A refrigerator works on the principle of thermodynamics and heat transfer. It utilizes a closed-loop system of refrigerant (usually a gas or a mixture of gases) that undergoes a continuous cycle of compression and expansion to transfer heat from the inside of the refrigerator to the outside, thus keeping the internal temperature cool.
Here's a simplified explanation of how a refrigerator works:
Compression: The process begins with the compressor, located at the back or bottom of the refrigerator, compressing the gaseous refrigerant. Compression increases the pressure and temperature of the gas.
Condensation: The high-pressure, high-temperature refrigerant gas flows through condenser coils located at the back or bottom of the fridge. Here, the gas releases its heat to the surrounding air and condenses into a liquid state due to the cooling effect. This step is crucial in expelling heat from the refrigerator.
Expansion: The high-pressure liquid refrigerant then passes through an expansion valve or capillary tube, where it undergoes a sudden drop in pressure. As a result, the refrigerant becomes a low-pressure, low-temperature mixture of liquid and gas.
Evaporation: The low-pressure, low-temperature refrigerant enters the evaporator coils inside the refrigerator's main compartment and freezer. As it absorbs heat from the inside of the fridge, the refrigerant evaporates back into a gaseous state. This absorption of heat cools the interior of the refrigerator.
Return to Compression: The cycle continues, with the gaseous refrigerant returning to the compressor, where it starts the process again.
Now, as for the efficiency of electric refrigerators compared to "normal" ones (assuming by "normal," you might be referring to non-electric or traditional iceboxes), electric refrigerators are significantly more efficient for several reasons:
Continuous Cooling: Electric refrigerators provide continuous cooling, while non-electric iceboxes rely on a finite supply of ice or other cooling methods that require regular replacement or replenishment. Electric refrigerators maintain a consistent temperature without the need for manual intervention.
Temperature Control: Electric refrigerators have adjustable temperature settings, allowing users to regulate the cooling according to their needs. Non-electric methods often lack this level of control.
Heat Pump Technology: Electric refrigerators use a heat pump system (as explained above), which is a highly efficient process for transferring heat. In contrast, traditional iceboxes or non-electric cooling methods tend to have lower efficiency in heat transfer.
Energy Efficiency: Modern electric refrigerators are designed to be energy-efficient, with technologies like improved insulation, better compressor efficiency, and advanced control systems to minimize power consumption.
Overall, electric refrigerators offer convenience, precise temperature control, and improved energy efficiency, making them the preferred choice for most households and commercial establishments today.