• Title/Summary/Keyword: "drop in" Performance test

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Experimental Ignition Delay Assessment of H2O2 Based Low Toxic Hypergolic Propellants with Variation of Reactive Additive Concentration (반응성 첨가제 농도에 따른 과산화수소 기반 저독성 접촉점화성 추진제의 점화지연 시험평가)

  • Rang, Seongmin;Kim, Kyu-Seop;Kwon, Sejin
    • Journal of Aerospace System Engineering
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    • v.14 no.3
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    • pp.24-31
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    • 2020
  • A study on the H2O2 based low toxic hypergolic propellant was conducted. The fuel candidates were chosen as a mixture of Amine solvent and reactive additive. The analytical performance was calculated via the NASA CEA code and 96% Isp of the NTO/UDMH was confirmed. The ignition delay measurement with drop test was performed and all candidates showed less than 10 ms in the best performance cases. Based on these results, the feasibility of high response H2O2 based low toxic hypergolic propellant was confirmed.

A Study on the Tolerance Band of Voltage Drop during Motor Startup for Refineries and Chemical Plants with Isolated Power Systems

  • Shin, Ho-Jeon;Cho, Man-Young;Chun, Hong-Il;Kim, Jin-Seok
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.486-493
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    • 2017
  • Refineries and chemical plants with isolated power systems that have a limited power supply are more susceptible to voltage changes from disturbances compared to power systems connected with a power company. Furthermore, most loads in such cases are induction motor loads, and therefore, transient voltage characteristics when starting a high-capacity motor must be examined. In general, high-capacity motors are customized appropriately to the load performance curve by the manufacturer during the construction of an industrial plant. Subsequently, when complying with the voltage drop permitted by international standards during the design process, power supply equipment such as transformers and generators is overdesigned. Therefore, a novel analysis is necessary on standards for startup and constraint voltage drops, as well as on identifying the voltage drop limitations for starting high-capacity motors in refineries and chemical plants with isolated power systems. In this study, field tests on an industrial plant were conducted, and simulations modeled under conditions identical to those of the field test system were performed using the general-purpose program ETAP in order to compare the results.

An improved 1-D thermal model of parabolic trough receivers: Consideration of pressure drop and kinetic energy loss effects

  • Yassine Demagh
    • Advances in Energy Research
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    • v.8 no.1
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    • pp.21-39
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    • 2022
  • In this study, the first law of thermodynamics was used to establish a one-dimensional (1-D) thermal model for parabolic trough receiver (PTR) taking into account the pressure drop and kinetic energy loss effects of the heat transfer fluid (HTF) flowing inside the absorber tube. The validation of the thermal model with data from the SEGS-LS2 solar collector-test showed a good agreement, which is consistent with the previously established models for the conventional straight and smooth (CSS) receiver where the effects of pressure drop and kinetic energy loss were neglected. Based on the developed model and code, a comparative study of the newly designed parabolic trough S-curved receiver versus the CSS receiver was conducted and solar unit's performances were analyzed. Without any supplementary devices, the S-curved receiver enhances the performance of the parabolic trough module, with a maximum of 0.16% compared to CSS receiver with the same sizes and mass flow rates. Thermal losses were reduced by 7% due to the decrease in the temperature of the outer surface of the receiver tube. In addition, it has been shown that from a mass flow rate of 9.5 kg/s the heat losses of the S-curved receiver remain unchanged despite the improvement in the heat transfer rate.

Performance Test of Air Filter Media (필터여재의 성능평가)

  • Ahn, K.H.;Bae, G.N.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.6 no.4
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    • pp.417-426
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    • 1994
  • Filter media performance was evaluated using monodisperse NaCl particles with Differential Mobility Analyzer and Ultrafine Condensation Particle Counter. Low or medium performance filters show that the most penetrating particles size(MPPS) is around $0.3{\mu}m$ in diameter and is shifted to smaller sizes as the filter face velocity increases. However, HEPA and ULPA filters show MPPS is around $0.15{\mu}m$ in diameter and is also shifted to $0.1{\mu}m$ in diameter as the face velocity increases. In case of electret filter, the MPPS is found around $0.04{\mu}m$ region for Boltzmann charge equilibrium particles. There is a tendency of strong collection efficiency decrease for large particles as the face velocity increases on the contrary to the other filters. One of the medium performance filter efficiency was compared with filtration theory and the good agreetment was found in the experimental range.

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The Effects of UBM and SnAgCu Solder on Drop Impact Reliability of Wafer Level Package

  • Kim, Hyun-Ho;Kim, Do-Hyung;Kim, Jong-Bin;Kim, Hee-Jin;Ahn, Jae-Ung;Kang, In-Soo;Lee, Jun-Kyu;Ahn, Hyo-Sok;Kim, Sung-Dong
    • Journal of the Microelectronics and Packaging Society
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    • v.17 no.3
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    • pp.65-69
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    • 2010
  • In this study, we investigated the effects of UBM(Under Bump Metallization) and solder composition on the drop impact reliability of wafer level packaging. Fan-in type WLP chips were prepared with different solder ball composition (Sn3.0Ag0.5Cu, and Sn1.0Ag0.5Cu) and UBM (Cu 10 ${\mu}m$, Cu 5 ${\mu}m$\Ni 3 ${\mu}m$). Drop test was performed up to 200 cycles with 1500G acceleration according to JESD22-B111. Cu\Ni UBM showed better drop performance than Cu UBM, which could be attributed to suppression of IMC formation by Ni diffusion barrier. SAC105 was slightly better than SAC305 in terms of MTTF. Drop failure occurred at board side for Cu UBM and chip side for Cu\Ni UBM, independent of solder composition. Corner and center chip position on the board were found to have the shortest drop lifetime due to stress waves generated from impact.

Experimental Study on Heat Transfer Performance of CO2 in a Multi-Tube Type Gas Cooler of Inner Diameter Tube of 1.77 mm (내경 1.77 mm의 다중관식 가스냉각기내 CO2 전열 성능에 대한 실험적 연구)

  • Son, Chang-Hyo
    • Journal of Hydrogen and New Energy
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    • v.19 no.5
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    • pp.439-444
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    • 2008
  • The heat capacity and pressure drop of $CO_2$ and coolant in a multi-tube type gas cooler were investigated experimentally. The main components of the refrigerant loop are a receiver, a $CO_2$ compressor, a mass flow meter, an evaporator and a multi-tube type gas cooler as a test section. The mass flowrate of $CO_2$ and coolant were varied from 0.06 to 0.075 [kg/s], respectively and the cooling pressure of gas cooler were from 8 to 10 [MPa]. The heat capacity of $CO_2$ in the test section is increased with the increment in mass flowrate of coolant, the cooling pressure and mass flowrate of $CO_2$. The pressure drop of $CO_2$ is decreased with the decrease in mass flowrate of coolant and $CO_2$, but decreased with increase in cooling pressure of $CO_2$. The heat capacity of $CO_2$ per unit heat transfer area of gas cooler is greatly high. Therefore, in case of the application of $CO_2$ at the multi-tube type gas cooler, it is expected to carry out the high-efficiency, high-performance and compactness of gas cooler.

A large scale model test to investigate the pressure drop and heat transer characteristics in the air side of two-row heat exchanger (2열 휜 튜브 열교환기의 공기측 압력강하 및 열전달 특성을 고찰하기 위한 확대 모형실험)

  • Gang, Hui-Chan;Kim, Mu-Hwan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.1
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    • pp.113-124
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    • 1997
  • This work is performed to investigate the pressure drop and heat transfer characteristics in the air side of finned-tube heat exchanger for air conditioner. Experimental apparatus and method are described to simulate the heat exchanger performance by using the three times enlarged model. The pressure drop and heat transfer coefficient were measured and compared for the heat exchangers with a plane fin and a commercial strip fin. The measured data for the strip fin agree well with those of prototype within a few percentages. For the plane fin, the measured data had similar trend to Gray & Webb's correlation at high air velocity, however a new correlation is needed to give more accurate prediction at low air velocity. It is found that most heat was transferred around the front row of the two-row heat exchanger, and the ratio of thermal load at the front tube row was increased for decreasing air velocity.

On the Safety and Performance Demonstration Tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and Validation and Verification of Computational Codes

  • Kim, Jong-Bum;Jeong, Ji-Young;Lee, Tae-Ho;Kim, Sungkyun;Euh, Dong-Jin;Joo, Hyung-Kook
    • Nuclear Engineering and Technology
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    • v.48 no.5
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    • pp.1083-1095
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    • 2016
  • The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V&V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V&V, and the performance test results of the model pump in sodiumshowed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

The Frost and Defrost Performances of Fin-and-Tube Heat Exchangers with Different Surface Treatment Characteristics (서로 다른 표면특성을 갖는 핀-관 열교환기의 착상과 제상 성능평가)

  • 최봉준;황준현;신종민
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.10
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    • pp.781-785
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    • 2002
  • The effects of different surfaces on dry and wet frosting test were experimentally investigated. The results of experiment were compared by the performance evaluation coefficient (PEC). Results showed that the air-side pressure drop of lacquer coated evaporator increased by 5% as compared to the plasma treated one. It was also found that the Plasma coated evaporator is lower than lacquer coated one in the PEC ratio.

The Experimental Evaluation of Inorganic Performanent′s Bonding Performance (무기질계 영구거푸집의 부착능력평가를 위한 실험 적 연구)

  • 김용성;강병훈;박선길;김병천;김우재;정상진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.1083-1088
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    • 2001
  • To do performance evaluations about inorganic permanent form mixed in admixture(fly ash, silica fume) and after placed concrete, it is examined reinforcement materials in the permanent form from shear strength, bond strength and flexural strength tests. In this study, permanent form was inserted with reinforcement metal fitting is strength-tested in several method. The result of this study is belows. ⑴ In bond strength test, Most specimens are satisfied with criterion-6 kgf/$cm^{2}$ ⑵ Irrelative with the inserted metal fitting's shape, unevenness and aggregate, Permanent form and after placed concrete have good condition in the shear strength test. ⑶ In flexural test, there is no drop out of permanent form. Most cracks are located in nearby the strain point

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