ENERGY TRANSFERS ANALYSIS

 

Compressor

If compression is adiabatic, q_1-2 = 0 and w = h₁- h₂

Power requirement, P = m (h₁- h₂ ), where m is the flow rate of working fluid per unit time.

 

Condenser

q_{1-2 =}   h₃- h₂+ w

w = 0, therefore q_2-3 = h₃- h_2, and rate of heat rejection Q_2-3 = m (h₃- h₂ )

 

Expansion valve

Q_{3-4 =}   h₄- h₃+ w

w = 0 at the expansion valve and process is adiabatic,

therefore h4= h₃

 

Evaporator

Q_4-1 =   h₁- h₄+ w

w = 0, therefore q_4-1 = h₁- h_4, and rate of heat rejection Q_4-1 = m (h₁- h₄)

 

Coefficient of Performance (COP)