Im trying to figure out how to calculate the pressure necessary to create a 30 degree celsius temperature drop in water, by using a small pressurized cylinder of air within the water. The volume of the water is .00075 m^3 and the volume of the canister is .00025 m^3. I calculated the amount of energy lost by the water to be 94.05 KJ. But im not sure how to calculate the corresponding pressure necessary in the pressurized air container to cause this temperature change in the water.(adsbygoogle = window.adsbygoogle || []).push({});

These are the values i was using:

Cair= 1.2KJ/kg*K

Mair=.0003kg

T1,air=293K

P1,air= 3bar (not sure if its enough)

Vair= 0.00025m^3

Cwater=4.18KJ/kg*K

Mwater=.75kg

T1,water=293K

T2,water=263K

P1,water=101.3Kpa

Vwater=0.00075m^3

I wasn't sure what values had to be assumed and but i assumed:

t=180seconds (for the air to escape the canister)

ρair= 1.204 kg/m^3

Any help is appreciated

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# Heat Transfer in thermos

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