Systems and methods for heating water using biofuel

摘要

The present invention may be embodied as a biofuel heating system comprising a controller for operating a fan based on a load operating parameter such that air flows along a flow path extending through a combustion chamber, through a burn-out port, through a burn-out chamber, through a heat exchange port, through a heat exchange chamber, and out of an exhaust port. A heat exchange system transfers heat energy from air flowing through the heat exchange chamber to a working fluid. The controller operates in a char mode based at least in part on the load operating parameter, and the biofuel remains within the combustion zone during the char mode.

主权项

1. A biofuel heating system for converting biofuel to heat energy to be delivered to a working fluid for transferring heat to a load formed by at least one of a domestic hot water system and a domestic space heating system, comprising:
a combustion chamber; a burn-out chamber; a burn-out port arranged to allow fluid to flow out of the combustion chamber and into the burn-out chamber; a heat exchange chamber; a heat exchange port arranged to allow fluid to flow out of the burn-out chamber and into the heat exchange chamber; an exhaust port arranged to allow fluid to flow out of the heat exchange chamber; a heat exchange system arranged at least partly within the heat exchange chamber, where the working fluid is circulated between the heat exchange system and the load; a fan arranged to cause fluid to flow out of the heat exchange chamber through the exhaust port; at least one load sensor configured to sense a load operating parameter corresponding to a working fluid temperature of the working fluid after the working fluid returns from the load to the heat exchange system; and a controller for operating the fan based on the load operating parameter such that air flows along a flow path extending through the combustion chamber, through the burn-out port, through the burn-out chamber, through the heat exchange port, through the heat exchange chamber, and out of the exhaust port; an under-fire damper; and an over-fire damper; whereby the heat exchange system transfers heat energy from air flowing through the heat exchange chamber to the working fluid; the controller operates in a char mode based at least in part on the load operating parameter, where
the biofuel remains within the combustion zone during the char mode, andwhen the controller operates in the char mode, the controller varies an under-fire damper state of the under-fire damper and varies an over-fire damper state of the over-fire damper.