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Park E.-S.,Korea Institute of Geoscience and Mineral Resources | Jung Y.-B.,Korea Institute of Geoscience and Mineral Resources | Song W.-K.,Korea Institute of Geoscience and Mineral Resources | Lee D.-H.,SK Engineering and Construction Co. | Chung S.-K.,Korea Institute of Geoscience and Mineral Resources
Engineering Geology | Year: 2010

This paper reports the background information and the initial results obtained from the pilot underground LNG (liquefied natural gas) storage cavern in Korea, where all natural gas is stored in the condition of liquid phase. Many attempts have been made in the past to store LNG underground in unlined containment, though without success. A new concept for storing LNG in a lined rock cavern has been developed to provide a safe and cost-effective solution. It consists of protecting the host rock against the extremely low temperature and providing a liquid and gas tight liner. One of the most significant problems related to underground storage of cryogenic material is the need to prevent the leakage of liquid and gas from the containment system to the rock mass caused by tensile failures due to shrinkage of the rock mass around the caverns. In order to verify the technical feasibility of this storage concept, a pilot plant was constructed for storing Liquefied Nitrogen and has been in operation since January 2004, though has now been decommissioned. The overall monitored results from the pilot operations confirmed that the construction and operation of underground LNG storage in lined rock caverns is technically feasible for a rock engineering point of view. The results of this study may promote the first ever real scale underground LNG storage system in a rock cavern in the world. © 2010.

Jung Y.-B.,Korea Institute of Geoscience and Mineral Resources | Park E.-S.,Korea Institute of Geoscience and Mineral Resources | Chung S.-K.,Korea Institute of Geoscience and Mineral Resources | Kim H.-Y.,SK Engineering and Construction Co.
Engineering Geology | Year: 2011

A new method of storing LNG (Liquefied Natural Gas) in a lined, hard rock cavern has been developed and verified by the construction and operation of a pilot plant in Korea. Creation of an ice ring is one of the core techniques in LNG storage in a lined rock cavern. The ice ring serves not only as a primary barrier against the intrusion of groundwater into an LNG cavern, but also as a secondary protection in case of leakage of LNG. Dry conditions within an ice ring protect a containment system against cracking due to the freezing of groundwater. Therefore, it is crucial to estimate and control the thickness and location of the ice ring when designing and operating an underground LNG storage cavern. In order to find suitable numerical scheme that simulates field results, the behavior of the ice ring around the pilot LNG cavern is investigated by hydro-thermal-coupled analyses. Through coupled analyses composed of three cases (CASE_1: constant thermal properties, CASE_2: temperature-dependent thermal properties, and CASE_3: phase change consideration in addition to CASE_2), the position and thickness of the ice ring, the temperature distributions and the groundwater level around the cavern are estimated and compared with measured data obtained from the pilot LNG cavern. The results show that the temperature distribution and groundwater level around the LNG cavern can be estimated reliably within an error of less than 4 °C and 1.0. m, respectively. The accuracy of numerical modeling is increased when the temperature-dependent properties are taken into account. The effect of phase change during freezing and thawing of groundwater is relatively small due to the dryness inside the ice ring and low porosity of the rock mass. These results imply that the adopted numerical method can be applied to full-scale underground LNG caverns for the control of the ice ring. © 2010 Elsevier B.V.

Lee C.,Chonnam National University | Hong S.-J.,Seoul Development Institute | Kim D.,SK Engineering and Construction Co | Lee W.,Korea University
Marine Georesources and Geotechnology | Year: 2015

A series of 1-D consolidation tests are performed on the undisturbed and remolded specimens for Busan and Incheon clays in order to propose empirical correlations predicting the compression index of natural clays. For both clays, the compression index is found to correlate best with wnand to have the weakest correlation with ILamong the four soil properties (wL, Ip, wn, IL). It is observed that, for Incheon clay, the multi-variable equation (wLand wn) moderately improves the accuracy of the empirical correlation, while, for Busan clay, it provides negligible improvement compared with the equations with a single soil property. In this study, the sedimentation state of natural clay is defined as the difference in the void ratio between the natural and remolded clays at yield stress (Δer,), and the prediction equations that can consider the sedimentation state are suggested. It is noted that, for Busan clay, the equations considering the sedimentation state provide a significantly better accuracy than the equations with multiple soil properties, whereas, for Incheon clay, both types of equations provide a similar accuracy. © 2015, Taylor & Francis Group, LLC.

Kwon K.,Sogang University | Hwang Y.H.,SK Engineering and Construction Co. | Kang H.,Sogang University | Kim D.,Sogang University
Transactions of the Korean Society of Mechanical Engineers, B | Year: 2013

In this study, we performed a numerical study of hydrogenfair combustion in the combustion chambcr of an ultra micro gas turbine. The supply flow rate and equivalence ratio are used as variables, and the commercial computational fluid dynamic program (STAR-CCM) is used for the numerical study of the combustion. The flow rate significantly affccts the flame position, flame temperature, and pressure ratio between the inlet and the outlet. The flame position is closc to the outlet in the combustion chamber, and the flame temperature and pressure ratio monotonously increases with the supply flow rate. The change in the equivalence ratio does not affect the flame position, The maximum flame temperature occurs under stoichiometric conditions. © 2013 The Korean Society of Mechanical Engineers.

Cho J.H.,Gas Technology Center | Ha H.,SK Engineering and Construction Co. | Kim D.-Y.,SK Engineering and Construction Co.
11AIChE - 2011 AIChE Spring Meeting and 7th Global Congress on Process Safety, Conference Proceedings | Year: 2011

A discussion on risks and risk mitigation measures associated with floating LNG (FLNG) projects covers the demand for natural gas; viability of FLNG; importance of enabling technologies; delayed start up of a FLNG and cost overrun; uncertainties of feed gas composition; political risks due to the government policy, laws, tax, political unrest, and strikes; repair-ability of complex and heavy systems; lack of operation experiences of the LNG transfer system; gas quality information; contingency planning; and technology qualification program for LNG transfers. This is an abstract of a paper presented at the 2011 AIChE Spring Meeting & 7th Global Congress on Process Safety (Chicago, IL 3/13-17/2011).

Kim D.-Y.,SK Engineering and Construction Co. | Cho J.H.,SK Engineering and Construction Co. | Woo S.-W.,SK Engineering and Construction Co. | Lee D.-H.,SK Engineering and Construction Co.
10th Topical Conference on Gas Utilization 2010 - Topical Conference at the 2010 AIChE Spring Meeting and 6th Global Congress on Process Safety | Year: 2010

Natural gas consumption is expected to grow significantly in the next decades. The need for building LNG import terminals with significant storage capacity is quite often a critical aspect due to restriction of land in the area of interest and environmental constraints. A new concept for the storage of LNG in underground mined rock caverns has been developed as very efficient in terms of land occupation, environmental and visual impact at ground surface, safety and cost. The concept consists of the combination of two well-proven technologies: the storage of gas and liquid hydrocarbons in underground mined cavern and the membrane containment system used for conventional LNG tanks and ocean carriers. The advantages of underground LNG storage in rock caverns are the following: Safety - storage less vulnerable to external hazards, Security - high protection against terrorism, Footprint - very limited surface impact, Environment - no visual impact, and Size - virtually no limitation of size. This paper describes the concept of storage system and the features of the process. The location flexibility and various unconventional LNG transferring methods to be allied to the Lined Rock Cavern (LRC) System have also been discussed. The unique features of LNG terminal process have been presented with reference to a 450,000 m3 storage and a 750 t/h of send-out capacity. Copyright © (2010) by AIChE.

Lee T.S.,Hanyang University | Kim D.-H.,SK Engineering and Construction Co. | Lee D.W.,Jeju National University
KSCE Journal of Civil Engineering | Year: 2011

This study focuses on developing a competency model for project construction team and project control team service, which are the essential responsibilities of construction companies, in order to provide a basic framework for manpower development including employment, education, performance measurement, and organizational ability improvement. Together, these attributes comprise the basics of human resource management and reflect the key characteristics of construction companies. This study analyzed several previous competency model studies, and derived job competency items from a questionnaire-based survey of corresponding job performers centering on various existing competency items established with respect to the characteristics of construction companies. In addition, through interviews with a specialist group, this study derived weights for setting competency levels and facilitating competency evaluation and formulated a project construction team and project control team affair competency model for construction companies. This study tested the validity of the formulated model by analyzing its correlation with the performance of actual construction projects. © 2011 Korean Society of Civil Engineers and Springer-Verlag Berlin Heidelberg.

Dinh C.,SK Engineering and Construction Co. | Cho J.,SK Engineering and Construction Co. | Yang J.,SK Engineering and Construction Co.
IGT International Liquefied Natural Gas Conference Proceedings | Year: 2010

The main industry concerns for liquefied natural gas (LNG) import regasification terminals are lowering costs while minimizing environmental impacts. There are several options that have been developed to use renewable energy in LNG regasification terminals. One viable LNG vaporization option that can mitigate industry concerns for terminals at some locations is to use ambient air, in combination with heat transfer fluids, as the heat source for LNG vaporization. This paper proposes novel regasification methods that use multi-temperature level (MTL) air heaters to achieve cost savings by reducing the total number of air heater bays. This concept is similar to chilling with multi-temperature refrigerants that use the warmest refrigerants before using the coldest refrigerants. This paper describes how LNG can be heated and then vaporized using cold heat transfer fluid (HTF) before applying hot HTF to save capital cost. Normally, HTFs exit air heaters at constant outlet temperatures in conventional schemes that require narrow temperature approaches to ambient air temperatures. This results in larger air heater heat transfer areas than required. Shifting some of the heating from hot to cold HTF at higher circulation rates increases the temperature approaches and thus reduces the air heater heat transfer areas. This paper discusses economic/technical advantages of MTL air heaters using environmentally friendly HTF systems in conventional shell and tube vaporizers (STV). This paper also discusses the advantages of potassium-based heat transfer fluids which have superior low temperature thermal characteristics and reduced environmental impacts in comparison with heat transfer fluids using conventional, ethylene glycol water- based solutions.

Cho J.H.,SK Engineering and Construction Co. | Ha H.,SK Engineering and Construction Co. | Kim D.-Y.,SK Engineering and Construction Co.
AIChE Annual Meeting, Conference Proceedings | Year: 2011

Energy demand in the next two decades is expected to increase by 50 percent or more, driven by the engine of economic growth. In parallel, the global demand for natural gas is anticipated to grow faster than the overall demand for liquid and fossil fuels. Economical monetization of stranded reserves to the market is key component in order to meet the overall natural gas demand. It is believed that the floating LNG plant is viable and will become industry trend in near future to develop significant associated and non-associated reserves, at deepwater or other remote locations. The development of these stranded reserves is critically dependent on enabling technologies, their relative maturity and cost effectiveness in application. The scale of gas reserves, distance to markets and supply volatility will determine the optimum technology invoked for FLNG. This paper presents risks associated in project development of a medium scale FLNG plant and discusses their risks mitigation.

Woo T.-H.,Seoul National University | Lee S.-H.,SK Engineering and Construction Co.
Energy Sources, Part A: Recovery, Utilization and Environmental Effects | Year: 2012

An earthquake could be a crucial result of nuclear power plants due to the massive power. It is a main point to keep the stability of the system without a radiation material leak from the reactor. For the safety assessment, the system dynamics predict for the random sampling quantification of an earthquake happening due to unexpected characteristics, which is one of the non-linear algorithms. The dynamical information is incorporated with the loop sequence of the time step procedures by the feedback simulations. The plant system factor is the highest value among three factors including estimation and earthquake factors. In the estimation factor, there is the highest value in 2012. In the earthquake factor, there is the highest value in 2028. The maximum value of summation for three factors is in the year 2030, which has the value of 20.52 times (= 389.85/19.00) higher than the initial value and highest than any other value. The tractable quantification for the safety assessment is obtained by a computer package. © 2012 Copyright Taylor and Francis Group, LLC.

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