Module 5 - Refrigeration and Heat Pumps

Module 5 - Refrigeration and heat pumps

1 An introduction to refrigeration and heat pumps
1.1 Coefficient of Performance

Tn Hot Reservoir Th Hot Reservoir

(Environment) CHouse)

-QH Desired
-Qu EFFECT

Wrei Wuer
Heat PUMD
y Refrigerator 3




Desired
*
Qu EFFECT -Q


TC Can Reservoir Tc Cold Reservoir

[Refrigeration Space ( [Environment(



The coefficient of performance (CoP) is the ratio of desired heat transfer to the net work required to
drive the heat transfer.

CoP = DesIReD output =
Qu =
Qu
REFRIGERATOR

REQUIRED INPUT Wer Qu -
Qu



CoP = Desired output :
HEATING Effect = QH =
QH
PUMP
Required Input Work Input Whet Qn-Qu


1.2 Ton of refrigeration

Refrigeration effect is the amount of heat extracted by the refrigerator from the refrigeration space.

One ton of refrigeration is defined as the amount of heat removed from 907 kg (2000 lb) of water at
0^C to form 907 kg (2000 lb) of ice within 24 hours.

1 ton of refrigeration = mass of water x latent heat
= 210 45 /min
= 3 5 .
W