• Title/Summary/Keyword: Heat pump

Search Result 1,576, Processing Time 0.027 seconds

Modeling and analysis of selected organization for economic cooperation and development PKL-3 station blackout experiments using TRACE

  • Mukin, Roman;Clifford, Ivor;Zerkak, Omar;Ferroukhi, Hakim
    • Nuclear Engineering and Technology
    • /
    • v.50 no.3
    • /
    • pp.356-367
    • /
    • 2018
  • A series of tests dedicated to station blackout (SBO) accident scenarios have been recently performed at the $Prim{\ddot{a}}rkreislauf-Versuchsanlage$ (primary coolant loop test facility; PKL) facility in the framework of the OECD/NEA PKL-3 project. These investigations address current safety issues related to beyond design basis accident transients with significant core heat up. This work presents a detailed analysis using the best estimate thermal-hydraulic code TRACE (v5.0 Patch4) of different SBO scenarios conducted at the PKL facility; failures of high- and low-pressure safety injection systems together with steam generator (SG) feedwater supply are considered, thus calling for adequate accident management actions and timely implementation of alternative emergency cooling procedures to prevent core meltdown. The presented analysis evaluates the capability of the applied TRACE model of the PKL facility to correctly capture the sequences of events in the different SBO scenarios, namely the SBO tests H2.1, H2.2 run 1 and H2.2 run 2, including symmetric or asymmetric secondary side depressurization, primary side depressurization, accumulator (ACC) injection in the cold legs and secondary side feeding with mobile pump and/or primary side emergency core coolant injection from the fuel pool cooling pump. This study is focused specifically on the prediction of the core exit temperature, which drives the execution of the most relevant accident management actions. This work presents, in particular, the key improvements made to the TRACE model that helped to improve the code predictions, including the modeling of dynamical heat losses, the nodalization of SGs' heat exchanger tubes and the ACCs. Another relevant aspect of this work is to evaluate how well the model simulations of the three different scenarios qualitatively and quantitatively capture the trends and results exhibited by the actual experiments. For instance, how the number of SGs considered for secondary side depressurization affects the heat transfer from primary side; how the discharge capacity of the pressurizer relief valve affects the dynamics of the transient; how ACC initial pressure and nitrogen release affect the grace time between ACC injection and subsequent core heat up; and how well the alternative feeding modes of the secondary and/or primary side with mobile injection pumps affect core quenching and ensure stable long-term core cooling under controlled boiling conditions.

An Estimation of Quantity of Unused Energy of River Water, Seawater and Treated Sewage as Heat Source and Its Availability in Large Facilities (대규모 시설에서 이용가능한 미활용 에너지의 부존량과 그 이용 가능성에 관한 조사연구-하천수.해수.하수처리수를 중심으로)

  • Heo, Jae-Yeong
    • Journal of National Security and Military Science
    • /
    • s.1
    • /
    • pp.423-446
    • /
    • 2003
  • While the demand for energy has shown a sharp increase recently, the supply seems to be limited by the fact that the conventional fossil fuel energy or nuclear energy has its own environmental problems such as, for example, global warming or nuclear waste disposal. To overcome such limited supply of energy, the utilization of natural thermal energy such as river water and seawater as well as treated sewage can be a substantial supplement. The potential use of the unused energy has become more and more feasible these days as the heat pump technology has been advanced. In the present study, the unused energy resources are estimated on regional and monthly basis for each resource by the method proposed here in order to establish the fundamental data for its utilization. The potential use of the unused energy is a1so discussed.

  • PDF

A Case Study on the Effective Thermal Conductivity Measurement in In-situ Thermal Response Test (현장열응답시험을 이용한 지중열전도도 측정 사례연구)

  • Kim, Min-Jun;Choi, Choong-Hyun;Woo, Jeong-Tae;Chang, Keun-Sun;Kang, Hee-Jeong;Seo, Jeong-Sik
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2010.11a
    • /
    • pp.123.2-123.2
    • /
    • 2010
  • 본 논문에서는 2008년 4월 이후 지열원 열펌프가 설치되어지는 현장에 시험공의 지중열전도도를 현장열응답법을 이용하여 측정하였으며, 그간에 측정된 지중열전도도를 이용하여 전국의 지중온도 및 지중열전도도의 산포도를 정리하였다. 지중열교환기의 심도가 150m일 때 지중온도 분포는 약 $12.0{\sim}19^{\circ}C$의 넓은 분포를 보였으나 대부분의 지중온도가 $15.0{\sim}17.0^{\circ}C$의 범위에 분포하였으며, 지중열전도도의 경우도 마찬가지로 1.50 ~ 9.00 W/mk 값으로 아주 넓은 분포를 보였으나 2.30 ~ 2.90W/mk 값이 가장 많이 나타냈다.

  • PDF

Analysis of Earth Design Parameter and Geothermal Heat Exchanger Length in Geothermal System (지열시스템의 지중 설계요소와 지중열교환기 길이 분석)

  • Park, Jong-II;Park, Kyung Soon
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
    • /
    • v.11 no.3
    • /
    • pp.1-6
    • /
    • 2015
  • In this study, we analyzed t he design condition for appropriate design factor at geothermal system design documents. It is intended to provide the proper information of geothermal system design condition when construct new building, designer can use design conditions more efficiently. Therefore, it is possible to plan for domestic geothermal system, through utilization at design element, to provide as a good information that can predict the approximate underground condition. Thus, provided the basic design conditions that can predict the capacity of the geothermal system. It will be the first step to solve the problem.

An Introduction to Regulations on Underground Injection Wells: A Case in Missouri (지하 유체주입 지하수 관정의 설치 및 허가에 관한 규정: 미국 미주리주)

  • Lee Jin-Yong
    • Journal of Soil and Groundwater Environment
    • /
    • v.10 no.5
    • /
    • pp.70-76
    • /
    • 2005
  • It is expected that use of groundwater wells for contaminated groundwater remediation, artificial groundwater recharge and geothermal heat pump systems is increasing in the future in Korea. Some practical confusions may be produced due to lack of regulations related to permits and registrations of these types of wells. This short note is intended to draw attention of relevant professionals by shortly introducing some relevant code of state regulations in Missouri, USA.

Development of Technology on Water Thermal Energy Utilization of Riverbank(including Alluvial and Riverbed deposits) Filtration (강변여과수(충적층 및 하상) 열자원 활용 기술 개발)

  • Kim, Hyoung-Soo;Seo, Min-Woo;Jung, Woo-Sung;Song, Yoon-Ho
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2005.11a
    • /
    • pp.591-594
    • /
    • 2005
  • Geothermal energy becomes to be one of the promising energy sources. In this study, technology using water thermal energy from riverbank filtration system(including alluvial and riverbed deposit) is reviewed and checked as an energy resources. The objects of this study are (1) long-term monitoring of alluvial and riverbed sites, (2) preliminary design of cooling and heating system at riverbank filtration facility, and (3) calculation of potential groundwater heat energy, including riverbank filtration system. Measuring data of alluvial and riverbank filtration show slight fluctuations comparing to temperature of atmospheric air which indicates that groundwater obtained from the riverbank filtration system have a sufficient potential as a source of cooling and heating energy.

  • PDF

Experimental study on natural circulation using liquid nitrogen for superconducting applications

  • Choi, Yeon Suk
    • Progress in Superconductivity and Cryogenics
    • /
    • v.15 no.3
    • /
    • pp.49-52
    • /
    • 2013
  • An experiment to investigate the natural circulation of a cryogen has been performed. The study is motivated mainly by our recent development of cryogenic cooling system for prototype superconducting cyclotron without any circulating pump. In the natural circulation loop system, a cooling channel is attached on the outer surface of the aluminium block and the liquid nitrogen passes through inside of the channel to cool the block indirectly. A cryocooler as a heat sink is located at the top to re-condense cryogenic vapor coming from the aluminium block in which electrical heater is installed as a heat source. The main dimensions are determined using the relevant analysis and the natural circulation loop is successfully fabricated. The temperature distributions in the loop are measured during initial cool-down process and in steady state, from which the modified Grashof numbers are calculated and compared with the existing correlation estimated with one-dimensional analysis for steady state flow.

Visualization of Marangoni Convection Behavior between Two Surfactant Dropwises in the Process of Steam Absorption (증기흡수시(蒸氣吸收時) 계면활성제액적간(界面活性劑液滴間)에 발생(發生)하는 마랑고니대류거동(對流擧動)의 가시화(可視化))

  • Rie, D.H.;Choi, K.K.;Kashiwagi, T.;Seo, J.Y.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.4 no.2
    • /
    • pp.65-71
    • /
    • 1992
  • In most absorption machines, absorption enhancement has been achieved by adding small amount of surfactant additive, which introduced the surface tension difference between absorbent and surfactant droplets in the vapor absorption. The aim of this study is to understand a basic mechanism of Marangoni convection and its effectiveness in the vapor absorption enhancement. In this study, nonflowing aqueous solution of LiBr 60 mass% was exposed to saturated water vapor under the condition that two dropwises surfactant were fixed on the absorbent surface. Our experiments achieved to visualize the enhanced heat and mass transfer phenomena by the effect of Marangoni convection through the laser holographic interferometry. Also, Marangoni convection behavior was obtained by using tracer method.

  • PDF

Production and Statistical Qualtity Control of Low-Heat High Strength Reacy-Mixed Concrete (저발열 고강도 레미콘 제조 및 통계적 품질관리)

  • Park, Yon-Dong;Noh, Jae-Ho;Han, Chung-Ho;Kim, Hoon
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1996.04a
    • /
    • pp.376-381
    • /
    • 1996
  • In this study, the quality contral of high strength reacy-mixed concrete with design compressive strength of 420 kgf/$\textrm{cm}^2$ placed at a tail building for a long period is statistically investigated. The amount of cast-in-place high strength concrete is by about $15000\textrm{m}^3$. The required average compressive striength is 500 kgf/$\textrm{cm}^2$ according to KS F 4009 with assumed coefficient of variation of 11%. Since there are many concrete members in this construction, fly ash is used to reduce the heat of hydration of concrete. As the results of this study, the average actual 28-day compressive strength is 498 kgf/$\textrm{cm}^2$ and the coefficient of variation is 6.7%. The placing speed is comparable to normal strength concrete, however, the pump pressure is higher than that of normal strength concrete.

  • PDF

Study on the performance analysis of SCW geothermal system by simulation and monitoring (모니터링 및 시뮬레이션을 통한 SCW형 지열 시스템의 성능인자 분석에 관한 연구)

  • Lee, SangJun;Nam, Yujin
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
    • /
    • v.9 no.2
    • /
    • pp.8-15
    • /
    • 2013
  • Recently, an interest in the use of renewable energy has been growing up due to the rise of raw material price, international oil price and depletion of fossil energy. Ground source heat pump system has a high efficiency by using the constant temperature of underground and various types of the systems have been installed and utilized in the building. there are few studies on the system performance factors in the SCW system. Furthermore, even though the performance of the system depends on the temperature of heat source, the research on their relationship is rare. In this research, in order to analyze the performance factor for the open-loop system the monitoring of the real building with the standing column well systems and the simulation with building model were conducted.