1. What is Carnot Efficiency?

The Carnot efficiency represents the maximum possible efficiency that a heat engine can achieve operating between two temperatures (hot and cold reservoirs). It establishes the theoretical upper limit for the efficiency of all heat engines.

2. How Does the Calculator Work?

The calculator uses the Carnot efficiency equation:

Where:

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

Explanation: The efficiency depends only on the temperature difference between the hot and cold reservoirs. Higher temperature differences yield higher efficiencies.

3. Importance of Carnot Efficiency

Details: Carnot efficiency is fundamental in thermodynamics as it sets the absolute maximum efficiency possible for any heat engine operating between two temperatures. It helps engineers evaluate the performance limits of real-world engines.

4. Using the Calculator

Tips: Enter both temperatures in Kelvin. The hot temperature must be greater than the cold temperature. Absolute zero (0K) is allowed for the cold temperature, but both values must be positive.

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 the theoretical maximum.

Q2: Can Carnot efficiency be greater than 100%?
A: No, the efficiency is always between 0% and 100% (when Tc = 0K, the theoretical maximum).

Q3: Does Carnot efficiency apply to refrigerators?
A: Yes, but in reverse. The coefficient of performance (COP) for refrigerators has a Carnot limit similar to engine efficiency.

Q4: Why use Kelvin instead of Celsius?
A: The equation requires absolute temperatures to avoid negative values or efficiencies >100%.

Q5: How can I increase Carnot efficiency?
A: Either increase the hot reservoir temperature or decrease the cold reservoir temperature (or both).