Bundled straw biomass direct-fired boiler capable of doing work through multi-stroke combustion

Abstract

The utility model discloses a bundled straw biomass direct-fired boiler capable of doing work through multi-stroke combustion, relates to the technical field of biomass direct-fired boilers, and solves the problems that straw cannot be normally combusted due to too high moisture and soil content after being collected and packaged under natural conditions or the heat conversion efficiency is low due to insufficient combustion. The multiple rows of material conveying mechanisms of the in-boiler transmission system located in the boiler body are used for repeatedly transferring biomass fuel back and forth till the biomass fuel falls onto the chain grate stoker from the material conveying mechanism on the lowermost layer; according to the biomass direct-fired boiler, the biomass direct-fired boiler structure for doing combustion work in the up-and-down positive and negative strokes in the boiler is adopted for heat supply production, the raw material obtaining range can be widened, the raw material purchasing cost is saved, the raw material consumption is reduced, production potential safety hazards are completely eradicated, and the failure rate of production equipment is reduced. The economic purpose of reducing cost and increasing efficiency in heat supply production is achieved fundamentally, and property safety of heat supply equipment and life safety of firemen are guaranteed.

Description

Technical Field

[0001] This utility model relates to the technical field of biomass direct-fired boilers, and in particular to a multi-pass combustion-powered baled straw biomass direct-fired boiler. Background Technology

[0002] Northeast my country boasts abundant straw reserves, convenient collection and baling conditions, and low-cost direct use as fuel. Furthermore, the pollutant emissions from straw combustion are significantly lower than those from coal combustion; with appropriate dust removal and denitrification processes, emissions can meet standards. Biomass baled straw direct combustion is an excellent alternative to coal for applications such as residential heating, industrial gasification, and grain drying. The biomass direct combustion boiler structure, featuring a two-stage combustion process (upper and lower forward strokes), was developed to address the problem of incomplete combustion and low heat conversion efficiency caused by excessive moisture and soil content in straw collected and baled under natural conditions.

[0003] If the moisture content of baled straw exceeds 30% and the soil content is greater than 15%, it will result in incomplete combustion or no combustion when it is used in a biomass straw direct combustion boiler modified from a traditional horizontal coal-fired boiler. At this time, the boiler can no longer be used normally.

[0004] Due to climate uncertainty, the availability of straw that meets combustion standards during harvesting and storage is highly uncertain. Compared to secondary processing of harvested straw, providing a direct-fired biomass baled straw stove suitable for applications with approximately 40% moisture and 20% soil content offers significant advantages in terms of both economy and environmental protection. It also provides a sustainable development path for comprehensive straw management and environmental protection. Utility Model Content

[0005] In view of the above-mentioned problems that straw cannot burn properly or has low heat conversion efficiency due to excessive moisture and soil content after being collected and baled under natural conditions, the purpose of this utility model is to provide a multi-pass combustion power generation direct-fired boiler for baled straw biomass.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A multi-pass combustion-powered direct-fired boiler for baled straw biomass includes: a boiler body 1, which has a combustion chamber 11 and a heat exchange chamber 12 inside. The heat exchange chamber 12 is located above the combustion chamber 11 and is connected to the combustion chamber 11.

[0008] The front side wall of the combustion chamber 11 is provided with a feed inlet 104; the side wall of the heat exchange chamber 12 is provided with a flue gas outlet 105.

[0009] It also includes: an in-furnace drive system 3 and a chain grate 4, wherein the chain grate 4 is installed at the bottom of the combustion chamber 11, and the in-furnace drive system 3 is installed inside the combustion chamber 11 and above the chain grate 4; the in-furnace drive system 3 includes: at least one row of material conveying mechanisms, and multiple rows of material conveying mechanisms arranged sequentially from top to bottom; the front end of the uppermost material conveying mechanism is located below the feed inlet 104; the in-furnace drive system 3 is used to repeatedly transfer biomass fuel and transfer biomass fuel to the chain grate 4;

[0010] The bottom of the combustion chamber 11 is provided with a slag discharge port 103; when biomass fuel falls from the front end of the lowest material conveying mechanism onto the chain grate 4, the chain grate 4 is located near the front side wall of the combustion chamber 11 and moves the completely burned biomass fuel backward, and the slag discharge port 103 is located on the rear side of the chain grate 4; when biomass fuel falls from the rear end of the lowest material conveying mechanism onto the chain grate 4, the chain grate 4 is located near the rear side wall of the combustion chamber 11 and moves the fully burned biomass fuel forward, and the slag discharge port 103 is located on the front side of the chain grate 4.

[0011] In the above-mentioned multi-pass combustion biomass direct-fired boiler for baled straw, when the front or rear end of any row of material conveying mechanism is located close to the side wall of the combustion chamber 11, the other end of the material conveying mechanism is spaced apart from the side wall of the combustion chamber 11, and the size of the spaced distance is greater than the maximum size of the biomass fuel.

[0012] In the above-mentioned multi-pass combustion biomass direct-fired boiler, for any two adjacent rows of material conveying mechanisms, if the front end of one row of material conveying mechanisms is located close to the front side wall of the combustion chamber 11, then the rear end of the other row of material conveying mechanisms is located close to the rear side wall of the combustion chamber 11.

[0013] In the above-mentioned multi-pass combustion-powered direct-fired boiler for baled straw biomass, the end of any row of material conveying mechanism closest to the side wall of the combustion chamber 11 is higher than the end furthest from the side wall of the combustion chamber 11.

[0014] The aforementioned multi-stroke combustion-powered baled straw biomass direct-fired boiler includes a material conveying mechanism comprising: multiple drive shafts located in the same plane and arranged parallel to each other; each drive shaft having its two ends rotatably connected to the left and right side walls of the combustion chamber 11; the multiple drive shafts rotating synchronously in a clockwise or counterclockwise direction; and the rotation direction of the multiple drive shafts being the same as the conveying direction of the biomass fuel located above them.

[0015] The aforementioned multi-stroke combustion-powered direct-fired boiler for baled straw biomass further includes: a baling shaft 5 and a coke-breaking shaft 106. The two ends of the baling shaft 5 are rotatably connected to the left and right side walls of the combustion chamber 11, respectively. The two ends of the coke-breaking shaft 106 are also rotatably connected to the left and right side walls of the combustion chamber 11, respectively. Both the baling shaft 5 and the coke-breaking shaft 106 are located above the chain grate 4. The baling shaft 5 and the coke-breaking shaft 106 rotate synchronously in a clockwise or counterclockwise direction, and the rotation direction of the baling shaft 5 and the coke-breaking shaft 106 is the same as the conveying direction of the chain grate 4.

[0016] The aforementioned multi-stroke combustion biomass direct-fired boiler also includes: a baling straw feeder 2, which is used to transfer biomass fuel to the feed inlet 104 of the boiler body 1 and push it into the combustion chamber 11; the baling straw feeder 2 includes: a structural frame 21, baffles 22 and a hopper 23, the rear end of the structural frame 21 is connected to the feed inlet 104 of the boiler body 1, baffles 22 are installed on the left and right sides of the structural frame 21, and the hopper 23 travels on the upper surface of the structural frame 21, and the hopper 23 is used to push the biomass fuel located on the structural frame 21 into the combustion chamber 11;

[0017] The bottom of the hopper 23 is equipped with wheels, and gears are rotatably mounted on the side of the hopper 23. A rack is provided on the upper surface of the structural frame 21. The gears mesh with the racks, and the hopper 23 moves on the structural frame 21 by driving the gears to rotate.

[0018] The aforementioned multi-pass combustion biomass direct-fired boiler for baled straw includes: water-cooled wall tubes 109; a boiler drum 108 is provided at the top of the heat exchange chamber 12; a burnout chamber 110 is provided on the front side of the heat exchange chamber 12; multiple water-cooled wall tubes 109 are evenly distributed on the left and right side walls of the boiler drum 108, the burnout chamber 110, and the combustion chamber 11; a water inlet 111 communicating with the water-cooled wall tubes 109 is provided on the rear side wall of the combustion chamber 11; and a drain outlet and / or exhaust outlet communicating with the water-cooled wall tubes 109 are provided on the heat exchange chamber 12.

[0019] The aforementioned multi-stroke combustion-powered direct-fired boiler for baled straw biomass further includes: a speed reducer unit 6, which is used to drive the operation of the in-furnace transmission system 3, the chain grate 4, the bale breaking shaft 5, and the coke breaking shaft 106.

[0020] The above-mentioned multi-pass combustion-powered direct-fired boiler for baled straw biomass includes a preheating arch 101 inclined at the top front side of the combustion chamber 11, a limiting arch 102 inclined at the top rear side of the combustion chamber 11, and a burnout arch 107 inclined at the bottom of the combustion chamber 11. The preheating arch 101 is located above the feed inlet 104, and the burnout arch 107 is located above the ash outlet 103. Air ducts 112 are provided on the left and right side walls of the combustion chamber 11.

[0021] Because this utility model employs the aforementioned technology, it has the following positive effects compared to existing technologies:

[0022] (1) In this utility model, the pot body is designed as a multi-pass smoke passage structure. The superheated flue gas exchanges heat with the water-cooled wall, smoke pipe, smoke box, pot drum, header and connecting pipe bundle through the pot body structure. A cast wall is added to the lower side of the pot drum to realize the two-pass smoke passage of the superheated flue gas, increase the heat exchange area between the flue gas and the pot body, and thus reduce the exhaust temperature.

[0023] (2) In this utility model, the biomass direct-fired boiler structure, which uses multiple forward and reverse strokes inside the furnace for combustion, can broaden the range of raw material acquisition, save raw material procurement costs, and reduce raw material consumption. At the same time, it can eliminate production safety hazards and reduce the failure rate of production equipment. It fundamentally achieves the economic goal of reducing costs and increasing efficiency in heating production, and protects the property safety of heating equipment and the life safety of boiler operators. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a multi-pass combustion-operated direct-fired boiler for baled straw biomass.

[0025] Figure 2 This is a cross-sectional view of a multi-pass combustion-operated direct-fired boiler for baled straw biomass, according to this utility model.

[0026] Figure 3 This is a side view of the main body of a multi-pass combustion direct-fired boiler for baled straw biomass, according to this utility model.

[0027] Figure 4 This is an axonometric view of the main body of a multi-pass combustion direct-fired boiler for baled straw biomass, according to this utility model.

[0028] In the attached diagram: 1. Boiler body; 2. Straw baling feeder; 3. Furnace transmission system; 4. Chain grate; 5. Bagged baling shaft; 6. Reducer unit; 11. Combustion chamber; 12. Heat exchange chamber; 21. Structural frame; 22. Baffle; 23. Hopper; 101. Preheating furnace arch; 102. Limiting furnace arch; 103. Slag discharge port; 104. Feed inlet; 105. Smoke outlet; 106. Coke crushing shaft; 107. Burnout furnace arch; 108. Boiler drum; 109. Water-cooled wall tubes; 110. Burnout chamber; 111. Water inlet; 112. Air duct. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0030] Please refer to Figures 1 to 4 As shown, a multi-pass combustion biomass direct-fired boiler for baled straw is illustrated, comprising: a boiler body 1, inside which are a combustion chamber 11 and a heat exchange chamber 12, the heat exchange chamber 12 being located above and connected to the combustion chamber 11; the combustion chamber 11 is used for burning biomass fuel; the heat exchange chamber 12 is used for heat exchange and external energy supply.

[0031] The front side wall of the combustion chamber 11 is provided with a feed inlet 104; the side wall of the heat exchange chamber 12 is provided with a flue gas outlet 105.

[0032] It also includes: an in-furnace drive system 3 and a chain grate 4. The chain grate 4 is installed at the bottom of the combustion chamber 11, and the in-furnace drive system 3 is installed inside the combustion chamber 11 and above the chain grate 4. The in-furnace drive system 3 includes: at least one row of material conveying mechanisms, and multiple rows of material conveying mechanisms are arranged sequentially from top to bottom. The front end of the uppermost material conveying mechanism is located below the feed inlet 104. The in-furnace drive system 3 is used to repeatedly move biomass fuel back and forth until the biomass fuel falls from the lowermost material conveying mechanism onto the chain grate 4.

[0033] The bottom of the combustion chamber 11 is provided with a slag discharge port 103. When biomass fuel falls from the front end of the bottom material conveying mechanism onto the chain grate 4, the chain grate 4 is located near the front side wall of the combustion chamber 11 and moves the completely burned biomass fuel to the rear. The slag discharge port 103 is located on the rear side of the chain grate 4. When biomass fuel falls from the rear end of the bottom material conveying mechanism onto the chain grate 4, the chain grate 4 is located near the rear side wall of the combustion chamber 11 and moves the fully burned biomass fuel forward. The slag discharge port 103 is located on the front side of the chain grate 4.

[0034] Furthermore, in a preferred embodiment, when any row of material conveying mechanisms is positioned near the side wall of the combustion chamber 11 at its front or rear end, its other end is spaced from the side wall of the combustion chamber 11. This space is larger than the maximum size of the biomass fuel, facilitating the conveying mechanism to move the biomass fuel from front to back or from back to front to the end. After the biomass fuel falls onto the next row of material conveying mechanisms located below, specifically: the biomass fuel enters through the feed inlet 104 and falls to the front end of the uppermost material conveying mechanism. The uppermost material conveying mechanism moves the biomass fuel backward until it falls to the rear end of the second layer of material conveying mechanisms. Then, the second layer of material conveying mechanisms moves it forward until it falls to the front end of the third layer of material conveying mechanisms... until the biomass fuel falls onto the chain grate 4. Then, the chain grate 4 moves the fully burned biomass fuel to the slag outlet 103.

[0035] Furthermore, in a preferred embodiment, for any two adjacent rows of material conveying mechanisms, if the front end of one row of material conveying mechanisms is located close to the front side wall of the combustion chamber 11, then the rear end of the other row of material conveying mechanisms is located close to the rear side wall of the combustion chamber 11.

[0036] Furthermore, in a preferred embodiment, the end of any material conveying mechanism near the side wall of the combustion chamber 11 is higher than the end away from the side wall of the combustion chamber 11.

[0037] Furthermore, in a preferred embodiment, any row of material conveying mechanisms includes: multiple drive shafts, which are located in the same plane and arranged parallel to each other. The two ends of each drive shaft are rotatably connected to the left and right side walls of the combustion chamber 11, respectively. The multiple drive shafts rotate synchronously in a clockwise or counterclockwise direction, and the rotation direction of the multiple drive shafts is the same as the conveying direction of the biomass fuel located above them.

[0038] Furthermore, in a preferred embodiment, it further includes: a packing breaker shaft 5 and a coke breaker shaft 106. The two ends of the packing breaker shaft 5 are rotatably connected to the left and right side walls of the combustion chamber 11, respectively. The two ends of the coke breaker shaft 106 are rotatably connected to the left and right side walls of the combustion chamber 11, respectively. Both the packing breaker shaft 5 and the coke breaker shaft 106 are located above the chain grate 4. The packing breaker shaft 5 and the coke breaker shaft 106 rotate synchronously in a clockwise or counterclockwise direction. The rotation direction of the packing breaker shaft 5 and the coke breaker shaft 106 is the same as the conveying direction of the chain grate 4.

[0039] Furthermore, in a preferred embodiment, it further includes: a baling straw feeder 2, which is used to transfer biomass fuel to the feed inlet 104 of the boiler body 1 and push it into the combustion chamber 11; the baling straw feeder 2 includes: a structural frame 21, baffles 22 and a hopper 23, the rear end of the structural frame 21 is connected to the feed inlet 104 of the boiler body 1, baffles 22 are installed on the left and right sides of the structural frame 21, the hopper 23 travels on the upper surface of the structural frame 21, and the hopper 23 is used to push the biomass fuel located on the structural frame 21 into the combustion chamber 11;

[0040] The bottom of the hopper 23 is equipped with wheels, and gears are rotatably mounted on the side of the hopper 23. The upper surface of the structural frame 21 is equipped with a rack, and the gears mesh with the rack. The hopper 23 moves on the structural frame 21 by driving the gears to rotate.

[0041] Furthermore, in a preferred embodiment, it further includes: water-cooled wall tubes 109, a boiler drum 108 is provided at the top of the heat exchange chamber 12, a combustion chamber 110 is provided on the front side of the heat exchange chamber 12, multiple water-cooled wall tubes 109 are evenly distributed on the left and right side walls of the boiler drum 108, the combustion chamber 110 and the combustion chamber 11, the multiple water-cooled wall tubes 109 are interconnected, a water inlet 111 communicating with the water-cooled wall tubes 109 is provided on the rear side wall of the combustion chamber 11, and a drain outlet and / or exhaust outlet communicating with the water-cooled wall tubes 109 are provided on the heat exchange chamber 12.

[0042] Furthermore, in a preferred embodiment, it further includes: a speed reducer 6, which is used to drive the operation of the furnace transmission system 3, the chain grate 4, the packing breaker shaft 5, and the coke breaking shaft 106.

[0043] Furthermore, in a preferred embodiment, the combustion chamber 11 is provided with an inclined preheating furnace arch 101 at the top front side, the combustion chamber 11 is provided with an inclined limiting furnace arch 102 at the top rear side, and the combustion chamber 11 is provided with an inclined burnout furnace arch 107 at the bottom. The preheating furnace arch 101 is located above the feed inlet 104; the burnout furnace arch 107 is located above the slag outlet 103; and air ducts 112 are provided on the left and right side walls of the combustion chamber 11.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention.

[0045] Based on the above, this utility model also has the following embodiments:

[0046] In a further embodiment of this utility model, such as Figures 1 to 4The diagram shows a multi-stroke combustion boiler for baled straw biomass, where the in-furnace transmission system 3 uses a row of material conveying mechanisms. This embodiment is based on a multi-stroke combustion boiler for baled straw biomass.

[0047] In a further embodiment of this utility model, the biomass direct-fired boiler structure of this utility model, which performs combustion work through multiple forward and reverse strokes inside the furnace, is composed of a straw baling feeder 2, a boiler body 1, an in-furnace transmission system 3, a matching fan, and a chain grate 4.

[0048] In a further embodiment of this utility model, the baling straw feeder 2 uses a reciprocating mechanical transmission to perform work. The gear of the hopper 23 is driven by a motor or by an external chain drive to realize the reciprocating movement of the hopper 23 on the structural frame 21. The baling straw feeder 2 pushes the baled straw in the hopper into the feed inlet 104 at the front end of the boiler combustion chamber. After the feeding is completed, the hopper 23 returns to the starting point according to the original stroke. After new baled straw is put in, the previous operation is repeated.

[0049] In a further embodiment of this utility model, the structural frame 21 of the straw baling feeder 2 is constructed by welding together components such as I-beams and steel plates; the transmission system consists of components such as a motor, reducer, chain, directional wheel set, transmission gear, rack, transmission shaft, and bearings; the support structure is constructed by welding square steel, I-beams, embedded parts, and precast cement parts to the boiler body structure and the ground; the sealing structure is constructed by welding and assembling color steel plates and square steel to form an outer covering frame, with internal components such as a closed door, lighting, monitoring, and limiters. Through the combination and arrangement of each link, the work of conveying baled straw into the boiler body is ensured to be completed stably, efficiently, and cleanly within the constrained stroke.

[0050] In a further embodiment of this utility model, the baling straw feeder 2 is formed by welding together a frame component and a support component made of I-beams to form a main frame structure. The two ends are respectively connected to the lower end of the boiler main body feed port and the ground embedded part, ensuring the fatigue resistance and impact resistance of the main structure. Adding steel plate components to the main frame structure serves two purposes: firstly, it acts as a platform for the transported straw material; secondly, it isolates the transmission system components of the baling straw feeder from the transported straw material, preventing straw, leaves, and debris from falling into the transmission system components and causing equipment malfunction during transport.

[0051] In a further embodiment of this utility model, the transmission system consists of a motor and a reducer as the power source. A chain drives the transmission shaft to rotate, generating torsional force. This torsional force drives the gears on both sides of the equipment to rotate. The gears mesh with the rack and pinion, moving in a directional manner along the track established by the rack and pinion. The directional wheel set and gears form a triangular structure, ensuring stable movement of the equipment during directional movement and preventing derailment or self-spinning. The transmission system components are connected to the feeding hopper; the components' operation drives the feeding hopper to achieve the purpose of feeding materials.

[0052] In a further embodiment of this utility model, the sealing structure covers the main body of the baling straw feeder. On the one hand, it prevents the leaf fluff and slag generated during the movement of straw materials from scattering and causing environmental pollution. On the other hand, it also improves the overall aesthetics of the baling straw feeder. The sealed structure is equipped with lighting, monitoring, limiters and other components to realize the supporting facilities for digital, visual remote operation of the baling straw feeder. The sealing door is set in the three-dimensional space between the sealed structure and the baling straw feeder. Its working principle is that when the feeding hopper transports the baled straw to the feed inlet 104 of the boiler body 1, the sealing door closes and the boiler door opens at the same time. This prevents the high-temperature air inside the boiler from mixing with the low-temperature air outside, which would cause the boiler temperature to drop and affect the boiler's thermal efficiency. The sealing door can prevent backfire at the boiler feed inlet 104 and solve the safety hazard. The sealed structure is reasonably set with maintenance and cleaning channels to facilitate the boiler operator to maintain and repair the components of each part of the baling straw feeder.

[0053] In a further embodiment of this utility model, the boiler body 1, as the core equipment for burning straw baled fuel, is composed of three sections: boiler, furnace, and grate. The boiler body 1 adopts a longitudinally arranged horizontal fire tube structure, wherein the three-dimensional height of the combustion zone of the furnace body is increased, such as... Figures 1 to 4 As shown, a multi-stroke combustion-operated direct-fired boiler for baled straw biomass, with a row of material conveying mechanisms, forms two combustion layers by adding a drive shaft. At the same time, there is a gap between the drive shafts, which allows the baled straw fuel to be fully oxygenated during combustion. This structure can promote the complete combustion of straw.

[0054] In a further embodiment of this utility model, the structure is briefly described as follows: the pot body adopts a longitudinally arranged flue pipe outer pot cylinder 108, the pot cylinder 108 is provided with a header, and the pot cylinder 108 is provided with a water-cooled wall pipe 109 on the side. The headers are arranged in a structure connected by tube bundles; the furnace body is composed of a furnace door, a feed inlet, a front wall of the upper fire port, a furnace arch, a drive shaft assembly of the upper combustion zone, a water-cooled wall pipe 109, a header, a header connecting pipe, and other components; the chain grate 4 is placed below the furnace body, and the grate surface and the furnace body form the lower combustion zone, i.e., the combustion chamber 11. The straw burnt material is discharged into the slag remover through the grate slag outlet 103.

[0055] In a further embodiment of this utility model, multiple air ducts 112 are distributed between multiple rows of drive shafts in the furnace transmission system 3, above and on both sides of the chain grate 4.

[0056] In a further embodiment of this utility model, the objective is achieved as follows: the boiler body is designed as a multi-pass flue gas structure, through which superheated flue gas exchanges heat with components such as water-cooled walls, flue pipes, flue gas boxes, boiler drum, headers and connecting pipe bundles. A cast-in-place wall is added to the lower side of the boiler drum to realize a two-way flue gas path for superheated flue gas, thereby increasing the heat exchange area between the flue gas and the boiler body and reducing the exhaust temperature.

[0057] In a further embodiment of this utility model, the furnace body is designed as a double combustion chamber structure. A header and connecting pipe bundle are installed on the front wall of the upper fire port at the top of the furnace body and inside the furnace arch, constraining the path of superheated flue gas while participating in heat exchange. The inner sides of the water-cooled walls, connecting pipe bundles, and header components on the furnace body's perimeter are enclosed by refractory brick masonry. The bottom of the furnace body connects to the grate surface, thus forming the furnace combustion chamber structure. A drive shaft assembly is installed in the middle of the combustion chamber, dividing it into upper and lower parts. The straw-bundled fuel rotates and burns in both combustion chambers, releasing heat. Because the combustion chamber is entirely enclosed by a combination of refractory materials such as masonry and casting, the straw does not directly contact the water-cooled walls, connecting pipe bundles, headers, etc., during combustion. Instead, heat is uniformly conducted through the refractory materials, thus solving the problem of pipe bundle corrosion.

[0058] In a further embodiment of this utility model, after the straw baled fuel enters the boiler through the feed inlet, the furnace door is closed by a motor. The furnace door and the feed inlet are connected to the boiler body by a flexible connecting pipe bundle and a connecting pipe bundle, and water is supplied. The heat released by the straw baled fuel entering the boiler and starting to burn can be exchanged between the furnace door and the feed inlet.

[0059] In a further embodiment of this invention, the baled straw fuel enters the upper combustion zone through the furnace door to begin preheating and combustion, and then moves at a constant speed towards the rear of the combustion chamber via a drive shaft structure. The drive shaft is arranged in a stepped, horizontal configuration towards the rear of the boiler to form a grate structure. The length of the drive shaft is greater than the width of the boiler. Sealed water boxes are installed at both ends of the shaft extending outside the furnace, and water pipes are connected to them. The shaft rotation is powered by an electric motor and a reducer. This power is converted into torque through a sprocket assembly and gears, driving the shaft to rotate in a directional and constant-speed manner. This design solves the problem of baled straw fuel stacking and compressing into a furnace arch during combustion in the upper combustion zone due to lack of stroke power, completely eliminating the risk of boiler component damage and smoke escaping from the furnace due to poor ventilation.

[0060] In a further embodiment of this invention, after the baled straw fuel travels from the upper combustion zone to the end of the upper combustion chamber, the unburned baled straw fuel falls into the lower combustion chamber. The lower combustion chamber is driven by the chain grate 4 to move the unburned baled straw fuel at a constant speed towards the ash outlet 103. During this movement, the bale-breaking shaft 5 works to evenly spread the unburned baled straw fuel for continued combustion, while the coke-breaking shaft 106 works to break and disperse the remaining coke residue into ash blocks that meet the ash discharge requirements and are discharged from the boiler. The rotation direction of the baled straw shaft 5 and the coke-breaking shaft 106 is the same as that of the drive wheel / driven wheel of the chain grate 4. The surfaces of the baled straw shaft 5 and the coke-breaking shaft 106 inside the furnace are fitted with teeth of varying lengths by welding. The rotation of the baled straw shaft 5 and the coke-breaking shaft 106 drives the teeth to do work to achieve the design requirements. The work of the baled straw shaft 5 can evenly spread the straw baled fuel that has been burned into an irregular shape. This design makes it easy for the straw baled fuel with a moisture content that exceeds the standard and is not easy to burn out to come into contact with sufficient oxygen and absorb the heat of the furnace to quickly dry and gasify for combustion. The work of the coke-breaking shaft 106 can break the slag blocks that are too large after the straw baled fuel is burned out into slag blocks that meet the discharge standards of the slag discharge machine. This design facilitates slag discharge and reduces the failure rate of the slag removal equipment.

[0061] In a further embodiment of this utility model, as described above, the biomass direct-fired boiler structure, which employs multiple forward and reverse strokes within the furnace for combustion, relaxes the standards for using straw as raw material. This increases the range of choices available to users during raw material collection and storage, reducing procurement costs. The baled straw fuel burns completely during combustion, reducing straw consumption. Simultaneously, the fully burned straw produces less ash, reducing slag emissions and minimizing unburned fuel due to high moisture content. The straw does not pile up or compress during combustion, eliminating safety hazards and reducing equipment failure rates. The combination of a drive shaft assembly and a grate to constrain the stroke ensures that the straw does not pile up or compress during combustion, fundamentally eliminating boiler safety hazards caused by non-human error.

[0062] In a further embodiment of this utility model, as summarized above, the biomass direct-fired boiler structure, which employs multiple forward and reverse strokes within the furnace for combustion, can broaden the range of raw material acquisition, save on raw material procurement costs, and reduce raw material consumption. Simultaneously, it eliminates production safety hazards and reduces equipment failure rates. Fundamentally, it achieves the economic goal of cost reduction and efficiency improvement in heating production, while ensuring the property safety of heating equipment and the life safety of boiler operators.

[0063] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A multi-stroke combustion work bundled straw biomass direct combustion boiler, characterized in that, include: The boiler body (1) has a combustion chamber (11) and a heat exchange chamber (12) inside. The heat exchange chamber (12) is located on the upper side of the combustion chamber (11) and is connected to the combustion chamber (11). The combustion chamber (11) has a feed inlet (104) on its front side wall; the heat exchange chamber (12) has a smoke outlet (105) on its side wall. It also includes: an in-furnace drive system (3) and a chain grate (4), wherein the chain grate (4) is installed at the bottom of the combustion chamber (11), and the in-furnace drive system (3) is installed in the combustion chamber (11) and located above the chain grate (4); the in-furnace drive system (3) includes: at least one row of material conveying mechanisms, and multiple rows of material conveying mechanisms are arranged sequentially from top to bottom; the front end of the material conveying mechanism located at the top layer is located below the feed inlet (104); the in-furnace drive system (3) is used to repeatedly transfer biomass fuel and transfer biomass fuel to the chain grate (4); The bottom of the combustion chamber (11) is provided with a slag outlet (103); when biomass fuel falls from the front end of the lowest material conveying mechanism onto the chain grate (4), the chain grate (4) is located near the front side wall of the combustion chamber (11) and moves the completely burned biomass fuel to the rear, and the slag outlet (103) is located on the rear side of the chain grate (4); when biomass fuel falls from the rear end of the lowest material conveying mechanism onto the chain grate (4), the chain grate (4) is located near the rear side wall of the combustion chamber (11) and moves the fully burned biomass fuel forward, and the slag outlet (103) is located on the front side of the chain grate (4).

2. The multi-trip combustion working bundled straw biomass direct-fired boiler of claim 1, wherein, When any material conveying mechanism is positioned with its front or rear end close to the side wall of the combustion chamber (11), its other end is spaced from the side wall of the combustion chamber (11), and the size of the space is greater than the maximum size of the biomass fuel.

3. The multi-trip combustion working bundled straw biomass direct-fired boiler of claim 1, wherein, For any two adjacent rows of material conveying mechanisms, if the front end of one row of material conveying mechanisms is located close to the front side wall of the combustion chamber (11), then the rear end of the other row of material conveying mechanisms is located close to the rear side wall of the combustion chamber (11).

4. The multi-trip combustion working bundled straw biomass direct-fired boiler of claim 2, wherein, The end of any material conveying mechanism that is near the side wall of the combustion chamber (11) is higher than the end that is away from the side wall of the combustion chamber (11).

5. The multi-pass combustion-powered direct-fired boiler for baled straw biomass according to claim 1, characterized in that, Any row of material conveying mechanisms includes: multiple drive shafts, which are located in the same plane and are arranged in parallel to each other. The two ends of each drive shaft are rotatably connected to the left and right side walls of the combustion chamber (11), respectively. The multiple drive shafts rotate synchronously in a clockwise or counterclockwise direction, and the rotation direction of the multiple drive shafts is the same as the transfer direction of the biomass fuel located above them.

6. The multi-trip combustion working bundled straw biomass direct-fired boiler of claim 1, wherein, Also includes: The two ends of the packing breaker (5) and the coke breaker (106) are rotatably connected to the left and right side walls of the combustion chamber (11), respectively. The two ends of the coke breaker (106) are rotatably connected to the left and right side walls of the combustion chamber (11), respectively. The packing breaker (5) and the coke breaker (106) are both located above the chain grate (4). The packing breaker (5) and the coke breaker (106) rotate synchronously in a clockwise or counterclockwise direction. The rotation direction of the packing breaker (5) and the coke breaker (106) is the same as the conveying direction of the chain grate (4).

7. The multi-trip combustion working bundled straw biomass direct-fired boiler of claim 1, wherein, Also includes: A baling straw feeder (2) is used to transfer biomass fuel to the feed inlet (104) of the boiler body (1) and push it into the combustion chamber (11); the baling straw feeder (2) includes: a structural frame (21), a baffle (22) and a hopper (23). The rear end of the structural frame (21) is connected to the feed inlet (104) of the boiler body (1). Baffles (22) are installed on the left and right sides of the structural frame (21). The hopper (23) travels on the upper surface of the structural frame (21). The hopper (23) is used to push the biomass fuel located on the structural frame (21) into the combustion chamber (11); The bottom of the hopper (23) is equipped with wheels, and gears are rotatably mounted on the side of the hopper (23). The upper surface of the structural frame (21) is equipped with a rack, and the gear meshes with the rack. The hopper (23) moves on the structural frame (21) by driving the gear to rotate.

8. The multi-trip combustion working bundled straw biomass direct-fired boiler of claim 1, wherein, Also includes: The heat exchange chamber (12) is equipped with a boiler drum (108) at the top of the water-cooled wall tube (109), a combustion chamber (110) is provided on the front side of the heat exchange chamber (12), and multiple water-cooled wall tubes (109) are evenly distributed on the left and right side walls of the boiler drum (108), the combustion chamber (110) and the combustion chamber (11). The rear side wall of the combustion chamber (11) is provided with a water inlet (111) communicating with the water-cooled wall tube (109), and the heat exchange chamber (12) is provided with a drain outlet and / or exhaust outlet communicating with the water-cooled wall tube (109).

9. The multi-trip combustion working bundled straw biomass direct-fired boiler as claimed in claim 1, wherein, Also includes: The speed reducer unit (6) is used to drive the operation of the furnace transmission system (3), chain grate (4), packing shaft (5) and coke breaking shaft (106).

10. The multi-pass combustion-powered direct-fired boiler for baled straw biomass according to claim 1, characterized in that, The combustion chamber (11) has an inclined preheating furnace arch (101) at the top front side, an inclined limiting furnace arch (102) at the top rear side, and an inclined burnout furnace arch (107) at the bottom. The preheating furnace arch (101) is located above the feed inlet (104); the burnout furnace arch (107) is located above the slag outlet (103); and air ducts (112) are provided on the left and right side walls of the combustion chamber (11).

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