| Title |
An experimental study on the improvement of performance for the storage type off-peak electricity water heater |
| Abstract |
Key words: Off-peak electricity(심야전기),Water heater(온수기) Thermal stratification(열층화), Dead zone(불용경계층)In this study, two types of hot water heaters using the off-peak electricity respectively, one with the diffuser, the other without diffuser, will be constructed and then thermal performance during the charging and discharging process will be analyzed.The results obtained in this study are as follows;First, maximizing thermal stratification with diffuser exhibited about 10% improvement in thermal performance compared to conventional equipment. Second, the sheath heater should be installed within 7cm at least from the bottom of tanks to eliminate the dead zone where natural convection by a sheath heater was not strong enough to heat up to the maximum temperature. Installing a sheath heater with 7cm far from the bottom can assure another 10% improvement in the view point of thermal capacity. It is respected that the avove results would improve to the increased efficiency when applied to design and suggested of a draft for the evaluation of the thermal performance of the storage type off-peak electricity water heater. |