• Title/Summary/Keyword: Water Exit Temperature

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Study on the Performance Analysis of an Axial-Type Turbine with Steam Injection (증기가 분사된 축류형 터빈의 성능해석에 관한 연구)

  • Cho, Soo-Yong;Kim, Soo-Yong
    • The KSFM Journal of Fluid Machinery
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    • v.4 no.4 s.13
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    • pp.28-36
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    • 2001
  • Performance analysis is conducted on an axial-type turbine which is used for fire extinction by injecting water or steam into the turbine. Loss models developed by Hacker and Okapuu are applied for predicting the performance of turbine. Pressure loss generated through a turbine is converted to the thermal efficiency, and thermal and gas properties are calculated within a turbine passage. Total-to-total efficiency, total-to-static efficiency, static temperature at the exit of turbine, output power, flow coefficient, blade loading coefficient, and expansion ratio are predicted with changing the amount of injected steam and the rotational speed. The 74 kW class gas turbine developed at KIMM is chosen for performance analysis. The 74 kW class turbine consists of 1 stage like a current developing gas turbine for fire extinction. Water or steam is injected at the end of combustor, and results show that efficiency and output power are dependent on the temperature of injected water or steam and the static temperature at the exit is decreased.

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Dynamic Simulation of Membrane Reactor for WGS Reaction (Water Gas Shift (WGS) 공정에 대한 분리막 반응기의 동적 모사)

  • Oh, Min;Yi, Yong;Hong, Seong-Uk
    • Membrane Journal
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    • v.20 no.3
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    • pp.228-234
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    • 2010
  • In this study, dynamic simulation of membrane reactor was performed for water gas shift reaction and temperature, hydrogen concentration, etc. were investigated as a function of time and position. Simulation results indicated that differences of hydrogen concentration, hydrogen partial pressure, and temperature in the radial direction, were larger in the entrance than in the exit. In addition, the hydrogen flux was the largest in the entrance, where the hydrogen partial pressure difference was the largest, and the conversion of carbon monoxide in the exit was about 0.65.

Test of Heat Recovery Performance of a Microturbine (마이크로터빈의 열회수 성능시험)

  • Jeon, Mu-Sung;Lee, Jong-Jun;Kim, Tong-Seop;Chang, Se-Dong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.8
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    • pp.629-635
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    • 2008
  • Recently, microturbines have received attention as a small-scale distributed power generator. Since the exhaust gas carries all of the heat release, the microturbine CHP (combined heat and power) system is relatively compact and easy to maintain. Generating hot water or steam is usual method of heat recovery from the microturbine. In this work, a heat recovery unit producing hot water was installed at the exhaust side of a 30 kW class microturbine and its performance characteristics following microturbine power variation was investigated. Heat recovery performance has been compared for different operating conditions such as constant hot water temperature and constant water flow rate. In particular, the influence of water flow rate and hot water temperature on the recovered heat was analyzed.

A Preliminary Study on the In-line Concentration Measurement of Absorbent Solution (흡수용액의 In-line 농도측정을 위한 기초연구)

  • 민병혁;황덕용;정시영;구기갑
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.2
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    • pp.152-158
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    • 2003
  • Titration method is one of the widely used methods for the concentration measurement of absorbent ammonia/water. However, this method is inconvenient because the solution should be extracted for the measurement. Moreover, significant error can be introduced by the evaporation of ammonia during the sampling and measuring procedure. In this study a reliable in-line concentration measurement method was proposed. To prove the validity of the concept, a measuring apparatus was designed, built, and tested with water. It is found that the location of flow inlet and exit is important in the measurement accuracy. The flow inlet and exit located in the middle of the test cell showed the best result. By the error analysis, it is expected that the ammonia concentration can be measured within the error of $\pm$0.18% assuming the error of 0.1 K in temperature measurement and 0.1 g in weight measurement.

A numerical study on the flow characteristics and condensed water inflow in the Venturi tube with T-branch tube (T-분지관이 부착된 벤튜리관의 유동특성과 응축수 유입에 대한 수치해석 연구)

  • Kim, S.I.;Park, S.H.;Hwang, J.G.
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.2
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    • pp.173-181
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    • 2019
  • This study was carried out numerically to investigate the flow characteristics in the Venturi tube with $90^{\circ}$ T-branch tube and the inflow of condensed water into the Venturi tube from the branch tube. In this study, the diameter of the branch tube(1, 2, 3mm) and the neck diameter of the Venturi tube(0.3, 0.9, 1.5mm) were varied. The flow rate of the water at the Venturi tube inlet is 80cc/min and the water temperature is 288K. The condensed water temperature at the branch tube inlet is 355K. It was found that the velocity and pressure of the fluid near the branch point in the Venturi tube were more dependent on the diameter of the Venturi tube than the diameter of the branch tube. The temperature of the mixed water at the exit of the Venturi tube was the highest when the Venturi tube's neck diameter is 0.9mm and the branch tube diameter is 2mm. This means that the condensed water is flowing well through the branch tube.

A MIXED CORE FOR SUPERCRITICAL WATER-COOLED REACTORS

  • Cheng, Xu;Liu, Xiao-Jing;Yang, Yan-Hua
    • Nuclear Engineering and Technology
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    • v.40 no.2
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    • pp.117-126
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    • 2008
  • In this paper, a new reactor core design is proposed on the basis of a mixed core concept consisting of a thermal zone and a fast zone. The geometric structure of the fuel assembly of the thermal zone is similar to that of a conventional thermal supercritical water-cooled reactor(SCWR) core with two fuel pin rows between the moderator channels. In spite of the counter-current flow mode, the co-current flow mode is used to simplify the design of the reactor core and the fuel assembly. The water temperature at the exit of the thermal zone is much lower than the water temperature at the outlet of the pressure vessel. This lower temperature reduces the maximum cladding temperature of the thermal zone. Furthermore, due to the high velocity of the fast zone, a wider lattice can be used in the fuel assembly and the nonuniformity of the local heat transfer can be minimized. This mixed core, which combines the merits of some existing thermal SCWR cores and fast SCWR cores, is proposed for further detailed analysis.

A Study of Temperature Distribution and Flooding Phenomena of Cathode now Channel in a PEM Unit Fuel Cell (고분자전해질형 단위 연료전지의 공기극 유로 채널 내 온도 분포와 플러딩 현상에 관한 연구)

  • Kim, Han-Sang;Ha, Tae-Hun;Min, Kyoung-Doug
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.101-104
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    • 2006
  • Water management is considered to be one of the main issues to be addressed for the performance improvement of proton exchange membrane (PEM) fuel cell. For good water management, the detailed information on the water distribution inside an operating PEM fuel cell should be available to main an adequate level of hydration in the PEM While avoiding performance decline due to liquid rater flooding. For the PEM fuel cell to be commercially viable as vehicle applications, the flooding on the cathode side should be minimized during the fuel ceil operation. In this study to investigate cathode flooding and its relation with temperature distribution in flow channels, visualization study was performed on the cathode side of a PEM fuel cell. For the direct visualization of temperature field and water transport in cathode flow channels, a transparent cell was designed and manufactured using quartz window. Water transport and its two-phase flow characteristics in flow channels were investigated experimentally. Also, the visualization of temperature distribution In cathode flow channels was made by using IR camera. Results indicated that the temperature rise near the exit of cathode flow channel was found. It is found that this area corresponds to the flooding area from both temperature and flooding visualization results It is expected that this study can effectively contribute to get the detailed data on water transport linked with heat management during the operation of a PEM fuel cell

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A study on a precision temperature control unit using thermoelectirc module (열전소자를 이용한 정밀 항온 유지 장치에 관한 실험 및 시뮬레이션 연구)

  • Park, Kyung-Seo;Song, Young-Joog;Im, Hong-Jae;Jang, Si-Yeol;Lee, Kee-Sung;Jeong, Jay;Shin, Dong-Hoon
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.1937-1941
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    • 2007
  • During a process of a nanoimprint for manufacturing LCD, a small temperature variation on the LCD glass can cause thermal stress and generate unexpected displacement. To avoid this trouble, a precision temperature control unit using thermoelectric modules is appropriate for nanoimprint processes. The unit consists of an air control system, a cooling water control system, and a power control system. The air control system includes a thermoelectric module, thermocouples measuring temperatures of air and a duct-stale fin, and two air fans. The heat generated by the thermoelectric module is absorbed by the cooling water control system. The power control system catches the temperature of the thermoelectric module, and a PID controller with SCR controls the input power of the thermoelectric module. Temperature control performance is evaluated by experiment and simulation. The temperature control unit is able to control the exit temperature about ${\pm}2^{\circ}C$ from the incoming fluid temperature, and the error range is ${\pm}0.1^{\circ}C$. However, the control time is approximately 30minute, which needs further study of active control

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An Analysis of Flashing Jet Behavior of Pressurized Water (물제트의 노즐 입구온도변화에 따른 증발특성 해석)

  • KIM, BOOSANG;KIM, HAKDEOK;LIM, HEECHANG;SONG, JUHUN
    • Transactions of the Korean hydrogen and new energy society
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    • v.30 no.6
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    • pp.585-592
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    • 2019
  • In this study, a flashing boiling phenomenon of pressurized water jet was numerically studied and validated against an experimental data in the literatures. The volume of fluid (VOF) technique was used to consider two-phase behavior of water, while the homogeneous relaxation model (HRM) model was used to provide the velocity of phase change. During the flashing boiling through a nozzle, a mach disk was observed near nozzle exit because of pressure drop resulting from two-phase under-expansion. The flashing jet structure, local distributions of temperature/vapor volume fraction/velocity, and position of the mach disk were examined as nozzle inlet temperature changed.

A study on the flow charateristics of temperature control valve by pressure compensation (압력 평형식 온도 조절 밸브의 유동특성 연구)

  • Kim, T.-A.;Kim, Youn J.
    • 유체기계공업학회:학술대회논문집
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    • 2001.11a
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    • pp.419-424
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    • 2001
  • TCV(Temperature control valve by pressure compensation) controls temperature constantly, when it is sending steam or high temperature water to heating device of heat exchanger. For designing TCV, the ratio of piston and hole diameters is one of the important design parameters. Numerical analysis is carried out to elucidate the flow characteristics in the TCV with different port areas of cold and hot waters, using the k-$\epsilon$ turbulence model and Cartesian cut-cell method. Numerical results show that the exit flow rate is mainly affected by pressure distribution in the piston.

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