A heat pump with refrigerant R22 is used for space heating between temperature limits of –200C and 250C. The heat required is 200MJ/h. Assume specific heat of vapour at the time of discharge as 0.98kJ/kg.K. Other relevant properties are given below. The enthalpy (in kJ/kg) of the refrigerant at isentropic compressor discharge is ______________
|
saturation temperature
|
pressure
|
Specific enthalpy
|
Specific entropy
|
|
Tst(0C)
|
P
(MPa)
|
$h_{f}$
$\left [ \frac{kJ}{Kg} \right ]$
|
$h_{g}$
$\left [ \frac{kJ}{Kg} \right ]$
|
$S_{f}$
$\left [ \frac{kJ}{Kg.K} \right ]$
|
$S_{g}$
 $\left [ \frac{kJ}{Kg} \right ]$
|
|
-20
|
0.2448
|
177.21
|
397.53
|
0.9139
|
1.7841
|
|
25
|
1.048
|
230.07
|
413.02
|
1.1047
|
1.7183
|