Resiliency - Cooling (page 3 of 3)
We plan to use a two-stage cooling system with an outer capsule temperate of 300 °C. We assume that the stage-2 Stirling cooler (outer capsule to Venusian atmosphere) has a linear relationship between the input power and temperature reduction.
By following the design of Landis and Mellot we calculate that our stage-2 Stirling engine will require 173 W of mechanical input power.
If we assume an error of 10% for this linear estimation, then we find that the outer capsule cooling system will require 190 W of power. From the 400 W of power output by the primary Stirling engine 190 W will go to the stage-2 cooling system and 10 W will be converted to electrical power in an alternator for charging the batteries, leaving 200 W of power to be used by the stage-1 Stirling cooler. Because the volume of the inner capsule is significantly smaller than the volume of the outer capsule, we believe that it will be possible to design a Stirling cooler capable of lowering the temperature of the inner capsule to 30 °C with 200 W of input power.
In the event that more power is needed, we can use additional GPHS units on the hot side of the primary Stirling engine.