buletinul institutului politehnic din iaşi - Universitatea Tehnică ...

Bul. Inst. Polit. Iaşi, t. LVIII (LXII), f. 4, 2012 37
Fig. 1 – Schematic representation of refrigeration system: where: T1 – refrigerant
temperature at suction compressor, ºC; T2 – refrigerant temperature at discharge
compressor, ºC; T3 refrigerant temperature at condenser inlet, ºC; T4 – refrigerant
temperature at condenser outlet, ºC; T5 – air temperature at inlet evaporator 1, ºC; T6 –
air temperature at outlet evaporator 1, ºC; T7 – refrigerant temperature at discharge of
evaporator 1, ºC; T8 – air temperature at inlet evaporator 2, ºC; T9 – air temperature at
outlet evaporator 2, ºC; T10 – refrigerant temperature at discharge of evaporator 2, ºC;
T11 – air temperature at condenser inlet, ºC; T12 – air temperature at condenser
outlet, ºC.
2.1. Calculation of the Theoretical Eco-efficiency Parameters
The theoretical eco-efficiency parameters discussed in this paper are: the
performance coefficient, annual energy consumption and TEWI factor. For
finding the eco-efficiency parameters, classic thermodynamics relations
together with parameters defined in Table 1 were used (Ţârlea et al., 2010).
i) Finding the performance coefficient
First of all was calculated the refrigerant mass flow by
0 M&
Φ
= ,
Δh
(1)
ev