Gas-fired refrigerators operate on the principle of absorption refrigeration, which uses a different method than conventional compressors to cool. The primary components of such a system include the evaporator, absorber, condenser, and generator.
In an absorption cycle, the generator is crucial as it heats a solution (typically ammonia and water), causing the ammonia to vaporize and move to the condenser. From there, it condenses into a liquid and flows to the evaporator, where it absorbs heat, thereby cooling the refrigerator's interior. The absorber then takes up the vaporized ammonia, allowing it to mix again with the water, repeating the cycle.
This cycle is distinct from mechanical refrigeration systems that rely on a compressor to circulate refrigerant and achieve cooling, which is found in other options. The correct answer highlights the unique aspects of an absorption system, showcasing the importance of these components in gas-fired refrigeration technology.