Achieving near-water-cooled power plant performance with air-cooled condensers

• Power plant condenser cooling accounts for 41% of US fresh water withdrawals.
• Power plants with air-cooled condensers (ACCs) suffer a 5–10% efficiency penalty.
• Simultaneous improvements to ACC heat transfer and pressure drop are needed.
• Emerging convection enhancement technologies could improve ACC performance.
• Hybrid wet-dry cooling improves ACC performance with minimal water consumption.

Power plants using air-cooled condensers suffer a 5–10% plant-level efficiency penalty compared to plants with once-through cooling systems or wet cooling towers. In this study, a model of a representative air-cooled condenser (ACC) system is developed to explore the potential to mitigate this penalty through techniques that reduce the air-side thermal resistance, and by raising the air mass flow rate. The ACC unit model is coupled to a representative baseload steam-cycle power plant model. It is found that water-cooled power-plant efficiency levels can be approached by using enhanced ACCs with a combination of significantly increased air flow rates (+68%), reduced air-side thermal resistances (−66%), and air-side pressure losses near conventional levels (+24%). Emerging heat-transfer enhancement technologies are evaluated for the potential to meet these performance objectives. The impact of ambient conditions on ACC operation is also examined, and two hybrid wet/dry cooling system technologies are explored to improve performance at high ambient temperatures. Results from this investigation provide guidance for the adoption and enhancement of air-cooled condensers in power plants.