Re:Goldman Sachs invests $250M in compressed air energy storage
by bumby on Wednesday January 12, 2022 @05:15PM
(#29913485)
An external pressure (usually water) keeps it at a constant pressure.
Think of a bag of air under water on the ocean floor. The height of the water column is (relatively) constant, so the pressure in the bag is also constant. The air is being compressed as it goes from sea level into the bag, but inside the bag, the pressure is always the same. If you define the system boundary as the bag, it's an isobaric system. The volume changes, but the pressure is constant. Contrast that to the compressor you might have in your garage where the rigid tank provides a constant volume, but the internal pressure changes.
Think of a bag of air under water on the ocean floor. The height of the water column is (relatively) constant, so the pressure in the bag is also constant. The air is being compressed as it goes from sea level into the bag, but inside the bag, the pressure is always the same. If you define the system boundary as the bag, it's an isobaric system. The volume changes, but the pressure is constant. Contrast that to the compressor you might have in your garage where the rigid tank provides a constant volume, but the internal pressure changes.