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bagofmilk
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R134-a Tables Use T or P??
Using the Saturated R134-a tables, I'm a little confused as to when I should look up values according to temperature or pressure.
In this particular problem:
Refrigerant-134a enters a compressor at 100kPa and -24ºC with a flow rate of 1.35 cfm and leaves at 800kPa and 60ºC. Determine the mass flow rate of R-134a and the power input to the compressor.
The equations I plan to use are: mdot = Q/v. And I think that to find power I can use
P = mdot * (u2 - u1)
The problem is that I don't know if I should look at the values according to T1=-24C or P1 = 100kPa (same for T2). Can anyone shed any light on this?
Using the Saturated R134-a tables, I'm a little confused as to when I should look up values according to temperature or pressure.
In this particular problem:
Refrigerant-134a enters a compressor at 100kPa and -24ºC with a flow rate of 1.35 cfm and leaves at 800kPa and 60ºC. Determine the mass flow rate of R-134a and the power input to the compressor.
The equations I plan to use are: mdot = Q/v. And I think that to find power I can use
P = mdot * (u2 - u1)
The problem is that I don't know if I should look at the values according to T1=-24C or P1 = 100kPa (same for T2). Can anyone shed any light on this?