How much power required to generate a particular pressure

In summary, when it comes to pressurizing a cylinder, there is no simple rule to connect power and pressure, and it is not as straightforward as just knowing the final pressure. Factors such as the type of fluid being compressed, the speed of compression, and the thermal properties of the container all play a role in determining the power required. It is important to consider these factors in order to accurately determine the power needed to pressurize a cylinder to a specific pressure.
  • #1
escape_velocity
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Are there any general guidelines or rule of thumb regarding how much power in watts would be required to pressurize a cylinder to a particular pressure and can I use this as a general rule,

For eg. I want to pressurize a vessel of volume 1 cu. m how much power would be required and can we generalize this so the this formula can be applied to a vessel of any volume?
 
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  • #2
There is no meaningful general relation between power and pressure. Not even between energy and pressure.
 
  • #3
Testing divers' compressed air cylinders is done by pressurising them with (nearly incompressible) water). If they 'fail' catastrophically, they just form a split and there is very little disturbance. There is very little energy stored.
OTOH, if a cylinder fails when being over-pressured with air, you have a BOMB on your hands. So much more energy involved. You can pressure test a cylinder with a few strokes of a manual water pump but an air compressor (a few h. p.) runs for minutes and everything gets too hot to touch.
No simple rule to connect the two. [emoji846]
 
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  • #4
sophiecentaur said:
No simple rule to connect the two. [emoji846]
What if I say that the fluid is "air" now would there be an equation for power to pressurize a cylinder with air to a particular pressure?
 
  • #5
escape_velocity said:
What if I say that the fluid is "air" now would there be an equation for power to pressurize a cylinder with air to a particular pressure?
OK But that is still not specific enough. Are we doing this quickly or very slowly? (Isothermal or Adiabatic) Diving cylinders are kept cool (in a water bath) during compression or their 'final' pressure will go down as their temperature drops.
Actually, if you Google Divers' Air compression, you may find some actual examples. That could answer your question if it is practical rather than theoretical.
 
  • #6
The pressure (and other info such as temperature) give you the energy stored in the tank.

Power = ΔEnergy/ΔTime so to calculate the power you need (at least) some info on how fast you are putting the air in.

Even then it's not that simple because (as Sophiecentaur says) the temperature may also depend on how fast you put the air in and factors such as the thermal mass of the container, how well insulated it is etc.

How accurate an answer do you need?
 
  • #7
sophiecentaur said:
OK But that is still not specific enough...
Actually, if you Google Divers' Air compression, you may find some actual examples. That could answer your question if it is practical rather than theoretical.
Let me provide some examples in hopes they may help:

Say, you are pressurizing a car tire to 200 kpa. You can:
1. Use a base mounted compressor with a tank, which can provide compressed air at thousands or tens of thousands of Watts.

2. You can stomp on a foot-pedal pump for a peak power of perhaps a thousand Watts.

3. You can use a hand-held bike pump with a peak power of perhaps 50 Wattts.

As you can see, all of these give the same result (an inflated tire) but require/use vastly different power to do it. The main difference is how long it takes. So you see, there is more to finding the power required than just the final pressure.
 
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Related to How much power required to generate a particular pressure

1. How is power related to pressure?

The power required to generate a particular pressure is directly proportional to the pressure. This means that as the pressure increases, the power required to generate it also increases.

2. What is the formula for calculating power required for a certain pressure?

The formula for calculating power required for a particular pressure is P = F/A, where P is the power, F is the force, and A is the area over which the force is applied.

3. How does the type of fluid affect the power required for a certain pressure?

The type of fluid being used can greatly affect the power required to generate a particular pressure. For example, a thicker or more viscous fluid will require more power to generate the same pressure compared to a thinner or less viscous fluid.

4. Is there a limit to the amount of power that can be used to generate a certain pressure?

There is no limit to the amount of power that can be used to generate a certain pressure. However, there may be practical limitations based on the equipment and resources available.

5. How can I reduce the power required to generate a particular pressure?

There are several ways to reduce the power required to generate a particular pressure, including using a more efficient pump or compressor, reducing friction in the system, and using a more suitable fluid for the application.

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