Exhaust Flow Control System and Method

• US 20160377298A1
• Filed: 06/29/2016
• Published: 12/29/2016
• Est. Priority Date: 12/03/2008
• Status: Active Grant

• Current Assignee: Oy Halton Group Ltd
• Original Assignee: Oy Halton Group Ltd
• Inventors: LIVCHAK, Andrey V., RACZEWSKI, Chester, SCHROCK, Derek W.
• Granted Patent: US 10,082,299 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F24C 15/2021 Arrangement or mounting of control or safety systems
• CPC Class Codes: F24C 15/2042 Devices for removing cooking fumes structurally associated with a cooking range e.g. downdraft F24C15/2007 takes precedence
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/33 to fire, excessive heat or smoke
• CPC Class Codes: F24F 11/38 Failure diagnosis
• CPC Class Codes: F24F 11/49 ensuring correct operation, e.g. by trial operation or configuration checks
• CPC Class Codes: F24F 11/526 giving audible indications
• CPC Class Codes: F24F 11/56 Remote control
• CPC Class Codes: F24F 11/64 using pre-stored data
• CPC Class Codes: F24F 11/76 by means responsive to temperature, e.g. bimetal springs
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2110/12 of the outside air
• CPC Class Codes: F24F 2110/40 Pressure, e.g. wind pressure
• CPC Class Codes: F24F 7/06 with forced air circulation, e.g. by fan positioning of a ventilator in or against a conduit
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
• CPC Class Codes: Y10T 137/0324 With control of flow by a condition or characteristic of a fluid

Abstract

A system and method for controlling the exhaust flow rate in an exhaust ventilation system including an exhaust hood positioned above a cooking appliance. The method can include measuring a temperature of the exhaust air in the vicinity of the cooking appliance, and measuring a radiant temperature of a surface of the cooking appliance, and determining an appliance status based on the measured exhaust air temperature and radiant temperature, and controlling the exhaust flow rate in response to the determined appliance status.

Claims

1. An exhaust ventilation system adapted for use with a cooking appliance, the exhaust ventilation system including an exhaust hood, comprising:

a control module coupled to a motor controller and adapted to determine a status of the cooking appliance based on a measured radiant temperature and a measured exhaust air temperature, and adapted to control an exhaust air flow rate based on the determined status of the cooking appliance;

an exhaust fan for removing exhaust air generated by the cooking appliance;

a motor controller coupled to control module and the exhaust fan;

at least one sensor coupled to the control module and adapted to measuring the radiant temperature of a surface of the cooking appliance;

at least one temperature sensor coupled to the control module and attached to the exhaust hood for measuring the temperature of the exhaust air.

2. The system of claim 1, wherein the at least one sensor for measuring the radiant temperature is an infrared sensor.

3. The system of claim 1, wherein the at least one sensor for measuring the exhaust air temperature is a temperature sensor.

4. The system of claim 1, wherein the control module controls the exhaust air flow rate by controlling a speed of the exhaust fan.

5. The system of claim 1, further comprising at least one motorized balancing damper attached to the exhaust hood to control a volume of the exhaust air that enters the exhaust hood.

6. The system of claim 5, wherein the control module further controls the exhaust air flow rate by controlling a position of the at least one motorized balancing damper.

7. The system of claim 1, wherein the status of the cooking appliance includes a cooking state, an idle state and an off state.

8. The system of claim 7, wherein the control module controls the exhaust flow rate by changing the exhaust flow rate between a design exhaust flow rate (Qdesign), an idle exhaust flow rate (Qidle), and an off exhaust flow rate, based on a change in the appliance status.

9. The system of claim 8, wherein the control module sets the exhaust flow rate to the design exhaust flow rate (Qdesign) when the appliance status is in the cooking state, to the idle exhaust flow rate (Qidle) when the appliance status is in the idle state, and to the off exhaust flow rate when the appliance is in the off state.

10. The system of claim 1, wherein the control module further determines a fluctuation in the radiant temperature.

11. The system of claim 10, wherein the control module determines that the cooking appliance is in the cooking state when there is a fluctuation in the radiant temperature and the radiant temperature is greater than a predetermined minimum radiant temperature, the cooking appliance is in the idle state when there is no fluctuation in the radiant temperature, and the cooking appliance is in the off state when there is no fluctuation in the radiant temperature and the radiant temperature is less than a minimum predetermined radiant temperature.

12. The system of claim 1, further including a temperature sensor for measuring an ambient temperature of the air in the vicinity of the ventilation system.

13. The system of claim 12, wherein the control module is further configured to determine a difference between the exhaust air temperature in the vicinity of the exhaust hood and the ambient temperature in the vicinity of the ventilation system.

14. The system of claim 13, wherein, based on the determined temperature difference, the control module determines that the cooking appliance is in the cooking state when the exhaust air temperature is greater than or equal to a maximum predetermined ambient temperature, the cooking appliance is in the idle state when the exhaust air temperature is less than the predetermined maximum ambient temperature, and the cooking appliance is in the off state when the exhaust air temperature is less than a predetermined ambient temperature.

15. The system of claim 1, wherein the system is calibrated before the control module controls the exhaust air flow.

16. A control module for controlling an exhaust flow rate in an exhaust ventilating system comprising an exhaust hood positioned above a cooking appliance, the control module comprising:

a processor configured to determine a status of the cooking appliance and for controlling the exhaust flow rate based on the determined appliance status.

17. The control module of claim 16, wherein the appliance status includes a cooking state, idle state and an off state.

18. The control module of claim 17, wherein the exhaust flow rate includes a design exhaust flow rate (Qdesign), an idle exhaust flow rate (Qidle), and an off exhaust flow rate.

19. The control module of claim 18, wherein the control module controls the exhaust flow rate by setting the exhaust flow rate to one of the design exhaust flow rate, the idle exhaust flow rate, and the off exhaust flow rate.

20. The control module of claim 19, wherein, when the appliance is in the cooking state, the control module changes the exhaust flow rate to the design air flow rate, when the appliance is in the idle cooking state the control module changes the exhaust flow rate to the idle exhaust flow rate and when the appliance is in the off state the control module changes the exhaust flow to the off exhaust flow rate.

21. The control module of claim 16, wherein the control module determines the appliance status by measuring an ambient temperature of the exhaust air generated by the cooking appliance, and by measuring a radiant temperature of the cooking appliance.

22. The control module of claim 19, wherein the control module is configured to determine that the appliance is in the cooking state when the exhaust air temperature is greater than or equal to a maximum predetermined ambient temperature, that the appliance is in an idle state when the exhaust air temperature is less than the predetermined maximum ambient temperature, and that the appliance is in an off state when the exhaust air temperature is less than a predetermined ambient temperature.

23. The control module of claim 19, wherein the control module is configured to determine that the appliance is in a cooking state when there is a fluctuation in the radiant temperature and the radiant temperature is greater than a predetermined minimum radiant temperature, that the appliance is in an idle state when there is no fluctuation in the radiant temperature, and that the appliance is in an off state when there is no fluctuation in the radiant temperature and the radiant temperature is less than a minimum predetermined radiant temperature.

24. The control module of claim 16, wherein the control module controls the exhaust air flow by controlling a speed of an exhaust fan attached to the exhaust hood.

25. The control module of claim 16, wherein the control module controls the exhaust air flow by controlling a position of at least one balancing damper attached to the exhaust hood.

26. The control module of claim 16, wherein the control module further calibrates the system before changing the exhaust flow rate.