Backup nitrogen generation device in fault state of air separation device

Abstract

The utility model discloses a backup nitrogen generation device in a fault state of an air separation unit. The backup nitrogen generation device in the fault state of the air separation unit comprises a liquid nitrogen storage tank, a controller, a liquid nitrogen pump and a gasifier. The liquid nitrogen storage tank is used for receiving liquid nitrogen when the air separation device works normally; the controller is in signal connection with the liquid nitrogen pump and is configured to detect the operation state of the air separation device and send a shutdown signal to the liquid nitrogen pump when the air separation device is shut down; an inlet of the liquid nitrogen pump is communicated with the liquid nitrogen storage tank, and the liquid nitrogen pump is configured to accelerate and pressurize after receiving a stop signal; the first end of the gasifier communicates with an outlet of the liquid nitrogen pump. The backup nitrogen generation device in the fault state of the air separation unit can generate nitrogen after the air separation unit breaks down, the nitrogen is used for a synthesis ammonia process and chemical production coking, normal proceeding of the synthesis ammonia process and the chemical production coking is guaranteed, and economic losses and secondary events of enterprises are avoided.

Description

Technical Field

[0001] The present application relates to the technical field of chemical equipment, and in particular to a backup nitrogen generating device in a faulty state of an air separation unit. Background Art

[0002] An air separation unit (ASU) is an industrial device used to separate various components in air. It separates gases like oxygen, nitrogen, and argon from air through methods such as deep freezing, adsorption, and membrane separation. It is widely used in metallurgy, chemical engineering, petroleum, machinery, mining, and food processing.

[0003] In the chemical industry, air separation units (ASUs) separate nitrogen from air and transport it to the ammonia synthesis process and to chemical production plants for use as coking gas. However, if an ASU fails and stops due to a malfunction, both the ammonia synthesis process and chemical coking must be interrupted, causing significant economic losses to the company and potentially leading to safety and environmental concerns. Summary of the Invention

[0004] The embodiments of the present application provide a backup nitrogen generator in the event of a failure of an air separation unit, thereby solving the technical problem in the prior art of shutting down the air separation unit due to a failure, resulting in suspension of synthetic ammonia production and interruption of gas supply for chemical coking.

[0005] An embodiment of the present application provides a backup nitrogen generation device for an air separation unit in a fault state, comprising: a liquid nitrogen storage tank, the liquid nitrogen storage tank being used to receive liquid nitrogen when the air separation unit is operating normally; a liquid nitrogen pump, the inlet of the liquid nitrogen pump being connected to the liquid nitrogen storage tank; a controller, the controller signal being connected to the liquid nitrogen pump and configured to detect the operating state of the air separation unit and send a stop signal to the liquid nitrogen pump when the air separation unit is shut down; and a vaporizer, the first end of the vaporizer being connected to the outlet of the liquid nitrogen pump; wherein the liquid nitrogen pump is configured to increase speed and pressure after receiving the stop signal.

[0006] In a possible implementation, the backup nitrogen generating device in the event of a failure of the air separation unit further includes: a nitrogen buffer device connected to a second end of the gasifier opposite to the first end.

[0007] In one possible implementation, the nitrogen buffer device includes a first buffer tank, a second buffer tank and a nitrogen compressor; the first buffer tank and the second buffer tank are arranged in parallel, and the inlet of the first buffer tank and the inlet of the second buffer tank are both connected to the second end of the vaporizer; the nitrogen compressor is connected to the first buffer tank.

[0008] In a possible implementation, the inlet of the second buffer tank is connected to the outlet of the air separation unit.

[0009] In a possible implementation, the backup nitrogen generating device in the event of a failure of the air separation unit further includes: a liquefaction device, wherein two ends of the liquefaction device are respectively connected to the air separation unit and the liquid nitrogen storage tank.

[0010] In a possible implementation, the gasifier includes an air bath gasifier.

[0011] The technical solutions provided in the embodiments of this application have at least the following technical effects:

[0012] The embodiment of the present application provides a backup nitrogen generating device in the event of a failure of an air separation unit. The backup nitrogen generating device in the event of a failure of the air separation unit includes a liquid nitrogen storage tank, a controller, a liquid nitrogen pump, and a vaporizer. The liquid nitrogen storage tank is used to receive liquid nitrogen when the air separation unit is operating normally. The controller can detect the operating status of the air separation unit and send a stop signal to the liquid nitrogen pump when the air separation unit is shut down. The liquid nitrogen pump increases speed and pressure after receiving the stop signal to transport the liquid nitrogen in the liquid nitrogen storage tank to the outside. The vaporizer vaporizes the liquid nitrogen to form nitrogen gas, which is used in the ammonia synthesis process and chemical product coking. Therefore, the backup nitrogen generating device in the event of a failure of the air separation unit can generate nitrogen gas for use in the ammonia synthesis process and chemical product coking after the air separation unit fails, thereby ensuring the normal operation of the ammonia synthesis process and chemical product coking, and avoiding economic losses and secondary events for the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0014] Figure 1 A schematic structural diagram of a backup nitrogen generator in the event of a failure of an air separation unit according to an embodiment of the present application;

[0015] Figure 2 This is a schematic structural diagram of the air bath gasifier provided in an embodiment of the present application.

[0016] Description of reference numerals:

[0017] 100-Liquid nitrogen storage tank; 200-Controller; 300-Liquid nitrogen pump; 400-Gasifier; 500-Nitrogen buffer device; 510-First buffer tank; 520-Second buffer tank; 530-Nitrogen compressor; 600-Liquefaction device; 700-Air separation unit. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0019] In the description of the embodiments of the present application, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, the terms "installed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood based on the specific circumstances.

[0020] The embodiment of the present application provides a backup nitrogen generating device in the event of a failure of an air separation unit, such as Figure 1 As shown, the backup nitrogen generating device in the event of a failure of the air separation unit includes a liquid nitrogen storage tank 100 , a controller 200 , a liquid nitrogen pump 300 and a vaporizer 400 .

[0021] The liquid nitrogen storage tank 100 is a device for storing liquid nitrogen. It is mainly based on low-temperature insulation technology, which keeps the liquid nitrogen at a low temperature by reducing heat transfer. The liquid nitrogen storage tank 100 is used to receive liquid nitrogen when the air separation unit 700 is operating normally.

[0022] The controller 200 is signal-connected to the liquid nitrogen pump 300 and is configured to detect the operating status of the air separation unit 700 and send a shutdown signal to the liquid nitrogen pump 300 when the air separation unit 700 is shut down. For example, the controller 200 may be a distributed control system (DCS) configured on the air separation unit 700. The DCS can monitor the operating status of the air separation unit 700 in real time and automatically shut down the unit when an abnormality is detected, and send a shutdown signal to the liquid nitrogen pump 300.

[0023] The inlet of the liquid nitrogen pump 300 is connected to the liquid nitrogen storage tank 100 and is configured to increase speed and pressure upon receiving a stop signal to transport the liquid nitrogen in the liquid nitrogen storage tank 100. When the air separation unit 700 is operating normally, the liquid nitrogen pump 300 is in a low-speed cold standby state or a power-off state. Upon receiving a stop signal from the air separation unit 700, the liquid nitrogen pump 300 rapidly increases speed and pressure to transport the liquid nitrogen in the liquid nitrogen storage tank 100; for example, the liquid nitrogen pump 300 increases speed and pressure to 3.0 MPa.

[0024] The vaporizer 400 is a device that heats liquid gas until it is vaporized (converted into gas). The first end of the vaporizer 400 is connected to the outlet of the liquid nitrogen pump 300. For example, Figure 2 As shown, vaporizer 400 comprises an air-bath vaporizer. This type of vaporizer utilizes the natural flow of air for heating, requiring no additional energy consumption. Its structure is relatively simple, typically consisting of aluminum heat exchange tubes and fins, making it easy to install and maintain. Of course, vaporizer 400 may also be a water-bath vaporizer, a steam-heated vaporizer, or other types.

[0025] After a failure occurs in the air separation unit 700, the controller 200 detects that the air separation unit 700 has stopped and sends a stop signal to the liquid nitrogen pump 300. After receiving the stop signal, the liquid nitrogen pump 300 increases speed and pressure to transport the liquid nitrogen in the liquid nitrogen storage tank 100 to the outside. The liquid nitrogen is vaporized into nitrogen gas after passing through the vaporizer 400 and enters the ammonia synthesis process and the chemical product coking workshop, ensuring the normal operation of the ammonia synthesis process and the chemical product coking workshop, and avoiding economic losses and secondary events for the enterprise.

[0026] Further, continue to refer to Figure 1 The backup nitrogen generating device in the event of a failure of the air separation unit further includes a nitrogen buffer device 500 , which is connected to a second end of the gasifier 400 relative to the first end.

[0027] The nitrogen buffer device 500 can reduce pressure fluctuations and reduce the impact of gas flow, so that the nitrogen entering the synthetic ammonia process and the chemical product coking workshop has a stable pressure, protecting equipment and pipelines and avoiding damage caused by excessive pressure fluctuations.

[0028] Specifically, the nitrogen buffer device 500 includes a first buffer tank 510, a second buffer tank 520, and a nitrogen compressor 530. The first buffer tank 510 and the second buffer tank 520 are arranged in parallel, with the inlet of the first buffer tank 510 and the inlet of the second buffer tank 520 both connected to the second end of the gasifier 400. The outlet of the first buffer tank 510 is connected to the ammonia synthesis equipment for transporting nitrogen to the ammonia synthesis process. The outlet of the second buffer tank 520 is connected to the chemical product coking equipment for using the nitrogen as chemical product coking gas. The nitrogen compressor 530 is connected to the first buffer tank 510 and can pressurize the nitrogen in the first buffer tank 510 to ensure that the nitrogen output from the first buffer tank 510 has a pressure sufficient for the ammonia synthesis process.

[0029] Furthermore, the inlet of the second buffer tank 520 is connected to the outlet of the air separation unit 700. When the air separation unit 700 operates normally, the nitrogen generated by the air separation unit 700 passes through the second buffer tank 520, which buffers the nitrogen to make the output nitrogen pressure more stable.

[0030] like Figure 1 As shown, the backup nitrogen generation device provided in the embodiment of the present application in the event of an air separation unit failure further includes a liquefaction device 600 , and both ends of the liquefaction device 600 are respectively connected to the air separation unit 700 and the liquid nitrogen storage tank 100 .

[0031] The liquefaction unit 600 is a device that converts gas into liquid by compressing and cooling the gas. When the air separation unit 700 is operating normally, the liquefaction unit 600 is used to liquefy part of the nitrogen output from the air separation unit 700 and transport it to the liquid nitrogen storage tank 100 for storage.

[0032] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0033] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A backup nitrogen generator for an air separation unit in a faulty state, characterized in that: include: a liquid nitrogen storage tank, wherein the liquid nitrogen storage tank is used to receive liquid nitrogen when the air separation unit operates normally; a liquid nitrogen pump, wherein the inlet of the liquid nitrogen pump is connected to the liquid nitrogen storage tank; a controller, the controller being signal-connected to the liquid nitrogen pump and configured to detect an operating state of the air separation unit and to send a stop signal to the liquid nitrogen pump when the air separation unit is shut down; a vaporizer, wherein a first end of the vaporizer is connected to an outlet of the liquid nitrogen pump; The liquid nitrogen pump is configured to increase speed and pressure after receiving the stop signal.

2. The backup nitrogen generator in case of failure of the air separation unit according to claim 1, characterized in that: Also includes: A nitrogen buffer device is connected to a second end of the gasifier opposite to the first end.

3. The backup nitrogen generator in case of failure of the air separation unit according to claim 2, characterized in that: The nitrogen buffer device includes a first buffer tank, a second buffer tank and a nitrogen compressor; The first buffer tank and the second buffer tank are arranged in parallel, and the inlet of the first buffer tank and the inlet of the second buffer tank are both connected to the second end of the gasifier; The nitrogen compressor is connected to the first buffer tank.

4. The backup nitrogen generator in case of failure of the air separation unit according to claim 3, characterized in that: The inlet of the second buffer tank is connected to the outlet of the air separation device.

5. The backup nitrogen generator in case of failure of the air separation unit according to claim 1, characterized in that: Also includes: A liquefaction device, wherein both ends of the liquefaction device are respectively connected to the air separation device and the liquid nitrogen storage tank.

6. The backup nitrogen generator in case of failure of the air separation unit according to claim 1, characterized in that: The gasifier includes an air bath type gasifier.

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