Taking into account the "Second Law of thermodynaics", what is the maximum percentage of heat at 700 C that can be converted into electricity if the waste heat was produced as steam at 100 C?
To determine the maximum percentage of heat at 700°C that can be converted into electricity, we can use the concept of thermal efficiency as dictated by the Second Law of Thermodynamics.
The Second Law of Thermodynamics states that the maximum efficiency of any heat engine (such as a steam turbine) is limited by the Carnot efficiency. The Carnot efficiency depends on the temperatures of the hot and cold reservoirs involved in the process.
In this case, we have a hot reservoir at 700°C and a cold reservoir at 100°C. The Carnot efficiency can be calculated using the following formula:
Carnot efficiency = 1 - (Tcold / Thot)
Where Tcold is the temperature of the cold reservoir (100°C + 273.15 = 373.15 Kelvin) and Thot is the temperature of the hot reservoir (700°C + 273.15 = 973.15 Kelvin).
Using these values, we can calculate the Carnot efficiency:
Carnot efficiency = 1 - (373.15 / 973.15) = 0.617 or 61.7%
Therefore, the maximum percentage of heat at 700°C that can be converted into electricity, considering the waste heat produced as steam at 100°C, is 61.7%.