Coal power unit thermodynamic system and control method thereof

Abstract

The invention relates to a coal power unit thermodynamic system and a control method thereof. The coal power unit thermodynamic system comprises a boiler, a pressure adjusting device and a steam turbine pressure cylinder. The pressure adjusting device is used for increasing steam pressure; a first air outlet of the boiler is communicated with the steam turbine pressure cylinder through the pressure adjusting device, and a second air outlet of the boiler is communicated with the steam turbine pressure cylinder; main steam in the boiler flows into the pressure adjusting device through a first air outlet of the boiler, the main steam is pressurized in the pressure adjusting device to form pressurized steam, and the pressurized steam flows into the steam turbine pressure cylinder. And reheat steam in the boiler flows into the steam turbine pressure cylinder through a second air outlet of the boiler, the steam turbine pressure cylinder conducts thermoelectric conversion through the pressurized steam and the reheat steam, and the thermoelectric conversion efficiency of the steam turbine pressure cylinder in the coal power unit thermodynamic system can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of power generation units, and in particular to a thermal system of a coal-fired power unit and a control method, device, computer equipment, computer-readable storage medium, and computer program product thereof. Background Art

[0002] Power generation from a coal-fired power plant is a complex energy conversion process involving the interconversion of multiple energy forms. The steam turbine in a coal-fired power plant's thermal system is a crucial component of this energy conversion process, and its operating efficiency and performance directly impact the overall efficiency and performance of the unit. In the boiler, coal is fed into the combustion chamber and burned, releasing a large amount of heat energy. Condensate in the boiler is heated and evaporated by the heating surfaces, forming high-temperature, high-pressure steam. After entering the turbine pressure cylinder, the steam expands on each stage of the blades, driving their rotation and converting the thermal energy into mechanical energy. This mechanical energy is converted into electrical energy by a generator and then transmitted to the outside world via transmission lines, achieving thermal-to-electrical conversion within the turbine pressure cylinder.

[0003] When traditional units are built, the goal is usually to generate more power, so the rated operating conditions are usually used as the design benchmark for the high-pressure cylinder of the turbine. However, with the development of new energy and the construction of new power systems, coal-fired power has gradually shifted to a regulatory and guaranteed power source. Ultra-supercritical units with large steam inlet volume generally operate at medium and low loads. When operating at medium and low loads, the main steam pressure is usually low, which easily leads to low thermoelectric conversion efficiency of the turbine pressure cylinder in the thermal system of the coal-fired power unit. Summary of the Invention

[0004] Based on this, it is necessary to provide a coal-fired power unit thermal system and its control method, device, computer equipment, computer-readable storage medium and computer program product that can improve the thermoelectric conversion efficiency of the turbine pressure cylinder in the thermal system of the coal-fired power unit to address the above technical problems.

[0005] In a first aspect, the present application provides a thermal system for a coal-fired power plant, the thermal system comprising: a boiler, a pressure regulating device, and a steam turbine pressure cylinder, wherein the pressure regulating device is used to increase steam pressure;

[0006] The first gas outlet of the boiler is communicated with the steam turbine pressure cylinder through the pressure regulating device, and the second gas outlet of the boiler is communicated with the steam turbine pressure cylinder;

[0007] The main steam in the boiler enters the pressure regulating device, and the main steam is pressure-regulated in the pressure regulating device to form boosted steam. The boosted steam enters the turbine pressure cylinder, and the reheated steam in the boiler enters the turbine pressure cylinder. The turbine pressure cylinder uses the boosted steam and the reheated steam to perform thermoelectric conversion.

[0008] In one embodiment, the thermal system of the coal-fired power unit further includes: a first valve, a second valve and a third valve; the first valve is arranged between the first air outlet of the boiler and the first air inlet of the turbine pressure cylinder, and is used to control the opening and closing of the passage between the first air outlet of the boiler and the first air inlet of the turbine pressure cylinder; the second valve is arranged between the first steam exhaust port of the pressure regulating device and the first air inlet of the turbine pressure cylinder, and is used to control the opening and closing of the passage between the first steam exhaust port of the pressure regulating device and the first air inlet of the turbine pressure cylinder; the third valve is arranged between the first steam exhaust port of the pressure regulating device and the second air inlet of the turbine pressure cylinder, and is used to control the opening and closing of the passage between the first steam exhaust port of the pressure regulating device and the second air inlet of the turbine pressure cylinder.

[0009] In one embodiment, when the load demand condition corresponding to the thermal system of the coal-fired power unit meets the preset low-load condition, the first valve and the third valve are in the closed state, and the second valve is in the open state; all the main steam in the boiler flows into the pressure regulating device, the main steam is pressurized in the pressure regulating device to form pressurized steam, and the pressurized steam flows into the turbine pressure cylinder through the second valve; when the load demand condition corresponding to the thermal system of the coal-fired power unit does not meet the preset low-load condition, the first valve and the third valve are in the open state, and the second valve is closed; a part of the main steam in the boiler flows into the pressure regulating device, the main steam is pressurized in the pressure regulating device to form pressurized steam, and the pressurized steam flows into the turbine pressure cylinder through the third valve, and another part of the main steam in the boiler flows into the turbine pressure cylinder through the first valve, and the turbine pressure cylinder uses the main steam for thermoelectric conversion.

[0010] In one embodiment, the steam turbine pressure cylinder includes a high-pressure cylinder and multiple groups of medium- and low-pressure cylinders connected in sequence, and each group of medium- and low-pressure cylinders includes one medium-pressure cylinder and two low-pressure cylinders; the ratio between the multiple groups of medium- and low-pressure cylinders corresponds to the historical load demand distribution information of the environment corresponding to the thermal system of the coal-fired power unit.

[0011] In one embodiment, the thermal system of the coal-fired power unit further includes: a plurality of fourth valves; the plurality of fourth valves are respectively arranged between the second air outlet of the boiler and the plurality of groups of medium and low pressure cylinders, and are used to adjust the opening of the passage between the second air outlet of the boiler and the medium pressure cylinder.

[0012] In one embodiment, the number of the fourth valves is consistent with the number of groups of the intermediate and low pressure cylinders, and each of the fourth valves is arranged between the intermediate pressure cylinder in each group of the intermediate and low pressure cylinders and the second air outlet of the boiler.

[0013] In one embodiment, the thermal system of the coal-fired power unit further includes a fifth valve; the fifth valve is arranged between the first air outlet of the boiler and the air inlet of the pressure regulating device, and is used to control the opening of the passage between the first air outlet of the boiler and the air inlet of the pressure regulating device.

[0014] In one embodiment, the thermal system of the coal-fired power unit further includes a high-pressure heating device, and the high-pressure heating device is connected to the second steam exhaust port of the pressure regulating device.

[0015] In one embodiment, the thermal system of the coal-fired power unit further includes a condenser, and the condenser is connected to the third exhaust port of the pressure regulating device.

[0016] In a second aspect, the present application provides a method for controlling a thermal system of a coal-fired power plant. The method comprises:

[0017] Obtaining thermal power demand information of the thermal system of the coal-fired power unit;

[0018] Determining load demand status information corresponding to the thermal system of the coal-fired power unit based on the thermal power demand information;

[0019] According to the load demand status information, controlling the pressure regulating device in the thermal system of the coal-fired power unit to regulate the pressure of the main steam discharged from the boiler to obtain pressurized steam;

[0020] The steam turbine pressure cylinder in the thermal system of the coal-fired power unit is controlled to perform thermoelectric conversion using the pressurized steam and the reheated steam discharged from the boiler.

[0021] In a third aspect, the present application further provides a thermal system control device for a coal-fired power unit, comprising:

[0022] An acquisition module, configured to acquire thermal power demand information of the thermal system of the coal-fired power unit;

[0023] a determination module, configured to determine load demand status information corresponding to the thermal system of the coal-fired power unit based on the thermal power demand information;

[0024] The control module is used to control the pressure regulating device in the thermal system of the coal-fired power unit to regulate the pressure of the main steam discharged from the boiler to obtain pressurized steam based on the load demand status information; and control the turbine pressure cylinder in the thermal system of the coal-fired power unit to use the pressurized steam and the reheated steam discharged from the boiler to perform thermoelectric conversion.

[0025] In a fourth aspect, the present application further provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0026] Obtaining thermal power demand information of the thermal system of the coal-fired power unit;

[0027] Determining load demand status information corresponding to the thermal system of the coal-fired power unit based on the thermal power demand information;

[0028] According to the load demand status information, controlling the pressure regulating device in the thermal system of the coal-fired power unit to regulate the pressure of the main steam discharged from the boiler to obtain pressurized steam;

[0029] The steam turbine pressure cylinder in the thermal system of the coal-fired power unit is controlled to perform thermoelectric conversion using the pressurized steam and the reheated steam discharged from the boiler.

[0030] In a fifth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0031] Obtaining thermal power demand information of the thermal system of the coal-fired power unit;

[0032] Determining load demand status information corresponding to the thermal system of the coal-fired power unit based on the thermal power demand information;

[0033] According to the load demand status information, controlling the pressure regulating device in the thermal system of the coal-fired power unit to regulate the pressure of the main steam discharged from the boiler to obtain pressurized steam;

[0034] The steam turbine pressure cylinder in the thermal system of the coal-fired power unit is controlled to perform thermoelectric conversion using the pressurized steam and the reheated steam discharged from the boiler.

[0035] In a sixth aspect, the present application further provides a computer program product, comprising a computer program, which, when executed by a processor, implements the following steps:

[0036] Obtaining thermal power demand information of the thermal system of the coal-fired power unit;

[0037] Determining load demand status information corresponding to the thermal system of the coal-fired power unit based on the thermal power demand information;

[0038] According to the load demand status information, controlling the pressure regulating device in the thermal system of the coal-fired power unit to regulate the pressure of the main steam discharged from the boiler to obtain pressurized steam;

[0039] The steam turbine pressure cylinder in the thermal system of the coal-fired power unit is controlled to perform thermoelectric conversion using the pressurized steam and the reheated steam discharged from the boiler.

[0040] The above-mentioned thermal system of the coal-fired power unit and its control method, device, computer equipment, computer-readable storage medium and computer program product, by arranging a pressure regulating device for boosting steam pressure between the turbine pressure cylinder and the boiler, the pressure regulating device can regulate the pressure of the main steam in the boiler before the main steam enters the turbine pressure cylinder. When the operating load of the thermal system of the coal-fired power unit is low, the main steam can be boosted by the pressure regulating device, thereby increasing the steam inlet pressure of the turbine pressure cylinder, thereby improving the thermoelectric conversion efficiency of the turbine pressure cylinder in the thermal system of the coal-fired power unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the structure of the thermal system of a coal-fired power unit in one embodiment;

[0042] Figure 2 This is a structural diagram of another embodiment in which the thermal system of a coal-fired power unit further includes a first valve, a second valve, and a third valve;

[0043] Figure 3 This is a schematic structural diagram of another embodiment in which the intermediate and low pressure cylinders of the steam turbine pressure cylinder in the thermal system of a coal-fired power unit are arranged in two groups;

[0044] Figure 4 This is a structural diagram of another embodiment in which the thermal system of a coal-fired power unit further includes a fourth valve;

[0045] Figure 5 This is a structural diagram of another embodiment in which the thermal system of a coal-fired power unit further includes a fifth valve;

[0046] Figure 6 This is a schematic structural diagram of a thermal system of a coal-fired power plant in a detailed embodiment;

[0047] Figure 7 1 is a flow chart of a method for controlling a thermal system of a coal-fired power plant in one embodiment;

[0048] Figure 8 This is a structural block diagram of a thermal system control device for a coal-fired power plant in one embodiment;

[0049] Figure 9FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment.

[0050] Description of Figure Numbers:

[0051] Boiler 11; first steam exhaust port of the boiler 111; second steam exhaust port of the boiler 112; pressure regulating device 12; first steam exhaust port of the pressure regulating device 121; second steam exhaust port of the pressure regulating device 122; third steam exhaust port of the pressure regulating device 123; steam turbine pressure cylinder 13; first air inlet 131 of the high-pressure cylinder; second air inlet 132 of the high-pressure cylinder; high-pressure cylinder 1301; first intermediate-pressure cylinder 1302; second intermediate-pressure cylinder 1303; first low-pressure cylinder 1304; second low-pressure cylinder 1305; third low-pressure cylinder 1306; fourth low-pressure cylinder 1307; first valve 14; second valve 15; third valve 16; fourth valve 17; fifth valve 18; high-pressure heating device 19; condenser 20; low-pressure heating device 21; first generator 22; second generator 23. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0053] The turbine pressure cylinder can be divided into high-pressure, intermediate-pressure, and low-pressure cylinders based on the steam inlet parameters. The high-pressure cylinder is located at the front of the turbine and is the initial stage for the main steam to enter the turbine pressure cylinder. The exhaust steam from the high-pressure cylinder enters the boiler reheater for heating before entering the intermediate-pressure cylinder to perform work. The exhaust steam from the intermediate-pressure cylinder enters the low-pressure cylinder. The exhaust steam from the low-pressure cylinder enters the condenser (the air-cooled island for air-cooled units) to condense into water before entering the heat recovery system and returning to the boiler.

[0054] Since the thermal system of traditional coal-fired power units is usually built with the goal of increasing power generation, the rated operating conditions are usually used as the design benchmark for the turbine pressure cylinder. That is, the high-pressure cylinder in a traditional steam turbine can only maintain efficient energy conversion under rated operating conditions. However, most units are currently operating at medium and low loads. Since the main steam parameters generated by the thermal system of the coal-fired power unit are different from the steam inlet volume, the steam inlet volume of the turbine pressure cylinder does not match the design value, which will lead to low thermal-electricity conversion efficiency of the turbine pressure cylinder.

[0055] In order to improve the thermal-electric conversion efficiency of the turbine pressure cylinder, such as Figure 1 As shown, the present application provides a thermal system 10 of a coal-fired power plant, which includes a boiler 11 , a pressure regulating device 12 and a steam turbine pressure cylinder 13 .

[0056] The pressure regulating device 12 is used to increase the steam pressure. The pressure regulating device 12 can be an active regulating turbine or a pre-mounted steam turbine, which is not limited here.

[0057] The first gas outlet 111 of the boiler 11 is communicated with the steam turbine pressure cylinder 13 through the pressure regulating device 12 , and the second gas outlet 112 of the boiler 11 is communicated with the steam turbine pressure cylinder 13 .

[0058] In this way, the exhaust steam in the boiler 11 can flow into the pressure regulating device 12 and the steam turbine pressure cylinder 13 through the first gas outlet 111 ; and the exhaust steam in the boiler 11 can flow into the steam turbine pressure cylinder 13 through the second gas outlet 112 .

[0059] The main steam in the boiler 11 flows into the pressure regulating device 12 through the first air outlet 111 of the boiler 11. The main steam is pressurized in the pressure regulating device 12 to form pressurized steam, which flows into the steam turbine pressure cylinder 13. The reheated steam in the boiler 11 flows into the steam turbine pressure cylinder 13 through the second air outlet 112 of the boiler 11. The steam turbine pressure cylinder 13 uses the pressurized steam and the reheated steam to perform thermoelectric conversion.

[0060] In this way, the main steam in the boiler 11 can be pressure-regulated by the pressure regulating device 12 before entering the turbine pressure cylinder 13. When the operating load of the thermal system 10 of the coal-fired power unit is low, the main steam can be pressurized by the pressure regulating device 12, thereby increasing the steam inlet pressure of the turbine pressure cylinder 13, and to a certain extent improving the thermoelectric conversion efficiency of the turbine pressure cylinder 13 in the thermal system 10 of the coal-fired power unit.

[0061] It is understandable that the operating load of a coal-fired power unit's thermal system is matched to the heat and power demand of its corresponding suppliers (e.g., residential users, industrial plant users, etc.). However, this heat and power demand is not fixed. Therefore, the coal-fired power unit's thermal system may operate in low-load, medium-load, or high-load conditions. However, when the load demand of the coal-fired power unit's thermal system meets the preset low-load condition, that is, when the coal-fired power unit's thermal system is in low-load conditions, the steam inlet to the turbine pressure cylinder in the coal-fired power unit's thermal system may not match the design value, resulting in low heat-to-electricity conversion efficiency in the turbine pressure cylinder. When the load demand of the coal-fired power unit's thermal system does not meet the preset low-load condition, that is, when the coal-fired power unit's thermal system is in high-load or medium-load conditions, the coal-fired power unit's thermal system may be unable to meet the load demand, resulting in the coal-fired power unit's thermal system being unable to meet the heat and power supply demand.

[0062] In one embodiment, referring to Figure 2The thermal system 10 of the coal-fired power unit further includes: a first valve 14 , a second valve 15 and a third valve 16 .

[0063] The first valve 14 is arranged between the first air outlet 111 of the boiler 11 and the first air inlet 131 of the turbine pressure cylinder 13, and is used to control the opening and closing of the passage between the first air outlet 111 of the boiler 11 and the first air inlet 131 of the turbine pressure cylinder 13; the second valve 15 is arranged between the first steam exhaust port 121 of the pressure regulating device 12 and the first air inlet 131 of the turbine pressure cylinder 13, and is used to control the opening and closing of the passage between the first steam exhaust port 121 of the pressure regulating device 12 and the first air inlet 131 of the turbine pressure cylinder 13; the third valve 16 is arranged between the first steam exhaust port 121 of the pressure regulating device 12 and the second air inlet 132 of the turbine pressure cylinder 13, and is used to control the opening and closing of the passage between the first steam exhaust port 121 of the pressure regulating device 12 and the second air inlet 132 of the turbine pressure cylinder 13.

[0064] Among them, the first valve 14, the second valve 15 and the third valve 16 can be stop valves, specifically, they have only two states: open and closed. The first valve 14, the second valve 15 and the third valve 16 can also be flow valves, specifically, they can achieve two states: open and closed by adjusting the opening of the flow valve (for example, when the opening of the flow valve is the maximum, the open state is achieved, and when the opening of the flow valve is the minimum, the closed state is achieved).

[0065] When the load demand condition corresponding to the thermal system 10 of the coal-fired power generation unit meets the preset low-load condition, the first valve 14 and the third valve 16 are in the closed state, and the second valve 15 is in the open state. When the load demand condition corresponding to the thermal system 10 of the coal-fired power generation unit does not meet the preset low-load condition, the first valve 14 and the third valve 16 are in the open state, and the second valve 15 is in the closed state.

[0066] The load demand status corresponding to the thermal system 10 of the coal-fired power plant is used to represent the load level corresponding to the heat and power demand of the supplier of the thermal system 10 of the coal-fired power plant under real-time conditions. When the load level represented by the load demand status corresponding to the thermal system 10 of the coal-fired power plant is less than a preset load level threshold, it is determined that the load demand status corresponding to the thermal system 10 of the coal-fired power plant meets the preset low load condition. The preset load level threshold can be set by the user as needed, or it can correspond to the rated load level corresponding to the steam turbine pressure cylinder 13. Specifically, the preset load level threshold is less than the rated load level corresponding to the steam turbine pressure cylinder 13. For example, the preset load level threshold can be 70%, or other values, which are not limited here.

[0067] When the load demand condition corresponding to the thermal system 10 of the coal-fired power unit meets the preset low-load condition, all the main steam in the boiler 11 flows into the pressure regulating device 12, and all the main steam is pressurized in the pressure regulating device 12 to form pressurized steam, which flows into the first air inlet 131 of the turbine pressure cylinder 13 through the second valve 15.

[0068] In this way, when the thermal system 10 of the coal-fired power unit is in a low-load operating condition, the pressure of the main steam can be increased to form boosted steam, so that the pressure of the steam entering the turbine pressure cylinder 13 is as high as possible, thereby improving the thermoelectric conversion efficiency of the turbine pressure cylinder 13 to a certain extent.

[0069] When the load demand condition corresponding to the thermal system 10 of the coal-fired power unit does not meet the preset low-load condition, a portion of the main steam in the boiler 11 flows into the pressure regulating device 12, and a portion of the main steam is pressurized in the pressure regulating device 12 to form pressurized steam, which flows into the second air inlet 132 of the turbine pressure cylinder 13 through the third valve 16, while another portion of the main steam flows into the first air inlet 131 of the turbine pressure cylinder 13 through the first valve 14.

[0070] In this way, when the thermal system of the coal-fired power unit is in a high-load operating condition, steam can be added to the turbine pressure cylinder 13 through the pressure regulating device 12, thereby ensuring the steam intake in the turbine pressure cylinder 13, and thus enabling the turbine pressure cylinder 13 to meet the thermal power supply requirements, that is, enabling the thermal system 10 of the coal-fired power unit to meet the thermal power supply requirements.

[0071] In one embodiment, the steam turbine pressure cylinder 13 includes a high-pressure cylinder and multiple groups of medium- and low-pressure cylinders connected in sequence, each group of medium- and low-pressure cylinders includes one medium-pressure cylinder and two low-pressure cylinders; the ratio between the multiple groups of medium- and low-pressure cylinders corresponds to the historical load demand distribution information of the thermal system of the coal-fired power unit corresponding to the environment in which it is located.

[0072] The historical load demand distribution information represents the distribution of load demand levels for the thermal system of the coal-fired power unit at a given moment in time. The ratios between multiple groups of intermediate and low-pressure cylinders represent the steam inlet information ratios between these groups. The ratios between multiple groups of intermediate and low-pressure cylinders include at least one of the intake volume ratio, the load ratio, and the flow area ratio. The sum of all the ratios between these groups is 1.

[0073] Take the example of setting up two sets of medium and low pressure cylinders, refer to Figure 3The turbine pressure cylinder 13 includes a high-pressure cylinder 1301, a first intermediate-pressure cylinder 1302, a second intermediate-pressure cylinder 1303, a first low-pressure cylinder 1304, a second low-pressure cylinder 1305, a third low-pressure cylinder 1306 and a fourth low-pressure cylinder 1307. The air inlet of the first intermediate-pressure cylinder 1302 is connected to the air inlet of the second intermediate-pressure cylinder 1303, the air inlet of the first intermediate-pressure cylinder 1302 is connected to the air inlet of the first low-pressure cylinder 1304 and the air inlet of the second low-pressure cylinder 1305 respectively, the air inlet of the second intermediate-pressure cylinder 1303 is connected to the air inlet of the third low-pressure cylinder 1306 and the air inlet of the third low-pressure cylinder 1307 respectively. The air inlet of the fourth low-pressure cylinder 1307 is connected, the first valve 14 is arranged between the first air outlet of the boiler 11 and the first air inlet 131 of the high-pressure cylinder 1301, the second valve 15 is arranged between the first steam exhaust port 121 of the pressure regulating device 12 and the first air inlet 131 of the high-pressure cylinder 1301, the third valve 16 is arranged between the first steam exhaust port 121 of the pressure regulating device 12 and the second air inlet 132 of the high-pressure cylinder 1301, and the second air inlet of the boiler 11 is respectively connected to the air inlets of the first intermediate-pressure cylinder 1302 and the second intermediate-pressure cylinder 1303.

[0074] Among them, the ratio between the first intermediate pressure cylinder 1302 and the second intermediate pressure cylinder 1303, the ratio between the first low pressure cylinder 1304 and the third low pressure cylinder 1306, and the ratio between the second low pressure cylinder 1305 and the fourth low pressure cylinder 1307 are equal. For example, the ratio between the above three groups of pressure cylinders can be 5:5, 4:6, or 7:3, etc., which is not limited here.

[0075] When the load demand condition corresponding to the thermal system 10 of the coal-fired power unit meets the preset low-load condition, all the main steam in the boiler 11 flows into the pressure regulating device 12, all the main steam is pressurized in the pressure regulating device 12 to form pressurized steam, and the pressurized steam flows into the first air inlet 131 of the high-pressure cylinder 1301 through the second valve 15. The high-pressure cylinder 1301 uses the pressurized steam for thermoelectric conversion; when the load demand condition corresponding to the thermal system 10 of the coal-fired power unit does not meet the preset low-load condition, part of the main steam in the boiler 11 flows into the pressure regulating device 12, part of the main steam is pressurized in the pressure regulating device 12 to form pressurized steam, and the pressurized steam flows into the second air inlet 132 of the high-pressure cylinder 1301 through the third valve 16, while the other part of the main steam flows into the first air inlet 131 of the turbine pressure cylinder 13 through the first valve 14, and the high-pressure cylinder 1301 uses the pressurized steam and part of the main steam for thermoelectric conversion.

[0076] The reheated steam in the boiler 11 flows into the first intermediate pressure cylinder 1302, the second intermediate pressure cylinder 1303, the first low pressure cylinder 1304, the second low pressure cylinder 1305, the third low pressure cylinder 1306 and the fourth low pressure cylinder 1307 through the second air outlet of the boiler 11. The first intermediate pressure cylinder 1302, the second intermediate pressure cylinder 1303, the first low pressure cylinder 1304, the second low pressure cylinder 1305, the third low pressure cylinder 1306 and the fourth low pressure cylinder 1307 use the reheated steam to perform thermoelectric conversion.

[0077] Among them, the high-pressure cylinder 1301, the first intermediate-pressure cylinder 1302, the second intermediate-pressure cylinder 1303, the first low-pressure cylinder 1304, the second low-pressure cylinder 1305, the third low-pressure cylinder 1306 and the fourth low-pressure cylinder 1307 are axially connected in sequence.

[0078] In this way, the high-pressure cylinder 1301, the first intermediate-pressure cylinder 1302, the second intermediate-pressure cylinder 1303, the first low-pressure cylinder 1304, the second low-pressure cylinder 1305, the third low-pressure cylinder 1306 and the fourth low-pressure cylinder 1307 can realize the conversion between thermal energy and mechanical energy through sequential axial connection, and then the conducted mechanical energy can be converted into electrical energy through the generator.

[0079] In one embodiment, the thermal system 10 of the coal-fired power generation unit further includes: a plurality of fourth valves.

[0080] Multiple fourth valves are respectively arranged between the second air outlet 112 of the boiler 11 and the intermediate pressure cylinders in the multiple groups of intermediate and low pressure cylinders (such as the first intermediate pressure cylinder 1302 and the second intermediate pressure cylinder 1303 mentioned above), and are used to adjust the opening of the passage between the second air outlet 112 of the boiler 11 and the intermediate pressure cylinders.

[0081] The greater the valve opening of the fourth valve is, the greater the opening of the passage between the second gas outlet 112 of the boiler 11 and the intermediate pressure cylinder is.

[0082] In one embodiment, the number of the fourth valves is consistent with the number of the groups of intermediate and low pressure cylinders, and each fourth valve is disposed between the intermediate pressure cylinder in each group of intermediate and low pressure cylinders and the second gas outlet 112 of the boiler 11 .

[0083] Take the example of setting up two sets of medium and low pressure cylinders, refer to Figure 4 A fourth valve 17 is provided between the second air outlet 112 of the boiler 11 and the first intermediate pressure cylinder 1302, for adjusting the opening of the passage between the second air outlet 112 of the boiler 11 and the first intermediate pressure cylinder 1302; another fourth valve 17 is provided between the second air outlet 112 of the boiler 11 and the second intermediate pressure cylinder 1303, for adjusting the opening of the passage between the second air outlet 112 of the boiler 11 and the second intermediate pressure cylinder 1303.

[0084] In this way, the steam intake amount of the first intermediate pressure cylinder 1302 and the second intermediate pressure cylinder 1303 can be adjusted through the fourth valve 17, and then the steam intake amount of the first low pressure cylinder 1304 and the second low pressure cylinder 1305 connected to the first intermediate pressure cylinder 1302 can be adjusted, as well as the steam intake amount of the third low pressure cylinder 1306 and the fourth low pressure cylinder 1307 connected to the second intermediate pressure cylinder 1303 can be adjusted.

[0085] In one embodiment, the ratio between the steam turbine pressure cylinder 13 and the pressure regulating device 12 corresponds to the load demand condition of the thermal system 10 of the coal-fired power unit.

[0086] Among them, the ratio between the turbine pressure cylinder 13 and the pressure regulating device 12 includes at least one of the intake volume ratio between the turbine pressure cylinder 13 and the pressure regulating device 12, the load ratio between the turbine pressure cylinder 13 and the pressure regulating device 12, and the flow area ratio between the turbine pressure cylinder 13 and the pressure regulating device 12.

[0087] It is understandable that when the load demand corresponding to the thermal system 10 of the coal-fired power unit does not meet the preset low-load conditions, there is a risk that the turbine pressure cylinder 13 cannot meet the thermal power supply requirements. At this time, the turbine pressure cylinder 13 can operate at the rated operating condition (maximum operating condition), and the pressure regulating device 12 has a portion of the main steam allocation and supplementary steam for the turbine pressure cylinder 13. Then, although the turbine pressure cylinder 13 can meet the thermal power supply requirements, the thermal power conversion efficiency of the turbine pressure cylinder 13 may still be low.

[0088] In one embodiment, the steam intake of the high-pressure cylinder 1301 in the steam turbine pressure cylinder 13 is greater than the steam intake of the pressure regulating device 12 .

[0089] In this way, the steam intake of the turbine pressure cylinder 13 can be increased to a certain extent. However, when the difference between the steam intake of the high-pressure cylinder 1301 and the steam intake of the pressure regulating device 12 is not large, the thermoelectric conversion efficiency of the turbine pressure cylinder 13 is still low.

[0090] In one embodiment, referring to Figure 5 The thermal system 10 of the coal-fired power unit also includes a fifth valve 18; the fifth valve 18 is arranged between the first gas outlet 111 of the boiler 11 and the air inlet of the pressure regulating device 12, and is used to control the opening of the passage between the first gas outlet 111 of the boiler 11 and the air inlet of the pressure regulating device 12.

[0091] Among them, when the load level represented by the load demand condition corresponding to the thermal system 10 of the coal-fired power unit is not lower than the load level corresponding to the rated operating condition of the turbine pressure cylinder 13, the turbine pressure cylinder 13 is in the rated operating condition, and the valve opening of the fifth valve 18 corresponds to the load level difference value. The load level difference value is the difference between the load level represented by the load demand condition corresponding to the thermal system 10 of the coal-fired power unit and the load level corresponding to the rated operating condition of the turbine pressure cylinder 13. The higher the load level difference value, the greater the valve opening of the fifth valve 18.

[0092] In this way, it is possible to ensure both high thermoelectric conversion efficiency of the steam turbine pressure cylinder 13 and satisfy the thermoelectric supply requirements.

[0093] In one embodiment, the thermal system 10 of the coal-fired power unit further includes a first generator, and the pressure regulating device 12 is connected to the first generator. When the load demand condition corresponding to the thermal system 10 of the coal-fired power unit does not meet the preset low-load condition, the first generator uses the heat loss between the pressure regulating device 12 and the turbine pressure cylinder 13 to perform thermoelectric conversion.

[0094] In this way, the heat loss between the pressure regulating device 12 and the turbine pressure cylinder 13 can be utilized through the first generator and converted into electrical energy, which can reduce the energy loss of the thermal system 10 of the coal-fired power unit to a certain extent.

[0095] In one embodiment, the thermal system 10 of the coal-fired power unit further includes a high-pressure heating device, which is connected to the second steam exhaust port 122 of the pressure regulating device 12 .

[0096] Among them, when the load demand condition corresponding to the thermal system 10 of the coal-fired power unit does not meet the preset low-load condition, the high-pressure heating device is in the open state.

[0097] In this way, when the load demand condition corresponding to the thermal system 10 of the coal-fired power unit does not meet the preset low-load condition, the exhaust steam temperature of the pressure regulating device 12 is low, and the temperature of the mixed water formed by mixing the condensate and the exhaust steam of the pressure regulating device 12 is low. Therefore, the above-mentioned mixed water is heated by the high-pressure heating device to ensure the return water temperature of the boiler 11.

[0098] In one embodiment, the thermal system 10 of the coal-fired power unit further includes a condenser, which is connected to the third exhaust port 123 of the pressure regulating device 12 .

[0099] When the thermal system 10 of the coal-fired power unit is in an accident condition, the exhaust steam of the pressure regulating device 12 flows into the condenser through the third exhaust port 123 . The accident condition is an abnormal operating condition.

[0100] In this way, the normal operation of the pressure regulating device 12 under accident conditions can be guaranteed.

[0101] In one of the detailed embodiments, taking the arrangement of two sets of medium and low pressure cylinders as an example, referring to Figure 6 The air inlet of the first intermediate pressure cylinder 1302 is connected to the air inlet of the second intermediate pressure cylinder 1303, the air inlet of the first intermediate pressure cylinder 1302 is connected to the air inlet of the first low pressure cylinder 1304 and the air inlet of the second low pressure cylinder 1305 respectively, the air inlet of the second intermediate pressure cylinder 1303 is connected to the air inlet of the third low pressure cylinder 1306 and the air inlet of the fourth low pressure cylinder 1307 respectively, the first valve 14 is set between the first air outlet of the boiler 11 and the first air inlet 131 of the high pressure cylinder 1301, the second valve 15 is set between the first exhaust port 121 of the pressure regulating device 12 and The third valve 16 is arranged between the first air inlet 131 of the high-pressure cylinder 1301 and the first exhaust port 121 of the pressure regulating device 12 and the second air inlet 132 of the high-pressure cylinder 1301. The second air inlet of the boiler 11 is connected to the air inlets of the first intermediate-pressure cylinder 1302 and the second intermediate-pressure cylinder 1303 respectively, and the exhaust port of the first low-pressure cylinder 1304, the exhaust port of the second low-pressure cylinder 1305, the exhaust port of the third low-pressure cylinder 1306 and the exhaust port of the fourth low-pressure cylinder 1307 are connected respectively. A fourth valve 17 is arranged between the second air outlet 112 of the boiler 11 and the first exhaust port 113 of the first low-pressure cylinder 1304. The first intermediate pressure cylinder 1302 is connected to the second intermediate pressure cylinder 1303, another fourth valve 17 is set between the high pressure cylinder 1301 and the second intermediate pressure cylinder 1303, the fifth valve 18 is set between the first air outlet 111 of the boiler 11 and the air inlet of the pressure regulating device 12, the high pressure heating device 19 is connected to the second exhaust port 122 of the pressure regulating device 12, the high pressure cylinder 1301, the first intermediate pressure cylinder 1302 and the second intermediate pressure cylinder 1303 respectively, the condenser 20 is connected to the first intermediate pressure cylinder 1302 and the second intermediate pressure cylinder 1303 respectively, and the condenser 20 is connected to the third exhaust port of the pressure regulating device 12 123 are connected, the low-pressure heating device 21 is connected with the first low-pressure cylinder 1304, the second low-pressure cylinder 1305, the third low-pressure cylinder 1306 and the fourth low-pressure cylinder 1307 respectively, the low-pressure heating device 21 is arranged between the high-pressure heating device 19 and the condenser 20, the pressure regulating device 12 is connected with the first generator 22, and the high-pressure cylinder 1301, the first intermediate-pressure cylinder 1302, the second intermediate-pressure cylinder 1303, the first low-pressure cylinder 1304, the second low-pressure cylinder 1305, the third low-pressure cylinder 1306, the fourth low-pressure cylinder 1307 and the second generator 23 are axially connected in sequence.

[0102] Among them, when the load demand condition corresponding to the thermal system 10 of the coal-fired power unit meets the preset low-load condition, all the main steam in the boiler 11 flows into the pressure regulating device 12, and all the main steam is pressurized in the pressure regulating device 12 to form pressurized steam, and the pressurized steam flows into the first air inlet 131 of the high-pressure cylinder 1301 through the second valve 15, and the high-pressure cylinder 1301 uses the pressurized steam to achieve thermoelectric conversion through the second generator 23; when the load demand condition corresponding to the thermal system 10 of the coal-fired power unit does not meet the preset low-load condition, a part of the main steam in the boiler 11 flows into the pressure regulating device 12, and a part of the main steam is pressurized in the pressure regulating device 12 to form pressurized steam, and the pressurized steam flows into the second air inlet 132 of the high-pressure cylinder 1301 through the third valve 16, and the other part of the main steam Steam flows into the first air inlet 131 of the steam turbine pressure cylinder 13 through the first valve 14, and the high-pressure cylinder 1301 uses the supercharged steam and part of the main steam to achieve thermoelectric conversion through the second generator 23; the heat loss between the pressure regulating device 12 and the high-pressure cylinder 1301 is achieved through the first generator 22 to achieve thermoelectric conversion; the reheated steam in the boiler 11 flows into the first intermediate-pressure cylinder 1302, the second intermediate-pressure cylinder 1303, the first low-pressure cylinder 1304, the second low-pressure cylinder 1305, the third low-pressure cylinder 1306 and the fourth low-pressure cylinder 1307 through the second air outlet of the boiler 11, and the first intermediate-pressure cylinder 1302, the second intermediate-pressure cylinder 1303, the first low-pressure cylinder 1304, the second low-pressure cylinder 1305, the third low-pressure cylinder 1306 and the fourth low-pressure cylinder 1307 use the reheated steam to achieve thermoelectric conversion through the second generator 23.

[0103] Among them, the condensate in the condenser flows into the low-pressure heating device 21, and the exhaust steam of the first low-pressure cylinder 1304, the second low-pressure cylinder 1305, the third low-pressure cylinder 1306 and the fourth low-pressure cylinder 1307 are discharged into the low-pressure heating device 21, and mixed with the condensate in the low-pressure heating device 21 to form mixed water, and the mixed water flows into the high-pressure heating device, and the exhaust steam of the high-pressure cylinder 1301, the first intermediate-pressure cylinder 1302 and the second intermediate-pressure cylinder 1303 are discharged into the high-pressure heating device 19, and the mixed water is heated with the exhaust steam of the high-pressure cylinder 1301, the first intermediate-pressure cylinder 1302 and the second intermediate-pressure cylinder 1303 in the high-pressure heating device 19 to form recycled water, and returned to the boiler 11.

[0104] Based on the same inventive concept, in one embodiment, Figure 7 As shown, a method for controlling the thermal system of a coal-fired power plant is provided, which is applied to Figures 1 to 6 The controller of the thermal system of a coal-fired power plant shown in FIG. is used as an example for explanation. The controller is electrically connected to each valve in the thermal system of the coal-fired power plant to adjust the valve opening of each valve. The controller is also electrically connected to each component in the thermal system of the coal-fired power plant to control each component. The method comprises the following steps:

[0105] Step 702: Obtain thermal power demand information of the thermal system of the coal-fired power unit.

[0106] The thermal power demand information is used to characterize the thermal power supply demand of the supplier corresponding to the thermal system of the coal-fired power unit, and the thermal power demand information is used to characterize at least one of the electricity demand and the water demand temperature.

[0107] As an embodiment, step 702 includes: the controller obtains heat and power demand information of the thermal system of the coal-fired power unit from a management server of the thermal system of the coal-fired power unit.

[0108] Step 704: Determine the load demand status information corresponding to the thermal system of the coal-fired power unit based on the thermal power demand information.

[0109] The load demand status information is used to characterize the load level required for the thermal system of the coal-fired power unit to operate, for example, 40%, 80%, 100%, or 105%, etc., which is not limited here.

[0110] As an embodiment, step 704 includes: based on the thermal power demand information, evaluating the thermal power demand corresponding to the thermal system of the coal-fired power unit, wherein the thermal power demand includes at least one of the electricity demand and the water demand temperature, and obtaining a mapping relationship between the thermal power demand and the load degree represented by the load demand status information, wherein specifically, the higher the thermal power demand, the greater the load degree represented by the load demand status information, and the mapping relationships between the electricity demand and the water demand temperature and the load degree represented by the load demand status information can be the same or different, and there is no limitation here; through the mapping relationship, the thermal power demand corresponding to the thermal system of the coal-fired power unit is mapped to the load demand status information corresponding to the thermal system of the coal-fired power unit.

[0111] Step 706 , based on the load demand information, control the pressure regulating device in the thermal system of the coal-fired power unit to pressurize the main steam discharged from the boiler to obtain pressurized steam.

[0112] As an embodiment, step 706 includes: determining a boost parameter of a pressure regulating device based on load demand status information, wherein the lower the load level represented by the load demand status information, the higher the boost level corresponding to the boost parameter of the pressure regulating device; and controlling the pressure regulating device in the thermal system of the coal-fired power unit to boost the main steam discharged from the boiler based on the boost parameter to obtain boosted steam.

[0113] Step 708: Control the steam turbine pressure cylinder in the thermal system of the coal-fired power unit to perform thermoelectric conversion using the pressurized steam and the reheated steam discharged from the boiler.

[0114] As an embodiment, step 708 includes: controlling the steam turbine pressure cylinder in the thermal system of the coal-fired power unit to convert the heat energy in the pressurized steam and the reheated steam discharged from the boiler into electrical energy.

[0115] In the above embodiment, the thermal power supply demand of the supplier corresponding to the thermal system of the coal-fired power unit is first quantified using thermal power demand information, thereby defining the load demand status information corresponding to the thermal system of the coal-fired power unit. Then, according to the load demand status information, the pressure regulating device can be controlled to pressurize the main steam discharged from the boiler to obtain pressurized steam, so that the pressurizing action matches the load demand status information corresponding to the thermal system of the coal-fired power unit, thereby increasing the steam inlet pressure of the turbine pressure cylinder and improving the thermoelectric conversion efficiency of the turbine pressure cylinder in the thermal system of the coal-fired power unit.

[0116] In one of the embodiments, the above method also includes: if it is detected that the load demand condition corresponding to the thermal system of the coal-fired power unit meets the preset low load condition, then the first valve and the third valve are controlled to be closed, and the second valve is controlled to be opened; if it is detected that the load demand condition corresponding to the thermal system of the coal-fired power unit meets the preset low load condition, then the second valve is controlled to be closed, and the first valve and the third valve are controlled to be opened.

[0117] In this way, when the thermal system of the coal-fired power unit is in a low-load condition, the pressure of the main steam can be increased to form boosted steam, so that the pressure of the steam entering the turbine pressure cylinder is as high as possible, and the thermoelectric conversion efficiency of the turbine pressure cylinder can be improved to a certain extent; when the thermal system of the coal-fired power unit is in a high-load condition, the turbine pressure cylinder can be supplemented with steam through the pressure regulating device to ensure the steam intake in the turbine pressure cylinder, so that the turbine pressure cylinder can meet the thermal power supply requirements, and the thermal system of the coal-fired power unit can meet the thermal power supply requirements.

[0118] In one embodiment, historical load demand distribution information of the thermal system of the coal-fired power unit corresponding to the environment in which it is located is obtained, and multiple groups of intermediate and low pressure cylinders are selected from multiple preset intermediate and low pressure cylinders based on the historical load demand distribution information.

[0119] Furthermore, based on the historical load demand distribution information, multiple groups of medium and low pressure cylinders are selected from multiple preset medium and low pressure cylinders, including: locating the load demand degree with the most distribution conditions from the historical load demand distribution information, and selecting multiple groups of medium and low pressure cylinders from multiple preset medium and low pressure cylinders based on the load demand degree with the most distribution conditions. Specifically, the sum of the proportions between all the selected multiple groups of medium and low pressure cylinders is 1, and there is a group of medium and low pressure cylinders among the multiple groups of medium and low pressure cylinders whose corresponding proportion is the same as the load demand degree with the most distribution conditions.

[0120] In this way, it is ensured that when designing multiple groups of medium and low pressure cylinders, the historical load demand distribution of the thermal system of the coal-fired power unit corresponding to the environment in which it is located is taken into consideration, so that when the thermal system of the coal-fired power unit is in operation, there is at least one group of medium and low pressure cylinders that can operate at its rated load, ensuring the thermoelectric conversion efficiency of at least one medium and low pressure cylinder in the thermal system of the coal-fired power unit.

[0121] In one embodiment, the valve control opening of each fourth valve is determined based on the load demand status information, wherein the valve control opening can be a target value of the valve control or an adjustment value of the valve control, which is not limited here; according to the valve control opening of each fourth valve, each fourth valve is controlled separately, wherein the closer the rated load level of the medium and low pressure cylinders corresponding to the fourth valve is to the load level represented by the load demand status information, the larger the valve control opening of the fourth valve.

[0122] In this way, it can be ensured that the steam intake amount of the medium and low pressure cylinders is greater when the corresponding rated load level is closer to the load level represented by the load demand status information, that is, the closer the medium and low pressure cylinders are to the rated power when the corresponding rated load level is closer to the load level represented by the load demand status information, thereby ensuring the thermoelectric conversion efficiency of the medium and low pressure cylinders to a certain extent.

[0123] In one embodiment, the valve control opening of the fifth valve is determined according to the load demand status information, and the fifth valve is controlled according to the valve control opening of the fifth valve.

[0124] Furthermore, based on the load demand status information, the valve control opening of the fifth valve is determined, including: determining the difference between the load degree represented by the load demand status corresponding to the thermal system of the coal-fired power unit and the load degree corresponding to the rated operating condition of the turbine pressure cylinder, obtaining the load degree difference value, and determining the valve control opening of the fifth valve based on the load degree difference value, wherein the higher the load degree difference value, the larger the valve control opening of the fifth valve.

[0125] In this way, both high thermoelectric conversion efficiency of the steam turbine pressure cylinder and meeting the thermoelectric supply requirements can be ensured.

[0126] In one embodiment, when the load demand condition corresponding to the thermal system of the coal-fired power unit does not meet the preset low load condition, the first generator is controlled to perform thermoelectric conversion on the heat loss between the pressure regulating device and the turbine pressure cylinder.

[0127] The load demand status corresponding to the thermal system of the coal-fired power unit is used to represent the load level corresponding to the thermal power demand of the supplier of the thermal system of the coal-fired power unit under real-time conditions. When the load level represented by the load demand status corresponding to the thermal system of the coal-fired power unit is less than a preset load level threshold, the load demand status corresponding to the thermal system of the coal-fired power unit is determined to meet the preset low load condition. The preset load level threshold can be set by the user as needed, or it can correspond to the rated load level corresponding to the steam turbine pressure cylinder. Specifically, the preset load level threshold is less than the rated load level corresponding to the steam turbine pressure cylinder. For example, the preset load level threshold can be 70%, or other values, which are not limited here.

[0128] In one of the embodiments, when the load demand condition corresponding to the thermal system of the coal-fired power unit does not meet the preset low-load condition, the high-pressure heating device is controlled to perform heating.

[0129] In this way, when the load demand condition corresponding to the thermal system of the coal-fired power unit does not meet the preset low-load condition, the exhaust steam temperature of the pressure regulating device is low, and the temperature of the mixed water formed by mixing the condensate and the exhaust steam of the pressure regulating device is low. Therefore, the above-mentioned mixed water is heated by the high-pressure heating device to ensure the return water temperature of the boiler.

[0130] In one embodiment, when the thermal system of the coal-fired power unit is in an accident condition, the pressure regulating device is controlled to discharge the exhaust steam into the condenser.

[0131] In this way, the normal operation of the pressure regulating device can be guaranteed under accident conditions.

[0132] In one of the detailed embodiments, the thermal power demand information of the thermal system of the coal-fired power unit is obtained; based on the thermal power demand information, the load demand status information corresponding to the thermal system of the coal-fired power unit is determined; according to the load demand status information, the pressure regulating device in the thermal system of the coal-fired power unit is controlled to pressurize the main steam discharged from the boiler to obtain pressurized steam; the turbine pressure cylinder in the thermal system of the coal-fired power unit is controlled to use the pressurized steam and the reheated steam discharged from the boiler to perform thermoelectric conversion; if it is detected that the load demand status corresponding to the thermal system of the coal-fired power unit meets the preset low load condition, the first valve and the third valve are controlled to be closed, and the second valve is controlled to be opened; if it is detected that the load demand status corresponding to the thermal system of the coal-fired power unit meets the preset low load condition, the second valve is controlled to be closed, and the first valve and the third valve are controlled to be opened; the historical load demand distribution information of the thermal system of the coal-fired power unit corresponding to the environment is obtained, and according to the historical load demand distribution information, multiple groups of medium and low pressure cylinders are selected from multiple preset medium and low pressure cylinders; according to the load demand status information, the Determine the valve control opening of each fourth valve, wherein the valve control opening can be a target value for valve control or an adjustment value for valve control, which is not limited here; control each fourth valve separately according to the valve control opening of each fourth valve, wherein the closer the rated load degree of the medium and low pressure cylinders corresponding to the fourth valve is to the load degree represented by the load demand status information, the larger the valve control opening of the fourth valve; determine the valve control opening of the fifth valve according to the load demand status information, and control the fifth valve according to the valve control opening of the fifth valve; when the load demand status corresponding to the thermal system of the coal-fired power unit does not meet the preset low load condition, control the first generator to convert the heat loss between the pressure regulating device and the turbine pressure cylinder into thermoelectricity; when the load demand status corresponding to the thermal system of the coal-fired power unit does not meet the preset low load condition, control the high-pressure heating device to heat; when the thermal system of the coal-fired power unit is in an accident condition, control the pressure regulating device to discharge the exhaust steam into the condenser.

[0133] In this way, the thermal power supply demand of the supplier corresponding to the thermal system of the coal-fired power unit is first quantified using thermal power demand information, thereby defining the load demand status information corresponding to the thermal system of the coal-fired power unit. Then, according to the load demand status information, the pressure regulating device can be controlled to pressurize the main steam discharged from the boiler to obtain pressurized steam, so that the pressurizing action matches the load demand status information corresponding to the thermal system of the coal-fired power unit, thereby increasing the steam inlet pressure of the turbine pressure cylinder and improving the thermoelectric conversion efficiency of the turbine pressure cylinder in the thermal system of the coal-fired power unit.

[0134] It should be understood that, although the steps in the flowcharts of the above embodiments are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts of the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily to be performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0135] Based on the same inventive concept, embodiments of the present application also provide a coal-fired power unit thermal system control device for implementing the aforementioned coal-fired power unit thermal system control method. The implementation solution provided by this device is similar to the implementation solution described in the aforementioned method. Therefore, the specific limitations in one or more embodiments of the coal-fired power unit thermal system control device provided below can be found in the above-mentioned limitations of the coal-fired power unit thermal system control method and will not be repeated here.

[0136] In one embodiment, Figure 8 As shown, a thermal system control device 800 for a coal-fired power plant is provided, comprising: an acquisition module 802, a determination module 804, and a control module 806, wherein:

[0137] An acquisition module 802 is used to obtain thermal power demand information of a thermal system of a coal-fired power unit;

[0138] Determination module 804, for determining load demand status information corresponding to the thermal system of the coal-fired power unit based on the thermal power demand information;

[0139] Control module 806 is used to control the pressure regulating device in the thermal system of the coal-fired power unit to regulate the pressure of the main steam discharged from the boiler to obtain pressurized steam based on the load demand status information; and control the turbine pressure cylinder in the thermal system of the coal-fired power unit to use the pressurized steam and the reheated steam discharged from the boiler to perform thermoelectric conversion.

[0140] In one embodiment, the control module 806 is also used to control the first valve and the third valve to close and the second valve to open if it is detected that the load demand condition corresponding to the thermal system of the coal-fired power unit meets the preset low load condition; if it is detected that the load demand condition corresponding to the thermal system of the coal-fired power unit meets the preset low load condition, the second valve to close and the first valve and the third valve to open.

[0141] In one embodiment, the acquisition module 802 is also used to obtain historical load demand distribution information of the thermal system of the coal-fired power unit corresponding to the environment in which it is located. The above-mentioned device also includes: a selection module, which selects multiple groups of medium and low pressure cylinders from multiple preset medium and low pressure cylinders based on the historical load demand distribution information.

[0142] In one embodiment, the determination module 804 is further used to determine the valve control opening of each fourth valve based on the load demand status information, and the control module 806 is further used to control each fourth valve separately according to the valve control opening of each fourth valve, wherein the closer the rated load level of the medium and low pressure cylinders corresponding to the fourth valve is to the load level represented by the load demand status information, the larger the valve control opening of the fourth valve.

[0143] In one embodiment, the determination module 804 is further configured to determine the valve control opening of the fifth valve according to the load demand status information, and the control module 806 is further configured to control the fifth valve according to the valve control opening of the fifth valve.

[0144] In one embodiment, the control module 806 is further configured to control the first generator to perform thermoelectric conversion on the heat loss between the pressure regulating device and the steam turbine pressure cylinder when the load demand corresponding to the thermal system of the coal-fired power unit does not meet the preset low load condition.

[0145] In one embodiment, the control module 806 is further configured to control the pressure regulating device to discharge the exhaust steam into the condenser when the thermal system of the coal-fired power unit is in an accident condition.

[0146] Each module in the aforementioned coal-fired power unit thermal system control device may be implemented in whole or in part through software, hardware, or a combination thereof. Each module may be embedded in or independent of a processor within a computer device in the form of hardware, or may be stored in a computer device memory in the form of software, so that the processor can call and execute the corresponding operations of each module.

[0147] In one embodiment, a computer device is provided. The computer device may be a controller, and its internal structure diagram may be as follows: Figure 9As shown. The computer device includes a processor, a memory, and a network interface connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device is used to store data such as operating condition information and rated operating conditions. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a method for controlling the thermal system of a coal-fired power unit is implemented.

[0148] Those skilled in the art will understand that Figure 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0149] In one embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor implements the specific steps of the above-mentioned embodiment of the method for controlling the thermal system of a coal-fired power plant when executing the computer program.

[0150] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the specific steps of the above-mentioned embodiment of the method for controlling the thermal system of a coal-fired power plant are implemented.

[0151] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the specific steps of the above-mentioned embodiment of the method for controlling a thermal system of a coal-fired power plant.

[0152] It should be noted that the user information (including but not limited to thermal power demand information, historical load demand distribution information, etc.) and data (including but not limited to data used for analysis, storage, and display, etc.) involved in this application are all authorized by the user or have been fully authorized by all parties. Furthermore, the acquisition, storage, processing, and transmission of this data comply with relevant laws and regulations.

[0153] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. Among them, any reference to memory, database or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processors (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like.

[0154] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0155] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A thermal system of a coal-fired power unit, characterized in that: The thermal system of the coal-fired power unit includes: a boiler, a pressure regulating device and a steam turbine pressure cylinder; The pressure regulating device is used to increase the steam pressure; the first gas outlet of the boiler is connected to the steam turbine pressure cylinder through the pressure regulating device, and the second gas outlet of the boiler is connected to the steam turbine pressure cylinder; The main steam in the boiler flows into the pressure regulating device through the first air outlet of the boiler, the main steam is pressurized in the pressure regulating device to form pressurized steam, the pressurized steam flows into the turbine pressure cylinder, and the reheated steam in the boiler flows into the turbine pressure cylinder through the second air outlet of the boiler, and the turbine pressure cylinder uses the pressurized steam and the reheated steam to perform thermoelectric conversion.

2. The thermal system of a coal-fired power plant according to claim 1, characterized in that: The thermal system of the coal-fired power unit further includes: a first valve, a second valve and a third valve; The first valve is arranged between the first air outlet of the boiler and the first air inlet of the steam turbine pressure cylinder, and is used to control the opening and closing of the passage between the first air outlet of the boiler and the first air inlet of the steam turbine pressure cylinder; The second valve is arranged between the first steam exhaust port of the pressure regulating device and the first air inlet of the steam turbine pressure cylinder, and is used to control the opening and closing of the passage between the first steam exhaust port of the pressure regulating device and the first air inlet of the steam turbine pressure cylinder; The third valve is arranged between the first exhaust port of the pressure regulating device and the second air inlet of the turbine pressure cylinder, and is used to control the opening and closing of the passage between the first exhaust port of the pressure regulating device and the second air inlet of the turbine pressure cylinder.

3. The thermal system of the coal-fired power plant according to claim 2, characterized in that: When the load demand condition corresponding to the thermal system of the coal-fired power unit meets the preset low-load condition, the first valve and the third valve are in the closed state, and the second valve is in the open state; All the main steam in the boiler flows into the pressure regulating device, the main steam is pressurized in the pressure regulating device to form pressurized steam, and the pressurized steam flows into the turbine pressure cylinder through the second valve; When the load demand condition corresponding to the thermal system of the coal-fired power unit does not meet the preset low-load condition, the first valve and the third valve are in the open state, and the second valve is in the closed state; A portion of the main steam in the boiler flows into the pressure regulating device, and the main steam is pressurized in the pressure regulating device to form pressurized steam. The pressurized steam flows into the turbine pressure cylinder through the third valve, and another portion of the main steam in the boiler flows into the turbine pressure cylinder through the first valve. The turbine pressure cylinder uses the main steam for thermoelectric conversion.

4. The thermal system of a coal-fired power plant according to claim 2, characterized in that: The steam turbine pressure cylinder includes a high-pressure cylinder and multiple groups of medium- and low-pressure cylinders connected in sequence, and each group of medium- and low-pressure cylinders includes a medium-pressure cylinder and two low-pressure cylinders; The ratio between the multiple groups of medium and low pressure cylinders corresponds to the historical load demand distribution information of the environment in which the thermal system of the coal-fired power unit is located.

5. The thermal system of the coal-fired power plant according to claim 4, characterized in that: The thermal system of the coal-fired power unit further includes: a plurality of fourth valves; The plurality of fourth valves are respectively arranged between the second air outlet of the boiler and the plurality of groups of medium and low pressure cylinders, and are used to adjust the opening of the passage between the second air outlet of the boiler and the medium pressure cylinder.

6. The thermal system of a coal-fired power plant according to claim 5, characterized in that: The number of the fourth valves is consistent with the number of groups of the intermediate and low pressure cylinders, and each of the fourth valves is arranged between the intermediate pressure cylinder in each group of the intermediate and low pressure cylinders and the second air outlet of the boiler.

7. The thermal system of a coal-fired power plant according to claim 2, characterized in that: The thermal system of the coal-fired power unit further includes a fifth valve; The fifth valve is arranged between the first air outlet of the boiler and the air inlet of the pressure regulating device, and is used to control the opening of the passage between the first air outlet of the boiler and the air inlet of the pressure regulating device.

8. The thermal system of a coal-fired power plant according to claim 1, characterized in that: The thermal system of the coal-fired power unit further includes a high-pressure heating device, which is connected to the second steam exhaust port of the pressure regulating device.

9. The thermal system of a coal-fired power plant according to any one of claims 1 to 8, characterized in that: The thermal system of the coal-fired power unit further includes a condenser, which is connected to the third exhaust port of the pressure regulating device.

10. A method for controlling a thermal system of a coal-fired power plant, applied to the thermal system of a coal-fired power plant according to any one of claims 1 to 9, characterized in that: The method comprises: Obtaining thermal power demand information of the thermal system of the coal-fired power unit; Determining load demand status information corresponding to the thermal system of the coal-fired power unit based on the thermal power demand information; According to the load demand status information, controlling the pressure regulating device in the thermal system of the coal-fired power unit to pressurize the main steam discharged from the boiler to obtain pressurized steam; The steam turbine pressure cylinder in the thermal system of the coal-fired power unit is controlled to perform thermoelectric conversion using the pressurized steam and the reheated steam discharged from the boiler.

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