Efficiency

The University of Maryland (UMD) will leverage recent advances in additive manufacturing to develop a next-generation air-cooled heat exchanger. The UMD team will assess the performance and cost of current state-of-the-art technology, including innovative manufacturing processes. The team will then utilize computer models to simulate a wide-range of novel heat exchanger designs that can radically enhance air-side heat transfer performance. The team will then physically build and test two 1 kilowatt (kW) prototype devices.

Sandia National Laboratories will develop a prototype DC-DC converter in a modular, scalable, mass-producible format that is capable of 10kW or greater and could fit onto a single circuit board. Inefficiency and construction costs associated with AC distribution/transmission and DC-AC conversion are motivating many to consider direct connection of PV to DC distribution (and even DC transmission) circuits.

Northeastern University will develop a new class of universal power converters that can be used in a wide range of applications including renewable energy systems, automotive, and manufacturing technologies. Northeastern will focus the project on the design, simulation, prototyping, and experimental evaluation for PV systems. This project proposes a new class of converters that can both step up and step down the voltage. This converter uses a very small film capacitor for transferring the power from the input to the output.

GeneSiC Semiconductor will lead a team to develop high-power and voltage (1200V) vertical transistors on free-standing gallium nitride (GaN) substrates. Bipolar junction transistors amplify or switch electrical current. NPN junction transistors are one class of these transistors consisting of a layer of p-type semiconductor between two n-type semiconductors. The output electrical current between two terminals is controlled by applying a small input current at the third terminal.

The Colorado School of Mines will develop a new method for the high-throughput discovery and screening of thermoelectric materials. The objective is to develop a new class of thermoelectric materials that can enable heat-to-electricity efficiencies greater than 20%. Aerosol spray deposition will be used to collect particles on the solid surfaces, allowing high throughput synthesis with finely tuned composition control.

Missouri S&T will combine a novel additive manufacturing technique, called ceramic on-demand extrusion, and ceramic fusion welding techniques to manufacture very high temperature heat exchangers for power cycles with intense heat sources. Enabling turbine operation at significantly higher inlet temperatures substantially increases power generation efficiency and reduces emissions and water consumption.

The University of Maryland will design, manufacture, and test high-performance, compact heat exchangers for supercritical CO2 power cycles. Two innovative additive manufacturing processes will enable high performance. One facilitates up to 100 times higher deposition rate compared with regular laser powder additive manufacturing. The other enables crack-free additive manufacturing of an advanced nickel-based superalloy and has the potential to print features as fine as 20 micrometers.

Michigan State University’s proposed technology is a highly scalable heat exchanger suited for high-efficiency power generation systems that use supercritical CO2 as a working fluid and operate at high temperature and high pressure. It features a plate-type heat exchanger that enables lower cost powder-based manufacturing. The approach includes powder compaction and sintering (powder metallurgy) integrated with laser-directed energy deposition additive manufacturing.

Michigan Technological University will use advanced ceramic-based 3D printing technology to develop next-generation light, low-cost, ultra-compact, high-temperature, high-pressure (HTHP) heat exchangers. These will be able to operate at temperatures above 1100°C (2012°F) and at pressures above 80 bar (1160 psi). Current technologies cannot produce the high density, monolithic sintered silicon carbide (SSiC) material required for high temperature, high pressure recuperators.

UTRC will develop a high temperature, high strength, low cost glass-ceramic matrix composite heat exchanger capable of a long operational life in a range of harsh environments with temperatures and pressures as high as 1100°C (2012°F) and 250 bar (3626 psi). UTRC designed its Counterflow Honeycomb Heat Exchanger (CH-HX) configuration with an oxidation-resistant material developed initially for gas turbine applications. Its core feature is a joint-free, 3D-woven assembly of webbed tubes and cylindrical shapes to reduce stress and simplify manufacturing.