CN216997679U

CN216997679U - Nitrogen recovery system

Info

Publication number: CN216997679U
Application number: CN202121454864.2U
Authority: CN
Inventors: 茹庆华; 薛祥龙; 林序飞
Original assignee: Shanghai Chinllenge Gases Co ltd
Current assignee: Shanghai Chinllenge Gases Co ltd
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2022-07-19
Anticipated expiration: 2031-06-29

Abstract

The utility model belongs to the technical field of nitrogen making equipment, and discloses a nitrogen recovery system which comprises an air separation device, a low-pressure buffer tank, a medium-pressure buffer tank and an automatic supercharger. Nitrogen generated by the air separation device can be sent out of the regulating valve and the nitrogen conveying pipe through the nitrogen outlet pipe and then split, part of the nitrogen enters the low-pressure buffer tank, and part of the nitrogen enters the medium-pressure buffer tank through the first pressurization pipe where the booster is located; and part of nitrogen enters the medium-pressure buffer tank through a second pressure increasing pipe where the automatic pressure increasing device and the automatic pressure increasing device regulating valve are arranged, and the second pressure increasing pipe is connected with the first pressure increasing pipe in parallel. According to the nitrogen recovery system provided by the utility model, the second pressure increasing pipe is connected with the first pressure increasing pipe in parallel, and the automatic pressure increasing device adjusting valve are arranged on the second pressure increasing pipe, so that redundant nitrogen is stored in the medium-pressure buffer tank through the second pressure increasing pipe, the nitrogen is discharged, and the noise pollution generated during the nitrogen discharge is further reduced.

Description

Nitrogen recovery system

Technical Field

The utility model relates to the technical field of nitrogen making equipment, in particular to a nitrogen recovery system.

Background

The nitrogen production equipment of the air separation plant is a gas separation equipment which takes air as a raw material and produces industrial gases such as oxygen, nitrogen and the like through rectification separation by virtue of different boiling points of oxygen and nitrogen. The separated nitrogen can be uninterruptedly supplied to enterprises with application requirements such as metallurgy, petrifaction, chemical engineering, chemical fertilizers, new energy, aerospace, medical treatment, electronics, machinery, food, metal heat treatment and the like.

Generally speaking, nitrogen supplied to downstream enterprises by a space division nitrogen making device of a space division factory comprises low-pressure nitrogen and medium-pressure nitrogen, and a regulating valve and a vent valve are arranged before the space division nitrogen making device is supplied to customers to ensure the stable operation of a nitrogen making device.

When the capacity or product order change of a downstream customer enterprise is reduced, redundant nitrogen is inevitably discharged to ensure the stable operation of the nitrogen making device, waste is caused, and a large amount of noise pollution is generated during nitrogen discharge.

Therefore, how to provide a nitrogen recovery system capable of reducing nitrogen venting, thereby saving resources and reducing noise pollution is a technical problem which needs to be solved urgently.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a nitrogen recovery system to solve the problem of large noise pollution caused by waste of nitrogen emptying at present.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a nitrogen recovery system comprising:

the outlet end of the air separation device is connected with the inlet end of a nitrogen outlet pipe, the middle part of the nitrogen outlet pipe is connected with the inlet end of a nitrogen conveying pipe, and a product discharge regulating valve is arranged on the nitrogen conveying pipe;

the inlet end of the low-pressure buffer tank is connected with the outlet end of the nitrogen conveying pipe, and the outlet end of the low-pressure buffer tank is communicated with the low-pressure conveying pipe;

the supercharger is arranged on a first supercharging pipe, and the inlet end of the first supercharging pipe is communicated with the outlet end of the nitrogen conveying pipe;

the automatic supercharger is arranged on a second supercharging pipe, the second supercharging pipe is connected with the first supercharging pipe in parallel, an automatic supercharger regulating valve is arranged on the second supercharging pipe, and the automatic supercharger regulating valve is arranged on one side of the inlet end of the automatic supercharger;

the inlet end of the medium-pressure buffer tank is connected with the outlet ends of the first pressurizing pipe and the second pressurizing pipe, and the outlet end of the medium-pressure buffer tank is communicated with the medium-pressure conveying pipe.

Preferably, the outlet end of the low-pressure delivery pipe is communicated with the outlet end of the medium-pressure delivery pipe through a medium-pressure low-pressure supplementing pipe, and a medium-pressure low-pressure supplementing regulating valve is arranged on the medium-pressure low-pressure supplementing pipe.

Preferably, the medium pressure supplementing low pressure regulating valve is a solenoid valve configured to allow nitrogen gas to flow from the medium pressure buffer tank to the low pressure buffer tank through the medium pressure supplementing low pressure pipe when the medium pressure supplementing low pressure regulating valve is opened.

Preferably, the nitrogen recovery system further comprises an outlet flow meter provided on the nitrogen outlet pipe between the air separation unit and the nitrogen delivery pipe.

Preferably, the nitrogen recovery system further comprises a nitrogen bleed valve disposed on the nitrogen outlet pipe, and the nitrogen bleed valve and the outlet flow meter are located on both sides of the nitrogen delivery pipe.

Preferably, an outlet of the nitrogen outlet pipe is provided with an emptying silencer.

Preferably, a low-pressure nitrogen pressure detection mechanism is arranged on the low-pressure buffer tank.

Preferably, the low-pressure nitrogen gas pressure detection mechanism is a pressure sensor.

Preferably, a medium-pressure nitrogen pressure detection mechanism is arranged on the medium-pressure buffer tank.

Preferably, the medium-pressure nitrogen pressure detection mechanism is a pressure sensor.

Has the advantages that:

according to the nitrogen recovery system provided by the utility model, the second pressure increasing pipe is connected with the first pressure increasing pipe in parallel, and the automatic pressure increasing device adjusting valve are arranged on the second pressure increasing pipe, so that redundant nitrogen is stored in the medium-pressure buffer tank through the second pressure increasing pipe, the nitrogen is discharged, and the noise pollution generated during the nitrogen discharge is further reduced.

Drawings

FIG. 1 is a schematic diagram of the nitrogen recovery system of the present invention.

In the figure:

1. an air separation plant; 111. a nitrogen outlet pipe; 2. a low-pressure buffer tank; 211. a low-pressure delivery pipe; 3. a medium pressure buffer tank; 311. a medium pressure delivery pipe; 4. the product is sent out of the regulating valve; 411. a nitrogen conveying pipe; 5. a supercharger; 511. a first booster duct; 6. a nitrogen bleed valve; 7. an automatic booster regulator valve; 8. an automatic supercharger; 811. a second booster duct; 9. a medium pressure nitrogen pressure detection mechanism; 10. a low-pressure nitrogen pressure detection mechanism; 11. discharging the device flowmeter; 12. a medium-pressure compensation low-pressure regulating valve; 121. a low-pressure pipe is compensated at medium pressure; 13. and (5) emptying the silencer.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not to be construed as limiting the utility model. It should be further noted that, for the convenience of description, only some structures related to the present invention are shown in the drawings, not all of them.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used in an orientation or positional relationship based on that shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

The present embodiment provides a nitrogen recovery system, as shown in fig. 1. The nitrogen recovery system comprises an air separation device 1, a low-pressure buffer tank 2, a supercharger 5, an automatic supercharger 8 and a medium-pressure buffer tank 3. The air separation apparatus 1 separates nitrogen from air by a rectification process by utilizing properties of different boiling points of various gases in air. The specific structure of the air separation plant 1 is the prior art and will not be described herein.

The outlet end of the air separation plant 1 is connected with the inlet end of the nitrogen outlet pipe 111, the middle part of the nitrogen outlet pipe 111 is connected with a nitrogen conveying pipe 411, and the nitrogen outlet pipe 111 and the nitrogen conveying pipe 411 are connected in a T shape. The nitrogen gas delivery pipe 411 is provided with a product discharge regulating valve 4. Alternatively, the product discharge adjustment valve 4 is an electromagnetic valve, and the flow rate of nitrogen gas in the nitrogen delivery pipe 411 can be controlled by controlling the product discharge adjustment valve 4.

The nitrogen delivery pipe 411 is connected with three pipelines at the outlet end: one of the pipelines is a low-pressure input pipe, one end of the low-pressure input pipe, which is far away from the nitrogen conveying pipe 411, is connected with the inlet end of a low-pressure buffer tank 2, the low-pressure buffer tank 2 is used for storing low-pressure nitrogen, the outlet end of the low-pressure buffer tank is connected with a low-pressure conveying pipe 211, and low-pressure gas is conveyed to downstream customers through the low-pressure conveying pipe 211; the other pipeline is a first booster pipe 511, a booster 5 is arranged on the first booster pipe 511, the booster 5 is used for boosting nitrogen, and the outlet end of the first booster pipe 511 is communicated with the medium-pressure buffer tank 3; the automatic booster comprises an automatic booster adjusting valve 7 and an automatic booster 8, wherein the automatic booster adjusting valve 7 is arranged on one side of an inlet end of the automatic booster 8, the flow of nitrogen gas conveyed to the automatic booster 8 can be controlled by adjusting the opening degree of a valve of the automatic booster adjusting valve 7, and an outlet end of the automatic booster 8 is communicated with the medium-pressure buffer tank 3, namely, the first booster pipe 511 and the second booster pipe 811 are arranged in parallel.

The outlet end of the medium pressure buffer tank 3 is communicated with a medium pressure delivery pipe 311, and the nitrogen gas of the medium pressure buffer tank 3 can be delivered through the medium pressure delivery pipe 311 according to the requirements of downstream users. Through adjusting 7 valve openings of automatic booster governing valves to set up automatic booster 8 and second pressure boost pipe 811, when the nitrogen gas demand was little, unnecessary nitrogen gas was stored in middling pressure buffer tank 3 through this pipeline pressure boost, thereby reduces the diffusion of nitrogen gas, the energy saving, and then the noise that produces when having reduced the diffusion. In addition, this nitrogen gas recovery system utilizes booster compressor 5 pressure boost nitrogen gas, does not need additionally to dispose equipment such as water supply, power supply, has reduced the input cost in earlier stage, has reduced later maintenance work simultaneously.

Optionally, the outlet end of the low pressure delivery pipe 211 is communicated with the outlet end of the medium pressure delivery pipe 311 through a medium pressure supplementing low pressure pipe 121, and the medium pressure supplementing low pressure regulating valve 12 is arranged on the medium pressure supplementing low pressure pipe 121. Optionally, the medium-pressure supplementing low-pressure regulating valve 12 is an electromagnetic valve, when the amount of nitrogen in the low-pressure buffer tank 2 is insufficient, the valve opening of the medium-pressure supplementing low-pressure regulating valve 12 can be regulated, so that the nitrogen stored in the medium-pressure buffer tank 3 is supplemented to the low-pressure buffer tank 2 properly, and the nitrogen is conveyed to a downstream user needing low-pressure nitrogen, thereby avoiding the waste of nitrogen, reducing the emission of nitrogen, and further reducing the noise generated by the emission of nitrogen.

In this embodiment, an outlet flow meter 11 is further provided between the air separation plant 1 and the nitrogen gas transport pipe 411. Optionally, a low-pressure nitrogen pressure detection mechanism 10 is arranged on the low-pressure buffer tank 2, and the low-pressure nitrogen pressure detection mechanism 10 monitors the pressure in the low-pressure buffer tank 2 in real time. A medium-pressure nitrogen pressure detection mechanism 9 is arranged on the medium-pressure buffer tank 3, and the medium-pressure nitrogen pressure detection mechanism 9 monitors the pressure in the medium-pressure buffer tank 3 in real time. The related valve adjusts the valve opening according to the measured value of the outlet device flow meter 11, the pressure value of the low-pressure nitrogen pressure detection mechanism 10 and the pressure value of the medium-pressure nitrogen pressure detection mechanism 9. Alternatively, the low-pressure nitrogen pressure detecting mechanism 10 and the medium-pressure nitrogen pressure detecting mechanism 9 are pressure sensors. The pressure range in the low-pressure buffer tank 2 is 0.5MPa-0.6 MPa; the pressure range in the medium-pressure buffer tank 3 is 1.3MPa-2.5 MPa.

Further, nitrogen gas recovery system still is provided with nitrogen gas and diffuses valve 6, and nitrogen gas is diffused valve 6 and is set up on nitrogen gas outlet pipe 111, and nitrogen gas is diffused valve 6 and goes out device flowmeter 11 and set up in the both sides of nitrogen gas conveyer pipe 411, and is less when user's nitrogen gas demand in the low reaches, and when unnecessary nitrogen gas can't rethread buffer tank 3 stores, nitrogen gas is diffused through nitrogen gas diffusion valve 6 to adjust pipe network pressure, guarantee system steady operation. The outlet of the nitrogen outlet pipe 111 is also provided with a discharge muffler 13 for reducing noise generated when the nitrogen is discharged.

In this embodiment, the system further includes a control mechanism, the control mechanism may be a centralized or distributed controller, for example, the controller may be a single-chip microcomputer or may be composed of a plurality of distributed single-chip microcomputers, and a control program (i.e., the PCL program) may be run in the single-chip microcomputers, so as to control the product to be sent out of the regulating valve 4, the nitrogen bleeding valve 6, and the medium-pressure compensation low-pressure regulating valve 12 to implement the functions thereof.

Optionally, in this embodiment, the PCL program is combined with the real-time pressure value detected by the pressure detection mechanism and the measurement value of the outlet device flowmeter 11 to control and adjust the opening of each valve, so that the degree of automation is high, the system runs stably, and the workload of an operator is greatly reduced. The control logic of the PCL program is as follows:

when the amount of nitrogen required by a downstream user is stable, the valve does not need to be frequently adjusted, and the adjustment range of the valve opening is small, the valve opening of the product sending adjusting valve 4 is adjusted according to the measured value of the outlet device flowmeter 11 and the amount of nitrogen required by the downstream user, one path of nitrogen passing through the product sending adjusting valve 4 enters the low-pressure buffer tank 2 and flows through the low-pressure conveying pipe 211 to be conveyed to the downstream user; one path is pressurized by a supercharger 5, enters a medium-pressure buffer tank 3, and is conveyed to downstream users through a medium-pressure conveying pipe 311; the nitrogen gas bleeding valve 6 adjusts the opening of the valve according to the measured value of the outlet device flowmeter 11 and the pressure condition in the pipe network, thereby controlling the bleeding amount of the nitrogen gas and stabilizing the normal operation of the system.

When the downstream user usage decreases, the product delivery regulating valve 4 increases the valve opening based on the measured value of the delivery meter 11 and the given parameter. When the product sent out governing valve 4 valve aperture when 90% above, automatic booster governing valve 7 was opened, and automatic booster governing valve 7 was crossed to nitrogen gas, through the pressure boost of automatic booster 8, flows through second booster pipe 811 and stores nitrogen gas to middling pressure buffer tank 3 to avoid increasing nitrogen gas diffusion valve 6 valve aperture, cause nitrogen gas extravagant.

If the downstream user continues to decrement, the opening degree of the valve of the product delivery regulating valve 4 is continuously increased to full opening, and redundant nitrogen still exists, the opening degree of the valve of the nitrogen bleeding valve 6 is increased, when the opening degree of the valve of the nitrogen bleeding valve 6 is increased to be more than 40%, if the pressure value detected by the medium-pressure nitrogen pressure measuring mechanism is lower than 2MPa, the booster 5 is started, and the nitrogen is pressurized by the booster 5 and then stored in the medium-pressure buffer tank 3; when the pressure value detected by the medium-pressure nitrogen pressure measuring mechanism is greater than 2.5MPa, stopping the booster 5, closing the automatic booster regulating valve 7, and stopping conveying nitrogen to the medium-pressure buffer tank 3 to prevent the medium-pressure buffer tank 3 from being damaged due to overlarge pressure; the booster 5 stops, and after the automatic booster governing valve 7 was closed, the pressure value was less than 2MPa to the downstream customer pressure in the buffer tank 3 in the middle pressure buffer tank 3 was carried to the interior nitrogen gas of middle pressure buffer tank 3, and booster 5 restarts, automatic booster governing valve 7 opened to the alarm appears, reminds out device flowmeter 11 and sets for the decrement.

If the measured value of the downstream user at the outlet device flowmeter 11 is a small amount of gas, the first expression is that the pressure value detected by the low-pressure nitrogen pressure detection mechanism 10 is small, the amount of nitrogen in the low-pressure buffer tank 2 cannot meet the requirements of the downstream user, if the pressure value detected by the low-pressure nitrogen pressure detection mechanism 10 is less than 0.5MPa, the valve of the medium-pressure compensation low-pressure regulating valve 12 is adjusted according to a set value, so that nitrogen stored in the medium-pressure buffer tank 3 is conveyed to the low-pressure buffer tank 2 through the medium-pressure compensation low-pressure pipe 121, and when the pressure value in the medium-pressure buffer tank 3 detected by the medium-pressure nitrogen pressure detection mechanism 9 is less than the low limit of 1.5MPa, an alarm appears to remind the outlet device flowmeter 11 of setting the amount of gas.

In order to ensure that the medium-pressure buffer tank 3 is not lower than the low limit gas supply and the medium-pressure nitrogen pressure measuring point is lower than 1.3MPa, a supercharger 5 is started; when the pressure measurement point of the medium-pressure nitrogen is higher than 1.6MPa, the booster 5 is stopped.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, adaptations and substitutions will occur to those skilled in the art without departing from the scope of the utility model. This need not be, nor should it be exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A nitrogen recovery system, comprising:

the air separation device (1), the outlet end of the air separation device (1) is connected with the inlet end of a nitrogen outlet pipe (111), the middle part of the nitrogen outlet pipe (111) is connected with the inlet end of a nitrogen conveying pipe (411), and a product discharge regulating valve (4) is arranged on the nitrogen conveying pipe (411);

the inlet end of the low-pressure buffer tank (2) is connected with the outlet end of the nitrogen conveying pipe (411), and the outlet end of the low-pressure buffer tank (2) is communicated with a low-pressure conveying pipe (211);

the supercharger (5), the supercharger (5) is arranged on a first supercharging pipe (511), and the inlet end of the first supercharging pipe (511) is communicated with the outlet end of the nitrogen conveying pipe (411);

the automatic supercharger (8), the automatic supercharger (8) is arranged on a second supercharging pipe (811), the second supercharging pipe (811) is connected with the first supercharging pipe (511) in parallel, an automatic supercharger regulating valve (7) is arranged on the second supercharging pipe (811), and the automatic supercharger regulating valve (7) is arranged on one side of the inlet end of the automatic supercharger (8);

the inlet end of the medium-pressure buffer tank (3) is connected with the outlet end of the first pressurizing pipe (511) and the outlet end of the second pressurizing pipe (811), and the outlet end of the medium-pressure buffer tank (3) is communicated with the medium-pressure conveying pipe (311).

2. A nitrogen recovery system according to claim 1, wherein the outlet of the low-pressure delivery pipe (211) communicates with the outlet of the medium-pressure delivery pipe (311) via a medium-pressure low-pressure compensator pipe (121), the medium-pressure low-pressure compensator pipe (121) being provided with a medium-pressure low-pressure regulator valve (12).

3. A nitrogen recovery system according to claim 2, wherein the intermediate pressure supplementing low pressure regulating valve (12) is a solenoid valve, the intermediate pressure supplementing low pressure regulating valve (12) being configured to allow nitrogen to flow from the intermediate pressure buffer tank (3) to the low pressure buffer tank (2) via the intermediate pressure supplementing low pressure pipe (121) when open.

4. A nitrogen recovery system according to claim 1, further comprising an outlet flow meter (11), said outlet flow meter (11) being provided on said nitrogen outlet pipe (111) between said air separation plant (1) and said nitrogen delivery pipe (411).

5. A nitrogen recovery system according to claim 4, further comprising a nitrogen bleed valve (6), said nitrogen bleed valve (6) being provided on the nitrogen outlet pipe (111), said nitrogen bleed valve (6) and said outlet flow meter (11) being located on both sides of the nitrogen delivery pipe (411).

6. A nitrogen recovery system, as claimed in claim 1, characterized in that the outlet of said nitrogen outlet pipe (111) is provided with a venting silencer (13).

7. The nitrogen recovery system according to claim 1, wherein the low-pressure buffer tank (2) is provided with a low-pressure nitrogen pressure detection mechanism (10).

8. The nitrogen recovery system of claim 7, wherein the low pressure nitrogen pressure detection mechanism (10) is a pressure sensor.

9. A nitrogen recovery system according to claim 1, wherein the medium pressure buffer tank (3) is provided with a medium pressure nitrogen pressure detection mechanism (9).

10. A nitrogen recovery system according to claim 9, wherein the medium pressure nitrogen pressure detection means (9) is a pressure sensor.