Saturated vapor R-410a at 60°C changes volume at constant

Solution 53 HP

Step 1 of 2

We have to the pressure and quality of Saturated vapor R-410a at 60°C when the volume changes to double.

The specific volume of saturated vapour of R-410a at 60o C can be found from the Table.5.1

in the book.

0.00497 m3/kg  kPa (saturated)

The specific volume of saturated vapour of R-140a, if the volume doubles at constant temperature is

Since the mass is constant, specific volume also doubles when the volume doubles.

      = 0.00994 m3/kg superheated vapour

The pressure of the R-140 at 60oC  and with specific volume 0.00994 m3/kg can be found by interpolating between 2000 kPa and 3000 kPa from the Table B.5.2 in the book.

m3/kg at 2000 kPa and m3/kg at 3000 kPa

      = 2000+(1000)(0.8)

      = 2800 kPa

The quality is 1 as it is in vapour state only.

Therefore, the new pressure and quality are 2800 kPa and 1.