Compressed Air and Power Systems Flashcards
6 cards from real CEM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Compressed Air and Power Systems flashcards as text
Compressed air systems are considered energy-intensive because:
Answer: Only 10-15% of electrical input is converted to useful work at the point of use; the rest is wasted as heat
The compression process generates large amounts of heat and has multiple energy conversion losses; only about 10-15% of electrical input reaches the end-use tool or process as useful work.
Reducing compressed air system header pressure by 2 psig typically reduces compressor energy consumption by approximately:
Answer: 0.5-1%
As a rule of thumb, each 2 psig reduction in discharge pressure reduces compressor energy consumption by approximately 0.5-1%, providing an easy, no-cost savings opportunity through pressure optimization.
In a compressed air system, air leaks are significant because:
Answer: Leaks waste compressed air continuously, forcing compressors to run longer and consume more electricity
Leaks in typical industrial compressed air systems waste 20-30% of total compressor output, requiring compressors to run additional hours to compensate for the constant air loss.
A compressor with a modulating control will save more energy than one with a load/unload control because:
Answer: Modulating control continuously matches compressor output to actual demand, reducing unloaded running losses
Modulating controls throttle compressor inlet valves to precisely match output to demand, while load/unload controls cycle between full load and unloaded (wasteful) operation.
Heat recovery from compressed air systems is feasible because:
Answer: About 80-93% of electrical energy input to compressors is converted to heat, which can be recovered for space or water heating
Since 80-93% of compression energy becomes heat in the compressed air and compressor components, this heat can be recovered using heat exchangers to provide useful building heat or hot water.
Pressure/flow controllers installed in compressed air systems save energy by:
Answer: Decoupling supply and demand sides, allowing lower supply pressure while maintaining stable header pressure for end uses
Pressure/flow controllers allow the supply side to operate at minimum safe pressure while providing a stable, slightly higher pressure to the demand side, reducing compressor energy without affecting end-use tools.