Normal pressure nitrogen rectifying tower heating pipeline

Abstract

The utility model belongs to air separation device rectifying column technical field relates to a normal pressure nitrogen rectifying column heating pipeline, including oxygen generator unit and rectifying column, rectifying column includes rectifying column upper tower and rectifying column lower tower, rectifying column upper tower inside is provided main cold, oxygen generator unit is connected to nitrogen compressor through interconnection pipeline, and the interconnection pipeline entrance end is connected to oxygen generator unit nitrogen gas export, and the interconnection pipeline export end is connected to nitrogen compressor entrance, and the interconnection pipeline is connected to rectifying column upper tower through heat exchanger with the drawing of stop operating pipeline, and the stop operating pipeline export end is connected to rectifying column upper tower top, and the rectifying column lower tower is connected with air pipeline, and rectifying column upper tower, main cold and rectifying column lower tower one side draw have blowing pipeline. The utility model reduces the power consumption of compression equipment and the power consumption of the cooling, dehumidification process, utilizes the connectivity of process pipe network, and the normal pressure nitrogen of running unit is introduced into the fractionating column system of shutdown unit to carry out normal pressure heating.

Description

Technical Field

[0001] This utility model belongs to the technical field of distillation towers in air separation units, specifically relating to a heating pipeline for an atmospheric pressure nitrogen distillation tower. Background Technology

[0002] A gas separation unit is an industrial equipment used to separate the various gas components in air and produce oxygen, nitrogen, argon, and other inert gases. The most common air separation method is cryogenic distillation. This method uses compression and deep freezing to liquefy air, and then, through cryogenic distillation, separates inert gases such as oxygen, nitrogen, and argon from the liquid air based on their different boiling points. This equipment is widely used in traditional metallurgy, new coal chemical industry, large-scale nitrogen fertilizer production, and specialized gas supply.

[0003] The conventional heating operation method of air separation unit relies on the positive flow air pipeline. The air compressor is started to compress the ambient air to a certain pressure. Then the compressed air needs to be cooled by the cooler and then the moisture is removed by the dehumidifier. Finally, the treated dry air is introduced into the distillation column to heat and blow away the column and main refrigeration equipment from bottom to top.

[0004] To achieve heating, a high-power air compressor must be started to compress and pressurize the air. The compressed high-pressure air needs to be throttled and depressurized through valves in subsequent processes, resulting in pressure energy loss. Moreover, it relies on the operation of multiple auxiliary machines such as air compressors, cooling water systems, and air dehumidification systems. When the air separation unit is shut down, the internal distillation tower, main refrigeration equipment and other equipment are at low or normal temperatures. Using compressed and cooled low-temperature air for heating is essentially a contradictory process of first cooling and then heating. The unreasonable use of energy causes additional energy loss.

[0005] There is an urgent need for a new type of heating pipeline that can overcome the above-mentioned defects in order to achieve the goals of energy saving, consumption reduction, simplified operation, and improved independence and economy of heating operation. Therefore, a heating pipeline for atmospheric pressure nitrogen distillation tower is proposed. Utility Model Content

[0006] The purpose of this invention is to provide a heating pipeline for an atmospheric pressure nitrogen distillation tower, which has the advantages of using atmospheric pressure nitrogen as a heat source, being energy-efficient and easy to operate, and solving the problems of high energy consumption, complex processes and unreasonable energy utilization caused by relying on compressed air for heating in the prior art.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a heating pipeline for an atmospheric pressure nitrogen distillation column, including an oxygen generator unit and a distillation column. The distillation column includes an upper distillation column and a lower distillation column. The upper distillation column is equipped with a main refrigeration unit. The oxygen generator unit is connected to a nitrogen compressor via a grid-connected pipeline. The inlet end of the grid-connected pipeline is connected to the nitrogen outlet of the oxygen generator unit, and the outlet end of the grid-connected pipeline is connected to the inlet of the nitrogen compressor. A grid-connected valve is installed on the grid-connected pipeline, and a... A shutdown pipeline is connected to the upper column of the distillation column via a heat exchanger. The inlet end of the shutdown pipeline is connected to the grid connection pipeline downstream of the grid connection valve, and the outlet end of the shutdown pipeline is connected to the top of the upper column of the distillation column. A shutdown valve is installed on the shutdown pipeline. An air pipeline is connected to the lower column of the distillation column. The air pipeline passes through a heat exchanger, and the outlet of the air pipeline is connected to the lower column of the distillation column. An air compressor, a cooler, and a dehumidifier are installed sequentially along the air inlet direction in the air pipeline. A purge pipeline is led out from one side of the upper column, the main refrigeration unit, and the lower column of the distillation column.

[0008] Preferably, the heat exchanger is a plate-fin heat exchanger.

[0009] Preferably, the grid connection valve and the shutdown valve are pneumatic valves.

[0010] Preferably, the purging pipeline includes multiple purging branches that are respectively led out from the upper column of the distillation column, the main refrigeration column and the lower column of the distillation column. The purging branches converge into the purging main pipe, and a main purging valve is installed on the purging main pipe.

[0011] Preferably, each of the blow-out branch pipes is equipped with a branch pipe valve.

[0012] Preferably, an air precooler is provided at the rear end of the dehumidifier.

[0013] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0014] 1. This utility model reduces the power consumption of compression equipment and the power consumption of cooling and dehumidification processes. It utilizes the connectivity of the process pipeline network to introduce atmospheric pressure nitrogen from the operating unit into the fractionation tower system of the shut-down unit for atmospheric pressure heating.

[0015] 2. This utility model has the advantages of using atmospheric pressure nitrogen as a heat source, being energy-efficient and easy to operate, and solving the problems of high energy consumption, complex processes and unreasonable energy utilization caused by relying on compressed air for heating in the prior art. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the heating pipeline of an atmospheric pressure nitrogen distillation column according to one embodiment;

[0018] In the diagram above, 1 is the oxygen generator unit, 2 is the grid connection pipeline, 3 is the nitrogen compressor, 4 is the grid connection valve, 5 is the shutdown pipeline, 6 is the heat exchanger, 7 is the upper column of the distillation column, 8 is the shutdown valve, 9 is the main refrigeration unit, 10 is the lower column of the distillation column, 11 is the air pipeline, 12 is the air compressor, 13 is the cooler, 14 is the dehumidifier, 15 is the purge branch pipe, 16 is the branch pipe valve, 17 is the purge main pipe, and 18 is the main purge valve. Detailed Implementation

[0019] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0020] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.

[0021] Example 1, such as Figure 1 As shown, a heating pipeline for an atmospheric pressure nitrogen distillation column includes an oxygen generator unit 1 and a distillation column. The distillation column includes an upper column 7 and a lower column 10. The upper column 7 is equipped with a main cooler 9. The oxygen generator unit 1 is connected to a nitrogen compressor 3 via a grid connection pipeline 2. During normal operation, the oxygen generator unit 1 continuously produces high-purity, near-ambient-temperature atmospheric pressure nitrogen, utilizing nitrogen that might otherwise be discharged or output as a low-pressure product to achieve energy cascade utilization. The inlet end of the grid connection pipeline 2 is connected to the nitrogen outlet of the oxygen generator unit 1, and the outlet end of the grid connection pipeline 2 is connected to the inlet of the nitrogen compressor 3. This is the nitrogen delivery path under normal operating conditions. The grid connection pipeline 2 is used to deliver the generated nitrogen to the nitrogen compressor 3 for pressurization during normal operation of the oxygen generator unit 1, for subsequent use or as a high-pressure product output. A grid connection valve 4 is installed on the grid connection pipeline 2. When heating is required, the grid connection valve 4 is closed, cutting off the path to the nitrogen compressor 3.

[0022] A shutdown pipeline 5 is led out from the grid connection pipeline 2, passing through a heat exchanger 6 and connecting to the upper column 7 of the distillation column. The inlet end of the shutdown pipeline 5 is connected to the grid connection pipeline 2 downstream of the grid connection valve 4, and the outlet end of the shutdown pipeline 5 is connected to the top of the upper column 7 of the distillation column. A shutdown valve 8 is installed on the shutdown pipeline 5. The shutdown pipeline 5 is a branch line led out from the grid connection pipeline 2 and is used to guide atmospheric pressure nitrogen to the distillation column that needs to be heated. The shutdown valve 8 is used to open or close the shutdown pipeline 5, and the heating operation is independent of the original nitrogen compression system. An air pipeline 11 is connected to the lower column 10 of the distillation column. The air pipeline 11 passes through the heat exchanger 6, and the outlet of the air pipeline 11 is connected to the lower column 10 of the distillation column. An air compressor 12, a cooler 13, and a dehumidifier 14 are sequentially installed along the air inlet direction of the air pipeline 11. The nitrogen is appropriately cooled to enter the distillation column at a milder temperature to avoid thermal shock, and the released heat is used to preheat the air. In heat exchanger 6, high-temperature atmospheric nitrogen from shut-down pipeline 5 undergoes indirect heat exchange with lower-temperature air from air pipeline 11. The air entering the lower column 10 of the distillation column is preheated, reducing the compression load of air compressor 12 and the cooling load of cooler 13.

[0023] The upper column 7, main cooler 9, and lower column 10 of the distillation column are connected by purge lines. Atmospheric nitrogen gas is introduced from the top of the upper column 7 and, relying on its light weight and fluidity, flows from top to bottom through the nitrogen-side channel of the main cooler 9, and finally exits from the corresponding purge port at the bottom of the lower column 10, carrying away moisture and impurities in the column. The sensible heat of the nitrogen gas is used to uniformly heat the column equipment.

[0024] The specific design of the aforementioned key components will be discussed in detail below:

[0025] The heat exchanger 6 is a plate-fin heat exchanger 6. The specific structure of the plate-fin heat exchanger 6 consists of baffles, fins, seals, and guide vanes, and is made into a compact unit by vacuum brazing. As a nitrogen-air heat exchanger 6, the nitrogen flow channel in the shutdown pipeline 5 and the air flow channel in the air pipeline 11 are arranged adjacent to each other inside the heat exchanger 6, and indirect heat exchange is carried out through metal baffles. The two fluids do not mix.

[0026] The grid-connected valve 4 and the shutdown valve 8 are pneumatic valves. A pneumatic valve is a valve driven by a pneumatic actuator. The pneumatic valve is connected to the PLC or DCS of the control system to realize remote and rapid automatic switching control.

[0027] The purging pipeline includes multiple purging branch pipes 15 extending from the upper column 7, main refrigeration unit 9, and lower column 10 of the distillation column, respectively. These branch pipes 15 converge into a main purging pipe 17, which is equipped with a main purging valve 18. Each branch pipe 15 is also equipped with a branch valve 16. The branch pipes 15 extend from the bottom liquid sac area of ​​the upper column 7, the bottom of the main refrigeration unit 9, and the bottom of the lower column 10, respectively. Each branch pipe 15 has an independent branch valve 16. All branch pipes 15 ultimately converge into a common main purging pipe 17, which is equipped with a main purging valve 18. By opening and closing different branch valves 16, operators can perform targeted purging of different sections and equipment. The main purging pipe 17 centrally directs gases containing moisture and impurities to a safe area for unified discharge, complying with environmental and safety regulations.

[0028] An air precooler is installed at the rear end of the dehumidifier 14. At the rear outlet side of the dehumidifier 14, an air precooler is also connected in series on the air duct 11. The air precooler further cools the compressed air, which has a low pressure dew point, that has already exited the dehumidifier 14. After being cooled by the air precooler, residual water vapor in the air further condenses and precipitates, making the air entering the distillation column drier and cleaner, reducing the risk of the heat exchanger 6 and the distillation column being blocked by moisture and carbon dioxide.

[0029] All standard parts used in this utility model can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art. In addition, the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0030] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A heating pipeline for an atmospheric pressure nitrogen distillation column, comprising an oxygen generator unit and a distillation column, the distillation column comprising an upper distillation column and a lower distillation column, wherein the upper distillation column is equipped with a main refrigeration unit, characterized in that, The oxygen generator unit is connected to the nitrogen compressor via a grid connection pipeline. The inlet end of the grid connection pipeline is connected to the nitrogen outlet of the oxygen generator unit, and the outlet end of the grid connection pipeline is connected to the inlet of the nitrogen compressor. A grid connection valve is installed on the grid connection pipeline. A shutdown pipeline is led out from the grid connection pipeline, passes through a heat exchanger, and is connected to the upper column of the distillation column. The inlet end of the shutdown pipeline is connected to the grid connection pipeline behind the grid connection valve, and the outlet end of the shutdown pipeline is connected to the top of the upper column of the distillation column. A shutdown valve is installed on the shutdown pipeline. An air pipeline is connected to the lower column of the distillation column. The air pipeline passes through a heat exchanger, and the outlet of the air pipeline is connected to the lower column of the distillation column. An air compressor, a cooler, and a dehumidifier are sequentially installed along the air inlet direction on the air pipeline. A purge pipeline is led out from one side of the upper column of the distillation column, the main refrigeration unit, and the lower column of the distillation column.

2. The heating pipeline for an atmospheric pressure nitrogen distillation column according to claim 1, characterized in that, The heat exchanger is a plate-fin heat exchanger.

3. The heating pipeline for an atmospheric pressure nitrogen distillation column according to claim 1, characterized in that, The grid connection valve and the shutdown valve are pneumatic valves.

4. The heating pipeline for an atmospheric pressure nitrogen distillation column according to claim 1, characterized in that, The purge pipeline includes multiple purge branches that are drawn from the upper column of the distillation column, the main refrigeration unit, and the lower column of the distillation column, respectively. The purge branches converge into the purge main pipe, which is equipped with a main purge valve.

5. The heating pipeline for an atmospheric pressure nitrogen distillation column according to claim 4, characterized in that, Each of the blow-off branch pipes is equipped with a branch pipe valve.

6. The heating pipeline for an atmospheric pressure nitrogen distillation column according to claim 1, characterized in that, An air precooler is installed at the rear end of the dehumidifier.

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