The 2008 NASA Tech Briefs "Create the Future Design Contest," presented by SolidWorks, recognized innovation in product design in six categories: Consumer Products, Machinery & Equipment, Medical, Safety & Security, Sustainable Technologies, and Transportation. Here is the winner of the Sustainable Technologies category, along with the two honorable mentions.

Efficient Air Conditioner

Lindsay Meek Perth, Australia

altThis design improves the energy efficiency of a residential air conditioner by replacing the traditional reciprocating compressor (bore and stroke) with a higher efficiency permanent magnet motor coupled to a scroll compressor. Recent advances in permanent magnet motors used in modern hybrid car electric drives and wind turbine generation have seen the incorporation of strong NdFeB magnets into the rotor, which greatly improves the motor efficiency. The compressor motor is then driven by a compact IGBT inverter stage with a motor controller, so motor current consumption can be optimized at the different operating speeds.

The other improvement that can be made is to replace the traditional refrigerant expansion valve with a similar scroll expander turbine coupled to a second permanent magnet generator. The decompression of the refrigerant gas through the turbine on its way to the condenser allows some of the work used to compress the gas to be recovered and converted back into electrical energy. The generator is connected to a second compact IGBT inverter stage with a motor controller, and can be controlled in conjunction with the compressor motor controller to regulate the pressure and flow rate of the gas through the system.

The two inverters are connected together via a common, high-voltage DC bus, so the electrical energy recovered from the decompression state can be reused by the compression stage, improving the overall efficiency of the refrigeration cycle. Finally, an AC-DC rectifier power supply is needed to provide the main work energy for the DC bus to keep the cycle operating. The above improvements should lower the power consumption by at least 30%.

For more information, contact the inventor at lindsaymeek@hotmailcom.

Honorable Mentions

Coupled Water Tower/Wind Turbine Controller

Andras Tanczos

Helsinki, Finland

altA coupled water tower/wind turbine controller stores wind energy in the water towers of the drinking water network. At strong winds, the extra electrical energy generated by the wind turbine can be used to pump water into the water tower. When there is no wind, this energy can be released with a hydro-turbine, and the water goes back to the wells. The pump of the water tower and the hydro-turbine are used to control the water level in the reservoir. The electricity from the wind turbine is used for pumping the water or for supplying the electrical grid. The controller can also be installed on existing water towers and water tanks placed on top of buildings.

Electromagnetic Rail Motor

Tim Cormier

Beavercreek, OH

altThe Electromagnetic Rail Motor (ERM) can power anything from aircraft and cars, to artificial human limbs. The ERM is based on the modern rail gun. By taking the two rails and forming a ring, a continuous rotational force is created that is easily managed and controlled. The speed of rotation can be directly controlled by adjusting the voltage, similar to a gas pedal. Once the ERM powers up, the motor rotation will accelerate to its terminal speed. The blades act as both rotational shafts and as propeller blades to help cool the motor during extremely high speeds. The rail housing holds the assembly together and keeps the rails in place to counter the immense separation force.

To view all of the contest entries online, click here.

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