What we did:
We were tasked with designing and installing a small BMS system that controls the operation of a gas boiler and a biomass boiler. The Biomass boiler would always be the preferred source of heat but in the event that it fails then it would be required to automatically switch over to a backup heat source, in this case a gas boiler. This was critical as it was not only supplying the heating to the building but also heating a vat of wax that was used in the factory for production.
We designed a pump overrun into the system to remove any excess heat from the boiler before switching so that the biomass boiler wouldn’t just keep heating up while the fire burns out.

Comments