Reached performances

A series a 39 steady-state performance points is achieved, by modifying the working conditions as indicated in the table below:

Working condition

Minimum value

Maximum value

First hot air source mean temperature

53.4 °C

86.4 °C

Second hot air source mean temperature

101 °C

163.2 °C

Air flow rate

0.071 kg/s

0.90 kg/s

Refrigerant flow rate

45 g/s

86 g/s

Condenser water flow rate

0.13 l/s

0.70 l/s

Condenser mean water temperature

13.2 °C

15 °C

Expander rotation speed

1771 rpm

2660 rpm

/

Three performance indicators are taken into account: the expander shaft power, the expander isentropic effectiveness, and the cycle efficiency.

The expander isentropic effectiveness is defined by: & =

Mir * (hr, su, exp hr, ex, exp, s)

W — W

And the cycle efficiency by: T]cycie = shexp —

Qevap

A shaft power ranging from 0.38 to 1.82 kW is obtained, corresponding to a mechanical isentropic effectiveness ranging from 43 to 68% and a maximum cycle efficiency of 7.4%. The pressure ratio over the expander varied from 2.7 to 5.4.