LNG storage tank pressure reducing device

Abstract

The utility model discloses an LNG (liquefied natural gas) storage tank pressure reducing device, which relates to the technical field of LNG storage tanks and comprises a tank body, a base is arranged at the bottom of the tank body, a circulating pipe communicated with the inside of the tank body is arranged on the side wall of the tank body, a conveying pipe communicated with the inside of the tank body is arranged at the top of the tank body, and a condenser is fixedly mounted at the upper end of the base. By means of the compressor and the condenser, BOG generated in the storage tank can be directly extracted, the BOG enters the condenser to be liquefied after being compressed and heated, the BOG is exhausted through the exhaust pipe to be recycled, resource waste is reduced, meanwhile, a refrigerant is driven by the water pump to enter the condenser and then is conveyed to the spray head through the hose to be sprayed out, and the BOG recovery efficiency is improved. The refrigerant is sprayed to the surface of the storage tank for cooling, so that BOG gas is quickly cooled and partially condensed, the volume and pressure of the BOG gas are reduced, finally, the pressure of the storage tank can be quickly reduced, and the condition that the pressure is quickly increased or is greatly increased can be effectively controlled in time.

Description

Technical Field

[0001] The utility model relates to the technical field of LNG storage tanks, in particular to a pressure reducing device for an LNG storage tank. Background Art

[0002] LNG storage tanks are equipment specially designed for storing liquefied natural gas. They fall into the category of special equipment and are classified as Class III pressure vessels. These tanks are usually made of 06Ni9DR material and undergo a series of rigorous manufacturing and testing processes, including flaw detection, water pressure and air pressure testing, and on-site inspection by the Technical Supervision Bureau to ensure their safety and durability. During use, the pressure in the tank will gradually increase due to the slow infiltration of external heat and the volatilization of light components in LNG. When the pressure approaches the design pressure of the tank, a pressure reduction operation is required to ensure the safety of the tank.

[0003] Reference publication (announcement) number: CN213146073U discloses a LNG storage tank pressure reduction device, which, through the cooperation between the rotating motor, impeller, connecting pipe and other related components, allows LNG with lower temperature from the lower layer of the tank body to be sucked in from the inlet pipe, flows out from the outlet pipe through the connecting pipe, enters the upper layer of LNG, and absorbs the vaporized BOG gas, thereby achieving the effect of pressure reduction, and effectively preventing the impact on the tank body caused by excessive tank pressure. However, in actual use, due to the limitations of pipeline pressure and flow conditions, the problem of pressure increase can only be alleviated to a certain extent, and it is difficult to control the pressure at the connecting pipe. It is difficult to accurately control pressure fluctuations during the flow process, which can easily cause damage to equipment and pipelines, and it is difficult to ensure safe and stable transportation. In view of this, the present application proposes a LNG storage tank pressure reduction device. Utility Model Content

[0004] The purpose of the utility model is to solve the shortcomings of the prior art and to propose a LNG storage tank pressure reduction device.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] An LNG storage tank pressure reduction device includes a tank body, a base is provided at the bottom of the tank body, a circulation pipe communicating with the interior is provided on the side wall of the tank body, a delivery pipe communicating with the interior is provided on the top of the tank body, a condenser is fixedly mounted on the upper end of the base, a door is provided on one side of the condenser via a hinged sealing connection, a plurality of brackets are symmetrically provided on the inner wall of the condenser, a first heat exchange fin and a second heat exchange fin are respectively installed between two of the brackets arranged in opposite positions, and a connecting pipe is provided between the first heat exchange fin and the second heat exchange fin;

[0007] A compressor is fixedly mounted on the top of the condenser, an air intake pipe is connected to one side of the compressor, an end of the air intake pipe away from the compressor is connected to the delivery pipe, the bottom of the compressor is connected to the inside of the condenser through an air outlet pipe, a water pump is fixedly mounted on one side of the condenser, and a hose is connected to the water pump;

[0008] A spray assembly is provided inside the tank body, and the spray assembly includes a bracket, which is fixedly connected to the inner wall of the tank body through a connecting rod, and a plurality of spray heads are installed on the bracket.

[0009] As a further preferred embodiment of the present technical solution, a storage tank is provided inside the tank body, and the bottom of the storage tank is engaged with the upper surface of the base, and the bottom of the delivery pipe is connected to the interior of the storage tank.

[0010] As a further preferred embodiment of the present technical solution, a liquid inlet pipe and an exhaust pipe are respectively connected to the side wall of the condenser, and one end of the liquid inlet pipe away from the condenser extends into the tank body.

[0011] As a further preferred embodiment of the present technical solution, a chamber for the flow of refrigerant is provided inside each of the first heat exchange plate and the second heat exchange plate, and the two chambers are connected to a connecting pipe.

[0012] The liquid inlet pipe is communicated with the inner chamber of the first heat exchange fin, and the water pump is communicated with the inner chamber of the second heat exchange fin through a pipeline.

[0013] As a further preferred embodiment of the present technical solution, one end of the hose away from the water pump extends into the tank body, and the hose is connected to the bracket through and through, and the multiple nozzles are all connected to the hose.

[0014] As a further preferred embodiment of the present technical solution, the multiple nozzles are arranged at equal distances, and the multiple nozzles are all arranged tilted upward.

[0015] The utility model has the following beneficial effects:

[0016] 1. The utility model uses a compressor and a condenser to directly extract the BOG gas generated inside the storage tank during the pressure reduction operation. After compression and temperature increase, the BOG gas enters the condenser for liquefaction and is discharged through the exhaust pipe to recover the BOG gas, thereby reducing resource waste. At the same time, the water pump drives the refrigerant into the condenser, which is then transported to the nozzle by a hose and sprayed onto the surface of the storage tank for cooling. The BOG gas is quickly cooled and partially condensed, thereby reducing its volume and pressure. Ultimately, the tank pressure can be quickly reduced. In the case of a rapid or large pressure increase, effective control can be carried out in a timely manner.

[0017] 2. The utility model transports the refrigerant into the tank through a circulation pipe. The refrigerant contacts the bottom of the tank to initially cool it down, reducing the volatilization and release of BOG gas in the tank. The refrigerant is then pumped into the first and second heat exchange plates by a water pump, where it contacts the compressed and heated gas to liquefy it. No other energy is required to create a cold source for the condenser. The refrigerant is finally transported to the nozzle for spraying to further cool and reduce the pressure of the tank, thereby improving energy utilization and reducing energy consumption of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the main structure of an LNG storage tank pressure reduction device proposed in the utility model;

[0019] Figure 2 This is a partial cross-sectional structural diagram of an LNG storage tank pressure reduction device proposed in the utility model;

[0020] Figure 3 This is a structural diagram of the compressor and condenser of an LNG storage tank pressure reduction device proposed in the utility model;

[0021] Figure 4 This is a schematic diagram of the upper cross-sectional structure of an LNG storage tank pressure reduction device proposed in the present utility model.

[0022] In the figure: 1. Tank body; 11. Base; 12. Circulation pipe; 13. Delivery pipe; 2. Condenser; 21. Box door; 22. Bracket; 23. First heat exchanger; 24. Second heat exchanger; 25. Connecting pipe; 26. Liquid inlet pipe; 27. Exhaust pipe; 3. Compressor; 31. Exhaust pipe; 32. Intake pipe; 4. Water pump; 41. Hose; 5. Spray assembly; 51. Bracket; 52. Connecting rod; 53. Nozzle. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0024] The utility model provides a technical solution: Figure 1 As shown, an LNG storage tank pressure reduction device includes a tank body 1, a base 11 is provided at the bottom of the tank body 1, a circulation pipe 12 is provided on the side wall of the tank body 1 and is connected to the interior thereof, a delivery pipe 13 is provided on the top of the tank body 1 and is connected to the interior thereof, a storage tank is provided inside the tank body 1, and the bottom of the storage tank is snap-fitted to the upper surface of the base 11 to improve the stability of the storage tank when placed, and the bottom of the delivery pipe 13 is connected to the interior of the storage tank. Further, as shown Figure 2As shown, the storage tank is set inside the tank body 1. After the refrigerant is added to the tank body 1 through the circulation pipe 12, the refrigerant gathers at the bottom of the tank body 1, which can make the storage tank partially immersed in the refrigerant, and can preliminarily reduce the temperature of the LNG inside the storage tank and reduce the volatilization of BOG gas. At the same time, under the closed shielding of the external tank body 1, the overall temperature inside the tank body 1 is reduced, the heat exchange with the outside air is reduced, and the thermal insulation performance of the storage tank is improved, thereby alleviating the internal pressure of the storage tank.

[0025] like Figure 3 As shown, the condenser 2 is fixedly installed on the upper end of the base 11, and a door 21 is provided on one side of the condenser 2 through a hinged sealing connection. A plurality of brackets 22 are symmetrically provided on the inner wall of the condenser 2. After a period of use, the first heat exchange fin 23 and the second heat exchange fin 24 can be directly cleaned or replaced by opening the door 21 to ensure that they maintain a good heat exchange rate. The first heat exchange fin 23 and the second heat exchange fin 24 are respectively installed between the two brackets 22, and a connecting pipe 25 is provided between the first heat exchange fin 23 and the second heat exchange fin 24. The interiors of the first heat exchange fin 23 and the second heat exchange fin 24 are both open. A chamber for the flow of refrigerant is provided, and the two chambers are connected to the connecting pipe 25. A liquid inlet pipe 26 and an exhaust pipe 27 are respectively connected on the side walls of the condenser 2. The liquid inlet pipe 26 extends into the tank body 1 at one end away from the condenser 2. The liquid inlet pipe 26 is connected to the internal chamber of the first heat exchange plate 23, and the water pump 4 is connected to the internal chamber of the second heat exchange plate 24 through a pipeline. Furthermore, after the water pump 4 draws the refrigerant inside the tank body 1 into the condenser 2 through the liquid inlet pipe 26, the refrigerant will flow from the right side of the first heat exchange plate 23 to the left side and enter the second heat exchange plate 24, so as to adjust the heat exchange efficiency of the condenser 2 with a stable flow direction.

[0026] A compressor 3 is fixedly mounted on the top of the condenser 2. An intake pipe 32 is provided on one side of the compressor 3. The end of the intake pipe 32 away from the compressor 3 is connected to the delivery pipe 13. The bottom of the compressor 3 is connected to the interior of the condenser 2 through the outlet pipe 31. The compressor 3 extracts the BOG volatilized in the delivery pipe 13 and pressurizes it. The heated gas is then transported to the condenser 2 for cooling, so that its temperature is reduced to below the liquefaction temperature. The condensed liquefied natural gas is transported to other places for storage or use, which can effectively improve energy utilization and avoid the waste of natural gas caused by direct emptying. A water pump 4 is fixedly mounted on one side of the condenser 2. A hose 41 is provided on the water pump 4. The end of the hose 41 away from the water pump 4 extends into the tank body 1, and the hose 41 is connected to the bracket 51. The liquid inlet end of the water pump 4 is connected to the second heat exchange fin 24. The refrigerant is finally transported through the hose 41 and finally sprayed onto the surface of the tank by the nozzle 53, so that the temperature of the LNG in the tank is further reduced and the pressure inside the tank is prevented from increasing.

[0027] like Figure 4As shown, a spray assembly 5 is provided inside the tank body 1, and the spray assembly 5 includes a bracket 51, which is fixedly connected to the inner wall of the tank body 1 through a connecting rod 52. A plurality of nozzles 53 are installed on the bracket 51, and the plurality of nozzles 53 are connected to the hose 41. The plurality of nozzles 53 are arranged at equal distances, and the plurality of nozzles 53 are tilted upward. It should be noted that when the plurality of tilted nozzles 53 are sprayed again, the refrigerant can be sprayed onto the top of the storage tank and flow down along the surface of the storage tank, which can effectively increase the contact time between the refrigerant and the surface of the storage tank and provide a better cooling effect. Furthermore, the plurality of nozzles 53 spray the surface of the storage tank at the same time, and cooperate with the work of the condenser 2 and the compressor 3 to quickly reduce the temperature of the storage tank. Special situations such as excessive pressure can be quickly handled to avoid the occurrence of emergencies.

[0028] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A LNG storage tank pressure reduction device, comprising a tank body (1), characterized in that: The bottom of the tank body (1) is provided with a base (11), a circulation pipe (12) communicating with the interior of the tank body (1) is provided on the side wall of the tank body (1), and a delivery pipe (13) communicating with the interior of the tank body (1) is provided on the top of the tank body (1). A condenser (2) is fixedly mounted on the upper end of the base (11), and a door (21) is provided on one side of the condenser (2) through a hinged sealing connection. A plurality of brackets (22) are symmetrically arranged on the inner wall of the condenser (2), and a first heat exchange fin (23) and a second heat exchange fin (24) are respectively installed between two brackets (22) arranged in opposite positions, and a connecting pipe (25) is provided between the first heat exchange fin (23) and the second heat exchange fin (24); A compressor (3) is fixedly mounted on the top of the condenser (2); an air intake pipe (32) is connected to one side of the compressor (3); an end of the air intake pipe (32) away from the compressor (3) is connected to the delivery pipe (13); the bottom of the compressor (3) is connected to the interior of the condenser (2) through an air outlet pipe (31); a water pump (4) is fixedly mounted on one side of the condenser (2); and a hose (41) is connected to the water pump (4); A spray assembly (5) is provided inside the tank body (1), and the spray assembly (5) comprises a bracket (51). The bracket (51) is fixedly connected to the inner wall of the tank body (1) via a connecting rod (52), and a plurality of spray heads (53) are mounted on the bracket (51).

2. The LNG storage tank pressure reduction device according to claim 1, characterized in that: A storage tank is provided inside the tank body (1), and the bottom of the storage tank is engaged with the upper surface of the base (11), and the bottom of the delivery pipe (13) is communicated with the inside of the storage tank.

3. The LNG storage tank pressure reduction device according to claim 1, characterized in that: A liquid inlet pipe (26) and an exhaust pipe (27) are respectively connected on the side wall of the condenser (2), and the end of the liquid inlet pipe (26) away from the condenser (2) extends into the tank body (1).

4. The LNG storage tank pressure reduction device according to claim 3, characterized in that: The first heat exchange plate (23) and the second heat exchange plate (24) are both provided with a chamber for the flow of refrigerant, and the two chambers are connected to a connecting pipe (25). The liquid inlet pipe (26) is in communication with the inner chamber of the first heat exchange plate (23), and the water pump (4) is in communication with the inner chamber of the second heat exchange plate (24) through a pipeline.

5. The LNG storage tank pressure reduction device according to claim 1, characterized in that: One end of the hose (41) away from the water pump (4) extends into the tank body (1), and the hose (41) is connected to the bracket (51) through and through, and the multiple nozzles (53) are all connected to the hose (41).

6. The LNG storage tank pressure reduction device according to claim 1, characterized in that: The multiple nozzles (53) are arranged at equal distances, and the multiple nozzles (53) are all arranged tilted upward.

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