Figure 2:
Test Facility
Compressed air is heated by the test facility to simulate the heat of
compression of a hypothetical turbocompressor.
Hot day conditions of 50ºC at the compressor inlet are assumed for all
data shown here. The compressed air
temperature is adjusted to simulate the projected compressor efficiency for the
range of stack operating pressures. As
power demand increases, the compressor accelerates forcing higher mass flow
through the cathode. As flow increases,
pressure and temperature are increased as shown in Table 1.
This table represents the conditions at Station 1 of Figure 1.
Table 1:
Enthalpy Wheel Inlet Conditions (Hot Day)
|
Power (%) |
25 |
50 |
100 |
|
Flow (SLPM) |
658 |
1328 |
3019 |
|
Pressure (atm abs) |
1.38 |
1.75 |
2.50 |
|
Temperature (ºC) |
87 |
118 |
169 |
A packed tower humidifier simulates a fuel cell cathode operating at a cathode exhaust condition of 80ºC saturated. (Station 3 of Figure 1) The simulation also includes a mass flow reduction corresponding to a Stoichimetic ratio of 2.0 and a typical second order stack pressure drop of 0.21 atm (3.0 psid) at full flow conditions.
