A biomass pellet combustion boiler and combustion method suitable for rice and wheat straw

Abstract

The present application provides a kind of biomass pellet combustion boiler and combustion method suitable for rice and wheat straw, including feeding device, drying chamber, gas device, gas cooling device and gas treatment device;The discharge port of the feeding device is connected with one end of the drying chamber, and the other end of the drying chamber is connected with the upper part of the gas device;Gas device is connected with gas cooling device and gas treatment device respectively;Gas treatment device is connected with gas device and gas cooling device respectively;Pyrolysis gas of gas device enters gas treatment device, and the gas that has occurred in gas device enters gas cooling device after cooling and then enters gas treatment device.The present application designs and optimizes each link used in rice and wheat straw biomass boiler, improves the combustion rate of biomass pellet through two pyrolysis, and improves the purity of biomass pellet combustion through two dust removal.

Description

Technical Field

[0001] This invention belongs to the field of biomass combustion boilers, and particularly relates to a biomass pellet combustion boiler and combustion method suitable for rice and wheat straw. Background Technology

[0002] With the continuous development of my country's industry, fossil energy is gradually becoming scarce, and the dependence on foreign primary energy sources is increasing year by year. Therefore, the development and utilization of rice and wheat straw energy—the fourth largest energy source—is of great significance. As a major agricultural producer in the world, my country produces approximately 900 million tons of crop straw annually. Of this, about 40% is used as feed, fertilizer, or straw returned to the field, while the majority is directly burned, resulting in resource waste. Currently, research on rice and wheat straw biomass pellet boilers in my country is still in its initial stage. Designing and optimizing all aspects of the use of rice and wheat straw biomass boilers to improve the combustion rate and purity of biomass pellets is of great strategic importance.

[0003] In recent years, with the introduction of dual-carbon goals, research on biomass boilers has been ongoing. Chinese patent CN115406099A discloses a boiler with a cooling device. The boiler combustion chamber connects multiple fire inlets and flues, and a water jacket cooling device provides circulating cooling for the boiler. This design is simple in structure, highly practical, and effectively prevents the combustion chamber and fire outlets from burning out, thus extending the service life of the new biomass boiler with the cooling device. However, it requires a large water-cooled box, occupying a lot of space and making installation inconvenient. Chinese patent CN218095976U discloses an anti-jamming reciprocating grate for biomass combustion boilers, including a furnace, power box, first grate, second grate, third grate, fourth grate, and fifth grate. This design effectively prevents biomass fuel from clogging and becoming embedded between adjacent grates, resulting in a low failure rate and high reliability. However, small particles can get stuck in the grate gaps during operation, causing difficulties in grate operation. Furthermore, the lower space isolated by the grate is not utilized, resulting in wasted space. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a biomass pellet combustion boiler and combustion method suitable for rice and wheat straw. The invention designs and optimizes each stage of the rice and wheat straw biomass boiler's operation, improving the combustion rate of biomass pellets through two pyrolysis processes and enhancing the purity of biomass pellet combustion through two dust removal processes.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A biomass pellet combustion boiler suitable for rice and wheat straw includes a feeding device, a drying chamber, a gas combustion device, a gas cooling device, and a gas treatment device.

[0007] The discharge port of the feeding device is connected to one end of the drying chamber, and the other end of the drying chamber is connected to the upper part of the gas device; the gas device is connected to the gas cooling device and the gas treatment device respectively; the gas treatment device is connected to the gas device and the gas cooling device respectively; the pyrolysis gas of the gas device enters the gas treatment device, and the gas that has already been generated by the gas device enters the gas cooling device for cooling before entering the gas treatment device.

[0008] In the above scheme, the feeding device includes a feed inlet, a feeder, and a discharge outlet; one end of the feeder is provided with a feed inlet, and the other end is provided with a discharge outlet, which is connected to one end of the drying chamber.

[0009] In the above scheme, the drying chamber includes a drying chamber cavity;

[0010] One end of the drying chamber is provided with a drying chamber inlet, which is used to connect with the discharge port and the hot air furnace. The other end of the drying chamber is provided with a biomass outlet. There is an upward bulge between the drying chamber inlet and the biomass outlet. A hot air outlet is provided above the bulge. The other end of the drying chamber is provided with a communicating cylindrical cavity. The inner diameter of the cylindrical cavity is smaller than the width of the connection surface with the drying chamber.

[0011] In the above scheme, the gas device includes a pyrolysis screw, a gas generator, a dust removal pipe, and a dust collector;

[0012] One end of the pyrolysis screw is provided with a pyrolysis screw inlet and a pyrolysis air inlet, and the pyrolysis screw inlet is connected to the drying chamber; the other end of the pyrolysis screw is provided with an interface communicating with the upper part of the gas generator, and the middle and rear section of the pyrolysis screw is provided with a pyrolysis gas outlet; the pyrolysis gas outlet is connected to the gas processing device.

[0013] The pyrolysis spiral bar has a spiral mechanism designed inside the central rod. The spiral mechanism includes a main shaft and a spiral blade. The spiral blade is installed on the main shaft. The main shaft is connected to the drive mechanism. The drive mechanism drives the main shaft to rotate the spiral blade. During the rotation, the spiral blade transports the rice and wheat straw forward.

[0014] The gas generator is provided with a reducing gas inlet; the lower part of the gas generator is provided with a generated gas outlet, which is connected to the dust collector inlet of the dust collector through a dust removal pipe, and the dust collector outlet of the dust removal pipe is connected to a gas cooling device.

[0015] In the above scheme, the gas cooling device includes at least a first heat exchanger, a second heat exchanger, and a third heat exchanger;

[0016] The inlet of the first heat exchanger is connected to the gas generator via a pipeline, the outlet of the heat exchanger is connected to the inlet of the second heat exchanger via a pipeline, the outlet of the second heat exchanger is connected to the inlet of the third heat exchanger via a pipeline, and the outlet of the third heat exchanger is connected to the inlet of the cyclone separator of the gas processing device via a pipeline.

[0017] Furthermore, the heat pipes of the first, second, and third heat exchangers are aluminum tubes with grooves machined on the inner wall and sealed at both ends. After the aluminum tubes are evacuated to a high vacuum, liquid working fluid is injected into them.

[0018] In the above scheme, the gas processing device includes a cyclone separator, a gas separation pipeline, a filter, a filter support frame, a condenser, and a condensation pipeline;

[0019] The upper part of the cyclone separator is provided with a pyrolysis gas inlet, a generated gas inlet, and a separated gas outlet; the pyrolysis gas inlet is connected to the gas device, the generated gas inlet is connected to the gas cooling device; the separated gas outlet is connected to the filter through a pipe; the bottom of the cyclone separator is provided with a liquid outlet.

[0020] The filter is mounted on a filter support frame; the filter is connected to the condenser inlet of the condenser via a condenser pipe, and the condenser outlet is used to connect to a gas-powered engine.

[0021] In the above scheme, the feeding device further includes a feeder support frame; the feeder support frame is installed at the lower part of the feeder, so that the feeder is at an angle of 40°~45° with the horizontal plane.

[0022] In the above scheme, the gas cooling device further includes a gas cooling device support frame; the first heat exchanger, the second heat exchanger, and the third heat exchanger are arranged in a row and installed on the heat exchanger support frame.

[0023] A combustion method for a biomass pellet boiler suitable for rice and wheat straw includes the following steps:

[0024] The biomass pellets of rice and wheat straw enter the feeder through the feed inlet of the feeding device, and enter the drying chamber through the discharge outlet. Hot air at a temperature of 350-380℃ is introduced into the drying chamber inlet to dry the rice and wheat straw. The hot air is discharged from the hot air outlet. After drying, the rice and wheat straw biomass pellets enter the pyrolysis screw through the drying chamber biomass outlet and the pyrolysis screw inlet.

[0025] The pyrolysis screw has a spiral mechanism designed inside its central rod. During rotation, the spiral blades transport the rice and wheat straw biomass pellets forward. Hot air at 390-410°C is introduced through the pyrolysis air inlet below the pyrolysis screw inlet to perform preliminary pyrolysis of the rice and wheat straw. The pyrolysis gas is discharged through the pyrolysis gas outlet and enters a cyclone separator through a pipeline from the pyrolysis gas inlet. The remaining rice and wheat straw biomass pellets enter the gas generator. Hot reducing gas is introduced through the reducing gas inlet of the gas generator to produce gas. Dust-laden gas passes through a dust removal pipe from the inlet. The gas enters the dust collector tangentially for dust removal. The dust collector is connected to the heat exchanger of the gas cooling device through a pipeline. The gas that has undergone dust removal enters the heat exchanger through the pipeline for cooling. It then passes through the outlet of the heat exchanger and the inlet of the generated gas to enter the cyclone separator. The gas enters the cyclone separation zone inside the cyclone separator. High-density droplets and dust particles flow out from the liquid outlet at the bottom of the cyclone separator. The rotating airflow enters the filter through the outlet of the cyclone separator. The purified gas enters the condenser through the condensation pipeline and is condensed in the condenser.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. This invention designs and optimizes each stage of the use of rice and wheat straw biomass boilers, improves the combustion rate of biomass pellets through two pyrolysis processes, and improves the purity of biomass pellet combustion through two dust removal processes.

[0028] 2. The pyrolysis screw of the present invention pushes rice and wheat straw into the gas generator in a spiral manner, and allows the rice and wheat straw to undergo preliminary pyrolysis during the spiral's forward movement, which can ensure that the rice and wheat straw undergoes more complete pyrolysis and improve its utilization rate.

[0029] 3. The gas device of the present invention uses a gas generator, which will not cause small particles to get stuck in the gaps between the grate during operation, making the grate difficult to operate, and will not cause waste of space.

[0030] 4. The gas cooling device of the present invention includes at least three heat exchangers arranged in a row and connecting pipes, which can fully cool the gas, without the need for a large water cooling box, occupying little space and being easy to install.

[0031] 5. The gas processing device of the present invention uses a dust filter and a cyclone separator to remove impurities from the generated gas. The generated gas is absorbed by the cyclone separator and then processed by the dust filter to obtain pure gas. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of a rice and wheat straw biomass pellet combustion furnace according to one embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the feeding device structure according to an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the drying chamber structure according to one embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of the structure of a gas device according to an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of the cooling device structure according to an embodiment of the present invention;

[0037] Figure 6 This is a schematic diagram of the structure of a gas processing device according to an embodiment of the present invention;

[0038] Figure 7 This is a schematic diagram of the structure of a gas-fired engine device according to an embodiment of the present invention;

[0039] Figure 8 This is a flowchart of the working process of a rice and wheat straw biomass pellet combustion furnace according to one embodiment of the present invention.

[0040] In the diagram, 1. Feeding device, 101. Inlet, 102. Feeder, 103. Drying chamber, 104. Feeder support frame, 105. Outlet, 106. Drying chamber inlet, 107. Hot air outlet, 108. Biomass outlet, 109. Cylindrical cavity, 110. Rump; 2. Gasification device, 201. Pyrolysis screw, 201-1. Pyrolysis screw inlet, 201-2. Pyrolysis air inlet, 201-3. Pyrolysis gas outlet, 202. Gas generator, 202-1. Reducing gas inlet, 202-2. Generated gas outlet, 203. Dust removal pipe, 204. Dust collector, 204-1. Dust collector inlet, 204-2. Dust collector outlet; 3. Gas cooling device, 301. Heat exchanger 1, 301-1. Heat exchanger 1 inlet. 301-2. Heat exchanger 1 outlet, 302. Heat exchanger 2, 302-1. Heat exchanger 2 inlet, 302-2. Heat exchanger 2 outlet, 303. Heat exchanger 3, 303-1. Heat exchanger 3 inlet, 303-2. Heat exchanger 3 outlet, 304. Gas cooling device support frame, 4. Gas processing device, 401. Cyclone separator, 401-1 pyrolysis gas inlet, 401-2. Reacted gas inlet, 401-3. Cyclone separator outlet, 402. Gas separation pipeline, 403. Filter, 404. Filter support frame, 405. Condenser, 405-1. Condenser inlet, 405-2. Condensed gas outlet, 406. Condensation pipeline, 5. Gas engine device, 501. Gas engine, 502. Gas pipe. Detailed Implementation

[0041] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0042] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "front," "rear," "left," "right," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0043] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] Figure 1 The image shows a preferred embodiment of the biomass pellet combustion boiler suitable for rice and wheat straw. The biomass pellet combustion boiler suitable for rice and wheat straw includes a feeding device 1, a gas combustion device 2, a gas cooling device 3, and a gas treatment device 4.

[0045] The discharge port 105 of the feeding device 1 is connected to one end of the drying chamber, and the other end of the drying chamber is connected to the upper part of the gas device 2; the gas device 2 is connected to the gas cooling device 3 and the gas treatment device 4 respectively; the gas treatment device 4 is connected to the gas device 2 and the gas cooling device 3 respectively; the pyrolysis gas of the gas device 2 enters the gas treatment device 4, and the generated gas of the gas device 2 enters the gas cooling device 3 for cooling before entering the gas treatment device 4.

[0046] This invention can remove dust from the gas produced by inhaled biomass pellets, and treat the gas to remove dust, cool down and condense it. The final purified and condensed gas can be used to enter a gas engine to provide power.

[0047] In one specific embodiment of the present invention, a gas device 2, a gas treatment device 4, and a gas cooling device 3 are sequentially arranged on the same side of the feeding device 1 from the inlet to the outlet, and a gas starting device 5 is fixed to one side of the gas cooling device 3.

[0048] like Figure 2 As shown, the feeding device 1 includes an inlet 101, a feeder 102, and an outlet 105; one end of the feeder 102 is provided with an inlet 101, and the other end is provided with an outlet 105, which is connected to one end of the drying chamber.

[0049] like Figure 3 As shown, in a specific embodiment of the present invention, the drying chamber includes a drying chamber cavity 103; one end of the drying chamber cavity 103 is provided with a drying chamber inlet 106, which is used to connect with the discharge port 105 and the hot air furnace; the other end of the drying chamber cavity 103 is provided with a biomass outlet 108 below; an upward bulge 110 is provided between the drying chamber inlet 106 and the biomass outlet 108; a hot air outlet 107 is provided above the bulge 110; the bulge 110 is used to resist part of the hot air entering the drying chamber, giving it a reaction force, and the hot air is discharged from the hot air outlet 107 above the bulge.

[0050] In one specific embodiment of the present invention, a cylindrical cavity 109 is provided at the other end of the drying chamber 103. The inner diameter of the cylindrical cavity 109 is smaller than the width of the connection surface with the drying chamber 103, so as to resist the biomass particles that impact forward under inertia. The biomass particles pass through the cylindrical cavity 109 and hit its inner wall, obtaining a reverse impact force. Under the action of gravity, they fall along the cylindrical cavity 109 to the biomass outlet 108 for discharge.

[0051] In one specific embodiment of the present invention, the feed inlet 101 is located at the bottom of the feeder 102, and the feeder 101 is designed with a transmission belt (not shown in the figure) for transporting rice and wheat straw.

[0052] In one specific embodiment of the present invention, the feeder support frame 104 is fixed to the lower part of the feeder, and the support frame is 4200mm high, so that the feeder is at an angle of 40°~45° with the horizontal plane. At this angle, the feeder track can overcome the gravity of rice and wheat straw and feed the material.

[0053] In one specific embodiment of the present invention, the drying chamber is located at the discharge port 105, but the two are not directly connected. The drying chamber inlet 106 is located below the discharge port 105. The drying chamber inlet 106 is designed to be larger than the discharge port 105 to ensure that all rice and wheat straws fall into the drying chamber under gravity. The hot air furnace is connected to the drying chamber inlet 106 through a pipe. Hot air at a temperature of 350-380℃ is introduced into the drying chamber inlet 106 to dry the rice and wheat straw and accelerate the transportation process of the rice and wheat straw in the drying chamber. The hot air is recycled from the hot air outlet 107 through a pipe to the hot air furnace, so that the biomass is discharged from the biomass outlet 108 of the drying chamber 103.

[0054] like Figure 4 As shown, the gas device 2 includes a pyrolysis screw 201, a gas generator 202, a dust removal pipe 203, and a dust collector 204;

[0055] One end of the pyrolysis spiral rod 201 is provided with a pyrolysis spiral rod inlet 201-1 and a pyrolysis air inlet 201-2, and the pyrolysis spiral rod inlet 201-1 is connected to the drying chamber; the other end of the pyrolysis spiral rod 201 is provided with an interface communicating with the upper part of the gas generator 202, and the middle and rear section of the pyrolysis spiral rod 201 is provided with a pyrolysis gas outlet 201-3; the pyrolysis gas outlet 201-3 is connected to the gas processing device 4;

[0056] The pyrolysis spiral rod 201 has a spiral mechanism designed in the inner central rod. The spiral mechanism includes a main shaft and a spiral blade. The spiral blade is installed on the main shaft. The main shaft is connected to the drive mechanism. The drive mechanism drives the main shaft to rotate the spiral blade. During the rotation, the spiral blade transports the rice and wheat straw forward.

[0057] The gas generator 202 is provided with a reducing gas inlet 202-1; the lower part of the gas generator 202 is provided with a generated gas outlet 202-2, which is connected to the dust collector inlet 204-1 of the dust collector 204 through a dust collector pipe 203, and the dust collector outlet 204-2 of the dust collector pipe 203 is connected to the gas cooling device 3.

[0058] In one specific embodiment of the present invention, the pyrolysis screw 201 is located above the gas generator 202, and the biomass outlet 108 is connected to the pyrolysis screw inlet 201-1. Rice and wheat straw biomass enters the pyrolysis screw 201 from the pyrolysis screw inlet 201-1. The central rod inside the pyrolysis screw 201 is designed with a screw mechanism, which includes a main shaft and a screw blade. The screw blade is mounted on the main shaft, and the main shaft is connected to a drive mechanism. The drive mechanism is preferably a motor. The motor drives the main shaft to rotate the screw blade, and the screw blade conveys the rice and wheat straw forward during the rotation. In one specific embodiment of the present invention, hot air at 390-410°C is introduced into the lower pyrolysis air inlet 201-2 to perform preliminary pyrolysis on the rice and wheat straw. The pyrolysis gas is discharged through the pyrolysis gas outlet 201-3 and connected to 401-1. Hot reducing gas is introduced into the air inlet 202-1 of the gas generator 202 to convert carbon in the rice and wheat straw into CO and hydrogen into H2, producing gas. The dust collector 204 is located to the right rear of the gas generator and is connected to the gas generator 202 through the dust collection pipe 203. The generated gas outlet 202-2 of the dust removal duct 203 is connected to the heat exchanger 301-1 via a pipe. Dust-laden gas enters tangentially from the inlet. While the airflow gains rotational motion, the airflow separates into upper and lower sections to form a double vortex motion. Dust is strongly separated at the boundary of the double vortex. Coarser dust particles are separated to the outer wall by the lower vortex airflow. Some of the dust is drawn out through the central opening of the bypass separation chamber, and the remaining dust is carried into the ash hopper by the downward airflow. The upper vortex airflow has an agglomeration effect on fine dust particles, thereby improving dust removal efficiency.

[0059] like Figure 5 As shown, the gas cooling device 3 includes at least a first heat exchanger 301, a second heat exchanger 302, and a third heat exchanger 303;

[0060] The first heat exchanger inlet 301-1 is connected to the gas generator 202 via a pipeline, the heat exchanger outlet 301-2 is connected to the second heat exchanger inlet 302-1 via a pipeline, the second heat exchanger outlet 302-2 is connected to the third heat exchanger inlet 303-1 via a pipeline, and the third heat exchanger outlet 303-2 is connected to the cyclone separator inlet 401-2 of the gas processing device 4 via a pipeline.

[0061] In one specific embodiment of the present invention, the gas cooling device 3 further includes a gas cooling device support frame 304; the first heat exchanger 301, the second heat exchanger 302, and the third heat exchanger 303 are arranged in a row and installed on the heat exchanger support frame 304.

[0062] In one specific embodiment of the present invention, the heat pipes of the first heat exchanger 301, the second heat exchanger 302, and the third heat exchanger 303 are aluminum tubes with grooves machined on the inner wall and sealed at both ends. After the aluminum tubes are evacuated to a high vacuum, liquid working fluid is injected. When one end of the aluminum tube is heated, the working fluid inside the tube vaporizes, absorbing the heat of vaporization from the heat source. After vaporization, the vapor flows to the other end and condenses upon encountering condensation, releasing latent heat into the heat dissipation area. The condensate flows back under the action of capillary force and gravity, and continues to be heated and vaporized. This repeated cycle transfers a large amount of heat from the heating area to the heat dissipation area through the phase change process of the working fluid.

[0063] like Figure 6 As shown, the gas processing device 4 includes a cyclone separator 401, a gas separation pipe 402, a filter 403, a filter support frame 404, a condenser 405, and a condensation pipe 406.

[0064] The upper part of the cyclone separator 401 is provided with a pyrolysis gas inlet 401-1, a generated gas inlet 401-2, and a separated gas outlet 401-3; the pyrolysis gas inlet 401-1 is connected to the gas device 2, the generated gas inlet 401-2 is connected to the gas cooling device 3; the separated gas outlet 401-3 is connected to the filter 403 through a pipe; the bottom of the cyclone separator 401 is provided with a liquid outlet;

[0065] The filter 403 is mounted on the filter support frame 404; the filter 403 is connected to the condenser inlet 405-1 of the condenser 405 through the condenser pipe 406, and the condenser outlet 405-2 is used to connect to the gas engine device 5.

[0066] The gas enters the cyclone separation zone inside the cyclone separator 401 through the pyrolysis gas inlet 401-1 and the generated gas inlet 401-2. When the gas containing impurities enters the cyclone separation tube axially, the airflow is strongly rotated by the guiding action of the guide vanes. The airflow spirals downward into the cyclone tube along the cylinder. The denser droplets and dust particles are thrown towards the wall of the device under the action of centrifugal force, and under the action of gravity, they fall down the cylinder wall and flow out of the dust discharge port of the cyclone tube to the liquid storage area at the bottom of the equipment, and flow out from the liquid outlet at the bottom of the cyclone separator 401. The rotating airflow contracts and flows towards the center within the cylinder, forming a secondary vortex that flows upward through the air guide pipe to the purified gas chamber, and then enters the filter 403 through outlet 401-3. The filter 403 is fixed by the filter support frame 404. When the dust-laden gas passes through the filter medium in the filter 403, the dust is trapped on its surface, and the clean gas is discharged through the gaps in the filter medium. The cyclone separator 401 is located to the right front of the filter 403 and is connected to the filter 403 through the gas separation pipe 402. The condenser 405 is located to the left of the filter 403 and is used to condense the gas at a higher temperature to improve thermal efficiency. The condenser inlet 405-1 of the condenser 405 is connected to the filter 403 through the gas condensation pipe 406.

[0067] like Figure 7 As shown, in a specific embodiment of the present invention, the gas processing device 4 is connected to the gas engine device 5. The gas engine device 5 mainly includes a gas engine 501 and a gas pipe 502. The gas engine 501 is located in front of the condenser 405. The gas engine 501 is connected to the condensed gas outlet 405-2 through the gas pipe 502. Gas enters the engine 501 from the condenser 405 through the gas pipe 502 to provide power.

[0068] like Figure 8As shown, rice and wheat straw biomass pellets enter the feeder 102 through the inlet 101 and enter the drying chamber 103 through the outlet 105 and the drying chamber inlet 106. Hot air at a temperature of 350-380℃ is introduced into the drying chamber through the hot air outlet 107 to dry the rice and wheat straw. The hot air is discharged from the biomass outlet 108. After drying, the rice and wheat straw biomass pellets enter the pyrolysis screw 201 through the pyrolysis screw inlet 201-1. The pyrolysis screw 201 has a screw mechanism designed in the central rod. During the rotation of the screw blades, the rice and wheat straw biomass pellets are conveyed forward. Hot air at 390-410℃ is introduced into the pyrolysis air inlet 201-2 below. The rice and wheat straw undergoes preliminary pyrolysis, and the pyrolysis gas is discharged through the pyrolysis gas outlet 201-3. It then enters the cyclone separator 401 through a pipeline from the pyrolysis gas inlet 401-1. The remaining rice and wheat straw biomass pellets enter the gas generator 202. Hot reducing gas is introduced into the gas generator 202 through its inlet 202-1 to produce gas. The dust collector 204 is located to the right rear of the gas generator and is connected to it through a dust collection pipe 203. The dust-laden gas enters tangentially from the inlet. While the airflow gains rotational motion, it also separates upwards and downwards, forming a double vortex motion. The dust undergoes strong separation at the boundary between the double vortices, with coarser dust particles carried by the downward vortex airflow. The dust is separated to the outer wall, with some of it being drawn out through the central opening of the bypass separation chamber. The remaining dust is carried into the ash hopper by the downward airflow. The upward swirling airflow has an agglomerating effect on fine dust particles, improving dust removal efficiency. The generated gas outlet 202-2 of the dust collector pipe 203 is connected to the heat exchanger 301 via a pipe. The gas that has undergone dust removal enters the first heat exchanger 301 through the pipe for initial cooling. Then, it exits from the first heat exchanger outlet 301-2 and enters the second heat exchanger 302 through the second heat exchanger inlet 302-1 for secondary cooling. Finally, it exits from the second heat exchanger outlet 302-2 and enters the third heat exchanger inlet 303-1 for further cooling. The heat exchanger 303 undergoes a third cooling process. Immediately afterwards, the gas enters the cyclone separator 401 through the outlet 303-2 of the third heat exchanger and the inlet 401-2 of the generated gas. The gas enters the cyclone separation zone inside the cyclone separator through the pyrolysis gas inlet 401-1 and the inlet 401-2 of the generated gas. When the gas containing impurities enters the cyclone separation tube axially, the airflow is strongly rotated by the guiding action of the guide vanes. The airflow spirals downward along the cylinder and enters the cyclone cylinder. The denser droplets and dust particles are thrown towards the wall under the action of centrifugal force and fall down the cylinder wall under the action of gravity, flowing out of the dust discharge port of the cyclone tube to the liquid storage area at the bottom of the equipment and flowing out from the liquid outlet at the bottom of the equipment.The rotating airflow contracts and flows towards the center within the cylinder, forming a secondary vortex that flows upward through the air guide pipe to the purified gas chamber. It then enters the filter 403 through the cyclone separator outlet 401-3. When the gas passes through the filter medium in the filter 403, dust is trapped on its surface, and the clean gas is discharged through the gaps in the filter medium. The purified gas enters the condenser 405 through the condenser pipe 406. After condensation in the condenser, it enters the gas engine 501 through the pipe to provide power.

[0069] In a specific embodiment of the present invention, preferably, the feeder 102 is 11800~11900mm long, the feed inlet 101 at the bottom of the feeder is 1700*490mm long and wide, the discharge outlet is 350*120mm long and wide, the drying chamber inlet is 600*370mm long and wide, the drying chamber inlet is smaller than the discharge outlet to ensure that the rice and wheat straw accurately enters the drying chamber cavity 103 for drying treatment, and the feeder support frame 104 is 4200mm high, supported in the middle of the feeder 102, and is at an angle of 40°~45° with the horizontal plane to facilitate the transportation of rice and wheat straw biomass pellets.

[0070] In a specific embodiment of the present invention, preferably, the pyrolysis spiral rod 201 has a diameter of 580~600mm and a length of 6000~6600mm, and is connected to the gas generator 202 through a pipe. It is designed with an internal spiral mechanism to fully expose and pyrolyze the rice and wheat straw biomass particles. The gas generator 202 is 3500~4000mm high and has a maximum diameter of 1900~2000mm. The dust removal pipe 203 has a diameter of 200mm and a length of 2400mm, and is used to connect the gas generator 202 and the dust collector 204 to discharge dust and impurity particles during the gas feeding and generation process, thereby obtaining relatively pure gas.

[0071] In a specific embodiment of the present invention, preferably, the heat exchanger 301 has a diameter of 450 mm and a length of 2700 mm, the three heat exchangers are arranged in a vertical row with their axes 685 mm apart, the heat exchanger support frame 303 is 4000 mm high and supports the heat exchangers, and the lowest heat exchanger is 1710 mm from the ground.

[0072] In a preferred embodiment of the present invention, the dust filter 403 has a diameter of 2000mm and a height of 6500~6600mm; the dust filter support frame 404 has a height of 3400~3500mm and a diameter of 95mm, and is used to fix the dust filter 403; the cyclone separator 501 has a diameter of 350mm and a height of 1535mm, and is connected to the dust filter 403 through a gas separation pipe 502 to filter the gas and ensure the purity of the gas; the condenser 405 has a length, width, and height of 1500*650*460mm, and is connected to the dust collector 403 through a gas condensation pipe 406 to facilitate the condensation of pure gas.

[0073] In one specific embodiment of the present invention, preferably, the gas engine 501 has a length, width and height of 2660*640*630mm, and is connected to the condenser through a gas pipe 502, so that the condensed pure gas enters the engine.

[0074] This invention designs and optimizes each stage of the use of rice and wheat straw biomass boilers. It improves the combustion rate of biomass pellets through two pyrolysis processes and improves the purity of biomass pellet combustion through two dust removal processes.

[0075] The pyrolysis screw 201 of the present invention pushes rice and wheat straw into the gas generator 202 in a spiral manner, and allows the rice and wheat straw to undergo preliminary pyrolysis during the spiral's forward movement, which can ensure that the rice and wheat straw undergoes more complete pyrolysis and improve its utilization rate.

[0076] The gas device of this invention uses a gas generator 202, which prevents small particles from getting stuck in the gaps between the grate during operation, thus avoiding difficulties in grate operation and also avoids wasting space.

[0077] The gas cooling device 3 of the present invention includes at least three heat exchangers arranged in a row and connecting pipes, which can fully cool the gas, without the need for a large water cooling box, occupying little space and being easy to install.

[0078] The gas processing device 4 of the present invention uses a dust filter 403 and a cyclone separator 401 to filter and remove impurities from the generated gas. The cyclone separator 401 absorbs the generated gas, and then the gas is processed by the dust filter 403 to obtain pure gas.

[0079] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0080] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A combustion method for a biomass pellet boiler suitable for rice and wheat straw combustion, characterized in that, The biomass pellet combustion boiler suitable for rice and wheat straw includes a feeding device (1), a drying chamber, a gasification device (2), a gas cooling device (3), and a gas treatment device (4). The outlet (105) of the feeding device (1) is connected to one end of the drying chamber, and the other end of the drying chamber is connected to the upper part of the gas device (2); the gas device (2) is connected to the gas cooling device (3) and the gas processing device (4) respectively; the gas processing device (4) is connected to the gas device (2) and the gas cooling device (3) respectively; the pyrolysis gas of the gas device (2) enters the gas processing device (4), and the generated gas of the gas device (2) enters the gas cooling device (3) for cooling before entering the gas processing device (4); The feeding device (1) includes an inlet (101), a feeder (102), and an outlet (105); one end of the feeder (102) is provided with an inlet (101), and the other end is provided with an outlet (105), and the outlet (105) is connected to one end of the drying chamber; The drying chamber includes a drying chamber cavity (103); one end of the drying chamber cavity (103) is provided with a drying chamber inlet (106), which is used to connect with the discharge port (105) and the hot air furnace; the other end of the drying chamber cavity (103) is provided with a biomass outlet (108); an upward bulge (110) is provided between the drying chamber inlet (106) and the biomass outlet (108); a hot air outlet (107) is provided above the bulge (110); the other end of the drying chamber cavity (103) is provided with a communicating cylindrical cavity (109); the inner diameter of the cylindrical cavity (109) is smaller than the width of the connection surface with the drying chamber cavity (103); The gasification device (2) includes a pyrolysis screw (201), a gas generator (202), a dust removal pipe (203), and a dust collector (204); one end of the pyrolysis screw (201) is provided with a pyrolysis screw inlet (201-1) and a pyrolysis air inlet (201-2), and the pyrolysis screw inlet (201-1) is connected to the drying chamber; the other end of the pyrolysis screw (201) is provided with an interface communicating with the upper part of the gas generator (202), and the middle and rear section of the pyrolysis screw (201) is provided with a pyrolysis gas outlet (201-3); the pyrolysis gas outlet (201-3) is connected to the gas processing device (4); the interior of the pyrolysis screw (201) The central rod is designed with a spiral mechanism, which includes a main shaft and a spiral blade. The spiral blade is installed on the main shaft, which is connected to the drive mechanism. The drive mechanism drives the main shaft to rotate the spiral blade, and the spiral blade transports the rice and wheat straw forward during the rotation. The gas generator (202) is provided with a reducing gas inlet (202-1). The lower part of the gas generator (202) is provided with a generated gas outlet (202-2). The generated gas outlet (202-2) is connected to the dust collector inlet (204-1) of the dust collector (204) through a dust removal pipe (203). The dust collector outlet (204-2) of the dust collector (204) is connected to the gas cooling device (3). The gas processing device (4) includes a cyclone separator (401), a gas separation pipe (402), a filter (403), a filter support frame (404), a condenser (405), and a condensation pipe (406). The upper part of the cyclone separator (401) is provided with a pyrolysis gas inlet (401-1), a generated gas inlet (401-2), and a separated gas outlet (401-3); the pyrolysis gas inlet (401-1) is connected to the gas device (2), the generated gas inlet (401-2) is connected to the gas cooling device (3); the separated gas outlet (401-3) is connected to the filter (403) through a pipe; the bottom of the cyclone separator (401) is provided with a liquid outlet; The filter (403) is mounted on the filter support frame (404); the filter (403) is connected to the condenser inlet (405-1) of the condenser (405) via the condenser pipe (406), and the condenser outlet (405-2) is used to connect to the gas engine (5); The biomass pellets of rice and wheat straw enter the feeder (102) from the feeding device (1), and enter the drying chamber cavity (103) through the drying chamber inlet (106) from the discharge port (105). Hot air at a temperature of 350-380℃ is introduced at the drying chamber inlet (106) to dry the rice and wheat straw. The hot air is discharged from the hot air outlet (107). After drying, the rice and wheat straw biomass pellets enter the pyrolysis screw (201) through the drying chamber biomass outlet (108) and the pyrolysis screw inlet (201-1). The pyrolysis spiral rod (201) has a spiral mechanism designed in the center rod. During the rotation of the spiral blades, the rice and wheat straw biomass particles are conveyed forward. Hot air at 390-410℃ is introduced into the pyrolysis air inlet (201-2) below the pyrolysis spiral rod inlet (201-1) to perform preliminary pyrolysis on the rice and wheat straw. The pyrolysis gas is discharged through the pyrolysis gas outlet (201-3) and enters the cyclone separator (401) through the pipeline from the pyrolysis gas inlet (401-1). The remaining rice and wheat straw biomass particles enter the gas generator (202). Hot reducing gas is introduced into the reducing gas inlet (202-1) of the gas generator (202) to generate gas. The dust-laden gas passes through the dust removal pipe (203) from the inlet. The gas enters the dust collector (204) tangentially for dust removal. The dust collector (204) is connected to the heat exchanger of the gas cooling device (3) through a pipe. The gas that has been dusted enters the heat exchanger through the pipe for cooling. It enters the cyclone separator (401) through the outlet of the heat exchanger and the gas inlet (401-2). The gas enters the cyclone separation zone inside the cyclone separator (401). The dense droplets and dust particles flow out from the liquid outlet at the bottom of the cyclone separator (401). The rotating airflow enters the filter (403) through the outlet (401-3) of the cyclone separator. The purified gas enters the condenser (405) through the condensing pipe (406) and is condensed in the condenser (405). The gas cooling device (3) includes at least a first heat exchanger (301), a second heat exchanger (302) and a third heat exchanger (303). The inlet (301-1) of the first heat exchanger is connected to the gas generator (202) via a pipeline, the outlet (301-2) of the first heat exchanger is connected to the inlet (302-1) of the second heat exchanger via a pipeline, the outlet (302-2) of the second heat exchanger is connected to the inlet (303-1) of the third heat exchanger via a pipeline, and the outlet (303-2) of the third heat exchanger is connected to the gas-generated inlet (401-2) of the cyclone separator (401) of the gas processing device (4) via a pipeline. The heat pipes of the first heat exchanger (301), the second heat exchanger (302), and the third heat exchanger (303) are aluminum tubes with grooves on the inner wall and sealed at both ends. After the aluminum tubes are evacuated, liquid working fluid is injected. The method includes the following steps: The biomass pellets of rice and wheat straw enter the feeder (102) through the feed inlet (101) of the feeding device (1), and enter the drying chamber (103) through the drying chamber inlet (106) through the discharge outlet (105). Hot air at a temperature of 350-380℃ is introduced at the drying chamber inlet (106) to dry the rice and wheat straw. The hot air is discharged from the hot air outlet (107). After drying, the rice and wheat straw biomass pellets enter the pyrolysis screw (201) through the drying chamber biomass outlet (108) and the pyrolysis screw inlet (201-1). The pyrolysis spiral rod (201) has a spiral mechanism designed in the center rod. During the rotation of the spiral blades, the rice and wheat straw biomass particles are conveyed forward. Hot air at 390-410℃ is introduced into the pyrolysis air inlet (201-2) below the pyrolysis spiral rod inlet (201-1) to perform preliminary pyrolysis on the rice and wheat straw. The pyrolysis gas is discharged through the pyrolysis gas outlet (201-3) and enters the cyclone separator (401) through the pipeline from the pyrolysis gas inlet (401-1). The remaining rice and wheat straw biomass particles enter the gas generator (202). Hot reducing gas is introduced into the reducing gas inlet (202-1) of the gas generator (202) to generate gas. The dust-laden gas passes through the dust removal pipe (203) from... The gas enters the dust collector (204) tangentially at the inlet for dust removal. The dust collector (204) is connected to the heat exchanger of the gas cooling device (3) through a pipe. The gas that has been dusted enters the heat exchanger through the pipe for cooling. It enters the cyclone separator (401) through the outlet of the heat exchanger and the gas inlet (401-2). It enters the cyclone separation zone inside the cyclone separator (401). The dense droplets and dust particles flow out from the liquid outlet at the bottom of the cyclone separator (401). The rotating airflow enters the filter (403) through the outlet (401-3) of the cyclone separator. The purified gas enters the condenser (405) through the condensing pipe (406) and is condensed in the condenser (405).

2. The combustion method for a biomass pellet boiler using rice and wheat straw according to claim 1, characterized in that, The feeding device (1) also includes a feeder support frame (104); the feeder support frame (104) is installed at the lower part of the feeder (102) so that the feeder (102) is at an angle of 40°~45° to the horizontal plane.

3. The combustion method for a biomass pellet boiler using rice and wheat straw according to claim 1, characterized in that, The gas cooling device (3) also includes a gas cooling device support frame (304); the first heat exchanger (301), the second heat exchanger (302), and the third heat exchanger (303) are arranged in a row and installed on the gas cooling device support frame (304).

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