In overall industrial gas supply system engineering design, factory electromechanical supporting, outdoor modular gas supply projects and skid-mounted integrated gas supply projects, membrane nitrogen generators have become the preferred gas source equipment for field oil and gas engineering, vehicle-mounted mobile gas supply, offshore platform gas supply and factory simple supporting gas supply projects. They own prominent engineering advantages including extremely simple mechanical structure, no moving vulnerable valves, low civil engineering dependence and all-weather unattended operation, compared with PSA nitrogen generators which require complex valve timing control and supporting civil construction. Simply understanding theoretical separation principles cannot meet the demands of project selection, on-site construction, system docking and long-term engineering operation and maintenance. From a full-dimensional engineering application perspective, this paper analyzes the engineering working logic, hierarchical hardware structure, standardized on-site construction process, boundary working condition adaptation parameters, system linkage commissioning specifications and common risk prevention points of membrane nitrogen generation systems based on Membrane Nitrogen Generator Working Principle, providing complete and operable technical references for general electromechanical contracting, factory gas supply renovation and outdoor skid-mounted gas supply projects.

　　In terms of underlying physical separation engineering principle, membrane nitrogen generation realizes nitrogen and oxygen separation relying on the selective permeation mechanism of polymer hollow fiber membranes, forming a pure physical steady-state separation engineering system without chemical reaction or adsorption and regeneration timing action. Different gas molecules in air have differentiated permeation rates: small molecules such as water vapor, oxygen and carbon dioxide penetrate the hollow fiber membrane wall and discharge rapidly, while nitrogen molecules with slow permeation rate are intercepted and enriched to form qualified product nitrogen. Different from the dynamic cycle engineering logic of dual-tower alternating pressure charging and pressure relief adopted by PSA nitrogen generators, Membrane Nitrogen Generator Working Principle adopts continuous steady-state air intake and separation mode. There is no severe pressure fluctuation or frequent valve opening and closing impact throughout operation, resulting in extremely low pressure impact load on the whole machine. It avoids common engineering installation defects such as pipeline resonance, interface air leakage and fuselage vibration fundamentally, adapting to offshore platforms, vehicle-mounted mobile and field temporary gas supply projects with strict seismic requirements.

　　In combination with modular hardware engineering architecture, the complete membrane nitrogen generation system consists of four series-connected engineering units, forming a closed-loop gas supply engineering pipeline complying with industrial electromechanical engineering design standards. The first stage is the front air pretreatment engineering unit, including refrigerated dryers, three-stage precision filters and gas storage buffer tanks. Its core engineering function is to remove liquid water, oil mist and solid dust from compressed air, and stabilize the intake air dew point below -40℃. From the perspective of engineering design, membrane modules are most vulnerable to irreversible membrane pore blockage caused by attached water vapor and oil contamination. Therefore, redundant design of the front purification system is the core guarantee link of the entire gas supply project, as well as a key mandatory indicator for project acceptance. The second stage is the pressure stabilization and regulation engineering unit, equipped with high-precision pneumatic pressure stabilizing valves and flow control valves. It keeps the inlet pressure of membrane modules stably within the standard engineering range of 0.8–1.0MPa with pressure fluctuation control error less than ±0.02MPa, preventing damage to hollow fiber membrane wires caused by sudden pressure changes and ensuring long-term stable nitrogen purity output. The third stage is the core membrane separation engineering unit, integrated by multiple hollow fiber membrane modules in parallel. The engineering design adopts parallel capacity expansion instead of series pressurization, which increases gas production flow on demand without changing the separation load of single membrane fiber. It ensures the annual performance attenuation rate of the system is lower than 1% during long-term operation. The fourth stage is the rear nitrogen buffering and detection engineering unit, built-in online purity analyzers, pressure transmitters and emergency vent valves. It feeds back real-time gas production parameters and automatically vents unqualified gas to ensure qualified gas source for rear-end gas supply pipelines.

　　Focusing on on-site engineering installation and layout specifications, the membrane nitrogen generator features excellent on-site engineering adaptability thanks to its minimalist structure, greatly reducing civil construction and pipeline construction costs. In terms of civil engineering requirements, the equipment requires no load-bearing foundation hardening, independent sound insulation machine room or special exhaust pressure relief duct. It can meet acceptance standards with simple horizontal installation on flat ground, cutting civil construction period by more than 60% compared with PSA nitrogen generation projects. In terms of pipeline docking engineering, the system operates under constant pressure throughout operation without matching pulse pressure pipelines. Standard general industrial pipe diameters can be directly connected to the original factory gas supply main pipe network without reconstructing original pipeline structures. In terms of spatial layout engineering, the integrated skid-mounted machine supports three installation modes: vertical type, horizontal type and outdoor rainproof cabinet type. It adapts to three extreme on-site working conditions including narrow machine rooms, open-air exposed environments and closed vehicle-mounted cabins, requiring no additional electromechanical structural modification. It meets the requirements of rapid site entry, quick pipeline connection and fast commissioning for emergency gas supply projects.

　　In view of boundary working condition engineering adaptation and parameter commissioning standards, this paper clarifies applicable working condition boundaries based on Membrane Nitrogen Generator Working Principle to prevent project rework caused by over-limit operation on site. The standard applicable ambient temperature ranges from -20℃ to +55℃. No auxiliary heating or cooling equipment is required under high and low temperature environments. There will be no molecular sieve failure in low temperature or valve timing disorder in high temperature, perfectly fitting field low-temperature projects in northern regions and open-air high-temperature factory projects in southern regions. In terms of nitrogen purity adjustment, stepless purity adjustment from 95% to 99.9% can be realized only by adjusting intake flow and working pressure without disassembling or modifying hardware, matching gas supply standards of different projects such as welding protection, pipeline purging, oil and gas replacement and explosion-proof inerting. Meanwhile, the system has no complex electrical timing program and strong anti-electromagnetic interference capability. It can operate stably in chemical plants and power transformation supporting projects with strong electromagnetic interference without electric control failure and unexpected shutdown.

　　Finally, this paper sorts out engineering application advantages and operation and maintenance specifications by comparing with similar nitrogen generation equipment from the perspective of full-life cycle engineering operation and maintenance and risk prevention. In terms of engineering loss, membrane nitrogen generators have no moving solenoid valves or adsorbent fillers, with 70% fewer annual maintenance inspection points than PSA nitrogen generators. There is no complicated maintenance work such as molecular sieve replacement and valve calibration. In terms of engineering failure rate, the steady-state continuous operation structure rarely causes mechanical faults, with the mean time between failures reaching 80,000 hours, greatly reducing later maintenance budgets of engineering projects. This paper also clarifies engineering operation taboos: direct connection of unpurified oil-containing compressed air to membrane modules, high-pressure impact exceeding 1.1MPa and long-term overload air intake are strictly prohibited. Following the above engineering specifications can extend the service life of membrane modules to 8–10 years.

　　In conclusion, Membrane Nitrogen Generator Working Principle endows the equipment with core engineering characteristics including low civil engineering dependence, low vibration interference, low maintenance difficulty, strong working condition adaptability and easy modular integration. Against the current engineering trend of fast project delivery, lightweight construction and unattended operation and maintenance, membrane nitrogen generation systems are more suitable for modular skid-mounted projects, outdoor mobile gas supply projects, offshore platforms and remote factory gas supply projects, providing integrated gas source solutions with simpler construction, higher stability and lower construction and operation costs for industrial gas supply electromechanical projects.