Final answer:
The statement regarding the refrigeration system is false, as the condenser operates at a higher temperature than the evaporator in order for the system to release heat to the environment and for the refrigerant to condense into a liquid.
Step-by-step explanation:
The statement that for a refrigeration system to operate correctly, the condenser must always be at a lower saturation temperature than the evaporator is false. In a refrigeration cycle, the condenser, where the refrigerant releases heat to the surrounding, actually operates at a higher temperature compared to the evaporator. The evaporator absorbs heat at a lower temperature, causing the refrigerant to vaporize. The compressor then raises the pressure and temperature of the vaporized refrigerant, sending it to the condenser. Inside the condenser, the high-temperature refrigerant releases heat to the surroundings and condenses into a liquid. The liquid refrigerant then returns to the evaporator through an expansion valve, where it cools due to the reduction in pressure, thus completing the cycle.
For instance, in a household refrigerator, as indicated in the question, the refrigerant absorbs heat from inside the refrigerator at the evaporator coils, causing it to vaporize. The compressor then compresses the vapor, increasing its temperature and pressure. When the high-pressure, high-temperature vapor arrives at the condenser coils, it releases its heat to the outside environment and changes back into a liquid. Therefore, the condenser must be at a higher saturation temperature so that it can release the absorbed heat effectively.
The coefficient of performance, KR, of a refrigerator is the ratio of the heat removed from the cold space (at the evaporator) to the work input (by the compressor). This underlines the importance of having higher and lower saturation temperatures at the condenser and evaporator, respectively.