The impact of the internal heat exchanger(IHX)on a transcritical CO
2
heat pump is investigated based on both theoretical and experimental methods. A thermodynamic analysis is conducted to study the influences of the IHX's heat transfer efficiency at different gas cooler outlet temperatures and discharge pressures. The theoretical results show that whether the IHX improves the system performance coefficient depends on the gas cooler outlet temperature. Experiments are performed on a transcritical CO
2
heat pump prototype
and the results indicate that IHX can reduce the optimal discharge pressure
and the degree of this reduction is enhanced with
the decrease of ambient temperature and the increase of inlet and outlet water temperatures. Applying IHX brings an increase of 6.65% in the coefficient of performance and a decrease of 6.22% in power consumption at most
but it leads to a higher compressor discharge temperature
hence it must be restricted at lower ambient temperature. Moreover
the differences between theoretical and experimental results are analysed
and a numerical correlation of the reduced value of optimal discharge pressure with the ambient temperature
inlet and outlet water temperatures is established based on the experimental data.
关键词
Keywords
references
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