CN113915607A

CN113915607A - Coal-fired boiler capable of fully combusting coal mixed with hydrogen

Info

Publication number: CN113915607A
Application number: CN202111395722.8A
Authority: CN
Inventors: 孙震; 薛冬梅; 顾时雨; 王星浩
Original assignee: Beijing Fengrunming Science And Trade Co ltd
Current assignee: Beijing Fengrunming Science And Trade Co ltd
Priority date: 2021-11-23
Filing date: 2021-11-23
Publication date: 2022-01-11

Abstract

The invention discloses a coal-fired boiler capable of fully combusting coal mixed with hydrogen, which comprises a coal feeder, a combustor, a hearth, a hydrogen storage, a preheater, a smoke pipe, a safety valve and the like. One side of the boiler is connected with a coal feeding device, the other side of the boiler is connected with an air inlet of mixed hydrogen, and the boiler is provided with an air blower and a hydrogen concentration detection device. The pulverized coal is ground by the coal grinding device and then is conveyed to the combustor through a pipeline, and meanwhile, the mixed air is preheated and conveyed into the hearth. The invention replaces the resource waste and heat loss caused by insufficient combustion and single fuel in the traditional coal-fired boiler.

Description

Coal-fired boiler capable of fully combusting coal mixed with hydrogen

Technical Field

The invention discloses a coal-fired boiler capable of fully combusting coal mixed with hydrogen, and relates to a boiler device capable of maximizing combustion efficiency by using mixed fuel.

Background

In recent years, the field of coal-fired boilers is continuously updated, and aiming at the problems existing in the use of the existing coal-fired boilers, the coal-fired boilers are continuously optimized in the aspects of energy conservation, emission reduction, energy consumption reduction and the like. Especially, how to improve the combustion efficiency of coal, while the combustion in the furnace is an integral coal powder oxidation heating process, we can divide it into two aspects: firstly, the combustion condition that stove wind coal ratio, one overgrate air ratio, combustor operating mode formed, firstly come from the influence of tertiary air and external world (mainly negative pressure, hourglass etc.), promptly also the disturbance of tertiary air and external world to the stove burning operating mode. Whether the combustion is stable depends on whether the combustion condition in the furnace can resist tertiary air and external disturbance.

Reasonable air-coal ratio, namely, the optimal excess air quantity is kept, namely, a reasonable oxygen quantity value is kept. The oxygen amount is designed to be 3-5%, and because the oxygen meter is positioned at the inlet of the 29 m economizer and is influenced by air leakage of a hearth and a flue (the air leakage hardly participates in combustion), different oxygen amounts of different furnaces and different load sections are kept to ensure that the coefficient of excess air in the furnaces is about 1.25. Generally, the oxygen amount is preferably controlled in the 200-150MW load section, and the oxygen amount is preferably controlled in the 150-100MW load section to be 6-8.

In a word, in the process of improving the heat efficiency of the coal combustion boiler, when the air-coal ratio is adopted, one condition cannot be ignored, namely the crushing degree of the coal. When the lump coal is ignited, ignition is needed, and the coal which is relatively broken is easier to ignite and burn, and meanwhile, if the coal which is too broken is similar to powder, the coal is burnt in the combustion chamber, and the problem of short combustion time exists.

The existing coal combustion boiler generally conveys coal into the boiler, the conveyed coal is different in size, the coal is not beneficial to combustion and effective utilization of the coal, for example, the coal blocks are too large, the problems of insufficient combustion and waste can be caused, and if the coal blocks are too small, the coal blocks can be burnt quickly. Some users make a requirement on the size of the purchased coal in advance, so that the specified size of the coal has long manufacturing period and the coal purchasing cost is increased.

The ignition point of hydrogen is high, but the ignition energy is small, so that the hydrogen can easily ignite and the flame propagation speed is high, and meanwhile, the density of the hydrogen is small, and the combustor with a common structure is difficult to ensure that the hydrogen and the oxygen in the air are fully mixed.

Disclosure of Invention

The invention aims to provide a coal-fired boiler capable of fully combusting coal and hydrogen, which can be used for forming combustion of coal and hydrogen in a hearth by proportioning coal raw materials in a certain proportion, and solving the problem of low coal combustion efficiency to the greatest extent.

The coal-fired boiler device comprises a coal feeding system, a combustion chamber, a gas conveying system and a plurality of connecting channels, wherein a coal feeding hopper feeds coal raw materials into a coal mill through a coal feeder, the coal mill is connected with a combustor through a pipeline, and the combustor feeds pulverized coal ground by the coal mill into a hearth through a primary air pipe.

The auxiliary burner comprises a spray pipe, a cooling cylinder, a nozzle, an air feeder and a valve, and is positioned at the front end of an air inlet of the boiler, and hydrogen-mixed gas enters the nozzle at a high speed through the spray pipe and is sprayed into the hearth to be mixed with the pulverized coal gas in the hearth; the auxiliary burner comprises a flow rate adjusting device, and the flow rate can be adjusted according to the target use amount.

The boiler is provided with a safety valve and is fixedly connected with a boiler body through a rubber fixing sleeve; the left side of the boiler safety valve is provided with an exhaust pipe which can maintain the stable pressure of the boiler; the boiler is provided with a pressure machine temperature detection meter.

Drawings

FIG. 1 is a schematic view of a coal-fired boiler with hydrogen-mixed coal for complete combustion.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, fig. 1 is a schematic view of a coal-fired boiler with coal and hydrogen mixed and fully combusted, which includes a coal feeding system gas conveying system and a boiler body, wherein the coal feeding system includes a coal feeding hopper (1), a coal feeder (2), a coal pulverizer (3), a burner (4), a hearth (5), a water wall (6), a smoke exhaust pipe (7), a superheater (8), a safety valve (9), an exhaust pipe (10), an auxiliary burner (11), an air inlet (12) and the like, the auxiliary burner (11) is a device for assisting hydrogen to combust, and includes a spray pipe, a cooling cylinder, a nozzle, an air blower, a valve and the like, and is located at the front end of the air inlet (12) of the boiler, and the hydrogen mixed gas enters the nozzle through the spray pipe at a high speed and is sprayed into the hearth to be mixed with pulverized coal gas in the hearth; the auxiliary burner comprises a flow rate adjusting device, and the flow rate can be adjusted according to the target use amount. The gas transmission system comprises a gas tank (13), a gas transmission pipe (14), a preheater (15), a blower (16) and the like; the air preheater (15) is connected with the air inlet (12) through an air inlet pipeline, and the air inlet channel comprises a blower (16); the preheater is connected with the gas tank (13) through a gas transmission pipeline (14).

Claims

1. A coal-fired boiler that coal mixes hydrogen and fully burns which characterized in that: the coal-fired boiler system comprises a coal feeding system gas transmission system and a boiler body, wherein the coal feeding system comprises a coal feeding hopper (1), a coal feeder (2), a coal pulverizer (3), a burner (4), a hearth (5), a water wall (6), a smoke exhaust pipe (7), a superheater (8), a safety valve (9), an exhaust pipe (10), an auxiliary burner (11), an air inlet (12) and the like; the coal mill (3) is connected with the combustor (4) through the same pipeline, and the coal powder at the coal mill is conveyed to the hearth (5) through a primary air conveying pipeline; the air inlet is externally connected with a hydrogen-mixed air inlet channel and enters the hearth through the air inlet (12).

2. The coal-fired boiler for the complete combustion of coal mixed with hydrogen according to claim 1, characterized in that: the safety valve (9) is fixedly connected with the boiler body through a rubber fixing sleeve; the left side of the boiler safety valve is provided with an exhaust pipe (10) which can maintain the stable pressure of the boiler; the boiler is provided with a pressure machine temperature detection meter.

3. The coal-fired boiler for the complete combustion of coal mixed with hydrogen according to claim 1, characterized in that: the gas transmission system comprises a gas tank (13), a gas transmission pipe (14), a preheater (15), a blower (16) and the like; the air preheater (15) is connected with the air inlet (12) through an air inlet pipeline, and the air inlet channel comprises a blower (16); the preheater is connected with the gas tank (13) through a gas transmission pipeline (14).

4. The coal-fired boiler for coal-mixed hydrogen complete combustion according to claim 1, characterized in that the gas tank (13) stores the air and hydrogen gas mixture in low temperature state, the hydrogen gas accounts for about 2.5-3% of the total gas; the gas tank outlet is provided with a control valve.

5. The coal-fired boiler for the complete combustion of coal mixed with hydrogen according to claim 1, characterized in that: furnace possesses water-cooling wall (6) in the boiler, still possesses in the furnace and sweeps ware (17), and the remaining gas passes through the sweeping clean-up with in the stove before the single burning, effectively prevents the detonation of residual gas.

6. The coal-fired boiler for the complete combustion of coal mixed with hydrogen according to claim 1, characterized in that: the auxiliary combustor (11) is a device for assisting hydrogen to combust, comprises a spray pipe, a cooling cylinder, a nozzle, an air feeder, a valve and the like, is positioned at the front end of an air inlet (12) of the boiler, and the hydrogen-mixed gas enters the nozzle through the spray pipe at a high speed and is sprayed into the hearth to be mixed with the pulverized coal gas in the hearth; the auxiliary burner comprises a flow rate adjusting device, and the flow rate can be adjusted according to the target use amount.