comprising: Step S1, when RB condition occurs, adjusting the opening of the regulating valve of the steam turbine to the opening corresponding to the current output power of the steam turbine; Step S2, adjusting the opening of the regulating valve according to the pressure control mode, so that the steam turbine front steam pressure is stabilized near the pressure set value, and judging whether the deviation of the measured value of the steam turbine front steam pressure from the pressure set value exceeds the deviation limit value, if yes, completing the control, otherwise entering step S3; Step S3, switching to valve control mode, and adjusting the opening of the regulating valve according to the valve control mode until the steam turbine front steam pressure tends to be stable; Step S4, restoring to pressure control mode, adjusting the opening of the regulating valve according to the pressure control mode, so that the steam turbine front steam pressure is stabilized near the pressure set value, if the deviation of the measured value of the steam turbine front steam pressure from the pressure set value does not exceed the deviation limit value, completing the control, otherwise returning to step S1.

2. The method of claim 1, wherein, In step S2, the adjusting of the opening of the regulating valve according to the pressure control mode specifically comprises: obtaining the measured value of the steam turbine front steam pressure; determining the first target opening according to the obtained measured value and the pressure set value; adjusting the opening of the regulating valve according to the determined first target opening.

3. The method of claim 1, wherein, In step S3, the adjusting of the opening of the regulating valve according to the valve control mode specifically comprises: obtaining the steam flow of the steam turbine; determining the second target opening according to the obtained steam flow; adjusting the opening of the regulating valve according to the determined second target opening.

4. The method of claim 3, wherein, The steam flow is represented by the sum of the percentages of the steam turbine feed water flow.

5. The method of claim 1, wherein, In step S3, during the adjusting of the opening of the regulating valve according to the valve control mode, the pressure set value tracks the actual measured value of the steam turbine front steam pressure.

6. The method of claim 5, wherein, In step S4, during the adjusting of the opening of the regulating valve according to the pressure control mode, the pressure set value is slowly switched from the actual measured value of the steam turbine front steam pressure to the rated value.

7. The method of claim 6, wherein, After the pressure set value is slowly switched from the actual measured value of the steam turbine front steam pressure to the rated value, the pressure set value is not allowed to be modified within a preset time, and the preset time is the shortest time required to stabilize the steam turbine front steam pressure.

8. A control device for the control of the steam pressure in front of the turbine of a multi-module high-temperature reactor, characterized in that Comprising a control module configured to perform the following steps: Step S1, when RB condition occurs, adjusting the opening of the regulating valve of the steam turbine to the opening corresponding to the current output power of the steam turbine; Step S2, adjusting the opening of the regulating valve according to the pressure control mode, so that the steam turbine front steam pressure is stabilized near the pressure set value, and judging whether the deviation of the measured value of the steam turbine front steam pressure from the pressure set value exceeds the deviation limit value, if yes, completing the control, otherwise entering step S3; Step S3, switching to valve control mode, and adjusting the opening of the regulating valve according to the valve control mode until the steam turbine front steam pressure tends to be stable; Step S4, restoring to pressure control mode, adjusting the opening of the regulating valve according to the pressure control mode, so that the steam turbine front steam pressure is stabilized near the pressure set value, if the deviation of the measured value of the steam turbine front steam pressure from the pressure set value does not exceed the deviation limit value, completing the control, otherwise returning to step S1.

9. An electronic device, comprising: A computer program product comprising a memory, a processor, and a program stored on the memory and executable on the processor, the program configured to implement the steps of the method of controlling the front steam pressure of a multi-module high-temperature reactor steam turbine according to any one of claims 1-7.

10. A readable storage medium, characterized by, A medium having stored thereon a program, the program, when executed on a processor, implementing the steps of the method of controlling the front steam pressure of a multi-module high-temperature reactor steam turbine according to any one of claims 1-7.

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