CN110813514B - A non-automatic self-adjusting gas-solid two-phase distributor - Google Patents

Abstract

A non-automatic self-adjusting gas-solid two-phase distributor, comprising a distributor body, the distributor body including a support top seat welded on the top of an outlet air powder substitute pipe, the support top seat including an inner ring and an outer ring, the diameter of the outer ring is the same as the original diameter. The diameter of the outlet air powder pipe of the coal mill is equal, a resistance element is arranged under the inner ring, the bottom end of the resistance element is provided with a limiting device, and a guide slide is arranged on the outlet air powder substitute pipe, and the guide slide is used to make the resistance element press The fixed route is deformed. In adjusting the air-powder flow rate, the invention can eliminate the actual operating conditions of the coal mill, dynamically adjust the flow resistance of each outlet air-powder pipe in real time, has fast response speed, small workload, small equipment change and convenient replacement.

Description

A non-automatic self-adjusting gas-solid two-phase distributor

technical field

The invention relates to the technical field of coal mill systems in coal-fired power stations, in particular to a non-automatic self-adjusting gas-solid two-phase distributor.

Background technique

In order to achieve ultra-low emission of nitrogen oxides, coal-fired power plants generally use low-nitrogen combustion technologies in the furnace, namely, concentration-lean separation burners, air staged combustion, and fuel staged combustion. The common core of the above technologies is to achieve a reducing atmosphere in the main combustion area (the excess air factor is less than 1) through precise control of pulverized coal and primary/secondary air.

Due to the large difference in coal quality and the error in the measurement of the primary air volume at the inlet of the coal mill, the actual operating conditions of the coal mill deviate from the design conditions, which will inevitably lead to large deviations in the air powder concentration and flow rate of each powder outlet pipe of the coal mill . Under the background of low nitrogen combustion, this deviation directly causes problems such as incomplete combustion or flame deflection in the furnace, high temperature corrosion in local areas, and overtemperature of the over/reheater wall temperature. At present, the main way to reduce the flow rate deviation of the coal mill air powder pipe is to carry out a primary air adjustment test, and manually adjust the outlet air powder pipe of the coal mill to adjust the opening of the shrinkage hole to increase/decrease the corresponding pipeline resistance. However, this method has the following shortcomings: the workload is large, and it is necessary to repeatedly measure the dynamic pressure of the air-powder pipe online and adjust the opening of the adjustable shrinkage hole; the accuracy is low, and the full-section measurement of the air-powder pipe cannot be realized, and the measuring instrument is easy to measure under poor coal quality conditions. Blockage occurs, and the reliability of the test data is insufficient; when there is a large deviation between the operating conditions and the test conditions, the improvement effect is limited, and regular testing and maintenance are required.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a non-automatic self-adjusting gas-solid two-phase distributor, so as to ensure that the flow of each air-powder pipe at the outlet of the coal mill is consistent in real time, and while reducing the primary air volume as much as possible The opening of the secondary air valve does not need to be offset on the same layer, and it cooperates with low-nitrogen combustion technologies such as concentration separation burners, air staged combustion, and fuel staged combustion to promote high-efficiency and low-nitrogen combustion of pulverized coal.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A non-automatic self-adjusting gas-solid two-phase distributor includes a distributor body, the distributor body includes a support top seat 1 welded on the top of an outlet air powder pipe, and the support top seat 1 includes an inner ring and an outer ring , the diameter of the outer ring is equal to the diameter of the outlet air powder pipe of the original coal mill, a resistance element 2 is arranged under the inner ring, the bottom end of the resistance element 2 is provided with a limiting device 3, and a guide slideway is arranged on the outlet air powder pipe 4. The guide slide 4 is used to deform the resistance element 2 according to a fixed route.

The top end of the resistance element 2 is welded with the inner ring of the support top seat 1, and the diameter increases step by step from top to bottom and extends to the wall surface of the outlet air powder pipe.

The resistance element 2 has a streamlined design and has certain elasticity and rigidity.

The outside of the dispenser body is coated with an anti-wear and anti-static coating.

The resistance element 2 is a positive pagoda-shaped resistance element, and the entire resistance element is in the shape of spiral expansion.

The resistance element 2 is in a spiral shape, the smallest ring diameter is equal to the outer diameter of the inner ring of the support head 1 , and the two are welded and fixed to each other, and the largest ring diameter is equal to the inner diameter of the outer ring of the support head 1 .

The diameter of the inner ring should ensure that the air flow velocity is greater than 18m/s. The inner and outer rings have four connection points, evenly distributed along the circumference of the ring.

Beneficial effects of the present invention:

In adjusting the air-powder flow rate, the invention can eliminate the actual operating conditions of the coal mill, dynamically adjust the flow resistance of each outlet air-powder pipe in real time, has fast response speed, small workload, small equipment change and convenient replacement.

The entire resistance element adopts a streamlined design with certain elasticity and stiffness, so that the regulator can drive the deformation of the resistance element by the impact force of the wind powder speed without relying on external power, and change the flow area (that is, the flow rate is large, the impact The force is large, the resistance element is deformed greatly, the flow area is reduced, and the flow resistance is increased) to achieve self-adjustment. The smallest ring diameter is equal to the outer diameter of the inner ring of the support top seat, and the two are welded and fixed to each other, and the largest ring diameter is equal to the diameter of the inner side of the outer ring of the support top seat. The outermost bottom end of the resistance element is provided with a limiting device and is connected with the guide slideway to ensure that it deforms according to the fixed route without overloading.

The limiting device is arranged at the bottom end of the positive pagoda-shaped resistance element, which limits the deformation range of the resistance element, ensures the normal operation of the resistance element without overloading, and improves the service life of the resistance element.

The guide slide can ensure that it deforms on the fixed track, which improves the efficiency of self-adjustment and prolongs the working life of the resistance element.

The anti-wear and anti-static coating covers all the device surfaces of the dispenser to prevent the electrostatic ignition caused by the collision and friction of wind powder, which may lead to accidents and prolong the service life of the dispenser.

Description of drawings

Figure 1 is a schematic diagram of a support top seat.

Figure 2 is a schematic diagram of a positive pagoda-shaped resistance element.

Figure 3 is a schematic diagram of the working principle when the air-powder flow rate is low.

Figure 4 is a schematic diagram of the working principle when the air-powder flow rate is high.

Detailed ways

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

Referring to FIG. 1 , it is a schematic diagram of the supporting top seat 1 of the present invention, which is divided into an inner ring and an outer ring. The diameter of the outer ring is equal to the diameter of the pulverized air pipe at the outlet of the original coal mill, and the diameter of the inner ring is determined by the operation rules and operating conditions of the coal mill, that is, the minimum wind speed that the inner ring diameter can pass through should ensure that no coal powder will block the pipe. , Generally speaking, the operating regulations of coal mills require that the flow rate of air powder shall not be lower than 18m/s, so the diameter of the inner ring should ensure that the flow rate of air powder is greater than 18m/s. There are four connection points on the inner and outer rings, which are evenly distributed along the circumference of the ring, which are used to fix the position of the inner and outer rings and increase the stability of the support top seat 1. The entire support top seat 1 is welded and fixed on the top of the air powder replacement pipe, and the inner ring is used to fix the pagoda-shaped resistance element.

Referring to Fig. 2, it is a schematic diagram of a positive pagoda-shaped resistance element in the device of the present invention. The entire resistance element 2 is in a spiral shape. The ring diameter is equal to the diameter of the inner side of the outer ring of the support top seat 1 . The outermost bottom end of the resistance element 2 is provided with a limiting device and is connected with the guide slideway 4 to ensure that it deforms according to a fixed route without overloading and prolongs the life of the resistance element. The resistance element 2 is a positive pagoda-shaped resistance element, which is the core element to ensure the real-time adaptive adjustment of the entire distributor. The entire resistance element is in the shape of a spiral expansion, which is designed to meet its demand for elasticity. The working process of the distributor uses the action of the primary wind speed and the elasticity and stiffness of the resistance element to change the resistance of the air-powder pipe to adjust the flow of the air-powder pipe.

For a single coal mill, a non-automatic self-adjusting gas-solid two-phase distributor is installed on each outlet air powder pipe instead, including the outlet air powder pipe, the supporting top seat (see Figure 1), the positive tower shape Resistance element (see Figure 2), anti-wear and anti-static coating, limit device 3, guide slide 4, etc.

Weld a support top seat 1 on the top of the outlet air powder pipe. The diameter of the outer ring of the support top seat 1 is equal to the diameter of the outlet air powder pipe of the original coal mill. The inner diameter of the support top seat 1 is based on the coal mill. The operating procedures and operating conditions are determined. The top of the positive pagoda-shaped resistance element 2 is welded to the inner ring of the support top seat 1, and the diameter is gradually increased from top to bottom to extend to the wall of the outlet air powder pipe. The positive pagoda-shaped resistance element 2 is a streamlined design, has certain elasticity and stiffness, and performs linear or nonlinear resistance distribution depending on space conditions and working conditions. The bottom end of the positive pagoda-shaped resistance element 2 is provided with a limit device 3 to prevent the resistance element from overloading. Improve the life of the resistance element; the guide slide 4 makes the positive pagoda-shaped resistance element 2 deform according to a fixed route; all the devices of the non-automatic self-adjusting gas-solid two-phase distributor are coated with anti-wear and anti-static coating.

When the flow velocity of a certain air-powder pipe of the same coal mill is too large, the momentum generated by the air-powder flow in the air-powder pipe causes the positive pagoda-shaped resistance element to deform and squeeze upward along the flow direction, so that the flow area in the air-powder pipe decreases. Small, the flow resistance increases, the flow rate of air powder decreases, and the flow rate of other air powder pipes increases accordingly, so that the flow rate of each air powder pipe at the outlet of the coal mill is automatically adjusted in real time without external power (see image 3).

The working principle of the present invention:

In the air-powder pipe without the non-automatic self-adjusting gas-solid two-phase distributor, it is affected by the physical space, that is, the length, elbow and air supply resistance of each conveying pipe are different, and the coal mill itself also has air-powder distribution. The problem of unevenness will cause the air powder flow rate of each air powder pipe to be inconsistent, which will lead to flame deflection, oxygen deficiency or peroxy combustion in some areas. After installing a non-automatic self-adjusting gas-solid two-phase distributor (each part is coated with anti-wear and anti-static coating), the impact force of the wind powder speed drives the deformation of the resistance element of the pagoda, changing the flow area (ie The larger the flow rate and the larger the impact force, the larger the deformation of the resistance element 2, resulting in a decrease in the flow area, an increase in the flow resistance, and a decrease in the speed of the wind powder), realizing self-adjustment.

Claims (7)

1. The utility model provides a two-phase distributor of passive self-interacting gas-solid, its characterized in that, includes the distributor body, the distributor body includes at export wind powder pipe top welded support footstock (1), support footstock (1) including inner circle and outer lane, the outer lane diameter equals with former coal pulverizer export wind powder pipe diameter, is located the inner circle below and is provided with resistance element (2), resistance element (2) bottom sets up stop device (3), is located to be provided with direction slide (4) on the export wind powder pipe, and direction slide (4) are used for making resistance element (2) take place to deform according to fixed route.

2. The passive self-adjusting gas-solid two-phase distributor according to claim 1, wherein the top end of the resistance element (2) is welded with the inner ring of the supporting top seat (1), and the diameter of the resistance element is gradually increased from top to bottom and extends to the wall surface of the outlet duct.

3. A passive self-regulating gas-solid two-phase distributor according to claim 1, wherein the resistance element (2) is of streamlined design, with a certain elasticity and rigidity.

4. The passive self-regulating gas-solid two-phase distributor according to claim 1, wherein the outer sides of the distributor body are coated with anti-wear and anti-static coatings.

5. A passive self-adjusting gas-solid two-phase distributor according to claim 1, wherein the resistance element (2) is a right-pagoda-shaped resistance element, the whole resistance element being in the shape of a helical enlargement.

6. A passive self-adjusting gas-solid two-phase distributor according to claim 1, characterized in that said resistance element (2) is helical, with the smallest diameter of the circle being equal to the diameter of the outside of the inner circle of the supporting top (1) and welded to each other, and the largest diameter of the circle being equal to the diameter of the inside of the outer circle of the supporting top (1).

7. The passive self-regulating gas-solid two-phase distributor according to claim 1, wherein the inner ring has a diameter such that the velocity of the wind powder is greater than 18m/s, and the inner and outer rings have four connecting points uniformly distributed around the circumference of the ring.

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