University of Wisconsin-Madison (UW-Madison)

In thermoelectric power generation, only about 40% of the energy in the fuel is converted into electricity. In other words, the power plant operates at about 40% efficiency. The remainder of the energy is converted to low-grade waste heat that must be removed to maintain the power plant’s efficiency. Most power plants use water from nearby rivers, lakes, or the ocean for cooling. The water may pass directly over tubes containing the plant’s heated condenser water, and then be returned, warmer, to the original source, or it may be evaporated to carry off the heat in water vapor. In areas with limited water or under drought conditions, dry-cooling systems use air to remove heat from the plant’s condenser water. However, present dry-cooling technology reduces the power plant’s efficiency and requires costly equipment. With water supplies becoming increasingly strained in many areas, economical dry-cooling approaches that do not reduce the efficiency of power plans are critically needed. Innovative methods to allow cooling below the daytime ambient air temperature and improve heat exchange between air and the plant’s recirculating condenser water will provide the keys to ensuring the continued efficiency of power generation while decreasing the burden on water supplies.

The University of Wisconsin (UW-Madison) and its partner Oak Ridge National Laboratory will develop enabling technologies for low-cost, high-performance air-cooled heat exchangers. The objective is to create an optimization algorithm in order to identify and design a novel heat exchanger topology with very high heat transfer performance. The team also plans to develop a high-thermal conductivity polymer composite filament that can be used in additive manufacturing (3D printing) to produce the high-performance heat exchanger design. Due to the design freedom enabled by additive manufacturing, the team plans to develop 3D heat exchanger geometries that optimize heat transfer and decrease the total footprint required for an air-cooled system. Both of these innovations could enhance air-side heat transfer and improve the efficiency and cost of heat exchangers.

If successful, UW-Madison’s innovative heat exchanger design will lower the cost of air-cooling systems without reducing the efficiency of power plant cooling.