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Thermal Energy Storage Optimization in Shopping Center Buildings Biyanto, Totok R.; Alhikami, Akhmad F.; Nugroho, Gunawan; Hantoro, Ridho; Bayuaji, Ridho; Firmanto, Hudiyo; Waluyo, Joko; Sonhaji, Agus Imam
Journal of Engineering and Technological Sciences Vol 47, No 5 (2015)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (419.021 KB) | DOI: 10.5614/j.eng.technol.sci.2015.47.5.7

Abstract

In this research, cooling system optimization using thermal energy storage (TES) in shopping center buildings was investigated. Cooling systems in commercial buildings account for up to 50% of their total energy consumption. This incurs high electricity costs related to the tariffs determined by the Indonesian government with the price during peak hours up to twice higher than during off-peak hours. Considering the problem, shifting the use of electrical load away from peak hours is desirable. This may be achieved by using a cooling system with TES. In a TES system, a chiller produces cold water to provide the required cooling load and saves it to a storage tank. Heat loss in the storage tank has to be considered because greater heat loss requires additional chiller capacity and investment costs. Optimization of the cooling system was done by minimizing the combination of chiller capacity, cooling load and heat loss using simplex linear programming. The results showed that up to 20% electricity cost savings can be achieved for a standalone shopping center building.
Characterization of Voltage Generation Obtained from Water Droplets on a Taro Leaf (Colocasia esculenta L) Surface Ena Marlina; Akhmad Faruq Alhikami; Metty Trisna Negara; Sekar Rahima Sahwahita; Mochammad Basjir
Journal of Earth Energy Engineering Vol. 12 No. 2 (2023)
Publisher : Universitas Islam Riau (UIR) Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jeee.2023.12916

Abstract

Voltage generation was obtained using a water droplet characterization on a taro (Colocasia esculenta L) leaf surface. This method relies on the superhydrophobic effect from the contact angle between the water droplet and the taro leaf’s surface allowing electron jumping and voltage generation. Water droplets were dropped on the top of taro leaf surface equipped with aluminum foil underneath as an electrode. The voltage was measured at various slope angles of 20°, 40° and 60° in a real-time basis. A digital camera was used to capture the droplet movement and characterization. It is found that the taro leaf has a surface morphology of nano-sized pointed pillars which created a superhydrophobic field. The energy generation was primarily obtained from the electron jump which was caused by the surface tension of the nano-stalagmite structure assisted by the minerals contained in the taro leaf surface. The results reported that the smaller the droplet radius (the smaller the droplet surface area), the greater the droplet surface tension and the greater the voltage generation. Furthermore, the highest voltage generation was obtained 321.2 mV at 20°-degree angle of slopes.
Cold Thermal Energy Storage (CTES) Study In A Hospital Building Akhmad Faruq Alhikami; Egi Dwi Gusuma; Moh. Fiqi Firmansah; Rusdan Aditya Aji Nugroho; Riswan Sepriyatno
G-Tech: Jurnal Teknologi Terapan Vol 8 No 1 (2024): G-Tech, Vol. 8 No. 1 Januari 2024
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33379/gtech.v8i1.3559

Abstract

This paper studies cold thermal energy storage in a hospital building. There are six CTES strategies to implement in the building includes full storage, levelling storage, partial storage 30%, partial storage 50%, partial storage 70%, and partial storage 90%. The energy consumption, electricity cost and chiller performances are evaluated to find the optimum mode.The results showed that levelling storage found the best mode for new cooling system investment with annual savings up to 10.5%. In addition the energy consumption is considered lower than normal cooling system. The chiller capacity of partial storage 30% is closed to normal cooling, thus this strategy is the best for replacement system with the annual savings up to 13%.
Investigation of Carburetor Venturi Bore Size in Internal Combustion Engines Using Ron 95 Fuel Mixed With Bioethanol Riswan Sepriyatno; Tri Sandi Arif Hamzah; Nur Rahmadani Jatu Matimbang; Akhmad Faruq Alhikami; Mochammad Khoirul Rosidin
G-Tech: Jurnal Teknologi Terapan Vol 8 No 2 (2024): G-Tech, Vol. 8 No. 2 April 2024
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33379/gtech.v8i2.4082

Abstract

This study presents the results of an investigation into the performance and exhaust emissions of a four-stroke, 1-cylinder internal combustion engine. In order for the engine to produce optimal energy, the right fuel is needed so as to reduce exhaust emissions, which are considered very dangerous for the survival of living things. Bioethanol is considered to optimize combustion reactions in the form of CO dan HC produced, but bioethanol contains less energy compared to gasoline. The purpose of this study is to analyze the fuel v-power shell of RON 95mixed with 15% bioethanol fuel with a comparison of carburetor venturi hole sizes 26 and 28. From the results obtained, fuels with bioethanol mixtures have lower levels of waste emissions while, performance is improved compared to non-mixed petrol fuels.
Catalytic Pyrolysis of Plastic Waste using Red Mud and Limestone: Pyrolytic Oil Production and Ignition characteristics Marlina, Ena; Alhikami, Akhmad Faruq; Mardiyani, Siti Asmaniyah; Trismawati, Trismawati; Yazirin, Cepi
Automotive Experiences Vol 7 No 3 (2024)
Publisher : Automotive Laboratory of Universitas Muhammadiyah Magelang in collaboration with Association of Indonesian Vocational Educators (AIVE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31603/ae.12830

Abstract

This study investigated the catalytic pyrolysis of polypropylene (PP) and low-density polyethylene (LDPE) using 10 wt.% red mud and 10 wt.% limestone catalysts in a batch reactor. The process was conducted at an operating temperature of 350°C with retention times of 30, 60, and 90 minutes. The effects of adding red mud and limestone catalysts on the yields of liquid, solid, and gas pyrolysis products were analyzed. The pyrolytic oil was further evaluated using droplet evaporation measurements, equipped with a K-type thermocouple and a CCD camera to monitor droplet evolution within an atmospheric chamber. The addition of catalysts enhanced the liquid product yield while reducing the solid yield. The catalytic pyrolysis successfully facilitated the isomerization of plastic polymers, breaking the carbon chains of PP with 10 wt.% red mud. Olefin content increased by up to 7.3% for both 10 wt.% red mud and 10 wt.% limestone. Furthermore, the evaporation rate constant of the catalytic pyrolysis oils improved by up to 8.3%. This study aims to provide new insights into utilizing local waste materials to enhance the quality of pyrolytic plastic products.
Enhancing Stoichiometric Methane-Air Flames: The Role of N2O Replacement Purwanto, Aris; Saputro, Herman; Alhikami, Akhmad Faruq; Munir, Fudhail Abdul
Automotive Experiences Vol 8 No 2 (2025)
Publisher : Automotive Laboratory of Universitas Muhammadiyah Magelang in collaboration with Association of Indonesian Vocational Educators (AIVE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31603/ae.13422

Abstract

The oxidizer is used in aviation propellants for its relatively high impulse density and non-toxic nature. At elevated temperatures, nitrous oxide (N₂O) decomposes into approximately 33% oxygen (O₂) and 67% nitrogen (N₂), providing a higher oxygen content than ambient air. This decomposition enables N₂O to produce higher flame temperatures than air. Previous studies have shown that N₂O addition improves flame stability in methane combustion systems. This study examined the substitution of O₂ with N₂O in stoichiometric methane–air premixed flames, using both numerical and experimental methods. One-dimensional and two-dimensional simulations with CHEMKIN PRO revealed that replacing air with N₂O increases flame temperature but reduces laminar flame speed, mainly due to lower local oxygen concentrations in the reaction zone. The simulations also showed that nitrogen oxides (NOₓ) emissions increase significantly in the post-reaction zone, while carbon monoxide (CO) and carbon dioxide (CO₂) emissions decrease. Experimental results confirmed that controlled N₂O addition enhances flame stability, but excessive concentrations can trigger combustion instabilities. Overall, the findings indicate that introducing up to 20% N₂O can increase flame temperature and reduce CO emissions in methane flames.