Thermal Energy Utilization

n Introduction

One avenue for reducing overall energy demand in the economy is to make efficient use of thermal energy. Argonne's 20 years of cutting-edge research in heat transfer and fluid flow have resulted in significant advances in three areas of thermal utilization: high-efficiency evaporators and condensers, improved load management and energy distribution through ice slurries for district cooling, and improved heat transfer fluids. To bring these advances to bear on problems important to U.S. industries and utilities, the Laboratory develops validated design correlations, predictive methods, and improved guidelines, for equipment/system operation.

For example, Modine Manufacturing and Argonne have worked in an extended partnership to develop and optimize condensers in air-conditioning systems. Argonne improved the empirical correlations of heat transfer variables that Modine uses in designing compact evaporators and condensers for automobiles. The company can now develop designs faster, with much less trial-and-error, and with greater assurance that the units will operate as predicted.

For district cooling, Argonne worked cooperatively for two years with Northern States Power of Minneapolis, Minn., and the Electric Power Research Institute to develop the first demonstration plant (80 tons) for ice slurry cooling. This approach to load management and energy distribution utilizes ice manufactured in a central plant at off-peak times. Argonne established that ice slurry can be pumped as easily as water and pioneered its use for district cooling. Ice slurry cooling would be advantageous in central city locations for cooling offices, residential buildings, factories, shopping facilities, or governmental complexes and in large food processing and industrial complexes such as petrochemical plants, where eliminating separate chillers would allow better load management and reduce costs.

Argonne staff have extensive experimental and analytical experience in heat transfer, multiphase flow, transient flow and mixing, thermally driven flows, and flow visualization by ultra-high-speed video. Large general-purpose test facilities and smaller single-purpose test apparatuses are available for experimentation and evaluation of component design.

n Compact Heat Exchangers

Develop design guidelines for compact heat exchangers (surface area density ratios over 700 m2/m3). Such devices offer the potential for significant energy and cost savings for heat-exchanger applications where reduced size, weight, surface area, or fluid inventory are of critical importance. Examples are the process and heat-utilization industries and air-conditioning for vehicles and buildings.

Develop correlations and predictive methods for designing and optimizing high-performance evaporators and condensers.

Identify low-temperature approaches.

Design for pure counterflow and uniform-temperature heating and cooling.

Operate apparatus for testing small-channel condensing and flow boiling.

Create flow visualizations for multiphase flow studies.

n Ice Slurry District Cooling

Design and test systems for using ice slurry to shift electric load and to lower overall energy distribution costs for district cooling. A slurry of 5 to 30% ice crystals in water would be piped to distributed users. Such systems eliminate individual users' chillers, and the high energy content of the ice slurry means the systems can use smaller pipes, pumps, and storage tanks and have lower pumping, air handling, and chilling costs than conventional chilled water systems.

Develop correlations and predictive methods for designing and optimizing ice slurry district cooling systems and components.

Conduct ice slurry flow and heat transfer experiments in pipes, heat exchangers, pumps, storage tanks and other equipment, such as ice particle makers (see photo of facility).

Study flow behavior, pressure drop, and heat transfer associated with dispersed or highly loaded slurries.

n Advanced Thermal Fluids

Developed a new class of heat transfer fluids, called "nanofluids," that conduct heat more efficiently, reducing energy loss and pumping costs. Such fluids (for which an Argonne patent is pending) have applications in hydronic heating and cooling systems for buildings; industrial process heating and cooling in petrochemical, textiles, pulp and paper, chemical, food, and other process plants; in utility power plants and district heating/cooling systems; in cooling systems for vehicles and planes; for cooling advanced electronic packages; and in many other situations that require small and light thermal systems with high heat transfer rates.

Increased heat transfer coefficient of water by 15% by adding nanometer-sized particles.

Drastically reduced pressure drop (by using friction-reducing additives).

Produced fluids with high energy-carrying capacity and high energy-storage density.

Use environmentally safe methods and materials.

Characterize flow properties, pressure drop, and heat transfer of advanced fluids with state-of-the-art instrumentation.

Operate pilot-scale heating/cooling system simulator.

n Contacts

For technical information contact Kenneth Kasza, Argonne National Laboratory, Bldg. 212, 9700 South Cass Avenue, Argonne, Illinois 60439; phone: 630/252-5224; fax: 630/252-4798; e-mail:

For information on working with Argonne, contact Paul Eichamer, Industrial Technology Development Center, Argonne National Laboratory, Bldg. 201, 9700 South Cass Avenue, Argonne, Illinois 60439; phone: 800/627-2596; fax: 630/252-5230.

This pilot demonstration facility at Argonne is dedicated to research on using ice slurries for load management in district cooling.

July 1998

Argonne National Laboratory is operated by The University of Chicago for the U.S. Department of Energy under contract No. W-31-109-Eng-38.

New heat transfer equipment and energy transport fluids improve energy utilization, reduce equipment costs, and improve energy distribution