Parameter estimation based models of water source heat pumps.

摘要

Scope and method of study. Most previously developed heat pump models, which are classified as ‘deterministic’ models in this thesis, are targeted at the design of the heat pump itself for improved performance. Only the models based on regression (classified as ‘equation-fit’ models in this thesis) are widely accepted in building energy calculation programs due to their minimal computational time and information requirements. Though ‘equation-fit’ models work effectively for many applications, they sometimes have low accuracy and are particularly problematic when the model is operating outside of the range of the manufacturer's catalog data. Furthermore, it is difficult to extend these models when different working fluids are used. This thesis has dealt with the modeling of water-to-water and water-to-air heat pumps in building energy calculation programs to overcome the drawbacks of the ‘deterministic’ and ‘equation-fit’ models.; Findings and conclusions. This thesis has described the development and validation of a parameter estimation based water-to-water heat pump model and a parameter estimation based water-to-air heat pump model for use in energy calculation programs. A parameter estimation modeling approach has been used to simulate the performance of reciprocating vapor compression water-to-water and water-to-air heat pumps. The models have been validated first by comparing simulation results to the manufacturers' catalog data. The models' performance compares favorably against the most detailed ‘deterministic’ model previously published, while not consuming an inordinate amount of computational time. As compared to ‘equation-fit’ models, the models retain the physically-based representation of the heat pump, which allows some extrapolation beyond the catalog data. They also perform significantly better than the equation-fit model when a limited number of operating points are utilized for estimation of parameters or coefficients. Three important extensions to the heat pump models—scroll compressors, rotary compressors and glycol/water mixtures have been discussed. The water-to-water and water-to-air heat pumps have also been validated using the monitored field data from existing experimental apparatus.