Performance analysis and optimization of solar thermal and heat pump combi-systems

Abstract

In the present research combinations of solar collectors and air-source heat pumps for domestic hot water (DHW) are addressed in terms of hydraulic layout and climate conditions In this study an attempt is made to install some monitoring sensors to monitor the experimental data The lab-scale solar combisystem was established and monitored in Tainan city Taiwan The solar combisystem can run in three modes: a solar hot water system a heat pump hot water system and a well as solar combisystem In addition TRNSYS software was engaged to simulate and examine the heating capacity of the domestic hot water systems with various hydraulic layouts A demonstration site for the solar collector and heat pump combisystem was utilized to verify the numerical results The corresponding parameters of the TYNSYS module were also discussed To compare a conventional solar domestic hot water (SDHW) system a single-tank solar combisystem and a dual-tank solar combisystem three different models were simulated using TRNSYS software after validating the simulation model All of the systems had the same load profile and delivered DHW at a constant temperature This guaranteed that each system delivered the same amount of energy for the entire simulation period thereby ensuring a common basis for comparison To determine the effect of climate conditions two different cities in Taiwan were simulated where Taipei represented a subtropical climate and Kaohsiung represented a tropical climate The results showed that the dual-tank solar combisystem employed in both Taipei and Kaohsiung had the lowest electrical consumption and operating cost where the incremental capital costs of the solar combisystems were considered and realistic payback periods were calculated to determine economic feasibility Furthermore in order to discuss the effect of climate conditions the Taguchi method was employed to optimize and analyzed the solar combisystem systems under various climate conditions and locations where Tainan represented a tropical monsoon climate; Lisbon represented a Mediterranean climate; Hong-Kong represented a subtropical monsoon climate; Osaka represented a humid subtropical climate and Madrid represented a Continental climate The optimum set of parameters and the contribution of each solar combisystem parameter in the five different locations were determined through the Taguchi method The results showed that the effect level of each solar combisystem parameter on performance were different in the different regions but the most significant parameter was the same in all region The results also revealed that the most significant parameter was different in the various solar combisystems The results facilitate a determination of the effect of climatic conditions on the performance of solar combisystems

Date of Award	2017 Aug 22
Original language	English
Supervisor	Yueh-Heng Li (Supervisor)