THERMAL MANAGEMENT OF ELECTRIC VEHICLE BATTERY PACKS

Ph.DDOCTOR OF PHILOSOPH

Enhancement of Durability Properties and Drying Shrinkage of Heat-treated Oil Palm Shell Species High-strength Lightweight Concrete

In this study, the effects of heat-treated and non-treated oil palm shell (OPS) species (dura and tenera) are investigated on the slump, density and compressive strength of oil palm shell concrete (OPSC). Two different species of OPS coarse aggregates are subjected to heat treatment at 65 and 130 °C with the duration of 1 h. The results show that the workability of the OPSC increases significantly with an increase in temperature of heat-treated of the tenera OPS aggregates. It is found that the maximum achievable 28-days and 180-days compressive strength is 51 and 54 MPa, respectively. Furthermore, rapid chloride penetration tests (RCPT), porosity measurement and water absorption tests were performance to signify the effects of heat treatment on different OPS species lightweight concrete (LWC). The use of heat-treated OPS LWC induced the advantageous of reducing the permeability and capillary porosity as well as water absorption. The results showed that the ideal of heat treatment method has enhanced the performance of drying shrinkage. Hence, the findings of this study are of primary importance as they revealed that the heat treatment on OPS species LWC can be used as a new environmentally friendly method to enhance the durability properties and drying shrinkage of OPS LWC

Exergy Analysis of Boiler Process Powered by Biogas Fuel in Ethanol Production Plant:A Preliminary Analysis

This paper investigates a fluidized bed boiler used in an ethanol production plant. The boiler uses biogas fuel produced by the waste system of the distillation unit within this ethanol plant. Using Engineering Equation Solver (EES), a mathematical model is developed by employing the exergy analysis. Before the study was undertaken, initial operating data of the components in the plant was collected. The results show that the boiler system has an overall efficiency of 68.238 %. The exergy efficiency in each component was also calculated. The evaporator and heat exchanger have the lowest efficiency at 45.97% and 28.96%, respectively. The efficiencies of the other components are 61.41% for the pump water pit, 54.42% for the soft water tank and 66.39% for the de-aerator

Development of hybrid aluminum-air battery fuel-cell system

Industrial 4.0 accelerates the need to introduce clean energy to accommodate the increase in electricity demand globally without causing environmental issues. Metal-air battery is a new type of energy storage system in which the metal anode is consumed to generate electricity through the electrochemical reaction. Among various types of the metal anode, aluminum is a promising energy carrier. Aluminum-air battery shows advantages such as high capacity, abundance, low cost, and being environmentally friendly. Traditional aqueous aluminum-air battery experiences restriction from application due to its self-corrosion issues. In this study, instead of reducing or limiting the self-corrosion issues, a different approach is proposed so to make use of the self-corrosion issues of the aluminum-air battery. By incorporating an additional hydrogen-air subcell to the aluminum-air battery, this hybrid system turned the self-corrosion issue into a beneficial reaction by utilizing the hydrogen gas produced from the aluminum anode as the fuel to power the hydrogen-air fuel cell and improving the overall power performance. The electrical performance of each system is studied experimentally using potassium hydroxide electrolytes. The hybrid system shows a great improvement as compared to a single system. The maximum power is improved by more than 40%. This study shows that the hybrid design is feasible in enhancing the aluminum-air battery performance and yet, maintaining low cost and low weight in nature

Analysis of the Polypropylene-Based Aluminium-Air Battery

Global energy demand is rising due to the rapid development and adoption of new technologies in every sector. Hence, there is a need to introduce a clean energy source that does not cause damage to the environment. Aluminium-air battery with its high theoretical specific volumetric capacity is an exciting alternative for post-lithium energy storage and has been at the forefront of energy research for years. However, the conventional aqueous electrolyte-based aluminium-air battery with bulky liquid storage, parasitic corrosion of aluminium in contact with the electrolyte, and formation of a passive oxide or hydroxide layer has precluded its widespread application. In order to achieve successful simplification and cost-effectiveness, a novel idea of a polypropylene-based aluminium-air battery is proposed. In this work, a polypropylene-based aluminium-air battery was constructed using aluminium foil as an anode, carbon fiber cloth as an air-cathode, and Polypropylene and Kimwipes as the separator. The effects of the electrolyte concentration on the aluminium-air battery were investigated and analyzed using various discharge currents. The study showed that the performance of the polypropylene separator is better than that of the Kimwipes separator. The battery capacity is negatively correlated with the concentrations of the electrolyte. At a discharge current of 30 mA, the aluminium-air battery has a specific capacity of 375 mAh g−1 when 1 M of potassium hydroxide was used as electrolyte

Numerical investigation for optimizing segmented micro-channel heat sink by Taguchi-Grey method

• Novel segmented micro-channel heat sink has been designed. • CFD models have been developed to simulate the performance of the segmented micro-channel. • Enhanced the cooling performance of the straight micro-channel. • Optimizing the segmented micro-channel using Taguchi-Grey method. • Optimized design parameters for segmented micro-channel have been identified. A B S T R A C T The scale-down trend increases the chips' density and the high power handling capability generates unnecessary heat which can disrupt the reliability of the electronic devices. Therefore, various types of cooling solution have been proposed to enhance heat dissipation from the electronic devices. One of the solution is using inexpensive straight-channel heat sink. However, the presence of large temperature gradient between the upstream and downstream in the straight-channel can shorten the life span of the device and subsequently reduce the reliability. In this study, a novel segmented micro-channel is introduced to improve the thermal performance of the straight-channel heat sink. Computational fluid dynamic analysis are performed to investigate the performance of the micro-channel heat sink. The bottom of the heat sink is subjected to a constant heat flux condition and water is used as a coolant. Following that, Taguchi-grey method is applied to optimize the design of the segmented micro-channel. The effect of fin width, fin length, fin transverse distance, number of segments, channel width and mass flow rate on the specific performance, variation of temperature and pressure drop are investigated. The results indicate that a three segments of segmented micro-channel, fin width-1 mm, fin length-2 mm, fin transverse distance-5 mm and channel width-1 mm have successfully enhance the heat transfer performance with minimum pressure drop. It is also found that the optimized micro-channel heat sink is able to cool the chip with heat flux of 800 W to 56.6 °C and pumping power of 0.13 W using 15 gs −1 of water

Novel thermal management system using mist cooling for lithium-ion battery packs

Thermal management system is crucial for a Lithium-ion battery pack as cycle life, driving range of electric vehicle, usable capacity and safety are heavily dependent on the operating temperature. Optimum operating temperature of Lithium-ion battery pack is about 25 oC – 40 oC. Power availability of the battery pack may differ according to the operating temperature. Although air cooling is the simplest and cheapest cooling solution, the cooling capacity is still limited by the low specific heat capacity. This will cause large variation of temperature of cells across the battery pack. In this study, mist cooling is proposed for battery pack thermal management system. Experiments and numerical simulations are conducted to investigate the thermal performance of conventional dry air cooling and mist cooling. Simulation results are then validated with the experimental data. The simulation results show that mist cooling can offer lower and more uniform temperature distribution compared to dry air cooling. Mist cooling with mass flow rate of 5 gs-1 and 3 % mist loading fraction is sufficient to ensure the surface temperature of the battery module maintained to below 40 oC. Therefore, mist cooling is a potential solution for the thermal management system of Lithium-ion battery pack

Techno-economic analysis with financial risk identification for solar power plant as post-mining land use in Indonesia

Post-mining land usage (PMLU) is a critical concern in Indonesia as the country needs to figure out alternatives for repurposing mined land into productive activities which could utilize the available potential. This paper analyzed the technical feasibility, economic viability, socioeconomics, and environmental impact of building a solar power plant as a post-mining land use option. Solar energy generation potential near the equator line can complement the land availability after coal mining operations cease. The technical analysis, financial model, and Monte Carlo simulation were conducted for the techno-economic analysis. The 300 MWp project was estimated to be able to generate 464 gigawatt-hours annually with a setup cost of around 3.1 trillion Rupiah (USD 200 million). The base case net present value (NPV) was 437 billion rupiah (USD 28 million), while the discounted payback period (DPP) was 13 years, suggesting the viability of the project. The simulation results returned 93.99 % certainty that the NPV would be positive, and 94.71 % certainty the DPP would be <25 years. The sensitivity analysis revealed that the top financial risk factors are loan interest, tax rate, feed-in tariff, operating cost, structure cost, array efficiency, solar irradiance, and inflation rate. Solar irradiance and inflation rate are systematic risks that cannot be controlled internally, and array efficiency is limited by 100 %. Five risk factors could be internally managed: loan interest, tax rate, feed-in tariff, operating cost, and structure cost. Furthermore, this system would offer additional socio-economic and environmental benefits such as job creation, biodiversity preservation, and pollution reduction. The system would generate 281,780 tCO2 annual GHG emission savings

Monte Carlo simulation-based financial risk identification for industrial estate as post-mining land usage in Indonesia

The issue of post-mining land usage is emerging in Indonesia due to the significant contribution of the mining industry to the country's economic development. Among the popular options for utilizing these lands is the establishment of industrial estates. The objective of this study is to investigate the complexities associated with identifying financial risks using an integrated framework to be implemented in industrial estates located on post-mining lands in Indonesia. The framework was constructed by combining traditional feasibility study methods with Monte Carlo simulation. The financial model was built using 31 input variables (assumptions) and 3 output variables (forecasts). The Monte Carlo simulation results revealed that there is an approximately 82.32% probability of the project's payback period being within 25 years, and a 94.23% probability of a positive net present value. Three input variables were found to contribute to 80% of the variation in average earnings. Additionally, five variables were identified as financial risk factors impacting net present value and discounted payback period. Out of the thirteen financial risk factors, ten were internal factors that require a management plan to mitigate them effectively. The framework contributed an emphasize on the importance of risk analysis as complementary analysis in a feasibility study

A review of methods for integrating risk management and multicriteria decision analysis in financial feasibility for post-coal-mining land usage selection

Coal mining is an economy activity that extract coal from underground. The land use after the mining operation ceased must be properly planned to mitigate the loss of employment, support economic diversification and sustainable development in future. Deciding the best post-mining land usage (PMLU) option fell into a multicriteria decision problem as the decision would have impact on many stakeholders, including corporations, workers, government, and local communities. This work reviewed past works related to PMLU with a specific interest in risk management and multi-criteria decision analysis. There were seven major categories for PMLU options discussed in the previous works, namely agriculture, forestry, water potential, industrial area, recreational, energy-related, and landfill site. The network visualization of keywords shown the lack of connection among PMLU, financial feasibility study, risk identification, risk simulation, and multi-criteria decision analysis. An integrated decision framework would contribute to fill the gap. Potential land developers and all related parties may utilize the outcome obtained from this review to optimize their PMLU decision for the betterment of the environment and communities that aligns with the current world activities toward sustainable development to give our planet a better future