1、 Basic functions of natural gas calorific value workstation

The calorific value chromatography workstation is mainly used to collect and process spectral signal data of combustible gases such as natural gas, coal gas, liquefied gas, etc., and calculate the concentration of each component in these gases. After that, the physical and chemical properties parameters of the combustible gases, such as average molecular weight, density, calorific value, and white number, are provided in the analysis report. With this software, a hierarchical spectral library directory framework can also be established to store spectra from different sampling points in different directories for management purposes. In addition, this software also comes with two tool based software. The "Report Generator" can generate various forms of statistical reports on the analysis results of samples collected at the same location, and the "Spectral Calculation Tool" can compare the differences between several sample spectra.

The first key to using the natural gas calorific value workstation software is to distinguish between the two major steps of "spectrum processing" and "quantitative calculation":

1. Spectral processing: The main task of this step is to correctly detect the peaks in the spectrum, establish appropriate baselines for these peaks, and establish appropriate segmentation lines for overlapping peaks. The program will process the spectrogram in real time during the process of collecting the spectrogram, but you can also reprocess the spectrogram after adjusting the "spectrogram processing parameters" or formulating the "spectrogram processing scheme" after the end of the spectrogram collection until you are satisfied. After completing this step, the program obtains information about the position, area, and height of the peaks detected in the spectrum.

Quantitative calculation: After obtaining the positions and sizes of each peak in the spectrum in step *, the correction factors of each gas component can be calculated using a known concentration standard sample based on this information, or vice versa, the concentration of each gas component in the test sample can be calculated using the correction factors

2、 Dual channel simultaneous operation

In the program, you can create and vertically tile two identical spectral window as shown in the figure below. Only one of the two spectral window is "current". Note that the commands in the menu (or icon buttons on the toolbar) are used for "current" spectral window. To switch another spectrum window to the "current" spectrum window, simply click the mouse anywhere within this window.

If the two spectral windows above are set as channel A and channel B respectively, and the spectra of the two channels are independently collected, processed, calculated, and saved within the two windows, it is impossible to merge the results of the two channels for normalization calculation. You can click the "Options" icon button on the toolbar to flip to the "Exchange" page and make the following settings (set the start exchange time to 0.1 minutes, the end exchange time to 5 minutes, and select "Exchange site connected to the back of the original spectrum"):

Natural gas calorific value analysis report:

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Serial number, retention time, name, concentration, peak area

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1 0.968 Oxygen 0.5 11465

2 1.556 Nitrogen 1 85982

3 2.762 Methane 80 856827

4 7.302 0 1702

5 13.498 Propane 3.5 119953

6 14.258 Dimethyl Ether 0.5 2927

7 15.664 isobutane 5 342787

8 16.697 Isobutene 1 74582

9 17.492 正丁烷 8 863731

10 18.917 Reverse Butene 0.5 20801

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Total 100 2380757

Under standard conditions (273.15K, 101325Pa):

Average molecular weight=16.228

高热值=32.742 (MJ/Nm3)=7820.353(KCal/Nm3)， 低热值=29.456 (MJ/Nm3)=7035.491(KCal/Nm3)

High calorific value Huabai number=43.741 (MJ/Nm3)=10447.367 (KCal/Nm3), low calorific value Huabai number=39.351 (MJ/Nm3)=9398.854 (KCal/Nm3)

Combustion potential=80.155

Density=0.7241 (kg/m3), relative density=0.560

Critical temperature=169.65 (K), critical pressure=4.083 (MPa)