Device for increasing ethane in feed gas in LNG (Liquefied Natural Gas) liquefying device

Abstract

The utility model provides a device for increasing ethane in feed gas in an LNG (Liquefied Natural Gas) liquefying device, which comprises a transport vehicle, a low-temperature plunger pump, an ethane heat exchanger and a driving motor, the transport vehicle is in pipeline connection with the ethane heat exchanger through the low-temperature plunger pump, and the low-temperature plunger pump is fixedly connected with an output shaft of the driving motor through a crank connecting rod speed regulating mechanism. The ethane heat exchanger is connected with a cold box through a pipeline, and the cold box is connected with an LNG storage tank through a pipeline. According to the utility model, a certain proportion of ethane is added into the feed gas CNG of the LNG liquefying plant, so that a process treatment method for improving the calorific value of the LNG is achieved, the quality of the LNG can be effectively improved, the high calorific value of the LNG is improved, the produced LNG is more popular with users, and if the ethane and the LNG have price difference, the economic benefit of the LNG liquefying plant can be improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to LNG liquefied gas technical field relates to LNG liquefying device in raw material gas in ethane increasing device. BACKGROUND

[0002] At present, the raw material of LNG liquefying plant is mostly pipeline gas, coal bed gas, sandstone gas, and the main component after liquefaction should meet the standard of liquefied natural gas, under normal circumstances, if the methane content in raw material gas is higher, it will lead to lower high heating value, although it meets the standard of liquefied natural gas, but its high heating value is really not high, especially city combustion customer. SUMMARY

[0003] The utility model discloses a LNG liquefying device in raw material gas in ethane increasing device to solve the problem in the above background art.

[0004] The utility model discloses a LNG liquefying device in raw material gas in ethane increasing device, including transport vehicle, cryogenic plunger pump, ethane heat exchanger and drive motor, the transport vehicle passes through cryogenic plunger pump and is connected with ethane heat exchanger pipeline, the cryogenic plunger pump passes through the output shaft fixed connection of crank connecting rod speed regulation mechanism and drive motor, the pipeline connection of ethane heat exchanger has cold box, the pipeline connection of cold box has LNG and is stored in the jar, the pipeline connection of ethane heat exchanger has respectively and goes to mixed refrigerant supplement pipeline and a plurality of dehydrocarbon column, a plurality of dehydrocarbon column pipeline connection has CNG raw material gas from the dehydration tower.

[0005] In the LNG liquefying device in raw material gas in ethane increasing device described above, the output shaft of the drive motor is fixedly connected with the input end of the crank connecting rod speed regulation mechanism, the crank connecting rod speed regulation mechanism includes a crank, a connecting rod and a connecting rod, the center of the crank is fixedly connected with the output shaft of the drive motor, the surface of the crank is rotatably connected with the connecting rod, the end of the connecting rod is rotatably connected with the connecting rod, and the connecting rod is fixedly connected with the center of the plunger inside the cryogenic plunger pump.

[0006] In the LNG liquefying device in raw material gas in ethane increasing device described above, one side of the drive motor is fixedly provided with an electric control cabinet, and the drive motor is electrically connected with the electric control cabinet.

[0007] In the LNG liquefying device in raw material gas in ethane increasing device described above, an electromagnetic valve is fixedly installed in the pipeline between the transport vehicle and the cryogenic plunger pump.

[0008] In the LNG liquefying device in raw material gas in ethane increasing device described above, a liquid outlet pipeline is fixedly arranged at the bottom of the ethane heat exchanger, the liquid outlet pipeline is sequentially provided with a first outlet, a second outlet and a third outlet, and the third outlet is connected with the pipeline of the cold box.

[0009] Compared with existing technologies, the advantages of the ethane addition device in the feed gas of the LNG liquefaction plant of this utility model are as follows: adding a certain proportion of ethane to the CNG feed gas of the LNG liquefaction plant to improve the calorific value of LNG can effectively improve the quality of LNG, increase its higher heating value, and make the produced LNG more popular with users. If there is a price difference between ethane and LNG, it can also improve the economic benefits of the liquefaction plant. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the ethane addition device in the feed gas of the LNG liquefaction unit of this utility model.

[0011] In the diagram, 1. Transport vehicle; 2. Cryogenic plunger pump; 3. Crank-connecting rod speed control mechanism; 4. Drive motor; 5. Electrical control cabinet; 6. Connecting rod; 7. Connecting rod; 8. Crank; 9. Cold box; 10. First outlet; 11. Second outlet; 13. Ethane heat exchanger; 14. Refrigerant replenishment pipeline; 15. Dehydrocarbonization tower; 16. Third outlet. Detailed Implementation

[0012] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0013] like Figure 1 As shown, the ethane addition device in the feed gas of the LNG liquefaction unit of this utility model includes a transport vehicle 1, a cryogenic plunger pump 2, an ethane heat exchanger 13, and a drive motor 4. The transport vehicle 1 is connected to the ethane heat exchanger 13 via the cryogenic plunger pump 2. The cryogenic plunger pump 2 is fixedly connected to the output shaft of the drive motor 4 via a crank-connecting rod speed regulating mechanism 3. The ethane heat exchanger 13 is connected to a cold box 9 via a pipeline. The cold box 9 is connected to an LNG storage tank via a pipeline. The ethane heat exchanger 13 is connected to a mixed refrigerant replenishment pipeline 14 and multiple dehydrogenation towers 15 via pipelines. The multiple dehydrogenation towers 15 are connected to CNG feed gas from a dehydration tower via pipelines.

[0014] like Figure 1 As shown, in the LNG liquefaction device of this utility model, the ethane addition device in the raw gas has a drive motor 4 whose output shaft is fixedly connected to the input end of the crank-connecting rod speed regulating mechanism 3. The crank-connecting rod speed regulating mechanism 3 includes a crank 8, a connecting rod 7 and a connecting rod 6. The center of the crank 8 is fixedly connected to the output shaft of the drive motor 4. The surface of the crank 8 is rotatably connected to the connecting rod 7. The end of the connecting rod 7 is rotatably connected to the connecting rod 6. The connecting rod 6 is fixedly connected to the center of the plunger inside the cryogenic plunger pump 2.

[0015] An electrical control cabinet 5 is fixedly installed on one side of the drive motor 4, and the drive motor 4 is electrically connected to the electrical control cabinet 5.

[0016] Specifically, the drive motor controller inside the electric control cabinet 5 controls the operation of the drive motor 4.

[0017] An electromagnetic valve is fixedly installed in the pipeline between the transport vehicle 1 and the low-temperature plunger pump 2.

[0018] The bottom of the ethane heat exchanger 13 is fixedly provided with a liquid outlet pipeline, which is sequentially provided with a first outlet 10, a second outlet 11 and a third outlet 16, and the third outlet 16 is connected with the pipeline of the cold box 9.

[0019] In specific implementation, ethane is transported to the liquefaction plant by the transport vehicle 1, introduced into the ethane low-temperature plunger pump 2 through the unloading arm, and pressurized to 5.5 MPa or above (C2H5-03, 0.5 MPa higher than the raw gas pressure) by the low-temperature plunger pump 2;

[0020] The transport vehicle 1 is connected with two pipelines, a liquid-phase pipeline C2H5-01 and a gas-phase return gas pipeline C2H5-02, wherein the return gas pipeline can introduce the ethane gas vaporized in front of the low-temperature plunger pump 2 back into the transport vehicle 1, otherwise the gas entering the low-temperature plunger pump 2 will affect the output;

[0021] The high-pressure liquid ethane C2H5-03 (-88.6℃) at the outlet of the low-temperature plunger pump 2 is heated and rewarmed in the ethane heat exchanger 13, and at the same time, the low-temperature cold energy carried is transferred / heat-exchanged to the raw gas CNG01 before entering the cold box 9 from the dealkylation tower 15, so that the raw gas CNG01 is cooled from 25℃ to 32℃ to -5℃ to -10℃, and then directly enters the cold box 9 to be liquefied. The raw gas CNG01 after temperature reduction can save more energy and increase production during the liquefaction process;

[0022] Through the ethane heat exchanger 13, the ethane is warmed from -88.6℃ to 25℃, vaporized into gaseous C2H5-04, and then according to different components, enters different positions of the CNG raw gas: if the ethane contains more than 10 ppm of carbon dioxide, it enters the pipeline network in front of the carbon dioxide removal tower through the second outlet 11, and after the carbon dioxide in the ethane + natural gas is absorbed by the MDEA aqueous solution in the absorption tower, enters the dehydration and dealkylation device, and then enters the cold box 9 to be liquefied; if the ethane does not contain carbon dioxide, but the content of heavy hydrocarbon (C4 and above) is more than 50 ppm, it enters the pipeline network in front of the dealkylation tower 15 through the first outlet 10, and after the hydrocarbon in the ethane + natural gas is adsorbed by the dealkylation device, enters the cold box 9 to be liquefied; if the ethane does not contain carbon dioxide and the content of heavy hydrocarbon (C4 and above) is not more than 50 ppm, it directly enters the cold box 9 to be liquefied through the third outlet 3.

[0023] What is not described in detail in the specification belongs to the prior art known to those skilled in the art. The specific embodiments described herein are merely illustrative of the spirit of the present application. Those skilled in the art to which the present application belongs can make various modifications or supplements to the described specific embodiments or replace them with similar ways, but will not deviate from the spirit of the present application or exceed the scope defined by the appended claims.

Claims

1. An ethane increasing device in a raw material gas in an LNG liquefaction device, comprising a transport vehicle (1), a low-temperature plunger pump (2), an ethane heat exchanger (13), and a driving motor (4), characterized in that, The transport vehicle (1) is connected with the ethane heat exchanger (13) through the low-temperature plunger pump (2), the low-temperature plunger pump (2) is fixedly connected with the output shaft of the driving motor (4) through the crank connecting rod speed regulation mechanism (3), the ethane heat exchanger (13) is connected with the cold box (9), the cold box (9) is connected with the LNG storage tank, the ethane heat exchanger (13) is respectively connected with the mixed refrigerant supplement pipeline (14) and a plurality of dehydrocarbon columns (15), and the plurality of dehydrocarbon columns (15) are connected with the CNG raw gas from the dehydration tower.

2. The LNG plant feed gas ethane augmentation apparatus of claim 1, wherein, The output shaft of the driving motor (4) is fixedly connected with the input end of the crank connecting rod speed regulation mechanism (3), the crank connecting rod speed regulation mechanism (3) comprises a crank (8), a connecting rod (7) and a connecting rod (6), the center of the crank (8) is fixedly connected with the output shaft of the driving motor (4), the surface of the crank (8) is rotatably connected with the connecting rod (7), the end of the connecting rod (7) is rotatably connected with the connecting rod (6), and the connecting rod (6) is fixedly connected with the plunger center of the low-temperature plunger pump (2).

3. The apparatus according to claim 2, wherein the apparatus is characterized by: One side of the driving motor (4) is fixedly provided with the electric control cabinet (5), and the driving motor (4) is electrically connected with the electric control cabinet (5).

4. The apparatus for increasing ethane in a feed gas in an LNG liquefying apparatus according to claim 1, wherein An electromagnetic valve is fixedly installed in the pipeline between the transport vehicle (1) and the low-temperature plunger pump (2).

5. The apparatus for increasing ethane in a feed gas in an LNG liquefaction plant as claimed in claim 1, wherein, The bottom of the ethane heat exchanger (13) is fixedly provided with a liquid outlet pipeline, the liquid outlet pipeline is sequentially provided with a first outlet (10), a second outlet (11) and a third outlet (16), and the third outlet (16) is connected with the pipeline of the cold box (9).

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