Temperature algorithm for water heater

Patent metadata

Field	Value
Publication number	US-10330344-B2
Application number	US-201715656878-A
Country	US
Kind code	B2
Filing date	Jul 21, 2017
Priority date	Jul 21, 2017
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A water heater including a storage tank including a water inlet and a water outlet, a pump, an upper temperature sensor, a lower temperature sensor, and an electronic processor. The electronic processor is configured to receive an upper temperature signal and a lower temperature signal, compare the upper temperature signal to a sum of a setpoint temperature threshold minus a temperature differential, and compare the lower temperature signal to a high limit temperature threshold. The electronic processor is further configured to activate the pump in response to the first upper temperature signal being less than the sum of the setpoint temperature threshold minus the temperature differential and the first lower temperature signal being less than the predetermined high limit temperature threshold.

First claim

What is claimed is:

1. A water heater comprising:
a storage tank including a water inlet and a water outlet;
a circulation pump configured to deliver water to an external heater of the water heater;
an upper temperature sensor configured to sense an upper temperature related to an upper area of the tank and output an upper temperature signal corresponding to the upper temperature;
a lower temperature sensor configured to sense a lower temperature related to a lower area of the tank and output a lower temperature signal corresponding to the lower temperature; and
an electronic processor configured to:
receive a first upper temperature signal and a first lower temperature signal;
compare the first upper temperature signal to a sum of a setpoint temperature threshold minus a preset temperature differential value;
compare the first lower temperature signal to a high limit temperature threshold; and
activate the circulation pump in response to the first upper temperature signal being less than the sum of the setpoint temperature threshold minus the temperature differential value and the first lower temperature signal being less than the predetermined high limit temperature threshold.

2. The water heater of claim 1 , wherein the electronic processor is further configured to:
while the circulation pump is activated, compare a second lower temperature signal to the predetermined high limit temperature threshold; and
in response to the second lower temperature signal being equal to or exceeding the predetermined high limit temperature threshold, deactivate the circulation pump.

3. The water heater of claim 2 , wherein the electronic processor is further configured to in response to the second lower temperature signal exceeding the predetermined high limit temperature threshold, place the water heater in a standby mode;
wherein, while in the standby mode, at least one selected from the group consisting of the predetermined setpoint temperature threshold and the predetermined high limit temperature threshold is updated.

4. The water heater of claim 3 , wherein the predetermined setpoint temperature threshold is updated based on a maximum temperature sensed by the upper temperature sensor while the storage tank is in the standby mode.

5. The water heater of claim 3 , wherein the electronic processor is further configured to
while the circulation pump is activated, determine at least one selected from the group consisting of a rate of temperature based on a third lower water temperature signal and a difference between a second upper water temperature signal and the third lower water temperature signal; and
deactivate the circulation pump in response to at least one selected from the group consisting of the rate of temperature increasing and the difference decreasing.

6. The water heater of claim 5 , wherein the electronic processor is further configured to:
activate the circulation pump in response to the first upper temperature signal being less than the sum of the predetermined setpoint temperature threshold minus the temperature differential value, the first lower temperature signal being less than the predetermined high limit temperature threshold, a third upper temperature signal being less than the predetermined setpoint temperature threshold and a fourth lower temperature signal being less than a second predetermined high limit threshold; and
in response to at least one selected from the group consisting of the third upper temperature signal being greater than or equal to the predetermined setpoint temperature threshold and the fourth lower temperature signal being equal or greater than the second predetermined high limit temperature threshold, deactivate the circulation pump.

7. The water heater of claim 6 wherein the electronic processor is further configured to:
in response to at least one selected from the group consisting of the third upper temperature signal being less than the predetermined setpoint temperature threshold and the fourth lower temperature signal being less than the second predetermined high limit temperature threshold, determine at least one selected from the group consisting of a second rate of temperature based on a fifth lower water temperature signal and a second difference between a fourth upper water temperature signal and the fifth lower water temperature signal; and
deactivate the circulation pump in response to at least one selected from the group consisting of the second rate of the temperature increasing and the second difference decreasing.

8. The water heater of claim 1 , wherein the predetermined high limit temperature threshold is determined based on the predetermined setpoint temperature threshold.

9. A method of operating a water heater, the water heater including a storage tank including a water inlet and a water outlet, a circulation pump configured to deliver water to an external heater of the water heater, an upper temperature sensor configured to sense an upper temperature related to an upper area of the tank and output an upper temperature signal corresponding to the upper temperature, and a lower temperature sensor configured to sense a lower temperature related to a lower area of the tank and output a lower temperature signal corresponding to the lower temperature, the method comprising:
receiving a first upper temperature signal and a first lower temperature signal;
comparing the first upper temperature signal to a sum of a setpoint temperature threshold minus a preset temperature differential value;
comparing the first lower temperature signal to a high limit temperature threshold; and
activating the circulation pump in response to the first upper temperature signal being less than the sum of the setpoint temperature threshold minus the temperature differential value and the first lower temperature signal being less than the predetermined high limit temperature threshold.

10. The method of claim 9 further comprising:
while the circulation pump is activated, comparing a second lower temperature signal to the predetermined high limit temperature threshold; and
in response to the second lower temperature signal being equal to or exceeding the predetermined high limit temperature threshold, deactivating the circulation pump.

11. The method of claim 10 further comprising in response to the second lower temperature signal exceeding the predetermined high limit temperature threshold, placing the water heater in a standby mode;
wherein, while in the standby mode, at least one selected from the group consisting of the predetermined setpoint temperature threshold and the predetermined high limit temperature threshold is updated.

12. The method of claim 11 wherein the predetermined setpoint temperature threshold is updated based on a maximum temperature sensed by the upper temperature sensor while the storage tank is in the standby mode.

13. The method of claim 11 further comprising
while the circulation pump is activated, determining at least one selected from the group consisting of a rate of temperature based on a third lower water temperature signal and a difference between a second upper water temperature signal and the third lower water temperature signal; and
deactivating the circulation pump in response to at least one selected from the group consisting of the rate of the temperature increasing and the difference decreasing.

14. The method of claim 13 further comprising:
activating the circulation pump in response to the first upper temperature signal being less than the sum of the predetermined setpoint temperature threshold minus the temperature diffe

Assignees

• Smith Corp A O

Inventors

• Teng Yingwu
• Schultz Michael William
• Mcdow Carl Edward

Classifications

• F24H9/124

  Mechanical Engineering · mapped topic

• F24H9/2007 Primary

  for water heaters · CPC title

• F24H9/133 Primary

  Storage heaters · CPC title

• F24H1/185

  using electric energy supply (F24H1/201 takes precedence) · CPC title

• F24D2240/22

  Placed at bottom position · CPC title