TY  - BOOK
AU  -  Kumar, Dileep
AU  - Chakraborty, Prodyut Ranjan
TI  - Numerical analysis of Latent heat thermal Energy Storage (LHTES) Performance: A2 D axisymmetric approach
U1  - 621.47 
PY  - 2018///
CY  - IIT Jodhpur
PB  - Department of Mechanical Engineering
KW  - Latent heat thermal Energy Storage (LHTES)
KW  - MTech Theses
KW  - Department of Mechanical Engineering
N2  - Shell and tube type latent heat thermal energy storage (STLHTES) device is numerically evaluated by applying fully implicit finite volume method. A 2-D axisymmetric numerical model is  developed  in  order  to  analyse  the  dynamic  behaviour  of  charging  and  discharging  of elementary unit  of STLHTES. The STLHTESconsists of a pipe of finite thickness carrying heat transfer fluid (HTF). It issurrounded by latent heat storage medium or the phase change material (PCM). In the 2-D axisymmetric PCM domain, diffusion dominated heat transfer mechanism is considered while the flow of HTF in 1-D is considered to be dominatedby convection. Coupling has  beendone  between  the  two  domains  through  energy  balance  at  the  pipe  wall  taking  half control  volume  at  the  boundary.  The  present  work  proposes  a  novel  scheme, liquid-fraction updating scheme, for solving the energy conservation equation in PCM domain. Comparison has been done between the base case (no thermal conductivity enhancement in the PCM by graphite incorporation)  and  other  cases  (where  thermal  conductivity  enhancement  of  PCM  is  done  by incorporation  of  graphite)  with  parametric  analysis  based  on  variable  pipe  sizes  of  HTF  pipe. During  graphite  incorporation,  anisotropic  effects  are  also  taken  into  account.  Simulations  are also performed to obtain the evolution of temperature in PCM and HTF domain along with extent of  melting/solidification  in  the  PCM  domain  for  different  values  of  fraction  of  graphite.  The analysis  shows   significant   reduction   in   cycle   time   for   charging   and   discharging   due   to incorporation  of  graphite  in  the  PCM  composite  and  increase  in  heat  transfer  rate  caused  by increase  in  Reynolds  number  following  smaller  pipe  sizes  of  HTF  pipe  (central  pipe  through which HTF flows). Key Words:LHTES, shell and tube  LHTES, Liquidfraction update  technique, Solidification, Melting, Charging, Discharging, anisotropy, graphite

ER  -