4 posts • joined Friday 29th February 2008 23:20 GMT
@Dave Bell & Ian Rogers
Yes, I used Kelvin for my calculation, as quick and simple use of a calculator would demonstrate. It should be obvious from sight that 1-(20/60) is not going to equal 0.12 in any case.
However, for readability, I provided celsius equivalents.
A Stirling Engine is just a particular type of heat engine.
Heat engines have a maximum theoretical efficency of 1-(T_c/T_h),
Where T_c is the "cold" temperature, and T_h is the "hot" temperature.
Given, say, temperatures of 20 and 60 degrees celsius, you'd get a maximum efficency value of about 12%.
The 70% figure is presumably 70% of 12% (~ 8.5%).