24 June 2014

THEORETICAL STUDY AND DEVELOPMENT OF ABSORPTION CHILLERS WITH ENHANCED AUXILIARY WASTE HEAT RECOVERY


Absorption chillers with auxiliary waste heat recovery using absorption heat pump cycles were initially developed in 1990s and their performance has been improved in terms of their fuel or steam consumption ratio. This improvement consists of the basic performance of absorption chillers and the amount of fuel or steam reduction by means of increasing the waste heat input. We studied the principle of these machines for this report by focusing on
the superposition model of a double-effect and a single-effect absorption cooling cycle. The quantity of waste heat in the recent co-generation systems is increasing due to the
expanding electric-generating capacities for ensuring the energy security of buildings and energy plants. This leads the demand for putting more waste heat into practical use.
Therefore, we have developed new absorption chillers with enhanced auxiliary waste heat. The fuel reduction ratio in these machines was increased from 25 to 40% for direct-fired
chillers and the steam reduction ratio for steam-driven chillers was also increased from 15 to 30%. The maximum cooling capacities driven by only auxiliary waste heat also reached
approximately 58% for the direct-fired machines and 50% for the steam-driven ones.