| High efficiency fuel injection system for gas appliances -> Monitor Keywords |
|
|
  High efficiency fuel injection system for gas appliancesUSPTO Application #: 20060204910Title: High efficiency fuel injection system for gas appliances Abstract: A unique control system is provided for fuel injection gas appliances to achieve efficient combustion by controlling the proportion of fuel and air variables. The combustion control system provides active feedback control of the combustion event and includes at least one detection sensor e.g. CO2 CO sensor and O2, to trigger the modulation of a gas valve to adjust pressure and gas flow to the combustion chamber of a gas appliance. A processor receives the concentration signal from the detection sensor to generate a proportionate control signal to modulate a pressure regulator of the gas valve thereby to control future combustion events to achieve maximum fuel combustion efficiency. Accordingly, the injection system varies the proportion of air to fuel inflow to a prescribed optimum range achieving efficient fuel combustion. (end of abstract) Agent: Frank Frisenda, Jr. Frisenda, Quinton & Nicholson - Las Vegas, NV, US Inventor: Yu-Shan Teng USPTO Applicaton #: 20060204910 - Class: 431076000 (USPTO) Related Patent Categories: Combustion, Timer, Programmer, Retarder Or Condition Responsive Control, By Combustion Or Combustion Zone Sensor, Combustion Product Composition Sensor The Patent Description & Claims data below is from USPTO Patent Application 20060204910. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] The present invention relates to an improved method and apparatus for fuel injection for gas appliances. [0002] Gas appliances such as heaters serve as floor heaters, space heaters, room heaters, central furnaces, clothes dryers and cooking ranges. Existing gas heating appliances typically employ manually operated gas valves to regulate and control gas flow to burners for combustion to generate heat from the burning of natural or propane gas. [0003] The fixed orifice in a conventional gas valve, however, is not capable of active adjustment of pressure and flow rate of gas into the burner resulting in inefficient combustion i.e. too little heat and too much exhaust generated from a gas-heating appliance. [0004] Excessive gas flow with inadequate air in the combustion mixture, or vise versa, will cause less heat and excess exhaust. Moreover, various ambient conditions such as altitudes in different parts of the world, are variable factors that can contribute to combustion efficiency. The components of conventional gas heating appliances are generally fixed and not self-adjusting to account for these various ambient conditions. [0005] Those skilled in the art have recognized a significant need for a variety of control systems that utilizes the concentration of carbon dioxide. [0006] U.S. Pat. No. 6,398,118 issued to Rosen, et al., discloses a system for monitoring and modifying the quality and temperature of air within a conditioned space including a blower unit, a damper unit for selectively admitting outside air into the conditioned space, a temperature moderating unit and a control unit. [0007] The Rosen system relates to the art of conditioning indoor living and working and other enclosed public spaces. More particularly, the patent discloses a system in which the carbon dioxide (CO.sub.2) level is monitored and controlled by apparatus in which the CO.sub.2 sensor and support circuitry is integral with a thermostat which also serves to conventionally control the temperature range within the conditioned space. [0008] The principle of operation of the CO.sub.2 sensor is stated to be that, the cell constituting the cathode, anode and solid electrolyte, becomes susceptible to readily measurable change in accordance with the CO.sub.2 concentration at the cell. This known effect appears to be due to a chemical reaction between the CO.sub.2 and the electrolyte which must be selected to enhance the extent of the change in accordance with the gas of interest. Combinations of electrodes and electrolytes suitable for the purpose are discussed, for example, by S. Azad, S. A. Akbar, S. G. Mhaisalkar, L. D. Birkefeld and K. S. Goto in the Journal of the Electrochemical Society, 139, 3690 (1992). One suitable combination which gives very good results for measuring CO.sub.2 concentration is: platinum (Pt) for the cathode, reference electrode 30; silver (Ag) for the anode, sensing electrode 31; and a mixture of Na.sub.2 CO.sub.3, BaCO.sub.3 and AG.sub.2 SO.sub.4 as the solid electrolyte. [0009] U.S. Pat. No. 6,286,482 issued to Flynn, et al., discloses a premixed charge compression ignition engine, and a control system, which effectively initiates combustion by compression ignition and maintains stable combustion while achieving extremely low oxides of nitrogen emissions, good overall efficiency and acceptable combustion noise and cylinder pressures. The Flynn engine and control system effectively controls the combustion history, that is, the time at which combustion occurs, the rate of combustion, the duration of combustion and/or the completeness of combustion, by controlling the operation of certain control variables providing temperature control, pressure control, control of the mixture's autoignition properties and equivalence ration control. The combustion control system provides active feedback control of the combustion event and includes a sensor, e.g. pressure sensor, for detecting an engine operating condition indicative of the combustion history, e.g. the start of combustion, and generating an associated engine operating condition signal. A processor receives the signal and generates control signals based on the engine operating condition signal for controlling various engine components to control the temperature, pressure, equivalence ration and backlash or autoignition properties so as to variably control the combustion history of future combustion events to achieve stable, low emission combustion in each cylinder and combustion balancing between the cylinders. [0010] The Flynn patent discloses a strategy for controlling the start and direction of combustion by varying the air/fuel mixture autoignition properties. The autoignition properties of the air/fuel mixture may be controlled by injecting gas, e.g. air, oxygen, nitrogen, ozone, carbon dioxide, exhaust gas, etc., into the air or air/fuel mixture either in the intake system. [0011] U.S. Pat. No. 6,392,536 issued to Tice, et al. discloses a multi-function detector which has at least two different sensors coupled to a control circuit. In a normal operating mode the control circuit, which would include a programmed processor, processes outputs from both sensors to evaluate if a predetermined condition is present in the environment adjacent to the detector. In this mode the detector exhibits a predetermined sensitivity. In response to a failure of one of the sensors, the control circuit processes the output of the remaining operational sensor or sensors so that the detector will continue to evaluate the condition of the environment with substantially the same sensitivity. [0012] U.S. Pat. No. 5,644,068 issued to Okamoto, et al. discloses a gas sensor of the thermal conductivity type suitable for the quantitative analysis of the fuel vapor content of a fuel-air mixture. The Okamoto gas sensor comprises a sensing element and a compensating element , each of which includes an electrically-heated hot member incorporated into a Wheatstone bridge circuit powered by a constant current supply circuit. The constant current supply circuit is adjusted and regulated such that the hot member of the sensing element is heated with an electric current of such an intensity that corresponds to a point of transition (Y) at which, at the interface of the hot member and the mixture, the predominant mode of heat transfer changes from thermal conduction to natural convection. [0013] The dislosures of the foregoing patents are hereby incorporated by this reference. [0014] While recognizing the advantages of control systems utilizing carbon dioxide as possible parameter, these systems do not strive to achieve combustion efficiency through the recognition of carbon dioxide, carbon monoxide and oxygen gas concentration as a critical factors for active feedback control. The present invention achieves these goals. SUMMARY OF THE INVENTION [0015] The present invention relates to an improved method and apparatus for fuel injection for gas appliances. [0016] A unique control system is provided for fuel injection gas appliances to achieve efficient combustion by controlling the proportion of fuel and air variables. The combustion control system provides active feedback control of the combustion event and preferably includes a CO.sub.2 CO sensor and O.sub.2 to trigger the modulation of a valve to adjust pressure and gas flow to combustion chamber of gas appliance. A processor receives the concentration signals from the sensors and generates control signals based on the concentration signal for controlling a pressure regulator of the gas valve so as to variably control future combustion events to achieve maximum fuel combustion efficiency. Accordingly, the control signal varies the proportion of air to fuel inflow to a prescribed optimum range achieving efficient fuel combustion. [0017] The present invention achieves improved combustion efficiency by adjustment of pressure and fuel flow related to changing ambient conditions. One embodied system comprises a CO.sub.2 sensor to measure the concentration of carbon dioxide out of combustion chamber of a gas heating appliance and relay the signal to an electronic circuitry; after receiving the signal, the electronic circuitry will activate a device to adjust pressure regulator of a gas valve to a prescribed optimum range. [0018] In one embodied form, the present invention provides an improved method and apparatus for achieving high efficiency of combustion by comprising active feedback control means based upon detection of the concentration of carbon dioxide. Assuming fixed exhaust gas flow from combustion, if the concentration level of carbon dioxide exceeds about nine percent (9%), the control means will accordingly decrease the air flow into the burner of the gas heating appliance. If the concentration of carbon dioxide in the exhaust gas is less than seven percent (7%), the control means will proportionately increase the intake air flow to the combustion chamber. Thus greatest combustion efficiency can be achieved by monitoring and maintaining the concentration of carbon dioxide within a range of between about 7 to 9 percent. [0019] In a second embodiment, the inventive system comprised a CO.sub.2 sensor, CO sensor, O.sub.2 sensor to trigger the modulation of gas valve to adjust pressure of gas pressure and gas flow to combustion chamber of gas appliance. In operation, modulation will take place in a range of concentration. For instance, in the case of CO.sub.2, modulation is within the range of 7 percent to 9 percent. Gas pressure and flow will be adjusted in responding to changes of concentration, way before CO.sub.2 reaches 7 percent or 9 percent. Actually, modulation of gas value can be to such an extent of virtually shutting down gas flow to a halt. [0020] The inventive system comprises a processor that receives the qualitative and quantative signal from the carbon dioxide sensor and provides feedback control to an electronic control unit (ECU). ECU receives the sensor signal and processes the signal to determine the appropriate adjustment, if any, to the flow of air to be mixed with fuel for combustion in the burner unit. The signal reflecting the carbon dioxide concentration in the exhaust gas is then compared to a predetermined database of desired airflow adjustment values. Based on the comparison of the actual airflow to the desired airflow adjustment value, the ECU then generates a plurality of output signals, for variably controlling a pressure regulator of a gas intake flow valve and other respective components of the system so as to effectively ensure, that the future carbon dioxide concentration in the exhaust gas is maintained within the prescribed optimum range. [0021] The combustion control scheme is most preferably implemented in software contained in ECU that includes a central processing unit such as a micro-controller, micro-processor, or other suitable micro-computing unit. Accordingly, the unique system achieves high efficiency combustion in a wide variety of gas heating appliances. BRIEF DESCRIPTION OF THE DRAWING Continue reading... Full patent description for High efficiency fuel injection system for gas appliances Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this High efficiency fuel injection system for gas appliances patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like High efficiency fuel injection system for gas appliances or other areas of interest. ### Previous Patent Application: Method and apparatus for utilising fugitive gases as a supplementary fuel source Next Patent Application: High efficiency fuel injection system for gas appliances Industry Class: Combustion ### FreshPatents.com Support Thank you for viewing the High efficiency fuel injection system for gas appliances patent info. IP-related news and info Results in 2.03487 seconds Other interesting Feshpatents.com categories: Qualcomm , Schering-Plough , Schlumberger , Seagate , Siemens , Texas Instruments , |
||
