Korea, Democratic People's Republic of
Hydrogen Economy Roadmap of Korea
Jan 2019
Publication
Hydrogen economy" refers to an economy where hydrogen is an important environmentally-friendly energy source brings out radical changes to the national economy and society as a whole and is a driving force behind economic growth.<br/>As hydrogen is not only a driver of innovative growth but also a means of using energy in a more eco-friendly way a hydrogen economy refers to the pursuit of a society that realizes the unlimited potential of hydrogen.<br/>This document summarises Korea's roadmap towards a hydrogen economy the expected benefits for both economic and environmental factors and the potential limitations. It also emphasises Korea's vision going forward on fuel cells hydrogen production hydrogen storage and transport and the hydrogen ecosystem as a whole.
Modeling and Economic Operation of Energy Hub Considering Energy Market Price and Demand
Feb 2022
Publication
This paper discusses the economic operation strategy of the energy hub which is being established in South Korea. The energy hub has five energy conversion devices: a turbo expander generator a normal fuel cell a fuel cell with a hydrogen outlet a small-scale combined heat and power device and a photovoltaic device. We are developing the most economically beneficial operation strategy for the operators who own the hub without making any systematic improvements to the energy market. First sixteen conversion efficiency matrices can be achieved by turning each device (except the PV) on or off. Next even the same energy must be divided into different energy flows according to price. The energy flow is controlled to obtain the maximum profit considering the internal load of the energy hub and the price fluctuations of the energy market. Using our operating strategy the return on investment period is approximately 9.9 years which is three years shorter than that without the operating strategy.
Numerical Study on Optics and Heat Transfer of Solar Reactor for Methane Thermal Decomposition
Oct 2021
Publication
This study aims to reduce greenhouse gas emissions to the atmosphere and effectively utilize wasted resources by converting methane the main component of biogas into hydrogen. Therefore a reactor was developed to decompose methane into carbon and hydrogen using solar thermal sources instead of traditional energy sources such as coal and petroleum. The optical distributions were analyzed using TracePro a Monte Carlo ray-tracing-based program. In addition Fluent a computational fluid dynamics program was used for the heat and mass transfer and chemical reaction. The cylindrical indirect heating reactor rotates at a constant speed to prevent damage by the heat source concentrated at the solar furnace. The inside of the reactor was filled with a porous catalyst for methane decomposition and the outside was surrounded by insulation to reduce heat loss. The performance of the reactor according to the cavity model was calculated when solar heat was concentrated on the reactor surface and methane was supplied into the reactor in an environment with a solar irradiance of 700 W/m2 wind speed of 1 m/s and outdoor temperature of 25 °C. As a result temperature methane mass fraction distribution and heat loss amounts for the two cavities were obtained and it was found that the effect on the conversion rate was largely dependent on a temperature over 1000 °C in the reactor. Moreover the heat loss of the full-cavity model decreased by 12.5% and the methane conversion rate increased by 33.5% compared to the semi-cavity model. In conclusion the high-temperature environment of the reactor has a significant effect on the increase in conversion rate with an additional effect of reducing heat loss.
A Study on the Prediction of the Temperature and Mass of Hydrogen Gas inside a Tank during Fast Filling Process
Dec 2020
Publication
The hydrogen compression cycle system recycles hydrogen compressed by a compressor at high pressure and stores it in a high-pressure container. Thermal stress is generated due to increase in the pressure and temperature of hydrogen in the hydrogen storage tank during the fast filing process. For the sake of safety it is of great practical significance to predict and control the temperature change in the tank. The hydrogen charging process in the storage tank of the hydrogen charging station was studied by experimentation and simulation. In this paper a Computational Fluid Dynamics (CFD) model for non-adiabatic real filling of a 50 MPa hydrogen cylinder was presented. In addition a shear stress transport (k-ω) model and real gas model were used in order to account for thermo-fluid dynamics during the filling of hydrogen storage tanks (50 MPa 343 L). Compared to the simulation results with the experimental data carried out under the same conditions the temperatures calculated from the simulated non-adiabatic condition results were lower (by 5.3%) than those from the theoretical adiabatic condition calculation. The theoretical calculation was based on the experimentally measured pressure value. The calculated simulation mass was 8.23% higher than the theoretical result. The results of this study will be very useful in future hydrogen energy research and hydrogen charging station developments.
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