Analyzing Compressed Air Energy Storage Systems: Key Calculations
School
Northeastern University**We aren't endorsed by this school
Course
ENSY 5200
Subject
Mechanical Engineering
Date
Dec 12, 2024
Pages
3
Uploaded by CountNightingale4586
HW#3P1.The above figure shows a problem, which is a modified system as shown inthe Compressed Air Energy Storage PowerPoint. A large tank with volumeof 125 m3is available. In this system the tank is not insulated and thecompressed air in the tank loses its energy and reduces its temperature to293K and the pressure at 10 bar. So, a combustor is used to increase thetemperature to 750 K. Calculate the energy of the fuel, mass of the fuelburning natural gas. (Assuming all the combustion process happens at onceand transfers all the mass from the tank to the combustor, i.e. m1=m3). Assume heating value of natural gas is 55MJ/kg of fuel( Cp = 1 kJ/kg.K)High pressure Low temperatureCombustorFuelHigh p & High T Gases1234ExhaustTankCompWc..
P2.The below figure provides operating data for a compressed air energy storagesystem using off-peak electricity to power a compressor that fills a cavern withpressurized air. The cavern shown in the figure has a volume of 105m3and initiallyholds air at 290 K, 1 bar, which corresponds to ambient air. After filling, the air inthe cavern is at 790 K, 21 bar. Assuming ideal gas behaviour for the air, determine a) the initial and final mass of air in the cavern, each in kg, and b) the work required by the compressor, in GJ. Ignore energy transfer due toheat interaction and kinetic and potential energy effects.P3.
A rigid copper tank, initially containing 1 m3 of air at 295 K, 5 bar, is connectedby a valve to a large supply line carrying air at 295 K, 15 bar. The valve is openedonly to fill the tank with air to a pressure of 15 bar. Finally, the air in the tank is at330 K. The copper tank, which has a mass of 20 kg, is at the same temperature asthe air in the tank, initially and finally. The specific heat of the copper is c = 0.385kJ/kg-K. Assuming ideal gas behavior for the air, determinea) the initial and final mass of air within the tank, each in kg, and b) the energy transfer due to heat interaction to the surroundings from thetank and its contents, in kJ, ignoring kinetic and potential energy effects.