saintthor / carnot

Carnot heat machine

carnot

Carnot heat machine

A Carnot engine can be constructed using a straight, closed cylinder with a piston in the middle. The piston divides the working fluid gas inside the cylinder into two equal parts. The cylinder can rotate counterclockwise on a vertical plane with its center point as the axis.

The heat source is located in the lower right quadrant (fourth quadrant) of the cylinder's rotational circle, and the cooling device is located in the upper left quadrant (second quadrant). The remaining areas are insulated. The working fluid gas in the two chambers separated by the piston will experience four states: isothermal expansion (lower right), adiabatic expansion (upper right), isothermal compression (upper left), and adiabatic compression (lower left) as it rotates one round starting from the bottom. Its working cycle is the Carnot cycle.

During the rotation of the cylinder, the average temperature of the working fluid gas on the right side is higher than that on the left side, so the piston trajectory is biased to the left. The torque generated by the gravity of the piston makes the cylinder rotate counterclockwise and do work on the outside.

After adiabatic expansion, the working fluid gas should be reduced from the heat source temperature to the cold source temperature; after adiabatic compression, the working fluid gas should be increased from the cold source temperature to the heat source temperature. Inaccuracy of temperature will affect the efficiency, and the temperature can be adjusted by adjusting the range of action of the cold and heat sources. For example, if the gas on one side decreases from the heat source temperature to the cold source temperature during adiabatic expansion, while the temperature increase on the other side exceeds the heat source temperature, then the range of the heat source can be reduced or the range of the cold source can be increased to make the temperatures on both sides match at the same time.