Patent Application
20110010075
1. Field of the Invention
This invention relates to the efficient operation of internal combustion engine (ICE) emission control systems, and more particularly relates to the use of exhaust sensors to measure and record exhaust products and to control those exhaust products by controlling the ratios of a first and a second fuel supplied to ICEs.
2. Background of the Invention
The ubiquity of internal combustion engines (ICEs) makes their byproducts an important concern. Unfortunately, science assigns to many of these byproducts harmful effects for human health and for the environment. Science also raises grave concerns about possible additional deleterious effects, not yet fully ascertained in scope, such as the possible effects stemming from climate change. These harmful and dangerous byproducts reside in the gases and particulate matter that comprise the exhaust of internal combustion engines.
The fuel burned by an internal combustion engine determines the constituent gasses and particulates found in that engine's exhaust. Gasoline and diesel fueled vehicles produce, by far, the most metric tons of internal combustion exhaust. Unfortunately these fuels result in a large variety of harmful gasses and particulates in the exhaust they produce.
Examples of detrimental exhaust products from gasoline and diesel include, but are not limited to: carbon monoxide (CO), carbon dioxide (CO2), nitrogen monoxide (NO), nitrous oxide (NO2), sulfur dioxide (SO2), hydrocarbons, such as benzene and polycyclic aromatic hydrocarbons (PAFs), and particulate matter. Carbon monoxide (CO), caused from incomplete combustion, reduces the ability of blood to carry oxygen, exacerbates diseases of the heart and lungs, and causes fatigue, dizziness and headaches. Scientific research points to CO2 as the primary contributor to climate change because of its demonstrated behavior of trapping electromagnetic energy from the sun.
Both nitrogen oxides (NO and NO2) and, especially SO2, cause acid rain. Additionally, both nitrogen oxides (NO and NO2) form a yellowish-brown haze and combine with oxygen to produce a gas that damages lung tissue. Additionally, nitrogen oxides combine with hydrocarbons to form ozone (O3), which produces a white haze that decreases lung capacity and can cause lung diseases such as asthma. Furthermore, NO2, like CO2, traps electromagnetic energy in the atmosphere.
As mentioned, hydrocarbons play an important role in ozone formation. Many hydrocarbons, such as benzene and many of the PAHS are known toxins and cancer causing carcinogens. Particulates cause lung damage and can include toxins and carcinogens.
Several alternate fuels offer the promise of reducing some or all of these detrimental exhaust products. Natural gas, both compressed and liquid, and propane figure prominently among these. Additional alternatives fuels include hydrogen, liquid nitrogen, and compressed air. Further examples include hydrogen enhanced fuels, biomass fuels, and alcohol fuels, among others.
Unfortunately, alternative fuels tend to burn at high temperatures that can damage engines, exhaust systems, and surrounding components. This is particularly true for engines that have been designed for traditional fuels, even after retrofitting takes place. Running entirely on alternative fuels, therefore, presents additional mechanical problems.
Furthermore, the infrastructure does not presently exist to make such fuels readily available to the consuming public. Additionally, alternative fuels require larger, and often pressurized, storage tanks, permitting reduced travel ranges. Importantly, the availability of alternative fuels is an obstacle to supplanting traditional fuels with alternative fuels. For example, most supplies of natural gas in the United States are already allocated to home heating and the production of electricity and a reliable method for the production source of hydrogen has yet to be discovered.
Practical considerations dictate, therefore, that emission reductions through the use of alternative fuels must be achieved in stages. To accommodate this reality, innovators have designed ICEs capable of running on both traditional fuels and alternative fuels at the same time. Furthermore with some modification, ICEs not originally designed to run on a combination of traditional and alternative fuels can be altered to run on two fuels, allowing for the gradual introduction of alternative fuels to the public. However, without proper controls, the addition of the second fuel may even make emissions worse.
The ratio of fuels delivered to ICEs manifests itself in terms of both performance metrics and exhaust products. Over time, several refinements have been made to the drive systems of ICEs that run on multiple fuels, resulting in systems that rely on feedback from system sensors to optimize the fuel ratios to ensure or approach desired performance metrics. However, these improvements do not capitalize on the ability of ICEs to reduce harmful exhaust products.
As discussed above, internal combustion engines produce a number of different exhaust products that, at different levels, adversely affect different aspects of human health and the environment in varying degrees. Over time, an understanding of the impact of these exhaust products has evolved and continues to evolve. For example, the Environmental Protection Agency (EPA) once characterized CO2 as a product of “perfect” combustion. Now, CO2 may become regulated as a greenhouse gas. Despite improving understanding as to the effects of various levels of exhaust products, presently, there exists no way to measure and control levels of individual exhaust products in real time.
In view of the foregoing, what is needed are a method, apparatus and system to measure and to record exhaust products from ICEs in real time. Such a method, apparatus, and system would also control exhaust products by controlling the ratio of fuels feed to ICEs based on measurement information. Ideally such an apparatus, system, and method would make the measurements available to interested parties, such as the driver of a vehicle and the EPA, in real time.
The invention has been developed in response to the present state of the art and, in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available methods, apparatai, and systems. Accordingly, the invention has been developed to provide improved a method, an apparatus, and a systems to measure, record, and control, exhaust products from an ICE. The features and advantages of the invention will become more fully apparent from the following description and appended claims, or may be learned by practice of the invention as set forth hereinafter.
Consistent with the foregoing, a method for measuring, recording, and controlling exhaust products from ICEs is disclosed herein. In certain embodiments, such a method may include measuring, in real time, potentially harmful exhaust products from an ICE. These measurements of exhaust products become the basis for a determination of appropriate flow rate values for a first fuel and a second fuel fed to an ICE to achieve a goal regarding the presence of one or more exhaust products. These flow rate values are then implemented to control the flow rates of the first and second fuel.
The method may further include increasing the second flow rate for the second fuel relative to the first flow rate for the first fuel. Additional measurements may then be made, including measurements of exhaust temperature. The measurements may then be compared to determine whether there has been a cessation in progress toward the goal regarding one or more exhaust products or if the exhaust temperature has exceeded a safety threshold, to determine when to stop increasing the ratio of the second fuel relative to the first. The increments by which the second fuel is increased relative to the first may be determined with reference to calibration measurements of exhaust products taken when known ratios of the two fuels are combusted after an ICE has been allowed to ideal for a period.
The flow rate of the first fuel may be controlled by interrupting an oxygen sensor, pre-existing or added after the fact, communicatively coupled to an electronic control unit controlling the first fuel rate to achieve a stoichiometric ratio. The method may continue by determining a false oxygen reading that will produce the desired flow rate. This false oxygen reading is then relayed to the electronic control unit. The method may also include storing a record of measurements and uploading the measurements to a server, making them available to interested parties.
In yet another embodiment of the invention, an apparatus/system may include an array of sensors disposed along the exhaust pipe of a vehicle with an ICE. A processor may be connected to the array of sensors. The processor may use input information from the array of sensors to determine flow rate values for the first fuel and the second fuel to achieve one or more goals regarding the presence of one or more exhaust products. The processor, in turn, may be connected to a first and second control disposed along the fuel lines of the first and second fuel to control the flow rates of the fuels.
The apparatus/system may also include a Global Positioning System (GPS) and a position to gravity sensor, providing additional information to the processor and a pyrometer providing exhaust temperature information to the processor. The processor may be disposed to interrupt the connection from an oxygen sensor to an electronic control unit controlling the flow rate of the first fuel to alter the information about oxygen levels to control the flow rate of the first fuel. The apparatus may also include a memory to record measurements and a transmitter to upload measurements to a server where they would be available to interested parties.
In certain embodiments, the processor may include an increase module that determines an amount by which to increase the flow rates of the two fuels. The processor may also include a relay module to relay information, including information about flow rates, to control units. Additionally, the processor may include a record module to record measurements of the exhaust products into memory and to access the measurements from memory. In some embodiments, the processor may also include an intercept module to alter oxygen readings from an oxygen sensor to achieve desired flow rates for the first fuel.
In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not, therefore, to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through use of the accompanying drawings, in which:
The components of the present invention, as described in with reference to the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the detailed description of the embodiments of the invention that follows is not intended to limit the scope of the invention, but rather to provide certain examples of presently contemplated embodiments in accordance with the invention. The presently described embodiments will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.
As will be appreciated by one skilled in the art, the present invention may be embodied as an apparatus, system, of method. Elements of the present invention may combine hardware and software components (including firmware, resident software, micro-code, etc.) in their embodiment that may all generally be referred to herein as a “module.” A module may be realized on a combination of one or more computer-usable or computer-readable medium(s) may be utilized. Without limitation, the computer-usable or computer-readable medium may be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium.
The module may also embody computer program code for carrying out operations. The code may be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages.
The present invention is described below with reference to flowchart illustrations and/or block diagrams of a method, apparatus, and systems according to embodiments of the invention. Each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, may be implemented by computer program instructions or code. These computer program instructions may be implemented on a processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
The array of exhaust product sensors 102 is affixed along the exhaust pipe 114 of an ICE 112. The individual sensors of the array 112 are disposed inside the exhaust pipe so that the exhaust 116 flows over them. In
The sensors may be implemented as Non-dispersive Infra-red (NDIR) sensors, or sensors that use different regions of the electromagnetic spectrum, such as ultraviolet wavelengths for SO2 detection. Additional sensing mechanisms may also play a role. Such sensors may include chemical and electrochemical based sensors. The array of sensors 102 is communicatively coupled, whether by wire or other means, to the processor 104 to deliver real time measurements of the exhaust products.
The processor 102 analyzes the information from the array of sensors 102 by implementing one or more of various algorithms to determine the proper flow rates of the first fuel and of the second fuel. The fuel rates are determined to achieve one or more goals concerning the presence of one or more exhaust products in the exhaust. The goal or goals may include limiting one or more exhaust products to a predetermined level. The goal or goals may also include limiting one or more exhaust product to the lowest possible level.
In certain embodiments, the processor 104 implements algorithms that rely on principals of probability law and/or Bayesian logic to determine appropriate flow rates. In alternative embodiments, the processor 104 implements algorithms that rely on comparisons between recent measurements stored in the memory 106, which is communicatively coupled to the processor 104. The processor 104 may implement additional types of algorithms.
The first fuel may be, but is not limited to, diesel or gasoline. The second fuel may be one of many alternative fuels, including but not limited to natural gas, both compressed and liquid, propane, hydrogen, liquid nitrogen, compressed air, hydrogen enhanced fuels, biomass fuels, and alcohol fuels. The second fuel tends to produce fewer harmful byproducts.
The processor 104 is communicatively coupled to a first control unit 108 and a second control unit 110. The first control unit 108 and the second control unit 110 are disposed, respectively, along the first fuel line 118 and the second fuel line 120 to control the flow rates of the first fuel and the second fuel. The processor 104 relays values for flow rates for the first and second fuel to the first control unit 118 and the second control unit 120, respectively, which are then implemented by the first control unit 118 and the second control unit 120, to control the first fuel flow rate and the second fuel flow rate, thereby controlling the exhaust products.
Additionally, the apparatus/system 200 may include a pyrometer 222 disposed near the ICE 212 to measure the temperature of the exhaust 216 from the ICE 212. In certain embodiments, a pre-existing pyrometer 222 may, or may not, be tapped into. Alternative fuels from which the second fuel may be selected are known to increase the temperatures within engines and exhaust systems, even to the point of becoming harmful to the engine and surrounding elements. The processor 204, which is communicatively connected to the pyrometer 222, may use exhaust temperature information to determine if a safety threshold has been crossed, approached, or the rate at which the threshold is being approached to determine appropriate flow rates for the second fuel.
Similarly, the apparatus/system 200 may include a throttle position sensor (TPS) 224 disposed along the throttle 226 to determine the amount of air being introduced to the ICE 212. In the presence of too much air, alternative fuels, from which the second fuel is selected, may also increase the temperature within engines and exhaust systems. As with the pyrometer 222, the processor 204, which is communicatively connected to the TPS 224, may use TPS 224 information to determine if a safety threshold has been crossed, approached, or the rate at which the threshold is being approached to determine appropriate flow rates for the second fuel.
The apparatus/system 200 may also include a GPS 228 and a position to gravity sensor 230 communicatively coupled to the processor 204, either of which may, or may not, be pre-existing to the vehicle. The GPS 228 and the position to gravity sensor 230 may provide the processor 204 acceleration and incline information that are relevant to engine loads and the proper flow rates for the first and second fuels, as determined by the processor 204.
In certain embodiments, the apparatus/system 200 may include an oxygen sensor 232, which may, or may not, be pre-existing to a vehicle, communicatively coupled to the processor 204. The processor 204 uses information about the level of oxygen in the exhaust 216 to produce a false oxygen reading with which to control the flow rate of the first fuel. In such embodiments, the first control unit 208 along the first fuel line 218 is a pre-existing electronic control unit that uses information about oxygen in the exhaust 216 from the oxygen sensor to determine the proper flow rate for the first fuel to achieve the stoichiometric balance between oxygen and the first fuel, as required for efficient engine operation. The processor 204 relays the false oxygen reading to the first control unit 208, thereby controlling the flow rate of the first fuel in accordance with the goal-appropriate, first-fuel-rate value determined by the processor 204.
Additionally, the apparatus/system 200 may also include a transmitter 234 communicatively coupled to the processor 204. The transmitter 224 is configured to upload measurements and/or records from the memory 206 and/or the processor 204 to a server (not shown). The server is configured to make the measurements and/or records accessible to predetermined, interested parties. Such parties may include, without limitation, the EPA and the driver/owner of a bi-fuel vehicle to which the apparatus/system 200 is attached.
Without limitation, the apparatus/system 100/200 in
In certain embodiments, the record module 310 receives, in real time, measurement information about exhaust product levels that is accessed by the determination module 308. In alternative embodiments, the determination model 308, or some other module receives the information. Several different architectures are possible.
At some point, the record module 310 records the real time measurement information in the memory device 306. Those skilled in the relevant art will recognize that there are many different formats possible for records of the real time measurements. The record module may also retrieve records and/or particular measurement information from the memory device to be relayed by the relay module 312 or analyzed by the determination module 308.
In certain embodiments, the determination module 308 applies one or more algorithms to the measurement information to determine proper flow rates for one or both of the two fuels. In certain embodiments, the determination module 308 applies probability laws and/or Bayesian logic to determine flow rates likely to achieve one or more goals with respect to one or more exhaust products given current exhaust product levels and, possibly, also given a current flow rate or given current flow rates. In alternative embodiments, the determination module 308 applies the comparison algorithm discussed above with respect to
The relay module 312 is configured to relay flow rates, as determined by the determination module 308, to control units 108/208 and 110/210 substantially similar to those described in connection with
The intercept module 316 determines a false oxygen level likely to cause a first control unit 108/208 to insure a first-fuel flow rate that matches the first-fuel flow rate determined by the determination module 308 or that is consistent with the second fuel rate as determined by the determination module 308 or increase module 316. In certain embodiments, the intercept module uses readings sent to the processor 304 from an oxygen sensor 232 substantially similar to the one in
If progress is not being made 512 toward a goal related to one or more exhaust products, the method 500 stops 520 increases to the second flow rate and the method 500 ends 522. However, if progress is being made 514, in certain embodiments, a determination is made with respect to exhaust temperature. If the exhaust temperature does not exceed a certain threshold 516, then the method 500 continues by again increasing 506 the flow rate of the second fuel, recording 508 additional measurements, and making another comparison 510. Conversely, if the exhaust temperature does exceed the threshold 518, the method 500 stops 520 increases to the second flow rate and the method 500 ends 522.
The method 500 may begin 502 again at varying time intervals after it has ended 522 to keep pace with varying engine loads and changing exhaust products. The determination as to exhaust temperature is an optional safety precaution that need not be employed in all embodiments. In embodiments where it is not employed, after the comparison 510, if progress is not being made toward a goal related to at least one exhaust product, increases of the second flow rate are stopped 520 and the method 500 ends 522. If progress is being made, the steps of increasing 506 the second fuel, recording 508 additional measurements, and comparing 510 recent measurements are repeated.
The first of these steps is to allow 624 an ICE to idle with a known ratio of a first and a second fuel being feed to the ICE. The next step is to record 626 measurements of exhaust products once those exhaust products have stabilized. These first two steps of allowing 624 an ICE to idle with a known fuel ratio and recording 626 measurements of exhaust products may be repeated many different times for different ratios of a first and a second fuel, including a scenario where the supplied fuel consists only of the first fuel. These records then serve as calibration points. The calibration products are specific to the ICE for which they are made and may be recorded whenever the present invention is installed, whether at the factory or by a qualified technician when the invention is installed as an “add on.”
The next step is then to determine 628 an incremental amount by which to increase the flow rate of the second fuel based on the calibration points. In certain embodiments, the determination may also be made based on real time measurements of exhaust products. The incremental amount can vary from one increase to another depending on exhaust products.
These steps commandeer a control system for the first fuel that is already pre-existing in many exhaust and fuel intake systems. Many exhaust systems are designed to include an oxygen sensor 232 similar to that described in relation to
The first of these commandeering steps is to reroute 724 the output of the oxygen sensor. In certain embodiments, the output from the oxygen sensor is rerouted to a processor 104/204/304. In alternative embodiments, it is simply disconnected. The next step is to determine 726 a false oxygen reading. In some embodiments, the false reading is determined so as to cause the first control unit 208 to control the flow rate of the first fuel so that is consistent with an increase in the second fuel. In some embodiments the output of the oxygen sensor 232 is used to determine the false oxygen reading.
The next step is to relay 728 the false oxygen reading to the control unit 108/208 to control the actual flow rate of the first fuel. These commandeering steps are not unique to methods such as those described in relation to
The architecture, functionality, and operation of possible implementations of the method, apparatus, and system in certain embodiments, flowcharts and block diagrams in the Figures are not exhaustive of the possible embodiments of the present invention. Additionally, each block in the flowcharts or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). Therefore, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.
