Vertical chain organic heat carrier biomass boiler

Abstract

The present application relates to a kind of vertical chain organic heat carrier biomass boiler, including combustion chamber, vertical furnace body being arranged at the top of combustion chamber, chain grate being arranged in the inside of combustion chamber, further including: coil assembly, it is arranged in the inside of furnace body, at least including inner layer coil and outer layer coil, organic heat carrier is passed in the inside of inner layer coil and outer layer coil;First return, by the inside of inner layer coil is formed, flue gas flows from bottom to top in first return;Second return, by the between inner layer coil and outer layer coil is formed, flue gas flows from top to bottom in second return;Third return, by the between outer layer coil and furnace inner wall is formed, flue gas flows from bottom to top in third return.The present application, by setting vertical furnace body, and first return and third return are designed as flue gas flows from bottom to top, with the direction of natural buoyancy of high-temperature flue gas consistent, so that flue gas generates natural suction in the process of flowing upwards, auxiliary induced draft fan drives flue gas flow, reduce the operating energy consumption of induced draft fan.

Description

Technical Field

[0001] This invention relates to the field of boiler technology, specifically to a vertical chain-grate organic heat carrier biomass boiler. Background Technology

[0002] An organic heat carrier biomass boiler is a special industrial device that uses biomass (such as sawdust, straw, rice husks, and other agricultural and forestry waste) as fuel, and utilizes the high-temperature heat energy generated by combustion to heat the organic heat carrier (heat transfer oil) to a high-temperature state. Its core function is to deliver the high-temperature heat transfer oil to the heat-using equipment through forced liquid-phase circulation using a circulating pump, indirectly providing stable and precise heat energy to meet the process requirements of high-temperature heating, drying, and reaction in industrial production.

[0003] With the increasing demands on heating equipment from industrial production, traditional single-pass or double-pass organic heat carrier boilers are no longer sufficient to meet the requirements in terms of thermal efficiency, floor space, and operational stability. To address this issue, Chinese Patent CN223179033U discloses a three-pass flue gas combustion organic heat carrier boiler. This boiler features three layers of coils inside the furnace body: an inner coil, a middle coil, and an outer coil, arranged from the inside out. The first pass is located on the inner side of the inner coil, the second pass is located between the inner and middle coils, and the third pass is located between the middle and outer coils. In this three-pass flue gas combustion organic heat carrier boiler, the three-pass design ensures sufficient heat exchange of the flue gas within the furnace, significantly improving thermal efficiency. However, this boiler uses a horizontal structure, and all three passes of the flue gas flow horizontally, making it impossible to utilize the upward buoyancy of the high-temperature flue gas to generate natural draft. The induced draft fan must provide all its power to overcome the flow turning losses and frictional resistance between each return stroke, which means that the induced draft fan needs to consume a lot of energy to maintain the flue gas flow, resulting in high operating energy consumption.

[0004] To address the aforementioned problems, this invention proposes a vertical chain-type organic heat carrier biomass boiler. Summary of the Invention

[0005] (1) Technical problems to be solved The purpose of this invention is to overcome the shortcomings of the prior art, adapt to practical needs, and provide a vertical chain-grate organic heat carrier biomass boiler to solve the above-mentioned technical problems.

[0006] (2) Technical solution To achieve the objectives of this invention, the technical solution adopted is as follows: A vertical chain grate biomass boiler with organic heat carrier includes a combustion chamber, a vertical furnace body disposed at the top of the combustion chamber, and a chain grate disposed inside the combustion chamber. It further includes: a coil assembly disposed inside the furnace body, comprising at least an inner coil and an outer coil, both of which contain organic heat carrier; a first pass formed by the inner side of the inner coil, in which flue gas flows from bottom to top; a second pass formed by the space between the inner and outer coils, in which flue gas flows from top to bottom, with the inlet of the second pass connected to the outlet of the first pass; and a third pass formed by the space between the outer coil and the inner wall of the furnace body, in which flue gas flows from bottom to top, with the inlet of the third pass connected to the outlet of the second pass.

[0007] Furthermore, both the inner and outer coils are spiral coils and are coaxially arranged.

[0008] Furthermore, the flue gas flow cross-sectional area of ​​the first pass is larger than that of the second and third passes.

[0009] Furthermore, the top of the furnace body is provided with a top turning space, through which the outlet of the first return stroke and the inlet of the second return stroke are connected; the bottom of the furnace body is provided with a bottom turning space, through which the outlet of the second return stroke and the inlet of the third return stroke are connected.

[0010] Furthermore, the top of the inner coil is axially lower than the top of the outer coil, and a first gap is formed between them, which constitutes part of the top turning space. The bottom of the inner coil is axially lower than the bottom of the outer coil, and a second gap is formed between them, which constitutes part of the bottom turning space.

[0011] Furthermore, it also includes a mounting base disposed between the furnace body and the combustion chamber, the mounting base having a flue gas passage that connects the first return path to the combustion chamber; the bottom of the inner coil is fixedly connected to the portion of the mounting base located inside the furnace body, a connecting seat is fixedly connected to the top inner side of the furnace body, and the top of the outer coil is fixedly connected to the connecting seat.

[0012] Furthermore, it also includes a flue gas outlet, which is fixedly connected to the top of the furnace body and communicates with the third pass.

[0013] Furthermore, the mounting base is provided with an ash discharge channel. The entrance of the ash discharge channel is connected to the bottom turning space. The ash discharge channel includes a vertical section and an inclined section. The upper end of the vertical section is connected to the bottom turning space, and the lower end of the vertical section is connected to the inclined section. The inclined section extends obliquely downward and penetrates the side wall of the mounting base. A self-discharging ash component is provided in the vertical section. The self-discharging ash component is used to automatically discharge the dust deposited in the bottom turning space during boiler operation.

[0014] Furthermore, the self-draining ash assembly includes a central shaft, which is coaxially arranged with the vertical section. An elastic spiral sheet is sleeved on the outside of the central shaft. The elastic spiral sheet is composed of a continuous spiral strip and forms multiple spiral coils along the axial direction. The elastic spiral sheet has a first state and a second state, and can switch between the first state and the second state. In the first state, an ash discharge gap is formed between adjacent spiral coils. In the second state, adjacent spiral coils are axially compressed and tightly pressed together to form a seal.

[0015] Furthermore, the self-draining ash assembly also includes a support rod, which is fixedly connected to the inner wall of the vertical section, and the central shaft is fixedly connected to the support rod. The elastic spiral plate has a fixed end and a free end. The fixed end is fixedly connected to the support rod, and a slip ring is slidably fitted on the surface of the central shaft. The free end is fixedly connected to the slip ring. When the slip ring moves the free end toward the fixed end, the elastic spiral plate switches from a first state to a second state. The central shaft has a cavity inside, and a permanent magnet that can slide axially is installed inside the cavity. The slip ring is made of ferromagnetic material, and the permanent magnet attracts the slip ring by magnetic force. An electromagnet is installed at one end of the cavity, and a spring is also installed inside the cavity. One end of the spring is fixedly connected to the permanent magnet, and the other end is fixedly connected to the support rod. When the elastic spiral plate is in the second state, the spring has a directional support to the permanent magnet. The force exerted by the support rod; when the electromagnet is de-energized, the spring pulls the permanent magnet towards the fixed end, and the permanent magnet drives the slip ring and free end towards the fixed end through magnetic force, so that the elastic spiral plate is in the second state; when the electromagnet is energized, the electromagnet attracts the permanent magnet and moves it away from the fixed end, and the permanent magnet drives the slip ring and free end away from the fixed end through magnetic force, so that the elastic spiral plate is in the first state; the support rod is located at the bottom of the central shaft, the fixed end is located at the lower end of the elastic spiral plate, and the electromagnet is located at the upper end of the cavity. When the elastic spiral plate is in the second state, the direction of the elastic force applied by the spring to the permanent magnet and the direction of the gravity of the permanent magnet both point towards the support rod, and the two are superimposed in the same direction to jointly maintain the clamping force of the sealing state; elastic sealing strips are provided on the inner and outer edges of the elastic spiral plate. Beneficial effects

[0016] In this invention, by setting up a vertical furnace body and designing the first and third passes with flue gas flowing from bottom to top, aligning with the natural buoyancy of the high-temperature flue gas, the flue gas generates natural draft during its upward flow, assisting the induced draft fan in driving the flue gas flow and thus reducing the operating energy consumption of the induced draft fan. Simultaneously, in the second pass, the flue gas flows from top to bottom. Although it needs to overcome buoyancy, this downward flow, together with the upward flow of the first and third passes, constitutes a compact three-pass layout. This significantly increases the heat exchange area within a limited space, allowing for full absorption of flue gas heat and improving boiler thermal efficiency. The reduction in induced draft fan energy consumption and the improvement in thermal efficiency create a synergistic effect, resulting in a comprehensive energy-saving effect superior to existing horizontal three-pass boilers.

[0017] In this invention, by setting the cross-sectional area of ​​the flue gas flow in the first pass to be larger than that in the second and third passes, the zoning optimization of the radiative and convective heating surfaces is achieved. Specifically, the larger cross-sectional area and lower flue gas velocity in the first pass facilitate sufficient radiative heat transfer from the high-temperature flue gas; while the smaller cross-sectional areas and higher flue gas velocities in the second and third passes enhance convective heat transfer in the narrow annular channels for medium- and low-temperature flue gas. This fully utilizes the physical characteristics of high efficiency in radiative heat transfer at high temperatures and good adaptability of convective heat transfer in medium- and low-temperature regions, achieving highly efficient synergy between radiation and convection in a vertical and compact structure, thereby improving boiler thermal efficiency and reducing exhaust gas temperature.

[0018] In this invention, a self-discharging ash assembly is installed in the vertical section of the ash discharge channel. Utilizing the properties of elastic spiral plates that form ash discharge gaps between adjacent spiral coils in a first state and form a seal when tightly pressed together in a second state, the dual functions of ash discharge and sealing are achieved. When ash discharge is required, the electromagnet is instantaneously energized, driving the elastic spiral plates to switch to the first state, where dust is automatically discharged under gravity. Furthermore, in this state, due to the tortuous path of the spiral channel and the partial filling of ash particles in the gaps, outside air is difficult to enter the boiler system in reverse, thus maintaining a stable negative pressure in the furnace. When sealing is required, the electromagnet is de-energized, and the elastic spiral plates automatically return to the compressed sealing state. This achieves intelligent control of on-demand ash discharge and automatic sealing, effectively preventing ash accumulation in the bottom turning space from obstructing flue gas flow, reducing flue gas flow resistance, and further reducing the operating energy consumption of the induced draft fan.

[0019] In this invention, the support rod is positioned below the central shaft, with the fixed end located at the lower end of the elastic spiral plate. When the elastic spiral plate is in the second state (compression and sealing state), the movable end is located below. At this time, the spring force and the gravity of the permanent magnet both point towards the support rod, and their combined effect allows the sealing state to be maintained for a long time without continuous power supply, achieving zero-energy sealing. Simultaneously, this sealing state is maintained by both spring force and gravity, automatically maintaining the seal even in the event of an accidental power outage, preventing the intake of cold air and providing fail-safe characteristics. Furthermore, because the movable end is located below, an empty area is formed above the vertical section. Accumulated dust falls into this space under gravity, and the weight of the dust itself applies additional pressure to the movable end, further enhancing the stability of the sealing state. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the front section structure of the present invention; Figure 2 For the present invention Figure 1 Enlarged structural diagram at point A; Figure 3 For the present invention Figure 1 Enlarged structural diagram at point B; Figure 4 This is a side sectional view of the present invention; Figure 5 This is a three-dimensional structural diagram of the mounting base of the present invention; Figure 6 This is a three-dimensional structural diagram of the self-draining ash assembly of the present invention; Figure 7 This is a side sectional view of the self-draining ash assembly of the present invention; Figure 8 For the present invention Figure 7 A magnified structural diagram at point C.

[0021] The attached figures are labeled as follows: 1. Combustion chamber; 2. Furnace body; 3. Chain grate; 4. Inner coil; 5. Outer coil; 6. First pass; 7. Second pass; 8. Third pass; 9. Mounting base; 901. Flue gas passage; 902. Ash discharge passage; 9021. Vertical section; 9022. Inclined section; 10. Connecting seat; 11. Flue gas outlet; 12. Self-discharging ash assembly; 1201. Central shaft; 12011. Cavity; 1202. Elastic spiral plate; 12021. Spiral ring; 12022. Fixed end; 12023. Free end; 1203. Support rod; 1204. Slip ring; 1205. Permanent magnet; 1206. Electromagnet; 1207. Spring; 1208. Elastic sealing strip. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1-8 The present invention is further illustrated by the embodiments: like Figure 1-8 As shown, a vertical chain grate organic heat carrier biomass boiler includes a combustion chamber 1, a vertical furnace body 2 disposed at the top of the combustion chamber 1, and a chain grate 3 disposed inside the combustion chamber 1. It also includes: a coil assembly disposed inside the furnace body 2, comprising at least an inner coil 4 and an outer coil 5, both of which are filled with organic heat carrier; a first pass 6 formed by the inner side of the inner coil 4, in which flue gas flows from bottom to top; a second pass 7 formed by the inner coil 4 and the outer coil 5, in which flue gas flows from top to bottom, and the inlet of the second pass 7 is connected to the outlet of the first pass 6; and a third pass 8 formed by the outer coil 5 and the inner wall of the furnace body 2, in which flue gas flows from bottom to top, and the inlet of the third pass 8 is connected to the outlet of the second pass 7.

[0023] Specifically, by setting up a vertical furnace body 2 and designing the first pass 6 and the third pass 8 so that the flue gas flows from bottom to top, consistent with the natural buoyancy of the high-temperature flue gas, the flue gas generates natural suction during its upward flow, assisting the induced draft fan in driving the flue gas flow, thereby reducing the operating energy consumption of the induced draft fan. Meanwhile, in the second pass 7, the flue gas flows from top to bottom. Although it needs to overcome buoyancy, this downward flow, together with the upward flow of the first pass 6 and the third pass 8, forms a compact three-pass layout. This significantly increases the heat exchange area within a limited space, allowing for full absorption of flue gas heat and improving boiler thermal efficiency. The reduction in induced draft fan energy consumption and the improvement in thermal efficiency create a synergistic effect, resulting in a comprehensive energy-saving effect superior to existing horizontal three-pass boilers.

[0024] In this embodiment, the chain grate 3 is a conventional chain-type mechanical grate in the art, comprising a driving sprocket, a driven sprocket, a grate chain surrounding the driving and driven sprockets, and several independent air chambers disposed below the grate chain. During operation, the driving sprocket is driven to rotate by a geared motor, causing the grate chain to move slowly from front to back. Biomass pellet fuel falls onto the front end of the grate chain through a hopper, and as the grate chain moves backward, it sequentially completes drying, ignition, combustion, and burnout. The ash and slag finally fall from the end of the grate chain into the slag discharge device. Each independent air chamber is connected to a primary air fan, and the air volume can be adjusted in sections along the length of the grate to adapt to the air requirements of the fuel at different combustion stages. The detailed structure, transmission method, and air chamber configuration of this chain grate 3 are all well-known technologies in the boiler field and will not be described in detail here.

[0025] In addition, organic heat carriers flow through the inner coil 4 and the outer coil 5, and the furnace body 2 is provided with inlets and outlets for the organic heat carrier to enter and exit (as shown in the figure). It should be noted that setting medium inlets and outlets in an organic heat carrier boiler and circulating the organic heat carrier within the coils is a conventional technical means in this field, and the specific connection method (such as series or parallel connection) can be selected according to actual needs, and will not be elaborated here. The main innovation of this invention lies in the vertical layout of the flue gas return and the structure of the self-draining ash assembly 12, and the arrangement of the inlet and outlet of the organic heat carrier can be achieved using known methods.

[0026] Both the inner coil 4 and the outer coil 5 are spiral coils and are coaxially arranged. Setting the inner coil 4 and the outer coil 5 as coaxial spiral coils facilitates manufacturing and on-site assembly, and ensures the uniformity of the annular gap between the two coils. This results in a uniform distribution and stable flow velocity of flue gas in the second pass 7, avoiding local overheating or flow deviation, and improving heat exchange efficiency and operational reliability.

[0027] The cross-sectional area of ​​the flue gas flow in the first pass (pass 6) is larger than that in the second pass (pass 7) and the third pass (pass 8). By setting the cross-sectional area of ​​the flue gas flow in the first pass (pass 6) to be larger than that in the second pass (pass 7) and the third pass (pass 8), the zoning optimization of the radiative and convective heating surfaces is achieved. Specifically, the larger cross-sectional area and lower flue gas velocity in the first pass (pass 6) are conducive to the full radiative heat transfer of high-temperature flue gas; while the smaller cross-sectional areas and higher flue gas velocities in the second and third passes (pass 8) are conducive to enhanced convective heat transfer of medium- and low-temperature flue gas within the narrow annular channel. This fully utilizes the physical characteristics of high efficiency in radiative heat transfer in the high-temperature region and good adaptability of convective heat transfer in the medium- and low-temperature region, achieving efficient synergy between radiation and convection in a vertical and compact structure, improving boiler thermal efficiency and reducing exhaust gas temperature.

[0028] The furnace body 2 has a top turning space at the top, through which the outlet of the first pass 6 and the inlet of the second pass 7 are connected. Similarly, the furnace body 2 has a bottom turning space at the bottom, through which the outlet of the second pass 7 and the inlet of the third pass 8 are connected. By providing both top and bottom turning spaces at the top and bottom of the furnace body 2, the flue gas from the outlet of the first pass 6 smoothly enters the second pass 7 via the top turning space, and the flue gas from the outlet of the second pass 7 smoothly enters the third pass 8 via the bottom turning space. This avoids excessive local resistance loss at the turning points and ensures smooth flue gas flow.

[0029] The top of the inner coil 4 is axially lower than the top of the outer coil 5, forming a first gap between them. This first gap constitutes part of the top turning space. The bottom of the inner coil 4 is axially lower than the bottom of the outer coil 5, forming a second gap between them. This second gap constitutes part of the bottom turning space. By setting the axial height difference between the top of the inner coil 4 and the top of the outer coil 5, the first gap between them directly constitutes the top turning space. Similarly, the second gap between the bottom of the inner coil 4 and the bottom of the outer coil 5 directly constitutes the bottom turning space. This eliminates the need for an additional independent turning smoke chamber component, simplifying the structure of the furnace body 2, reducing manufacturing costs, and avoiding the risk of flue gas leakage at welds or joints.

[0030] It also includes a mounting base 9, located between the furnace body 2 and the combustion chamber 1. A flue gas passage 901 is provided on the mounting base 9, connecting the first pass 6 and the combustion chamber 1. The bottom of the inner coil 4 is fixedly connected to the portion of the mounting base 9 located inside the furnace body 2. A connecting seat 10 is fixedly connected to the top inner side of the furnace body 2, and the top of the outer coil 5 is fixedly connected to the connecting seat 10. By setting the mounting base 9 between the furnace body 2 and the combustion chamber 1, and providing a flue gas passage 901 on the mounting base 9, the high-temperature flue gas generated in the combustion chamber 1 can directly enter the first pass 6 through the flue gas passage 901, resulting in a short path and low resistance. Simultaneously, the bottom of the inner coil 4 is fixed to the portion of the mounting base 9 located inside the furnace body 2, and the top of the outer coil 5 is fixed to the connecting seat 10 at the top inner side of the furnace body 2, forming a stable support structure and improving the boiler's operational reliability.

[0031] It also includes a flue gas outlet 11, which is fixedly connected to the top of the furnace body 2 and communicates with the third pass 8. By fixing the flue gas outlet 11 to the top of the furnace body 2 and communicating with the third pass 8, the low-temperature flue gas that has completed the three-pass heat exchange can be directly discharged from the top of the furnace body 2.

[0032] In this embodiment, an induced draft fan (not shown in the figure) is connected to the rear end of the flue gas outlet 11. This induced draft fan is a conventional centrifugal or axial flow fan in the art, used to create negative pressure in the flue gas duct, forcing the flue gas to flow sequentially through the first pass 6, the second pass 7, and the third pass 8, and finally discharged from the flue gas outlet 11. The selection and installation method of the induced draft fan are well-known technologies in the boiler field, and its specific parameters can be calculated and determined according to the boiler capacity and system resistance, which will not be elaborated here. This invention does not improve the structure of the induced draft fan itself, but the improvement lies in the vertical layout of the flue gas return path to reduce the energy consumption of the induced draft fan.

[0033] An ash discharge channel 902 is provided on the mounting base 9. The inlet of the ash discharge channel 902 communicates with the bottom turning space. The ash discharge channel 902 includes a vertical section 9021 and an inclined section 9022. The upper end of the vertical section 9021 communicates with the bottom turning space, and the lower end of the vertical section 9021 communicates with the inclined section 9022. The inclined section 9022 extends obliquely downward and penetrates the side wall of the mounting base 9. A self-discharging ash component 12 is provided in the vertical section 9021. The self-discharging ash component 12 is used to automatically discharge the dust deposited in the bottom turning space during boiler operation. An ash discharge channel 902 communicating with the bottom turning space is provided on the mounting base 9. The ash discharge channel 902 is composed of a vertical section 9021 and an inclined section 9022 extending obliquely downward, and a self-discharging ash component 12 is provided in the vertical section 9021. By setting up the ash discharge channel 902, the dust deposited in the bottom turning space automatically falls into the vertical section 9021 under the action of gravity, and is smoothly discharged outside the furnace through the inclined section 9022. By setting up the self-discharging ash component 12, ash can be automatically discharged during boiler operation, avoiding ash accumulation and clogging of the flue gas channel 901, ensuring smooth flue gas flow, and thus reducing the operating energy consumption of the induced draft fan.

[0034] The self-draining ash removal assembly 12 includes a central shaft 1201, which is coaxially arranged with the vertical section 9021. An elastic spiral sheet 1202 is sleeved on the outside of the central shaft 1201. The elastic spiral sheet 1202 is composed of a continuous spiral strip and forms multiple spiral coils 12021 along the axial direction. The elastic spiral sheet 1202 has a first state and a second state, and can switch between the two states. In the first state, an ash removal gap is formed between adjacent spiral coils 12021. In the second state, adjacent spiral coils 12021 are axially compressed and tightly pressed together to form a seal. By using the elastic spiral sheet 1202 composed of a continuous spiral strip, the adjacent spiral coils 12021 form an ash removal gap in the first state, allowing ash to fall and be discharged by gravity. In the second state, adjacent spiral coils 12021 are tightly pressed together to form a seal, preventing outside air from entering the boiler system in reverse. This elastic spiral sheet 1202 integrates ash removal and sealing functions, and has a simple structure.

[0035] The self-draining ash assembly 12 also includes a support rod 1203, which is fixedly connected to the inner wall of the vertical section 9021. The central shaft 1201 is fixedly connected to the support rod 1203. The elastic spiral plate 1202 has a fixed end 12022 and a free end 12023. The fixed end 12022 is fixedly connected to the support rod 1203. A slip ring 1204 is slidably sleeved on the surface of the central shaft 1201. The free end 12023 is fixedly connected to the slip ring 1204. The slip ring 1204 drives the free end 12023 to move towards... When the fixed end 12022 moves, the elastic spiral plate 1202 switches from the first state to the second state; a cavity 12011 is provided inside the central shaft 1201, and a permanent magnet 1205 that can slide along the axial direction is provided inside the cavity 12011. The slip ring 1204 is made of ferromagnetic material, and the permanent magnet 1205 attracts the slip ring 1204 by magnetic force. Preferably, the central shaft 1201 is made of non-magnetic material (such as stainless steel) with a wall thickness of 3-5mm to ensure that the magnetic force of the permanent magnet 1205 can effectively penetrate the cavity. An electromagnet 1206 is provided at one end of the body 12011, and a spring 1207 is also provided inside the cavity 12011. One end of the spring 1207 is fixedly connected to the permanent magnet 1205, and the other end is fixedly connected to the support rod 1203. The spring 1207 is a tension spring. When the elastic helical plate 1202 is in the second state, the spring 1207 exerts a force on the permanent magnet 1205 pointing towards the support rod 1203. When the electromagnet 1206 is de-energized, the spring 1207 pulls the permanent magnet 1205 toward the fixed end. When the permanent magnet 1205 moves in the direction of 12022, it drives the slip ring 1204 and the free end 12023 to move towards the fixed end 12022 through magnetic force, so that the elastic spiral plate 1202 is in the second state; when the electromagnet 1206 is energized, the electromagnet 1206 attracts the permanent magnet 1205 to move away from the fixed end 12022, and the permanent magnet 1205 drives the slip ring 1204 and the free end 12023 away from the fixed end 12022 through magnetic force, so that the elastic spiral plate 1202 is in the first state.

[0036] Specifically, when ash discharge is required, the electromagnet 1206 is momentarily energized, driving the elastic spiral plate 1202 to switch to the first state, whereby the dust is automatically discharged under gravity. Furthermore, in this state, due to the tortuous path of the spiral channel and the partial filling of ash particles in the gaps, outside air is difficult to enter the boiler system in reverse, thus maintaining a stable negative pressure in the furnace. When sealing is required, the electromagnet 1206 is de-energized, and the elastic spiral plate 1202 automatically returns to the compressed sealing state via the spring 1207. This achieves intelligent control of on-demand ash discharge and automatic sealing, effectively preventing ash accumulation in the bottom turning space from obstructing flue gas flow, reducing flue gas flow resistance, and further reducing the operating energy consumption of the induced draft fan.

[0037] Furthermore, in this embodiment, the support rod 1203 is located at the bottom of the central shaft 1201, the fixed end 12022 is located at the lower end of the elastic spiral plate 1202, and the electromagnet 1206 is located at the upper end of the cavity 12011. When the elastic spiral plate 1202 is in the second state, the direction of the elastic force applied by the spring 1207 to the permanent magnet 1205 and the direction of the gravity of the permanent magnet 1205 both point towards the support rod 1203. The two are superimposed in the same direction and together maintain the clamping force of the sealing state.

[0038] Specifically, by positioning the support rod 1203 below the central shaft 1201, the fixed end 12022 is located at the lower end of the elastic spiral plate 1202. When the elastic spiral plate 1202 is in the second state, the movable end is located below. At this time, the elastic force of the spring 1207 and the gravity of the permanent magnet 1205 both point towards the support rod 1203. The two forces are superimposed in the same direction, allowing the sealing state to be maintained for a long time without continuous power supply, achieving zero-energy sealing. At the same time, this sealing state is maintained by the force of the spring 1207 and gravity, and can automatically maintain the seal even in the event of an accidental power outage, preventing the intake of cold air from the outside and providing fail-safe characteristics. In addition, since the movable end is located below, an empty area is formed above the vertical section 9021. Dust accumulates and falls into this space under the action of gravity, and the gravity of the dust itself applies an additional clamping force to the movable end, thereby further enhancing the stability of the sealing state.

[0039] Both the inner and outer edges of the elastic spiral sheet 1202 are provided with elastic sealing strips 1208. By providing the elastic sealing strips 1208, when the elastic spiral sheet 1202 is in a compressed sealing state, it can fill the microscopic gaps between the inner edge and the central shaft 1201, and between the outer edge and the inner wall of the vertical section 9021, further enhancing the sealing effect. Simultaneously, when the movable end of the elastic sealing strip 1208 moves axially, it slides tightly against the surface of the central shaft 1201, scraping away dust adhering to the central shaft 1201, thereby reducing the adverse effects of dust accumulation on the magnetic force transmission between the permanent magnet 1205 and the slip ring 1204.

[0040] Working principle: When this vertical chain grate organic heat carrier biomass boiler is in use, the induced draft fan is first turned on to create a slight negative pressure in the furnace and flue. Then, the chain grate 3 and the blower are started. The biomass pellet fuel is dried, ignited, burned and burned out in sequence on the chain grate 3. The high-temperature flue gas generated enters the first pass 6 at the bottom of the furnace body 2 through the flue gas channel 901 on the mounting base 9. The flue gas flows from bottom to top and undergoes radiative heat exchange with the organic heat carrier in the inner coil 4. Then, the flue gas enters the second pass 7 through the top turning space and flows from top to bottom, undergoing convective heat exchange in the annular gap between the inner coil 4 and the outer coil 5. Then, the flue gas enters the third pass 8 through the bottom turning space and flows from bottom to top again, undergoing convective heat exchange between the outer coil 5 and the inner wall of the furnace body 2. Finally, it is discharged from the exhaust port 11 at the top of the furnace body 2. The organic heat carrier enters through the inlet on the furnace body 2, flows sequentially through the inner coil 4 and the outer coil 5, absorbs the heat from the flue gas, and is then discharged from the outlet. During boiler operation, dust deposited in the bottom turning space falls into the vertical section 9021 of the ash discharge channel 902. The ash discharge component 12 is normally in the second state. When ash discharge is required, the electromagnet 1206 is energized instantaneously, and the elastic spiral plate 1202 switches to the first state to form an ash discharge gap. The dust is automatically discharged through the inclined section 9022 under the action of gravity. After the power is cut off, the elastic spiral plate 1202 automatically restores the seal by the force of the spring 1207 and the gravity of the permanent magnet 1205, realizing on-demand ash discharge and zero-energy sealing.

[0041] The embodiments disclosed herein are preferred embodiments, but are not limited thereto. Those skilled in the art can readily grasp the spirit of the present invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A vertical chain grate organic heat carrier biomass boiler, comprising a combustion chamber (1), a vertical furnace body (2) disposed at the top of the combustion chamber (1), and a chain grate (3) disposed inside the combustion chamber (1), characterized in that, Also includes: The coil assembly is located inside the furnace body (2) and includes at least an inner coil (4) and an outer coil (5), both of which are filled with organic heat carriers. The first pass (6) is formed by the inner side of the inner coil (4), and the flue gas flows from bottom to top in the first pass (6); The second pass (7) is formed between the inner coil (4) and the outer coil (5). The flue gas flows from top to bottom in the second pass (7). The inlet of the second pass (7) is connected to the outlet of the first pass (6). The third pass (8) is formed between the outer coil (5) and the inner wall of the furnace body (2). The flue gas flows from bottom to top in the third pass (8). The inlet of the third pass (8) is connected to the outlet of the second pass (7).

2. A vertical chain-grate organic heat carrier biomass boiler as described in claim 1, characterized in that: The inner coil (4) and the outer coil (5) are both spiral coils and are coaxially arranged.

3. A vertical chain-grate organic heat carrier biomass boiler as described in claim 1, characterized in that: The cross-sectional area of ​​flue gas flow in the first pass (6) is larger than that in the second pass (7) and the third pass (8).

4. A vertical chain-grate organic heat carrier biomass boiler as described in claim 1, characterized in that: The furnace body (2) has a top turning space at the top, and the outlet of the first return (6) and the inlet of the second return (7) are connected through the top turning space. The furnace body (2) has a bottom turning space at the bottom, and the outlet of the second return (7) and the inlet of the third return (8) are connected through the bottom turning space.

5. A vertical chain-grate organic heat carrier biomass boiler as described in claim 4, characterized in that: The top of the inner coil (4) is axially lower than the top of the outer coil (5), and a first gap is formed between them, which constitutes part of the top turning space. The bottom of the inner coil (4) is axially lower than the bottom of the outer coil (5), and a second gap is formed between them, which constitutes part of the bottom turning space.

6. A vertical chain-grate organic heat carrier biomass boiler as described in claim 4, characterized in that: It also includes a mounting base (9) disposed between the furnace body (2) and the combustion chamber (1), and a flue gas passage (901) is provided on the mounting base (9), which connects the first return (6) and the combustion chamber (1); The bottom of the inner coil (4) is fixedly connected to the part of the mounting base (9) located inside the furnace body (2), and a connecting seat (10) is fixedly connected to the top of the inner side of the furnace body (2). The top of the outer coil (5) is fixedly connected to the connecting seat (10).

7. A vertical chain-grate organic heat carrier biomass boiler as described in claim 1, characterized in that: It also includes a flue gas outlet (11), which is fixedly connected to the top of the furnace body (2) and communicates with the third return (8).

8. A vertical chain-grate organic heat carrier biomass boiler as described in claim 6, characterized in that: The mounting base (9) is provided with an ash discharge channel (902). The entrance of the ash discharge channel (902) is connected to the bottom turning space. The ash discharge channel (902) includes a vertical section (9021) and an inclined section (9022). The upper end of the vertical section (9021) is connected to the bottom turning space, and the lower end of the vertical section (9021) is connected to the inclined section (9022). The inclined section (9022) extends obliquely downward and penetrates the side wall of the mounting base (9). A self-discharging ash assembly (12) is provided in the vertical section (9021). The self-discharging ash assembly (12) is used to automatically discharge the dust deposited in the bottom turning space during boiler operation.

9. A vertical chain-grate organic heat carrier biomass boiler as described in claim 8, characterized in that: The self-draining ash assembly (12) includes a central shaft (1201), which is coaxially arranged with the vertical section (9021). An elastic spiral sheet (1202) is sleeved on the outside of the central shaft (1201). The elastic spiral sheet (1202) is composed of a continuous spiral strip and forms multiple spiral coils (12021) along the axial direction. The elastic spiral sheet (1202) has a first state and a second state and can switch between the first state and the second state. In the first state, a ash discharge gap is formed between adjacent spiral rings (12021). In the second state, adjacent spiral rings (12021) are axially compressed and tightly pressed together to form a seal.

10. A vertical chain-grate organic heat carrier biomass boiler as described in claim 9, characterized in that: The self-draining ash assembly (12) also includes a support rod (1203), which is fixedly connected to the inner wall of the vertical section (9021), and the central shaft (1201) is fixedly connected to the support rod (1203); The elastic spiral sheet (1202) has a fixed end (12022) and a free end (12023). The fixed end (12022) is fixedly connected to the support rod (1203). A slip ring (1204) is slidably sleeved on the surface of the central shaft (1201). The free end (12023) is fixedly connected to the slip ring (1204). When the slip ring (1204) drives the free end (12023) to move toward the fixed end (12022), the elastic spiral sheet (1202) switches from a first state to a second state. The central shaft (1201) has a cavity (12011) inside, and a permanent magnet (1205) that can slide along the axis is provided inside the cavity (12011). The slip ring (1204) is made of ferromagnetic material. The permanent magnet (1205) attracts the slip ring (1204) by magnetic force. An electromagnet (1206) is provided at one end of the cavity (12011). A spring (1207) is also provided inside the cavity (12011). One end of the spring (1207) is fixedly connected to the permanent magnet (1205), and the other end is fixedly connected to the support rod (1203). When the elastic spiral plate (1202) is in the second state, the spring (1207) exerts a force on the permanent magnet (1205) pointing towards the support rod (1203). When the electromagnet (1206) is de-energized, the spring (1207) pulls the permanent magnet (1205) to move toward the fixed end (12022). The permanent magnet (1205) drives the slip ring (1204) and the free end (12023) to move toward the fixed end (12022) through magnetic force, so that the elastic spiral plate (1202) is in the second state. When the electromagnet (1206) is energized, the electromagnet (1206) attracts the permanent magnet (1205) and moves it away from the fixed end (12022). The permanent magnet (1205) drives the slip ring (1204) and the free end (12023) away from the fixed end (12022) through magnetic force, so that the elastic spiral plate (1202) is in the first state. The support rod (1203) is located at the bottom of the central shaft (1201), the fixed end (12022) is located at the lower end of the elastic spiral plate (1202), and the electromagnet (1206) is located at the upper end of the cavity (12011). When the elastic spiral plate (1202) is in the second state, the direction of the elastic force applied by the spring (1207) to the permanent magnet (1205) and the direction of the gravity of the permanent magnet (1205) both point towards the support rod (1203). The two are superimposed in the same direction and together maintain the clamping force of the sealing state. The inner and outer edges of the elastic spiral sheet (1202) are provided with elastic sealing strips (1208).

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