Dynamic Control of Pressure Drop Oscillation in a Microchannel Cooling System

Abstract

While microchannel evaporator based cooling systems are efficient in removing high heat fluxes they are prone to the instability mechanism called pressure drop oscillation. The instability can lead to poor cooling performance, system fatigue and even mechanical failure of the cooling system. To address this challenge, a system level approach with dynamic control of cooling performance is studied in this paper. This approach provides an efficient and reliable technique for thermal management and avoidance of flow instability, even in the presence of large and time-varying heat loads. This study considers a system operating on a vapor compression cycle consisting of a microchannel evaporator, compressor, condenser, electronic expansion valve, and an accumulator. The stability and cooling performance of the system is analyzed under different operating conditions via computational simulation of fluid flow and heat transfer. Based on the understanding gained from this analysis, a dynamic control strategy is developed to stabilize and maintain the system at the optimum operating conditions using feed-forward and feed-back controllers.

Additional information

Funding

This work is supported primarily by the Office of Naval Research (ONR) Award N00014-16-1-2690 entitled “Distributed System Level Thermal Management of High Transient Heat Loads using Microchannel Evaporators” and in part by the Center for Automation Technologies and Systems (CATS) under a block grant from the New York State Empire State Development Division of Science, Technology and Innovation (NYSTAR).

Notes on contributors

Qi Jin

Qi Jin is a Ph.D student in the Department of Mechanical, Aerospace and Nuclear Engineering at Rensselaer Polytechnic Institute. His research interests are microchannel cooling, active control and system stability. He received B.Eng. from Nanjing University of Science and Technology in 2012, China, and M.S. from Tongji University in 2015, China.

John T. Wen

John T. Wen is a Professor in the Department of Electrical, Computer, and Systems Engineering with a joint appointment in the Department of Mechanical, Aerospace, and Nuclear Engineering at Rensselaer Polytechnic Institute. His research interest lies in the modeling and control of dynamical systems with applications to precision motion, robot manipulation, thermal management, lighting systems and materials processing. He received B.Eng. from McGill University in 1979, M.S. from University of Illinois in 1981, and Ph.D. from Rensselaer Polytechnic Institute in 1985, all in Electrical Engineering.

Shankar Narayanan

Shankar Narayanan is an Assistant Professor in the Department of Mechanical, Aerospace and Nuclear Engineering at Rensselaer Polytechnic Institute. His current research interests include multiscale transport analysis, phase-change in micro- and nano-structured surfaces for developing environmentally sustainable thermal energy systems. He received B.Eng. from Osmania University in 2004, India, M.S. from Pennsylvania State University in 2006, and Ph.D. from Georgia Institute of Technology in 2011. He was a post-doctoral researcher in Massachusetts Institute of Technology from 2012 to 2015.