GB2518015A - Exhaust turbine throttled normally aspirated and turbocharger throttled turbocharger eco-boost type engines - Google Patents

Abstract

Turbocharger (compressor 10/turbine 11) is braked by variable speed motor-generator (M-G) 8 controlled by a throttle position sensor (TPS) connected to a throttle control system (TCS) and engine control unit (ECU), and whose maximum speed is lim­ited by boost pressure sensor 15. M-G 8 outputs power to a variable speed M-G connected to the engine's crank, or to a battery-pack, upon throttle lift-off and when it is braked by a connected vehicle's braking system and accumulated power is subsequently discharged into the engine crank via the M-G conn­ected to the engine crank such that turbocharger engine throttling and the M-G 8 output increases or, less economically, boosts turbo pressure. When idling at low/sub-zero temperatures, bypass valve 13 is closed so that the engine becomes only ex­haust throttled, and at high ambient temperatures bypass valve 12 is closed so that compressor 10 adiabatically expansion refrigerates charge air, and intercooler bypass valve 23 opens when temperature sensors 21 & 22 sense such cooling. A similar Normally Aspirated system (fig.1) is also disclosed.

Description

EXHAUST TURBINE THROTTLED NORMALLY ASPIRATED and TURBOCHARGER THROTTLED TURBOCHARGED ECO-BOOST TYPE ENGINES.

= = = == = = = = = == = = = = = = = = = = = = = = = = = = = = = = = = = = === = = = = = This invention relates to throttle controlling normally aspira- ted spark ignition internal combustion (i.e.) engines by con-trotting the speed of variable speed electric power generators, or the mechanical gearing of continuously variable gear-drive power transmitting transmissions (CUTs), connected to exhaust system turbines, and the motorised valves in bypasses of such said turbines by means of an electronic throttle control system (TCS) connected to a throttle position sensor (IPS). It simi- larly relates to throttle controlling the turbo's of turbochar-ged engines and valves in bypasses around their turbines and compressors, and sequentially controlling the said bypass val-ves so as to predominantly obtain adiabatic expansion cooling of intake air at higher ambients and, vice versa, to obviate excessive: intake air expansion cooling at low and sub-zero am-bients and also maximise catalytic converter temperatures at such ambients by predominantly throttling exhaust gases. Also, it relates to how such throttling systems can brake an i.c.en-gine and its drivetrain upon throttle lift-off to generate a power output when there is a battery-pack, or other means, for accumulating such power, and subsequently discharging it to in-crease on-power throttling electric power generation without necessarily expansion throttling intake air at low and sub-zero ambients -which can freeze-up intake manifolds, the prevention of which, in eco-boost engines with intake throttle controlled superchargers, prevents power generation from residual i.c.en-gine, exhaust and catalytic system heatsl throttle lift-off power generation is generated from recovered i.c.engine recip-rocating and rotating masses kinetic energies, the aforesaid residual heat energies and it's air pumping, and such throttle braking additionally recovers moving vehicle mass kinetic en-ergy. With such turbo throttled turbo-engines, intercooled charge air can be refrigerated at higher engine speeds by ex-pansion turbines connected to variable speed generators/N-Gs whose speed is controlled, via the engine management computer (ECU), by a temperature sensor in the engine's intake manifold, or alternatively by a direct expansion (DX)-air intercooler, or indirect DX chilled water-to-air intercooler -with either such DX system possibly slaved off a vehicle's air-conditioning re-frigeration system at such engine speeds. It also relates to the use of pre-rotating and de-rotating volutes (patent pend-ing) with any axial inlet compressors and axial outlet turbines used in these systems to increase their spooling-up rate, turbo efficiency in the order of 25 to 30% -reducing compressor heat input and exhaust turbine heat extraction by similar %ages.

Such throttle controlled i.c.engines can be used to not only power means of transport, but also to generate electric power highly efficiently from a generator or generators connected to such i.c.engines, whether they are statically fixed or in a parked or bay docked means of transport (connected via a cable and multi-pin connector, or otherwise, to power absorbing and controlling means, which say be buffered by power accumu]ating/ discharging means which may be in the transport means (allowing reverse charging). In this way vehicles could be used to. power domestic premises, fully or part power commercial premises and reverse power utility power connections (minimising power sta-tion requirements and electrical grid distribution losses).

Bayram's claimed invention for "Exhaust throttling at low am- bient temperatures of engines having intake air expansion cool- ing throttling systems" addresses the shortcomings of his ear- tier filed patent application for "Variable speed positive dis- placement superchargers plus air-cycle refrigerated boosted in- to tercooling" (being a developm!nt of his much earlier filed app-lication for "Air-cycle refrigerated boosted intercoolinq") and the shortcomings of Ford's Ecoboost similar such system. In Ford's system, intake charge air is increasingly re-heated as ambient temperatures drop to maintain a constant minimum tern-perature above that that would cause intake manifold freeze-up, however such increasing re-heat increasingly reduces exhaust gas temperatures to it's turbo's turbine such that eco-boost energy increasingly reduces, as is also similarly the case in Bayram's system when the bypass around its throttling super- charger increasingly opens to obviate excess expansion refri-geration at lower ambients that, in both cases, would likely cause intake manifold feeze-up at low and idling engine speeds.

However, Bayram's "Exhaust throttling at low ambient tempera-tures of engines having intake air expansion cooling throttlinà systems" (collectively eco-boost engines) claimed invention is relatively complex, requiring the use of both intake and ex-haust positive displacement adiabatic engines with separately controlled variable speed motor-generators (N-Gs) -but no separate starter motor and s!parate alternator..n To provide provide the same anti-freezing-up operational power outputting efficiency and similar throttle responsiveness as that system, but more simply, the the present invention proposes throttle controlling turbochargers only or, more basically, exhaust tar-bines in normally aspirated i.c. engines -which also obviates the tip seal/lubrication concerns of exhaust system positive displacement adiabatic engines such as a Wankel one.

Ordinarily, throttling an engine's exhaust system would be li-able to cause engine overheating when the engine is throttle idled and ambient temperatures are high. However, in the basic exhaust only turbine throttling system, at idle maximum thrott-le braking of the turbine it would be outputting power via it's connected generator to a motor inputting such power into the so controlled engine's crank. With such power input to the engine, idling rpm and combustion event heat input to the engine's cooling system would be significantly lower than would be the case with a conventionally throttled intake such that any pro- pensity for overheating when idling at htgh ambient tempera- turn *due to back pressure in the exhaust system is thereby in-herently offset -fuel consumption reduction being maximum at idle, reducing to none, and no exhaust back pressure, at wide open throtte (wot). In the turbocharged throttling system èx-haunt turbines would be bypassed at such operating conditions and intake compressors' throttled such that not only would idling rpm be reduced but also intake air would be adiabatic- ally expansion cooled. -With the exhaust throttling system there can be no throttle cooling of intake air, and with turbocharger throttling systems there can only be expansion cooling of intake air at throttle openings less than wot, but charge air is adiabatically expan-sio*n refrigerated at all throttle openings in supercharger throttled ecu-boost engines. However, intake air could be di- rect expansion (DX) refrigerated by utilising the excess capa- city available from belt-driven compressor air-con--ditioning (fl/C) system that becomes available and increases as engine rpm and vehicle speed increases to offset increased in- tercooling requirement as both engine airflow and boost press-ure parallel increases, or variabe speed electric compressors could be used (condenser capacity in either case increases as vehicle speed increases), or a dedicated DX intercooling re-frigeration system could be used for high performance/racing turbo engines. N.B. The tubes in anyrefrigeration intercooling coil not have any joints within the charge air airstream, and would be no more likely to burst in a catastrophic vehicle than a vehicle's A/C refrigeration system's components and inter-connecting pipework, and if there was a an unlikely pin hole leak in any such tube it would almost certainly be discovered when the refrigeration system was presure tested or vacuum de- hydrated and, in any case, any such leak would mostly harmless-ly dissipate when the engine was not running or, at worst, any leak quantitities that become hazardous after experiencing a combustion event would be diluted with combustion gases and be rapidly dissipated by an exhaust system designed to harmlessly dissipate carbon monoxide. Alternatively a chilled water re- frigeration system could be used and a chilled water-to-air in-tercooler coil utilised in the charge air intake system.

Alternatively, for high Summer ambient temperature zones and or to enable use of high charge air boost pressures, intercooled intake air could be refrigerated by an expansion turbine braked by a variable speed generator controlled, via the engine's en-gine management computer (ECU), by a temperature sensor in the engine's intake manifold.

Conventionally, i.c.engine power can be increased by enrichen-ing the air fuel (a/f) mixture, which reduces peak cylinder combustion and exhaust gas temperatures, but this reduces the potential heat energy that can possibly be extracted by the ex- haust turbines in the aforementioned throttle controlled turbo-charger system. However, off-throttle late-event direct fuel injection by engine fuel injectors into the engine's cylinders, or fuel injection into the engine's exhaust system upstream of such turbochargers, can be used to increase the power output of the said turbos' exhaust turbines such that, in effect the en-gine becomes a hybrid piston turbojetted i.c.engine. (With a SC) catalytic converter equipped computir controlled engine only fuel injection downstream of the converter should be used. 3.

Such fuel injection can be increased if bottled liquid nitrous oxide (N2 0) is sprayed, or compressor compressed air is also similarly injected, allowing Lambda sensed control of such in- jections -which could be accompanied with the spraying of liq-uid $12 0 injection into the intake system. and fuel enrichment.

Afterbarning fuel injection downstream of the turbo's turbine into an open exhaust system, especially if accompanied by N2 0 or compressed air injection, could be used to genErate jet thrust from a suitably sized, possibly variable, efflux nozzle -applicable to military vehicles, high altitude drones, speed record cars and boats, dragsters and altitude record planes.

The invention will now be described by way of example and with reference to the accompanying schematic drawings in which: Figure 1 shows a system for usefully throttling, even at idle at sub-zero ambients, normally aspirated engines for city cars, urban buses and urban commercial vehicles..

Figure 2 shows a system for usefully throttling turbo-inter- cooled engines when idling at sub-zero ambients, ex- pansion cooling charge air when idling at high ambi-ents and usefully Limiting charge air boost pressure.

Figure 3 shows a twin-turbo system, with one (1) smaller than the other and dedicated for efficient power generation and throttle contro.l at idle and Low engine speeds.

Figure 4 shows a figure 2 system, that can usefully throttle at sub-zero ambient idle, has a cooling turbine for air-cycle refrigerating charge air at high boost pressures and or when ambients are htgh -for when ambients are very high and or for generating high specific bhps.

Figure 5 shows an. alternatively DX charge air refrigerated fig- 30. ure 4 system -less suited to very high ambients.

Figure 6 shows a figure 2 system with exhaust fuel injection upstream of the turbocharger (patent application filed) -a hybrid piston-turbine engine suitable for high performance power boosting Figure 7 shows a figure 6 system, less catalytic converter, with exhaust tail-pipe injection of fuel and N2 0 (patent application filed) -a hybrid piston-turbine-rocket engine suitable for dragsters, speed record cars and boats, and altitude record planes.

In figure 1, variable speed generator l's shaft is common with the input shaft of Rotrex gear-drive power transmitter 2 whose output shaft is common with exhaust turbine 3's shaft, whose exhaust gases are de-rotated by volute 4, and Rotrex 2's output shaft is common with exhaust turbine 3's shaft. Rotrex power transmitter 2 and generator l's windings are insulated from the high temperature exhaust gases in turbine 3 by insulation spa-cer 5 (which if the assembly is horizontal should comprise of end-grain balsawood sanwiched between plates -so that all of the asemblies' components can be rigidly held together by heavy duty end and intermediate plates bolted, together with high ten- sile bolts to obviate side loads being imposed on the compo-nents' ball bearings, a La Rover K series engines) and a hollow insulated common carbon fibre shaft, or similarsuch means.

Generator j1 speed is controlled by outputs from a TPS connec-ted, via the ECU, to the i.c.engine's ICS, which also controls turbine 3's bypass valve 6 when a wot or high-rate throttle movement is detected or, less economically, with bypass valve 5 closed, increases generator l's nominal speed above it's actual S speed, i.e. such that it acts a motor. Catalytic converter 7 is upstream of turbine 3 so that at idle at sub-zero ambients it's temperature and efficacy would be much higher than it would be with a butterfly valve throttled i.c.enqine -catalytic con-verter 7 and the exhaust system from the i.c.engine up to and including turbine 3 should, in any case, be insulated to maxi-mise exhaust heat extraction and the power output of turbine 3.

Power output from generator 1 is input to an ti-S connected to the i.c.engine, which can also be the i.c.engine's starter mo-tor and be connected via it to the starter powering battery and or a battery-pack or other means for accumulating/dischar-ging power which may have a mains power plug-in connector, alt of which would commonly apply to any of the following examples.

In figure 2, variable speed generator S's shaft is common with the input shaft of Rotrex gear-drive power transmitter 9 whose output shaft is common with compressor 10 and turbine it's common shaft. Generator S's speed is controlled by outputs from a TPS, via the i.c.engine's TCS and ECU, which opens compressor [0's and turbine it's bypass valves 12 & 13, or whichever one is not then open, when it detects a wot or high-rate throttle movement and or increases generator 5t nominal speed above it's actual speed when the ICS is so enabled by the engine man-agement computer. Inputs from intake manifold freeze sensor 14, intake manifold charge pressure sensor 15 and exhaust gas tem-perature sensor 16 control, via the ECU, compressor an4 turbine bypass valves 12 & 13 overlappingly together, or separately1 to limit control or maintain the parameter settings of sensors 14, and 16. Volute 17 pre-rotates airflow entering compressér 10 and volute 18 de-rotates exhaust gases exiting turbine 9. In- tercooler 19 and fan 20 cool charge air except when compress-or tO's discharge is cooler than at its inlet, i.e. when it is adiabatically throttling, as sensed by temperature sensors 21 & 22 which, via the ECU, shuts down intercooler fan 20 and opens intercooler motorised bypass damper 23. In the figure 2 arrangement generator 8 is separated from hot exhaust turbine 11 by compressor 10 to absolutely minimise any heat transfer from exhaust gases into the windings of generator S -and where this assemblage may be horizontal the component parts should be rigidly held together as per the way mentioned for a horizontal figure 1 arrangement. Alternatively, compressor 10 and turbine 11 could be non-interconnected and separate, and each be conn-ected to a generator and a gear drive.

In figure 3, motorised dampers 24 & 25 are closed at idle anØ idling rpm is controlled by controlling the braking speed of 11-6 26. Upon throttle application from idle motorised dampers 24 & 25 are modulated open and maximum boost pressure is con-trolled by pressure sensor 27 which, via the ECU, controls the braking speed of 11-6 26 -and vice versa. When enabled and when the IPS senses wot or high-rate throttle movement turbines 28 & 29 and compressors 30 & 31 speeds are accelerated by increasing 11-6 26's nominal speed above it's actual speed (such that it acts as a motor) untiL pressure sensor 27 limits maximum boost pressure, and vice versa.

In figure 4, cooling turbine 32's shaft is common with variable speed generator 33's, and generator 33's speed is controlled by outputs, via the ECU, from charge air temperature sensor 34.

In figure 5, refrigerant liquid line solenoid valve 35, up-stream of thermostatic expansion valve (1EV) 36, is energised, via the ECU, by an output from charge air temperature sensor 37 when a relay is enabled by both the A/C compressor's power control feed and a hot gas pressure sensor set below the A/C compressors head pressure trip-out condition. L5

In figure 6, fuel injection control valve 38 opens in response to IPS sensing of a wot and is modulatingly controlled by out-puts from intake system mass airflow (P1AF) sensor 39, as and wnen the system is manually enabled, and vice versa.

In figure 7, fuel injector control valve 40 and a N2 0 or com-pressed air injector control valve 41 are manually enabled and then modulatingly controlled up to any pre-set opening limits, via a controller from PInE sensor 42, and disabled upon IPS sen-sing of throttle lift-off.

In such systems variable high speed digital type M-Gs could simply be directly connected to turbochargers. However, such would the high low speed torque of an electric sotor adequately sized to handle the power output of a throttled (to limit boost pressure) turbocharger at wot, that it would overcome the iner-tia of relatively small diameter lightweight turbo rotors at engine idling speed (**), even when geared-up by a geared power transmitter, which by multiplying their speed relative to that of the connected P1-B similarly multiplies their rate of accel-eration, i.e. throttle responsiveness from low speeds. With a CUT, throttle reponsiveness can be varied from a drag racing type mode to a slower maximum economy mod?, or allow manual pre-setting adjustment of the turbo gear-drive ratio. In any case, quick low speed responsiveness can be provided by simply opening turbine and compressor bypass valves and then closing them when reverse flow through the turbine and compressor by-passes is sensed. (**) Because of the electrical power input to the L.c.engine's crank from an P1-S throttle braking a turbo sufficiciently to idle the i.c.engine, npt only would the idle speed be consequently lower than it would be than if it was butterfly valve throttled, but the held-back sum ofthe atmo-spheric and or exhaust pressure differences would be greater, i.e. the pressure available to spool-up the turbo (when P1-13 braking is instantly relaxed or reversed) before the i.c.en- gine has spun-up -however slower *unbraking of the M-&, allow-ing engine boost to build-up, maximises fuel economy.

Where such throttling and power boosting systems way be applied to engines with multiple banks of cylinders, multiple parallel such systems per engine could be provided to obviate complex inefficient connections to multiple manifolds, simplify and im-prove engine bay packaging and allow commonalities with smaller non-multibank cylinder engines to increase economies of scale.

In such systems power is transmitted between their variable speed generators and one (1), or more, variable speed genera-tors connected to the engine's crank/drivetrain, and or to the wheels of a so engine system powered vehicle, and to the en-gine's starter/ancillaries battery, or such systems' power is transmitted via one (I), or more, CVTs similarly so connected.

to Such systems' throttle controlling generators or CUTs dan also be controlled by a vehicle's braking system, or any other conn-ected braking system, to brake the engine and any connected drivetrain to throttle the passage of air through turbines and or compressors upon throttle lift-oft where there is a battery- L5 pack, or other means for accumulating/discharging power, to ab- sorb such power generation and subsequently input such harvest-ed power into the engine and any drivetrain and or wheels.

It should be understood that any variable speed generator that has it's nominal speed increased above it's actual speed be- comes a motor so that a variable speed generator, by. defi-nition, is not necessarily only ever a generator -and that a variable speed M-G, similarly, may only ever output electrical power or may only ever output mechanical power. Where a gener- ator's or motor's nominal speed is fixed, momentarily or other-wise, it's actual function at any one moment is dependent upon whether or not the speed of means connected to it is above or below it's nominal speed. In this invention the speed of vari-able speed generators may be so varied that they act as motors such that throttling turbines are accelerated to act as super-chargers/compressors, and vice versa with compressors.

Claims (10)

1. CLAIMS: 1) A spark ignition internal combustion (icc.) engine's thrott- ling system comprising of one (1), or more, adiabatsc en-gines in its exhaust system, integral or external means for bypassing exhaust gases within or around such adiabatic en-gines, motorised valves in such bypasses, one (1), or wore, variable speed electric power generators, or variable gear gear-drive power transmitters, connected to said exhaust adiabatic engines, a throttle control system tICS), means for controlling said variable speed generators, or variable to gear gear-drives, means for controlling said bypass motor-ised valves, means for transmitting power between the said variable speed generators, or var3able gear gear-drives, and the i.c.engine and any means connected to it for accumu-lating/discharging power whose control means are connected to a brake control system and the said itS.
2. 2) A spark ignition i.c.engine's throttling system according to claim 1, in which there are one (1), or sore, intake system adiabatic engines connected to one (1), or sore, variable generators, or variable gear-drives, connected to the ICS, means for bypassing air within, or around the said intake adiabatic engines, motorised valves in such bypasses conn-ected to the ICS and means for also connecting aforesaid generators, or gear-drives, to control means connected to means for sensing i.c.engine cylider intake air pressure.
3. 3) A spark ignition i.c.engine's throttling system according to claim 2, in which there are exhaust adiabatic engines, in- take adiabatic engines and variable generators, or gear-drives, fixed to a common shaft and exhaust bypass motorised valve control means are connected to means sensing i.c.en-gine cylinder intake temperatures or freeze conditions.
4. 4) A spark ignition i.c.engine's throttling system according to any of the preceding claims, in which there are fixed gear-drive power transmitters transmitting power between one U).or more, of the generators and one (1), or more, of the adiabatic engines.
5. #0 5) A spark ignition i.c.engine's throttling system according to claim 4, in which there are continuously variable trans-mission CCVI) gear-drives substituted for fixed-gear drives, and their actuator control means are connected to the itS, or to means sensing i.c.engine speed, or both such sensing means, or manual setting means.
6. 6) A spark ignition i.c.engine's throttling system according to any of the preceding claims in which there are adiabatic en-gines in the i.c.engine's intake system, in which there are means connecting such adiabatic engines to the claim l's any means connected to the i.c.engine for accumulating/dis-charging power there are.
7. 7) A spark ignition i.c.engine's throttling system according to any preceding claim, in which there are means sensing high rates of throttle movement, connected via the TCS and con-trol means varying the speed of one (1), or more, of the variable speed generators, for varying the nominal speed of such generators above the speed of the means they are conn-ected to such that they then act as motors, i.e.. de facto motor-generators.
8. 8) A spark ignition i.c.engine's throttling system according to any precechny claim, in which there are means for injecting fuel into the exhaust system connected to the ICS and or switching means.
9. 9) A spark ignition i.c.engine's throttling system according to claim 8, in which there are also means for injecting oxygen rich fluids into the exhaust system connected to control means connected to means sensing downstream exhaust con-dition and to means sensing the said injection flow of fuel into the exhaust system. a()
10. 10) A spark ignition i.c.engine's throttling system according to any preceding claim, in which there are means for conn-ecting any such system connected to accumulating/discharging power means to external power generating, or absorbing, as means, or to means for either generating or absorbing power.Amendments to the claims have been filed as follows CLAIMS: fl A spark-ignstion internal combustion (i.c.) engine having an exhaust throttling system comprising of one (I), or more, throttle controlled adiabatic engines in its exhaust system, variable speed electric motor-generators or variable ratio S gear-drive power transmitters connected to such said exhaust adiabatic engines, a throttle control system (ICS) controll-ing such said motor-generators or year-drives and means for transmitting power between said motor-generators or gear-drives and the i.e. engine. to2) A spark ignition i.c.engine exhaust throttling system accor- ding to claim 3, in which there are means for bypassing ex- haust gases around the moving parts of the throttle con-trolled exhaust adiabatic engines and which incorporate IS motorised valves connected to the ICS.3) 4 spark ignition i.c.engine exhaust throttling system accor- ding to claim I or claim 2, in which there are power accumu-lating-discharging means connected to the i.c.engine, the exhaust throttling adiabatic engines, the itS and a brake control system.4) A spark ignition i.c.engine exhaust throttling system accor- ding to any of the preceding claims, in which there are non-variable power transmitters transmitting power between one (1), or more, of any of the motor-generators and one (1), or more, of any of the the exhaust throttle controlled adia-batic engines.5) A spark ignition c.engine exhaust throttling system accor-ding to claim 4, in which continuously variable transmission (CVI) gear-drives are substituted for the fixed-gear drives, and in which CVI actuator control means are connected to the ICS and or to means sensing i.c.engine speed, or both such sensing means, or manually variable setting means.10) 4 spark ignition i.c.engine exhaust throttling system according to any preceding claim, in which where the i.c.en- gine is in a vehicle there are means for connecting the ve-hicle to power discharging means, and or to power absorbing means, and or to power accumulating-discharging means, 11) A spark ignition i.c.engine exhaust throttling system according to claim 10, in which there is a remote ICS.