9 results about "Micro gas chromatography" patented technology

This invention discloses a method for visualizing and detecting the internal flow field of a MEMS gas chromatograph column based on background schlieren imaging, relating to the fields of microelectromechanical systems (MEMS) and microfluidics. The method includes the following steps: S1, preparation of the MEMS micro gas chromatograph column chip; S2, establishment of the background schlieren optical link; S3, acquisition of the reference image; S4, acquisition of the flow image; S5, extraction of the displacement field; S6, inversion from displacement to refractive index / density gradient; S7, reconstruction and visualization output of flow field quantities such as velocity / pressure; S8, localization of local defects and updating of structural parameters; S9, experimental-simulation closed-loop iterative optimization. This invention applies BOS quantitative visualization technology to the internal diagnostics of MEMS-grade chromatographic columns, enabling rapid closed-loop correction and iteration of CFD models, reducing theoretical plate height, increasing the number of theoretical plates, reducing pressure drop, and increasing peak capacity. This provides a reliable experimental verification and optimization method for next-generation high-resolution, low-power, miniaturized aerospace-grade chromatographic columns.

The invention discloses a fuel cell hydrogen-oxygen cross direct detection method and system based on anode tail gas ultramicro oxygen analysis, anode tail gas is collected and pretreated, the concentration of micro oxygen in the anode tail gas is directly measured by using a high-sensitivity oxygen analysis technology, and grading risk assessment and early warning are performed based on the concentration value. According to the method, the limitation of a traditional indirect diagnosis method is broken through, direct evidence of hydrogen and oxygen intermixing is provided, ultrahigh sensitivity detection from ppb level to ppm level is realized, multiple technical paths of MEMS electrochemistry, TDLAS laser spectrum and miniature gas chromatography are provided for different scenes such as vehicle-mounted scenes, power station scenes and research and development scenes, the interference of a hydrogen-rich environment is effectively overcome, and the method has the advantages of high sensitivity, high sensitivity and the like. The system has the advantages of fast response, high precision and strong reliability, can realize early warning and predictive maintenance, and greatly improves the operation safety of the fuel cell.

The invention discloses a novel single-phase 400KV power transformer and a using method thereof, and relates to the technical field of power transformers, the novel single-phase 400KV power transformer comprises a single-phase power transformer, the single-phase power transformer comprises an oil tank and a high-voltage bushing, and high-voltage side pieces are arranged on the two sides of the high-voltage bushing. During use, when the miniature gas chromatograph detects that the content of gas released in the insulating oil exceeds the standard, the oil pump is started, impurities in the insulating oil are removed through cooperation between the coarse filter plate and the fine filter plate, the insulating oil with the impurities filtered is conveyed into the negative pressure tank, the negative pressure pump is started, and the insulating oil is discharged from the negative pressure tank. The inside of the negative pressure tank is in a micro-negative pressure state, water escapes from the oil, impurities and water in the insulating oil are filtered, then the release amount of gas in the insulating oil is detected through the micro gas chromatograph, whether the transformer operates normally or not is judged, and the filtering assembly is matched with the cooling assembly.

To minimize noise in the analog section of the temperature acquisition circuit of a mining micro gas chromatograph, ensuring that voltage changes accurately reflect thermistor variations while avoiding current surges from the digital section's micro gas pump startup / shutdown and solenoid valve opening / closing, this invention proposes a mining micro gas chromatograph with a temperature acquisition circuit. The separation performance of the micro-chromatographic chip is significantly affected by temperature control accuracy. The temperature acquisition circuit collects the voltage across the thermistor of the micro-chromatographic chip, amplifies it, and transmits it to an analog-to-digital converter to convert the analog signal into a digital signal.

Micro gas chromatographic devices are provided having a microfluidic separation column and a plurality of capillaries where the capillaries have been independently configured in terms of the capillary length, capillary width, the packing density and packing geometry of the capillary using one or more micro pillars, the tortuosity of the capillary path, and the presence and identity of the stationary phase for use in micro gas chromatographic separation of complex mixtures of compounds. Through the plurality of capillaries, the devices are capable of discriminating between complex samples even in instances where complete separation of the components is not possible. Methods of fabrication and methods of use of the devices are also provided. The devices can be readily fabricated using known techniques. The devices can be used for the analysis of complex mixtures of compounds containing tens or hundreds of compounds in which just a few differ in presence or concentration.

This invention belongs to the field of gas detection technology, specifically relating to a device and method for detecting the decomposition products of perfluoroalkyl nitrile (PFAN) in insulating gases. The device includes a gas acquisition module, a pretreatment module, a multi-technology co-processing module, a detection chamber, and an intelligent data processing and control system. The gas acquisition module collects and concentrates gas samples through a sampling unit in the gas chamber and a low-temperature enrichment unit. The pretreatment module purifies the gas and converts complex components through a high-efficiency filter, a dryer, and a catalytic conversion unit. The multi-technology co-processing module uses a micro gas chromatography unit to separate the gas and an infrared spectroscopy unit for qualitative analysis. The gas-sensitive sensor array in the detection chamber enables multi-dimensional detection. The intelligent data processing and control system's storage module stores multiple databases, and the analysis module calls these databases to analyze data from multiple modules, achieving sampling, detection, and intelligent analysis of the decomposition products. This solves the problems of missed detections, lack of specificity, and low efficiency in existing detection methods.

This invention discloses an operation control method for a CO₂ circulating catalytic biomass gasification polygeneration unit, relating to the field of distributed biomass energy utilization and process control technology. The method includes the following steps: inerting and purging are performed based on the gas supply and atmosphere control unit to determine the unit's operating boundaries; during the pyrolysis stage, active sites are constructed in situ on the carbon through alkali metal Na / K dosage control; during the gasification stage, recycled CO₂ and / or purified flue gas are introduced and the CO₂ / steam ratio is controlled to drive the reaction unit to stably produce gas and generate biochar as a byproduct; tar and dust are controlled through staged condensation-filtration-switchable catalytic cracking; a micro gas chromatography calibration dataset is established and sensor array data is fused; soft measurement and closed-loop control are used to adjust the feed rate, bed temperature, and recycled CO₂ ratio; and emergency shutdown is executed when safety interlock conditions such as backfire, CO leakage, and pressure difference abnormalities are triggered. This method solves the problems of large calorific value fluctuations, easy tar blockage, and high monitoring and control costs in distributed biomass gasification, achieving improved efficiency and safe and stable operation.

The invention discloses a structural design and processing technology of a high aspect ratio micro gas chromatographic column based on a hot reflux technology, and belongs to the technical field of glass processing. The silicon-glass high-aspect-ratio micro gas chromatographic column cannot be obtained by anodic bonding; and the problems of difficulty in preparation of a high-aspect-ratio structure, poor surface quality and stress concentration in existing glass micromachining are solved. According to the invention, efficient preparation of the high aspect ratio microstructure of the glass is realized, no obvious defect exists on the surface, and stress and cracks are effectively inhibited; according to the structural design of the miniature gas chromatographic column, the snakelike layout and the optimized depth-to-width ratio design are adopted, so that the separation efficiency is improved, a foundation is laid for high theoretical plate number and excellent separation degree, and the rapid separation requirement is met; the processing technology is stable, the silicon-glass bonding airtightness is good, and the method is suitable for on-site detection and on-line monitoring scenes; and batch preparation can be realized by the wafer-level process, the cost is reduced, and industrial application is facilitated.

The present application relates to the field of electrochemical engineering, and specifically discloses a kind of PEM electrolytic water hydrogen production system energy efficiency online monitoring method, comprising: by full working condition permeation characteristic experiment, the physical residual network soft measurement model with Fick diffusion law and Henry law hard constraint is constructed, it is converted into.onnx format and deployed to edge gateway;Secondly, real-time acquisition multi-channel working condition signal, after filtering, down-sampling and normalization processing form standardized input vector, online output transient hydrogen permeation flux;Again, according to Faraday's law, hydrogen permeation flux is equivalent to virtual current component, and the effective electrolysis current of real participation electrolysis is obtained after deduction;Subsequently, an external closed loop calibration mechanism is established, and the true value is obtained by a micro gas chromatograph, and only the model output bias is adjusted to correct drift;Finally, based on the effective electrolysis current calculation theoretical hydrogen production rate, combined with the measured value, the real Faraday efficiency is obtained by eliminating the interference of permeation;Real-time monitoring of the real energy efficiency of PEM electrolytic water hydrogen production system is realized.