Researches on A Novel Gas Heat Pump with Multi-stage Transmission Ratios

摘要

This study reviews current researches on gas heat pumps (GHP) in which the gas engine and the compressor are connected with a single-stage or fixed transmission ratio (engine's speed/compressor's speed). A novel concept of gas heat pump with multi-stage transmission ratios is presented in this paper. Compared with conventional GHP with a fixed transmission ratio, the novel GHP renders its engine to operate with a higher efficiency under more heating/cooling operation conditions to enhance the primary energy ratio (PER) further. Advantages from multi-stage transmission ratio connection, such as PER improvement and running speed extension of compressor are theoretically analyzed. Results show that GHP with multi-stage transmission ratios has a higher PER and broader compressor speed range, and in particular, through transmission ratio switch under different load conditions, it is beneficial for engine to run with higher efficiency during a whole-year operation.