Coal-fired unit device and control method thereof

Abstract

The invention discloses a coal-fired unit device and a control method of the coal-fired unit device. The coal-fired unit device comprises boiler equipment and a power generation assembly. The boiler equipment comprises a flue gas line and a steam-water line, and high-temperature flue gas in a first heat exchange section of the flue gas line heats boiler water in a second heat exchange section of the steam-water line, so that the boiler water is converted into steam. And the steam in the second heat exchange section drives the power generation assembly to generate power, after the steam drives the power generation assembly to generate power, the steam is recondensed into boiler water, and the recondensed boiler water flows back to the second heat exchange section to be heated again. The smoke line is provided with a smoke flow dividing assembly, and the smoke flow dividing assembly is located on the first heat exchange section and used for dividing high-temperature smoke in the first heat exchange section, so that the steam amount is adjusted, and then peak regulation is conducted on the power generation assembly. The device has high variable load capacity and can meet the requirement for deep peak regulation of a power system.

Description

Technical Field

[0001] The present invention specifically relates to a coal-fired unit device and a control method of the device. Background Art

[0002] As the country vigorously promotes renewable energy power, coal-fired power will shift from main power to guarantee power, using the flexibility of coal-fired power to absorb renewable energy power and ensure the stability of the power system. However, traditional coal-fired units have limited load-changing capabilities and cannot provide sufficient capacity for renewable energy power, limiting the degree of deep peak regulation of the power system.

[0003] Specifically, when traditional coal-fired units are performing peak load regulation, they mainly control the heat released in the boiler by adjusting the amount of pulverized coal fed into the boiler. However, the boiler and its water circulation system have a certain thermal inertia. After changing the feed flow of pulverized coal, the steam output does not change immediately, which will cause a delay in the regulation process. Moreover, adjusting the feed flow of pulverized coal too quickly may affect the stability of the combustion process. If the supply of pulverized coal changes too much, it is easy to cause safety hazards such as incomplete combustion or overheating.

[0004] In summary, the existing coal-fired units have limited load-changing capabilities and cannot meet the deep peak-shaving needs of the power system. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a coal-fired unit device and a control method for the device in view of the above-mentioned deficiencies in the prior art. The device has a strong variable load capacity and can meet the needs of deep peak regulation of the power system.

[0006] According to an embodiment of a first aspect of the present invention, a coal-fired unit device is provided, comprising: a boiler device and a power generation component; the boiler device comprises a flue gas circuit and a steam-water circuit, the flue gas circuit comprises a main flue gas circuit, high-temperature flue gas flows in the main flue gas circuit, and the main flue gas circuit comprises a first heat exchange section; the steam-water circuit comprises a main circulation loop, boiler water flows in the main circulation loop, and the main circulation loop comprises a second heat exchange section, the first heat exchange section is coupled to the second heat exchange section, the high-temperature flue gas in the first heat exchange section heats the boiler water in the second heat exchange section, so that the boiler water is converted into steam; the second heat exchange section is connected to the power generation component, the steam output in the second heat exchange section drives the power generation component to generate electricity, and after driving the power generation component to generate electricity, the steam is re-condensed into boiler water, and the re-condensed boiler water flows back to the second heat exchange section for heating again; a shunt flue gas component is arranged on the flue gas circuit, and the shunt flue gas component is located in the first heat exchange section, and is used to shunt the high-temperature flue gas in the first heat exchange section, thereby adjusting the steam amount, and then peaking the power generation component.

[0007] Preferably, the coal-fired unit device also includes a steam generator, and the steam generator includes a cold side channel and a hot side channel; the steam-water circuit also includes a water flow branch, one end of the water flow branch is connected to the main circulation loop, and the other end is connected to the cold side channel of the steam generator, the water flow branch is located downstream of the power generation component, specifically between the condensate outlet of the power generation component and the reflux inlet of the second heat exchange section, the re-condensed boiler water part flows back to the second heat exchange section for reheating, and the rest flows into the cold side channel through the water flow branch, the flue gas circuit also includes a flue gas circuit A flue gas branch, one end of which is connected to the first heat exchange section, and the other end of which is connected to the hot side channel of the steam generator. The diverting flue gas component is located at a corresponding position of the flue gas branch, and is used to divert the high-temperature flue gas in the first heat exchange section, so that part of the high-temperature flue gas continues to flow along the first heat exchange section, thereby exchanging heat with the second heat exchange section, and the remaining high-temperature flue gas enters the hot side channel of the steam generator through the flue gas branch; when the high-temperature flue gas passes through the hot side channel, it heats the re-condensed boiler water in the cold side channel, so that the boiler water is converted into industrial steam for output.

[0008] Preferably, a shunt feed water pump is provided on the water flow branch, and the shunt feed water pump is located between the inlet of the water flow branch and the cold side channel of the steam generator, and the shunt feed water pump is used to adjust the flow rate of boiler water entering the water flow branch.

[0009] Preferably, the device also includes a control unit, which is electrically connected to the diverter flue gas component, and the control unit is used to adjust the opening of the diverter flue gas component according to the target electric power value of the power generation component, thereby adjusting the flow rate of the high-temperature flue gas in the first heat exchange section and the flow rate of the high-temperature flue gas diverted to the flue gas branch, thereby adjusting the power generation power of the power generation component; the control unit is also electrically connected to the diverter water pump, and is used to adjust the opening of the diverter water pump according to the target flow value of the industrial steam output, thereby adjusting the flow rate of the boiler water entering the water flow branch, thereby adjusting the flow rate of the industrial steam output.

[0010] Preferably, the device also includes a steam compressor and a water spray cooler, wherein the steam compressor and the water spray cooler are located downstream of the cold side channel of the steam generator, and the water flow branch is connected to the steam compressor and the water spray cooler in sequence through the cold side channel; the steam compressor is used to adjust the pressure of the industrial steam output, and the water spray cooler is used to adjust the temperature of the industrial steam output.

[0011] Preferably, the first heat exchange section includes a furnace section, and the furnace section is used for coal powder combustion to generate high-temperature flue gas. The second heat exchange section includes a water-cooled wall section, and the water-cooled wall section is located between the reflux inlet and the power generation component, and one end of the water-cooled wall section is connected to the reflux inlet, and the other end is connected to the power generation component. The water-cooled wall section is accommodated in the furnace section. When the high-temperature flue gas passes through the furnace section, it heats the boiler water in the water-cooled wall section so that the boiler water is converted into steam. The water-cooled wall section is used to output steam to the power generation component to drive the power generation component to power generation; the flue gas branch includes a furnace flue gas branch, the diverter flue gas assembly includes a furnace diverter flue gas unit, one end of the furnace flue gas branch is connected to the side wall of the furnace section, and the other end is connected to the hot side channel of the steam generator; the furnace diverter flue gas unit corresponds to the furnace flue gas branch, and the furnace diverter flue gas unit is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the furnace section, thereby exchanging heat with the water-cooled wall section, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator through the furnace flue gas branch.

[0012] Preferably, the first heat exchange section also includes a hot side section of an economizer, the hot side end of the economizer is located downstream of the furnace section and communicated with the furnace section, the second heat exchange section also includes a cold side section of an economizer, the cold side section of the economizer is located between the reflux inlet and the water-cooled wall section, one end of the cold side section of the economizer is communicated with the reflux inlet, and the other end is communicated with the water-cooled wall section, the cold side section of the economizer is accommodated in the hot side end of the economizer, and when the high-temperature flue gas flows through the hot side section of the economizer, the boiler water returning to the cold side end of the economizer is preheated; the flue gas branch It also includes an economizer flue gas branch, and the diverter flue gas assembly also includes an economizer diverter flue gas unit. One end of the economizer flue gas branch is connected to the side wall of the hot side section of the economizer, and the other end is connected to the hot side channel of the steam generator. The economizer diverter flue gas unit corresponds to the economizer flue gas branch. The economizer diverter flue gas unit is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the economizer, thereby exchanging heat with the cold side section of the economizer, and the remaining high-temperature flue gas enters the hot side channel of the steam generator through the economizer flue gas branch.

[0013] Preferably, the first heat exchange section further includes a first superheater hot side section, the first superheater hot side section is located between the furnace section and the economizer hot side section, one end of the first superheater hot side section is connected to the furnace section, and the other end is connected to the economizer hot side section, the second heat exchange section further includes a first superheater cold side section, the first superheater cold side section is located between the water-cooled wall section and the power generation component, one end of the first superheater cold side section is connected to the water-cooled wall section, and the other end is connected to the power generation component, the first superheater cold side section is accommodated in the first superheater hot side section, and when the high temperature flue gas passes through the first superheater hot side section, it will heat the first superheater The steam in the cold side section is heated to increase the steam temperature; the flue gas branch also includes a first superheater flue gas branch, and the diverter flue gas assembly also includes a first superheater diverter flue gas unit, one end of the first superheater flue gas branch is connected to the side wall of the first superheater hot side section, and the other end is connected to the hot side channel of the steam generator, the first superheater diverter flue gas unit is located at the first superheater flue gas branch, and is used to divert the high-temperature flue gas, so that part of the high-temperature flue gas continues to flow along the first superheater hot side section, thereby exchanging heat with the first superheater cold side section, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator through the first superheater flue gas branch.

[0014] Preferably, the first heat exchange section further includes a second superheater hot side section, the second superheater hot side section is located downstream of the first superheater hot side section, the furnace section is connected to the second superheater hot side section through the first superheater hot side section, the second heat exchange section further includes a second superheater cold side section, the second superheater cold side section is located between the water-cooled wall section and the first superheater cold side section, one end of the second superheater cold side section is connected to the water-cooled wall section, and the other end is connected to the first superheater cold side section, the second superheater cold side section is accommodated in the second superheater hot side section, and when the high-temperature flue gas passes through the second superheater hot side section, it will heat the second superheater cold side section. The steam is heated to increase the steam temperature; the flue gas branch also includes a second superheater flue gas branch, and the diverter flue gas assembly also includes a second superheater diverter flue gas unit, one end of the second superheater flue gas branch is connected to the side wall of the hot side section of the second superheater, and the other end is connected to the hot side channel of the steam generator, the second superheater diverter flue gas unit is located at the second superheater flue gas branch, and is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the second superheater, thereby exchanging heat with the cold side section of the second superheater, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator through the second superheater flue gas branch.

[0015] Preferably, the power generation component includes a turbine cylinder and a generator, and the number of the turbine cylinders is multiple, and the multiple turbine cylinders are connected to the rotor of the generator. The water-cooled wall section is connected to the multiple turbine cylinders in sequence through the second superheater cold side section and the first superheater cold side section. The steam output by the water-cooled wall section flows through the second superheater cold side section and the first superheater cold side section in sequence. After the steam is heated once by the high-temperature flue gas in the second superheater hot side section and heated twice by the high-temperature flue gas in the first superheater hot side section, the multiple turbine cylinders are driven to drive the rotor of the generator to rotate, so as to achieve power generation.

[0016] Preferably, the first steam turbine cylinder among the multiple steam turbine cylinders through which the steam output by the water-cooled wall section flows in sequence is set as the first steam turbine cylinder, and the other steam turbine cylinders are set as the second steam turbine cylinders; the first heat exchange section also includes a first reheater hot side section, the first reheater hot side section is located between the first superheater hot side section and the second superheater hot side section, one end of the first reheater hot side section is connected to the first superheater hot side section, and the other end is connected to the second superheater hot side section; the second heat exchange section also includes a first reheater cold side section, the first reheater cold side section is located between the first steam turbine cylinder and the second steam turbine cylinder, the first steam turbine cylinder is connected to the second steam turbine cylinder through the first reheater cold side section; the first reheater cold side section is accommodated in the first reheater hot side section, the temperature of the steam decreases after driving the first steam turbine cylinder to generate electricity, and when the high-temperature flue gas passes through the first reheater hot side section, the steam in the first reheater cold side section is reheated to increase the steam temperature.

[0017] Preferably, the flue gas branch also includes a first reheater flue gas branch, and the diverter flue gas unit also includes a first reheater diverter flue gas unit, one end of the first reheater flue gas branch is connected to the side wall of the hot side section of the first reheater, and the other end is connected to the hot side channel of the steam generator; the first reheater diverter flue gas unit is located at the first reheater flue gas branch, and the first reheater diverter flue gas unit is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the first reheater, thereby exchanging heat with the cold side section of the first reheater, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator through the first reheater flue gas branch.

[0018] Preferably, the first heat exchange section further includes a second reheater hot side section, the second reheater hot side section is located downstream of the first reheater hot side section and is connected to the first reheater hot side section, the second reheater hot side section is connected in parallel to the second superheater hot side section and the economizer hot side section, the second heat exchange section further includes a second reheater cold side section, the second reheater cold side section is located between the first turbine cylinder and the first reheater cold side section, the first turbine cylinder is connected to the second turbine cylinder through the second reheater cold side section and the first reheater cold side section, the second reheater cold side section is accommodated in the second reheater hot side section, and when the high temperature flue gas flows through the second reheater hot side section, it will affect the The steam in the cold side section of the second reheater is reheated; the flue gas branch also includes a second reheater flue gas branch, and the diverter flue gas unit also includes a second reheater diverter flue gas unit, one end of the second reheater flue gas branch is connected to the side wall of the hot side section of the second reheater, and the other end is connected to the hot side channel of the steam generator; the second reheater diverter flue gas unit is located at the second reheater flue gas branch, and the second reheater diverter flue gas unit is used to divert the high-temperature flue gas, so that part of the high-temperature flue gas continues to flow along the hot side section of the second reheater, thereby exchanging heat with the cold side section of the second reheater, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator through the second reheater flue gas branch.

[0019] Preferably, the device also includes a flue gas treatment device, the main flue gas path is connected to the flue gas treatment device, the flue gas treatment device is located downstream of the first heat exchange section, and is used to denitrify, remove dust, desulfurize and / or decarbonize the high-temperature flue gas discharged from the first heat exchange section.

[0020] According to an embodiment of the second aspect of the present invention, there is provided a control method for the above-mentioned coal-fired unit device, comprising:

[0021] Acquire a unit load parameter of the coal-fired unit device, wherein the unit load parameter includes a target electric power value;

[0022] Acquiring actual output parameters of the coal-fired unit, wherein the actual output parameters include actual electric power values ​​of power generation components;

[0023] According to the actual electric power value of the power generation component and the target electric power value in the unit load parameter, a flue gas regulation step is performed on the coal-fired unit device to adjust the actual electric power value of the power generation component until the actual electric power value of the power generation component reaches the target electric power value;

[0024] The flue gas regulating step includes: controlling the diverting flue gas component to regulate the high-temperature flue gas flow in the first heat exchange section.

[0025] The coal-fired unit device in the present invention exchanges heat between the high-temperature flue gas in the first heat exchange section and the boiler water in the second heat exchange section, so that the boiler water is converted into steam, and the steam is used to drive the power generation component to generate electricity. By setting a diversion flue gas component in the flue gas line, the diversion of the high-temperature flue gas in the flue gas line can be achieved, and then the flow of the high-temperature flue gas in the first heat exchange section can be adjusted, that is, the heat received by the boiler water can be adjusted, and then the amount of steam generated can be adjusted, thereby adjusting the power generation of the power generation component (turbine and generator). This coal-fired unit device does not need to adjust the feed amount of coal powder in the boiler, and directly adjusts the flow of high-temperature flue gas entering the first heat exchange section, so as to quickly adjust the heat received by the boiler water, and can reduce the influence of thermal inertia. Therefore, this coal-fired unit device has a strong variable load capacity and can meet the needs of deep peak regulation of the power system.

[0026] In addition, the high-temperature flue gas diverted from the main flue gas path in this device directly enters the hot side channel of the steam generator. Moreover, after the steam in the steam-water circuit drives the power generation component to generate electricity, the thermal energy is converted into mechanical energy and electrical energy, and the steam is re-condensed into boiler water. Part of the re-condensed boiler water flows back to the second heat exchange section for reheating, and the rest flows into the cold side channel through the water flow branch. Heat exchange is carried out between the hot side channel and the cold side channel of the steam generator, so that the re-condensed boiler water is converted into industrial steam output. Therefore, this coal-fired unit device can also achieve thermal and electrical decoupling, and has the effect of stable output of industrial steam while ensuring power output. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of a coal-fired unit device in some embodiments of the present invention;

[0028] Figure 2 is a schematic diagram of the internal structure of a boiler device in some embodiments of the present invention;

[0029] Figure 3 It is a schematic diagram of the flow sequence of high-temperature flue gas and steam in some embodiments of the present invention.

[0030] In the figure: 1- boiler equipment, 2- furnace split flue gas unit (water-cooled wall split flue gas damper), 3- water-cooled wall section (water-cooled wall), 4- first superheater split flue gas unit (high-temperature superheater split flue gas damper), 5- first superheater cold side section (high-temperature superheater), 6- first reheater split flue gas unit (high-temperature reheater split flue gas damper), 7- first reheater cold side section (high-temperature reheater), 8- second reheater split flue gas unit (low-temperature reheater split flue gas damper), 9- second reheater cold side section (low-temperature reheater), 10- second superheater split flue gas unit (low-temperature superheater split flue gas damper), 11- 2. Superheater cold side section (low-temperature superheater), 12- economizer diverter flue gas unit (economizer diverter flue gas damper), 13- economizer cold side section, 14- high-pressure cylinder, 15- medium-pressure cylinder, 16- low-pressure cylinder, 17- generator, 18- condenser, 19- condensate pump, 20- low-pressure heater, 21- deaerator, 22- feed water pump, 23- high-pressure heater, 24- flue gas treatment equipment (environmental protection device), 25- induced draft fan, 26- steam generator, 27- diverter feed water pump, 28- steam compressor, 29- water spray desuperheater, 30- furnace section (furnace), 31- horizontal flue, 32- tail shaft flue. DETAILED DESCRIPTION

[0031] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "upper", "lower", "upstream", "downstream" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience and simplification of the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0033] In the description of the present invention, the terms “first”, “second” and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connect", "set", "install", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0035] First, the application scenario of this coal-fired unit is explained:

[0036] This coal-fired unit device can be used in the scenario of coal-fired power generation. Under the policy of vigorously promoting renewable energy power in the country, coal-fired power will shift from main power to guaranteed power, using the flexibility of coal-fired power to absorb renewable energy power and ensure the stability of the power system. However, the variable load capacity of traditional coal-fired units is limited, and it cannot provide sufficient capacity for renewable energy power, which limits the degree of deep peak regulation of the power system. Specifically, when performing peak regulation, traditional coal-fired units mainly control the heat released in the boiler by adjusting the feed amount of coal powder in the boiler, that is, controlling the heat output of high-temperature flue gas. However, the boiler and its water circulation system have a certain thermal inertia. After changing the feed flow rate of coal powder, the steam production will not change immediately. There will be a delay in the adjustment process before the boiler reaches a balanced state again. Moreover, adjusting the fuel flow too quickly may affect the stability of the combustion process. If the fuel supply changes too much, it is easy to cause safety hazards such as incomplete combustion or overheating. In summary, during the operation of traditional coal-fired units, their minimum load and adjustment range are limited, and they cannot quickly and effectively adapt to the rapid changes in renewable energy power generation. This means that when the power generation from renewable energy fluctuates greatly, traditional coal-fired units cannot be adjusted in time, resulting in limited deep peak-shaving capabilities of the power system.

[0037] In addition, during the deep peak regulation process, coal-fired power plants also face the problem of reduced profits due to reduced power generation. Generating income through steam extraction from steam turbines for heat and steam supply will limit the flexibility of the unit and affect the unit's variable load operation capability.

[0038] In other words, reducing the steam production by reducing the heat released in the boiler, thereby reducing the power generation, will lead to a decrease in the profitability of the entire coal-fired power plant. At present, in order to increase the profitability of coal-fired power plants, it is usually chosen not to reduce the heat released in the boiler, but to extract some excess steam from the steam turbine to reduce the power generation of the steam turbine; the extracted steam can be used as industrial steam output, thereby realizing the revenue generation of coal-fired batteries. However, when the steam turbine is in operation, there is a lower limit of the required steam. This lower limit is to ensure that the steam turbine can start, operate and maintain the necessary kinetic energy normally. If the steam intake is too low (that is, the steam input of the steam turbine is too low), the steam turbine will not be able to operate normally. Moreover, when the steam pressure in the steam turbine is too low, steam cannot be successfully extracted from the steam turbine, which requires sufficient air intake in the steam turbine to ensure the stability of steam supply. Therefore, the steam that can be extracted from the steam turbine is limited, and it will limit the flexibility of the unit and affect the variable load operation capability of the unit.

[0039] In general, the steam extraction supply of the steam turbine in coal-fired power plants limits the variable load capacity of the unit, and the variable load of the unit will affect the stability of the steam supply. Only better thermal and electrical decoupling can ensure the stability of the steam supply and fully exert the flexibility of the unit.

[0040] In view of the above difficulties, the present invention proposes a coal-fired unit device for realizing a wide-load steam supply operation mode of coal-fired power generation, and realizing thermal-electric decoupling by heating the shunt feed water in the deaerator 21 with the shunt flue gas in the boiler to generate shunt steam. The shunt flue gas damper and the shunt feed water pump 27 are used to adjust the flue gas shunt flow rate and the feed water flow rate respectively to ensure the variable load capacity of the unit; the water spray desuperheater 29 is used to adjust the shunt steam parameters to ensure the stability of steam supply. This technology realizes the steam supply stability and unit flexibility of the coal-fired power steam supply unit, bringing steam supply benefits and peak load compensation under variable load operation to the power plant.

[0041] Example 1

[0042] See also Figure 1 The present invention discloses a coal-fired unit device, including: a boiler device 1 and a power generation component.

[0043] The boiler equipment 1 includes a flue gas circuit and a steam-water circuit. The flue gas circuit includes a main flue gas circuit, in which high-temperature flue gas flows, and the main flue gas circuit includes a first heat exchange section. The steam-water circuit includes a main circulation loop, in which boiler water flows, and the main circulation loop includes a second heat exchange section. The first heat exchange section is coupled to the second heat exchange section. The high-temperature flue gas in the first heat exchange section heats the boiler water in the second heat exchange section, so that the boiler water is converted into steam. The second heat exchange section is connected to the power generation component. The steam output in the second heat exchange section drives the power generation component to generate electricity. After driving the power generation component to generate electricity, the steam is re-condensed into boiler water. The re-condensed boiler water flows back to the second heat exchange section for heating again. A shunt flue gas component is provided on the flue gas circuit. The shunt flue gas component is located in the first heat exchange section and is used to shunt the high-temperature flue gas in the first heat exchange section, thereby adjusting the flow of the high-temperature flue gas that heats the boiler water in the second heat exchange section, thereby adjusting the steam volume, and then peaking the power generation component.

[0044] It should be noted that the device converts the boiler water into steam by exchanging heat between the high-temperature flue gas in the first heat exchange section and the boiler water in the second heat exchange section, and the steam is used to drive the power generation component to generate electricity. By setting a diversion flue gas component in the flue gas line, the diversion of the high-temperature flue gas in the flue gas line can be achieved, and then the flow of the high-temperature flue gas in the first heat exchange section can be adjusted, that is, the heat received by the boiler water can be adjusted, and then the amount of steam generated can be adjusted, thereby adjusting the power generation power of the power generation component (steam turbine and generator 17). This coal-fired unit device does not need to adjust the feed amount of coal powder in the boiler, but directly adjusts the flow of high-temperature flue gas entering the first heat exchange section, so as to quickly adjust the heat received by the boiler water and reduce the influence of thermal inertia. Therefore, this coal-fired unit device has a strong variable load capacity and can meet the needs of deep peak regulation of the power system.

[0045] In some embodiments, the coal-fired unit device further includes a steam generator, and the steam generator includes a cold side channel and a hot side channel. The steam-water circuit further includes a water flow branch, one end of which is connected to the main circulation loop, and the other end is connected to the cold side channel of the steam generator. The water flow branch is located downstream of the power generation component, specifically between the condensed water outlet of the power generation component and the reflux inlet of the second heat exchange section. The re-condensed boiler water part flows back to the second heat exchange section for reheating, and the rest flows into the cold side channel through the water flow branch. The flue gas circuit further includes a flue gas branch, one end of which is connected to the first heat exchange section, and the other end is connected to the hot side channel of the steam generator. The shunt flue gas component is located at the corresponding position of the flue gas branch, and is used to shunt the high-temperature flue gas in the first heat exchange section, so that part of the high-temperature flue gas continues to flow along the first heat exchange section, thereby exchanging heat with the second heat exchange section, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator through the flue gas branch. When the high-temperature flue gas passes through the hot side channel, it heats the re-condensed boiler water in the cold side channel, so that the boiler water is converted into industrial steam output.

[0046] In this embodiment, the high-temperature flue gas diverted from the main flue gas path directly enters the hot side channel of the steam generator. Moreover, after the steam in the steam-water circuit drives the power generation component to generate electricity, the thermal energy is converted into mechanical energy and electrical energy, and the steam is re-condensed into boiler water. The re-condensed boiler water partly flows back to the second heat exchange section for reheating, and the rest flows into the cold side channel through the water flow branch. Heat exchange is performed between the hot side channel and the cold side channel of the steam generator, so that the re-condensed boiler water is converted into industrial steam output. Therefore, this coal-fired unit device can also achieve thermal and electrical decoupling, and has the effect of stable output of industrial steam while ensuring power output.

[0047] Furthermore, a shunt feed water pump 27 is provided on the water flow branch, and the shunt feed water pump 27 is located between the inlet of the water flow branch and the cold side channel of the steam generator. The shunt feed water pump 27 is used to adjust the flow rate of boiler water entering the water flow branch.

[0048] Furthermore, the device further includes a control unit, which is electrically connected to the shunt flue gas assembly, and the control unit is used to adjust the opening of the shunt flue gas assembly according to the target electric power value of the power generation assembly, thereby adjusting the flow rate of the high-temperature flue gas in the first heat exchange section and the flow rate of the high-temperature flue gas shunted to the flue gas branch, thereby adjusting the power generation power of the power generation assembly. The control unit is also electrically connected to the shunt feed water pump 27, and is used to adjust the opening of the shunt feed water pump 27 according to the target flow value of the industrial steam output, thereby adjusting the flow rate of the boiler water entering the water flow branch, thereby adjusting the flow rate of the industrial steam output.

[0049] The device also includes a steam compressor 28 and a water spray cooler 29, which are located downstream of the cold side channel of the steam generator. The water flow branch is connected to the steam compressor 28 and the water spray cooler 29 in sequence through the cold side channel; the steam compressor 28 is used to adjust the pressure of the industrial steam output, and the water spray cooler 29 is used to adjust the temperature of the industrial steam output.

[0050] In contrast, in the existing technology, electric heat conversion equipment is mostly used in conjunction with energy storage facilities for thermoelectric decoupling, which has many energy conversion steps and low energy utilization. Energy storage elements have energy losses, and the energy storage capacity is highly dependent on energy storage materials. The process is complex and not continuous, and the intermittent steam extraction affects the stability of the unit, which in turn affects the stability of the unit and steam supply.

[0051] This coal-fired unit device directly uses the split flue gas in the steam generator to heat the split feed water, and adjusts the steam parameters according to user needs through the steam compressor 28 and the water spray desuperheater 29 to supply stable industrial steam, avoiding the steam extraction and steam supply in each cylinder of the steam turbine, and can achieve the flexibility of the unit and the stability of steam supply under the large-scale variable load of the coal-fired power unit. The whole process is continuously stable and adjustable, with high energy utilization and deep thermal and electrical decoupling.

[0052] In some embodiments, the boiler device 1 comprises a burner, which is used to inject fuel (coal powder) into the furnace and mix it with air to ensure sufficient combustion of the fuel, thereby generating heat. The burner can adjust the amount of coal fed into the furnace.

[0053] See also Figure 1 and Figure 2 The first heat exchange section includes a furnace section 30 (i.e., the furnace of the boiler), which is used for coal powder combustion to generate high-temperature flue gas. The second heat exchange section includes a water-cooled wall section 3 (i.e., the water-cooled wall of the boiler), which is located between the reflux inlet and the power generation component, one end of which is connected to the reflux inlet, and the other end is connected to the power generation component. The water-cooled wall section 3 is accommodated in the furnace section 30. When the high-temperature flue gas passes through the furnace section 30, it heats the boiler water in the water-cooled wall section 3, so that the boiler water is converted into steam. The water-cooled wall section 3 is used to output steam to the power generation component to drive the power generation component to generate electricity.

[0054] The flue gas branch includes a furnace flue gas branch, and the shunt flue gas assembly includes a furnace shunt flue gas unit 2. One end of the furnace flue gas branch is connected to the side wall of the furnace section 30, and the other end is connected to the hot side channel of the steam generator. The furnace shunt flue gas unit 2 corresponds to the furnace flue gas branch. The furnace shunt flue gas unit 2 is used to shunt the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the furnace section 30, thereby exchanging heat with the water-cooled wall section 3, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator through the furnace flue gas branch.

[0055] Of course, the steam-water circuit of the boiler equipment 1 also includes a water replenishment inlet, which is connected to the water-cooled wall section 3 in the steam-water circuit for replenishing boiler water to ensure that there is sufficient boiler water in the steam-water circuit for water-steam circulation.

[0056] In this embodiment, the high-temperature flue gas in the furnace section 30 is heat exchanged with the boiler water in the water-cooled wall section 3, so that the boiler water is converted into steam. In addition, the high-temperature flue gas in the furnace section 30 can be diverted through the furnace flue gas branch and the furnace diverting flue gas unit 2, thereby adjusting the heat received by the water-cooled wall end to adjust the amount of steam generated.

[0057] Furthermore, the first heat exchange section further includes an economizer hot side section, which is located downstream of the furnace section 30 and communicated with the furnace section 30. The second heat exchange section further includes an economizer cold side section 13, which is located between the reflux inlet and the water-cooled wall section 3, one end of the economizer cold side section 13 is communicated with the reflux inlet, and the other end is communicated with the water-cooled wall section 3. The economizer cold side section 13 is accommodated in the economizer hot side section, and when the high-temperature flue gas flows through the economizer hot side section, the re-condensed boiler water that flows back into the economizer cold side section 13 is preheated. The flue gas branch also includes an economizer flue gas branch, and the diverter flue gas assembly also includes an economizer diverter flue gas unit 12. One end of the economizer flue gas branch is connected to the side wall of the hot side section of the economizer, and the other end is connected to the hot side channel of the steam generator. The economizer diverter flue gas unit 12 corresponds to the economizer flue gas branch. The economizer diverter flue gas unit 12 is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the economizer, thereby exchanging heat with the economizer cold side section 13, and the remaining high-temperature flue gas enters the hot side channel of the steam generator through the economizer flue gas branch.

[0058] like Figure 1 and Figure 2 As shown, in this embodiment, the high-temperature flue gas in the hot side section of the economizer is used to exchange heat with the boiler water returning in the cold side section 13 of the economizer to preheat the returning boiler water, and the preheated boiler water flows into the water-cooled wall section 3. By setting up the economizer, the residual heat in the high-temperature flue gas can be effectively utilized to reduce heat waste. In addition, the high-temperature flue gas in the hot side section of the economizer can be diverted through the economizer flue gas branch and the economizer diverting flue gas unit 12, thereby adjusting the amount of heat received during the preheating of the boiler water. Further, by adjusting the amount of heat received during the preheating of the boiler water, the amount of steam generated in the water-cooled wall section 3 can be adjusted.

[0059] The first heat exchange section also includes a first superheater hot side section, which is located between the furnace section 30 and the economizer hot side section, one end of which is connected to the furnace section 30, and the other end of which is connected to the economizer hot side section. The second heat exchange section also includes a first superheater cold side section 5, which is located between the water-cooled wall section 3 and the power generation component, one end of which is connected to the water-cooled wall section 3, and the other end of which is connected to the power generation component. The first superheater cold side section 5 is accommodated in the first superheater hot side section, and when the high-temperature flue gas passes through the first superheater hot side section, the steam in the first superheater cold side section 5 is heated to increase the steam temperature.

[0060] The flue gas branch also includes a first superheater flue gas branch, and the diverter flue gas assembly also includes a first superheater diverter flue gas unit 4. One end of the first superheater flue gas branch is connected to the side wall of the hot side section of the first superheater, and the other end is connected to the hot side channel of the steam generator. The first superheater diverter flue gas unit 4 is located at the first superheater flue gas branch, and is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the first superheater, thereby exchanging heat with the first superheater cold side section 5, and the remaining high-temperature flue gas enters the hot side channel of the steam generator through the first superheater flue gas branch.

[0061] The first superheater is Figure 3 The steam generated in the water-cooled wall section 3 flows through the cold side of the high-temperature superheater, and the high-temperature flue gas in the high-temperature superheater heats the steam to reach the superheating temperature.

[0062] In this embodiment, the steam in the cold side section 5 of the first superheater is heated by the high-temperature flue gas in the hot side section of the first superheater so that the steam reaches the superheating temperature. By setting the first superheater, the residual heat in the high-temperature flue gas can be effectively utilized to reduce the waste of heat. In addition, the high-temperature flue gas in the hot side section of the first superheater can be diverted through the first superheater flue gas branch and the first superheater diverter flue gas unit 4, thereby adjusting the heat received by the steam to adjust the temperature and pressure of the steam. Further, by adjusting the temperature and pressure of the steam, the power generation efficiency of the steam turbine can be adjusted. For example, the thermal efficiency of the steam turbine generally increases with the increase of the steam temperature and pressure. High-temperature and high-pressure steam can provide more energy and enable the steam turbine to operate at a higher thermodynamic cycle efficiency, thereby improving the power generation efficiency.

[0063] The first heat exchange section also includes a second superheater hot side section, which is located downstream of the first superheater hot side section, and the furnace section 30 is connected to the second superheater hot side section through the first superheater hot side section. The second heat exchange section also includes a second superheater cold side section 11, which is located between the water-cooled wall section 3 and the first superheater cold side section 5, and one end of the second superheater cold side section 11 is connected to the water-cooled wall section 3, and the other end is connected to the first superheater cold side section 5. The second superheater cold side section 11 is accommodated in the second superheater hot side section, and when the high-temperature flue gas passes through the second superheater hot side section, the steam in the second superheater cold side section 11 is heated to increase the steam temperature. The flue gas branch also includes a second superheater flue gas branch, and the shunting flue gas assembly also includes a second superheater shunting flue gas unit 10. One end of the second superheater flue gas branch is connected to the side wall of the hot side section of the second superheater, and the other end is connected to the hot side channel of the steam generator. The second superheater shunting flue gas unit 10 is located at the second superheater flue gas branch, and is used to shunt the high-temperature flue gas, so that part of the high-temperature flue gas continues to flow along the hot side section of the second superheater, thereby exchanging heat with the second superheater cold side section 11, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator through the second superheater flue gas branch.

[0064] The second superheater is Figure 3 The low temperature superheater in the water wall section 3. The low temperature here means that when the high temperature flue gas passes through the first superheater, the heat in the high temperature flue gas is transferred to the steam, so that the heat of the high temperature flue gas entering the second superheater is reduced. The steam generated in the water-cooled wall section 3 flows through the cold side of the low temperature superheater and the cold side of the high temperature superheater in turn. The steam is first heated once in the cold side of the low temperature superheater so that the steam reaches the initial superheating temperature; then, it is heated twice in the cold side of the high temperature superheater so that the steam reaches the target superheating temperature.

[0065] like Figure 1 As shown, in this embodiment, the steam in the second superheater cold side section 11 is heated by the high-temperature flue gas in the hot side section of the second superheater, so that the steam reaches the initial superheating temperature. By setting the second superheater, the residual heat in the high-temperature flue gas can be further utilized to reduce the waste of heat. In addition, the high-temperature flue gas in the hot side section of the second superheater can be diverted through the second superheater flue gas branch and the second superheater diverter flue gas unit 10, thereby adjusting the heat received by the steam to adjust the temperature and pressure of the steam. Furthermore, by adjusting the temperature and pressure of the steam, the power generation efficiency of the steam turbine can be adjusted.

[0066] In some embodiments, the power generation assembly includes a steam turbine cylinder and a generator 17, the number of steam turbine cylinders is multiple, and the multiple steam turbine cylinders are connected to the rotor of the generator 17, the water-cooled wall section is sequentially connected to the multiple steam turbine cylinders through the second superheater cold side section 11 and the first superheater cold side section 5, the steam output by the water-cooled wall section 3 flows through the second superheater cold side section 11 and the first superheater cold side section 5 in sequence, and the high-temperature flue gas output by the furnace section 30 flows through the first superheater hot side section and the second superheater hot side section in sequence. After the steam is heated once by the high-temperature flue gas in the second superheater hot side section, and the high-temperature flue gas in the first superheater hot side section is heated twice, the multiple steam turbine cylinders are driven to drive the rotor of the generator to rotate to achieve power generation. In other words, the high-temperature flue gas heats the steam passing through the second superheater cold side section 11 once, and heats the steam passing through the first superheater cold side section 5 twice. The steam outlet of the cold side section of the first superheater is connected to multiple steam turbine cylinders in sequence, and the steam after secondary heating drives the multiple steam turbine cylinders in sequence, thereby driving the rotor of the generator 17 to rotate to achieve power generation.

[0067] Specifically, the first steam turbine cylinder among the multiple steam turbine cylinders through which the steam output by the water-cooled wall section flows in sequence is set as the first steam turbine cylinder, and the other steam turbine cylinders are set as the second steam turbine cylinder. The first heat exchange section also includes a first reheater hot side section, which is located between the first superheater hot side section and the second superheater hot side section. One end of the first reheater hot side section is connected to the first superheater hot side section, and the other end is connected to the second superheater hot side section. The second heat exchange section also includes a first reheater cold side section 7, which is located between the first steam turbine cylinder and the second steam turbine cylinder. The first steam turbine cylinder is connected to the second steam turbine cylinder through the first reheater cold side section 7. The first reheater cold side section 7 is accommodated in the first reheater hot side section. The temperature of the steam decreases after driving the first steam turbine cylinder to generate electricity. When the high-temperature flue gas passes through the first reheater hot side section, the steam in the first reheater cold side section 7 is reheated to increase the steam temperature.

[0068] For example, Figure 1 As shown, the steam turbine includes three turbine cylinders, namely, a high-pressure cylinder 14, an intermediate-pressure cylinder 15 and a low-pressure cylinder 16. In this embodiment, the first turbine cylinder is the high-pressure cylinder 14, and the second turbine cylinder includes the intermediate-pressure cylinder 15 and the low-pressure cylinder 16. After the high-temperature and high-pressure steam heated by the first superheater and the second superheater drives the high-pressure cylinder 14 to drive the generator 17 to generate electricity, the temperature and pressure of the steam decrease. The first reheater is a high-temperature reheater. The high-temperature flue gas generated in the furnace section 30 passes through the hot side section of the first superheater and enters the hot side section of the first reheater. The steam after temperature and pressure reduction flows back to the cold side section 7 of the first reheater, and the steam in the cold side section 7 of the first reheater is reheated by the high-temperature flue gas in the hot side section of the first reheater to increase the temperature and pressure of the steam.

[0069] Furthermore, the flue gas branch also includes a first reheater flue gas branch, and the diverter flue gas unit also includes a first reheater diverter flue gas unit 6. One end of the first reheater flue gas branch is connected to the side wall of the hot side section of the first reheater, and the other end is connected to the hot side channel of the steam generator. The first reheater diverter flue gas unit 6 is located at the first reheater flue gas branch, and the first reheater diverter flue gas unit 6 is used to divert the high-temperature flue gas, so that part of the high-temperature flue gas continues to flow along the hot side section of the first reheater, thereby exchanging heat with the first reheater cold side section 7, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator through the first reheater flue gas branch.

[0070] In this embodiment, the first reheater is Figure 3 The high-temperature reheater in the steam turbine can further utilize the residual heat in the high-temperature flue gas by setting the first reheater to reduce heat waste. In addition, the high-temperature flue gas in the hot side section of the first reheater can be diverted by the first reheater flue gas branch and the first reheater diverter flue gas unit 6, thereby adjusting the heat received by the steam to adjust the temperature and pressure of the steam. By adjusting the temperature and pressure of the steam, the power generation efficiency of the intermediate pressure cylinder 15 and the low pressure cylinder 16 (the second steam turbine cylinder) of the steam turbine can be adjusted.

[0071] like Figure 3 As shown, the first heat exchange section also includes a second reheater hot side section, which is located downstream of the first reheater hot side section and communicated with the first reheater hot side section, and the second reheater hot side section is connected in parallel to the second superheater hot side section and the economizer hot side section. The second heat exchange section also includes a second reheater cold side section, which is located between the first steam turbine cylinder and the first reheater cold side section 7, and the first steam turbine cylinder is communicated with the second steam turbine cylinder through the second reheater cold side section and the first reheater cold side section 7. The second reheater cold side section is accommodated in the second reheater hot side section, and the high-temperature flue gas reheats the steam in the second reheater cold side section when flowing through the second reheater hot side section.

[0072] The flue gas branch also includes a second reheater flue gas branch, and the shunt flue gas unit also includes a second reheater shunt flue gas unit 8. One end of the second reheater flue gas branch is connected to the side wall of the hot side section of the second reheater, and the other end is connected to the hot side channel of the steam generator. The second reheater shunt flue gas unit 8 is located at the second reheater flue gas branch. The second reheater shunt flue gas unit 8 is used to shunt the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the second reheater, thereby exchanging heat with the cold side section of the second reheater, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator through the second reheater flue gas branch.

[0073] It should be noted that the second reheater is Figure 3In the low-temperature reheater, the high-temperature flue gas generated in the furnace section 30 passes through the first superheater hot side section, the first reheater hot side section and the second superheater hot side section in sequence, and then enters the first reheater hot side section. The temperature of the high-temperature flue gas in the hot side of the low-temperature reheater is lower than the temperature of the high-temperature flue gas in the hot side of the high-temperature reheater. The cooled and depressurized steam flowing out of the high-pressure cylinder 14 flows through the second reheater cold side section and the first reheater cold side section 7 in sequence. The steam is first reheated once in the cold side of the low-temperature reheater so that the steam reaches the initial reheating temperature; then, it is reheated twice in the cold side of the high-temperature superheater so that the steam reaches the target reheating temperature.

[0074] In this embodiment, by providing a second reheater, the residual heat in the high-temperature flue gas can be further utilized to reduce heat waste. In addition, by using the second reheater flue gas branch and the second reheater shunt flue gas unit 8, the high-temperature flue gas in the hot side section of the second reheater can be shunted, thereby adjusting the heat received by the steam to adjust the temperature and pressure of the steam. By adjusting the temperature and pressure of the steam, the power generation efficiency of the intermediate pressure cylinder 15 and the low pressure cylinder 16 of the steam turbine can be adjusted.

[0075] Specifically, the diverter smoke assembly includes a furnace diverter smoke unit 2, an economizer diverter smoke unit 12, a first superheater diverter smoke unit 4, a second superheater diverter smoke unit 10, a first reheater diverter smoke unit 6, and a second reheater diverter smoke unit 8. The above diverter smoke units can all be implemented by using existing diverter smoke dampers, and the diverter smoke dampers can be driven by electric or pneumatic driving methods. Of course, the diverter smoke unit can also use other existing diverter valves to open and close the high-temperature smoke.

[0076] In some embodiments, the device also includes a flue gas treatment device 24, the main flue gas path is connected to the flue gas treatment device 24, and the flue gas treatment device 24 is located downstream of the first heat exchange section, and is used to denitrify, remove dust, desulfurize and / or decarbonize the high-temperature flue gas discharged from the first heat exchange section.

[0077] In this embodiment, the high-temperature flue gas is subjected to environmental protection treatment by the flue gas treatment equipment 24, specifically one or more of denitrification, dust removal, desulfurization and decarbonization treatment. The flue gas treatment equipment 24 can be one or more of the existing denitrification equipment, dust removal equipment, desulfurization equipment and decarbonization equipment connected in series to achieve the above treatment.

[0078] It can be seen that the present invention belongs to the technical field of heat and steam supply, variable load operation, deep peak regulation, thermal-electric decoupling and multi-stage heat utilization of flue gas for coal-fired units, and specifically relates to a coal-fired power wide load steam supply operation mode.

[0079] In this embodiment, a coal-fired unit device is proposed for realizing a wide-load steam supply operation mode for coal-fired power plants. In the process of stable steam supply and variable-load power generation in coal-fired power plants, a diverter flue gas baffle is arranged near the heating surface in the flue to draw out diverted flue gas, and a diverter feed water pump 27 is used in the deaerator 21 to draw out diverted feed water. The diverted flue gas heats the diverted feed water in the steam generator to generate steam, and a steam compressor 28 and a water spray desuperheater 29 are used to adjust the steam temperature and pressure based on customer needs to supply stable steam. The steam turbine no longer extracts steam for steam supply, which improves the variable-load capacity of the unit, realizes the thermal-electric decoupling of the steam supply unit of the coal-fired power plant, and has both steam supply stability and unit flexibility. In other words, in order to solve the problem of complete thermal-electric decoupling of steam supply stability and unit flexibility of coal-fired power steam supply units, this embodiment proposes a wide-load steam supply operation mode for coal-fired power plants, which improves the compatibility of steam supply stability and unit flexibility, and creates additional benefits.

[0080] like Figure 1 As shown, the following is a specific description of the system flow of the coal-fired power wide-load steam supply operation mode, and the system flow includes two lines, namely the flue gas line and the steam-water line.

[0081] The main flue gas circuit is connected to the boiler (specifically the flue of the boiler), the environmental protection device and the induced draft fan in sequence. The flue gas circuit in the boiler includes the flue gas side of the water-cooled wall (i.e. the furnace section 30 mentioned above, because the water-cooled wall is actually a water-cooled pipe on the side wall of the furnace, and the flue gas actually flows in the furnace), the flue gas side of the high-temperature superheater, the flue gas side of the high-temperature reheater and the flue gas side of the low-temperature reheater (or the flue gas side of the low-temperature superheater and the flue gas side of the economizer). The water-cooled wall is located around the furnace in the boiler, the high-temperature superheater and the high-temperature reheater are located in the horizontal flue 31 in the boiler, and the low-temperature reheater, the low-temperature superheater and the economizer are located in the tail shaft flue 32 in the boiler. The first flue gas branch line (i.e. the above-mentioned furnace flue gas branch line) is connected to the boiler furnace, the water-cooled wall split flue gas damper, the steam generator (hot side channel) and the environmental protection device in sequence; the second flue gas branch line (i.e. the first superheater flue gas branch line) is connected to the boiler horizontal flue 31 (specifically the first superheater hot side section of the boiler horizontal flue 31), the high-temperature superheater split flue gas damper, the steam generator and the environmental protection device in sequence; the third flue gas branch line (i.e. the first reheater flue gas branch line) is connected to the boiler horizontal flue 31 (specifically the first reheater hot side section of the boiler horizontal flue 31), the high-temperature reheater split flue gas damper, the steam generator and the environmental protection device in sequence; the fourth flue gas branch line (i.e. the second reheater The first flue gas branch is connected to the boiler tail shaft flue 32 (specifically, the second reheater hot side section of the boiler tail shaft flue 32), the low-temperature reheater diverter flue gas damper, the steam generator and the environmental protection device in sequence; the fifth flue gas branch (i.e., the second superheater flue gas branch) is connected to the boiler tail shaft flue 32 (specifically, the second superheater hot side section of the boiler tail shaft flue 32), the low-temperature superheater diverter flue gas damper, the steam generator and the environmental protection device in sequence; the sixth flue gas branch (i.e., the economizer flue gas branch) is connected to the boiler tail shaft flue 32 (specifically, the economizer hot side section of the boiler tail shaft flue 32), the economizer diverter flue gas damper, the steam generator and the environmental protection device in sequence.

[0082] like Figure 3As shown, the main steam-water circuit includes the steam-water side of the water-cooled wall (i.e., the water-cooled wall section), the steam-water side of the low-temperature superheater (i.e., the second superheater cold side section 10), the steam-water side of the high-temperature superheater (i.e., the first superheater cold side section 5), the high-pressure cylinder 14, the low-temperature reheater, the steam-water side of the high-temperature reheater (i.e., the second reheater cold side section 9 and the first reheater cold side section 7), the medium-pressure cylinder 15, the low-pressure cylinder 16, the condenser 18, the condensate pump 19, the low-pressure heater 20, the deaerator 21, the high-pressure heater 23, and the steam-water side of the economizer (i.e., the economizer cold side section 13). The separate steam-water circuit includes the deaerator 21, the split feedwater pump 27, the steam generator, the steam compressor 28, and the water spray desuperheater 29, which are connected in sequence. In addition, the high-pressure cylinder 14, the medium-pressure cylinder 15, the low-pressure cylinder 16 and the generator 17 are connected in sequence to generate electricity, and the deaerator 21, the diverter water pump 27, the steam generator, the steam compressor 28 and the water spray desuperheater 29 are connected in sequence to generate steam supply.

[0083] The combustion mode of the boiler includes a suspended combustion boiler and a boiling combustion boiler, etc. The circulation mode of the boiler includes a natural circulation boiler, a forced circulation boiler, a controlled circulation boiler and a direct current boiler, etc.

[0084] The internal heating surface of the boiler includes water-cooled wall, high-temperature superheater, high-temperature reheater, low-temperature superheater, low-temperature reheater, economizer, but is not limited to other multi-stage reheaters or superheaters such as covered ceiling superheater and platen superheater. The internal diverter flue gas damper of the boiler includes water-cooled wall diverter flue gas damper, high-temperature superheater diverter flue gas damper, high-temperature reheater diverter flue gas damper, low-temperature reheater diverter flue gas damper, low-temperature superheater diverter flue gas damper and economizer diverter flue gas damper, but is not limited to diverter flue gas dampers opened at other heating surface positions.

[0085] The water-cooled wall, high-temperature superheater, high-temperature reheater, low-temperature superheater, low-temperature reheater, economizer and other heating surfaces can be arranged in the boiler horizontally or vertically or both. The temperature of the steam-water side is 100-700°C, the pressure of the steam-water side is 0.1-40Mpa, and the temperature of the flue gas side is 100-1700°C.

[0086] The water-cooled wall shunt smoke damper (i.e., furnace shunt smoke damper) is located at the lower end, middle end, and upper end of the water-cooled wall around the boiler furnace, and the number of arrangements can be multiple. In other words, the number of furnace smoke branches can be multiple, and the number of furnace shunt smoke dampers can also be multiple, and the number of furnace shunt smoke dampers is the same as the number of furnace smoke branches. Multiple furnace smoke branches are arranged along the central axis of the furnace and are connected to the side walls of the furnace. A shunt smoke damper is correspondingly provided at the entrance of each furnace smoke branch. By adjusting the opening of the shunt smoke damper, the flow rate of the smoke diverted out of the furnace can be adjusted. The high-temperature superheater flue gas diversion damper is located on the boiler wall near the high-temperature superheater in the boiler horizontal flue 31, and the number of arrangements can be multiple; the high-temperature reheater flue gas diversion damper is located on the boiler wall near the high-temperature reheater in the boiler horizontal flue 31, and the number of arrangements can be multiple; the low-temperature reheater flue gas diversion damper is located on the boiler wall near the low-temperature reheater in the boiler tail shaft flue 32, and the number of arrangements can be multiple; the low-temperature superheater flue gas diversion damper is located on the boiler wall near the low-temperature superheater in the boiler tail shaft flue 32, and the number of arrangements can be multiple; the economizer flue gas diversion damper is located on the boiler wall near the economizer in the boiler tail shaft flue 32, and the number of arrangements can be multiple. All diversion flue gas dampers do not need to exist at the same time, and can exist independently or in association and coupling. The water-cooled wall diverter flue gas damper, high-temperature superheater diverter flue gas damper, high-temperature reheater diverter flue gas damper, low-temperature reheater diverter flue gas damper, low-temperature superheater diverter flue gas damper and economizer diverter flue gas damper are driven electrically or pneumatically, and the opening can be adjusted to 0-100%. The diverted flue gas flow accounts for 0-100% of the main flue gas flow, and the diverted flue gas temperature is 100-1000°C.

[0087] The environmental protection device includes pollutant removal facilities such as denitrification, dust removal, desulfurization and decarbonization.

[0088] The deaerator 21 includes vacuum type, thermal type, chemical type, etc. The working pressure of the thermal deaerator 21 is 0.1-2MPa, the working temperature is 100-500°C, the water inlet temperature is 100-200°C, the water outlet temperature is 100-200°C, and the steam extraction source includes the steam extraction from the high-pressure cylinder 14, the steam extraction from the medium-pressure cylinder 15, the steam extraction from the low-pressure cylinder 16, and auxiliary steam.

[0089] The feed water pump 22 and the split feed water pump 27 are respectively connected to the deaerator 21 , and the flow rate of the split feed water pump 27 accounts for 30-70% of the sum of the flow rates of the feed water pump 22 and the split feed water pump 27 .

[0090] The temperature of the steam-water side of the steam generator is 100-700°C, the pressure of the steam-water side is 0.1-40Mpa, and the temperature of the flue gas side is 100-1700°C.

[0091] The split water supply pump 27 is used to adjust the pressure of the split water supply, and the pressure adjustment range is 0.1-20 MPa. The steam compressor 28 is used to adjust the steam pressure based on the steam supply parameters, and the pressure adjustment range is 0.1-20 MPa.

[0092] The water spray desuperheater 29 is used to adjust the temperature of the steam based on the steam supply parameters, and the temperature adjustment range is 0 to 50°C.

[0093] Reference Figure 1 , a system flow of a wide-load steam supply operation mode of coal-fired power, the system flow includes two lines, namely a steam-water line and a flue gas line. The main steam-water line includes a water-cooled wall, a low-temperature superheater, a high-temperature superheater, a high-pressure cylinder 14, a low-temperature reheater, a high-temperature reheater, a medium-pressure cylinder 15, a low-pressure cylinder 16, a condenser 18, a condensate pump 19, a low-pressure heater 20, a deaerator 21, a high-pressure heater 23, and an economizer connected in a closed loop in sequence. The steam-water line includes a deaerator 21, a shunt feed water pump 27, a steam generator, a steam compressor 28, and a water spray desuperheater 29 connected in sequence. The main flue gas line includes a boiler, an environmental protection device, and an induced draft fan connected in sequence, and the flue gas line in the boiler includes a water-cooled wall, a high-temperature superheater, a high-temperature reheater, and a low-temperature reheater (or a low-temperature superheater and an economizer) connected in sequence. The first flue gas circuit includes a boiler, a water-cooled wall diverter flue gas damper, a steam generator and an environmental protection device connected in sequence; the second flue gas circuit includes a boiler, a high-temperature superheater diverter flue gas damper, a steam generator and an environmental protection device connected in sequence; the third flue gas circuit includes a boiler, a high-temperature reheater diverter flue gas damper, a steam generator and an environmental protection device connected in sequence; the fourth flue gas circuit includes a boiler, a low-temperature reheater diverter flue gas damper, a steam generator and an environmental protection device connected in sequence; the fifth flue gas circuit includes a boiler, a low-temperature superheater diverter flue gas damper, a steam generator and an environmental protection device connected in sequence; the sixth flue gas circuit includes a boiler, an economizer diverter flue gas damper, a steam generator and an environmental protection device connected in sequence. In addition, the high-pressure cylinder 14, the medium-pressure cylinder 15, the low-pressure cylinder 16 and the generator 17 are connected in sequence to generate electricity, and the deaerator 21, the diverter water pump 27, the steam generator, the steam compressor 28 and the water spray desuperheater 29 are connected in sequence to generate steam supply.

[0094] Under normal operation of the above system, the unit load is 80%, the coal supply is fixed, the total flue gas volume is fixed, the opening of each split flue gas damper is fixed, the split flue gas flow rate is fixed and the split flue gas temperature is fixed; the flow rate of the feed water pump 22 is fixed, the flow rate of the split feed water pump 27 is fixed; the industrial steam supply temperature, pressure and flow rate are fixed.

[0095] When the unit load needs to be maintained below 40%, the coal supply is reduced, the total flue gas volume is reduced, and the opening of each shunt flue gas damper is increased to keep the shunt flue gas flow rate and the shunt flue gas temperature fixed; the flow rate of the water supply pump 22 is reduced, and the flow rate of the shunt water supply pump 27 is fixed; by adjusting the steam compressor 28 and the water spray cooler 29, steam with a fixed temperature, pressure and flow rate can still be supplied. Specifically, the fixed flow rate of the shunt water supply pump 27 means that after the user determines the target flow rate value of the industrial steam output, the actual output flow rate of the shunt water supply pump 27 is adjusted to the target flow rate value, and then maintained at the level of this target flow rate value. When the user modifies the target flow rate value, the actual output flow rate of the shunt water supply pump 27 needs to be readjusted until the output level of the target flow rate value is reached again.

[0096] When the unit load needs to be maintained at 100%, the coal supply is increased, the total flue gas volume increases, and the opening of each diversion flue gas damper is reduced to keep the diversion flue gas flow rate and the diversion flue gas temperature fixed; the flow of the feed water pump 22 is increased, and the flow of the diversion feed water pump 27 is fixed; by adjusting the steam compressor 28 and the water spray desuperheater 29, steam with a fixed temperature, pressure and flow rate can still be supplied.

[0097] Conventional steam supply needs to be extracted from each cylinder of the steam turbine, and the steam turbine needs to maintain sufficient steam intake to ensure the stability of steam supply, which limits the variable load capacity of the unit. After transformation through the method proposed by the present invention, stable steam supply no longer restricts the steam turbine to maintain a certain amount of steam intake, and the variable load capacity of the unit is improved compared with the original, realizing thermal and electrical decoupling of the steam supply unit in the coal-fired power plant, and achieving both steam supply stability and unit flexibility.

[0098] This device has the following beneficial effects:

[0099] 1. Steam parameters can be adjusted according to user needs to supply stable industrial steam, obtain steam supply benefits, and improve the thermal efficiency of power plants through cogeneration of heat and power;

[0100] 2. At the same time, it avoids the need to extract steam from each cylinder of the steam turbine, which can achieve the flexibility of the unit under a relatively large load change of the coal-fired power unit and obtain compensation for the peak load regulation process of the power grid system.

[0101] 3. The overall system transformation cost is low, the whole process is continuously stable and adjustable, easy to operate, with high energy utilization rate and deep degree of thermal and electric decoupling.

[0102] Example 2

[0103] The present invention also discloses a control method for the coal-fired unit device in embodiment 1, comprising the following steps:

[0104] Obtaining unit load parameters of a coal-fired unit, where the unit load parameters include a target electric power value;

[0105] Acquire actual output parameters of the coal-fired unit, the actual output parameters including actual electric power values ​​of the power generation components;

[0106] According to the actual electric power value of the power generation component and the target electric power value in the unit load parameter, a flue gas adjustment step is performed on the coal-fired unit device to adjust the power generation power of the power generation component until the actual electric power value of the power generation component reaches the target electric power value;

[0107] The flue gas regulation step includes: controlling the diverting flue gas component to regulate the high-temperature flue gas flow in the first heat exchange section.

[0108] The flue gas adjustment step further includes: adjusting the coal supply of the boiler equipment 1 to adjust the total flue gas in the boiler equipment 1 .

[0109] Specifically, the step of: performing a flue gas adjustment step on the coal-fired unit device according to the actual electric power value and the target electric power value in the unit load parameter to adjust the actual electric power value of the power generation component until the actual electric power value of the power generation component reaches the target electric power value, including:

[0110] Compare the target electric power value with the actual electric power value:

[0111] If the target load circuit is greater than the actual electric power value, the coal supply is increased to increase the total flue gas in the boiler equipment 1.

[0112] And, reduce the opening of the split flue gas component to increase the high-temperature flue gas flow in the first heat exchange section, thereby increasing the amount of steam output to the steam turbine, thereby increasing the actual electric power value of the power generation component;

[0113] If the target load circuit is less than the actual electric power value, the coal supply is reduced to reduce the total flue gas in the boiler equipment 1.

[0114] Also, the opening of the flue gas diversion component is increased to reduce the high-temperature flue gas flow in the first heat exchange section, thereby reducing the amount of steam output to the turbine, thereby reducing the actual electric power value of the power generation component.

[0115] Furthermore, the unit load parameter also includes: a target flow value of industrial steam output. The actual output parameter of the coal-fired unit also includes: an actual flow value of industrial steam output.

[0116] Compare the target flow value of industrial steam output with the actual flow value of industrial steam output:

[0117] If the target flow rate value of the industrial steam output is greater than the actual flow rate value, the flow rate of the shunt feedwater pump 27 is increased to increase the flow rate of the boiler water entering the steam generator, thereby increasing the flow rate of the industrial steam output until the actual flow rate value of the industrial steam output reaches the target flow rate value;

[0118] If the target flow value of the industrial steam output is less than the actual flow value, the flow of the diversion water pump 27 is reduced to reduce the flow of boiler water entering the steam generator, thereby reducing the flow of the industrial steam output until the actual flow value of the industrial steam output reaches the target flow value.

[0119] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A coal-fired unit, characterized in that: include: Boiler equipment (1) and power generation components; The boiler equipment (1) comprises a flue gas circuit and a steam-water circuit, the flue gas circuit comprises a flue gas main circuit, high-temperature flue gas flows in the flue gas main circuit, and the flue gas main circuit comprises a first heat exchange section; The steam-water circuit includes a main circulation loop, boiler water is introduced into the main circulation loop, the main circulation loop includes a second heat exchange section, the first heat exchange section is coupled to the second heat exchange section, and the high-temperature flue gas in the first heat exchange section heats the boiler water in the second heat exchange section, so that the boiler water is converted into steam; The second heat exchange section is connected to the power generation component, and the steam output from the second heat exchange section drives the power generation component to generate electricity. After driving the power generation component to generate electricity, the steam is re-condensed into boiler water, and the re-condensed boiler water flows back to the second heat exchange section for reheating; The flue gas line is provided with a diverting flue gas component, which is located in the first heat exchange section and is used to divert the high-temperature flue gas in the first heat exchange section, thereby adjusting the steam volume and further peaking the power generation component.

2. The coal-fired unit device according to claim 1, characterized in that: Also included is a steam generator (26), the steam generator (26) including a cold side channel and a hot side channel; The steam-water circuit also includes a water flow branch, one end of which is connected to the main circulation loop, and the other end of which is connected to the cold side channel of the steam generator (26). The water flow branch is located downstream of the power generation component, specifically between the condensed water outlet of the power generation component and the reflux inlet of the second heat exchange section. The re-condensed boiler water part flows back to the second heat exchange section for reheating, and the rest flows into the cold side channel through the water flow branch. The flue gas circuit further comprises a flue gas branch, one end of the flue gas branch is in communication with the first heat exchange section, and the other end is in communication with the hot side channel of the steam generator (26); the flue gas diversion component is located at a corresponding position of the flue gas branch, and is used to divert the high-temperature flue gas in the first heat exchange section, so that part of the high-temperature flue gas continues to flow along the first heat exchange section, thereby exchanging heat with the second heat exchange section, and the rest of the high-temperature flue gas enters the hot side channel of the steam generator (26) through the flue gas branch; When the high-temperature flue gas passes through the hot-side channel, it heats the re-condensed boiler water in the cold-side channel, so that the boiler water is converted into industrial steam output.

3. The coal-fired unit device according to claim 2, characterized in that: A shunt feed water pump (27) is provided on the water flow branch, and the shunt feed water pump (27) is located between the inlet of the water flow branch and the cold side channel of the steam generator (26). The shunt feed water pump (27) is used to adjust the flow rate of boiler water entering the water flow branch.

4. The coal-fired unit device according to claim 3, characterized in that: It also includes a control unit, which is electrically connected to the smoke diversion component, and is used to adjust the opening of the smoke diversion component according to the target electric power value of the power generation component, thereby adjusting the flow rate of the high-temperature smoke in the first heat exchange section and the flow rate of the high-temperature smoke diverted to the smoke branch, thereby adjusting the power generation power of the power generation component; The control unit is also electrically connected to the bypass feed water pump (27) and is used to adjust the opening of the bypass feed water pump (27) according to the target flow value of the industrial steam output, thereby adjusting the flow of boiler water entering the water flow branch, thereby adjusting the flow of the industrial steam output.

5. The coal-fired unit device according to claim 3, characterized in that: It also includes a steam compressor (28) and a water spray desuperheater (29), wherein the steam compressor (28) and the water spray desuperheater (29) are located downstream of the cold side channel of the steam generator (26), and the water flow branch is connected to the steam compressor (28) and the water spray desuperheater (29) in sequence through the cold side channel; The steam compressor (28) is used to adjust the pressure of the industrial steam output, and the water spray desuperheater (29) is used to adjust the temperature of the industrial steam output.

6. The coal-fired unit device according to claim 2, characterized in that: The first heat exchange section comprises a furnace section (30), the furnace section (30) is used for coal powder combustion to generate high-temperature flue gas, the second heat exchange section comprises a water-cooled wall section (3), the water-cooled wall section (3) is located between the reflux inlet and the power generation component, one end of the water-cooled wall section (3) is connected to the reflux inlet, and the other end is connected to the power generation component, the water-cooled wall section (3) is accommodated in the furnace section (30), when the high-temperature flue gas passes through the furnace section (30), the boiler water in the water-cooled wall section (3) is heated, so that the boiler water is converted into steam, and the water-cooled wall section (3) is used to output steam to the power generation component to drive the power generation component to generate electricity; The flue gas branch comprises a furnace flue gas branch, the split flue gas assembly comprises a furnace split flue gas unit (2), one end of the furnace flue gas branch is in communication with the side wall of the furnace section (30), and the other end is in communication with the hot side channel of the steam generator (26); The furnace diversion flue gas unit (2) corresponds to the furnace flue gas branch, and the furnace diversion flue gas unit (2) is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the furnace section (30) to exchange heat with the water-cooled wall section (3), and the remaining high-temperature flue gas enters the hot side channel of the steam generator (26) through the furnace flue gas branch.

7. The coal-fired unit device according to claim 6, characterized in that: The first heat exchange section further comprises an economizer hot side section, the hot side end of the economizer is located downstream of the furnace section (30) and is in communication with the furnace section (30), the second heat exchange section further comprises an economizer cold side section (13), the economizer cold side section (13) is located between the reflux inlet and the water-cooled wall section (3), one end of the economizer cold side section (13) is in communication with the reflux inlet, and the other end is in communication with the water-cooled wall section (3), the economizer cold side section (13) is accommodated in the hot side end of the economizer, and when the high-temperature flue gas flows through the hot side section of the economizer, the boiler water returning to the cold side end of the economizer is preheated; The flue gas branch also includes an economizer flue gas branch, and the diverter flue gas component also includes an economizer diverter flue gas unit (12). One end of the economizer flue gas branch is connected to the side wall of the hot side section of the economizer, and the other end is connected to the hot side channel of the steam generator (26). The economizer diverter flue gas unit (12) corresponds to the economizer flue gas branch. The economizer diverter flue gas unit (12) is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the economizer, thereby exchanging heat with the cold side section (13) of the economizer, and the remaining high-temperature flue gas enters the hot side channel of the steam generator (26) through the economizer flue gas branch.

8. The coal-fired unit device according to claim 7, characterized in that: The first heat exchange section further comprises a first superheater hot side section, the first superheater hot side section is located between the furnace section (30) and the economizer hot side section, one end of the first superheater hot side section is in communication with the furnace section (30), and the other end is in communication with the economizer hot side section, the second heat exchange section further comprises a first superheater cold side section (5), the first superheater cold side section (5) is located between the water-cooled wall section (3) and the power generation component, one end of the first superheater cold side section (5) is in communication with the water-cooled wall section (3), and the other end is in communication with the power generation component, the first superheater cold side section (5) is accommodated in the first superheater hot side section, and when the high-temperature flue gas passes through the first superheater hot side section, the steam in the first superheater cold side section (5) is heated to increase the steam temperature; The flue gas branch also includes a first superheater flue gas branch, and the diverter flue gas assembly also includes a first superheater diverter flue gas unit (4). One end of the first superheater flue gas branch is connected to the side wall of the hot side section of the first superheater, and the other end is connected to the hot side channel of the steam generator (26). The first superheater diverter flue gas unit (4) is located at the first superheater flue gas branch and is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the first superheater, thereby exchanging heat with the first superheater cold side section (5), and the rest of the high-temperature flue gas enters the hot side channel of the steam generator (26) through the first superheater flue gas branch.

9. The coal-fired unit device according to claim 8, characterized in that: The first heat exchange section further comprises a second superheater hot side section, the second superheater hot side section is located downstream of the first superheater hot side section, the furnace section (30) is connected to the second superheater hot side section through the first superheater hot side section, the second heat exchange section further comprises a second superheater cold side section (11), the second superheater cold side section (11) is located between the water-cooled wall section (3) and the first superheater cold side section (5), one end of the second superheater cold side section (11) is connected to the water-cooled wall section (3), and the other end is connected to the first superheater cold side section (5), the second superheater cold side section (11) is accommodated in the second superheater hot side section, and when the high-temperature flue gas passes through the second superheater hot side section, the steam in the second superheater cold side section (11) is heated to increase the steam temperature; The flue gas branch also includes a second superheater flue gas branch, and the diverter flue gas assembly also includes a second superheater diverter flue gas unit (10). One end of the second superheater flue gas branch is connected to the side wall of the hot side section of the second superheater, and the other end is connected to the hot side channel of the steam generator (26). The second superheater diverter flue gas unit (10) is located at the second superheater flue gas branch and is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the second superheater, thereby exchanging heat with the second superheater cold side section (11), and the rest of the high-temperature flue gas enters the hot side channel of the steam generator (26) through the second superheater flue gas branch.

10. The coal-fired unit device according to claim 9, characterized in that: The power generation assembly includes a steam turbine cylinder and a generator. The number of the steam turbine cylinders is multiple, and the multiple steam turbine cylinders are all connected to the rotor of the generator. The water-cooled wall section (3) is connected to a plurality of steam turbine cylinders in sequence through the second superheater cold side section (11) and the first superheater cold side section (5). The steam output by the water-cooled wall section (3) flows through the second superheater cold side section (11) and the first superheater cold side section (5) in sequence. After the steam is heated once by the high-temperature flue gas in the second superheater hot side section and heated twice by the high-temperature flue gas in the first superheater hot side section, it drives the plurality of steam turbine cylinders to drive the rotor of the generator to rotate, thereby generating electricity.

11. The coal-fired unit device according to claim 10, characterized in that: The first steam turbine cylinder among the plurality of steam turbine cylinders through which the steam outputted by the water-cooled wall section (3) flows in sequence is set as the first steam turbine cylinder, and the other steam turbine cylinders are set as the second steam turbine cylinders; The first heat exchange section further comprises a first reheater hot side section, the first reheater hot side section is located between the first superheater hot side section and the second superheater hot side section, one end of the first reheater hot side section is connected to the first superheater hot side section, and the other end is connected to the second superheater hot side section; The second heat exchange section further comprises a first reheater cold side section (7), wherein the first reheater cold side section (7) is located between the first steam turbine cylinder and the second steam turbine cylinder, and the first steam turbine cylinder is connected to the second steam turbine cylinder through the first reheater cold side section (7); The first reheater cold side section (7) is accommodated in the first reheater hot side section. The temperature of the steam decreases after driving the first steam turbine cylinder to generate electricity. When the high-temperature flue gas passes through the first reheater hot side section, the steam in the first reheater cold side section (7) is heated again to increase the steam temperature.

12. The coal-fired unit device according to claim 11, characterized in that: The flue gas branch further comprises a first reheater flue gas branch, the split flue gas unit further comprises a first reheater split flue gas unit (6), one end of the first reheater flue gas branch is in communication with the side wall of the first reheater hot side section, and the other end is in communication with the hot side channel of the steam generator (26); The first reheater flue gas diversion unit (6) is located at the first reheater flue gas branch, and the first reheater flue gas diversion unit (6) is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the first reheater, thereby exchanging heat with the first reheater cold side section (7), and the remaining high-temperature flue gas enters the hot side channel of the steam generator (26) through the first reheater flue gas branch.

13. The coal-fired unit device according to claim 12, characterized in that: The first heat exchange section further comprises a second reheater hot side section, the second reheater hot side section is located downstream of the first reheater hot side section and is in communication with the first reheater hot side section, the second reheater hot side section is connected in parallel to the second superheater hot side section and the economizer hot side section, the second heat exchange section further comprises a second reheater cold side section (9), the second reheater cold side section (9) is located between the first steam turbine cylinder and the first reheater cold side section (7), the first steam turbine cylinder is in communication with the second steam turbine cylinder through the second reheater cold side section (9) and the first reheater cold side section (7), the second reheater cold side section (9) is accommodated in the second reheater hot side section, and when the high-temperature flue gas flows through the second reheater hot side section, the steam in the second reheater cold side section (9) is reheated; The flue gas branch further comprises a second reheater flue gas branch, the split flue gas unit further comprises a second reheater split flue gas unit (8), one end of the second reheater flue gas branch is in communication with the side wall of the hot side section of the second reheater, and the other end is in communication with the hot side channel of the steam generator (26); The second reheater flue gas diversion unit (8) is located at the second reheater flue gas branch, and the second reheater flue gas diversion unit (8) is used to divert the high-temperature flue gas so that part of the high-temperature flue gas continues to flow along the hot side section of the second reheater, thereby exchanging heat with the second reheater cold side section (9), and the remaining high-temperature flue gas enters the hot side channel of the steam generator (26) through the second reheater flue gas branch.

14. The coal-fired unit device according to any one of claims 6 to 13, characterized in that: It also includes a flue gas treatment device (24), the main flue gas path is connected to the flue gas treatment device (24), and the flue gas treatment device (24) is located downstream of the first heat exchange section and is used to perform denitrification, dust removal, desulfurization and / or decarbonization treatment on the high-temperature flue gas discharged from the first heat exchange section.

15. A control method for a coal-fired unit according to any one of claims 1 to 14, characterized in that: include: Acquire a unit load parameter of the coal-fired unit device, wherein the unit load parameter includes a target electric power value; Acquiring actual output parameters of the coal-fired unit, wherein the actual output parameters include actual electric power values ​​of power generation components; According to the actual electric power value of the power generation component and the target electric power value in the unit load parameter, a flue gas regulation step is performed on the coal-fired unit device to adjust the power generation power of the power generation component until the actual electric power value of the power generation component reaches the target electric power value; The flue gas regulating step includes: controlling the diverting flue gas component to regulate the high-temperature flue gas flow in the first heat exchange section.

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