Storage system for distributed-energy generation using liquid air combined with liquefied natural gas

Kim, Juwon,Noh, Yeelyong,Chang, Daejun Elsevier 2018 APPLIED ENERGY Vol.212 No.-

<P><B>Abstract</B></P> <P>This study proposed a storage-generation system for a distributed-energy generation using liquid air combined with liquefied natural gas (LNG). The system comprised three main sites: the renewable-electricity sources (RESs), liquid-air energy storage (LAES), and natural-gas combustion. The low-priced off-peak electricity generated by the RESs was supplied to the LAES. The supplied electricity and previously stored cold energies liquefied the air. At the on-peak time, the liquid air and LNG were pressurized, re-gasified, and burnt immediately after mixing to generate the high-priced electricity while their cold energy was stored in thermal media. The proposed system was evaluated in terms of the thermodynamic, environmental, and economic performances. Its round-trip and storage efficiencies were 64.2% and 73.4%, respectively. The exergy efficiency of the storage-site, the generation-site, and the system was 70.2%, 75.1%, and 62.1%, respectively. The levelized cost of energy (LCOE) ranged from 142.5 to 190.0 $/MWh depending on the sizes and the storage time. The proposed system was compared to the diabatic compressed air-energy storage (CAES) systems and the adiabatic LAES system. The sensitivity analyses compared the systems for the fixed power output and storage time, and for the option to use natural gas. The proposed system showed better storage and round-trip efficiencies than those of comparison systems. Its LCOE was competitive with those of the compared systems except for the under-ground CAES system. The proposed system was an economic and viable option considering the geographical limitations and the environment impacts of the CAES system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A storage-generation system using liquid air and liquefied natural gas is proposed. </LI> <LI> Round-trip and storage efficiencies of the system are 64.2% and 73.4% respectively. </LI> <LI> Exergy efficiencies of the storage and the system are 70.2% and 62.1% respectively. </LI> <LI> LCOE ranges from 142.5 to 190.0 $/MWh, depending on the sizes and the storage time. </LI> <LI> The proposed system is an economic option without geographical limitations. </LI> </UL> </P>

녹차추출물처리 마른멸치의 저장 중 품질안정성

강수태,오광수,최철용,강진영,윤재웅,조영제 경상대학교 농업생명과학연구원 2008 농업생명과학연구 Vol.42 No.1

To develop the high quality boiled-dried anchovy, the boiled- dried anchovy with green tea extract(BAG) was prepared and examined the storage stability and shelf-life during storage at room temperature and -20℃. The moisture contents of boiled-dried anchovy(TA) and boiled-dried anchovy with green tea extract(BAG) were 22.9% and 22.4%, repectively, and these contents decreased slightly during storage. Also pH of both sample(BAG and TA) were slightly decreased for storage period. The VBN content of TA was increased slightly since then storage at room temperature 10th day and storage at -20℃ 50th day, while BAG was increased very little during storage. The POV contents of BAG and TA showed the highest value 31.4 meq/kg and 77.7 meq/kg at room temperature storage 10th day, and then decreased little by little. In case of -20℃ frozen storage, those showed that highest value 24.8 meq/kg and 47.7 meq/kg in each at storage 50th day and then decreased. The TBA contents of both sample were increased continuously during storage, increasing ratio of TA was higher compared with BAG. In changes of color values of both sample during room temperature storage, L values were decreased and a and b values were increased generally. -20℃ storage revealed a similar tendency, but change ratio were very lower than room temperature storage. From the results of these experiments, the present BAG had a retard effects on interaction with lipid oxidation, and could be reserved a superior storage stability compared with conventional boiled-dried anchovy during experimental storage periods. 우리나라 전통수산건제품인 마른멸치의 고품질화를 위한 연구로서, 녹차추출물을 분무처리한 마른멸치(분무처리 녹차멸치)를 가공하여 상온 및 저온 저장 중 품질안정성과 shelf-life 특성에 대하여 살펴보았다. 상온 및 -20℃ 동결저장 중 일반마른멸치 및 분무처리 녹차멸치의 수분함량은 약간씩 감소하는 경향을 보였으며, pH는 저장기한이 경과할수록 양 시료 모두 약간씩 감소하는 경향을 나타내었다. 일반마른멸치의 경우 휘발성염기질소 함량은 상온저장 10일 및 동결저장 50일째 이후 약간씩 증가하는 경향을 보였으나, 분무처리 녹차멸치는 상온 및 동결저장 기간 중 휘발성염기질소 함량의 증가가 거의 없었다. 상온저장 중 일반마른멸치 및 분무처리 녹차멸치의 과산화물값은 모두 저장 10일경에 각각 77.7 meq/kg 및 31.4 meq/kg으로 최고값을 나타낸 후 감소하였고, 동결저장에서는 저장 50일 경에 각각 47.7 meq/kg 및 24.8 meq/kg으로 최고값을 나타낸 후 점차 감소하는 경향을 나타내었다. TBA값은 양 시료 모두 상온 및 저온저장 중 계속 증가하는 경향을 보이고 있었으며, 일반마른멸치 C의 증가폭이 분무처리 녹차멸치에 비해 월등히 컸다. 상온저장 중 시료 마른멸치의 색조변화는 다소간의 차이는 있으나 대체로 명도는 감소하였고, 적색도 및 황색도는 증가하였다. 동결저장의 경우 상온저장과 유사한 경향을 보이고 있었으나 상온저장에 비해 그 변화폭이 크지 않았으며, 특히 분무처리 녹차멸치는 육색이 안정하게 유지되는 것으로 나타났다. 녹차추출물을 분무처리한 마른멸치는 종래의 일반마른멸치에 비해 상온 및 -20℃ 동결저장 중 지질산화, 갈변 등 품질저하현상이 상당히 억제되었고 품질이 양호하게 유지되었다.

백제왕실(국영) 창고시설의 특징과 운영

소재윤 국립문화재연구원 2012 헤리티지:역사와 과학 Vol.45 No.4

Storage facility of the pre-historic Korea is classified into the subterranean, ground and overground types. The rectangular-shaped subterranean Storage facilities have been identified in the Pungnaptoseong, the Gong mountain fortress site and the Gwanbukri site. Feature no. 196 at Gyeongdang District in Pungnaptoseong yielded a large quantity of glazed potteries, and a wooden storage at the Gwanbukri site contained a large amount of fruit seeds. These storage facilities might be functioned as the warehouse for the highest group rather than the storage for the emergency such as war and flooding and stipend of government officials. This article subdivided into “state storage”on the concept of the former that“ royal storage”on the concept of the latter. If it look on the state storage at large, this include the royal storage too. But it subdivided to help article understand because Baekjae changed from state storage to royal storage by change and specialization of system after 4th. The reason why the diversification of storage pits was closely related to the unification of local polities and the concentration of political power in the state-level. Therefore, it might reflect the political circumstances the ruling elites attempted to heighten their authority in terms of the organizing tax collecting system. And divided the time of storage is confirmed separative storage pits in the suburbs of capital city. There is hight probability of top local polities or nation that have possessional a role. This is to cover on frequent war in the Three States. On the other hand, state storage is located around ancent road that linked castle gate that is divided into center and periphery depending on function and position of storage. Center is located royal storage focusing in the presumed royal palace that periphery is located state storage to provide service to the public. It is presumed that located with the government office. 고대 창고시설은 사용면에 따라 지하식, 지상식, 고상식으로 크게 나누어진다. 이 중 본고에서 다루고자 하는 형식은 평면 장방형의 지하식 창고시설로써 백제 도성지역인 풍납토성, 공산성, 관북리유적 등에서 확인된다. 풍납토성에서는 경당지구 196 호 유구에서 젓갈류를 저장한 시유도기가 다량 출토되었고, 관북리유적에서는 목곽고에서 다량의 과일 씨앗류 등이 출토되었 다. 이는 전란이나 수해 등을 대비한 대민지원이나 관리의 녹봉 등을 위한 창고라기보다 왕실 등 최상위계층에 공급하기 위한 저장시설로 판단된다. 본 논문에서는 전자의 개념을 국영창고로, 후자를 왕실창고로 세분하였다. 국영창고는 국가가 운영하는 모든 창고를 말하는데 광의의 개념으로 보면 왕실창고도 이에 포함된다. 하지만 4세기 전반 이 후 국영 창고에서 왕실 창고 등 창고체제 변화 및 분화가 나타나는 것으로 보이기 때문에 이에 대한 이해를 돕고자 세분하였 다. 창고의 분화가 나타나는 이유는 지역 정치체들의 통합과 국가 권력 집중화가 이루어지면서 일반 읍락으로부터 조세수취를 통해 지배자집단의 권위를 나타내는 것과 연관될 것으로 보인다. 또한 창고의 분화가 나타나기 시작한 시점에는 취락과 별도 의 독립적인 수혈군들이 도성 근교지역에서 확인된다. 이 수혈군은 소유의 주체가 지역 최고의 정치체 혹은 국가일 가능성이 높기 때문에 당시 삼국간 잦은 전쟁에 대비하기 위한 곡식 등의 물자 비축용일 가능성을 제기해보고자 한다. 한편 국영 창고는 성문과 연결된 도로 주변에 위치하는데 창고의 기능 및 위치에 따라 중심권역과 주변권역으로 나누어 볼 수 있다. 중심권역은 추정 왕궁지를 중심으로 하는 왕실창고가 위치하며 주변권역은 상평창과 같은 대민지원 등의 국영창고가 위치했을 것으로 보인다. 그리고 이와 관련된 관청 등의 관리기관이 함께 자리했을 것으로 추정된다.

Knowledge-storage Model for Regional Innovation with Co-creation

Hyun Jong Kim,Soon Goo Hong,Hyung Rim Choi,Min Je Cho 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.1

Co-creation refers to when diverse stakeholders in a community utilize IT to communicate and cooperate in a manner that allows all participants to create new value. To effectively utilize co-creation for regional innovation, knowledge storage is necessary to allow users to solve problems that arise in the community. Therefore, in this study, a knowledge-storage model was developed to systematically store cases of regional innovation and community problem solving, to effectively retrieve the cases required by users, and to utilize co-creation. To this end, a literature review and expert interviews were carried out to analyze user requirements, and the concept, functions, architecture, data structures, and attributes of co-creation knowledge storage were defined. In addition, the processes through which knowledge storage was utilized for regional innovation were presented as a scenario. This study’s contributions include the accumulation of research data related to co-creation knowledge storage for regional innovation and new case-based follow-up studies related to knowledge storage. This study also contributes to practical work by presenting the possibility of local governments or institutions establishing and utilizing knowledge storage to solve problems in regional innovation.

제올라이트를 이용한 화학축열에 대한 실험적 연구

하승호,박정훈,이수헌,김광호 대한설비공학회 2017 설비공학 논문집 Vol.29 No.8

There are three main methods to store heat energy; sensible heat storage, latent heat storage, and thermochemical heat storage. Thermochemical heat storage has the highest storage density among the three methods, so this study focused on the thermochemical heat storage method. Experiments were conducted in this study with Zeolite 13x as thermochemical material in a large-scale reactor with 8 kg of Zeolite 13x. Experiments analyzed storage density of Zeolite 13x with respect to four different heating temperatures (50℃, 100℃, 150℃, 200℃) in heat storage process. As a result, they showed 40~50 percent of storage efficiency in the experiment. Experiments also revealed that reactions between Zeolite 13x and water vapor were reversible and stable, but efficiency of the system was low, compared with sensible heat storage systems or latent heat storage systems.

Long-Term Structural Integrity Evaluation for Wolsong Silo Storage Systems

Kyungho Roh,Sunghwan Chung,Taehyung Na 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

On-site storage facility using concrete silo dry storage systems for spent nuclear fuel at Wolsong NPP site came into operation in 1992 and was expanded four times, and a total of 300 silo dry storage systems are currently in operation. The design lifetime of silo dry storage systems has been licensed for 50 years. As the dry storage systems are subject to time constraints for a limited lifetime, countries operating the dry storage systems are working to ensure the long-term integrity of dry storage systems and IAEA also recommends that the dry storage systems be assessed for long-term storage. To demonstrate the long-term integrity due to material degradation during the licensed design lifetime, the structural integrity of silo dry storage systems was evaluated by considering the material degradation characteristics of concrete. The concrete compressive strength results measured so far by the rebound hammer method, which is an internationally standardized nondestructive test method for converting hardness into compressive strength using the correlation between rebound number and strength at the time of a Schmidt hammer strike, were analyzed in accordance with Wolsong NPP’s procedure to quantify the degradation characteristics, and the prediction of concrete strengths for 20 years and 50 years after construction of the silo dry storage systems was determined, respectively. Based on these residual compressive strengths, structural analyses of the silo dry storage systems were carried out under normal, off-normal and accident conditions of the related regulations, and the structural integrity of silo dry storage systems was reevaluated. It was confirmed the silo dry storage systems are able to maintain structural integrity up to the design lifetime of 50 years even if the concrete is deteriorated.

Prediction of Air Movement and Temperature Distribution at Different Store Methods Using 3-D CFD Simulation in Forced-Air Cooling Facility

Yang, Gil Mo,Koh, Hak Kyun 한국농업기계학회 2002 Agricultural and Biosystems Engineering Vol.3 No.2

Temperature is the most influential environment parameter which affects the quality change of agricultural products in cold storage. Therefore, it is essential to keep the uniform temperature distribution in the storage room. This study was performed to analyze the air movement and temperature distribution in the forced recirculating cold storage facility and to simulate optimum storage method of green groceries using 3-D CFD(three dimensional computational fluid dynamics) computer simulation which applied the standard κ-ε turbulence model and FVM(finite volume method). The simulation was validated by the experimental results for onion storage and the simulation model was used to simulate the temperature and velocity distribution in the storage room with reference to the change of storage method such as location of storage, no stores, bulk storage, and pallet storage. In case of no stores, internal airflow was circulated without stagnation and consequently air movement and temperature distribution were uniform. In case of bulk storage, air movement was stagnated so much and temperature distribution of onion was not uniform. Furthermore, the inner temperature of onion roses more than the initial temperature of storage. In case of pallet storage, air movement and temperature distribution of onion were so uniform that the danger of quality change was decreased.

아파트 규모별 수납 실태 및 거주자 요구 조사

이지순,최연진,박지현,윤정숙 한국주거학회 2002 한국주거학회 논문집 Vol.13 No.6

The purpose of this study was to examine needs of residents on the storage according to unit size in apartment. In order to achieve our goal, the questionnaire survey was used. We sampled the questionnaire surveys of 250 households in Seoul whose apartment sizes had been more than 20 pyung. The data collected by the questionnaire survey was analyzed by examining the frequency, percentage on the SPSS/PC+. The results of the study were obtained as follows: 1) In research on the actual storage condition, Residents tended to feel constraint on the storage of the season goods and the storage satisfaction on the service area was found lowest. Therefore, there needed to design the balcony more efficiently for the storage and the interior storage for the season goods. 2) In research on consciousness and attitude about the storage, residents tended to keep the goods of no use and prefered to arrange neatly rather than use conveniently. Therefore, there needed more efficient space in the balcony for the storage of the goods of no use and the closed furniture rather than the open furniture was suited for arrangement. 3) In research on the storage needs, needs for the built-in furniture in all apartment sizes showed highly and residents wanted a space for the exclusive use of the storage. In a solution, it was proposed to equip with the interior storage and the exterior cooperative storage. In the conclusion, needs of residents on the storage according to apartment size were different little. The small size apartment had the serious storage problems and wanted the efficient space plan for storage.

Energy Geo-Storage − Analysis and Geomechanical Implications

Cesar Pasten,J. Carlos Santamarina 대한토목학회 2011 KSCE JOURNAL OF CIVIL ENGINEERING Vol.15 No.4

The increasing energy demand, the mismatch between generation and load, and the growing use of renewable energy accentuate the need for energy storage. In this context, energy geo-storage provides various alternatives, the use of which depends on the quality of surplus energy. In terms of power and energy capacity, large mechanical energy storage systems such as Compressed Air Energy Storage (CAES) and Pumped Hydro Storage (PHS) are cost-effective and suitable for centralized power generation. In contrast,sensible and latent heat storage are appropriate for distributed applications when excess heat is involved. Energy density estimations highlight the advantages of compressed air over elevated water, and latent heat over sensible heat storage. From a geotechnical standpoint, the operation of geo-storage systems exerts complex effective stress, temperature, wet-dry, and freeze-thaw cycles. Although these excitations may not cause monotonic failure, they lead to ratcheting or shakedown behavior, both of which must be carefully analyzed to ensure the proper long-term cyclic response of energy geo-storage systems.

Prediction of Air Movement and Temperature Distribution at Different Store Methods Using 3-D CFD Simulation in Forced-Air Cooling Facility

Yang, G.M.,Koh, H.K. Korean Society for Agricultural Machinery 2002 Agricultural and Biosystems Engineering Vol.3 No.2

Temperature is the most influential environment parameter which affects the quality change of agricultural products in cold storage. Therefore, it is essential to keep the uniform temperature distribution in the storage room. This study was performed to analyze the air movement and temperature distribution in the forced recirculating cold storage facility and to simulate optimum storage method of green groceries using 3-D CFD(three dimensional computational fluid dynamics) computer simulation which applied the standard $textsc{k}$-$\varepsilon$ turbulence model and FVM(finite volume method). The simulation was validated by the experimental results for onion storage and the simulation model was used to simulate the temperature and velocity distribution in the storage room with reference to the change of storage method such as location of storage, no stores, bulk storage, and pallet storage. In case of no stores, internal airflow was circulated without stagnation and consequently air movement and temperature distribution were uniform. In case of bulk storage, air movement was stagnated so much and temperature distribution of onion was not uniform. Furthermore, the inner temperature of onion roses more than the initial temperature of storage. In case of pallet storage, air movement and temperature distribution of onion were so uniform that the danger of quality change was decreased.