Energy storage type vertical fluidized bed furnace

Abstract

The invention discloses an energy storage type vertical fluidized bed fluidized bed furnace which comprises a combustion chamber, a dust remover and a settling chamber independently arranged between the combustion chamber and the dust remover. An inlet and an outlet are symmetrically formed in the two sides of the settling chamber, a smoke pipeline is arranged at the top of the combustion chamber and communicated with the inlet, the dust remover is provided with a cyclone pipeline, the cyclone pipeline is communicated with the outlet, and the sectional area of the outlet is larger than that of the inlet; a partition plate extending downwards from the inner wall of the top of the settling chamber enables the inner space of the settling chamber to form a U-shaped flow channel, the U-shaped flow channel comprises a first flow channel, a bottom flow channel and a second flow channel, and an inverted-cone-shaped inner cavity is formed below the bottom flow channel. According to the invention, secondary combustion of unburnt particles before entering the dust remover is realized, the combustible content in the flue gas is obviously reduced, the carbon deposition risk of subsequent dust removal equipment is reduced, the temperature of the flue gas entering the dust remover is reduced, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of fluidized bed boilers, and particularly to an energy storage type vertical fluidized bed boiler. Background Art

[0002] Fluidized bed boilers are combustion devices widely used in the fields of energy, chemical industry, etc. Their core structures include a furnace body and a cyclone separator (dust collector). The furnace body, as the combustion chamber, usually adopts a steel structure shell with thermal insulation bricks and refractory bricks lined inside to reduce heat loss and protect the furnace body structure. The cyclone separator is installed at the outlet of the combustion chamber to separate solid particles in the flue gas, so that the solid particles return to the fluidized bed to continue to participate in the reaction or combustion, reducing the carry-out amount of solid particles. The combustion chamber is mainly composed of a wind distribution system, a fluidized bed, a feeding and slag discharging system, etc. The wind distribution system includes an air chamber and a wind distribution plate. The air chamber is located at the bottom of the fluidized bed boiler and is a space for accommodating and distributing air flow. The wind distribution plate is installed above the air chamber and is a key component of the wind distribution system. The fluidized bed includes a dense phase section and a dilute phase section. The dense phase section is the area in the fluidized bed boiler where the bed material concentration is relatively high and the fluidization state is relatively intense. Its lower part is connected to the wind distribution plate, and its upper part is connected to the dilute phase section. In the dense phase section, solid particles are in a strong tumbling and mixing state under the action of air flow, forming a boiling-like phenomenon. In the dilute phase section, the concentration of solid particles is relatively low, and the particles mainly rise with the air flow in a suspended state.

[0003] However, the combustion efficiency of existing fluidized bed boilers is low, resulting in unburned substances (chemical incomplete combustion or mechanical incomplete combustion) in the flue gas. The combustion condition is usually 850 - 950 °C (the outlet temperature of the combustion chamber). Since the cyclone separator is installed at the outlet of the combustion chamber, the cyclone separator is in long-term high-temperature operation, and it is difficult to guarantee the equipment life and separation efficiency. At the same time, there are equipment safety problems caused by secondary combustion and a decrease in system efficiency caused by carbon deposition. For example, sticky substances such as unburned tar and semi-coke cool with the flue gas (especially in the low-temperature area of the separator, such as the bottom of the cone), and will adhere to the wall surface to form a coking layer, which gradually thickens, resulting in a reduction in the cross-sectional area of the flow channel and a decrease in separation efficiency (weakening of the centrifugal force); after unburned solid carbon particles (residual carbon), volatile combustibles (such as CO, tar, unpyrolyzed hydrocarbons) and high-concentration dust (containing combustible components) enter the cyclone separator, the uneven temperature rise during secondary combustion causes thermal stress in the separator shell. Long-term repeated action will cause weld cracking and flange seal failure. The local high temperature (up to 800 - 1000 °C) exceeds the temperature resistance limit of the equipment refractory layer (such as ceramic lining) or the metal shell, resulting in the peeling of the refractory layer and the deformation / cracking of the shell, and even causing equipment explosion.

[0004] Therefore, in the design of existing fluidized bed boilers, there are problems of low combustion efficiency and equipment safety problems caused by secondary combustion in the separator. Summary of the Invention

[0005] The object of the present invention is to provide an energy storage type vertical fluidized bed boiling furnace to solve one or more technical problems existing in the prior art and at least provide a beneficial option or create conditions.

[0006] To solve the above technical problems, the technical solutions adopted by the present invention are as follows: First, the present invention provides an energy storage type vertical fluidized bed boiling furnace, which includes a combustion chamber, a dust collector, and a sedimentation chamber independently arranged between the combustion chamber and the dust collector; An inlet and an outlet are symmetrically arranged on both sides of the sedimentation chamber. A flue gas pipe is provided at the top of the combustion chamber and the flue gas pipe is communicated with the inlet. The dust collector has a cyclone pipe, and the cyclone pipe is communicated with the outlet. The cross-sectional area of the outlet is larger than that of the inlet; The sedimentation chamber is provided with a partition plate extending downward from the inner wall of the top, so that the internal space of the sedimentation chamber forms a U-shaped flow channel. The U-shaped flow channel includes a first flow channel, a bottom flow channel, and a second flow channel connected in sequence. A conical cavity is provided below the bottom flow channel; The flue gas in the flue gas pipe enters the first flow channel from the inlet, flows downward along the first flow channel to the bottom flow channel, the flue gas impacts on the wall of the conical cavity and rebounds, and forms turbulent mixing in the bottom flow channel. The flue gas carries unburned fine particles and mixes and burns again. The flue gas after re-combustion flows upward along the second flow channel to the outlet and enters the cyclone pipe.

[0007] In this technical solution, the high-temperature flue gas generated by the combustion chamber enters the inlet of the sedimentation chamber through the flue gas pipe at the top. The flue gas moves downward in the first flow channel of the U-shaped flow channel and impacts the wall surface of the conical cavity under the action of gravity acceleration. The kinetic energy of the particulate matter is lost after colliding with the wall, and part of the large particles settle to the bottom area of the cone. The rebound effect of the conical cavity prolongs the residence time of the particles and promotes the pre-sedimentation of the large particles. The rebound air flow forms vortex turbulence in the bottom flow channel and / or the conical cavity, so that the unburned fine particles are fully mixed with the high-temperature flue gas. During the mixing process, volatile substances and residual carbon are reignited in the turbulent flow field to complete the secondary combustion reaction. The flue gas after combustion rises along the second flow channel. The circuitous path of the U-shaped flow channel enables the high-temperature flue gas to complete partial heat exchange in the sedimentation chamber, and the content of particulate matter or residual ash in the flue gas decreases, and the content of combustibles decreases significantly, reducing the temperature of the flue gas entering the dust collector and prolonging the service life of the equipment.

[0008] Compared with the traditional method that relies on a single combustion chamber to complete the combustion process, where unburned substances directly enter the separator, leading to risks of coking and secondary combustion, an energy storage type vertical fluidized bed boiling furnace provided by this technical solution involves a combustion chamber, a sedimentation chamber, and a dust collector. By setting up an independent sedimentation chamber with a specific shape and a U-shaped flow channel structure to guide the flow path of the flue gas, the effects of flue gas sedimentation and complete combustion are improved by increasing the flue gas flow path. And secondary combustion occurs in the inverted cone-shaped inner cavity and the bottom flow channel to form energy storage. The flue gas and unburned particles in the first flow channel are continuously added for combustion, enabling continuous energy storage at the bottom of the sedimentation chamber. At the same time, the impact of the flue gas on the inverted cone-shaped inner cavity is increased to form turbulent mixing, prolonging the flue gas residence time and creating conditions for turbulent mixing, promoting the secondary combustion of incompletely burned particles, reducing the entry of unburned substances into the dust collector, thus solving the equipment safety problems caused by secondary combustion, reducing the load on the dust collector and improving the combustion efficiency, and having the advantages of extending the equipment life and improving the operation safety.

[0009] This application realizes the secondary combustion of unburned particles before they enter the dust collector, significantly reducing the combustible content in the flue gas. The turbulent mixing effect improves the combustion efficiency and reduces the risk of carbon deposition in subsequent dust removal equipment. The rebound effect of the inverted cone-shaped inner cavity prolongs the particle residence time and promotes the pre-sedimentation of large particles. The circuitous path of the U-shaped flow channel enables partial heat exchange of the high-temperature flue gas in the sedimentation chamber, reducing the temperature of the flue gas entering the dust collector and extending the service life of the equipment.

[0010] As an extension of the above solution, there is a spiral return pipe outside the sedimentation chamber that spirals downwards. The inlet end of the return pipe is connected to the second flow channel, and the outlet end is connected to the first flow channel, and the inlet end and the outlet end respectively penetrate the wall of the sedimentation chamber obliquely along the spiral direction.

[0011] In this extended technical solution, the spiral return pipe actively guides unburned particles back to the bottom of the sedimentation chamber for re-combustion, reducing the concentration of combustibles entering the dust collector. In the prior art, the flue gas flow path is a one-way straight line, while this extended solution uses a spiral return structure to strengthen turbulent mixing, enabling the particles to fully contact with oxygen. The inclined cutting method matches the inner wall curve of the sedimentation chamber, improving the turbulent effect of the flue gas in the bottom flow channel. The unburned particles undergo multiple cycles of combustion in the sedimentation chamber, and the carbon content is significantly reduced, reducing the risk of carbon deposition in subsequent dust removal equipment, effectively reducing the proportion of incompletely burned fine particles and combustibles in the flue gas entering the dust collector, and avoiding local high temperature and thermal stress problems caused by secondary combustion in the dust collector.

[0012] As an extension of the above solution, the return pipe is provided with a return fan and an oxygen supply branch, and the position of the outlet end is flush with the bottom of the partition plate so that the flue gas and air or oxygen in the return pipe are sprayed obliquely downwards and tangentially to the inner wall of the sedimentation chamber at the outlet end position into the bottom flow channel and / or the inverted cone-shaped inner cavity.

[0013] In this extended solution, the outlet end is flush with the bottom of the partition plate, so that the mixed gas flowing out from the outlet end forms a swirling flow along the tangential direction of the inner wall below the partition plate at an inclined downward injection angle, without being blocked by the partition plate, and directly enters the bottom flow channel. This swirling flow generates a centrifugal force in the inverted conical inner cavity, enabling the unburned fine particles to come into full contact with oxygen and burn again. At the same time, the turbulence enhances the mixing uniformity of oxygen and particles, avoiding the formation of local high-temperature regions.

[0014] As an extension of the above solution, the combustion chamber sequentially includes, from bottom to top: An air chamber, connected to an external blower one. A dense phase section, with a distributor plate provided between it and the air chamber. The dense phase section adopts a conical structure with a smaller cross-sectional area at the lower part and a larger cross-sectional area at the upper part, so that the high-speed airflow near the distributor plate can lift the particles to form a fluidized state. A lean phase section, which reduces the flow velocity of the gas entering from the dense phase section. A flue gas outlet, arranged at the top of the lean phase section, and connected to the sedimentation chamber through a flue gas pipeline.

[0015] In this extended technical solution, through the dual flow velocity control of the conical expansion of the dense phase section and the expansion of the cross-sectional area of the lean phase section, a staged combustion and particle circulation mechanism is formed, and multiple fluidizations and combustion reactions of the particles are completed in the combustion chamber. This solves the problem of secondary combustion of the dust collector caused by the outflow of unburned particles in the combustion chamber. By regulating the flow velocity in stages, the residence time of the particles in the high-temperature zone is extended, promoting the settlement of large particles and their return to the dense phase section to complete the combustion cycle, reducing the combustible content in the flue gas, and thus reducing the risk of carbon deposition and thermal stress damage to subsequent equipment.

[0016] As an extension of the above solution, heat exchange buried pipes are provided in the dense phase section, and the heat exchange buried pipes are connected to an external heat exchange mechanism. The fluid medium in the heat exchange buried pipes transports heat to the external heat exchange mechanism, realizing the cascade utilization of energy. At the same time, the temperature of the dense phase section is maintained stable in the interval where the combustibles can fully react. The heat conduction effect of the heat exchange buried pipes suppresses the local over-temperature phenomenon and controls the generation amount of nitrogen oxides within the emission standard limits.

[0017] As an extension of the above solution, the lean phase section includes: An expansion section, which is cylindrical and connected to the dense phase section at the bottom. The cross-sectional area of the expansion section is greater than or equal to the cross-sectional area of the uppermost part of the dense phase section. A contraction section, connected to the flue gas outlet at the top and to the expansion section at the bottom, with a gradually decreasing cross-sectional area from bottom to top to enable the fine particles carried by the airflow to settle back to the expansion section and / or the dense phase section.

[0018] Compared with the existing dilute-phase section of the fluidized bed furnace, which has a single equal-diameter or gradually expanding structure and can only unidirectionally adjust the flow rate by changing the cross-sectional area, and cannot control particle sedimentation in stages. The extended solution forms a synergistic effect of a sudden drop and a slow rise in the flow rate within the dilute-phase section through a combined structure of an expansion section and a contraction section, realizing stepped particle sedimentation.

[0019] As an extension of the above solution, a air distribution pipeline is provided on one side of the combustion chamber. One end of the air distribution pipeline is connected to an external blower two. A number of air distribution branch pipes are provided on the air distribution pipeline, and the air distribution branch pipes communicate with the combustion chamber.

[0020] In this extended solution, through multi-branch air distribution in different regions, a multi-stage oxygen supply mechanism ensures that the fuel is fully burned at different spatial levels in the combustion chamber, reducing carbon deposition, coking and thermal stress damage in the dust collector from the source.

[0021] As an extension of the above solution, the oxygen supply branch of the return pipeline of the sedimentation chamber communicates with one of the air distribution branch pipes of the air distribution pipeline, expanding the air flow distribution function of the air distribution pipeline to the oxygen supply branch, realizing air flow linkage between the combustion chamber and the sedimentation chamber. When the air flow is sprayed obliquely into the bottom flow channel of the sedimentation chamber at the outlet end, due to the injection angle being tangent to the inner wall, a swirling effect can be formed in the turbulent mixing area, eliminating the accumulation of combustion residues caused by insufficient oxygen supply and prolonging the contact time between unburned fine particles and oxygen.

[0022] As an extension of the above solution, a heat exchange pipeline is provided in the inverted cone-shaped inner cavity. The heat exchange pipeline flows through an air preheater, and the air preheater is arranged in the air supply channel between the air chamber and the blower one, converting the waste heat of the flue gas into the preheating energy of the combustion air, which not only reduces the operating temperature of the subsequent equipment but also improves the combustion efficiency.

[0023] As an extension of the above solution, an exhaust pipeline is provided at the top of the dust collector. The exhaust pipeline is connected to a spray drying tower. An aggregate area is provided at the bottom of the dust collector, and the aggregate area is connected to the dense-phase section through a return device. This extended solution improves the fuel utilization rate by using the circulating combustion of particles and reduces the content of combustibles in the flue gas; the synergistic effect of the return device and the spray drying tower realizes the closed-loop control of combustion and purification, improving the safety and stability of the system operation. Brief Description of the Drawings

[0024] The following further describes the present invention in conjunction with the drawings and embodiments; Figure 1 It is a schematic structural diagram of a vertical fluidized bed furnace in the embodiment; Figure 2 It is a schematic structural diagram of one side of the sedimentation chamber in the embodiment; Figure 3 It is a schematic structural diagram of the other side of the sedimentation chamber in the embodiment; Figure 4 It is a schematic diagram of one side structure of the combustion chamber of the embodiment; Figure 5 It is a schematic diagram of the other side structure of the combustion chamber of the embodiment.

[0025] In the drawings: 100: Combustion chamber, 110: Flue gas pipe, 120: Air chamber, 121: Blower 1, 122: Air distribution plate, 130: Dense phase section, 140: Dilute phase section, 141: Enlargement section, 142: Contraction section, 150: Flue gas outlet, 160 Air distribution pipe, 161: Air distribution branch pipe, 170: Blower 2, 200: Sedimentation chamber, 210: Inlet, 220: Outlet, 230: Baffle, 231: First flow channel, 232: Bottom flow channel, 233: Second flow channel, 234: Inverted cone-shaped inner cavity, 240: Return pipe, 241: Inlet end, 242: Outlet end, 300: Dust collector, 310: Cyclone pipe, 320: Exhaust pipe, 330: Aggregate area, 400: Spray drying tower. Detailed implementation manners

[0026] This part will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the drawings. The role of the drawings is to supplement the description of the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the protection scope of the present invention.

[0027] In the description of the present invention, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] In the description of the present invention, if there are descriptions with words such as "several", its meaning is one or more, and the meaning of multiple is more than two. Understanding such as greater than, less than, exceeding, etc. does not include the present number, and understanding such as above, below, within, etc. includes the present number.

[0029] In the description of the present invention, unless otherwise clearly defined, words such as setting, installation, connection, etc. should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0030] Referring to Figures 1 to 5 , several embodiments of an energy storage type vertical fluidized bed boiling furnace of the present invention are given below.

[0031] Such as Figure 1 And2 As shown, in some embodiments, an energy storage type vertical fluidized bed boiling furnace includes a combustion chamber 100, a dust collector 300, and a sedimentation chamber 200 independently arranged between the combustion chamber 100 and the dust collector 300. An inlet 210 and an outlet 220 are symmetrically arranged on both sides of the sedimentation chamber 200. A flue gas pipe 110 is provided at the top of the combustion chamber 100, and the flue gas pipe 110 is communicated with the inlet 210. The dust collector 300 has a cyclone pipe 310, and the cyclone pipe 310 is communicated with the outlet 220. The cross-sectional area of the outlet 220 is larger than that of the inlet 210. Among them, the sedimentation chamber 200 refers to an independent cavity arranged between the combustion chamber 100 and the dust collector 300, which can be formed by welding steel plates into a double-layer jacket structure, and the interlayer is filled with heat insulation materials to achieve temperature control. The diameter of the inlet pipe can be 10%-30% smaller than that of the outlet pipe. The cross-sectional area difference forms a flow velocity gradient, and a turbulent effect induced by a velocity difference is generated in the flow path turning area.

[0032] The sedimentation chamber 200 is provided with a partition plate 230 extending downward from the inner wall of the top, so that the internal space of the sedimentation chamber 200 forms a U-shaped flow path. The U-shaped flow path includes a first flow path 231, a bottom flow path 232, and a second flow path 233 connected in sequence. An inverted conical inner cavity 234 is provided below the bottom flow path 232. The flue gas in the flue gas pipe 110 enters the first flow path 231 from the inlet 210, flows downward along the first flow path 231 to the bottom flow path 232, the flue gas impacts on the wall of the inverted conical inner cavity 234 and rebounds to form turbulent mixing in the bottom flow path 232, and the flue gas carries the incompletely burned fine particles to mix and burn again. The flue gas after re-combustion flows upward along the second flow path to the outlet and enters the cyclone pipe. Among them, the U-shaped flow path refers to a circuitous channel separated by the partition plate 230. The partition plate 230 can be made of a high-temperature resistant ceramic composite material, and its vertical extension depth can be 70%-90% of the height of the sedimentation chamber 200. This design prolongs the residence time by changing the movement direction of the flue gas, and promotes particle sedimentation and secondary reaction. The inverted conical inner cavity 234 refers to a conical cavity arranged below the bottom flow path 232, and the cone angle range can be 30-60 degrees. The conical inner wall has a rebounding effect on the downward flowing flue gas, increases the momentum exchange between the particles and the air flow, and strengthens the suspension time of the unburned particles.

[0033] Specifically, the high-temperature flue gas generated by the combustion chamber 100 enters the inlet 210 of the sedimentation chamber 200 through the flue gas pipeline 110 at the top. The flue gas moves downward in the first flow channel 231 of the U-shaped flow channel and impacts the wall surface of the inverted cone-shaped inner cavity 234 under the action of gravity acceleration. After the particulate matter collides with the cavity wall, its kinetic energy is lost, and some large particles settle to the bottom area of the cone. The rebounding airflow forms a vortex turbulence in the bottom flow channel, enabling the unburned fine particles to be fully mixed with the high-temperature flue gas. During the mixing process, volatile substances and residual carbon are reignited in the turbulent flow field to complete the secondary combustion reaction. And energy storage is formed by secondary combustion in the inverted cone-shaped inner cavity and the bottom flow channel. The flue gas and unburned particles in the first flow channel are continuously added for combustion, causing continuous energy storage at the bottom of the sedimentation chamber 200. The flue gas after combustion carries residual particles and rises along the second flow channel 233, and some particles settle. When the purified flue gas enters the cyclone pipeline, its temperature has decreased, and the combustible content has significantly decreased.

[0034] In the prior art, fluidized bed boilers generally adopt a layout mode in which the combustion chamber is directly connected to the cyclone separator. The flue gas generated by the combustion chamber carries unburned particles and directly enters the separator, resulting in the separator being in a high-temperature environment for a long time. Substances such as tar and semicoke remaining in the flue gas are likely to form a coking layer on the separator wall surface, leading to problems such as a reduction in the cross-sectional area of the flow channel and a decline in separation efficiency. Unburned substances may undergo secondary combustion inside the separator, generating local high-temperature hot spots, causing problems such as spalling of the refractory layer of the equipment, deformation of the shell, and even the risk of deflagration. The temperature at the outlet of the combustion chamber is usually in the range of 800 - 950 °C, and the continuous impact of the high-temperature flue gas accelerates the thermal fatigue failure of the separator components. To solve the above problems, in this embodiment, by setting a sedimentation chamber with a specific shape, the flue gas is guided to form a U-shaped flow path, the flow path of the flue gas is extended, and secondary combustion and primary dust removal are completed in the U-shaped flow channel. The structural design of the inverted cone-shaped inner cavity changes the flow mode of the traditional straight flue, and uses the kinetic energy - potential energy conversion to strengthen the gas-solid contact. The cross-sectional area difference between the inlet and the outlet forms an adaptive flow rate adjustment mechanism, avoiding the problem of particle escape caused by a constant flow rate in the traditional scheme.

[0035] Through this embodiment, secondary combustion of unburned particles is achieved before entering the dust collector, significantly reducing the combustible content in the flue gas. The turbulent mixing effect improves the combustion efficiency and reduces the risk of carbon deposition in subsequent dust removal equipment. The rebounding effect of the inverted cone-shaped inner cavity prolongs the particle residence time and promotes the pre-sedimentation of large particles. The tortuous path of the U-shaped flow channel enables partial heat exchange of the high-temperature flue gas in the sedimentation chamber, reducing the temperature of the flue gas entering the dust collector and extending the service life of the equipment.

[0036] In some embodiments, such as Figure 2 and 3As shown in the figure, a reflux pipe 240 that spirals downward is provided on the outside of the sedimentation chamber 200. The inlet end 241 of the reflux pipe 240 communicates with the second flow channel 233, and the outlet end 242 communicates with the first flow channel 231. The inlet end 241 and the outlet end 242 respectively penetrate the wall of the sedimentation chamber 200 obliquely along the spiral direction. Among them, the reflux pipe 240 refers to a spiral channel provided on the outside of the sedimentation chamber 200, which can be made of a high-temperature resistant alloy material specifically, and a wear-resistant lining is provided on the inner wall of the pipe to realize the circulating flow of high-temperature flue gas. The way that the inlet end 241 obliquely cuts into the wall of the sedimentation chamber 200 can reduce the pressure loss caused by the sudden change of the flow channel, and at the same time enhance the particle capture efficiency by using the tangential velocity component of the flue gas. The inclined cutting structure where the outlet end 242 communicates with the first flow channel 231 enables the reflux flue gas to be sprayed into the bottom flow channel 232 at a tangential angle, forming a swirl mixing effect and promoting the collision between unburned particles and fresh flue gas.

[0037] Specifically, during the upward flow of the flue gas in the second flow channel 233, part of the flue gas carrying incompletely burned particles is sucked into the inlet end 241 of the reflux pipe 240 and flows downward along the spiral path. When the outlet end 242 obliquely cuts into the first flow channel 231, the reflux flue gas forms a countercurrent mixture with the flue gas in the secondary combustion, prolonging the residence time of the particles in the turbulent region at the bottom of the sedimentation chamber 200, and enabling the unburned carbon particles to burn secondary in a high-temperature environment.

[0038] Compared with the prior art, in the traditional fluidized bed boiling furnace, the flue gas at the outlet of the combustion chamber is directly introduced into the cyclone separator, and the overheating of the equipment is caused by the secondary combustion of unburned particles in the separator. In this embodiment, the unburned particles are actively guided back to the bottom of the sedimentation chamber for re-combustion through the spiral reflux pipe, reducing the concentration of combustibles entering the dust collector. In the prior art, the flow path of the flue gas is a one-way straight line, while in this embodiment, the spiral reflux structure is adopted to strengthen the turbulent mixing, enabling the particles to be in full contact with oxygen. Most of the traditional reflux channels are vertical or horizontal straight pipes. The inclined cutting method in this embodiment matches the curved surface of the inner wall of the sedimentation chamber, improving the mixing of the reflux flue gas and the flue gas in combustion.

[0039] This embodiment effectively reduces the proportion of fine particles and combustibles that are not completely burned in the flue gas from entering the dust collector, avoiding the problems of local high temperature and thermal stress caused by secondary combustion in the dust collector. The unburned particles undergo multiple cycles of combustion in the sedimentation chamber, and the carbon content is significantly reduced, reducing the risk of carbon deposition in the subsequent dust removal equipment. The inclined cutting structure of the reflux pipe optimizes the flow pattern of the flue gas and improves the combustion efficiency.

[0040] In some embodiments, such as Figure 2 and 3As shown in the figure, the reflux pipeline 240 is provided with a reflux fan (not shown in the figure) and an oxygen supplement branch 243. The position of the outlet end 242 is flush with the bottom of the partition plate 230, so that the flue gas and air or oxygen in the reflux pipeline 240 are sprayed into the bottom flow channel 232 and the inverted conical inner cavity 234 obliquely downward and tangentially to the inner wall of the sedimentation chamber 200 at the outlet end 242. Among them, the reflux fan refers to a device used to drive the flue gas circulation. Specifically, a centrifugal fan can be used to realize it. The flue gas is sucked from the second flow channel 233 and pressurized and transported to the outlet end 242 by the centrifugal force generated by the rotation of the impeller. The oxygen supplement branch 243 refers to a pipeline branch for supplementing oxygen or air. Specifically, a metal pipeline connected by a flange can be used and an external gas source is connected. The oxygen supplement amount is controlled by adjusting the valve. The position of the outlet end 242 being flush with the bottom of the partition plate 230 means that the installation height of the end of the reflux pipeline 240 is at the same horizontal plane or adjacent position as the lowest point of the partition plate 230, avoiding the blockage of the partition plate when the mixed gas is ejected. The injection method of being obliquely downward and tangential to the inner wall means that the mixed gas is sprayed along a trajectory at a certain angle with the tangential direction of the inner wall, so that the air flow direction matches the inner wall radian. In this embodiment, through the combination of active oxygen supplementation and swirling injection, a controllable oxygen concentration field and turbulent mixing conditions are formed at the bottom of the sedimentation chamber, effectively solving the problem of incomplete combustion of unburned particles due to lack of oxygen, and at the same time avoiding the risk of structural damage caused by air flow impact. The full secondary combustion of the incompletely burned particles in the sedimentation chamber is realized, the thermal stress influence of local high temperature on the cavity wall is inhibited, the oxygen utilization rate and combustion efficiency are improved, and at the same time the risk of carbon deposition and coking caused by uneven turbulent mixing is reduced, and the service life of the equipment is prolonged.

[0041] In some embodiments, as Figure 1 and 4 shown, the combustion chamber 100 sequentially includes from bottom to top: An air chamber 120, connected to an external blower 121; A dense phase section 130, with a distributor plate 122 provided between it and the air chamber 120. The dense phase section 130 adopts a conical structure with a smaller cross-sectional area at the lower part and a larger cross-sectional area at the upper part, so that the high-speed air flow near the distributor plate 122 can lift the particles to form a fluidized state; A dilute phase section 140, which reduces the flow rate of the gas entering the dense phase section 130; A flue gas outlet 150, arranged at the top of the dilute phase section 140, and connected to the sedimentation chamber 200 through a flue gas pipeline 110.

[0042] Among them, the air chamber 120 refers to the air flow distribution space located at the bottom of the combustion chamber. Specifically, a closed chamber can be formed by welding steel plates, and a wind distribution plate is arranged at the top of the chamber to achieve uniform air flow distribution. Its function is to provide a stable air flow pressure through the first blower and avoid local air flow accumulation. The conical structure of the dense phase section 130 refers to the geometric shape with a gradually expanding cross-section from bottom to top. Specifically, a truncated cone or pyramid frustum structure can be adopted. It reduces the upward air flow velocity by expanding the flow cross-sectional area, thereby prolonging the residence time of particles in the high-temperature zone. The increase in the cross-sectional area of the dilute phase section 140 means that the size of the flow channel is larger than the outlet size at the top of the dense phase section 130. Specifically, a cylindrical or rectangular flared structure can be adopted. It causes the unburned large particles to settle back to the dense phase section due to gravity by a sudden drop in flow velocity. The flue gas outlet 150 is arranged at the top of the dilute phase section, which means that the gas channel is located at the highest point of the combustion chamber. Specifically, a metal pipe can be connected by a flange, which ensures that the low-speed flue gas carries the smallest particle size particles into the subsequent system.

[0043] The first blower 121 transports air to the air chamber 120. After being evenly distributed by the wind distribution plate 122, a high-speed air flow is formed to lift the particles in the dense phase section 130 to form a fluidized bed. The conical structure of the dense phase section 130 causes the air flow velocity to gradually decrease with the increase in height. After the particles experience intense fluidized mixing at the bottom of the dense phase section 130, when they enter the dilute phase section 140 with the upward air flow, the flow velocity drops suddenly, and the larger unburned particles settle back to the dense phase section 130 due to gravity to continue participating in the combustion reaction. The flue gas carrying a small amount of fine particles enters the sedimentation chamber 200 from the top flue gas outlet 150 after two velocity regulations, effectively avoiding the entry of high-concentration unburned particles into downstream equipment.

[0044] In this embodiment, through the dual flow velocity control of the conical expansion of the dense phase section 130 and the expansion of the cross-sectional area of the dilute phase section 140, a staged combustion and particle circulation mechanism is formed, and multiple fluidization and combustion reactions of particles are completed in the combustion chamber 100. It solves the problem of secondary combustion of the dust collector caused by the outflow of unburned particles in the combustion chamber. By regulating the flow velocity in stages, the residence time of particles in the high-temperature zone is prolonged, promoting the settlement of large particles back to the dense phase section to complete the combustion cycle, reducing the combustible content in the flue gas, and thus reducing the risk of carbon deposition and thermal stress damage to subsequent equipment.

[0045] In some embodiments, heat exchange buried pipes (not shown in the figure) are provided in the dense phase section, and the heat exchange buried pipes are connected to an external heat exchange mechanism. The heat exchange buried pipe refers to a heat exchange device embedded in the combustion area of the dense phase section. Specifically, a serpentine coil or spiral tube structure can be adopted, and rapid heat transfer is achieved through the high thermal conductivity of the metal material. The external heat exchange mechanism refers to a heat transfer system that forms a closed cycle with the heat exchange buried pipe. Specifically, a water cooling circuit or a steam generating device can be adopted.

[0046] In this embodiment, heat is transferred to the heat exchange mechanism (air preheater or waste heat boiler) of the peripheral device through a fluid medium to achieve cascaded energy utilization. At the same time, the temperature of the dense phase section is maintained stable within the range where the combustible substances react sufficiently. The temperature of the dense phase section is dynamically controlled by adjusting the flow rate of the cooling medium. For example, when the detected temperature exceeds the set threshold, the power of the circulation pump can be increased to accelerate heat dissipation, and the bed temperature is strictly controlled within 800 - 1000 °C (such as the optimal temperature range: it needs to be maintained at 850 - 950 °C, matching the temperature of the combustion chamber to avoid additional heating energy consumption. If it is lower than 800 °C, the combustion rate of carbon particles will decrease significantly, easily leading to incomplete combustion; if it is higher than 1000 °C, it will promote the formation of thermal NO x generation, increasing the risk of nitrogen oxide emissions), inhibiting the generation of thermal NO x generation (at this temperature, the reaction rate between N2 and O2 in the air is extremely low), and at the same time ensuring that the nitrogen element in the fuel is reduced in the form of NH3, HCN, etc., reducing fuel NO x .

[0047] This embodiment realizes the instant recovery and precise regulation of the heat in the combustion core area, so that the temperature of the dense phase section is always maintained within the optimal range required for complete combustion of the fuel, and the proportion of unburned carbon particles drops to an acceptable level. At the same time, the heat dissipation effect of the heat exchange buried pipe inhibits the local over-temperature phenomenon, and controls the generation amount of nitrogen oxides within the emission standard limit.

[0048] In some embodiments, as Figure 4 shown, the dilute phase section 140 includes: An enlarged section 141, which is cylindrical and connected to the bottom of the dense phase section 130. The cross-sectional area of the enlarged section 141 is greater than or equal to the cross-sectional area of the uppermost part of the dense phase section 130; the enlarged section refers to a cylindrical structure with a cross-sectional area larger than that of the dense phase section, and specifically can be realized by using a cylinder with the same axis as the bottom of the dense phase section and a larger diameter. When the air flow enters the dilute phase section through the sudden change of the cross-sectional area, the flow velocity drops suddenly, reducing the gas kinetic energy and causing larger particles to settle due to gravity; A contraction section 142, with the top connected to the flue gas outlet 150 and the bottom connected to the enlarged section 141. The cross-sectional area gradually decreases from bottom to top so that the fine particles carried by the air flow settle back to the enlarged section 141 and / or the dense phase section 130. The contraction section refers to a conical structure with a cross-sectional area gradually decreasing from bottom to top, and specifically can be realized by using a variable-diameter pipe section with a smaller top diameter than the bottom diameter. By forming a velocity gradient through the gradual change of the cross-sectional area, the residual fine particles settle when the air flow velocity is lower than the terminal velocity of the particles.

[0049] Specifically, in the expansion section, the sudden drop in the air flow velocity is caused by the increase in the cross-sectional area, which prompts the larger carried particles to settle back into the dense phase section due to the weakened kinetic energy, achieving rough separation; in the contraction section, the cross-sectional area gradually decreases, causing the air flow velocity to gradually increase during the upward process. When the air flow velocity is lower than the terminal velocity of the particles, the residual fine particles settle back into the expansion section or the dense phase section due to the velocity decay, achieving fine separation. The combination of the two sections forms a dual sedimentation mechanism of first reducing the velocity for rough separation and then slowing down for fine separation, gradually reducing the particle carrying amount in a stepped manner.

[0050] Compared with the existing dilute phase section of the fluidized bed furnace, which has a single equal-diameter or gradually expanding structure and can only unidirectionally adjust the flow velocity through the change in the cross-sectional area, and cannot control particle sedimentation in stages. In this embodiment, through the combined structure of the expansion section and the contraction section, a synergistic effect of a sudden drop and a slow rise in the flow velocity is formed in the dilute phase section, achieving stepped particle sedimentation, effectively reducing the outflow of fine particles carried by the air flow in the dilute phase section, and at the same time improving the efficiency of the unburned particles returning to the combustion chamber for continuous reaction.

[0051] In some embodiments, as Figures 3 - 5 shown, one side of the combustion chamber 100 is provided with an air distribution pipeline 160. One end of the air distribution pipeline 160 is connected to an external blower two 170. A number of air distribution branch pipes 161 are provided on the air distribution pipeline 160, and the air distribution branch pipes 161 communicate with the combustion chamber 100. Among them, the air distribution pipeline 160 refers to the air flow distribution channel connecting the blower two 170 and each area of the combustion chamber 100, and the air injection direction is controlled through the design of the branch pipe position; The oxygen supplementation branch 243 of the return pipeline 240 of the precipitation chamber 200 communicates with one of the air distribution branch pipes 161 of the air distribution pipeline 160. Specifically, a metal pipeline with a regulating valve can be used to be flange-connected to the oxygen supplementation branch. Driven by the external blower two, the air flow distribution function of the air distribution pipeline is extended to the oxygen supplementation branch, realizing the air flow linkage between the combustion chamber and the precipitation chamber. When the air flow is sprayed obliquely into the bottom flow channel of the precipitation chamber at the outlet end, due to the spraying angle being tangent to the inner wall, a swirling effect can be formed in the turbulent mixing area, eliminating the accumulation of combustion residues caused by insufficient oxygen supplementation and prolonging the contact time between the unburned fine particles and oxygen.

[0052] In this embodiment, air is distributed in different regions through multiple branch pipes, and the multi-stage oxygen supplementation mechanism ensures that the fuel is fully burned at different spatial levels in the combustion chamber, reducing carbon deposition, coking and thermal stress damage in the dust collector from the source.

[0053] In some embodiments, a heat exchange pipe is provided in the inverted conical inner cavity. The heat exchange pipe refers to a heat exchange element arranged in the inverted conical inner cavity, and specifically, it can be realized by arranging a serpentine coil structure circumferentially along the conical surface. For example, it can be a hollow pipe made of stainless steel or heat-resistant alloy steel. The heat exchange pipe flows through an air preheater, and the air preheater is arranged in the air supply channel between the air chamber and the blower 1. The air preheater refers to a heat exchange device for heating combustion air, and specifically, it can be realized by arranging a shell-and-tube heat exchanger structure in the air supply channel. Its shell side can be connected to the output end of the heat exchange pipe to form a closed cycle. After the preheated air enters the air distribution plate, it can increase the combustion reaction rate in the dense phase section, promote the complete combustion of fuel particles, and convert the waste heat of the flue gas into the preheating energy of the combustion air, which not only reduces the operating temperature of subsequent equipment but also improves the combustion efficiency.

[0054] In some specific embodiments, the heat exchange pipe can be arranged parallel to the inner wall surface of the inverted conical inner cavity at intervals, and the circulating medium can be heat-conducting oil or high-pressure water. The air preheater can be arranged as a multi-group finned tube bundle structure. Its air inlet is flange-connected to the outlet flange of the blower 1, and its air outlet is butt-connected to the air chamber inlet through an expansion joint. Through the turbulent heat transfer enhancement in the inverted cone part, the waste heat of the flue gas is converted into the preheating energy of the combustion air, which not only reduces the operating temperature of subsequent equipment but also improves the combustion efficiency. In some embodiments, as Figure 1 shown, an exhaust pipe 320 is provided at the top of the dust collector 300, and the exhaust pipe 320 is connected to the spray drying tower 400. The connection between the exhaust pipe and the spray drying tower means that the flue gas treated by the dust collector is transported to the spray drying tower for further treatment, and specifically, it can be realized by a metal pipe connected by a flange. The residual combustibles in the flue gas are adsorbed or reactively decomposed after contacting the atomized adsorbent in the spray drying tower. A collection area 330 is provided at the bottom of the dust collector 300, and the collection area 330 is connected to the dense phase section through a return device (not shown in the figure). The collection area refers to the area at the bottom of the dust collector for collecting the separated solid particles, and specifically, it can be realized by an inverted conical structure combined with a lock gas discharge valve, so that the unburned fine particles gather here and are stably transported to the return device. The connection between the return device and the dense phase section means that the particles in the collection area are re-introduced into the high-temperature fluidized area of the combustion chamber through mechanical or pneumatic conveying equipment, and specifically, it can be realized by a screw conveyor or an L-shaped valve combined with a pneumatic injection device, so that the particles participate in the combustion reaction again in the dense phase section.

[0055] This embodiment effectively reduces the residence time of unburned particles in the dust collector, preventing the problem of flow channel blockage caused by the formation of a coking layer; the circulating combustion of particles improves the fuel utilization rate and reduces the combustible content in the flue gas, thus avoiding the risks of equipment overheating or deflagration caused by secondary combustion; the synergistic effect of the return device and the spray drying tower realizes the closed-loop control of combustion and purification, enhancing the safety and stability of the system operation.

[0056] The above has specifically described the preferred embodiments of the present invention. However, the present invention is not limited to the described embodiments. Those skilled in the art can also make various equivalent variations or substitutions without departing from the spirit of the present invention, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A vertical fluidized bed boiling furnace for energy storage, characterized in that, It includes a combustion chamber (100), a dust collector (300), and a sedimentation chamber (200) independently arranged between the combustion chamber (100) and the dust collector (300); An inlet (210) and an outlet (220) are symmetrically arranged on both sides of the sedimentation chamber (200). A flue gas pipe (110) is provided at the top of the combustion chamber (100), and the flue gas pipe (110) is communicated with the inlet (210). The dust collector (300) has a cyclone pipe (310), and the cyclone pipe (310) is communicated with the outlet (220). The cross-sectional area of the outlet (220) is larger than that of the inlet (210); The sedimentation chamber (200) is provided with a partition plate (230) extending downward from the inner wall of the top, so that the internal space of the sedimentation chamber (200) forms a U-shaped flow channel. The U-shaped flow channel includes a first flow channel (231), a bottom flow channel (232), and a second flow channel (233) connected in sequence. A inverted conical inner cavity (234) is provided below the bottom flow channel (232); The flue gas of the flue gas pipe (110) enters the first flow channel (231) from the inlet (210), flows downward along the first flow channel (231) to the bottom flow channel (232), the flue gas impacts on the wall of the inverted conical inner cavity (234) and rebounds to form a turbulent mixture in the bottom flow channel (232). The flue gas carries unburned fine particles to mix and burn again. The flue gas after re-combustion flows upward along the second flow channel (233) to the outlet (220) and enters the cyclone pipe (310).

2. The energy storage type vertical fluidized bed boiling furnace according to claim 1, characterized in that: There is also a return pipe (240) spiraling downward from top to bottom outside the sedimentation chamber (200). The inlet end (241) of the return pipe (240) is communicated with the second flow channel (233), and the outlet end (242) is communicated with the first flow channel (231). The inlet end (241) and the outlet end (242) respectively penetrate the wall of the sedimentation chamber (200) obliquely along the spiraling direction.

3. The energy storage type vertical fluidized bed boiling furnace according to claim 2, characterized in that: The return pipe (240) is provided with a return fan and an oxygen supplement branch (243). The position of the outlet end (242) is flush with the bottom of the partition plate (230) so that the flue gas and air or oxygen in the return pipe (240) are sprayed obliquely downward and tangentially to the inner wall of the sedimentation chamber (200) at the position of the outlet end (242) into the bottom flow channel (232) and / or the inverted conical inner cavity (234).

4. A vertical fluidized bed boiling furnace for energy storage according to claim 1, characterized in that: The combustion chamber (100) sequentially includes from bottom to top: An air chamber (120), which is connected to an external blower one (121); A dense phase section (130), and a air distribution plate (122) is arranged between the dense phase section (130) and the air chamber (120). The dense phase section (130) adopts a conical structure with a smaller cross-sectional area at the lower part and a larger cross-sectional area at the upper part, so that the high-speed air flow near the air distribution plate (122) can lift the particles to form a fluidized state; A lean phase section (140), which reduces the flow rate of the gas entering the dense phase section (130); The flue gas outlet (150) is provided at the top of the dilute phase section (140) and is connected to the sedimentation chamber (200) through a flue gas pipeline (110).

5. The vertical fluidized bed boiling furnace of an energy storage type according to claim 4, wherein: Heat exchange buried pipes are provided in the dense phase section (130), and the heat exchange buried pipes are connected to an external heat exchange mechanism.

6. The vertical fluidized bed boiling furnace of an energy storage type according to claim 4, characterized in that: The dilute phase section (140) includes:[[]] An enlarged section (141), which is cylindrical and is connected to the dense phase section (130) at the bottom, and the cross-sectional area of the enlarged section (141) is greater than or equal to the cross-sectional area of the uppermost part of the dense phase section (130); A contraction section (142), which is connected to the flue gas outlet (150) at the top and is connected to the enlarged section (141) at the bottom, and the cross-sectional area gradually decreases from bottom to top so that the fine particles carried by the airflow settle back to the enlarged section (141) and / or the dense phase section (130).

7. The energy storage type vertical fluidized bed boiling furnace according to claim 6, characterized in that: A air distribution pipeline (160) is provided on one side of the combustion chamber (100). One end of the air distribution pipeline (160) is connected to an external blower two (170). A number of air distribution branch pipes (161) are provided on the air distribution pipeline (160), and the air distribution branch pipes (161) communicate with the combustion chamber (100).

8. The energy storage type vertical fluidized bed boiling furnace according to claim 7, characterized in that: The oxygen supplement branch (243) of the return pipeline (240) of the sedimentation chamber (200) communicates with one of the air distribution branch pipes (161) of the air distribution pipeline (160).

9. The energy storage type vertical fluidized bed boiling furnace according to claim 4, wherein: Heat exchange pipes are provided in the inverted conical inner cavity (234). The heat exchange pipes flow through an air preheater, and the air preheater is arranged in the air supply channel between the air chamber (120) and the blower one (121).

10. The energy storage type vertical fluidized bed boiling furnace according to claim 1, characterized in that: An exhaust pipeline (320) is provided at the top of the dust collector (300). The exhaust pipeline (320) is connected to a spray drying tower (400). An aggregate area (330) is provided at the bottom of the dust collector (300), and the aggregate area (330) is connected to the dense phase section (130) through a return device.

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