• Journal of the Korean Institute of Gas
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• v.14 no.6
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• pp.27-30
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• 2010

This paper presents the system design process of district community cooling system using LNG cold energy. The newly developed LNG cooling system includes several heat exchangers, LNG storage tank, thermal mass storage tank, several cold energy storage tanks, gas air-conditioners, compressors, constant pressure regulators, cold energy and hot energy supply pipes. In addition, the gas air-conditioner system is installed to supply not sufficient cold energy due to low level of city gas consumptions during a summer period. This system design is very effective and safe to supply cold energy mass of fresh air by exchanging two thermal masses of an air and 200kcal/kg cold energy of LNG. The district community cooling system with LNG cold energy does not produce CO2 and freon gases in the air.

• Journal of the Korean Institute of Gas
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• v.15 no.3
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• pp.1-5
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• 2011

For the hydrogen liquefaction, the large amount of energy is consumed, because precooling, liquefaction and ortho/para conversion heats should be eliminated. In this paper the basic design and thermal analysis are carried out to reduce the energy consumption by using LNG cold energy for precooling process in hydrogen liquefaction processes. The LNG cold energy utilization for hydrogen precooling enables not only to get energy saving for liquefaction, but to recover the wasted cold energy to sea water at the LNG terminal. The results show that the energy saving rate for liquefaction using LNG cold energy is almost 75% of current industrial hydrogen liquefaction plant. The demand flow-rate of LNG is only 15T/D for 1T/D hydrogen liquefaction.

• Journal of the Korean Institute of Gas
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• v.10 no.4 s.33
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• pp.34-40
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• 2006

This paper provides a fusion technology between a district cooling energy system and an environment conservation policy based on the energy savings and reusable cold energy resources. The district heating and cooling systems are very effective ways for an energy saving, a cost reduction and a safety control. It is necessary to equalize the energy savings and an environmental preservation policy for an improved human lift. A gasification process of a liquefied natural gas, cooling water from deep seawater and an ice water thermal storage system may produce a cold energy. A district cooling system is used to cool an apartment, office buildings and factory facilities with a cooling energy supply pipeline. LNG cooling energy will switch a conventional air-conditioning system, which is operated by on electrical energy and a Freon refrigerant. Coincident with significant clean energy and operating cost savings, LNG cold energy system owen radical reductions in an air-borne pollutant, $CO_2$ and the release of environmentally harmful refrigerants compared with that of the conventional air-conditioning system. This study provides useful information on the fusion technology of a LNG cold energy usage and energy savings, and environmental conservation.

• 에너지협의회보
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• s.11
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• pp.37-43
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• 1989

• Journal of the Korean Institute of Gas
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• v.7 no.4 s.21
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• pp.36-43
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• 2003

This paper provides the possibility of the district cooling system by using a LNG cold thermal energy. A liquefied natural gas provides a plenty of cooling source energy during a gasification of a liquefied natural gas. In recent, an ice thermal storage system is used for cooling a building, and a deep water source cooling system has been introduced as a district cooling system in which is used to cool the office towers and other large buildings in old and new downtown. LNG cooling energy refers to the reuse of a large body of naturally cold fluids as a heat sink for process and comfort space cooling as an alternative of conventional, refrigerant based cooling systems. Coincident with significant clean energy and operating cost savings, LNG cold energy cooling system offers radical reductions in air-borne pollutants and the release of environmentally harmful refrigerants in comparison to the conventional air-conditioning system. This study provides useful information on the basic design concepts, environmental considerations and performance related to the application of LNG cold thermal energy.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.1
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• pp.96-103
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• 2014

A liquefied natural gas(LNG) in cryogenic liquid is converted back into gaseous form for distribution to residential and industrial consumers. In this re-gasification process, LNG supplies a plenty of cold thermal energy about $83.7{\times}10^4kJ/kg$. The LNG cold thermal energy is utilized for the re-liquefaction process of cryogenic fluids such as Nitrogen, Hydrogen and Helium, and ice manufacturing process and air-conditioning system in some advanced countries. Therefore, it is also necessary to establish the recovery systems of the LNG cold thermal energy around Incheon, Pyungtaek and Tongyung LNG import terminals in our country. Methane is used as working fluid in this paper, which is the major component of LNG over 85 % by volume, in order to investigate the flow behavior characteristics of LNG with phase change at low heat flux. This paper presents the effects of pipe diameters, pipe inclinations and saturation pressures on the flow boundaries of methane flowing in a cryogenic heat exchanger tube, together with those of nitrogen, propane, R11 and R134a. The outcomes obtained from this theoretical researches are also compared with previous experimental data. It was also found that the effect of pipe inclination on the methane flow boundaries was significant.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1997.10a
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• pp.3-8
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• 1997

본 연구에서는 복합발전시스템의 외기온도 변화로 인한 출력저하 문제를 극복할 수 있는 LNG 냉열 이용 복합발전 시스템을 제안하였다. 본 연구에 의해 제안된 LNG 냉열 이용 복합발전 시스템의 타당성을 검토하기 위해 ASPEN과 GateCycle을 이용한 시뮬레이션 모델을 구성하였고, 모델에 의해 예측한 결과를 실제 발전소 성능시험결과와 비교하여, 본 시뮬레이션 방법의 예측정확도를 검증하였다. 본 시뮬레이션 방법을 토대로 LNG 냉열을 이용하여 가스터빈의 유입공기를 냉각시켰을 경우의 복합발전 시스템 성능변화를 분석하였다. 그 결과 LNG 냉열을 이용하여 유입 공기를 원하는 온도까지 냉각시켜 하절기에도 출력을 일정하게 유지시킬 수 있음을 확인할 수 있었고, 이를 위한 기스터빈과 LNG 간의 열교환기 설계기준도 제시하였다.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.3
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• pp.276-281
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• 2019

The process of separating oxygen and nitrogen from the air is mainly performed by electric liquefaction, which consumes a lot of electricity, resulting in higher operating costs. On the other hand, when used for cold energy of LNG, electric power can be reduced compared to the electric Linde cycle. Currently, LNG cold energy is used in the cold refrigeration warehouse, separation of air-liquefaction, and LNG cold energy generation in Japan. In this study, the system using LNG cold energy and the Linde cycle process system were simulated by PRO/II simulators, respectively, to cool the elevated air temperature from the compressor to about $-183^{\circ}C$ in the air liquefaction separation process. The required amount of electricity was compared with the latent heat utilization fraction of LNG, the LNG supply pressure, and the LNG cold energy usage. At the air flow rate of $17,600m^3/h$, the power source unit of the Linde cycle system was $0.77kWh/m^3$, compared with $0.3kWh/m^3$.

• Journal of the Korean Institute of Gas
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• v.24 no.4
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• pp.56-61
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• 2020

For the hydrogen liquefaction, the large amount of energy is consumed, due to precooling, liquefaction and o-p conversion processes. The aim of this work is to improve the performance of hydrogen liquefaction process by introducing the new energy saving processes, that are the liquid nitrogen precooling process by using LNG cold energy, and the new design of cold box insulation using cold air circulation. The results show that the indirect use of LNG cold energy in precooling process enables not only to get energy saving, but to make safer operation of liquefaction plant. In new cold box, the energy loss of equipments could be reduced by nearly 35%~50% compared to the present perlite insulation, if insulation structure is organised as 3mm steel wall/20cm PUF/5cm air/20cm PUF/equipment. Additionally the equipments installed in cold box can get cooling effect, if the temperature is higher than the temperature of cold air. The application of this results can gives to increase the liquid yield of about 50% substantially in industrial hydrogen liquefaction plant.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.663-664
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• 2016

Temperature difference power generation using sea water is a method repeatedly closed liquefaction and gasification by using the ammonia (refrigerant) of the deep sea water and surface water with a temperature difference between turning the turbine. The larger the temperature difference between the nature of the temperature characteristic energy generation development, the better. This is the story that the surface waters of the deep-water temperature difference is large. But the winter is not large temperature difference between surface water and deep water has lowered energy efficiency. And desalination technologies accounted for 97% of the earth, but we can not eat the technology to convert sea water into fresh water, fresh water produced by the desalination technology that is available for various industries such as irrigation, drinking water in the vessel.In this paper, LNG transport vessels, based on the LNG transport ship to the temperature difference power generation using cold energy of thermal energy and LNG marine diesel engines, which use the existing order to improve the temperature of the surface waters of the season that is the current problem we propose that a complex development of desalination and desalination of seawater freezing research into hybrid research and utilizing the cold energy of the engine.