| Popis: |
In this investigation, the effect of the size and pattern of domestic loads, on systems using stratified storage, was evaluated by experimental techniques. Several microprocessor based control strategies were also tested with the aim of improving the overall performance. It was found that in a typical domestic stratified solar water heating system, reducing the collector flow rate from 0.01 to 0.0033 1/s.m 2 may decrease the energy collected by 5% but raise the solar fraction by 7%. Changing the daily load pattern from evening peak to noon peak caused a 17% rise in solar fraction; changing to a morning peak produced a 30% drop in solar fraction. Increasing the volume of daily load from 175 litres at 60°C to 231 litres at 45°C could increase the solar fraction by 45%. A further 10% rise in solar fraction may be achieved by the appropriate interaction of the user coupled with a novel control strategy. More tests are needed to quantify the long term benefits. |
