Detailed and dynamic variable speed air source heat pump water heater model: Combining a zonal tank model approach with a grey box heat pump model. (August 2018)

• Record Type: Journal Article
• Authors: Deutz, Kevin Ruben; Charles, Gaspard-Louis; Cauret, Odile; Rullière, Romuald; Haberschill, Philippe
• Is Part Of: International journal of refrigeration. Volume 92(2018)
• Page Start: 55
• Page End: 69
• Publication Date: 2018-08
• Subjects: Modeling -- Air source heat pump water heater -- Domestic hot water -- Simulation -- Stratification -- Energy performance; Modélisation -- Chauffe-eau aérothermique à pompe à chaleur -- Eau chaude sanitaire -- Simulation -- Stratification -- Performance énergétique; Refrigeration and refrigerating machinery -- Periodicals; 621.56
• DOI: 10.1016/j.ijrefrig.2018.05.022
• Languages: English
• ISSNs: 0140-7007

Abstract

Highlights: A dynamic grey box thermodynamic model is used to model the heat pump components. A zonal model allows to model convection and thermal stratification in the tank. An experimental set up is used to evaluate the model accuracy in various conditions. The developed model allows to accurately predict the energy performance and comfort. Abstract: Air Source Heat Pump Water Heaters (ASHPWHs) are efficient and fast-developing sanitary hot water production systems for the building sector. However, it was shown that their energy performance can still be improved. Therefore, a dynamic grey box Modelica based model is developed representing a split type ASHPWH with a mantle heat exchanger. The thermal storage model includes a zonal model to model convection during heat-ups and the heat pump is modeled using the TIL ® thermal component library. The model is first compared to dynamic experimental data during 9 heat-up tests under various operating conditions, including low temperature defrosting stages. On such heating periods, the overall mean relative error reached is of 2% for the COP and the maximum temperature error over the height of the tank is less than 1 °C. The model is reproducible and can be used to conduct further design based optimization studies.