Physics design point of high-field stellarator reactors

The ongoing development of electromagnets based on High Temperature Superconductors has led to the conceptual exploration of high-magnetic-field fusion reactors of the tokamak type, operating at on-axis fields above 10 T. In this work we explore the consequences of the potential future availability of high-field three-dimensional electromagnets on the physics design point of a stellarator reactor. We find that, when an increase in the magnetic field strength $B$ is used to maximally reduce the device linear size $R\sim B^{-4/3}$ (with otherwise fixed magnetic geometry), the physics design point is largely independent of the chosen field strength/device size. A similar degree of optimization is to be imposed on the magnetohydrodynamic, transport and fast ion confinement properties of the magnetic configuration of that family of reactor design points. Additionally, we show that the family shares an invariant operation map of fusion power output as a function of the auxiliary power and relative density variation. The effects of magnetic field over-engineering and the $R(B)$ scaling of design points with constant neutron wall loading are also inspected. In this study we use geometric parameters characteristic of the \emph{helias} reactor, but most results apply to other stellarator configurations.

Mitigating Aircraft Auxiliary Power Unit Carbon Dioxide (CO2) Emissions During the Aircraft Turnaround Process from the Use of Solar Power at the Airport Gate: The Case of Moi International Airport, Kenya

One of the most pervasive trends in the global airport industry in recent times has been the adoption of green renewable technologies. Many airports around the world have now installed photovoltaic (PV) solar systems as a key environmental measure. One of the critical areas of energy management at an airport is the provision of power and cooling at the gate, which is used during the aircraft turnaround process. Historically, the aircraft auxiliary power unit (APU) was the primary power source during the aircraft turnaround process. In recent times, airports have transitioned to the use of fixed electrical ground power (FEGP) and preconditioned air to mitigate the emissions from use of aircraft auxiliary power unit (APUs). Based on an instrumental case study research approach, this study has examined how Moi International Airport in Kenya has mitigated the airport’s carbon footprint by using a green, renewable energy system. The study’s qualitative data was examined by document analysis. The case study revealed that Moi International Airport has installed a photovoltaic (PV) solar system with a 500kW capacity that is used to primarily provide solar power at the airport’s apron area. The photovoltaic (PV) solar system has delivered Moi International Airport with an important environmental related benefit as it has enabled the airport to reduce it carbon footprint, as the photovoltaic (PV) solar system has reduced the airport’s carbon dioxide (CO2) emissions by an estimated 1,300 tonnes per annum.

Schedule Planning and Maintenance Activities Auxiliary Power Unit (APU) Boeing 737-500 Aircraft With Reliability Method

Penelitian ini bertujuan untuk merencanakan jadwal dan aktifitas maintenance yang yangefektif pada sistem auxiliary power unit sehingga tidak terjadi lagi kegagalan ataupun kerusakan yang tidak di rencanakan atau terjadi secara tiba – tiba. Kegagalan pada peralatan auxiliary power unit ada sering terjadi pada beberapa sistem kerja yaitu electrical system, Lubrication System dan Ignition System, di mana hal ini menimbulkan kerugian yang cukup besar bagi perusahaan penerbangan. Metode penelitian ini menggunakan pendekatan kualitatif dan kuantitatif, analisis kualitatif menggunakan metode Failure Mode Effect and Critically Analysis (FMECA) dengan menganalisis faktor – faktor penyebab kegagalan dan efek terjadinya kegagalan, dengan hasil penyebab kegagalan pada beberapa sitem kerja auxiliary power unit (APU) adalah sebagai berikut electrical system adalah pada komponen start Relay, Lubrication System adalah pada komponen Oil Filter, Ignition System adalah pada igniter plug. Dari hasil analisis FMECA tersebut di lakukan analisis kuantitatif dengan analisis dilakukan menggunakan metode reliability, parameter kehandalan dihitung dengan probabilitas distribusi Weibull, untuk menentukan batas kritis waktu operasional komponen ataupun part sistem yang merupakan batas kehandalan suatu sistem auxiliary power unit. Batas kritis operasional electrical system adalah sebesar 434 jam terbang, lubrication system adalah 1186 jam terbang, dan Ignition system adalah sebesar 1610 jam terbang, selanjutnya hasil tersebut di gunakan untuk menentukan jadwal maintenance yang efektif di dukung dengan perencanaan aktifitas maintenance yang tepat untuk menghilangkan penyebab – penyebab kegagalan pada peralalatan auxiliary power unit.

Optimization and realization on the coordination control strategy for auxiliary power unit of range-extended electric vehicle

The auxiliary power unit (APU) is a major power source of range-extended electric vehicle (R-EEV). Excellent coordination control strategy of APU has a great significance impact on improving the overall electrical control system performance of R-EEV. A coordination control strategy based on parameters adapt fuzzy-PID is proposed to ensure the dynamic and static response characteristics of the coordination control system. Firstly, the APU high precision simulation control model is built in GT-Power and Matlab-Simulink. Three coordination control strategies based on traditional PID control method are designed, namely, engine speed control model (ESCM), generator torque control model (GTCM), and APU speed-torque control model (AS-TCM). The three coordination control strategies are simulated on working conditions, which include start-up working condition, power raised working condition, and power reduced working condition. Combined with the PID control principle, the control performance and inherent limitations of three traditional PID control strategies (TPCS) are analyzed and compared. Then, according to the above simulation results of analysis and comparation, the parameters adapt fuzzy-PID control strategy (PAF-PCS) is designed and simulated. The results show that three control parameters ( kp, ki, kd) are changed in real time to ensure the flexibility and adaptability of the control system and improve the stability and robustness of control system. Finally, the results of bench test show that power responds quickly and no oscillation and fixed-point power generation works smoothly, which are basically consistent with the simulation results. Therefore, the PAF-PCS proposed in this paper has good feasibility and effectiveness.

POTENSI SEKAM PADI SEBAGAI BAHAN BAKAR ALTERNATIF PLTBm DI SUMATERA BARAT

Sekam padi merupakan biomassa yang melimpah di Indonesia, salah satunya di Provinsi Sumatera Barat. Provinsi ini merupakan salah satu Provinsi penghasil beras terbesar di luar Pulau Jawa. Pada tahun 2019 Provinsi Sumatera Barat menghasilkan padi sebesar 1.482.996 ton-GKG. Sekam padi merupakan hasil sampingan dari penggilingan padi menjadi beras. Produksi sekam padi pada tahun 2019 di provinsi Sumatera Barat adalah sebesar 370.749 ton, sekitar 25%-nya dari produksi padi. Potensi energi sekam padi di Provinsi Sumatra Barat pada tahun 2019 dengan nilai kalor 13,44 MJ/kg adalah sebesar 4.982.866.594 MJ. Sekam padi sebagai bahan bakar PLTBm mempunyai manfaat mengurangi ketergantungan terhadap sumber energi fosil dan memanfaatkan limbah proses penggilingan padi. Teknologi PLTBm dengan menggunakan alat konversi energi biomassa secara thermal dapat berupa Gasifikasi, pembakaran dan pirolisis. Perhitungan kapasitas terpasang PLTBm diasumsikan menggunakan gasifikasi dengan teknologi pembangkit mesin diesel. Berdasarkan hasil perhitungan kapasitas terpasang PLTBm Provinsi Sumatra Barat adalah sebesar 58,7 MW. Energi listrik gross yang diproduksi PLTBm Provinsi Sumatra Barat adalah sebesar 465.068 MWh. Setelah dikurangi Auxiliary power/house load PLTBm, produksi energi listrik net yang dijual atau dimanfaatkan adalah sebesar 444.140 MWh. Dengan dipasangnya PLTBm maka akan menghasilkan penurunan emisi gas rumah kaca dalam satu tahun sekitar 479.902 ton- CO2 ekivalen.

Studying reliability of marine pump systems by using technical supervision data

The article describes the analysis of the ship systems’ reliability at the stage of the technical design, which is based on the reliability data of individual system elements and mathematical methods of reliability theory. During the ship operation maintenance deficiencies can lead to the equipment failure, which can be prevented by the methods of instrumental diagnostics of system elements, maintenance repairs regardless of the current technical condition, and classification inspection during the ship operation. Collecting the detailed data on changes in the functional reliability of ship mechanical systems, which could confirm or deny the advantages of each of the existing methods is not enough. There has been carried out collecting, processing and analyzing the actual data on the life cycles of various pumps of ship systems at different stages of service life, as well as beyond the designated service life or operating time. There are examined the general ship systems and auxiliary power units of icebreakers and floating structures. The examined equipment has standard pumps with different capacity and efficiency. Service life, assigned resource (operating time), frequency of repair are taken as the criteria of pump reliability and durability. There have been shown the actual life cycles of pumps in dependence of the service life in years on the operating time in hours; in addition, data on the passage of maintenance repairs, maintenance, inspection of the technical condition, as well as replacement or extension of the service life are plotted on the graphs. It has been inferred that some of the pumps in the ship's systems should be replaced before the full resource was developed, while the performance of the systems as a whole was preserved or restored as a result of repairs; some pumps have exceeded their specified resource, but during the technical inspection their operation was extended, the operability of the systems was also preserved.

Humidification-dehumidification desalination process using green hydrogen and heat recovery

We propose the use of green hydrogen as a fuel for a seawater heater in a humidification / dehumidification (HDH) desalination plant to increase its productivity, to allow scaling to large dimensions without negative environmental effects, and to guarantee continuous operation. We develop a mathematical model of the proposed HDH configuration. For operating conditions that guarantee very low NOX production, the fuel consumption is ~0.03 kg of H2 per kg of pure water produced. If the exhaust gases from the seawater heater are used for heat recovery, the GOR of the equipment may increase by up to 39 % in relation to the same equipment operating without heat recovery. The operation cost of freshwater is comparable to the costs obtained by other equipment in the literature. If the water produced in the combustion of hydrogen is condensed during the heat recovery process and then added to the freshwater produced, the production cost is reduced by 20 %. We found that an excess of air in the air+fuel mix beyond the minimum value appropriate for a low NOX generation does not provide significant benefits. The efficiency of the seawater heater has an impact on the production of pure water, but this impact is strongly mitigated by the heat recovery process. Fuel consumption increases proportionally with the decrease in the effectiveness of the heat recovery device, which is a key parameter for optimal performance. A hydrogen heater is also a good alternative as an auxiliary power source to guarantee continuous operation. On sunny hours a H2 heater may be used to increase productivity preheating the seawater, and at night the system could operate 100 % based on H2.

Design of Prototype Aircraft Noise Monitoring System Using Microcontroller

This paper was presented a design of aircraft noise monitoring system using microcontroller. This system is for monitoring noise levels to make it easier to analyze and measure noise that can be accessed remotely. The measurement results are accessed through a browser with IP address access (Internet Protocol) from the local server esp32 and also OLED 0.96 inc. Taking the noise value for 10 seconds with data samples every 1 second with aircraft noise sources consisting of APU (Auxiliary Power Unit), dual pack on and engine motoring. With each noise value of 61.5 dB, 75.6 dB and 82.5 dB.