Installation method of hot air purge anti-blocking device for rotary air preheater

Abstract

The present invention is an installation method of a hot air purge anti-blocking device for a rotary air preheater, and the method comprises the following steps: step one, making a new support beam for the pipeline; step two, assembling the pipeline of the anti-blocking device; step three, setting the pipeline interface; step four, making and installing a newly installed isolation fan-shaped plate; wherein the newly installed isolation fan-shaped plate is arranged side by side with the original isolation fan-shaped plate; step five, hoisting a new support beam and pipeline, and positioning the support point; step six, making an inner wind box of the isolation fan-shaped plate and welding the fan-shaped plate static seal; step seven, installing a pressure sampling tube and a thermocouple sampling tube; step eight, making an on-site operating platform for adjusting the air door and the switch gate door; step nine, installing the insulation and outer protective plate in place. The present invention can safely and quickly install the anti-blocking device, and ensure the installation quality and the fixed stability of the anti-blocking device.

Description

Technical Field

[0001] The invention belongs to the technical field of power plants, and in particular relates to an installation method of a hot air purge anti-blocking device for a rotary air preheater. Background Art

[0002] Air preheater is a heating surface where the flue gas in the tail flue of the boiler preheats the air before entering the boiler to a certain temperature through the internal heat sink. It is a device used to improve the heat exchange performance of the boiler and reduce energy consumption. Air preheaters are generally divided into three types: plate type, rotary type and tube type.

[0003] The application range of air preheaters is relatively wide. As long as a large amount of high-temperature flue gas is generated, air preheaters can be used in any industry, such as coal-fired power plants. In the process of coal-fired power generation, a large amount of hot flue gas waste heat will be generated after the coal is burned. This part of waste heat is recovered through a heat exchanger. Therefore, the air preheater will be installed at the tail of the boiler, and the heat carried by the flue gas discharged from the flue will be introduced into the expander before the boiler through the plate, preheating the air to a certain temperature, and assisting the combustion of coal to help heat up. The role of the power plant air preheater can be divided into three main functions.

[0004] 1. Reduce heat loss. The air preheater can heat the flue gas heat in the tail flue after the boiler is incinerated and heat the air entering the boiler. The recovery rate of flue gas waste heat can reach more than 97%, reducing a large amount of waste heat loss.

[0005] 2. Improve boiler efficiency. The temperature of flue gas recovered after air preheating is relatively high. This part of heat is used to preheat the air and then assist combustion, which can help the boiler equipment to increase the inlet air temperature. It can not only recover flue gas heat energy, but also improve boiler efficiency.

[0006] 3. Improve combustion efficiency. After fully recovering the waste heat, the heat loss of flue gas can be reduced, and the exhaust temperature can also be reduced. After increasing the heat content of air, the combustion effect of coal is better, and the combustion efficiency of coal will also be improved.

[0007] For example, the document "Study on Segment Monitoring Model for Ash Accumulation in Three-compartment Rotary Air Preheater" (Journal of Power Engineering, October 2016) has studied this. Most large power plants use three-compartment rotary air preheaters. Due to the compact structure of the heat transfer elements and the relatively narrow channels, ash accumulation is prone to occur. In severe cases, the channels will be blocked, resulting in reduced heat transfer efficiency.

[0008] Since the air preheater has heat exchange, there will inevitably be heat and condensation. Therefore, there will often be dust on its heat transfer elements. The accumulation of dust will affect the heat exchange efficiency, thereby affecting the normal use of the air preheater. Long-term use will inevitably cause blockage. How to overcome these problems and avoid the blockage of the air preheater is a more serious problem. The current means can only be through regular inspection and maintenance. Regular inspection and maintenance require shutdown, which will affect production efficiency. Therefore, how to avoid the blockage of the air preheater without stopping the machine is an urgent problem that needs to be solved.

[0009] The applicant has made improvements to this end and designed a rotary air preheater hot air purge anti-blocking device. However, due to the large size of the air preheater and the fact that the anti-blocking device is basically arranged around the air preheater, a specific method is required for installation. Summary of the invention

[0010] In view of the above shortcomings of the prior art, the present invention provides an installation method for a hot air purge anti-blocking device for a rotary air preheater, which can safely and quickly install the anti-blocking device and ensure the installation quality and stable fixation of the anti-blocking device.

[0011] Another object of the present invention is to provide an installation method for a hot air purge anti-blocking device for a rotary air preheater, which method can enable the anti-blocking device to be accurately connected to the air preheater, has high installation efficiency and good sealing effect, thereby increasing the service life of the air preheater.

[0012] A method for installing a hot air purge anti-blocking device for a rotary air preheater, the method comprising the following steps:

[0013] Step 1: Make new support beams for the pipeline; since the anti-blocking device requires the addition of new pipelines, the pipelines need to be supported, so the support beams must be built first, and the support beams need to be made separately in advance.

[0014] Step two is to assemble the pipes of the anti-blocking device. The pipes of the anti-blocking device are hot air cleaning pipes. In order to facilitate installation, the hot air cleaning pipes used for the anti-blocking device need to be organized first and then hoisted.

[0015] Step three, set up the pipeline interface. Since the anti-blocking device needs to be connected with the air preheater, a pipeline interface needs to be set up on the air preheater. Open a hole in the primary air outlet mother pipe of the air preheater as the pipeline interface of the hot air cleaning pipeline.

[0016] Step 4: In order to seal, a new isolation fan-shaped plate needs to be installed, and the new isolation fan-shaped plate is set side by side with the original isolation fan-shaped plate. The height of the new isolation fan-shaped plate needs to be adjusted to be 3mm (±1mm) lower than the old fan-shaped plate to facilitate welding, prevent leakage, and have a better sealing effect.

[0017] Step five, add support beams and pipe hoisting, as well as support point positioning; here you need to first find the support points, then weld and fix the support beams, and then hoist the pipes onto the support beams.

[0018] Step 6: manufacturing the inner bellows of the isolation fan-shaped plate and welding the fan-shaped plate static seal;

[0019] Step seven, installation of pressure sampling tube and thermocouple sampling tube. Install pressure sampling tube and thermocouple sampling tube in a straight pipe without disturbance, according to the principle of 3D in front and 2D in the back, with pressure in front and thermocouple in the back.

[0020] Step 8: Production of on-site operation platform for adjusting damper and opening and closing gate

[0021] Step nine, install the insulation and outer protective panels in place.

[0022] The beneficial effects of the present invention are:

[0023] The present invention supports and fixes the pipeline of the anti-blocking device through a support beam, and installs and seals the pipeline of the anti-blocking device through an isolation sector plate, thereby ensuring the installation quality and the fixing stability of the anti-blocking device.

[0024] The present invention enables the anti-blocking device to be accurately connected to the air preheater, has high installation efficiency and good sealing effect, thereby increasing the service life of the air preheater. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Flowchart implemented by the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] like Figure 1 As shown, the installation method of the hot air purge anti-blocking device of the rotary air preheater implemented by the present invention comprises the following steps:

[0028] Step 1: Make new support beams for the pipeline; since the anti-blocking device requires the addition of new pipelines, the pipelines need to be supported, so the support beams must be built first, and the support beams need to be made separately in advance.

[0029] Step two is to assemble the pipes of the anti-blocking device. The pipes of the anti-blocking device are hot air cleaning pipes. In order to facilitate installation, the hot air cleaning pipes used for the anti-blocking device need to be organized first and then hoisted.

[0030] Step three, set up the pipeline interface. Since the anti-blocking device needs to be connected with the air preheater, a pipeline interface needs to be set up on the air preheater. Open a hole in the primary air outlet mother pipe of the air preheater as the pipeline interface of the hot air cleaning pipeline.

[0031] Step 4: In order to seal, a new isolation fan-shaped plate needs to be installed, and the new isolation fan-shaped plate is set side by side with the original isolation fan-shaped plate. The height of the new isolation fan-shaped plate needs to be adjusted to be 3mm (±1mm) lower than the old fan-shaped plate to facilitate welding, prevent leakage, and have a better sealing effect.

[0032] Step five, add support beams and pipe hoisting, as well as support point positioning; here you need to first find the support points, then weld and fix the support beams, and then hoist the pipes onto the support beams.

[0033] Step 6: manufacturing the inner bellows of the isolation fan-shaped plate and welding the fan-shaped plate static seal;

[0034] Step seven, installation of pressure sampling tube and thermocouple sampling tube. Install pressure sampling tube and thermocouple sampling tube in a straight pipe without disturbance, according to the principle of 3D in front and 2D in the back, with pressure in front and thermocouple in the back.

[0035] Step 8: Production of on-site operation platform for adjusting damper and opening and closing gate

[0036] Step nine, install the insulation and outer protective panels in place.

[0037] Specifically, the installation precautions are:

[0038] 1. Use the secondary fan-shaped plate at the cold end of the air preheater to cut off the adjustment device near the side of the secondary fan-shaped plate at the cold end, clean the edges, and do not cut off the static seal of the original fan-shaped plate to ensure tight sealing. Repair welding should be performed on loose parts first.

[0039] Use the provided wind box positioning device to cut a groove on the truss bottom plate on the secondary air side of the original cold end truss.

[0040] 2. Install the newly added isolation fan-shaped plate and the old secondary fan-shaped plate close together. Note that the position of the air outlet slot must correspond to the heating surface of the rotor, and that the slot can completely cover all component packages of the air preheater.

[0041] 3. After the isolation fan-shaped plate is in place, adjust the height of the newly installed isolation fan-shaped plate. Install it 3mm lower than the original secondary fan-shaped plate. Weld one side to the original fan-shaped plate and fix it. Pay attention to smoothing the weld after welding. You can also use channel steel to weld and fix the inner side of the fan-shaped plate to the truss to ensure it is firm.

[0042] 4. Install the static seal on the side of the isolation sector plate close to the secondary cooling area first, and weld it tightly to the truss to prevent leakage.

[0043] 5. Seal the empty space at the tail of the fan-shaped plate with a triangular plate and the outer arc plate of the fan-shaped plate.

[0044] 6. Assemble the air spray box device on site according to the drawings, and pay attention to distinguish the front and back during assembly.

[0045] 7. Insert the front part of the assembled blower box device (the blower box with inspection hole) into the slot opened in the truss, and weld it tightly to the isolation fan-shaped plate and the truss.

[0046] 8. Connect the air spray box and the main hot air circular duct.

[0047] 9. Use NO.20a channel steel to make pipeline support steel beams at appropriate locations on site. They have sufficient supporting force. Use the provided support and hanger devices to support and fix the pipelines on site to ensure reasonable expansion.

[0048] 10. Install the corresponding metal expansion joints, elbows, closing gates and adjusting baffle devices according to the positions on the drawings.

[0049] 11. After all equipment is installed, seal it with welding to ensure it is tightly sealed.

[0050] 12. All parts in contact with hot air are insulated, among which the air jet duct is insulated with nano aerogel insulation felt, and the rest of the parts are insulated with conventional aluminum silicate needle blanket / aluminum silicate fiberboard insulation materials.

[0051] The data is summarized in the following table:

[0052]

[0053]

[0054] The quality control requirements for installation are as follows:

[0055] 1. All pipelines, isolation fan plates, static seals and other equipment are tightly sealed and no leakage is allowed.

[0056] 2. When setting up equipment such as baffles, expansion joints, and measuring points, try to reuse existing platforms.

[0057] 3. The horizontality of the isolation sector plate and the old sector plate shall not exceed 3mm / m.

[0058] 4. The deviation angle between the isolation fan-shaped plate and the old fan-shaped plate shall be constructed according to the drawing to ensure that the air outlet covers the entire heating surface.

[0059] 5. The pipes are hung and supported firmly without vibration, and the effects of thermal expansion are fully considered.

[0060] 6. The pipes, elbows, isolation fan-shaped plates and other locations are reasonably insulated and have good thermal insulation effects.

[0061] 7. The baffle opening indication is obvious. Through cold adjustment, the electric baffle can ensure free adjustment from 0 to 100 degrees.

[0062] 8. The sealing gap between the newly added fan-shaped plate and the old fan-shaped plate is 3-5mm larger than the actual measured value before the transformation to ensure safety.

[0063] In summary, the present invention supports and fixes the pipeline of the anti-blocking device through the support beam, and installs and seals the pipeline of the anti-blocking device through the isolation fan-shaped plate, thereby ensuring the installation quality and the fixation stability of the anti-blocking device.

[0064] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for installing a hot air purge anti-blocking device for a rotary air preheater, characterized in that The method comprises the following steps: Step 1: Make additional support beams for the pipeline; Step 2, assembling the pipeline of the anti-blocking device; Step 3: Set up the pipeline interface; Step 4: manufacturing and installing a new isolation sector plate; wherein the new isolation sector plate is arranged side by side with the original isolation sector plate; Step 5: Add support beams and pipe hoisting, as well as support point positioning; first find the support points, then weld and fix the support beams, and then hoist the pipes onto the support beams; Step 6: manufacturing the inner bellows of the isolation fan-shaped plate and welding the fan-shaped plate static seal; Step 7: Installation of pressure sampling tube and thermocouple sampling tube; Step 8: Making the on-site operation platform for adjusting the damper and opening and closing the gate door; Step nine, install the insulation and outer protective panels in place.

2. The installation method of the hot air purge anti-blocking device for a rotary air preheater according to claim 1 is characterized in that In step three, a hole is opened in the primary air outlet main pipe of the air preheater to serve as a pipe interface for the hot air cleaning pipe.

3. The installation method of the hot air purge anti-blocking device for a rotary air preheater according to claim 1 is characterized in that In step 4, the height of the newly installed isolation fan-shaped plate needs to be adjusted to be 3 mm lower than the old fan-shaped plate.

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