Heat Engine & Refrigerator

Cycle Type

P-V Diagram

Compression

Expansion

Isothermal

Piston Animation

Current Stroke: -

Energy Flow

Four Strokes

Intake

Compression

Power

Exhaust

Efficiency Analysis

Thermal Efficiency η 0%

Carnot Efficiency η_C 0%

COP 0

Parameters

Temperatures

Hot Reservoir T_h: 500 K Cold Reservoir T_c: 300 K

Volumes

Compression Ratio: 8:1 Max Pressure: 50 bar

Animation Controls

Animation Speed: 1x Show P-V Path Show Energy Flow Show Temperature

Quick Presets

Thermodynamic Equations

Thermal Efficiency η η = W/Q_h = 1 - Q_c/Q_h

COP (Cooling): COP_cooling = Q_c/W

COP (Heating): COP_heating = Q_h/W

Carnot Efficiency η_C η_Carnot = 1 - T_c/T_h

First Law: ΔU = Q - W

Ideal Gas: PV = nRT

What are Heat Engines and Refrigerators?

Heat engines and refrigerators are thermodynamic systems that operate on cycles to convert heat into work (heat engines) or transfer heat from cold to hot reservoirs using work (refrigerators/heat pumps).

Heat Engines

Heat engines operate on thermodynamic cycles that convert thermal energy into mechanical work. The working fluid undergoes heating, expansion, cooling, and compression processes.

Refrigerators and Heat Pumps

Refrigerators and heat pumps operate on reverse thermodynamic cycles. They require work input to transfer heat from cold to hot reservoirs.

Carnot Cycle

The Carnot cycle is the most efficient possible heat engine cycle, consisting of two isothermal and two adiabatic processes. It represents the theoretical upper limit of efficiency.

Otto and Diesel Cycles

Otto cycle models spark-ignition engines. Diesel cycle models compression-ignition engines. Key difference: Otto uses spark ignition with premixed fuel-air, while Diesel uses compression ignition.

Real-World Applications

Automobiles, power plants, household appliances, air conditioning, industrial refrigeration.

Historical Context

The study of heat engines began in the 18th century with the Industrial Revolution. James Watt's improved steam engine (1769) revolutionized manufacturing. Sadi Carnot's 1824 work established the theoretical foundation of thermodynamics.