System and method for controlling temperature of a liquid residing within a tank

• US 20060190141A1
• Filed: 04/21/2006
• Published: 08/24/2006
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: A. O. Smith Corporation
• Original Assignee: A. O. Smith Corporation
• Inventors: Patterson, Wade C., Phillips, Terry G.
• Granted Patent: US 7,603,204 B2
• Time in Patent Office: Days
• US Class Current: 700/299
• CPC Class Codes: F24D 17/0031 with accumulation of the heated water
• CPC Class Codes: F24H 15/14 Cleaning; Sterilising; Preventing contamination by bacteria or microorganisms, e.g. by replacing fluid in tanks or conduits
• CPC Class Codes: F24H 15/172 Scheduling based on user demand, e.g. determining starting point of heating
• CPC Class Codes: F24H 15/174 Supplying heated water with desired temperature or desired range of temperature
• CPC Class Codes: F24H 15/223 in the water storage tank
• CPC Class Codes: F24H 15/269 Time, e.g. hour or date
• CPC Class Codes: F24H 15/281 Input from user
• CPC Class Codes: F24H 15/37 of electric heaters
• CPC Class Codes: F24H 15/395 Information to users, e.g. alarms
• CPC Class Codes: F24H 15/421 using pre-stored data
• CPC Class Codes: F24H 15/45 remotely accessible
• CPC Class Codes: F24H 15/486 using timers
• CPC Class Codes: F24H 9/2021 Storage heaters
• CPC Class Codes: F24H 9/28 characterised by the graphical user interface [GUI]
• CPC Class Codes: G01K 7/42 Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature
• CPC Class Codes: G05D 23/1917 using digital means
• CPC Class Codes: G05D 23/1951 with control of the working time of a temperature controlling device

Abstract

A system for controlling a temperature of a liquid residing within a tank comprises a temperature sensor, a temperature control element, memory, and logic. The temperature sensor is configured to detect the temperature of the liquid residing within the tank, and the temperature control element is coupled to the tank. The memory stores data indicative of a usage history of the tank, and the logic is configured to automatically control the temperature control element based on the data.

Claims

1. A system for controlling a temperature of a liquid residing within a tank, comprising:

a temperature sensor configured to detect the temperature of the liquid;

a temperature control element configured to alter the temperature of the liquid;

a clock; and

logic configured to track usage of the temperature control element by monitoring an activation state of the temperature control element during a first time period while the temperature control element is being controlled based on a first temperature threshold, the logic further configured to automatically select, based on a time value indicated by the clock and the usage of the temperature control element during the first time period, a second temperature threshold for controlling the temperature control element during a second time period, the logic further configured to perform a comparison between the selected temperature threshold and a value indicative of the temperature detected by the temperature sensor during the second time period and to control the temperature control element during the second time period based on the comparison.

2. The system of claim 1, wherein the temperature control element comprises a heating element.

3. The system of claim 1, wherein the logic is configured to automatically generate data indicative of a usage history of the temperature control element, the logic further configured to automatically select the threshold based on the data.

4. The system of claim 3, wherein the logic is configured to activate and deactivate the temperature control element based on the temperature threshold and another temperature threshold, thereby providing an activation hysteresis for the temperature control element, the logic further configured to change the activation hysteresis based on the data.

5. The system of claim 3, wherein the data defines a schedule, the schedule having a plurality of time slots, each time slot associated with a respective temperature threshold by the data depending on a total amount of time that the temperature control element is activated during a corresponding time period, and wherein the logic is configured to select the second threshold for controlling the temperature control element during the second time period by determining that the second threshold is associated, by the data, with the time slot corresponding to the second time period.

6. The system of claim 1, wherein the logic is configured to determine a total amount of time that the temperature control element is activated during the first time period and to select the second temperature threshold based on the total amount of time.

7. A system, comprising:

a tank;

a temperature sensor configured to detect a temperature of a liquid residing within the tank;

a temperature control element coupled to the tank;

memory for storing data indicative of a usage history of the temperature control element; and

logic configured to automatically monitor the temperature control element in order to automatically define the data, the logic further configured to automatically select, based on the data, a threshold to be used for controlling the temperature control element and to control the temperature control element based on a comparison of the threshold to a value indicative of the temperature detected by the temperature sensor, wherein the usage history defines a schedule of classified time slots, each of the time slots classified based on an amount of time that the temperature control element is activated during a time period corresponding to the respective time slot.

8. The system of claim 7, wherein the logic is configured to ensure that the temperature control element is periodically controlled such that an amount of bacteria within the tank remains within a desired range.

9. The system of claim 7, wherein the logic is configured to control the temperature control element such that the temperature control element has an activation hysteresis, the logic configured to change the activation hysteresis based on the data.

10. The system of claim 9, wherein the logic is configured to decrease the hysteresis in response to a prediction that a high usage event associated with the tank is imminent.

11. The system of claim 7, wherein the logic is configured to associate each of the time slots with a respective temperature threshold based on a classification of said each time slot by the logic.

12. A system, comprising:

a tank;

a temperature sensor coupled to the tank;

a temperature control element for controlling a temperature of a liquid residing within the tank; and

logic configured to determine a value indicative of a total amount of time that the temperature control element is activated during a first time period and to establish a temperature threshold for a second time period based on the value, the logic configured to perform a comparison between the temperature threshold and a value indicative of a temperature of the liquid detected by the temperature sensor during the second time period, the logic further configured to control the temperature control element based on the comparison.

13. The system of claim 12, wherein the logic is further configured to change an activation hysteresis for the temperature control element based on the value.

14. The system of claim 12, wherein the logic is configured to determine the value by summing a plurality of activation times of the temperature control element.

15. The system of claim 12, wherein the logic is further configured to automatically monitor the temperature control element and to automatically define a schedule based on the monitored temperature control element, the schedule having a plurality of time slots, each time slot associated with a respective temperature threshold, wherein the temperature threshold established for the second time period is associated, by the data, with a time slot corresponding to the first and second time periods, and wherein the logic, when defining the data, is configured to associate, based on the value, the temperature threshold established for the second time period with the time slot corresponding to the first and second time periods and.

16. A method, comprising the steps of:

selectively activating a temperature control element to keep a liquid within a tank within a desired temperature range during a first time period;

detecting activations of the temperature control element during the first time period;

automatically selecting a temperature threshold for the temperature control element based on the detecting step and a time value indicated by a clock;

measuring a temperature of the liquid during a second time period;

comparing a value indicative of the measured temperature to the temperature threshold; and

activating the temperature control element based on the comparing step.

17. The method of claim 16, further comprising the step of determining an amount of time that the temperature control element is activated during the first time period, wherein the selecting step is further based on the determined amount of time.

18. The method of claim 16, further comprising the steps of:

automatically defining data indicative of a usage history of the temperature control element based on the detecting step; and

automatically selecting different temperature thresholds for the temperature control element based on the data.

19. The method of claim 16, further comprising the steps of:

automatically monitoring an activation state of the temperature control element over time;

automatically defining a schedule based on the monitoring step, the schedule having a plurality to time slots; and

automatically associating each of the time slots with a respective temperature threshold, wherein the automatically selecting step is based on the associating step.

20. The method of claim 19, wherein the associating step comprises the step of associating the selected temperature threshold with a time slot corresponding to the second time period based on the activating step.

21. A method, comprising the steps of:

detecting changes in temperature of a liquid within a tank over time;

activating a temperature control element based on the changes in temperature;

tracking an activation state of the temperature control element;

defining, based on the tracking step, a schedule of classified time slots, each of the time slots classified based on an amount of time that the temperature control element is activated during a time period corresponding to the respective time slot;

automatically selecting a temperature threshold based on the schedule of the classified time slots; and

controlling the temperature control element based on the selected temperature threshold.