Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
THERMAL ANALYSIS OF COMBINED SOLAR-HEAT PUMP DOMESTIC WATER HEATING SYSTEMS
Submission Author:
Juliana Emanuella Gonçalves , SC
Co-Authors:
Sergio Colle, Allan Ricardo Starke
Presenter: Juliana Emanuella Gonçalves
doi://10.26678/ABCM.ENCIT2016.CIT2016-0670
Abstract
Previous studies carried out on combined solar-heat pump water heating systems have demonstrated that substantial energy savings can be obtained by combining both technologies to deliver domestic hot water (DHW). In this paper, two configurations of combined systems were proposed: a dual tank solar system combined to an air-source heat pump as backup heater and a dual tank solar-assisted water-to-water heat pump system. Reference systems were also undertaken in this study: an electric shower head, a single tank traditional solar system and a dual tank traditional solar system. The four systems of interest were modeled in the TRNSYS software and simulated for a typical meteorological year (TMY) using climate data of Florianópolis/SC. All of the systems had the same load profile and delivered DHW at constant temperature. Each system delivers therefore the same amount of energy. The additional cost due to both the second tank and the heat pump do not justify the energy savings for a single-family residential home. However if the system is applied to a larger load, such as multi-residential buildings, hospitals or hotels, the potential for energy and cost savings is significant, which improves economic justifiability through economies of scale. This paper focuses therefore on DWH large loads. The results show that the solar energy collected by the single tank traditional solar hot water system is capable of meeting more than 80% of the total amount of energy inputted into the system. The overall operating costs are thus reduced by the same percentage, if compared to an electric shower. The results show that the introduction of the heat pump to the design allowed the system to further reduce operating costs. The dual tank solar system combined to an air-source heat pump system further reduces the operating costs by more than 90% in relation to an electric shower.
Keywords
combined systems, heat pump, solar thermal energy, solar domestic hot water system
