초록 ▼

A water heater having a water tank and a heating source disposed proximate to the water tank such that the heating source may heat water within the water tank. A temperature sensor is provided that is partially thermally isolated from the water in the water tank. A controller may be provided that at

A water heater having a water tank and a heating source disposed proximate to the water tank such that the heating source may heat water within the water tank. A temperature sensor is provided that is partially thermally isolated from the water in the water tank. A controller may be provided that at least partially compensates for the partial thermal isolation of the temperature sensor and regulates the heating source. In some instances, the temperature sensor may be at least partially disposed within a thermally isolating mass.

대표청구항 ▼

1. A water heater comprising: a temperature sensing assembly including: a housing that defines a polymeric well with an enclosed end and an open end;a temperature sensor situated in the polymeric well adjacent the enclosed end, with one or more sensor wires extending from the temperature sensor towa

1. A water heater comprising: a temperature sensing assembly including: a housing that defines a polymeric well with an enclosed end and an open end;a temperature sensor situated in the polymeric well adjacent the enclosed end, with one or more sensor wires extending from the temperature sensor toward the open end;a water tank for holding water, the water tank having a wall with an aperture extending through the wall, wherein at least part of the polymeric well of the housing extends through the aperture in the wall such that the enclosed end of the polymeric well is exposed to water in the water tank, at least part of the housing remaining outside of the water tank;a heating source disposed proximate the water tank for heating the water in the water tank;the temperature sensor of the temperature sensing assembly producing a temperature signal that is related to an actual temperature of the water in the water tank, wherein the temperature signal includes at least at times a thermal differential and/or thermal lag relative to the actual temperature of the water in the water tank due to a partial thermal isolation of the temperature sensor caused at least in part by the temperature sensor being separated from the water in the water tank by the polymeric well of the housing; anda controller in communication with the temperature sensor via the one or more sensor wires, the controller configured to determine, at least while the heating source is energized during a current heating cycle, a command temperature to be used in controlling the water heater during the current heating cycle, the command temperature based at least in part on the temperature signal in order to at least partially compensate for the thermal differential and/or thermal lag of the temperature signal, the controller further configured to regulate the heating source based at least in part upon the command temperature. 2. The water heater of claim 1, wherein the housing is configured to screw into threads of the water tank. 3. The water heater of claim 1, wherein the controller also determines a command temperature while the heating source is not energized to at least partially compensate for the thermal lag of the temperature signal. 4. The water heater of claim 3, wherein the controller determines the command temperature from the temperature signal using a first order approximation or a second order approximation. 5. The water heater of claim 4, wherein the first order approximation is changed to the second order approximation when a condition is detected. 6. The water heater of claim 1, wherein the controller is configured to determine if water is being drawn from the water tank or if the water heater is in a recovery period, based upon temperature changes measured by the temperature sensor. 7. The water heater of claim 1, wherein the controller determines the command temperature from the temperature signal using a first equation when the water heater is in a water draw period and a second equation when the water heater is in a recovery period. 8. The water heater of claim 7, wherein the controller determines the command temperature from the temperature signal using a third equation when the water heater is in a standby period. 9. The water heater of claim 1, wherein the command temperature represents an estimate, calculated by the controller, of an actual water temperature within the water tank. 10. A method of controlling water temperature of water within a water heater water tank, the water heater including a heat source and a temperature sensor that is disposed within a housing of a temperature sensing assembly, the housing including a polymeric well having an enclosed end and an open end, with the enclosed end extending into the water tank and exposed to water in the water tank, at least part of the housing remaining outside of the water tank, the temperature sensor producing a temperature signal that is related to an actual temperature of the water in the water tank, wherein the temperature signal includes at least at times a thermal differential and/or thermal lag relative to the actual temperature of the water in the water tank due to a partial thermal isolation of the temperature sensor caused at least in part by the temperature sensor being separated from the water in the water tank by the polymeric well of the housing, the method comprising the steps of: monitoring the temperature signal provided by the temperature sensor;determining, at least while the heat source is energized during a current heating cycle, a command temperature based on the temperature signal based at least in part on the temperature signal in order to at least partially compensate for the partial thermal isolation of the temperature sensor from the water in the water tank; andcontrolling the heat source during the current heating cycle based at least in part upon the command temperature. 11. The method of claim 10, further comprising determining an operating mode of the water heater by watching for changes in the temperature signal. 12. The method of claim 11, wherein the step of determining a command temperature comprises compensating in accordance with a first mathematical relationship when the water heater is in a water draw mode. 13. The method of claim 12, wherein the step of determining a command temperature comprises compensating in accordance with a second mathematical relationship when the water heater is in a recovery mode, wherein the second mathematical relationship is different from the first mathematical relationship. 14. The method of claim 13, wherein the step of determining a command temperature comprises compensating in accordance with a third mathematical relationship when the water heater is in a standby mode, wherein the third mathematical relationship is different from the first and second mathematical relationships. 15. The method of claim 10, wherein the step of determining a command temperature comprises compensating in accordance with a first order approximation to account for the thermal isolation of the temperature sensor. 16. The method of claim 10, wherein the water heater also includes an ambient temperature sensor, and the step of determining a command temperature further comprises accounting for an ambient temperature value. 17. A water heater comprising: a temperature sensing assembly including: a housing that defines a polymeric well with an enclosed end and an open end;a temperature sensor situated in the polymeric well adjacent the enclosed end, with one or more sensor wires extending from the temperature sensor toward the open end;a water tank for holding water, the water tank having a wall with an aperture extending through the wall, wherein at least part of the polymeric well of the housing extends through the aperture in the wall such that the enclosed end of the polymeric well is exposed to water in the water tank, at least part of the housing remaining outside of the water tank;a heating source disposed proximate the water tank for heating the water in the water tank;the temperature sensor of the temperature sensing assembly producing a temperature signal that is related to an actual temperature of the water in the water tank, wherein the temperature signal includes at least at times a thermal differential and/or thermal lag relative to the actual temperature of the water in the water tank due to a partial thermal isolation of the temperature sensor caused at least in part by the temperature sensor being separated from the water in the water tank by the polymeric well of the housing; anda controller in communication with the temperature sensor via the one or more sensor wires, the controller configured to determine a current command temperature based at least in part on a current temperature signal in order to at least partially compensate for the thermal differential and/or thermal lag of the temperature signal, the controller further configured to regulate the heating source based at least in part upon the current command temperature;wherein the current command temperature represents an estimate, calculated by the controller, of an actual water temperature within the water tank. 18. The water heater of claim 17, wherein the controller determines the command temperature from the temperature signal using a first equation when the water heater is in the water draw period and a second equation when the water heater is in a recovery period. 19. The water heater of claim 18, wherein the controller determines the command temperature from the temperature signal using a third equation when the water heater is in a standby period.