What were we trying to achieve in the first place:
Our goal from starting the project was to make a scaled down prototype of a mid-scale compressed air energy storage system. The constraints of a scaled down system are expected. However, these limit the way the results compare to a scaled-up system.
The final solution is a scaled-down version of a mid-scale compressed air energy storage system.
Strengths:
- We can use the prototype to understand mid-scale compressed air energy storage systems
- We are collecting data on temperature, pressure, output power and roundtrip efficiency. This data is beneficial for determining design choices and modeling a larger system
- The system works as we expected it to work! The water temperature in the heat exchanger rises when the system is charged and we are able to produce enough power to light nine 12-24 Volt DC halogen bulbs.
Weaknesses:
- The heat exchanger doesn’t collect as much heat as a larger system would since the compressor doesn’t run as long. This makes our scaled-up calculations harder to approximate accurately.
- The turbine structure of the expansion system changes when the CAES is scaled up
- The system only runs for 3-4 minutes when the pressure is 75 psi and it takes 20 minutes to charge. This would be an issue for a full-scale system. However, through modeling with the chemical engineers, a scaled-up system should charge and discharge for equal amounts of time.
Lessons Learned as we built the system
- These aren’t necessarily weaknesses but these are lessons we learned that we could improve for the next rendition of the design and for when the design is scaled up.
- The system gets loud when the pressure is high. We need to check noise levels to see if hearing protection is necessary when the pressure is raised over 75 psi. As the system is scaled up the noise may increase and it is worth considering how the noise levels could be lowered.