Unloading device of low-temperature liquid tank car

Abstract

The unloading device comprises a tank car mechanism, a tank mechanism and an unloading mechanism, the tank car mechanism comprises a car body, a car body gas phase connector and a car body liquid phase connector, and the car body gas phase connector and the car body liquid phase connector are arranged on the car body. The tank mechanism comprises a tank body, and a tank body gas phase interface and a tank body liquid phase interface which are arranged on the tank body; the unloading mechanism is communicated with the vehicle body gas phase connector, the unloading mechanism is communicated with the tank body gas phase connector, and the vehicle body liquid phase connector is communicated with the tank body liquid phase connector. Under the action of the pressure difference, liquefied natural gas in the vehicle body is transferred into the tank body, the tank body does not need to be subjected to pressure relief and diffusion, after unloading is finished, the gaseous natural gas in the vehicle body is transferred into the tank body through the unloading mechanism, the natural gas can be collected completely, and the unloading loss of the natural gas is reduced to the maximum extent.

Description

Technical Field

[0001] The utility model relates to the field of natural gas storage and transportation, and particularly relates to a truck unloading device for cryogenic liquids. Background Art

[0002] Compressed natural gas trucks are widely used in the field of compressed natural gas storage and transportation. During the unloading process of compressed natural gas trucks, a compressed natural gas unloading device is required to unload the compressed natural gas in the compressed natural gas truck into a compressed natural gas tank.

[0003] In related technologies, a liquefied natural gas filling and unloading structure is proposed, which includes a liquefied natural gas storage tank, a liquefied natural gas tank connected to the liquefied natural gas storage tank, a liquefied natural gas submersible pump installed between the liquefied natural gas storage tank and the liquefied natural gas tank, a return gas valve and a liquid outlet valve installed on the pipeline between the liquefied natural gas storage tank and the liquefied natural gas submersible pump, an upper liquid inlet valve and a lower liquid inlet valve, a check valve installed on the pipeline between the lower liquid inlet valve and the liquefied natural gas tank, a liquid phase hose and a tank upper liquid inlet valve, a tank lower liquid inlet valve, a pressurized liquid phase valve, a pressurized gas phase hose, a pressurized vaporizer, and a pressurized liquid phase hose are also installed on the pipeline of the liquefied natural gas tank.

[0004] Aiming at the above-mentioned related technologies, there are the following defects: on the one hand, after unloading, the residual pressure in the truck is generally between 0.3 MPa and 0.5 MPa, resulting in the phenomenon that the residual liquid cannot be unloaded completely, causing waste. On the other hand, the operation of the pressurized vaporizer and the submersible pump causes the temperature of the tank to rise, and the generated natural gas vapor causes the pressure of the tank to rise. When the pressure reaches the critical value, the safety valve automatically opens to relieve pressure, resulting in waste of natural gas. Content of the Utility Model

[0005] The purpose of the present utility model is to overcome the above-mentioned technical deficiencies, and propose a truck unloading device for cryogenic liquids, which solves the technical problems that the residual liquid in the vehicle body cannot be unloaded completely, causing waste; and the gaseous natural gas in the tank is easy to overflow, causing waste in the prior art.

[0006] To achieve the above technical purpose, the technical solution of the present utility model provides a truck unloading device for cryogenic liquids, including a truck mechanism, where the truck mechanism includes a vehicle body and a vehicle body gas phase interface and a vehicle body liquid phase interface provided on the vehicle body;

[0007] A tank mechanism, where the tank mechanism includes a tank body and a tank body gas phase interface and a tank body liquid phase interface provided on the tank body; and,

[0008] An unloading mechanism, where the unloading mechanism is connected to the vehicle body gas phase interface, the unloading mechanism is connected to the tank body gas phase interface, and the vehicle body liquid phase interface is connected to the tank body liquid phase interface.

[0009] In some embodiments, the unloader mechanism includes a regenerator, a compressor, an air cooler, and an oil-gas separator. The compressor is provided with a first air inlet, a second air inlet, and an exhaust port. The first outlet of the regenerator is communicated with the vehicle body gas-phase interface, the first inlet of the regenerator is communicated with the tank body gas-phase interface, the second outlet of the regenerator is communicated with the first air inlet of the compressor, the exhaust port of the compressor is communicated with the inlet of the air cooler, the outlet of the air cooler is communicated with the inlet of the oil-gas separator, the first outlet of the oil-gas separator is communicated with the second inlet of the regenerator, and the second outlet of the oil-gas separator is communicated with the second air inlet of the compressor.

[0010] In some embodiments, a first tank body gas pipe is provided between the tank body gas-phase interface and the first inlet of the regenerator, and a tank body gas-phase valve and a fourth valve are provided on the first tank body gas pipe.

[0011] In some embodiments, a first vehicle body gas pipe is provided between the first outlet of the regenerator and the vehicle body gas-phase interface, and a second valve and a vehicle body gas-phase valve are provided on the first vehicle body gas pipe.

[0012] In some embodiments, a liquid flow pipe is provided between the vehicle body liquid-phase interface and the tank body liquid-phase interface, and a vehicle body liquid-phase valve and a tank body liquid-phase valve are provided on the liquid flow pipe.

[0013] In some embodiments, the first vehicle body gas pipe is communicated with the first inlet of the regenerator, and the exhaust port is communicated with the liquid flow pipe.

[0014] In some embodiments, a second vehicle body gas pipe is provided between the first vehicle body gas pipe and the first inlet of the regenerator, and a first valve is provided on the second vehicle body gas pipe.

[0015] In some embodiments, a second tank body gas pipe is provided between the first outlet of the regenerator and the liquid flow pipe, and a third valve and a fifth valve are provided on the second tank body gas pipe.

[0016] In some embodiments, the second tank body gas pipe is communicated with the first tank body gas pipe.

[0017] In some embodiments, the compressor is a skid-mounted compressor.

[0018] Compared with the prior art, the beneficial effects of the present utility model include: under the action of the unloader mechanism, the gaseous natural gas in the tank body is transferred to the vehicle body, the pressure in the vehicle body increases, and the pressure in the tank body decreases. Under the action of the pressure difference, the liquid natural gas in the vehicle body is transferred to the tank body, and there is no need to depressurize and release the tank body. After the unloading is completed, the gaseous natural gas in the vehicle body is transferred to the tank body through the unloader mechanism, achieving full recovery and minimizing the unloading loss of natural gas. Description of the Drawings

[0019] Figure 1 is the overall structural schematic diagram of the unloading device provided by the present utility model;

[0020] Figure 2 is the schematic diagram of the unloading process provided by the present utility model;

[0021] Figure 3 is the schematic diagram of the process of recovering the residual pressure of the car body to the liquid phase of the tank body provided by the present utility model;

[0022] Figure 4 is the schematic diagram of the process of recovering the residual pressure of the car body to the gas phase of the tank body provided by the present utility model.

[0023] Explanation of reference numerals in the drawings:

[0024] 1, tank truck mechanism; 11, car body; 12, car body gas phase interface; 13, car body liquid phase interface; 2, tank mechanism; 21, tank body; 22, tank body gas phase interface; 23, tank body liquid phase interface; 3, unloading mechanism; 31, compressor; 311, first air inlet; 312, second air inlet; 313, exhaust port; 32, regenerator; 321, first inlet; 322, second inlet; 323, first outlet; 324, second outlet; 33, air cooler; 331, oil and gas separator; 34, first tank body gas pipe; 35, tank body gas phase valve; 36, fourth valve; 37, first car body gas pipe; 38, second valve; 39, car body gas phase valve; 4, liquid flow pipe; 41, car body liquid phase valve; 42, tank body liquid phase valve; 5, second car body gas pipe; 51, first valve; 6, second tank body gas pipe; 61, third valve; 62, fifth valve. Detailed implementation manners

[0025] In order to make the purpose, technical solutions and advantages of the present 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 only used to explain the present utility model and are not used to limit the present utility model.

[0026] The present utility model provides an unloading device for a cryogenic liquid tank truck, and its structure is as shown in Figure 1 - Figure 4 and includes a tank truck mechanism 1, a tank mechanism 2 and an unloading mechanism 3.

[0027] The tank truck mechanism 1 includes a car body 11 and a car body 11 gas phase interface and a car body 11 liquid phase interface provided on the car body 11.

[0028] The tank mechanism 2 includes a tank body 21 and a tank body 21 gas phase interface and a tank body 21 liquid phase interface provided on the tank body 21.

[0029] The unloading mechanism 3 is connected to the gas-phase interface of the vehicle body 11, the unloading mechanism 3 is connected to the gas-phase interface of the tank body 21, and the liquid-phase interface of the vehicle body 11 is connected to the liquid-phase interface of the tank body 21.

[0030] During use, when unloading, the gas-phase interface of the tank body 21 is connected to the unloading mechanism 3, the unloading mechanism 3 is then connected to the gas-phase interface of the vehicle body 11, the liquid-phase interface of the tank body 21 is connected to the liquid-phase interface of the vehicle body 11, and the unloading mechanism 3 is started to transfer the gaseous natural gas in the tank body 21 into the vehicle body 11. The pressure of the gas in the vehicle body 11 increases, and the pressure in the tank body 21 decreases. Under the action of the pressure difference, the liquid natural gas in the vehicle body 11 is transferred into the tank body 21. The pressure difference is used for unloading instead of a submersible pump, and there is no need for the vehicle body 11 to self-boost, and there is no need to vent the pressure of the tank body 21. After the unloading is completed, the gaseous natural gas in the vehicle body 11 is pumped back into the tank body 21, the pressure in the vehicle body 11 can be unloaded to below 0.15 MP, and the remaining liquid is unloaded completely, minimizing the unloading loss.

[0031] In the present utility model, under the action of the unloading mechanism 3, the gaseous natural gas in the tank body 21 is transferred into the vehicle body 11, the pressure in the vehicle body 11 increases, and the pressure in the tank body 21 decreases. Under the action of the pressure difference, the liquid natural gas in the vehicle body 11 is transferred into the tank body 21. There is no need to vent the pressure of the tank body 21. After the unloading is completed, under the action of the unloading mechanism 3, the gaseous natural gas in the vehicle body 11 is transferred into the tank body 21, and the pressure in the vehicle body 11 decreases, achieving maximum recovery and minimizing the unloading loss of natural gas.

[0032] In order to transfer the liquid natural gas in the vehicle body 11 into the tank body 21, please refer to Figure 1 In a preferred embodiment, the unloading mechanism 3 includes a regenerator 32, a compressor 31, an air cooler 33, and an oil-gas separator 331. The compressor 31 is provided with a first intake port 311, a second intake port 312, and an exhaust port 313. The first outlet 323 of the regenerator 32 is connected to the gas-phase interface of the vehicle body 11, the first inlet 321 of the regenerator 32 is connected to the gas-phase interface of the tank body 21, the second outlet 324 of the regenerator 32 is connected to the first intake port 311 of the compressor 31, the exhaust port 313 of the compressor 31 is connected to the inlet of the air cooler 33, the outlet of the air cooler 33 is connected to the inlet of the oil-gas separator 331, the first outlet 323 of the oil-gas separator 331 is connected to the second inlet 322 of the regenerator 32, and the second outlet 324 of the oil-gas separator 331 is connected to the second intake port 312 of the compressor 31.

[0033] During use, the regenerator 32, compressor 31, air cooler 33, and oil-gas separator 331 are started. Under the driving force of the compressor 31, the low-temperature gaseous natural gas in the tank body 21 sequentially passes through the gas-phase interface of the tank body 21, regenerator 32, first air inlet 311, compressor 31, exhaust port 313, air cooler 33, oil-gas separator 331, regenerator 32, and the gas-phase interface of the vehicle body 11 and then enters the vehicle body 11.

[0034] The specific steps are as follows. First, after the low-temperature gaseous natural gas in the tank body 21 enters the regenerator 32, under the action of the regenerator 32, the low-temperature gaseous natural gas is heated to the normal temperature state. Then, the normal-temperature gaseous natural gas in the regenerator 32 enters the compressor 31, and the normal-temperature gaseous natural gas is compressed. Then, the normal-temperature gaseous natural gas in the compressor 31 enters the air cooler 33, and the normal-temperature gaseous natural gas is converted back into low-temperature gaseous natural gas again. During the cooling process, a small amount of the low-temperature gaseous natural gas may liquefy and be converted into low-temperature liquid natural gas.

[0035] Then, under the action of the compressor 31, the low-temperature gaseous natural gas in the air cooler 33 enters the oil-gas separator 331. The oil-gas separator 331 completely separates the small amount of low-temperature liquid natural gas doped in the low-temperature gaseous natural gas. The small amount of low-temperature liquid natural gas in the oil-gas separator 331 flows back into the compressor 31 again for recycling.

[0036] Then, the low-temperature gaseous natural gas in the oil-gas separator 331 enters the regenerator 32 again, and the regenerator 32 cools the low-temperature gaseous natural gas again. Finally, the low-temperature gaseous natural gas enters the vehicle body 11. When the pressure in the vehicle body 11 is 0.2 MPa higher than the pressure in the tank body 21, under the action of the pressure difference, the liquid natural gas in the vehicle body 11 sequentially passes through the liquid-phase interface of the vehicle body 11 and the liquid-phase interface of the tank body 21 and then enters the tank body 21.

[0037] To transfer the gaseous natural gas in the tank body 21 to the regenerator 32, please refer to Figure 2 , in a preferred embodiment, a first tank body 21 gas pipe is provided between the gas-phase interface of the tank body 21 and the first inlet 321 of the regenerator 32. A tank body 21 gas valve and a fourth valve 36 are provided on the first tank body 21 gas pipe.

[0038] During use, the tank body 21 gas valve and the fourth valve 36 are opened, and the gaseous natural gas in the tank body 21 sequentially passes through the gas-phase interface of the tank body 21 and the first tank body 21 gas pipe and then reaches the regenerator 32.

[0039] To transfer the gaseous natural gas at the regenerator 32 to the vehicle body 11, please refer to Figure 2, in a preferred embodiment, a first vehicle body 11 gas pipe is provided between the first outlet 323 of the regenerator 32 and the gas-phase interface of the vehicle body 11, and a second valve 38 and a vehicle body 11 gas-phase valve are provided on the first vehicle body 11 gas pipe.

[0040] During use, open the second valve 38 and the vehicle body 11 gas-phase valve, and the gaseous natural gas in the regenerator 32 enters the vehicle body 11 after passing through the first vehicle body 11 gas pipe and the gas-phase interface of the vehicle body 11 in sequence.

[0041] In order to transfer the liquefied natural gas in the vehicle body 11 to the tank 21, please refer to Figure 2 , in a preferred embodiment, a liquid flow pipe 4 is provided between the liquid-phase interface of the vehicle body 11 and the liquid-phase interface of the tank 21, and a vehicle body 11 liquid-phase valve and a tank 21 liquid-phase valve are provided on the liquid flow pipe 4.

[0042] During use, when the pressure in the vehicle body 11 is 0.2 MPa higher than the pressure in the tank 21, open the vehicle body 11 liquid-phase valve and the tank 21 liquid-phase valve, and the liquefied natural gas in the vehicle body 11 enters the tank 21 after passing through the liquid-phase interface of the vehicle body 11, the liquid flow pipe 4 and the liquid-phase interface of the tank 21 in sequence. When there is about 500 kg of liquefied natural gas remaining in the vehicle body 11, turn off the compressor 31.

[0043] In order to recover the gaseous natural gas in the vehicle body 11 to the liquid-phase interface of the tank 21 of the tank 21, please refer to Figure 3 , in a preferred embodiment, the first vehicle body 11 gas pipe is connected to the first inlet 321 of the regenerator 32, and the exhaust port 313 is connected to the liquid flow pipe 4.

[0044] During use, when recovering the gaseous natural gas in the vehicle body 11 to the liquid-phase interface of the tank 21 of the tank 21, the gaseous natural gas in the vehicle body 11 passes through the gas-phase interface of the vehicle body 11, the first vehicle body 11 gas pipe, the regenerator 32, the first air inlet 311, the compressor 31, the exhaust port 313, the air cooler 33, the oil-gas separator 331, the regenerator 32, the liquid flow pipe 4 and the liquid-phase interface of the tank 21 in sequence and then enters the tank 21. The liquefied natural gas in the oil-gas separator 331 flows back into the compressor 31 for recycling. The gaseous natural gas liquefies after contacting the liquefied natural gas in the tank 21 and is stored in the tank 21. When the pressure in the vehicle body 11 drops to 0.15 MPa, the compressor 31 automatically shuts down, completing the recovery of the gaseous natural gas in the vehicle body 11.

[0045] In order to transfer the gaseous natural gas in the vehicle body 11 to the regenerator 32, please refer to Figure 3 , in a preferred embodiment, a second vehicle body 11 gas pipe is provided between the first vehicle body 11 gas pipe and the first inlet 321 of the regenerator 32, and a first valve 51 is provided on the second vehicle body 11 gas pipe.

[0046] During use, when transferring the gaseous natural gas in the vehicle body 11 to the regenerator 32, open the gas-phase valve of the vehicle body 11 and the first valve 51. The natural gas in the vehicle body 11 sequentially passes through the gas-phase interface of the vehicle body 11, the first vehicle body 11 trachea, the second vehicle body 11 trachea, and the first inlet 321 of the regenerator 32 and then reaches the regenerator 32.

[0047] In order to transfer the gaseous natural gas at the regenerator 32 to the liquid-phase interface of the tank body 21 of the tank body 21, please refer to Figure 3 , in a preferred embodiment, a second tank body 21 trachea is provided between the first outlet 323 of the regenerator 32 and the liquid flow pipe 4, and a third valve 61 and a fifth valve 62 are provided on the second tank body 21 trachea.

[0048] During use, when transferring the gaseous natural gas at the first outlet 323 of the regenerator 32 to the liquid-phase interface of the tank body 21 of the tank body 21, open the third valve 61, the fifth valve, and the liquid-phase valve of the tank body 21. The natural gas at the regenerator 32 sequentially passes through the first outlet 323 of the regenerator 32, the second tank body 21 trachea, the liquid flow pipe 4, and the liquid-phase interface of the tank body 21 and then enters the tank body 21.

[0049] In order to recover the gaseous natural gas in the vehicle body 11 to the gas-phase interface of the tank body 21 of the tank body 21, please refer to Figure 4 , in a preferred embodiment, the second tank body 21 trachea is communicated with the first tank body 21 trachea.

[0050] During use, when recovering the gaseous natural gas in the vehicle body 11 to the gas-phase interface of the tank body 21 of the tank body 21, open the gas-phase valve of the vehicle body 11, the gas-phase valve of the tank body 21, the first valve 51, and the third valve 61. The gaseous natural gas in the vehicle body 11 sequentially passes through the gas-phase interface of the vehicle body 11, the first vehicle body 11 trachea, the second vehicle body 11 trachea, the regenerator 32, the first air inlet 311, the compressor 31, the exhaust port 313, the air cooler 33, the oil-gas separator 331, the regenerator 32, the second tank body 21 trachea, the first tank body 21 trachea, and the gas-phase interface of the tank body 21 and then enters the tank body 21. The liquid natural gas in the oil-gas separator 331 flows back into the compressor 31 for recycling. As the gaseous natural gas is injected, the pressure in the tank body 21 increases.

[0051] In order to improve the convenience of using the compressor 31, please refer to Figure 4 , in a preferred embodiment, the compressor 31 is a skid-mounted compressor 31.

[0052] During use, the skid-mounted compressor 31 has the characteristics of being easy to install, easy to relocate, and having a small footprint.

[0053] To better understand the present utility model, the following is a detailed description of the working principle of the technical solution of the unloading device of a cryogenic liquid tanker of the present utility model in conjunction with Figure 1 - Figure 4 : During unloading, the gas-phase interface of the tank body 21 is connected to the unloading mechanism 3, and the unloading mechanism 3 is then connected to the gas-phase interface of the vehicle body 11. The liquid-phase interface of the tank body 21 is connected to the liquid-phase interface of the vehicle body 11. The unloading mechanism 3 is started to transfer the gaseous natural gas in the tank body 21 into the vehicle body 11. The pressure of the compressed gas in the vehicle body 11 increases, and the pressure in the tank body 21 decreases. Under the action of the pressure difference, the liquid natural gas in the vehicle body 11 is transferred into the tank body 21. The unloading by the pressure difference replaces the submersible pump and there is no need for the vehicle body 11 to self-pressurize. At the same time, there is no need to discharge the pressure of the tank body 21. After the unloading is completed, the gaseous natural gas in the vehicle body 11 is pumped back into the tank body 21, and the pressure in the vehicle body 11 can be unloaded to below 0.15 MP, and the remaining liquid can be completely unloaded, minimizing the unloading loss.

[0054] The specific embodiments of the present utility model described above do not constitute a limitation on the protection scope of the present utility model. Any other corresponding changes and deformations made according to the technical concept of the present utility model shall be included in the protection scope of the claims of the present utility model.

Claims

1. An unloading device for a cryogenic liquid tank truck, characterized in that, Comprising: A tank truck mechanism, the tank truck mechanism including a vehicle body and a vehicle body gas phase interface and a vehicle body liquid phase interface provided on the vehicle body; A tank mechanism, the tank mechanism including a tank body and a tank body gas phase interface and a tank body liquid phase interface provided on the tank body; and, A truck unloading mechanism, the truck unloading mechanism being connected to the vehicle body gas phase interface, the truck unloading mechanism being connected to the tank body gas phase interface, and the vehicle body liquid phase interface being connected to the tank body liquid phase interface.

2. The unloading device for a cryogenic liquid tanker according to claim 1, characterized in that, The truck unloading mechanism includes a regenerator, a compressor, an air cooler, and an oil and gas separator. The compressor is provided with a first air inlet, a second air inlet, and an exhaust port. The first outlet of the regenerator is connected to the vehicle body gas phase interface, the first inlet of the regenerator is connected to the tank body gas phase interface, the second outlet of the regenerator is connected to the first air inlet of the compressor, the exhaust port of the compressor is connected to the inlet of the air cooler, the outlet of the air cooler is connected to the inlet of the oil and gas separator, the first outlet of the oil and gas separator is connected to the second inlet of the regenerator, and the second outlet of the oil and gas separator is connected to the second air inlet of the compressor.

3. The unloading device for a cryogenic liquid tanker according to claim 2, characterized in that, A first tank body gas pipe is provided between the tank body gas phase interface and the first inlet of the regenerator, and a tank body gas valve and a fourth valve are provided on the first tank body gas pipe.

4. The unloading device for a cryogenic liquid tanker according to claim 2, characterized in that, A first vehicle body gas pipe is provided between the first outlet of the regenerator and the vehicle body gas phase interface, and a second valve and a vehicle body gas valve are provided on the first vehicle body gas pipe.

5. The unloading device for a cryogenic liquid tanker according to claim 4, characterized in that, A liquid flow pipe is provided between the vehicle body liquid phase interface and the tank body liquid phase interface, and a vehicle body liquid phase valve and a tank body liquid phase valve are provided on the liquid flow pipe.

6. The unloading device for a cryogenic liquid tank truck according to claim 5, characterized in that, The first vehicle body gas pipe is connected to the first inlet of the regenerator, and the exhaust port is connected to the liquid flow pipe.

7. The unloading device for a cryogenic liquid tank truck according to claim 6, characterized in that A second vehicle body gas pipe is provided between the first vehicle body gas pipe and the first inlet of the regenerator, and a first valve is provided on the second vehicle body gas pipe.

8. The unloading device for a cryogenic liquid tanker according to claim 6, characterized in that, A second tank body gas pipe is provided between the first outlet of the regenerator and the liquid flow pipe, and a third valve and a fifth valve are provided on the second tank body gas pipe.

9. The unloading device for a cryogenic liquid tanker according to claim 8, characterized in that, The second tank body gas pipe is connected to the first tank body gas pipe.

10. The unloading device of a cryogenic liquid tanker according to claim 2, characterized in that, The compressor is a skid-mounted compressor.

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