Coal-fired unit peak regulation system combined with biomass pyrolysis process

Abstract

The utility model provides a coal-fired unit peak regulation system combined with biomass pyrolysis process, which is characterized in that the coal-fired unit peak regulation system comprises a pyrolysis reactor, a boiler, a recirculation flue, a water vapor subsystem and a generator, the pyrolysis reactor is used for generating pyrolysis gas, charcoal and biological methanol according to biomass, high-temperature flue gas and high-temperature superheated steam, and the boiler is used for generating the pyrolysis gas, the charcoal and the biological methanol according to the pyrolysis gas, the charcoal and the biological methanol. The boiler is connected with the pyrolysis reactor and used for carrying out combustion reaction according to input fuel and pyrolysis gas output by the pyrolysis reactor to generate high-temperature flue gas, and the recycling flue is connected with the boiler and the pyrolysis reactor and used for inputting part of the high-temperature flue gas generated by the boiler into the pyrolysis reactor; the steam subsystem is used for absorbing heat generated by the boiler to generate steam to drive the generator to work. In conclusion, the system can achieve coupling of the pyrolysis process and the combustion process, the energy utilization efficiency is improved, and stable combustion during low-load operation of the boiler is helped.

Description

Technical Field

[0001] The utility model relates to a peak-shaving system for a coal-fired unit, in particular to a peak-shaving system for a coal-fired unit combined with a biomass pyrolysis process. Background Art

[0002] my country's energy endowment of abundant coal, low oil, and limited natural gas dictates a coal-based energy structure. However, the greenhouse effect caused by coal combustion is a significant challenge facing all of humanity. To achieve carbon peak and carbon neutrality as quickly as possible, my country is gradually shifting from a coal-based power generation structure to one dominated by renewable energy. However, due to my country's growing energy demand, the cyclical and unstable nature of renewable energy, and the lagging development of energy storage technology, coal-fired boiler units must be retained for baseload and peak-shaving functions.

[0003] Deep peak shaving also presents several challenges. For example, when the load decreases on the furnace side, the combustion temperature drops, leading to unstable combustion and even flameout, resulting in significant economic losses. Furthermore, operating the boiler at low load can significantly reduce energy efficiency.

[0004] Therefore, how to ensure that the boiler operates under high load conditions is an urgent problem that needs to be solved. Utility Model Content

[0005] The utility model is developed to solve the above problems, and aims to provide a coal-fired unit peak-shaving system combined with a biomass pyrolysis process.

[0006] The utility model provides a coal-fired unit peak-shaving system combined with a biomass pyrolysis process, which is used to produce pyrolysis gas, biochar and biomethanol based on biomass, and has the following characteristics: a pyrolysis reactor, a boiler, a recirculating flue, a water vapor subsystem and a generator, wherein the pyrolysis reactor is used to generate pyrolysis gas, biochar and biomethanol based on biomass, high-temperature flue gas and high-temperature superheated steam, the boiler is connected to the pyrolysis reactor, and is used to carry out a combustion reaction based on the input fuel and the pyrolysis gas output by the pyrolysis reactor to generate high-temperature flue gas, the recirculating flue is respectively connected to the boiler and the pyrolysis reactor, and is used to input part of the high-temperature flue gas generated by the boiler into the pyrolysis reactor, and the water vapor subsystem is used to absorb the heat generated by the boiler to generate water vapor to drive the generator to work.

[0007] In the coal-fired unit peak-shaving system combined with the biomass pyrolysis process provided by the present invention, it can also have the following characteristics: wherein, the boiler includes a furnace, a horizontal flue and a tail flue connected in sequence, one end of the recycling flue is arranged at the connection between the horizontal flue and the tail flue, and the other end of the recycling flue is arranged at the lower part of the pyrolysis reactor, and the high-temperature flue gas generated in the furnace is discharged in sequence through the horizontal flue and the tail flue.

[0008] The coal-fired unit peak-shaving system combined with the biomass pyrolysis process provided by the present invention may also have the following features: wherein, the water vapor subsystem includes an economizer, a water-cooled wall, a radiation superheater, a high-temperature superheater and a turbine assembly connected in sequence, the water-cooled wall is arranged in the furnace, the radiation superheater and the high-temperature superheater are both arranged in the horizontal flue, and the turbine assembly drives the generator to work by doing work through water vapor.

[0009] In the coal-fired unit peak-shaving system combined with the biomass pyrolysis process provided by the present invention, it can also have the following characteristics: wherein, the turbine assembly includes a superheated steam turbine, a high-temperature reheater and a reheated steam turbine connected in sequence, the superheated steam turbine, the reheated steam turbine and the generator are coaxially connected in sequence, and the high-temperature reheater is arranged in the horizontal flue.

[0010] The coal-fired unit peak-shaving system combined with the biomass pyrolysis process provided by the present invention may also have the following features: wherein, the water vapor subsystem also includes a heater, which is respectively connected to the high-temperature superheater and the water-cooled wall, and is arranged in the pyrolysis reactor to provide heat to the pyrolysis reactor, and part of the water vapor output by the high-temperature superheater enters the water-cooled wall through the heater.

[0011] The coal-fired unit peak-shaving system combined with the biomass pyrolysis process provided by the present invention may also have the following characteristics: the ratio of the water vapor flowing through the heater to the total water vapor output by the high-temperature superheater is less than 20%.

[0012] The coal-fired unit peak-shaving system combined with the biomass pyrolysis process provided by the present invention may also have the following characteristics: wherein the boiler includes an oil burner nozzle for controlling the amount of pyrolysis gas input into the boiler from the pyrolysis reactor.

[0013] The coal-fired unit peak-shaving system combined with the biomass pyrolysis process provided by the present invention may also have the following characteristics: wherein the ratio of the high-temperature flue gas input into the pyrolysis reactor from the recycled flue to all the high-temperature flue gases generated by the boiler is less than 10%.

[0014] The coal-fired unit peak-shaving system combined with the biomass pyrolysis process provided by the present invention may also have the following characteristics: wherein the pyrolysis reactor is a fluidized bed type or a fixed bed type.

[0015] Functions and effects of utility models

[0016] According to the coal-fired unit peak-shaving system combined with the biomass pyrolysis process involved in the utility model, because, on the one hand, the pyrolysis gas generated by the pyrolysis reactor is input into the boiler to achieve stable combustion during the boiler peak-shaving process; on the other hand, part of the high-temperature flue gas generated by the boiler is input into the pyrolysis reactor to provide a portion of heat and serve as a carrying gas. In addition, the heat generated by the boiler reaction is used to flow part of the water vapor that absorbs heat through the pyrolysis reactor to provide a portion of the heat required for the pyrolysis reaction. Therefore, the coal-fired unit peak-shaving system combined with the biomass pyrolysis process of the utility model can achieve the coupling of the pyrolysis process and the combustion process, improve the utilization efficiency of energy, and help the boiler to burn stably when operating at low load. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a peak-shaving system for a coal-fired unit in an embodiment of the present utility model. DETAILED DESCRIPTION

[0018] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the following embodiments and drawings specifically illustrate the coal-fired unit peak-shaving system combined with the biomass pyrolysis process of the present invention.

[0019] This embodiment provides a coal-fired unit peak-shaving system combined with a biomass pyrolysis process, hereinafter referred to as the coal-fired unit peak-shaving system, which is used to produce pyrolysis gas, biochar and biomethanol from biomass.

[0020] Figure 1 It is a schematic diagram of a peak-shaving system for a coal-fired unit in an embodiment of the present utility model.

[0021] like Figure 1 As shown, the coal-fired unit peak-shaving system 100 includes a pyrolysis reactor 10 , a boiler 20 , a recycling flue 30 , a steam subsystem 40 and a generator 50 .

[0022] The pyrolysis reactor 10 is used to generate pyrolysis gas, biochar and biomethanol from biomass, high-temperature flue gas and high-temperature superheated steam. In this embodiment, the biochar is used as a purification material for flue gas or polluted water.

[0023] The pyrolysis reactor 10 is a fluidized bed type or a fixed bed type.

[0024] The boiler 20 is connected to the pyrolysis reactor 10 and is used to perform a combustion reaction based on the input fuel and the pyrolysis gas output by the pyrolysis reactor 10 to generate high-temperature flue gas.

[0025] In this embodiment, the fuel is coal, and further, the coal is in powder form.

[0026] The boiler 20 includes a furnace 201, a horizontal flue 202, a tail flue 203 and an oil burner nozzle (not shown in the figure) connected in sequence.

[0027] The high-temperature flue gas generated in the furnace 201 is discharged through the horizontal flue 202 and the tail flue 203 in sequence.

[0028] The oil burner nozzle is used to control the amount of pyrolysis gas input from the pyrolysis reactor 10 to the boiler 20 .

[0029] In this embodiment, pyrolysis gas is delivered to boiler 20 via the oil burner nozzle for stable combustion during peak load regulation. When stable combustion is not required, the oil burner nozzle stops delivering pyrolysis gas to boiler 20, and the pyrolysis gas continues to react in pyrolysis reactor 10 to produce biomethanol.

[0030] The recirculation flue 30 is connected to the boiler 20 and the pyrolysis reactor 10 respectively, and is used to input part of the high-temperature flue gas generated by the boiler 20 into the pyrolysis reactor 10.

[0031] One end of the recycling flue 30 is arranged at the connection between the horizontal flue 202 and the tail flue 203 , and the other end of the recycling flue 30 is arranged at the lower part of the pyrolysis reactor 10 .

[0032] The ratio of the high-temperature flue gas inputted into the pyrolysis reactor 10 from the recirculating flue 30 to all the high-temperature flue gas generated by the boiler 20 is less than 10%.

[0033] The steam subsystem 40 is used to absorb the heat generated by the boiler 20 to generate steam to drive the generator 50 to work.

[0034] The steam subsystem 40 includes an economizer 401, a water-cooled wall 402, a radiation superheater 403, a high-temperature superheater 404, a turbine assembly 405 and a heat supply 406 connected in sequence.

[0035] The water-cooled wall 402 is disposed in the furnace 201 .

[0036] The radiation superheater 403 and the high-temperature superheater 404 are both arranged in the horizontal flue 202 .

[0037] The turbine assembly 405 drives the generator 50 to work by using the steam.

[0038] The turbine assembly 405 includes a superheated steam turbine 4051, a high-temperature reheater 4052 and a reheated steam turbine 4053 connected in sequence.

[0039] The superheated steam turbine 4051, the reheated steam turbine 4053 and the generator 50 are coaxially connected in sequence.

[0040] The high-temperature reheater 4052 is arranged in the horizontal flue 202.

[0041] In this embodiment, the radiation superheater 403, the high-temperature superheater 404 and the high-temperature reheater 4052 are sequentially arranged in the horizontal flue 202 along the flow direction of the high-temperature flue gas.

[0042] The heat supplier 406 is connected to the high-temperature superheater 404 and the water-cooled wall 402 respectively, and is disposed in the pyrolysis reactor 10 for providing heat to the pyrolysis reactor 10 .

[0043] Part of the water vapor output by the high-temperature superheater 404 enters the water-cooled wall 402 through the heater 406 .

[0044] The ratio of the water vapor flowing through the heater 406 to the total water vapor output by the high-temperature superheater 404 is less than 20%.

[0045] In this embodiment, the process occurring in the pyrolysis reactor 10 is an endothermic process, and the heat absorbed comes from the high-temperature flue gas flowing into the pyrolysis reactor 10 and the water vapor flowing through the pyrolysis reactor 10 .

[0046] The flow process of the high-temperature flue gas in this embodiment is specifically as follows:

[0047] The combustion reaction in furnace 201 generates high-temperature flue gas, which then flows out of the flue consisting of horizontal flue 202 and tail flue 203. During this process, it flows through radiation superheater 403, high-temperature superheater 404, high-temperature reheater 4052, and economizer 401. In addition, part of the high-temperature flue gas in the above process flows into pyrolysis reactor 10 through recirculation flue 30.

[0048] The specific cycle of water vapor in this embodiment is as follows:

[0049] First, liquid water enters economizer 401 to generate steam. The steam then passes through water-cooled wall 402, radiant superheater 403, and high-temperature superheater 404 in sequence. The steam then enters superheated steam turbine 4051 to perform work. After performing work, the steam enters high-temperature reheater 4052 for heating, then enters reheated steam turbine 4053 to perform work. After performing work, the steam re-enters economizer 401. During this process, superheated steam turbine 4051 and reheated steam turbine 4053 convert thermal energy into mechanical energy, which is then converted into electrical energy by generator 50. Furthermore, during this process, some steam does not enter superheated steam turbine 4051 but instead flows into heater 406 to provide heat for the pyrolysis process in pyrolysis reactor 10. After releasing heat, the steam enters water-cooled wall 402 to continue the subsequent steam cycle.

[0050] Functions and Effects of the Embodiments

[0051] According to the coal-fired unit peak-shaving system combined with the biomass pyrolysis process involved in this embodiment, on the one hand, the pyrolysis gas generated by the pyrolysis reactor is input into the boiler to achieve stable combustion during the boiler peak-shaving process; on the other hand, a portion of the high-temperature flue gas generated by the boiler is input into the pyrolysis reactor to provide a portion of heat and serve as a carrier gas. In addition, the heat generated by the boiler reaction is used to flow some of the heat-absorbed water vapor through the pyrolysis reactor to provide a portion of the heat required for the pyrolysis reaction. In short, this system can achieve the coupling of the pyrolysis and combustion processes, improve energy utilization efficiency, and help stabilize combustion when the boiler is operating at low load.

[0052] Those skilled in the art should understand that the present invention is not limited to the above-described embodiments. The above-described embodiments and the specification are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A coal-fired unit peak-shaving system combined with a biomass pyrolysis process, used to produce pyrolysis gas, biochar and biomethanol from biomass, characterized in that: include: Pyrolysis reactor, boiler, recirculation flue, steam subsystem and generator, The pyrolysis reactor is used to generate the pyrolysis gas, the biochar and the biomethanol according to the biomass, high-temperature flue gas and high-temperature superheated steam. The boiler is connected to the pyrolysis reactor and is used to perform a combustion reaction based on the input fuel and the pyrolysis gas output from the pyrolysis reactor to generate the high-temperature flue gas. The recirculation flue is connected to the boiler and the pyrolysis reactor respectively, and is used to input part of the high-temperature flue gas generated by the boiler into the pyrolysis reactor. The water vapor subsystem is used to absorb the heat generated by the boiler to generate water vapor to drive the generator.

2. The coal-fired unit peak-shaving system combined with biomass pyrolysis process according to claim 1 is characterized in that: in, The boiler comprises a furnace, a horizontal flue and a tail flue connected in sequence. One end of the recirculation flue is arranged at the connection between the horizontal flue and the tail flue, and the other end of the recirculation flue is arranged at the lower part of the pyrolysis reactor. The high-temperature flue gas generated in the furnace is discharged through the horizontal flue and the tail flue in sequence.

3. The coal-fired unit peak-shaving system combined with biomass pyrolysis process according to claim 2 is characterized in that: in, The steam subsystem includes an economizer, a water wall, a radiation superheater, a high-temperature superheater and a turbine assembly connected in sequence. The water-cooled wall is arranged in the furnace, The radiation superheater and the high-temperature superheater are both arranged in the horizontal flue. The turbine assembly drives the generator to work by using the steam to perform work.

4. The coal-fired unit peak-shaving system combined with the biomass pyrolysis process according to claim 3 is characterized in that: in, The turbine assembly includes a superheated steam turbine, a high-temperature reheater and a reheated steam turbine connected in sequence. The superheated steam turbine, the reheated steam turbine and the generator are coaxially connected in sequence. The high-temperature reheater is arranged in the horizontal flue.

5. The coal-fired unit peak-shaving system combined with biomass pyrolysis process according to claim 3 is characterized in that: in, The water vapor subsystem further includes a heater, The heat supplier is connected to the high-temperature superheater and the water-cooled wall respectively, and is arranged in the pyrolysis reactor to provide heat to the pyrolysis reactor. Part of the water vapor output by the high-temperature superheater passes through the heater and enters the water-cooled wall.

6. The coal-fired unit peak-shaving system combined with biomass pyrolysis process according to claim 5, characterized in that: in, The ratio of the water vapor flowing through the heater to the total water vapor output by the high-temperature superheater is less than 20%.

7. The coal-fired unit peak-shaving system combined with biomass pyrolysis process according to claim 1 is characterized in that: in, The boiler includes an oil burner nozzle for controlling the amount of the pyrolysis gas input into the boiler from the pyrolysis reactor.

8. The coal-fired unit peak-shaving system combined with biomass pyrolysis process according to claim 1 is characterized in that: in, The ratio of the high-temperature flue gas input from the recirculating flue to the pyrolysis reactor to all the high-temperature flue gas generated by the boiler is less than 10%.

9. The coal-fired unit peak-shaving system combined with biomass pyrolysis process according to claim 1, characterized in that: in, The pyrolysis reactor is of fluidized bed type or fixed bed type.

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