Wärmereservoirs

Wärmereservoirs, also known as thermal reservoirs or heat reservoirs, are fundamental concepts in thermodynamics. They represent hypothetical or actual bodies that can exchange heat energy with a system without undergoing a significant change in their own temperature. This means their heat capacity is considered infinitely large relative to the amount of heat being transferred. In essence, they act as inexhaustible sources or sinks of thermal energy.

There are two primary types of Wärmereservoirs: hot reservoirs and cold reservoirs. A hot reservoir is a body that can supply heat to a system at a constant, higher temperature. Conversely, a cold reservoir is a body that can absorb heat from a system at a constant, lower temperature. These reservoirs are crucial for understanding the principles of heat engines and refrigerators, which operate by transferring heat between a hot and a cold reservoir.

Examples of practical approximations to Wärmereservoirs include large bodies of water like oceans or lakes, the atmosphere, or even massive industrial heat storage systems. While no real-world reservoir is truly infinite, these large-scale systems can often serve as effective approximations for thermodynamic calculations due to their immense thermal mass. The concept allows for simplified analysis of energy transfer processes and the efficiency limits of thermodynamic cycles.