Answer:
the power input to the compressor is 7.19Kw
Explanation:
Hello!
To solve this problem follow the steps below.
1. We will call 1 the refrigerant state at the compressor inlet and 2 at the outlet.
2. We use thermodynamic tables to determine enthalpies in states 1 and 2.
(note: Through laboratory tests, thermodynamic tables were developed, these allow to know all the thermodynamic properties of a substance (entropy, enthalpy, pressure, specific volume, internal energy etc ..)
through prior knowledge of two other properties such as pressure and temperature. )
h1[quality=1, P=0.12Mpa)=237KJ/Kg
h2(P=1.2Mpa, t=70C)=300.6KJ/kg
3.
uses the first law of thermodynamics in the compressor that states that the energy that enters a system is the same that must come out
Q=heat=0.32kJ/s
W=power input to the compressor
m=mass flow=0.108kg/S
m(h1)+W=Q+m(h2)
solving for W
W=Q+m(h2-h1)
W=0.32+0.108(300.6-237)=7.19Kw
the power input to the compressor is 7.19Kw
