An adiabatic cooling tower is a type of heat rejection system that combines dry cooling and evaporative cooling principles to efficiently cool water or other process fluids. It’s designed to reduce water consumption and energy usage compared to traditional cooling towers, especially in warmer climates.
Here’s a breakdown of how it works:
Key Features:
- Adiabatic Pre-Cooling:Adiabatic cooling towers utilize adiabatic pre-cooling pads (often made of cellulose) that are wetted with water. When air passes through these pads, some of the water evaporates, cooling the air before it enters the heat exchanger.
- Closed-Circuit Cooling:The process fluid (like water or a refrigerant) flows through a closed-loop coil, separated from the cooling air and the water used for pre-cooling. This prevents contamination of the process fluid.
- Dry Cooling Mode:When the ambient air temperature is low enough, the adiabatic cooling tower can operate as a dry cooler, with the pre-cooling pads bypassed or used minimally, minimizing water consumption.
- Adiabatic Mode:When the ambient temperature is higher, the adiabatic pre-cooling system activates, using water evaporation to lower the air temperature and improve cooling performance.
How it works:
- Warm process fluid enters the heat exchanger coils .
- Dry air is drawn across the coils, absorbing heat from the fluid .
- In adiabatic mode, the air is first passed through wetted pads to be pre-cooled .
- The cooled air then passes across the heat exchanger coils, further cooling the process fluid .
- The cooled process fluid is then recirculated back to the system .
- The water used for pre-cooling either evaporates or is drained, depending on the system design .