CN113294785A - Chain grate gasification device using whole bundle of wrapped crop straw as fuel - Google Patents

Abstract

The invention relates to a traveling grate gasification device taking a whole bundle of wrapped crop straws as fuel, which can quickly ignite the whole bundle of wrapped crop straws entering a traveling grate (12) through an ignition device with a fan (18), gasify the whole bundle of wrapped crop straws (2) for a long time at low intensity and low temperature on the traveling grate (12) of the traveling grate gasification device taking the whole bundle of wrapped crop straws as fuel, effectively avoid the combustion to form coking, thereby retaining the fertilizer value of combustion ash residues of the crop straws, discharge flue gas generated by gasification in the horizontal direction through a flue gas discharge pipeline (14) and enter a vortex post-combustion module (58) for continuous combustion, and improve the combustion quality and the thermal efficiency by combining other technologies. The hot air chamber (22) between two layers of top plates arranged above the traveling grate (12) can be used as a primary air supply preheater of a traveling grate gasification device taking whole bundles of crop straws as fuel to realize air preheating.

Description

Chain grate gasification device using whole bundle of wrapped crop straw as fuel

Technical Field

The invention provides a device which enables whole bundles of crop straws to be gasified and combusted on a chain grate for a long time at low temperature and low intensity, the low temperature can prevent ash from coking or melting, so that the high fertilizer value of the straw ash is kept, and the low-intensity and low-flow-rate smoke can reduce the dust content of tail smoke. The flue gas generated by the gasification of the device can be discharged in a horizontal side direction, the output performance of cleaner combustion and higher efficiency can be realized by the downstream flue gas combustion device comprising the vortex supercharging combustion module, and the device is particularly suitable for converting the existing boiler system from fossil fuel into biomass fuel such as crop straws.

Background

According to the patent of cn201921249917.x and the like, the boiler using biomass including crop straws as fuel is to mechanically segment and crush the whole bundle of wrapped crop straws before combustion, and as a result, the flying straws or scattered straw particles cannot stably stay in a combustion bed to be sufficiently combusted, but fly into the pipeline or a heat exchange surface and the like of a combustion system along with flue gas, so that the tail flue gas emission value is deteriorated.

More air capable of burning the straws is gathered around the scattered straws, so that the low-temperature smoldering of the straw fuel is difficult to realize generally, and the combustion value of the combustible components in the flue gas during downstream combustion is greatly reduced after the combustible components are burnt.

The straw burning is accompanied with a large amount of flames, so that uncontrollable high temperature can occur at partial point positions in a burning area, nitrogen monoxide is easily generated, valuable low-melting-point mineral nutrients and the like in the burning ash of the crop straws can be lost due to the high temperature, the coke residue can be formed at the high temperature, the difficulty in utilizing and disposing the burning ash of the straws is increased, and the important plant nutrients such as potassium in the cultivated soil can be gradually exhausted due to the fact that the high temperature is high.

The combustion temperature and the combustion time of the flue gas in the vortex post-combustion device and the like can be effectively controlled to realize clean combustion, a biomass boiler which can effectively and continuously gasify and combust a large number of whole bundles of wrapped crop straws on a chain grate and almost horizontally and laterally discharge the produced flue gas for downstream combustion is not available at present, and a thermodynamic system which combines a chain grate gasification combustion system with the vortex post-combustion device and the like with the residence time of 2 seconds is not available at present.

According to the patent of CN202011175398.4, although the whole bundle of wrapped straws can be gasified at low temperature, low strength and low speed and the flue gas is discharged in a horizontal side direction, when the whole bundle of wrapped straws is too much, the whole bundle of wrapped straws can be mutually extruded due to gravity superposition to increase the straw density and influence the gasification combustion effect, so that the heat output amplification is limited.

In known combustion systems such as CN201911376547.0 traveling grate stoker, the flue gas is discharged upwards along the vertical direction for continuous combustion, and there are also devices for discharging the flue gas downwards for continuous combustion, but these devices are limited by the structure and cannot make the downstream combustion chamber large enough and ensure the flue gas to stay and burn for a long enough time, so the flue gas cannot achieve sufficient and clean combustion.

This may also be another reason why it is not currently known to use a larger, independently arranged, wide grate-grate straw gasification unit, which does not include water cooling, as part of a modular crop straw thermalization system.

Disclosure of Invention

The invention aims to invent a gasification combustion device with a chain grate structure, which can directly use a large number of whole bales of crop straws as fuel, can effectively and continuously gasify for a long time at low strength and low temperature, can almost laterally discharge flue gas generated by gasification in a horizontal direction, continuously complete the sufficient and clean combustion of the downstream, and can realize higher heat efficiency and higher heat output.

The device of the invention uses a well-known chain grate and continuously and directly uses a large amount of whole bales of crop straws as fuel for gasification combustion, the flue gas produced by gasification can be almost horizontally and laterally discharged and downstream clean combustion is carried out, and the width and the length of the chain grate of the device of the invention can adopt large sizes so as to realize large amount of gasification combustion and large heat power output.

The device pushes the whole bundle of wrapped crop straws into the chain grate side by side without unpacking and chopping the whole bundle of crop straws firstly, and a large amount of straws are gasified on the chain grate at the same time point, so that enough combustible smoke can be produced even if the gasification intensity is low.

In the actual operation, the problem of coking hardly occurs when the gasification time of the high-quality straw fuel exceeds 60 minutes.

Therefore, in order to ensure that the gasification time of the straw fuel is not less than 1 hour, the minimum length of the chain grate in meters can be calculated according to the following formula:

the travelling grate gasification device taking the whole bundle of wrapped crop straws as fuel is designed according to the principle, the gasification time of each bundle of crop straws can be prolonged by adjusting combustion air supply through the travelling grate, when the travelling grate gasification device taking the whole bundle of wrapped crop straws as fuel operates at the maximum designed combustion power, the gasification time of the round whole bundle of wrapped crop straws with the diameter of 1.3-1.45m is at least 60 minutes, the gasification time of the square whole bundle of wrapped crop straws with the diameter of 1.2x0.8x2.4m is at least 90 minutes, the gasification time of the square whole bundle of wrapped crop straws with the diameter of 1.2x1.3x2.4m can be at least 150 minutes, and the like, so that the low-strength and low-temperature gasification of the crop straws with enough duration can be realized.

When only the broken crop straws are combusted at the last 1.5 meters of the chain grate, the primary air can be adjusted by the isobaric air supply chamber arranged at the bottom of the chain grate so as to control the crop straw gasification speed at the position.

The combustible flue gases produced by the gasification are discharged through lateral flue gas discharge channels arranged in an almost horizontal direction into a downstream, external combustion space or device, in which a downstream, external swirl post-combustion module is preferred.

The cross section of the flue gas discharge channel is designed to be gradually narrowed, so that the sufficient flue gas flow velocity can be ensured.

When the device of the invention uses round and round whole bale crop straw fuel, the round whole bale crop straw can form approximate honeycomb arrangement under the driving force of the sliding shield of the chain grate when the round whole bale crop straw falls on the chain grate with the round plane.

In this way, the gaps between the round whole bales of crop straw can be minimized, but the flue gas or the mixture of the flue gas and the air can enter the gaps from the lower part of the round whole bales of crop straw and form a combustion chamber.

The smoldering area closest to the bottom of the chain grate can be covered by the straws at the upper part, so that the hot flue gas can be prevented from directly rising to the top, the heat of the smoldering area can be better used for the gasification of the straws covered at the upper part, the combustion air quantity required by the gasification is reduced to the maximum extent, and the CO in the combustible flue gas generated by the gasification is reduced₂And nitrogen content and realizes high calorific value of the gasified and produced flue gas.

The whole bale of crop straw is obliquely fed above a sliding push shield which pushes the straw from a feeding cartridge, and then the position of the whole bale of crop straw can be corrected through the sliding push shield.

In order to ensure that the entire bale of crop straw which has just been pushed onto the traveling grate starts to burn immediately from below, an ignition channel with an opening is arranged closest to the rear side of the traveling grate, in the invention the hot flue gases in the hot flue gas channel are pressurized by mixing in fresh air coming in from the air inlet, hot flue gases adjusted to a target temperature of 480 ℃ to 600 ℃ measured in front of the fan and blown from below into the entire bale of crop straw which has just been pushed in, in such a way that the entire bale of crop straw is ignited.

The hot flue gases required for ignition can be introduced through a hot flue gas channel of more than 4m length, which sucks combustion air in a controlled temperature range in an amount that is well in excess of the actual demand in order to make the hot flue gases burn substantially completely and is pressurized by a fan into the ignition channel.

The fan can be designed to be free from the influence of heat radiation and chemical substances so as to prolong the service life of the fan, the rear panel of the fan and the rear part of the fan impeller can be cooled by air, and cooling air is sucked in through a small blade on the back of the fan impeller through a gap between a fan shaft and the rear panel of the fan or other openings of the fan and the like.

The furnace wall of the chain grate gasification device taking whole bundles of crop straws as fuel adopts materials such as common refractory bricks.

The gasification chamber above the traveling grate and the upper edge of the flue gas discharge channel of the apparatus according to the invention are provided with a first, lower layer of a top plate, which is mainly made of a refractory material and may or may not contain water cooling, which covers the entire traveling grate and the flue gas discharge channel in an almost horizontal direction and is fixed to the side wall of the furnace, which is made of refractory bricks.

The first layer of roof in the implementation of the invention preferably adopts a roof mode of an architectural algae well beam structure. A second roof plate, which does not contain water cooling, is arranged above a space above the first roof plate and is fixed to the furnace side wall made of refractory bricks.

When the whole bundle of crop straws is gasified and combusted, a small amount of heat can penetrate upwards through the first layer of top plate and enter the space between the first layer of top plate and the second layer of top plate.

Fresh air enters a space between the first layer top plate and the second layer top plate from an air inlet or other places between the first layer top plate with or without water cooling and the second layer top plate without water cooling, is preheated and then enters the bottom of the traveling grate as primary combustion air supply.

The chain grate of the invention can be formed by modular units with the same size, and the modular units can be delivered to a thermodynamic system site for assembly after being prefabricated in a factory.

Drawings

FIG. 1 is a side view of the apparatus of the present invention, which is mainly composed of a traveling grate gasification apparatus using whole bales of crop straw as fuel located on the left side (front) and a feeding cartridge clip located on the right side (rear) and used for straw bale drying and waste flue gas dust removal.

Fig. 2 shows in plan view a steam boiler system with two traveling grate stoker gasifiers fuelled with bales of crop straw.

FIG. 3 shows a cross-sectional side view of a traveling grate gasification unit fueled by a bale of crop straw.

Fig. 4 shows a cross-sectional view of the flue gas discharge channel (14) of the grate-fed gasification unit fueled by bales of crop straw, directed towards the post-swirl combustion module (58).

Fig. 5 shows a complete top view of a traveling grate stoker gasification unit fueled by a whole bale of crop straw.

Fig. 6 is a side view of a chain grate gasification device using whole bales of crop straw as fuel, which is mainly constructed by refractory materials and the like and is arranged at the lower part of the chain grate gasification device in a top plate construction mode of an algae well beam structure, and is provided with a first layer top plate without water cooling and a second layer top plate without water cooling arranged at the upper part of the chain grate gasification device.

Fig. 7 shows in a side view the design of the sealing structure between two adjacent algae well beam structure top plates (15) and a long algae well beam structure top plate (66) of a first layer top plate which is mainly made of refractory materials and does not contain water cooling and is positioned at the lower part of the traveling grate stoker gasification device taking whole bundles of crop straws as fuel and adopting the structure mode of the algae well beam structure top plate.

Fig. 8 shows in cross-section a partial configuration of a traveling grate stoker gasification unit fueled by a whole bale of crop straw comprising furnace walls (16).

Figure 9 shows the fan (18) in the operating position.

Fig. 10 shows a cross-sectional view of the ignition device comprising the ignition channel (11).

In the figure: 1-loading vehicle with front-mounted bale turning function, 2-whole bale of crop straw, 3-loading elastic clip capable of being used for drying straw bale and removing dust from waste flue gas, 4-slideway, 5-hot air channel, 6-moisture chimney, 7-locking door, 8-automatic fire extinguisher, 9-elastic frame, 10-sliding push shield, 11-ignition channel, 12-chain grate, 13-ignition port, 14-flue gas discharge channel, 15-top plate of algal well beam structure, 16-furnace wall, 17-hot flue gas channel, 18-fan, 19-air inlet, 20-igniter, 21-gasification chamber, 22-hot air chamber, 23-corrugated steel plate, 24-heat insulation layer, 25-hot air conduit for combustion, 26-grate air supply fan, 27-fresh air, 28-circular arc surface, 29-bent steel plate, 30-longitudinal fixing piece, 31-radiating fin, 32-heat insulation material layer, 33-fireproof concrete layer, 34-stainless steel hook, 35-plywood, 36-expansion joint, 37-graphite fiber end socket, 38-ceramic block, 39-high temperature resistant block heat insulation material, 40-steel beam, 41-threaded pull rod, 42-fan base, 43-fan bracket, 44-fan shell, 45-fan impeller, 46-fan rear panel, 47-small blade, 48-soft seal, 49-movable support rod, 50-fan shaft, 51-motor base plate, 52-fan cooling air inlet, 53-stainless steel shell and 54-vermiculite heat insulation layer, 55-fire-resistant special-shaped blocks, 56-whole bundle of crop straw advancing direction, 57-ash conveyer belt, 58-vortex post-combustion module, 59-section reducing device, 60-vortex post-combustion module with superheated steam, 61-gas-steam heat exchange module, 62-tail flue gas heat exchanger, 63-bag dust remover, 64-isobaric air supply chamber, 65-grate module unit, 66-long algae well beam structure top plate, 67-flue gas nozzle, 68-preheated secondary air supply pipeline, 69-speed adjustable fan, 70-secondary air supply port, 71-metal baffle, 72-U-shaped sealing cover, 73-metal V-shaped plate, 74-air controller, 75-flue gas, 76-ceramic material cementing agent, 77-tertiary air, 78-combustion chamber.

Detailed Description

The invention will be explained in more detail below by way of an example of a steam boiler with a combustion power of 60MW, in which a whole bundle of crop stalks is used as fuel.

Fig. 1 shows an overview of the traveling grate stoker gasification unit of the invention fueled by whole bales of crop straw, which is intended to achieve the production of combustible flue gas with up to 30MW of combustion power through long term low temperature, low intensity gasification.

Before the whole bundle of crop straws (2) enters the chain grate gasification device taking the whole bundle of the crop straws as fuel, the whole bundle of the crop straws is dried and preheated in a feeding cartridge (3) which can be used for drying the straw bundle and removing dust from waste flue gas, and simultaneously, the tail flue gas of the chain grate gasification device taking the whole bundle of the crop straws as fuel can be removed dust.

The grate-grate gasification device using the whole bundle of wrapped crop straw as fuel can use round or square whole bundle of wrapped crop straw (2), and round, 1.2x0.8x24m and 1.2x1.3x2.4m square whole bundle of wrapped crop straw (2) with the diameter of 1.3-1.45m are preferably used in the embodiment.

The whole bundle is packaged by a loading vehicle (1) with a front-mounted bag turning functionAfter the crop straws (2) are put into the feeding clip (3) which is designed according to CN202120299452.X and can be used for straw bale drying and waste flue gas dust removal, hot air or tail waste heat flue gas can be used for drying the whole bale of crop straws, and the tail waste heat flue gas can be used for removing dust when the whole bale of crop straws are dried by using the tail waste heat flue gas as a heat source. The whole bundle of wrapped crop straw can be a square bundle or a round bundle, but the density is less than 95kg/m³The round whole bale crop straw is more suitable for hot air or tail waste heat smoke to pass through.

Because the round plane of the round whole bundle of wrapped crop straws (2) is placed on the slideway (4) made of Polytetrafluoroethylene (PTFE) and the like, the movement is easier because of the air cushion effect. The waste flue gas which wraps the crop straws and takes away the moist moisture is discharged through a moist chimney (6).

A lock-catch door (7) is arranged at the joint of the chain grate gasification device taking the whole bundle of crop straws as fuel and the feeding clip (3) which can be used for straw bundle drying and waste smoke dust removal, and the automatic fire extinguishing device (8) is used for extinguishing fire. The device can be used in the construction of devices that meet higher combustion output and operate under supervision.

When the whole bundle of wrapped crop straws (2) from the feeding clip (3) which can be used for straw bale drying and waste smoke dust removal are fed into the sliding push shield (10), the whole bundle of wrapped crop straws firstly fall on the elastic frame (9) of a fixed shaft and fall to the front edge of the bottom sliding push shield (10) along with the elastic frame (9) of the fixed shaft, then the whole bundle of wrapped crop straws is pushed into the chain grate (12) by the sliding push shield (10) and is ignited at an ignition port (13) which is positioned above an ignition channel (11) at the forefront of the chain grate (12), and the structure mode is such that the device can also use square fuel of the whole bundle of wrapped crop straws (2).

The large amount of straw above the chain grate (12) can prevent the flue gas from rapidly flowing upwards, so the whole bundle of crop straw (2) receiving preheated air from the lower part of the chain grate (12) is basically in a smoldering state, thus being more beneficial to the gasification of the whole bundle of crop straw (2) and minimizing the consumption of air supply, and the result is that CO in the flue gas generated by the gasification is₂Has small ratio to nitrogen component, and high heat productivity is favorable for downstreamClean combustion and high thermal efficiency are achieved.

The traveling grate (12) in this embodiment has a width of about 5.4m and a length of about 18.6m, and can accommodate 50 round whole bales of 1.4m diameter crop straw for simultaneous gasification.

The minimum length of the chain grate stoker according to the previous formula is:

therefore, when the chain grate length in this example is set to 18.8m, the gasification intensity is reduced and coking and dust are reduced.

The gasification time of the whole bundle of wrapped crop straw (2) is about 74 minutes at full load power output, and can be as long as several hours at low load operation. Thus, the whole bale of crop straw (2) can realize low-strength and low-temperature gasification, and hardly generates any coking. The temperature of the ash discharged by gasification is lower than 300 ℃, so that the ash is conveyed out of the chain grate gasification device taking the whole bundle of crop straws as fuel by the common high-temperature resistant ash conveyer belt (57) in a dry state. Meanwhile, the outflow speed of the flue gas generated by gasification is low, so that the dust content in the downstream flue gas can be reduced to the maximum extent.

According to the steam boiler which is used for small-scale power generation and comprises two chain grate gasification devices taking whole bundles of wrapped crop straws as fuel, each chain grate gasification combustion module can be simultaneously fed with 4 rows of whole bundles of wrapped crop straws (2), the combustion output power of the chain grate gasification devices during low-temperature and low-intensity gasification can reach 60MW, and in the embodiment, flue gas from the two chain grate gasification devices taking whole bundles of wrapped crop straws as fuel is almost horizontally and laterally discharged into a convergent vortex post-combustion module (58) designed according to CN201811069841.6 and a vortex post-combustion module (60) with superheated steam for continuous combustion.

In the embodiment, any one of the two chain grate gasification devices taking the whole bundle of wrapped crop straws as fuel can be stopped at any time according to the requirement of output, and when the stopped chain grate gasification combustion module is restarted, the vortex post-combustion module (58) can change the output power of the system at any time according to the requirement without generating the problem of emission deterioration of the whole thermodynamic system.

According to the design of CN201811060700.4, 3 independent gas-steam heat exchange modules (61) of 18 tons/hour are arranged in the embodiment, and the heat exchange process is always carried out on the whole heat exchange surface, so that the highest heat exchange efficiency is obtained.

The tail flue gas heat exchanger (62) of this embodiment is designed according to CN201910297070.0, and the hot-air that the heat transfer produced can be used for dry whole bundle package crop straw (2) in the material loading cartridge clip or can also remove dust to tail waste flue gas, and the dust removal to tail flue gas can also be gone on simultaneously in combination with sack cleaner (63).

The chain grate gasification combustion device which takes the whole bundle of crop straws as fuel and almost horizontally releases flue gas eliminates the function transition of the combustion system with the existing design structure through an additional process, thereby realizing the maximization of the system efficiency of the device.

According to fig. 3, the sliding push shield (10) for pushing four rows of whole bale crop straws adopts a circular arc-shaped surface (28), and the sliding push shield (10) adopts the circular arc-shaped surface (28) for pushing the whole bale of crop straws (2) to be arranged like a honeycomb on the chain grate (12), so that the gap between the whole bale of crop straws (limited to the round bales) (2) is minimized, and most of the combustion air from the bottom of the chain grate (12) blows into the whole bale of crop straws (2).

The fuel begins to burn after the combustion air entering the space between the whole bundle of wrapped crop straws (2) fully contacts with the fuel, the whole bundle of wrapped crop straws (2) can expand to a certain degree after the polyethylene net or rope binding the whole bundle of wrapped crop straws is burnt out, and the straws of the straws are in a dog-tooth staggered shape to a certain degree, so that the straws are prevented from flying together with the flowing of the smoke gas to reduce the dust amount in the downstream smoke gas.

An ignition channel (11) crossing the chain grate (12) is arranged at the forefront part of the chain grate (12), the ignition channel (11) can realize that the whole bundle of crop straws (2) enters the chain grate (12) to start gasification and combustion, and 480-600 ℃ hot flue gas is blown into the whole bundle of the bundle of crop straws (2) from the lower part of the chain grate (12) through an ignition port (13) and starts combustion.

The traveling grate (12) in this embodiment has a width of 5.4m and a length of 18.9m, and is assembled from 8 grate module units (65) of about 2.3m, manufactured at the factory, on site, the width of the grate module units (65) being suitable for common truck and container transportation.

The furnace wall (16) of the present embodiment is constructed of refractory bricks or the like in a known manner, and the furnace wall (16) further includes a free space in which a high-temperature resistant block heat insulator (39) can be placed.

In the embodiment, an upper layer of top plate and a lower layer of top plate are arranged on the upper sides of a gasification chamber (21) and a smoke discharge channel (14) above a traveling grate (12), a first layer of top plate at the lower part adopts a top plate with an algae well beam structure, a second layer of top plate at the upper part is composed of a supporting corrugated steel plate (23) and a heat insulation layer (24), and a hot air chamber (22) between the two layers of top plates is used as a combustion air preheater of the device.

The furnace wall (16) of the chain grate gasification device taking the whole bundle of the crop straws as the fuel is mainly constructed by refractory bricks, high-temperature-resistant heat-insulating material blocks and the like. A first layer of algae well beam structure top plate (15) which is mainly made of refractory materials and the like and does not contain water cooling and a long algae well beam structure top plate (66) are arranged in the space above the chain grate and the smoke discharge channel, and the top plates cover the smoke discharge channel (14) extending above the whole chain grate (12) and almost horizontally and are fixed on a furnace wall (16). A water-free, water-cooled second ceiling plate made of a heat insulating layer (24) and a corrugated steel plate (23) is arranged above the hot air chamber (22) above the first ceiling plate, and the second ceiling plate is also fixed to a furnace wall (16) made of refractory bricks or the like.

Fresh air enters a hot air chamber (22) between the first layer top plate and the second layer top plate from an air inlet (19) between the first layer top plate and the second layer top plate which does not contain water cooling, is heated and then is sucked out by a grate air supply fan (26) through a hot air duct (25) for combustion and a preheated secondary air supply duct (68).

The opening of the almost horizontal flue gas discharge channel (14) is at a minimum distance of about 0.5m above the whole bale of crop straw (2), the flue gas flows to the flue gas discharge channel (14) at a speed of less than 4m/s, the bottom of the flue gas discharge channel (14) is designed to be beveled to avoid ash dust deposition, and almost no dust flows out with the flue gas. The gasification of whole bales of crop straw (2) can be optimally regulated by means of 14 isobaric air supply chambers (64) below the traveling grate (12).

Fig. 4 shows a flue gas nozzle (67) with a gradually narrowing flue gas discharge channel (14) to increase the flow rate of flue gas (75) discharge, the flue gas nozzle (67) being provided with a cross-sectional reduction device (59) to change the cross-sectional area of flue gas (75) outflow and thus the system heat output.

A plurality of secondary air supply openings (70) are arranged in the smoke discharge channel (14), wherein the secondary air supply is not selected to be sucked under negative pressure but is preferably blown into the smoke discharge channel (14) under pressure by a speed-adjustable fan (69) so that the secondary air supply can be better mixed with smoke (75) in the smoke discharge channel (14).

The traveling grate stoker gasification device using whole bales of crop straw as fuel can reduce NOx emission by supplying combustion air supply step by step, wherein secondary air supply passes through a flue gas discharge channel (14) and tertiary air supply (77) passes through a vortex post-combustion module (58).

In the embodiment, the round whole bundle of wrapped crop straws (2) is used, and when the flat surface of the whole bundle of wrapped crop straws (2) falls on the chain grate (12), the whole bundle of wrapped crop straws (2) is approximately arranged like a honeycomb under the action of the arc surface (28) of the sliding pushing shield (10) of the chain grate. In this way, the gaps between the whole bales of crop straw (2) can be minimized, but flue gas or a mixture of flue gas and air can enter the gaps from below the round whole bales of crop straw and form individual combustion chambers (78).

In fig. 5 it is also seen that the hot flue gas channel (17) extends in the furnace wall (16), and by controlling the amount of air entering the air inlet (19) it is ensured that the hot flue gas is sufficiently combusted before it comes into contact with the fan (18), so that the fan (18) is prevented from being exposed to open flame and radiation. Furthermore, an igniter (20) for blowing the burning liquefied gas or fuel into the hot flue gas channel (17) is arranged in the hot flue gas channel (17).

Fig. 6 shows in detail the structure of the algae well beam structure roof (15) not containing water cooling, the long algae well beam structure roof (66) and the second layer roof not containing water cooling, which are mainly constructed of refractory materials and the like, in the algae well beam roof construction manner at the lower part. The fireproof concrete layer (33) and the heat insulation material layer (32) at the bottom of the top plate of the algae well beam structure are hung on fireproof stainless steel hooks (34) welded on the bent steel plates (29) bent upwards, and the stainless steel hooks in the embodiment are preferably section bars Q245R (20G) with higher heat resistance.

The radiating fins (31) of the first layer of top plate welded to the curved steel plate (29) are arranged perpendicular to the advancing direction of the chain grate (12), the curved steel plate (29) is welded with the longitudinal fixing pieces (30), and the longitudinal fixing pieces (30) can prevent the curved steel plate (29) from being excessively heated and stretched.

The stainless steel hook (34) is also flexible in the longitudinal direction due to its curvature, thus protecting the refractory concrete layer (33) from tensile deformation. The algae well beam structure top plate (15) and the long algae well beam structure top plate (66) are adjacently arranged at a gap of 8-10mm, the gap is covered by a U-shaped sealing cover (72), and the U-shaped sealing cover (72) is provided with a graphite fiber sealing head (37).

The two long algae shaft beam structure top plates (66) in the embodiment are not on a horizontal line, and can be welded to a vertical metal V-shaped plate (73) during assembly, and the metal V-shaped plate (73) can be slightly bent to resist certain heat stretching.

The sealing structure of the top plate of the algae shaft beam structure is shown in detail in fig. 7. Wooden plywood (35) can be inserted when pouring refractory concrete, and these plywood (35) will burn off after the device of the invention starts to operate and form expansion joints.

Fig. 8 contains more information on the structure of the furnace wall (16) of the example traveling grate gasification unit fueled by a whole bale of crop straw. The wall thickness (16) of the furnace of the present example, which is mainly made of refractory stone and is approximately 70 cm thick, contains free space inside the furnace wall filled with high temperature resistant block insulation material (39), and also makes it possible to arrange hot flue gas channels (17) inside the furnace wall.

The bent steel plates (29) of the algae shaft beam structure top plate (15) and the long algae shaft beam structure top plate (66) in the example are firmly fixed on the floor of a concrete structure through a steel cross beam (40) and an externally arranged threaded pull rod (41) with a threaded piece, so that the compressive strength of the chain grate gasification combustion device is enhanced.

The metal-clad baffle (71) is spaced from the furnace wall (16) and fresh air (27) enters from below to reduce radiation loss of the thermodynamic system.

The thermodynamic system can be quickly started from a static state by using an igniter (20) for blowing burning liquefied gas or fuel oil into the hot flue gas channel (17), and fresh cooling air can be simultaneously sucked through the air inlet (19) to reduce the temperature of the burning liquefied gas or fuel oil when the burning liquefied gas or fuel oil is blown into the igniter (20) in the hot flue gas channel (17) so as to avoid influencing a fan (18) in the hot flue gas channel (17).

The construction of the fan (18) is illustrated in detail in fig. 9, with the aim of improving the operational reliability and the service life of the fan (18). Wherein the stainless steel fan shaft (50) of the fan (18) has a low thermal conductivity. Therefore, the bearing of the fan shaft (50) is hardly overheated, and the fan shaft (50) can be cooled by the outside air sucked from the gap between the fan shaft (50) and the fan rear panel (46), the fan cooling air inlet (52), and the like.

For this purpose, the small blades (47) are arranged in the coaxial direction at the back of the fan impeller (45), and the slight negative pressure generated after the small blades (47) are operated can ensure that fresh cooling air enters and cools the rear part of the fan impeller (45), so that the service lives of the fan impeller (45) and the fan (18) are prolonged, and the fan (18) can be easily and quickly cleaned and maintained even in the system combustion process.

The fan wheel (45), the fan rear panel (46) and the motor drive part etc. can pivot together by means of a moving strut (49), the fan rear panel (46) will press against the soft seal (48) after lowering, and no extra fixing means is needed during operation, even if a small amount of air enters and is directly allowed as part of the combustion air feed, because of the negative pressure generated when the fan wheel (45) operates.

Fig. 10 shows a cross-section of an ignition device comprising an ignition channel (11) which traverses the entire traveling grate (12) with the ignition channel (11) and which is not equipped with a cooling system, so that in this example the housing (53) is made of stainless steel, only the insulating layer (54) of vermiculite is provided therein, and the ignition channel (11) is formed inwardly of refractory concrete. The hot smoke passes through an ignition channel (11) and blows the hot smoke with the temperature of 480-600 ℃ into the whole bale of crop straw (2) under pressure through an ignition port (13) constructed by a meshed refractory special-shaped block (55) and a ceramic material cementing agent (76) to be ignited.

The speed of the fan (18) is minimized for this purpose, and the speed of the traveling grate (12) is reduced to a very low level when the combustion capacity of the system is reduced, at which time the ignition device is no longer needed.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims (19)

1. A chain grate gasification device taking whole bundle of wrapped crop straws as fuel comprises a chain grate, wherein the whole bundle of wrapped crop straws which are not crushed are gasified and combusted on the chain grate, and at least one vortex post-combustion module is arranged at the downstream outside the chain grate gasification device taking the whole bundle of wrapped crop straws as fuel; characterized in that the flue gas discharge channel (14) extends almost horizontally and its cross section tapers and narrows in the direction of flue gas flow.

2. The traveling grate gasification device fueled by whole bales of crop straw as claimed in claim 1 wherein the length of the traveling grate (12) of the traveling grate gasification device fueled by whole bales of crop straw expressed in meters should be no shorter than:

3. the traveling grate gasification unit fueled by bales of crop straw as set forth in claim 1 wherein the primary air for the gasification combustion is adjusted and completed by means of the isobaric air supply chamber (64) and the gasification combustion time of the bales of crop straw (2) is not less than 60 minutes when the traveling grate gasification unit fueled by bales of crop straw is operated at the maximum design combustion power.

4. The traveling grate stoker gasification unit fueled by whole bales of crop straw as claimed in claim 1 wherein the round bales of crop straw (2) are arranged in a nearly honeycomb fashion with their round planes falling on the traveling grate (12) after being pushed by the arc surface (28) of the sliding pusher shield (10).

5. The travelling grate stoker gasification unit fueled by bales of crop straw as claimed in claim 1 wherein, at the inlet of the front most bales of crop straw (2) on the travelling grate stoker (12), there is arranged an ignition unit with ignition ports (13) traversing the whole travelling grate stoker (12) and connecting to an ignition channel (11), and the hot flue gas from the hot flue gas duct (17) is blown into the bales of crop straw (2) pushed onto the travelling grate stoker (12) by the fan (18).

6. A moving grate stoker gasification unit fueled with bales of crop straw as claimed in claim 5 wherein the hot flue gas path (17) to the ignition path (11) is more than 4m long and the hot flue gas path (17) is provided with air inlets (19).

7. The traveling grate stoker gasification unit fueled with bales of crop straw as claimed in claim 5 wherein the hot flue gases in the hot flue gas path (17) are conditioned to a target temperature of 480 ℃ to 600 ℃ measured before the fan (18) by mixing in fresh air entering from the air inlet (19).

8. The traveling grate stoker gasification unit fueled with bales of crop straw as claimed in claim 5 wherein the fan wheel (45) of the fan (18) pivots with the fan back plate (46).

9. The traveling grate stoker gasification unit fueled by whole bales of crop straw as claimed in claim 5 wherein the fan impeller (45) has its back side coaxially oriented with the small blades (47).

10. The traveling grate stoker gasification unit fueled with bales of crop straw as claimed in claim 9 wherein there is a free air gap and fan cooling air intake (52) between the fan shaft (50) and the fan back panel (46).

11. The traveling grate stoker gasification unit fueled by whole bales of crop straw as claimed in claim 1 wherein the gasification chamber (21) above the traveling grate stoker (12) and the upper side of the flue gas discharge channel (14) are provided with upper and lower decks with a hot air chamber (22) therebetween.

12. The traveling grate stoker gasification unit fueled with bales of crop straw as claimed in claim 11 wherein the first lower roof is preferably of the algae shaft beam structure roof design in architectural design, each of the algae shaft beam structure roof (15) and the long algae shaft beam structure roof (66) comprising a bent steel plate (29), the bent steel plate (29) being firmly attached to the longitudinal fixture (30) above it.

13. The traveling grate stoker gasification unit fueled by whole bale of crop straw as claimed in claim 12 wherein the lowest part of the algae shaft beam structure top plate (15), the long algae shaft beam structure top plate (66) is the thermal insulation material layer (32) and the fire resistant concrete layer (33), the thermal insulation material layer (32) and the fire resistant concrete layer (33) are fixed by the stainless steel hook (34) welded to the curved steel plate (29).

14. The moving grate stoker gasification unit fueled with whole bales of crop straw as claimed in claim 12 wherein the bent steel plates (29) of the top plates (15, 66) of the dune beam structure are firmly fixed to the concrete structure floor by a steel cross beam (40) and externally arranged threaded tie rods (41) with threaded members.

15. The traveling grate stoker gasification unit fueled by whole bales of crop straw as claimed in claim 12 wherein the bent steel plates (29) are bent upwards and a U-shaped cover (72) with a graphite fiber cap (37) is placed over the adjacent two bent steel plates (29) or the two bent steel plates (29) are welded firmly to a V-shaped metal plate (73).

16. The traveling grate stoker gasification unit fueled by whole bales of crop straw as claimed in claim 12 wherein the fins (31) of the first tier roof welded to the curved steel plate (29) are arranged perpendicular to the traveling direction of the traveling grate stoker (12).

17. The traveling grate gasification unit fueled by bales of crop straw as claimed in claim 1 wherein fresh air (27) is preheated by entering a hot air plenum (22) disposed in the space above the traveling grate (12) between the lower first roof and the upper second roof.

18. The traveling grate gasification unit fueled by bales of crop straw as claimed in claim 1 wherein the traveling grate (12) is comprised of grate module units (65), the width of the grate module units (65) being suitable for transportation by conventional trucks and containers.

19. The chain grate gasification unit fueled by bales of crop straw as claimed in claim 1 wherein the bales of crop straw (2) from the loading clips (3) used for straw bale drying and waste flue gas dust removal are fed to the sliding shield (10) to first fall on a fixed shaft springing rack (9) and with the fixed shaft springing rack (9) to the front of the bottom sliding shield (10).

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