PNEUMATIC HYBRID I.C. ENGINE HAVING WATER INJECTION

Abstract

An I.C. engine (and vehicles incorporating the same) connected with an air reservoir and having means of introducing water (or other evaporable fluid). The air reservoir can be used to store energy (in the form of compressed air) while braking the engine and/or allow compressed air to power the engine or to improve its performance. The evaporable fluid can be used: to increase engine efficiency, to increase power, for cooling, as a knock inhibitor, to allow an increased compression ratio, for NOx reduction, to effect other emissions, to aid in controlling HCCI, etc. The cooling effect of evaporable fluid is complementary to storing energy pneumatically since cooler air can be stored more efficiently. Other advantages are also discussed. This engine disclosure further contemplates means to recapture evaporable fluid for reuse (unburned hydrocarbons etc. may also be captured similarly).

Claims

1. A pneumatic hybrid internal combustion engine with means of introducing evaporable fluid into said engine, comprising: (a) an internal combustion engine, excluding split-cycle type engines, with means of air intake, compression, power extraction, and exhaust, (b) at least one combustion chamber, (c) at least one air reservoir, with means of fluid communication to the engine, (d) means for opening and closing fluid communication between engine and air reservoir, to allow air flow between the air reservoir and the engine, (e) means for introducing evaporable fluid, such as but not limited to water, into engine.

2. The engine of claim 1 further comprising electronic means, such as a computer, for controlling said engine.

3. The engine of claim 1 wherein the evaporable fluid is introduced directly into the combustion chamber.

4. The engine of claim 1 wherein the evaporable fluid is introduced via the intake manifold.

5. The engine of claim 1 further comprising means for altering the temperature of the evaporable fluid before introduction.

6. The engine of claim 1 further comprising a forced induction device, such as a turbocharger.

7. The engine of claim 1 wherein the power stroke is longer than the compression stroke, such as Atkinson or Miller cycle.

8. The engine of claim 1 further comprising means for the air reservoir to receive air from an alternate source, such as but not limited to, an air compressor.

9. The engine of claim 1 further comprising means to alter the temperature of the air which moves through the air passage between the air reservoir and the engine.

10. The engine of claim 1 further comprising an emissions aftertreatment, such as but not limited to, catalytic converter, diesel oxidation catalyst, diesel particulate filter, selective catalytic reduction and/or ammonia oxidation catalyst.

11. The engine of claim 1 further comprising means for purifying the evaporable fluid, such as a filter.

12. The engine of claim 1 further comprising means of collecting evaporable fluid for said introduction into the engine.

13. The engine of claim 12 further comprising means whereby the evaporable fluid is collected from the ambient, such as condensate from an air conditioning unit.

14. The engine of claim 12 further comprising means whereby the evaporable fluid is collected from the exhaust, such as but not limited to, cooling the exhaust through a heat exchanger to condense fluid out.

15. The engine of claim 12 further comprising means for collecting unburned hydrocarbons from the exhaust.

16. The engine of claim 12 further comprising means for collecting soot from the exhaust.

17. The engine of claim 12 further comprising means for introducing unburned hydrocarbons and/or soot into the combustion chamber.

18. The engine of claim 1 further comprising a vehicle.

Description

DRAWINGSFIGURES

[0079] FIG. 1 shows an internal combustion engine with means to communicate with an air reservoir and means for introducing water, in accordance with one embodiment.

[0080] FIG. 2 shows an internal combustion engine with means to communicate with an air reservoir, means for introducing water, a computer, a turbocharger, and means for recollecting water from the exhaust for re-introduction, in accordance with a second embodiment.

[0081] FIG. 3 shows an internal combustion engine with means to communicate with an air reservoir, means for introducing water, a computer, a turbocharger, and means for recollecting water from the ambient for introduction, in accordance with a third embodiment.

[0082] FIG. 4 shows the pneumatic hybrid I.C. engine, with means of introducing evaporable fluid, in a vehicle.

DRAWINGSREFERENCE NUMERALS

[0083] 10internal combustion engine [0084] 12cylinder [0085] 14piston [0086] 16cylinder head [0087] 18combustion chamber [0088] 20water injector [0089] 22intake valve [0090] 24intake manifold [0091] 26fuel injector [0092] 28valve to open/close fluid communication with air reservoir [0093] 30air passage to air reservoir, could also contain means for exchanging heat to/from the air passing through it. [0094] 32air reservoir [0095] 33valve (or similar means) permitting the air reservoir to be filled by an external source [0096] 34for spark ignition engines this can represent a spark plug, for compression ignition engines this can represent a glow plug, it could also represent other means for igniting the charge or be omitted. [0097] 36exhaust valve [0098] 38exhaust manifold [0099] 42heat exchanger [0100] 43A.C. unit [0101] 44filter [0102] 46pump [0103] 47device for heating or cooling evaporable fluid [0104] 48computer [0105] 50turbocharger [0106] 52aftertreatment [0107] 54Vehicle

DETAILED DESCRIPTION

FIG. 1First Embodiment

[0108] One embodiment of this disclosure is illustrated in FIG. 1. In this embodiment the base engine 10 has a cylinder 12, a piston 14, and a cylinder head 16. These are for illustration and explanation, but are not intended to limit the present disclosure to engines having cylinders and pistons. The combustion chamber 18 is also shown.

[0109] Normal Operation:

[0110] During normal operation intake valve 22 is opened as the piston 14 moves down for the intake stroke. During the intake stroke, or shortly thereafter, water is introduced from water injector 20. Water may be introduced as a mist to allow it to mix with the intake air. Water may be introduced at multiple times if doing so gives most desirable results. Fuel may be introduced from fuel injector 26 during intake, compression and/or power stroke as is appropriate for the fuel being used. During compression all valves are closed. The amount of water introduced can be tuned such that all of the water will be evaporated by approximately TDC. This allows for cooling of the charge during the full compression stroke, since the water absorbs heat as it evaporates. The additional mass of the water vapor effectively increases the compression ratio of the engine. Increased compression ratio leads to increased efficiency and power density. The charge is ignited at approximately TDC. As the fuel burns it heats the charge. Water vapor expands more than air when heated, increasing the pressure for pushing the piston 14 down for the power stroke. The peak temperature is lower due to the injected water which reduces the amount of NOx formed. The engine also enjoys the other benefits of water introduction as previously mentioned in this disclosure. At approximately BDC the exhaust valve 38 is opened and the piston 14 moves up for the exhaust stroke.

[0111] Braking and Storing Energy:

[0112] When braking of the engine, or vehicle, is desired the engine can store energy in the air reservoir. The intake valve 22 opens as the piston 14 moves down drawing air in, at approximately BDC the intake valve closes. The piston 14 begins to compress the fresh air. When the pressure in the cylinder 12 and the pressure in the air reservoir 32 are approximately equal, the air reservoir valve 28 opens. Air is compressed into the air reservoir 32, providing braking while storing energy pneumatically.

[0113] Stored energy can be used later to power the engine.

[0114] Straight pneumatic mode:

[0115] At about TDC the air reservoir valve 28 is opened (with other valves closed) allowing high pressure air to push the piston 14 down, powering the engine. The air reservoir valve 36 may be closed immediately to conserve pressurized air, or it may be held open for a time to increase power output. At or before about BDC the air reservoir valve 28 should be closed. At about BCD the exhaust valve 36 is opened, the piston 14 moves up exhausting the air. Then the cycle repeats.

[0116] Valve 33 allows for the air reservoir 32 to be filled by external means, such as an air compressor. This can save fuel as the engine could run on compressed air for a time.

[0117] Pneumatic 4 Cycle Mode:

[0118] At about TDC the air reservoir valve 28 is opened (with other valves closed) allowing high pressure air to push the piston 14 down. At about BDC, water is introduced via injector 20. Fuel is introduced via injector 26 when appropriate depending on the fuel. The piston 14 moves up compressing the charge and evaporating the water (as in normal operation). The fuel burns increasing temperature of the charge and driving the piston 14 down for power stroke. At about BDC the exhaust valve 38 is opened for the exhaust stroke. Then the cycle repeats.

[0119] Pneumatic 2 Cycle Mode:

[0120] At approximately TDC the air reservoir valve 28 is opened allowing pressurized air into the combustion chamber, shortly thereafter this valve is closed. Fuel is injected. Water may also be injected as desired. The charge is ignited and the pressure increases. High pressure pushes the piston 14 down for the power stroke. At about BDC the exhaust valve 36 opens, the piston 14 moves up exhaling the exhaust. Then the cycle begins again immediately.

FIG. 2Second Embodiment

[0121] The second embodiment has all the components and potential modes as the first embodiment and also shows additional components. Computer 48 may be used to control the engine. It may read in information from the engine. It may be used to control and/or optimize: valve timing, fuel injection timing and amount, and water injection timing and amount. The computer could use feedback from the engine to optimize its controls. The computer could also be used for many other things that could come to mind by someone with ordinary skill in the art.

[0122] Turbocharger 50 allows energy in the exhaust to be used to increase air flow into the engine, which can increase power and/or efficiency. Aftertreatment 52 is to assist in reducing emissions. It could comprise but is not limited to, any one or combination of the following: catalytic converter, diesel oxidation catalyst, diesel particulate filter, selective catalytic reduction and/or ammonia oxidation catalyst.

[0123] Heat exchanger 42 is used to separate the water from the exhaust gases to be used for re-introduction into the engine. As the exhaust gases are cooled the water condenses and can be separated. This heat exchanger could also be used to collect other liquids, such as hydrocarbons. It could also be used to collect solid particles such as soot, which could be burned in the engine or disposed of. Filter 44 may be used to clean the water before it is re-introduced into the engine. The filter could be cleaned or disposed of. Pump 46 can be used to assist in the flow of water, and/or to increase the pressure of water, for introduction into the engine. Device 47 is for altering the temperature of the evaporable fluid as may be desirable to give best results. Device 47 could be a heat exchanger, heater, refrigeration unit or any suitable device able to heat and or cool the evaporable fluid.

[0124] Air passage 30 could also contain means for exchanging heat to/from the air passing through it. One example of this could be a heat exchanger to cool the air going into the air reservoir to allow more air to be stored in it. Another example could be a mesh which could hold heat as the air is compressed into the air reservoir, then return heat to the air when it is returned to the combustion chamber.

FIG. 3Third Embodiment

[0125] The third embodiment has similar functions and modes of operation as the first and second embodiments. But the third embodiment shows means of collecting evaporable fluid from the ambient, in this case an A.C. unit 43. Water often collects on A.C. units because they are cooler then the surrounding air. Thus they could also serve as a means of collecting water for injection into the engine. This embodiment also shows water injector 20 in an alternative location, allowing the evaporable fluid to be introduced in the intake manifold.

FIG. 4Forth Embodiment

[0126] The fourth embodiment shows a vehicle 54 with, the pneumatic hybrid I.C. engine with means of introducing evaporable fluid.