BOG recovery device

Abstract

The utility model relates to the technical field of BOG recovery, in particular to a BOG recovery device. The BOG recovery device comprises a heat exchange tank, a spiral gas guide pipe is fixedly installed in the heat exchange tank through a support, a gas inlet pipe is fixedly installed on a pipe head at the top of the spiral gas guide pipe, an internal thread connector is fixedly installed on the gas inlet pipe, and an exhaust pipe is fixedly installed on a pipe head at the bottom of the spiral gas guide pipe. And an air stagnation component is mounted on the exhaust pipe. According to the BOG recovery device provided by the utility model, when the BOG air pressure borne by the piston column is smaller than the elastic force of the spring, the piston column abuts against the limiting ring under the elastic force action of the spring, and the exhaust port is sealed by the piston column at the moment, so that the retention time of BOG in the spiral air guide pipe is greatly prolonged, and the BOG is gathered in the spiral air guide pipe for continuous heat exchange and cooling; when the air pressure discharged into the spiral air guide pipe is larger than the elastic force of the spring, the piston column presses the spring downwards to open the exhaust port, BOG can be discharged out of the butt joint pipe, and the short flow phenomenon easily occurring when the BOG output fluctuates is eliminated.

Description

Technical Field

[0001] This utility model relates to the field of BOG recycling technology, and in particular to a BOG recycling device. Background Technology

[0002] Boiling gas (BOG) is the gas produced after LNG evaporates and vaporizes. If it is not discharged in time, it will cause the pressure in the storage tank to rise. Since the pressure inside the storage tank will increase after BOG is formed, and the storage tank cannot completely isolate the external temperature, releasing BOG to the outside will pollute the space, thus causing the problem of BOG not being recovered and being directly discharged to pollute the environment.

[0003] Currently, most BOG recovery devices commonly used in the industry employ simple heat exchange tube structures to cool and liquefy BOG. ​​The heat exchange tubes in traditional devices are mostly straight or simple U-shaped structures. The residence time of BOG in the tubes is short and the contact area with the coolant is limited, resulting in insufficient cooling of BOG. ​​Some BOG cannot be effectively pre-cooled, making it difficult to liquefy later. Consequently, the recovery efficiency cannot meet actual needs. Furthermore, when BOG is directly discharged into the recovery tank after heat exchange, if there are fluctuations in the amount of BOG (such as a sudden rise or fall in tank pressure), phenomena such as "short flow" are likely to occur. When the BOG pressure is too low, there is also a risk that the gas in the recovery tank may flow back into the heat exchange system.

[0004] Therefore, it is necessary to provide a new BOG recycling device to solve the above-mentioned technical problems. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a BOG recycling device.

[0006] The BOG recovery device provided by this utility model includes a heat exchange tank. An inlet pipe for liquid inlet and a drain pipe for liquid outlet are fixedly installed on the heat exchange tank. A spiral air guide pipe is fixedly installed inside the heat exchange tank by a bracket. An air inlet pipe is fixedly installed at the top of the spiral air guide pipe, and an internal threaded connector is fixedly installed on the air inlet pipe. An exhaust pipe is fixedly installed at the bottom of the spiral air guide pipe, and the bottom of the exhaust pipe has a sealed structure. A connecting pipe is fixedly installed on the side wall of the exhaust pipe, and an exhaust port is provided at the connection between the connecting pipe and the exhaust pipe.

[0007] The exhaust pipe is equipped with a gas-blocking component for sealing the exhaust port. The gas-blocking component includes a piston rod, which is installed inside the connecting pipe and slidably connected to the connecting pipe. A spring is fixedly installed at the bottom of the piston rod, and the other end of the spring is fixedly connected to the bottom of the exhaust pipe.

[0008] Preferably, the gas stagnation component further includes a limiting ring, which is fixedly installed inside the exhaust pipe and located above the exhaust port.

[0009] Preferably, the air inlet pipe extends from the top of the heat exchange tank, the exhaust pipe extends from the bottom of the heat exchange tank, and the exhaust port is located outside the heat exchange tank.

[0010] Preferably, an inner edge ring is fixedly installed in the inner cavity of the internal threaded connector, and the inner edge ring is located at the root of the internal thread, and a filter screen is placed on the inner edge ring.

[0011] Preferably, a ring of heat dissipation fins is fixedly embedded on the outer wall of the heat exchange tank.

[0012] Preferably, the inlet pipe is close to the inner top wall of the heat exchange tank, and the outlet pipe is close to the inner bottom wall of the heat exchange tank.

[0013] Compared with related technologies, the BOG recycling device provided by this utility model has the following advantages:

[0014] In this invention, when the BOG pressure on the piston rod is less than the spring force, the piston rod abuts against the limiting ring under the spring force, sealing the exhaust port. This significantly increases the residence time of BOG in the spiral air guide tube, allowing BOG to accumulate and continuously exchange heat and cool down. When the air pressure in the spiral air guide tube exceeds the spring force, the piston rod depresses the spring, exposing the exhaust port and allowing BOG to be discharged from the connecting pipe. When the air pressure in the spiral air guide tube again falls below the spring force, the piston rod returns to its original position, allowing subsequent BOG to remain in the spiral air guide tube for heat exchange and cooling. This also eliminates the short-flow phenomenon that easily occurs when BOG generation fluctuates. Attached Figure Description

[0015] Figure 1 A schematic diagram of a preferred embodiment of the BOG recycling device provided by this utility model;

[0016] Figure 2 A schematic diagram showing the connection between the intake pipe, the spiral air guide pipe and the exhaust pipe provided by this utility model;

[0017] Figure 3 for Figure 2 A schematic diagram of the cross-section of the exhaust pipe shown;

[0018] Figure 4 for Figure 1 The diagram shows the structure of the filter screen.

[0019] The following are the labels in the diagram: 1. Heat exchange tank; 11. Liquid inlet pipe; 12. Liquid outlet pipe; 2. Spiral air guide pipe; 3. Air inlet pipe; 31. Internal threaded joint; 32. Inner edge ring; 4. Exhaust pipe; 5. Connecting pipe; 5a. Exhaust port; 6. Air stagnation component; 61. Piston column; 62. Spring; 63. Limiting ring; 7. Filter screen; 8. Heat dissipation fins. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0021] The specific implementation of this utility model will be described in detail below with reference to specific embodiments.

[0022] Please see Figures 1 to 4 This utility model provides a BOG recovery device, which includes a heat exchange tank 1, a spiral air guide pipe 2, and a gas stagnation component 6.

[0023] In the embodiments of this utility model, please refer to Figures 1 to 4 The heat exchange tank 1 is fixedly equipped with an inlet pipe 11 for liquid inlet and a drain pipe 12 for liquid outlet. The inlet pipe 11 is close to the inner top wall of the heat exchange tank 1, and the drain pipe 12 is close to the inner bottom wall of the heat exchange tank 1, so that the coolant after heat exchange at the bottom can be quickly discharged.

[0024] A spiral air guide pipe 2 is fixedly installed inside the heat exchange tank 1 by a bracket. An air inlet pipe 3 is fixedly installed at the top of the spiral air guide pipe 2, and an internal threaded connector 31 is fixedly installed on the air inlet pipe 3. An exhaust pipe 4 is fixedly installed at the bottom of the spiral air guide pipe 2, and the bottom of the exhaust pipe 4 is a sealed structure. The air inlet pipe 3 extends out of the top of the heat exchange tank 1, and the exhaust pipe 4 extends out of the bottom of the heat exchange tank 1. The exhaust port 5a is located outside the heat exchange tank 1. A connecting pipe 5 is fixedly installed on the side wall of the exhaust pipe 4, and an exhaust port 5a is provided at the connection between the connecting pipe 5 and the exhaust pipe 4. An inner edge ring 32 is fixedly installed in the inner cavity of the internal threaded connector 31, and the inner edge ring 32 is located at the root of the internal thread. A filter screen 7 is placed on the inner edge ring 32.

[0025] It should be noted that the filter screen 7 is placed on the inner edge ring 32, and then the LNG storage tank pressure relief pipe is threadedly fixed to the internal threaded connector 31 via a threaded quick-connect coupling. In this way, the filter screen 7 is firmly pressed into the internal threaded connector 31 by the threaded quick-connect coupling. The connecting pipe 5 is connected to the inlet of the BOG recovery tank. When the LNG storage tank produces enough BOG, the resulting high pressure forces the BOG through the internal threaded connector 31 into the inlet pipe 3. The filter screen 7 can filter the BOG, reducing impurities generated when the gas flows through the pipe. Subsequently, the BOG enters the spiral gas guide pipe 2 inside the heat exchange tank 1 through the inlet pipe 3.

[0026] Connect the inlet pipe 11 to the coolant supply pipe, then turn on the coolant pump to allow coolant to enter the heat exchange tank 1 through the inlet pipe 11. Connect the drain pipe 12 to the recovery tank input pipe so that the heat-exchanged liquid can enter the recovery tank. Because the air inlet pipe 3 extends from the top of the heat exchange tank 1 and the exhaust pipe 4 extends from the bottom of the heat exchange tank 1, the coolant initially enters the heat exchange tank 1 and is located on the liquid surface, while the coolant at the bottom of the heat exchange tank 1 that has undergone longer heat exchange is discharged through the drain pipe 12. The designed spiral air guide pipe 2 greatly increases the travel path of the BOG within the heat exchange tank 1, thereby effectively and rapidly cooling the BOG.

[0027] Among them, a ring of heat dissipation fins 8 are fixedly embedded on the outer wall of the heat exchange tank 1. The heat dissipation fins 8 increase the contact area between the heat exchange tank 1 and the outside air, accelerate the dissipation of heat from the coolant in the heat exchange tank 1, and avoid the decrease in heat exchange efficiency caused by the continuous rise in coolant temperature.

[0028] In addition, a check valve can be installed on the pressure relief pipe of the LNG storage tank to prevent BOG backflow.

[0029] In the embodiments of this utility model, please refer to Figures 1 to 4 The exhaust pipe 4 is equipped with a gas blocking component 6 for blocking the exhaust port 5a. The gas blocking component 6 includes a piston rod 61, which is installed in the connecting pipe 5 and slidably connected to the connecting pipe 5. A spring 62 is fixedly installed at the bottom of the piston rod 61, and the other end of the spring 62 is fixedly connected to the bottom of the exhaust pipe 4. The gas blocking component 6 also includes a limiting ring 63, which is fixedly installed in the exhaust pipe 4 and is located above the exhaust port 5a.

[0030] It should be noted that when the BOG pressure acting on the piston rod 61 is less than the spring force of the spring 62, the piston rod 61 abuts against the limiting ring 63 under the spring force of the spring 62. At this time, the piston rod 61 seals the exhaust port 5a, thus greatly increasing the residence time of BOG in the spiral air guide tube 2, allowing BOG to accumulate in the spiral air guide tube 2 for continuous heat exchange and cooling. When the air pressure discharged into the spiral air guide tube 2 is greater than the spring force of the spring 62, the piston rod 61 presses down on the spring 62, exposing the exhaust port 5a, allowing BOG to be discharged from the connecting pipe 5. When the air pressure in the spiral air guide tube 2 is again less than the spring force of the spring 62, the piston rod 61 returns to its original position, allowing subsequent BOG to remain in the spiral air guide tube 2 for heat exchange and cooling, while also eliminating short-flow phenomena that are prone to occur when BOG generation fluctuates.

[0031] The circuits and controls involved in this utility model are all existing technologies, and will not be described in detail here.

[0032] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A BOG recovery device comprising a heat exchange tank (1), a liquid inlet pipe (11) and a liquid outlet pipe (12) are fixedly installed on the heat exchange tank (1), characterized in that: a spiral air guide pipe (2) is fixedly installed in the heat exchange tank (1) through a support, a pipe head at the top of the spiral air guide pipe (2) is fixedly installed with an air inlet pipe (3), an internal thread joint (31) is fixedly installed on the air inlet pipe (3), a pipe head at the bottom of the spiral air guide pipe (2) is fixedly installed with an air outlet pipe (4), the bottom of the air outlet pipe (4) is a sealed structure, a butt joint pipe (5) is fixedly installed on the side wall of the air outlet pipe (4), and an air outlet (5a) is arranged at the communication part of the butt joint pipe (5) and the air outlet pipe (4); an air retention component (6) is installed on the air outlet pipe (4) for blocking the air outlet (5a), the air retention component (6) comprises a piston column (61), the piston column (61) is installed in the butt joint pipe (5) and is in sliding connection with the butt joint pipe (5), a spring (62) is fixedly installed at the bottom of the piston column (61), and the other end of the spring (62) is fixedly connected with the bottom of the air outlet pipe (4).

2. The BOG recovery apparatus according to claim 1, characterized in that, The air retention component (6) further comprises a limiting ring (63), the limiting ring (63) is fixedly installed in the air outlet pipe (4), and the limiting ring (63) is located above the air outlet (5a).

3. The BOG recovery apparatus according to claim 1 or 2, characterized in that, The air inlet pipe (3) extends out of the top of the heat exchange tank (1), the air outlet pipe (4) extends out of the bottom of the heat exchange tank (1), and the air outlet (5a) is located outside the heat exchange tank (1).

4. The BOG recovery apparatus according to claim 3, characterized in that, An inner edge ring (32) is fixedly installed in the joint inner cavity of the internal thread joint (31), and the inner edge ring (32) is located at the root of the internal thread, and a filter screen (7) is placed on the inner edge ring (32).

5. The BOG recovery apparatus according to claim 1 or 2 or 4, characterized in that, A plurality of annularly distributed heat dissipation fins (8) are fixedly embedded on the outer wall of the heat exchange tank (1).

6. The BOG recovery apparatus of claim 1, wherein, The liquid inlet pipe (11) is close to the inner top wall of the heat exchange tank (1), and the liquid outlet pipe (12) is close to the inner bottom wall of the heat exchange tank (1).

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