Quicker air separation plant starting and purging device

Abstract

The invention relates to the technical field of electric power, in particular to a faster air separation unit starting and purging device. The device is composed of a liquid nitrogen storage tank, a water bath module, a supercharger and a heat exchanger, the liquid nitrogen storage tank is connected with the water bath module, the supercharger is connected with the heat exchanger, the water bath module is connected with the heat exchanger, and the discharge end of the heat exchanger is connected with an online analyzer. According to the air separation plant starting purging device provided by the invention, dry low-pressure nitrogen is added at an inlet of a high-exchange channel of a supercharger to serve as a purging gas source, an online analyzer is added at a purging sampling point, a pipeline which is difficult to purge at the section is emphatically purged, the purging progress at the starting stage is accelerated, the overall starting time is shortened, and energy conservation and consumption reduction are realized.

Description

Technical Field

[0001] The invention relates to the field of electric power technology, and in particular to a faster start-up purge device for air separation equipment. Background Art

[0002] During the cold-keeping startup phase of the air separation system, it is necessary to purge the pipelines outside the cold box. The purpose of the purge is to remove solid impurities and moisture in the pipelines to prevent blockage of equipment and pipelines after cooling. The purge range includes the booster pipeline, booster high-speed exchange channel, expander booster end pipeline, expansion end pipeline, high-speed exchange channel, cryogenic pump pipeline, and high-speed exchange channel. The purge dew point is required to be below -60°C. The booster high-speed exchange channel needs to be purged after the booster pipeline has been purged and qualified.

[0003] However, the existing purge device has the following defects: through multiple cold-start purge operations, it was found that during the purge stage, the purge time of the supercharger high-pressure heat exchanger channel was the longest. After analysis, it was found that the temperature of the purge air was reduced after passing through the high-pressure heat exchanger with low temperature. When it was discharged at the dew point sampling port, the water vapor in the surrounding air condensed quickly, extending the overall startup time, increasing the power consumption of the unit, and affecting the startup indicators. Summary of the invention

[0004] The present invention proposes a faster startup purge device for air separation equipment. At the entrance of the high-pressure exchange channel of the booster, dry low-pressure nitrogen is added as the purge gas source, and an online analyzer is added at the purge sampling point to focus on purging this section of the pipeline that is difficult to purge, thereby accelerating the purge progress in the startup phase, shortening the overall startup time, and achieving energy saving and consumption reduction.

[0005] The technical solution adopted by the present invention is: a faster start-up purge device for air separation equipment, which consists of a liquid nitrogen storage tank, a water bath module, a booster, and a heat exchanger. The liquid nitrogen storage tank is connected to the water bath module, the booster is connected to the heat exchanger, the water bath module is connected to the heat exchanger, and the discharge end of the heat exchanger is connected to an online analyzer.

[0006] As a further improvement of the present invention, the volume of the liquid nitrogen storage tank is 30m 3 And the liquid level is higher than 5m.

[0007] As a further improvement of the present invention, a valve V1 is provided between the liquid nitrogen storage tank and the water bath module.

[0008] As a further improvement of the present invention, a valve V2 is provided between the booster and the heat exchanger.

[0009] As a further improvement of the present invention, an air inlet valve V3 is provided between the water bath module and the heat exchanger.

[0010] As a further improvement of the present invention, a discharge valve V4 is provided at the discharge end of the heat exchanger.

[0011] Beneficial effects of the present invention: the purge device of the present invention uses low-pressure nitrogen to purge for 0.5 hours, and the dew point of the high-change channel of the booster quickly meets the requirements, while the purge stage of the traditional method needs to be extended by 1 hour to complete. By comparison, it can be found that the startup cost is reduced, and the overall startup time of the unit is shortened, which improves the operating capacity of the unit and achieves the effect of energy saving and consumption reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The present invention is a schematic diagram of a process flow of a faster air separation equipment startup purge device. DETAILED DESCRIPTION

[0013] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and implementation methods. It should be understood that the implementation methods described herein are only used to explain this application and are not used to limit this application.

[0014] Embodiment 1:

[0015] This embodiment provides Figure 1 The quicker air separation equipment startup purge device shown is composed of a liquid nitrogen storage tank, a water bath module, a booster, and a heat exchanger. The liquid nitrogen storage tank is connected to the water bath module, the booster is connected to the heat exchanger, the water bath module is connected to the heat exchanger, and the discharge end of the heat exchanger is connected to an online analyzer. The volume of the liquid nitrogen storage tank is 30m 3 And the liquid level is higher than 5m, which makes it easy to use a pressurizer to increase the pressure of the liquid nitrogen storage tank to 0.5Mpa. A valve V1 is provided between the liquid nitrogen storage tank and the water bath module to control the on-off between the liquid nitrogen storage tank and the water bath module. A valve V2 is provided between the booster and the heat exchanger to control the on-off between the booster and the heat exchanger. An air inlet valve V3 is provided between the water bath module and the heat exchanger to control the on-off between the water bath module and the heat exchanger. A discharge valve V4 is provided at the discharge end of the heat exchanger to control the discharge of the purge gas source.

[0016] Embodiment 2:

[0017] In summary, if Figure 1 As shown, during use, before purging the high-change channel of the booster, first increase the pressure of the liquid nitrogen storage tank to 0.5Mpa through the liquid nitrogen storage tank pressurizer, control the temperature of the water bath module above 65°C, and ensure that there is enough steam to heat the water bath. Open valve V1 to send out the liquid nitrogen. After the liquid nitrogen is vaporized by the water bath module, open the air inlet valve V3, close the booster control valve V2, open the discharge valve V4 during purging, adjust the purge gas volume by controlling the air inlet valve V3, monitor the online dew point through the online analyzer, and perform manual analysis and testing to detect whether the dew point is qualified.

[0018] Embodiment three:

[0019] In summary, during use, the entire purge operation can be carried out before the unit is started. Due to the independent purge gas source, it is not affected by whether the unit is started. The booster high-change channel is purged in advance and qualified, which does not affect the overall purge progress, shortens the startup time, and achieves energy saving and consumption reduction.

[0020] The above implementation modes are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned implementation modes, a person skilled in the art should understand that the technical solutions described in the aforementioned implementation modes can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the implementation modes of the present invention.

Claims

1. A faster air separation equipment startup purge device, consisting of a liquid nitrogen storage tank, a water bath module, a booster, and a heat exchanger, characterized in that: The liquid nitrogen storage tank is connected to the water bath module, the booster is connected to the heat exchanger, the water bath module is connected to the heat exchanger, and the discharge end of the heat exchanger is connected to an online analyzer.

2. A faster air separation plant startup purge device according to claim 1, characterized in that: The volume of the liquid nitrogen storage tank is 30m 3 And the liquid level is higher than 5m.

3. A faster air separation plant startup purge device according to claim 1, characterized in that: A valve V1 is provided between the liquid nitrogen storage tank and the water bath module.

4. A faster start-up purge device for air separation equipment according to claim 1, characterized in that: A valve V2 is provided between the booster and the heat exchanger.

5. A faster start-up purge device for air separation equipment according to claim 1, characterized in that: An air inlet valve V3 is provided between the water bath module and the heat exchanger.

6. A faster air separation plant startup purge device according to claim 1, characterized in that: A discharge valve V4 is provided at the discharge end of the heat exchanger.

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