Heat Pump Technology Feasibility Analysis for Dishwashers

Abstract

In this thesis an innovative method for water heating in a Dishwasher is proposed and analysed. The idea is to use a Heat Pump in place of electric resistance heater to reduce the energy consumption of the appliance. For this three HP concepts are proposed and math-modeled using Dymola and TIL. The model results show that there is a huge potential for energy savings for dishwashers and similar appliances which uses water at elevated temperatures for their process. Results show that overall energy consumption of the dishwashers can be reduced by 40% compared to conventional ones. Due to the limitations of a simple Heat Pump cycle, two more concepts are generated which also has the benefit of waste heat recovery from the hot drain water/after water hence makes them more practical. The analysis of all three concepts is done for normal temperature water inlet type. The first concept model is inspired by an existing Heat Pump Dishwasher (reference machine). Validation is done using experimental data of the reference machine for time, temperature and energy. Overall the Heat Pump technology seems to be a promising heating solution for such appliances which require heated water for their functioning. The model results can be further used to design and/or optimize energy efficient HP dishwasher platforms in the future.