An experimental study on thermal storage characteristics in the thermally stratified water storage system

성층 축열 시스템에서의 열 저장 특성에 관한 실험적 연구

  • Koh, J.Y. (Graduate School of Mechanical Eng., Inha Uuiversity) ;
  • Kim, Y.K. (Dept. of Refrigeration & Air-Conditioning, Kyonggi Institute of Technology) ;
  • Lee, C.M. (Dept. of Mechanical Eng., Yuhan College) ;
  • Yim, C.S. (Dept. of Mechanical Eng., Inha University)
  • 고재윤 (인하대학교 대학원 기계공학과) ;
  • 김영기 (경기공업대학 공조냉동과) ;
  • 이채문 (유한대학 기계공학과) ;
  • 임장순 (인하대학교 기계공학과)
  • Published : 2001.12.31

Abstract

This study describes the experimental study that focuses on the effects that distributor shapes and flow rate variations have an influence on the stratification in a rectangular thermal storage tank. Experiments were carried out under the conditions that the flow rates of working fluid are 20, 10 and $5\ell$/min. The storage tank is initially filled with chilled water of $1^{\circ}C$, and is extracted through the bottom at the same rate as the return warm water from load is entered through the distributor at the top of the tank. The thermo-cline forms at the top of the storage tank as the warm water enters the tank from the load through the distributor and the thermo-cline thickness increases with time. Emphasis is given to the effects of mixing at the inlet that increases the thermo-cline decay Flow rate variation and inlet distributor shapes are the important parameters in deciding the performance of a storage system. Stratification degree increases with decreasing in inlet flow rate under $10\ell$/min. Experiments shows that better thermal stratification can be obtain using the distributor to limit momentum mixing at the inlets and outlets. Also, 12% of improvement in the thermal energy usage has been achieved using the modified distributor discharging same flow rate in each lateral ports.

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