Method for separating particles in gas-solid two-phase flow and recovering steam by using separation baffle

Abstract

The invention relates to the field of energy power engineering, and discloses a method for separating particles in gas-solid two-phase flow and recovering steam by using a separation baffle, which comprises the following steps: step 1, arranging a flat plate type separation baffle at an outlet of an elbow of a main steam pipeline, and forming a separation area between the separation baffle and the inner wall of the main steam pipeline; 2, solid particles in the gas-solid two-phase flow tend to the wall face of the pipeline at the elbow of the pipeline due to the inertia effect and enter a separation area; and 3, discharging the solid particles entering the separation area from the main steam pipeline through an eduction pipe. A flat-plate-type separation baffle is installed at an outlet of a main steam pipeline elbow, and the distance between the baffle and the outlet of the elbow is 0.5 time of the inner diameter of the pipeline; separating the particles by inertia and pressure difference, so that the particles deviate from a steam path to enter a separation area to be discharged; the particle separation efficiency is improved, the separation efficiency of particles with the particle size of 100 micrometers or above reaches 60% or above, and erosion damage of solid particles to flow passage components of a steam turbine is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of energy and power engineering, and in particular to a method for separating particles in a gas-solid two-phase flow and recovering steam by utilizing a separation baffle. Background Art

[0002] In modern thermal power units, due to long-term operation and high temperature and high pressure environment, oxides will be produced on the inner wall of the main steam pipeline. These oxide particles will flow into the turbine with the main steam. After solid particles enter the turbine, they may cause serious erosion damage to the flow-through components of the turbine, thereby affecting the operating stability and efficiency of the unit. With the increase of the initial temperature and initial pressure of steam in high-parameter and large-capacity units, it is easier to cause oxides in boilers and steam pipelines to fall off. Moreover, as more and more ultra-supercritical units are used to undertake peak load tasks, their units will inevitably operate alternately under different loads, and the solid particle erosion problem will become more serious. Whether the solid particle erosion problem is solved or not is one of the keys to determine whether high-parameter and large-capacity units can demonstrate economic efficiency and safety. Therefore, how to effectively separate solid particles from gas-solid two-phase flow and reduce erosion damage to the turbine has become one of the important technical challenges in the operation of thermal power units. In addition, the operation of thermal power units requires improving overall thermal efficiency and avoiding waste of steam resources, which is also the focus of continuous attention in today's power industry.

[0003] In the prior art, conventional particle separation methods often rely on equipment such as filters or cyclone separators, but these devices usually have disadvantages such as complex structure, large size, and high maintenance cost. In addition, when traditional separation equipment works in a high temperature and high pressure environment, the service life of the equipment is shortened, increasing the frequency of maintenance and replacement. At the same time, during the separation process, due to the high speed of steam carrying solid particles, the pressure loss of steam is often large, which has a negative impact on the operating efficiency of the system. In addition, while separating solid particles, traditional equipment fails to effectively recover the steam carried during the separation process, resulting in a waste of steam resources and reduced unit efficiency.

[0004] There is a major problem with the separation methods in the prior art: the solid particle separation efficiency is low in the main steam pipeline of the thermal power unit, especially for particles with larger particle sizes, which often cannot be separated efficiently. At the same time, the existing separation device causes a large system pressure loss during the separation process, which affects the operating efficiency of the thermal power unit. In addition, the steam resources carried during the separation process cannot be effectively recovered, which further leads to steam waste and reduced unit efficiency. These problems limit the operating performance and economy of the thermal power unit. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle, which solves the problem that the solid particle separation efficiency in the main steam pipeline of the existing thermal power unit is low, especially for particles with larger particle size, which often cannot be separated efficiently.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for separating particles in a gas-solid two-phase flow and recovering steam using a separation baffle, comprising the following steps:

[0007] Step 1: a flat-plate separation baffle is arranged at the outlet of the main steam pipeline elbow, and a separation area is formed between the separation baffle and the inner wall of the main steam pipeline;

[0008] Step 2: Solid particles in the gas-solid two-phase flow tend to the pipe wall due to inertia at the pipe elbow and enter the separation area;

[0009] Step 3: Discharge the solid particles entering the separation area from the main steam pipeline through the outlet pipe;

[0010] Step 4: Introduce the steam carried by the particles discharged from the outlet pipe into the boiler soot blower to perform soot blowing operation to recycle the steam.

[0011] Preferably, the inlet end of the separation baffle is arranged downstream of the elbow outlet, at a distance of 0.5 times the inner diameter of the main steam pipe, and the separation area formed between the separation baffle and the inner wall of the main steam pipe is used to receive particles gathered from the elbow.

[0012] Preferably, the inlet height of the separation baffle is 20% of the inner diameter of the main steam pipe. By adjusting the inlet height of the separation baffle, it is ensured that the solid particles deviate from the main steam flow due to inertia, enter the separation area, and complete the separation of the particles and the main steam in the separation area.

[0013] Preferably, the inner diameter of the outlet pipe is 32 mm. The outlet pipe is used to discharge solid particles entering from the separation area. The inner diameter design of the outlet pipe can meet the discharge requirements of the gas-solid two-phase flow and avoid particle clogging and accumulation.

[0014] Preferably, the separation device is used to separate solid particles with a particle size of 100 μm and above. When the particle size is larger, the inertia of the particle increases, the probability of entering the separation area increases, and the separation efficiency is greater than 60%.

[0015] Preferably, the gas-solid two-phase flow in the main steam pipe is a dilute particle phase. When the solid particles pass through the pipe elbow, they are deflected toward the pipe wall due to inertia and form particle aggregation in the lower pipe wall area of ​​the elbow. The separation device achieves effective separation of solid particles through this phenomenon.

[0016] Preferably, the separation device is arranged in the direction of the lower pipe wall at the elbow outlet, and the separation baffle causes the particles to enter the separation area through inertia. The distance between the separation baffle and the inner wall of the main steam pipe is designed to include the aggregation height of most particles at this location, thereby achieving effective separation of particles.

[0017] Preferably, the separation baffle is used to separate solid particles from the steam flow, and the separated solid particles are discharged through the outlet pipe. The separation baffle works based on the pressure difference in the steam flow to ensure that the solid particles enter the separation area when flowing through the pipeline.

[0018] Preferably, the outlet of the outlet pipe is connected to a boiler sootblower, and the solid particles discharged from the outlet pipe and part of the steam carried enter the boiler sootblower together, and the sootblower uses the outlet steam to perform sootblowing operation on the heating surface.

[0019] Preferably, the pressure loss caused by the separation device does not exceed 40 kPa. The separation area is designed so that after the solid particles enter the separation area, the flow resistance of the gas-solid separation is maintained within the range allowed by the system, reducing the impact on the heat consumption of the system. The separation device is used for the main steam pipeline of a supercritical or ultra-supercritical thermal power unit, which is suitable for high temperature and high pressure operating environments and reduces the erosion damage caused by solid particles entering the turbine when the thermal power unit participates in peak operation. The separation device is used to reduce the entry of solid particles into the flow-through components of the turbine. The outlet pipe directly introduces the mixture of solid particles and steam discharged from the main steam pipeline into the boiler sootblower, recycles this part of the steam, and reduces the steam loss of the unit.

[0020] The present invention provides a method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle. It has the following beneficial effects:

[0021] 1. The present invention effectively utilizes the inertia and pressure difference of solid particles to achieve efficient separation of particles from main steam by installing a flat separation baffle at the outlet of the main steam pipe bend. The structural design and position arrangement of the separation baffle (0.5 times the inner diameter of the pipe at the outlet of the bend) enable particles in the gas-solid two-phase flow to deviate from the steam flow path, enter the separation area and be discharged through the outlet pipe. This design can improve the separation efficiency of particles without significantly increasing the complexity of the system, especially for particles with a particle size of 100μm and above, the separation efficiency can reach more than 60%, effectively reducing the erosion damage of particles to turbine components.

[0022] 2. The present invention effectively controls the pressure loss of the system during the separation process by optimizing the design of the separation baffle and the outlet pipe. The inlet height of the separation baffle and the inner diameter of the outlet pipe are precisely designed so that the solid particles will not produce excessive resistance to the main steam flow when entering the separation area and the discharge pipe. Numerical simulation shows that the pressure loss of the entire separation process is controlled within 40 kPa, which significantly reduces the impact on the overall efficiency of the thermal power unit, thereby maintaining the normal operation of the system and avoiding unnecessary energy loss.

[0023] 3. In order to deal with the wear problem of equipment in high temperature and high pressure environment, the present invention applies a highly wear-resistant ceramic coating to the separation baffle and the inner wall of the outlet pipe. The coating has good wear resistance and high temperature resistance, and can effectively reduce the impact and friction of particles on the inner wall of the equipment, thereby extending the service life of the equipment. In addition, the coating also has excellent anti-erosion performance, can maintain chemical stability in a high temperature and high pressure steam environment, and avoids damage to the equipment caused by erosion. The durability and stability of the equipment are significantly improved, the maintenance frequency is reduced, and the long-term operating cost is reduced.

[0024] 4. The present invention not only achieves efficient separation of solid particles, but also can introduce the separated steam into the boiler sootblower through the outlet pipe to recycle the steam. Part of the steam carried during the separation process is no longer discharged directly, but is introduced into the sootblower to remove the ash accumulation on the boiler heating surface. This design not only avoids the waste of steam, but also reduces the need for traditional sootblower to extract additional steam from the system, thereby reducing the heat consumption rate of the unit. By recovering part of the steam, the present invention effectively improves the overall operating efficiency of the thermal power unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart of the present invention;

[0026] Figure 2 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Embodiment 1:

[0029] Please refer to the attached Figure 1-2 The embodiment of the present invention provides a method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle, comprising the following steps:

[0030] Step 1: a flat-plate separation baffle is arranged at the outlet of the main steam pipeline elbow, and a separation area is formed between the separation baffle and the inner wall of the main steam pipeline;

[0031] Step 2: Solid particles in the gas-solid two-phase flow tend to the pipe wall due to inertia at the pipe elbow and enter the separation area;

[0032] Step 3: Discharge the solid particles entering the separation area from the main steam pipeline through the outlet pipe;

[0033] Step 4: Introduce the steam carried by the particles discharged from the outlet pipe into the boiler soot blower to perform soot blowing operation and recover the steam.

[0034] In one embodiment, the presence of solid particles in the main steam pipe of a thermal power unit is a common problem, especially as the design of the elbow increases, the inertia will cause the particles to adhere to the lower pipe wall and aggregate. If these particles are not effectively separated, they will enter the steam turbine with the steam flow, causing erosion damage to the components. Therefore, how to effectively separate the particles at the elbow outlet has become one of the core technologies designed in this embodiment. In response to this problem, this embodiment proposes a technical solution of installing a separation device at the elbow outlet of the main steam pipeline, guiding the particles into the separation area through a separation baffle, and then discharging them through a deducting pipe, and realizing steam recovery.

[0035] In this embodiment, the separation baffle is installed at the elbow outlet of the main steam pipeline and forms a separation area with the inner wall of the pipeline. The separation device uses the inertia effect and pressure difference change in the gas-solid two-phase flow to separate particles. The specific position is arranged at 0.5 times the inner diameter of the pipeline from the elbow outlet, and the separation baffle is perpendicular to the lower pipe wall. Since solid particles gradually gather towards the lower pipe wall due to inertia at the elbow, the separation baffle effectively utilizes this phenomenon to guide the particles to the separation area.

[0036] First, the flow of gas-solid two-phase flow in the pipeline is described by the following formula:

[0037] The viscous drag on the particle is:

[0038]

[0039] The Reynolds number Re is:

[0040]

[0041] Among them: C D is the resistance coefficient; ρ p is the particle density; d p is the particle size; μ is the fluid dynamic viscosity.

[0042] The movement trajectory of the particles is affected by inertia. When it passes through the elbow, the inertia causes it to gradually deviate to the lower pipe wall. Based on this phenomenon, the separation device is arranged downstream of the pipe elbow, and the particles are guided out of the main steam flow through the separation area formed by the separation baffle. The inlet height of the separation baffle is set to 20% of the inner diameter of the main steam pipe to ensure that the particles can smoothly enter the separation area.

[0043] In this embodiment, the particles have a relatively large particle size (100 μm and above), a high Reynolds number, and a significant inertial force, so that the separation baffle can effectively separate the particles from the main steam flow.

[0044] Outlet pipe design and particle discharge overview

[0045] After the particles enter the separation area, they need to be discharged through the outlet pipe, and the design of the outlet pipe needs to fully consider factors such as the flow characteristics of the gas-solid two-phase flow, particle size, and pressure conditions. The technical solution of this embodiment not only needs to ensure smooth particle discharge, but also needs to reduce steam loss during the discharge process and recycle this part of the steam. To this end, the outlet pipe in this embodiment is designed with a specific inner diameter and connection method, so that the particles and steam can be efficiently discharged and enter the subsequent boiler soot blower.

[0046] The inner diameter of the outlet pipe is 32 mm, and the length and bending radius are calculated and optimized according to the flow rate, particle size and pressure of the gas-solid two-phase flow. The outlet pipe is connected to the separation area with a high-temperature and high-pressure flange structure to ensure that there is no leakage under high-temperature conditions. The design parameters of the outlet pipe are derived from the simulation of the flow trajectory of the particles, simulating the movement of the particles at different flow rates, and determining the optimal pipe diameter based on the pressure loss and flow rate requirements.

[0047] After the particles are discharged, part of the steam is introduced into the boiler soot blower to ensure the reasonable recovery of steam. In this embodiment, the bending radius and length of the outlet pipe are optimized to avoid the accumulation or blockage of particles during the discharge process. The discharge speed of the outlet pipe is controlled within an acceptable range, and the pressure drop during the particle discharge process is calculated by the following formula:

[0048]

[0049] Where: ΔP is the pressure loss, f is the friction coefficient, L is the length of the outlet pipe, D is the inner diameter of the outlet pipe, ρ is the fluid density, and v is the velocity of the particles.

[0050] Overview of Particle Separation and Vapor Recovery

[0051] After the solid particles are successfully separated, part of the steam carried by them will inevitably be discharged. However, this embodiment proposes a technical solution to recover the discharged steam together with the particles. This part of the steam will be introduced into the boiler soot blower, and the high pressure of the steam will be used to remove the ash on the boiler pipes, while reducing steam loss.

[0052] In this embodiment, steam is discharged through the outlet pipe and enters the boiler soot blower together with the particles. The main function of the soot blower is to blow away the accumulated soot inside the boiler with high-pressure steam to clean the heating surface. The soot blower is connected to the outlet pipe through a pipeline, and a steam flow control valve is provided at the connection to adjust the amount of steam entering the soot blower according to the actual operation requirements of the boiler. The design of the recovery system ensures that the flow path and flow rate of the steam can be accurately controlled after the particle separation to avoid excessive steam waste.

[0053] During this process, the system pressure loss is maintained within a reasonable range. By calculating the steam flow rate and particle discharge rate, the system pressure loss does not exceed 40 kPa. By optimizing the pressure drop at various points in the system, it is ensured that the overall heat rate of the system will not increase significantly during the particle separation and steam recovery process.

[0054] The inlet end of the separation baffle is arranged downstream of the elbow outlet, with a distance of 0.5 times the inner diameter of the main steam pipe. The separation area formed between the separation baffle and the inner wall of the main steam pipe is used to receive particles gathered from the elbow.

[0055] In one embodiment, the separation baffle is arranged at a position

[0056] The installation position of the separation baffle is crucial to the effect of particle separation and must be precisely arranged in the particle aggregation area in the gas-solid two-phase flow. According to the flow characteristics in the elbow, due to inertia and the curved pipe, the particles will deviate to the pipe wall and gather at the outlet of the elbow, especially in the lower pipe wall area.

[0057] The inlet height of the separation baffle is 20% of the inner diameter of the main steam pipe. By adjusting the inlet height of the separation baffle, it is ensured that the solid particles deviate from the main steam flow due to inertia and enter the separation area, and the separation of the particles and the main steam is completed in the separation area.

[0058] In one embodiment, the inlet end of the separation baffle is located downstream of the elbow outlet, at a distance of 0.5 times the inner diameter of the main steam pipe. This distance is obtained through numerical simulation analysis of the inertial effect of gas-solid two-phase flow and the phenomenon of particle adhesion to the wall. In gas-solid two-phase flow, the inertia of solid particles is one of the main forces. Inertia will cause particles to move against the wall at the bend of the pipe, especially to gather in the lower pipe wall area of ​​the elbow. When the separation baffle is arranged at a distance of 0.5 times the pipe diameter from the elbow outlet, the maximum number of particles can be captured to enter the separation area. The flat plate structure of the separation baffle ensures that the particles deviate from the main steam flow path under the action of inertial force and enter the separation area formed by the baffle.

[0059] In addition, the installation position of the separation baffle has also been optimized through the pipeline structure design to ensure that it will not hinder the normal flow of the main steam. Through multiple simulations of steam flow rate, pressure and particle trajectory, this position is determined to be the best position for particle separation. In the actual engineering design, the separation baffle is installed through a special high-temperature resistant fixed bracket to ensure its stability and durability under long-term high temperature and high pressure conditions.

[0060] The inner diameter of the outlet pipe is 32 mm. The outlet pipe is used to discharge solid particles entering from the separation area. The inner diameter design of the outlet pipe can adapt to the discharge requirements of gas-solid two-phase flow and avoid particle clogging and accumulation.

[0061] In one embodiment, the inlet height of the separation baffle is set to 20% of the inner diameter of the main steam pipe. This height is verified through precise fluid mechanics simulation to ensure that solid particles can smoothly deviate from the main steam flow and enter the separation area. Specifically, solid particles in the gas-solid two-phase flow tend to the pipe wall under the inertia at the bend, and the design of this height can fully ensure that the solid particles deviate from the main steam flow under the action of inertia and enter the separation area along the baffle.

[0062] Through calculation and simulation, it was found that at a height of 20% of the inner diameter, the flow trajectory of the particles best matches the separation area. At the same time, the height design of the baffle also takes into account the avoidance of excessive flow resistance of the steam flow, ensuring that during the particle separation process, the main steam flow can still smoothly pass through the separation baffle without affecting the flow characteristics of the main steam.

[0063] The separation device is used to separate solid particles with a particle size of 100 μm and above. When the particle size is larger, the inertia of the particle increases, the probability of entering the separation area increases, and the separation efficiency is greater than 60%.

[0064] The gas-solid two-phase flow in the main steam pipe is a dilute particle phase. When the solid particles pass through the pipe elbow, they are deflected toward the pipe wall due to inertia and form particle aggregation in the lower pipe wall area of ​​the elbow. The separation device achieves effective separation of solid particles through this phenomenon.

[0065] The separation device is arranged in the direction of the lower pipe wall at the elbow outlet, and the separation baffle causes the particles to enter the separation area through inertia. The spacing between the separation baffle and the inner wall of the main steam pipe is designed to include the aggregation height of most particles at this location, thereby achieving effective separation of particles.

[0066] The separation baffle is used to separate solid particles from the steam flow. The separated solid particles are discharged through the outlet pipe. The separation baffle works based on the pressure difference in the steam flow to ensure that the solid particles enter the separation area when flowing through the pipeline.

[0067] The outlet of the outlet pipe is connected to the boiler soot blower. The solid particles discharged from the outlet pipe and part of the steam carried enter the boiler soot blower together. The soot blower uses the outlet steam to blow the heating surface.

[0068] The pressure loss caused by the separation device does not exceed 40 kPa. The design of the separation area ensures that after the solid particles enter the separation area, the flow resistance of gas-solid separation is kept within the range allowed by the system, reducing the impact on the system heat consumption. The separation device is used for the main steam pipeline of supercritical or ultra-supercritical thermal power units, suitable for high temperature and high pressure operating environments, and reduces the erosion damage caused by solid particles entering the turbine when the thermal power unit participates in peak operation. The separation device is used to reduce the entry of solid particles into the flow-through parts of the turbine. The outlet pipe directly introduces the solid particles discharged from the main steam pipeline into the boiler soot blower. This part of the steam is recycled to reduce the steam loss of the unit.

[0069] In one embodiment, the inner diameter of the outlet pipe is set to 32 mm. Through numerical simulation, it is determined that this inner diameter can ensure the smooth discharge of solid particles while keeping the pressure loss of the system to a minimum. By analyzing the effect of different inner diameters on particle flow, the inner diameter of 32 mm can ensure that particles will not be blocked in the outlet pipe, and will not cause excessive wear on the pipe wall due to excessive flow speed.

[0070] The design of the outlet pipe is based on the analysis of the flow of solid particles to ensure that the particles and steam maintain an appropriate speed when discharged. The pipe is made of high temperature and corrosion resistant alloy material, and its inner wall is finely processed to ensure that the inner surface of the outlet pipe is smooth, reduce the friction between the particles and the pipe wall, and ensure that the particles will not accumulate during the outlet process, ensuring the overall efficiency of the system.

[0071] In one embodiment, the separation device is suitable for separating solid particles with a particle size of 100 μm and above. Through the analysis of particle distribution, it is found that when particles with a size of 100 μm and above flow in the pipeline, the inertial force plays a dominant role, making it easier for them to deviate to the pipe wall and gather at the outlet of the elbow. The design of the separation baffle is based on this principle to guide the particles into the separation area.

[0072] In actual working conditions, the larger the particle size, the more obvious the inertia effect, and the higher the separation efficiency. After multiple verifications, when the particle size is 100μm and above, the separation efficiency can reach more than 60%. The structural design of the separation device is optimized for this particle size range to ensure that under complex working conditions, the number of particles entering the turbine can be effectively reduced, reducing the erosion damage to turbine components.

[0073] In one embodiment, the gas-solid two-phase flow in the main steam pipe is a dilute particle phase, which means that the density of the particles is low and the particles exist in a low concentration in the fluid. At the elbow, the solid particles tend to gather on the lower wall of the pipe due to inertia. By analyzing the flow characteristics in the dilute particle phase, this embodiment adopts a separation baffle design so that the particles are effectively captured at the elbow outlet and enter the separation area.

[0074] The flow characteristics of gas-solid two-phase flow determine the movement trajectory of solid particles at the elbow, especially under the condition of dilute particle phase, the inertia force of particles plays a major role in their separation. Through numerical simulation and actual testing, it is determined that the separation device arranged downstream of the elbow outlet can capture these particles to the maximum extent, ensuring that they will not enter the turbine, thereby reducing the wear on the unit components.

[0075] In one embodiment, the separation baffle is arranged in the direction of the lower pipe wall at the outlet of the elbow, and the distance between the separation baffle and the inner wall of the main steam pipe is designed to include the gathering height of most particles at this location, so that effective separation of particles can be achieved. This distance is obtained by analyzing the force on solid particles in the flow, ensuring that under the action of inertial force, the particles can deviate from the steam flow and enter the separation area.

[0076] Through fluid simulation, the trajectory of particle movement along the wall at different flow rates and particle sizes was analyzed, and the installation position of the separation baffle was finally determined. This design ensures that the separation baffle can capture particles at the outlet of the elbow and discharge them out of the system through the outlet pipe without causing significant interference to the steam flow.

[0077] Preferred example:

[0078] In a preferred embodiment, the anti-wear coating of the separation baffle and the inner wall of the outlet pipe

[0079] In high temperature and high pressure environment, the friction between solid particles and the inner wall of the separation baffle and the outlet pipe may cause component wear, especially when the particle size is large, long-term use may cause wear of the inner wall material. Therefore, by introducing a special anti-wear coating, the service life of the equipment can be further extended and maintenance costs can be reduced.

[0080] In this preferred embodiment, the inner wall of the separation baffle and the outlet pipe are coated with a high wear-resistant ceramic coating, which can significantly improve the wear resistance of the inner wall. Specifically, the coating is composed of high-temperature resistant ceramic material and can maintain stable wear resistance at high temperatures up to 700°C or above. The thickness of the coating is set according to the actual wear degree, generally 0.5 mm to 1 mm, to ensure that the inner wall is not worn by solid particles during long-term operation.

[0081] On the inner wall of the outlet pipe, the coating not only enhances the wear resistance, but also reduces the friction coefficient between the particles and the inner wall, reduces the energy loss of the particles during the discharge process, and ensures that the particles can be discharged smoothly. At the same time, the ceramic coating also has excellent anti-erosion performance, can maintain chemical stability in a high temperature and high pressure water vapor environment, and prevent the inner wall of the pipe from being damaged by water vapor corrosion.

[0082] In addition, this preferred embodiment can also add high temperature resistant metal materials, such as chromium or nickel alloy, into the coating as needed to further improve its erosion resistance, which is particularly suitable for steam environments containing acidic gases.

[0083] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for separating particles in a gas-solid two-phase flow and recovering steam using a separation baffle, characterized in that: The following steps are involved: Step 1: a flat-plate separation baffle is arranged at the outlet of the main steam pipeline elbow, and a separation area is formed between the separation baffle and the inner wall of the main steam pipeline; Step 2: Solid particles in the gas-solid two-phase flow tend to the pipe wall due to inertia at the pipe elbow and enter the separation area; Step 3: Discharge the solid particles entering the separation area from the main steam pipeline through the outlet pipe; Step 4: Introduce the steam carried by the particles discharged from the outlet pipe into the boiler soot blower to perform soot blowing operation to recycle the steam.

2. A method for separating particles in a gas-solid two-phase flow and recovering steam using a separation baffle according to claim 1, characterized in that: The inlet end of the separation baffle is arranged downstream of the elbow outlet, and the distance is 0.5 times the inner diameter of the main steam pipe. The separation area formed between the separation baffle and the inner wall of the main steam pipe is used to receive particles gathered from the elbow.

3. The method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle according to claim 1, characterized in that: The inlet height of the separation baffle is 20% of the inner diameter of the main steam pipeline. By adjusting the inlet height of the separation baffle, it is ensured that large-sized solid particles enter the separation area, thereby completing the separation of particles and main steam.

4. The method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle according to claim 1, characterized in that: The inner diameter of the outlet pipe is 32 mm. The outlet pipe is used to discharge solid particles entering from the separation area. The inner diameter design of the outlet pipe can meet the discharge requirements of the gas-solid two-phase flow and avoid particle blockage and accumulation.

5. The method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle according to claim 1, characterized in that: The separation device is used to separate solid particles with a particle size of 100 μm and above. When the particle size is larger, the inertia of the particle increases, the probability of entering the separation area increases, and the separation efficiency is greater than 60%.

6. The method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle according to claim 1, characterized in that: The gas-solid two-phase flow in the main steam pipe is a dilute particle phase. The solid particles are deflected toward the pipe wall due to inertia when passing through the pipe elbow, and form particle aggregation in the lower pipe wall area of ​​the elbow. The separation device realizes effective separation of solid particles from the main steam through this phenomenon.

7. The method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle according to claim 1, characterized in that: The separation device is arranged in the direction of the lower pipe wall at the elbow outlet. The particles gather under the action of inertia and enter the separation area through the separation baffle. The distance between the separation baffle and the inner wall of the main steam pipe is designed to include the gathering height of most particles at this location, thereby realizing effective separation of particles.

8. The method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle according to claim 1, characterized in that: The separation baffle is used to separate solid particles from the steam flow. The separated solid particles are discharged through the outlet pipe. The separation baffle works based on the pressure difference in the steam flow to ensure that the solid particles enter the separation area when flowing through the pipeline.

9. The method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle according to claim 1, characterized in that: The outlet of the outlet pipe is connected to the boiler soot blower, and the solid particles discharged from the outlet pipe and part of the steam carried enter the boiler soot blower together, and the soot blower uses the outlet steam to perform soot blowing operation on the heating surface.

10. The method for separating particles in a gas-solid two-phase flow and recovering steam by using a separation baffle according to claim 1, characterized in that: The pressure loss caused by the separation device does not exceed 40 kPa. The design of the separation area ensures that after the solid particles enter the separation area, the flow resistance of the gas-solid separation is maintained within the range allowed by the system, reducing the impact on the heat consumption of the system. The separation device is used for the main steam pipeline of a supercritical or ultra-supercritical thermal power unit, and is suitable for high temperature and high pressure operating environments. It can reduce the erosion damage caused by solid particles entering the turbine when the thermal power unit participates in peak operation. The separation device is used to reduce the entry of solid particles into the flow-through components of the turbine. The outlet pipe directly introduces the mixture of solid particles and steam discharged from the main steam pipeline into the boiler sootblower, and recycles this part of the steam to reduce the steam loss of the unit.

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