Supercritical carbon dioxide boiler gas temperature compound control method and related device

Abstract

This invention belongs to the field of thermal control in thermal power plants, and discloses a method and related apparatus for composite temperature control of supercritical carbon dioxide boilers. The method includes: calculating a coal quantity increment command based on the main temperature deviation and reheat temperature deviation; obtaining the coal quantity command for the next time step based on the coal quantity increment command; calculating a recirculated flue gas quantity increment based on the reheat temperature deviation, the superheated gas-cooled wall outlet working fluid temperature deviation, and the reheated gas-cooled wall outlet working fluid temperature deviation; obtaining the recirculated flue gas quantity command for the next time step based on the recirculated flue gas quantity increment; calculating the superheated side flue gas damper opening increment based on the main temperature deviation and reheat temperature deviation; calculating the reheated side flue gas damper opening increment based on the superheated side flue gas damper opening increment; and obtaining the flue gas damper opening command for the next time step based on the superheated side flue gas damper opening increment and the reheated side flue gas damper opening increment. This invention can effectively improve the peak-shaving capacity of supercritical carbon dioxide boilers.

Description

Technical Field

[0001] This invention belongs to the field of thermal control technology for thermal power plants, and relates to the field of supercritical carbon dioxide boiler control, particularly to a method and related device for combined temperature control of supercritical carbon dioxide boilers. Background Technology

[0002] Supercritical carbon dioxide power cycles have potential advantages such as wide adaptability to heat sources, flexibility and efficiency under all operating conditions, and high system compactness, which can help coal-fired power generating units transform and upgrade from main power sources to basic support and system regulation power sources. As the heat source equipment of supercritical carbon dioxide power cycles, supercritical carbon dioxide boilers are key to achieving flexible and efficient operation of supercritical carbon dioxide coal-fired power generating units due to their deep peak shaving capability and rapid load change capability.

[0003] However, compared to traditional supercritical steam boilers, the heat transfer mechanism of supercritical carbon dioxide boilers has undergone significant changes, mainly in the following three aspects: 1) The working fluid temperature at the boiler inlet is high and the working fluid is far from the high specific heat zone, resulting in poor thermal conductivity and low cooling capacity for the boiler tube walls, which easily leads to overheating of the furnace radiant heating surface tube walls; 2) The reheat gas heat absorption ratio is increased, and for large-capacity supercritical carbon dioxide boilers, the reheater increases the furnace radiant heating surface, exacerbating the risk of overheating of the furnace heating surface; 3) The working fluid inside the boiler tubes is in the superheated zone throughout the heat absorption process with a small temperature rise, resulting in a large working fluid flow rate, making it difficult for jet cooling to achieve the expected effect. The above changes in the heat transfer mechanism make it difficult to directly apply the steam temperature control strategy of traditional supercritical water boilers to supercritical carbon dioxide boilers; therefore, it is necessary to develop an effective air temperature control strategy based on the heat transfer characteristics of supercritical carbon dioxide boilers. Summary of the Invention

[0004] In view of the technical problems existing in the prior art, the present invention provides a method and related device for combined air temperature control of supercritical carbon dioxide boiler, so as to solve the technical problem that the steam temperature control strategy of traditional supercritical water boiler is difficult to be directly applied to supercritical carbon dioxide boiler due to the change in the heat transfer mechanism of supercritical carbon dioxide boiler.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] This invention provides a method for combined temperature control in a supercritical carbon dioxide boiler, comprising:

[0007] Based on the main temperature deviation and reheat temperature deviation, the coal quantity increment command is calculated; based on the coal quantity increment command, the coal quantity command for the next moment is obtained.

[0008] Based on the reheat gas temperature deviation, the superheated gas-cooled wall outlet working fluid temperature deviation, and the reheated gas-cooled wall outlet working fluid temperature deviation, the recirculated flue gas volume increment is calculated; based on the recirculated flue gas volume increment, the recirculated flue gas volume command for the next moment is obtained.

[0009] Based on the main temperature deviation and the reheat temperature deviation, the opening increment of the superheated side flue gas damper is calculated; based on the opening increment of the superheated side flue gas damper, the opening increment of the reheated side flue gas damper is calculated; based on the opening increments of the superheated side flue gas damper and the reheated side flue gas damper, the flue gas damper opening command for the next moment is obtained.

[0010] Furthermore, the process of calculating the coal quantity increment command based on the primary temperature deviation and the reheat temperature deviation includes:

[0011] Obtain load commands from the unit's coordinated control system;

[0012] The main temperature setpoint is calculated based on the load command in the unit coordination control system; the main temperature deviation is calculated based on the main temperature setpoint and the real-time main temperature value.

[0013] The first coal quantity increment instruction is calculated based on the main temperature deviation;

[0014] The reheat temperature setpoint is calculated based on the load command in the unit coordination control system; the reheat temperature deviation is calculated based on the reheat temperature setpoint and the real-time reheat temperature.

[0015] The second coal quantity increment command is calculated based on the reheat temperature deviation.

[0016] Furthermore, the process of obtaining the next coal quantity instruction based on the coal quantity increment instruction includes:

[0017] Based on the load command in the unit coordination and control system, obtain the coal quantity command feedforward;

[0018] The first coal quantity increment command, the second coal quantity increment command, and the coal quantity command feedforward are superimposed to obtain the coal quantity command for the next moment.

[0019] Furthermore, based on the reheat gas temperature deviation, the superheated gas-cooled wall outlet working fluid temperature deviation, and the reheated gas-cooled wall outlet working fluid temperature deviation, the process of calculating the recirculated flue gas volume increment includes:

[0020] Obtain load commands from the unit's coordinated control system;

[0021] The reheat temperature setpoint is calculated based on the load command in the unit coordination control system; the reheat temperature deviation is calculated based on the reheat temperature setpoint and the real-time reheat temperature.

[0022] The increment of the first recirculated flue gas volume is calculated based on the reheat temperature deviation;

[0023] Based on the load command in the unit coordination control system, the setpoint of the working fluid temperature at the outlet of the superheated gas-cooled wall is calculated; based on the setpoint of the working fluid temperature at the outlet of the superheated gas-cooled wall and the real-time value of the working fluid temperature at the outlet of the superheated gas-cooled wall, the deviation of the working fluid temperature at the outlet of the superheated gas-cooled wall is calculated.

[0024] The increment of the second recirculated flue gas volume is calculated based on the temperature deviation of the working fluid at the outlet of the superheated gas-cooled wall.

[0025] Based on the load command in the unit coordination control system, the setpoint of the reheat gas-cooled wall outlet working fluid temperature is calculated; based on the setpoint of the reheat gas-cooled wall outlet working fluid temperature and the real-time value of the reheat gas-cooled wall outlet working fluid temperature, the deviation of the reheat gas-cooled wall outlet working fluid temperature is calculated.

[0026] The increment of the third recirculated flue gas volume is calculated based on the temperature deviation of the working fluid at the outlet of the reheat gas-cooled wall.

[0027] Furthermore, the process of obtaining the recirculated flue gas volume command for the next moment based on the increase in recirculated flue gas volume includes...

[0028] Based on the load command in the unit coordination control system, the recirculated flue gas volume command feedforward is obtained;

[0029] The first recirculated flue gas volume increment, the second recirculated flue gas volume increment, the third recirculated flue gas volume increment, and the recirculated flue gas volume command feedforward are superimposed to obtain the recirculated flue gas volume command at the next moment.

[0030] Furthermore, based on the main temperature deviation and the reheat temperature deviation, the increment of the superheated side flue gas damper opening is calculated; the process of calculating the increment of the reheated side flue gas damper opening based on the increment of the superheated side flue gas damper opening includes:

[0031] Obtain load commands from the unit's coordinated control system;

[0032] The main temperature setpoint is calculated based on the load command in the unit coordination control system; the main temperature deviation is calculated based on the main temperature setpoint and the real-time main temperature value.

[0033] The reheat temperature setpoint is calculated based on the load command in the unit coordination control system; the reheat temperature deviation is calculated based on the reheat temperature setpoint and the real-time reheat temperature.

[0034] The difference between the main temperature deviation and the reheat temperature deviation is calculated based on the main temperature deviation and the reheat temperature deviation.

[0035] The increment of the flue gas damper opening on the superheated side is calculated based on the difference between the main temperature deviation and the reheat temperature deviation.

[0036] The increment of the flue gas damper opening on the superheated side is processed by a proportional element K to obtain the increment of the flue gas damper opening on the reheated side.

[0037] Furthermore, the process of obtaining the flue gas damper opening command for the next moment based on the superheated side flue gas damper opening increment and the reheated side flue gas damper opening increment includes:

[0038] Obtain the main gas flow signal from the boiler main controller;

[0039] Based on the main gas flow signal in the boiler main controller, the feedforward command for the opening degree of the superheated flue gas damper and the feedforward command for the opening degree of the reheated flue gas damper are calculated.

[0040] The superheated side flue gas damper opening increment is superimposed with the superheated side flue gas damper opening command feedforward to obtain the superheated side flue gas damper opening command at the next moment.

[0041] The reheat side flue gas damper opening increment is superimposed with the reheat side flue gas damper opening command feedforward to obtain the reheat side flue gas damper opening command at the next moment.

[0042] This invention also provides a supercritical carbon dioxide boiler temperature composite control system, comprising:

[0043] The fuel quantity control module is used to calculate the coal quantity increment command based on the main temperature deviation and reheat temperature deviation; and to obtain the coal quantity command for the next moment based on the coal quantity increment command.

[0044] The flue gas recirculation control module is used to calculate the recirculated flue gas volume increment based on the reheat gas temperature deviation, the superheated gas-cooled wall outlet working fluid temperature deviation, and the reheated gas-cooled wall outlet working fluid temperature deviation; and to obtain the recirculated flue gas volume command for the next moment based on the recirculated flue gas volume increment.

[0045] The flue gas damper control module is used to calculate the opening increment of the superheated side flue gas damper based on the main temperature deviation and the reheat temperature deviation; calculate the opening increment of the reheated side flue gas damper based on the opening increment of the superheated side flue gas damper; and obtain the flue gas damper opening command for the next moment based on the opening increments of the superheated side flue gas damper and the reheated side flue gas damper.

[0046] The present invention also provides an electronic device, comprising:

[0047] A processor is used to execute computer programs;

[0048] A computer-readable storage medium storing a computer program, which, when executed by the processor, performs the supercritical carbon dioxide boiler temperature composite control method.

[0049] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the supercritical carbon dioxide boiler temperature composite control method.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0051] The supercritical carbon dioxide boiler air temperature composite control method provided by this invention can effectively control the wall temperature of the furnace radiant heating surface of a supercritical carbon dioxide boiler, improve the control accuracy of the main heat medium temperature and reheat medium temperature, and enhance the peak-shaving capacity of the supercritical carbon dioxide boiler. Specifically, based on the main heat medium temperature deviation and the reheat medium temperature deviation, the coal quantity command for the next moment is obtained, and the boiler heat load is adjusted by adjusting the coal quantity, thereby controlling the main gas temperature and reheat gas temperature. This method is further enhanced by controlling the reheat gas temperature deviation, the superheated gas cold wall outlet working medium temperature deviation, and the reheat gas cold wall temperature. The deviation of the outlet working fluid temperature is used to obtain the recirculated flue gas volume command for the next moment, thereby adjusting the boiler heat load by adjusting the coal quantity and controlling the main gas temperature and reheat gas temperature. At the same time, based on the flue gas recirculation volume command, the reheat gas temperature can be further adjusted, while controlling the furnace superheated gas cold wall and reheat gas cold wall to prevent overheating. Meanwhile, based on the increase in the opening degree of the superheated side flue gas damper and the increase in the opening degree of the reheated side flue gas damper, the flue gas damper opening command for the next moment is obtained, enabling fine adjustment of the main gas temperature and reheat gas temperature through the tail flue gas damper.

[0052] The supercritical carbon dioxide boiler temperature composite control system, electronic equipment, and computer-readable storage medium provided by this invention possess all the advantages of the aforementioned supercritical carbon dioxide boiler temperature composite control method. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the heating surface arrangement of the supercritical carbon dioxide boiler in Example 1;

[0054] Figure 2 A flowchart of the supercritical carbon dioxide boiler temperature composite control method provided in Example 1;

[0055] Figure 3 This is a schematic diagram of the fuel quantity and flue gas recirculation control logic in Example 1;

[0056] Figure 4 This is a schematic diagram of the flue gas damper control logic in Example 1;

[0057] Figure 5 This is a structural block diagram of the supercritical carbon dioxide boiler temperature composite control system provided in Example 2;

[0058] Figure 6This is a structural block diagram of the electronic device provided in Example 3. Detailed Implementation

[0059] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0060] This invention provides a method for combined temperature control in a supercritical carbon dioxide boiler, comprising the following steps:

[0061] Step 100: Calculate the coal quantity increment command based on the main temperature deviation and the reheat temperature deviation; obtain the coal quantity command for the next moment based on the coal quantity increment command.

[0062] Step 200: Calculate the recirculated flue gas volume increment based on the reheat gas temperature deviation, the superheated gas-cooled wall outlet working fluid temperature deviation, and the reheated gas-cooled wall outlet working fluid temperature deviation; obtain the recirculated flue gas volume command for the next moment based on the recirculated flue gas volume increment.

[0063] Step 300: Based on the main temperature deviation and the reheat temperature deviation, calculate the opening increment of the superheated side flue gas damper; based on the opening increment of the superheated side flue gas damper, calculate the opening increment of the reheated side flue gas damper; based on the opening increments of the superheated side flue gas damper and the reheated side flue gas damper, obtain the flue gas damper opening command for the next moment.

[0064] The supercritical carbon dioxide boiler air temperature composite control method described in this invention can effectively control the wall temperature of the furnace radiant heating surface of the supercritical carbon dioxide boiler, improve the control accuracy of the main heat medium temperature and the reheat medium temperature, and enhance the peak-shaving capacity of the supercritical carbon dioxide boiler.

[0065] The following specific embodiments further explain the supercritical carbon dioxide boiler temperature composite control method provided by the present invention:

[0066] Example 1

[0067] In this embodiment 1, the combined temperature control process of a supercritical carbon dioxide boiler is taken as an example; as shown in the attached... Figure 1 As shown, attached Figure 1 The diagram shows the arrangement of the heating surfaces of the supercritical carbon dioxide boiler. The lower furnace is equipped with superheated gas-cooled walls, the upper furnace with reheated gas-cooled walls, the horizontal flue with high-temperature superheaters and high-temperature reheaters, and the vertical flue with two sides. One side is equipped with a low-temperature superheater and a parallel economizer, and the other side is equipped with a low-temperature reheater and a parallel economizer. The flue outlet of the economizer is equipped with a flue gas damper. The flue is merged after the flue gas damper, and environmental protection facilities and air preheaters are arranged there.

[0068] As attached Figure 2 As shown in the figure, this embodiment 1 provides a method for combined temperature control of a supercritical carbon dioxide boiler, including the following steps:

[0069] Step 1: Calculate the coal quantity increment command based on the main temperature deviation and reheat temperature deviation; obtain the coal quantity command for the next time step based on the coal quantity increment command. See attached diagram for details. Figure 3 As shown, the steps are as follows:

[0070] Step 11: Obtain load commands from the unit coordination control system (CCS).

[0071] Step 12: Calculate the main temperature setpoint according to the load command in the unit coordination control system; specifically, calculate the main temperature setpoint using the first preset function F1(x) based on the load command in the unit coordination control system; calculate the main temperature deviation based on the main temperature setpoint and the real-time main temperature value; specifically, subtract the real-time main temperature value from the main temperature setpoint to obtain the main temperature deviation.

[0072] Step 13: Calculate the first coal quantity increment command based on the main temperature deviation; specifically, perform PID calculation on the main temperature deviation to obtain the first coal quantity increment command.

[0073] Step 14: Calculate the reheat temperature setpoint based on the load command in the unit coordination control system; specifically, calculate the reheat temperature setpoint using the third preset function F3(x) based on the load command in the unit coordination control system; calculate the reheat temperature deviation based on the reheat temperature setpoint and the real-time reheat temperature value; specifically, subtract the real-time reheat temperature value from the reheat temperature setpoint to obtain the reheat temperature deviation.

[0074] Step 15: Calculate the second coal quantity increment command based on the reheat gas temperature deviation; specifically, perform PID calculation on the reheat gas deviation to obtain the second coal quantity increment command.

[0075] Step 16: Obtain the coal quantity instruction for the next moment based on the coal quantity increment instruction; specifically, based on the load instruction in the unit coordination control system, use the second preset function F2(x) to obtain the coal quantity instruction feedforward; superimpose the first coal quantity increment instruction, the second coal quantity increment instruction and the coal quantity instruction feedforward to obtain the coal quantity instruction for the next moment.

[0076] Step 2: Based on the reheat gas temperature deviation, the superheated gas-cooled wall outlet working fluid temperature deviation, and the reheated gas-cooled wall outlet working fluid temperature deviation, calculate the recirculated flue gas volume increment; based on the recirculated flue gas volume increment, obtain the recirculated flue gas volume command for the next time step. See attached diagram for details. Figure 3 As shown, the steps are as follows:

[0077] Step 21: Obtain load commands from the unit coordination control system (CCS).

[0078] Step 22: Calculate the reheat temperature setpoint based on the load command in the unit coordination control system; specifically, calculate the reheat temperature setpoint using the third preset function F3(x) based on the load command in the unit coordination control system; calculate the reheat temperature deviation based on the reheat temperature setpoint and the real-time reheat temperature value; specifically, subtract the real-time reheat temperature value from the reheat temperature setpoint to obtain the reheat temperature deviation.

[0079] Step 23: Calculate the first recirculated flue gas volume increment based on the reheat temperature deviation; specifically, perform PID calculation on the reheat temperature deviation to obtain the first recirculated flue gas volume increment.

[0080] Step 24: Calculate the setpoint of the superheated gas-cooled wall outlet working fluid temperature based on the load command in the unit coordination control system; specifically, calculate the setpoint of the superheated gas-cooled wall outlet working fluid temperature using the fifth preset function F5(x) based on the load command in the unit coordination control system; calculate the superheated gas-cooled wall outlet working fluid temperature deviation based on the setpoint and the real-time value of the superheated gas-cooled wall outlet working fluid temperature; specifically, calculate the superheated gas-cooled wall outlet working fluid temperature deviation by subtracting the real-time value of the superheated gas-cooled wall outlet working fluid temperature from the setpoint.

[0081] Step 25: Calculate the second recirculated flue gas volume increment based on the temperature deviation of the working fluid at the outlet of the superheated gas-cooled wall; specifically, perform PID calculation on the temperature deviation of the working fluid at the outlet of the superheated gas-cooled wall to calculate the second recirculated flue gas volume increment.

[0082] Step 26: Calculate the reheat gas-cooled wall outlet working fluid temperature setpoint based on the load command in the unit coordination control system; specifically, calculate the reheat gas-cooled wall outlet working fluid temperature setpoint using the sixth preset function F6(x) based on the load command in the unit coordination control system; calculate the reheat gas-cooled wall outlet working fluid temperature deviation based on the reheat gas-cooled wall outlet working fluid temperature setpoint and the real-time reheat gas-cooled wall outlet working fluid temperature; specifically, subtract the real-time reheat gas-cooled wall outlet working fluid temperature from the reheat gas-cooled wall outlet working fluid temperature setpoint to obtain the reheat gas-cooled wall outlet working fluid temperature deviation.

[0083] Step 27: Calculate the increment of the third recirculated flue gas based on the temperature deviation of the working fluid at the outlet of the reheat gas-cooled wall; specifically, perform PID calculation on the temperature deviation of the working fluid at the outlet of the reheat gas-cooled wall to calculate the increment of the third recirculated flue gas.

[0084] Step 28: Obtain the recirculated flue gas volume command for the next moment based on the recirculated flue gas volume increment; specifically, based on the load command in the unit coordination control system, calculate the recirculated flue gas volume command feedforward using the fourth preset function F4(x); superimpose the first recirculated flue gas volume increment, the second recirculated flue gas volume increment, the third recirculated flue gas volume increment and the recirculated flue gas volume command feedforward to obtain the recirculated flue gas volume command for the next moment.

[0085] Step 3: Based on the main air temperature deviation and the reheat air temperature deviation, calculate the opening increment of the superheated side flue gas damper; based on the superheated side flue gas damper opening increment, calculate the opening increment of the reheated side flue gas damper; based on the superheated side flue gas damper opening increment and the reheated side flue gas damper opening increment, obtain the flue gas damper opening command for the next moment. Specifically, see attached... Figure 4 As shown, the steps are as follows:

[0086] Step 31: Obtain load commands from the unit coordination control system (CCS).

[0087] Step 32: Calculate the main temperature setpoint according to the load command in the unit coordination control system; specifically, calculate the main temperature setpoint using the first preset function F1(x) based on the load command in the unit coordination control system; calculate the main temperature deviation based on the main temperature setpoint and the real-time main temperature value; specifically, subtract the real-time main temperature value from the main temperature setpoint to obtain the main temperature deviation.

[0088] Step 33: Calculate the reheat temperature setpoint based on the load command in the unit coordination control system; specifically, calculate the reheat temperature setpoint using the third preset function F3(x) based on the load command in the unit coordination control system; calculate the reheat temperature deviation based on the reheat temperature setpoint and the real-time reheat temperature value; specifically, subtract the real-time reheat temperature value from the reheat temperature setpoint to obtain the reheat temperature deviation.

[0089] Step 34: Calculate the difference between the main temperature deviation and the reheat temperature deviation based on the main temperature deviation and the reheat temperature deviation; specifically, subtract the reheat temperature deviation from the main temperature deviation to obtain the difference between the main temperature deviation and the reheat temperature deviation.

[0090] Step 35: Calculate the opening increment of the superheated side flue gas damper based on the difference between the main temperature deviation and the reheat temperature deviation; specifically, perform PID calculation on the difference between the main temperature deviation and the reheat temperature deviation to calculate the opening increment of the superheated side flue gas damper.

[0091] Step 36: The increment of the superheated side flue gas damper opening is processed by a proportional element K to obtain the increment of the reheated side flue gas damper opening; wherein, the value of the proportional element K is determined according to the operating status of the on-site equipment; preferably, the value of the proportional element K is -1.

[0092] Step 37: Calculate the superheated side flue gas damper opening command feedforward and the reheated side flue gas damper opening command feedforward based on the main gas flow signal in the boiler main controller; specifically, based on the main gas flow signal in the boiler main controller, calculate the superheated side flue gas damper opening command feedforward using the seventh preset function F7(x); and calculate the reheated side flue gas damper opening command feedforward using the eighth preset function F8(x) based on the main gas flow signal in the boiler main controller.

[0093] Step 38: Superimpose the superheated side flue gas damper opening increment with the superheated side flue gas damper opening command feedforward to obtain the superheated side flue gas damper opening command for the next moment; specifically, superimpose the superheated side flue gas damper opening increment with the superheated side flue gas damper opening command feedforward, and generate the superheated side flue gas damper opening command for the next moment through manual / automatic switching function or MFT switching function.

[0094] Step 39: Superimpose the reheat side flue gas damper opening increment with the reheat side flue gas damper opening command feedforward to obtain the reheat side flue gas damper opening command for the next moment; specifically, superimpose the reheat side flue gas damper opening increment with the reheat side flue gas damper opening command feedforward, and generate the reheat side flue gas damper opening command for the next moment through manual / automatic switching function or MFT switching function.

[0095] It should be noted that the first preset function F1(x), the second preset function F2(x), the third preset function F3(x), the fourth preset function F4(x), the fifth preset function F5(x), and the sixth preset function F6(x) are obtained by linear interpolation based on the thermodynamic calculation of supercritical carbon dioxide boilers; the seventh preset function F7(x) and the eighth preset function F8(x) are obtained by calculation based on the thermodynamic performance of supercritical carbon dioxide boilers.

[0096] Control principle explanation:

[0097] During peak-shaving operation, the coal quantity and working fluid flow rate of a supercritical carbon dioxide boiler will change. Considering the thermal inertia of the process of heat transfer from the flue gas to the working fluid through the boiler tube wall, the changes in the main air temperature and reheat air temperature will be delayed with load adjustment. Therefore, temperature control can avoid the boiler temperature from being too high or too low during peak-shaving operation.

[0098] Specifically, in this embodiment 1, the boiler heat load is adjusted by the amount of fuel, thereby controlling the main gas temperature and reheat gas temperature; the amount of flue gas recirculation further regulates the reheat gas temperature, while controlling the furnace superheated gas-cooled wall and reheat gas-cooled wall to prevent overheating; on this basis, the main gas temperature and reheat gas temperature are finely adjusted by the flue gas damper at the tail flue; more specifically, during the operation of the supercritical carbon dioxide boiler, when the main gas temperature and reheat gas temperature deviate from the design value, the overall heat load of the boiler is adjusted by the amount of coal, which can quickly and effectively control the main gas temperature and reheat gas temperature; when the supercritical carbon dioxide boiler is running at low load and variable load, the flue gas recirculation can further regulate the reheat gas temperature, while controlling the furnace radiant heating surface gas-cooled wall to prevent overheating; on this basis, when the deviation between the main gas temperature and reheat gas temperature is large, the flue gas damper control can be used as an auxiliary adjustment means to accelerate the adjustment process of the main gas temperature and reheat gas temperature.

[0099] Example 2

[0100] As attached Figure 5 As shown in the figure, this embodiment 2 provides a supercritical carbon dioxide boiler temperature composite control system, including a fuel quantity control module, a flue gas recirculation control module, and a flue gas damper control module.

[0101] The fuel quantity control module calculates the coal quantity increment command based on the main air temperature deviation and the reheat air temperature deviation; and obtains the coal quantity command for the next time step based on the coal quantity increment command. The flue gas recirculation control module calculates the recirculated flue gas quantity increment based on the reheat air temperature deviation, the superheated gas wall outlet working fluid temperature deviation, and the reheated gas wall outlet working fluid temperature deviation; and obtains the recirculated flue gas quantity command for the next time step based on the recirculated flue gas quantity increment. The flue gas damper control module calculates the superheated side flue gas damper opening increment based on the main air temperature deviation and the reheat air temperature deviation; calculates the reheated side flue gas damper opening increment based on the superheated side flue gas damper opening increment; and obtains the flue gas damper opening command for the next time step based on the superheated side flue gas damper opening increment and the reheated side flue gas damper opening increment.

[0102] Optionally, the fuel control module is specifically used for:

[0103] The system acquires load commands from the unit coordination control system; calculates the main temperature setpoint based on the load commands; calculates the main temperature deviation based on the main temperature setpoint and the real-time main temperature; calculates the first coal quantity increment command based on the main temperature deviation; calculates the reheat temperature setpoint based on the load commands from the unit coordination control system; calculates the reheat temperature deviation based on the reheat temperature setpoint and the real-time reheat temperature; calculates the second coal quantity increment command based on the reheat temperature deviation; obtains the coal quantity command feedforward based on the load commands from the unit coordination control system; and superimposes the first coal quantity increment command, the second coal quantity increment command, and the coal quantity command feedforward to obtain the coal quantity command for the next moment.

[0104] Optionally, the flue gas recirculation control module is specifically used for:

[0105] Obtain the load command from the unit coordination control system; calculate the reheat temperature setpoint based on the load command; calculate the reheat temperature deviation based on the reheat temperature setpoint and the real-time reheat temperature; calculate the first recirculated flue gas volume increment based on the reheat temperature deviation; calculate the superheated gas wall outlet working fluid temperature setpoint based on the load command from the unit coordination control system; calculate the superheated gas wall outlet working fluid temperature deviation based on the superheated gas wall outlet working fluid temperature setpoint and the real-time superheated gas wall outlet working fluid temperature; calculate the second recirculated flue gas volume increment based on the superheated gas wall outlet working fluid temperature deviation. The following steps are taken: 1. Calculate the reheat gas-cooled wall outlet working fluid temperature setpoint based on the load command in the unit's coordinated control system. 2. Calculate the reheat gas-cooled wall outlet working fluid temperature deviation based on the setpoint and real-time values. 3. Calculate the third recirculated flue gas volume increment based on the reheat gas-cooled wall outlet working fluid temperature deviation. 4. Obtain the recirculated flue gas volume command feedforward based on the load command in the unit's coordinated control system. 5. Superimpose the first, second, and third recirculated flue gas volume increments with the recirculated flue gas volume command feedforward to obtain the recirculated flue gas volume command for the next moment.

[0106] Optionally, the flue gas damper control module is specifically used for:

[0107] Obtain load commands from the unit's coordinated control system; calculate the main temperature setpoint based on the load commands from the unit's coordinated control system; calculate the main temperature deviation based on the main temperature setpoint and the real-time main temperature value; calculate the reheat temperature setpoint based on the load commands from the unit's coordinated control system; calculate the reheat temperature deviation based on the reheat temperature setpoint and the real-time reheat temperature value; calculate the difference between the main temperature deviation and the reheat temperature deviation based on the main temperature deviation and the reheat temperature deviation; calculate the superheated side flue gas damper opening increment based on the difference between the main temperature deviation and the reheat temperature deviation; and adjust the superheated side flue gas damper opening increment accordingly. The opening increment of the hot-side flue gas damper is processed by the proportional circuit K to obtain the opening increment of the reheat-side flue gas damper; the main gas flow signal in the boiler main controller is obtained; based on the main gas flow signal in the boiler main controller, the feedforward command for the superheat-side flue gas damper opening and the feedforward command for the reheat-side flue gas damper opening are calculated; the opening increment of the superheat-side flue gas damper opening and the feedforward command for the superheat-side flue gas damper opening are superimposed to obtain the opening command for the superheat-side flue gas damper at the next moment; the opening increment of the reheat-side flue gas damper opening and the feedforward command for the reheat-side flue gas damper opening are superimposed to obtain the opening command for the reheat-side flue gas damper at the next moment.

[0108] Example 3

[0109] As attached Figure 6 As shown, this embodiment 3 provides an electronic device, including: a memory for storing a computer program; a processor for executing the computer program to implement the steps of the supercritical carbon dioxide boiler temperature composite control method; or, the processor executing the computer program to implement the functions of each module in the above-mentioned supercritical carbon dioxide boiler temperature composite control system.

[0110] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a preset function, the instruction segments describing the execution process of the computer program in the electronic device.

[0111] The electronic device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The electronic device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the above are examples of electronic devices and do not constitute a limitation on the electronic device. It may include more components than described above, or combine certain components, or different components. For example, the electronic device may also include a communication interface, input / output devices, network access devices, and a bus.

[0112] The processor can be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (OPGs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor, or any conventional processor. The processor is the control center of the electronic device, connecting various parts of the electronic device via various communication interfaces and lines.

[0113] The memory can be used to store the computer program and / or module. The processor implements various functions of the electronic device by running or executing the computer program and / or module stored in the memory and by calling the data stored in the memory.

[0114] The memory may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function (such as sound playback, image playback, etc.). The data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). Furthermore, the memory may include high-speed random access memory and non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart memory cards, secure digital cards, flash memory cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0115] Example 4

[0116] This embodiment 4 also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the supercritical carbon dioxide boiler temperature composite control method.

[0117] If the modules / units integrated in the supercritical carbon dioxide boiler temperature composite control system are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0118] Based on this understanding, the present invention can implement all or part of the processes in the above-mentioned supercritical carbon dioxide boiler temperature composite control method, or it can be accomplished by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the above-mentioned supercritical carbon dioxide boiler temperature composite control method. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or preset intermediate form, etc.

[0119] The computer-readable storage medium may include any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory, random access memory, electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0120] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A supercritical carbon dioxide boiler gas temperature compound control method, characterized by, include: Based on the main temperature deviation and reheat temperature deviation, the coal quantity increment command is calculated; based on the coal quantity increment command, the coal quantity command for the next moment is obtained. The incremental amount of recirculated flue gas is calculated based on the reheat gas temperature deviation, the superheated gas-cooled wall outlet working fluid temperature deviation, and the reheated gas-cooled wall outlet working fluid temperature deviation. Based on the increase in recirculated flue gas volume, obtain the recirculated flue gas volume command for the next moment; Based on the main temperature deviation and the reheat temperature deviation, the opening increment of the superheated side flue gas damper is calculated; based on the opening increment of the superheated side flue gas damper, the opening increment of the reheated side flue gas damper is calculated; based on the opening increments of the superheated side flue gas damper and the reheated side flue gas damper, the flue gas damper opening command for the next moment is obtained. The process of calculating the increase in recirculated flue gas volume based on the reheat gas temperature deviation, the superheated gas-cooled wall outlet working fluid temperature deviation, and the reheated gas-cooled wall outlet working fluid temperature deviation includes: Obtain load commands from the unit's coordinated control system; The reheat temperature setpoint is calculated based on the load command in the unit coordination control system; the reheat temperature deviation is calculated based on the reheat temperature setpoint and the real-time reheat temperature. The increment of the first recirculated flue gas volume is calculated based on the reheat temperature deviation; Based on the load command in the unit coordination control system, the setpoint of the working fluid temperature at the outlet of the superheated gas-cooled wall is calculated; based on the setpoint of the working fluid temperature at the outlet of the superheated gas-cooled wall and the real-time value of the working fluid temperature at the outlet of the superheated gas-cooled wall, the deviation of the working fluid temperature at the outlet of the superheated gas-cooled wall is calculated. The increment of the second recirculated flue gas volume is calculated based on the temperature deviation of the working fluid at the outlet of the superheated gas-cooled wall. Based on the load command in the unit coordination control system, the setpoint of the reheat gas-cooled wall outlet working fluid temperature is calculated; based on the setpoint of the reheat gas-cooled wall outlet working fluid temperature and the real-time value of the reheat gas-cooled wall outlet working fluid temperature, the deviation of the reheat gas-cooled wall outlet working fluid temperature is calculated. The increment of the third recirculated flue gas volume is calculated based on the temperature deviation of the working fluid at the outlet of the reheat gas-cooled wall. The process of obtaining the recirculated flue gas volume command for the next moment based on the increase in recirculated flue gas volume includes: Based on the load command in the unit coordination control system, the recirculated flue gas volume command feedforward is obtained; The first recirculated flue gas volume increment, the second recirculated flue gas volume increment, the third recirculated flue gas volume increment, and the recirculated flue gas volume command feedforward are superimposed to obtain the recirculated flue gas volume command at the next moment.

2. The supercritical carbon dioxide boiler gas temperature compound control method according to claim 1, characterized in that, The process of calculating the coal quantity increment command based on the primary temperature deviation and the reheat temperature deviation includes: Obtain load commands from the unit's coordinated control system; The main temperature setpoint is calculated based on the load command in the unit coordination control system; the main temperature deviation is calculated based on the main temperature setpoint and the real-time main temperature value. The first coal quantity increment instruction is calculated based on the main temperature deviation; The reheat temperature setpoint is calculated based on the load command in the unit coordination control system; the reheat temperature deviation is calculated based on the reheat temperature setpoint and the real-time reheat temperature. The second coal quantity increment command is calculated based on the reheat temperature deviation.

3. The supercritical carbon dioxide boiler gas temperature compound control method according to claim 2, characterized in that, The process of obtaining the next coal quantity instruction based on the coal quantity increment instruction includes: Based on the load command in the unit coordination and control system, obtain the coal quantity command feedforward; The first coal quantity increment command, the second coal quantity increment command, and the coal quantity command feedforward are superimposed to obtain the coal quantity command for the next moment.

4. The supercritical carbon dioxide boiler gas temperature compound control method according to claim 1, characterized in that, The increment of the flue gas damper opening on the superheated side is calculated based on the main temperature deviation and the reheat temperature deviation. The process of calculating the reheat side flue gas damper opening increment based on the superheat side flue gas damper opening increment includes: Obtain load commands from the unit's coordinated control system; The main temperature setpoint is calculated based on the load command in the unit coordination control system; the main temperature deviation is calculated based on the main temperature setpoint and the real-time main temperature value. The reheat temperature setpoint is calculated based on the load command in the unit coordination control system; the reheat temperature deviation is calculated based on the reheat temperature setpoint and the real-time reheat temperature. The difference between the main temperature deviation and the reheat temperature deviation is calculated based on the main temperature deviation and the reheat temperature deviation. The increment of the flue gas damper opening on the superheated side is calculated based on the difference between the main temperature deviation and the reheat temperature deviation. The increment of the flue gas damper opening on the superheated side is processed by a proportional element K to obtain the increment of the flue gas damper opening on the reheated side.

5. The supercritical carbon dioxide boiler gas temperature compound control method according to claim 4, characterized in that, The process of obtaining the flue gas damper opening command at the next moment based on the superheated side flue gas damper opening increment and the reheated side flue gas damper opening increment includes: Obtain the main gas flow signal from the boiler main controller; Based on the main gas flow signal in the boiler main controller, the feedforward command for the opening degree of the superheated flue gas damper and the feedforward command for the opening degree of the reheated flue gas damper are calculated. The superheated side flue gas damper opening increment is superimposed with the superheated side flue gas damper opening command feedforward to obtain the superheated side flue gas damper opening command at the next moment. The reheat side flue gas damper opening increment is superimposed with the reheat side flue gas damper opening command feedforward to obtain the reheat side flue gas damper opening command at the next moment.

6. A supercritical carbon dioxide boiler gas temperature compound control system, characterized by, The method for implementing the combined temperature control of a supercritical carbon dioxide boiler as described in claim 1 includes: The fuel quantity control module is used to calculate the coal quantity increment command based on the main temperature deviation and reheat temperature deviation; and to obtain the coal quantity command for the next moment based on the coal quantity increment command. The flue gas recirculation control module is used to calculate the recirculated flue gas volume increment based on the reheat gas temperature deviation, the superheated gas-cooled wall outlet working fluid temperature deviation, and the reheated gas-cooled wall outlet working fluid temperature deviation; and to obtain the recirculated flue gas volume command for the next moment based on the recirculated flue gas volume increment. The flue gas damper control module is used to calculate the opening increment of the superheated side flue gas damper based on the main temperature deviation and the reheat temperature deviation; calculate the opening increment of the reheated side flue gas damper based on the opening increment of the superheated side flue gas damper; and obtain the flue gas damper opening command for the next moment based on the opening increments of the superheated side flue gas damper and the reheated side flue gas damper.

7. An electronic device, comprising: include: A processor is used to execute computer programs; A computer-readable storage medium storing a computer program, which, when executed by the processor, performs the supercritical carbon dioxide boiler temperature composite control method as described in any one of claims 1-5.

8. A computer-readable storage medium storing a computer program, the computer-readable storage medium comprising: When the computer program is executed by the processor, it implements the supercritical carbon dioxide boiler temperature composite control method as described in any one of claims 1-5.

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