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A Microfabricated Flow Controller for Refrigerant Expansion



David A. Yashar, Piotr A. Domanski, Don DeVoe


A flow controller for refrigerant expansion is reported. Devices are fabricated using a micromolding technique developed for thick nickel electroplating. The device consists of a short tube restrictor with an integrated normally-open valve which, when actuated, presents a controllable blockage into the flow passage to obstruct the flow. Fabricated devices are evaluated with compressed air, with up to 22 % reduction in mass flow rate at maximum actuation of the restrictor. The devices are also evaluated in a 1.5 2 kW R134a vapor compression system, with the ability to control mass flow found to be greatly influenced by the vapor compression cycle s operational parameters. After the inlet pressure, the level of subcooling proved to be the most important parameter. For a cycle operating between 29 C and 4 C saturation temperatures in the condenser and evaporator, respectively, actuation of the device reduced the refrigerant mass flow rate by 3.5 % with 0.6 C subcooling and up to 10.8 % with 5 C subcooling.
IEEE Journal of Microelectromechanical Systems (Journal of MEMs)


microfabricated valve, refrigerant expansion, SU-8


Yashar, D. , Domanski, P. and DeVoe, D. (2007), A Microfabricated Flow Controller for Refrigerant Expansion, IEEE Journal of Microelectromechanical Systems (Journal of MEMs), [online], (Accessed April 24, 2024)
Created October 1, 2007, Updated February 19, 2017