18 results about "Micro gas chromatography" patented technology

The invention discloses an organic sample analysis method based on micro gas chromatography and a chromatographic analyzer, particularly relates to the technical field of micro gas chromatography, and is used for solving the problems of unstable separation performance and low complex sample detection precision caused by insufficient uniformity of a stationary phase coating of an existing micro chromatographic column. The method comprises the following steps: constructing a stationary phase distribution initial profile by continuously pre-charging carrier gas, alternately applying segmented temperature gradient, micro-negative pressure and directional pulse flow to remodel a uniform distribution layer, generating a correction factor set of a temperature-resistance coupling relationship by combining a correction mixture and a tracer gas pulse, dynamically adjusting a carrier gas flow velocity and a temperature program to generate a matched operation curve, and finally, carrying out dynamic calibration. High-precision separation detection and quantitative analysis are achieved, stable separation performance is maintained in a miniaturized structure by cooperatively controlling stationary phase distribution optimization and real-time parameter feedback correction, and the detection precision and reproducibility of a wide-boiling-range organic mixture are improved.

The invention belongs to the technical field of gas detection, and particularly relates to a device and a method for detecting decomposition products of insulating gas perfluoroalkyl nitrile. The device comprises a gas collection module, a pretreatment module, a multi-technology combination module, a detection gas chamber and an intelligent data processing and control system, wherein the gas collection module collects and concentrates a gas sample through an equipment gas chamber sampling unit and a low-temperature enrichment unit; the pretreatment module purifies gas and converts complex components through a high-efficiency filter, a dryer and a catalytic conversion unit; the multi-technology combination module is used for separating gas by using a micro gas chromatography unit and carrying out qualitative analysis by using an infrared spectrum unit; a gas sensitive sensor array of the detection gas chamber realizes multi-dimensional detection; a storage module of the intelligent data processing and control system stores various databases, an analysis module calls the databases to analyze multi-module data, and sampling, detection and intelligent analysis of decomposition products are achieved. The problems that existing detection has a leak detection condition and lacks pertinence and high efficiency are solved.

The utility model relates to pesticide residue detection technical field, concretely is nut pesticide residue gas chromatogram micro detection cabin, including the micro gas chromatograph body of setting in the base, the base top hinged has a pair of side covers, and the base includes base and adjusting seat, and the base is equipped with a plurality of support columns, and the four corners of adjusting seat top surface all are screw -threaded connection screw -threaded resistance pole, and the four corners of adjusting seat top surface all are embedded with level bubble. The nut pesticide residue gas chromatogram micro detection cabin, through setting level bubble parallel with the edge on the adjusting seat top surface, can directly show the equipment level state, so that adjusting screw -threaded resistance pole can be independent fine adjustment adjusting seat each corner height, realizes horizontal calibration, and the support column of base four all around can adjust the overall support height with handle bolt, adjusts the temporary detection platform of different flatness, ensures that the equipment is always in the horizontal working state when the temporary detection in the field, reduces the detection error caused by the inclination.

The utility model belongs to the technical field of gas detection and sampling, and particularly relates to an earthquake precursor negative pressure hot spring gas sampling device of a miniature gas chromatograph, which comprises an outer shell, a water storage box mounted in the outer shell, a flow valve connected to the top end of the water storage box, an air inlet connected to the flow valve, an electronic barometer mounted on the air inlet, and a gas outlet connected to the air inlet. The top end of the water storage box is communicated with a one-way sample inlet, the bottom side of the water storage box is communicated with the bottom end of a water drainage pipe, the top end of the water drainage pipe is communicated with the bottom of a snakelike condensation pipe, the snakelike condensation pipe is inserted into a first heat exchange fin in a penetrating mode, a semiconductor chilling plate is installed on the first heat exchange fin, the hot end of the semiconductor chilling plate is tightly attached to a base plate of a second heat exchange fin, and a cooling fan is installed on the second heat exchange fin. An external inert gas pressure tank is utilized to realize stable and automatic sample loading of a sample, so that the working efficiency and the detection precision are improved; by combining the unique design of the snake-shaped condensation pipe and the semiconductor chilling plate, the moisture in the sample gas can be quickly and effectively removed, and the reliability of the detection result is improved.

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 multi-source monitoring and multi-mode analysis coal thermal reaction comprehensive testing device, which comprises an oil-filled expansion tank and an oil bath reaction chamber, the oil-filled expansion tank and the oil bath reaction chamber form a circulation loop through a pipeline, and a temperature sensor in and a temperature sensor out are respectively arranged in an oil inlet and an oil outlet of the oil bath reaction chamber. The sample bin of the oil bath reaction chamber is also connected with an Air-N2 gas supply device through a gas inlet pipeline, the sample bin is also connected with a mu-GC micro gas chromatographic instrument through a gas outlet pipeline, and the temperature sensor in, the temperature sensor out, the Air-N2 gas supply device and the mu-GC micro gas chromatographic instrument are jointly connected with a programmable logic controller (PLC) through signal cables. The problems that in the prior art, oil temperature stratification is difficult to find, temperature level sampling and continuous temperature rising need to be carried out separately, and the gas flow cannot be adjusted according to needs to maintain the needed low-oxygen seepage condition are solved. The invention further discloses a coal body thermal reaction comprehensive testing method based on multi-source monitoring and multi-mode analysis.

The present invention discloses an organic sample analysis method and chromatographic analyzer based on micro gas chromatography, specifically relating to the technical field of micro gas chromatography analysis. The method is used to solve the problems of unstable separation performance and low detection accuracy of complex samples caused by insufficient uniformity of the stationary phase coating in existing micro chromatographic columns. The method constructs an initial profile of the stationary phase distribution by continuously pre-flushing the carrier gas, alternately applies a segmented temperature gradient, a micro-negative pressure, and a directional pulse flow to reshape the uniform distribution layer, combines a calibration mixture with a tracer gas pulse to generate a correction factor set for the temperature-resistance coupling relationship, dynamically adjusts the carrier gas flow rate and temperature program to generate a matching operating curve, and achieves high-precision separation detection and quantitative analysis. By synergistically controlling the optimization of the stationary phase distribution and real-time parameter feedback correction, stable separation performance is maintained in a miniaturized structure, and the detection accuracy and reproducibility of organic mixtures with a wide boiling range are improved.

The invention relates to the technical field of robots, in particular to a classroom air quality management and epidemic disease early warning robot system and a dynamic regulation and control method. Comprising a mobile monitoring module, an intelligent analysis module, an early warning decision module and a dynamic regulation and control module. The mobile monitoring module is used for collecting air quality data in a classroom and feeding back the air quality data to the intelligent analysis module; the mobile monitoring module carries a micro gas chromatography module, a laser particle counter, a non-dispersive infrared CO2 sensor, an infrared thermal imager, a temperature and humidity sensor and a gas sensitive sensor array; the intelligent analysis module carries out fusion processing on the air quality data collected by the mobile monitoring module and constructs an aerosol diffusion model, and the intelligent analysis module and the early warning decision module realize data interaction through a shared memory; the disease transmission risk can be reduced through intelligent regulation and control.

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.

The invention discloses an underground gas sampling detection system and method in the technical field of gas detection. The method comprises the following steps: acquiring underground gas sampling data acquired by a self-adaptive sampling module; based on underground gas sampling data, after the target volume flow is calculated through a dynamic flow control equation, the power of a micro-flow pump of the self-adaptive sampling module is adjusted in real time; based on underground gas sampling data, after a leakage risk index is calculated in real time through a leakage risk index equation, whether nitrogen blowback purification is started or not is judged; and based on underground gas sampling data, predicting the concentration through the steady-state concentration prediction model, and judging whether to trigger the start of the micro gas chromatograph-mass spectrometer or not. The influence of air pressure fluctuation is eliminated through dynamic flow control, the sample spatial representativeness is ensured, the thermorheological effect is overcome through a temperature compensation mechanism, and the sampling precision is greatly improved.

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.

The invention discloses an underground fire area land sub-carrier and mother-carrier detection device based on intelligent optical fiber communication and explosion prediction, and relates to the field of collaborative operation of coal mine emergency rescue cluster robots, and the underground fire area land sub-carrier and mother-carrier detection device comprises a communication system, a mother carrier and a sub-carrier unmanned aerial vehicle; the communication system comprises an intelligent winch device and an optical fiber, and is in signal connection with the ship body and the unmanned aerial vehicle through the optical fiber; the mother ship comprises a ship body and a deck, the ship body comprises a walking device and an energy supply device, a miniature gas chromatographic analysis module is carried in the deck, a plurality of sub-ship unmanned aerial vehicle parking platforms are arranged on the upper portion of the deck, and each sub-ship unmanned aerial vehicle parking platform comprises a charging module and an optical fiber intelligent scaling module; the optical fiber intelligent scaling module is connected with the unmanned aerial vehicle through an optical fiber, and the unmanned aerial vehicle collects gas for analysis or returns to a mother ship for analysis; according to the invention, the problems of unstable communication, incapability of realizing high-confidence judgment of an explosion source and insufficient endurance in traditional coal mine fire area detection are solved, and the gas detection precision and the explosion early warning capability in a high-risk environment are improved.

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.