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Journal : JOURNAL OF SCIENCE AND APPLIED ENGINEERING

Heat Flux Condensation on Coconut Shell Activated Charcoal Porous Media Djoko Hari Praswanto; Mochtar Asroni; Thomas Priyasmanu; Tutut Nani Prihatmi
JOURNAL OF SCIENCE AND APPLIED ENGINEERING Vol 3, No 2 (2020): JSAE
Publisher : Widyagama University of Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31328/jsae.v3i2.1770

Abstract

One way to keep the air humidity is by increasing the heat transfer with the porous media model. Increasing heat transfer depends on the value of the heat flux on the porous media. The heat flux value can be determined by inserting the porous media into the test section and then flow the vapor. The amount of heat absorbed is influenced by the large diameter of the porous on the media used. Therefore, this study aimed to optimize coconut shell charcoal by activating the charcoal. The purpose of activating coconut shell charcoal is to enlarge the pores so that it absorbs heat better than charcoal that has not been activated. The research method used is an experimental method and compares the results of research with previous studies. The porous media was vaporized for 60 minutes with a vapor temperature of 30 °C, while the vapor speed was varied, namely 1 m/s, 2m/s and 3 m/s. From the research results, that by using coconut shell activated charcoal, the heat flux value was higher than using coconut shell charcoal media. This is because the pore size in activated charcoal is larger and more numerous than charcoal that has not been activated so that it absorbs more heat. In addition, the greater the vapor speed, the higher the heat flux, because in the test section more vapor enters than vapor that comes out so that the porous media has a long time to absorb heat in the vapor. The heat transfer that occurs in porous media includes forced convection heat transfer because it has a value of Gr/Re2 < 1.
Effect of Hydrogen (g) Mixture with Refrigerant on the Pressure of Cooling Machine Components Djoko Hari Praswanto; S Djiwo; M. Asroni; A. Nugroho
JOURNAL OF SCIENCE AND APPLIED ENGINEERING Vol 4, No 1 (2021): JSAE
Publisher : Widyagama University of Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31328/jsae.v4i1.3497

Abstract

Refrigerant is substance or chemical composition which alternately compressed and condensed into a liquid and then expanded into vapor or gas when pumped through the cooling system. Alternative refrigerants are needed to replace full the halogenated refrigerants which are believed to contribute to ozone depletion in the atmosphere. In the last decade, many research and development of studies on the synthesis and characterization alternative refrigerants have been carried out. With replace a limited Ozone Depleting Substance (ODS) with any alternative can involve major changes in the design of various components such as insulation, lubricants, heat exchangers and motors. The purpose of this research is to determine the effect of hydrogen mixture with refrigerant R134a on the pressure of each component. This research used an experimental method on a direct cooling device. The data which obtained from the experimental results on this cooling machine then will process to determine the pressure that occurs in each component of the cooling machine. Based on the results of this research, the effect of the hydrogen mixture on refrigerant R134a on the performance of the cooling machine is the differences density of each mixture ratio. If more of hydrogen additions there, the density of result mixture also getting smaller. This will affect the pressure that occurs in the compressor because the relationship between density and pressure is directly proportional. The conclusion is the refrigerant from a mixture of hydrogen gas and Freon R134a is suitable for use as a refrigerant for air condition. Because at 60 minutes, the mixture ratio of 85%:15% can reduce the water temperature slowly until 20.2ºC. The slow cooling is felt bad when applied on the food preservation. 
Analysis of Hydrogen Gas Production Results in Water Electrolysis Process on Genset Characteristics Djoko Hari Praswanto; Soeparno Djiwo; Bima R. P. D Palevi
JOURNAL OF SCIENCE AND APPLIED ENGINEERING Vol 6, No 1 (2023): JSAE
Publisher : Widyagama University of Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31328/jsae.v6i1.4236

Abstract

Hydrogen gas is a type of alternative fuel for transportation that can serve a number of other potential needs. Water electrolysis is one way to get hydrogen gas. This study aims to determine the results of water electrolysis with three catalysts and mixed metal electrodes which are then applied to generator motor engines. The research method used was an experimental method with variations in electrolysis using KOH and NaOH base catalysts, H2SO4 acid catalysts, and stainless steel 316 electrodes. The best results for H2 gas production in this study were obtained with a 2M H2SO4 catalyst with a gas yield of 244.9mL H2 gas, while The lowest yield in this study was the 1M concentration of 1M NaOH catalyst of 12.5mL. The best results for H2 gas production were varied with pertalite fuel and then tested with a generator engine. Testing the generator motor engine is measured arm length and mass with a machine dynamometer. After testing, the data is obtained which is then analyzed to obtain the value of torque (Nm) and electric motor power (kW), and driving motor power (HP). The maximum energy produced pertalite + H2 gas has increased by 2.27kW on the electric motor and power of 4.13HP on the driving motor, while for pertalite fuel alone the power generated is 1.44kW on the electric motor and power of 2.62HP on the driving motor.[1]        S. A. Grigoriev, V. N. Fateev, D. G. Bessarabov, and P. Millet, “Current status, research trends, and challenges in water electrolysis science and technology,” Int. J. Hydrogen Energy, vol. 45, no. 49, pp. 26036–26058, 2020, doi: 10.1016/j.ijhydene.2020.03.109.[2]        Y. Song, X. Zhang, K. Xie, G. Wang, and X. Bao, “High-Temperature CO2 Electrolysis in Solid Oxide Electrolysis Cells: Developments, Challenges, and Prospects,” Adv. Mater., vol. 31, no. 50, pp. 1–18, 2019, doi: 10.1002/adma.201902033.[3]        A. Nechache and S. Hody, “Alternative and innovative solid oxide electrolysis cell materials: A short review,” Renew. Sustain. Energy Rev., vol. 149, 2021, doi: 10.1016/j.rser.2021.111322.[4]        O. Schmidt, A. Gambhir, I. Staffell, A. Hawkes, J. Nelson, and S. Few, “Future cost and performance of water electrolysis: An expert elicitation study,” Int. J. Hydrogen Energy, vol. 42, no. 52, pp. 30470–30492, 2017, doi: 10.1016/j.ijhydene.2017.10.045.[5]        S. Wang, A. Lu, and C. J. Zhong, “Hydrogen production from water electrolysis: role of catalysts,” Nano Converg., vol. 8, no. 1, 2021, doi: 10.1186/s40580-021-00254-x.[6]        N. A. Burton, R. V. Padilla, A. Rose, and H. Habibullah, “Increasing the efficiency of hydrogen production from solar powered water electrolysis,” Renew. Sustain. Energy Rev., vol. 135, no. July 2020, p. 110255, 2021, doi: 10.1016/j.rser.2020.110255.[7]        J. Brauns and T. Turek, “Alkaline water electrolysis powered by renewable energy: A review,” Processes, vol. 8, no. 2, 2020, doi: 10.3390/pr8020248.[8]        S. Anwar, F. Khan, Y. Zhang, and A. Djire, “Recent development in electrocatalysts for hydrogen production through water electrolysis,” Int. J. Hydrogen Energy, vol. 46, no. 63, pp. 32284–32317, 2021, doi: 10.1016/j.ijhydene.2021.06.191.[9]        W. Tong et al., “Electrolysis of low-grade and saline surface water,” Nat. Energy, vol. 5, no. 5, pp. 367–377, 2020, doi: 10.1038/s41560-020-0550-8.[10]      T. Nguyen, Z. Abdin, T. Holm, and W. Mérida, “Grid-connected hydrogen production via large-scale water electrolysis,” Energy Convers. Manag., vol. 200, no. September, p. 112108, 2019, doi: 10.1016/j.enconman.2019.112108.[11]      A. Buttler and H. Spliethoff, “Current status of water electrolysis for energy storage, grid balancing and sector coupling via power-to-gas and power-to-liquids: A review,” Renew. Sustain. Energy Rev., vol. 82, no. February, pp. 2440–2454, 2018, doi: 10.1016/j.rser.2017.09.003.[12]      I. V. Pushkareva, A. S. Pushkarev, S. A. Grigoriev, P. Modisha, and D. G. Bessarabov, “Comparative study of anion exchange membranes for low-cost water electrolysis,” Int. J. Hydrogen Energy, vol. 45, no. 49, pp. 26070–26079, 2020, doi: 10.1016/j.ijhydene.2019.11.011.[13]      L. Peng and Z. Wei, “Catalyst Engineering for Electrochemical Energy Conversion from Water to Water: Water Electrolysis and the Hydrogen Fuel Cell,” Engineering, vol. 6, no. 6, pp. 653–679, 2020, doi: 10.1016/j.eng.2019.07.028.[14]      S. Klemenz, A. Stegmüller, S. Yoon, C. Felser, H. Tüysüz, and A. Weidenkaff, “Holistic View on Materials Development: Water Electrolysis as a Case Study,” Angew. Chemie - Int. Ed., vol. 60, no. 37, pp. 20094–20100, 2021, doi: 10.1002/anie.202105324.[15]      H. K. Ju, S. Badwal, and S. Giddey, “A comprehensive review of carbon and hydrocarbon assisted water electrolysis for hydrogen production,” Appl. Energy, vol. 231, no. May, pp. 502–533, 2018, doi: 10.1016/j.apenergy.2018.09.125.[16]      F. ezzahra Chakik, M. Kaddami, and M. Mikou, “Effect of operating parameters on hydrogen production by electrolysis of water,” Int. J. Hydrogen Energy, vol. 42, no. 40, pp. 25550–25557, 2017, doi: 10.1016/j.ijhydene.2017.07.015.[17]      F. Gutiérrez-Martín, L. Amodio, and M. Pagano, “Hydrogen production by water electrolysis and off-grid solar PV,” Int. J. Hydrogen Energy, vol. 46, no. 57, pp. 29038–29048, 2021, doi: 10.1016/j.ijhydene.2020.09.098.