SYSTEM AND METHOD FOR ESTIMATING AND INDICATING TEMPERATURE CHARACTERISTICS OF TEMPERATURE CONTROLLED LIQUIDS

• US 20090293816A1
• Filed: 08/06/2009
• Published: 12/03/2009
• Est. Priority Date: 05/11/2005
• 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 8,064,757 B2
• Time in Patent Office: Days
• US Class Current: 122/14.22
• CPC Class Codes: F24D 19/1051 for domestic hot water
• CPC Class Codes: F24H 15/174 Supplying heated water with desired temperature or desired range of temperature
• CPC Class Codes: F24H 15/225 at different heights of the tank
• 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 15/414 using electronic processing, e.g. computer-based
• CPC Class Codes: F24H 9/2021 Storage heaters

Abstract

Embodiments of the present disclosure generally pertain to systems and methods for estimating and indicating temperature characteristics of temperature controlled liquids. A system in accordance with one exemplary embodiment of the present disclosure has a tank filled at least partially with a liquid, such as water, and the system has a plurality of temperature sensors mounted on the tank. During operation, a controller compares temperatures sensed by these temperature sensors to a predefined temperature profile for the liquid within the tank in order to estimate the likely temperature characteristics of such liquid. The controller then reports these estimated temperature characteristics via a user interface. As an example, the controller may estimate and report the amount of liquid above a threshold temperature that can be drawn from the tank. Based on the reported temperature characteristics, a user may make decisions about whether or how to use liquid drawn from the tank.

Claims

1. A water heater comprising:

a tank;

a heating source;

a first temperature sensor positioned at a first location with respect to the tank;

a second temperature sensor positioned at a second location with respect to the tank;

a processor coupled to the first temperature sensor, the second temperature sensor, and the heating element, the processor receives a first temperature value from the first temperature sensor, receives a second temperature value from the second temperature sensor, and controls the operation of the heating source; and

a computer readable memory storing water tank temperature profile information and a set of computer instructions, and

wherein the computer instructions, when executed on the processor, cause the processor to

receive the first temperature reading and the second temperature reading,

access the water tank temperature profile information,

determine an estimated temperature profile for water in the tank based on the first temperature value, the second temperature value, and the water tank temperature profile information.

2. The water heater of claim 1, wherein the first temperature value is a voltage and wherein the processor includes an analog-to-digital converter that receives the voltage.

3. The water heater of claim 1, wherein the computer instructions, when executed on the processor, further cause the processor to control the operation of the heating source based on at least one of the first temperature value and the second temperature value.

4. The water heater of claim 1 wherein the computer instructions, when executed on the processor, further cause the processor to control the operation of the heating source based on the estimated temperature profile.

5. The water heating system of claim 1 further comprising a second heating source,

wherein the first temperature sensor is positioned near the heating source and the second temperature sensor is positioned near the second heating source.

6. The water heating system of claim 5, wherein the heating source is positioned near the top of the tank and the second heating source is positioned near the bottom of the tank.

7. The water heater of claim 1, wherein the estimated temperature profile includes an estimated amount of hot water in the tank.

8. The water heater of claim 1, wherein the water tank temperature profile information includes a list of combinations of first temperature values and second temperature values and an estimated amount of hot water corresponding to each of the combinations.

9. The water heater of claim 8, wherein the computer instructions, when executed on the processor, further cause the processor to

identify a combination from the water tank temperature profile information that most closely matches the first temperature value and the second temperature value, and

identify the estimated amount of hot water corresponding to the combination.

10. The water heater of claim 9, wherein the computer instructions, when executed on the processor, cause the processor to determine the estimated amount of hot water corresponding to the predetermined combination most closely matching the first temperature reading and the second temperature reading by:

determining a first value by calculating a difference between the first temperature value from the first temperature sensor and a first temperature value from a first predetermined combination;

determining a second value by calculating a difference between the second temperature value from the second temperature sensor and a second temperature value from the first predetermined combination;

determining a third value by calculating a difference between the first temperature value from the first temperature sensor and a first temperature value from a second predetermined combination;

determining a fourth value by calculating a difference between the second temperature value from the second temperature sensor and a second temperature value from the second predetermined combination;

selecting an estimated amount of hot water corresponding to the first predetermined combination when a sum of the first value and the second value is greater than a sum of the third value and the fourth value; and

selecting an estimated amount of hot water corresponding to the second predetermined combination when the sum of the third value and the fourth value is greater than the sum of the first value and the second value.

11. The water heater of claim 7, wherein the water tank temperature profile information includes a list of combinations of first temperature values, second temperature values, first temperature changes, and second temperature changes and an estimated volume of hot water corresponding to each of the combinations, and wherein the computer executable instruction, when executed by the processor, further cause the processor to

determine a first temperature change by calculating a difference between the first temperature value from the first temperature sensor and at least one previous first temperature value from the first temperature sensor,

determine a second temperature change by calculating a difference between the second temperature value from the second temperature sensor and at least one previous second temperature value from the second temperature sensor, and

determine the estimated amount of hot water corresponding to the combination most closely matching the first temperature value, the second temperature value, the first temperature change, and the second temperature change.

12. The water heating system of claim 7 further comprising a display, and wherein the computer instructions, when executed on the processor, further cause the processor to display the estimated amount of hot water on the display.

13. The water heating system of claim 12, wherein the computer instructions, when executed on the processor, further cause the processor to display the estimated amount of hot water on the display as an estimated total number of gallons of hot water in the tank.

14. The water heating system of claim 12, wherein the computer instructions, when executed on the processor, further cause the processor to display the estimated volume of hot water on the display as an estimated percentage of hot water in a total volume of water in the tank.

15. A method of controlling a water heater, the water heater including a tank, a heating source, a first temperature sensor positioned at a first location with respect to the tank, a second temperature sensor positioned at a second location with respect to the tank, a memory, and a processor coupled to the first temperature sensor, the second temperature sensor, and the heating element, the method comprising the following acts performed by the processor:

receiving a first temperature value from the first temperature sensor;

receiving a second temperature value from the second temperature sensor;

accessing water tank temperature profile information from the computer readable memory;

determining an estimated temperature profile for water in the tank based on the first temperature value, the second temperature value, and the water tank temperature profile information.

16. The method of claim 15, wherein the act of receiving the first temperature value includes receiving a voltage indicative of the temperature of the water located near the first temperature sensor.

17. The method of claim 15, further comprising controlling the operation of the heating source based on at least one of the first temperature value and the second temperature value.

18. The method of claim 15, further comprising controlling the operation of the heating source based on the estimated temperature profile.

19. The method of claim 15, wherein the act of determining an estimated temperature profile for water in the tank includes estimating an amount of hot water in the tank.

20. The method of claim 15, wherein the act of accessing water tank temperature profile information includes accessing a list of combinations of first temperature values and second temperature values and an estimated amount of hot water corresponding to each of the combinations.

21. The method of claim 20, wherein the act of determining an estimated temperature profile for water in the tank includes:

identifying a combination from the accessed water tank temperature profile information that most closely matches the first temperature value and the second temperature value, and

identifying the estimated amount of hot water corresponding to the combination.

22. The method of claim 21, wherein the act of identifying a combination from the accessed water tank temperature profile information that most closely matches the first temperature value and the second temperature value includes:

determining a first value by calculating a difference between the first temperature value received from the first temperature sensor and a first temperature value from a first accessed combination,

determining a second value by calculating a difference between the second temperature value received from the second temperature sensor and a second temperature value from the first accessed combination,

determining a third value by calculating a difference between the first temperature value received from the first temperature sensor and a first temperature value from a second accessed combination,

determining a fourth value by calculating a difference between the second temperature value received from the second temperature sensor and a second temperature value from the second accessed combination,

selecting an estimated amount of hot water corresponding to the first accessed combination when a sum of the first value and the second value is greater than a sum of the third value and the fourth value, and

selecting an estimated amount of hot water corresponding to the second accessed combination when the sum of the third value and the forth value is greater than the sum of the first value and the second value.

23. The method of claim 15, wherein the act of accessing water tank temperature profile information includes accessing a list of combinations of first temperature values, second temperature values, first temperature changes, and second temperature changes and an estimated volume of hot water corresponding to each of the combinations, and wherein the act of determining an estimated temperature profile includes:

determining a first temperature change by calculating a difference between the first temperature value received from the first temperature sensor and at least one previous first temperature value received from the first temperature sensor,

determining a second temperature change by calculating a difference between the second temperature value received from the second temperature sensor and at least one previous second temperature value received from the second temperature sensor, and

determining the estimated amount of hot water corresponding to the accessed combination that most closely matches the first temperature value, the second temperature value, the first temperature change, and the second temperature change.

24. The method of claim 19, wherein the water heater further includes a display, and wherein the method further comprises displaying the estimated amount of hot water in the tank on the display.

25. The method of claim 19, further comprising calculating the estimated amount of hot water in the tank as an estimated total number of gallons of hot water in the tank.

26. The method of claim 19, further comprising calculating the estimated amount of hot water in the tank as an estimated percentage of hot water in a total volume of water in the tank.

27. A method of calibrating a water heating system, the method comprising:

providing a water heater test system that includes a first tank, a water outlet, a water inlet, a first heating source, and a first number of temperature sensors, wherein the first number of temperature sensors includes a first temperature sensor and a plurality of additional temperature sensors;

activating the heating source when the temperature sensed by the first temperature sensor is below a first threshold;

drawing water from the first tank through the water outlet and adding water to the first tank through the water inlet;

receiving a temperature value from each of the additional temperature sensors;

comparing the temperature value from each of the additional temperature sensors to a second threshold;

estimating an amount of hot water in the first tank based on the number of temperature values from each of the additional temperature sensors that exceed the second threshold; and

storing temperature profile data to a first computer readable memory, wherein the temperature profile data includes an estimated amount of hot water in the first tank and a corresponding temperature reading from the first temperature sensor.

28. The method of claim 27, further comprising the acts of

providing a second water heater that includes a second tank, a second heating source, a second number of temperature sensors, and a controller with a computer readable memory,

wherein the second tank is the same size as the first tank,

wherein the second heating source is positioned in the second tank at a location on the second tank that corresponds to the location of the first heating source on the first tank,

wherein the second number of temperature sensors includes a second temperature sensor positioned proximate to the second heating element, and

wherein the second number of temperature sensors is smaller than the first number of temperature sensors;

electronically transferring the temperature profile data to the second computer readable memory; and

estimating an amount of hot water in the second tank based on the temperature profile data.

29. The method of claim 28,

wherein the first number of temperature sensors includes a third temperature sensor positioned within the first tank,

wherein the second number of temperature sensors includes a fourth temperature sensor positioned at a location on the second tank that corresponds to the location of the third temperature sensor on the first tank,

wherein the act of storing temperature profile data further includes storing temperature profile data that includes the estimated amount of hot water in the first tank and a corresponding combination of the temperature value from the first temperature sensor and a temperature value from the third temperature sensor, and

wherein the act of estimating the amount of hot water in the second tank based on the temperature profile data includes:

receiving a temperature value from the second temperature sensor,

receiving a temperature value from the fourth temperature sensor,

determining a stored combination from the temperature profile data that most closely matches a combination of the temperature value from the second temperature sensor and the temperature value from the fourth temperature sensor,

determining the estimated amount of hot water that corresponds to the most closely matching stored combination.

30. The method of claim 29, further comprising:

monitoring a rate of change in the temperature reading from the first temperature sensor; and

monitoring a rate of change in the temperature reading from the third temperature sensor,

wherein the act of storing temperature profile data further includes storing temperature profile data that includes the estimated amount of hot water in the first tank and a corresponding combination of the temperature value from the first temperature sensor, the temperature value from the third temperature sensor, the rate of change in the temperature value from the first temperature sensor, and the rate of change in the temperature value from the third temperature sensor.

31. The method of claim 30, further comprising

monitoring a rate of change in the temperature value from the second temperature sensor;

and

monitoring a rate of change in the temperature value from the fourth temperature sensor,

wherein the act of estimating the amount of hot water in the second tank based on the temperature profile data further includes;

determining a stored combination from the temperature profile data that most closely matches a combination of the temperature value from the second temperature sensor, the temperature value from the fourth temperature sensor, the rate of change in the temperature value from the second sensor, and the rate of change in the temperature value from the fourth sensor, and

determining the estimated amount of hot water that corresponds to the most closely matching stored combination.

32. The method of claim 28, wherein the second number of temperature sensors includes only two temperature sensors consisting of the second temperature sensor located proximate to the second heating element and located near the top of the second tank, and a fourth temperature sensor located proximate to a fourth heating element and located near the bottom of the second tank.

33. The method of claim 27, wherein the first number of temperature sensors includes at least 50 additional temperature sensors.

34. A water heating system comprising:

a tank;

a heating element coupled to the tank;

a temperature sensor positioned at a first location to sense a temperature of water within the tank near the first location;

a processor coupled to the temperature sensor and the heating element, wherein the processor receives a temperature value from the temperature sensor and controls the operation of the heating element; and

a computer readable memory storing water tank temperature profile information and a set of computer instructions,

wherein the water tank temperature profile information includes a list of predetermined water tank conditions and an estimated amount of hot water corresponding to each of the predetermined water tank conditions, wherein the water tank condition includes a temperature reading from the temperature sensor, and

wherein the set of computer instructions, when executed on the processor, cause the processor to;

receive the temperature value from the temperature sensor,

determine a current water tank condition based at least in part on the temperature value from the temperature sensor,

access the water tank temperature profile information, and

determine the estimated amount of hot water corresponding to the stored water tank condition most closely matching the current water tank condition.