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

• US 7,881,831 B2
• Filed: 10/12/2009
• Issued: 02/01/2011
• Est. Priority Date: 11/15/2001
• Status: Expired due to Fees

• Current Assignee: A. O. Smith Corporation
• Original Assignee: A. O. Smith Corporation
• Inventors: Patterson, Wade C., Phillips, Terry G.
• Primary Examiner(s): Bahta; Kidest
• Application Number:
  US12/577,457
• Publication Number:
  US 20100030396A1
• Time in Patent Office: 477 Days
• Field of Search: 219438-486, 219/490, 219/481, 219/497, 219/502, 219/505, 219/508, 392450-458, 307 38- 41, 700/299, 700/300, 432/36, 432/44
• 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 water heating system including a tank to store water, a temperature sensor positioned to detect a temperature of the water, and a temperature control element configured to alter the temperature of the water. The system also includes a controller configured to control the temperature of the water based on a first temperature threshold during a first time period and monitor the amount of time that the temperature control element is in either the activated state or the deactivated state during the first time period. The control then determines a second temperature threshold for a subsequent time period based on the monitored amount of time.

Claims

1. A water heating system comprising:

a tank to store water;

a temperature sensor positioned to detect a temperature of the water;

a temperature control element configured to alter the temperature of the water, the temperature control element having an activated state and a deactivated state; and

a controller including a processor and a memory that stores computer instructions that, when executed by the processor, cause the controller to

control the temperature of the water based on a first temperature threshold during a first time period by controlling the temperature control element,

the first temperature threshold being one of a first plurality of temperature thresholds and the first time period being one of a first plurality of time periods,

each time period of the first plurality of time periods including a respective temperature threshold of the first plurality of temperature thresholds,

monitor the amount of time that the temperature control element is in at least one of the activated state and the deactivated state during the first time period,

determine a second temperature threshold for a subsequent time period,

the second temperature threshold being one of a second plurality of temperature thresholds and the subsequent time period being one of a subsequent plurality of time periods,

each time period of the subsequent plurality of time periods including a respective temperature threshold of the second plurality of temperature thresholds,

each time period of the subsequent plurality of time periods corresponding to a respective time period of the first plurality of time periods, including the first time period corresponding to the subsequent time period,

the second temperature threshold being determined based on the monitored amount of time, and

control the temperature of the water based on the second temperature threshold during the subsequent time period.

2. The system of claim 1, wherein the temperature control element includes an electric heating element.

3. The system of claim 1, wherein the computer instructions, when executed by the processor, further cause the controller to automatically generate a usage history schedule, the schedule dividing a first day into a plurality of time slots and including information related to usage history during each of the first plurality of time periods in each of the plurality of time slots.

4. The system of claim 3, wherein the information related to usage history includes an indication of the amount of time that the temperature control element was in the at least one of the activated state and the deactivated state during a previous occurrence of each of the plurality of time slots.

5. The system of claim 3, wherein the information related to usage history includes an indication of expected demand for the water during a future occurrence of each of the plurality of time slots.

6. The system of claim 3, wherein the information related to usage history includes a temperature threshold for each of the plurality of time slots based on the amount of time that the temperature control element was in the at least one of the activated state and the deactivated state during a previous occurrence of each of the plurality of time slots.

7. The system of claim 3, wherein the plurality of subsequent time periods correspond to occurrences of the plurality of time slots on a second day, and wherein the subsequent time period corresponds to the same time slot as the first time period.

8. The system of claim 3, wherein the plurality of time slots are of equal duration.

9. The system of claim 3, wherein the usage history schedule further divides each day of a week into a plurality of corresponding time slots, wherein the first plurality of time periods includes a plurality of time periods throughout a first week each corresponding to one of the plurality of time slots in the usage history schedule, and wherein the plurality of subsequent time periods includes a plurality of time periods throughout a second week each corresponding to one of the plurality of time slots in the usage history schedule.

10. The system of claim 1, wherein the controller is positioned proximate to the tank.

11. The system of claim 1, wherein the controller includes a remote device and a local device proximate to the tank, and wherein the remote device is in communication with the local device.

12. A method of heating water within a water heater, the water heater including a tank to store water, a temperature sensor positioned to detect a temperature of the water, a temperature control element configured to alter the temperature of the water, the temperature control element having an activated state and a deactivated state, and a controller including a processor and a memory that stores computer executable instructions, the method comprising:

controlling the temperature of the water based on a first temperature threshold during a first time period by controlling the temperature control element;

monitoring a first amount of time that the temperature control element is in at least one of the activated state and the deactivated state during the first time period;

storing the monitored first amount of time to the memory;

controlling the temperature of the water based on a second temperature threshold during a second period of time by controlling the temperature control element, the second period of time occurring after the first period of time;

monitoring a second amount of time that the temperature control element is in the at least one of the activated state and the deactivated state during the second time period;

storing the monitored second amount of time to the memory;

determining a third temperature threshold based on the stored first amount of time;

controlling the temperature of the water based on the third temperature threshold during a third period of time by controlling the temperature control element, the third period of time occurring after the second period of time;

determining a fourth temperature threshold based on the stored second amount of time; and

controlling the temperature of the water based on the fourth temperature threshold during a fourth period of time by controlling the temperature control element, the fourth period of time occurring after the third period of time.

13. The method of claim 12, wherein controlling the temperature control element includes controlling an electric heating element.

14. The method of claim 12, further comprising automatically generating a usage history schedule, the schedule dividing a first day into a plurality of time slots and including information related to usage history during each of the first plurality of time periods in each of the plurality of time slots.

15. The method of claim 14, wherein generating a usage history schedule further includes storing an indication of the amount of time that the temperature control element was in the at least one of the activated state and the deactivated state during a previous occurrence of each of the plurality of time slots.

16. The method of claim 14, wherein generating a usage history schedule further includes storing an indication of expected demand for the water during a future occurrence of each of the plurality of time slots.

17. The method of claim 14, wherein generating a usage history schedule further includes storing a temperature threshold for each of the plurality of time slots based on the amount of time that the temperature control element was in the at least one of the activated state and the deactivated state during a previous occurrence of each of the plurality of time slots.

18. The method of claim 14, wherein the first period of time and the second period of time correspond to occurrences of two of the plurality of time slots on a first day, and wherein the third period of time and the second period of time correspond to the same two respective time slots on a second day.

19. The method of claim 14, wherein the usage history schedule further divides each day of a week into a plurality of corresponding time slots, wherein the first period of time and the second period of time correspond to two of the plurality of time slots in the usage history schedule during a first week, and wherein the third period of time and the fourth period of time correspond to the same two respective time slots in the usage history schedule during a second week.

20. The method of claim 14, wherein the time slots are of equal duration.

21. A system for controlling a temperature of water residing within a tank, comprising a processor and a memory that stores computer executable instructions that, when executed by the processor, cause the system to:

receive a signal from a temperature sensor indicative of a temperature of the water residing in the tank;

send a signal to a heating element that causes the heating element to heat the water within the tank according to one of a plurality of activation states, the plurality of activation states including at least a first activated state and a first deactivated state;

access a schedule of expected water usage stored on the memory, the schedule of expected water usage based on the amount of time that the heating element operated in a first activation state during each of a first plurality of time periods, the first plurality of time periods corresponding to time periods within a first day;

select a temperature threshold for a second time period from a second plurality of time periods based on the schedule of expected water usage, the second plurality of time periods corresponding to the same time periods on a second day as the first plurality of time periods on the first day;

maintain the temperature of the water within the tank at the temperature threshold during the second time period by sending signals to the heating element that cause the heating element to heat the water within the tank according to one or more of the plurality of activation states; and

update the schedule of expected water usage based on the amount of time that the heating element operated in the first activation state during the second time period.