| Note: Positive Displacement one-way valves reed-valves # 59 are used to prevent detrimental air reversal flow as well as preventing surging pulsations occurrences from the IFT inverted-turbo-turbocharger |
| normal turbocharger are used for air charging task in open-loop system Inverted Function Turbocharger are used for air scavenging task in closed-loop system |
As per the Boyle & Mariotte's law: p1v1 = p2v2 (due to the fact that the LTCev is an unequal volume closed-loop system) erating mostly at constant temperature, the pressure conditions will change as shown, due to successive closures of VVICC valve while the IFT ( pump) is energised as illustrated here |
Canadian Patent CA 2,732,477 US PATENT 8,683,987 IFT : Inverted-Function-Turbocharger : New patented Otto cycle gas-exchange facilitating technology aka: "an unequal volume" closed-loop exhaust gas driven (positive-displacement (One -way-valve # 59) mainly turbo-scavenging & minimal pressure air charging rotary pump provided by using an IFT minimum pressure blow-down turbine required mainly for simultaneously reducing air volume V1 P1 from an Otto cycle multiple-cylinder engine's contracting VVICC (V1) during said Otto cylinder's intake-cycle and timely transfer said evacuated VVICC's V1 P1 air volume & pressure into another expanding cylinder's VVICC (2) +other volumes 2* of said cylinder performing its exhaust-cycle larger combined volume to advantageously allowing therefore to only minimally increase said timely exhaust cycle cylinder'sVVICC V2 's pressure. An Inverted Function Turbocharger's blow-down power recovery turbine of a light turbo compound engine variant is used to recuperate normally lost exhaust cycle's gas velocity's energy to drive the IFT's impeller that is used to rarefy air pressure of an enclosed contracting cylinder's VVICCs' air volume (while said cylinder is performing its Otto intake cycle), instead of charging air pressure into said cylinder as a conventional charging turbocharger. Reducing VVICC's pressure is a mandatory condition for generating indirect pneumatic air-coupling. The IFT is used for CAIC Otto cycle engine: reducing air Δp pressure within the small VVICC enclosed volume of a CAIC Otto cycle (throttled) S.I. engine, to allow to generate indirect pneumatic coupling by allowing ambient air pressure in the cylinder provided by the available atmospheric pressure force to overcome the IFT's reduced air pressure induced into a cylinder's VVICC of said cylinder performing its Otto Intake cycle to assist Otto intake cycle pumping task and cost effectively emulate UAIC direct fuel injection system's no-pumping-loss friction ability to provide adequate advantageous intake-cycle-dynamic-pressure Δp = O in spite of using air-flow impiding cost effective throttle, yet to prevent pumping-loss friction at part-load and provide the lowest GHG emission I.C.E engine, and being as efficient as cost effective as possible as a suitable ICE component for reducing the inherently high cost of extended range electric hybrid vehicles; and generating pumping-gain when Delta P or ∆p becomes less than zero.
Both share general layout appearance and construction. Both have an exhaust gas driven turbine Both turbines are more effective at higher engine loads. For different reasons, both can advantageously be electrically assisted
Task: to raise air pressure of a high volume of air charge for admission into the cylinders
used in an open loop system The turbocharger's compressor charging task is intensive, (as it compresses a substantially larger volume of air into a significantly smaller cylinde's volume at a significantly higher pressure; this results in higher pressure ratio work. IFT inverted-function-turbocharger AKA:"TURBOSCAVENGER" IFT's limited task: to timely dynamically reduces the air pressure of one small volume (dry sump cylinder's VVICC's) during a cylinder's Otto intake cycle and only bring it to ideal intake cycle Δp condition. IFT's inertia can provide beneficial assistance to maintain turbo adequate rotational energy at low engine loads. IFT's inertia assist controlling temporary surging, is advantageously used near the end of VVICC cycle IFT's only pressure work is to successively and alternately creates a suitable air under-pressure condition in a small enclosed cylinder's VVICC while said cylinder is performing its intake cycle and let air expand into a substantially much larger enclosed expansion volume (s). (as Boyle's & Mariotte's law) IFT is used in a closed loop system. IFT inverted-function-turbochargers are used in uniquely adapted
The boost threshold of a turbocharger system relates to the minimum turbo RPM needed for the turbo to be physically capable to increase the air pressure of an ambient volume from an unlimited amount of air of an open-loop system to increase an undetermined volume of air pressure with required boost pressure above said ambient air pressure into a closed chamber. Scavenging capacity threshold of IFT inverted function turbocharger is unrelated to turbo lag The scavenging capacity threshold of inverted function turbocharger relates to the minimum turbo RPM needed for the inverted function turbocharger to be physically capable to generate predetermined reduced Δp air pressure level difference between two unequal volume closed chambers of a closed-loop system The IFT: inverted function turbocharger's compressor (impeller) evacuates and reduces the pressure of a quite small limited air volume VVICC within a (silent) closed-loop system and displaces said small limited air volume (V1) into significantly much larger total enclosed crankcase volumes (V2) of said closed-loop system of the engine while intentionally only minimally raising its (PV1) pressure to therefore requiring only a moderate charging pressure ratio from the IFT's impeller, that can still be available at lighter engine loads and may be temporary optionally electrically assisted for mild electric hybrids or could use stop-start technology for certain vehicle's unique for frequent recurring while effectively generating useful under-pressure condition in the smaller volume chamber (VVICC) being evacuated while only generating minimal pressure increase level in the much larger volume (VVICC)'s expansion chamber. In general, due to the much larger displaced air volume involved, the boost threshold of a turbocharger occurs at a higher RPM than the RPM where the scavenging threshold capacity of an inverted function turbocharger threshold occurs. The inverted function turbocharger indeed also benefits from the reduced pumping load by allowing the inverted function turbocharger rotating speed momentum to be maintained as the pumped VVICC air volume is continually reducing through VVICC evacuation process and it repetitively operates momentary at near surging condition of each VVICC evacuation cycle due to Otto contracting VVICC volume cycles compressor successively increases speed temporarily to higher RPM at the end of the VVICC scavenging cycle as it operates in a positive displacement pulsating mode in a rarefied atmosphere of the VVICC at near surging conditions. The light turbo compound engine variant is a new turbo compound Otto cycle engine whose supplemental energy source provided to the engine is supplied by an ”indirect pneumatic coupling” process resulting from conveniently exploiting timely existing pneumatic pressure level differences exerted separately onto each opposing faces of the piston performing its Otto intake cycle. Actual pneumatic assistance coupling is conveniently provided by available ambient atmospheric pressure energy potential allowed and capable* of exerting more absolute pressure onto the working face of said piston conjointly with the provided timely reduced ambient pressure level exerted onto the piston under-face facing VVICC of a cylinder performing its intake cycle. Said timely ambient VVICC under-pressure being provided by an inverted function turbocharger or I.F.T. Said I.F.T. is used to reduce the ambient pressure onto the under face of the piston to provides Otto Intake cycle pneumatic pumping assistance resulting from unique indirect pneumatic coupling generated by the available atmospheric pressure potential energy instead of using prior-art heavier and more complex direct mechanical or electrical coupling. Indirect pneumatic coupling can be achieved when the available ambient atmospheric air pressure energy level can selectively and timely be allowed to expose a piston’s crown of a piston performing its Otto intake cycle to a significantly higher pneumatic pressure than the supplied pneumatic under-pressure provided by the IFT (inverted function turbocharger) in a VVICC of a cylinder performing its Otto intake cycle. UAIC strategy Otto cycle ( GDI S.I. & C.I engines) are capable* of providing the highest level of pumping-gain throughout the engine load range.while CAIC strategy engine are only capable*to produce pumping-gain at higher engine load range
the IFT's configuration can be benefit from optional with variable vanes or the IFT can benefit from coming 42 volts electrical assistance. Idle-stop technology should be advantageously used for CAIC strategy engine instead of sustained idling, as the efficiency gain of the an non-electrically assisted IFT is virtually inexistant during idling mode; although than that, once operated at part-load, the engine response and ample low end torque is immediate, and fuel efficiency ready increases immediately from moderate engine load. NOTE: " most electric hybrid vehicles propulsion system does not require any contribution from the Otto ICE component operation for low power and low speed operations." NOTE: pending optimisation development LTCev's unique "VVICC air / stray-oil" separation control" minimizes VVICC's stray-oil migration intimate contact into IFT's impeller that can negatively affect IFT's operation's efficiency due to intimate mixing of blow-by water vapours that results from negatively affecting blending and accelerating engine oil and increasing its contamination as well as increasing workload on PCV system Positive Crankcase Ventilation 's operation. |
hic inceptant futura |
| Jean-Pierre Marcil |
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TM
| site copyright R&DMI |
| TM |
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| reed-valve # 59 (check-valve) fitted before & after pump |
| see larger version of fig.2 at the very bottom of this page |
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| Reed-Valve |
| Reed-Valve |
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| Inverted Function Turbocharger |
| Inverted Function Turbocharger |
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| TURBOSCAVENGER TM |
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