The system consists of two main parts, a solar assisted heat pump, with refrigerant as its working fluid, and a water desalination section with preheats, as shown in Figure 1.

The solar assisted heat pump provides heating and cooling to the desalination process, with a serpentine tube solar evaporator collector that absorbs solar radiation and ambient energy. Refrigerant R134a is used as the heat pump’s working fluid. The serpentine tube, with 9.52 mm diameter was soldered at the back of the absorber plate. The bottom of the collector was insulated with polyurethane material. An open type reciprocating compressor, directly coupled to a three phase induction motor was used in the system. A frequency inverter controls the speed of the motor. Refrigerant passes through condenser coil, located at the bottom of the desalination chamber. To ensure complete condensation of the refrigerant, it is allowed to pass through a 250 l

[4] LEP: (Liquid Entry Pressure) if the feed pressure is higher than the LEP, then the liquid penetrates the membrane pores and the hydrophobicity is lost [8]. The LEP depends on many factors, but the main one is the membrane pore size, logically the bigger the pore size is, the smaller the LEP is and so is the working pressure.

[5] In the case of C3, the optimal cycle parameters correspond to evaporation at critical conditions.

Considering the stability of ORC operation, the maximum allowed evaporation temperature was bounded, in this analysis, to a value of 145 °C, 9 °C bellow the fluid critical temperature.