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Öğe A critical review on renewable battery thermal management system using heat pipes(Springer, 2023) Afzal, Asif; Razak, R. K. Abdul; Samee, A. D. Mohammed; Kumar, Rahul; Agbulut, smit; Park, Sung GoonThe critical review presented here exclusively covers the studies on battery thermal management systems (BTMSs), which utilize heat pipes of different structural designs and operating parameters as a cooling medium. The review paper is divided into five major parts, and each part addresses the role of heat pipes in BTMS categorically. Experimental studies, numerical analyses, combined experimental and numerical investigations, optimum utilization of a phase-change material (PCM) with a heat pipe (HP), oscillating heat pipe (OHP), and micro heat pipes combined with PCM for Li-ion BTMS using heat pipes are presented. The usage of HP's and PCM can keep the temperature of the battery system in the desirable limit for a longer duration compared to other traditional and passive methods. More emphasis is made on how one can achieve a suitable cooling system design and structure, which may tend to enhance the energy density of the batteries, improve thermal performance at maximum and minimum temperature range. Arrangement of battery cells in a pack or module, type of cooling fluid used, heat pipe configuration, type of PCM used, working fluid in a heat pipe, and surrounding environmental conditions are reviewed. According to the study, the battery's effectiveness is significantly influenced by temperature. The usage of flat HPs and heat sink proves to be the best cooling method for keeping the battery working temperature below 50 degrees C and reduces the heat sink thermal resistance by 30%. With an intake temperature of 25 degrees C and a discharge rate of 1 L per minute, an HP that uses water as a coolant is also effective at regulating battery cell temperature and maintaining it below the permissible 55 degrees C range. Using beeswax as a PCM in HPs reduces the temperature of BTMS by up to 26.62 degrees C, while the usage of RT44 in HPs reduces the temperature of BTMS by 33.42 degrees C. The use of fins along with copper spreaders drastically decreases the temperature capability of HPTMS by 11 degrees C. MHPA shows excellent performance in controlling the battery temperature within 40 degrees C. The effective thermal management can be done by incorporating heat pipe alone or by coupling with liquid cooling or metal plate. However, extensive and extended research is required to improve thermal management to safely and effectively use the battery for day-to-day applications.Öğe Melting numerical simulation of hydrated salt phase change material in thermal management of cylindrical battery cells using enthalpy-porosity model(Elsevier, 2023) Afzal, Asif; Jilte, Ravindra; Samee, Mohammed; Agbulut, Umit; Shaik, Saboor; Park, Sung Goon; Alwetaishi, MamdoohBattery thermal management using different cooling techniques is rapidly growing. Understanding the proper cooling and melting process when phase change materials (PCM) are used is of prime importance in this area. Hence, a transient thermal-fluid and melting process of hydrated salt PCM enclosed in a battery module with six cylindrical cells is numerically investigated to understand the melting process of the PCM. Four structural models S1, S2, S3, and S4 are constructed for the present numerical simulation. The battery cell wall is kept at a constant temperature of 35celcius, while the rectangular enclosure walls are assumed to be insulated. A finite volume scheme -based CFD (computational fluid dynamics) software is used to simulate the melting process of hydrated salt PCM. In order to capture the phase change phenomenon from solid to liquid, an enthalpy-porosity equation is solved. The temporal temperature distribution, liquid fraction, velocity and enthalpy are analyzed. The results obtained by the numerical computation suggest that the battery cell arrangement used in S1 and S2 model at the initial time step gives better space for temperature distribution and liquid fraction up to the time step of 420 s, while S3 and S4 model after a time interval of 420 s provide better scope for temperature distribution and complete melting of hydrated PCM.Öğe Single- and combined-source typical metrological year solar energy data modelling(Springer, 2023) Afzal, Asif; Buradi, Abdulrajak; Alwetaishi, Mamdooh; Agbulut, Umit; Kim, Boyoung; Kim, Hyun-Goo; Park, Sung GoonPrediction of solar energy data is very crucial for the effective utilization of freely available renewable energy abundantly in nature. Solar energy data are widely available which must be carefully prepared and arranged for modelling. In this work, typical meteorological year (TMY) data made available by the Korea institute of energy research (KIER) and the National renewable energy laboratory (NREL) are used for modelling in different phases. TMY data at single-point location and multiple locations from KIER are initially used for training of machine learning (ML) algorithms. Later, the TMY data from NREL and KIER are combined and then modelled using radius nearest neighbour (RNN), decision tree regressor (DTR), random forest regressor (RFR), and X-gradient boosting (XGB) algorithms. The solar energy parameters modelled in this work are dew point temperature (DPT), dry bulb temperature (DBT), relative humidity (RH), surface pressure (SP), windspeed (WS), and solar insolation of horizontal plane (IHP). Quantitative analysis of the algorithms is also performed in each stage of the work. The modelling indicates that the DBT, DPT, RH, and SP are able to be predicted with a minimum accuracy of over 90% in each stage. The WS and IHP data when modelled from a single-source TMY data provide superior accuracy than when they are combined. RFR and XGB have outperformed overall as they provide good accuracy for WS and IHP data as well. RNN and DTR achieved 100% accuracy in training, while RFR and XGB showed slightly lower training accuracy due to their avoidance of overfitting. There are errors in testing for RNN/DTR. Using RNN/DTR, the training errors are 0% in all cases, while in some cases like DTP the error by RFR/XGB up to 3%, whereas RNN/DTR testing errors go up to 5% and in case of RFR/XGB they are up to 7.5%. For RH modelling RFR/XGB, training errors are max 6%. RNN/DTR testing errors go up to 11%, while for RFR/XGB up to 7.5% which indicates their robustness. It is observed that many solar parameters, when combined with different source data, can be predicted easily with good accuracy, while WS and IHP become a little bit challenging to model.Öğe Waste to fuel: Pyrolysis of waste transformer oil and its evaluation as alternative fuel along with different nanoparticles in CI engine with exhaust gas recirculation(Pergamon-Elsevier Science Ltd, 2023) Sathish, Thanikodi; Surakasi, Raviteja; Kishore, T. Lakshmana; Rathinasamy, Saravanan; Ağbulut, Ümit; Shaik, Saboor; Park, Sung GoonThe present research aims to produce the alternative fuel from waste electric transformer oil through two levels pyrolysis process with potassium hydroxide catalyst, enhance it by 150 ppm of 30-50 nm sized Zinc oxide and Cerium oxide nanoparticles and then tested with/without EGR method to achieve low exhaust emissions. The experiments were performed on a single-cylinder, four-stroke CI engine at varying engine loads from 0 to 100% with an increment of 25% at a fixed engine speed of 1500 rpm. The results obtained from the combined test fuels have been compared with reference (conventional) diesel fuel. The performance of fuels like Diesel, PBWTO, PBWTO/ZnO, PBWTO/CeO2, and with working conditions like PBWTO/ZnO +20% EGR and PBWTO/CeO2 +20% EGR were recorded respectively at full load conditions in which HC emission as 11, 19, 14, 13, 15 and 15 ppm, 32.9%, smoke opacity as 32.9%, 39.5%, 16.6%, 19.3%, 20.1%. WTO addition into diesel fuel increased the CO emission; however, it is reduced with the nanoparticle addition. That is, PBWTO/ZnO, PBWTO/CeO2, PBWTO/ZnO +20% EGR and PBWTO/CeO2 +20% EGR have produced 0.058%, 0.046%, 0.056%, and 0.043% of lesser CO emission than PBWTO fuel respectively. In particular, EGR ensured noteworthy NOx emissions. For example, D, PBWTO, PBWTO/ZnO, PBWTO/CeO2, PBWTO/ZnO +20% EGR and PBWTO/CeO2 +20% EGR have emitted 1248 ppm, 1427 ppm, 1484 ppm, 1156 ppm, 831 ppm and 821 ppm of NOx emission, respectively. Due to the lower calorific value, higher viscosity, and poor atomization of WTO-added test fuels, the engine per-formance worsened. Accordingly, under full load condition, BTE was found to be 30.12%, 27.35%, 25.44%, 26.04%, 24.67%, and 25.26%, and BSFC was calculated to be 342, 410, 456, 450, 470, and 459 g/kWh for D, PBWTO, PBWTO/ZnO, PBWTO/CeO2, PBWTO/ZnO +20% EGR and PBWTO/CeO2 +20% EGR, respectively. In the conclusion, it is well-noticed that waste transformer oil can be used as a fuel substitute in CI engines with no modification on the vehicular system, and the addition of nanoparticles is a very good solution to mitigate the high exhaust pollutants arising from the use of WTO substitutes.
