Method for Monitoring the Energy Content of a Water Storage Tank System

A hot water tank device, the hot water tank device comprising a tank, a cold-water inlet, a heated water outlet, a cold-water temperature sensor, a heating device and a controller component,

• the tank containing water, wherein the tank receives incoming cold-water at the cold-water inlet and outputs heated water through the heated water outlet when a tapping event occurs,
• the heated water outlet being located in an upper portion of the tank and the cold-water inlet being located in a lower portion of the tank with the heating device being thermally coupled to water in between the cold-water inlet and the heated water outlet,
• the cold-water temperature sensor being arranged in the lower portion of the tank configured to determine a temperature of the water in vicinity of the cold-water inlet,
• wherein the water within the tank is heated by operation of the heating device thermally coupled to the water, the operation of the heating device is controlled by said controller component,
• the cold-water temperature sensor being configured to successively measure incoming cold-water temperatures in successive cold-water temperature measurements in a defined measuring rate,
• the controller component being configured to determine a beginning of a tapping event when a difference of two successive incoming cold-water temperatures of two successive cold-water temperature measurements exceeds a predetermined first temperature difference threshold,
• the cold-water temperature sensor being further configured to successively measure incoming water temperatures during an adequate time period after the beginning of said tapping event,
• the controller component being configured to derive the actual incoming water temperature as an average of the incoming water temperatures measured during said adequate time period, and
• the controller component being configured to determine the thermal energy content of the hot water tank device as a function of said derived actual incoming cold-water temperature.

A controller system for controlling a heat up of a hot water tank, comprising

• a cold-water temperature sensor configured to be attached at a place of a tank, which contains water and comprises a water inlet configured for receiving incoming cold-water and a water outlet configured for allowing water heated to exit,
• wherein said cold-water temperature sensor is configured to measure an actual incoming cold-water temperature and to output an actual cold-water temperature signal representative of said actual incoming cold-water temperature and
• a control unit comprising microprocessor software integrated in an electronic device,
• wherein said control unit is configured to receive said actual cold-water temperature signal transmitted by said cold-water temperature senor,
• wherein said control unit is configured to identify a tapping event and to control a heating device when said tapping event is identified in order to heat water in the tank depending on a thermal energy content calculated as a function of an actual incoming cold-water temperature measured by said cold-water temperature sensor.

A method of controlling a heat up of a hot water tank having a control unit with a receiver interface circuit, a control circuit arrangement and a transmitter interface circuit, the method comprising the steps of:

• measuring a first tank temperature of said hot water tank with a temperature sensor mounted to said hot water tank;
• receiving, by said receiver interface circuit, a first tank temperature signal generated and transmitted by said temperature sensor, which represents said first tank temperature;
• generating, by said control circuit arrangement, an activation signal to activate a heating device, when said control circuit arrangement calls for heat;
• feeding an actual incoming cold-water temperature signal into said control circuit arrangement, wherein said actual incoming cold-water temperature signal represents an actual incoming cold-water temperature of cold-water, which flows into said hot water tank;
• generating, by said control circuit arrangement, a parameter based on said actual incoming cold-water temperature signal;
• measuring a second tank temperature of said hot water tank with said temperature sensor after said incoming cold-water flowed into said hot water tank, wherein said second tank temperature is related to a thermal energy content of said hot water tank;
• receiving, by said receiver interface circuit, a second tank temperature signal generated and transmitted by said temperature sensor, which represents said second tank temperature;
• modifying, by said control circuit arrangement, said parameter based on said second tank temperature signal;
• performing, by said control circuit arrangement, a comparison of a set point value with said parameter, which is modified based on said second tank temperature signal;
• processing, by said control circuit arrangement, said activation signal depending on said comparison;
• and
• transmitting, by said transmitter interface circuit to a receiver interface circuit of a heating device, said activation signal, which is processed depending on said comparison.