Smoke circulation hydrogen-doped combustion peak regulation and combustion stabilization system and method

Abstract

The embodiment of the invention provides a flue gas circulation hydrogen-doped combustion peak regulation and combustion stabilization system. The flue gas circulation hydrogen-doped combustion peak regulation and combustion stabilization system comprises a boiler, a water electrolysis device, a flue gas-hydrogen mixer and a flue gas-hydrogen combustor. The boiler is provided with a burner, and the flue gas-hydrogen burner is arranged on the lowermost layer of the boiler; the water electrolysis device is powered by the power supply device, an anode outlet of the water electrolysis device is communicated with a combustion improver inlet of the combustor, and a cathode outlet of the water electrolysis device is communicated with a hydrogen inlet of the flue gas-hydrogen mixer; a flue gas outlet of the boiler is respectively communicated with an inlet of the chimney and a flue gas inlet of the flue gas-hydrogen mixer; and a mixing outlet of the flue gas-hydrogen mixer is communicated with an inlet of the flue gas-hydrogen burner. According to the system, through hydrogen-doped combustion and oxygen-enriched combustion, boiler combustion is stable and safe during deep peak regulation of a unit, coal consumption is reduced, and cost is saved.

Description

Technical Field

[0001] The disclosed embodiments belong to the technical field of coal-fired power units, and specifically relate to a flue gas circulation hydrogen-blended combustion peak-shaving and stable combustion system and method. Background Art

[0002] With the accelerated construction of the "Global Energy Internet" proposed by the State Grid, new energy sources such as wind power and solar power are connected to the grid on a large scale. However, their unstable output characteristics have led to an increasing difference in the peak and valley of power load, increasing the peak-shaving pressure on the power grid. However, my country's current energy situation and power installed capacity structure determine that coal-fired power units will bear the main peak-shaving task.

[0003] Generally speaking, the main modes of peak load regulation of coal-fired power units are: low-load operation, two-shift operation, low steam reactive operation and rotation peak load regulation. Among them, the low-load operation mode is an operation mode that changes the load of the unit to meet the peak load regulation needs of the system. Most of the coal-fired power units connected to the grid in my country are dispatched by the power grid. Generally, the peak load range of the unit is 50% to 100% of the rated output of the unit. Most of the coal-fired power units with a capacity of 300MW and above in service use low-load operation to participate in peak load regulation. Deep regulation of coal-fired units is the norm, but for supercritical and above parameter units, frequent deep regulation to load operation below 25% has a greater impact on the safety of the unit. Long-term low-load operation reduces the economy and even sacrifices the safety of the equipment.

[0004] Hydrogen energy is a secondary energy source with abundant sources, green and low carbon, and wide applications. As a green and clean energy carrier, truly low-carbon, large-scale, sustainable and affordable preparation and utilization of hydrogen is an important development direction and is of great significance to carbon emission reduction.

[0005] Hydrogen can be produced through fossil energy reforming, industrial by-product gas purification, etc., and can also be produced through water electrolysis. Combining water electrolysis hydrogen production technology with renewable energy power generation technology, hydrogen produced from renewable energy can optimize my country's energy structure and improve the safety of the entire energy system.

[0006] In view of the above problems, it is necessary to propose a flue gas circulation hydrogen-blended combustion peak-shaving and stabilizing combustion system and method that is reasonably designed and effectively solves the above problems. Summary of the invention

[0007] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a flue gas circulation hydrogen-blended combustion peak-shaving and stable combustion system and method.

[0008] One aspect of the embodiments of the present disclosure provides a flue gas circulation hydrogen-blended combustion peak-shaving and stable combustion system, including a boiler, a water electrolysis device, a flue gas-hydrogen mixer, and a flue gas-hydrogen burner;

[0009] The boiler is provided with a burner, and the flue gas-hydrogen burner is arranged at the bottom layer of the boiler;

[0010] The water electrolysis device is powered by a power supply device, the anode outlet of the water electrolysis device is connected to the combustion-supporting agent inlet of the burner, and the cathode outlet of the water electrolysis device is connected to the hydrogen inlet of the flue gas-hydrogen mixer;

[0011] The flue gas outlet of the boiler is respectively connected to the chimney inlet and the flue gas inlet of the flue gas-hydrogen mixer;

[0012] The mixing outlet of the flue gas-hydrogen mixer is communicated with the inlet of the flue gas-hydrogen burner.

[0013] Optionally, the system further comprises a generator and a steam turbine;

[0014] The inlet of the steam turbine is connected to the steam outlet of the boiler, and the outlet of the steam turbine is connected to the generator to drive the generator to generate electricity;

[0015] The power supply device includes a plant power device. When the power consumption of the power grid is low or the dispatching load is lower than the minimum stable combustion load of the boiler, the plant power device uses part of the electric energy output by the generator to power the water electrolysis device.

[0016] Optionally, it also includes a power peak-shaving distribution switch, and the power peak-shaving distribution switch is electrically connected to the generator.

[0017] Optionally, the power supply device further includes a renewable energy power generation device;

[0018] Within the normal load range, the renewable energy power generation device supplies power to the water electrolysis device.

[0019] Optionally, an oxygen delivery pipeline is connected between the anode outlet of the water electrolysis device and the inlet of the burner;

[0020] The oxygen delivery pipeline is sequentially provided with an oxygen storage device, an oxygen shut-off door, an oxygen compressor, an oxygen check valve and an oxygen regulating valve; wherein,

[0021] The inlet of the oxygen storage device is connected to the anode outlet of the water electrolysis device.

[0022] Optionally, a hydrogen delivery pipeline is connected between the cathode outlet of the water electrolysis device and the flue gas-hydrogen mixer;

[0023] The hydrogen delivery pipeline is sequentially provided with a hydrogen storage device, a hydrogen shut-off valve, a hydrogen compressor, a hydrogen check valve and a hydrogen regulating valve; wherein,

[0024] The inlet of the hydrogen storage device is connected to the cathode outlet of the water electrolysis device.

[0025] Optionally, it also includes a smoke main pipeline, a smoke circulation pipeline and a smoke exhaust pipeline;

[0026] The inlet of the main flue gas line is connected to the flue gas outlet of the boiler, and an induced draft fan is arranged in series on the main flue gas line;

[0027] The outlet of the main flue gas pipeline is respectively connected to the inlet of the flue gas circulation pipeline and the inlet of the flue gas exhaust pipeline;

[0028] The outlet of the flue gas exhaust pipeline is connected to the chimney, wherein a desulfurization tower is arranged in series on the flue gas exhaust pipeline;

[0029] The outlet of the flue gas circulation pipeline is communicated with the flue gas inlet of the flue gas-hydrogen mixer.

[0030] Optionally, a smoke shutoff valve, a smoke regulating valve and a smoke check valve are sequentially arranged on the smoke circulation pipeline; wherein,

[0031] The outlet of the flue gas check valve is communicated with the flue gas-hydrogen mixer.

[0032] Optionally, the bottom layer of the boiler is provided with multiple layers of flue gas-hydrogen burners.

[0033] Another aspect of the embodiments of the present disclosure provides a flue gas circulation hydrogen-blended combustion peak-shaving and combustion stabilization method, which adopts the flue gas circulation hydrogen-blended combustion peak-shaving and combustion stabilization system described above.

[0034] The flue gas circulation hydrogen-blended combustion peak-shaving and stable combustion system and method of the disclosed embodiment, by arranging a flue gas-hydrogen burner at the bottom layer of the boiler, the hydrogen prepared by the water electrolysis device is mixed with the flue gas in the flue gas-hydrogen mixer and then transported to the flue gas-hydrogen burner. By mixing the flue gas with hydrogen for combustion, the carbon emissions of the unit can be reduced, the combustion conditions of the coal-fired or gas-fired unit at low load can be stabilized, and the flexibility of the boiler can be increased; in addition, hydrogen can effectively reduce its deflagration risk in an inert environment and improve the safety of the system. The oxygen prepared by the water electrolysis device can be used as a combustion aid for the boiler burner to carry out oxygen-enriched combustion. The prepared oxygen is mixed with the primary air for powder feeding and then passed to the furnace for combustion, which can make the unit burn coal with poor quality, save costs, and further stabilize the combustion conditions of the unit at low load. The flue gas circulation hydrogen-blended combustion peak-shaving and stable combustion system can make the boiler burn stably and safely, reduce coal consumption, and save costs when the unit is deeply peak-shaving through hydrogen-blended combustion and oxygen-enriched combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1This is a structural schematic diagram of a flue gas circulation hydrogen-blended combustion peak-shaving and stabilizing combustion system in one embodiment of the present disclosure. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solutions of the embodiments of the present disclosure, the embodiments of the present disclosure are further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0037] like Figure 1 As shown, one aspect of an embodiment of the present disclosure provides a flue gas circulation hydrogen-blended combustion peak-shaving and stabilizing combustion system, comprising a boiler 1, a water electrolysis device 2, a flue gas-hydrogen mixer 3, and a flue gas-hydrogen burner 4.

[0038] The boiler 1 is provided with a burner 5, wherein the boiler 1 may be a coal (gas) fired boiler, and correspondingly, the burner 5 may be a coal (gas) fired burner.

[0039] The flue gas-hydrogen burner 4 is arranged at the lowest level of the boiler 1 .

[0040] The water electrolysis device 2 is powered by a power supply device, the anode outlet of the water electrolysis device 2 is connected to the combustion aid inlet of the burner 5, and the cathode outlet of the water electrolysis device 2 is connected to the hydrogen inlet of the flue gas-hydrogen mixer 3.

[0041] The flue gas outlet of the boiler 1 is communicated with the inlet of the chimney 6 and the flue gas inlet of the flue gas-hydrogen mixer 3 respectively.

[0042] The mixing outlet of the flue gas-hydrogen mixer 3 is communicated with the inlet of the flue gas-hydrogen burner 4 .

[0043] Specifically, the hydrogen prepared by the water electrolysis device 2 and a part of the flue gas generated by the boiler 1 are mixed in the flue gas-hydrogen mixer 3 according to a preset ratio to form hydrogen-doped flue gas, and the hydrogen-doped flue gas enters the flue gas-hydrogen burner 4, which is arranged at the bottom of the traditional coal-fired or gas-fired burner. The combustion chamber is completely covered with refractory materials. Since the temperature of hydrogen combustion is very high, reaching 2000℃~3000℃, by adjusting the mixing ratio of hydrogen and flue gas, the flue gas temperature after combustion can be controlled at about 1500℃, and then sprayed into the furnace. By burning flue gas mixed with hydrogen, the carbon emissions of the unit can be reduced, the combustion conditions of coal-fired or gas-fired units at low load can be stabilized, and the flexibility of the boiler can be increased. The oxygen prepared by the water electrolysis device 2 is mixed with the primary air for powder feeding and then enters the burner 5 through the combustion agent inlet of the burner 5 for combustion, which can make the unit burn coal with poor quality, save costs, and further stabilize the combustion conditions of the unit at low load. Another part of the flue gas generated by the boiler 1 is discharged through the chimney 6.

[0044] The flue gas circulation hydrogen-blended combustion peak-shaving and stable combustion system of the disclosed embodiment is provided with a flue gas-hydrogen burner at the bottom layer of the boiler. The hydrogen prepared by the water electrolysis device is mixed with the flue gas in the flue gas-hydrogen mixer and then transported to the flue gas-hydrogen burner. By mixing the flue gas with hydrogen for combustion, the carbon emissions of the unit can be reduced, the combustion conditions of the coal-fired or gas-fired unit at low load can be stabilized, and the flexibility of the boiler can be increased. In addition, hydrogen can effectively reduce its deflagration risk in an inert environment and improve the safety of the system. The oxygen prepared by the water electrolysis device can be used as a combustion aid for the boiler burner to carry out oxygen-enriched combustion. The prepared oxygen is mixed with the primary air for powder feeding and then passed to the furnace for combustion. The unit can burn coal with poor quality, save costs, and further stabilize the combustion conditions of the unit at low load. The flue gas circulation hydrogen-blended combustion peak-shaving and stable combustion system can make the boiler burn stably and safely, reduce coal consumption, and save costs when the unit is deeply peak-shaving through hydrogen-blended combustion and oxygen-enriched combustion.

[0045] For example, Figure 1 As shown, the system further includes a steam turbine 7 and a generator 8. The inlet of the steam turbine 7 is connected to the steam outlet of the boiler 1, and the outlet of the steam turbine 7 is connected to the generator 8 to drive the generator 8 to generate electricity.

[0046] The power supply device includes a plant power device. When the power consumption of the power grid is low or the dispatching load is low and the boiler has the lowest stable combustion load, the plant power device uses part of the electric energy output by the generator 8 to power the water electrolysis device 2.

[0047] For example, Figure 1 As shown, the system also includes an electricity peak-shaving distribution switch 9 , which is electrically connected to the generator 8 .

[0048] Specifically, when the power consumption of the power grid is low or the dispatching load is lower than the minimum stable combustion load of the boiler, the water electrolysis device is started, the power peak-shaving distribution switch 9 is turned on, and part of the power output by the generator 8 is used by the plant power device to power the water electrolysis device 2, and the water electrolysis device 2 starts to electrolyze water to produce hydrogen and oxygen, and the hydrogen is mixed with flue gas for combustion, and the oxygen assists the boiler to stabilize combustion. The power output by the generator 8 is used by the plant power device to produce hydrogen in the water electrolysis device 2, so that the unit can reduce the power supply to the grid at a higher power and realize the peak-shaving function of the thermal power unit.

[0049] In the disclosed embodiments, the peak-shaving capacity of the unit can be improved by the peak-shaving distribution switch and the plant power device of the present invention. When the unit is deeply peak-shaving, under the load conditions required by the power grid, a certain proportion of electricity can be used to electrolyze water to produce hydrogen and oxygen through the plant power device, so that the unit can reduce the amount of electricity connected to the grid at a higher power. Under such operating conditions, the boiler does not have to convert the dry state to the wet state during deep peak-shaving, thereby increasing the flexibility and safety of the boiler. At the same time, the unit still operates at a higher power during deep peak-shaving, and the boiler operates relatively efficiently, which can effectively reduce coal consumption.

[0050] For example, Figure 1 As shown, the power supply device also includes a renewable energy power generation device. Within the normal load range, the renewable energy power generation device supplies power to the water electrolysis device 2. The renewable energy power generation device can use unstable power or valley peak power generation such as photovoltaic power generation and wind power generation in the factory area. The type of the renewable energy power generation device is not specifically limited in this embodiment and can be selected according to actual needs.

[0051] In this embodiment, the renewable energy power generation device is used to power the water electrolysis device, which can further save coal and reduce costs.

[0052] For example, Figure 1 As shown, an oxygen delivery pipeline 10 is connected between the anode outlet of the water electrolysis device 2 and the inlet of the burner 5 of the boiler 10. The oxygen prepared by the water electrolysis device 2 can enter the burner 5 of the boiler 1 through the oxygen delivery pipeline 10.

[0053] Furthermore, an oxygen storage device 11, an oxygen shutoff door 11a, an oxygen compressor 12, an oxygen check valve 13 and an oxygen regulating valve 14 are sequentially arranged on the oxygen delivery pipeline 10. The inlet of the oxygen storage device 11 is connected to the anode outlet of the water electrolysis device 2. In the system, the oxygen shutoff door 11a, the oxygen compressor 12, the oxygen check valve 13 and the oxygen regulating valve 14 are connected to the PLC control system or the plant DCS.

[0054] Specifically, the oxygen prepared by the water electrolysis device 1 can be stored by the oxygen storage device 11. When oxygen needs to be introduced into the burner 5 of the boiler 1, the oxygen compressor 12, the oxygen check valve 13 and the oxygen regulating valve 14 can be opened to transport oxygen and adjust the oxygen flow rate.

[0055] For example, Figure 1 As shown, a hydrogen delivery pipeline 15 is connected between the cathode outlet of the water electrolysis device 2 and the flue gas-hydrogen mixer 3. The hydrogen prepared by the water electrolysis device 2 can be delivered to the flue gas-hydrogen mixer 3 through the hydrogen delivery pipeline 15.

[0056] Furthermore, a hydrogen storage device 16, a hydrogen shutoff door 16a, a hydrogen compressor 17, a hydrogen check valve 18 and a hydrogen regulating valve 19 are sequentially arranged on the hydrogen delivery pipeline 15, wherein the inlet of the hydrogen storage device 16 is connected to the cathode outlet of the water electrolysis device 2. In the system, the hydrogen shutoff door 16a, the hydrogen compressor 17, the hydrogen check valve 18 and the hydrogen regulating valve 19 are connected to the PLC control system or the plant DCS.

[0057] Specifically, the hydrogen prepared by the water electrolysis device 1 can be stored by the hydrogen storage device 16. When hydrogen needs to be introduced into the flue gas-hydrogen mixer 3, the hydrogen compressor 17, the hydrogen check valve 18 and the hydrogen regulating valve 19 can be opened to transport the hydrogen and adjust the hydrogen flow rate.

[0058] For example, Figure 1 As shown, the system further includes a smoke main pipeline 20 , a smoke circulation pipeline 21 and a smoke exhaust pipeline 22 .

[0059] The inlet 20 of the flue gas main line is connected to the flue gas outlet of the boiler 1, and an induced draft fan 23 is arranged in series on the flue gas main line 20. The outlet of the flue gas main line 20 is respectively connected to the inlet of the flue gas circulation pipeline 21 and the inlet of the flue gas exhaust pipeline 22. The outlet of the flue gas exhaust pipeline 22 is connected to the chimney 6, wherein a desulfurization tower 24 is arranged in series on the flue gas exhaust pipeline 22. The outlet of the flue gas circulation pipeline 21 is connected to the flue gas inlet of the flue gas-hydrogen mixer 3.

[0060] Specifically, the flue gas generated by the boiler 1 enters the flue gas main pipeline 20, and a part of the flue gas is discharged into the flue gas exhaust pipeline 22 by the output of the induced draft fan 23, and is discharged through the chimney 6 after being processed by the desulfurization tower 24 in the flue gas exhaust pipeline 22. A part of the flue gas is discharged into the flue gas circulation pipeline 21 by the output of the induced draft fan 23, and enters the flue gas-hydrogen mixer 3 through the transportation of the flue gas circulation pipeline 21, and is mixed with the hydrogen entering the flue gas-hydrogen mixer 3. In other words, another part of the flue gas participates in the flue gas circulation of the system through the transportation of the flue gas circulation pipeline 21.

[0061] Exemplarily, a flue gas shutoff door 25, a flue gas regulating door 26 and a flue gas check valve 27 are sequentially arranged on the flue gas circulation pipeline 21; wherein, the outlet of the flue gas check valve 27 is connected to the flue gas-hydrogen mixer 3. The flue gas shutoff door 25, the flue gas regulating door 26 and the flue gas check valve 27 are used to control the transportation of flue gas and the regulation of flue gas flow rate.

[0062] It should be noted that, in this embodiment, the flue gas-hydrogen mixer 3 can use compressed hydrogen to induce flue gas for mixing, which can effectively reduce the impact of the system on the output of the induced draft fan 23.

[0063] It should be noted that the bottom layer of the boiler 1 is provided with multiple layers of flue gas-hydrogen burners 4. The number of flue gas-hydrogen burners 4 is not specifically limited in this embodiment and can be selected according to the capacity of the unit.

[0064] Another aspect of the disclosed embodiment provides a flue gas circulation hydrogen-blended combustion peak shaving and stabilizing combustion method, which uses the flue gas circulation hydrogen-blended combustion peak shaving and stabilizing combustion system described above. The specific structural features of the flue gas circulation hydrogen-blended combustion peak shaving and stabilizing combustion system have been described in detail above and will not be repeated here.

[0065] The specific process of the flue gas circulation hydrogen-blending combustion peak-shaving and stable combustion method of this embodiment can be as follows:

[0066] Within the normal load range, a renewable energy power generation device can be used to power the water electrolysis device 2. The hydrogen and oxygen produced by the water electrolysis device 2 can be respectively stored in the hydrogen storage device 16 and the oxygen storage device 11 for standby use, or oxygen can be used to assist the boiler in stabilizing combustion, reduce the ignition point temperature of coal powder, increase the combustion rate and scale of coal powder, and use hydrogen mixed with flue gas for cyclic combustion to stabilize combustion and save coal.

[0067] When the power grid is in low power consumption or the dispatching load is lower than the minimum stable combustion load of the boiler, the water electrolysis device is started, the power peak-shaving distribution switch 9 is turned on, and part of the electric energy output by the generator 8 is used by the plant power device to power the water electrolysis device 2. The water electrolysis device 2 starts to electrolyze water to produce hydrogen and oxygen, and the hydrogen is mixed with the flue gas for combustion, and the oxygen assists the boiler in stable combustion.

[0068] The flue gas circulation hydrogen-blended combustion peak-shaving and stable combustion method of the disclosed embodiment adopts the flue gas circulation hydrogen-blended combustion peak-shaving and stable combustion system described above. By blending flue gas with hydrogen for combustion, the carbon emissions of the unit can be reduced, the combustion conditions of coal-fired or gas-fired units at low loads can be stabilized, and the flexibility of the boiler can be increased. In addition, hydrogen can effectively reduce its deflagration risk in an inert environment and improve the safety of the system. Through oxygen-enriched combustion, the unit can burn coal of poor quality, saving costs, further stabilizing the combustion conditions of the unit at low loads, and making the boiler burn stably and safely during deep peak shaving of the unit, reducing coal consumption and saving costs.

[0069] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the embodiments of the present disclosure, but the embodiments of the present disclosure are 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 embodiments of the present disclosure, and these modifications and improvements are also considered to be within the protection scope of the embodiments of the present disclosure.

Claims

1. A flue gas circulation hydrogen-blending combustion peak-shaving and stable combustion system, characterized in that: It includes boiler, water electrolysis device, flue gas-hydrogen mixer, flue gas-hydrogen burner; The boiler is provided with a burner, and the flue gas-hydrogen burner is arranged at the bottom layer of the boiler; The water electrolysis device is powered by a power supply device, the anode outlet of the water electrolysis device is connected to the combustion-supporting agent inlet of the burner, and the cathode outlet of the water electrolysis device is connected to the hydrogen inlet of the flue gas-hydrogen mixer; The flue gas outlet of the boiler is respectively connected to the chimney inlet and the flue gas inlet of the flue gas-hydrogen mixer; The mixing outlet of the flue gas-hydrogen mixer is communicated with the inlet of the flue gas-hydrogen burner.

2. The system according to claim 1, characterized in that The system also includes a generator and a steam turbine; The inlet of the steam turbine is connected to the steam outlet of the boiler, and the outlet of the steam turbine is connected to the generator to drive the generator to generate electricity; The power supply device includes a plant power device. When the power consumption of the power grid is low or the dispatching load is lower than the minimum stable combustion load of the boiler, the plant power device uses part of the electric energy output by the generator to power the water electrolysis device.

3. The system according to claim 2, characterized in that It also includes a power peak-shaving distribution switch, which is electrically connected to the generator.

4. The system according to any one of claims 1 to 3, characterized in that: The power supply device also includes a renewable energy power generation device; Within the normal load range, the renewable energy power generation device supplies power to the water electrolysis device.

5. The system according to any one of claims 1 to 3, characterized in that: An oxygen delivery pipeline is connected between the anode outlet of the water electrolysis device and the inlet of the burner; The oxygen delivery pipeline is sequentially provided with an oxygen storage device, an oxygen shut-off door, an oxygen compressor, an oxygen check valve and an oxygen regulating valve; wherein, The inlet of the oxygen storage device is connected to the anode outlet of the water electrolysis device.

6. The system according to any one of claims 1 to 3, characterized in that: A hydrogen delivery pipeline is connected between the cathode outlet of the water electrolysis device and the flue gas-hydrogen mixer; The hydrogen delivery pipeline is sequentially provided with a hydrogen storage device, a hydrogen shut-off valve, a hydrogen compressor, a hydrogen check valve and a hydrogen regulating valve; wherein, The inlet of the hydrogen storage device is connected to the cathode outlet of the water electrolysis device.

7. The system according to any one of claims 1 to 3, characterized in that: It also includes a smoke main pipeline, a smoke circulation pipeline and a smoke exhaust pipeline; The inlet of the main flue gas line is connected to the flue gas outlet of the boiler, and an induced draft fan is arranged in series on the main flue gas line; The outlet of the main flue gas pipeline is respectively connected to the inlet of the flue gas circulation pipeline and the inlet of the flue gas exhaust pipeline; The outlet of the flue gas exhaust pipeline is connected to the chimney, wherein a desulfurization tower is arranged in series on the flue gas exhaust pipeline; The outlet of the flue gas circulation pipeline is communicated with the flue gas inlet of the flue gas-hydrogen mixer.

8. The system according to claim 7, characterized in that The smoke circulation pipeline is provided with a smoke shutoff valve, a smoke regulating valve and a smoke check valve in series; wherein, The outlet of the flue gas check valve is communicated with the flue gas-hydrogen mixer.

9. The system according to any one of claims 1 to 3, characterized in that: The bottom layer of the boiler is provided with multiple layers of flue gas-hydrogen burners.

10. A flue gas circulation hydrogen-blending combustion peak-shaving and combustion stabilization method, characterized in that: A flue gas circulation hydrogen-blending combustion peak-shaving and stabilizing combustion system as described in any one of claims 1 to 9 is adopted.

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