Performance improvement by using dual heaters in a storage-type domestic electric water-heater

Effect of inlet design on the performance of storage-type domestic electrical water heaters

“…More recently, Sezai et al [12] examined the effect of heating-element location on thermal performance of a larger EWH having 120 L cylindrical storage-tank. They found that when the heating element attached horizontally at the lateral surface of the storage tank and activated, thermal stratification occurred.…”

An experimental study of influence of hot water consumption rate on the thermal stratification inside a horizontal mantle storage tank

“…In a perfectly-stratified tank which there is no mixing and with negligible heat losses to the ambient and the cold fluid, the maximum theoretical discharging efficiency that can be achieved is 100% [16]. However, we presumed that degradation of thermal stratification as a result of mixing reduces the discharging efficiency, and thus calculated the fraction of energy that can be extracted from the storage tank by the time the discharged water temperature falls below a specified value.…”

“…[16]. The initial temperature profile of the water during formation of stratification in the tank was noted instantly before drawing off hot water and the initial energy stored in the tank, relative to the temperature of the cold inlet water T ci , is:…”

“…This efficiency defined as the fraction of the energy exploited during the time t, when the temperature of the discharged water drops to a predetermined temperature [16]. The discharging efficiency is calculated from:…”

Performance of Thermosyphon Solar Water Heaters in Series

“…In addition, η 1 reached the maximum at S2 due to lower heat losses caused by lower operating temperature, and then gradually declined. Note that the maximum theoretical discharging efficiency could reach 100% [25]. The amount of accumulated energy in the tanks was obtained by multiplying the difference between the average temperatures of the water collected in the tanks and of the water at entry to the collector.…”