Research in the miniaturization of thermomechanical systems in recent years has proven to be both rewarding and challenging. Micro-scale devices have tremendous technological potential but come with a new set of design problems. One such problem is energy storage. Heat actuated systems, driven primarily by thermal energy, take advantage of...
Novel fluidic devices that utilize an array of microchannels to achieve their designed purpose are discussed. Examples of devices include: fuel reforming using Microreactors, chip cooling using microchannel heat sinks, and microchannel devices used for biological applications. The devices that have directly contributed to this research include: a microchannel water...
The performance of a combined Stirling-ORC power cycle is evaluated, and an integrated microchannel heat exchanger is designed as an annular cold-side heat rejector for a free piston Stirling engine. Reasonable designs for a combined cycle can increased power output efficiency by 3 - 9% compared to that of a...
The organic Rankine cycle (ORC) is a versatile approach in the utilization of waste heat in the production of electricity, clean drinking water, and cooling. The efficiency of these cycles must be maximized to make them economical. Parameters for the optimization of ORCs such as evaporator and condenser temperature have...
Hot engine exhaust and industrial process exhaust represents a resource that is often rejected to the environment without further utilization. This resource is prevalent in the transportation and industrial process sectors, but stationary engine-generator systems also typically do not utilize this resource. Engine exhaust is considered high grade heat and...
In the current study a thermally activated cooling system that combines an ORC system with a vapor compression cooling cycle was developed and tested under laboratory conditions. This combined system
can utilize waste heat or other thermal sources such as solar and geothermal to generate power and
cooling. Hot oil...
Heat activated cooling has the potential of utilizing thermal sources that currently go unused such as engine exhaust heat or industrial waste heat. Using these heat sources can provide enhanced energy utilization and reduced fuel usage in applications where cooling is needed. The concept developed here uses waste heat from...
Rising energy demands and the continual push to find more energy efficient technologies have been the impetus for the investigation of waste heat recovery techniques. Diesel engine exhaust heat utilization has the potential to significantly reduce the consumption of fossil fuels and reduce the release of greenhouse gases, because diesel...
A microchannel heat exchanger was designed for diesel waste heat recovery and its performance was evaluated. The 21x15x8 cm unit was constructed from diffusion brazed stainless steel lamina and weighed 11 kg. Operating from a 13.4 kW generator with an exhaust temperature of 500 °C the unit delivered 11.1 kW...
A new adhesive bonding method is introduced for microlamination architectures, for producing low-temperature microchannel arrays in a wide variety of metals. Sheet metal embossing and chemical etching processes have been used to produce sealing bosses and flow features, resulting in approximately 50% fewer laminae over traditional methods. These lamina designs...