|Q1. What is the principle of this gtemperature
stratification type of heat storage tankh?
A1. Water produces buoyant
force due to density variations with temperatures. In
words, in a stationary tank, warmed-up water (12 dec
C) has lower density than that of chilled water (5 dec
upward (i.e., forms stratification). If the flow velocity
is designed by reducing the inlet velocity enough not
to damage stratification formed due to the density variations,
the temperature stratification can be formed, even though
the system is of multi-tank type. Consequently, heat
storage and radiation with less mixing loss can be achieved.
|Q2. What is the conventional type of
heat storage tank, not of temperature stratification type?
|A2. It is referred to gConnection pipe
typeh, on which water inlets and outlets of each tank
are generally arranged in a staggered configuration.
The efficiency is said to be approximately 60%.
|Temperature stratification type
|Connection pipe type
|Q3. What precautions should be taken
when making a proposal?
A3. Each heat storage tank divided
should have approximately same capacity (water volume)
and arranged in parallel.
|Q4. If this system applicable to not
only chilled water but also hot water?
A4. Yes, it is applicable (but no
accomplishments yet). In order to apply to hot water,
however, directions of water inlet and outlet should
|Q5. Does this system cause a substantial
increase in the costs?
A5. No, not much, if the introduction
of build-up type heat storage tank was originally planned
and the waterproofing heat insulation work was included
in the plan. Aside from the waterproofing heat insulation
work, the initial costs increase by approximately 200,000
yen per tank. Through the use of PVC header pipes and
distributors, the costs are brought in line. Furthermore,
providing no flow control mechanism also helps cut the
initial costs and maintenance costs.
Even though the initial costs increase, the capacity
possible to be stored substantially increases and the
use of low-cost nighttime power also increases in portion.
As a result, the increase in the initial costs can be
recovered in one to three years.