Power cells and heat transfer systems for combined heat and power, and related systems and methods

A combined heat and power system for use with a heating appliance, the system comprising:

• a combustion component having a plurality of burners, wherein an individual burner is operably coupleable to a fuel supply and an air supply to receive fuel and air, respectively, for combustion resulting in a flue gas;
• a power generation module including:
• a first heat exchanger thermally coupled to the combustion component to receive heat from the flue gas;
• a power generation component thermally coupled to the first heat exchanger to generate an electrical output from at least a portion of the heat received at the first heat exchanger;
• and
• a second heat exchanger thermally coupled to the power generation component, the second heat exchanger operably coupleable to an external heat exchanger to transfer a first portion of unused heat from the power generation module;
• and
• a recuperator operably coupleable between the plurality of burners and the air supply, wherein the recuperator is thermally coupled to the power generation module to direct a second portion of the unused heat into thermal communication with the air.

A method for operating a combined heat and power system, the method comprising:

• combusting, within a combustion component, a mixture to produce combustion heat carried by a flue gas, the mixture including a fuel and air;
• directing at least a portion of the combustion heat into a first heat exchanger of a power cell component;
• generating, from at least some of the portion of the combustion heat, an electrical output at the power cell component;
• directing unused heat not converted into the electrical output to a second heat exchanger;
• and
• transferring at least a portion of the unused heat from the second heat exchanger to a fluid in a heating appliance.