GC-2020B Liquefied Natural Gas Analyzer

GC-2020B Liquefied Natural Gas AnalyzerDue to the illegal addition of dimethyl ether in liquefied gas transport tankers, the calorific value of liquefied gas has decreased, endangering the interests of users and causing huge economic losses to liquefied gas stations. In response to this situation, Shandong Dongchen Jinzhi Instrument Co., Ltd. has launched a fully automatic liquefied gas detection dedicated gas chromatograph (portable), which has the advantages of low price, convenient use, and simple operation.

GC-2020B Liquefied Natural Gas AnalyzerDetailed introduction:

Liquefied gas detection dedicated gas chromatograph (portable) is a fully automatic portable gas detection equipment produced by Shandong Dongchen Jinzhi Instrument Co., Ltd. It is widely used in storage and distribution stations, liquefied gas stations, thermal companies, etc.

Product Overview:
Due to the fact that some liquefied petroleum gas supply units reduce costs by blending excessive amounts of dimethyl ether when transporting and selling liquefied petroleum gas. This not only damages the economic interests of liquefied gas stations, but also poses a hidden danger to the personal and property safety of consumers. Dimethyl ether is usually called methyl ether. Although it is combustible (similar in properties to liquefied petroleum gas), its calorific value is lower than that of liquefied petroleum gas, and it has a swelling effect on the rubber sealing ring of gas cylinders. Long term filling of liquefied petroleum gas mixed with dimethyl ether may cause gas cylinder valves to leak, resulting in safety hazards such as explosions.
To this end, relevant departments have established and promoted the implementation of regulatory systems: firstly, the procurement acceptance system. Wholesale and filling units of liquefied petroleum gas shall inspect whether the purchased liquefied petroleum gas contains excessive dimethyl ether and control the product quality. The second is the product purchase and sales ledger system. Record sales volume and flow;
Liquefied gas sales companies want to know the percentage of each component in the purchased liquefied gas? Is there dimethyl ether in liquefied gas? How much dimethyl ether is there? What is the content of dimethyl ether after blending in liquefied gas? What is the purity of dimethyl ether in the purchased liquefied gas?
As a liquefied gas sales enterprise, if these are not known, not only will it suffer economic and reputational losses, but it will also bring serious safety hazards to customers. At the same time, if it is inspected by the quality department, it will be severely punished.
The principle requires liquefied petroleum gas filling stations to conduct dimethyl ether content testing for each batch.
For the safety of the lives and property of the general public, and to protect the rights and economic interests of liquefied petroleum gas users from infringement, in accordance with the spirit of the "Notice on Gas Cylinder Filling Issues" issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, strict testing requirements are strictly implemented for liquefied petroleum gas filling stations within the jurisdiction, and timely testing is required for each batch of liquefied gas. This requires that each liquefied gas filling unit must be equipped with a gas chromatograph to achieve real-time monitoring. We should also play a role in inspection, supervision, and management, conduct random sampling and testing of various filling stations, and investigate and punish units that violate regulations.

Principle of Instrumental Analysis:

Liquefied gas analysis includes air, methane, ethane, ethylene, propane, propylene, isobutane, n-butane, isobutene, isobutene, isobutene, maleic, isopentane, n-pentane, and illegally added dimethyl ether components, excluding alkynes. A gas chromatograph with a thermal conductivity detector is used to separate the components in the sample through a liquefied gas analysis column with a six way valve injection. The signals are converted into digital signals through a workstation connected to the instrument, and the content results of each component are displayed on a computer workstation.

Main technical indicators:

1. Basic error: ± 0.5% F.S ± 1 word
2. Cold end compensation error: ≤± 2.0 ℃
3. Sampling period: 0.5 seconds
4. Control cycle: The control cycle for relay output is adjustable from 2 to 120 seconds, while for others it is 2 seconds
5. Relay contact output: AC220V/(resistive load) or AC220V/0.3A (inductive load)
6. Drive solid-state relay signal output: Drive current ≥ 15mA, voltage ≥ 9V
7. Drive thyristor pulse output: phase shifted or zero crossing trigger pulse with amplitude ≥ 3V and width ≥ 40us
8. Continuous PID regulation analog output: 0-10mA (load 500 ± 200 Ω), 4-20mA (load 250 ± 100 Ω),
Or 0-5V (load ≥ 100k Ω), 1-5V (load ≥ 100k Ω)
9. Working power supply: AC85V~242V (switch mode power supply), 50/60Hz, or other special orders
10. Working environment: a non corrosive gas environment with a temperature range of 0-50.0 ℃, relative humidity not exceeding 85%, and no strong electromagnetic interference
11. Detector:
Thermal conductivity detector (TCD):
Sensitivity: S ≥ 10000mv. ml/mg (n-hexadecane)
Dynamic range: ≥ 106
Baseline noise: ≤ 20uV (with a carrier gas of 99.999% hydrogen)
Instrument installation:
① Place the instrument on a stable workbench, and the natural gas analyzer and liquefied petroleum gas analyzer have integrated data acquisition workstations. The analyzer's LCD display screen has online and offline analysis icons placed on the desktop.
② Pour potassium hydroxide into a glass, then add 500ml Wahaha purified water, stir and melt before pouring into the water inlet above the instrument. Observe the liquid level on the front of the instrument and continue adding water to the middle position. After 10 minutes, turn on the power switch of the instrument and the upper left power switch of the computer. The pressure will automatically rise to 0.3Mpa and observe if the flow display is 0 or 10. The pressure gauge at the bottom right of the instrument will rise to 0.1Mpa. If it is normal, click the bridge flow (green) button at the back of the instrument. The instrument installation is complete.
Sample analysis:
When taking liquefied gas, be careful to empty the air in the sampling bag (to prevent errors in analysis caused by air entering), and then replace the sample three times repeatedly. After taking, immediately clamp it with a spring clip. When injecting, align the outlet of the sampling bag with the sample inlet on the instrument, remove the spring clip, and adjust the injection valve to the sampling position. Squeeze the sampling bag by hand for about 20 seconds, then rotate the valve to the injection position. The computer will automatically collect data and wait for the sample to peak.
When taking liquid phase, the sampling bag needs to be heated to fully vaporize the liquefied gas before injection!

Notes:
During use, the liquid level should be observed in a timely manner, and if it is below the lower mark, water should be added promptly.
The instrument is prohibited from pressing "bridge flow" without pressure and should be immediately shut down. Contact the manufacturer at 1516512 and 1315
Instrument execution basis:
GB/T 10410-2008 Gas Chromatography Analysis of Constant Components in Artificial Gas and Liquefied Petroleum Gas
GB25035-2010 Dimethyl Ether for Urban Gas Use
Application case of portable gas chromatograph for liquefied gas detection:
Typical customer: China Resources Gas Group Corporation