CN110686276A - Graded combustion normal-pressure hot water stove and using method thereof - Google Patents

Abstract

The invention provides a graded combustion atmospheric pressure hot water stove and a method of using the same. The atmospheric pressure hot water stove includes a furnace chamber, and the furnace chamber is divided into a main combustion area and a heat exchange area that are communicated. Coal-fired After entering the furnace, it is burned in the main combustion area, and the flue gas generated by the combustion is exchanged in the heat exchange area; the bottom of the main combustion area is provided with an air distribution plate, and at least two independent air chambers are set close to the bottom of the air distribution plate. , through the air chamber to the main combustion area to assist briquette combustion, the air inlet of the air chamber is provided with an independent windshield, and the air inlet ratio of the corresponding air chamber is controlled by adjusting the opening of the windshield, so as to adjust the main air inlet. The combustion atmosphere of different zones in the combustion zone. The invention further optimizes the staged combustion by improving the air distribution method, and achieves the purpose of reducing _NOx , improving the sulfur solidification rate of briquette coal and reducing carbon black emission through the control of the combustion atmosphere.

Description

A kind of atmospheric pressure hot water stove with staging combustion and using method thereof

technical field

The invention belongs to the technical field of combustion equipment, and relates to an atmospheric pressure hot water stove and a use method thereof, in particular to a graded combustion atmospheric pressure hot water stove and a use method thereof.

Background technique

Civil coal-fired stoves mainly refer to small household coal-fired stoves that use loose coal as fuel (including bituminous coal and anthracite) for cooking or heating purposes; civil coal-fired stoves also include stoves that use honeycomb and briquettes as fuel.

At present, there are two main types of civilian stoves on the market:

The positive burning furnace is the simplest and most common direct combustion method in the traditional way. When the solid fuel is burned, the flame spreads along the natural flow direction of the hot flue gas. The combustion intensity is high and the firepower is strong, which can meet the cooking needs of users. Positive firing furnaces are suitable for low volatile fuels such as anthracite. Although the positive-burning furnace has good cooking ability, when using bituminous coal or briquette made of bituminous coal as raw material, since the coal is heated and heated up after the coal is added, the volatilization is analyzed, and it is immediately discharged with the flue gas, and the volatiles are difficult to burn. Exhausted, resulting in a large amount of black smoke (tar, CO, VOC, oxides of sulfur and nitrogen, etc.), which seriously pollutes the environment. In addition, when the positive-burning furnace is used for heating, it is necessary to frequently add coal, and the combustion intensity and pollutant emissions change greatly when coal is added, which has strong instability and periodicity.

The reverse combustion furnace is a combustion method in which the flame propagates against the natural flow direction of the hot flue gas when the solid fuel is burned. It has the characteristics of delaying the speed of volatilization analysis. The furnace temperature is high, the combustion is sufficient, and black smoke can be basically eliminated. It is suitable for heating with high volatile fuel such as bituminous coal. However, _backburning has high combustion intensity and high combustion zone temperature, resulting in high SO2 and NOx emission concentrations. In order to effectively eliminate smoke, anti-burning furnaces mostly use multi-return flues, so the cooking power is weak, which is not suitable for cooking, and can only be used for heating, which is difficult to be accepted by most ordinary people.

A large number of experimental studies have shown that the current civil stoves on the market have defects such as strong combustion periodicity, difficult load adjustment, short fire sealing time, and large coal consumption. Regardless of whether it is a forward-burning furnace or a reverse-burning furnace, it will heat up rapidly after coal is added, and the volatile matter will be rapidly precipitated, resulting in the rapid precipitation and emission of a large amount of sulfur and nitrogen oxides.

The furnace does not match the raw coal, which leads to the high combustion temperature and excess air coefficient of the furnace, which not only often causes coking in the furnace to affect normal use, but also increases the _NOx emission concentration, and is not conducive to the self-fixation of sulfur in the coal ash during the combustion process in the furnace. or added sulfur-fixing agent. Bituminous coal with high volatile content (Vdaf is greater than about 15%) is burned in a traditional forward-burning furnace, and a large amount of black smoke is emitted; when burned in a reverse-burning furnace, a large amount of coal tar will adhere to the furnace hearth and tail flue, which will affect the replacement. At the same time, the heat effect causes the flue to be blocked, which affects the ventilation and is difficult to clean.

CN109578976A discloses a layer-fired boiler, which is characterized in that the furnace body of the layer-fired boiler includes a first cavity and a second cavity connected at the bottom; the top of the first cavity is provided with a coal feeding port, and the first cavity A pre-combustion tuyere is set on the furnace wall in the middle of the furnace and/or a pre-combustion air duct is arranged in the middle of the first cavity. The area under the pre-combustion tuyere and/or the pre-combustion air duct is the semi-coke reduction and pre-combustion area; A space for the circulation of materials is left between the chain grate; the top of the second cavity is provided with a steam drum, and the bottom of the steam drum is provided with a rear arch on the furnace wall of the second cavity, forming smoke on the upper part of the first chain grate In the air circulation area, the upper part of the flue gas circulation area is provided with a burn-out tuyere; at least two air chambers are arranged below the first chain grate, and a gap is left between the first chain grate and the furnace wall of the second cavity.

CN205065702U discloses a burn-out air device arranged vertically and horizontally for tangential boiler air graded combustion, including a furnace, a hot air box, a pulverized coal pipe, a primary air nozzle, a secondary air nozzle, a compact burn-out air nozzle, and a corner separated combustion Exhaust air vents and wall-type separation burnout air vents; among them, the furnace is divided into main combustion area, reduction area and burnout area from bottom to top. Primary air vents, secondary air vents and compact burnout air vents are arranged in On the furnace wall of the main combustion area of the furnace, the corner separated burnout air nozzles are arranged at the corners of the furnace burnout area, and the wall-type separated burnout air nozzles are arranged on the furnace wall of the furnace burnout area; the outlet of the hot air box is divided into two parts. Multiple paths, the first path is connected to the inlet of the secondary air nozzle in the main combustion area, the second path is connected to the inlet of the compact burnout air nozzle, the third path is connected to the entrance of the separated burnout air nozzle at the corner, and the fourth path is connected to the wall type Separate the inlet of the exhaust air nozzle; the outlet of the pulverized coal pipeline is connected to the pulverized coal inlet of the primary air nozzle.

CN107238111A discloses a coal-fired heating furnace, a coal feeding port is provided on one side of the top of the main body of the coal-fired heating furnace, and a chimney is provided on the opposite side of the top of the coal-fired heating furnace body and the coal feeding port; the inner upper part of the main body of the coal-fired heating furnace is provided A water jacket partition is arranged vertically with the furnace top, and the water jacket partition divides the upper part of the main body of the coal-fired heating furnace into a dry distillation pyrolysis area connected with the coal feeding port and a flue gas burnout heat exchange area connected with the chimney; The lower area of the water jacket partition in the main body of the coal heating furnace is the semi-coke combustion area; a grate is inclined at the lower part of the semi-coke combustion area, and a primary tuyere is arranged below the grate; the semi-coke combustion area is connected to the flue gas combustion area. A secondary air outlet is arranged at the junction of the exhausted heat exchange areas; and a heating water heat exchange pipe is arranged in the exhausted heat exchange area of the flue gas.

However, existing staged combustion furnaces are mainly designed for burning loose coal. Due to the uneven size of scattered coal and the small gap between coal particles/blocks, the height of the furnace body is low, the thermal intensity of the semi-coke combustion area is high, and the combustion temperature is as high as 1300 °C or more. The tendency of semi-char nitrogen to generate nitrogen oxides is increased, which offsets the reduction effect of staged combustion on _NOx .

If the briquette is used as fuel in the staging combustion furnace, due to the regular shape of the briquette and the large porosity, the pyrolysis gasification zone is easily overheated, and the coal seam on the coal side is completely burned (burned through) and the pyrolysis gasification zone and gasification zone are lost. The difference between the combustion zones makes it impossible to achieve the effect of staged combustion to remove nitrogen oxides, which also causes the instability (or periodicity) of combustion and pollutant emissions caused by operations such as coal addition and slag removal. In addition, in order to improve the burnout rate, the combustion area has high combustion intensity and high temperature. When using bituminous coal with low melting point, it is easy to coke, which affects the normal use of the stove. Due to the high combustion temperature in the combustion zone, when high-sulfur coal with a sulfur-fixing agent is used as the raw material for briquette, the sulfur-fixing effect of the briquette is poor, and it is difficult to achieve the goal of "burning high-sulfur coal with low-sulfur emissions". It can be seen that the existing staged combustion furnace has little effect on reducing pollutant emissions, and because the pyrolysis gas easily affects the combustion atmosphere in the combustion area, it is easy to cause coking in the combustion area, and the combustion cannot be sustained and stable.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the purpose of the present invention is to provide a staged combustion atmospheric pressure hot water stove and a method for using the same. The invention further optimizes staged combustion by improving the air distribution method, and reduces the The purpose of NO _x , improving the solid sulfur rate of briquette and reducing the emission of carbon black.

For this purpose, the present invention adopts the following technical solutions:

In the first aspect, the atmospheric pressure hot water stove includes a furnace, and the furnace is divided into a main combustion area and a heat exchange area that are connected. Heat exchange takes place in the hot zone.

The bottom of the main combustion area is provided with an air distribution plate, and at least two independent air chambers are set close to the bottom of the air distribution plate. Set up an independent wind deflector, and adjust the proportion of the air intake of the corresponding wind chamber by adjusting the opening of the wind deflector, so as to adjust the share distribution and thermal environment of different zones in the main combustion zone.

The invention further optimizes the staged combustion by improving the air distribution method, and achieves the purpose of reducing _NOx , improving the sulfur solidification rate of briquette coal and reducing carbon black emission through the control of the combustion atmosphere.

As a preferred technical solution of the present invention, the main combustion zone is divided into a pyrolysis gasification zone, a low temperature combustion zone, a high temperature combustion zone and an oxygen-enriched burnout zone along the conveying direction of the briquette.

The briquette first enters the pyrolysis and gasification zone. After drying and pyrolysis under oxygen-lean conditions, part of the briquette precipitates out volatile matter into coke, and then enters the low-temperature combustion zone. Under the low-temperature oxygen-lean condition and reducing atmosphere, the volatile matter in A part of nitrogen is converted into nitrogen, and the other part of nitrogen is released in the form of NH ₃ and HCN. The coke after pyrolysis and gasification moves to the high temperature combustion zone under external mechanical force and burns out. The reducing flue gas produced by the pyrolysis gasification and the semi-coke layer in the combustion zone (including the low temperature combustion zone and the high temperature combustion zone) reduce _NOx to generate harmless N ₂ , CO ₂ and H ₂ O. In the oxygen-enriched reburn zone, the CO and soot are burnt out using the burn-off air.

As a preferred technical solution of the present invention, two mutually independent air chambers are arranged close to the lower part of the air distribution plate, and the air is supplied to the main combustion area through the air chambers to assist the combustion of the briquette.

The two air chambers are respectively recorded as the primary air chamber and the secondary air chamber along the conveying direction of the briquette. The combustion zone delivers secondary air.

The air inlet of the primary air chamber is provided with a primary air baffle that can be opened and closed, and the air inlet of the secondary air chamber is provided with a secondary air baffle that can be opened and closed. The opening of the secondary air baffle controls the ratio of the air intake of the primary air and the secondary air.

The corresponding part of the air distribution board above the primary air chamber is a primary air distribution board, and a part of the primary air distribution board is located in the pyrolysis gasification zone, and the other part is located in the low temperature combustion zone, which is located in the pyrolysis gasification zone. Part of the primary air distribution board does not have air holes, and part of the primary air distribution board located in the low temperature combustion zone has air holes.

The part of the air distribution board corresponding to the upper part of the secondary air chamber is a secondary air distribution board, the air holes are provided on the secondary air distribution board, and a part of the secondary air distribution board is located in the high temperature combustion zone. , the other part is located in the oxygen-enriched burnout area, and the burnout air duct is set above the part of the secondary air air distribution plate located in the oxygen-enriched burnout area.

For the existing atmospheric pressure hot water heater, the traditional one air chamber is optionally divided into two independent small air chambers. By adjusting the opening of the primary air baffle and the secondary air baffle, the primary air and the The proportion of secondary air controls the share distribution, thermal environment and combustion atmosphere of the low temperature combustion zone and the high temperature combustion zone, thereby achieving the purpose of reducing _NOx .

As a preferred technical solution of the present invention, three mutually independent air chambers are arranged close to the bottom of the air distribution plate, and the air is supplied to the main combustion area through the air chambers to assist the combustion of the briquette.

The three air chambers are respectively recorded as the primary air chamber, the secondary air chamber and the tertiary air chamber along the briquette conveying direction. The corresponding main combustion area delivers secondary air, and the tertiary air is delivered to its corresponding main combustion area through the tertiary air chamber.

The air inlet of the primary air chamber is provided with a primary air baffle that can be opened and closed, the air inlet of the secondary air chamber is provided with a secondary air baffle that can be opened and closed, and the inlet of the tertiary air chamber The air outlet is provided with a tertiary air baffle that can be opened and closed, and the air intake ratio of the primary air, the secondary air and the tertiary air is controlled by adjusting the opening of the primary air baffle, the secondary air baffle and the tertiary air baffle.

The corresponding part of the air distribution board above the primary air chamber is a primary air distribution board, and a part of the primary air distribution board is located in the pyrolysis gasification zone, and the other part is located in the low temperature combustion zone, which is located in the pyrolysis gasification zone. Part of the primary air distribution board does not have air holes, and part of the primary air distribution board located in the low temperature combustion zone has air holes.

The part of the air distribution board corresponding to the upper part of the secondary air chamber is a secondary air distribution board, the main combustion area corresponding to the secondary air distribution board is a high temperature combustion area, and the secondary air distribution board Open air vents.

The corresponding part of the air distribution plate above the tertiary air chamber is a tertiary air distribution plate, the main combustion zone corresponding to the tertiary air distribution plate is an oxygen-enriched burnout zone, and the tertiary air distribution plate is provided with air holes, An exhaust air duct is arranged above the tertiary air distribution plate.

For the existing atmospheric pressure hot water heaters, the traditional one air chamber is optionally divided into three independent small air chambers. By adjusting the opening of the primary air baffle and the secondary air baffle, the primary air and the The proportion of secondary air controls the share distribution, thermal environment and combustion atmosphere of the low temperature combustion zone and the high temperature combustion zone, thereby achieving the purpose of reducing _NOx . By controlling the opening of the tertiary air baffle, an oxygen-rich high-temperature combustion environment is created, and the briquette is burned out on the tertiary air distribution plate. By controlling the share distribution, thermal environment and combustion atmosphere of the low-temperature combustion zone and the high-temperature combustion zone, the combustion temperature of the low-temperature combustion zone and the high-temperature combustion zone can be reduced, and the solid sulfur rate of the briquette can be improved while ensuring that the briquette is burnt out. To achieve the purpose of reducing SO ₂ emissions.

As a preferred technical solution of the present invention, the main combustion zone and the heat exchange zone are communicated through a flue gas burnout passage, and the flue gas passes through the flue gas burnout passage and enters the heat exchange zone after being burnt out in the main combustion zone.

Preferably, the flue gas inlet of the flue gas burnout channel is a constricted structure.

Preferably, a burnout air duct is arranged at the flue gas inlet of the flue gas burnout channel.

Preferably, a refractory layer is laid on the inner wall of the flue gas burnout channel.

Under the condition that the primary air and secondary air are fully graded and distributed, the flue gas burnout channel is designed as a constriction structure, and the air is supplied from both sides of the constriction to increase the wind speed of the burnout air and improve the mixing of heat flow flue gas and air. To ensure uniformity, lay a refractory layer on the inner wall of the flue gas burnout channel to form a part of the thermal insulation area to ensure that the temperature of the burnout wind area is above 650 °C to achieve the purpose of further smoke elimination and carbon black removal.

As a preferred technical solution of the present invention, a flue gas outlet is provided at the top of the heat exchange zone.

Preferably, the flue gas outlet is connected to the primary air chamber or the secondary air chamber.

Preferably, a flue gas baffle is longitudinally arranged in the heat exchange area, the flue gas baffle is located at the top of the heat exchange area, and the flue gas baffle divides the heat exchange area into a return passage and a smoke exhaust. The flue gas is discharged from the flue gas outlet through the return passage and the smoke exhaust passage in turn.

Preferably, the top of the return passage is provided with a flue gas circulation port, and the flue gas circulation port is connected to the primary air chamber or the secondary air chamber through a flue gas circulation pipeline.

In the present invention, the low-oxygen flue gas at the tail of 120-200°C is introduced into the primary air chamber, or the 600-650°C flue gas at the top of the return passage is introduced into the primary air chamber, which can strengthen the reducing atmosphere in the low-temperature combustion zone to a greater extent. Provide a thermal environment that makes more use of lean-oxygen combustion, and control the share distribution, thermal environment and combustion atmosphere of the low-temperature combustion zone and the high-temperature combustion zone to achieve the purpose of reducing NOx. In addition, the tail low-oxygen flue gas can also be introduced into the secondary air chamber to reduce the combustion intensity of the high-temperature combustion area and prolong the combustion time of the briquette on the air distribution board.

As a preferred technical solution of the present invention, the atmospheric pressure hot water stove also includes a coal bunker and a coal feeding device.

The briquette is stored in the coal bunker, the coal feeding device is connected to the coal outlet of the coal bunker and the coal inlet of the furnace, and the coal feeding device is used to push the briquette stored in the coal bunker into the furnace Inside.

In a second aspect, the present invention provides a method of using the atmospheric pressure hot water stove described in the first aspect, and the using method includes:

After the briquette enters the furnace, it falls into the air distribution plate, and the air chamber supplies air to the main combustion area to support combustion. By adjusting the opening of the air baffles at the air inlets of different air chambers, the proportion of the air intake of the corresponding air chambers is controlled, thereby adjusting the main combustion area. According to the distribution of shares and thermal environment in different zones, the briquette burns through the combustion atmosphere of different zones in the main combustion zone in turn to form flue gas, which is discharged from the heat exchange zone.

As a preferred technical solution of the present invention, the use method specifically includes:

After the briquette enters the furnace, it falls into the air distribution plate, and the air is supplied to the main combustion area through the primary air chamber and the secondary air chamber to support combustion. After the exhaust area is exhausted, the heat is exchanged and discharged from the heat exchange area. During the combustion process, the opening of the primary air baffle and the secondary air baffle is adjusted to control the air intake ratio of the primary air and the secondary air, and then adjust the low temperature combustion area and the high temperature combustion area. The share distribution and thermal environment in the area.

Preferably, the temperature of the pyrolysis gasification zone is 300-600°C, for example, it can be 300°C, 320°C, 340°C, 360°C, 380°C, 400°C, 420°C, 440°C, 460°C, 480°C °C, 500°C, 520°C, 540°C, 560°C, 580°C, or 600°C, but are not limited to the recited values, and other unrecited values within this range of values also apply.

Preferably, the volume content of oxygen in the pyrolysis gasification zone is less than or equal to 3%, such as 0.5%, 1.0%, 1.5%, 2.0%, 2.5% or 3.0%, but is not limited to the listed values, the The same applies to other non-recited values within the numerical range.

Preferably, the temperature of the low temperature combustion zone is 700-900°C, for example, it can be 700°C, 710°C, 720°C, 730°C, 740°C, 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C or 900°C, but not limited to the listed values, other unlisted values within the range The same applies to numerical values.

Preferably, the volume content of oxygen in the low temperature combustion zone is 5-8%, for example, 5.0%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9% %, 6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.8%, 6.9%, 7.0%, 7.1%, 7.2%, 7.3%, 7.4%, 7.5%, 7.6%, 7.7%, 7.8%, 7.9% or 8.0%, but are not limited to the recited values, other non-recited values within this range of values also apply.

Preferably, the temperature of the high temperature combustion zone is 900-1200°C, for example, it can be 900°C, 910°C, 920°C, 930°C, 940°C, 950°C, 960°C, 970°C, 980°C, 990°C, 1000°C, 1100°C or 1200°C, but are not limited to the recited values, and other unrecited values within the range of values are equally applicable.

Preferably, the volume content of oxygen in the high temperature combustion zone is 8-10%, for example, it can be 8.0%, 8.1%, 8.2%, 8.3%, 8.4%, 8.5%, 8.6%, 8.7%, 8.8%, 8.9% %, 9.0%, 9.1%, 9.2%, 9.3%, 9.4%, 9.5%, 9.6%, 9.7%, 9.8%, 9.9% or 10.0%, but not limited to the recited values, other The values listed also apply.

Preferably, the temperature of the oxygen-enriched burnout zone is 800-1000°C, such as 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C °C, 900°C or 1000°C, but are not limited to the recited values, and other unrecited values within the range of values apply equally.

Preferably, the oxygen volume content of the oxygen-rich burnout zone is 10-12%, such as 10.0%, 10.1°C, 10.2°C, 10.3°C, 10.4°C, 10.5°C, 10.6°C, 10.7°C, 10.8°C , 10.9°C, 11.0°C, 11.1°C, 11.2°C, 11.3°C, 11.4°C, 11.5°C, 11.6°C, 11.7°C, 11.8°C, 11.9°C or 12.0°C, but are not limited to the listed values, within the range of the values Other non-recited values also apply.

Preferably, the air intake ratio of the primary air and the secondary air is (20-40): (60-80), for example, it can be 20:80, 30:70 or 40:60, but it is not limited to the listed value, other non-recited values within this value range also apply.

Preferably, the using method further comprises: circulating the low-oxygen flue gas discharged from the normal pressure hot water heater to the primary air chamber.

Preferably, the volume content of oxygen in the hypoxic flue gas is 6-8%, such as 6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.8% , 6.9%, 7.0%, 7.1%, 7.2%, 7.3%, 7.4%, 7.5%, 7.6%, 7.7%, 7.8%, 7.9% or 8.0%, but not limited to the recited values, within the range of Other non-recited values also apply.

Preferably, the temperature of the hypoxic flue gas is 120-200°C, such as 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C or 200°C, but Not limited to the recited values, other non-recited values within this range of values are equally applicable.

Preferably, the using method further comprises: introducing the flue gas in the return passage into the primary air chamber.

Preferably, the temperature of the flue gas in the return passage is 600-650°C, such as 600°C, 605°C, 610°C, 615°C, 620°C, 625°C, 630°C, 635°C, 640°C, 645°C or 650°C, but not limited to the recited values, and other non-recited values within this range of values are also applicable.

As a preferred technical solution of the present invention, the use method specifically includes:

After the briquette enters the furnace, it falls into the air distribution plate, and the air is supplied to the main combustion area through the primary air chamber, the secondary air chamber and the tertiary air chamber to support combustion. In the combustion process, adjust the opening of the primary air baffle, the secondary air baffle and the tertiary air baffle to control the primary air, secondary air and tertiary air. The proportion of air intake, and then adjust the share distribution and thermal environment in the low temperature combustion zone, the high temperature combustion zone and the oxygen-enriched burnout zone.

Preferably, the temperature of the pyrolysis gasification zone is 300-600°C, for example, it can be 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C ℃, 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 490℃, 500℃, 510℃, 520℃, 530℃, 540℃, 550℃, 560°C, 570°C, 580°C, 590°C or 600°C, but are not limited to the recited values, other unrecited values within this range of values are equally applicable.

Preferably, the volume content of oxygen in the pyrolysis gasification zone is less than or equal to 3%, such as 0.5%, 1.0%, 1.5%, 2.0%, 2.5% or 3.0%, but is not limited to the listed values, the The same applies to other non-recited values within the numerical range.

Preferably, the temperature of the low temperature combustion zone is 600-900°C, for example, it can be 600°C, 620°C, 640°C, 660°C, 680°C, 700°C, 720°C, 740°C, 760°C, 780°C, 800°C, 820°C, 840°C, 860°C, 880°C, or 900°C, but are not limited to the recited values, and other unrecited values within the range of values are equally applicable.

Preferably, the volume content of oxygen in the low temperature combustion zone is 6-8%, such as 6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.8%, 6.9% %, 7.0%, 7.1%, 7.2%, 7.3%, 7.4%, 7.5%, 7.6%, 7.7%, 7.8%, 7.9% or 8.0%, but not limited to the recited values, other The values listed also apply.

Preferably, the temperature of the high temperature combustion zone is 900-1200°C, for example, it can be 900°C, 910°C, 920°C, 930°C, 940°C, 950°C, 960°C, 970°C, 980°C, 990°C, 1000°C, 1100°C or 1200°C, but are not limited to the recited values, and other unrecited values within the range of values are equally applicable.

Preferably, the volume content of oxygen in the high temperature combustion zone is 8-10%, for example, it can be 8.0%, 8.1%, 8.2%, 8.3%, 8.4%, 8.5%, 8.6%, 8.7%, 8.8%, 8.9% %, 9.0%, 9.1%, 9.2%, 9.3%, 9.4%, 9.5%, 9.6%, 9.7%, 9.8%, 9.9% or 10.0%, but not limited to the recited values, other The values listed also apply.

Preferably, the temperature of the oxygen-enriched burnout zone is 800-900°C, such as 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C °C or 900°C, but are not limited to the recited values, and other unrecited values within this range of values are equally applicable.

Preferably, the oxygen volume content of the oxygen-rich burnout zone is 10-12%, such as 10.0%, 10.1°C, 10.2°C, 10.3°C, 10.4°C, 10.5°C, 10.6°C, 10.7°C, 10.8°C , 10.9°C, 11.0°C, 11.1°C, 11.2°C, 11.3°C, 11.4°C, 11.5°C, 11.6°C, 11.7°C, 11.8°C, 11.9°C or 12.0°C, but are not limited to the listed values, within the range of the values Other non-recited values also apply.

Preferably, the air intake ratio of the primary air, the secondary air and the tertiary air is (5-15): (10-40): (45-85), for example, it can be 5:10:85, 15:10 :75, 5:40:55 or 15:40:45, but not limited to the recited values, other non-recited values within the numerical range are also applicable.

Preferably, the using method further comprises: circulating the low-oxygen flue gas discharged from the normal pressure hot water heater to the secondary air chamber;

Preferably, the volume content of oxygen in the hypoxic flue gas is 6-8%, such as 6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.8% , 6.9%, 7.0%, 7.1%, 7.2%, 7.3%, 7.4%, 7.5%, 7.6%, 7.7%, 7.8%, 7.9% or 8.0%, but not limited to the recited values, within the range of Other non-recited values also apply.

Preferably, the temperature of the hypoxic flue gas is 120-200°C, such as 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C or 200°C, but Not limited to the recited values, other non-recited values within this range of values are equally applicable.

The numerical range described in the present invention not only includes the above-mentioned exemplified point values, but also includes any point value between the above-mentioned numerical ranges that are not exemplified. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list them. The specific point value included in the above range.

The system refers to an equipment system, a plant system or a production plant.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The present invention further optimizes the staged combustion by improving the air distribution method, and achieves the purpose of reducing NOx, improving the briquette sulfur fixation rate and reducing carbon black emissions through the control of the combustion atmosphere.

(2) In the present invention, the low-oxygen flue gas at the tail of 120-200°C is introduced into the primary air chamber, or the 600-650°C flue gas at the top of the return passage is introduced into the primary air chamber, which can greatly strengthen the low-temperature combustion zone. The reducing atmosphere provides a thermal environment that makes more use of lean oxygen combustion, and controls the distribution, thermal environment and combustion atmosphere of the low-temperature combustion zone and the high-temperature combustion zone, so as to achieve the purpose of reducing _NOx . In addition, the tail low-oxygen flue gas can also be introduced into the secondary air chamber to reduce the combustion intensity of the high-temperature combustion area and prolong the combustion time of the briquette on the air distribution board.

Description of drawings

Fig. 1 is the structural representation of the atmospheric pressure hot water stove of staged combustion provided by embodiment 1;

Fig. 2 is the structural representation of the atmospheric pressure hot water stove of staged combustion provided by embodiment 5;

Fig. 3 is the structural representation of the atmospheric pressure hot water stove of staged combustion provided by embodiment 9;

Fig. 4 is the distribution curve diagram of cumulative combustion share along the height of coal seam in Example 2;

Fig. 5 is the distribution curve diagram of temperature along the height direction of coal seam in embodiment 2;

Fig. 6 is the distribution curve diagram of temperature along the coal seam in the moving direction of the grate in Example 2;

Fig. 7 is the distribution curve diagram of cumulative combustion share along the height of coal seam in Example 6;

Fig. 8 is the distribution curve diagram of temperature along the height direction of coal seam in embodiment 6;

FIG. 9 is a graph showing the distribution curve of the temperature of the coal seam along the moving direction of the grate in Example 6. FIG.

Among them, 1- coal bunker; 2- coal pushing device; 3- primary air baffle; 4- secondary air baffle; 5- primary air chamber; 6- secondary air chamber; 7- primary air distribution panel; 8 - Secondary air distribution board; 9- Burnout air duct; 10 - Pyrolysis gasification zone; 11 - Low temperature combustion zone; 12 - High temperature combustion zone; 13 - Oxygen-enriched burnout zone; 14 - Flue gas heat exchange 15-smoke outlet; 16-tertiary air baffle; 17- tertiary air chamber; 18- tertiary air distribution board; 19- refractory layer.

Detailed ways

The technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments.

In a specific embodiment, the present invention provides an atmospheric pressure hot water stove with staged combustion. The main combustion area and the heat exchange area 14 are connected, and the coal is burned in the main combustion area after entering the furnace, and the flue gas generated by the combustion is exchanged in the heat exchange area 14 . The main combustion zone is divided into a pyrolysis gasification zone 10 , a low temperature combustion zone 11 , a high temperature combustion zone 12 and an oxygen-enriched burnout zone 13 along the briquette conveying direction.

An air distribution plate is arranged at the bottom of the main combustion area, and at least two independent air chambers are arranged close to the bottom of the air distribution plate. The air is supplied to the main combustion area through the air chamber to assist the combustion of briquette. The air inlet of the air chamber is provided with an independent air inlet. By adjusting the opening of the wind deflector, the air intake ratio of the corresponding air chamber is controlled, thereby adjusting the combustion atmosphere of different zones in the main combustion zone.

Optionally, as shown in FIG. 1 , two independent air chambers are arranged under the air distribution plate, and the two air chambers are respectively denoted as primary air chamber 5 and secondary air chamber 6 along the briquette conveying direction. The primary air chamber 5 sends the primary air to its corresponding main combustion area, and the secondary air chamber 6 conveys the secondary air to its corresponding main combustion area.

The air inlet of the primary air chamber 5 is provided with a primary air baffle 3 that can be opened and closed, and the air inlet of the secondary air chamber 6 is provided with a secondary air baffle 4 that can be opened and closed. The opening degree of the air baffle 4 controls the air intake ratio of the primary air and the secondary air.

The corresponding part of the air distribution plate above the primary air chamber 5 is the primary air air distribution plate 7. A part of the primary air air distribution plate 7 is located in the pyrolysis gasification zone 10, and the other part is located in the low temperature combustion zone 11, which is located in the pyrolysis gasification zone 10. The part of the primary air distribution plate 7 is not provided with air holes, and the part of the primary air air distribution plate 7 located in the low temperature combustion zone 11 is provided with air holes. The part of the air distribution board corresponding to the upper part of the secondary air chamber 6 is the secondary air distribution board 8, and the secondary air distribution board 8 is provided with air holes. In the oxygen-enriched burn-out zone 13, a burn-out air duct 9 is arranged above part of the secondary air distribution plate 8 in the oxygen-enriched burn-out zone 13.

Optionally, three independent air chambers are set up close to the air cloth plate, and the three air chambers are respectively recorded as primary air chamber 5, secondary air chamber 6 and tertiary air chamber 17 along the briquette conveying direction. Chamber 5 delivers primary air to its corresponding main combustion area, secondary air is delivered to its corresponding main combustion area through secondary air chamber 6 , and tertiary air is delivered to its corresponding main combustion area through tertiary air chamber 17 .

The air inlet of the primary air chamber 5 is provided with a primary air baffle 3 that can be opened and closed, the air inlet of the secondary air chamber 6 is provided with a secondary air baffle 4 that can be opened and closed, and the air inlet of the tertiary air chamber 17 is provided with an openable and closable air baffle 4. The opening and closing of the tertiary air baffle 16 controls the proportion of the air intake of the primary air, the secondary air and the tertiary air by adjusting the opening of the primary air baffle 3, the secondary air baffle 4 and the tertiary air baffle 16.

The corresponding part of the air distribution plate above the primary air chamber 5 is the primary air air distribution plate 7. A part of the primary air air distribution plate 7 is located in the pyrolysis gasification zone 10, and the other part is located in the low temperature combustion zone 11, which is located in the pyrolysis gasification zone 10. The part of the primary air distribution plate 7 is not provided with air holes, and the part of the primary air air distribution plate 7 located in the low temperature combustion zone 11 is provided with air holes. The part of the air distribution plate corresponding to the upper part of the secondary air chamber 6 is the secondary air distribution plate 8, the main combustion zone corresponding to the secondary air distribution plate 8 is the high temperature combustion zone 12, and the secondary air air distribution plate 8 is provided with air holes . The corresponding part of the air distribution plate above the tertiary air chamber 17 is the tertiary air distribution plate 18, the main combustion zone corresponding to the tertiary air distribution plate 18 is the oxygen-enriched burnout zone 13, and the tertiary air distribution plate 18 is provided with air holes. An exhaust air duct 9 is arranged above the air distribution air plate 18 .

The main combustion zone and the heat exchange zone 14 are communicated through a flue gas burnout passage, and the flue gas passes through the flue gas burnout passage and enters the heat exchange zone 14 after being burnt out through the main combustion zone. The flue gas inlet of the flue gas burnout passage is of a constricted structure, a burnout air duct 9 is arranged at the flue gas inlet of the flue gas burnout passage, and a refractory layer 19 is laid on the inner wall of the flue gas burnout passage.

The top of the heat exchange area 14 is provided with a flue gas outlet 15 , and the flue gas outlet 15 is connected to the primary air chamber 5 or the secondary air chamber 6 . A flue gas baffle is longitudinally arranged in the heat exchange area 14, the flue gas baffle is located at the top of the heat exchange area 14, and the heat exchange area 14 is divided into a return passage and a smoke exhaust passage, and the flue gas passes through the return passage and the smoke exhaust passage in turn. It is discharged from the flue gas outlet 15, and the top of the return passage is provided with a flue gas circulation port, and the flue gas circulation port is connected to the primary air chamber 5 or the secondary air chamber 6.

The atmospheric pressure hot water stove also includes a coal bunker 1 and a coal feeding device 2. The coal bunker 1 stores briquette, and the coal feeding device 2 is connected to the coal outlet of the coal bunker 1 and the coal inlet of the furnace, and is used to feed the coal bunker. The briquette stored in 1 is pushed into the furnace.

In another specific embodiment, the present invention provides a staged combustion atmospheric pressure water heater and a method of using the same according to the above-mentioned specific embodiment, and the method of use specifically includes:

After the briquette enters the furnace, it falls into the air distribution plate, and the air chamber supplies air to the main combustion area to support combustion. By adjusting the opening of the air baffles at the air inlets of different air chambers, the proportion of the air intake of the corresponding air chambers is controlled, thereby adjusting the main combustion area. According to the distribution of shares and thermal environment in different zones, the briquette burns through the combustion atmosphere of different zones in the main combustion zone in turn to form flue gas, which is discharged from the heat exchange zone 14 after heat exchange.

Example 1

This embodiment provides an atmospheric pressure hot water stove with staged combustion. As shown in FIG. 1 , the atmospheric pressure hot water stove includes a furnace, and the furnace is divided into a main combustion area and a heat exchange area 14 that communicate with each other. After entering the furnace, it is burned in the main combustion zone, and the flue gas generated by the combustion is exchanged for heat in the heat exchange zone 14 . The main combustion zone is divided into a pyrolysis gasification zone 10 , a low temperature combustion zone 11 , a high temperature combustion zone 12 and an oxygen-enriched burnout zone 13 along the briquette conveying direction.

An air distribution plate is set at the bottom of the main combustion area, and two independent air chambers are set close to the bottom of the air distribution plate. The chamber 5 delivers primary air to its corresponding main combustion area, and the secondary air is delivered to its corresponding main combustion area through the secondary air chamber 6 .

The air inlet of the primary air chamber 5 is provided with an openable and closable primary air baffle 3, and the air inlet of the secondary air chamber 6 is provided with an openable and closable secondary air baffle 4. By adjusting the primary air baffle 3 And the opening degree of the secondary air baffle 4 controls the air intake ratio of the primary air and the secondary air.

The corresponding part of the air distribution plate above the primary air chamber 5 is the primary air distribution plate 7. A part of the primary air distribution plate 7 is located in the pyrolysis gasification zone 10, and the other part is located in the low temperature combustion zone 11, located in the pyrolysis gasification zone 11. Part of the primary air air distribution plate 7 in the combustion zone 10 is not provided with air holes, and part of the primary air air distribution plate 7 located in the low temperature combustion zone 11 is provided with air holes. The part of the air distribution board corresponding to the upper part of the secondary air chamber 6 is the secondary air distribution board 8, and the air holes are provided on the secondary air distribution board 8, and a part of the secondary air distribution board is located in the high temperature combustion zone. 12. The other part is located in the oxygen-enriched burn-out area 13, and a burn-out air duct 9 is arranged above the part of the secondary air distribution plate 8 located in the oxygen-enriched burnout area 13.

A flue gas outlet 15 is arranged on the top of the heat exchange area 14, and a flue gas baffle plate is longitudinally arranged in the heat exchange area 14. The flue gas baffle plate is located on the top of the heat exchange area 14, and the flue gas baffle plate divides the heat exchange area into 14 parts. For the return passage and the smoke exhaust passage, the flue gas is discharged from the flue gas outlet 15 after passing through the return passage and the smoke exhaust passage in sequence.

The atmospheric pressure hot water stove also includes a coal bunker 1 and a coal feeding device 2. The coal bunker 1 stores briquette, and the coal feeding device 2 is connected to the coal outlet of the coal bunker 1 and the coal inlet of the furnace, and is used to feed the coal bunker. The briquette stored in 1 is pushed into the furnace.

Example 2

The briquette is burnt and treated by using the graded combustion atmospheric hot water stove provided in Example 1, and the treatment method specifically includes the following steps:

After the briquette enters the furnace, it falls into the air distribution plate, and the primary air chamber 5 and the secondary air chamber 6 supply air to the main combustion area to support combustion. 12 and the oxygen-enriched burnout zone 13 are exchanged for heat and discharged from the heat exchange zone 14. During the combustion process, the opening of the primary air baffle 3 and the secondary air baffle 4 is adjusted to control the air intake ratio of the primary air and the secondary air. , the inlet air ratio of the primary air is 20%, and the air inlet ratio of the secondary air is 80%, and the temperature and oxygen content of each zone are controlled. Among them, the temperature of the pyrolysis and gasification zone 10 is 300 ° C, and the oxygen volume content is ≤ 3% The temperature of the low temperature combustion zone 11 is 700°C, and the oxygen volume content is 8%; the temperature of the high temperature combustion zone 12 is 1200°C, and the oxygen volume content is 10%; the temperature of the oxygen-rich burnout zone 13 is 1000°C, and the oxygen volume content is 10%. The proportion distribution and combustion atmosphere in the low temperature combustion zone 11 and the high temperature combustion zone 12 are adjusted to 12%.

The distribution law of the cumulative combustion share along the feed length is shown in Figure 4 (taking the coal feed end as the measurement point), and the temperature distribution along the height direction of the coal seam is shown in Figure 5 (taking the high temperature combustion area on the air distribution plate as the measurement point), along the grate The temperature distribution of the coal seam in the moving direction is shown in Figure 6.

The SO ₂ concentration and NO _x concentration in the tail flue gas were sampled and detected, and the detection results were: SO ₂ concentration of 600mg/m ³ and NO _x concentration of 300mg/m ³ .

Example 3

The briquette is burnt and treated by using the graded combustion atmospheric hot water stove provided in Example 1, and the treatment method specifically includes the following steps:

After the briquette enters the furnace, it falls into the air distribution plate, and the primary air chamber 5 and the secondary air chamber 6 supply air to the main combustion area to support combustion. 12 and the oxygen-enriched burnout zone 13 are exchanged for heat and discharged from the heat exchange zone 14. During the combustion process, the opening of the primary air baffle 3 and the secondary air baffle 4 is adjusted to control the air intake ratio of the primary air and the secondary air. , the inlet air ratio of the primary air is 30%, and the air inlet ratio of the secondary air is 70%, and the temperature and oxygen content of each zone are controlled. Among them, the temperature of the pyrolysis and gasification zone 10 is 400 ° C, and the volume content of oxygen is ≤ 3% The temperature of the low temperature combustion zone 11 is 800°C, and the oxygen volume content is 7%; the temperature of the high temperature combustion zone 12 is 1150°C, and the oxygen volume content is 9%; the temperature of the oxygen-rich burnout zone 13 is 950°C, and the oxygen volume content is 950°C The proportion distribution and combustion atmosphere in the low temperature combustion zone 11 and the high temperature combustion zone 12 were adjusted to 11%.

The SO ₂ concentration and NO _x concentration in the tail flue gas were sampled and detected, and the detection results were: SO ₂ concentration 550mg/m ³ , NOx concentration 280mg/m ³ .

Example 4

The briquette is burnt and treated by using the graded combustion atmospheric hot water stove provided in Example 1, and the treatment method specifically includes the following steps:

After the briquette enters the furnace, it falls into the air distribution plate, and the primary air chamber 5 and the secondary air chamber 6 supply air to the main combustion area to support combustion. 12 and the oxygen-enriched burnout zone 13 are exchanged for heat and discharged from the heat exchange zone 14. During the combustion process, the opening of the primary air baffle 3 and the secondary air baffle 4 is adjusted to control the air intake ratio of the primary air and the secondary air. , the inlet air ratio of the primary air is 40%, and the air inlet ratio of the secondary air is 60%, and the temperature and oxygen content of each zone are controlled. Among them, the temperature of the pyrolysis gasification zone 10 is 600 ℃, and the oxygen volume content is ≤ 3% The temperature of the low temperature combustion zone 11 is 900°C, and the oxygen volume content is 5%; the temperature of the high temperature combustion zone 12 is 1100°C, and the oxygen volume content is 8%; the temperature of the oxygen-rich burnout zone 13 is 800°C, and the oxygen volume content is 8%. The proportion distribution and combustion atmosphere in the low temperature combustion zone 11 and the high temperature combustion zone 12 are adjusted to 10%.

The SO ₂ concentration and NO _x concentration in the tail flue gas were sampled and detected, and the detection results were: SO ₂ concentration 500mg/m ³ , NOx concentration 260mg/m ³ .

Example 5

This embodiment provides an atmospheric pressure hot water stove with staged combustion. As shown in FIG. 2 , the atmospheric pressure hot water stove includes a furnace chamber. The furnace chamber is divided into a main combustion area and a heat exchange area 14 that communicate with each other. After the coal enters the furnace, it is burned in the main combustion zone, and the flue gas produced by the combustion undergoes heat exchange in the heat exchange zone 14 . The main combustion zone is divided into a pyrolysis gasification zone 10 , a low temperature combustion zone 11 , a high temperature combustion zone 12 and an oxygen-enriched burnout zone 13 along the briquette conveying direction.

An air distribution plate is set at the bottom of the main combustion area, and three independent air chambers are set up close to the bottom of the air distribution plate. 17. The primary air is sent to its corresponding main combustion area through the primary air chamber 5, the secondary air is conveyed to its corresponding main combustion area through the secondary air chamber 6, and three times through the tertiary air chamber 17 to its corresponding main combustion area. wind.

The air inlet of the primary air chamber 5 is provided with a primary air baffle 3 that can be opened and closed, the air inlet of the secondary air chamber 6 is provided with a secondary air baffle 4 that can be opened and closed, and the air inlet of the tertiary air chamber 17 is provided with an openable and closable air baffle 4. The opening and closing of the tertiary air baffle 16 controls the proportion of the air intake of the primary air, the secondary air and the tertiary air by adjusting the opening of the primary air baffle 3, the secondary air baffle 4 and the tertiary air baffle 16.

The corresponding part of the air distribution plate above the primary air chamber 5 is the primary air air distribution plate 7. A part of the primary air air distribution plate 7 is located in the pyrolysis gasification zone 10, and the other part is located in the low temperature combustion zone 11, which is located in the pyrolysis gasification zone 10. The part of the primary air distribution plate 7 is not provided with air holes, and the part of the primary air air distribution plate 7 located in the low temperature combustion zone 11 is provided with air holes. The part of the air distribution plate corresponding to the upper part of the secondary air chamber 6 is the secondary air distribution plate 8, the main combustion zone corresponding to the secondary air distribution plate 8 is the high temperature combustion zone 12, and the secondary air air distribution plate 8 is provided with air holes . The corresponding part of the air distribution plate above the tertiary air chamber 17 is the tertiary air distribution plate 18, the main combustion zone corresponding to the tertiary air distribution plate 18 is the oxygen-enriched burnout zone 13, and the tertiary air distribution plate 18 is provided with air holes. An exhaust air duct 9 is arranged above the air distribution air plate 18 .

A flue gas outlet 15 is arranged on the top of the heat exchange area 14, and a flue gas baffle plate is longitudinally arranged in the heat exchange area 14. The flue gas baffle plate is located on the top of the heat exchange area 14, and the flue gas baffle plate divides the heat exchange area into 14 parts. For the return passage and the smoke exhaust passage, the flue gas is discharged from the flue gas outlet 15 after passing through the return passage and the smoke exhaust passage in sequence.

The atmospheric pressure hot water stove also includes a coal bunker 1 and a coal feeding device 2. The coal bunker 1 stores briquette, and the coal feeding device 2 is connected to the coal outlet of the coal bunker 1 and the coal inlet of the furnace, and is used to feed the coal bunker. The briquette stored in 1 is pushed into the furnace.

Example 6

The briquette is burnt and treated by using the graded combustion atmospheric pressure hot water stove provided in Example 5, and the treatment method specifically includes the following steps:

After the briquette enters the furnace, it falls into the air distribution plate, and the primary air chamber 5, the secondary air chamber 6 and the tertiary air chamber 17 send air to the main combustion area to support combustion. 11. The high temperature combustion zone 12 and the oxygen-enriched burnout zone 13 are discharged from the heat exchange zone 14 after heat exchange. During the combustion process, the openings of the primary air baffle 3, the secondary air baffle 4 and the tertiary air baffle 16 are adjusted. Control the air intake ratio of primary air, secondary air and tertiary air. The air intake ratio of primary air is 5%, the air intake ratio of secondary air is 10%, and the air intake ratio of tertiary air is 85%. The oxygen content, wherein the temperature of the pyrolysis gasification zone 10 is 400°C, and the oxygen volume content is ≤3%; the temperature of the low temperature combustion zone 11 is 700°C, and the oxygen volume content is 8%; the temperature of the high temperature combustion zone 12 is 1200 ℃, the oxygen volume content is 10%; the temperature of the oxygen-enriched burnout zone 13 is 900°C, and the oxygen volume content is 12%, and then the share distribution and combustion atmosphere in the low temperature combustion zone 11 and the high temperature combustion zone 12 are adjusted.

The distribution law of cumulative combustion share along the feed length is shown in Figure 7 (taking the coal feed end as the measurement point), and the temperature distribution along the height of the coal seam is shown in Figure 8 (taking the high temperature combustion area on the air distribution plate as the measurement point), along the grate The temperature distribution of the coal seam in the moving direction is shown in Figure 9.

The SO ₂ concentration and NO _x concentration in the tail flue gas were sampled and detected, and the detection results were: SO ₂ concentration 500mg/m ³ , NOx concentration 260mg/m ³ .

Example 7

The briquette is burnt and treated by using the graded combustion atmospheric hot water stove provided in Example 5, and the treatment method specifically includes the following steps:

After the briquette enters the furnace, it falls into the air distribution plate, and the primary air chamber 5, the secondary air chamber 6 and the tertiary air chamber 17 send air to the main combustion area to support combustion. 11. The high temperature combustion zone 12 and the oxygen-enriched burnout zone 13 are discharged from the heat exchange zone 14 after heat exchange. During the combustion process, the openings of the primary air baffle 3, the secondary air baffle 4 and the tertiary air baffle 16 are adjusted. Control the air intake ratio of primary air, secondary air and tertiary air. The air intake ratio of primary air is 15%, the air intake ratio of secondary air is 25%, and the air intake ratio of tertiary air is 60%. The oxygen content, wherein the temperature of the pyrolysis gasification zone 10 is 500°C, and the oxygen volume content is ≤3%; the temperature of the low temperature combustion zone 11 is 800°C, and the oxygen volume content is 7%; the temperature of the high temperature combustion zone 12 is 1150 ℃, the oxygen volume content is 9%; the temperature of the oxygen-enriched burnout zone 13 is 850°C, and the oxygen volume content is 11%, and then the share distribution and combustion atmosphere in the low temperature combustion zone 11 and the high temperature combustion zone 12 are adjusted.

The SO ₂ concentration and NO _x concentration in the tail flue gas were sampled and detected, and the detection results were: SO ₂ concentration 450mg/m ³ and NOx concentration 220mg/m ³ .

Example 8

The briquette is burnt and treated by using the graded combustion atmospheric hot water stove provided in Example 5, and the treatment method specifically includes the following steps:

After the briquette enters the furnace, it falls into the air distribution plate, and the primary air chamber 5, the secondary air chamber 6 and the tertiary air chamber 17 send air to the main combustion area to support combustion. 11. The high temperature combustion zone 12 and the oxygen-enriched burnout zone 13 are discharged from the heat exchange zone 14 after heat exchange. During the combustion process, the openings of the primary air baffle 3, the secondary air baffle 4 and the tertiary air baffle 16 are adjusted. Control the proportion of air intake of primary air, secondary air and tertiary air, the proportion of intake air of primary air is 15%, the proportion of intake air of secondary air is 40%, and the proportion of intake air of tertiary air is 45%. The oxygen content, wherein the temperature of the pyrolysis gasification zone 10 is 600°C, and the oxygen volume content is ≤3%; the temperature of the low temperature combustion zone 11 is 900°C, and the oxygen volume content is 6%; the temperature of the high temperature combustion zone 12 is 1000 ℃, the oxygen volume content is 8%; the temperature of the oxygen-enriched burnout zone 13 is 800°C, and the oxygen volume content is 12%, and then the share distribution and combustion atmosphere in the low temperature combustion zone 11 and the high temperature combustion zone 12 are adjusted.

The SO ₂ concentration and NO _x concentration in the tail flue gas were sampled and detected, and the detection results were: SO ₂ concentration 400mg/m ³ , NOx concentration 200mg/m ³ .

Example 9

This embodiment provides an atmospheric pressure hot water stove with staged combustion. As shown in FIG. 3 , the atmospheric pressure hot water stove includes a furnace chamber. The furnace chamber is divided into a main combustion area and a heat exchange area 14 that communicate with each other. After the coal enters the furnace, it is burned in the main combustion zone, and the flue gas produced by the combustion undergoes heat exchange in the heat exchange zone 14 . The main combustion zone is divided into a pyrolysis gasification zone 10 , a low temperature combustion zone 11 and a high temperature combustion zone 12 along the briquette conveying direction.

An air distribution plate is set at the bottom of the main combustion area, and two independent air chambers are set close to the bottom of the air distribution plate. The chamber 5 delivers primary air to its corresponding main combustion area, and the secondary air is delivered to its corresponding main combustion area through the secondary air chamber 6 .

The air inlet of the primary air chamber 5 is provided with an openable and closable primary air baffle 3, and the air inlet of the secondary air chamber 6 is provided with an openable and closable secondary air baffle 4. By adjusting the primary air baffle 3 And the opening degree of the secondary air baffle 4 controls the air intake ratio of the primary air and the secondary air.

The corresponding part of the air distribution plate above the primary air chamber 5 is the primary air distribution plate 7. A part of the primary air distribution plate 7 is located in the pyrolysis gasification zone 10, and the other part is located in the low temperature combustion zone 11, located in the pyrolysis gasification zone 11. Part of the primary air air distribution plate 7 in the combustion zone 10 is not provided with air holes, and part of the primary air air distribution plate 7 located in the low temperature combustion zone 11 is provided with air holes. The corresponding part of the air distribution plate above the secondary air chamber 6 is the secondary air air distribution plate 8 , the secondary air distribution plate 8 is provided with air holes, and the secondary air distribution plate is located in the high temperature combustion zone 12 .

The main combustion area and the heat exchange area 14 are communicated through a flue gas burnout passage, and the flue gas passes through the flue gas burnout passage from the main combustion area, and enters the heat exchange area 14 for heat exchange after being burnt out in the flue gas burnout passage. The flue gas inlet of the flue gas burnout passage is of a constricted structure, and a burnout air duct 9 is arranged at the flue gas inlet, and a refractory layer 19 is laid on the inner wall of the flue gas burnout passage.

The atmospheric pressure hot water stove also includes a coal bunker 1 and a coal feeding device 2. The coal bunker 1 stores briquette, and the coal feeding device 2 is connected to the coal outlet of the coal bunker 1 and the coal inlet of the furnace, and is used to feed the coal bunker. The briquette stored in 1 is pushed into the furnace.

The applicant declares that the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should Changes or substitutions that can be easily conceived within the technical scope all fall within the protection scope and disclosure scope of the present invention.

Claims (10)

1. the atmospheric pressure hot water stove of a graded combustion, it is characterized in that, described normal pressure hot water stove comprises hearth, and described hearth is divided into the main combustion zone and the heat exchange zone that communicates, and burning coal enters the hearth After burning in the main combustion zone, the flue gas generated by the combustion is exchanged for heat in the heat exchange zone; The bottom of the main combustion area is provided with an air distribution plate, and at least two independent air chambers are set close to the bottom of the air distribution plate. Set up an independent wind deflector, and adjust the proportion of the air intake of the corresponding wind chamber by adjusting the opening of the wind deflector, so as to adjust the share distribution and thermal environment of different zones in the main combustion zone. 2 . The atmospheric pressure hot water stove according to claim 1 , wherein the main combustion zone is divided into a pyrolysis gasification zone, a low temperature combustion zone, a high temperature combustion zone and an oxygen-enriched combustion zone along the briquette conveying direction. 3 . Exhausted area. 3 . The atmospheric pressure hot water stove according to claim 2 , wherein two independent air chambers are arranged under the air cloth air plate, and the air is supplied to the main combustion area to assist the briquette through the air chambers. 4 . combustion; The two air chambers are respectively recorded as the primary air chamber and the secondary air chamber along the conveying direction of the briquette. The combustion area conveys secondary air; The air inlet of the primary air chamber is provided with a primary air baffle that can be opened and closed, and the air inlet of the secondary air chamber is provided with a secondary air baffle that can be opened and closed. The opening of the secondary air baffle controls the air intake ratio of the primary air and the secondary air; The corresponding part of the air distribution board above the primary air chamber is a primary air distribution board, and a part of the primary air distribution board is located in the pyrolysis gasification zone, and the other part is located in the low temperature combustion zone, which is located in the pyrolysis gasification zone. Part of the primary air distribution board does not have air holes, and part of the primary air distribution board located in the low temperature combustion zone has air holes; The part of the air distribution board corresponding to the upper part of the secondary air chamber is a secondary air distribution board, the air holes are provided on the secondary air distribution board, and a part of the secondary air distribution board is located in the high temperature combustion zone. , the other part is located in the oxygen-enriched burnout area, and the burnout air duct is set above the part of the secondary air air distribution plate located in the oxygen-enriched burnout area. 4 . The atmospheric pressure hot water stove according to claim 2 , wherein three mutually independent air chambers are arranged close to the bottom of the cloth air plate, and the air is supplied to the main combustion area through the air chambers to assist the briquette combustion. 5 . ; The three air chambers are respectively recorded as the primary air chamber, the secondary air chamber and the tertiary air chamber along the briquette conveying direction. The corresponding main combustion area delivers secondary air, and the tertiary air is delivered to its corresponding main combustion area through the tertiary air chamber; The air inlet of the primary air chamber is provided with a primary air baffle that can be opened and closed, the air inlet of the secondary air chamber is provided with a secondary air baffle that can be opened and closed, and the inlet of the tertiary air chamber The air outlet is provided with a tertiary air baffle that can be opened and closed, and the air intake ratio of the primary air, the secondary air and the tertiary air is controlled by adjusting the opening of the primary air baffle, the secondary air baffle and the tertiary air baffle; The corresponding part of the air distribution board above the primary air chamber is a primary air distribution board, and a part of the primary air distribution board is located in the pyrolysis gasification zone, and the other part is located in the low temperature combustion zone, which is located in the pyrolysis gasification zone. Part of the primary air distribution board does not have air holes, and part of the primary air distribution board located in the low temperature combustion zone has air holes; The part of the air distribution board corresponding to the upper part of the secondary air chamber is a secondary air distribution board, the main combustion area corresponding to the secondary air distribution board is a high temperature combustion area, and the secondary air distribution board open air holes; The corresponding part of the air distribution plate above the tertiary air chamber is a tertiary air distribution plate, the main combustion zone corresponding to the tertiary air distribution plate is an oxygen-enriched burnout zone, and the tertiary air distribution plate is provided with air holes, An exhaust air duct is arranged above the tertiary air distribution plate. 5. The atmospheric pressure hot water stove according to any one of claims 1-4, wherein the main combustion area and the heat exchange area are communicated through a flue gas burnout passage, and the flue gas is burned through the main combustion area. After exhaustion, it enters the heat exchange area through the flue gas burnout channel; Preferably, the flue gas inlet of the flue gas burnout channel is a constricted structure; Preferably, a burnout air duct is arranged at the flue gas inlet of the flue gas burnout channel; Preferably, a refractory layer is laid on the inner wall of the flue gas burnout channel. 6. The atmospheric pressure hot water stove according to any one of claims 1-5, wherein a flue gas outlet is provided at the top of the heat exchange zone; Preferably, the flue gas outlet is connected to the primary air chamber or the secondary air chamber; Preferably, a flue gas baffle is longitudinally arranged in the heat exchange area, the flue gas baffle is located at the top of the heat exchange area, and the flue gas baffle divides the heat exchange area into a return passage and a smoke exhaust. The flue gas is discharged from the flue gas outlet through the return passage and the exhaust passage in turn; Preferably, the top of the return passage is provided with a flue gas circulation port, and the flue gas circulation port is connected to the primary air chamber or the secondary air chamber through a flue gas circulation pipeline. 7. The atmospheric pressure hot water stove according to any one of claims 1-6, wherein the atmospheric pressure hot water stove further comprises a coal bunker and a coal feeding device; The briquette is stored in the coal bunker, the coal feeding device is connected to the coal outlet of the coal bunker and the coal inlet of the furnace, and the coal feeding device is used to push the briquette stored in the coal bunker into the furnace Inside. 8. a method of using the atmospheric pressure hot water stove according to any one of claims 1-7, the method of using comprising: After the briquette enters the furnace, it falls into the air distribution plate, and the air chamber supplies air to the main combustion area to support combustion. By adjusting the opening of the air baffles at the air inlets of different air chambers, the proportion of the air intake of the corresponding air chambers is controlled, thereby adjusting the main combustion area. According to the distribution of shares and thermal environment in different zones, the briquette burns through the combustion atmosphere of different zones in the main combustion zone in turn to form flue gas, which is discharged from the heat exchange zone. 9. The use method according to claim 8, wherein the use method specifically comprises: After the briquette enters the furnace, it falls into the air distribution plate, and the air is supplied to the main combustion area through the primary air chamber and the secondary air chamber to support combustion. After the exhaust area is exhausted, the heat is exchanged and discharged from the heat exchange area. During the combustion process, the opening of the primary air baffle and the secondary air baffle is adjusted to control the air intake ratio of the primary air and the secondary air, and then adjust the low temperature combustion area and the high temperature combustion area. The share distribution and thermal environment in the area; Preferably, the temperature of the pyrolysis gasification zone is 300-600°C; Preferably, the oxygen volume content of the pyrolysis gasification zone is less than or equal to 3%; Preferably, the temperature of the low temperature combustion zone is 700-900°C; Preferably, the volume content of oxygen in the low temperature combustion zone is 5-8%; Preferably, the temperature of the high temperature combustion zone is 900-1200°C; Preferably, the volume content of oxygen in the high temperature combustion zone is 8-10%; Preferably, the temperature of the oxygen-enriched burnout zone is 800-1000°C; Preferably, the oxygen volume content of the oxygen-enriched burnout zone is 10-12%; Preferably, the air intake ratio of the primary air and the secondary air is (20-40): (60-80); Preferably, the using method further comprises: circulating the low-oxygen flue gas discharged from the normal pressure hot water heater to the primary air chamber; Preferably, the oxygen volume content in the hypoxic flue gas is 6-8%; Preferably, the temperature of the hypoxic flue gas is 120-200°C; Preferably, the using method further comprises: introducing the flue gas in the return passage into the primary air chamber; Preferably, the temperature of the flue gas in the return passage is 600-650°C. 10. The use method according to claim 8, wherein the use method specifically comprises: After the briquette enters the furnace, it falls into the air distribution plate, and the air is supplied to the main combustion area through the primary air chamber, the secondary air chamber and the tertiary air chamber to support combustion. In the combustion process, adjust the opening of the primary air baffle, the secondary air baffle and the tertiary air baffle to control the primary air, secondary air and tertiary air. The proportion of air intake, and then adjust the share distribution and thermal environment in the low temperature combustion zone, the high temperature combustion zone and the oxygen-enriched burnout zone; Preferably, the temperature of the pyrolysis gasification zone is 300-600°C; Preferably, the oxygen volume content of the pyrolysis gasification zone is less than or equal to 3%; Preferably, the temperature of the low temperature combustion zone is 600-900°C; Preferably, the volume content of oxygen in the low temperature combustion zone is 6-8%; Preferably, the temperature of the high temperature combustion zone is 900-1200°C; Preferably, the volume content of oxygen in the high temperature combustion zone is 8-10%; Preferably, the temperature of the oxygen-enriched burnout zone is 800-900°C; Preferably, the oxygen volume content of the oxygen-enriched burnout zone is 10-12%; Preferably, the air intake ratio of the primary air, the secondary air and the tertiary air is (5-15): (10-40): (45-85); Preferably, the using method further comprises: circulating the low-oxygen flue gas discharged from the normal pressure hot water heater to the secondary air chamber; Preferably, the oxygen volume content in the hypoxic flue gas is 6-8%; Preferably, the temperature of the hypoxic flue gas is 120-200°C.

Images