Thermal Effects of Alternative Environmentally Friendly Material Instead of Silicone in Battery Modules

Nowadays, the demand for electric vehicles is increasing rapidly. One of the most important components of electric vehicles is the battery pack. The reduction of their carbon footprint and recyclability is getting more important. For that reason, the usage of environmentally friendly materials or production methods in their production should be studied. This paper aims to investigate an alternative material for silicone which is used to avoid vibration of the battery cells inside of the battery module. Synthesized Hydrogel, which is not hazardous to the environment, is suggested instead of silicone. Besides its environmentally friendly property, Hydrogel does not use any other curing process like silicone and thus reduces the curing process time and energy that is spent for the application of the silicone which is 100 oC and 5 hours. The heat generation of the battery cells inside of the battery module is also numerically analyzed with electrochemical thermal modeling and the comparison of the silicone and suggested Hydrogel material instead of silicone is performed. The results showed that Hydrogel can be used instead of silicone and this material can remove the curing process during the production of the module and can reduce the carbon footprint of the battery module

Effect of aspect ratio on entropy generation in a rectangular cavity with differentially heated vertical walls

In the present study, entropy generation in rectangular cavities with the same area but different aspect ratios is numerically investigated. The vertical walls of the cavities are at different constant temperatures while the horizontal walls are adiabatic. Heat transfer between vertical walls occurs by laminar natural convection. Based on the obtained dimensionless velocity and temperature values, the distributions of local entropy generation due to heat transfer and fluid friction, the local Bejan number and local entropy generation number are determined and related maps are plotted. The variation of the total entropy generation and average Bejan number for the whole cavity volume at different aspect ratios for different values of the Rayleigh number and irreversibility distribution ratio are also evaluated. It is found that for a cavity with high value of Rayleigh number (i.e., Ra = 10(5)), the total entropy generation due to fluid friction and total entropy generation number increase with increasing aspect ratio, attain a maximum and then decrease. The present results are compared with reported solutions and excellent agreement is observed. The study is performed for 10(2) < Ra < 10(5), 10(-4) < 0 < 10(-2), and Pr = 0.7

Experimental Study on Silica gel / Ethanol Adsorption characteristics for Low-Grade Thermal Driven Adsorption Refrigeration Systems

There has been an increasing interest in adsorption cooling and heat pumps as the most feasible green alternative to conventional vapor compression technology. Recent developments in adsorption cooling highlighted the need for cost-efficient adsorption pairs of advanced adsorption characteristics. In response, this article experimentally investigates and models silica gel/ethanol pair adsorption characteristics that can utilize low-temperature heat sources, such as those available in the emerging electric vehicles and PV/T systems. The investigated characteristics are the porous structure stability, isosteric heat of adsorption, adsorption diffusion energy, adsorption isotherm, and adsorption kinetic under extended operating conditions 15-55ºC. The results showed the high affinity of silica gel towards ethanol to provide sub-zero cooling. Silica gel showed no structure deterioration during the repetitive adsorption/desorption cycles of net 22% cyclic ethanol uptake. The chemical adsorption of silica gel/ethanol showed a high level of adsorption/desorption reversibility with minimal hysteresis, which the Langmuir model best simulated. The heat of adsorption was determined to be 4.49x10⁴ J/mol, which was higher than the diffusion energy of 1.80x10⁴ J/mol due to the slow physical mobility of ethanol molecules inside silica gel pores. The Elovich kinetic model was the most suitable for simulating the chemical adsorption/desorption processes. The material level cyclic analysis showed the potential of 22 kJ/kgads cooling effect and 0.97 coefficient of performance by utilizing a 55ºC heat source, widely available in PV/T systems and electric vehicles

Cooling Strategy Optimization of a Permanent Magnet Synchronous Motor

In this study, 250 kW, 9 phase, outer rotor types of Permanent Magnet Synchronous Motor (PMSM) are taken into consideration. To optimize the cooling efficiency of the motor, firstly, the motor geometry is obtained, and the e-magnetic model of the geometry is validated with the manufacturer`s data. Secondly, by using the validated e-magnetic model, the cooling system of the motor was analyzed by using the thermal model of the Motor-CAD. The thermal model is also validated with the real-time experiments which are held on an electric bus at constant speed experimentally. For finding the best cooling strategy for the motor, after validation, the effect of the mass flow rate, the type of the cooling refrigerant, the cooling pipe diameter size, and the change of torque are analyzed on the validated model. The results showed us that mass flow rate and torque have a significant effect on winding temperature, and the Taguchi method showed that [mass flow rate (A)=50 l/min, pipe diameter (B) = 17.7 mm, number of turns (C)=20, type of fluid (D)= EGW50/50, torque (E)=2000 Nm] is the best cooling design parameters for the cooling strategy of the considered PMSM