Reversible heat pump model for seasonal performance optimization

Parametric modelling of domestic air-source heat pumps

“…3 shows that defrosting results in a significant fall in the average heat delivered by the heat pump with only a very small fall in average power consumption. Also, these changes take effect at ambient air temperature below approximately 7 o C. Note that these findings are similar to those reported in [14].…”

“…This seems reasonable since, at the low temperatures involved, winter air states tend to be close to saturation at most times and this means that dry bulb or wet bulb temperature may therefore be used alternatively to some extent. In common with the work reported here, Kinab et al [14] adopted the model based on ambient dry bulb temperature which, whilst applied to CoP rather than Q c (as in the present work), indicates results that are broadly in agreement with those reported here.…”

“…This model has the advantages of requiring far fewer fitting coefficients than other models reported in the literature (i.e. [14,17]), as well as leading to a definitive compressor performance variable -the isentropic efficiency -which can be directly compared with alternative compressor types. …”

“…In this simple model, the impact of wet bulb temperature on defrost intensity and frequency has not been considered. Indeed Kinab et al [14] reviewed two similar defrosting models one of which is based on ambient dry bulb temperature and the other on ambient wet bulb temperature. They concluded that the two provided similar results regarding average corrections to heating capacity during low ambient temperatures when defrosting would occur.…”

“…Kinab et al [14] develop a very detailed steady-state model of a reversible air-to-water heat pump which explicitly calculates the compressor efficiency and so can be used to compare compressor performances. However the compressor regression model is parameterised through 18 fitted coefficients (9 each for power and mass flow rate).…”