DI Engines 1

[AlexNeo]

hi!!

will DI engines ever be used in the US? NOx is a catalyst problem. but are there any developments in the field of catalysts that will solve the probelm?

HC's and particulates are related to in-cylinder phenomena such as wall wetting, pool fires and insufficient time for oxidation of particulates etc. there is lot of reserach going on to identify methods to eliminate these causes. but how long will the auto industry fund DI research projects? is it true that ford and GM are trying to cut spending in DI research? have they given up on DI research?

cadillac claims to have a v-12, 750 hp DI with more torque, fuel economy and low emissions. but they havent said how they achieved all three. its for their new concept car which they claim is inspired by the F-22 fighter aircraft.
it also has cylinder de-activation.

 

[jaymaec]

http://www.citroen.co.uk/level4/technicalSpecification.asp?pagetype=c5&lhn=c5

and

http://www.citroen.co.uk/level4/generalpage.asp?pagetype=techcurrent#top

HPi-DIRECT INJECTION PETROL ENGINE

Citroën has introduced a new high-pressure direct injection petrol engine, the first engine of this type to be developed by a European carmaker.

This new HPi petrol engine, which has been developed in co-operation with Citroën's sister company Peugeot, has a capacity of two litres and develops 143 bhp, but it offers specific advantages over the previous generation of petrol units in several other key areas.
Fuel consumption is up to 21% lower.

C02 emissions are also reduced by a similar amount.

More torque is available at low speed.
All this is achieved by using the most advanced technology available today - lean-burn stratified-charge direct fuel injection - and marks the latest step in an ambitious engine development policy initiated in 1998 with the HDi high-pressure common rail diesel engine.
;-)
Jay

 

[ivymike]

If you want to increase the amount of oxygen in the intake charge, a common method for doing this is to inject N2O (nitrous). Pure oxygen is far too dangerous for most applications (welding would be an exception, I guess).

 

[tomthorp]

Jay, Don't believe everything you read. A lot of this stuff is 50% hype and 50% BS. I do not think they are even offering a "gasoline" DI engine. In fact Peugeot is starting to switch it's scooters to OCP this year.
" are they slow learners, or ahead of the pack?" You be the judge.

Note excerpts below from recent article:

Automotive News Europe, Nov 19, 2001

PSA's Folz launches quest for quality. (PSA/PEUGEOT-CITROEN CEO Jean-Martin Folz)(Interview)(Statistical Data Included) Sylviane de Saint-Seine.
Full Text: COPYRIGHT 2001 Crain Communications, Inc.

PSA/PEUGEOT-CITROEN Chief Executive Officer Jean-Martin Folz wants European suppliers to match the quality standards of their Japanese counterparts. PSA is learning more about Japanese suppliers in its role as purchasing leader in the new small-car venture with Toyota.

In particular, the 54-year-old Folz urged makers of electronic components to better accommodate the needs of the car industry.

Helped by strong sales in France and the rest of Europe, Folz said PSA would stick to its production and profit objectives for 2001. He also called for a state incentive to scrap old, polluting cars.

Automotive News Europe reporter Sylviane de Saint-Seine interviewed Folz on November 5 in Paris.

Given the current economic situation in Europe and South America, your two main markets, are you revising your production and financial objectives?

With our first-half results, our third-quarter sales and our registration figures for October in France and in Europe, there is no reason to revise our 2001 objectives - that is 3 million vehicles, 4.8 percent operating margin and operating income of E2.6 billion. But that's as I speak. The year is not over.

What about your 2004 objectives set last February - 3.5 million vehicles, 25 new models, annual investment of E3 billion and 6 percent operating margin?

We stick by them.

Assuming times get tougher in the car industry, could we see a revival of government-funded car purchase incentives of the kind we saw in the mid-1990s?

I hope not. I am against state incentives for new cars. They just distort the market. But what would be very useful is a cash incentive to scrap old cars. They pollute much more than new cars because they are often poorly maintained and badly tuned, and because anti-pollution technology has made so much progress since they were built. One could think of a subsidy targeted toward low-income owners of old cars, and its beneficiaries could do whatever they like with the money. They would not have to buy a new car, unlike the incentives we had a few years ago.

Any prospect of such an incentive?

Not at present, although I have been pushing this idea to anyone who would listen. Still, it may be gaining ground. I heard that (VW Chairman Ferdinand) Piech mentioned something along those lines not long ago.

How is the situation in South America? Are you cutting production?

We did cut production in our Palomar plant in Argentina in early spring. We went from two shifts to one. Overall sales in Brazil, which rose in the first half, have been falling in the second half. But we count on producing between 20,000 and 23,000 cars there this year, as planned. Picasso and 206 are off to a good start. For September, Peugeot and Citroen had a 5 percent market share between them. It is the highest ever.

How do you judge the quality of components coming from suppliers?

We have been insisting on quality being considered from the design stage. Co-development of products has been helping to improve quality. However, European auto suppliers still have room for progress compared with their Japanese counterparts.

Isn't the growing use of modules, whereby Tier 1 suppliers assemble components they haven't manufactured, detrimental to quality?

On the contrary, this means suppliers will have to tighten quality control. They will share the same preoccupations as us in managing the quality of their own suppliers. The real challenge is to focus on quality from a very early start in the development process.

It is said that Toyota, your partner in the small-car project, aims to have only two suppliers for any one part. Do you share this goal?

Not particularly. We are not very far from that anyway. Given the restructuring that has taken place in the supplier industry, we have no more than three or four suppliers per component. Each new car model is a chance for us to put them in competition.

Is there a specific problem with electronic components?

Yes. I think electronic component makers haven't quite realized yet we've become a key market for them. Electric and electronic systems represent roughly 20 percent of the cost of a car and that proportion may reach 40 percent in future. They don't seem to have taken that into account and it shows in their prices, which are too high. Moreover, they don't seem to have realized that a car's life span is greater than, say, a mobile phone's.

Do you mean their components aren't durable enough?

I mean they change them too often. They should manufacture each component for a longer period. Sometimes we have to rethink the electronic architecture of a car because the original component isn't available anymore. After all, the car industry is proving a more stable customer than many others. The fluctuations aren't as wild as in other industries using electronics. We're a steady source of cash flow. Electronics manufacturers ought to realize this and be more prepared to accommodate our needs.

Is it necessary to own as much as 71.6 percent of Faurecia? Is it the best possible use of your resources?

One thing is certain: PSA will retain 50 percent of Faurecia for as long as I can see. It's a good investment, with good growth prospects. Our stake in Faurecia exceeds 70 percent because the company needed our help to acquire Sommer-Allibert. One can imagine that this stake will go down following, for instance, an acquisition that would be paid in shares by Faurecia. But there's nothing on the agenda. The basic fact is: We have more than 70 percent of Faurecia and that's not bothering us.

Isn't it a contradiction to hang onto your supplier when so many carmakers do just the opposite and spin them off? Can't this cause conflicts of interest for Faurecia?

No. The real measure of independence is the customer list. In this respect, Faurecia is far more independent than many of those suppliers that have been spun off, such as Delphi or Visteon. Only 25 percent of Faurecia's sales are with us.

Isn't there a sentimental element here? After all, Pierre Peugeot, now head of PSA's supervisory board, nurtured Ecia (which was merged with Bertrand Faure to create Faurecia in 1998) for many years.

I don't see sentiments playing a crucial part in business life. PSA's strategy has been to build what was Ecia into a large supplier group.

Are you going to offer direct injection throughout your entire gasoline engine lineup as Volkswagen says it will do?

No, we haven't made that decision. Direct injection does make perfect sense for diesel, but for gasoline, there are several techniques that can be used to make it more efficient - for instance electro-magnetic valve. Aside from Volkswagen, no one has said it wants to generalize direct injection.

Would you consider a partnership in that field?

No. In principle, we don't enter partnership in research - only in development and manufacturing.

Are there any outside buyers for PSA's diesel particle-filter technology?

We pioneered it and now everyone is busy developing its own. In a year or so, nearly everyone will have one available. They will be second-generation filters, even better performing than what we have now. That's the rule of the game. It is rare for a profitable technology to remain proprietary for a long time. From an industry-wide perspective, I think there is no longer scope for a carmaker to come up with a radically new technology and enjoy a crucial and lasting advantage over its competitors. I don't think we'll see key technological leaps of the kind that Citroen enjoyed with the front-wheel drive, for instance.

Regarding the small car you're developing with Toyota, is it true that it will sell for E7,500?

I can only repeat it will sell for less than our respective entry-level cars [Peugeot 106 and Citroen Saxo], which are around E8,000. I don't think anyone can say what the price for this car will be since it will be launched in 2005. As for its cost, I would not reveal it even under torture.

 

[riktoo]

Oxygen injection into the induction charge can be made relatively safely.
The low efficiency of reciprocating engines is as mentionned above is a thermodynamic problem. Lots of heat energy is loss.
The Polymotor plastic engine solved part of the problem.
In more current engines we a a choice to use ceramic coatings which act as heat tranfer barriers .
The injection of pure oxygen into the fuel charge opens up a new chapter in engine design. Yes the pistons may melt down IF they are not adapted to this set -up. This is why I am talking about new engine designs ,not using unadapted engines.
Now we can be negative and see only the objections and difficulties of this application.We should rather concentrate on ways to do it .We certainly have the technology and heat resistant materials to produce an engine with pure oxygen injection.
I am always amazed by engineers who say : ``it cant be done``Somehow ,they should have been pharmacists or something else which requires less imagination.

 

[ivymike]

I don't think anyone is saying "it can't be done," I think they're saying something more like "you'd blow yourself up if you did it." Have you looked into the dangers associated with pure oxygen? The first thing that comes to my mind is that almost anything will burn readily when exposed to pure O2 (including aluminum).

 

[GregLocock]

Without opening my thermo books I find myself ina quandary. On the one hand it seems 'obvious' that the combustion efficiency would be improved if we removed N2 from the combustion chamber, as it is inert (effectively).

On the other hand we have another thread with people extolling the virtues of adding water to the chamber, as an inert working fluid.

So, which is better? I kind of incline towards #2, on the basis that diesel engines ar emore efficient than gas engines, partly because they have a lot of excess working fluid in the cycle (or is it just because they get more complete combustion?).
Cheers

Greg Locock

 

[ivymike]

I thought that the higher compression ratios were the reason diesels were more efficient?

 

[JayMaechtlen]

hi, guys
I was logged in as JAYMAEC - now I'll use this identity at home and work.

It doesn't sound like Citroen is abandoning DI for petrol, just not claiming it across the board.
Again, it is listed as an available engine in several models.
Of course, you may be right- but the article you included doesn't seem to support your statement.

mike- I think the diesel efficiency is due both to higher compression, lower pumping losses at part power, and maybe improved thermo cycle (closer to constant pressure expansion?)

cheers
Jay

 

[ivymike]

yeah, I regularly engage the mouth before the brain when posting here...

I forgot all about the lack of a throttle, the fact that diesels can run lean (and thus use less fuel at low load), etc. There may also have been some benefit (historically speaking) to the lower amount of smog control hardware attached to diesels. Proper use of a turbo can further boost the efficiency if a diesel. I'm sure I'm still forgetting some important factors, which is somewhat disappointing since some of my (paying) work has to do with improving the efficiency of diesels...

 

[charliebPE]

Wow!

I go away for a couple days and come back to find a lot of interest in my question.

Thanks, especially to Tom, for providing the technical explanations as to why GDI doesn't seem to work. As I read it, the fundamental physical problem is that liquid fuel droplets are too large and haven't been uniformly mixed. And the low-sulfur fuel "solution" looks like a bandaid.

I'm guessing the pump and injector technology is not up to snuff. (But again, it's just a guess and I defer to you guys who know more than I.) That is, at 150 bar or about 2 ksi the pump is fairly low pressure. The diesel guys I've worked with brought me in to help them with a slightly radical injector (based on U.S. Pat. 6,279,842) that would operate at 2 000 bar. The lab model worked pretty well. The claim is that opening the valve a very small amount at such high pressure works well to atomize diesel fuel.

Anyway, I'm sure my ignorance of the subject is showing!

Charlie

 

[americamper]

As far as direct injection is concerned,isn't the ficht injection on outboard motors a direct injection.Also would a direct injection with a variable exhaust that uses a O2 sensor in exhaust to adjust the exhaust as far as amount of unburn't fuel not being combusted.forgive the ignorance just asking.

 

[kimbo1]

ricktoo,
Todays engines have about 30 % thermal efficiency (not 25%) and the combustion efficiency( what happens in the cylinder) is actually about 90% so you are a bit misled thinking mixing a liquid with a vapour is the problem. this is why I cannot understand the benefits claimed from a couple of working examples of vapourisers on petrol engines - as they only really have 10% or so to play with. Even the best combined cycle turbines only get 50% efficiency or so.

 

[kimbo1]

tomthorp, are you on orbital's payroll? I suspect there will be some servings of humble pie going around in the next year or two with so much DI bashing going on and some of the smartest engineers in the world from citroen puegot and mitsubishi working on this.

for everyone else - Don't forget we are talking about evolution not revolution here - contrary to some opinions here we are not talking about 75% potential increases in efficiency here, but more like 5-10% i don't read all the magazines but as a practising mech engineer I can offer some sense to some of you guys getting a bit carried away!!!

 

[SWB]

I can envision a day where the inlet valves are replaced by a multitude of air/fuel injectors, at least partially so.

 

[tomthorp]

Kimbo 1, No I don't work for Orbital, but I wish I did. I do happen to be a long time stock holder in OE. Check it out:

http://finance.yahoo.com/q?s=oe&d=t,

http://groups.yahoo.com/group/oec2/messages/?expand=1.

As far as humble pie is concerned, no problem, I've been eating it all my life.

IMHO I think Orbital's OCP low pressure air assisted DI system will be in 50% of the ICE's in the world in the next 10 years. I am trying to be conservative.

Have a nice day, Tom

 

[tomthorp]

Caterpillar Patenting Diesel Engines With OCP Fuel Injection

We all knew it was only a matter of time before the
diesel manufacturers started using OCP. I say this bexause Mercury Marine is now selling Optimax out boards burning JP-5 to the US Military. Also E P Bassus is converting Tohatsu OCP to burn a variety of heavy fuels to the UK Military. Orbital has known for many years that diesel would work with OCP injectors. Now it is happening. I look for a variety of 2S and 4S heavy fuel applications, both SIDI and CIDI using Orbital's OCP fuel injection systems.

Similar to Gasoline OCP, except air and EGR gasses are mixed and
compressed to the desirable temperature and pressure prior to
entering the OCP injector to be mixed with diesel.


United States Patent Application 20040112344
Kind Code A1
Wark, Christopher G. ; et al. June 17, 2004

----------------------------------------------------------------------
----------
Temperature control for gas assisted fuel delivery


Abstract
A method and apparatus for atomizing fuel being delivered for
combustion. The method and apparatus includes providing a stream of
pressurized gas, controlling a temperature of the stream of gas to a
desired temperature, and injecting a quantity of fuel into the stream
of gas, wherein the desired temperature is selected to atomize the
fuel to a desired fuel droplet size.


----------------------------------------------------------------------
----------
Inventors: Wark, Christopher G.; (Peoria, IL) ; Choi, Cathy Y.;
(Morton, IL)
Correspondence Name and Address: CATERPILLAR INC.
100 N.E. ADAMS STREET
PATENT DEPT.
PEORIA
IL
616296490


Serial No.: 321157
Series Code: 10
Filed: December 17, 2002

U.S. Current Class: 123/568.15; 123/585
U.S. Class at Publication: 123/568.15; 123/585
Intern'l Class: F02M 025/07



----------------------------------------------------------------------
----------

Claims

----------------------------------------------------------------------
----------


What is claimed is:

1. A method for atomizing fuel being delivered for combustion,
including the steps of: providing a stream of pressurized gas;
controlling a temperature of the stream of gas to a desired
temperature; and injecting a quantity of fuel into the stream of gas;
wherein the desired temperature is selected to atomize the fuel to a
desired fuel droplet size.

2. A method, as set forth in claim 1, wherein providing a stream of
pressurized gas includes the step of providing a stream of
pressurized air.

3. A method, as set forth in claim 1, wherein providing a stream of
pressurized gas includes the step of providing a stream of
pressurized exhaust gas recirculation (EGR) gas.

4. A method, as set forth in claim 1, wherein providing a stream of
pressurized gas includes the step of providing a stream of at least
one of pressurized air and pressurized exhaust gas recirculation
(EGR) gas.

5. A method, as set forth in claim 1, wherein controlling a
temperature of the stream of gas includes the step of controlling a
temperature of the stream of gas to a temperature within a range from
about 100 degrees Celsius to about 500 degrees Celsius.

6. A method, as set forth in claim 1, wherein controlling a
temperature of the stream of gas includes the step of controlling a
temperature of the stream of gas to a temperature within a range from
about 300 degrees Celsius to about 500 degrees Celsius.

7. A method, as set forth in claim 1, wherein the desired temperature
is selected to atomize the fuel to a desired fuel droplet size of
about 10 microns.

8. A method, as set forth in claim 1, wherein the desired temperature
is selected to atomize the fuel to a desired fuel droplet size of
less than 10 microns.

9. A method, as set forth in claim 1, wherein injecting a quantity of
fuel includes the step of injecting a quantity of liquid fuel into
the stream of gas.

10. A method for providing atomized fuel to a combustion chamber,
including the steps of: providing a stream of gas; pressurizing the
gas to a desired pressure; controlling a temperature of the stream of
gas to a desired temperature; and injecting a quantity of fuel into
the stream of gas; wherein the desired pressure and the desired
temperature are selected to provide atomized fuel at less than a
specified fuel droplet size.

11. An apparatus for atomizing fuel being delivered for combustion,
comprising: a source of gas being delivered in a stream; a compressor
located such that the stream of gas passes therethrough and is
pressurized; a temperature control unit located such that the stream
of gas passes therethrough and is controlled to a desired
temperature; a fuel injector for injecting fuel into the stream of
gas after the gas passes through the compressor and the temperature
control unit, wherein the fuel is atomized to a desired fuel droplet
size as a function of the desired temperature; and a combustion
chamber for receiving the atomized fuel for combustion.

12. An apparatus, as set forth in claim 11, wherein the source of gas
is at least one of air and exhaust gas recirculation (EGR) gas.

13. An apparatus, as set forth in claim 11, wherein the desired
temperature is within a range from about 100 to 500 degrees Celsius.

14. An apparatus, as set forth in claim 11, wherein the desired
temperature is within a range from about 300 to 500 degrees Celsius.

15. An apparatus, as set forth in claim 11, wherein the desired fuel
droplet size is about 10 microns.

16. An apparatus, as set forth in claim 11, wherein the desired fuel
droplet size is less than 10 microns.
----------------------------------------------------------------------
----------

Description

----------------------------------------------------------------------
----------


TECHNICAL FIELD

[0001] This invention relates generally to a method and apparatus for
atomizing a liquid fuel and, more particularly, to a method and
apparatus for controlling a size of atomized fuel droplets by
temperature control of a gas for gas assisted fuel delivery.

BACKGROUND

[0002] Atomization of a liquid, e.g., a liquid fuel used for
combustion, is often desired. For example, when introducing a liquid
fuel into a combustion chamber, the most efficient combustion takes
place when the fuel is completely vaporized and preferably when the
fuel has completely and thoroughly mixed with ambient gases also
present in the chamber. The fuel vaporizes more quickly and readily
when the fuel has been atomized to the smallest droplet size
possible.

[0003] Gas assist injectors have long been used to atomize fuel prior
to entry into combustion chambers. For example, in U.S. Pat. No.
4,759,335, Ragg et al. disclose a system which injects fuel directly
into a combustion chamber by the use of compressed gas, i.e.,
compressed air.

[0004] More recently, in U.S. Pat. No. 5,241,938, Takagi et al.
disclose a fuel injector which includes an air assist passage for
atomizing the fuel during injection.

[0005] In U.S. Pat. No. 5,746,189, Kuzuya et al. disclose a gas
assist system in which exhaust gas recirculation (EGR) gas is used
with gas assist injectors. The EGR gas offers the added benefit of
keeping combustion temperature down in the combustion chamber.

[0006] All of the above listed references and others are effective to
atomize fuel to an extent, but may not be sufficient for some
applications, such as when a homogeneous mixture of fuel and air is
desired.

[0007] The present invention is directed to overcoming one or more of
the problems as set forth above.

"SUMMARY OF THE INVENTION

[0008] In one aspect of the present invention a method for atomizing
fuel being delivered for combustion is disclosed. The method
includes the steps of providing a stream of pressurized gas,
controlling a temperature of the stream of gas to a desired
temperature, and injecting a quantity of fuel into the stream of
gas, wherein the desired temperature is selected to atomize the fuel
to a desired fuel droplet size.

[0009] In another aspect of the present invention an apparatus for
atomizing fuel being delivered for combustion is disclosed. The
apparatus includes a source of gas being delivered in a stream, a
compressor located such that the stream of gas passes therethrough
and is pressurized, a temperature control unit located such that the
stream of gas passes therethrough and is controlled to a desired
temperature, a fuel injector for injecting fuel into the stream of
gas after the gas passes through the compressor and the temperature
control unit, wherein the fuel is atomized to a desired fuel droplet
size as a function of the desired temperature, and a combustion
chamber for receiving the atomized fuel for combustion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a block diagram illustrating a preferred embodiment
of the present invention;

[0011] FIG. 2 is a block diagram illustrating an alternate
embodiment of the present invention;

[0012] FIG. 3 is a block diagram illustrating yet another alternate
embodiment of the present invention; and

[0013] FIG. 4 is a flow diagram illustrating a preferred method of
the present invention.

DETAILED DESCRIPTION

[0014] Referring to the drawings, a method and apparatus 100 for
atomizing fuel being delivered for combustion is disclosed.

[0015] Referring to FIG. 1 in particular, a block diagram
illustrating a preferred embodiment is shown. A combustion chamber
102 receives fuel and air, combusts the fuel/air mixture, and
exhausts the gases from combustion. The combustion chamber 102 may
be part of an internal combustion engine (not shown), as is well
known in the art.

[0016] A portion of the exhaust gas may be routed through an exhaust
gas recirculation (EGR) system 110. EGR systems are well known in
the art and need not be described further.

[0017] The EGR gas may be sent through a fuel injector 104, in
particular, a gas assist fuel injector 104. Gas assist fuel
injectors are configured to pass a stream of high pressure gas
therethrough. Fuel, in particular liquid fuel such as diesel,
gasoline, and the like, is received by the fuel injector 104, which
causes the fuel to enter the stream of gas. The gas assisted fuel
then atomizes prior to entry into the combustion chamber. It is
noted that the fuel injector 104 may be configured for injection
into an intake port (not shown) or directly into the combustion
chamber 102.

[0018] The EGR gas may pass through a compressor 108 prior to
entering the fuel injector 104. Gas assist injectors typically
require the gas to enter under pressure high enough to overcome the
pressure in the combustion chamber 102. Although the EGR gas may
have enough pressure initially, it may be required under some engine
operating conditions to compress the gas still further.

[0019] In the preferred embodiment, the EGR gas passes through a
temperature control unit 106 prior to entering the fuel injector
104. An elevated temperature of the gas is desired for the present
invention. Preferably, the temperature of the gas as it enters the
fuel injector 104 is within a range from about 100 degrees Celsius
to about 500 degrees Celsius. More particularly, it is preferred
that the temperature of the gas is within a range from about 300
degrees Celsius to about 500 degrees Celsius. Typical temperatures
of gases for gas assist injectors, as used in the cited art
references, range from about 30 degrees Celsius to about 50 degrees
Celsius.

[0020] The temperature control unit 106 may increase the temperature
of the gas to a desired value. However, the temperature control unit
106 may also decrease the temperature of the gas, for example when
EGR gas is used and the temperature already exceeds the desired
value. Although an elevated temperature of the gas is desired to
achieve the desired results, a temperature which exceeds the desired
range, e.g., above 500 degrees Celsius, may cause coking in the
combustion chamber 102, may cause combustion to take place too soon,
and may cause excessive component wear.

[0021] Referring to FIG. 2, a block diagram depicting an alternate
embodiment of the present invention is shown.

[0022] The exhaust gas from the combustion chamber 102 passes
through a turbo-charger 202. In addition, fresh air enters the turbo-
charger 202. It is well known in the art that the exhaust gas passes
through a turbine portion (not shown) of the turbo-charger 202,
which drives a compressor portion (not shown), which in turn
compresses the air entering the turbo-charger 202. The compressed
air is then delivered to an engine as intake air, preferably through
an intake manifold (not shown).

[0023] In the embodiment of FIG. 2, however, a portion of the
compressed air is delivered to the fuel injector 104, for use in gas
assisted injection of the fuel. The compressed air may, however,
first pass through a temperature control unit 106 to achieve a
desired temperature of the air. Although the turbo-charger 202 may
heat the air somewhat during the compression process, it may be
desired to heat the air an additional amount. Alternatively, it may
be desired to cool the air an amount to achieve the desired
temperature prior to entering the fuel injector 104.

[0024] Referring to FIG. 3, a block diagram illustrating another
alternate embodiment of the present invention is shown.

[0025] A source of fresh air is delivered to a compressor 108. The
compressor 108 may be an isolated air compressor used primarily for
purposes of the present invention, or may be a compressor used for
some other purpose as well, such as an air brake compressor on a
large truck.

[0026] The compressed air is delivered to the fuel injector 104 for
gas assist purposes as described above. Preferably, the compressed
air is delivered through a temperature control unit 106 to either
heat or cool the air to the desired temperature.

INDUSTRIAL APPLICABILITY

[0027] Operation of the present invention may best be described with
reference to the flow diagram of FIG. 4, which depicts a preferred
method of the present invention.

[0028] In a first control block 402, a stream of gas is provided.
The stream of gas may be air, EGR gas or some other suitable source
of gas for use in a gas assist injector.

[0029] In a second control block 404, the stream of gas is
pressurized, for example by one of the compressor methods described
above.

[0030] In a third control block, the temperature of the gas is
controlled to within a desired temperature range, for example from
about 300 degrees Celsius to about 500 degrees Celsius. It is noted
that, although compression of the gas is described as taking place
prior to temperature control of the gas, it may be desired to
achieve temperature control prior to compression without deviating
from the scope of the invention.

[0031] In a fourth control block 408, fuel is injected into the
stream of gas as the gas passes through the fuel injector 104.
Preferably, the chosen temperature of the gas results in atomization
of the fuel into droplets having a size of about 10 microns and
less. Without temperature control of the gas, typical fuel droplet
size would range from about 30 to about 100 microns.

[0032] Other aspects can be obtained from a study of the drawings,
the disclosure, and the appended claims. "

Have a nice day, Tom

 

[Azmio]

Greg Locock

"Sure, But the Orbital engines are usually 2 strokes, so for a given engine size (ALL other things being equal) the torque is doubled, for a given speed. "

This is something new to me. Knowing that 2 stroke in general has much lower volumetric efficiency if compared to 4 stroke for every induction cycle, will it still be possible to double the torque?

Let me know more about this orbital engine

 

[tomthorp]

What do you want to know Greg?

Here's their website:

http://www.orbeng.com/orbital/

Here's a club where we discuss various aspects of Orbital Engine:

http://finance.groups.yahoo.com/group/oec2/messages

Let me know what you are looking for.

Tom

 

[GregLocock]

Azmio, which bit of "All other things being equal" don't you understand?

Cheers

Greg Locock

 

[Azmio]

Greg

When all other things being equal, I understand it as things like bore and stroke, cylinders, displacement to be the same.

Therefore, since 2 stroke doesnot use poppet valve and instead relying more on ports somewhere in the middle, one full stroke would not yield the full induction stroke as the 4 stroke induction stroke.

That's why when you mentioned about doubling the torque, it can only happen when every induction stroke for the 2 stroke engine would yield the exact same volumetric efficiency as the 4 stroke engine.

Well I hope that I have clarified the "which bit of "All other things being equal" don't you understand?" to you.

So back to my question again, is the Orbital engine really doubled the torque when all else being equal?