Uniform gas distribution device for conical part of circulating fluidized bed and implementation method of uniform gas distribution device

Abstract

The invention discloses a device for uniformly distributing gas at a conical part of a circulating fluidized bed and an implementation method of the device. The device comprises a main air pipe, a main fluidized gas pressure buffer chamber, a partial pressure chamber and a bottom constant-speed flow field, the upper part of the main air pipe is connected with a main fluidizing gas pressure buffer chamber, and a constant-speed flow field is arranged at the upper part of the main fluidizing gas pressure buffer chamber; the pressure buffer chamber is of a conical structure, and a plurality of partial pressure chambers are arranged at the same horizontal height above the interior of the pressure buffer chamber and are used for uniformly controlling the flow rate and the gas amount of fluidized gas. The invention aims to solve the problem of non-uniform air flow distribution in a conical part area. The airflow distribution effect of the circulating fluidized bed is optimized, and the operation efficiency and stability of the circulating fluidized bed are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of circulating fluidized beds, and in particular to a device for uniformly distributing gas in a conical part of a circulating fluidized bed and an implementation method thereof. Background Art

[0002] In the existing circulating fluidized bed (CFB) technology, the cone gas distribution plate is a key component to achieve uniform distribution of the cone fluidizing gas.

[0003] However, the cone air distribution plate designs that are widely used at present are mostly based on traditional orifice plates or slit structures. Such designs have obvious defects in actual operation.

[0004] First, the pressure loss and uneven velocity distribution of the gas passing through the orifice plate or slits lead to uneven distribution of the fluidizing gas in the cone, which affects the combustion efficiency and stability of the CFB. Second, the orifice plate or slits are prone to clogging during long-term operation, increasing the cost of maintenance and replacement.

[0005] In addition, a wind distribution device for a fluidized bed reactor with publication number CN107448932A has a complex design, lacks flexibility, and is difficult to adapt to fluidization requirements under different working conditions.

[0006] In summary, the prior art has an uneven distribution of fluidizing gas in the cone, the orifice plate or the gap is easily blocked in long-term operation, and the design is complex and lacks flexibility. Summary of the invention

[0007] In order to overcome the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a device for uniformly distributing air in the cone of a circulating fluidized bed and its implementation method, aiming to solve the problem of uneven airflow distribution in the cone area, optimize the airflow distribution effect of the circulating fluidized bed, and effectively improve the operating efficiency and stability of the circulating fluidized bed.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A device for uniformly distributing gas in the cone of a circulating fluidized bed, comprising a main air duct 1, a mainstream fluidized gas pressure buffer chamber 2, a pressure dividing chamber 8 and a bottom uniform velocity flow field 9;

[0010] The upper part of the main air duct 1 is connected to the mainstream gas pressure buffer chamber 2, and a uniform flow field 9 is arranged on the upper part of the mainstream gas pressure buffer chamber 2;

[0011] The pressure buffer chamber 2 is a conical structure, and a plurality of pressure-dividing chambers 8 are arranged at the same level above the inside of the pressure buffer chamber 2. The pressure-dividing chambers 8 are used to uniformly control the flow rate and gas volume of the fluidizing gas.

[0012] The pressure dividing chambers 8 are evenly arranged, and the shape structure of a single pressure dividing chamber 8 is a conical structure; the bottom of the conical structure of the pressure dividing chamber 8 is an open structure, and the opening structure is a pressure dividing air inlet 3. A uniform speed air outlet valve 5 is arranged inside the conical structure, and the uniform speed air outlet valve 5 is located above the pressure dividing air inlet 3. A pressure dividing buffer chamber 4 is formed between the pressure dividing air inlet 3 and the uniform speed air outlet valve 5. The uniform speed air outlet valve 5 is a spherical structure and does not contact the side wall of the conical structure of the pressure dividing chamber 8, forming a uniform pressure-bearing air outlet 6. A limiting lever 7 is installed on the side wall of the pressure dividing chamber 8 above the uniform speed air outlet valve 5. The limiting lever 7 is used to limit the upward movement of the uniform speed air outlet valve 5, so as to control the maximum valve position of the uniform speed air outlet valve 5.

[0013] The partial pressure air inlet 3 is a cylindrical air inlet; the opening angle 10 of the partial pressure air inlet 3 is 30-60°.

[0014] The number of the pressure-dividing chambers 8 is greater than or equal to one, and they are evenly distributed and arranged at the bottom of the uniform flow field 9 .

[0015] The uniform speed air outlet valve 5 is a spherical structure; the uniform speed air outlet valve has a one-way flow guide and an adjustable valve core.

[0016] The flow rate of air intake through the partial pressure air inlet 3 and the flow rate of air intake through the main air duct 1 are inversely proportional to the designed number of partial pressure air inlet 3, which is used to achieve uniform distribution of gas.

[0017] A method for implementing a device for uniformly distributing gas in the cone portion of a circulating fluidized bed comprises the following steps:

[0018] Step 1: The mainstream gas enters the mainstream gas pressure buffer chamber 2 through the main air duct 1, and after passing through the pressure buffer chamber 2, the gas with stable pressure is sent to the pressure dividing chamber 8;

[0019] Step 2: When the air starts to enter, due to the existence of the gravity of the uniform outlet valve 5, the pressure difference before and after the valve is less than the gravity of the uniform outlet valve 5, and the uniform outlet valve 5 is not opened. When the pressure difference before and after the uniform outlet valve 5 is equal to or greater than the pressure difference between the pressure buffer chamber 2 of the main stream of the divided port and the uniform pressure outlet 6, the uniform outlet valve 5 opens, and the gas enters the uniform pressure outlet 6 of the pressure chamber 8;

[0020] Step 3: The gas enters the uniform pressure outlet 6 of the pressure dividing chamber 8. When the pressure difference before and after the uniform outlet valve 5 is too large, the opening of the uniform outlet valve 5 becomes larger. However, due to the existence of the limit lever 7, the maximum opening is fixed, thereby increasing the pressure difference before and after.

[0021] Step 4: The gas enters the uniform pressure outlet 6 of the pressure chamber 8. According to the principle of spherical turbulence of the Bernoulli equation, the outlet air flows out in parallel to achieve the purpose of uniform gas distribution.

[0022] In step 2, when the pressure of the partial pressure air inlet 3 is greater than the sum of the pressures of the uniform speed air outlet valve 5 and the uniform speed pressure air outlet 6, the uniform speed air outlet valve 5 is pushed open; the limit lever 7 limits the position and opening of the uniform speed air outlet valve 5, and the gas enters the uniform speed pressure air outlet 6 and forms a parallel airflow; the uniform speed pressure air outlet 6 is connected to the bottom uniform speed flow field 9 and forms a parallel airflow to achieve the purpose of gas distribution.

[0023] Beneficial effects of the present invention:

[0024] In the present invention, the main air duct is connected to the mainstream gas pressure buffer chamber, and receives the airflow through the pressure-dividing air inlet in the pressure-dividing chamber. When the pressure at the air inlet is sufficient, the uniform-speed air outlet valve is pushed to open, and the gas enters the bottom uniform-speed flow field in the form of parallel airflow through the uniform-speed pressure-bearing air outlet, thereby achieving uniform air distribution in the cone area.

[0025] The mainstream gas pressure buffer chamber plays a role in stabilizing the pressure and ensuring the pressure balance of each pressure chamber inlet. The uniform outlet valve has a one-way flow guide and an adjustable valve core to meet different gas distribution requirements. The valve core material is high temperature resistant and has a smooth surface, which is suitable for high temperature environments.

[0026] The uniform pressure outlet is designed with a specific opening angle and number to optimize the air flow distribution effect. The entire device has a compact structure and flexible operation, which can effectively improve the operating efficiency and stability of the circulating fluidized bed. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0028] Figure 2 A plan layout of a pressure divider chamber.

[0029] Figure 3 This is a partial view of the pressure divider chamber.

[0030] Among them: 1. Main air duct; 2. Main flow gas pressure buffer chamber; 3. Pressure-dividing air inlet; 4. Pressure-dividing buffer chamber; 5. Uniform air outlet valve; 6. Uniform pressure outlet; 7. Limit lever; 8. Pressure-dividing chamber; 9. Uniform flow field. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0032] like Figure 1-Figure 3 As shown, the device of the present invention comprises a main air duct 1, a mainstream gas pressure buffer chamber 2, a pressure dividing chamber 8 and a bottom uniform flow field 9;

[0033] The upper part of the main air duct 1 is connected to the mainstream gas pressure buffer chamber 2; the pressure-dividing air inlet 3 of each pressure-dividing chamber 8, when the pressure of the pressure-dividing air inlet 3 is greater than the sum of the pressures of the uniform velocity air outlet valve 5 and the uniform velocity pressure air outlet 6, the uniform velocity air outlet valve 5 is pushed open; the limit lever 7 can limit the position and opening of the uniform velocity air outlet valve 5, and the gas enters the uniform velocity pressure air outlet 6 and forms a parallel airflow; the uniform velocity pressure air outlet 6 is connected to the bottom uniform velocity flow field 9 and forms a parallel airflow to achieve the purpose of air distribution.

[0034] The pressure dividing chamber 8 comprises a pressure dividing air inlet 3 , a pressure dividing buffer chamber 4 , a uniform speed air outlet valve 5 , a uniform speed pressure bearing air outlet 6 and a limit lever 7 .

[0035] The mainstream gas pressure buffer chamber 2 is relatively large in volume and has a pressure buffering effect, ensuring the pressure balance of the pressure-dividing air inlet 3 of each pressure-dividing chamber 8. When the pressure of the pressure-dividing air inlet 3 is greater than the sum of the pressures of the uniform speed air outlet valve 5 and the uniform speed pressure-bearing air outlet 6, the gas channel opens. This structure has multiple pressure stabilizing effects.

[0036] The uniform air outlet valve 5 also has a one-way flow guiding function, and the valve core size can be adjusted to change the output range of uniform air outlet;

[0037] The valve core material of the uniform speed outlet valve 5 needs to be selected in consideration of the need to withstand high temperatures above 1200 degrees Celsius in the gasification furnace and require a smooth surface and non-sticky ash. Therefore, the uniform speed outlet valve 5 uses but is not limited to silicon carbide ceramics and zirconium oxide ceramics as the valve body material. The use of this material not only has good high temperature resistance, but also the surface smoothness can meet certain requirements.

[0038] The mainstream fluidizing gas pressure buffer chamber 2 corresponds to the spatial layout of the cone of the circulating fluidized bed. The cone has a slightly larger volume, which can achieve the functions of gas buffering and pressure stabilization. The main air duct 1 is connected to the pressure inlet 3 of the pressure chamber to deliver the pressure-stable gas to the pressure chamber 8.

[0039] The mainstream gas pressure buffer chamber 2 is relatively large in volume and has a pressure buffering effect, ensuring the pressure balance of the partial pressure inlet 3 of each partial pressure chamber 8. When the pressure of the partial pressure inlet 3 is greater than the sum of the pressures of the uniform speed outlet valve 5 and the uniform speed pressure outlet 6, the gas channel opens. This structure has multiple pressure stabilizing effects.

[0040] The opening angle of the partial pressure air inlet 3 is 30-60°.

[0041] The number of the pressure-dividing chambers 8 is greater than or equal to one, and they are evenly distributed and arranged at the bottom of the uniform flow field 9 .

[0042] like Figure 2 As shown, the spacing between the tops of the pressure-dividing chambers 8 is related to the number of uniform distributions and the opening area of ​​the pressure-dividing chambers 8, the bottom area of ​​the uniform flow field 9, and the arrangement.

[0043] The control method of the present invention is as follows:

[0044] Step 1: The mainstream gas enters the mainstream gas pressure buffer chamber 2 through the main air duct 1. The volume of the cone is slightly larger, which can achieve the function of gas caching and pressure stabilization. The main air duct 1 is connected to the pressure inlet of the pressure chamber to deliver the pressure-stable gas to the pressure chamber 8.

[0045] Step 2: When the air intake starts, the gas entering the pressure dividing chamber 8 does not open due to the pressure difference between the pressure buffer chamber 2 of the main stream of the sub-port gas and the uniform pressure outlet 6 before and after the uniform speed outlet valve 5 and the gravity of the uniform speed outlet valve 5. When the pressure difference of the gas is equal to or greater than the pressure difference between the pressure buffer chamber 2 of the main stream of the sub-port gas and the uniform pressure outlet, the uniform speed outlet valve 5 opens, and the gas enters the uniform pressure outlet 6 of the pressure dividing chamber 8;

[0046] Step 3: The gas enters the uniform pressure outlet 6 of the pressure dividing chamber. When the pressure difference before and after the uniform outlet valve 5 is too large, the opening of the uniform outlet valve 5 becomes larger. However, due to the existence of the limit lever 7, the maximum opening is fixed, thereby increasing the pressure difference before and after.

[0047] Step 4: The gas enters the uniform pressure outlet 6 of the pressure chamber 8. According to the principle of spherical turbulence of the Bernoulli equation, the outlet air flows out in parallel to achieve the purpose of uniform gas distribution.

Claims

1. A device for uniformly distributing gas in the cone of a circulating fluidized bed, characterized in that: It comprises a main air duct (1), a mainstream gas pressure buffer chamber (2), a pressure dividing chamber (8) and a bottom uniform velocity flow field (9); The upper part of the main air duct (1) is connected to the mainstream gas pressure buffer chamber (2), and a uniform flow field (9) is arranged on the upper part of the mainstream gas pressure buffer chamber (2); The pressure buffer chamber (2) is a conical structure, and a plurality of pressure-dividing chambers (8) are arranged at the same level above the inside of the pressure buffer chamber (2). The pressure-dividing chambers (8) are used to uniformly control the flow rate and gas volume of the fluidizing gas.

2. The device for uniformly distributing gas in the cone of a circulating fluidized bed according to claim 1, characterized in that: The pressure dividing chambers (8) are arranged evenly, and the shape structure of a single pressure dividing chamber (8) is a conical structure; the bottom of the conical structure of the pressure dividing chamber (8) is an open structure, and the open structure is a pressure dividing air inlet (3); a uniform speed air outlet valve (5) is arranged inside the conical structure, and the uniform speed air outlet valve (5) is located above the pressure dividing air inlet (3); a pressure dividing buffer chamber (4) is formed between the pressure dividing air inlet (3) and the uniform speed air outlet valve (5); the uniform speed air outlet valve (5) is a spherical structure and does not contact the side wall of the conical structure of the pressure dividing chamber (8), forming a uniform speed pressure-bearing air outlet (6); a limit lever (7) is installed on the side wall of the pressure dividing chamber (8) above the uniform speed air outlet valve (5); the limit lever (7) is used to limit the upward movement of the uniform speed air outlet valve (5) to achieve control of the maximum valve position of the uniform speed air outlet valve (5).

3. The device for uniformly distributing gas in the cone of a circulating fluidized bed according to claim 2, characterized in that: The partial pressure air inlet (3) is a cylindrical air inlet; the opening angle (10) of the partial pressure air inlet (3) is 30 to 60 degrees.

4. The device for uniformly distributing gas in the cone of a circulating fluidized bed according to claim 2, characterized in that: The number of the pressure-dividing chambers (8) is greater than or equal to one, and they are evenly distributed and arranged at the bottom of the uniform flow field (9).

5. The device for uniformly distributing gas in the cone of a circulating fluidized bed according to claim 2, characterized in that: The uniform speed air outlet valve (5) is of a spherical structure; the flow rate of air entering the partial pressure air inlet (3) and the flow rate of air entering the main air duct (1) are inversely proportional to the designed number of the partial pressure air inlet (3), so as to achieve uniform distribution of gas.

6. The method for implementing the device for uniformly distributing gas in the cone of a circulating fluidized bed according to any one of claims 1 to 5, characterized in that: The steps include: Step 1: The mainstream gas enters the mainstream gas pressure buffer chamber (2) through the main air duct (1), and after passing through the pressure buffer chamber (2), the gas with stable pressure is sent to the pressure dividing chamber (8); Step 2: When the air starts to enter, due to the existence of the gravity of the uniform air outlet valve (5), the pressure difference before and after the valve is less than the gravity of the uniform air outlet valve (5), and the uniform air outlet valve (5) is not opened. When the pressure difference before and after the uniform air outlet valve (5) is equal to or greater than the pressure difference between the pressure buffer chamber (2) of the main stream of the divided-port gas and the uniform pressure-bearing air outlet (6), the uniform air outlet valve (5) opens, and the gas enters the uniform pressure-bearing air outlet (6) of the pressure-dividing chamber (8); Step 3: When the gas enters the uniform pressure outlet (6) of the pressure dividing chamber (8), and the pressure difference before and after the uniform outlet valve (5) is too large, the opening of the uniform outlet valve (5) becomes larger, but due to the existence of the limit lever (7), the maximum opening is fixed, thereby increasing the pressure difference before and after. Step 4: The gas enters the uniform pressure outlet (6) of the pressure chamber (8). According to the principle of spherical turbulence of the Bernoulli equation, the outlet air flows out in parallel to achieve the purpose of uniform gas distribution.

7. The method for implementing the device for uniformly distributing gas in the cone of a circulating fluidized bed according to claim 6, characterized in that: In step 2, when the pressure of the partial pressure air inlet (3) is greater than the sum of the pressures of the uniform velocity air outlet valve (5) and the uniform velocity pressure air outlet (6), the uniform velocity air outlet valve (5) is pushed open; the limit lever (7) limits the position and opening of the uniform velocity air outlet valve (5), and the gas enters the uniform velocity pressure air outlet (6) and forms a parallel airflow; the uniform velocity pressure air outlet (6) is connected to the bottom uniform velocity flow field (9) and forms a parallel airflow to achieve the purpose of gas distribution.

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