Experimental study on transient behavior of embedded spiral-coil heat exchanger
Other literature type
Jassim, E. I.
Spiral coil offers a substantial amount of heat transfer area at a
considerably low cost as it does not only have a lower wall resistance but
it also achieves a better heat transfer rate in comparison to conventional
<i>U</i>-tube arrangement. The general aim of the study is to assess different
configurations of spiral coil heat exchangers that can eventually operate in
a highly efficient manner.
The paper documents the transient behavior of spiral-shaped tubes when the
coil is embedded in a rectangular conducting slab. Different arrangements
and number of turns per unit length, with fixed volumes, are considered in
order to figure out the optimal configuration that maximizes the performance
of the heat transfer. The implementation presented in the study is conducted
to demonstrate the viability of the use of a large conducting body as
supplemental heat storage.
The system uses flowing water in the coil and stagnant water in the
container. The copper-made coils situated in the center of the slab carries
the cold fluid while the container fluid acts as a storage-medium. The water
temperature at several depths of the container was measured to ensure
uniformity in the temperature distribution of the container medium.
Results have shown that the coil orientation, the number of loops, and the
Reynolds number, substantially influence the rate of the heat transfer. The
vertically-embedded spiral coil has a better performance than the
horizontally-embedded spiral coil. Doubling the number of loops is shown to
enhance the performance of the coil. Increasing Reynolds Number leads to
better coil performance.