Fluid Flow and Heat Transfer Characteristics of Ethylene Glycol and Water in Copper-Based Microchannel Devices

Metal-based microchannel heat exchangers (MHEs) offer potential solutions to applications demanding high heat flux removal, such as cooling of high-performance microelectronic and energy-efficient lighting modules. Efficient fabrication of metal-based MHEs and quantitative flow and heat transfer measurements on them are critical for establishing the economic and technical feasibility of such devices. Adopting metal-based MHEs in many applications demands quantification of flow and heat transfer performance with application-relevant coolants, e.g. ethylene glycol (EG)/water mixtures rather than pure water. As a first step in this direction, we report here fabrication and assembly of all-Cu MHE prototypes, as well as results of flow and heat transfer testing using pure EG and pure water as the fluid medium. Results of heat transfer testing indicate sensitivity of overall heat transfer performance to entrance length effects, which in the case of pure EG, is significantly influenced by its physical properties under the testing condition.