What characterizes a multiple stage mechanical refrigeration system?

A multiple stage mechanical refrigeration system is characterized by its composition of two or more distinct stages of compression. Each stage operates with its own components, which typically include a compressor, condenser, expansion device, and evaporator. This setup allows for varying pressures and temperatures at each stage, optimizing the system's efficiency and capacity.

By utilizing multiple stages, the system can handle larger refrigeration loads and provide better performance under varying operating conditions. This is especially important in industrial applications or large-scale refrigeration systems, where energy efficiency and effective temperature control are crucial.

Other options do not accurately represent the nature of a multiple stage refrigeration system. For instance, a system with only one compressor and evaporator coil simplifies the process and does not leverage the advantages provided by multiple stages. Relying solely on natural cooling processes indicates passive systems, which do not involve mechanical compression stages, while limiting operation to single-unit setups does not harness the benefits of multiple stages required for enhanced performance.