Liquid low-temperature ethylene gasification temperature and pressure rise system and method

Abstract

The invention belongs to the technical field of ethylene storage and transportation, and particularly discloses a liquid low-temperature ethylene gasification heating and boosting system which comprises a low-temperature ethylene storage tank, an ethylene gasifier, an ethylene superheater and an ethylene buffer tank, an ethylene immersed pump column is arranged in the low-temperature ethylene storage tank, and the upper portion of the ethylene immersed pump column is communicated with an immersed pump ethylene delivery pipeline. An outlet of the immersed pump ethylene delivery pipeline is connected to a tube bundle inlet on the ethylene gasifier, and a tube bundle outlet on the ethylene gasifier is connected to the ethylene superheater through a pipeline. The invention provides a liquid low-temperature ethylene gasification heating and boosting system and method, and an ethylene gasifier provided by the invention uses propane as a medium, cools chilled water after heat exchange of a downstream production device, and recycles the cooling capacity of ethylene at the same time; the ethylene superheater selects steam as a heat source, and the unique structural design is combined, so that the defects that the vaporizer is easy to frost and freeze are overcome.

Description

Technical Field

[0001] The present invention belongs to the technical field of ethylene storage and transportation, and particularly relates to a system and method for gasifying, heating up, and boosting the pressure of liquid cryogenic ethylene. Background Art

[0002] Due to the characteristics of ethylene, that is, ethylene is gaseous at normal temperature and pressure, and has a relatively high vapor pressure and is flammable and explosive. Ethylene transportation and storage are mainly in liquid state, and most of the storage methods are low-pressure and low-temperature methods. While the downstream users of ethylene usually use gaseous state at normal temperature and high pressure.

[0003] Currently, the methods of transporting the stored liquid ethylene to the downstream are basically the same. First, the pressure of the liquid ethylene is increased and then transported to the ethylene vaporizer for vaporization. After vaporization, the ethylene is heated to normal temperature and then sent to the downstream for use.

[0004] The vaporizers currently used in factories mainly include electric heating type, water bath type, air temperature type, and steam type. The electric heating type vaporizer consumes a large amount of electricity and is not safe; the water bath type vaporizer is easily frozen if not operated carefully, and has a large potential safety hazard; the air temperature type vaporizer is more energy-saving and has a small investment cost compared with other vaporizers and is widely used, but it is greatly affected by the external environment. Especially in winter with low temperature, the external frost is difficult to melt, and the use effect is greatly reduced; the steam type vaporizer directly heats the liquid ethylene to normal temperature, which not only easily causes damage to the welds under the thermal expansion and contraction of the equipment, but also consumes a large amount of steam. In the chemical industry, energy conservation and consumption reduction are always given top priority, and the above-mentioned vaporizers cannot recover the cold energy of ethylene. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above problems existing in the prior art, and provide a system and method for gasifying, heating up, and boosting the pressure of liquid cryogenic ethylene. The provided ethylene vaporizer uses propane as a medium to cool the chilled water after heat exchange in the downstream production device, and at the same time, the cold energy of ethylene is recovered and reused; the ethylene superheater selects steam as the heat source, and combines with a unique structural design to avoid the disadvantages of easy frosting and freezing of the above-mentioned vaporizers.

[0006] To achieve the above technical purpose and reach the above technical effect, the present invention is realized through the following technical solutions:

[0007] In a first aspect, the present invention provides a system for gasifying, heating up, and boosting the pressure of liquid cryogenic ethylene, including a cryogenic ethylene storage tank, an ethylene vaporizer, an ethylene superheater, and an ethylene buffer tank. An ethylene submersible pump column is arranged in the cryogenic ethylene storage tank. The upper part of the ethylene submersible pump column is communicated with a pipeline for sending ethylene by the submersible pump. The outlet of the pipeline for sending ethylene by the submersible pump is connected to the inlet of the tube bundle on the ethylene vaporizer. The outlet of the tube bundle on the ethylene vaporizer is connected to the ethylene superheater through a pipeline. The pipeline outlet on the ethylene superheater is connected to the ethylene buffer tank through a pipeline;

[0008] An ethylene submersible pump is provided inside the ethylene submersible pump column.

[0009] Furthermore, the ethylene vaporizer is a single-shell pass heat exchanger;

[0010] Inside the ethylene vaporizer, an upper tube bundle and a lower tube bundle are provided from top to bottom. The outlet of the pipeline for the ethylene sent by the submersible pump is connected to the upper tube bundle;

[0011] Propane liquid is filled inside the ethylene vaporizer, and the liquid level of the propane liquid is between the upper tube bundle and the lower tube bundle;

[0012] The tube bundle inlet of the lower tube bundle is connected to a chilled water supply pipeline, and the tube bundle outlet of the lower tube bundle is connected to a chilled water return pipeline.

[0013] Furthermore, the ethylene superheater includes a shell-and-tube heat exchanger and a condensate tank provided at the lower end of the shell-and-tube heat exchanger;

[0014] The tubes inside the shell-and-tube heat exchanger are located at the upper end inside the shell-and-tube heat exchanger.

[0015] Furthermore, a steam pipeline is connected to the top of the ethylene superheater. The steam pipeline is used to introduce low-pressure steam into the ethylene superheater, and a steam control valve is also provided on the steam pipeline.

[0016] Furthermore, the volume of the tubes inside the shell-and-tube heat exchanger accounts for 2 / 3 of the internal volume of the shell-and-tube heat exchanger.

[0017] Furthermore, a remote level gauge for the condensate tank is provided on the condensate tank;

[0018] A steam condensate discharge pipeline is provided at the bottom of the condensate tank. The steam condensate discharge pipeline is used to discharge steam condensate;

[0019] A steam condensate control valve is provided on the steam condensate discharge pipeline.

[0020] Furthermore, an ethylene flowmeter for the ethylene sent by the submersible pump is provided on the pipeline for the ethylene sent by the submersible pump;

[0021] A return ethylene pipeline is also connected to the pipeline for the ethylene sent by the submersible pump. The outlet of the return ethylene pipeline is connected to a low-temperature ethylene storage tank;

[0022] A return ethylene control valve is provided on the return ethylene pipeline.

[0023] Furthermore, an ethylene thermometer for the vaporized ethylene is provided on the pipeline between the ethylene vaporizer and the ethylene superheater;

[0024] An overheated ethylene thermometer is provided on the pipeline between the ethylene superheater and the ethylene buffer tank.

[0025] Furthermore, a remote pressure gauge for the ethylene buffer tank is provided on the ethylene buffer tank;

[0026] A pipeline for sending out ethylene from the buffer tank is also provided on the ethylene buffer tank.

[0027] In a second aspect, the present invention provides a method for vaporizing, heating up, and boosting the pressure of liquid cryogenic ethylene, which is realized by using a system for vaporizing, heating up, and boosting the pressure of liquid cryogenic ethylene provided in the embodiment of the first aspect of the present invention. The method includes the following steps:

[0028] The ethylene submersible pump pressurizes the ethylene in the cryogenic ethylene storage tank to obtain pressurized ethylene. The pressurized ethylene is sent through the pipeline for sending out ethylene from the submersible pump to the ethylene vaporizer for vaporization to obtain vaporized ethylene. The vaporized ethylene is transported to the ethylene superheater for heating up to obtain heated ethylene. The heated ethylene is transported to the ethylene buffer tank for stable pressure storage to obtain high-pressure normal-temperature gaseous ethylene.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. The present invention provides a system for vaporizing, heating up, and boosting the pressure of liquid cryogenic ethylene. The provided ethylene vaporizer uses propane as a medium to cool the chilled water after heat exchange in the downstream production device, and at the same time, the cold energy of ethylene is recovered and reused; the ethylene superheater selects steam as the heat source, and combined with a unique structural design, it avoids the disadvantages of the above-mentioned vaporizer being prone to frosting and freezing.

[0031] 2. In the present invention, the ethylene superheater adopts a shell-and-tube heat exchanger. Among them, there are no tubes at the lower part of the shell-and-tube heat exchanger, and a condensate tank is connected to the lower part of the heat exchanger. This setting can reduce the stress concentration caused by the temperature difference, improve the stability and safety of the shell-and-tube heat exchanger; and can optimize the flow path of the materials in the shell-and-tube heat exchanger, reduce the flow resistance, and further improve the heat exchange efficiency.

[0032] 3. In the present invention, an ethylene submersible pump column is provided in the cryogenic ethylene storage tank, an ethylene submersible pump is provided in the ethylene submersible pump column, and a return ethylene pipeline is also connected to the pipeline for sending out ethylene from the submersible pump. The outlet of the return ethylene pipeline is connected to the cryogenic ethylene storage tank, which can ensure a constant amount sent to the ethylene vaporizer. Description of the Drawings

[0033] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute an improper limitation to the present invention. In the drawings:

[0034] Figure 1It is a schematic structural diagram of the system for gasifying, heating up, and boosting the pressure of liquid cryogenic ethylene provided by the present invention.

[0035] Among them, the reference numerals are: 1, cryogenic ethylene storage tank; 2, ethylene submersible pump column; 2a, ethylene submersible pump; 3, ethylene vaporizer; 4, ethylene superheater; 5, ethylene buffer tank; 31, upper tube bundle; 32, lower tube bundle; 41, shell-and-tube heat exchanger; 42, condensate tank; L1, ethylene pipeline sent out by the submersible pump; L2, ethylene return pipeline; L3, ethylene pipeline sent out by the vaporizer; L4, ethylene pipeline sent out by the superheater; L5, ethylene pipeline sent out by the buffer tank; L6, chilled water supply pipeline; L7, chilled water return pipeline; L8, steam pipeline; L9, steam condensate discharge pipeline; V1, ethylene return regulating valve; V2, chilled water supply regulating valve; V3, steam regulating valve; V4, steam condensate regulating valve; TIC1, thermometer for vaporized ethylene; TIC2, thermometer for superheated ethylene; LIC1, remote liquid level gauge for the condensate tank; PIC1, remote pressure gauge for the ethylene buffer tank; FIC1, flowmeter for ethylene sent out by the submersible pump. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "periphery", etc. indicating the orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention.

[0038] In the first aspect, as Figure 1 shown, the present invention provides a system for gasifying, heating up, and boosting the pressure of liquid cryogenic ethylene, including a cryogenic ethylene storage tank 1, an ethylene vaporizer 3, an ethylene superheater 4, and an ethylene buffer tank 5;

[0039] An ethylene submersible pump column 2 is provided inside the cryogenic ethylene storage tank 1, that is, the ethylene submersible pump column 2 is located inside the cryogenic ethylene storage tank 1; an ethylene submersible pump 2a is provided inside the ethylene submersible pump column 2;

[0040] The upper part of the ethylene submersible pump column 2 is connected to an ethylene pipeline L1 sent out by the submersible pump, and the outlet of the ethylene pipeline L1 sent out by the submersible pump is connected to the tube bundle inlet on the ethylene vaporizer 3;

[0041] There is an ethylene pipeline L3 sent out from the vaporizer between the ethylene vaporizer 3 and the ethylene superheater 4. Specifically, the outlet of the upper tube bundle of the ethylene vaporizer 3 is connected to the inlet of the tube side of the ethylene superheater 4 through the ethylene pipeline L3 sent out from the vaporizer;

[0042] There is an ethylene pipeline L4 sent out from the superheater between the ethylene superheater 4 and the ethylene buffer tank 5. The outlet of the tube side of the ethylene superheater 4 is connected to the ethylene buffer tank 5 through the ethylene pipeline L4 sent out from the superheater;

[0043] The gaseous ethylene in the ethylene buffer tank 5 is sent to the downstream for use through its top outlet;

[0044] Specifically, there is an ethylene submersible pump 2a in the ethylene submersible pump column 2. The ethylene submersible pump 2a can increase the ethylene at 10 - 20 Kpa in the low-temperature ethylene storage tank 1 to 1.8 - 2.0 Mpa, and send it to the ethylene vaporizer 3 through the ethylene submersible pump column 2 and the ethylene pipeline L1 sent out by the submersible pump.

[0045] As Figure 1 shown, in some embodiments of the present invention, the ethylene vaporizer 3 is a single-shell heat exchanger;

[0046] Inside the ethylene vaporizer 3, there are an upper tube bundle 31 and a lower tube bundle 32 from top to bottom, and there is no connection between the upper tube bundle 31 and the lower tube bundle 32;

[0047] Since the outlet of the ethylene pipeline L1 sent out by the submersible pump is connected to the inlet of the tube bundle on the ethylene vaporizer 3. Specifically, the outlet of the ethylene pipeline L1 sent out by the submersible pump is connected to the upper tube bundle 31;

[0048] The ethylene vaporizer 3 is filled with propane liquid, and the liquid level of the propane liquid is between the upper tube bundle 31 and the lower tube bundle 32;

[0049] The inlet of the tube bundle of the lower tube bundle 32 is connected to a chilled water supply pipeline L6, and the outlet of the tube bundle of the lower tube bundle 32 is connected to a chilled water return pipeline L7;

[0050] Specifically, the inlet of the tube bundle of the lower tube bundle 32 is connected to a chilled water supply pipeline L6, the outlet of the tube bundle of the lower tube bundle 32 is connected to a chilled water return pipeline L7, and a chilled water supply regulating valve V2 is also provided on the chilled water supply pipeline L6; the chilled water supply pipeline L6 is used to supply chilled return water to the lower tube bundle 32, and the chilled water return pipeline L7 is used to send out the chilled water after heat exchange;

[0051] The working principle of the ethylene vaporizer 3 is as follows: The liquid cryogenic ethylene from the cryogenic ethylene storage tank 1 enters the ethylene vaporizer 3 through the upper tube bundle 31, and the chilled return water enters the lower tube bundle 32 through the chilled water supply pipeline L6. That is, the material in the upper tube bundle of the ethylene vaporizer 3 is ethylene, and the material in the lower tube bundle is chilled return water. The liquid cryogenic ethylene from the cryogenic ethylene storage tank 1 exchanges heat with the propane in the shell side of the ethylene vaporizer 3. The gaseous propane is cooled and liquefied, and at the same time, the ethylene is heated and vaporized. The propane falls by its own gravity, exchanges heat with the chilled water in the lower tube bundle 32, and then vaporizes and rises again. Using propane as a medium, the chilled water takes away the cold of the low-temperature liquid ethylene.

[0052] As Figure 1 shown, in some embodiments of the present invention, the chilled return water inlet of the chilled water supply pipeline L6 can be connected to the downstream production device, that is, the chilled water supply pipeline L6 can also be the chilled return water pipeline of the downstream production device; and the outlet of the chilled water return pipeline L7 at the outlet of the lower tube bundle can be connected to the downstream production device, that is, the chilled water return pipeline L7 at the outlet of the lower tube bundle 32 can also be the chilled water supply pipeline sent to the downstream production device;

[0053] The downstream production device refers to a production device using ethylene as a raw material, including but not limited to the vinyl acetate production device; in this downstream production device, a chilled return water pipeline and a chilled water supply pipeline are generally provided. Thus, the system for vaporizing, heating, and boosting the pressure of the liquid cryogenic ethylene provided by the present invention can be connected to the downstream production device. That is, the chilled water supply pipeline L6 can be the chilled return water pipeline of the downstream production device, and the chilled water return pipeline L7 at the outlet of the lower tube bundle 32 is the chilled water supply pipeline sent to the downstream production device, reducing the dependence on external energy, not only significantly reducing energy consumption but also reducing cold waste;

[0054] Specifically, the chilled water supply pipeline L6 can also be connected to the chilled return water pipeline of the downstream production device, and the chilled water return pipeline L7 at the outlet of the lower tube bundle 32 can also be connected to the chilled water supply pipeline of the downstream production device.

[0055] As Figure 1 shown, in some embodiments of the present invention, the ethylene superheater 4 includes a shell-and-tube heat exchanger 41 and a condensate tank 42 provided at the lower end of the shell-and-tube heat exchanger 41;

[0056] The tubes in the shell-and-tube heat exchanger 41 are located at the upper end inside the shell-and-tube heat exchanger 41;

[0057] Specifically, the upper end inside the shell-and-tube heat exchanger 41 is tubes, there are no tubes in the lower part of the shell-and-tube heat exchanger 41, and the volume of the tubes in the shell-and-tube heat exchanger 41 accounts for 2 / 3 of the internal volume of the shell-and-tube heat exchanger 41. The lower part of the shell-and-tube heat exchanger 41 is connected to a condensate tank 42;

[0058] The shell-and-tube heat exchanger 41 with this special structural design can reduce the stress concentration caused by temperature difference, improve the stability and safety of the shell-and-tube heat exchanger; and can optimize the flow path of the materials in the shell-and-tube heat exchanger, reduce the flow resistance, and further improve the heat exchange efficiency; at the same time, by regulating the liquid level in the condensate tank 42, it is possible to prevent the tubes in the shell-and-tube heat exchanger 41 from coming into contact with the condensate in the condensate tank 42, thereby avoiding freezing and blockage and extending the service life of the shell-and-tube heat exchanger 41.

[0059] As Figure 1 shown, in some embodiments of the present invention, a remote liquid level gauge LIC1 for the condensate tank 42 is provided on the condensate tank 42;

[0060] A steam condensate discharge pipeline L9 is provided at the bottom of the condensate tank 42, and the steam condensate discharge pipeline L9 is used to discharge the steam condensate in the condensate tank 42;

[0061] A steam condensate regulating valve V4 is provided on the steam condensate discharge pipeline L9;

[0062] Specifically, during actual operation, the remote liquid level gauge LIC1 of the condensate tank at the lower part of the ethylene superheater 4 can set the liquid level to 50% and can automatically control the steam condensate regulating valve V4 on the steam condensate discharge pipeline L9, so that the tubes in the ethylene superheater 4 do not come into contact with the condensate, thereby avoiding the possibility of freezing and blockage;

[0063] The high-pressure normal-temperature gaseous ethylene after the ethylene superheater 4 is heated is sent to the ethylene buffer tank 5 through the superheater outlet ethylene pipeline L4.

[0064] As Figure 1 shown, in some embodiments of the present invention, a submersible pump outlet ethylene flowmeter FIC1 is provided on the submersible pump outlet ethylene pipeline L1;

[0065] A reflux ethylene pipeline L2 is also connected to the submersible pump outlet ethylene pipeline L1, and the outlet of the reflux ethylene pipeline L2 communicates with the low-temperature ethylene storage tank 1;

[0066] A reflux ethylene regulating valve V1 is provided on the reflux ethylene pipeline L2;

[0067] Specifically, a submersible pump outlet ethylene flowmeter FIC1 is installed on the submersible pump outlet ethylene pipeline L1, and a reflux ethylene pipeline L2 is added to the submersible pump outlet ethylene pipeline L1, and a reflux ethylene regulating valve V1 is provided on the reflux ethylene pipeline L2; the purpose of this setting is to make the set value of the submersible pump outlet ethylene flowmeter FIC1 on the submersible pump outlet ethylene pipeline L1 adjustable, generally set to 16 m 3 / h, and automatically control the reflux ethylene regulating valve V1 to ensure a constant amount sent to the ethylene vaporizer 3.

[0068] As Figure 1As shown, in some embodiments of the present invention, a vaporized ethylene thermometer TIC1 is provided on the pipeline between the ethylene vaporizer 3 and the ethylene superheater 4; that is, the vaporized ethylene thermometer TIC1 is provided on the ethylene pipeline L3 sent out by the vaporizer; during actual operation, the vaporized ethylene thermometer TIC1 can be set to -25°C.

[0069] As Figure 1 shown, in some embodiments of the present invention, the vaporized ethylene thermometer TIC1 can be set to -25°C and automatically control the chilled water regulating valve V2 on the chilled water supply pipeline L6, so that the vaporized ethylene temperature is stabilized at -25°C to ensure that ethylene is completely vaporized; at the same time, the chilled water return at -2°C from the downstream production device is cooled to -7°C.

[0070] As Figure 1 shown, in some embodiments of the present invention, a steam pipeline L8 is connected to the top of the ethylene superheater 4. The steam pipeline L8 is used to introduce low-pressure steam into the ethylene superheater 4, and a steam regulating valve V3 is also provided on the steam pipeline L8.

[0071] As Figure 1 shown, in some embodiments of the present invention, a superheated ethylene thermometer TIC2 is provided on the pipeline between the ethylene superheater 4 and the ethylene buffer tank 5; that is, the superheated ethylene thermometer TIC2 is provided on the ethylene pipeline L4 sent out by the superheater.

[0072] The ethylene vaporized by the ethylene vaporizer 3 is sent to the ethylene superheater 4 through the ethylene pipeline L3 sent out by the vaporizer; the superheated ethylene thermometer TIC2 on the ethylene pipeline L4 sent out by the superheater can be set to 25°C and can automatically control the steam regulating valve V3 on the steam pipeline L8.

[0073] As Figure 1 shown, in some embodiments of the present invention, a remote pressure gauge PIC1 for the ethylene buffer tank is provided on the ethylene buffer tank 5.

[0074] A pipeline L5 for sending out ethylene from the buffer tank is also provided on the ethylene buffer tank 5. The gaseous ethylene in the ethylene buffer tank 5 is sent to the downstream for use through the pipeline L5 for sending out ethylene from the buffer tank at the top.

[0075] Since the high-pressure normal-temperature gaseous ethylene after the ethylene superheater 4 is heated is sent to the ethylene buffer tank 5 through the ethylene pipeline L4 sent out by the superheater, the remote pressure gauge PIC1 for the ethylene buffer tank provided at the top of the ethylene buffer tank 5 can set the pressure to 1.8 - 2.0 Mpa and automatically control the frequency modulation of the ethylene submersible pump 2a to further maintain the stability of the sent high-pressure normal-temperature gaseous ethylene; the stable ethylene is sent to the downstream for use through the pipeline L5 for sending out ethylene from the buffer tank.

[0076] The present invention provides a system for gasifying, heating and pressurizing liquid low-temperature ethylene, which is simple to operate, highly automated, safe and reliable; the ethylene vaporizer 3 uses propane as a medium to cool the chilled water after heat exchange in the downstream production device, and at the same time recovers the cold energy of the ethylene; the ethylene superheater 4 uses steam as a heat source, combined with a unique structural design, to avoid the above-mentioned vaporizer's easy frost and freezing characteristics.

[0077] In a second aspect, the present invention provides a method for gasifying, heating and pressurizing liquid low-temperature ethylene, which is implemented by using a system for gasifying, heating and pressurizing liquid low-temperature ethylene provided in the first aspect of the present invention, and the method comprises the following steps:

[0078] S1, ethylene submersible pump 2a pressurizes the ethylene in the low-temperature ethylene storage tank 1 to obtain pressurized ethylene; in this process, ethylene submersible pump 2a can increase the ethylene of 10-20Kpa in the low-temperature ethylene storage tank 1 to 1.8-2.0Mpa, and then delivers the ethylene to ethylene vaporizer 3 through ethylene submersible pump column 2 and submersible pump ethylene pipeline L1;

[0079] S2, the pressurized ethylene is sent out of the ethylene pipeline L1 through the submersible pump to the ethylene vaporizer 3 for vaporization to obtain vaporized ethylene; in this process, the liquid low-temperature ethylene (i.e., pressurized ethylene) from the low-temperature ethylene storage tank 1 enters the ethylene vaporizer 3 through the upper tube bundle 31, and the refrigerated return water enters the lower tube bundle 32 through the refrigerated water upper water pipeline L6, that is, the material in the upper tube bundle of the ethylene vaporizer 3 is ethylene, and the material in the lower tube bundle is refrigerated return water. The liquid low-temperature ethylene from the low-temperature ethylene storage tank 1 exchanges heat with the propane in the shell side of the ethylene vaporizer 3, and the gaseous propane is liquefied when cooled, and the ethylene is vaporized at the same time; the propane falls by its own gravity, and is vaporized and rises again after heat exchange with the refrigerated water in the lower tube bundle 32; the propane is used as a medium, and the refrigeration of the low-temperature liquid ethylene is taken away by the refrigerated water;

[0080] S3, the vaporized ethylene is transported to the ethylene superheater 4 for heating to obtain heated ethylene; in this process, heated ethylene (i.e., high-pressure normal-temperature gaseous ethylene) after being heated by the ethylene superheater 4 is obtained;

[0081] S5, the heated ethylene is transported to the ethylene buffer tank 5 for pressure stabilization storage to obtain high-pressure room-temperature gaseous ethylene; during this process, the ethylene buffer tank remote pressure gauge PIC1 arranged on the top of the ethylene buffer tank 5 can set the pressure to 1.8-2.0 MPa and automatically control the frequency modulation of the ethylene submersible pump 2a, further maintaining the stability of the high-pressure room-temperature gaseous ethylene delivered;

[0082] S6. The stable ethylene is sent out of the buffer tank through the ethylene pipeline L5 to the downstream for use.

[0083] The present invention provides a system and method for gasifying, heating up, and boosting the pressure of liquid cryogenic ethylene. This system is easy to control, capable of achieving precise parameter adjustment and automated operation, ensuring the stability and reliability of the system. In addition, the system fully considers the uniformity and stability of the heat exchange process in its design, that is, it uses an efficient heat exchange medium and optimizes the process design, making the heat exchange process gentle and stable, and avoiding equipment loss or degradation of material properties caused by drastic temperature fluctuations. Moreover, the system can recover and reuse the cold energy of ethylene, reducing the dependence on external energy sources, not only significantly reducing energy consumption but also reducing cold energy waste, which conforms to the development concept of green energy conservation.

[0084] The present invention provides a system and method for gasifying, heating up, and boosting the pressure of liquid cryogenic ethylene, which has significant economic benefits and outstanding environmental benefits, and has broad application prospects and popularization value.

[0085] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0086] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A system for gasifying liquid low-temperature ethylene to increase temperature and pressure, characterized in that: It comprises a low-temperature ethylene storage tank, an ethylene vaporizer, an ethylene superheater and an ethylene buffer tank. The low-temperature ethylene storage tank is provided with an ethylene submersible pump column. The upper part of the ethylene submersible pump column is connected with a pipeline for delivering ethylene from the submersible pump. The outlet of the pipeline for delivering ethylene from the submersible pump is connected to the tube bundle inlet on the ethylene vaporizer. The tube bundle outlet on the ethylene vaporizer is connected to the ethylene superheater through a pipeline. The pipeline outlet on the ethylene superheater is connected to the ethylene buffer tank through a pipeline. An ethylene submersible pump is arranged in the ethylene submersible pump column.

2. A system for gasifying, heating and pressurizing liquid low-temperature ethylene according to claim 1, characterized in that: The ethylene gasifier is a single shell heat exchanger; The interior of the ethylene gasifier is provided with an upper tube bundle and a lower tube bundle from top to bottom, and the outlet of the submersible pump ethylene delivery pipeline is connected to the upper tube bundle; The ethylene gasifier is filled with propane liquid, and the liquid level of the propane liquid is located between the upper tube bundle and the lower tube bundle; The tube bundle inlet of the lower tube bundle is connected with a chilled water supply pipeline, and the tube bundle outlet of the lower tube bundle is connected with a chilled water return pipeline.

3. The system for gasifying, heating and pressurizing liquid low-temperature ethylene according to claim 1, characterized in that: The ethylene superheater comprises a shell and tube heat exchanger and a condensate tank arranged at the lower end of the shell and tube heat exchanger; The tubes in the tube heat exchanger are located at the upper end of the tube heat exchanger.

4. A system for gasifying, heating and pressurizing liquid low-temperature ethylene according to claim 3, characterized in that: The top of the ethylene superheater is connected with a steam pipeline, and the steam pipeline is used to introduce low-pressure steam into the ethylene superheater. A steam regulating valve is also arranged on the steam pipeline.

5. The system for gasifying, heating and pressurizing liquid low-temperature ethylene according to claim 3, characterized in that: The volume of the tubes in the tube heat exchanger accounts for 2 / 3 of the internal volume of the tube heat exchanger.

6. The system for gasifying, heating and pressurizing liquid low-temperature ethylene according to claim 3, characterized in that: The condensate tank is provided with a condensate tank remote liquid level gauge; A steam condensate delivery pipeline is provided at the bottom of the condensate tank, and the steam condensate delivery pipeline is used to discharge the steam condensate; A steam condensate regulating valve is arranged on the steam condensate delivery pipeline.

7. The system for gasifying, heating and pressurizing liquid low-temperature ethylene according to claim 1, characterized in that: The submersible pump ethylene delivery pipeline is provided with a submersible pump ethylene delivery flowmeter; The submersible pump ethylene delivery pipeline is also connected to a return ethylene pipeline, and the outlet of the return ethylene pipeline is connected to a low-temperature ethylene storage tank; The reflux ethylene pipeline is provided with a reflux ethylene regulating valve.

8. The system for gasifying, heating and pressurizing liquid low-temperature ethylene according to claim 1, characterized in that: A vaporized ethylene thermometer is provided on the pipeline between the ethylene vaporizer and the ethylene superheater; A superheated ethylene thermometer is provided on the pipeline between the ethylene superheater and the ethylene buffer tank.

9. The system for gasifying, heating and pressurizing liquid low-temperature ethylene according to claim 1, characterized in that: The ethylene buffer tank is provided with an ethylene buffer tank remote pressure gauge; The ethylene buffer tank is also provided with a buffer tank ethylene delivery pipeline.

10. A method for gasifying, heating and pressurizing liquid low-temperature ethylene, which is implemented by using the system for gasifying, heating and pressurizing liquid low-temperature ethylene according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: The ethylene submersible pump pressurizes the ethylene in the low-temperature ethylene storage tank to obtain pressurized ethylene, and the pressurized ethylene is sent out of the ethylene pipeline through the submersible pump to the ethylene vaporizer for vaporization to obtain vaporized ethylene, and the vaporized ethylene is transported to the ethylene superheater for heating to obtain heated ethylene, and the heated ethylene is transported to the ethylene buffer tank for pressure-stabilized storage to obtain high-pressure, room-temperature gaseous ethylene.

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