Investigation on temperature uniformity of single-phase manifold microchannel heat exchanger for use in electric vehicle battery cooling/heating

• Main Author: Chan, Zhi Hui
• Other Authors: Ooi Kim Tiow
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/158396
• Institution: Nanyang Technological University

The impact of temperature non-uniformity on battery cells greatly affects the range and longevity of Electric Vehicles (EVs). Hence, it is important for electric vehicles to have effective thermal management. When batteries are charged and discharged, a great amount of heat is generated. This heat will affect the battery cell’s performance and its ability to hold a charge, in extreme cases it can lead to thermal runaways. As batteries are arranged in an array of cells, it is essential to monitor not only the average temperature of the cold plate in a cooling system, but also the temperature uniformity, to ensure not hot spots are present. Hot spots can cause certain parts of the battery cell array to deteriorate and poses the similar risk of heat related incidents. The purpose of this study is to evaluate the temperature uniformity of the MMHX compared to a microchannel heat exchanger. A uniformity factor that allows for comparison between the two types of heat exchangers was selected, this considers the limitations of the investigation and the experiment setup. The parameters used to evaluate the temperature uniformity are mainly a temperature uniformity index and the centreline temperatures along the flow direction. The experiment was conducted at 2L/min and 6L/min for both configurations. The experiment findings of of this study shows that the temperature uniformity index in the MMHX is better than that of the straight microchannels. This is consistent at higher flowrates, but the difference in the temperature uniformity indexes are significantly lower. Hence, this indicates that MMHX can be considered to give better temperature uniformity at low flowrate applications.