How to calculate the compressed air consumption of equipment

The calculation of compressed air consumption of equipment is a comprehensive problem, which needs to be considered in combination with equipment type, work demand, gas parameters and environmental factors. The following is a detailed calculation method and related factor analysis:

definition of 1. compressed air consumption

refers to the volume of compressed air consumed by equipment per unit of time, usually in the form cubic meters per minute (m & sup3;/min) for the unit. The calculation should take into account the compressed air pressure, temperature, humidity and other parameters, as well as the efficiency of the equipment and environmental factors.

2. calculation method

1. Formula method

calculation formula:

q=T+273.15⋅(1+0.00367T)V⋅P

• Q compressed air consumption (m & sup3;/min)
• V air compressor displacement (m & sup3;/min)
• P compressed air pressure (MPa)
• T: Compressed air temperature (℃)

example:
the displacement of an air compressor in a factory is 10m & sup3;/min, the pressure is 0.7MPa, the temperature is 25 ℃, substitute the formula to calculate:

q=25+273.15⋅(1+0.00367⋅25)10⋅0.7 ≈9.32m³/min

2. Estimation method

total gas consumption consists:

total gas consumption = gas consumption of existing equipment + gas consumption of post-treatment equipment + leakage + reserve

• gas consumption of existing equipment: sum of rated gas consumption of all gas-using equipment.
• Gas consumption of post-treatment equipment: Air consumption of post-processing equipment such as dryers and filters (usually 7% of the processing capacity).
• Leakage: Estimated by system air leakage test (air leakage rate exceeding 5% shall be overhauled).
• Reserves: The amount of gas reserved for future expansion or peak demand (usually 10%-20% increase).

3. Test method

by timing pumping test measure the volume of gas storage tank and pipeline, and calculate the actual gas volume of compressor:

1. measuring the volume of gas tanks and pipes(Unit: m & sup3;).

2. Full load operation of compressor, close the air valve of the air tank and the factory air system.

3. Depressurization to 0.48MPa, Record the time required for the gas tank to pump to 0.69MPa (unit: second).

4. calculation formula:

c=T⋅PA V⋅(P2 −P1 )⋅60

• C compressor capacity (m & sup3;/min)
• V: Gas tank and pipe volume (m & sup3;)
• P₂ final pressure (MPa)
• P₁ initial pressure (MPa)
• T: Time (seconds)
• P_A atmospheric pressure (0.1MPa at sea level)

if the calculation result is close to the rated gas volume of the compressor, it indicates that the system load is too high and the gas supply needs to be increased.

3. influencing factors

1. equipment type and job requirements:

• different equipment has different requirements on the pressure and flow of compressed air (such as 0.8MPa for forging hammer and 0.5-0.6MPa for pneumatic tools).

2. Gas Parameters:

• pressure: The higher the pressure, the greater the air consumption.
• Temperature: The increase in temperature causes the gas to expand and the gas consumption increases.
• Humidity: Water content shall be calculated after separation.

3. Safety, leakage and development factor:

• allowance is required for future expansion, leakage and equipment efficiency degradation.

4. Environmental factors:

• elevation: The higher the altitude, the thinner the air, the lower the efficiency of the air compressor.
• Temperature: The ambient temperature affects the cooling effect and gas density of the air compressor.

4. Industry Application Examples

Device Type	compressed air pressure	gas consumption range
forging hammer	0.8MPa	high
molding machine	0.6MPa	medium
air-moving tools	0.5-0.6MPa	medium
machine tool fixture	0.3-0.4MPa	low

5. considerations

1. unit conversion:

• 1bar = 0.1MPa,1MPa = 10kg/cm² to avoid unit confusion.

2. Regular maintenance:

• check the pressure gauge and pressure regulator to ensure that the pressure is stable within a safe range.

3. Professional consulting:

• for complex equipment or gas consumption calculation, it is recommended to consult professional air compressor suppliers or engineers.

Summary: The calculation of the compressed air consumption of the equipment needs to take into account the equipment requirements, gas parameters and environmental factors. Users should choose the appropriate calculation method according to actual needs and follow the manufacturer's recommended settings to ensure safe and efficient operation.