A closed, vertical cylinder is divided into two parts A and B by a thermally non-conducting frictionless piston. The upper part A contains air at ambient temperature, 20C, and the initial volume is 150 L. The lower part B contains R-134a at -15C, quality 20%, and initial volume of 50L. Heat is now transferred from a heat source to part B, causing the piston to move upward until the volume of B reaches 145L. Neglect the piston mass, such that the pressures in A and B are always equal and assume the temperature in A remains constant during the process.
a) What is the final pressure in A and the final temperature in B.
b) Calculate the work done by the R-134a during the process.
c) Calculate the heat transfer to the R-134a during the process.
d) What is the heat transfer to (or from) the air in A?