Kajian Numerik Penerapan Heat Pump sebagai Sarana Penyimpanan Energi Skala Jala-Jala dari Pembangkit Energi Terbarukan

Utilization of New Renewable Energy (EBT) today must be carried out because of its abundantpotential. One of the uses is to use energy storage with a heat pump system sourced from EBT. To supportthis, it is necessary to use a heat exchanger in an energy storage system which is expected to make theheating or cooling system faster with the right refrigerant. Therefore, a study was carried out using theapplication of a heat pump system with the addition of a heat exchanger as a place to store energyoriginating from Renewable Energy. The method used is process simulation using DWSIM. The refrigerantused is R-600a, R-407C. R-410a, R-22, and ammonia. Ammonia was chosen because it produces aCoefficient of Performance of 3.012 with a condenser outlet temperature of 102.854°C. The storagemedium used is silica sand

Penggunaan Metode Risk Based Inspection API 581 Tahun 2000 sebagai Dasar Analisis Risiko Sistem Producer Gas PLTSa Surakarta

Abstract – The Surakarta Waste Power Plant (PLTSa) is planned to start operating in 2023. PLTSa uses gasification process technology to process waste. In the waste gasification process, the gas produced is syngas or producer gas, which is a mixed gas consisting of hydrogen compounds (H2), carbon monoxide (CO), and several compounds with small concentrations such as carbon dioxide (CO2) and methane (CH4). The syngas production process begins with the waste gasification process in the Gasifier equipment where the waste is heated at high temperatures until it reaches the conditions for gasification. Furthermore, syngas will go through a gas conditioning process. In this process, the properties of syngas changes in each equipment and pipe line it passes through. Each property of syngas can affect the metal material which is the basic material of equipment and pipes so that it can result in system failure. With the difference in fluid properties and pipe and equipment materials in the system, there will be differences in damage mechanisms, which means that there are also differences in inspection treatment in each part of the plant. Thus, determining the right inspection program can be done by conducting a risk analysis based on the API 581 2000 standard

Kajian Numerik Penerapan Push-Pull Ventilation dengan Rasio Kecepatan 6 dan 8 untuk Melindungi Pekerja Pabrik dari Penularan Covid-19

Abstract - The transmission of COVID-19 is still spreading in the world, including in Indonesia. The increasing number of positive cases of COVID-19 in Indonesia, one of the causes is transmission from industrial clusters. Keeping a minimum distance of 1 to 2 meters between workers is difficult to implement. This is due to the limitations of layout, area, and work systems in the industry. Therefore, a system is needed to protect industrial workers from potential exposure to COVID-19. One of the technologies that has a high potential to be applied is the air-curtain. In this analyzes the push-pull air curtain where there is push-pull ventilation that is able to protect workers from microdroplet inhalation. The extent to which push-pull ventilation is able to withstand droplet bursts using push-pull ventilation velocity ratios of 8 and 6. To be able to find out this, a simulation was carried out with Salome s, OpenFOAM, ParaView software. The results of the simulation carried out that the velocity ratio of 8 can withstand droplet bursts, having a percentage of droplets that penetrate 22.7 percent. Meanwhile, the ratio of 6 has a percentage value of droplets that penetrates 6.38 percen

Analisis Kinerja Perpindahan Panas Fluida Perantara untuk Intermediate Fluid Vaporizer pada Sistem Regasifikasi Gas Alam Cair

Abstract - PLTGU fuel was originally from high-speed diesel fuel to LNG. For this reason, a regasification system is needed to support this process. For this reason, a regasification terminal is needed to facilitate the process. In procuring a small-scale floating Liquified Natural Gas (LNG) regasification terminal, a regasification tool with a relatively small size but good performance is required. Intermediate Fluid Vaporizer (IFV) as a regasification tool is very suitable to be used because when compared to other types of regasification equipment, IFV has the simplest structure and shape and relatively small size, as well as its performance, is quite good in the regasification process. IFV uses an intermediate fluid for the LNG evaporation process to the gas phase. The type of medium fluid that is widely used in IFV today is Propane. However, the use of Propane still has several risks, one of which is fire. With these problems, research was made to replace Propane with a more adequate fluid. The analysis was carried out using the Aspen Hysys  software to get the working pressure, then for the numerical simulation using the OpenFoam software. The selected fluid must have good heat transfer performance. From the results of the study, it can be concluded that overall both from the value of heat transfer area, heat transfer coefficient, working pressure, and in terms of environmental friendliness, the intermediary fluid substitute for propane has the highest value according to the Intermediate Fluid Scoring is R-500. R-500 is suitable to replace propane as an intermediate fluid

KAJIAN NUMERIK PENGARUH PROFIL SUDU TERHADAP KINERJA TURBIN HYDROKINETIC DARRIEUS SEBAGAI WAVE AND CURRENT ENERGY CONVERTER

New and Renewable Energy (EBT) resources in Indonesia are still not fully utilized,especially from the the maritime sector. Currently, the EBT mix has only reached 11.2 percent, stillbelow the 2025 energy mix target of 23 percent and the potential for EBT which reaches more than 400Gigawatts (GW) has only been utilized at 10 GW or 2.5 percent of the total reserves. (EBTKE PublicRelations, 2021). The form of wave and current energy is one of the new renewable energies from thesea which has the potential to be used as electrical energy with very large energy reserves. In this FinalProject research, a 2D modeling simulation based on CFD (Computational Fluid Dynamics) wascarried out on the Darrieus hydrokinetic turbine as an ocean wave energy converter device.Simulations were carried out to analyze the effect of the blade profile on the Torque Coefficient (Ct)and Power Coefficient (Cp) values. In this study, wave data from one of the South Java Waters wasused. The highest Coefficient of Torque (Ct) and Coefficient of Power (Cp) values were obtained forthe NACA 0021 symmetrical blade profile with a variation of TSR = 0.25 and ? = 0.5, namely Ct =0.335 and Cp = 0.167 while for the asymmetrical blade profile NACA 63-415 with a variation of TSR= 0.25 and ? = 5 for Ct = 0.263 and Cp = 0.13

Simulasi Laju Perpindahan Panas Serrated Finned Tube pada Heat Exchanger dengan Menggunakan Kondisi Batas Periodik

Heat exchanger is a tool that use for exchange the heat to be cool and heat the fluid. Heat exchanger is widely used for air conditioning, chemical processing, and power plants by using coal, natural gas, etc as fuel. Greater heat exchanger capacity needs greater fuel requirements used, it is necessary to design optimization in the heat exchanger. Using fin in the heat exchanger tube is one way to increase the heat transfer rate because of increases the surface area. From previous research, serrated fin is one type of fin with high efficiency because it can increase the value of fluid turbulence. The aim of this research is to know the  heat transfer rate that occurs in serrated finned tube, assumed that each side is periodic boundry condition. The result shows that periodic boundry condition can be apply for serrated finned tube in heat exchanger simulation, with error between this study and previous study by Martinez (2015)  is less than 5%

Studi Numerik Pengaruh Sudut Kemiringan Push Nozzle pada Air Curtain Terhadap Pola Aliran Push-Pull Ventilation

COVID-19 cases will continue to spread throughout the world until 2023, including inIndonesia, and have many negative impacts, especially for the industrial world because it is difficultto enforce a minimum distance of 1-2 meters between employees. One technology that has highpotential to be applied is the air curtain. This journal analyzes push-pull ventilation to protectworkers from microdroplet inhalation. In this study, two variations of the push-pull ventilation speedratio (Vs/Vb) were used, namely 4 and 6. As well as using a variation of the push nozzle slope, namely10°. In this study, running was carried out with two models, namely modeling without a mannequinand with a mannequin. To complete this research, simulations were carried out using theComputational Fluid Dynamics (CFD) method using Salome, OpenFOAM, and ParaView software.So, the results obtained in modeling without a mannequin, the speed ratio of 6 is the most optimalratio with the least amount of average discharge that goes out of bounds, namely 0.582 m3/s. Whilethe results of the push-pull modeling with the mannequin show that no droplets penetrate the aircurtain at all variations of the velocity ratio, the velocity ratio of 6 is the velocity ratio that has aover-blow flow pattern that is very effective in holding down spray from droplets

Pengaruh Penambahan Becker Mewis Duct pada Perfoma Propeller B-series

Pollution due to sea transportation is a problem that requires consistent handling. Recent years of research in the field of shipping have focused on reducing exhaust emissions by increasing fuel efficiency and decarbonization. Decarbonization in the shipping industry can be achieved by using energy saving devices to reduce fuel consumption. The Energy Saving Device commonly used in the shipping world is the Becker-Mewis duct (BMD). This study used a variation of the NACA profile on the Becker-Mewis duct fin. The CFD (Computational Fluid Dynamics) method is used to analyze the thrust coefficient and torque coefficient. Becker-Mewis duct was added to increase thrust and torque values. From the results of the analysis that has been carried out without variations from NACA, the thrust coefficient is 0.1526, the torque coefficient is 0.0162 and the efficiency is 0.5261. With the NACA 4412 variation, it has a thrust coefficient of 0.2579, a torque coefficient of 0.0252 and an efficiency of 0.5728. The NACA 4415 variation has a thrust coefficient of 0.2663, a torque coefficient of 0.0260 and an efficiency of 0.5743. With increased efficiency, the addition of Becker-Mewis duct can increase the performance of the propelle

Kajian Numerik Pengaruh Push dan Pull Velocity terhadap Pola Aliran Pada Downward Push-Pull Air Curtain

Transmission of COVID-19 is still increasing in the world, such as in China andIndonesia. One of the reasons for the increasing number of positive cases of COVID-19 isthe occurrence of transmission from industrial clusters, the implementation of a minimumsocial distancing of 1 to 2 meters between workers is difficult to do. This is due to limitationsin layout, area, and industrial work systems. Thus, a system is needed to protect industrialworkers from potential exposure to COVID-19. One technology that has high potential to beapplied is air curtain. From these problems, this research will carry out an analysis of theoptimum push-pull discharge and air velocity, and the regime map for downward push-pullair curtain, the method used to carry out the analysis is Computional Fluid Dynamics (CFD)where the stages of the CFD process are preprocessing, processing, postprocessing. Thesoftware used to complete this final project is SALOME for the preprocessing,, OpenFOAMfor the processing, and for the postprocessing stage using ParaView. From the simulationresults that have been carried out, the results show that at a nozzle blow speed of 6,24 m/s,with a suction nozzle speed of 37,44 m/s, these are the optimum blow speed and suction nozzlevalues and are able to withstand droplet dispersion

Kajian Numerik Terhadap Pola Aliran Upward Push-Pull Air Curtain dengan Rasio Kecepatan 8 dan 10 untuk Mencegah Penularan Covid-19 pada Pekerja Pabrik Manufaktur

Abstract – COVID-19 continues to spread globally, including in Indonesia. One of the contributing factors to the increasing number of positive COVID-19 cases in Indonesia is the transmission within industrial clusters. Maintaining a minimum distance of 1 to 2 meters between workers is challenging due to the constraints imposed by the industry's work systems, space, and layout. Consequently, there is a need for a mechanism to safeguard industrial workers from potential COVID-19 exposure. The air-curtain technology emerges as a promising solution with significant potential for application. In this study, the focus is on the push-pull air curtain, which incorporates push-pull ventilation to protect employees from inhaling microdroplets. The study assesses the capability of push-pull ventilation to withstand droplet bursts at two velocity ratios: 8 and 10. To investigate this, a simulation was conducted using Salome's, Open FOAM , Para view tools, and Jupiter Notebook. The simulation results demonstrate that a velocity ratio of 8 effectively resists droplet bursts, with only 0.007 percent of droplets able to penetrate the system. Meanwhile, the ratio of 10 showed a slightly lower effectiveness, with 0.05 percent of droplets penetrating the system. These findings highlight the potential of the push-pull air curtain technology in mitigating COVID-19 transmission risks in industrial settings. &nbsp