A very common hybrid configuration of heat pump systems with boilers is by using an open header (shunt connection). An open header creates an additional hydraulic separation between the two energy-supplying systems. These types of configurations become interesting if there is a need for the possibility of operating these systems together and if it is not wanted to use an additional switching 3-way valve.https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089369973. HP & Boiler - Switchable serial Configuration. Make sure that the “Reverse drag flow power on return” block is correctly filled in in order to avoid making design mistakes. https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089204625/Shunt
...
All of the parameters for the on/off control of the boilers and heat pump have been explained previously on the HP & Boiler - Parallel configuration page. The only additional remark is the pump control over the shunt connection. The constant standard temperature difference is set on 1 degree, but can even be reduced up to 0.5 degrees. The sensor
Notices/Remarks
The user should lock the nominal thermal power and temperatures of the HP. If not, the software will calculate with the propagated power and return temperature from the installation.
...
This template is a combination of the previous template “HP & Boiler - Reverse shunt in return - HP on/off control” and the template Air Source Heat Pump modulation- Modulating.
The modulating control of the HP can easily be changed to a stage control by replacing the heat pump part with the template Heat Pump stages.
...
The boiler will act as a top-up installation. This means that if the heat pumps are not able to reach the desired installation supply temperature, the boilers will turn on and increase the supply temperature to the required level. The major difference between connection the boilers via a shunt connection in the supply and connection the heat pump via shunt in the return line is whether the installation volume flow rate will be circulated completely through the heat pump’s storage tank. In cases of a variable flow system where the installation volume flow rate is limited, implementing heat pumps directly and the boilers via shunt might improve the relative contribution of the heat pump. However, this is very case dependant dependent and should be checked with simulations. A possible negative consequence is that the storage tank experiences a higher volume flow rate in design conditions, This could negatively affect the stratification of the buffer vessel and increase the amount of heat pump start/stops.
...
This template is a combination between the previous template “HP & Boiler - Reverse shunt in supply - HP on/off control” and the template Air Source Heat Pump modulation- Modulating.
The modulating control of the HP can easily be changed to a stage control by replacing the heat pump part with the template Heat Pump stages.
...
This template is a combination between the previous template “HP & Boiler - Reverse shunt in supply - HP on/off control - LT and HT header separated” and the template Air Source Heat Pump modulation- Modulating.
The modulating control of the HP can easily be changed to a stage control by replacing the heat pump part with the template Heat Pump stages.
...