Lip Huat Saw

Thermal management of lithium-ion battery pack with liquid cooling

Electric Vehicles (EVs) are projected as the most sustainable solutions for future transportation. EVs have many advantages over conventional hydrocarbon internal combustion engines including energy efficiency, environmental friendliness, noiselessness and less dependence on fossil fuels. However, there are also many challenges which are mainly related to the battery pack, such as battery cost, driving range, reliability, safety, battery capacity, cycle life, and recharge time. The performance of EVs is greatly dependent on the battery pack. Temperatures of the cells in a battery pack need to be maintained within its optimum operating temperature range in order to achieve maximum performance, safety and reliability under various operating conditions. Poor thermal management will affect the charging and discharging power, cycle life, cell balancing, capacity and fast charging capability of the battery pack. Hence, a thermal management system is needed in order to enhance the performance and to extend the life cycle of the battery pack. In this study, the effects of temperature on the Li-ion battery are investigated. Heat generated by LiFePO4 pouch cell was characterized using an EV accelerating rate calorimeter. Computational fluid dynamic analyses were carried out to investigate the performance of a liquid cooling system for a battery pack. The numerical simulations showed promising results and the design of the battery pack thermal management system was sufficient to ensure that the cells operated within their temperature limits.

Integration of active and passive cool roof system for attic temperature reduction

The aim of this project is to study the capability of cool roof system in the reduction of heat transmission through metal roof into an attic. The cool roof system is designed in active and passive methods to reduce the thermal loads imposed to a building. Two main features are introduced to this cool roof system, which is thermal insulation coating (TIC) and moving air cavity (MAC) that served as active and passive manner, respectively. For MAC, two designs are introduced. Normal MAC is fabricated by six aluminium tubes whereby each aluminium tube is made up by sticking up of five aluminium cans. While improved MAC is also made by six aluminium tubes whereby each aluminium tube is custom made from steel rods and aluminium foils. MAC provides ventilation and heat reflection under the metal roof before the heat transfer into attic. It also coupled with three solar powered fans to increase heat flow inside the channel. The cool roof that incorporated TIC, MAC with solar powered fans and opened attic inlet s...

Enhancement of durability properties of heat-treated oil palm shell species lightweight concrete

Oil palm shell (OPS) are non-hazardous waste materials and can be used as alternative coarse aggregates to substitute depleting conventional raw materials. A study on preparing the OPS species (dura and tenera) lightweight concrete (LWC) using with and without heat-treated OPS aggregate has been investigated. Two different species of OPS coarse aggregate are subjected to heat treatment at 65 and 130 °C with duration of 1 hour. The results reveal that the slump value of the OPSC increases significantly with an increase in temperature of heat treatment of the tenera OPS aggregates. It is found that the maximum achievable 28-days and 180-days compressive strength is 45.6 and 47.5 MPa, respectively. Furthermore, rapid chloride penetration test (RCPT) and water absorption tests were performance to signify the effects of heat-treated on OPS species LWC. The use of heat-treated OPS LWC induced the advantageous of reducing the permeability and capillary porosity as well as water absorption. Hence, the findings of...