Coal-fired power plant boiler under-pressure gas blending combustion system

Abstract

The utility model belongs to the technical field of blending combustion carbon reduction of a thermal power plant, and particularly provides a coal-fired thermal power plant boiler under-pressure gas blending combustion system, which is characterized by comprising a power station boiler (1), a steam turbine generator (3), a gas supply device (4), a gas supply device (5), a gas supply device (6), a gas supply device (7) and a gas supply device (8), and the power station boiler (1) is used for burning coal to produce steam and supplying the steam to the steam turbine generator (3). The pressurized combustible gas comes from hydrogen prepared by coal gasification or mixed gas of certain components; and the pressure reducing equipment is arranged at the upstream of the power station boiler (1) and is used for feeding the pressurized combustible gas into the power station boiler (1) after reducing the pressure of the pressurized combustible gas. In the system, the power station boiler (1) uses coal as main fuel to produce steam, combustible gas can also be combusted to support combustion or replace part of coal, the pressure reduction equipment reduces the pressure of the pressurized combustible gas and then feeds the pressurized combustible gas into the power station boiler (1) to be combusted, and the pressure requirement of blending combustion is met.

Description

Technical Field

[0001] This application belongs to the technical field of carbon reduction through co-firing in thermal power plants, and particularly relates to a system for co-firing pressurized gas in a coal-fired power plant boiler. Background Technology

[0002] In existing technologies, coal-fired power plants reduce carbon emissions by co-firing combustible gases such as hydrogen and carbon monoxide or by directly using them as the main fuel to replace a portion of the coal.

[0003] Currently, combustible gases, whether stored in advance or produced on the spot, are usually under high pressure. There is a problem of how to treat pressurized combustible gases before they enter the boiler in order to meet the combustion requirements. Utility Model Content

[0004] This application provides a system for pressurized gas co-firing in a coal-fired power plant boiler, comprising:

[0005] Power plant boilers are used to burn coal to produce steam and supply it to steam turbine generators;

[0006] Power plant boilers can co-fire pressurized combustible gases to replace part of the raw coal;

[0007] Pressurized combustible gases originate from hydrogen produced by coal gasification or a mixture of gases with certain components;

[0008] Pressure reducing equipment is installed upstream of the power plant boiler to reduce the pressure of pressurized combustible gas before sending it into the power plant boiler.

[0009] Furthermore, the pressure-reducing device is a gas turbine, which generates electricity using pressurized combustible gas, and the high-temperature flue gas generated by the gas turbine is supplied to the power plant boiler.

[0010] Furthermore, the electricity generated by the gas turbine can be incorporated into the plant's power supply or directly provided to users.

[0011] Furthermore, the pressure reducing equipment is a turbine power generation device, which uses pressurized combustible gas to generate electricity and recover pressure energy, and the combustible gas is supplied to the power plant boiler.

[0012] Furthermore, the green electricity generated by the turbine power generation unit is either incorporated into the plant's power supply or directly provided to users.

[0013] Furthermore, the pressure reducing device is a regulating valve, which is used to regulate the pressure of combustible gas to meet the requirements for co-firing in the furnace.

[0014] Furthermore, the pressure reducing device is a gas storage tank, which is used for the storage and pressure reduction of combustible gases.

[0015] The above-mentioned technical solution of this utility model has at least the following beneficial technical effects:

[0016] In a pressurized gas co-firing system for a coal-fired power plant boiler, the boiler uses coal as the main fuel to produce steam, and can also burn combustible gas to assist combustion or replace part of the coal. The pressure reducing device reduces the pressure of the pressurized combustible gas before it is put into the furnace for combustion, so as to meet the pressure requirements for co-firing. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or in the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a structural diagram of a pressurized gas co-firing system for a coal-fired power plant boiler, according to one embodiment of this application.

[0019] in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0020] 1. Power plant boiler; 21. Gas turbine; 22. Turbine power generation unit; 23. Control valve; 24. Gas storage tank; 3. Steam turbine generator; 4. Gasification furnace. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the various embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the various embodiments below is for ease of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0022] Currently, existing technologies present the problem of how to treat pressurized combustible gases before they enter the boiler in order to meet the combustion requirements.

[0023] To address the aforementioned problems, one embodiment of this application provides a system for pressurized gas co-firing in a coal-fired power plant boiler, comprising:

[0024] The power plant boiler 1 uses coal as the main fuel to produce high-temperature and high-pressure steam, and the steam turbine generator 3 uses the high-temperature and high-pressure steam to generate electricity.

[0025] The power plant boiler 1 can co-fire pressurized combustible gas to aid combustion or replace part of the raw coal. Optionally, in addition to pulverized coal burners, the power plant boiler 1 is also equipped with gas fuel burners. The combustible gas is burned in the power plant boiler 1 through the gas fuel burners, which plays a role in aiding combustion or replacing part of the coal. It should be noted that "pressurized" in this application refers to the pressure of the pressurized combustible gas being higher than the gas fuel inlet pressure of a conventional power plant boiler 1.

[0026] The pressurized combustible gas can be a mixed gas (containing at least carbon dioxide, carbon monoxide, and hydrogen) produced by the gasifier 4 through coal gasification, or hydrogen separated from the mixed gas, or hydrogen stored in other ways. Generally, the mixed gas produced by the gasifier 4 and the hydrogen obtained by separating the mixed gas are both in a high-pressure state as described in this application. Therefore, this application provides a pressure reducing device, which is located upstream of the power plant boiler 1. It can reduce the pressure of the pressurized combustible gas to a low pressure before sending it into the power plant boiler 1 to meet the pressure conditions for co-firing in the power plant boiler 1.

[0027] In one optional embodiment of this application, the pressure reducing device is a gas turbine 21, that is, a gas turbine 21 is provided upstream of the power plant boiler 1; the gas turbine 21 can generate electricity by burning pressurized combustible gas and obtain depressurized high-temperature flue gas; the high-temperature flue gas still contains high heat, generally 500-600℃, so the high-temperature flue gas is transported to the power plant boiler 1 to participate in the production of steam, which not only reduces the pressure of the pressurized combustible gas (converted into high-temperature flue gas), but also makes full and gradual use of its calorific value.

[0028] Preferably, the electricity generated by the gas turbine 21 is incorporated into the plant's power supply or directly supplied to users.

[0029] In one optional embodiment of this application, the pressure-reducing device turbine power generation unit 22 generates electricity using the pressure of pressurized combustible gas. For example, the pressure of the mixed gas produced by the gasifier 4 gasifying coal is 4-6 MPa, and the pressure of the turbine power generation unit 22 after generating electricity is 0.3-0.4 MPa, which can meet the requirements of co-firing in the power plant boiler 1. This method not only obtains electrical energy, but also reduces the pressure of the pressurized combustible gas. The composition of the combustible gas after depressurization remains basically unchanged, and it continues to burn and produce steam in the power plant boiler 1.

[0030] Preferably, the turbine power generation unit 22 produces green electricity, which can be used as power for the coal-fired power plant or directly supplied to users.

[0031] In one optional embodiment of this application, the pressure reducing device is a regulating valve 23. Before the pressurized combustible gas enters, such as in a power plant boiler 1, the pressure is adjusted by the regulating valve 23 to meet the conditions for co-firing in the boiler.

[0032] In an optional embodiment of this application, the pressure-reducing device is a gas storage tank 24, which can store pressurized combustible gas and reduce its pressure, for example, with a volume of 400M³. 2 The hydrogen storage tank has an internal pressure of 1-2 MPa, and the inlet pressure of the combustible gas can be further adjusted by adjusting the outlet flow rate.

[0033] In the above embodiments, the gas turbine 21, turbine power generation device 22, regulating valve 23, and gas storage tank 24 can be installed individually upstream of the power plant boiler 1, or they can be installed in combination. For example, the regulating valve 23 can be installed between the turbine power generation device 22 and the power plant boiler 1, or between the gas storage tank 24 and the power plant boiler 1, to further control the inlet pressure of the combustible gas.

[0034] In a pressurized gas co-firing system for a coal-fired power plant boiler according to this application, the power plant boiler 1 uses coal as the main fuel to produce steam, and can also burn combustible gas to assist combustion or replace part of the coal. The pressure reducing device reduces the pressure of the pressurized combustible gas before sending it into the power plant boiler 1 for combustion to meet the pressure requirements for co-firing. Specifically, the gas turbine 21 upstream of the coal-fired boiler reduces the pressure of the pressurized combustible gas while making full and gradual use of its calorific value. The turbine power generation device 22 not only uses the pressure of the pressurized combustible gas to generate electricity, but also plays a role in reducing the pressure. The gas storage tank 24 and the regulating valve 23 can temporarily store and regulate the pressure of the pressurized combustible gas so that the combustible gas is co-fired according to the power generation load of the power plant boiler 1.

[0035] In the description of this utility model, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this utility model, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0036] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this application and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this application should be included within the protection scope of this application. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A system for pressurized gas co-firing in a coal-fired power plant boiler, characterized in that, include: A power plant boiler (1) is used to burn coal to produce steam and supply it to a steam turbine generator (3); The power plant boiler (1) can co-fire pressurized combustible gas to replace part of the raw coal; the pressurized combustible gas is derived from hydrogen produced by coal gasification or a mixture of certain components. A pressure reducing device is installed upstream of the power plant boiler (1) to reduce the pressure of the pressurized combustible gas before sending it into the power plant boiler (1).

2. The system according to claim 1, characterized in that, The pressure reducing device is a gas turbine (21), which generates electricity using the pressurized combustible gas, and the high-temperature flue gas generated by the gas turbine (21) is supplied to the power plant boiler (1).

3. The system according to claim 2, characterized in that, The electrical energy of the gas turbine (21) is either incorporated into the plant's power supply or directly supplied to users.

4. The system according to claim 1, characterized in that, The pressure reducing device is a turbine power generation device (22), which uses pressurized combustible gas to generate electricity and recover pressure energy, and the low-pressure combustible gas is supplied to the power plant boiler (1).

5. The system according to claim 4, characterized in that, The green electricity produced by the turbine power generation unit (22) is either incorporated into the plant's power supply or directly provided to users.

6. The system according to claim 1, characterized in that, The pressure reducing device is a regulating valve (23), which is used to regulate the pressure of pressurized combustible gas to meet the requirements for co-firing in the furnace.

7. The system according to claim 1, characterized in that, The pressure reducing device is a gas storage tank (24), which is used for the storage and depressurization of pressurized combustible gas.

Images