System and approach for water heater comfort and efficiency improvement

• US 10,132,510 B2
• Filed: 12/09/2015
• Issued: 11/20/2018
• Est. Priority Date: 12/09/2015
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Heil, David, Khosla, Ravindra, Hazzard, Frederick
• Primary Examiner(s): Norman, Marc
• Application Number:
  US14/964,392
• Publication Number:
  US 20170167736A1
• Time in Patent Office: 1,077 Days
• Field of Search: 236 20 R, 236 25 R, 236 46 R, 236 46 C
• CPC Class Codes: F24D 19/1069 regulation in function of the temperature of the domestic hot water
• CPC Class Codes: F24D 19/1081 counting of energy consumption
• CPC Class Codes: F24D 2240/26 Vertically distributed at fixed positions, e.g. multiple sensors distributed over the height of a tank, or a vertical inlet distribution pipe having a plurality of orifices
• CPC Class Codes: F24H 15/156 Reducing the quantity of energy consumed; Increasing efficiency
• CPC Class Codes: F24H 15/175 where the difference between the measured temperature and a set temperature is kept under a predetermined value
• CPC Class Codes: F24H 15/184 Preventing harm to users from exposure to heated water, e.g. scalding
• CPC Class Codes: F24H 15/223 in the water storage tank
• CPC Class Codes: F24H 15/36 of burners
• 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 15/479 for programming the system
• CPC Class Codes: F24H 15/486 using timers
• CPC Class Codes: G05B 19/042 using digital processors G05B19/05 takes precedence
• CPC Class Codes: G05B 2219/2658 Heat pump
• CPC Class Codes: G05D 23/01 without auxiliary power

Abstract

A system for heating water to improve safety and efficiency. The system may have normal operation measured in time. After a time of normal operation, a water temperature setpoint may be checked. If the setpoint is not at a certain level, normal operation may continue. If the setpoint is within the certain level, water temperature may be measured. If the water temperature is less than a desired level, one or more draws of water may be measured for a preset temperature drop. If the draws do not meet the temperature drop, a return to check the setpoint may be made. If the draws meet the temperature drop, the setpoint may be reduced and a time of normal operation may be measured to determine whether a burn cycle occurs within the time. If not, normal operation may continue; but if so, a return to check the setpoint may be made.

Claims

1. A water heater control mechanism comprising:

a processor having a memory;

a temperature sensor situated in a tank of a water heater, and connected to the processor;

a heater connected to a valve or switch;

a controller connected to the processor, the controller configured to receive at least a temperature setpoint and communicate the controller setpoint to the processor;

an actuator attached to the valve and connected to the processor; and

a program situated in the memory; and

wherein;

the processor has a normal operation for controlling temperature of water in the tank relative to a setpoint for temperature of the water;

the program provides steps that comprise;

timing a length of normal operation;

reading the temperature setpoint if the timing of a length of the normal operation exceeds a first pre-determined time;

reading the temperature sensor if a reading of the temperature setpoint is between an upper pre-determined temperature and a lower pre-determined temperature;

measuring one or more draws in terms of time and temperature if the reading of the temperature sensor is equal to or greater than said upper pre-determined temperature;

reducing a setting of the temperature setpoint if the terms of time and temperature are within pre-defined terms of time and temperature for one of the one or more draws;

timing to when a burn cycle occurs from the step of reducing a setting of the temperature setpoint; and

reading the temperature setpoint if a time until said burn cycle occurs is greater than a second pre-determined time.

2. The mechanism of claim 1, wherein if the reading of the temperature setpoint is not between the two pre-determined temperatures, then the processor returns to normal operation.

3. The mechanism of claim 2, wherein the two pre-determined temperatures for the temperature setpoint are between A degrees Fahrenheit and B degrees Fahrenheit.

4. The mechanism of claim 2, wherein the pre-determined temperature for the temperature sensor is C degrees Fahrenheit.

5. The mechanism of claim 1, wherein a return to reading the temperature setpoint occurs if the terms of time temperature for a draw are not within the pre-defined terms of time and temperature for a draw.

6. The mechanism of claim 5, wherein the pre-defined terms of time and temperature comprise J draws with a period between D minutes and E minutes between the draws with a temperature drop of F degrees Fahrenheit in G minutes on each draw.

7. The mechanism of claim 1, wherein if the timing of the length of the normal operation does not exceed the pre-determined time, then the processor continues in normal operation.

8. The mechanism of claim 1, wherein if the reading of the temperature sensor is less than said upper pre-determined temperature, then the processor returns to normal operation.

9. The mechanism of claim 1, wherein a return of the processor to normal operation if the time until the burn cycle occurs is equal to or less than the pre-determined time.

10. The mechanism of claim 9, wherein the pre-determined time for when the burn cycle occurs is H hours.

11. A fluid heater system comprising:

a tank;

a heater at the tank;

a fluid input on the tank;

a fluid output on the tank;

a heater control device connected to the heater, the heater control device including at least a valve connected to the gas burner and an actuator that controls the valve;

a controller configured to receive input signals and control parameters including at least a temperature setpoint and output control signals;

a temperature sensor situated in the tank;

a timer; and

a processor connected to the controller, heater control device, the temperature sensor, and the timer; and

wherein;

the processor controls the heater control device, adjusts the temperature setpoint and operates a timer in response to the temperature sensor, according to a program;

a setpoint above a predetermined threshold of the temperature setpoint can result in a temperature of a fluid in the tank greater than a temperature indicated by the temperature setpoint due to temperature stratification of the fluid in the tank; and

the program limits a return to a setpoint just during excess demand cycles, to reduce the temperature of the fluid in the tank increased by temperature stratification.

12. The system of claim 11, wherein a maximum temperature of a fluid in the tank is controlled by the processor and heater control device according to the program.

13. The system of claim 11, wherein:

the heater is a gas burner;

the heater control device is connected to the processor;

the program tracks a history of the valve that reveals a number of times that a burner turns on and off and the total on-time of the burner; and

after a sequence of a pre-determined number of times that the burner turns on and off, the program limits a return to the temperature setpoint by a certain number of degrees less than the setpoint of the temperature setpoint according to the total on-time of the burner and amount of fluid draw from the tank within a given period of time.

14. The system of claim 11, wherein the heater is electric.

15. The system of claim 11, wherein steps of the program comprise:

i) measuring a time of a normal operation of the processor;

ii) checking a setpoint of the temperature setpoint if a time of the normal operation exceeds an A minute duration;

iii) detecting a temperature less than B degrees Fahrenheit of the fluid if the setpoint of the temperature setpoint is between C degrees Fahrenheit and D degrees Fahrenheit to take the processor out of normal operation;

iv) making E draws of fluid from the tank within an F minute duration between a G minute duration and an H minute duration with a temperature drop detected by the temperature sensor greater than I degrees Fahrenheit of a J minute duration on each draw occurring then results in reducing the setpoint by K degrees Fahrenheit between L degrees Fahrenheit and M degrees Fahrenheit, or in absence of each draw occurring as such results in going to step iii);

v) measuring a time of another normal operation of the processor; and

vi) determining that an electric heat cycle has occurred within an N minute duration and thus resulting in returning to step iii), or determining that an electric heat cycle has not occurred thus resulting in the processor remaining in normal operation.

16. The system of claim 15, wherein A, B, C, D, E, F, G, H, I, J, K, L, M and N are numbers having units as fitting in their respective contexts.

17. The system of claim 16, wherein one or more items can be selected from a group comprising A is between 5 and 300, B is between 40 and 120, C is 80, D is 200, E is between 1 and 10, F is between G and H, G is 5, H is 250, I is between 5 and 125, J is between 1 and 60, K is between L and M, L is 0, M is 50, and N is between 10 and 600.

18. A water heater comprising:

a tank;

a water heater attached to the tank;

a control device connected to the water heater, the heater control device including at least a valve connected to the gas burner and an actuator that controls the valve;

a temperature sensor in the tank;

a temperature setpoint mechanism; and

a controller connected to the control device and temperature sensor, the controller configured to receive input signals and control parameters including at least a temperature setpoint and output control signals; and

wherein the processor operates according to a program that causes normal operation of the heater to be overridden by an occasional setpoint adjustment to ensure efficiency and a supply safe hot water temperature; and

wherein the program comprises;

checking the setpoint of the temperature setpoint;

continuing normal operation if the setpoint is at an acceptable setting;

obtaining a temperature of water in the tank from the temperature sensor if the setpoint is not at a predetermined setting;

returning to normal operation if the temperature of the water is at predetermined magnitude;

obtaining a temperature drop evaluation of one or more draws of water if the temperature of the water is not at a predetermined magnitude;

rechecking to the setpoint if the temperature drop evaluation is high;

reducing the setpoint if the temperature drop evaluation is low;

starting timing normal operation of the heater to detect whether a burn cycle occurs within a predetermined period of time;

rechecking the setpoint if the burn cycle occurs; and

continuing normal operation if a burn cycle does not occur.