Thermal Management System Using Phase Change Material for Lithium-ion Battery

The lithium-ion battery is promising energy storage that provides proper stability, no memory effect, low self-discharge rate, and high energy density. During its usage, batteries generate heat caused by energy loss due to the transition of chemical energy to electricity and the electron transfer cycle. Consequently, a thermal management system by cooling methods in the battery is needed to control heat. One of the cooling methods is a passive cooling system using a phase change material (PCM). PCM can accommodate a large amount of heat through small dimensions. It is easy to apply and requires no power in the cooling system. This study aims to find the best type of PCM criteria for a Lithium-ion battery cooling system. The research was conducted by simulations using computational fluid dynamics. The variations were using PCM Capric Acid and PCM Hexacosane, with thickness variations of 3 mm, 6 mm, and 9 mm. Hexacosane PCM with 9 mm thickness indicates the best result to reduce heat up to 6.54°K, demonstrating a suitable passive cooling system for Li-ion batteries.

Performance evaluation of sub ground passive cooling system with Ecotech software simulation (Case study: Pasio Christi Church at Cibunut, Kuningan, West Java)

The church in Cibunut, Kuningan, West Java has implemented a sub ground passive cooling system in its renovated building in 2018. This sub ground passive cooling system has not been widely applied in tropical regions, however the church is trying to implement it. This system is supported by making air wells and flowing cold air through distribution pipes into the room. Because not many people have implemented this system, performance evaluation through an ecotect software simulation is used to determine the success of the system in cooling the room. The research was carried out with the following steps: (i) Data collection in the form of CAD drawings of Cibunut Church building, (ii) Simulation using ecotect software, and (iii) Analysis of simulation results with thermal comfort standards in the tropics. The results of this study are conclusions from the results of simulations and analyzes, as an illustration in applying of the sub ground passive cooling system. This research helps illustrate the difference between buildings that have not applied sub ground passive cooling and buildings that have applied sub ground passive cooling.

Active cooling photovoltaic with IoT facility

Harvesting energy from the sun makes the photovoltaic (PV) power generation a promising technology. To obtain a consistent state of charge (SOC), consistent energy must be harvested and efficiently directed to the battery. Overcharging or undercharging phenomena decreases the lifetime of the battery. Besides, the effect of irradiance toward solar in term of sunlight intensity effects the efficiency and hence, sluggish the SOC. The main problem of the solar panel revealed when the temperature has increased, the efficiency of solar panel will also be decreased. This manuscript reports the finding of developing an automatic active cooling system for a solar panel with a real time energy monitoring system with internet-of-things (IoT) facility. The IoT technology assists user to measure the efficiency of the solar panel and SOC of the battery in real time from any locations. The automatic active cooling system is designed to improve the efficiency of the solar panel. The effectiveness of the proposed system is proven via the analysis of the effect of active cooling toward efficiency and SOC of photovoltaic system. The results also tabulate the comparative studies of active-to-passive cooling system, as well as the effect of cooling towards SOC and efficiency of the solar panel.

SISTEM SUBGROUND PASSIVE COOLING PADA GEREJA DI CIBUNUT, KUNINGAN, JAWA BARAT

Subground passive cooling is a passive cooling technique that is carried out by flowing cold air in the ground into the room. The Pasio Christi Church in Cibunut, Kuningan, West Java was founded in 1965. Then the church implemented a passive cooling subground system through renovations carried out on May 11, 2018. This passive cooling system is usually carried out in areas with subtropical to cold climates, however Cibunut who has a tropical climate tries to implement this system. In fact, there is concern if the system is implemented in the tropics, such as humidity entering the system, causing fungal problems that can have an impact on health. . Therefore this research describes the application of the subground passive cooling system in tropical climates with the following steps: (i) data collection in the form of literature studies, (ii) identification of the subground passive cooling system of Cibunut Church, (iii) elaboration of theory regarding subground passive cooling, (iv) analysis of the application of subground passive cooling of the Cibunut church with the results of theoretical elaboration. This research is expected to be able to contribute in science, especially regarding the application of subground passive cooling systems in tropical climates.Abstrak: Subground passive cooling merupakan teknik pendinginan pasif yang dilakukan dengan mengalirkan udara dingin dalam tanah ke dalam ruangan. Gereja Pasio Christi di Cibunut, Kuningan, Jawa Barat didirikan sejak 1965. Lalu gereja ini menerapkan sistem subground passive cooling melalui renovasi yang dilakukan pada 11 Mei 2018. Sistem pendinginan pasif ini biasanya dilakukan pada wilayah dengan iklim subtropis hingga iklim dingin, namun demikian Cibunut yang beriklim tropis mencoba untuk menerapkan sistem ini. Padahal ada kekawatiran jika sistem ini diterapkan di wilayah tropis, seperti kelembaban yang masuk dalam sistem sehingga muncul permasalahan jamur yang dapat berdampak pada kesehatan. Oleh karena itu pada penelitian ini mendiskripsikan mengenai penerapan sistem subground passive cooling pada wilayah beriklim tropis dengan langkah-langkah sebagai berikut : (i) pengumpulan data dalam bentuk studi literatur, (ii) identifikasi sistem subground passive cooling Gereja Cibunut, (iii) elaborasi teori mengenai subground passive cooling, (iv) analisis penerapan subground passive cooling gereja Cibunut dengan hasil elaborasi teori. Dari penelitian ini diharapkan mampu memberikan sumbangsih dalam keilmuan terutama mengenai penerapan sistem subground passive cooling pada wilayah beriklim tropis.

Numerical Thermal Performance Investigation of an Electric Motor Passive Cooling System Employing Phase Change Materials

This study investigates the cooling performance of a passive cooling system for electric motor cooling applications. The metal-based phase change materials are used for cooling the motor and preventing its temperature rise. As compared to oil-based phase change materials, these materials have a higher melting point and thermal conductivity. The flow field and transient heat conduction are simulated using the finite volume method. The accuracy of numerical values obtained from the simulation of the phase change materials is validated. The sensitivity of the numerical results to the number of computational elements and time step value is assessed. The main goal of adopting the phase change material based passive cooling system is to maintain the operational motor temperature in the allowed range for applications with high and repetitive peak power demands such as electric vehicles by using phase change materials in cooling channels twisted around the motor. Moreover, this study investigates the effect of the phase change material container arrangement on the cooling performance of the under study cooling system.

Melting of PCMs Embedded in Copper Foams: An Experimental Study

A smart possible way to cool electronics equipment is represented by passive methods, which do not require an additional power input, such as Phase Change Materials (PCMs). PCMs have the benefit of their latent heat being exploited during the phase change from solid to liquid state. This paper experimentally investigates the melting of different PCMs having different melting temperatures (42, 55 and 64 °C). Two copper foams, having 10 PPI and relative densities of 6.7% and 9.5%, i.e., porosities of 93.3% and 90.5%, respectively, are used to enhance the thermal conductivity of PCMs. The block composed by the PCM and the copper foam is heated from one side, applying three different heat fluxes (10, 15 and 20 kW m−2): the higher the heat flux, the higher the temperature reached by the heated side and the shorter the time for a complete melting of the PCM. The copper foam with a relative density of 9.5% shows slightly better performance, whereas the choice of the melting temperature of the PCM depends on the time during which the passive cooling system must work. The effect of the foam material is also presented: a copper foam presents better thermal performances than an aluminum foam with the same morphological characteristics. Finally, experimental dimensionless results are compared against values predicted by a correlation previously developed.