Air flow conversion
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Dear experts, I need help with converting the flow rate under operating conditions to the flow rate under standard conditions. Different manufacturers give me different values, which has confused me. The requirements at the point of use are as follows: air volume of 7000 m3/h, pressure of 0.25 MPa, operating temperature of 55°C, local atmospheric pressure of 83 kPa, and humidity of 74%. I need to know what standard condition flow rate in Nm3 is required from the air compressor in order to meet these requirements The local average temperature is 28°C. My calculation gives 19,155 Nm3/h. I would appreciate it if experts could provide their insights and corrections. :L
For this issue, one must first consider the temperature, pressure, and flow rates specified on the equipment label. Some units use the old standard of 20°C; some have values specified on labels, while others use 0°C under standard conditions – and the problem might lie in this. There is also the display error of the instrument, for reference.
I think you have it backwards; the air volume required by the manufacturing process is generally a value calculated based on conservation laws and expressed under standard conditions, or the value measured by flow meters is also usually under standard conditions. The operating flow rate of a compressor is generally the actual flow rate; the higher the pressure, the greater the flow rate
Standard-condition flow rate = Operating-condition flow rate × (Operating pressure in Mpa × 1000 + Actual atmospheric pressure in Kpa) × 273.15 / 101.325 × (Operating temperature in °C + 273.15). What is the problem with this calculation?