Anti-disturbance precipitation type cooling water pretreatment device for LNG ship reliquefaction system and use method of anti-disturbance precipitation type cooling water pretreatment device

Abstract

The invention discloses an anti-disturbance precipitation type cooling water pretreatment device for an LNG (Liquefied Natural Gas) ship reliquefaction system and a using method. The anti-disturbance precipitation type cooling water pretreatment device is mounted on a connecting pipeline between a marine fresh water system and the reliquefaction system; according to the utility model, suspended impurities in fresh water can be subjected to pre-pretreatment in a fresh water conveying stage, and cooling water can be stored to precipitate the impurities in the cooling water, so that the purity of the cooling water entering the reliquefaction device is ensured, and the replacement period of a filter element at a cooling water inlet of the reliquefaction device is prolonged; and meanwhile, an anti-disturbance effect can also be achieved, so that the flow speed and the pressure of cooling water flowing into the cooling water inlet of the reliquefaction device are ensured to be stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shipbuilding, in particular to an anti-disturbance sedimentation type cooling water pretreatment device for an LNG ship reliquefaction system and a use method thereof. BACKGROUND

[0002] During the operation of an LNG ship, the reliquefaction system has extremely strict requirements for the water quality of the cooling water, and the specific indicators include: the conductivity needs to be lower than 10 muS / cm, the suspended solids content needs to be controlled below 1 NTU, and the microbial content must be extremely low. However, the water quality of the ship's own fresh water system often cannot meet these requirements, mainly manifested as high suspended solids content (10-50 NTU), excessive ion content, and prominent microbial pollution risk.

[0003] At present, there are various pretreatment technologies on the ship: multi-stage filtration system, chemical treatment method, etc., but the above-mentioned technologies have many shortcomings. The filter core of the multi-stage filtration system is replaced frequently, and the annual average maintenance cost is high; the chemical treatment method may introduce new pollutants. In addition, there are serious compatibility problems between systems: the working pressure of the ship's fresh water system and the reliquefaction system is not matched, direct connection will cause unstable flow and leakage risk; the existing system lacks real-time monitoring capability, and it is difficult to discover water quality mutations in time.

[0004] Although the existing technology provides various water quality pretreatment schemes, there is still a significant technical gap for the cooling water supply link of the LNG ship reliquefaction system. At present, the cooling water supply of the LNG ship reliquefaction system mostly uses a filtration system, but the ship's fresh water system has high suspended solids content, which often causes the filter core at the cooling water inlet of the reliquefaction device to be blocked, the filter core is replaced frequently, and the cost is high. SUMMARY

[0005] Therefore, the present application provides an anti-disturbance sedimentation type cooling water pretreatment device for an LNG ship reliquefaction system and a use method thereof, which is aimed at the problem of frequent replacement of filter cores in the cooling water supply link of the LNG ship reliquefaction system, and the device is arranged on the connecting pipeline between the ship's fresh water system and the reliquefaction system to pretreat the ship's fresh water.

[0006] An anti-disturbance sedimentation type cooling water pretreatment device for an LNG ship reliquefaction system is arranged on the connecting pipeline between the ship's fresh water system and the reliquefaction system, and the anti-disturbance sedimentation type cooling water pretreatment device is arranged to include a water tank, a water tank fixing flange arranged at one end of the water tank, an outlet pipeline arranged at the other end of the water tank, and an inlet pipeline. A filter cartridge is arranged in the water tank, the upper end of the filter cartridge is fixed to the water tank fixing flange and the inlet pipeline fixing flange of the inlet pipeline through fasteners, and the lower end of the filter cartridge extends downward into the water tank from the center of the water tank fixing flange.

[0007] Preferably, the filter cartridge comprises a filter screen, a ring-shaped flange extending from the filter screen, and a plurality of fastener fixing holes on the ring-shaped flange corresponding to the flange holes on the water tank fixing flange and the inlet pipe fixing flange.

[0008] Preferably, the filter screen of the filter cartridge has a mesh size of 1-2 times the mesh size of the filter screen.

[0009] Preferably, the water tank fixing flange is arranged at the top center of the water tank, and the outlet pipe is arranged at a position away from the central axis of the water tank by a certain distance.

[0010] Preferably, the bottom of the filter cartridge is more than 100 mm away from the bottom of the water tank.

[0011] Preferably, the anti-disturbance sedimentation type cooling water pretreatment device is arranged at a position not less than 500 mm away from the cooling water inlet of the reliquefaction device.

[0012] Preferably, a plurality of lifting lugs are arranged on the inlet pipe fixing flange.

[0013] A use method of the anti-disturbance sedimentation type cooling water pretreatment device for the reliquefaction system of an LNG ship, specifically comprising the following steps:

[0014] S1, installing the anti-disturbance sedimentation type cooling water pretreatment device on the connecting pipeline of the reliquefaction system between the fresh water pump and the reliquefaction device;

[0015] S2, during the initial start of the reliquefaction system, closing the valve at the cooling water inlet of the reliquefaction device, using the fresh water pump to pump the cooling water to the anti-disturbance sedimentation type cooling water pretreatment device, and the cooling water enters the filter cartridge from the inlet pipe of the anti-disturbance sedimentation type cooling water pretreatment device, and the large particle suspended matter in the water is filtered out by the filter cartridge and stored in the water tank.

[0016] When the water tank is full or the water level in the water tank reaches a certain height, the valve at the cooling water inlet of the reliquefaction device is opened, and the cooling water in the water tank is transported to the reliquefaction device through the pipeline.

[0017] Preferably, when the anti-disturbance sedimentation type cooling water pretreatment device needs to be overhauled, the pipeline where the anti-disturbance sedimentation type cooling water pretreatment device is arranged is closed, the fasteners fixing the filter cartridge and the water tank fixing flange and the inlet pipe fixing flange are loosened, the inlet pipe is removed, the filter cartridge is taken out of the water tank for cleaning and maintenance, and after the cleaning and maintenance work is completed, the filter cartridge is reset and put into use again.

[0018] The beneficial effects of the present application are:

[0019] 1. The anti-disturbance sedimentation type cooling water pretreatment device of the present application is installed on the connecting pipeline between the ship freshwater system and the reliquefaction system, can perform front-end pretreatment on the suspended impurities in the freshwater during the freshwater delivery stage, can store the cooling water to make the impurities in the cooling water to be precipitated, so as to ensure the purity of the cooling water entering the reliquefaction device, to prolong the replacement cycle of the filter element at the cooling water inlet of the reliquefaction device, and can also play an anti-disturbance role to ensure the stability of the cooling water flow rate and pressure flowing into the cooling water inlet of the reliquefaction device.

[0020] 2. The anti-disturbance sedimentation type cooling water pretreatment device of the present application is installed on the connecting pipeline between the ship freshwater system and the reliquefaction system, not only solves the problem of frequent replacement of the filter element in the cooling water supply link of the LNG ship reliquefaction system, but also solves the problem of mismatch between the working pressure of the ship freshwater system and the reliquefaction system, so as to cause the instability of the inlet flow of the reliquefaction device and the leakage risk, reduces the operation cost of the reliquefaction system, improves the stability of the system operation, and further ensures the safety of the ship operation. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0022] Figure 1 is a structural schematic diagram of the present application.

[0023] Figure 2 is a semi-partial schematic diagram of the present application.

[0024] The meanings of the reference numerals in the drawings are as follows:

[0025] 1 is an inlet pipe, 2 is an inlet pipe fixing flange, 3 is a lifting lug, 4 is a water tank fixing flange, 5 is a filter cartridge, 6 is a water tank, and 7 is an outlet pipe. DETAILED DESCRIPTION

[0026] In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be described below by specific embodiments shown in the drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of the known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0027] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0028] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0029] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0030] To better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings.

[0031] This invention provides an anti-disturbance sedimentation cooling water pretreatment device for LNG ship reliquefaction systems. The anti-disturbance sedimentation cooling water pretreatment device is installed between the ship's freshwater system and the reliquefaction system, specifically on the connecting pipeline used to connect the freshwater pump and the reliquefaction unit. It is used to pre-treat suspended impurities in the cooling water during the cooling water transportation process, and can store the cooling water to allow impurities to settle within it, thereby ensuring the purity of the cooling water entering the reliquefaction unit and extending the replacement cycle of the filter element at the cooling water inlet of the reliquefaction unit.

[0032] The anti-disturbance sedimentation cooling water pretreatment device includes a water tank 6, a water tank fixing flange 4 located at one end of the water tank 6, an outlet pipe 7 located at the other end of the water tank 6, and an inlet pipe 1. A filter cylinder 5 is installed inside the water tank 6. The upper end of the filter cylinder 5 is fixed to the water tank fixing flange 4 and the inlet pipe fixing flange 2 of the inlet pipe 1 by fasteners, and the lower end extends downward into the water tank 6 from the center of the water tank fixing flange 4.

[0033] Specifically, the water tank fixing flange 4 is located at the top center of the water tank 6, and the center of the water tank fixing flange 4 is provided with a through hole for the filter cylinder 5 to pass through; the outlet pipe 7 is located at a position at a set distance from the central axis of the bottom of the water tank 6, preferably, the outlet pipe 7 can be located at a position near the edge of the bottom of the water tank 6.

[0034] The filter cylinder 5 includes a filter screen and an annular folded edge extending from the filter screen. The annular folded edge has multiple fastener fixing holes that correspond one-to-one with the flange holes on the water tank fixing flange 4 and the inlet pipe fixing flange 2. During installation, the filter cylinder 5 is passed through the through hole in the center of the water tank fixing flange 4 to extend into the water tank 6, and its annular folded edge is stacked on the water tank fixing flange 4. Then, the inlet pipe fixing flange 2 of the inlet pipe 1 is stacked on the annular folded edge of the filter cylinder 5. The filter cylinder 5 and the inlet pipe 1 are rotated so that the fastener fixing holes on the annular folded edge and the flange holes on the inlet pipe fixing flange 2 are aligned with the flange holes on the water tank fixing flange 4. Finally, the three are fixed together with bolts.

[0035] The filter element at the cooling water inlet of the reliquefaction unit has a filtration mesh size that is 1-2 times that of the filter screen.

[0036] Preferably, in order to effectively ensure the pre-sedimentation effect of the cooling water in the water tank 6, the bottom of the filter cylinder 5 is more than 100mm away from the bottom of the water tank 6.

[0037] Preferably, the anti-disturbance sedimentation cooling water pretreatment device is located at a distance of not less than 500 mm from the cooling water inlet of the reliquefaction unit.

[0038] To facilitate the disassembly and assembly of the inlet pipe 1, multiple lifting lugs 3 are provided on the inlet pipe fixing flange 2.

[0039] This invention also provides a method for using an anti-disturbance sedimentation cooling water pretreatment device for an LNG ship reliquefaction system, specifically including the following steps:

[0040] S1, the anti-disturbance sedimentation cooling water pretreatment device is installed on the connecting pipeline between the fresh water pump and the reliquefaction device in the reliquefaction system;

[0041] S2, at the initial stage of the reliquefaction system startup, the valve at the cooling water inlet of the reliquefaction device is closed, and the cooling water is pumped to the anti-disturbance sedimentation cooling water pretreatment device using a fresh water pump. The cooling water enters the filter cartridge 5 from the inlet pipe 1 of the anti-disturbance sedimentation cooling water pretreatment device. After the large particulate suspended matter in the water is filtered out by the filter cartridge 5, it is stored in the water tank 6.

[0042] When the water tank 6 is full or the water level in the tank reaches the set height, open the valve at the cooling water inlet of the reliquefaction unit and transport the cooling water in the water tank 6 from the outlet pipe 7 to the reliquefaction unit.

[0043] When the anti-disturbance sedimentation cooling water pretreatment device needs maintenance, shut off the pipeline where it is located, loosen the fasteners of the fixed filter cylinder 5 to the fixed flange 4 of the water tank and the fixed flange 2 of the inlet pipe, remove the inlet pipe 1, take the filter cylinder 5 out of the water tank 6 for cleaning and maintenance, and after the cleaning and maintenance work is completed, reset it and put it back into use.

[0044] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A disturbance-resistant sedimentation-type cooling water pretreatment device for LNG ship reliquefaction systems, characterized in that, The anti-disturbance sedimentation cooling water pretreatment device is installed on the connecting pipeline between the marine freshwater system and the reliquefaction system. The anti-disturbance sedimentation cooling water pretreatment device includes a water tank (6), a water tank fixing flange (4) installed at one end of the water tank (6), an outlet pipe (7) installed at the other end of the water tank (6), and an inlet pipe (1). A filter cylinder (5) is installed inside the water tank (6). The upper end of the filter cylinder (5) is fixed to the water tank fixing flange (4) and the inlet pipe fixing flange (2) of the inlet pipe (1) by fasteners, and the lower end extends downward into the water tank (6) from the center of the water tank fixing flange (4).

2. The anti-disturbance sedimentation cooling water pretreatment device for LNG ship reliquefaction systems according to claim 1, characterized in that, The filter cylinder (5) includes a filter screen and an annular folded edge extending from the filter screen. The annular folded edge is provided with a plurality of fastener fixing holes that correspond one-to-one with the flange holes on the water tank fixing flange (4) and the inlet pipe fixing flange (2).

3. The anti-disturbance sedimentation cooling water pretreatment device for LNG ship reliquefaction systems according to claim 2, characterized in that, The filter element at the cooling water inlet of the reliquefaction unit has a mesh size that is 1-2 times that of the filter screen.

4. The anti-disturbance sedimentation cooling water pretreatment device for LNG ship reliquefaction systems according to claim 1, characterized in that, The water tank fixing flange (4) is located at the top center of the water tank (6), and the outlet pipe (7) is located at a set distance from the central axis of the bottom of the water tank (6).

5. The anti-disturbance sedimentation cooling water pretreatment device for LNG ship reliquefaction systems according to claim 1, characterized in that, The bottom of the filter cylinder (5) is more than 100mm away from the bottom of the water tank (6).

6. The anti-disturbance sedimentation cooling water pretreatment device for LNG ship reliquefaction systems according to claim 1, characterized in that, The anti-disturbance sedimentation cooling water pretreatment device is located at a distance of not less than 500 mm from the cooling water inlet of the reliquefaction unit.

7. The anti-disturbance sedimentation cooling water pretreatment device for LNG ship reliquefaction systems according to claim 1, characterized in that, The inlet pipe fixing flange (2) is equipped with multiple lifting lugs (3).

8. A method of using the anti-disturbance sedimentation cooling water pretreatment device for an LNG ship reliquefaction system according to any one of claims 1-7, characterized in that, Specifically, the following steps are included: S1, the anti-disturbance sedimentation cooling water pretreatment device is installed on the connecting pipeline between the fresh water pump and the reliquefaction device in the reliquefaction system; S2, at the initial stage of the reliquefaction system startup, the valve at the cooling water inlet of the reliquefaction device is closed, and the cooling water is pumped to the anti-disturbance sedimentation cooling water pretreatment device using a fresh water pump. The cooling water enters the filter cylinder (5) from the inlet pipe (1) of the anti-disturbance sedimentation cooling water pretreatment device. After the large particulate suspended matter in the water is filtered out by the filter cylinder (5), it is stored in the water tank (6). When the water tank (6) is full or the water level in the water tank reaches the set height, open the valve at the cooling water inlet of the reliquefaction device and transport the cooling water in the water tank (6) from the outlet pipe (7) to the reliquefaction device.

9. The method according to claim 8, characterized in that, When the anti-disturbance sedimentation cooling water pretreatment device needs maintenance, shut off the pipeline where it is located, loosen the fasteners of the fixed filter cylinder (5) and the fixed flange (4) of the water tank and the fixed flange (2) of the inlet pipe, remove the inlet pipe (1), take the filter cylinder (5) out of the water tank (6) for cleaning and maintenance, and reset and put it back into use after the cleaning and maintenance work is completed.

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