Q: When designing and selecting a transformer oil chromatography online monitoring system for a substation, what mainly restricts the repeatability of dissolved gas detection?
A: Most deviations do not come from the sensor itself, but from the extraction and transmission process of gases in the oil. The approach of the JH-02 transformer oil chromatography online monitoring system is to adopt a built-in oil circulation system, allowing the oil sample to complete circulation and degassing inside the device, reducing dead volume and residue caused by external pipeline connections. Compared with external sampling followed by re-injection, built-in circulation helps shorten a single detection cycle and maintain stable oil sample conditions during continuous monitoring.
Q: How does the degassing method affect the minimum detectable concentration and response time?
A: Degassing efficiency directly determines the amount of gas entering the chromatographic column. The JH-02 adopts vacuum degassing, causing characteristic gases dissolved in oil to be released under vacuum conditions, then sent to a dedicated composite chromatographic column for separation, and combined with high-sensitivity gas sensors to detect low-concentration components. During engineering selection, attention should be paid to the consistency of the degassing rate and the sealing performance of the degassing chamber, because sealing failure can lead to air ingress and interfere with the interpretation of components such as methane and acetylene. The advantage of vacuum degassing is that it also has a good extraction effect on low-solubility gases, but it places higher requirements on the reliability of vacuum maintenance and valve action sequence.
Q: What role do constant temperature control and data processing play in the entire system?
A: The separation effect of the chromatographic column is sensitive to temperature. The JH-02 is equipped with a high-precision constant temperature control system, keeping the column temperature stable during operation, reducing retention time drift, and facilitating component identification through peak position comparison. In terms of data processing, the system adopts data processing algorithms and diagnostic technology to perform trend analysis on multi-component concentrations and trigger prompts according to preset attention values. During design and selection, the form of the alarm linkage interface should be clarified to facilitate connection to the station monitoring platform.
Q: What practices can be referenced for on-site installation and oil sample maintenance?
A: For oil sample collection, delivery, and moisture control, relevant requirements in standards such as GB7597, GB/T7601, GB/T14542, and DL/T596 can be referenced, and sampling and maintenance cycles should be formulated according to the actual operating conditions of the equipment. The installation location should avoid areas with strong vibration and direct exposure to heat sources, and the oil circuit interface must confirm that the sealing material is compatible with transformer oil. For designers who use engineering parameters as the basis for selection, the degassing method, constant temperature accuracy, detection component range, and communication interface are key points to verify, and specific values should be based on the product's factory technical documents.
