내연기관에 적용하기 위한 10 kW급유기랭킨사이클의 구심 터빈에 관한 실험적 연구

신동길,김영민,류영현 한국마린엔지니어링학회 2018 한국마린엔지니어링학회지 Vol.42 No.4

Internal combustion engines are used as the main power source in various fields. They emit carbon dioxide during the combustion process. Among the various ways to reduce carbon dioxide, one would be to reduce fuel consumption. In this study, we compare and analyze the performance of the radial turbine applied to the expander of the 10 kW class ORC system. Waste heat of the engine is recovered to reduce the fuel consumption of the internal combustion engine. The ORC system was constructed using R134a as the working fluid, and the experiment was conducted. The expander is a permanent magnet synchronous type generator with two poles and an integral radial turbine. The maximum number of revolutions is 100,000 rpm. The expander is the most important core component to improve the efficiency of the ORC system. The heat source of the ORC system can be divided into exhaust heat and cooling water heat. The authors have constructed and tested a high temperature oil boiler to simulate the heat of the individual hot exhaust and a low temperature steam boiler, to simulate the engine coolant heat of the low temperature boiler. 내연기관은 다양한 분야에서 주 동력원으로 사용되고 있는데, 연소과정에서 이산화탄소를 배출한다. 이산화탄소를줄이기 위한 여러 가지 방법 중에서 연료소모량을 줄이는 방법이 있다. 본 연구에서는 내연기관의 연료 소모량을 줄이기 위해서 엔진 폐열 회수를 위한 10 kW급 ORC 시스템의 팽창기로 적용된 구심 터빈 성능을 비교, 분석하였다. R134a 를 작동유체로 사용하여 ORC시스템을 구성하여 실험을 수행하였다. 팽창기는 2극을 가진 영구자석동기 발전기와 일체형 구심 터빈으로서, 최대 회전수는 100,000 rpm 이다. 팽창기는 ORC 시스템의 효율향상을 위해서 가장 중요한 부품이라고 할 수 있다. ORC 시스템의 열원은 배기열과 냉각수열로 구분할 수 있다. 고온 열매체인 배기열을 모사할 수 있는고온 가스 보일러와 저온 열매체인 엔진 냉각수열을 모사할 수 있는 저온 스팀 보일러를 각각 구성하여 실험 하였다.

Design and optimization of multi-component organic rankine cycle using liquefied natural gas cryogenic exergy

Lee, U.,Kim, K.,Han, C. Pergamon Press 2014 ENERGY Vol.77 No.-

In this study, an ORC (organic Rankine cycle) utilizing both low-grade steam from a pulverized coal power plant and LNG (liquefied natural gas) cold exergy is proposed and optimized. The proposed ORC is composed of a pump, a preheater, an evaporator, a superheater, a reheater, a two stage turbine, and a condenser which utilizing LNG as cold sink of the working fluid. The ORC uses R601-R23-R14 ternary mixture as its working fluid and is integrated with a steam cycle as a bottoming cycle. By utilizing the hot and cold exergy of low-pressure steam and LNG that are initially wasted, the ORC is able to generate additional power without consuming fossil fuel. The non-isothermal condensing nature of the ternary mixture working fluid can reduce the exergy loss of the system, and the consequent power generation and efficiency of the ORC are significantly improved. Power generation from the ternary mixture ORC is increased by about 56% and 59% as compared with the pure and binary mixture ORCs, respectively. Important design parameters such as pump discharge pressure, working fluid composition, and turbine inlet and outlet pressure are also optimized to recover the maximum power from the ORC.

Efficacies of Sodium Carboxymethylcellulose, Oxidized Regenerated Cellulose and Vitamin E in Prevention Against Postoperative Adhesion Formation in Dogs

김정은,권영삼,장광호 한국임상수의학회 2010 한국임상수의학회지 Vol.27 No.6

This study was performed to compare the efficacy of the sodium carboxymethylcellulose (SCMC), oxidized regenerated cellulose (ORC), and their combination with vitamin E for the prevention of postoperative adhesions in the dog. Twenty five dogs were randomly divided into five groups ; non-treated group (Control Group), SCMC-treated group (SCMC Group), ORC-treated group (ORC Group), vitamin E and SCMC-treated group (SCMC + E Group),and vitamin E and ORC-treated group (ORC + E group). After laparotomy, 5 abrasions were made to induce intraperitoneal adhesions on the surface of the ileal serosa. The adhesions were occurred in serosa to mesentary (37.6%),serosa to serosa (24%), serosa to omentum (8.8%) and serosa to parietal peritoneum (3.2%). The incidences of adhesions were 92%, 84%, 64%, 56% and 68% in Control, SCMC, ORC, SCMC+E and ORC + E Group, respectively. The adhesion scores in SCMC+E Group were significantly lower than those in the other groups (p < 0.01). In conclusion,this study showed that oral supplements of vitamin E and intraperitoneal administration of 2% SCMC solution were effective on reducing intraperitoneal adhesions in the dog.

Comprehensive assessment of the impact of operating parameters on sub 1-kW compact ORC performance

Jang, Yongtae,Lee, Jaeseon Pergamon 2019 Energy Conversion and Management Vol. No.

<P><B>Abstract</B></P> <P>The heat source and sink temperatures are important external variables that determine the performance of power cycles, such as the ideal Carnot cycle and Rankine cycle. In addition to these external operating variables, variations in the mass flow rate within the system can significantly change the operating characteristics of the power cycle. In this study, the combined effects of these operating variables on the compact Rankine cycle performance were investigated experimentally. A compact ORC with R245fa working fluid and scroll expander was experimentally evaluated at 100–140 °C heat source, 10–30 °C heat sink and 0.042–0.060 kg/s mass flow rate conditions.</P> <P>Comprehensive experiments showed that the external parameters have significant effects on ORC operating temperature and pressure. In particular, the electrical output was well predicted by the parameter of change in the pressure difference rather than the expansion ratio of the expander. It was also found that the mechanical efficiency of expander increased nonlinearly when decreasing the heat source temperature and increasing the pressure difference of expander. The generator efficiency was not affected by the operating parameters as the expander rotational speed was linearly proportional to the electrical power. The maximum system performance showed 0.246 kW electrical output and 1.61% thermal efficiency in contrast to 0.796 kW net fluidic output and 5.72% fluidic thermal efficiency where they were in different conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effects of operating parameters are investigated through compact ORC experiments. </LI> <LI> R245fa and a scroll expander were used for the ORC. </LI> <LI> Expander inlet and outlet pressure difference well predicts ORC electrical output. </LI> <LI> ORC operation and performance characteristics are discussed. </LI> <LI> The strategy to find the optimized operation is proposed for high ORC performance. </LI> </UL> </P>

Dual parallel organic Rankine cycle (ORC) system for high efficiency waste heat recovery in marine application

Yun, Eunkoo,Park, Hyunjun,Yoon, Sang Youl,Kim, Kyung Chun Korean Society of Mechnical Engineers 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.6

<P> A dual parallel organic Rankine cycle (ORC) system is proposed for the efficient waste heat recovery of marine applications, which present a relatively large variation of waste heat relative to sailing conditions. Simulations for single and dual ORC systems are conducted with a wide range of heat input. The performance results are compared to evaluate the benefits of the proposed dual configuration. Annual total power outputs produced by single and dual ORCs are calculated to assess the appropriateness of applying the dual ORC to a marine engine by using four models of fuel consumption distribution based on the actual sailing data of a container ship. Results demonstrate the ability of dual ORC to produce more total power output than the single ORC. </P>

유기랭킨사이클 적용 스크롤 팽창기 성능 특성 연구

신동길(Dong Gil Shin),김영민(Young Min Kim),김창기(Chang Gi Kim) 대한설비공학회 2011 설비공학 논문집 Vol.23 No.12

The rapid increases in global energy demand and global warming need renewable energy sources such as solar thermal energy, biomass energy and waste heat. A ORC-based micro-CHP system(< 10 kWe) is one of the effective means to use renewable energy and solve energy problems because of its compactness, flexibilities and lower cost compared to other systems. The most important core components of the ORC is the expander which has a strong effect on the cycle efficiency. In the range of power output from 1 to 10 kW, the scroll expander is a good choice due to its performance and reliability. In this study, we have carried out an experimental study on an ORC equipped with oil-free scroll expander working with refrigerant R134a. We have measured power output and thermal efficiencies of the ORC and analyzed correlation between volumetric efficiencies of the expander and thermal efficiencies of the ORC.

고분자 전해질 막 연료전지에 적용된 ORC의 효율에 대한 해석적 연구

김동규(Dongkyu Kim),김선엽(Seonyeob Kim),류진우(Jinwoo Yoo),신동규(Dongkyu Shin),고재선(Jaeseon Ko),송한호(Han Ho Song),김민수(Min Soo Kim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

In order to enhance efficiency of system, many researcher have been studied for reusing wasted heat from system. Several combined systems, such as combined heat and power plant, geothermal ORC system and solar ORC system, have been developed. This paper suggest novel power plant combined polymer electrolyte membrane fuel cell(PEMFC) and organic rankine cycle(ORC). At first, normal PEMFC system model is develpoed which include fuel providing system, air providing system and thermal management system. And then, TMS part is revised to introduce ORC. After proper coolant and capacity is selected for ORC, efficiency of ORC is analyzed. Lastly, influences to PEMFC are also studied.

ORC-OQ²PSK 변조 기반의 근거리 무선통신 시스템에서 기기 간 상호 간섭의 영향 분석

전상엽(Sang Yeop Jeon),김명진(Myoung Jin Kim) 대한전자공학회 2016 전자공학회논문지 Vol.53 No.3

동일한 공간에서 다수의 근거리 무선 네트워크(WPAN)가 작동하는 네트워크 환경을 구축하는 경우 기기 간 간섭의 영향을 고려할 필요가 있다. 사용하는 변조 방식에 따라 인접한 주파수 채널의 간섭 신호가 주는 영향이 차이가 있을 수 있다. 스펙트럼의 부엽이 큰 변조 방식을 사용하는 경우 다른 주파수 채널을 사용하더라도 간섭으로서 영향을 미칠 수 있으며, 간섭원의 공간상 거리에 따라 심각한 성능 저하가 발생할 가능성도 있다. 본 논문에서는 ORC-OQ²PSK 변조 기반의 WPAN에서 인접 주파수 채널을 사용하는 기기로부터의 간섭 영향을 분석하였다. 분석 결과를 기존 GFSK 기반의 WPAN과 비교하여 ORC-OQ2PSK 변조 기반의 WPAN에 대한 타당성 검증을 수행하였다. To establish a network environment where multiple wireless personal area networks(WPAN) are simultaneously operating in the same area, we need to consider the effects of inter-device interference. The extent of interference effect from neighboring frequency channel interferer may be different depending on the modulation types that are used for constructing the wireless network. If a modulation scheme with high spectral side lobes is used, the spatial separation between devices plays a major role in determining the amount of interference from neighboring frequency channel interferer. In this paper, we investigate the effect of inter-device interference in the overlapped raised cosine offset quadrature-quadrature phase shift keying (ORC-OQ²PSK) modulation based WPAN. By comparing the results with those of GFSK modulation based WPAN, we verify the feasibility of ORC-OQ2PSK based WPAN.

ORC-OQ2PSK 변조 기반의 근거리 무선통신 시스템에서 기기 간 상호 간섭의 영향 분석

전상엽,김명진 대한전자공학회 2016 전자공학회논문지 Vol.53 No.3

To establish a network environment where multiple wireless personal area networks(WPAN) are simultaneously operating in the same area, we need to consider the effects of inter-device interference. The extent of interference effect from neighboring frequency channel interferer may be different depending on the modulation types that are used for constructing the wireless network. If a modulation scheme with high spectral side lobes is used, the spatial separation between devices plays a major role in determining the amount of interference from neighboring frequency channel interferer. In this paper, we investigate the effect of inter-device interference in the overlapped raised cosine offset quadrature-quadrature phase shift keying (ORC-OQ2PSK) modulation based WPAN. By comparing the results with those of GFSK modulation based WPAN, we verify the feasibility of ORC-OQ2PSK based WPAN. 동일한 공간에서 다수의 근거리 무선 네트워크(WPAN)가 작동하는 네트워크 환경을 구축하는 경우 기기 간 간섭의 영향을 고려할 필요가 있다. 사용하는 변조 방식에 따라 인접한 주파수 채널의 간섭 신호가 주는 영향이 차이가 있을 수 있다. 스펙트럼의 부엽이 큰 변조 방식을 사용하는 경우 다른 주파수 채널을 사용하더라도 간섭으로서 영향을 미칠 수 있으며, 간섭원의 공간상 거리에 따라 심각한 성능 저하가 발생할 가능성도 있다. 본 논문에서는 ORC-OQ2PSK 변조 기반의 WPAN에서 인접 주파수 채널을 사용하는 기기로부터의 간섭 영향을 분석하였다. 분석 결과를 기존 GFSK 기반의 WPAN과 비교하여 ORC-OQ2PSK 변조 기반의 WPAN에 대한 타당성 검증을 수행하였다.

Evidence of DNA Replication Licensing and Paternal DNA Degradation by MCM7 and ORC2 in the Mouse One-cell Embryo

Chang Jin Kim,Tae Hoon Kim,Eun-Woo Lee,Kyung-Bon Lee 대한의생명과학회 2017 Biomedical Science Letters Vol.23 No.4

This study was investigated to test whether paternal DNA that was destined for degradation was properly licensed by testing for the presence of mini-chromosome maintenance protein (MCM) 7 and origin recognition complex (ORC) 2 in the paternal pronuclei. ORC2 is one of the first licensing protein to come on and MCM7 is one of the last licensing protein to come on. Zygotes were prepared by injection of control and treated sperm injection (ICSI). To control for DNA breakage, epididymal spermatozoa were treated with DNase I to fragment the DNA, then injected into oocytes. The presence of MCM7 and ORC2 in the pronuclei of mouse zygotes was tested by immunohistochemistry, just before the onset of DNA synthesis, at 5 h after fertilization, and after DNA synthesis began, at 9 h post fertilization. We found that in all cases, both MCM7 and ORC2 were present in both pronuclei at 5 h after sperm injection, just before DNA synthesis began. This indicates that no matter how extensive the DNA damage, recruitment of licensing proteins to the origins of replication was not inhibited. Sperm DNA fragmentation does not prevent licensing of DNA replication origins. Furthermore, the embryo recognizes DNA that is damaged by nucleases. Our data indicate that the one-cell embryo does harbor a mechanism to prevent the replication of severely damaged DNA from spermatozoa, even though the embryos do not undergo classical apoptosis.