The system utilizes a radiation sensing device which views an electrically heated emissive igniter to provide proof-of-ignitability detection of the igniter. Optimally a photovoltaic array may be employed to self-power the electronic circuitry and fuel intake valve to the burner of a combustion device. In one embodiment there is also provides a second emission device viewed by the first photovoltaic array or a second photovoltaic device which views a second emissive device which is thermally heated upon activation of the burner. The electronic signals generated by the second light sensing device can be used to prove ignition of the combustion gases. When the second light sensing device is a photovoltaic array, power may be generated for recharging a storage battery, which in turn, can be used to electrically heat the emissive igniter. In the simpler case where the second emissive device is powered by the gas flame, means are provided for turning off the igniter. Thermal sensing may be provided to verify temperature of the system. The system thereby provides a means for affording the significant safety features of proof-of-ignitability and proof-of-ignition to a combustion apparatus.
CROSS REFERENCE TO RELATED APPLICATIONS
This invention is a continuation in part of our prior patent applications. This application is copending with applicants' prior applications entitled, "Photovoltaic Control Systems", PCT/US 84/101038, (U.S. Pat. No. 4,263,791,U.S. Ser. No. 659,074, (abandoned) filed July 3, 1984, and Oct. 5, 1984, respectively; applicants' abandoned application Ser. No. 517,699, filed July 25, 1983; applicants' application entitled "Photovoltaic Oxygen Depletion Sensor", Ser. No. 693,869, filed Jan. 22, 1985 (abandoned); applicants' application entitled "Self-Powered Intermittent Ignition and Control System for Gas Combustion Appliances", Ser. No. 937,609 filed Dec. 3, 1986 (abandoned); "Photovoltaic Controlled Electronic Valves", Ser. No. 701,369, (abandoned) filed Feb. 13, 1985; "Photovoltaic Control Systems", Ser. No. 048,961, (U.S. Pat. No. 4,793,799) filed May 11, 1987; and the patent disclosure "Photovoltaic Controls and Electrically Powered Emissive Ignition Devices", Disclosure Document No. 135523, filed Mar. 1, 1985, and collected into the later patent applications mentioned above. The full text of these applications are incorporated herein by reference.
A temperature sensor for detecting temperature of a heating element of an igniter such as a glow plug includes optic means disposable near the igniter for receiving at least a portion of electromagnetic energy emitted by the heating element and coupling the received electromagnetic energy to a circuit means for producing an output related to the temperature of the igniter in relation to a characteristic of the received electromagnetic energy. In one embodiment, the optic means comprises optic fibers that receive electromagnetic energy emitted by the heating element and couple that energy to a photosensitive detector.
A temperature control system for a gas-fired appliance which uses a thermoelectric device to develop power for recharging a primary energy source, such as a rechargeable battery. The present invention provides a reliable and efficient system for controlling and powering a temperature control system.
A fuel/air control system for use in controlling the operation of a surface combustion burner includes a photodetector that provides electrical signal equivalents of burner flame emission to a controller. The controller simultaneously receives signals indicative of the fuel/air mixture. The controller fits the emission and fuel air mixture data to a fourth order polynomial. Thereafter, the mathematical inflection point is computed and the corresponding fuel/air mixture is determined. The controller then generates command signals to adjust and maintain the burner at the inflection point fuel/air mixture. Multiple burner control can also be achieved with the present fuel/air control system without the need to sample exhaust gas.
A gas fired appliance measures infrared emissions from a metal object heated in a combustion chamber to evaluate combustion. Associated circuitry uses the evaluation to control operational parameters of the appliance, including fuel and air fed to the appliance. A second metal object, prior to fuel ignition, is electrically heated to emit infrared radiation. Infrared emissions from the second metal object, indicative of the temperature thereof, are monitored to assure an ignition temperature to ignite a combustible air and fuel mixture. A fan directs a stream of ambient air upon the second metal object to cool the same and reduce the infrared emanating therefrom. The reduction in infrared from the second metal object is monitored to verify proper fan operation.
Apparatus and methods for igniting fuel include an electrostatic fuel nozzle that produces an atomized fuel spray; and a catalytic igniter for igniting the atomized fuel spray.
