ELECTRONICALLY CONTROLLED HOT WATER RECIRCULATION PUMP

• US 20110231022A1
• Filed: 02/17/2011
• Published: 09/22/2011
• Est. Priority Date: 02/18/2010
• Status: Active Grant

• Current Assignee: Taco, Inc.
• Original Assignee: Taco, Inc.
• Inventors: Gonzales, Christian, McNamara, Michael E., Kellicker, Robert
• Granted Patent: US 8,594,853 B2
• Time in Patent Office: Days
• US Class Current: 700/282
• CPC Class Codes: F24D 17/0078 Recirculation systems
• CPC Class Codes: F24D 19/1051 for domestic hot water
• CPC Class Codes: F24D 19/1063 counting of energy consumption
• CPC Class Codes: G05D 7/0617 specially adapted for fluid materials

Abstract

A water pump controlled by a microcontroller and operated to pump hot water for specific recirculation periods during a multi-day cycle. The recirculation periods are determined from hot water usage data logged by the microcontroller during a logging period occurring in the previous multi-day cycle. A preferred cycle is during a seven-day, or one-week, period.

Claims

1. A smart pump for a building hot water system comprising:

a microcontroller;

a sensor for sensing the opening of a water tap on the hot water system and operatively connected to the microcontroller, the microcontroller receiving, logging and recording data signals from the sensor indicating the flow of hot water to a tap during a pre-defined data logging period;

a water pump mechanism coupled to and controlled by the microcontroller in accordance with a recorded hot water usage data pattern generated from occurrences of hot water usage logged by the microcontroller during a prior pre-defined data logging period, the water pump mechanism operating to recirculate hot water through the hot water system.

2. The smart pump of claim 1 further comprising an automatic operation switch coupled to the microcontroller for controlling the operation of the smart pump.

3. The smart pump of claim 1 where a signal interface circuit couples the microcontroller to the water pump mechanism allowing the microcontroller to control the operation of the water pump mechanism.

4. The smart pump of claim 1 where the microcontroller has input ports for receiving signals from one or more sensors for detecting hot water usage by sensing a temperature change in the hot water system.

19. The smart pump of claim 1 where the microcontroller is integrated with and housed within the water pump mechanism.

5. A method for controlling the flow of hot water in a building hot water system, the hot water system comprising a source of hot water, a piping system for containing a flow of hot water, a water pump mechanism operatively connected to the piping system for causing the flow of hot water from the source through the piping system, a sensor for sensing the flow of hot water through the hot water system, a microcontroller operatively connected to the sensor to receive a signal indicating the flow of hot water, the microcontroller also being capable of logging and recording the signal during a pre-defined data logging period, and for controlling the pump to cause hot water flow during a subsequent data logging period;

the method comprising;

during a pre-defined data logging period, logging and recording on the microcontroller, signals from the sensor indicating the times for the periods of a flow of hot water through the hot water system during each day of the data logging period to obtain usage patterns data during the data logging period; and

during a succeeding pre-defined data period controlling the operation of the water pump mechanism with the microcontroller to operate the water pump mechanism to maintain a flow of hot water in accordance with the logged usage pattern data obtained during the previous defined data logging period.

6. The method of claim 5 further comprising:

during the succeeding pre-defined data period, logging and recording on the microcontroller, signals from the sensor indicating the times for the periods of a flow of hot water through the hot water system during each day of the succeeding data period to obtain usage patterns data during the succeeding data logging period updating the logged usage pattern data obtained during the succeeding defined data logging period, representing the water usage patterns upon expiration of the succeeding pre-defined data logging period; and

operating the water pump mechanism during a second succeeding data period, in accordance with the updated data.

7. The method of claim 5 where each succeeding pre-defined data period comprises one or more recirculation periods each day of the pre-defined data period, each recirculation period including a start usage cycle and an end usage cycle, as defined from the previously logged and recorded data.

8. The method of claim 5 where the microcontroller is programmed to place the smart pump into an idle mode when no hot water usage is detected for a pre-defined period of time during any data period.

9. The method of claim 8 where the pre-defined period of time is 36 hours.

10. The method of claim 7 where the sensor signals a start usage cycle determined by a time rate of change of water temperature of K degrees per L minutes after the water pump mechanism has been off for M minutes where K, L and M are pre-defined variables representing real numbers greater than zero.

11. The method of claim 7 where a start usage cycle occurs when the water pump mechanism has been off for P minutes and the water remains hot, where P is a variable representing a real number greater than zero.

12. The method of claim 7 where the end usage cycle occurs when no hot water usage is detected for a pre-defined period of time, Z, where Z is a variable representing a real number greater than zero.

13. The method of claim 12 where Z equals 2.8 hours.

14. The method of claim 7 where a pre-run time X and a post-run time Y are applied to the start usage cycles and to the end usage cycles respectively where X and Y are variables representing time periods in minutes, hours, seconds or any combination thereof.

15. The method of claim 5 further comprising operating the water pump mechanism in a pulse mode based on a selection made with an automatic switch.

16. The method of claim 5 where upon restoration of power after a power outage the water pump mechanism can return to its operating status immediately prior to the power outage.

17. The method of claim 5 where, upon restoration of power after a power outage, the water pump mechanism starts a new data logging period.

18. The method of claim 5 where the data togging period is 7 calendar days.