22 May 2008

NOVEL COMPACT SORPTION GENERATORS FOR HEAT PUMP APPLICATIONS


A new type of liquid-solid heat exchanger-reactor (carbon-ammonia) has been
developed for use in adsorption cycles. It has the requirement to be of low thermal mass and
also to have good heat transfer. The design solution chosen is a novel plate heat exchanger.
It uses nickel brazed shims and spacers to create adsorbent layers only 4 mm thick between
pairs of liquid flow channels of very low thermal mass. Prototype sorption generators have
been manufactured and are being evaluated. The design is being used in a gas-fired heat
pump, intended to replace a combi-boiler in the UK or similar climate.
The heat pump uses two generators operating out of phase in a regenerative cycle. The
system is described. Initial heat and mass transfer experiments on the generator are
presented together with predictions of performance in the chosen application.