ELECTRONIC MIXING VALVE IN STANDARD HOT WATER HEATER

• US 20140026970A1
• Filed: 05/14/2013
• Published: 01/30/2014
• Est. Priority Date: 07/24/2012
• Status: Active Grant

• Current Assignee: Haier US Appliance Solutions, Inc. DBA GE Appliances (Haier Group Company)
• Original Assignee: General Electric Company
• Inventors: DuPlessis, Samuel, Zimmer, Thomas
• Granted Patent: US 9,244,466 B2
• Time in Patent Office: Days
• US Class Current: 137/3
• CPC Class Codes: F24D 17/0031 with accumulation of the heated water
• CPC Class Codes: F24D 19/1051 for domestic hot water
• CPC Class Codes: F24H 9/2021 Storage heaters
• CPC Class Codes: G05D 23/132 with temperature sensing element
• CPC Class Codes: G05D 23/1393 characterised by the use of electric means
• CPC Class Codes: Y10T 137/0329 Mixing of plural fluids of diverse characteristics or conditions

Abstract

A hot water heater includes a hot water tank having a cold water inlet line and a hot water outlet line, an electronically controlled mixing valve fluid coupled to the cold water inlet line and the hot water outlet line and mixed output line and a controller operatively coupled to the mixing valve. A temperature sensor is operatively coupled to the mixed output line and the controller, the controller being operative in response to the sensor to detect a temperature of the water in the mixed output line, compare a setpoint temperature to the detected temperature of the water in the mixed output line, and regulate a flow of one or both of cold water from the cold water input line and hot water from the hot water output line through the electronically controlled mixing valve to maintain the detected temperature at the setpoint temperature.

Claims

1. A hot water heater system comprising:

a hot water tank having a cold water inlet line and a hot water outlet line;

an electronically controlled mixing valve fluid coupled to the cold water inlet line and the hot water outlet line;

a mixed output line from the electronically controlled mixing valve;

a controller operatively coupled to the electronically controlled mixing valve;

a temperature sensor operatively coupled to the mixed output line and the controller, the controller being operative in response to the sensor to;

detect a temperature of water in the mixed output line;

compare a setpoint temperature of a desired hot water temperature output to the detected temperature of the water in the mixed output line; and

regulate a flow of one or both of cold water from the cold water input line and hot water from the hot water output line through the electronically controlled mixing valve to maintain the detected temperature of the water in the mixed output line at the setpoint temperature.

2. The hot water heater system of claim 1, further comprising a water flow sensor in the mixed output line coupled to the controller, the controller being operative in response to the water flow sensor to:

detect a flow demand from the water flow sensor; and

set a state of the electronically controlled mixing valve to an initial cold water delivery state, wherein only cold water from the cold water inlet is enabled to flow through the electronically controlled mixing valve and gradually enable a flow of hot water from the hot water outlet through the electronically controlled mixing valve until the detected temperature of the water from the mixed output line reaches the setpoint temperature.

3. The hot water heater system of claim 2, wherein the controller is operative in response to the water flow sensor to:

detect a no flow state from the water flow sensor; and

switch the state of the electronically controlled mixing valve to a home state that closes off flow of hot water through the mixing valve.

4. The hot water heater system of claim 2, further comprising a cold water inlet to the hot water tank on the cold water inlet line, a temperature sensor thermally coupled to the cold water inlet configured to detect a temperature of the cold water inlet, the controller being operative in response to the temperature sensor to:

detect a change in temperature of the cold water inlet; and

switch the state of the electronically controlled mixing valve to the initial cold water delivery state when the change exceeds a predetermined threshold.

5. The hot water heater system of claim 1, further comprising a temperature sensor in the hot water outlet line and the hot water tank, each temperature sensor being coupled to the controller, the controller being operative in response to each temperature sensor to:

compare a temperature of water in the hot water outlet line to the setpoint temperature and the detected temperature of water in the mixed output line; and

regulate a flow of one or both of the cold water and hot water through the electronically controlled mixing valve to maintain the detected temperature at the setpoint temperature.

6. The hot water heater system of claim 1, wherein the controller is operative in response to the temperature sensor to:

determine that the detected temperature of the water in the mixed output line exceeds a pre-determined temperature; and

disable a heating of water in the hot water tank.

7. The hot water heater system of claim 1, wherein the controller is operative in response to the temperature sensor to:

determine that the detected temperature of the water in the mixed output line exceeds a pre-determined temperature; and

enable only a flow of cold water from the cold water inlet line through the electronically controlled mixing valve.

8. The hot water heater system of claim 1, wherein the electronically controlled mixing valve comprises a servo or stepper motor coupled with a water valve.

9. A method for controlling an electronically controlled mixing valve for a hot water heater, the electronically controlled mixing valve fluidly coupled to a cold water inlet line to the hot water heater and a hot water outlet line from the hot water heater, and providing a flow of water in a mixed output line, the method comprising:

detecting a temperature of water in the mixed output line;

comparing the detected temperature to a setpoint temperature; and

controlling a flow of water from one or both of the cold water inlet line and hot water outlet line through the electronically controlled mixing valve to regulate the detected temperature of the water in the mixed output line to correspond to the setpoint temperature.

10. The method of claim 9, further comprising:

detecting a flow state of hot water from the hot water tank;

setting a state of the electronically controlled mixing valve to an initial cold water state;

enabling an initial flow of cold water from the cold water inlet line through the mixing valve and to the mixed output line; and

enabling a gradual flow of hot water from the hot water outlet line through the mixing valve until the setpoint temperature is reached in the mixed output line.

11. The method of claim 10, further comprising:

detecting no-flow state of the hot water from the hot water tank; and

setting the state of the electronically controlled mixing valve to prevent a flow of hot water from the hot water inlet line through the mixing valve.

12. The method of claim 11, further comprising:

detecting a change in temperature of the cold water inlet; and

determining the flow state or no flow state when the detected change in temperature exceeds a predetermined threshold.

13. The method of claim 12, wherein the flow state is determined when the detected change in temperature is a decrease in temperature and the no flow state is determined when the detected change in temperature is an increase in temperature.

14. The method of claim 9, wherein controlling the flow of water through the electronically controlled mixing valve comprises:

regulating the flow of cold water and hot water through the electronically controlled mixing valve so that the detected temperature of the water in the mixed output line is in a warm state; and

gradually increasing the flow of hot water through the electronically controlled mixing valve until the detected temperature is the setpoint temperature.

15. The method of claim 9, further comprising:

determining that the detected temperature of the water in the mixed output line exceeds a pre-determined temperature; and

disabling a heating of water in the hot water tank.

16. The method of claim 9, further comprising:

determining that the detected temperature of the water in the mixed output line exceeds a pre-determined temperature; and

enabling only a flow of cold water from the cold water inlet line through the electronically controlled mixing valve.

17. A hot water heater control system comprising;

a hot water heater;

a mixing valve coupled to an output of the hot water heater, the mixing valve including a non-heated water input and a heated water input and a mixed water output;

a temperature control configured to enable setting of a temperature setpoint of the mixed water output;

a controller coupled to the mixing valve and the temperature control and configured to control the mixing valve to regulate a temperature of the mixed water output to be at the setpoint temperature; and

wherein the controller is configured to;

detect the temperature of the mixed water output;

determine if the detected temperature exceeds a pre-determined temperature threshold;

control the mixing valve to reduce a temperature of the mixed water output if the detected temperature exceeds a pre-determined temperature threshold; and

stop a flow of water from the mixing valve if a decrease in the detected temperature is not detected within a pre-determined time period.

18. The hot water heater control system of claim 17, wherein the controller is configured to control the mixing valve to increase a temperature of the mixed water output if the detected temperature is below the pre-determined temperature threshold.

19. The hot water heater control system of claim 18, wherein the controller is configured to:

detect a water flow event;

set a state of the mixing valve to a first position to enable a flow of non-heated water through the mixing valve;

determine that the temperature of the mixed water output is below the setpoint temperature;

set the state of the mixing valve to a second position to enable an increasing flow of heated water through the mixing valve until the temperature of the mixed water output is determined to be at the setpoint temperature; and

set the state of the mixing valve to the first position at an end of the water flow event.

20. The hot water heater control system of claim 19, further comprising a water inlet to the hot water heater tank coupled to the non-heated water input, a temperature sensor coupled to the water inlet, and wherein the controller is configured to detect a flow event by determining that a temperature of the water inlet decreased by a pre-determined temperature amount within a pre-determined time period.