Functions of the DHW circuit
6 Functions of the DHW circuit
6.1DHW heating in the storage tank charging system
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| TLP | Heat exchanger | |
| SLP |
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| charging pump | |
| TW | VFS/VFT | Flow sensors | ||
| VFS | ||||
TLP VFT | SF1 | SLP | Storage tank | ||
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| ZP |
| charging pump | |
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| SF1 | Storage sensor 1 | ||
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| SF2 | SF2 | Storage sensor 2 | |
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| KW | ZP | Circulation pump | |
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| TW | DHW | |
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| KW | Cold water |
Fig. 5 · DHW heating in a storage tank charging system
Start storage tank charging
The controller begins charging the storage tank when the water temperature measured at sen- sor SF1 falls below the DHW demand ON by 0.1 °C. If the flow temperature in the system is higher than the required charging temperature, the controller attempts to reduce it in the heat- ing circuit for maximum 3 minutes before the heat exchanger pump together with the storage tank charging pump start to run.
When there is no heating operation or when the flow temperature in the system is lower, the heat exchanger charging pump is switched on immediately. The storage tank charging pump is switched on when the temperature currently measured at storage sensor VFT has reached the temperature measured at sensor SF1.
If a storage tank thermostat is used, the storage tank charging pump is switched on when the temperature T = Charging temperature – 5 °C is reached at sensor VFT.
Note!
The charging temperature VFT is regulated by the primary valve in system Anl 2. In systems Anl 4, 5 and 10, the charging temperature VFT is only regulated by the primary valve when the DHW demand has the highest set point and has priority.
In all other systems (Anl 7, 8 and 9) the mixing valve regulates the charging temperature VFT.
When the Circulation pump function is active, the circulation pump remains in operation ac- cording to the time schedule. The pump is switched off when this function is deactivated.
52EB 5179 EN
