Hearth anti-coking structure of biomass fluidized bed furnace and biomass fluidized bed furnace
By installing a cooling water tank and air cap system at the bottom of the biomass fluidized bed furnace, the surface temperature of the furnace bed is reduced, solving the coking problem caused by excessively high local temperatures during startup and operation of the biomass fluidized bed furnace, and achieving an effective anti-coking effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DONGGUAN CITY WONDERFUL CERAMICS IND PARK
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-12
AI Technical Summary
Biomass fluidized bed furnaces are prone to coking in the furnace during production start-up and operation, especially when the local temperature in the furnace is too high or the blower pressure and speed are not appropriate, which can cause ash particles to melt and stick to coke, resulting in furnace shutdown accidents.
A cooling water tank is installed at the bottom of the furnace of the biomass fluidized bed furnace. The cooling water tank is filled with flowing coolant. Combustion air is blown to the bed material layer through the air distribution plate and air cap to reduce the surface temperature of the furnace bed and prevent coking.
It effectively prevents and reduces the phenomenon of melting and slagging caused by local temperature rise, reduces the difficulty of production management and operation of biomass fluidized bed furnace, and improves the furnace's anti-slagging ability.
Smart Images
Figure CN224229986U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of biomass fluidized bed furnace equipment, and in particular to a furnace anti-coking structure for a biomass fluidized bed furnace and the biomass fluidized bed furnace itself. Background Technology
[0002] Biomass energy is a clean and renewable energy source. It is mainly made from raw materials such as straw, rice straw, rice husks, peanut shells, corn cobs, camellia shells, cottonseed husks, cotton stalks, and other "three wastes" biomass, which are processed into block or granular forms of environmentally friendly new energy.
[0003] Coking frequently occurs in the furnace during the start-up and operation of biomass fluidized bed furnaces. The main reason for coking is that the temperature of the furnace bed exceeds the melting point of the ash. The higher the temperature in the combustion zone of the furnace, the easier it is for the ash to soften or melt, and the greater the possibility of coking. During the start-up and operation of biomass fluidized bed furnaces, improper setting of operating parameters often results in low blower pressure and velocity, improper forced draft and induced draft in the furnace, causing local temperature rise in the furnace, poor cooling conditions for ash particles, and resulting in melting and coking. Moreover, coking in the combustion zone of the furnace usually occurs first on the furnace bed surface, in the vortex zone or "dead zone" of the airflow, and in the corners, edges, and near the fire baffle of the furnace bed where aerodynamic conditions are poor. If appropriate measures are not taken in time to deal with the localized coking, it will quickly develop into a serious state of coking on a large plate of the entire furnace bed, causing a shutdown accident.
[0004] Therefore, existing technologies have shortcomings and need to be improved and developed. Utility Model Content
[0005] The technical problem to be solved by this utility model is to provide a furnace anti-coking structure for a biomass fluidized bed furnace and a biomass fluidized bed furnace, in order to solve the problem of furnace coking that often occurs in the production start-up and operation of biomass fluidized bed furnaces in the prior art.
[0006] The technical solution adopted by this utility model to solve the technical problem is as follows:
[0007] A coking prevention structure for the furnace chamber of a biomass fluidized bed furnace, comprising:
[0008] Furnace;
[0009] A bed material layer is provided at the bottom of the furnace.
[0010] A cooling water tank is disposed below the bed material layer, and the top of the cooling water tank is attached to the bed material layer. The cooling water tank is used to fill with flowing coolant to cool the bed material layer.
[0011] An air distribution plate is located below the cooling water tank, and the air distribution plate has several air guide holes.
[0012] A number of air caps are provided, which are installed through the cooling water tank. The air caps are connected to a number of air guide holes on the air distribution plate. The top of the air caps is provided with ventilation holes. The air caps are used to blow the combustion air transported through the air guide holes to the bed material layer through the ventilation holes.
[0013] In one embodiment of this utility model, the body of the cooling water tank is a metal plate.
[0014] In one embodiment of the present invention, the furnace anti-coking structure further includes a cooling water pool disposed outside the furnace body of the biomass fluidized bed furnace and connected to the cooling water tank, the cooling water pool being used to hold coolant.
[0015] In one embodiment of this utility model, the cooling water tank is provided with an inlet pipe and an outlet pipe, both of which are connected to the cooling water pool; a water pump is provided between the cooling water pool and the inlet pipe, and the water pump is used to circulate and deliver coolant to the cooling water tank.
[0016] In one embodiment of this utility model, the furnace anti-coking structure further includes:
[0017] A bellows is located below the air distribution plate, and several air guide holes on the air distribution plate are connected to the bellows.
[0018] An air supply duct is connected to the air box;
[0019] A blower is connected to the end of the air supply pipe away from the air box, and the blower is used to generate combustion air.
[0020] In one embodiment of the present invention, the wind cap includes: a wind cap body and an air guide connected to each other; the air guide is disposed inside the cooling water tank and penetrates through the cooling water tank; the wind cap body is disposed above the cooling water tank, and the ventilation hole is formed on the wind cap body.
[0021] In one embodiment of this utility model, the wind cap body and the air guide part are separately arranged.
[0022] In one embodiment of this utility model, the wind cap body and the air guide are integrally formed.
[0023] In one embodiment of this utility model, the hood is a metal hood.
[0024] This utility model also provides a biomass fluidized bed furnace, wherein the biomass fluidized bed furnace includes the anti-coking structure of the furnace chamber as described above.
[0025] The beneficial effects achieved by this utility model are:
[0026] This utility model provides a coking prevention structure for the furnace chamber of a biomass fluidized bed furnace and the biomass fluidized bed furnace itself. The coking prevention structure for the furnace chamber includes: a furnace chamber; a bed material layer disposed at the bottom of the furnace chamber; a cooling water tank disposed below the bed material layer, with the top of the cooling water tank in close contact with the bed material layer, the cooling water tank being filled with flowing coolant to cool the bed material layer; an air distribution plate disposed below the cooling water tank, the air distribution plate having several air guide holes; and several air caps disposed through the cooling water tank, the air caps being connected to the several air guide holes on the air distribution plate; the top of each air cap has a ventilation hole, the air cap being used to blow combustion air transported through the air guide holes to the bed material layer through the ventilation hole. This invention indirectly reduces the surface temperature of the bed material by installing a cooling water tank filled with flowing coolant at the bottom of the furnace of a biomass fluidized bed furnace. During the start-up and operation of the biomass fluidized bed furnace, it can prevent and reduce the phenomenon of melting and coking caused by local temperature rise and poor cooling conditions of ash particles in the bed material of the biomass fluidized bed furnace. Attached Figure Description
[0027] Figure 1 This is a front view of a preferred embodiment of the anti-coking structure of the furnace of the biomass fluidized bed furnace in this utility model.
[0028] Figure 2 yes Figure 1 Enlarged view of point A in the middle.
[0029] Figure 3 This is a top view of a preferred embodiment of the anti-coking structure of the furnace of the biomass fluidized bed furnace in this utility model.
[0030] Explanation of reference numerals in the attached figures:
[0031] 100. Furnace chamber; 200. Bed material layer; 300. Cooling water tank; 310. Coolant; 320. Water inlet pipe; 330. Water outlet pipe; 340. Water pump; 400. Air distribution plate; 410. Air guide hole; 500. Air cap; 510. Air cap body; 520. Air guide section; 600. Cooling water pool; 700. Air box; 800. Air supply pipe. Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of this utility model clearer and more explicit, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0033] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.
[0034] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0035] During startup and operation of a biomass fluidized bed furnace, temperature fluctuations within the furnace and changes in bed pressure can cause ash from the fluidized bed combustion of biomass pellets to react with sand particles in the bed, resulting in coking. This invention addresses this issue by employing a circulating cooling water tank to cool the furnace bed surface, thereby reducing its temperature and preventing coking caused by excessively high temperatures. This minimizes the impact of furnace coking on production and simplifies the management and operation of the biomass fluidized bed furnace.
[0036] Please see Figure 1 and Figure 2This utility model provides an anti-coking structure for the furnace 100 of a biomass fluidized bed furnace, including: furnace 100, bed material layer 200, cooling water tank 300, air distribution plate 400 and several air caps 500. A bed material layer 200 is disposed at the bottom of the furnace 100; a cooling water tank 300 is disposed below the bed material layer 200, and the top of the cooling water tank 300 is fitted to the bed material layer 200. The cooling water tank 300 is used to fill with flowing coolant 310 to cool the bed material layer 200; an air distribution plate 400 is disposed below the cooling water tank 300, and the air distribution plate 400 has several air guide holes 410; several air caps 500 are disposed through the cooling water tank 300, and the air caps 500 are connected to the several air guide holes 410 on the air distribution plate 400; the top of the air caps 500 has ventilation holes, and the air caps 500 are used to blow the combustion air transported through the air guide holes 410 to the bed material layer 200 through the ventilation holes.
[0037] Specifically, this invention installs a cooling water tank 300 between the air distribution plate 400 and the bed material layer 200. The cooling water tank 300 can hold circulating coolant 310, thereby cooling the bed material layer 200. The air cap 500 passes through the cooling water tank 300 and is connected to the air distribution plate 400. In this way, the combustion air is blown into the furnace 100 of the fluidized bed furnace through the ventilation holes on the air distribution plate 400 and the air cap 500, blowing up the sand and biomass pellets of the bed material layer 200 covering the outer surface of the cooling water tank 300, thus achieving fluidized bed combustion.
[0038] This invention indirectly reduces the surface temperature of the bed material layer 200 by installing a cooling water tank 300 filled with flowing coolant 310 at the bottom of the furnace chamber 100 of the biomass fluidized bed furnace. This can prevent and reduce the melting and coking phenomenon of the bed material layer 200 of the biomass fluidized bed furnace caused by local temperature rise and poor cooling conditions of ash particles. Furthermore, the structure is simple and the operation is easy, which can reduce the difficulty of production management and operation of the biomass fluidized bed furnace.
[0039] In one embodiment, the cooling water tank 300 has a metal plate as its casing. Specifically, metal has good thermal conductivity. The flowing liquid filling the cooling water tank 300 contacts the metal plate on top of the casing, carrying away some of the heat from the metal plate through heat exchange. This also indirectly carries away some of the heat from the sand particles in the bed material layer 200 covering the upper surface of the metal plate, thereby reducing the temperature of the bed material layer 200. In one embodiment, the top of the cooling water tank 300 is made of a heat-resistant metal plate, while the rest is made of ordinary metal plates. This is because the top of the cooling water tank 300 is in direct contact with the furnace 100 at high temperatures, thus requiring the use of a heat-resistant metal plate.
[0040] This invention uses a metal plate as the housing of the cooling water tank 300, enabling the coolant 310 in the cooling water tank 300 to exchange heat with the bed material layer 200, thereby reducing the temperature of the bed material layer 200. This prevents and reduces the phenomenon of melting and coking caused by improper setting of operating parameters during the start-up and operation of the biomass fluidized bed furnace, resulting in low blower pressure and wind speed, improper blowing and induced draft in the furnace 100, local temperature rise in the furnace bed, ash particle turbulence, and poor cooling conditions.
[0041] In one embodiment, the anti-coking structure of the furnace 100 further includes a cooling water pool 600 disposed outside the furnace body of the biomass fluidized bed furnace and connected to the cooling water tank 300, the cooling water pool 600 being used to hold coolant 310.
[0042] Specifically, this embodiment of the application also includes a cooling water pool 600 to facilitate the flow of coolant 310 in the cooling water tank 300. Furthermore, the cooling water pool 600 is located outside the biomass fluidized bed furnace, enabling natural cooling and also providing auxiliary cooling for the cooling water pool 600.
[0043] This invention improves the cooling effect of a biomass fluidized bed furnace by installing a cooling water pool 600 connected to the cooling water tank 300 outside the furnace body, thereby enabling the coolant 310 in the cooling water tank 300 to flow and maintain a low temperature. The cooling water pool 600 of this invention can also improve natural heat dissipation efficiency by increasing its area. Furthermore, a temperature sensor can be installed in the cooling water pool 600 to automatically replenish cold water to balance the temperature when the water temperature exceeds a set value.
[0044] In one embodiment, see Figure 3 The cooling water tank 300 is provided with an inlet pipe 320 and an outlet pipe 330, both of which are connected to the cooling water pool 600. A water pump 340 is provided between the cooling water pool 600 and the inlet pipe 320, and the water pump 340 is used to circulate and deliver coolant 310 to the cooling water tank 300.
[0045] Specifically, the cooling water tank 300 is filled with coolant 310, which circulates through the inlet pipe 320, outlet pipe 330, and water pump 340 to the cooling water pool 600. The flow rate of coolant 310 in and out of the cooling water tank 300 can be adjusted by frequency converter control of water pump 340.
[0046] The water pump 340 of this utility model can provide a stable flow rate to ensure that the coolant 310 circulates as needed. The water pump 340 can adjust the flow rate to cope with sudden high heat loads.
[0047] In one embodiment, the anti-coking structure of the furnace 100 further includes:
[0048] The air box 700 is located below the air distribution plate 400, and a plurality of air guide holes 410 on the air distribution plate 400 are connected to the air box 700.
[0049] Air supply duct 800 is connected to the air box 700;
[0050] A blower is connected to the end of the air supply pipe 800 away from the air box 700, and the blower is used to generate combustion air.
[0051] Specifically, the combustion air with high pressure generated by the blower of the fluidized bed furnace enters the air box 700 through the air supply pipe 800 and is then blown into the furnace chamber 100 of the fluidized bed furnace through the air guide hole 410 of the air distribution plate 400, the air cap 500 and the ventilation hole on the air cap 500. This blows up the bed material sand and biomass pellets covering the outer surface of the cooling water tank 300, thus achieving combustion in a fluidized state.
[0052] The bellows 700 of this invention serves as a pressure stabilizing chamber, which distributes airflow evenly through the air guide holes 410 on the air distribution plate 400, avoiding excessively high or low local wind speeds, ensuring uniform oxygen distribution in the combustion zone, and reducing incomplete combustion. Furthermore, the bellows 700 serves as a buffer layer, reducing mechanical wear caused by direct airflow impact on the air distribution plate 400 and extending the life of the air guide holes 410.
[0053] In one embodiment, the hood 500 includes: a hood body 510 and an air guide 520 connected to each other; the air guide 520 is disposed inside the cooling water tank 300 and extends through the cooling water tank 300; the hood body 510 is disposed above the cooling water tank 300, and the ventilation hole is opened on the hood body 510.
[0054] Specifically, in this invention, because a cooling water tank 300 is provided, a portion of the air cap 500 penetrates the cooling water tank 300, and another portion is located on the upper surface of the cooling water tank 300. This invention refers to the portion penetrating the cooling water tank 300 as the air guide section 520, and the portion located on the upper surface of the cooling water tank 300 as the air cap body 510. In the biomass fluidized bed furnace, the air cap body 510 evenly distributes the air supplied by the blower into the furnace chamber 100, ensuring sufficient contact between biomass fuel and oxygen. The airflow ejected from the air cap body 510 suspends the biomass particles and fluidizes them, enhancing gas-solid mixing and increasing the combustion rate. The top of the air cap body 510 in this invention is umbrella-shaped, and the ventilation holes can be opened on the side of the air cap body 510.
[0055] The wind cap 500 of this utility model includes a wind cap body 510 and an air guide 520, which can be adapted to the cooling water tank 300. The combustion air with high wind pressure generated by the blower of the fluidized bed furnace enters the air box 700 through the air supply pipe 800, and is then blown into the combustion chamber of the fluidized bed furnace through the air distribution plate 400, the air guide 520 and the ventilation holes on the wind cap body 510. This blows up the bed material sand and biomass pellets covering the outer surface of the cooling water tank 300, achieving combustion in a fluidized state.
[0056] In one embodiment, the hood body 510 and the air guide 520 are separately configured.
[0057] Specifically, since the air cap body 510 is located at the bottom of the combustion chamber and is easily damaged, this utility model separates the air cap body 510 and the air guide 520. When the air cap body 510 is damaged, only the air cap body 510 needs to be replaced, and the air guide 520 does not need to be replaced. In addition, the air cap body 510 is exposed outside the cooling water tank 300, making it easy to disassemble and improving maintenance efficiency.
[0058] In another embodiment, the hood body 510 and the air guide 520 are integrally formed.
[0059] Specifically, the wind cap body 510 and the air guide 520 of this utility model can also be set as one unit. The wind cap 500 set as one unit is less likely to generate eddies, making the airflow more stable, with a simple structure and lower cost.
[0060] In one embodiment, the hood 500 is a metal hood 500.
[0061] Specifically, the wind cap 500 of this utility model is made of metal, such as heat-resistant stainless steel, heat-resistant cast iron, or high-chromium alloy steel. This is because the metal wind cap 500 can withstand high temperatures for a long time and is not easily deformed or cracked. Metal (especially high-hardness alloy steel) can withstand the long-term scouring of ash and fuel particles carried by high-speed airflow, resulting in a longer service life. Furthermore, the metal wind cap 500 can withstand the impact of fuel particles and is not easily broken.
[0062] Alternatively, if the hood body 510 and the air guide 520 are separate components, the hood body 510 can be made of high-temperature resistant metal, while the air guide 520 can be made of ordinary metal.
[0063] This utility model also provides a biomass fluidized bed furnace, which includes the anti-coking structure of the furnace chamber as described above.
[0064] In summary, this utility model discloses a furnace anti-coking structure for a biomass fluidized bed furnace and the biomass fluidized bed furnace itself. The furnace anti-coking structure includes: a furnace chamber; a bed material layer disposed at the bottom of the furnace chamber; a cooling water tank disposed below the bed material layer, with the top of the cooling water tank in close contact with the bed material layer, the cooling water tank being filled with flowing coolant to cool the bed material layer; an air distribution plate disposed below the cooling water tank, the air distribution plate having several air guide holes; and several air caps disposed through the cooling water tank, the air caps being connected to the several air guide holes on the air distribution plate; the top of each air cap has a ventilation hole, the air cap being used to blow combustion air transported through the air guide holes to the bed material layer through the ventilation hole. This invention indirectly reduces the surface temperature of the bed material by installing a cooling water tank filled with flowing coolant at the bottom of the furnace of a biomass fluidized bed furnace. During the start-up and operation of the biomass fluidized bed furnace, it can prevent and reduce the phenomenon of melting and coking caused by local temperature rise and poor cooling conditions of ash particles in the bed material of the biomass fluidized bed furnace.
[0065] It should be understood that the application of this utility model is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A furnace anti-coking structure for a biomass fluidized bed furnace, characterized in that, include: Furnace; A bed material layer is provided at the bottom of the furnace. A cooling water tank is disposed below the bed material layer, and the top of the cooling water tank is attached to the bed material layer. The cooling water tank is used to fill with flowing coolant to cool the bed material layer. An air distribution plate is located below the cooling water tank, and the air distribution plate has several air guide holes. A number of air caps are provided, which are installed through the cooling water tank. The air caps are connected to a number of air guide holes on the air distribution plate. The top of the air caps is provided with ventilation holes. The air caps are used to blow the combustion air transported through the air guide holes to the bed material layer through the ventilation holes.
2. The anti-coking structure of the furnace chamber of the biomass fluidized bed furnace according to claim 1, characterized in that, The cooling water tank is made of metal plate.
3. The anti-coking structure of the furnace chamber of the biomass fluidized bed furnace according to claim 1, characterized in that, The furnace anti-coking structure also includes a cooling water pool located outside the biomass fluidized bed furnace and connected to the cooling water tank, the cooling water pool being used to hold coolant.
4. The anti-coking structure of the furnace chamber of the biomass fluidized bed furnace according to claim 3, characterized in that, The cooling water tank is equipped with an inlet pipe and an outlet pipe, both of which are connected to the cooling water pool. A water pump is installed between the cooling water pool and the inlet pipe, and the water pump is used to circulate coolant to the cooling water tank.
5. The anti-coking structure of the furnace chamber of the biomass fluidized bed furnace according to claim 1, characterized in that, The furnace anti-coking structure also includes: A bellows is located below the air distribution plate, and several air guide holes on the air distribution plate are connected to the bellows. An air supply duct is connected to the air box; A blower is connected to the end of the air supply pipe away from the air box, and the blower is used to generate combustion air.
6. The anti-coking structure of the furnace chamber of the biomass fluidized bed furnace according to claim 1, characterized in that, The wind cap includes: a wind cap body and an air guide section connected to each other; the air guide section is disposed inside the cooling water tank and extends through the cooling water tank; the wind cap body is disposed above the cooling water tank, and the ventilation holes are opened on the wind cap body.
7. The anti-coking structure of the furnace of the biomass fluidized bed furnace according to claim 6, characterized in that, The wind cap body and the air guide part are separately arranged.
8. The anti-coking structure of the furnace chamber of the biomass fluidized bed furnace according to claim 6, characterized in that, The hood body and the air guide are integrated into one unit.
9. The anti-coking structure of the furnace of the biomass fluidized bed furnace according to claim 1, characterized in that, The hood is a metal hood.
10. A biomass fluidized bed boiler, characterized in that, The biomass fluidized bed furnace includes the anti-coking structure of the furnace chamber as described in any one of claims 1 to 9.