TITLE.PM5

718 ENGINEERING THERMODYNAMICS dharm \M-therm\Th14-1.pm5 C.O.P.(Carnot ref.) = T TT 2 12 − i.e., 2.99 = 235 T 1 − 235 ∴ T 1 =^23 ...

REFRIGERATION CYCLES 719 dharm \M-therm\Th14-1.pm5 Solution. T 2 = – 5 + 273 = 268 K ; T 1 = 35 + 273 = 308 K Heat leakage from ...

720 ENGINEERING THERMODYNAMICS dharm \M-therm\Th14-1.pm5 ∴ W = 425.96 400 10 × .19 = 16720.7 kJ/h = 4.64 kJ/s or 4.64 kW Hence l ...

REFRIGERATION CYCLES 721 dharm \M-therm\Th14-1.pm5 Heat removed by the plant /min = 320 20 1000 8 .29×× = 800725 kJ/h (i) Capaci ...

722 ENGINEERING THERMODYNAMICS dharm \M-therm\Th14-1.pm5 T= 5 + 273 = 268 K 3 T= 1000 + 273 = 1273 K 1 T= 25 + 273 = 298 K 4 T ...

REFRIGERATION CYCLES 723 dharm \M-therm\Th14-1.pm5 In this system, work gained from expander is employed for compression of air, ...

724 ENGINEERING THERMODYNAMICS dharm \M-therm\Th14-1.pm5 But R = cp γ γ F − HG I KJ (^1) J (J = 1 in S.I. units) ∴ WWcomp.− exp. ...

REFRIGERATION CYCLES 725 dharm \M-therm\Th14-2.pm5 Solution. Fig. 14.6 shows the working cycle of the refrigerator. Given : p 2 ...

726 ENGINEERING THERMODYNAMICS dharm \M-therm\Th14-2.pm5 = n n− 1 R[(T^4 – T^3 ) – (T^1 – T^2 )] The value of R can be calculate ...

REFRIGERATION CYCLES 727 dharm \M-therm\Th14-2.pm5 (i)Mass of air circulated per minute, m : For the expansion process 1-2, we h ...

728 ENGINEERING THERMODYNAMICS dharm \M-therm\Th14-2.pm5 (iii)Piston displacement of compressor and expander. (iv)Bore of compre ...

REFRIGERATION CYCLES 729 dharm \M-therm\Th14-2.pm5 (ii)Mass of air in circulation : Refrigerating effect per kg of air = cp (T 3 ...

730 ENGINEERING THERMODYNAMICS dharm \M-therm\Th14-2.pm5 (v)Power required to drive the unit : C.O.P. = Refrigerating effect Wor ...

REFRIGERATION CYCLES 731 dharm \M-therm\Th14-2.pm5 The vapour at low temperature and pressure (state ‘2’) enters the “compressor ...

732 ENGINEERING THERMODYNAMICS dharm \M-therm\Th14-2.pm5 14.3.4. Vapour compression cycle on temperature-entropy (T-s) diagram.. ...

REFRIGERATION CYCLES 733 dharm \M-therm\Th14-2.pm5 When the vapour is superheated after compression. If the compression of the ...

734 ENGINEERING THERMODYNAMICS dharm \M-therm\Th14-2.pm5 Liquid line dg f s (Entropy) Saturation line Rn T 2 a b 12 e Evaporatio ...

REFRIGERATION CYCLES 735 dharm \M-therm\Th14-2.pm5 Refer Fig. 14.13. The chart is dividing into three areas that are separated f ...

736 ENGINEERING THERMODYNAMICS dharm \M-therm\Th14-2.pm5 compression it becomes superheated at the end of compression as given b ...

REFRIGERATION CYCLES 737 dharm \M-therm\Th14-2.pm5 The following points may be noted : (i)As the discharge temperature required ...