Understanding the Electrolux Refrigeration System

The Electrolux refrigeration system, also known as the Servel system or a three-fluid absorption system, is a type of absorption refrigerator. Unlike typical vapor compression refrigeration systems that use a compressor driven by mechanical energy, the Electrolux system uses a heat source (like gas, electricity, or solar energy) to drive the refrigeration cycle.

How Electrolux System Achieves Circulation

A key characteristic of the Electrolux system is its unique method for circulating the refrigerant (ammonia) and the absorbent (water). It utilizes the principle of thermosiphon action and the presence of an inert gas (hydrogen) to maintain the partial pressure difference needed for evaporation.

Here's a simplified overview of the circulation process:

• The strong ammonia-water solution is heated in a boiler.
• Ammonia vapor is driven off from the solution.
• The vapor rises to the condenser, where it cools and condenses into liquid ammonia.
• The hot, weak ammonia-water solution flows by gravity to the absorber.
• Liquid ammonia flows by gravity (assisted by the presence of hydrogen) from the condenser to the evaporator.
• In the evaporator, the liquid ammonia evaporates at a low partial pressure (due to the hydrogen gas), absorbing heat and creating the cooling effect.
• The ammonia vapor and hydrogen gas mixture flows to the absorber.
• In the absorber, the weak ammonia-water solution absorbs the ammonia vapor. The hydrogen gas, being insoluble, separates and flows back to the evaporator.
• The now strong ammonia-water solution flows by gravity to the boiler, completing the cycle.

This entire circulation of the liquid refrigerant (ammonia-water solution and liquid ammonia) happens solely due to density differences caused by heating and cooling, gravity, and the careful arrangement of components and pressures, without requiring a mechanical pump.

No Liquid Pump in Electrolux Refrigeration

Based on its operating principle, the Electrolux refrigeration system is specifically designed to avoid the use of any moving parts like liquid pumps or compressors. The circulation of the working fluids is achieved using thermal energy input and gravitational forces, aided by the partial pressure effects of the inert gas (hydrogen).

Therefore, the Electrolux system of refrigeration has no liquid pump.