Nitrogen replacement system for LNG (liquefied natural gas) ship and shore base

Abstract

The utility model provides an LNG (Liquefied Natural Gas) ship and shore-based nitrogen replacement system which comprises a shore-based nitrogen filling valve, a concentric reducing pipe, a first connecting pipe, a first ball valve, a first adapter, a nitrogen conveying pipe, a second adapter, a second ball valve, a second connecting pipe and a functional pipe which are sequentially connected from a shore-based nitrogen filling station to an LNG ship, a thermometer, a flowmeter and a pressure gauge are respectively arranged in the concentric reducing pipe and the functional pipe, and a dew-point meter, an oxygen concentration detector and an exhaust ball valve are further arranged in the functional pipe. According to the nitrogen replacement system, data information such as flow, temperature, pressure and dew point of nitrogen in the system can be effectively monitored, the flow of the nitrogen entering a cargo hold of a ship can be adjusted through control of different ball valves, and meanwhile the problem that air remains after the nitrogen replacement system is installed can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of pipelines, in particular to a pipeline system for replacing gas in a cargo hold when filling an LNG ship with nitrogen. Background Art

[0002] When an LNG carrier is under repair at a shipyard, it is crucial to replace the air in the cargo hold with nitrogen to ensure that LNG can be safely refueled after the repair. After the repair is completed, the nitrogen from the shore must be transported to the ship's LNG cargo hold with the help of a connecting device to exhaust the air in the cargo hold, lower the dew point of the gas in the cargo hold, inertize the cargo hold, and prevent static electricity from exploding.

[0003] However, the existing connection technology has obvious defects. At present, pure nitrogen is directly connected from the liquid nitrogen truck to the LNG ship only through pipelines, which has many problems. First, it is impossible to effectively monitor the key parameters of nitrogen such as flow, temperature, pressure, dew point, etc., and it is difficult to accurately grasp the transportation status of nitrogen, so it is impossible to ensure the effect and safety of nitrogen replacement. Secondly, the nitrogen flow entering the ship's cargo hold cannot be adjusted, and the replacement process cannot be flexibly controlled according to actual needs. Furthermore, the mutual interference between the pipe systems on the ship's filling station side brings great inconvenience to the installation, affecting the work efficiency and convenience of operation. In addition, the existing technology cannot purge the air in the pipe system, which may cause residual air in the pipe system, affecting the quality and effect of nitrogen replacement. Utility Model Content

[0004] In order to solve the above problems, the utility model proposes a LNG ship and shore-based nitrogen replacement system, including a shore-based nitrogen filling valve, a concentric reducer, a first connecting pipe, a first ball valve, a first adapter, a nitrogen delivery pipe, a second adapter, a second ball valve, a second connecting pipe and a functional pipe connected in sequence from a shore-based nitrogen filling station to the LNG ship.

[0005] Furthermore, an open-hole blind plate is provided between the concentric reducer and the first connecting pipe.

[0006] Furthermore, a through-hole blind flange is provided between the second connecting pipe and the functional pipe.

[0007] Furthermore, an LNG ship-side nitrogen filling flange is provided between the functional pipe and the LNG ship.

[0008] Furthermore, a first thermometer, a first flow meter, and a first pressure gauge are also provided on the concentric reducer.

[0009] Furthermore, the functional pipe is also provided with a second thermometer, a second flow meter, a second pressure gauge and a dew point meter. Furthermore, the functional pipe further includes an oxygen concentration detector and an exhaust ball valve.

[0010] Furthermore, a first functional pipe flange is provided at one end of the functional pipe connected to the second connecting pipe, and the first functional pipe flange is adapted to the through-hole blind plate flange. A second functional pipe flange is provided at the other end of the functional pipe, and the second functional pipe flange is adapted to the nitrogen filling on the LNG ship side.

[0011] Furthermore, the concentric reducer includes a first diameter end and a second diameter end, the diameter of the first diameter end is smaller than the diameter of the second diameter end, the first diameter end is connected to the shore-based nitrogen filling valve, and the second diameter end is connected to the first connecting pipe.

[0012] Furthermore, the exhaust ball valve is arranged below the functional pipe, and the opening of the exhaust ball valve faces downward.

[0013] Therefore, the beneficial effects of the utility model are:

[0014] 1. The utility model can effectively monitor the flow, temperature, pressure, dew point and other data information of nitrogen.

[0015] 2. The utility model can adjust the flow of nitrogen entering the ship's cargo hold through ball valve control.

[0016] 3. The adapter of the utility model can be matched with pipelines of various angles and forms, and the connection is convenient to avoid pipeline interference and is easy to install.

[0017] 4. The utility model can solve the problem of residual air in the pipeline after installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 This is a schematic diagram of the pipeline system connection of the utility model.

[0020] Figure 2 It is a partial schematic diagram of the functional tube in the utility model.

[0021] Reference numerals

[0022] 1 Shore-based nitrogen filling valve

[0023] 2 Concentric reducers

[0024] 2-1 First pipe diameter end

[0025] 2-2 Second pipe diameter end

[0026] 2-3 First Thermometer

[0027] 2-4 First flow meter

[0028] 2-5 First pressure gauge

[0029] 3 First connecting pipe

[0030] 4. First ball valve

[0031] 5 First adapter

[0032] 6 Nitrogen delivery pipe

[0033] 7 Second adapter

[0034] 8 Second ball valve

[0035] 9 Second connecting pipe

[0036] 10 Functional tube

[0037] 10-1 Functional pipe first flange

[0038] 10-2 Second flange of functional pipe

[0039] 10-3 Second thermometer

[0040] 10-4 Second flow meter

[0041] 10-5 Second pressure gauge

[0042] 10-6 Dew Point Meter

[0043] 10-7 oxygen concentration detector

[0044] 10-8 Exhaust Ball Valve

[0045] 11 Blind plate for opening

[0046] 12 Through hole blind flange

[0047] 13 LNG ship side nitrogen filling flange

[0048] 100 shore-based nitrogen filling stations

[0049] 200LNG Ship DETAILED DESCRIPTION

[0050] The following is an explanation of the implementation of the present application by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification.

[0051] In the following description, please refer to the accompanying drawings, which describe several embodiments of the present application. It should be understood that other embodiments may also be used, and mechanical composition, structure, electrical and operational changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description should not be considered restrictive, and the scope of the embodiments of the present application is limited only by the claims of the published patents. The terms used here are only for describing specific embodiments and are not intended to limit the present application. Spatially related terms, such as "upper", "lower", "left", "right", "below", "below", "lower", "above", "upper", etc., may be used in the text to facilitate the description of the relationship between an element or feature shown in the figure and another element or feature.

[0052] Although the terms first, second, etc. are used to describe various elements or parameters in this article in some instances, these elements or parameters should not be limited by these terms. These terms are only used to distinguish one or parameter part from another or parameter. For example, the first end can be referred to as the second end, and similarly, the second end can be referred to as the first end, without departing from the scope of the various described embodiments. The first end and the second end are both describing one end, but unless the context clearly indicates otherwise, they are not the same end.

[0053] Furthermore, as used in this article, the singular forms "one", "an" and "the" are intended to include the plurality forms as well, unless there is an indication to the contrary in the context. It should be further understood that the terms "comprise", "include" indicate the presence of the described features, steps, operations, elements, components, projects, kinds, and / or groups, but do not exclude the presence, occurrence or addition of one or more other features, steps, operations, elements, components, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Exceptions to this definition will only occur when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way.

[0054] like Figure 1 , which is a schematic diagram of the connection between an LNG ship and a shore-based nitrogen replacement system of the utility model. The utility model comprises a shore-based nitrogen filling valve 1, a concentric reducer 2, a first connecting pipe 3, a first ball valve 4, a first adapter 5, a nitrogen delivery pipe 6, a second adapter 7, a second ball valve 8, a second connecting pipe 9 and a functional pipe 10 which are sequentially connected from a shore-based nitrogen filling station 100 to an LNG ship 200.

[0055] An open hole blind plate 11 is arranged between the concentric reducer 2 and the first connecting pipe 3. The concentric reducer 2 includes a first pipe diameter end 2-1 and a second pipe diameter end 2-2. The pipe diameter of the first pipe diameter end 2-1 is smaller than the pipe diameter of the second pipe diameter end 2-2. The first pipe diameter end 2-1 and the second pipe diameter end 2-2 are in a gradually opening trumpet shape. The first pipe diameter end 2-1 is connected to the shore-based nitrogen filling valve 1, and the second pipe diameter end 2-2 is connected to the first connecting pipe 3.

[0056] A through-hole blind flange 12 is arranged between the second connecting pipe 9 and the functional pipe 10, and a functional pipe first flange 10-1 is arranged at one end of the functional pipe 10 connected to the second connecting pipe 9, and the functional pipe first flange 10-1 is adapted to the through-hole blind flange 12, and a functional pipe second flange 10-2 is arranged at the other end of the functional pipe 10, and the functional pipe second flange 10-2 is adapted to the nitrogen filling flange 13 on the LNG ship side, and the nitrogen filling flange 13 on the LNG ship side is the own flange of the LNG ship 200 filling station.

[0057] It should be noted that the first thermometer 2-3, the first flowmeter 2-4, and the first pressure gauge 2-4 are also provided on the concentric reducer 2. In the specific installation, the first thermometer 2-3, the first flowmeter 2-4, and the first pressure gauge 2-5 have an angle with each other, that is, the first thermometer 2-3, the first flowmeter 2-4, and the first pressure gauge 2-5 are installed along the outer diameter of the pipeline in a staggered manner to facilitate reading of the values. Similarly, the second thermometer 10-3, the second flowmeter 10-4, and the second pressure gauge 10-5 provided on the functional pipe 10 are also installed in a staggered manner. In addition, the functional pipe 10 also includes a dew point meter 10-6, an oxygen concentration detector 10-7, and an exhaust ball valve 10-8. The exhaust ball valve 10-8 is provided below the functional pipe 10, and the opening of the exhaust ball valve 10-8 faces downward. In terms of installation sequence, the gas flow must first flow through the second thermometer 10-3, the second flow meter 10-4 and the second pressure gauge 10-5, and then flow to the dew point meter 10-6 and the oxygen concentration detector 10-7.

[0058] Furthermore, the dew point meter 10-6 and the oxygen concentration detector 10-7 are installed above the exhaust ball valve 10-8, so that the nitrogen quality can be monitored at any time. If the exhaust ball valve is not sealed tightly, the values ​​of the oxygen concentration detector 10-7 and the dew point meter 10-6 will change. At the beginning of the nitrogen opening, the air in the pipeline system needs to be blown out from the exhaust ball valve 10-8. The standard for whether the purge is clean is to judge whether the oxygen content is zero and whether the dew point reaches the dew point of nitrogen through the oxygen concentration detector 10-7.

[0059] In specific operation, the pipeline system of the utility model first performs a tightness test, opens the nitrogen filling valve 1, the first ball valve 4, the second ball valve 8 of the shore-based nitrogen station, closes the exhaust ball valve 10-8, closes the valve on the filling pipe on board, and when the pressure of the first pressure gauge 2-5 reaches 3 bar, stops the gas supply, closes the nitrogen filling valve 1 of the shore-based nitrogen station, and observes the first pressure gauge 2-5 and the second pressure gauge 10-5 at rest. If the pressure does not drop for 30 minutes, it is confirmed that the connection between the shore-based nitrogen filling station 100 and the LNG ship 200 is good and the sealing is good. If the pressure drops, check each joint, eliminate the leak, and repeat the tightness test until the pressure is maintained stable for 30 minutes.

[0060] Then purge the air in the pipeline, keep the nitrogen filling valve 1, the first ball valve 4, and the second ball valve 8 of the shore-based nitrogen station open, open the exhaust ball valve 10-8, and continue to discharge nitrogen until the value of the oxygen concentration detector 10-7 is continuously zero and the value of the dew point meter 10-8 is close to the dew point of nitrogen, confirm that the oxygen in the connecting device is discharged cleanly, and close the exhaust ball valve 10-8.

[0061] Subsequently, the cargo hold air replacement work is carried out. After the pipeline is blown clean, the LNG ship filling pipe valve is opened and nitrogen is added to the liquefied natural gas cargo hold in the LNG ship to replace the air in the liquefied natural gas cargo hold. The temperature, pressure, flow rate, dew point, oxygen content and other values ​​of the nitrogen supplied to the cargo hold during the replacement process are recorded as required.

[0062] If the pipeline is damaged during operation, or the nitrogen flow needs to be adjusted, it can be achieved by controlling the switches of the nitrogen filling valve 1, the first ball valve 4 and the second ball valve 8 of the shore-based nitrogen station.

[0063] After the air replacement in the liquefied natural gas cargo tank is completed, first close the LNG ship filling station valve, then open the exhaust ball valve 10-8, and then close the nitrogen filling valve 1 of the shore-based nitrogen station. After the pressure of the connecting device is balanced with the outside of the pipeline, the connecting device can be removed.

[0064] In the present invention, unless otherwise clearly stipulated and limited, for example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, for ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0065] The above are preferred implementations of the present utility model. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present utility model. These improvements and modifications should also be regarded as the protection scope of the present utility model.

Claims

1. A LNG ship and shore-based nitrogen replacement system, characterized in that: The system from the shore-based nitrogen filling station to the LNG ship includes a shore-based nitrogen filling valve, a concentric reducer, a first connecting pipe, a first ball valve, a first adapter, a nitrogen delivery pipe, a second adapter, a second ball valve, a second connecting pipe and a functional pipe which are sequentially connected to the shore-based nitrogen station.

2. The LNG ship and shore-based nitrogen replacement system according to claim 1, characterized in that: An open-hole blind plate is arranged between the concentric reducer and the first connecting pipe.

3. The LNG ship and shore-based nitrogen replacement system according to claim 1, characterized in that: A through-hole blind flange is also provided between the second connecting pipe and the functional pipe.

4. The LNG ship and shore-based nitrogen replacement system according to claim 1, characterized in that: An LNG ship-side nitrogen filling flange is also provided between the functional pipe and the LNG ship.

5. The LNG ship and shore-based nitrogen replacement system according to claim 1, characterized in that: The concentric reducer is also provided with a first thermometer, a first flowmeter, and a first pressure gauge.

6. The LNG ship and shore-based nitrogen replacement system according to claim 1, characterized in that: The functional pipe is also provided with a second thermometer, a second flow meter, a second pressure gauge and a dew point meter.

7. The LNG ship and shore-based nitrogen replacement system according to claim 6, characterized in that: The functional pipe further includes an oxygen concentration detector and an exhaust ball valve.

8. The LNG ship and shore-based nitrogen replacement system according to claim 3, characterized in that: A first functional pipe flange is arranged at one end of the functional pipe connected to the second connecting pipe, and the first functional pipe flange is adapted to the through-hole blind plate flange. A second functional pipe flange is arranged at the other end of the functional pipe, and the second functional pipe flange is adapted to the nitrogen filling on the LNG ship side.

9. The LNG ship and shore-based nitrogen replacement system according to claim 1, characterized in that: The concentric reducer includes a first diameter end and a second diameter end, the diameter of the first diameter end is smaller than the diameter of the second diameter end, the first diameter end is connected to the shore-based nitrogen filling valve, and the second diameter end is connected to the first connecting pipe.

10. The LNG ship and shore-based nitrogen replacement system according to claim 7, characterized in that: The exhaust ball valve is arranged below the functional pipe, and the opening of the exhaust ball valve faces downward.

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