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.
