Read the following data for a NH₃ based refrigeration plant and answer the questions
A single cylinder, single acting compressor bore and stroke : 16 cm and 24 cm
Speed : 110 RPM
The indicated mean effective pressure : 2.1 bar
Thepressure limits : 9.7262 bar and 2.6785 bar
The temperatures at entry and exit of condenser 38°C and 16°C
The mass flow rate of cooling water : 14 kg/min
The rise in temperature of water : 8°C
The mass of ice produced : 56 kg/hr @20°C

Pressure, bar	Saturation temperature	Enthalpy, h, kJ/kg		Specific heat, Cp, kJ/kg K
Liquid	Vapour	Liquid	Vapour
9.7262	24	313.11	1482.49	4.791	3.113
2.6785	-12	144.91	1447.91	4.545	2.482

Assume: L_ice = 335 kJ/kg and C_p,water = 4.19 kJ/kg K

1)Find the compressor work, kW

a.2.26

b.1.86

c.3.23

d.2.65

2)COP

a. 2.76

b. 2.42

c. 4.32

d.3.51

3)Mass flow rate of NH₃, kg/min

a.0.375 b.1.23 c. 0.826 d.2.642

4)The refrigeration effect in kJ/kg

a. 1562.1

b.1043.2

c.2214.3

d.883.2

5)The quality of NH₃ entering the compressor

a. 0.77

b.0.79

c.0.68

d. 0.9

poralla vinay , 6 Years ago

Grade 12th pass