CN212565871U

CN212565871U - Biomass cooking stove with inclined fire grate

Info

Publication number: CN212565871U
Application number: CN202021687904.3U
Authority: CN
Inventors: 聂亚洲; 单明; 杨旭东
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2020-08-13
Filing date: 2020-08-13
Publication date: 2021-02-19
Anticipated expiration: 2030-08-13

Abstract

The utility model provides a biomass cooking stove with an inclined grate, which comprises a feeding system, a combustion system, an ignition system and an air supply system; the combustion system comprises a combustion chamber communicated with the feeding system, a chain grate which is positioned in the middle of the combustion chamber and is obliquely arranged, and a plurality of limiting plates which are distributed on the chain of the chain grate at equal intervals, wherein the rotation direction of the chain grate is required to ensure that the biomass granular fuel is conveyed to the tail end of the chain grate from the lower end of the feeding pipe, and the rotation speed of the chain grate is required to be matched with the burnout speed of the biomass granular fuel, so that the combustion process is finished before the biomass granular fuel falls off on the chain grate; the air supply system supplies air to the chain grate and the top of the combustion chamber respectively. The utility model discloses a put the traveling grate stoker to one side, nitrogen oxide in the pellet fuel volatile when the upward movement, reacts with the high temperature carbon layer of traveling grate stoker upper end, effectively reduces nitrogen oxide's in the flue gas concentration.

Description

Biomass cooking stove with inclined fire grate

Technical Field

The utility model relates to a living beings cooking stove with slope grate belongs to living beings clean utilization technical field.

Background

In areas with abundant biomass resources, biomass particles are used for cooking, which is a mode more and more paid attention by the public. Compared with direct combustion of biomass, the emission of pollutants such as carbon monoxide, PM2.5, sulfur dioxide and the like of biomass particles is obviously reduced. The emissions of nitrogen oxides from the combustion of biomass particles are relatively high. The large boiler can adopt a complex SNCR (Selective Non-Catalytic Reduction) or SCR (Selective Catalytic Reduction) method for denitration, but a household small-sized furnace does not have the condition to adopt the treatment mode. Analyzed from the combustion mechanism, the source of nitrogen oxides in biomass particle furnaces is mainly fuel nitrogen. Fuel nitrogen can be divided into volatile nitrogen and coke nitrogen, which react with each other in a complex manner during combustion. At present, in order to reduce the emission of nitrogen oxides of biomass particle stoves, air is generally adopted for staged combustion, namely, air is divided into primary air and secondary air which are respectively fed into the stoves. The main way for the user to control the emission of nitrogen oxides by the small-sized stove is to supply air in stages, and the generation rate of the nitrogen oxides is controlled by changing the proportion of primary air supply and secondary air supply. However, only by means of graded air supply, the emission reduction capability of nitrogen oxides is extremely limited, and new low-nitrogen emission technology and equipment suitable for household small biomass stoves need to be developed.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming prior art's weak point, providing a living beings cooking stove with slope grate, this living beings granule stove on air classification's basis, changes traditional pellet fuel distribution mode, and nitrogen oxide's concentration in the flue gas can be reduced by a wide margin to the reduction characteristic of make full use of high temperature carbon layer.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides a biomass cooking stove with an inclined grate, which is characterized in that the biomass cooking stove comprises a feeding system, a combustion system, an ignition system and an air supply system; wherein the content of the first and second substances,

the feeding system comprises a storage bin, a feeding auger and a feeding pipe, wherein the feeding auger and the feeding pipe are sequentially communicated with the lower part of the storage bin;

the combustion system comprises a combustion chamber communicated with the feeding pipe, a chain grate which is positioned in the combustion chamber and is obliquely arranged in the middle of the combustion chamber, and a plurality of limiting plates which are distributed on the chain of the chain grate at equal intervals; the lower end and the higher end of the chain grate are respectively a feeding side and a tail end, a discharge port of the feeding pipe is arranged close to the feeding side of the chain grate, the rotating direction of the chain grate is required to ensure that the biomass granular fuel is conveyed to the tail end of the chain grate from the lower end of the feeding pipe, and the rotating speed of the chain grate is matched with the burnout speed of the biomass granular fuel, so that the combustion process is finished before the biomass granular fuel falls off on the chain grate; the bottom in the combustion chamber is provided with a slag storage chamber respectively at the feed side and the tail end which are opposite to the chain grate, and the top of the combustion chamber is provided with a flame outlet;

the ignition system comprises an ignition fan positioned outside the combustion chamber and an electric heating wire fixed on the side wall of the combustion chamber close to the feeding side of the chain grate;

the air supply system comprises an air feeder, a proportional air valve, a primary air supply pipe, a secondary air supply pipe and a primary air supply exhaust pipe; the air outlet of the air feeder is connected with the air inlets of the primary air supply pipe and the secondary air supply pipe through a proportional air valve; the air outlet of the primary air supply pipe is connected with the primary air supply calandria and is used for providing oxygen required by combustion for the biomass granular fuel on the chain grate furnace; the air outlet of the secondary air supply pipe is connected with an annular drainage air duct positioned on the outer wall of the combustion chamber, and supports the high-temperature oxidation reaction of the biomass particles in the combustion chamber under the action of secondary air.

Further, the side wall of the upper part of the combustion chamber is recycled and used for restricting the movement path of the volatile components of the biomass particle fuel in the combustion chamber, and the volatile components of the biomass particle fuel are enabled to be close to and react with the high-temperature carbon layer above the chain grate.

The utility model has the advantages of it is following and outstanding effect: firstly, the air quantity of each level is adjusted through a proportional air valve, so that the device can be flexibly adapted to different biomass granular fuels; the combustion time of the biomass granular fuel on the chain grate is sequentially prolonged from bottom to top, the carbon content is sequentially increased from bottom to top, the reducing capability is sequentially enhanced from bottom to top, combustion products of the biomass granular fuel at the lower part of the chain grate can participate in the carbon layer reaction of the upper area, and the yield of nitrogen oxides is obviously reduced; the automatic feeding switch is arranged, so that the feeding speed is matched with the rotating speed of the chain grate, and the combustion stability is ensured; and fourthly, by controlling the starting, stopping and rotating speed of the driving motor and the induced draft fan, the real-time monitoring of the temperature, the temperature and other parameters of multiple points in the combustion chamber is realized, and the automatic operation and the multi-parameter adjustment are favorably realized.

Drawings

Fig. 1 is a cross-sectional view of a biomass cooking stove with an inclined grate according to the present invention.

Fig. 2 is a schematic structural view of the traveling grate stokers with different inclination angles in the biomass cooking stove with the inclined grate according to the present invention.

Fig. 3 is a top view and a partial enlarged view of a primary air supply exhaust pipe of a biomass cooking stove with an inclined grate according to the present invention.

The parts in the figure represent: 1-a first slag storage chamber, 2-a limiting plate, 3-a driving motor, 4-an ignition fan, 5-an electric heating wire, 6-a storage bin, 7-a feeding auger, 8-a feeding pipe, 9-a flame outlet, 10-a secondary air supply port, 11-a combustion chamber, 12-a chain grate, 13-a secondary air supply pipe, 14-a proportional air valve, 15-an air feeder, 16-a primary air supply pipe, 17-a primary air supply pipe, 18-a second slag storage chamber and 19-a pressure equalizing chamber.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

In order to better understand the present invention, the following detailed description provides an example of the application of a biomass cooking stove with inclined grate.

Referring to fig. 1 to 3, a biomass cooking stove with an inclined grate according to an embodiment of the present invention includes a feeding system, a combustion system, an ignition system, and an air supply system; wherein the content of the first and second substances,

the feeding system comprises a storage bin 6, a feeding auger 7 and a feeding pipe 8 which are sequentially communicated with the lower part of the storage bin 6;

the combustion system comprises a combustion chamber 11 communicated with a feeding pipe 8, a traveling grate 12 which is positioned in the combustion chamber 11 and is obliquely arranged at the middle part, and a plurality of limiting plates 2 which are distributed on a traveling grate 12 chain at equal intervals; the lower end of the chain grate 12 is a feeding side, the higher end is a tail end, a discharge port of the feeding pipe 8 is arranged close to the feeding side of the chain grate 12, the chain grate 12 is driven by the driving motor 3 positioned outside the combustion chamber 11, the rotation direction of the chain grate 12 is required to ensure that the biomass granular fuel is conveyed to the tail end of the chain grate 12 (positioned in the upper area of the combustion chamber 11) from the lower end of the feeding pipe 8, and the rotation speed of the chain grate 12 is required to be matched with the burnout speed of the biomass granular fuel, so that the combustion process is finished before the biomass granular fuel falls on the chain grate 12; the inclination angle range of the chain grate 12 is 25-45 degrees, the combustion time of biomass granular fuel on the chain grate 12 is sequentially increased from bottom to top, the carbon content is sequentially increased from bottom to top, the reducing capability is sequentially increased from bottom to top, after the inclined arrangement is adopted, the combustion product of the biomass granular fuel at the lower part of the chain grate 12 can react with the high-temperature carbon layer at the upper part of the chain grate 12, the yield of nitrogen oxide is obviously reduced, the inclination angle of the chain grate 12 needs to be adjusted according to the type of the biomass granules, and the inclination angle when the emission concentration of the nitrogen oxide is lowest can be found through a pre-experiment; the bottom in the combustion chamber 11 and the feed side and the tail end which are opposite to the chain grate 12 are respectively provided with a slag storage chamber (1 and 18) for collecting ash falling from the feed side and the tail end of the chain grate 12, and the top of the combustion chamber 11 is provided with a flame outlet 9; the limiting plate 2 is used for limiting the position of the biomass granular fuel on the chain grate 12, so that the biomass granular fuel moves along with the chain grate 12, and holes can be reserved in the limiting plate 12 to facilitate the flow of wind;

the ignition system comprises an ignition fan 4 positioned outside the combustion chamber 11 and an electric heating wire 5 fixed on the side wall of the combustion chamber 11 close to the feeding side of the chain grate 12;

the air supply system comprises an air feeder 15, a proportional air valve 14, a primary air supply pipe 16, a secondary air supply pipe 13 and a primary air supply exhaust pipe 17; the blower 15 and the proportional air valve 14 are both positioned outside the combustion chamber 11, and the air outlet of the blower 15 is connected with the air inlets of the primary air supply pipe 16 and the secondary air supply pipe 13 through the proportional air valve 14; an air outlet of the primary air supply pipe 16 penetrates through the side wall of the combustion chamber 11 to be connected with an equalizing chamber 19 and a primary air supply calandria 17 which are arranged at the chain grate 12, and is used for providing oxygen required by combustion for the biomass granular fuel on the chain grate 12; the air outlet of the secondary air supply pipe 13 is connected with an annular drainage air channel positioned on the outer wall of the combustion chamber 11, secondary air enters the combustion chamber 11 through an opening 10 with the reserved diameter of 6-10mm on the inner side of the annular drainage air channel, and the high-temperature oxidation reaction of biomass particles in the combustion chamber 11 is further supported under the action of the secondary air.

Further, the side wall of the upper part of the combustion chamber 11 is recycled for restricting the moving path of the volatile components of the biomass particle fuel in the combustion chamber 11, and the volatile components of the biomass particle fuel are promoted to approach the high-temperature carbon layer above the chain grate 12 and react with the high-temperature carbon layer.

Furthermore, a feeding switch can be arranged, so that the feeding speed is matched with the rotating speed of the chain grate 12, and the combustion stability of the biomass granular fuel is ensured.

The utility model discloses an each component part is conventional product.

The principle and the working process of the utility model are as follows:

and opening the feeding auger 7 to feed a proper amount of biomass granular fuel to the chain grate 12. Power is supplied to the electric heating wire 5, and the ignition fan 3 is turned on. After the biomass granular fuel on the traveling grate 12 is ignited, the switch of the blower 15 is turned on, the proportional air valve 14 is adjusted to a proper opening degree, and air starts to be supplied to the combustion chamber 11. And opening a switch of the driving motor 3, adjusting to a lower speed, and continuously feeding the biomass granular fuel to the chain grate 12. The heating wire 5 and the ignition fan 3 still continue to work, and when the reading of the temperature sensor in the upper area of the combustion chamber 11 reaches 700 ℃, the ignition system is powered off and closed. At this point, the temperature in the combustion chamber 11 is already sufficient to support the continued combustion of the biomass pellet fuel. The speed of rotation of the traveling grate 12 is adjusted so that the combustion process is completed when the biomass pellet falls off the traveling grate 12. Preliminary experiments are required to determine the rotational speed of the traveling grate 12 when the combustion of the biomass pellet fuel is performed. The biomass particle fuel is normally combusted on the traveling grate 12, and the generated flue gas containing nitrogen oxides flows upwards. The upper region of the traveling grate 12 is dominated by a carbon layer, and nitrogen oxides in the flue gas are reduced to nitrogen in the reducing atmosphere in the upper region of the traveling grate 12. When it is desired to shut down the oven, it is first necessary to stop the addition of biomass pellet fuel to the traveling grate 12. After the biomass granular fuel on the traveling grate 12 is burnt out, the power supply of the motor and the fan is cut off. Finally, the ash in the slag storage chambers (1 and 18) is cleaned, maintained and the like.

The present invention and its embodiments have been described above schematically, without limitation, and what is shown in the drawings is only one of the embodiments of the present invention and is not actually limited thereto. Therefore, if the person skilled in the art receives the teaching of the present invention, the protection scope of the present invention shall not be limited to the embodiments and the embodiments similar to the above-mentioned technical solution without creative design.

Claims

1. A biomass cooking stove with an inclined grate is characterized by comprising a feeding system, a combustion system, an ignition system and an air supply system; wherein the content of the first and second substances,

the feeding system comprises a storage bin (6), and a feeding auger (7) and a feeding pipe (8) which are sequentially communicated with the lower part of the storage bin (6);

the combustion system comprises a combustion chamber (11) communicated with the feeding pipe (8), a chain grate (12) which is positioned in the combustion chamber (11) and is obliquely arranged at the middle part, and a plurality of limiting plates (2) which are distributed on the chain of the chain grate (12) at equal intervals; the lower end and the higher end of the chain grate (12) are respectively a feeding side and a tail end, a discharging port of the feeding pipe (8) is tightly attached to the feeding side of the chain grate (12), the rotating direction of the chain grate (12) is required to ensure that the biomass granular fuel is conveyed to the tail end of the chain grate (12) from the lower end of the feeding pipe (8), the rotating speed of the chain grate (12) is required to be matched with the burnout speed of the biomass granular fuel, and the combustion process is finished before the biomass granular fuel falls on the chain grate (12); the bottom in the combustion chamber (11) is provided with a slag storage chamber respectively at the feed side and the tail end which are opposite to the chain grate (12), and the top of the combustion chamber (11) is provided with a flame outlet (9);

the ignition system comprises an ignition fan (4) positioned outside the combustion chamber (11) and an electric heating wire (5) fixed on the side wall of the combustion chamber (11) close to the feeding side of the chain grate (12);

the air supply system comprises an air feeder (15), a proportional air valve (14), a primary air supply pipe (16), a secondary air supply pipe (13) and a primary air supply exhaust pipe (17); an air outlet of the blower (15) is connected with air inlets of the primary air supply pipe (16) and the secondary air supply pipe (13) through a proportional air valve (14); an air outlet of the primary air supply pipe (16) is connected with a primary air supply calandria (17) and is used for providing oxygen required by combustion for the biomass granular fuel on the chain grate (12); the air outlet of the secondary air supply pipe (13) is connected with an annular drainage air duct positioned on the outer wall of the combustion chamber (11) and supports the high-temperature oxidation reaction of biomass particles in the combustion chamber (11) under the action of secondary air.

2. The biomass cooking stove according to claim 1, characterised in that the side walls of the upper part of the combustion chamber (11) are recovered.

3. The biomass cooking stove according to claim 1, wherein the feed rate is controlled to match the rotational speed of the traveling grate (12).

4. The biomass cooking stove according to claim 1, wherein the angle of inclination of the travelling grate stokers (12) is in the range of 25 ° to 45 °.

5. The biomass cooking stove according to claim 1, characterized in that a pressure equalizing chamber (19) is provided between the connection of the outlet of the primary air supply pipe (16) and the primary air supply exhaust pipe (17) and on one side of the traveling grate (12).

6. The biomass cooking stove according to claim 1, wherein the restriction plate (2) may be provided with holes.