Gas Chromatograph for Transformer Oil Testing

l  Introduction

Using gas chromatography to determine the content of dissolved gases in insulating oil is an effective method for power generation and power supply companies to determine whether there are latent overheating, discharge and other faults in oil-filled power equipment in operation. Thus to ensure the safe and effective operation of the power grid. It is also a necessary means for manufacturers of oil-filled electrical equipment to carry out factory inspection of their equipment.

GC-7960TO gas chromatograph is the new type automatic gas chromatograph released by U-Therm International (H.K.) Limited, it was the improved model of our GC-7960. The instrument adopts large screen LCD monitor, audio-visual display, easy operation. Meanwhile the instrument is with digital interface, through one piece of communication cable realizing real-time data and signal acquisition, data processing and testing result on the computer. The artistic and compact appearance design, equipped with modern computer control technology, which makes GC-7960TO become veritable, new type and high-performance gas chromatograph.

l  Application scope

This instrument is a latest model gas chromatograph equipped with large LCD. It has the function of Power-down, Overheat, gas-cutting protection, can suggest the user in English and fifth-order temperature-programmed. This kind of gas chromatograph is equipped with two testing room-- FID, TCD and methanator. It is widely used in power sector, corporation that produce oil immersed electrical apparatus, Transformer factory, wire cannula factory, and enterprises-power plant, power supply bureau, other units for gas analyzing like chemical processing of coal and Bruckhausen. The high-effective gas chromatograph is widely used in the transformer oil testing for measuring the dissolved gas in the oil.

l  Main technical characteristics

(1)       The instrument adopts large screen LCD technology, audio-visual display, easy operation.

(2)       Self-diagnostic function, show trouble location.

(3)       Touching type keyboard is convenient for the user to set the operating data

(4)       The high-performance electronic components were used to improve the stability & precision. The life-span is longer with the extension function is better.

(5)       Data power failure protection function, the operating data set by the instrument could be saved for long time after power failure.

(6)       Has the over temperature protection device. When the temperature is over setting limit, the instrument will stop heating and report malfunction on the display.

(7)       Large screen liquid crystal English display shows the instrument parameter intuitively, greatly convenient for the user to set parameters, such as each channel temperature, heating, detector, bridge current, etc; Intuitively operate the functions, such as FID auto ignition, on-off bridge current, open and close temperature control, open and close heating and each time event, etc.

(8)       Split/splitless inlet system with diaphragm purge function makes the system more stable with better precision.

(9)       Flexible design which can install 4 detectors simultaneously, each detector has independent electronic controller and signal output port.

(10)    Flexible design for connecting different types of pack column and capillary column; 4 columns could be installed at the same time.

(11)    Main control circuit adopts advanced microprocessor, large capacity of Memory, making the data saving more reliable. Meanwhile integrated design that integrating the measurement, control, power supply in one piece of circuit board, improve the anti-interference performance and reliability of instrument.

(12)    Adopt temperature controlling circuit of microprocessor, temperature accuracy of controlled object each heating zone reaches 0.1 degree.

(13)    Intelligent double back opening door technology, ensure that instrument column box temperature has good temperature control accuracy, and could cool quickly.

(14)    With standard 9-steps heating program, expandable to 21 steps program heating, fitting for analysis of complex samples of wide boiling point.

(15)    Unit type integral structure design, convenient installation and maintenance.

l  Main technical index

Column Oven: RT－450℃, precision ±0.01℃(@200℃).
Inlet: RT－450℃, precision ±0.01℃(@200℃).
Detector: RT－450℃, precision ±0.01℃(@200℃).
Up to six channels of temperature control: suitable for multi-channel temperature control needs such as adding reformer.
 Column Oven parameters:
Temperature control accuracy: room temperature 8℃－420℃accuracy±0.1℃.
 Column Oven volume:280mm×300mm×280mm.
 Program heating order: 9 steps. (Can be increased to 21 steps)
 Program heating rate:1℃－50℃.
 Constant temperature holding time of each order:0－300min(1min increment)
 Automatic rear door opening design ensures fast cooling.
 High-power, low-noise rotating fan ensures temperature uniformity.

Thermal conductivity detector(TCD): is used in macro analysis of gas, liquid.

Nitrogen phosphorus detector(NPD):is used in detection of trace nitrogen and phosphorus compounds.
Flame photometric detector (FPD):is used in detection of trace sulfur and phosphorus compounds.

Electron capture detector (ECD): detect the compound which could capture electrons.

l  Main Testing Parameter for Transformer Oil:

1.        Column compartment temperature: with a room temperature from 4 to 420; temperature control accuracy is ±0.1.

2.        Testing room temperature: with a room temperature from 16 to 420; temperature control accuracy is ±0.1.

3.        Reburner temperature: with a room temperature from 15 to 420; temperature control accuracy is ±0.1.

4.        TCD sensitivity，minimum detectable concentration: H₂<2ppm, O₂<5ppm, N₂<10ppm

5.        The range of detectable concentration for hydrocarbon such as FID methane, ethylene and acetylene is below 0.1ppm; for CO and CO2 is below 2ppm.

6.        TCD sensitivity, S>3000mv.ml/mg (C6H6)

7.        Common Testing Dissolved Gases

8.        Optional Testing Gases

Oxygen＜20ppm

Nitrogen＜20ppm

9.        Power Supply: 220V±22V，50Hz，

10.     Total Power: ＜2kW

11.     Weight: 60KG

12.     Size: 60cm×55cm×55cm

l  High sensitivity detector parameter ensures the accuracy of data

Supplying List

Oscillator

Technical Parameters

Comply with GB/T 17623 "Gas Chromatography Method for Determination of Dissolved Gas Component Content in Insulating Oil"

Technical Parameters:

Temperature control range: room temperature -100℃

Temperature control accuracy: 50℃±0.2℃

Temperature control method: digital PID automatic control

Oscillation amplitude: 35mm

Oscillation frequency: 275±3 times/min

Sample placement method: 4 100ml syringes

Working voltage: AC220V±20%

Power frequency: 50Hz±5%

Ambient temperature: 10℃-40℃;

Environmental humidity: ≤85%

Dimensions: length 49cm*width 30cm*height 30cm

Instrument weight: 12KG