Question

In an absorption type refrigeration system, heating in generator, refrigeration in evaporator and cooling by cooling water in condenser, take place at 95°C, -5°C and 30°C respectively. What is the maximum COP of the system?
1. 1.17
2. 1.35
3. 1.52
4. 1.78

Answer 1

Correct Answer - Option 2 : 1.35

Concept:

COP of Vapor Absorption Refrigeration Cycle (VARS):

\({\left( {COP} \right)_{VARS}} = \left( {\frac{{{T_G} - {T_0}}}{{{T_G}}}} \right) \cdot \left( {\frac{{{T_E}}}{{{T_0} - {T_E}}}} \right)\)

TG is the generator temperature, TE is the evaporator temperature and T0 is the environment temperature

Calculation:

Given:

TG = 95°C = 368 K, TE = -5°C = 268 K, T0 = 30°C = 303 K.

COP of Vapor Absorption Refrigeration Cycle (VARS):

\({\left( {COP} \right)_{VARS}} = \left( {\frac{{{T_G} - {T_0}}}{{{T_G}}}} \right) \cdot \left( {\frac{{{T_E}}}{{{T_0} - {T_E}}}} \right)\)

\({\left( {COP} \right)_{VARS}} = \left( {\frac{{{368}\; - \;{303}}}{{{368}}}} \right) \cdot \left( {\frac{{{268}}}{{{303}\; - \;{268}}}} \right)=1.352\)