Application scope and detection indicators

Suitable for determining the content of dissolved gas components in insulation oil and the gas content in insulation oil in the power industry.

Execution standards:

GB/T 17623-1998Gas chromatography method for determining the content of dissolved gas components in insulating oil

DL/T 722-2000Guidelines for Analysis and Determination of Dissolved Gases in Transformer Oil

DL/T 703-1999Determination of Gas Content in Insulating Oil by Gas Chromatography

Testing indicators:

1. One injection, injection volume of 1 mL, detection concentration in oil:

2. Qualitative repeatability: Deviation ≤ 1%

3. Quantitative repeatability: Deviation ≤ 3%

Product Introduction

1.1Determination of dissolved gas component content in insulating oil

The determination of dissolved gas content in insulating oil by gas chromatography is to determine whether there are latent overheating, discharge and other faults in the oil filled power equipment during operation, in order to ensure the safety of the power grid. It is also a means for oil filled electrical equipment manufacturers to conduct factory inspections on their equipment.

GC-2001The insulating oil gas chromatography analyzer can adopt flexible and versatile analysis processes according to different user needs, such as single column/double column dual detector process or double column triple detector process. One injection can complete the full analysis of dissolved gas components (including hydrogen, oxygen, methane, ethylene, ethane, acetylene, carbon monoxide, and carbon dioxide) in insulating oil. According to the national standard, the dissolved gas in the insulation oil sample is extracted, separated by a chromatographic column, detected by a chromatographic detector, and then analyzed and managed through a dedicated chromatographic workstation. This method meets the requirements for gas chromatography in the national standard GB/T 17623-1998 "Determination of dissolved gas components in insulating oil by gas chromatography" and the power industry standard DL/T 722-2000 "Guidelines for analysis and determination of dissolved gases in transformer oil".

1.2Determination of gas content in insulating oil

The gas content of insulating oil is an important indicator for oil quality supervision. At present, the carbon dioxide elution method developed according to the DL/T450-1991 method is only applicable to the determination of oil products without acidic gases, while the vacuum pressure difference method developed according to the DL/T423-91 method has limitations due to the difficulty in popularizing vacuum instruments.

GC-2001The process design of the insulation oil gas chromatography analyzer fully complies with the provisions of the chromatographic process design in the power industry standard DL/T 703-1999 "Gas Chromatography Determination of Gas Content in Insulation Oil" of the People's Republic of China. The machine is equipped with a high-sensitivity thermal conductivity detector and a hydrogen flame ionization detector, as well as a nickel catalyst converter, which can achieve the complete determination of five gas components dissolved in transformer oil: hydrogen, oxygen, nitrogen, carbon monoxide, and carbon dioxide. Its performance meets the requirements of gas chromatography in DL/T 703-1999 "Gas Chromatography Method for Determination of Gas Content in Insulating Oil".

Performance characteristics

l Adopting a flexible and versatile analysis process to meet the different detection needs of users.

l One injection can simultaneously analyze nine gases including CO, CO2, H2, O2, N2, CH4, C2H6, C2H4, and C2H2 in insulating oil.

l Micro conversion furnace design, with higher conversion rate, can meet the pursuit of smaller detection limits for CO and CO2.

l CO、 CO2 is detected by FID through a methane converter, while H2, O2, and N2 are detected by TCD.

l H2The actual detection concentration can reach 0.2ppm, and CO/CO2 can reach 0.05ppm (additional accessory configuration is required)

l The workstation has powerful data processing, database management, and graphics management functions

l Multi user and multi device management facilitates the retrieval requirements of management departments, automatically calculates correction factors, and can calibrate the average multiple times

l Provide multiple fault diagnosis methods such as three ratio retrieval, TD visualization, and component concentration visualization

Detector parameters

1.Hydrogen flame ionization detector (FID)

◎The collection electrode adopts a cylindrical structure and a quartz nozzle

◎Detection limit: ≤ 6 ×10^-12g/s(Hexadecane)/Isodecane)

◎Baseline noise: 5 ×10^-14A

◎Baseline drift: ≤ 1 ×10^-13A/30min

◎Linear: ≥10⁷

◎automatic ignition

2.Thermal conductivity detector (TCD)

◎Adopting a semi diffusive structure

◎The power supply adopts constant current control mode

◎Sensitivity: S ≥ 3000mv. ml/mg (n-hexadecane/isodecane) HTCD high-sensitivity thermal conductivity detector S ≥ 10000mv. ml/mg (n-hexadecane/isodecane)；Digital amplification 1, 2, 4, 8 times optional

◎Baseline noise: ≤ 10 μ v

◎Baseline drift: ≤ 30 μ v/30min

◎Linear: ≥10⁵

◎Stability of carrier gas flow rate: ≤ 1%.