Nitrogen production system of air separation device

Abstract

The utility model relates to the technical field of air separation devices, in particular to an air separation device nitrogen production system which comprises an air separation device connected with a normal-pressure nitrogen conveying pipe and a low-pressure nitrogen conveying pipe. The normal-pressure nitrogen conveying pipe is connected with a water cooling tower, the water cooling tower is connected with an air cooling tower through a pipeline I, and the pipeline I is connected with a water chilling unit; the first pipeline is connected with a first heat exchange medium connector of a heat exchanger. The low-pressure nitrogen conveying pipe is connected with a second heat exchange medium connector of the heat exchanger. Low-pressure nitrogen in the low-pressure nitrogen conveying pipe exchanges heat with water flowing to the air cooling tower in the water cooling tower, so that the cooling capacity of the low-pressure nitrogen can be recovered, and after being conveyed to a user, the low-pressure nitrogen can be directly used by the user and does not need to be reheated; and the energy consumption of the water chilling unit is reduced, so that more energy is saved.

Description

Technical Field

[0001] This utility model relates to the field of air separation equipment technology, specifically a nitrogen production system for an air separation equipment. Background Technology

[0002] An air separation unit is an industrial equipment used to separate the various components of air into gases such as oxygen, low-pressure nitrogen, atmospheric nitrogen, and argon. Currently, the low-pressure nitrogen separated by an air separation unit is directly transported to users through pipelines. However, the low-pressure nitrogen has a low temperature, and users need to heat it before use, resulting in energy waste. Utility Model Content

[0003] The main purpose of this invention is to provide a nitrogen production system for an air separation unit, in order to solve the problem in the prior art where the low-pressure nitrogen produced by the air separation unit is directly delivered to the user, and the user needs to heat the low-pressure nitrogen before use, resulting in energy waste.

[0004] To achieve the above objectives, this utility model provides a nitrogen production system for an air separation unit, including an air separation unit connected to an atmospheric pressure nitrogen delivery pipe and a low pressure nitrogen delivery pipe; the atmospheric pressure nitrogen delivery pipe is connected to a water-cooled tower, the water-cooled tower is connected to an air-cooled tower via a pipeline, and a chiller unit is connected to the pipeline; the pipeline is connected to a first heat exchange medium interface of a heat exchanger, and the low pressure nitrogen delivery pipe is connected to a second heat exchange medium interface of the heat exchanger.

[0005] Furthermore, an isolation pipe 1 that can isolate the heat exchanger is connected to the first pipeline, and an isolation pipe 2 that can isolate the heat exchanger is connected to the low-pressure nitrogen delivery pipe; valves are installed on the isolation pipe 1 and the isolation pipe 2; a valve is installed on the first pipeline near the heat exchanger, and a valve is installed on the low-pressure nitrogen delivery pipe near the heat exchanger.

[0006] Furthermore, the atmospheric pressure nitrogen delivery pipe is connected to the compressor inlet via pipe two, and the compressor outlet is connected to pipe three.

[0007] Furthermore, the refrigerant inside the chiller unit is R22.

[0008] Furthermore, the heat exchanger is a plate heat exchanger.

[0009] Furthermore, valves are installed on both the atmospheric pressure nitrogen delivery pipe and the second pipeline.

[0010] This invention recovers the cooling capacity of low-pressure nitrogen by exchanging heat between the low-pressure nitrogen in the low-pressure nitrogen delivery pipe and the water flowing from the water-cooled tower to the air-cooled tower. After the low-pressure nitrogen is delivered to the user, the user can use it directly without reheating. It also reduces the energy consumption of the chiller unit, thus making it more energy-efficient. Attached Figure Description

[0011] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0012] Figure 1 This is a schematic diagram of the nitrogen production system of the air separation unit in the embodiment;

[0013] In the diagram: 1. Air separation unit; 2. Atmospheric pressure nitrogen delivery pipe; 3. Low pressure nitrogen delivery pipe; 4. Water cooling tower; 5. Pipeline 1; 6. Air cooling tower; 7. Chiller unit; 8. Heat exchanger; 9. Isolation pipe 1; 10. Isolation pipe 2; 11. Compressor; 12. Pipeline 2; 13. Pipeline 3. Detailed Implementation

[0014] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0015] like Figure 1 As shown in the embodiment of this utility model, a nitrogen production system for an air separation unit is provided, including an air separation unit 1. The air separation unit 1 is connected to an atmospheric pressure nitrogen delivery pipe 2 and a low-pressure nitrogen delivery pipe 3. The nitrogen pressure in the atmospheric pressure nitrogen delivery pipe 2 is 12-15 kPa and the temperature is 15-19°C. The nitrogen pressure in the low-pressure nitrogen delivery pipe 3 is 410-420 kPa and the temperature is 2-6°C. The atmospheric pressure nitrogen delivery pipe 2 is connected to a water-cooled tower 4. The atmospheric pressure nitrogen is delivered to the water-cooled tower 4 to cool the water inside the water-cooled tower 4. The water-cooled tower 4 is connected to an air-cooled tower 6 through a pipe 5. A water pump is installed on the pipe 5, and a chiller unit 7 is connected to the pipe 5. The water in the water-cooled tower 4 is delivered to the air-cooled tower 6 for cooling the upper section of the air-cooled tower. The pipe 5 is connected to the first heat exchange medium interface of a heat exchanger 8, and the low-pressure nitrogen delivery pipe 3 is connected to the second heat exchange medium interface of the heat exchanger 8. The heat exchanger 8 is a plate heat exchanger.

[0016] Pipeline 5 is connected to isolation pipe 9, which can isolate heat exchanger 8, and low-pressure nitrogen delivery pipe 3 is connected to isolation pipe 10, which can isolate heat exchanger 8; valves are installed on isolation pipe 9 and isolation pipe 10; valves are installed on pipeline 5 near heat exchanger 8 and on low-pressure nitrogen delivery pipe 3 near heat exchanger 8.

[0017] The atmospheric pressure nitrogen delivery pipe 2 is connected to the inlet of the compressor 11 via pipe 2 12, and the outlet of the compressor 11 is connected to pipe 3 13. The compressor 11 is used to compress nitrogen to about 0.8MPa and deliver it to the pipeline network.

[0018] The refrigerant inside chiller unit 7 is R22.

[0019] Valves are installed on both the atmospheric pressure nitrogen delivery pipe 2 and the pipeline 12 to control the direction and flow rate of nitrogen.

[0020] In this embodiment, the low-pressure nitrogen in the low-pressure nitrogen delivery pipe 3 exchanges heat with the water flowing from the water-cooled tower 4 to the air-cooled tower 6 through a heat exchanger 8, thus recovering the cooling capacity of the low-pressure nitrogen. After heat exchange, the temperature of the low-pressure nitrogen is 14-18℃. After the low-pressure nitrogen is delivered to the user, the user can use it directly without further heating. The initial temperature of the water flowing from the water-cooled tower 4 to the air-cooled tower 6 is 18-22℃, and the temperature of the water after heat exchange is 14-18℃. The water after heat exchange is then cooled to 8-12℃ by the chiller unit 7 before being introduced into the air-cooled tower 6. Due to the pre-cooling of the water by the heat exchanger 8, the energy consumption of the chiller unit 7 is reduced, thus achieving greater energy savings.

[0021] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A nitrogen production system for an air separation unit, comprising an air separation unit (1), wherein the air separation unit (1) is connected to an atmospheric pressure nitrogen delivery pipe (2) and a low pressure nitrogen delivery pipe (3); the atmospheric pressure nitrogen delivery pipe (2) is connected to a water-cooled tower (4), the water-cooled tower (4) is connected to an air-cooled tower (6) via a pipeline (5), and a chiller unit (7) is connected to the pipeline (5); characterized in that, The first pipe (5) is connected to the first heat exchange medium interface of the heat exchanger (8), and the low-pressure nitrogen delivery pipe (3) is connected to the second heat exchange medium interface of the heat exchanger (8).

2. The nitrogen production system for an air separation unit as described in claim 1, characterized in that, The first pipe (5) is connected to an isolation pipe (9) that can isolate the heat exchanger (8), and the low-pressure nitrogen delivery pipe (3) is connected to an isolation pipe (10) that can isolate the heat exchanger (8); valves are provided on the first isolation pipe (9) and the second isolation pipe (10); a valve is provided on the first pipe (5) near the heat exchanger (8), and a valve is provided on the low-pressure nitrogen delivery pipe (3) near the heat exchanger (8).

3. The nitrogen production system for an air separation unit as described in claim 1, characterized in that, The atmospheric pressure nitrogen delivery pipe (2) is connected to the inlet of the compressor (11) via pipe two (12), and the outlet of the compressor (11) is connected to pipe three (13).

4. The nitrogen production system of the air separation unit as described in claim 1, characterized in that, The refrigerant inside the chiller unit (7) is R22.

5. The nitrogen production system for an air separation unit as described in claim 1, characterized in that, The heat exchanger (8) is a plate heat exchanger.

6. The nitrogen production system for an air separation unit as described in claim 1, characterized in that, Valves are provided on both the atmospheric pressure nitrogen delivery pipe (2) and the second pipe (12).

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