Question

A fairly efficient steam turbine engine fired by coal is used to drive an electric generator. The generator operates between 2100°C and 385°C.

(a) Determine the maximum possible efficiency of the engine.


Answer: 72.3 %


Formula:

e = 1 - (Tc / Th) = 1 - (Qc / Qh) = ( W / Qh)


Explanation: Unsure??


(b) The engine absorbs 1.15 105 J from the hot reservoir every second. If the actual efficiency of the engine is 40.3%, determine the mechanical power the engine delivers.


Answer: 46 kW


Explanation:

Energy absorbed by the engine (J) * actual efficiency of the engine (%) = mechanical power the engine delivers (kW)


How does 1 - (385/2100) = 72.3 % ?
What do I Plug in to make e = 72.3 %

Answer 1

The maximum efficiency of a steam turbine engine fired by coal can be calculated using the formula e = 1 - (Tc / Th), where Tc is the temperature of the cold reservoir and Th is the temperature of the hot reservoir. Plugging in the values provided, the maximum efficiency is 81.8%.

Step-by-step explanation:

The maximum possible efficiency of a steam turbine engine can be determined using the formula: e = 1 - (Tc / Th). In this formula, Tc represents the temperature of the cold reservoir (385°C) and Th represents the temperature of the hot reservoir (2100°C). Plugging in these values, the maximum efficiency can be calculated as follows:

e = 1 - (385/2100) = 0.818

To convert this to a percentage, multiply by 100:

Maximum efficiency = 0.818 * 100 = 81.8%

Answer 2

Use kelvin not celsius

C + 273 = K

This will fix my problem of the equation not making sense.