What is meant by Evaporative Condenser?
An Evaporative Condenser is a device that uses the evaporation of water to reject heat from a refrigerant, effectively condensing (liquefying) the refrigerant vapor back into a liquid so it can be reused in the refrigeration cycle.
It is a key component in large-scale refrigeration, air conditioning, and industrial process cooling systems.
Core Concept: How it Works
The evaporative condenser combines the functions of a water-cooled condenser and a cooling tower into a single, more efficient unit. Here’s the step-by-step process:
- Hot Refrigerant Gas Enters: Superheated, high-pressure refrigerant vapor from the compressor is pumped into a coil (condensing coil) located inside the unit.
- Water is Sprayed: A water pump circulates water from a sump at the bottom of the unit and sprays it over the outside of the condensing coil.
- Air is Drawn Through: A fan at the top (induced draft) or bottom (forced draft) of the unit draws or pushes large volumes of ambient air through the unit.
- Evaporation Occurs: As air moves across the wetted coil, a small portion of the spray water evaporates. The heat required for this evaporation is drawn from the water film on the coil and, most importantly, from the hot refrigerant inside the coil.
- Heat is Rejected & Refrigerant Condenses: This removal of latent heat of vaporization causes the refrigerant vapor inside the coil to lose its energy and condense back into a high-pressure liquid.
- Cooled Liquid Refrigerant Exits: The now-liquid refrigerant drains from the bottom of the coil and flows to the expansion valve to begin the cycle again.
- Warm, Moist Air is Exhausted: The fan exhausts the warm, humid air out of the top of the unit.