16 September 2011

DEVELOPMENT OF ABSORPTION HEAT PUMP CHILLERS WITH IMPROVED HEATING EFFICIENCY BY APPLYING HEAT PUMP CYCLE


Improvements have continually been made in the performance of absorption
chiller-heaters in the cooling mode. On the other hand, the heating performance has not been improved because of the difficulty in constructing an appropriate heat pump cycle. The
purpose of this study is to improve the heating performance of absorption chiller-heaters by using a heat pump cycle in the heating mode. We call these machines “Absorption heat
pump chillers (AHPC)”. The main difficulty of constructing an AHPC is reducing the pressure of the high temperature generator. We applied two-stage evaporator and absorber to reduce the pressure. Consequently, we developed two types of AHPCs. The first type is a doubleeffect absorption heat pump chiller. In the heating mode, this machine uses 12°C water as a heat source to provide 45°C water for space heating. The coefficient of performance (COP) in the heating mode was calculated at 2.2. The second type is a double-output absorption heat pump chiller. This provides chilled and hot water simultaneously. The experimental
results from this machine showed a combined heating and cooling COP of 3.3.