The measured net gas flow rate is too low
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The instruments used in our company’s purification section to measure the flow rate of clean coal gas employ Pitot tube measurement. However, since their installation, the measured values have been on the low side. We have analyzed the installation method, temperature and pressure compensation, as well as the design parameters, but no issues were found. Nevertheless, the flow rate does change with variations in load, and this trend is normal. After analysis, two reasons were identified, and I would like to seek advice from fellow sailors: 1. The composition of the clean gas varies significantly; the designed density of the gas components is 0.51, but the actual density fluctuates between 0.53 and 0.7, with values as high as 0.8 at times. However, the net gas volume is 12,000 NM3 per hour lower than the calculated value, suggesting that changes in the composition have little impact on the measured values. 2. There is a problem with the Pitoba single-component unit itself; the manufacturer initially designed it to use kilograms as the unit of measurement, and only later changed it to cubic meters, which may result in errors. I would like to ask fellow sailors if anyone has had similar experiences; I’d appreciate some advice.
Are the components derived from test data?
Regularly test the components, and adjust the transmitter parameters based on the density values resulting from changes in those components.
The values are obtained through laboratory analysis; normally, a sample is taken once a day, and after analysis, the density is calculated using a weighted average
Adjust regularly according to the gas density……
Maybe the flow meter itself isn’t accurate; it’s difficult to measure fluids. I’m not an expert at all, and I don’t understand flow meters of this type nor the calculation formulas, so this is just a guess.