Skid-mounted membrane separation nitrogen generation device and control method thereof

Abstract

The invention discloses a skid-mounted membrane separation nitrogen generation device and a control method thereof, and relates to the technical field of nitrogen generation control. Comprising a first air compressor, a second air compressor, a first gas-water separator, a second gas-water separator, a heat preservation heater, a first drainage valve, a second drainage valve, a pollution discharge box, a pry interior temperature sensor, a freezing dryer, a third drainage valve, a first filter, a fourth drainage valve, a heater and a membrane group. The first air compressor is provided with a first main motor, a first oil cooling fan, a first air cooling fan, a first lubricating oil temperature sensor, a first frequency converter, a second frequency converter and a third frequency converter; the second air compressor is provided with a second main motor, a second oil cooling fan, a second air cooling fan and a second lubricating oil temperature sensor; the control system is used for controlling the first oil cooling fan and the first air cooling fan to rotate reversely through the second frequency converter and the third frequency converter when the temperature in the skid body is lower than the first preset temperature. The electric energy consumption can be reduced, the working efficiency is improved, and unattended operation is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of nitrogen production control, and particularly relates to a skid-mounted membrane separation nitrogen production device and a control method thereof. BACKGROUND

[0002] At present, the skid-mounted membrane separation nitrogen production device is widely used in the coal industry due to the advantages of not needing a plant and being convenient to move, but also because of the use mode of not needing a plant, the nitrogen production device must fully adapt to the outdoor climate, which leads to the need for good heat dissipation in summer and insulation heating in winter. The inventor found in research that the existing skid-mounted membrane separation nitrogen production device has the following defects.

[0003] 1. The conventional skid-mounted membrane separation nitrogen production device is internally provided with a complete set of insulation heating device, and the insulation heating device needs to be powered for a long time in the standby condition of the device in winter, which not only increases the production cost but also causes waste of electric energy.

[0004] 2. Most of the air compressors matched with the existing skid-mounted membrane separation nitrogen production device adopt fixed frequency control, and the air volume is adjusted by manually adjusting the opening degree of the air suction valve. Most air compressors self-regulate the speed, and the running speed needs to be set artificially. The single air volume not only depends excessively on the operator but also cannot realize unattended operation, has low nitrogen production efficiency, poor reliability, and causes resource waste.

[0005] Therefore, how to provide an effective scheme to reduce electric energy consumption and improve nitrogen production efficiency has become a difficult problem to be solved in the prior art. SUMMARY

[0006] The purpose of the present application is to provide a skid-mounted membrane separation nitrogen production device and a control method thereof to solve the above-mentioned problems existing in the prior art.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: In a first aspect, the present application provides a skid-mounted membrane separation nitrogen production device, which comprises a skid body and a first air compressor, a second air compressor, a first gas-water separator, a second gas-water separator, an insulation heater, a first drain valve, a second drain valve, a blowdown tank, a skid temperature sensor, a cold dryer, a third drain valve, a first filter, a fourth drain valve, a heater and a membrane group arranged in the skid body. The first air compressor is provided with a first main motor, a first oil-cooled fan, a first air-cooled fan, a first lubricating oil temperature sensor, a first frequency converter, a second frequency converter and a third frequency converter, the first frequency converter is electrically connected with the first main motor, the second frequency converter is electrically connected with the first oil-cooled fan, the third frequency converter is electrically connected with the first air-cooled fan, the first air compressor is communicated with the first gas-water separator through a pipeline, the drainage end of the first gas-water separator, the first drainage valve and the blowdown tank are sequentially communicated through a pipeline, the pipeline between the first air compressor and the first gas-water separator is provided with the heat preservation heater and / or the pipeline between the first drainage valve and the blowdown tank is provided with the heat preservation heater; The second air compressor is provided with a second main motor, a second oil-cooled fan, a second air-cooled fan and a second lubricating oil temperature sensor, the second air compressor is communicated with the second gas-water separator through a pipeline, the drainage end of the second gas-water separator, the second drainage valve and the blowdown tank are sequentially communicated through a pipeline; The outlet of the first gas-water separator and the outlet of the second gas-water separator are both communicated with the cold dryer through a pipeline, the cold dryer, the first filter, the heater and the membrane group are sequentially communicated through a pipeline, the third drainage valve is arranged between the drainage port of the cold dryer and the blowdown tank, and the fourth drainage valve is arranged between the drainage port of the first filter and the blowdown tank; The pry-in temperature sensor, the first frequency converter, the second frequency converter and the third frequency converter are all connected with the control system of the pry-in membrane separation nitrogen generating device, and the control system is used for controlling the first oil-cooled fan and the first air-cooled fan to reverse through the second frequency converter and the third frequency converter when the pry-in temperature sensor detects that the temperature in the pry body is lower than a first preset temperature, so as to blow the heat generated by the first air compressor in the process of compressing air into the pry body, and heat the equipment in the pry body.

[0008] In one possible design, the pry-in temperature sensor includes a first pry-in temperature sensor and a second pry-in temperature sensor, the first pry-in temperature sensor and the second pry-in temperature sensor are arranged at different positions in the pry body, and the control system is used for controlling the first oil-cooled fan and the first air-cooled fan to reverse through the second frequency converter and the third frequency converter when the average temperature in the pry body detected by the first pry-in temperature sensor and the second pry-in temperature sensor is lower than the first preset temperature.

[0009] In a possible design, the prying membrane separation nitrogen generating device further comprises a first stop valve and a second stop valve, the membrane group comprises a first membrane group and a second membrane group, the heater, the first stop valve and the first membrane group are sequentially communicated through pipelines, and the heater, the second stop valve and the second membrane group are sequentially communicated through pipelines.

[0010] In a possible design, the prying membrane separation nitrogen generating device further comprises a first pressure sensor, a first temperature sensor, a second pressure sensor and a second temperature sensor, the first pressure sensor and the first temperature sensor are arranged on a pipeline between the first air compressor and the first gas-water separator, the second pressure sensor and the second temperature sensor are arranged on a pipeline between the second air compressor and the second gas-water separator, the first pressure sensor, the first temperature sensor, the second pressure sensor and the second temperature sensor are connected with a control system of the prying membrane separation nitrogen generating device, the control system is further configured to determine whether to start the first air compressor according to a temperature detected by the first temperature sensor before starting the first air compressor, control start and stop of the first oil-cooled air fan according to a temperature detected by the first lubricating oil temperature sensor, and control a rotating speed of the first air-cooled air fan according to a temperature detected by the second temperature sensor when the first oil-cooled air fan and the first air-cooled air fan are controlled to reverse.

[0011] In a possible design, the prying membrane separation nitrogen generating device further comprises a first switch valve, a third pressure sensor, a third temperature sensor and a fourth temperature sensor, the first switch valve, the third pressure sensor, the third temperature sensor and the fourth temperature sensor are connected with a control system of the prying membrane separation nitrogen generating device, the third pressure sensor is arranged between the first gas-water separator and the cold dryer, and the third pressure sensor is arranged between the second gas-water separator and the cold dryer, the third temperature sensor is arranged on a pipeline between the first filter and the heater, the heater, the first switch valve and the membrane group are sequentially communicated through pipelines, the fourth temperature sensor is arranged on a pipeline between the first switch valve and the membrane group, and the control system is further configured to control the first switch valve to be conducted with the membrane group based on a temperature detected by the third temperature sensor, a pressure detected by the third pressure sensor and a temperature detected by the fourth temperature sensor, or control the first switch valve to be conducted with an internal space of the pry body.

[0012] In a possible design, the prying membrane separation nitrogen generating device further comprises a second filter, the first switch valve, the second filter and the membrane group are sequentially communicated through pipelines, and the fourth temperature sensor is arranged on a pipeline between the second filter and the membrane group.

[0013] In a possible design, the skid-mounted membrane separation nitrogen generating device further includes a regulating valve, a nitrogen analyzer, a flow sensor, a second switch valve, and a fourth pressure sensor, all of which are connected to the control system of the skid-mounted membrane separation nitrogen generating device, the membrane group, the regulating valve, the second switch valve, and the gas end are sequentially connected through pipelines, the nitrogen analyzer, the flow sensor, and the fourth pressure sensor are all arranged on the pipeline between the regulating valve and the second switch valve, the control system is further configured to adjust the opening degree of the regulating valve based on the flow detected by the flow sensor and the flow preset by a user, and the control system is further configured to control the first exhaust port of the second switch valve to be in conduction with the gas end or control the second exhaust port of the second switch valve to be in conduction based on the nitrogen concentration detected by the nitrogen analyzer.

[0014] In a possible design, the skid-mounted membrane separation nitrogen generating device further includes a humidity sensor, which is arranged on the pipeline between the cold dryer and the first filter.

[0015] In a possible design, the skid-mounted membrane separation nitrogen generating device further includes a liquid level sensor, which is arranged in the blowdown tank.

[0016] In a second aspect, the present application provides a control method of a skid-mounted membrane separation nitrogen generating device, which is applied to the control system of the skid-mounted membrane separation nitrogen generating device in the first aspect or any one of the possible designs of the first aspect, and includes the following steps. detecting the temperature in the skid body through the skid-in temperature sensor; when the temperature in the skid body is lower than a first preset temperature, controlling the first oil-cooled air blower and the first air-cooled air blower to reverse through the second frequency converter and the third frequency converter, so as to blow the heat generated by the first air compressor in the process of compressing air to the skid body, and heat the equipment in the skid body.

[0017] Advantages: This invention uses a temperature sensor inside the skid to detect the temperature inside the skid. When the temperature sensor detects that the temperature inside the skid is lower than a first preset temperature, the second and third frequency converters control the first oil-cooled fan and the first air-cooled fan to reverse, so as to blow the heat generated by the first air compressor during air compression into the skid to heat the equipment inside. In this way, the heat generated by the air compressor during air compression can be recovered to heat the equipment inside the skid. In winter or low-temperature environments, there is no need for long-term power supply of insulation and heating devices, thus reducing energy consumption. At the same time, the frequency converter of the first air compressor can automatically adjust according to the nitrogen consumption, without relying on manual adjustment and control. This improves work efficiency, enables unattended operation, reduces production costs, saves resources, and facilitates practical application and promotion. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the skid-mounted membrane separation nitrogen generator provided in the embodiments of this application; Figure 2 A flowchart illustrating the control method of the skid-mounted membrane separation nitrogen generator provided in this application embodiment.

[0019] icon: 1-First main motor; 2-First oil-cooled fan; 3-First air-cooled fan; 4-First pressure sensor; 5-First temperature sensor; 6-First air-water separator; 7-First air compressor; 8-First drain valve; 9-Insulation heater; 10-First frequency converter; 11-Second frequency converter; 12-Third frequency converter; 13-First lubricating oil temperature sensor; 21-Second main motor; 22-Second oil-cooled fan; 23-Second air-cooled fan; 24-Second pressure sensor; 25-Second temperature sensor; 26-Second air-water separator; 27-Second air compressor; 28-Second drain valve; 29-Second lubricating oil temperature sensor; 31-Inside the first skid Temperature sensor; 32-Second skid internal temperature sensor; 33-Liquid level sensor; 34-Drain tank; 35-Skid body; 41-Third pressure sensor; 42-Refrigerated dryer; 43-Third drain valve; 44-Humidity sensor; 45-First filter; 46-Fourth drain valve; 47-Third temperature sensor; 48-Heater; 49-First switching valve; 50-Second filter; 51-Fourth temperature sensor; 52-First shut-off valve; 53-First membrane module; 54-Second shut-off valve; 55-Second membrane module; 56-Regulating valve; 57-Nitrogen analyzer; 58-Flow sensor; 59-Second switching valve; 60-Fourth pressure sensor. Detailed Implementation

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0021] It should be understood that although the terms first, second, etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another. For example, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit, without departing from the scope of the exemplary embodiments of the invention.

[0022] It should be understood that the term "and / or" that may appear in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" that may appear in this document describes another relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " that may appear in this document generally indicates that the related objects before and after it are in an "or" relationship.

[0023] To reduce power consumption and improve nitrogen production efficiency, this application provides a skid-mounted membrane separation nitrogen generator and its control method. The skid-mounted membrane separation nitrogen generator and its control method can reduce power consumption, improve working efficiency, and achieve unattended operation.

[0024] like Figure 1 As shown, the first aspect of this embodiment provides a skid-mounted membrane separation nitrogen generator, which includes a skid body 35 and a first air compressor 7, a second air compressor 27, a first gas-water separator 6, a second gas-water separator 26, a heat preservation heater 9, a first drain valve 8, a second drain valve 28, a sewage tank 34, a skid-mounted temperature sensor, a refrigerated dryer 42, a third drain valve 43, a first filter 45, a fourth drain valve 46, a heater 48, and a membrane module disposed within the skid body 35.

[0025] The first air compressor 7 is equipped with a first main motor 1, a first oil-cooled fan 2, a first air-cooled fan 3, a first lubricating oil temperature sensor 13, a first frequency converter 10, a second frequency converter 11, and a third frequency converter 12. The first frequency converter 10 is electrically connected to the first main motor 1, the second frequency converter 11 is electrically connected to the first oil-cooled fan 2, and the third frequency converter 12 is electrically connected to the first air-cooled fan 3. The first air compressor 7 is connected to the first air-water separator 6 through a pipeline. The drain end of the first air-water separator 6, the first drain valve 8, and the sewage tank 34 are sequentially connected through a pipeline. The pipeline between the first air compressor 7 and the first air-water separator 6 is equipped with the heat preservation heater 9, and / or the pipeline between the first drain valve 8 and the sewage tank 34 is equipped with the heat preservation heater 9.

[0026] The second air compressor 27 is equipped with a second main motor 21, a second oil-cooled fan 22, a second air-cooled fan 23, and a second lubricating oil temperature sensor 29. The second air compressor 27 is connected to the second air-water separator 26 through a pipeline. The drain end of the second air-water separator 26, the second drain valve 28, and the sewage tank 34 are connected in sequence through a pipeline.

[0027] The outlets of the first gas-water separator 6 and the second gas-water separator 26 are both connected to the refrigerated dryer 42 via pipelines. The refrigerated dryer 42, the first filter 45, the heater 48, and the membrane module are connected in sequence via pipelines. The third drain valve 43 is located between the drain outlet of the refrigerated dryer 42 and the sewage tank 34. The fourth drain valve 46 is located between the drain outlet of the first filter 45 and the sewage tank 34.

[0028] In one or more embodiments, the skid-mounted membrane nitrogen generator further includes a level sensor 33, which is disposed within the wastewater tank 34. By installing the level sensor 33, when the detected liquid level exceeds a set height, the user can be prompted to perform timely environmental protection measures. If the user fails to take timely action and the detected value of the level sensor further increases, the skid-mounted membrane nitrogen generator can be automatically shut down to ensure that wastewater does not flow freely and achieves environmentally friendly operation.

[0029] In one or more embodiments, the skid-mounted membrane nitrogen generator further includes a humidity sensor 44, which is disposed in the pipeline between the refrigerated dryer 42 and the first filter 45. The humidity sensor 44 can be used to indicate the operating status of the refrigerated dryer 42. When the humidity detected by the humidity sensor 44 is within the set humidity range, it indicates that the refrigerated dryer 42 is operating well; otherwise, it prompts the user to check the refrigerated dryer 42 in a timely manner.

[0030] The skid-mounted temperature sensor, the first frequency converter 10, the second frequency converter 11, and the third frequency converter 12 are all connected to the control system of the skid-mounted membrane separation nitrogen generator. The control system is used to control the first oil-cooled fan 2 and the first air-cooled fan 3 to reverse through the second frequency converter 11 and the third frequency converter 12 when the skid-mounted temperature sensor detects that the temperature inside the skid 35 is lower than the first preset temperature, so as to blow the heat generated by the first air compressor 7 during the air compression process into the skid 35 to heat the equipment inside the skid 35.

[0031] In this embodiment, the skid-in-skid temperature sensor includes a first skid-in-skid temperature sensor 31 and a second skid-in-skid temperature sensor 32. The first skid-in-skid temperature sensor 31 and the second skid-in-skid temperature sensor 32 are disposed at different positions inside the skid body 35. The control system is used to control the first oil-cooled fan 2 and the first air-cooled fan 3 to reverse through the second frequency converter 11 and the third frequency converter 12 when the average temperature inside the skid body 35 detected by the first skid-in-skid temperature sensor 31 and the second skid-in-skid temperature sensor 32 is lower than the first preset temperature.

[0032] The refrigerated dryer 42, the first filter 45, the heater 48, and the membrane module are connected sequentially via pipelines. During nitrogen generation using the skid-mounted membrane separation nitrogen generator, when compressed air passes through the first gas-water separator 6 and the second gas-water separator 26, moisture in the air condenses into a liquid state due to pressure and temperature changes, settling at the bottom of both separators. This separates the compressed air from the moisture, which is then discharged into a drain tank via the first drain valve 8 and the second drain valve 28, thus preventing damage to the membrane module. The refrigerated dryer 42 further separates the moisture by cooling the compressed air, causing the moisture to condense into a liquid state, which is then discharged into the drain tank via the third drain valve 43, further preventing damage to the membrane module. The heater 48 preheats the compressed air, improving membrane separation efficiency and preventing icing, thereby ensuring the normal operation of the skid-mounted membrane separation nitrogen generator and the quality of the nitrogen.

[0033] In winter standby mode, the skid-mounted membrane separator nitrogen generator can supply a heat preservation heater 9 to prevent the pipeline of the first air compressor 7 from freezing. The control system is also used to determine whether to start the first air compressor 7 based on the temperature detected by the first temperature sensor 5 before starting the first air compressor 7. Specifically, before starting the first air compressor 7, the control system detects the temperature detected by the first temperature sensor 5. Only when the temperature detected by the first temperature sensor 5 is higher than the allowable start-up temperature will the control system control the first air compressor 7 to start. The power of the first air compressor 7 is provided by the first main motor 1, which is controlled by the first frequency converter 10.

[0034] The control system is also used to control the start and stop of the first oil cooler 2 based on the temperature detected by the first lubricating oil temperature sensor 13. Specifically, the first oil cooler 2 can be controlled based on the temperature detected by the first lubricating oil temperature sensor 13. The temperature detected by the first lubricating oil temperature sensor 13 serves as temperature feedback. When the temperature is higher than the set temperature, the control system controls the first oil cooler 2 to start through the second frequency converter. When the temperature is lower than the set temperature, the control system controls the first oil cooler 2 to stop.

[0035] In one or more embodiments, the skid-mounted membrane nitrogen generator further includes a first shut-off valve 52 and a second shut-off valve 54. The membrane modules include a first membrane module 53 and a second membrane module 55. The heater 48, the first shut-off valve 52, and the first membrane module 53 are sequentially connected via pipelines, as are the heater 48, the second shut-off valve 54, and the second membrane module 55. The operation of the first shut-off valve 52 and the second shut-off valve 54 is based on the cumulative operating time of the first membrane module 53 and the second membrane module 55, with the shorter cumulative operating time taking priority to ensure that the operating times of the first membrane module 53 and the second membrane module 55 are as consistent as possible, so that the nitrogen generator operates under optimal conditions.

[0036] In one or more embodiments, the skid-mounted membrane nitrogen generator further includes a first pressure sensor 4, a first temperature sensor 5, a second pressure sensor 24, and a second temperature sensor 25. The first pressure sensor 4 and the first temperature sensor 5 are both disposed in the pipeline between the first air compressor 7 and the first gas-water separator 6. The second pressure sensor 24 and the second temperature sensor 25 are both disposed in the pipeline between the second air compressor 27 and the second gas-water separator 26. The first pressure sensor 4, the first temperature sensor 5, the second pressure sensor 24, and the second temperature sensor 25 are all connected to the control system of the skid-mounted membrane nitrogen generator.

[0037] The control system is also used to control the speed of the first air-cooled fan 3 based on the temperature detected by the second temperature sensor 25 when controlling the first oil-cooled fan 2 and the first air-cooled fan 3 to reverse. Specifically, the forward and reverse rotation and speed control of the first oil-cooled fan 2 can be fuzzy controlled based on the first skid-in-the-skid temperature sensor 31, the second skid-in-the-skid temperature sensor 32, and the second temperature sensor 25. When the average temperature detected by the first skid-in-the-skid temperature sensor 31 and the second skid-in-the-skid temperature sensor 32 is lower than the set temperature, the first oil-cooled fan 2 can be controlled to reverse. The second temperature sensor 25 is then compared synchronously. If the temperature detected by the second temperature sensor 25 is lower than the set temperature, the first oil-cooled fan 2 runs at its maximum speed under the control of the second frequency converter 11. At this time, all the heat generated by the lubricating oil is blown into the skid body 35 by the first oil-cooled fan 2 to heat the equipment inside the skid body 35.

[0038] In one or more embodiments, the skid-mounted membrane nitrogen generator further includes a first switching valve 49, a third pressure sensor 41, a third temperature sensor 47, and a fourth temperature sensor 51. The first switching valve 49, the third pressure sensor 41, the third temperature sensor 47, and the fourth temperature sensor 51 are all connected to the control system of the skid-mounted membrane nitrogen generator. The third pressure sensor 41 is located between the first gas-liquid separator 6 and the refrigerated dryer 42, and is also located between the second gas-liquid separator 26 and the refrigerated dryer 42. The third temperature sensor 47 is located in the pipeline between the first filter 45 and the heater 48. The heater 48, the first switching valve 49, and the membrane module are sequentially connected through pipelines. The fourth temperature sensor 51 is located in the pipeline between the first switching valve 49 and the membrane module.

[0039] The control system is also used to control the first outlet of the first switching valve 49 to be connected to the diaphragm assembly based on the temperature detected by the third temperature sensor 47, the pressure detected by the third pressure sensor 41, and the temperature detected by the fourth temperature sensor 51, or to control the second outlet of the first switching valve 49 to be connected to the internal space of the skid 35.

[0040] Specifically, when the temperature data detected by the third temperature sensor 47 is greater than the set temperature value, the pressure data detected by the third pressure sensor 41 is greater than the set pressure value, and the temperature data detected by the fourth temperature sensor 51 is less than the set temperature value, the airflow in the first switching valve 49 is controlled to be output from the first outlet through the pipeline to the second filter 50. When the temperature data detected by the third temperature sensor 47 is less than the set temperature value, or the pressure data detected by the third pressure sensor 41 is less than the set pressure value, or the data detected by the fourth temperature sensor 51 is greater than the set temperature value, the airflow in the first switching valve 49 is controlled to be discharged from the second outlet into the skid body 35.

[0041] In one or more embodiments, the skid-mounted membrane nitrogen generator further includes a second filter 50. The first switching valve 49, the second filter 50, and the membrane module are sequentially connected via pipelines. The fourth temperature sensor 51 is located in the pipeline between the second filter 50 and the membrane module. By setting the second filter 50, oil mist and impurities in the compressed air can be removed a second time, protecting the membrane module and improving the purity of nitrogen, thereby ensuring the normal operation of the skid-mounted membrane nitrogen generator and the quality of nitrogen.

[0042] In one or more embodiments, the skid-mounted membrane nitrogen generator further includes a regulating valve 56, a nitrogen analyzer 57, a flow sensor 58, a second switching valve 59, and a fourth pressure sensor 60. The regulating valve 56, the nitrogen analyzer 57, the flow sensor 58, the second switching valve 59, and the fourth pressure sensor 60 are all connected to the control system of the skid-mounted membrane nitrogen generator. The membrane module, the regulating valve 56, the second switching valve 59, and the gas consumption end are sequentially connected through pipelines. The nitrogen analyzer 57, the flow sensor 58, and the fourth pressure sensor 60 are all located in the pipeline between the regulating valve 56 and the second switching valve 59.

[0043] When the temperature data detected by the fourth temperature sensor 51 is greater than the lower limit setting value and less than the upper limit setting value, and the first outlet of the first switching valve 49 outputs airflow to the second filter 50, the first shut-off valve 52 and the second shut-off valve 54 open one of the valves with the shorter cumulative operating time according to the cumulative operating time, and the airflow reaches the regulating valve 56 through the first membrane group 53 or the second membrane group 55.

[0044] The control system is also used to adjust the opening of the regulating valve 56 based on the flow rate detected by the flow sensor 58 and the flow rate preset by the user. The control system is also used to control the first exhaust port of the second switching valve 59 to be connected to the gas-using end based on the nitrogen concentration detected by the nitrogen analyzer 57, or to control the second exhaust port of the second switching valve 59 to be connected.

[0045] Specifically, the opening of the regulating valve 56 is fed back by the flow sensor 58 and adjusted according to the flow rate set by the user. At the same time, it is linked to the data of the nitrogen analyzer 57 to adjust the valve opening while ensuring that the purity of the output nitrogen is qualified. When the nitrogen concentration detected by the nitrogen analyzer 57 is greater than the set concentration value, the second switching valve 59 is activated, and the airflow flows from the exhaust port of the second switching valve 59 to the user's gas supply end. When the nitrogen concentration detected by the nitrogen analyzer 57 is less than the set concentration value, the second switching valve 59 is activated, and the airflow is discharged from the exhaust port of the second switching valve 59.

[0046] When the user adopts the flow control mode, the opening of the regulating valve 56 can be adjusted according to the flow rate set by the user and feedback is given based on the data of the flow sensor 58. The first frequency converter 10 can be adjusted according to the pressure data detected by the fourth pressure sensor 60 and can be limited according to the pressure data detected by the first pressure sensor 4. At this time, the skid-mounted membrane separation nitrogen generator works in the flow control mode to achieve continuous adjustment of 0~50% flow rate.

[0047] The fourth pressure sensor 60 is used to indicate the current air supply pressure and alert the user to any leaks in the delivery pipeline. When the user sets the air consumption to any value between 0% and 50%, the control system can automatically start the first air compressor 7, which is driven by the first frequency converter 10 to the first main motor 1. When the user sets the air consumption to any value between 50% and 100%, the control system can automatically start the second air compressor 27. The second air compressor 27 operates at full load and outputs 50% of the air volume. The first air compressor 7 is adjusted by the first frequency converter 10 to output the remaining 0% to 50% of the air volume. At this time, the two air compressors achieve automatic adjustment of the air volume from 0% to 100% according to the control program, realizing unattended operation and reducing production costs.

[0048] The skid-mounted membrane separation nitrogen generator provided by this invention detects the temperature inside the skid using an internal temperature sensor. When the temperature sensor detects that the temperature inside the skid is lower than a first preset temperature, the first oil-cooled fan and the first air-cooled fan are reversed via a second and a third frequency converter. This reverses the flow of heat generated by the first air compressor during air compression, directing it towards the skid to heat the equipment inside. This recovers the heat generated by the air compressor during air compression to heat the equipment inside the skid. In winter or low-temperature environments, there is no need for a heating device to be continuously powered, thus reducing energy consumption. Furthermore, the frequency converter on the first air compressor allows it to automatically adjust according to nitrogen usage, eliminating the need for manual control. This improves work efficiency, enables unattended operation, reduces production costs, saves resources, and facilitates practical application and promotion.

[0049] Please see Figure 2 The second aspect of this application provides a control method for a skid-mounted membrane separation nitrogen generator, which is applied to the control system of the skid-mounted membrane separation nitrogen generator described in the first aspect or any one of the first aspects. The control method for the skid-mounted membrane separation nitrogen generator may include, but is not limited to, the following steps S201-S202.

[0050] Step S201. Detect the temperature inside the skid using the skid internal temperature sensor.

[0051] Step S202. When the temperature inside the skid is lower than the first preset temperature, the first oil-cooled fan and the first air-cooled fan are reversed by the second frequency converter and the third frequency converter to blow the heat generated by the first air compressor during the air compression process into the skid to heat the equipment inside the skid.

[0052] The working process, working details and technical effects of the control method for the skid-mounted membrane separation nitrogen generator provided in the second aspect of this embodiment can be found in the first aspect of the embodiment, and will not be repeated here.

[0053] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A skid-mounted membrane separation nitrogen generator, characterized in that, Includes a skid (35) and a first air compressor (7), a second air compressor (27), a first air-water separator (6), a second air-water separator (26), a heat-insulating heater (9), a first drain valve (8), a second drain valve (28), a sewage tank (34), a temperature sensor inside the skid, a refrigerated dryer (42), a third drain valve (43), a first filter (45), a fourth drain valve (46), a heater (48), and a membrane module; The first air compressor (7) is equipped with a first main motor (1), a first oil-cooled fan (2), a first air-cooled fan (3), a first lubricating oil temperature sensor (13), a first frequency converter (10), a second frequency converter (11) and a third frequency converter (12). The first frequency converter (10) is electrically connected to the first main motor (1), the second frequency converter (11) is electrically connected to the first oil-cooled fan (2), and the third frequency converter (12) is electrically connected to the first air-cooled fan (3). The first air compressor (7) is connected to the first gas-water separator (6) through a pipeline. The drain end of the first gas-water separator (6), the first drain valve (8) and the sewage tank (34) are connected in sequence through a pipeline. The pipeline between the first air compressor (7) and the first gas-water separator (6) is equipped with the heat preservation heater (9) and / or the pipeline between the first drain valve (8) and the sewage tank (34) is equipped with the heat preservation heater (9). The second air compressor (27) is equipped with a second main motor (21), a second oil-cooled fan (22), a second air-cooled fan (23), and a second lubricating oil temperature sensor (29). The second air compressor (27) is connected to the second air-water separator (26) through a pipeline. The drain end of the second air-water separator (26), the second drain valve (28), and the sewage tank (34) are connected in sequence through a pipeline. The outlets of the first gas-water separator (6) and the second gas-water separator (26) are connected to the refrigerated dryer (42) through pipelines. The refrigerated dryer (42), the first filter (45), the heater (48) and the membrane module are connected in sequence through pipelines. The third drain valve (43) is located between the drain outlet of the refrigerated dryer (42) and the sewage tank (34). The fourth drain valve (46) is located between the drain outlet of the first filter (45) and the sewage tank (34). The skid-mounted temperature sensor, the first frequency converter (10), the second frequency converter (11), and the third frequency converter (12) are all connected to the control system of the skid-mounted membrane separation nitrogen generator. The control system is used to control the first oil-cooled fan (2) and the first air-cooled fan (3) to reverse through the second frequency converter (11) and the third frequency converter (12) when the temperature inside the skid (35) is detected by the skid-mounted temperature sensor to be lower than the first preset temperature, so as to blow the heat generated by the first air compressor (7) during the air compression process into the skid (35) to heat the equipment inside the skid (35).

2. The skid-mounted membrane separation nitrogen generator according to claim 1, characterized in that, The skid-in-the-lever temperature sensor includes a first skid-in-the-lever temperature sensor (31) and a second skid-in-the-lever temperature sensor (32). The first skid-in-the-lever temperature sensor (31) and the second skid-in-the-lever temperature sensor (32) are located at different positions inside the skid body (35). The control system is used to control the first oil-cooled fan (2) and the first air-cooled fan (3) to reverse through the second frequency converter (11) and the third frequency converter (12) when the average temperature inside the skid body (35) detected by the first skid-in-the-lever temperature sensor (31) and the second skid-in-the-lever temperature sensor (32) is lower than the first preset temperature.

3. The skid-mounted membrane separation nitrogen generator according to claim 1, characterized in that, It also includes a first shut-off valve (52) and a second shut-off valve (54). The membrane assembly includes a first membrane assembly (53) and a second membrane assembly (55). The heater (48), the first shut-off valve (52) and the first membrane assembly (53) are connected in sequence through pipelines. The heater (48), the second shut-off valve (54) and the second membrane assembly (55) are connected in sequence through pipelines.

4. The skid-mounted membrane separation nitrogen generator according to claim 3, characterized in that, It also includes a first pressure sensor (4), a first temperature sensor (5), a second pressure sensor (24), and a second temperature sensor (25). The first pressure sensor (4) and the first temperature sensor (5) are both installed in the pipeline between the first air compressor (7) and the first air-water separator (6). The second pressure sensor (24) and the second temperature sensor (25) are both installed in the pipeline between the second air compressor (27) and the second air-water separator (26). Both the first air compressor (7) and the second temperature sensor (25) are connected to the control system of the skid-mounted membrane separation nitrogen generator. The control system is also used to determine whether to start the first air compressor (7) based on the temperature detected by the first temperature sensor (5) before starting the first air compressor (7), to control the start and stop of the first oil-cooled fan (2) based on the temperature detected by the first lubricating oil temperature sensor (13), and to control the speed of the first air-cooled fan (3) based on the temperature detected by the second temperature sensor (25) when controlling the first oil-cooled fan (2) and the first air-cooled fan (3) to reverse.

5. The skid-mounted membrane separation nitrogen generator according to claim 4, characterized in that, It also includes a first switching valve (49), a third pressure sensor (41), a third temperature sensor (47), and a fourth temperature sensor (51). The first switching valve (49), the third pressure sensor (41), the third temperature sensor (47), and the fourth temperature sensor (51) are all connected to the control system of the skid-mounted membrane separation nitrogen generator. The third pressure sensor (41) is located between the first gas-liquid separator (6) and the refrigerated dryer (42), and the third pressure sensor (41) is located between the second gas-liquid separator (26) and the refrigerated dryer (42). The third temperature sensor (47) is located between the first filter (45) and... The pipeline between the heaters (48), the heaters (48), the first switching valve (49) and the membrane assembly are connected in sequence through the pipeline. The fourth temperature sensor (51) is disposed in the pipeline between the first switching valve (49) and the membrane assembly. The control system is also used to control the first outlet of the first switching valve (49) to be connected to the membrane assembly based on the temperature detected by the third temperature sensor (47), the pressure detected by the third pressure sensor (41) and the temperature detected by the fourth temperature sensor (51), or to control the second outlet of the first switching valve (49) to be connected to the internal space of the skid (35).

6. The skid-mounted membrane separation nitrogen generator according to claim 5, characterized in that, It also includes a second filter (50), the first switching valve (49), the second filter (50) and the membrane assembly are connected in sequence through a pipeline, and the fourth temperature sensor (51) is located in the pipeline between the second filter (50) and the membrane assembly.

7. The skid-mounted membrane separation nitrogen generator according to claim 5, characterized in that, It also includes a regulating valve (56), a nitrogen analyzer (57), a flow sensor (58), a second switching valve (59), and a fourth pressure sensor (60). The regulating valve (56), the nitrogen analyzer (57), the flow sensor (58), the second switching valve (59), and the fourth pressure sensor (60) are all connected to the control system of the skid-mounted membrane separation nitrogen generator. The membrane module, the regulating valve (56), the second switching valve (59), and the gas consumption end are connected in sequence through pipelines. The nitrogen analyzer (57), the flow sensor (58), the second switching valve (59), and the fourth pressure sensor (60) are all connected to the control system of the skid-mounted membrane separation nitrogen generator. The sensor (58) and the fourth pressure sensor (60) are both located in the pipeline between the regulating valve (56) and the second switching valve (59). The control system is also used to adjust the opening of the regulating valve (56) based on the flow rate detected by the flow sensor (58) and the flow rate preset by the user. The control system is also used to control the first exhaust port of the second switching valve (59) to be connected to the gas-using end based on the nitrogen concentration detected by the nitrogen analyzer (57), or to control the second exhaust port of the second switching valve (59) to be connected.

8. The skid-mounted membrane separation nitrogen generator according to claim 1, characterized in that, It also includes a humidity sensor (44), which is disposed in the pipeline between the refrigerated dryer (42) and the first filter (45).

9. The skid-mounted membrane separation nitrogen generator according to claim 1, characterized in that, It also includes a liquid level sensor (33), which is disposed inside the sewage tank (34).

10. A control method for a skid-mounted membrane nitrogen generator, applied to the control system of the skid-mounted membrane nitrogen generator according to any one of claims 1-9, characterized in that, include: The temperature inside the skid body (35) is detected by the temperature sensor inside the skid. When the temperature inside the skid (35) is lower than the first preset temperature, the first oil-cooled fan (2) and the first air-cooled fan (3) are reversed by the second frequency converter (11) and the third frequency converter (12) to blow the heat generated by the first air compressor (7) during the air compression process into the skid (35) to heat the equipment inside the skid (35).

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