Specifications

29
Planning guide
Glandless high-efficiency pumps
Heating, air-conditioning, cooling
Wilo-Stratos / Stratos-Z / Stratos-D / Stratos-ZD
Wilo Building Services catalogue – 50 Hz – Heating, air-conditioning, cooling – Edition 2011/2012 – Subject to change without prior notice
Secondary hot water circulation application
(Wilo-Stratos-Z/Stratos-ZD)
Pumps which are used in secondary hot water circulation systems are
subject to specific requirements that are fulfilled by the
Wilo-
Stratos-Z/Stratos-ZD series:
• The fluids are potable water and water for food-processing compa-
nies in accordance with TrinkwV 2001 (German drinking water ordi-
nance). Any formation of lime deposits is ta
ken into account by the
design, meaning that a total carbonate hardness of 20°dH is permis-
sible at a max. fluid temperature of +80 °C.
• All plastic parts that come into contact with the pumped fluid comply
with KTW recommendations.
• The differential pressure control modes p-c and p-v enable the
automatic adjustment of the pump output in volume flow-variable
se
condary hot water circulation systems with thermostatically con-
trolling line shut-off valves.
• The manual control mode enables the optimum manual adjustment
of the pump output to the constant volume flow circulation system.
This
can be done with the Wilo-IR-Monitor/IR-Module for example.
The criterion for this is the temperature of the secondary hot water in
the circulatio
n pipe, which must not be more than 5 K below the stor-
age temperature when it enters the secondary hot water storage
tank.
High-efficiency pumps
The efficiency of the hydraulics and motor determine the pump's
overall efficiency. Both components were doubled with the Wilo-
Stratos pump com
pared to the glandless pumps previously used in
building services, thus resulting in a considerable improvement.
The applied ECM technology
drastically reduces the annual power
consumption, That results in considerable savings compared to con-
ventional pumps.
ECM technology
The new ECM technology is the basis for the outstanding efficiency
of Wilo-Stratos pumps. It includes:
EC motor
EC stands for electronically commutated m
otor. Its basis is a syn-
chronous motor with permanent magnet rotor. The rotating stator's
magnetic field is generated by electronic commutation, meaning that
the stator windings are activated specifically for the interaction of
the electrical and magnetic poles.
Comparison of the motor components
Wilo-TOP-E with AC motor
Wilo-Stratos with EC motor
This has the following benefits:
• The magnetic field required in the rotor does not need to be generat-
ed with any losses.
• Especially in the partial load range (up to 98% of the operating time),
the difference in efficiency is even greater than it already is in the full
l
oad range compared to an asynchronous motor.
• Higher speeds are possible compared to an asynchronous motor. This
results in the reduction of the size and weight of the pump with simi-
la
r hydraulics.
Wet rotor encapsulation
The rotor of the glandless pump motor runs in the fluid. This fluid lu-
bricates the bearings and cools the motor. The current-carrying sta-
tor is
separated from the fluid by a can, referred to as wet rotor en-
capsulation. This wet rotor encapsulation has a direct effect on the
efficiency
• due to the size of the necessary gap between stator and rotor,
• and due to the magnetic resistance of the selected can material.
The improvement in terms of efficiency of the Wilo-Stratos pump
here i
s the result of:
• Reduction of the air gap and
• Application of an innovative can material with smaller losses to the
magnetic flux between stator and rotor.
Hydraulic optimisation
The hydraulic conditions are optimised by means
of a 3D spiral hous-
ing and 3D impeller as well as a smooth surface in the pump housing
(cataphoretic coating). The suction throat seal between impeller and
pum
p housing reduces radial gap losses. Axial losses are reduced by
the sealing lip on the front side of the impeller.
Annual power consumption of a heating pump (DN 30) with setback operation*
Comparison of different pump types
High-efficiency pump Stratos 30/1-12
Energy-saving pump TOP-E 30/1-10
Standard pump TOP-S 30/10
* Load profile with 5500 operating hours per year:
1832
0 1000 2000
Power consumption [kWh/a]
1216
396
2% ( 110 hrs.) at 100% Q N (peak load)
25% (1375 hrs.) at 65% Q
N (partial load)
40% (2200 hrs.) at 30% Q
N (low load)
33% (1815 hrs.) setback operation