Electronic mixing valve in standard hot water heater

Patent metadata

Field	Value
Publication number	US-9244466-B2
Application number	US-201313893858-A
Country	US
Kind code	B2
Filing date	May 14, 2013
Priority date	Jul 24, 2012
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

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.

First claim

What is claimed is:

1. A hot water heater system comprising:
a hot water tank having a heater, a cold water inlet line, and a hot water outlet line;
an electronically controlled mixing valve fluidly 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; and

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

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 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;
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; and stopping the flow of water from the mixed output line if a decrease in the detected temperature is not detected within a pre-determined time period.

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 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
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

Assignees

• Gen Electric

Inventors

• Duplessis Samuel
• Zimmer Thomas

Classifications

• G05D23/132 Primary

  with temperature sensing element · CPC title

• F24D17/0031

  with accumulation of the heated water · CPC title

• G05D23/1393 Primary

  characterised by the use of electric means · CPC title

• Y10T137/0329

  Mixing of plural fluids of diverse characteristics or conditions · CPC title

• F24D19/1051

  for domestic hot water · CPC title