The purpose of this dissertation is to theoretically and experimentally study the transient and steady state performance of a residential heat pump (AC/HP). Several different refrigerants and system configurations were studied.; Many points were addressed experimentally. The performance of R-407C relative to R-22 was evaluated in terms of steady state, cyclic, and seasonal performance. The combination of the steady state and cyclic performances showed that R-407C has a 4.3% lower cooling seasonal efficiency than R-22 and up to a 7.0% lower heating seasonal efficiency than R-22 The seasonal performance was used to show that R-407C poses a greater global warming threat than R-22. The performance of a vapor to liquid line heat exchanger was also evaluated with these fluids. Furthermore, the performance of the AC/HP was quantified with different expansion devices.; The final facet of the experimental work was to measure the concentration of R-32/R-134a (30/70 wt.%) and R-407C as a function of time. The results of these measurements indicated that the steady state circulated concentration of the refrigerant mixtures shifted away from the less volatile component relative to the charged concentration. The concentration shift was attributed to the velocity difference between the phases.; The theoretical aspect of this dissertation was addressed by the development of a fully implicit, distributed parameter simulation capable of modeling the transient and steady state aspects of an AC/HP. For steady state, the simulation solves the complete continuity, species, energy and momentum equations, while transiently only the momentum equation is omitted. This simulation is the first capable of representing the significant transient and steady state physics of an AC/HP operating with pure and mixed refrigerants while utilizing minimal empirical data. The simulation was used to study several different system configurations transiently and at steady state with both R-22 and R-32/R-134a (30/70 wt.%).
展开▼
