"Vapor compression refrigeration cycle - Irreversible compressor"
 
T_evap = 5
T_cond = 40
eta_comp = 0.8 "compressor isentropic efficiency"
 
"Point 1: evaporator outlet (saturated vapor)"
x[1] = 1
T[1] = T_evap
P[1] = pressure(R134a, T = T[1], x = x[1])
h[1] = enthalpy(R134a, T = T[1], x = x[1])
s[1] = entropy(R134a, T = T[1], x = x[1])
 
"Point 2: compressor outlet (isentropic compression)"
s_is[2] = s[1]
P[2] = pressure(R134a, T = T_cond, s = s_is[2]) 	"same pressure for points 2 and 2is"
h_is[2] = enthalpy(R134a, T = T_cond, s = s_is[2])
W_comp_is = h_is[2] - h[1] 	"reversible compressor work"
eta_comp = W_comp_is/W_comp	"calculation for the irreverssible compressor work"
h[2] = h[1] + W_comp
s[2] = entropy(R134a, P = P[2], h = h[2])
T[2] = temperature(R134a, P = P[2], h = h[2])
 
"Point 3: condenser outlet (saturated liquid)"
x[3] = 0
P[3] = P[2]
h[3] = enthalpy(R134a, T = T_cond, x = x[3])
s[3] = entropy(R134a, T = T_cond, x = x[3])
T[3] = temperature(R134a, P = P[3], x = x[3])
 
"Point 4: expansion valve outlet (isenthalpic expansion)"
P[4] = P[1]
h[4] = h[3]
s[4] = entropy(R134a, P = P[4], h = h[4])
x[4] = quality(R134a, P = P[4], h = h[4])
T[4] = temperature(R134a, P = P[4], h = h[4])
 
"Cycle performance"
Q_evap = h[1] - h[4]
COP = Q_evap/W_comp