Abstract:
The air supply to internal combustion engines using variable compression ratio and variable fuel supply VCRC, is improved. The improvements involve increasing thermal efficiency and/or reducing production of pollutants by this engine. The improvements can also be used with other engines that are regulated by fuel supply such as two-stroke diesel engines. These improvements are directed to engines in two basic categories; those with mechanical blowers only and those with turbo charging.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is the U.S. national phase, under 35 U.S.C. §371, of PCT/U.S. 2014/033146, filed Apr. 7, 2014, published as WO2014/168861 A2 and A3 on Oct. 16, 2014 and claiming priority to U.S. patent application No. 61/809,525, filed Apr. 8, 2013, the disclosures of which are expressly incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to air supply concepts for internal combustion (IC) engines designed to improve engine efficiency, improve power to weight ratios, and reduce emitted pollutants in a configuration which is readily manufacturable. The realizations are most applicable to variable compression ratio and charge engines (VCRC engines as described in U.S. Pat. No. 6,708,654) used in automotive applications; particular those used in passenger vehicles or light-duty trucks. 
       BACKGROUND OF THE INVENTION 
       [0003]    A major objective of the invention is to provide a prime mover heat engine with higher average efficiency. This is vitally needed in today&#39;s political climate. Overall system efficiency is needed. Power spent in manufacture is equally as that spent in powering the system. A lighter weight and smaller configuration is needed much more than has heretofore been the case. This is particularly true at power demands much less than the engine&#39;s maximum. This is the mission of the passenger automobile. For this application, efficiency at low engine torque at moderate speeds is of prime interest since most of the time an automobile engine operates at approximately 10% of its maximum power output at moderate speeds-typically 1,500 to 3,000 rpm. 
         [0004]    The engineering terminology used in this specification follows standard mechanical engineering practice. 
       Current Standard Automotive Practice:  
       [0005]    Currently, standard automotive practice is usually to employ a spark-ignition (SI) engine with an average thermal efficiency around 20%. That is, about 20% of the thermal energy of the fuel used is transferred to mechanical energy during an average driving cycle. Alternatively, a compression-ignition (CI) engine, more commonly called a diesel engine, is used and has a somewhat higher efficiency (ca. 25%) at average passenger car usage. The added efficiency of the CI engine is, in passenger car application, somewhat offset by the added weight of current CI engines. A typical passenger car using a CI engine is no more efficient than a car of equal performance using a SI engine. The comparison of apparent fuel mileage (miles per gallon or mpg) differences between cars powered by SI engines and those by CI engines is obscured by the difference in energy content of diesel fuel and gasoline. Diesel fuel has more energy for a given volume, liter or gallon, than has gasoline. Thus an accurate comparison of a CI car that gave 40 mpg with a spark-engine driven car giving 35 mpg would show that the two vehicles use about the same amount of energy. Even more exact comparisons, that consider performance of the two autos shows that the CI-driven car is often less efficient than a vehicle of equivalent performance powered by a SI engine. Support for this argument comes from the choice by Toyota in the use of an SI engine for the Prius. The Prius is designed to provide the ultimate in fuel mpg using contemporary techniques 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    Systems and methods in accordance with the invention deliver increased efficiency and/or decreased pollution when used with a VCRC engine. Especially advantageous are the realizations applied to the engine in passenger car or light truck use. The value realized is increased efficiency at low power at moderate speeds. This is the average mission for all passenger vehicles and most light trucks. All realizations presented could be used for other IC engine types as well. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Discussion of Intent of the Invention:  
         [0007]      FIG. 1  is a block diagram that displays the intent of the invention. The invention is to gain efficiency and/or reduce pollution of the VCRC engine. This goal is best met with turbo charging.  FIG. 4  and  FIG. 5  show these.  FIG. 2  and  FIG. 3  show systems that are simpler and less in first cost. 
         Systems to Reduce Pollution by Decreasing Engine Air Flow: 
         [0008]    The  FIG. 2  shows the details of system  201 . System  201  maintains exhaust temperature of engine  205  above a minimum. It varies speed of blower  206  for this purpose by controlling coupling  208 . In this manner, exhaust flow  213  is held hot enough. This is needed to allow a thermal reactor or catalytic converter (not shown) to oxidize pollutants. 
           [0009]    System  301  shown in  FIG. 3  holds exhaust temperature high by controlling blow-off valve  302 . This is done to regulate air flow through engine  205 . 
         Systems Using a Turbocharger to Increase Efficiency: 
         [0010]      FIG. 4  shows a system  401  using a turbocharger plus a mechanical blower/motor  406 . Blower/motor  406  is of the type of blower that can function as a motor. Such is the case if input pressure to blower/motor  406  is higher than its output. Speed of blower/motor  406  relative to engine  205  speed is varied by regulation of coupling  408 . Coupling  408  is controlled by a servo mechanism in response to a signal from a pressure sensor at flow  214 . An override from the temperature exhaust at flow  213  also controls coupling  408 . This override maintains the temperature needed by the oxidizing system mentioned in discussion of  FIG. 1 . In this way, the thermal reactor or catalyst is effective in reducing pollution. 
           [0011]    System  501 ,  FIG. 5 , shows a turbocharger  517  directly coupled to an electrical motor/generator  502 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Basic Intentions of the Invention: 
       [0012]      FIG. 1  is a block diagram outlining the thrust of the invention&#39;s intentions. It outlines the fundamental processes of systems  201 ,  301 ,  401  and  501 . 
         [0013]    Flow through the power system can be described thusly. Air is supplied to engine  205  by blower  206 , turbo-compressor  415  plus blower/motor  406  or by turbo-compressor  515 . Engine  205  uses some of this air to generate mechanical power from burning fuel. Air supplied over that needed to burn aids efficiency. This is well known in the art. Excess air also cools processes inside engine  205 . 
         [0000]    Systems that Reduce Air Flow to Reduce Pollution: 
         [0014]    Systems  201  and  301  are intended to control the pollution output of engine  205 . Both do this by controlling the flow of air to engine  205 . System  201  limits flow by using controllable coupling  208  to regulate speed of blower  206 . Air supplied is in accordance with speed of blower  206 . Coupling  308  in system  301  is fixed. Blower  306 , therefore, runs at a fixed ratio of the speed of engine  205 . Air is varied in system  301  by venting some of the air before the air is being injected to engine  205 . System  301  varies vent or blow-off valve  302  in response to the temperature measured in exhaust gas flow  213 . 
       System Regulating Exhaust Temperature by Blower Speed: 
       [0015]    System  201  diminishes pollution by including a thermal reactor or catalytic oxidizer. Neither of these are shown in  FIG. 2 . Their use and placement in IC engines is well known in the art. Either of these devices requires gas above a certain temperature to deoxidize well. IC engines like VCRC and CI engines display exhaust temperature opposite to leanness. Thus reducing their air supply will increase exhaust temperature for both. 
         [0016]      FIG. 2  shows a system  201  that can accomplish this. Air flow  203  entering through air intake  207  is pumped by blower  206  into engine  205 . Blower  206  is driven by controllable coupling  208 . Speed of blower  206  is regulated to maintain temperature of exhaust flow  213 . This temperature is held high enough for proper oxidizing of pollutants. Reducing the speed of blower  206  by regulating coupling  208  accomplishes this temperature control. After blower  206 , air flow  214  into engine  205  is at a higher pressure than is its input flow  203 . Before engine  205 , the air flows through throttle valve  204 , then through manifold  215 . Throttle valve  204  can be regulated by a servo mechanism, not shown. Valve  204  can provide auxiliary vehicle braking when such is desired. It does this by imposing a pressure drop on flow  214  driven by blower  206 .  FIG. 2  depicts a three cylinder engine  205 . Exhaust flow  213  from engine  205  flows through exhaust pipes  209 . From thence, exhaust flow  213  goes through muffler  210  to leave system  201  through system exhaust outlet  216 . As noted, exhaust flow  213  is oxidized in thermal or catalytic reactors, not shown for clarity. 
         [0017]    In all concepts,  201 ,  301 ,  401  and  501 , a blow-off valve  202  protects engine  205 . It is possible for pressure in flow  214  to be high enough to harm engine  205 . Such can occur through controller malfunction or blockage in flow through engine  205 . Blow-off valve  202  is possibly a simple spring loaded valve. As such it is almost completely reliable. Valves like this will almost always function as designed. The only valve more reliable is a frangible diaphragm. This could serve in place of the spring-loaded blow-off valve  202  shown. A frangible diaphragm could also be placed in parallel with a spring loaded valve. This would ensure almost perfect reliability. The frangible diaphragm in parallel should be set at higher pressure than blow-off valve  202 . 
       Heating Exhaust by Venting Blower Output; 
       [0018]      FIG. 3  shows system  301 . This holds temperature of exhaust flow  213  high enough by venting excess flow from blower  206 . Only the inlet air flow  214  not vented through a vent valve  302 , which is controlled by a servo mechanism and which servo mechanism regulates the exhaust temperature above a defined minimum, flows through engine  205 . In system  301  coupling  308  is a simple drive. Speed of blower  206  is a fixed ratio of engine  205  speed through coupling  308 . Inlet air flow  214  goes though regulated vent valve  302  or to engine  205 . Thus, flow to engine  205  is limited. It is easier to control a simple vent valve  302  than to adjust a transmission coupling  208  to different ratios. As a result, system  301  is less costly and probably more reliable than system  201 . System  301  could, however, be less efficient. 
       Turbocharger Plus Blower System: 
       [0019]    System  401 , shown in  FIG. 4 , depicts turbocharged IC engine with the addition of blower/motor  406  used after the output of turbo-compressor  415  of turbocharger  417 . Blower/motor  406  serves two functions. The most basic use is to start the VCRC engine in two-stroke mode. Since the most efficient form of the VCRC is two-stroke, this function is important. After starting, there is usually enough energy in turbocharging to continue engine running. Ricardo, Harry R., The High Speed Internal Combustion Engine, Fourth Edition, Blackie &amp; Son, Ltd., 1967, referred to as Ricardo, states on p 200, “. . . for there is energy enough and to spare in the exhaust to provide the power needed [to drive the turbo-compressor] . . . ”. Blower/motor  406  will maintain airflow if there is insufficient energy in the turbocharging for running. 
         [0020]    The second function is to utilize some of the exhaust energy that the turbocharger  417  has in excess. Currently, this excess energy is dissipated across what is called a ‘waste gate’. This mechanism is generally a simple pressure dropping valve. In any event, it wastes energy. System  401  delivers some of this energy to the load by the output of the turbo-compressor  415 . The excess pressure drives the blower/motor  406  as a motor. Output of blower/motor  406  adds to output of engine  205  for the load. 
         [0021]      FIG. 4  shows the mechanism for doing this. The output of turbo-compressor  415  is directed to the input of blower/motor  406 . Speed of blower/motor  406 , relative to engine  205  speed, is varied by regulation of coupling  408 . Coupling  408  is regulated by a servo mechanism in response to a signal from a pressure sensor at air inlet flow  214 . An override from the temperature at exhaust flow  213  also controls coupling  408 . This maintains the temperature needed by the oxidizing system mentioned in discussion of  FIG. 1 . In this way, the thermal reactor or catalyst is effective in reducing pollution. The slower that blower/motor  406  does rotate, the less air is supplied to engine  205 . There is a limit to this correlation. If almost no air is supplied, the exhaust will be almost zero. In this case, there will be low temperature measured at exhaust flow  213 . Those skilled in the art of servo control design know how to compensate for this eventuality. 
         [0022]    Need for the override is limited. The exhaust  213  flow in system  401  will normally be hot enough for proper deoxidizing operation. During an initial warm-up phase of engine  205 , this may not be true. Coupling  408  may then slow blower/motor  406  to maintain flow  213  hot enough. 
       Turbocharger Driving Electrical Motor/Generator: 
       [0023]    System  501 , is shown in  FIG. 5 . This system absorbs any excess energy in driving motor/generator  502  as a generator. The power so generated could be used in a multiplicity of ways. Many methods are obvious to those skilled in the art. One is to send the power so generated to an electric system, if the vehicle using IC engine  205  is designed in a hybrid mode. A hybrid vehicle&#39;s motive power is shared between IC engine and electric motor. Another method is to use electrical output to support auxiliary subsystems in use. That power not so utilized could be dissipated across a power resistor. Alternately, the extra power could be stored in a battery for later use. 
         [0024]    While preferred embodiments of air supply concepts to improve efficiency of VCRC engines in accordance with the present invention have been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes could be made without departing from the true spirit and scope of the subject invention which is accordingly to be limited only by the appended claims.