1. What is Carnot Efficiency?

The Carnot efficiency represents the maximum possible efficiency that a heat engine can achieve operating between two reservoirs at different temperatures. It's a theoretical limit based on the second law of thermodynamics.

2. How Does the Calculator Work?

The calculator uses the Carnot efficiency formula:

Where:

• \( \eta \) — Carnot efficiency (dimensionless, often expressed as percentage)
• \( T_c \) — Absolute temperature of the cold reservoir (Kelvin)
• \( T_h \) — Absolute temperature of the hot reservoir (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 provides the upper limit for real heat engines. While no real engine can reach this efficiency, it serves as a benchmark for comparing actual engine performance.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: Why can't real engines reach Carnot efficiency?
A: Real engines have irreversibilities like friction, heat loss, and finite temperature differences during heat transfer.

Q2: What are typical Carnot efficiency values?
A: For steam turbines (T_h≈800K, T_c≈300K), η≈62.5%. For car engines (T_h≈2000K, T_c≈300K), η≈85%.

Q3: Can efficiency be 100%?
A: No, unless T_c=0K (absolute zero), which is impossible to achieve. Even then, quantum effects would prevent 100% efficiency.

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

Q5: How to increase Carnot efficiency?
A: Either increase the hot reservoir temperature or decrease the cold reservoir temperature.