How to calculate the gas consumption of equipment into cubic

The calculation of equipment gas consumption (converted to cubic meters) should be combined with equipment parameters, running time and gas status (such as pressure and temperature). The following are detailed steps and examples:

1. Core Formula

1. volume flow calculation
   if the rated gas consumption (unit: Nm & sup3;/h) of the equipment under standard conditions (0°C,1 atm) is known, it can be directly multiplied by the operating time:

total gas consumption (Nm & sup3;)= rated flow (Nm & sup3;/h)× operation time (h)

2. actual State Transition
   if the equipment is marked with the flow rate under actual working conditions (such as m & sup3;/h), it needs to be converted to standard cubic meters (Nm & sup3;) through the ideal gas state equation:

V standard = V actual × P standard × T actual P actual × T standard

• P standard = 101.325kPa(1 atm)
• T standard = 273.15K(0°C)
• P actual and T actual are the pressure and temperature under actual working conditions (need to be converted into absolute values, such as temperature 273.15).

2. calculation steps

1. determine equipment parameters

   • rated flow (unit: Nm & sup3;/h or m & sup3;/h)
   • running time (hours)
   • pressure (Pa or kPa) and temperature (°C) under actual operating conditions.

2. Convert actual flow to standard flow (if required)
   if the equipment is marked with actual working condition flow (e. g. 5 m & sup3;/h @ 20°C, 200 kPa):

V standard = 5 × 101.325 ×(20 273.15)200 × 273.15 & asymp;9.1Nm & sup3;/h

3. calculate total gas consumption
   if the equipment runs for 8 hours:

total gas consumption = 9.1Nm & sup3;/h × 8h = 72.8Nm & sup3;

3. simplified method (approximate calculation)

if the actual working condition is close to the standard condition (e. g. the pressure change is small and the temperature is between 0-40°C), the calculation can be simplified:

total gas consumption (Nm & sup3;)& asymp; Actual flow (m & sup3;/h)× operation time (h)× 101.325P actual × t actual 273.15273.15

4. example

scene: The rated flow rate of an air compressor is 10 Nm & sup3;/min, running for 2 hours.
Calculation:

total gas consumption = 10Nm & sup3;/min × 60min/h × 2h = 1200Nm & sup3;

scene: The marked flow rate of a certain equipment is 8 m & sup3;/h (actual working condition: 25°C,150 kPa), running for 5 hours.
Calculation:

V standard = 8 × 101.325 ×(25 273.15)150 × 273.15 & asynmp; 10.3Nm & sup3;/h
total gas consumption = 10.3 × 5=51.5Nm & sup3;

5. considerations

1. unification of units: Ensure that the units of pressure (kPa/Pa), temperature (°C to K) and time (hours/minutes) are consistent.
2. Type of gas: The molar mass of different gases (e. g. air, nitrogen) may affect the density, but the standard cubic meter has implied temperature and pressure correction, and no additional adjustment is required.
3. dynamic change: If the equipment flow fluctuates with pressure/temperature, it needs to be calculated in sections or averaged.

Through the above method, the gas consumption of the equipment can be accurately calculated and converted to cubic meters (Nm & sup3;). For more accurate results, it is recommended to use a gas flow meter or consult the equipment supplier to obtain the rated flow under standard conditions.