Fuel Transfer System Research Articles

Fault-Tolerant Control of Degrading Systems with On-Policy Reinforcement Learning

We propose a novel adaptive reinforcement learning control approach for fault tolerant control of degrading systems that is not preceded by a fault detection and diagnosis step. Therefore, a priori knowledge of faults that may occur in the system is not required. The adaptive scheme combines online and offline learning of the on-policy control method to improve exploration and sample efficiency, while guaranteeing stable learning. The offline learning phase is performed using a data-driven model of the system, which is frequently updated to track the system’s operating conditions. We conduct experiments on an aircraft fuel transfer system to demonstrate the effectiveness of our approach.

Properties of bioliquids and their impacts on combustion and boiler operation

This study reports the results of a detailed analysis of 203 samples of bioliquid used as a substitute for heavy fuel oil in oil-fired power plants. Bioliquid is a mixture of various vegetable oils, animal fats and its byproducts. The heating value of bioliquid is approximately the same as that of heavy fuel oil; however, bioliquid has significantly less N and S components and exhibits better combustion reactivity.For a commercial electricity generation, demonstration tests firing bioliquid in 75, 90, and 100 MW oil-fired boilers were conducted, and the results were compared with those obtained by firing heavy fuel oil. Further, the impacts of bioliquid fuel characteristics on combustion and boiler operation were also investigated. During the bioliquid firing, the heat absorption in the furnace decreased and the furnace exit gas temperature increased in comparison to the heavy fuel oil firing. No serious problems occurred in the boiler operation, and NOx and SOx emissions remarkably decreased. With minor modifications on the fuel transfer system and atomization devices, bioliquid could successfully replace heavy fuel oil in the existing oil-fired boilers. The limited values for 18 fuel properties of bioliquid are suggested by considering the stable boiler operation and environmental safety.

Analysis of Irradiated Pebble Bed Fuel Transfer System in Hot Cell 101 Radiometallurgy Installation

As the operating body that has authority to construct and operate a non-commercial nuclear reactor in Indonesia, BATAN has decided to develop RDE, an HTGR based nuclear reactor with pebble bed fuels type. As the post-irradiation examination facility, IRM has to prepared and developed PIE for pebble bed fuel in hot cell. Mechanisms and supporting apparatus has to be considered during transfer processes from RDE sites to hot cell. This paper aims to analyze technical design of pebble bed fuel compatibility to existing transfer system in hot cell 101 such as wall-plug and transfer cask dimension, storage rack and fuel remote handling system. Several associated R&Ds on hot cell facility in HTGR countries are reviewed to get safer and simpler transfer system. Based on determined RDE fuels and wall plug dimension, RSG-GAS existing transfer cask can be adopted. Storage rack in hot cell 101 need to be modified and for easier handling by using manipulator, aids need to be added. The technical compatibility based on the results of the study indicates that the hot cell 101 is ready to executePIE of RDE pebble bed fuels.

Reducing the hydrocarbon gas diffusion and increasing the pressure-impact strength of fuel transfer pipelines for use in the automotive industry using radiation crosslinked polyamide 12

The main aim of this study was to reduce the rate of daily hydrocarbons (HC) released into the atmosphere from polyamide-based automotive fuel transfer system pipes due to diffusion using radiation processing technology. The second aim of this study was to improve the pressure level and impact strength of these pipelines. In order to manage these aims, layer by layer extruded pipelines constructed from different types of thermoplastic materials (i.e. PA6, EVOH and radiation crosslinkable 5% 1,3,5-triallyl-1,3,5-triazin-2,4,6(1H,3H,5H)-trion (TAIC) containing PA12 (Creamid-12)) were irradiated using γ-rays (up to 100 kGy) at room temperature to carry out a radiation-induced crosslinking process. The mechanical properties of the samples were evaluated using tensile and cold impact tests. Sol-gel analysis of the irradiated samples was performed to determine the gel content, gelation dose and chain scission/crosslinking ratio. The Charlesby–Pinner and Charlesby–Rosiak equations were used for our calculations. The change in the HC diffusion of the crosslinked pipes was measured using a sealed housing for evaporative determination (SHED) device. An improvement in the pressure resistance was observed for the samples under an increasing fluid pressure using a blasting test device. The SHED results showed that the gas permeability value is reduced ~1.9 fold in the 65 kGy irradiated fuel transfer pipelines. The blasting test results indicate that the average pressure resistivity of the 65 kGy irradiated and 76.5% cross-linked pipe samples was ~19% greater than that observed for the unirradiated samples. The results of this study show that the radiation cross-linking process is an excellent strategy to reduce the daily hydrocarbon emissions from new generation fuel transfer pipelines.

Evaluation of thermal hydraulic safety of a nuclear fuel assembly in a mast assembly of nuclear power plant

We investigated the thermal–hydraulic safety of spent fuel bundles installed in a mast assembly, assuming a lock-up accident of a fuel transfer system. For this, flow analysis with Computational Fluid Dynamics (CFD) for the natural convection and subsequent safety evaluation with 1-D Nuclear Power Plant (NPP) safety analysis code were carried out. Prior to the natural convection analysis for the mast assembly using CFD code, we performed benchmark calculations against two experimental data sets obtained by Betts and Bokhari (2000) and PNL (Pacific Northwest Laboratory, 1980). This was done to select the proper physical models for a natural convection flow analysis and to ensure the reliability of prediction of natural convection flow in the fuel bundle geometry. Finally, we performed a main natural convection analysis for the fuel assembly inside the mast assembly. From this calculation, we observed a stable natural circulation flow between the mast assembly and pool side, and obtained coolant velocity at the inlet of the spent fuel bundle. This flow condition is given as a boundary condition for the 1-D NPP safety analysis code, which is used to predict the Critical Heat Flux and then departure from the nucleate boiling ratio.

Design of long-distance fuel transfer system of underground nuclear power plant WENG song-feng

Design of long-distance fuel transfer system of underground nuclear power plant WENG song-feng

입력성형기법을 이용한 핵연료이송시스템의 수중이동 시의 진동제어

In this paper, residual sway control of objects that are moved underwater is investigated. The fuel transfer system in a nuclear power plant transfers the nuclear fuel rods underwater. The research on the dynamics of the loads transferred in different mediums (water and air) and their control methods have not been fully developed yet. The attenuation characteristics of the fuel transfer system have been studied to minimize its residual vibration by considering the effects of hydrodynamic forces acting on the fuel rod. First, a mathematical model is derived for the underwater fuel transfer system, and then experiments have been conducted to study the dynamic behavior of the rod while it travels underwater. Lastly, the residual vibration at the end point is minimized using the input shaping technique.

A computerized optimization framework for the morphological matrix applied to aircraft conceptual design

This paper presents a formal mathematical framework for the use of the morphological matrix in a computerized conceptual design framework. Within the presented framework, the matrix is quantified so that each solution principle is associated with a set of characteristics such as weight, cost, performance, etc. Selection of individual solutions is modeled with decision variables and an optimization problem is formulated. The applications are the conceptual design of subsystems for an Unmanned Aerial Vehicle and an aircraft fuel transfer system. Both the system models and the mathematical framework are implemented in MS Excel.

스마트무인기 연료계통 제트펌프의 내부 유동 특성에 관한 실험적 연구

The jet pumps are widely used to transfer the fuel between the tanks in an aircraft fuel supply system. However detailed design procedures for determining the size of components of the jet pumps are not known so well. In this paper, the flow characteristics of the jet pump, which is applied in the fuel transfer system for the smart UAV (Unmanned Aerial Vehicle), were experimentally investigated using the acrylic jet pump model for the visualization of the internal flow. The pressure distributions within the jet pump were measured, and then the loss coefficients of each part were calculated. The effects of Reynolds number and the distances (S) between the exit of the primary nozzle and the mixing chamber entrance were investigated. In addition, cavitation phenomena were considered through the flow visualization inside the jet pump. As a conclusion from the experiment, the contraction shape of the primary nozzle has a strong effect on the loss coefficient of the nozzle and the cavitation occurrence. Cavitation starts around the nozzle exit, and then it propagates to the full flow fields of the jet pump.

Optimal Conceptual Design of Aircraft Fuel Transfer Systems

This paper describes early considerations that have to be made when designing an aircraft fuel system. Emphasis is placed on illustrating the impact of top-level aircraft requirements on low-level practicalities such as fuel system design. Choosing between concepts is one of the most critical parts of any design process. Different concepts have different advantages, and the concept that is the best choice is often dependent on the top-level requirements. This paper shows how optimization has been used successfully at Saab Aerospace as a tool that supports concept selection. The example studied is the design of a fuel transfer system for a ventral drop tank and the optimization results in different conceptual designs depending on the top-level requirements.

A Robust Method for Hybrid Diagnosis of Complex Systems

The AI model-based diagnosis community has developed qualitative reasoning mechanisms for fault isolation in dynamic systems. Their emphasis has been on the fault isolation algorithms, and little attention has been paid to robust online detection and symbol generation that are essential components of a complete diagnostic solution. This paper discusses a robust diagnosis methodology for hybrid systems that combines fault detection with a combined qualitative and quantitative fault isolation scheme. We focus on fault detection, symbol generation, and parameter estimation, and illustrate the effectiveness of this method by running experiments on the fuel transfer system of aircraft

Fuel Removal Equipment for Three Mile Island Unit 2

The basic defueling system used at Three Mile Island Unit 2 consisted of (a) a shielded work platform mounted on the reactor vessel, (b) cylindrical canisters suspended from the work platform with intravessel debris loading, (c) dry cask handling of the canisters inside containment from the vessel to the fuel transfer system, (d) wet transfer of canisters from inside containment to the spent-fuel pit, and (e) wet storage in the spent-fuel pit until processed for shipping. Requirements for removing core debris changed substantially as knowledge of actual core conditions was attained, thwarting efforts to anticipate tooling demands. Logistics, operator proficiency, and tooling reliability determined overall productivity. Poor underwater visibility dramatically reduced productivity. Operator training and tool testing on full-scale mock-ups were essential to effective operations. The experience gained in designing and using the various tools is summarized as lessons learned.

Utility Combustion Turbine Evaluation of Coal Liquid Fuels

A comprehensive field test was performed to evaluate the suitability of H-Coal middle distillate and full-range Exxon Donor Solvent (EDS) coal-derived liquids (CDLs) as utility combustion turbine fuels. A Westinghouse W251AA 26 MW combustion turbine operated by the Philadelphia Electric Company was the test engine. No. 2 petroleum distillate fuel was also fired to establish baseline data. This program was sponsored by the Electric Power Research Institute. Site modifications included a temporary CDL storage and fuel transfer system, water storage and injection equipment, an instrumented combustor, engine and emissions instrumentation and data acquisition systems, and industrial hygiene facilities required for the proper handling of the CDLs. The overall results of testing were positive for using such CDL fuels in combustion turbines for power generation. With the exception of higher combustor metal temperatures with the CDLs, and persistent fuel filter plugging with the EDS fuel (which occurred even with increased fuel temperature and filter size), the engine operated satisfactorily during approximately 80 hr of total running over the standard range of load and water injection conditions.