• Transactions of the Korean hydrogen and new energy society
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• v.25 no.3
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• pp.255-263
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• 2014

This paper deals with a construction plan of hydrogen fueling stations on express highways using geographic information system. We analyzed the existing hydrogen fueling stations and production facilities to construct the hydrogen supply system to satisfy the hydrogen demands. Also, we suggested the necessary number and locations of hydrogen fueling stations on express highways for operating fuel cell vehicles. As a result, we need to construct at least 6 hydrogen stations on express highways in 2020 and 14 hydrogen stations in 2025. In 2030, when fuel cell vehicles are expected to spread over the whole nation, 114 hydrogen stations are needed to construct on express highways. This study mainly utilized the information of distances between hydrogen production facilities and fueling stations. However, we need to analyze the other factors such as traffic and income data. Also, it is necessary to make a suitable construction plan of hydrogen fueling stations that should be constructed on each district using geographic information system.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.5
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• pp.447-455
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• 2023

SAE J2601, hydrogen fueling protocols, proposes two charging methods. The first is the table-based fueling protocol, and the second is the MC formula-based fueling protocol. Among them, MC formula-based fueling protocol calculates and supplies the target pressure and pressure ramp rate (PRR) using the pre-cooling temperature of the hydrogen and the physical parameters of the tank in the vehicle. The coefficient of the MC formula for deriving MC varies depending on the physical parameters of the tank in the vehicle. However, most studies use the MC coefficient derived from SAE J2601 as it is, despite the difference in the physical parameters of the tank applied to the study and the tank used to derive the MC coefficient from SAE J2601. In this study, the MC coefficient was derived by applying the hydrogen tank currently used, and the difference with the fueling performance using the MC coefficient proposed in SAE J2601 was verified. In addition, the difference was confirmed by comparing and analyzing the fueling performance of the table-based method currently used in hydrogen fueling stations and the MC formula-based method using MC coefficient derived in this study.

• Journal of Drive and Control
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• v.19 no.2
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• pp.36-44
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• 2022

Hydrogen energy as an alternative source of energy has been receiving tremendous support around the world, and research is being actively conducted accordingly. However, most of the studies focus on hydrogen storage tanks and only are few studies on interpreting the hydrogen filling system itself. In this study, with reference to SAE J2601, a hydrogen fueling protocol, a simulation model was developed that can confirm the behavior of the vehicle's internal tank during hydrogen fueling. With respect to factors such as fuel supply temperature, ambient temperature, and pressure increase rate, the developed model can check the change of temperature and pressure in the tank and the state of hydrogen charging during hydrogen fueling. The validity of the developed simulation model was confirmed by comparing the simulation results with the experimental results presented in SAE J2601.

• Journal of the Korean Vacuum Society
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• v.16 no.6
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• pp.489-495
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• 2007

The assembly of the main system of the KSTAR tokamak has been recently completed, and the preparation for the 1st plasma and test operations is progressed. The fueling system established for these purposes uses only one port placed at the opposite side of the pumping duct, and has a difficulty of attaining a uniform and fast supply of fuel particles to the plasma. At the base operation stage after finishing the test operation, the fueling system must be improved to provide a uniform fueling and a feed-back control in accordance with a high-density tokamak plasma maintained for a long period. As a part for understanding the points to be improved in the fueling system, a Monte Carlo simulation on the gas fueling into the tokamak plasma has been executed. After modeling the vacuum vessel and the plasma of quasi-D shapes as tori of rectangular cross-sections, the influences of the position and the number of the fueling inputs on the particle density distribution for a given pumping probability and mean free path were investigated.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.682-688
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• 2023

In this paper, analyzes the type of failure and its effect on the hydrogen fueling nozzle used in hydrogen station. Failure of hydrogen fueling nozzle was analyzed using a qualitative risk assessment method, failure mode and effect analysis. The failure data of hydrogen fueling nozzles installed in domestic hydrogen stations are collected, and the failure types are classified, checked the main components causing the failure. Criticality analysis was derived based on frequency and severity depending on the failure mode performed. A quality function is developed by a performance test evaluation item of the hydrogen fueling nozzle, and the priority order of design characteristics is selected. Through the analysis results, the elements to improve the main components for enhancing the quality and maintenance of the hydrogen fueling nozzle were confirmed.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.331-336
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• 2001

Theoretical approach was taken to the whole CNG refueling process. In particular, this study was focused on the prediction of flow rate at any given piping configuration of CNG system, in order that a simulation program for the CNG refueling system should be developed. The simulation result of refueling process was compared with experimental result obtained from various kinds of fueling configuration. The simulation results showed a satisfactory agreement within 10% errors in fueling time, fueling amount, and residual pressure. The developed program would be used a good engineering tools for estimating fueling performance for a any given CNG station.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.5
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• pp.356-364
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• 2021

During the hydrogen fueling process, hydrogen temperature inside the compressed tank were limited below 85℃ due to the allowable pressure of tank material. The chiller system to cool compressed hydrogen used R407C, greenhouse gas with a high global warming potential (GWP), as a refrigerant. To reduce greehouse gas emission, it should be replaced by refrigerant with a low GWP. This study proposes a chiller system for fueling hydrogen with R290, consisted in propane, by applying the C3 pre-cooled system use d in the LNG liquefaction process. The proposed system consisted of hydrogen compression and cooling sections and optimized the operating pressure through exergy analysis. It was also compared to the exergy efficiency with the existing system at the optimal operating pressure. The result showed that the optimal operating pressure is 700 kPa in 2-stage, 840 kPa/490 kPa in 3-stage, and the exergy efficiency increased by 17%.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.103-109
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• 2009

Aircraft fuel cost is the largest airline expenses in airlines who play a major role in air transportation system. Airlines have been making a great effort to save fuel as much as they can. Among these efforts, the systematic fueling strategy has been taken a growing attention since it is recognized as a very cost-effective fuel management strategy. The systematic fueling strategy is the fuel saving strategy in which extra amount of fuel is loaded to utilize the fueling cost differentiation among the cities where the aircraft operate. In this paper, the aircraft fueling optimization model is proposed. The proposed model is to calculate precise amount of loaded fuel to minimize overall fuel cost assuming that the aircraft routing for all aircrafts and fueling cost in all airports where the aircraft fly are given. Compared with heuristic fueling strategy, the result of the proposed model is promising. Therefore, it is expected that the proposed model plays a major role in fuel management strategy in airline operation.

• Journal of the Society of Disaster Information
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• v.18 no.3
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• pp.520-531
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• 2022

Purpose: Based on the risk evaluation of hydrogen fueling stations, this study aims to find a plan to strengthen management safety by examining profitability and management risk, which are major concerns of employers. Method: The risk evaluation was divided into 'acceptable risk' and 'allowable risk' over time from the stage of installation of hydrogen fueling stations, and compared and analyzed with the results of existing studies. Result: Existing studies have been appropriately applied to the risk assessment performed at the stage of installing hydrogen fueling stations. However, possible risks could be found at the operational stage. In other words, it was derived that an evaluation of management risk was also necessary. And through this, it was confirmed that the safety of hydrogen fueling stations was strengthened. Conclusion: The risk assessment that precedes the stage of installing hydrogen fueling stations is appropriate because significant results have been derived from the 'acceptable risk' assessment. However, the operator needs to evaluate the risks that may occur at the operating stage, that is, the 'allowable risks' and prepare countermeasures. Therefore, it is proposed to add management risk assessment items to build and operate safer hydrogen fueling stations.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.39-39
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• 1999

The KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak is a nuclear fusion experimental device for a long pulse/steady-state plasma operation, adopting fully superconducting magnets. In accordance with completion of the basic design of the torus vacuum vessel and the enclosing cryostat, the vacuum pumping and gas fueling basic design has been developed to fulfil the physics requirements. The ultra-high vacuum pumping and sophisticated gas fueling system of the machine is essential to achieve such roles for optimized plasma performance and operation. Recently the vacuum exhaust system using dedicated pumping ports for the vacuum vessel and cryostat has been modified to meet more reliable and successful performance of the KSTAR[Fig. 1].In order to achieve the required base pressure of 5 x 10-9 torr, the total impurity load to the vessel internal is limited to ~5 x 10-5 torr-1/x, while the cryostat base pressure is kept as ~5 x 105 torr to mitigate the thermal load applied to the superconducting magnets. Each KSTAR fueling system will be separately capable of fueling gas at a rate of 50 torr-1/x, consistent with the given pumping throughput. In order to initiate a plasma discharge in KSTAR, the vacuum vessel is filled to a gas pressure of few 10-6 to few 10-4 torr, and additional gas injection is required to maintain and increase the plasma density during the course of the discharge period.