1. What is Carnot Efficiency?

Carnot efficiency (η) represents the maximum possible efficiency that a heat engine operating between two reservoirs can achieve, according to the second law of thermodynamics. It depends only on the temperatures of the hot and cold reservoirs.

2. How Does the Calculator Work?

The calculator uses the Carnot efficiency formula:

Where:

• \( \eta \) — Thermal efficiency (dimensionless)
• \( T_c \) — Cold reservoir temperature (Kelvin)
• \( T_h \) — Hot reservoir temperature (Kelvin)

Explanation: The efficiency increases as the temperature difference between the hot and cold reservoirs increases.

3. Importance of Carnot Efficiency

Details: Carnot efficiency establishes the theoretical maximum efficiency for any heat engine, serving as a benchmark for real-world thermal systems like power plants and refrigerators.

4. Using the Calculator

Tips: Enter both temperatures in Kelvin (absolute temperature scale). The hot temperature must be greater than the cold temperature for meaningful results.

5. Frequently Asked Questions (FAQ)

Q1: Why can't real engines achieve Carnot efficiency?
A: Real engines have irreversibilities like friction, heat loss, and finite temperature differences that prevent them from reaching this theoretical maximum.

Q2: What are typical Carnot efficiency values?
A: For a steam turbine (T_h≈800K, T_c≈300K), η≈62.5%. Real efficiencies are typically half of this value.

Q3: Can efficiency be 100%?
A: Only if T_c=0K (absolute zero) or T_h=∞, both physically impossible scenarios.

Q4: Does this apply to refrigerators?
A: Yes, but in reverse - the coefficient of performance (COP) has a Carnot limit of T_c/(T_h-T_c).

Q5: How to convert Celsius to Kelvin?
A: K = °C + 273.15. Always use absolute temperatures in these calculations.