| 摘要 |
<p>An apparatus for estimating heated water is adapted for use with a hot water tank 2 having a cold water inlet 8 at a bottom of the tank and a heated water outlet 6 at a top of the tank. An internal heat source 4 such as a heat exchange coil or immersion heater heats water in the tank. The apparatus includes a control unit 14 and first 10 and second 12 temperature sensors, measuring water temperature at the bottom of the tank or at the inlet and water temperature at a point between the top and bottom of the tank, ideally at the same height as the heat source, respectively. The control unit derives temperature profiles of the water within the tank using the measurements. Each profile has a section of constant temperature gradient which approximates the temperature gradient within an intermediate volume fraction of the tank, and a first section of substantially constant temperature which approximates the substantially constant temperature within a top volume fraction of the tank. The variation of temperature profiles over time are used to estimate the volume of heated water drawn off from the tank or the amount of heated water available.</p> |
