EC POWER XRGI 20G-TO, Manual

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Version 1.0 - 2012 Manual XrGi 20G-To
3.4. hydraulic inteGration oF the XrGi 20G-to
The return temperature of the heating system should not normally exceed 65 °C. Return temperatures may be as high as 70 °C,
but this affects the commercial viability and the storage capacity of the system. If other heat sources are included in the sys-
tem, such as heat pumps or a condensing boiler, their demands on system temperatures must also be taken into account
when designing the system. As a general rule, the lower the return temperature, the more efficient the system is as a whole.
Before the system is installed, heating circuits that often cause high return temperatures, such as industrial water treatment
units, convector heaters, etc., should be considered in particular. If these heating groups can be expected to cause major
fluctuations in or high return temperatures, these should be minimised by taking appropriate measures (e.g. return temperature
control valves or hydraulics for variable volumes, e.g. injection devices, etc.)
The XRGI system can generate flow temperatures in the range 80–85 °C, irrespective of heating system return temperatures.
On the following pages we have put together a selection of tried and tested hydraulics. They share a common principle: they
feed heat to loads without any pressure differential and works like a hydraulic header. The XRGI system controls provide the
network with the necessary amount of flow water to achieve the required flow temperature (thermal energy) via the primary
flow of the header. The non-return valve in the overflow (header) is needed to prevent temporary overflows on the primary side
in case of major load fluctuations, since such overflows might cause the XRGI to shut down at random.
The installation models shown can therefore be used to create the known distributor circuits (e.g. mixer circuit) at no additional
cost, and without the risk of hydraulic malfunctions on the consumer side.
The basic circuits in this section show how the XRGI components are connected hydraulically. They include set ups of sing-
le- and multi-module systems, without including other heat sources or loads. They therefore provide the starting point for the
circuits in section 4.3, which add heat sources of different kinds, outputs and characteristics.
Up to three Power Units can be connected via the Q60-Heat Distributor, depending on the return temperature of the heating
system and on the volumes of water this involves as for the XRGI system. Multi-module systems via coupled Q60-Heat Distri-
butors have the advantage that the piping is simple and elegant.
There are four methods we can use when integrating the XRGI in heating systems:
1. Parallel integration with Flow Control
2. Parallel integration without Flow Control with multiple systems
3. Heating return increase
4. Heating return increase with multiple systems
The heat source is arranged in parallel with the Power Units. The network temperature must be given at the point where the
Power Unit and storage tank flows mix. It can be set via the Flow Control or an external control.
3.4.1. system temperatures
3.4.2. selecting the right hydraulics
3.4.2.1. Basic hydraulic circuits of XrGi components
3.4.3. integration into heating system
3.4.3.1 parallel integration with or without Flow Control