The Effect of Discharge Configurations on the Thermal Behaviour of a Multi-tank Storage System

This paper presents the results of an experimental study conducted on a multi-tank thermal storage. The purpose of the study was to investigate the thermal behaviour of the stratified tank system when subjected to standard draw profiles. The experimental set up consisted of a charge loop to simulate a solar collector input, three commercially available 270 L domestic hot water tanks and three side-arm, natural convection heat exchangers. The system was charged using two 3 kW electric heaters which produced a variable input power to simulate the variation in output of a typical fixed orientation solar collector. Realistic hot water draws were conducted according to the specifications of the Canadian Standard Association, CSA-F379.1, for Solar Domestic Hot Water Systems. Tests were performed over 2 days for three different plumbing configurations, and compared with simulated results produced in the TRNSYS simulation environment. Comparisons between system configurations were based on stratification levels and hot water delivery temperatures.