Steam contained in a piston & cylinder appartus is initially at 200kPa, and x=0.
ID: 1856106 • Letter: S
Question
Steam contained in a piston & cylinder appartus is initially at 200kPa, and x=0.8. This pressure is sufficient to hold the piston against a set of stops on the cylinder wall. The steam is cooled until at P=100kPa when the piston begins to descend in a constant pressure process. The cooling continues until the volume has been reduced to half of its original value. 1) What is the quality of the steam at the point when the piston first begins to descend (State 2)? 2) What is the quality of the steam at the final condition (State 3)?Explanation / Answer
two processe happens 1st pressure is reduced to 100kPa
and then volume is made half
so the inital specific volume =0.2*0.001061+0.8*0.88573=0.7087
so the 2nd process the mass and the volume dint change so the specific volume remain constant
so same specific volme at 100kPa =0.001043+x*1.69400=0.7087=0.41177
b)as the volume reduces to half so
the specific volume reduces to half
so 0.7087/2=0.001043+x*1.69400=0.2085