How to set the meter head and DCS range for vortex flowmeters
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I have a question. To measure the nitrogen flow rate using a vortex flow meter, temperature and pressure compensation by the DCS is required; the DCS has a measurement range of 0–20,000 Nm3/h. The vortex flow meter outputs the flow rate under operating conditions of 0.8 MPa (A) and 30℃ ； Under standard conditions of 0.1 MPa (A) and 20°C, what should be the flow range of the vortex flow meter in m3/h?
15472 – this value is calculated based on the conditions you provided. However, 20 degrees Celsius is not the standard condition; 0 degrees Celsius is.
Thank you for your answer! However, the result I obtained by using the formula P0*V0/T0=P1*V1/T1 was 2615 m3/h. Where P0=0.101325, V0=20000, T0=293.15 ； P1=0.8, T1=303.15
Regarding standard conditions, Section 6.1.4 of the \"HGT 20507-2014 Specifications for the Selection and Design of Automated Instruments\" specifies that the pressure is 0.1013 MPa and the temperature is 0°C or 20°C℃； Article 7.1.1 of the \"SHT 3005-2016 Standards for the Selection and Design of Automation Instruments in the Petrochemical Industry\" specifies that the standard conditions are a pressure of 0.101325 MPa and a temperature of 0°C.
I’m sorry; I mistook 20,000 cubic meters for the operating flow rate. Your result is correct – I used the same formula as well.
Why is my calculation different from yours? How did you do the calculation? 😓😓😓
In essence, it’s just the DCS temperature and pressure compensation algorithm that is used here. The DCS algorithm calculates values under standard conditions based on known conditions in operation, while what you need is to calculate the conditions in operation based on known standard condition values.
Before ordering, vortex flowmeters need to be calculated using specialized software; they can be set to display values under standard conditions or under actual operating conditions, depending on the specific requirements of the user. If it matches the DCS display, the corresponding data should be provided to the manufacturer at the time of ordering, so that the manufacturer can set it up at the factory with the same range and engineering units as those of the DCS.