A assembled air inlet grate and low-nitrogen gasification combustion device

Abstract

The present invention discloses a assembled air inlet grate and a low-nitrogen gasification combustion device. The assembled air inlet grate includes a grate plate and a plurality of hanging members. The plurality of hanging members are all arranged vertically and distributed circumferentially. On one side of the upper end of each hanging member away from each other, there is a hanging portion, and on one side of the lower end of each hanging member close to each other, there is a supporting portion. The grate plate is horizontally arranged among the plurality of hanging members and is supported on the supporting portions of the plurality of hanging members to jointly enclose a trough-shaped receiving pool. Biomass pellet fuel is used to be loaded in the receiving pool. The hanging portions at the upper ends of the plurality of hanging members are used to be hung on the inner wall of the furnace body. There are first air inlet holes penetrating the side wall of the receiving pool on the hanging member or between two adjacent hanging members, and there are second air inlet holes penetrating up and down between the upper ends of the hanging member or between the upper ends of two adjacent hanging members. The structure is simple, and the biomass pellet fuel can be pyrolyzed into low-nitrogen combustible gas in the receiving pool.

Description

Technical Field

[0001] The invention belongs to the field of biomass low-nitrogen gasification combustion devices, and in particular relates to an assembled air inlet grate and a low-nitrogen gasification combustion device. Background Art

[0002] Biomass pellet fuel is a clean renewable energy with the advantages of large supply, wide source and low pollution. Biomass pellet fuel is composed of combustibles, inorganic matter and water. Its elements are mainly C, H, O, and contain a small amount of N and S. The pollutants produced by the combustion of biomass pellet fuel are mainly CO, NO x and particulate matter emissions, so CO, NO x , PM is also the main control target for pollutant emissions from the combustion of biomass pellet fuel. The types and properties of biomass pellet fuel, the design structure of boilers and burners, the feeding method and air intake method, as well as the parameters of feeding and air intake have a great impact on pollutant emissions. The currently commonly used biomass stoves are mostly installed with burners on the original equipment, or are roughly modified by installing a feeding system on the original coal-fired boiler. They do not meet the low-nitrogen combustion characteristics of biomass pellet fuels, and emissions generally exceed the standard. In terms of the air intake position, the existing biomass pellet fuel stoves mostly enter the bottom of the furnace at one time to provide the oxygen required for the pyrolysis and gasification of biomass pellet fuel and the combustion of fixed carbon. In order to obtain stronger firepower, there is a common phenomenon of excessive intake air velocity (intake air velocity refers to the volume of air passing through the combustion chamber per unit time). Excessive intake air velocity will entrain the ash particles produced by the bottom and fuel combustion, increase the mass concentration of particulate matter emitted by fuel combustion, and excessive intake air velocity will also cause the violent combustion of biomass pellet fuel to produce very high temperatures, increase the conversion rate of N elements in biomass pellet fuel, and increase NO x The emission volume, higher temperature will also make the burning biomass particles appear molten or semi-molten state, and coking will occur when the combustible material is exhausted and the temperature drops. (Note: the type and performance of biomass particles are different, which also has a great influence on the degree of coking.) If the coking is serious, it will affect the combustion effect of biomass pellet fuel, make the fuel burn incompletely, reduce thermal efficiency and increase emission of pollutants. In particularly serious cases, the fuel cannot burn normally and cause flameout. If a fuel with a low coking rate is selected, the cost will increase. Therefore, the coking of biomass pellet fuel during combustion is also a difficult problem in biomass combustion technology. In addition, the grates of biomass combustion furnaces are mostly grate-shaped, which can only allow air to pass through the biomass particles on the grate plate from bottom to top to enter the combustion chamber. At this time, the biomass pellet fuel is in full contact with the air, which will cause the biomass pellet fuel to burn violently and coke. Summary of the invention

[0003] In order to solve the above technical problems, one of the objectives of the present invention is to provide an assembled air inlet grate with a simple structure and an assembled style.

[0004] To achieve the above object, the technical solution of the present invention is as follows: A assembled air inlet grate, comprising grate plates and a plurality of hanging members. The plurality of hanging members are all vertically arranged and distributed circumferentially. On one side of the upper end of each hanging member that is far away from each other, there is a hanging portion. On one side of the lower end of each hanging member that is close to each other, there is a supporting portion. The grate plates are horizontally arranged among the plurality of hanging members and are supported on the supporting portions of the plurality of hanging members to jointly enclose a trough-shaped receiving pool. Biomass pellet fuel is used to be contained in the receiving pool. The hanging portions at the upper ends of the plurality of hanging members are used to be hung on the inner wall of the furnace body. On the hanging member or on two adjacent hanging members, there is a first air inlet hole that penetrates the side wall of the receiving pool. Between the upper end of the hanging member or between the upper ends of two adjacent hanging members, there is a second air inlet hole that penetrates up and down.

[0005] The beneficial effect of the above technical solution is that: By using a plurality of hanging members to be hung on the furnace wall of the furnace body in a ring shape, and the grate plates are horizontally supported among the plurality of hanging members. At this time, the grate plates and the plurality of hanging members jointly enclose a trough-shaped structure, which is convenient to assemble and can be locally replaced and maintained when partially damaged. Since the grate plates are covered with ash-dropping holes that penetrate up and down (for the ash generated after the combustion of the biomass pellet fuel above the grate plates to fall downward. Since there is a stack of biomass pellet fuel above the grate plates of this grate, the air below the grate plates will not flow upward through the ash-dropping holes), and the air below this assembled air inlet grate can mainly enter the receiving pool through the area between the hanging members and the inner wall of the furnace body and finally through the first air inlet hole for the pyrolysis gasification of the biomass pellet fuel, and the remaining part can enter above the receiving pool through the second air inlet hole. Among them, the biomass pellet fuel at the bottom of the receiving pool is pyrolyzed into combustible gas, and the combustible gas overflows upward above the receiving pool and mixes with air above the receiving pool and then burns violently to form an open flame.

[0006] In the above technical solution, the hanging member includes a vertical rod, a bottom rod and a rod head. The vertical rod is vertically arranged, and the bottom rod is horizontally arranged in the inner and outer direction. The lower end of the vertical rod is vertically connected to the middle of the upper end of the bottom rod. The inner end of the bottom rod constitutes the supporting portion of the hanging member, and the outer end of the bottom rod constitutes the abutting portion of the hanging member, which is used to abut against the inner wall of the furnace body. The upper end of the vertical rod is connected to the inner lower end of the rod head. The outer lower end of the rod head is recessed upward with a horizontally penetrating notch, and the notch constitutes the hanging portion of the hanging member.

[0007] The beneficial effect of the above technical solution is that: Its structure is simple, and when the abutting portion at the outer end of the bottom rod abuts against the inner wall of the furnace body, it can ensure that the vertical rod remains vertical and at the same time avoid the hanging member from shaking.

[0008] In the above technical solution, the upper end of the rod head is an inclined surface that slopes upward from the inside to the outside.

[0009] The beneficial effects of the above technical solution are as follows: In this way, the deposition of biomass pellet fuel on the upper end of the rod head can be avoided.

[0010] In the above technical solution, the upper inner end of the bottom rod is an inclined surface that slopes downward from the outside to the inside, and the edge of the grate is supported at the upper inner end of the bottom rod.

[0011] The beneficial effects of the above technical solution are as follows: In this way, the edge of the grate is supported at the upper inner end of the bottom rod, thereby extruding the bottom rod outward. At this time, the contact portion is in more stable contact with the inner wall of the furnace body.

[0012] In the above technical solution, the adjacent sides of the two adjacent rod heads extend to fit together, the adjacent sides of the inner ends of the two adjacent bottom rods extend to fit together, the adjacent sides of the outer ends of the two adjacent bottom rods have a vertically penetrating gap to jointly enclose an air vent with the inner wall of the furnace body, and there is a gap between the two adjacent vertical rods to form the first air inlet.

[0013] The beneficial effects of the above technical solution are as follows: In this way, an annular cavity is formed between the multiple vertical rods and the inner wall of the furnace body. The air below the assembled air inlet grate can enter the annular cavity through the air vents at the inner ends of the two adjacent bottom rods, and the air in the annular cavity can enter the receiving pool through the first air inlet. By setting gaps between the two adjacent vertical rods to jointly enclose the first air inlet, the assembly is made more convenient.

[0014] In the above technical solution, vertical grooves penetrating through are respectively recessed on both sides of each rod head, and the lower end of the groove is located outside the corresponding vertical rod. The grooves on the adjacent sides of the two adjacent rod heads jointly enclose the second air inlet.

[0015] The beneficial effects of the above technical solution are as follows: In this way, the grooves on the adjacent sides of the two adjacent rod heads enclose the second air inlet, so that the air in the annular cavity can enter above the assembled air inlet grate through the second air inlet.

[0016] The second object of the present invention is to provide a low-nitrogen gasification combustion device with a simple structure and capable of realizing low-nitrogen gasification combustion.

[0017] To achieve the above object, another technical solution of the present invention is as follows: A low-nitrogen gasification combustion device includes a furnace body and the assembled air inlet grate as described above. A horizontally disposed hanging ring is circumferentially protruded in the middle of the furnace body. The assembled air inlet grate is placed in the furnace body and is hung on the hanging ring through the hanging parts of a plurality of the hanging members. The assembled air inlet grate divides the interior of the furnace body into a combustion chamber located above and an ash cleaning chamber located below. An ash cleaning port communicating with the ash cleaning chamber is provided on the side wall of the furnace body, and an ash cleaning door is arranged at the ash cleaning port. A primary air inlet communicating with the ash cleaning chamber and a secondary air inlet communicating with the combustion chamber are provided on the side wall of the furnace body. Both the primary air inlet and the secondary air inlet are used to communicate with the air outlet of a blower, and air volume regulating valves are respectively arranged at the communication positions.

[0018] The beneficial effects of the above technical solution are as follows: The structure is simple, and the assembled air inlet grate is used in the furnace body, making its production convenient and maintenance more convenient. The combustible gas generated after the pyrolysis of biomass pellet fuel burns more fully with the air introduced from the secondary air inlet in the combustion chamber.

[0019] The above technical solution further includes a feeding auger. The discharge port of the feeding auger penetrates into the furnace body and is located in the middle of the interior of the combustion chamber. The feeding auger is used to feed biomass pellet fuel into the combustion chamber.

[0020] The beneficial effects of the above technical solution are as follows: The structure is simple, so that the biomass pellet fuel is piled up in a conical shape when fed into the accommodation pool, which is more conducive to the prior pyrolysis gasification of the biomass pellet fuel on the bottom wall of the accommodation pool.

[0021] In the above technical solution, a ring groove-shaped partition wall is convexly provided inward in the middle corresponding to the height direction of the combustion chamber. The partition wall and the side wall of the furnace body jointly enclose an annular cavity. The secondary air inlet communicates with the annular cavity. Air outlet holes communicating with the annular cavity are circumferentially and spacedly arranged at the partition wall, and the discharge end of the feeding auger passes through the annular cavity and enters the middle position inside the inner ring of the partition wall.

[0022] The beneficial effects of the above technical solution are as follows: The structure is simple, so that the air introduced from the secondary air inlet can be fully mixed with the combustible gas and burn violently in the area above the partition wall in the combustion chamber, and the air introduced into the combustion chamber through the second air inlet hole makes the combustible gas burn and have an open flame in the area below the partition wall in the combustion chamber, so that the combustible gas burns more fully, and the secondary air in the annular cavity can cool the discharge port of the feeding auger to prevent the biomass pellet fuel in the feeding auger from burning.

[0023] In the above technical solution, a dome is further provided at the upper end of the furnace body to seal the upper end of the furnace body, and a fire outlet is provided at the upper end of the side wall of the furnace body near the dome.

[0024] The beneficial effects of the above technical solution are as follows: In this way, the flame can be effectively gathered and guided, so that the flame generated by the primary combustion and the unburned CO can be fully fused with oxygen after sufficient secondary air distribution, and complete combustion can be achieved, realizing zero emission of CO, and at the same time, the combustion is more complete. Description of the Drawings

[0025] Figure 1 It is a front view of the assembled air inlet grate described in Embodiment 1 of the present invention;

[0026] Figure 2 It is a front view of the assembled air inlet grate described in Embodiment 1 of the present invention;

[0027] Figure 3 It is a side view of the hanging part described in Embodiment 1 of the present invention;

[0028] Figure 4 It is a front view of the hanging part described in Embodiment 1 of the present invention;

[0029] Figure 5 It is a bottom view of multiple hanging parts distributed around the inner wall of the furnace body in Embodiment 1 of the present invention;

[0030] Figure 6 It is a front view of the inner side of the hanging part in Embodiment 1 of the present invention;

[0031] Figure 7 It is a bottom view of multiple hanging parts distributed around the inner wall of the furnace body in Embodiment 1 of the present invention;

[0032] Figure 8 It is a structural schematic diagram of two grate plates of the assembled air inlet grate described in Embodiment 1 of the present invention;

[0033] Figure 9 It is a cross-sectional view of the low-nitrogen gasification combustion device described in Embodiment 2 of the present invention;

[0034] Figure 10 It is a schematic diagram of the distribution of carbon fire piles in the grate in Embodiment 2 of the present invention;

[0035] Figure 11 It is a cross-sectional view of the low-nitrogen gasification combustion device described in Embodiment 3 of the present invention.

[0036] In the figure: 1 assembled air inlet grate, 11 grate plate, 12 hanging parts, 121 vertical rod, 122 bottom rod, 123 rod head, 1231 notch, 1232 groove, 13 ventilation hole, 14 first air inlet hole, 15 second air inlet hole, 2 furnace body, 21 hanging ring, 22 combustion chamber, 22a primary combustion chamber, 22b secondary combustion chamber, 23 ash cleaning chamber, 231 ash cleaning port, 232 ash cleaning door, 24 primary air inlet, 25 secondary air inlet, 26 air volume regulating valve, 27 sandwich wall, 271 air outlet hole, 28 dome, 29 fire outlet, 3 blower, 4 feeding auger, 5 carbon fire pile. Detailed implementation mode

[0037] The principles and features of the present invention will be described below. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0038] Embodiment 1

[0039] As Figure 1 and Figure 2 shown, this embodiment provides an assembled air inlet grate, which includes a grate plate 11 and a plurality of hanging parts 12. The plurality of hanging parts 12 are all vertically arranged and distributed circumferentially. A hanging part is arranged on one side of the upper end of each hanging part 12 away from each other, and a supporting part is arranged on one side of the lower end of each hanging part 12 close to each other. The grate plate 11 is horizontally arranged between the plurality of hanging parts 12 and is supported on the supporting parts of the plurality of hanging parts 12 to jointly enclose a trough-shaped receiving pool. Biomass pellet fuel is used to be contained in the receiving pool. The hanging parts at the upper ends of the plurality of hanging parts 12 are used to be hung on the inner wall of the furnace body 2. A first air inlet hole 14 penetrating the side wall of the receiving pool is arranged on the hanging part 12 or between two adjacent hanging parts 12. A second air inlet hole 15 penetrating up and down is arranged between the upper ends of the hanging part 12 or between the upper ends of two adjacent hanging parts 12. By using a plurality of hanging parts to be hung on the furnace wall of the furnace body in a ring shape, and the grate plate is horizontally supported between the plurality of hanging parts. At this time, the grate plate and the plurality of hanging parts jointly enclose a trough-shaped structure, which is convenient to assemble and can be locally replaced and maintained when partially damaged. Since the grate plate is covered with ash dropping holes penetrating up and down (for the ash generated after the combustion of the biomass pellet fuel above the grate plate to fall downward. Since the biomass pellet fuel is stacked above the grate plate of this grate, the air below the grate plate will not flow upward through the ash dropping holes), and the air below this assembled air inlet grate can mainly enter the receiving pool through the area between the hanging part and the inner wall of the furnace body and finally through the first air inlet hole for the pyrolysis gasification of the biomass pellet fuel, and the remaining part can enter above the receiving pool through the second air inlet hole. The biomass pellet fuel at the bottom of the receiving pool is pyrolyzed into combustible gas. The combustible gas overflows upward above the receiving pool and mixes with air above the receiving pool and then burns violently to form an open flame.

[0040] In addition, the grate is characterized by air intake from the side, which can fundamentally reduce the conversion rate of N element in biomass pellet fuel and ultimately reduce the emission of NO x emissions. It can also reduce dust (since the primary air does not enter from below the biomass pellet fuel, it will not blow up the biomass pellet fuel to generate dust), reduce the emission of particulate matter in the emitted pollutants, and can effectively prevent or reduce coking.

[0041] Among them, after the assembled air intake grate is assembled, it can be integrally in the shape of a circular trough or a rectangular trough, and its specific shape depends on the cross-section of the furnace body.

[0042] Such as Figure 3 and Figure 4 shown, in the above technical solution, the hanging part 12 includes a vertical rod 121, a bottom rod 122 and a rod head 123. The vertical rod 121 is vertically arranged, and the bottom rod 122 is horizontally arranged in the inner and outer directions. The lower end of the vertical rod 121 is vertically connected to the middle of the upper end of the bottom rod 122. The inner end of the bottom rod 122 constitutes the supporting part of the hanging part 12, and the outer end of the bottom rod 122 constitutes the abutting part of the hanging part 12, which is used to abut against the inner wall of the furnace body 2. The upper end of the vertical rod 121 is connected to the inner lower end of the rod head 123. A horizontally penetrating notch 1231 is concavely provided in the outer lower end of the rod head 123, and the notch 1231 constitutes the hanging part of the hanging part 12. Its structure is simple. When the abutting part at the outer end of the bottom rod abuts against the inner wall of the furnace body, it can ensure that the vertical rod remains vertical and avoid the hanging part from shaking.

[0043] In the above technical solution, the upper end of the rod head 123 is an inclined surface that slopes upward from the inside to the outside, so as to avoid the deposition of biomass pellet fuel at the upper end of the rod head.

[0044] In the above technical solution, the inner upper end of the bottom rod 122 is an inclined surface that slopes downward from the outside to the inside. The edge of the grate 11 is supported at the inner upper end of the bottom rod 122. In this way, the edge of the grate is supported at the inner upper end of the bottom rod, thereby extruding the bottom rod outward. At this time, the abutting part abuts more firmly against the inner wall of the furnace body.

[0045] Such as Figure 5 and Figure 7As shown, in the above technical solution, the adjacent sides of two adjacent said rod heads 123 extend to be mutually attached, the inner ends of two adjacent said bottom rods 122 extend to be mutually attached on the side close to each other, there is a vertically penetrating gap on the side where the outer ends of two adjacent said bottom rods 122 are close to each other to jointly enclose an air vent 13 with the inner wall of the furnace body 2, and there is a gap between two adjacent said vertical rods 121 to form the first air inlet 14. In this way, there is an annular cavity between multiple vertical rods and the inner wall of the furnace body, and the air below the assembled air inlet grate can enter the annular cavity through the air vent formed by the air vents at the inner ends of two adjacent bottom rods. The air in the annular cavity can enter the receiving pool through the first air inlet. By setting a gap between two adjacent vertical rods to jointly enclose the first air inlet, it makes the assembly more convenient.

[0046] In the above technical solution, vertical grooves 1232 penetrating vertically are respectively recessed on both sides of each said rod head 123, and the lower end of the groove 1232 is located outside the corresponding said vertical rod 121. The grooves 1232 on the side where two adjacent said rod heads 123 are close to each other jointly enclose the second air inlet 15. In this way, the grooves on the side where two adjacent rod heads are close to each other enclose the second air inlet, so that the air in the annular cavity can enter above the assembled air inlet grate through the second air inlet.

[0047] As Figure 8 shown, in this embodiment, multiple said grate plates can be provided, and the multiple grate plates are evenly arranged in multiple hanging parts and supported at multiple supporting parts, so that the lower ends of the tubular parts formed by enclosing multiple hanging parts are blocked by the multiple grate plates to jointly form a trough shape.

[0048] Among them, the inner end and the outer end in this embodiment are referenced to the annular structure formed by enclosing multiple said hanging parts. The inner side of the ring is the inner end, and the outer side of the ring is the outer end. See the solid arrows in Figure 7 for details.

[0049] In this embodiment, the widths of the inner ends of the said rod heads and the bottom rods are both greater than the width of the vertical rods, and both sides of the two side rod heads and both sides of the inner ends of the bottom rods protrude from both sides of the vertical rods, and the grooves are arranged in the middle of the protruding positions on both sides of the rod heads. In this way, when two adjacent rod heads and two adjacent inner ends of the bottom rods are abutted, the first air inlet and the second air inlet can be enclosed.

[0050] Figure 7 The dotted arrow in

[0051] Embodiment 2

[0052] As Figure 9As shown in the figure, this embodiment provides a low-nitrogen gasification combustion device, which includes a furnace body 2 and the assembled air inlet grate 1 described in Embodiment 1. A horizontally disposed hanging ring 21 is circumferentially and convexly provided in the middle of the furnace body 2. The assembled air inlet grate 1 is placed in the furnace body 2 and is hung on the hanging ring 21 through the hanging parts of a plurality of the hanging members 12. The assembled air inlet grate 1 divides the interior of the furnace body 2 into a combustion chamber 22 located above and an ash cleaning chamber 23 located below. There is an ash cleaning port 231 on the side wall of the furnace body 2 that communicates with the ash cleaning chamber 23, and an ash cleaning door 232 is provided at the ash cleaning port 231. There is a primary air inlet 24 on the side wall of the furnace body 2 that communicates with the ash cleaning chamber 23 and a secondary air inlet 25 that communicates with the combustion chamber 22. Both the primary air inlet 24 and the secondary air inlet 25 are used to communicate with the air outlet of the fan 3, and air volume regulating valves 26 are respectively provided at the connection points. Its structure is simple, and the use of the assembled air inlet grate in the furnace body makes its production convenient and maintenance more convenient. Moreover, the biomass pellet fuel in the holding tank can be pyrolyzed into combustible gas, and the combustible gas burns in the combustion chamber and further burns under the air introduced through the secondary air inlet.

[0053] The above technical solution further includes a feeding auger 4. The discharge port of the feeding auger 4 penetrates into the furnace body 2 and is located in the middle of the interior of the combustion chamber 22. The feeding auger 4 is used to feed biomass pellet fuel into the combustion chamber 22. Its structure is simple. In this way, the biomass pellet fuel is piled up in a conical shape when being fed into the holding tank, which is more conducive to the preferential pyrolysis gasification of the biomass pellet fuel on the bottom wall of the holding tank (wherein, the structure of the feeding auger belongs to the prior art and will not be elaborated here).

[0054] In the above technical solution, a ring groove-shaped clamping wall 27 is convexly provided inward in the middle corresponding to the height direction of the combustion chamber 22. The clamping wall 27 and the side wall of the furnace body 2 jointly enclose an annular cavity. The secondary air inlet 25 communicates with the annular cavity. Air outlet holes 271 communicating with the annular cavity are circumferentially and spacedly arranged at the clamping wall 27. And the discharge end of the feeding auger 4 passes through the annular cavity and enters the middle position inside the clamping wall 27. Its structure is simple. In this way, the air introduced through the secondary air inlet can be fully mixed with the combustible gas and burn violently in the area above the clamping wall in the combustion chamber, and the air introduced into the combustion chamber through the second air inlet hole makes the combustible gas burn and produce an open flame in the area below the clamping wall in the combustion chamber. This makes the combustion of the combustible gas more complete, and the secondary air in the annular cavity can cool the discharge port of the feeding auger to prevent the biomass pellet fuel in the feeding auger from burning.

[0055] Among them, in this embodiment, the combustion chamber can be divided into a primary combustion chamber and a secondary combustion chamber. The area below the sandwich wall in the combustion chamber is the primary combustion chamber, and the area above the sandwich wall is the secondary combustion chamber. Among them, the second air inlet hole introduces primary air into the primary combustion chamber. At this time, the combustible gas is ignited in the primary combustion chamber and an open flame appears. The unburned combustible gas enters the secondary combustion chamber and is more fully mixed with the secondary air and burns violently.

[0056] As Figure 10 shown, in this embodiment, a feeding auger (whose driving motor speed is adjustable) is provided between the primary combustion chamber and the secondary combustion chamber to send the biomass pellet fuel to the central position of the furnace. During combustion, the biomass pellet fuel gradually forms a conical carbon fire pile 5 (substantially formed by the accumulation of carbonized biomass pellet fuel) in the grate. The feeding auger can be manually controlled to adjust the feeding speed of the biomass pellet fuel according to the heat demand, so that the biomass pellet fuel evenly falls to the top of the carbon fire pile and spreads downward and outward along the conical slope. That is, the newly added biomass pellet fuel is on the conical surface of the carbon fire pile, and the carbon fire pile itself burns gradually from bottom to top. That is, the newly added biomass pellet fuel pyrolyzes and gasifies on the conical surface of the carbon fire pile, and at the same time is carbonized into the upper surface of the carbon fire pile and overflows flammable gas upward. The primary air enters the primary combustion chamber from the periphery of the grate through the second air inlet hole, so as to form a suspended open flame above the conical carbon fire pile [the flammable gas generated by the pyrolysis and gasification of the biomass pellet fuel is fully mixed and burned with the primary air in the primary combustion chamber, and burns suspended at a distance of 20 - 30 mm from the surface of the fixed carbon fire pile. Due to the conical surface of the carbon fire pile, the contact area between the flammable gas and the primary air is increased to a large extent, so that the flammable gas can be more fully burned in the primary combustion chamber]. And this low-nitrogen gasification combustion device introduces sufficient secondary air into the secondary combustion chamber through the secondary air inlet, so that the flammable gas can be further fully burned in the secondary combustion chamber and all be converted into heat (especially enabling the full combustion of CO in the flammable gas, achieving zero emission of CO, and thus being safer and more environmentally friendly). Among them, Figure 10 the dotted arrow in Figure 7 is similar to the dotted arrow in

[0057] Both the primary air and the secondary air of the low-nitrogen gasification combustion device provided in this embodiment are provided by a blower (an air inlet flow regulating valve may be provided at the air inlet of the blower (it can be an air inlet flow regulating baffle, which belongs to the prior art and will not be elaborated here. It is used to regulate the total air inlet flow rate at the air inlet of the blower). The air outlets of the blower are respectively communicated with the primary air inlet and the secondary air inlet, and air volume regulating valves are respectively arranged at the communication points, so that the flow rate ratio of the primary air and the secondary air can be adjusted (the distribution principle of the primary air and the secondary air is: the flow rate of the primary air should be as small as possible, and the flow rate of the secondary air should be as large as possible, but neither should be too large or too small). The primary air of the low-nitrogen gasification combustion device provided in this embodiment enters the grate from the first air inlet hole at the edge of the grate, which can maximize the pyrolysis gasification of the biomass pellet fuel on the surface of the carbon fire pile. When the generated combustible gas burns suspended in the primary combustion chamber, it will not have a great impact on the temperature of the upper surface of the carbon fire pile. The relatively small primary air inlet flow rate can also make the carbon fire pile pyrolyze under a relatively gentle state, so that the inside of the carbon fire pile maintains a relatively low pyrolysis temperature. The relatively low pyrolysis temperature can greatly reduce the conversion rate of N element in the biomass pellet fuel, so as to reduce NO x emissions from the source, and at the same time can effectively prevent or reduce the occurrence of coking in the grate.

[0058] Embodiment 3

[0059] As Figure 11 shown, similar to Embodiment 1, the difference is that a dome 28 for sealing the upper end of the furnace body 2 is further provided at the upper end of the furnace body 2 described in the above technical solution. An outlet 29 is provided at the upper end of the side wall of the furnace body 2 near the dome 28. In this way, the flame can be effectively gathered and guided, so that the flame generated by the primary combustion and the unburned CO are fully mixed with oxygen after sufficient secondary air distribution and completely burned, realizing zero CO emissions, and at the same time the combustion is more complete.

[0060] Figure 11 The dotted arrow in the figure indicates the flow direction of the flame.

[0061] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A assembled air inlet grate, characterized in that It includes a grate plate (11) and a plurality of hanging members (12). The plurality of hanging members (12) are all vertically arranged and distributed circumferentially. On one side of the upper end of each hanging member (12) that is far from each other, there is a hanging portion. On one side of the lower end of each hanging member (12) that is close to each other, there is a supporting portion. The grate plate (11) is horizontally arranged between the plurality of hanging members (12) and is supported on the supporting portions of the plurality of hanging members (12) to jointly enclose a trough-shaped receiving pool. Biomass pellet fuel is used to be contained in the receiving pool. The hanging portions at the upper ends of the plurality of hanging members (12) are used to hang on the inner wall of the furnace body (2). There is a first air inlet hole (14) penetrating through the side wall of the receiving pool on the hanging member (12) or between two adjacent hanging members (12). There is a second air inlet hole (15) vertically penetrating between the upper end of the hanging member (12) or between the upper ends of two adjacent hanging members (12); The hanging member (12) includes a vertical rod (121), a bottom rod (122) and a rod head (123). The vertical rod (121) is vertically arranged, and the bottom rod (122) is horizontally arranged in the inner and outer direction. The lower end of the vertical rod (121) is vertically connected to the middle of the upper end of the bottom rod (122). The inner end of the bottom rod (122) constitutes the supporting portion of the hanging member (12), and the outer end of the bottom rod (122) constitutes the abutting portion of the hanging member (12), which is used to abut against the inner wall of the furnace body (2). The upper end of the vertical rod (121) is connected to the inner lower end of the rod head (123). A horizontally penetrating notch (1231) is concavely provided in the outer lower end of the rod head (123), and the notch (1231) constitutes the hanging portion of the hanging member (12); The upper end of the rod head (123) is an inclined surface that slopes upward from the inside to the outside; The inner upper end of the bottom rod (122) is an inclined surface that slopes downward from the outside to the inside; The sides of two adjacent rod heads (123) that are close to each other extend to fit together. The inner ends of two adjacent bottom rods (122) that are close to each other extend to fit together. There is a vertically penetrating gap between the outer ends of two adjacent bottom rods (122) that are close to each other to jointly enclose a ventilation hole (13) with the inner wall of the furnace body (2). There is a gap between two adjacent vertical rods (121) to constitute the first air inlet hole (14); Vertically penetrating grooves (1232) are respectively concavely provided on both sides of each rod head (123), and the lower end of the groove (1232) is located outside the corresponding vertical rod (121). The grooves (1232) on the sides of two adjacent rod heads (123) that are close to each other jointly enclose the second air inlet hole (15).

2. The assembled air inlet grate according to claim 1, wherein, The edge of the grate plate (11) is supported at the inner upper end of the bottom rod (122).

3. A low-nitrogen gasification combustion device, characterized in that, Comprising a furnace body (2) and the assembled air inlet grate (1) as described in claim 1 or 2, a horizontally disposed hanging ring (21) is circumferentially and convexly provided in the middle of the furnace body (2). The assembled air inlet grate (1) is placed inside the furnace body (2) and is hung on the hanging ring (21) through the hanging parts of a plurality of the hanging members (12). The assembled air inlet grate (1) divides the interior of the furnace body (2) into a combustion chamber (22) located above and an ash cleaning chamber (23) located below. The side wall of the furnace body (2) has an ash cleaning port (231) communicating with the ash cleaning chamber (23), and an ash cleaning door (232) is provided at the ash cleaning port (231). The side wall of the furnace body (2) has a primary air inlet (24) communicating with the ash cleaning chamber (23) and a secondary air inlet (25) communicating with the combustion chamber (22). Both the primary air inlet (24) and the secondary air inlet (25) are used to communicate with the air outlet of a blower (3), and air volume regulating valves (26) are respectively provided at the communication positions.

4. The low-nitrogen gasification combustion device according to claim 3, wherein, It further comprises a feeding auger (4). The discharge port of the feeding auger (4) penetrates into the furnace body (2) and is located in the middle of the interior of the combustion chamber (22). The feeding auger (4) is used to feed biomass pellet fuel into the combustion chamber (22).

5. The low nitrogen gasification combustion device according to claim 4, characterized in that, A circumferentially grooved clamping wall (27) is convexly provided inwardly in the middle corresponding to the height direction of the combustion chamber (22). The clamping wall (27) and the side wall of the furnace body (2) jointly enclose an annular cavity. The secondary air inlet (25) communicates with the annular cavity. Air outlet holes (271) communicating with the annular cavity are circumferentially and spacedly provided at the clamping wall (27), and the discharge end of the feeding auger (4) passes through the annular cavity and enters the middle position inside the clamping wall (27).

6. The low-nitrogen gasification combustion device according to claim 5, characterized in that, A dome (28) for sealing the upper end of the furnace body (2) is further provided at the upper end of the furnace body (2). An outlet opening (29) is provided at the upper end of the side wall of the furnace body (2) near the dome (28).

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