• Title/Summary/Keyword: ORC

Search Result 127, Processing Time 0.025 seconds

Cycle Analysis and Experiment for a Small-Scale Organic Rankine Cycle Using a Partially Admitted Axial Turbine (부분분사 축류형 터빈을 이용한 소규모 유기랭킨 사이클의 실험 및 예측에 관한 연구)

  • Cho, Soo-Yong;Cho, Chong-Hyun
    • The KSFM Journal of Fluid Machinery
    • /
    • v.18 no.5
    • /
    • pp.33-41
    • /
    • 2015
  • Organic Rankine cycle (ORC) has been used to generate electrical or mechanical power from low-grade thermal energy. Usually, this thermal energy is not supplied continuously at the constant thermal energy level. In order to optimally utilize fluctuating thermal energy, an axial-type turbine was applied to the expander of ORC and two supersonic nozzle were used to control the mass flow rate. Experiment was conducted with various turbine inlet temperatures (TIT) with the partial admission rate of 16.7 %. The tip diameter of rotor was to be 80 mm. In the cycle analysis, the output power of ORC was predicted with considering the load dissipating the output power produced from the ORC as well as the turbine efficiency. The predicted results showed the same trend as the experimental results, and the experimental results showed that the system efficiency of 2 % was obtained at the TIT of $100^{\circ}C$.

Selection of Working fluid for the Organic Rankine Cycle to Utilize Low-Temperature Waste Heat (저온 폐열을 이용하기 위한 유기랭킨 사이클의 작동유체 선정에 관한 연구)

  • Cho, Soo-Yong;Cho, Chong-Hyun
    • New & Renewable Energy
    • /
    • v.10 no.4
    • /
    • pp.36-46
    • /
    • 2014
  • Low-grade heats are wasted even though an amount of their energy is huge. In the small and medium industrial complex sites, large amount of low-grade thermal energy generated during the manufacturing process is wasted if it is not used directly for building heating or air-conditioning. In order to utilize this waste thermal energy more efficiently, organic Rankine cycle (ORC) was adopted. The range of operating temperature of ORC was set to $60^{\circ}C$ from $30^{\circ}C$ applicable low-temperature waste heat. A study was conducted to select an appropriate organic working fluid based on these operating conditions. More than 60 working fluids were screened. Eleven working fluids were selected based on the requirements as working fluid for ORC such as environmentally friendly, safety, and good operation on the expander. Finally, six working fluids were selected by considering the operating temperature ranges. Then, a cycle analysis was conducted with these six working fluids. As a results, R-245fa and R-134a appeared as appropriate working fluids for ORC operating at low-temperature condition based on the system efficiency and the turbine output power.

Effects of Working Fluids on the Performance Characteristics of Organic Rankine Cycle (ORC) Using LNG Cold Energy as Heat Sink (LNG 냉열을 열싱크로 이용하는 유기랭킨사이클(ORC)의 작동유체에 따른 성능 특성)

  • Kim, Kyoung Hoon;Ha, Jong Man;Kim, Kyung Chun
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.25 no.2
    • /
    • pp.200-208
    • /
    • 2014
  • This paper presents thermodynamic performance analysis of organic Rankine cycle (ORC) using low temperature heat source in the form of sensible energy and using liquefied natural gas (LNG) as heat sink to recover the cryogenic energy of LNG. LNG is able to condense the working fluid at a very low condensing temperature in a heat exchanger, which leads to an increased power output. Based on the mathematical model, a parametric analysis is conducted to examine the effects of eight different working fluids, the turbine inlet pressure and the condensation temperature on the system performance. The results indicate that the thermodynamic performance of ORC such as net work production or thermal efficiency can be significantly improved by the LNG cold energy.

Thermal and Flow Analysis of Organic Rankine Cycle System Pipe Line for 250 kW Grade Waste Gas Heat Recovery (250kW급 폐열회수 시스템용 유기랭킨사이클 배관 열유동해석에 관한 연구)

  • Kim, Kyoung Su;Bang, Se Kyoung;Seo, In Ho;Lee, Sang Yun;Yi, Chung Seob
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.18 no.4
    • /
    • pp.26-33
    • /
    • 2019
  • This study is a thermal and flow analysis of Organic Rankine Cycle (ORC) pipe line for 250 kW grade waste gas heat recovery. We attempted to obtain the boundary condition data through the process design of the ORC, which can produce an electric power of 250 kW through the recovery of waste heat. Then, we conducted a simulation by using STAR-CCM+ to verify the model for the pipe line stream of the 250 kW class waste heat recovery system. Based on the results of the thermal and flow analyses of each pipe line applied to the ORC system, we gained the following conclusion. The pressure was relatively increased at the pipe outside the refracted part due to the pipe shape. Moreover, the heat transfer amount of the refrigerant gas line is relatively higher than that of the liquid line.

Determination of selenium in milk powder by octopole reaction cell ICP-MS (Octopole Reaction Cell이 장착된 ICP-MS에 의한 분유 중 셀레늄의 정량)

  • Cho, Sung-Eel;Kim, Mi-Ju;Kim, Yong-Ha;Min, Young-Keun;Kim, Young-Sang
    • Analytical Science and Technology
    • /
    • v.19 no.3
    • /
    • pp.203-210
    • /
    • 2006
  • The determination of trace selenium in milk powder has been studied by octopole reaction cell(ORC)-ICP-MS. The interferences by polyatomic ions and other concomitant molecular species could be removed remarkably by using $H_2$ as reaction gas in ORC. Compared to the normal mode (no cell gas), the $H_2$ cell gas mode improved the accuracy and precision. The quantitative result was average 102.7% and it was slightly higher than certified standard value of milk powder and the RSD was 7.6%.

Feasibility of a Solar Thermal Organic Rankine Cycle Power Plant for an Apartment Complex with Aspen Plus® (ASPEN PLUS®를 이용한 태양열 유기랭킨사이클 열병합 발전시스템의 공동주택 적합도 분석)

  • Im, Seokyeon;Kim, Hyung-Geun;Yu, Sangseok
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.39 no.4
    • /
    • pp.317-324
    • /
    • 2015
  • In this study, a solar thermal system is designed to provide hot water and electricity for improvement of solar thermal energy availability in an apartment complex. The electricity is generated with Organic Rankine Cycle (ORC) by the solar thermal energy. R134a, R141b and R245fa are selected for operating fluid of the solar thermal ORC system. ORC with R245fa shows the best performance based on the variation of pressure. The irreversibility of component showed that the technology advance of the evaporator ensures a performance improvement. The sensitivity study results indicate that the turbine performance is most effective way to improve the performance of ORC system. An economic analysis showed that approximately 50% more income could be achieved by a solar thermal ORC system with a hot water supply.

A Study on the Refrigerant Characteristics of the Organic Rankine Cycle Power System Using the Waste Heat of the Main Propulsion Engine (선박 주 추진 엔진폐열을 이용하는 고온도차발전시스템의 냉매특성에 관한 연구)

  • Song, Young-uk;Jee, Jae-hoon;Park, Sang-kyun;Oh, Cheol
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.27 no.6
    • /
    • pp.839-845
    • /
    • 2021
  • In this study, it shows the efficiency of each refrigerant through simulation method for ORC (Organic Rankine Cycle) power generation that converts waste heat discarded by ship exhaust into electricity for the purpose of reducing CO2 emission and increasing ship waste heat recovery. by Simulation was performed with waste heat from the exhaust gas which is relatively high temperature and cooling sea water which is relatively low temperature from ships. As a result of the sea water cooling ORC power generating system, efficiency of the working fluid with R717 is highest as a 2.86 % and the next working fluid is R152a, R134a, R143a and R125a.

Effect of Electrochemical Oxidation-Reduction Cycles on Surface Structures and Electrocatalytic Oxygen Reduction Activity of Au Electrodes

  • Lim, Taejung;Kim, Jongwon
    • Journal of the Korean Chemical Society
    • /
    • v.60 no.5
    • /
    • pp.310-316
    • /
    • 2016
  • Oxidation-reduction cycling (ORC) procedures are widely used for cleaning nanoparticle surfaces when investigating their electrocatalytic activities. In this work, the effect of ORC on the surface structures and electrocatalytic oxygen reduction activity of Au electrodes is analyzed. Different structural changes and variations in electrocatalysis are observed depending on the initial structure of the Au electrodes, such as flat bulk, nanoporous, nanoplate, or dendritic Au. In particular, dendritic Au structures lost their sharp-edge morphology during the ORC process, resulting in a significant decrease in its electrocatalytic oxygen reduction activity. The results shown in this paper provide an insight into the pretreatment of nanoparticle-based electrodes during investigation of their electrocatalytic activities.

Thermodynamic Performance Analysis of Ammonia-Water Rankine Cycle and Organic Rankine Cycle Using Cold Energy of LNG (LNG 냉열을 이용하는 암모니아-물 랭킨 사이클과 유기 랭킨 사이클의 열역학적 성능 특성 해석)

  • KIM, KYOUNG HOON
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.31 no.4
    • /
    • pp.363-371
    • /
    • 2020
  • Recently, the technologies to utilize the cold energy of liquefied natural gas (LNG) have attracted significant attention. In this paper, thermodynamic performance analysis of combined cycles consisting of ammonia Rankine cycle (AWR) and organic Rankine cycle (ORC) with LNG Rankine cycle to recover low-grade heat source and the cold energy of LNG. The mathematical models are developed and the effects of the important system parameters such as turbine inlet pressure, ammonia mass fraction, working fluid on the system performance are systematically investigated. The results show that the thermal efficiency of AWR-LNG cycle is higher but the total power production of ORC-LNG cycle is higher.

Thermodynamic Performance Analysis of Regenerative Organic Rankine Cycle using Turbine Bleeding (터빈 추기를 이용한 재생 유기랭킨사이클의 열역학적 성능 해석)

  • KIM, KYOUNG HOON;HWANG, SEON;KIM, MAN-HOE
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.26 no.4
    • /
    • pp.377-385
    • /
    • 2015
  • This paper presents a thermodynamic performance analysis of regenerative organic Rankine cycle (ORC) using turbine bleeding to utilize low-grade finite thermal energy. Refrigerant R245fa was selected as the working fluid. Special attention is paid to the effects of the turbine bleeding pressure and the turbine bleed fraction on the thermodynamic performance of the system such as net power production and thermal efficiency. Results show that the thermal efficiency has an optimum value with respect to the turbine bleeding pressure and the net power production is lower than the basic ORC while the thermal efficiency is higher.