8 Hydraulic connection
53
Company ROTEX ESU - 07/2008
8
Hydraulic connection
8.1
Important information on the hydraulic connection
In order to prevent injuries and material damage occurring, take note of the precautions below which relate to the hydraulic
system connection of the ROTEX E-SolarUnit.
Scalding protection
During operation of the ROTEX E-SolarUnit, the storage tank temperature may exceed 60 °C, particularly when solar power is
used. To prevent scalding injuries occurring, install scalding protection in the system (hot water mixer device,
e. g. VTA32
15 60 16
).
Corrosion protection
In a few regions, the water utility company supplies corrosive domestic water, which can result in corrosion damage even if high-
quality stainless steel is used. Ask your water utility whether the use of hot water storage tanks made from stainless steel results
in problems with corrosion in your area.
Suitable water treatment may be needed.
8.2
Storage tank
Design
– All plastic, double shell design (corrosion-free).
– Space between the internal and external tank filled with foam to give excellent heat insulation (low surface losses).
– External wall 3 – 4 mm thick (impact-resistant and shockproof).
Method of operation
The pressureless storage water serves as heat storage medium. Useful heat is supplied and removed via the spiral heat exchanger,
which is made from a stainless steel corrugated pipe (1.4404), and is completely immersed in the storage tank water.
The hot water zone in the storage tank acts as a heat storage tank and flow heater combined (see Figure 2-2, page 9). The cold
water which flows out when the hot water is removed is first routed to the storage tank at the very bottom of the heat exchanger,
where it cools the lower area of the storage tank down as much as possible. If necessary, the hot water zone is heated up by the
electric heat generator. Water flows through the heat exchanger for storage charging (SL-WT) from top to bottom. This improves
efficiency and the yield of the solar heating system. On its way to the top, the domestic water continuously absorbs the heat of
the storage tank water. Since the flow direction makes use of the counter flow principle, and the heat exchanger is shaped like
a spiral, there is definite temperature stratification within the storage tank. As high temperatures can be maintained for a very
long time in the upper section of the storage tank, a high hot water output is achieved even if water is drawn off over a long
period of time.
– With the ROTEX ESU the SL-WT ends about 40 cm above the bottom of the tank. Only the hot water zone above that point
is heated by the boiler. The water below that point in the tank is heated by solar power alone.
Water hygiene
Separating the unpressurised storage tank water from the hot water flowing in the corrugated pipe heat exchanger ensures that
the ROTEX ESU delivers optimum levels of hygiene:
– There are no zones with a low flow rate or zones that are not heated on the hot water side.
– It is impossible for sludge, rust or other sediments to be deposited, as can be the case with other large volume tanks.
– The water which is fed into the system first is also discharged first (first in, first out principle).
Heating storage tank water
During initial start-up, the storage tank is filled once with unpressurised storage tank water, which is then never changed.
The storage tank water can be heated in various ways:
– By the integrated electric heat generator
– Via an additional solar heating system (ROTEX Solaris system) that is connected directly to the unpressurised area
– Via an additional heat source (e. g. hot water heating pump) that is connected directly to the unpressurised area
Содержание E-Solar Unit ESU 509
Страница 70: ...14 Notes 70 FA ROTEX ESU 07 2008...
