Refrigerator Block Diagram and Working | New Topic

In this note, we are going to know about the Refrigerator Block Diagram and Working as well. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.

Author Name: Arun Paul.

Refrigerator Block Diagram and Working – Explanation

Here we have discussed the block diagram and working principle of refrigerator or fridge –

• Thermostat: The thermostat is a temperature-sensitive control that measures the internal temperature of the refrigerator. When the temperature inside the fridge climbs over the predetermined limit, the thermostat turns on the compressor. Conversely, when the desired temperature is attained, the compressor is turned off to prevent overcooling. This automatic on-off control promotes a steady cooling environment while lowering energy use. It is necessary to regulate the complete cooling cycle.
• Compressor: The compressor works as the refrigeration system’s pump. It condenses low-pressure refrigerant vapor from the evaporator coil into high-pressure, high-temperature gas. This process elevates the refrigerant’s pressure and temperature, allowing it to efficiently release heat in the condenser. When the thermostat detects an increase in internal temperature, the compressor, which is normally located at the back or bottom of the fridge, begins the refrigeration cycle.
• Condenser Coil: The condenser coil receives high-pressure gas from the compressor. As the refrigerant flows through these coils, it emits heat into the surrounding air, frequently aided by a fan or ventilation. This heat release causes the refrigerant to condense into a high-pressure liquid. The coils are often located on the refrigerator’s outer back side and aid in the removal of heat from the interior to the outside environment.
• Expansion Device (Capillary Tube or Expansion Valve): The expansion device is a small tube or valve that controls the flow of refrigerant into the evaporator. As the high-pressure liquid refrigerant goes through this apparatus, its pressure decreases substantially. This sudden drop in pressure causes the liquid refrigerant to cool immediately. The cool, low-pressure refrigerant is now prepared to absorb heat in the evaporator coil. It is crucial in preparing the refrigerant for efficient cooling.
• Evaporator Coil: The evaporator coil is positioned in the refrigerator or freezer section. It absorbs heat from the contents housed inside. The cool, low-pressure refrigerant that enters the evaporator absorbs heat and converts to gas. This procedure cools the compartment and maintains the low temperature needed to preserve food. The refrigerant, now at low pressure, returns to the compressor to resume the cycle.
• Cooling Box / Refrigerator Compartment: The cooling box is an insulated storage area where food and beverages are kept. It gets cold air or is immediately cooled by the evaporator coil. The heat from stored things is absorbed by the refrigerant in the evaporator, which keeps the surroundings continuously chilly. Good insulation around the box reduces heat transmission from the outside, improving efficiency and keeping food fresher for longer.