Can a Device Output Two Air Streams at Different Temperatures and Pressures?

[joseph3141]

Homework Statement

I have a device where air (can assume ideal) comes in at 1.25 atm and 75 degrees F. It outputs two streams at 1.0 atm. One of the streams has a temperature of -15 F, and the other at 90 F.

Is this device possible?

Homework Equations

I believe h = cpdeltaT and PV=nRT may become useful, although none were given in the problem.

The Attempt at a Solution

I know I have to use the energy conservation here, I just am not sure how to apply it.

I have tried a lot of things to figure this out. I just don't know how to account for the flowing? I believe I can look up enthalpy values on there own with the temperature info of each stream. Does enthalpy account for the flow of air? If so, can I take enthalpy at beginning = enthalpy of output stream 2 + output stream 3? If these don't add up is not possible?

 

[nate808]

Hi there,

Based on the information provided, it is possible for the device to output two streams at different temperatures and pressures. This is because the device is most likely using a heat exchanger, which allows for the transfer of heat between two streams of fluids at different temperatures and pressures.

To analyze this further, we can use the ideal gas law (PV=nRT) to calculate the number of moles of air in each stream. From there, we can use the specific heat capacity (cp) and the change in temperature (deltaT) to calculate the change in enthalpy (h) for each stream. This will give us an idea of how much heat is being transferred between the two streams.

If the change in enthalpy for each stream does not add up, it is possible that there are other factors at play such as heat loss or gain from the surroundings. In that case, further analysis and calculations would be needed to determine the feasibility of the device.

Overall, it is important to consider all the variables and equations involved in order to fully understand the functioning of the device and determine its possibility.