Joule-Thomson process is extremely useful and economical for attaining low temperature. The process can be categorized as

The Joule-Thomson process, also known as the throttling process, occurs when a real gas or liquid is forced through a valve or porous plug while being thermally insulated from its surroundings [1]. In this process, the exchange of heat with the environment is not possible, making it an adiabatic expansion [2]. However, the defining characteristic of the Joule-Thomson expansion is that the enthalpy of the fluid remains constant between the inlet and the outlet (H1 = H2) [2]. Therefore, it is specifically categorized as an isoenthalpic (or isenthalpic) process [1]. While it is technically an irreversible adiabatic process, the term 'isoenthalpic' uniquely describes the conservation of enthalpy that distinguishes this effect in thermal machines like refrigerators and air conditioners [1].

Sources

1. [2] https://www.sciencedirect.com/topics/engineering/throttling-process