Experimental device and method for gaseous product metering and drying sampling

Abstract

The invention provides an experimental device and method for gaseous product metering and drying sampling. The experimental device for gaseous product metering and drying sampling comprises a gas-liquid separating unit, a liquid level tracing balance metering unit, a drying unit and a sampling unit. By means of the experimental device, different quantities of experimental gaseous products, especially, gaseous products subjected to low-temperature gas-liquid separating can be automatically and accurately metered, and the influence of volatile light hydrocarbons with C4 or above on quantitation of the gaseous products can be eliminated; in combination with a dryer, the chromatographic analysis quality of obtained gas samples is improved; the requirement for collecting different gaseous products can be met through a sampler, the gaseous products can also be stored for a long term and conveniently transported, subsequent chromatograph sample introduction analysis can be conveniently carried out, and the metering precision can reach the level within 5 mL. Thus, a complete solution is provided for metering, drying and sampling of laboratory gaseous products.

Description

technical field [0001] The invention belongs to the technical field of metering equipment, and relates to an experimental device and an experimental method for gas product metering and drying sampling. Background technique [0002] After the chemical experiment is completed, it is necessary to measure the output of gas products, and it is also necessary to inject samples into the chromatograph after sampling to obtain the composition of the gas components. Take the simulation experiment of hydrocarbon generation and expulsion in petroleum geological research as an example. After the experiment is completed, the gas product is generally used to drain the gas into an inverted bottle filled with brine, and the volume is directly measured; Part of the water is used to preserve the sample; later, the chromatographic needle is inserted into the rubber stopper to take air for component analysis. But the composition of the actual gas product is complex, C 4 -C 13 For hydrocarbons...

AI Technical Summary

Problems solved by technology

For example: the "electronic gas meter" disclosed by CN1920494A (application number 200610127033.8), drives the slide bar of the variable resistor through the airflow, and counts and measures in experiments. The advantages are high accuracy, long service life and small volume. The disadvantage is that the airflow must be balanced. , the current is normal, and when the flow rate is small, the error is large due to friction; CN103852125A discloses "a volumetric small flow gas metering device", through two solenoid valves and counters, the automatic injection of full volume gas is realized. Metering, the advantage is that the gas volume can still be accurately measured when the gas volume is small, and the disadvantage is that the gas soluble in the liquid cannot be measured, the measurement error caused by the pressure difference of the liquid column is ignored, and sampling cannot be performed, and dehumidification is not performed; CN104677777A discloses "rock residual gas content "Test device and its test method", which includes three components: vibration, sealed broken sample, and gas metering. It pays attention to the problem of how to measure all the gas. The disadvantage is that, first, when the gas volume is low, there will be a sucking back problem; second, Helium expulsion cannot completely expel the air; third, there is no information about the water-soluble CO 2 Explanation of the gas metering method; CN105203176A discloses "a new type of gas metering device for liquid discharge method", which describes a method that does not need to be immersed in liquid in the liquid discharge and gas collection method. The advantage is simple, and the disadvantage is that there are still water vapor mixed in, water column Measuring errors caused by unbalanced pressure, and the mixing of water vapor during chromatographic sampling; the "gas metering device" disclosed in CN104596608A uses radio frequency capacitance equipment to measure liquid level changes, which solves the problem of heavy manual metering workload, but it has not yet been corrected. The water vapor contained in it is dried, which is not conducive to sampling

CN105067386A discloses "a kind of reflux gas sampler". Through the gravity reflux method, the gas passes through the hydrophilic glass fiber and stainless steel fiber filter fiber to remove the liquid mist. The advantage is that it can effectively remove dust and large flow liquid mist. The disadvantage is that the volume Large, for gas products with small gas volume, it cannot meet the high-precision sampling of chromatography (2-10mL)

[0005] At the metering level, the existing technology uses manual or instrumental drainage metering, which is very time-consuming in operation and has low precision; although instrumental metering avoids artificiality, it does not consider the pressure difference caused by the imbalance of the liquid column. The difference greatly affects the accuracy of the results for compressible gases, and the subsequent sampling is not considered, and the problems of moisture affecting component analysis and brine crystallization blocking the chromatographic inlet are not solved;

[0006] At the application level, the existing technology is applied to geothermal simulation experiments such as diagenesis, hydrocarbon generation and expulsion, and there are dead angles in gas measurement, and the measurement accuracy is not high; the manual operation takes more than 30 minutes, and the human skin is easily exposed to high-concentration salt water during sampling; Gas samples are often stored together with saline. Long-term storage of rubber plugs will cause air leakage due to aging. The maximum effective storage time is limited to 2 weeks.

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