Waste heat recovery, household appliances, residential
With the United States being the world’s second largest consumer of primary energy, research into areas of significant consumption can provide large impacts in terms of the global energy consumption. Buildings account for 41% of U.S. total energy consumption with the residential sector making up a majority. Household appliances account for the second largest site energy consumption at 27%, after the HVAC system for the U.S. residential sector. Thermally integrating residential appliances by leveraging waste heat recovery goes outside U.S. federal standards and has not been adequately explored by connecting all residential appliances. Limited studies exist focused only on single appliances connected to waste heat recovery or being thermally integrated. As part of a thermally connected system, individual appliance models are developed in Modelica and are tuned with available experimental data from the manufacturer. The dishwasher (DW) has better opportunity as a heat sink to offset the internal heater, 0.17 kWh of electricity/cycle for heating wash water. Due to the integration approach required with the dishwasher, a detailed accounting of major components is required. The thermal mass of the DW cavity and dishware, the fluctuating flow rates of each spray arm, and the final water sump temperature required are all captured. After tuning, the DW model of the traditional system shows an agreement within ±5% for most water sump temperatures.