Common Data for Question 01 & 02
A refrigerator operates between 120kPa and 800kPa in an ideal vapor compression cycle with R-134a as the refrigerant. The refrigerant enters the compressor as saturated vapor and leaves the condenser as saturated liquid. The mass flow rate of the refrigerant is 0.2 kg/s. Properties for R–134a are as follows. (GATE-ME-12)
|
Saturated R – 134a
|
|
P (kPa)
|
T(0C)
|
hf
(kJ/kg)
|
hg
(kJ/kg)
|
sf
(kJ/kg.K)
|
sg
(kJ/kgK
|
|
120
|
-22.32
|
22.5
|
237
|
0.093
|
0.95
|
|
800
|
31.31
|
95.5
|
267.3
|
0.354
|
0.918
|
|
Superheated R-134a
|
|
P (kPa)
|
T(0C)
|
|
H(kJ/kg)
|
S(kJ/kg.K)
|
|
|
800
|
40
|
|
276.45
|
0.95
|
|
- The rate at which heat is extracted, in kJ/s from the refrigerated space is
(a) 28.3 (b) 42.9
(c) 34.4 (d) 14.6
2 . The power required for the compressor in kW is
(a) 5.94 (b) 1.83
(c) 7.9 (d) 39.5