Low-dew-point pipeline system manufacturing and mounting auxiliary device and method

Abstract

The invention relates to a manufacturing and mounting method of a low-dew-point nitrogen pipeline system, which is mainly applied to the ground test process of a rocket engine and other low-dew-point nitrogen industries with high dew point requirements, in particular to occasions where a plurality of storage containers are used in parallel. By installing the auxiliary device on the storage container, the cleanliness and dryness of the storage container can be effectively controlled, and therefore the purpose of conveying low-dew-point nitrogen is achieved. Comprising an auxiliary device, a storage container and a conveying pipeline. The storage container is used for storing high-pressure and low-dew-point nitrogen; the auxiliary device is used for performing positive pressure protection on the storage container, the nitrogen purity and dew point requirements in the storage container can be ensured by using a small amount of nitrogen, the high-purity nitrogen consumption in the field installation process can be greatly reduced, and the auxiliary device is energy-saving, environment-friendly and obvious in economic benefit. And the conveying pipeline is a pipeline for supplying nitrogen to the storage container.

Description

Technical Field

[0001] The invention relates to the field of gas transportation, and in particular to a low dew point pipeline system manufacturing and installation auxiliary device and method. Background Art

[0002] The dew point of a gas refers to the temperature at which water vapor in the gas begins to condense under specific conditions.

[0003] Low dew point high purity gas pipelines have very high requirements for the construction process and construction procedures, and each link must be completed strictly in accordance with the corresponding procedures. If there is a leak or loss of control in a certain link in the middle, it may have a serious impact on the quality of the entire gas, and even affect the quality of the process products (including purity, dryness, and cleanliness). This requires that each link in the construction process of high purity gas pipelines must ensure that the purity of the gas coming out of the gas source after passing through the intermediate links and reaching the gas use point can still meet the process requirements for gas. Therefore, during the welding process of the storage container and the pipeline, the positive pressure protection of the external inflation device can be used to strictly control the dryness and cleanliness of the gas in the storage container during the welding process. Summary of the invention

[0004] In view of this, the present invention provides a low dew point nitrogen pipeline manufacturing and installation auxiliary device to ensure the dryness and cleanliness of the nitrogen.

[0005] Before shipment, the storage container is purged and replaced with heated nitrogen, and sealed and shipped with 0.05MPa nitrogen. After arriving at the installation site, it is connected to the low dew point piping system to make installation auxiliary devices. Only a small amount of nitrogen can be used to ensure the nitrogen purity inside the equipment and the final dew point requirements, which can greatly reduce the consumption of high-purity nitrogen during on-site installation.

[0006] Assume the storage container has a capacity of 20m 3 If it is installed directly, water vapor in the air will enter the storage container by free diffusion. In this case, nitrogen blowing and replacement are required at the installation site, which takes about 10 times (nitrogen consumption is about 200m 3 ) can achieve the final nitrogen purity and dew point requirements, and the use of low dew point piping system to make and install auxiliary devices only requires 0.2m 3 (0.05m 3 / h flow rate nitrogen continuous purging for 4h) Continuous purging of high-purity nitrogen can meet the corresponding purity and dew point requirements, with obvious economic benefits, greatly reducing gas consumption, energy saving and environmental protection.

[0007] In particular, plugs (inlet plug 4 and outlet plug 6) are installed at the inlet and outlet of the container before leaving the factory. A DN20 opening is reserved on the plug, and a welding nozzle is installed on the opening for connection with the auxiliary inflation device during on-site installation. The welding nozzle can be a Star Arrow Y series interface, a special joint for gas cylinders, a ferrule joint, a threaded joint, etc., and a plug is installed in conjunction with it. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the specific implementation of the present invention, the drawings required for the specific implementation are briefly introduced below.

[0009] Figure 1 Make an installation diagram for the storage container outlet pipeline in the embodiment of the present invention;

[0010] Figure 2 is a diagram of an auxiliary device in an embodiment of the present invention;

[0011] Figure 3 A diagram of a deflation device in an embodiment of the present invention;

[0012] Figure 4 An installation diagram is made for the storage container inlet pipeline in an embodiment of the present invention. DETAILED DESCRIPTION

[0013] like Figure 1 The figure includes 1. storage container; 2. auxiliary device; 3. inlet flange; 4. flange blind plate welding pipe nozzle; 5. outlet flange; 6. outlet flange blind plate; 7. pipeline reserved welding pipe nozzle; 8. first switch valve; 9. gas cylinder group; 10. second switch valve; 11. pressure measuring point of pressure reducer inlet; 12. pressure reducer; 13. pressure measuring point of pressure reducer outlet; 14. filter; 15. venting device; 16. third switch valve; 17. fourth switch valve; 18. check valve; 19. fifth switch valve;

[0014] The auxiliary device 2 is composed of a gas cylinder group 9, a second switch valve 10, a pressure measuring point 11 for the inlet of the pressure reducer, a pressure reducer 12, a pressure measuring point 13 for the outlet of the pressure reducer, a filter 14, a venting device 15, and a third switch valve 16 connected in sequence;

[0015] The gas cylinder group can be a general nitrogen cylinder group with a capacity of 15L-50L and a pressure level of 15-30MPa. The nitrogen purity is selected according to the nitrogen purity requirements in the storage container. The recommended nitrogen purity is above 99.99%. The pressure measuring point 11 is selected according to the pressure level of the gas cylinder group. The pressure measuring point with the same pressure level within the pressure level of 15-30MPa is selected. The pressure measuring point 13 is a pressure measuring point with a pressure level of 0.2MPa.

[0016] The pressure reducing valve should be a pressure reducing valve with the same pressure rating within the range of 15-30MPa according to the pressure rating of the gas cylinder group. It is recommended to use a manual pressure reducing valve made of brass.

[0017] The filter should be 5um-20um filter according to the nitrogen purity requirement in the storage container;

[0018] The bleed device is connected to the main pipeline of the auxiliary device 2 through a tee. The bleed device consists of a bleed hand valve and a one-way valve. The bleed hand valve is generally recommended to use a DN6 pressure level 10MPa bleed hand valve. The one-way valve is generally recommended to use a DN6 one-way valve with an opening pressure difference of 0.1MPa.

[0019] In particular, it is necessary to prefabricate the pipe with flanges in advance, and the pipe flanges match the storage container flanges;

[0020] After wiping each interface clean with a white cloth, connect the gas cylinder group 9, the second switch valve 10, the pressure reducing device inlet pressure measuring point 11, the pressure reducing valve 12, the pressure reducing device outlet pressure measuring point 13, the filter 14, the air release device 15, and the third switch valve 16 in sequence according to the schematic diagram to form the auxiliary device 2;

[0021] Open the manual valve 16, ensure that the pressure reducing valve 12 is in a completely closed state, slowly open the second manual switch valve 10, observe the pressure value shown at the pressure measuring point 11, and confirm that the nitrogen cylinder is full;

[0022] Slowly open the pressure reducing valve 12, the pressure measuring point 13 starts to display the pressure value, and the gas flow can be felt at the outlet of the third switch valve 16, which proves that the auxiliary device is working normally. Continue to purge for 10 minutes, purge the pipeline from the gas cylinder group 9 to the third switch valve 16 of the auxiliary device, block the pipe mouth with a wet white silk cloth, and continue to purge until there is no visible excess on the white silk cloth, and the purge is completed;

[0023] If the pressure measuring point 13 does not display a pressure value after the pressure reducing valve 12 is opened to a certain degree, and there is no gas flow at the outlet of the third switch valve 16, then the auxiliary device fails. There are three possibilities: 1) the second switch valve 10 or the third switch valve 16 is not opened; 2) the third switch valve 16 is not closed; 3) the filter 14 is clogged, and the filter 14 should be removed for cleaning, and the inspections are carried out in sequence until the fault is eliminated;

[0024] After the white silk cloth inspection is passed, keep the pressure reducing valve 12 open, and there is obvious gas flow at the outlet of the third switch valve 16. Remove the plug of the welding pipe nozzle 4 on the storage container 1. At this time, there is airflow flowing outward from the storage container 1 at the welding pipe nozzle 4. Quickly connect the auxiliary device 2 to the welding pipe nozzle 4 and tighten the joint. It is specially noted that the above actions should be completed before the outward airflow at the welding pipe nozzle 4 disappears;

[0025] Remove the plug at the welding pipe nozzle 6 on the storage container 1. At this time, there is airflow flowing outward from the storage container 1 at the welding pipe nozzle 6. Open the pressure reducing valve 12 appropriately. The airflow flowing outward from the storage container 1 at the welding pipe nozzle 6 increases accordingly. When the pressure value displayed by the pressure measuring point 13 is stable at 0.11-0.12MPa, the installation work can be started.

[0026] Remove the blind plates at 6 welding nozzles of the storage container 1, and install the prefabricated flanged pipe on the flange of the storage container 1;

[0027] After the pipeline installation is completed, continue to install the first switch valve 8 on the flange end face of the pipeline outlet;

[0028] Manually open the first switch valve 8 to purge and replace the prefabricated flanged pipeline and the first switch valve 8 for 10 minutes;

[0029] After the outlet pipeline is installed, close the first switch valve 8;

[0030] Remove the auxiliary device from the storage container inlet, and quickly seal the welding nozzle 4 with a plug when removing it. At this point, the storage container outlet pipeline is installed;

[0031] Install the blind plate at the other end of the first switch valve 8, connect the gas-filled auxiliary device 2 to the reserved welding nozzle 7 of the pipeline, and start installing the valve 19 at the inlet end of the storage container 1;

[0032] Turn on the auxiliary device, and there will be airflow from the storage container 1 to the outside at the welding pipe nozzle 4. Open the pressure reducing valve 12 appropriately, and the airflow from the storage container 1 to the outside at the welding pipe nozzle 4 will increase accordingly. When the pressure value displayed by the pressure measuring point 13 is stable at 0.11-0.12MPa, you can start the installation work;

[0033] Remove the blind plates at the four welding nozzles of the storage container 1, and install the prefabricated flanged pipe on the flange of the storage container 1;

[0034] Continue to install the fourth switch valve 19 on the flange end surface at the other end of the pipeline;

[0035] For storage containers using the system in parallel, other storage containers can be installed in sequence according to this process.

Claims

1. A low dew point pipeline system manufacturing and installation auxiliary device and method, used for the manufacturing and installation of low dew point gas transmission pipelines, characterized in that: The device comprises a storage container, a manufacturing and installation auxiliary device and a conveying pipeline.

2. The low dew point piping system manufacturing and installation auxiliary device according to claim 1 is characterized in that The transported medium is a gas with a higher dew point requirement.

3. The storage container according to claim 1 is used to store high-pressure, low-dew-point nitrogen or other gases, and is particularly suitable for use in parallel with multiple storage containers.

4. According to claim 3, the storage container needs to have plugging plates (inlet plugging plate 4 and outlet plugging plate 6) installed at the inlet and outlet before leaving the factory.

5. According to claim 4, a DN20 opening is reserved on the inlet and outlet plugging plates of the container, and a welding nozzle is installed on the opening for connection with auxiliary devices during on-site installation.

6. The auxiliary device according to claim 1 is composed of a gas cylinder group, a valve, a pressure reducer, a pressure measuring point, a filter, and a deflation device.

7. According to the auxiliary device described in claim 1, during the welding process between the storage container and the pipeline, the positive pressure protection of the external auxiliary inflation device can be used to strictly control the cleanliness and dryness of the gas in the storage container during the welding process, thereby achieving the purpose of conveying low dew point nitrogen.

8. According to claim 7, the low dew point piping system is used to make the installation auxiliary device, which only requires about 0.2m 3 Continuous purging of high-purity nitrogen can achieve the corresponding purity and dew point requirements, with obvious economic benefits, greatly reducing gas consumption, and saving energy and protecting the environment.

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