Cryogenic fluids, such as nitrogen, are essential in engineering sciences, particularly for their applications in cooling and liquefaction processes. Nitrogen exists as a liquid at -196°C, and not at room temperature (RT). The liquefaction process involves using the ideal gas law, where pressurizing the gas heats it up. By cooling the gas while maintaining pressure and then allowing it to expand through a nozzle, the temperature drops sufficiently to achieve liquefaction. The Joule-Thomson effect is a key principle in this process, enabling temperature changes through gas expansion. For enhanced cooling, an expansion engine can be utilized, which further reduces energy and temperature. References for deeper understanding include resources on cryogenic air separation and detailed explanations of the Joule-Thomson effect.
