Offshore gas turbine air intake filter

Abstract

The offshore gas turbine air intake filter device comprises an air intake section, a first filter section, a second filter section and an air outlet section arranged in sequence along the air intake direction; the first filter section comprises an inertial separation structure for capturing and separating liquid salt mist in the airflow through centrifugal inertia effect; the second filter section comprises hydrophobic modified filter material with surface energy below 15 mN / m for filtering solid particles in the airflow and inhibiting the attachment of residual liquid salt mist to vaporize and precipitate crystals; the device further comprises a liquid collection and discharge unit arranged at the bottom of the first filter section for collecting and discharging the salt liquid condensed by the liquid salt mist separated by the first filter section. The offshore gas turbine air intake filter device can improve the problem of frequent filter blockage caused by salt mist crystallization on the filter material, help to improve the service life of the filter material and reduce the replacement frequency.

Description

Technical Field

[0001] This application relates to the field of gas turbine intake treatment technology, and more specifically, to an intake filtration device for offshore gas turbines. Background Technology

[0002] In the intake systems of offshore gas turbines, traditional filter media in the intake filtration devices, after intercepting liquid salt mist in high-humidity, high-salt-mist environments, readily absorb moisture, concentrate, and crystallize on the filter media fibers. These salt crystals then bind and adhere to solid dust, forming a hard, mixed scale layer. This leads to rapid clogging of the filter media pores, a sharp increase in system operating resistance, and the need for frequent filter media replacement. Therefore, there is an urgent need for an intake filtration device that can efficiently separate liquid salt mist and reduce the frequency of filter media replacement. Summary of the Invention

[0003] This application provides at least one offshore gas turbine inlet filtration device, which can improve the problem of frequent clogging of the filter media caused by salt spray crystallization, thus helping to improve the service life of the filter media and reduce the replacement frequency.

[0004] This application provides an offshore gas turbine inlet filtration device, comprising an inlet section, a first filtration section, a second filtration section, and an outlet section arranged sequentially along the inlet direction; The first filtration section includes an inertial separation structure, which is used to capture and separate liquid salt mist in the airflow through centrifugal inertial effect; The second filtration section includes hydrophobically modified filter media with a surface energy of less than 15 mN / m. The hydrophobically modified filter media is used to filter solid particles in the airflow and can inhibit the adhesion of residual liquid salt spray to vaporize and crystallize.

[0005] In one optional embodiment, the inertial separation structure is a multi-layered, parallel, staggered corrugated plate, with an S-shaped airflow channel formed between the corrugated plates.

[0006] In one alternative embodiment, the corrugated plate surface is coated with a superhydrophobic coating.

[0007] In one optional embodiment, the hydrophobically modified filter material is a fiber filter material modified by in-situ graft polymerization of nano-silica and fluorocarbon monomers.

[0008] In one optional embodiment, the hydrophobic modified filter material adopts a three-layer gradient composite structure, including a coarse filter layer, a main filter layer, and a hydrophobic protective layer.

[0009] In one optional embodiment, the device further includes a liquid collection and discharge unit disposed at the bottom of the first filtration section, which is used to collect the salt liquid condensed from the liquid salt mist separated by the first filtration section and discharge it.

[0010] In one optional embodiment, the liquid collection and discharge unit includes a liquid collection tank and a discharge valve. The liquid collection tank is located below the first filtration section and is used to collect dripping liquid salt mist. The liquid collection tank is provided with a discharge port and a guiding flow slope. The guiding flow slope is used to direct the dripping liquid salt mist to the discharge port. The discharge valve is provided at the discharge port and is used to open to discharge the salt solution.

[0011] In one optional embodiment, the device further includes a flow stabilization and pressure equalization section, which is disposed between the first filter section and the second filter section, for making the airflow uniformly distributed into the second filter section.

[0012] In one optional embodiment, the device further includes a housing, in which the air inlet section, the first filter section, the second filter section and the air outlet section are all integrated. The end of the housing near the air outlet section is provided with a flange structure for connecting to the gas turbine air inlet section.

[0013] In one optional embodiment, the housing is made of 316L stainless steel or fiberglass, and the inner wall of the housing is provided with a hydrophobic and anti-corrosion coating.

[0014] The above-mentioned technical solution of this application has the following beneficial technical effects: The nearshore gas turbine inlet filtration device of this application embodiment achieves efficient graded treatment of liquid salt spray and solid particles through the combination of an inertial separation structure and hydrophobic modified filter media. It not only significantly reduces the liquid salt spray load in contact with the hydrophobic filter media in the second filtration stage, but also inhibits the formation of salt crystals by utilizing hydrophobic modification. This effectively avoids the problem of rapid clogging caused by the adhesion of salt crystals and dust to traditional filter media, thereby greatly improving the service life of the filter media, reducing the frequency of filter media replacement, reducing the risk of sudden increase in system operating resistance, and improving the reliability and maintenance economy of gas turbine inlet filtration in nearshore high humidity and high salinity environments.

[0015] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. These drawings are incorporated in and constitute a part of this specification. They illustrate embodiments conforming to this application and, together with the specification, serve to explain the technical solutions of this application. It should be understood that the following drawings only show some embodiments of this application and should not be considered as limiting the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This paper shows a schematic diagram of the structure of an offshore gas turbine inlet filtration device provided in an embodiment of this application; In the diagram: 1. Air inlet section; 2. First filtration section; 21. Inertial separation structure; 3. Second filtration section; 31. Hydrophobic modified filter media; 4. Air outlet section; 5. Liquid collection and discharge unit; 51. Liquid collection tank; 52. Drain valve; 6. Flow stabilization and pressure equalization section; 61. Porous flow equalization plate; 7. Shell; 71. Flange structure. Detailed Implementation

[0018] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0019] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0020] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0021] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] refer to Figure 1 This application provides an air intake filtration device for an offshore gas turbine, which is installed at the front end of the offshore gas turbine's air intake system. The device includes an air intake section 1, a first filtration section 2, a second filtration section 3, and an air outlet section 4 arranged sequentially along the air intake direction. The first filtration section 2 includes an inertial separation structure 21, which is used to capture and separate liquid salt mist in the airflow through centrifugal inertial effect. The second filtration section 3 includes a hydrophobic modified filter material 31, the surface energy of which is below 15 mN / m. This material is used to filter solid particles in the airflow and can inhibit the adhesion of residual liquid salt mist to vaporize and crystallize. When the device is in use, the air intake section 1 introduces humid air containing salt mist and solid particles. It first enters the inertial separation structure 21 of the first filter section 2. The liquid salt mist particles in the airflow are efficiently captured and separated by the centrifugal inertial effect and the droplet collision and coalescence effect. The separated salt liquid drips down under the action of gravity. Then the airflow enters the second filter section 3, where the remaining solid particles are filtered by the hydrophobic modified filter material 31 with a surface energy of less than 15mN / m. At the same time, its low surface energy characteristics can inhibit the adhesion of a small amount of residual liquid salt mist on the filter material, avoid the salt from absorbing moisture, concentrating and crystallizing, thereby preventing the salt crystals from combining with dust to form a clogging scale layer.

[0024] It should be noted that the air intake filtration device in this embodiment constructs a graded and phase-separated synergistic removal mechanism, consisting of a front-end centrifugal process to remove liquid salt mist and a rear-end hydrophobic fine filtration process to remove solid dust. This achieves efficient and coordinated purification of salt mist and dust, without interference and with synergistic effects. Specifically, the front-end centrifugal design significantly reduces the salt load on the rear-end filter media, thereby inhibiting salt crystallization and clogging within the filter media. The rear-end hydrophobic fine filtration design inhibits the adhesion of residual liquid salt mist to the filter media, preventing crystallization and clogging of the filter pores as the salt mist passes through. The entire device exhibits minimal fluctuations in operating resistance, and the service life and replacement cycle of the filter media are significantly extended.

[0025] In some embodiments, the inertial separation structure 21 is a multi-layered, parallel, staggered corrugated plate (such as a zigzag or arc-shaped type), forming an S-shaped airflow channel between the corrugated plates. In use, the airflow containing liquid salt spray repeatedly changes direction in the continuous S-shaped channel formed between the plates. The airflow rapidly turns within the channel and forms a swirling centrifugal effect, causing the salt spray droplets to collide with the plate wall inertially, coalesce, and grow, thus achieving pre-removal of salt spray.

[0026] In this embodiment, an arc-shaped guide groove can be provided on the corrugated plate to enhance the centrifugal inertial force of the airflow. For example, the arc-shaped guide groove is located at the trough of the corrugated plate, and the cross-section of the arc-shaped guide groove is arc-shaped. In use, the arc-shaped guide groove can provide the airflow with a preset turning path with a larger curvature, forcing the airflow to move along a sharper and smaller arc, thereby enhancing the centrifugal inertial force of the airflow.

[0027] In this embodiment, the arc-shaped guide grooves are evenly distributed along the airflow direction. For example, arc-shaped guide grooves can be provided at the troughs of the corrugated plate. As a reinforcing structure on the corrugated plate, the guide grooves affect the local strength. The evenly distributed distribution ensures that the structural reinforcement effect is uniformly distributed across the entire corrugated plate, which is conducive to forming a regular and predictable flow field. This allows the airflow to stably undergo a cycle of "acceleration-turning-stabilization-re-acceleration," minimizing uncontrollable vortices and avoiding the local airflow turbulence that may exist in groove-free areas.

[0028] In this embodiment, the corrugated plate surface is coated with a superhydrophobic coating (e.g., 15-30 μm thick). For example, the static water contact angle is ≥150° and the roll-off angle is ≤5°. By coating the corrugated plate surface with a superhydrophobic coating, its surface possesses extremely strong hydrophobicity and extremely low surface energy. When the liquid salt spray droplets captured during inertial separation impact or adhere to the plate surface, the superhydrophobic coating ensures that the salt spray droplets do not wet, spread, adhere to the plate surface, or remain, and quickly slide off under gravity, preventing salt backflow, secondary entrainment, and evaporation crystallization.

[0029] It should be noted that the construction of the inertial separation structure 21 can be selected according to the actual situation, and this embodiment does not impose specific limitations on it.

[0030] In some embodiments, the hydrophobically modified filter media 31 is a fiber filter media modified by in-situ graft polymerization of nano-silica and fluorocarbon monomers. This modified filter media, through the synergistic effect of chemical grafting and physical roughening, endows the filter media with durable and highly efficient hydrophobic properties. It effectively prevents liquid salt spray from settling on the filter media fibers, avoiding the key problem of salt hygroscopic concentration forming a hard, mixed scale layer. This significantly slows down the rate of pore clogging, reduces filtration resistance growth, and greatly extends the service life of the filter media in nearshore high-humidity, high-salt environments. Furthermore, this design allows the filter media to operate stably for extended periods in environments with relative humidity exceeding 95%.

[0031] In some embodiments, the hydrophobically modified filter media 31 employs a three-layer gradient composite structure, including a coarse filtration layer, a main filtration layer, and a hydrophobic protective layer. For example, the base material of the hydrophobically modified filter media 31 is made of ultrafine glass fiber or polyester filament fiber, and the surface of the filter media undergoes nano-hydrophobic modification treatment, reducing the surface energy to below 15 mN / m. The three-layer gradient composite structure, by intercepting particles in stages from large to small, not only significantly improves filtration efficiency but also optimizes resistance distribution, preventing a single filter layer from rapidly clogging due to instantly bearing all the particle load.

[0032] It should be noted that the filtration accuracy of the hydrophobic modified filter media 31 can be selected according to actual conditions, and this embodiment does not impose specific limitations on it. For example, the filtration accuracy of the hydrophobic modified filter media 31 can be 0.3~1μm.

[0033] In some embodiments, the device further includes a liquid collection and discharge unit 5, which is disposed at the bottom of the first filter section 2 and is used to collect the salt liquid condensed from the liquid salt mist separated by the first filter section 2 and discharge it. By providing the liquid collection and discharge unit 5, it is possible to achieve non-retention collection and discharge of dripping salt liquid, shorten the time that the salt liquid is exposed to the airflow inside the system, and eliminate the possibility of droplets evaporating and crystallizing in critical areas of the system.

[0034] In this embodiment, the liquid collection and discharge unit 5 includes a liquid collection tank 51 and a discharge valve 52. The liquid collection tank 51 is located below the first filter section 2 and is used to collect dripping liquid salt mist. The liquid collection tank 51 is provided with a discharge port and a guiding slope. The guiding slope is used to direct the dripping liquid salt mist to the discharge port. The discharge valve 52 is located at the discharge port and is used to open to discharge the salt solution. This design... In this embodiment, splash guards can be installed on one or both sides of the flow ramp to prevent brine from splashing. By adding splash guards on both sides of the flow ramp of the collection tank 51, a physical barrier can be formed to block brine splashing or droplet rebound that may be caused by liquid flow impact or airflow disturbance, ensuring that the brine flow path is stable and concentrated into the drain outlet.

[0035] It should be noted that the structure of the liquid collection and discharge unit 5 can be selected according to the actual situation, and this embodiment does not impose specific limitations on it.

[0036] It should also be noted that the guiding slope can be the sloping bottom surface of the collection tank 51, or it can be an independent ramp extending downwards from the top of the collection tank 51 towards the drain outlet. The slope of the guiding slope can be selected according to the actual situation, and this embodiment does not impose a specific limitation. For example, the guiding slope can be inclined at an angle of 3° to 5° towards the drain outlet.

[0037] In some embodiments, the device further includes a flow stabilization and pressure equalization section 6, which is disposed between the first filter section 2 and the second filter section 3, and is used to ensure that the airflow is evenly distributed into the second filter section 3. Specifically, a porous flow equalization plate 61 can be provided in the flow stabilization and pressure equalization section 6 to ensure that the airflow is evenly distributed into the filter media section, without flow deviation, short circuit, or local wear. By setting the flow stabilization and pressure equalization section 6 between the inertial separation structure 21 (first filter section 2) and the hydrophobic modified filter media 31 (second filter section 3), the airflow after inertial separation can achieve a more uniform flow velocity and a stable pressure distribution in this area, thereby eliminating local eddies or uneven flow velocity, ensuring that the airflow enters the subsequent hydrophobic modified filter media 31 smoothly and evenly for filtration, thus avoiding the problem of excessive local load on the filter media or decreased filtration efficiency caused by uneven airflow, and helping to extend the service life of the hydrophobic modified filter media 31.

[0038] In some embodiments, the device further includes a housing 7, in which the inlet section 1, the first filter section 2, the second filter section 3, the outlet section 4, and the liquid collection and discharge unit 5 are all integrated. A flange structure 71 for connecting to the gas turbine inlet section 1 is provided at one end of the housing 7 near the outlet section 4. By integrating the inlet section 1, the first filter section 2, the second filter section 3, the outlet section 4, and the liquid collection and discharge unit 5 into a single complete housing 7, and directly connecting it to the gas turbine inlet using the flange structure 71 at the outlet end of the housing 7, the entire filtration device forms a compact, standard-interface independent module, facilitating transportation and overall installation.

[0039] In this embodiment, the housing 7 is made of 316L stainless steel or fiberglass, and the inner wall of the housing 7 is coated with a hydrophobic and anti-corrosion coating. By using 316L stainless steel or fiberglass as the material of the housing 7, and combining it with the hydrophobic and anti-corrosion coating on the inner wall, the entire device and the surface of the internal flow channels have excellent corrosion resistance and hydrophobic properties. This enables it to resist the erosion of the high humidity and high salt spray environment of the nearshore area for a long time, and reduces the adhesion and residue of droplets on the wall surface, thereby structurally ensuring the long-term stable operation of the internal filtration function.

[0040] The nearshore gas turbine inlet filtration device of this application embodiment achieves efficient graded treatment of liquid salt spray and solid particles through the combination of inertial separation structure 21 and hydrophobic modified filter media 31. It not only significantly reduces the liquid salt spray load in contact with the hydrophobic filter media in the second filtration section 3, but also inhibits the formation of salt crystals by utilizing hydrophobic modification. This effectively avoids the problem of rapid clogging caused by salt crystals and dust adhesion in traditional filter media, thereby greatly improving the service life of the filter media, reducing the frequency of filter media replacement, reducing the risk of sudden increase in system operating resistance, and improving the reliability and maintenance economy of gas turbine inlet filtration in nearshore high humidity and high salinity environments.

[0041] Example A distributed energy station at a port on the southeast coast of my country is equipped with a 1.5MW gas turbine generator set. The station is located less than 800 meters from the coastline and is in a high-humidity, high-salt-spray, and high-dust-laden-sea-wind environment all year round. Salt spray corrosion is particularly severe from April to October each year.

[0042] Before the installation of the system of this invention, the unit used a combination of conventional plate and frame filter and ordinary metal corrugated demister. In actual operation, serious problems were exposed: the filter media would show obvious salt crystallization and blockage after 10 to 15 days of operation in a high humidity and high salt environment, and the intake resistance would increase by more than 300 Pa, requiring the unit to be shut down and the filter media replaced; at the same time, obvious salt corrosion spots and slight corrosion marks appeared on the surface of the compressor blades, the unit output decreased, the vibration value increased, the number of shutdowns for maintenance reached more than 12 times a year, the operation and maintenance costs were high and the power supply reliability was poor.

[0043] After adopting the air intake filtration device of this embodiment, the first filtration section efficiently captures liquid salt mist through a strong centrifugal effect. The superhydrophobic coating allows the salt mist droplets to quickly slide off, collect, and be discharged, without sticking to the walls, crystallizing, or leaving residue. The filter media of the second filtration section, due to its surface hydrophobic and salt-repellent modification treatment, does not absorb moisture, does not caking, and does not crystallize, continuously and stably intercepting dust and trace solid salt particles. The system operated continuously for 180 days, with the air intake resistance consistently maintained between 85Pa and 95Pa, without crystallization, blockage, corrosion, or leakage. The salt mist removal efficiency remained stable at over 96%, and the total purification efficiency reached 99.98%. During this period, the filter media did not need to be replaced, the unit did not need to be shut down for maintenance due to air intake system problems, and the gas turbine compressor blades showed no new corrosion, pitting, or scaling. The unit output was stable, efficiency improved, and vibration levels remained at excellent levels. The continuous trouble-free operation time increased by more than 7 times, completely solving the long-standing problem of coastal salt mist crystallization and blockage that had plagued the power station. Economic benefits, reliability, and safety were significantly improved in all aspects.

[0044] One or more embodiments in this specification are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this specification should be included within the protection scope of this application.

[0045] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An air intake filtration device for a near-shore gas turbine, characterized in that, It includes an intake section, a first filter section, a second filter section, and an exhaust section arranged sequentially along the intake direction; The first filtration section includes an inertial separation structure, which is used to capture and separate liquid salt mist in the airflow through centrifugal inertial effect; The second filtration section includes hydrophobically modified filter media with a surface energy of less than 15 mN / m. The hydrophobically modified filter media is used to filter solid particles in the airflow and can inhibit the adhesion of residual liquid salt spray to vaporize and crystallize.

2. The near-shore gas turbine inlet air filtration device according to claim 1, characterized in that, The inertial separation structure consists of multiple layers of corrugated plates arranged in a parallel staggered manner, with S-shaped airflow channels formed between the corrugated plates.

3. The near-shore gas turbine inlet filtration device according to claim 2, characterized in that, The surface of the corrugated plate is coated with a superhydrophobic coating.

4. The near-shore gas turbine inlet air filtration device according to claim 1, characterized in that, The hydrophobically modified filter media is a fiber filter media modified by in-situ graft polymerization of nano-silica and fluorocarbon monomers.

5. The near-shore gas turbine inlet air filtration device according to claim 1, characterized in that, The hydrophobic modified filter media adopts a three-layer gradient composite structure, including a coarse filtration layer, a main filtration layer, and a hydrophobic protective layer.

6. The near-shore gas turbine inlet air filtration device according to claim 1, characterized in that, The device further includes a liquid collection and discharge unit, which is located at the bottom of the first filtration section and is used to collect the salt liquid condensed from the liquid salt mist separated by the first filtration section and discharge it.

7. The near-shore gas turbine inlet air filtration device according to claim 6, characterized in that, The liquid collection and discharge unit includes a liquid collection tank and a discharge valve. The liquid collection tank is located below the first filtration section and is used to collect dripping liquid salt mist. The liquid collection tank is provided with a discharge port and a guiding flow slope. The guiding flow slope is used to direct the dripping liquid salt mist to the discharge port. The discharge valve is provided at the discharge port and is used to open to discharge the salt solution.

8. The near-shore gas turbine inlet air filtration device according to claim 1, characterized in that, The device further includes a flow stabilization and pressure equalization section, which is disposed between the first filter section and the second filter section, and is used to ensure that the airflow is evenly distributed into the second filter section.

9. The near-shore gas turbine inlet air filtration device according to claim 1, characterized in that, The device also includes a housing, in which the air inlet section, the first filter section, the second filter section and the air outlet section are all integrated. The end of the housing near the air outlet section is provided with a flange structure for connecting to the gas turbine air inlet section.

10. The near-shore gas turbine inlet air filtration device according to claim 9, characterized in that, The housing is made of 316L stainless steel or fiberglass, and the inner wall of the housing is provided with a hydrophobic and anti-corrosion coating.

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