Determine the phase and specific volume of r22 at 5°c and 500 kpa.

Question

I know is a super heated vapor but I don't understand how to find the specific volume. I think I have interpolate but the values for that are not shown in my tables or I at least I think are not shown.

Answer 1

Hey there Jesus,

You are correct in your analysis of the phase. at 5°C, the saturation pressure of R22 is 584.1 kPa. The provided pressure of the working fluid is 500 kPa, which is below the saturation pressure of the working fluid at 5°C. According to rules of pressure at constant temperature, if the pressure of the working fluid is below the saturation pressure, the phase of the fluid is a superheated vapor.

At this point, you need to look at your provided superheated vapor tables for R22 and locate where the temperature reads 5°C and the pressure at the top of the column reads 500 kPa. Due to these values being a multiple of 5 and/or 50, there is less likely the need for interpolation. At 5°C and 500 kPa in the superheated vapor tables for R22, find the specific volume column, v, and it reads 0.0482 m³/kg.

You mentioned that your values do not show these values. If you follow these steps and it still does not show up, I recommend talking to your instructor and/or seeking a different property tables booklet.

Hope this helps!!!

-Andrew Evans