Gas chromatograph with oil-gas separation function and gas chromatography process for determination of trace moisture in insulating oil

Abstract

The invention relates to a gas chromatograph with an oil-gas separation function and a gas chromatography process for the determination of trace moisture in insulating oil. According to the chromatograph, a determination gas passage and a backblowing gas passage are formed in a manner that a three-way valve, pressure stabilizing valves, an electromagnetic valve, a six-way valve, a sample feeder, chromatographic columns, connecting pipelines, joints and the like are connected according to a certain sequence and the passage switchover of the six-way valve and the on / off of the electromagnetic valve are carried out. The gas chromatograph and the gas chromatography process have the positive and beneficial effects that the situation that a moisture peak form is not affected during analysis can be guaranteed, and a fed oil sample and oil vapor can be back-blown out of a chromatographic system in time, so that the pollution to an analytical column and a detector pool body caused by residual oil is avoided; due to a designed sample inlet structure, the situation that oil samples difficult to be gasified are stopped at a sample inlet during sample inletting can be effectively guaranteed; during backblowing, the residual oil can be smoothly discharged from the chromatographic system conveniently; gas passage structures are simple, the manufacture is easier compared with that of a high-temperature direct oil-gas separation sample feeder, and the effect of oil-gas separation function realizing is obvious; and the overall sealing performance of a system is good.

Description

technical field [0001] The invention relates to the technical field of gas chromatographic analysis, in particular to a gas chromatograph based on the principle of backflushing with oil-gas separation function and a gas chromatographic process for measuring trace moisture in insulating oil. Background technique [0002] Insulating oil is generally used in the power industry to ensure insulation between transformers and related parts in bushings. With the operation of these equipment, some traces of water will be mixed into the oil, which will greatly reduce the insulation performance of the insulating oil, shorten the normal service life of the transformer and bushing, and may also cause some accidents, causing huge losses and harm. Therefore, the monitoring of micro-water in insulating oil has become an important indicator of oil quality monitoring. Standards such as GB / T 7595-2008 (transformer oil quality in operation) have clear regulations on water in oil, and GB / T 76...

AI Technical Summary

Problems solved by technology

Under normal circumstances, the requirements for this type of injector are: ①It can withstand the high temperature of 200°C for a long time; ②The material used can allow water molecules to pass through freely, and the oil sample can be effectively trapped in the injector;③ After each oil sample is injected, the residual oil must be able to be discharged from the injector in time to prevent oil-water interaction and affect the instantaneous gasification of micro-water, but the air tightness of the gas system cannot be affected during this process; ④ water molecules can The internal volume of the injector in contact should be as small as possible, otherwise the micro-water peak will broaden and cannot be quantified

Due to the high requirements on the performance of the sampler, there is no such micro sampler in the market that can effectively realize the oil-water separation function under high temperature conditions.

However, if a general gas chromatograph is used, only a few injections will seriously pollute the chromatographic column, and even pollute the thermal conductivity cell, which will not only make the measurement impossible, but also damage the precious chromatograph.

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