U.S. patent application number 12/140193 was filed with the patent office on 2008-12-25 for system and method for engine lubrication.
This patent application is currently assigned to CRR DEVELOPMENTS PTY LTD. Invention is credited to Christopher Romano, Robert Romano.
Application Number | 20080314686 12/140193 |
Document ID | / |
Family ID | 40135314 |
Filed Date | 2008-12-25 |
United States Patent
Application |
20080314686 |
Kind Code |
A1 |
Romano; Robert ; et
al. |
December 25, 2008 |
SYSTEM AND METHOD FOR ENGINE LUBRICATION
Abstract
The invention resides in an internal combustion engine (20)
comprising an air intake system (24) operatively connected to a
cylinder (21), a gaseous phase fuel delivery system (25)
operatively connected to the cylinder (21), and a liquid phase
lubricant injection system (10) operatively connected to the
cylinder (21). An atomised portion of liquid phase lubricant is
injected into a mixture of gaseous phase fuel and air by the liquid
phase lubricant injection system (10) to lubricate components of
the cylinder (21) prior to burning the mixture in the cylinder
(21).
Inventors: |
Romano; Robert; (Carina
Heights, AU) ; Romano; Christopher; (Carina Heights,
AU) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Assignee: |
CRR DEVELOPMENTS PTY LTD
Morningside
AU
|
Family ID: |
40135314 |
Appl. No.: |
12/140193 |
Filed: |
June 16, 2008 |
Current U.S.
Class: |
184/6.5 ;
123/196R |
Current CPC
Class: |
F01M 1/14 20130101; F01M
1/08 20130101; F01M 3/04 20130101 |
Class at
Publication: |
184/6.5 ;
123/196.R |
International
Class: |
F01M 1/04 20060101
F01M001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 20, 2007 |
AU |
2007-902861 |
Claims
1. An internal combustion engine, comprising: an air intake system
operatively connected to a cylinder; a gaseous phase fuel delivery
system operatively connected to the cylinder; and a liquid phase
lubricant injection system operatively connected to the cylinder;
wherein during use an atomised portion of liquid phase lubricant is
injected into a mixture of gaseous phase fuel and air by the liquid
phase lubricant injection system to lubricate components of the
cylinder prior to burning the mixture in the cylinder.
2. The internal combustion engine according to claim 1, wherein the
liquid phase lubricant system comprises one or more lubricant
injectors located in an intake manifold of the engine.
3. The internal combustion engine according to claim 2, wherein the
lubricant injector is positioned adjacent an intake valve of the
cylinder.
4. The internal combustion engine according to claim 1, wherein the
liquid phase lubricant system comprises one or more lubricant
injectors located in a cylinder head of the engine.
5. The internal combustion engine according to claim 1, wherein the
lubricant injector injects the liquid phase lubricant immediately
prior to or during an intake stroke of the engine.
6. The internal combustion engine according to claim 1, wherein the
gaseous phase fuel is coal bed methane (CBM), coal mine methane
(CMM), abandoned mine methane (AMM), landfill gas, biogas, liquid
petroleum gas (LPG), or natural gas.
7. The internal combustion engine according to claim 1, wherein the
liquid phase lubricant is a mineral or synthetic oil.
8. A method for lubricating a dry fuel internal combustion engine,
the method including the steps of: i) injecting an atomised portion
of liquid phase lubricant into a mixture of gaseous phase fuel and
air contained in an intake manifold of the engine; ii) drawing the
mixture into a cylinder of the engine; and iii) allowing the
atomised liquid phase lubricant contained in the mixture to
lubricate components of the cylinder prior to burning the mixture
in the cylinder.
9. The method of claim 8, wherein step i) occurs immediately prior
to or during an intake stroke of the engine.
10. The method of claim 8, wherein the gaseous phase fuel is coal
bed methane (CBM), coal mine methane (CMM), abandoned mine methane
(AMM), landfill gas, biogas, liquid petroleum gas (LPG), or natural
gas.
11. The method of claim 8, wherein the liquid phase lubricant is a
mineral or synthetic oil.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to lubrication of internal
combustion engines. In particular, although not exclusively, the
invention relates to a system and method for lubricating engine
cylinder walls using lubricant injectors.
BACKGROUND TO THE INVENTION
[0002] Flammable gas is considered a waste bi-product of many
industrial processes. For example, coal mine gas (commonly known as
firedamp) consists primarily of highly flammable methane that is
produced during the geochemical process of carbonizing organic
material into coal. Coal mine gas has produced many lethal
explosions in coal mines. Therefore, coal mines today are generally
elaborately and carefully ventilated to ensure that explosive
concentrations of coal mine gas are removed. However, rather than
simply venting coal mine gas directly to the atmosphere as
pollution, coal mine gas is sometimes captured and used as a fuel
to run engines that can perform useful work at a mine site. For
example, large, stationary engines fuelled by coal mine gas can be
coupled to electric generators. Resulting electricity then can be
used at a mine site or fed back into a public power grid.
[0003] Other industrial processes also generate flammable waste
gases that can be used to power generator engines. For example,
landfill gas and biogas consist primarily of mixtures of methane,
carbon dioxide and nitrogen and are commonly produced in landfills
and other organic waste sites as organic substances decompose. To
prevent hazardous and other unwanted conditions such as foul
odours, landfill gas and biogas can be extracted from a waste site
using perforated cylinders that are piped through waste material.
The extracted gas then can be used as a fuel.
[0004] The waste gas engines used to run generators at industrial
sites are generally massive and powerful engines such as
turbocharged and intercooled 12- to 20-cylinder V-engines. Such
engines typically run continuously at a constant speed to produce a
steady output of thousands of horsepower. The engines are thus
complex and expensive but must be highly reliable to ensure low
operating costs and profitable investment returns.
[0005] Unfortunately, many waste gases such as methane are
relatively `dry` fuels that can result in significant wear and
deterioration of engine parts. In a typical liquid fuelled gasoline
or diesel engine, the fuel itself can effectively lubricate exposed
engine components such as valve stems and piston cylinder walls.
However, in waste gas fuelled engines, the waste gases generally do
not provide significant lubrication to prevent wear on the engine
components such as valve stems and piston cylinder walls.
Methane-powered engines also suffer from an abrasive crystalline
build-up on the valve stems and piston cylinder walls due to a
chemical product in the gas which is unable to be pre-filtered.
Without some form of additional lubrication or wear protection,
these engines can be subject to high maintenance costs and
premature failure.
[0006] Proposed solutions to the need for additional lubrication in
waste gas engines resulting from `dry` fuel have included adding
lubricants to waste gas in a waste gas fuel tank, and using
low-friction coatings on susceptible engine components. However,
many of these solutions are impractically expensive and still do
not provide for the engine reliability required to make the use of
waste gas engines economical and profitable.
[0007] There is therefore a need to overcome or alleviate the above
discussed problems associated with fuel-induced high wear and the
resulting low service life of waste gas engines.
OBJECTS OF THE INVENTION
[0008] An object of the present invention is to overcome or
alleviate one or more limitations of the prior art and/or provide a
consumer with a useful commercial choice by providing a system and
method for engine lubrication of `dry` fuel engines.
SUMMARY OF THE INVENTION
[0009] In one form, although it need not be the only, or indeed the
broadest form, the invention resides in an internal combustion
engine comprising:
[0010] an air intake system operatively connected to a
cylinder;
[0011] a gaseous phase fuel delivery system operatively connected
to the cylinder; and
[0012] a liquid phase lubricant injection system operatively
connected to the cylinder;
[0013] wherein during use an atomised portion of liquid phase
lubricant is injected into a mixture of gaseous phase fuel and air
by the liquid phase lubricant injection system to lubricate
components of the cylinder prior to burning the mixture of gaseous
phase fuel and air in the cylinder.
[0014] Preferably, the liquid phase lubricant system comprises one
or more lubricant injectors located in an intake manifold of the
engine.
[0015] More preferably, each lubricant injector is positioned
adjacent an intake valve of a cylinder.
[0016] Alternatively, the liquid phase lubricant system comprises
one or more lubricant injectors located in a cylinder head of the
engine.
[0017] The lubricant injector preferably injects the liquid phase
lubricant immediately prior to or during an intake stroke of the
engine.
[0018] The gaseous phase fuel is preferably coal bed methane (CBM),
coal mine methane (CMM), abandoned mine methane (AMM), landfill
gas, biogas, liquid petroleum gas (LPG) or natural gas.
[0019] The liquid phase lubricant preferably comprises a mineral or
synthetic oil.
[0020] In another form, the invention provides a method for
lubricating a dry fuel internal combustion engine, the method
comprising the following steps:
[0021] injecting an atomised portion of liquid phase lubricant into
a mixture of gaseous phase fuel and air contained in an intake
manifold of the engine;
[0022] drawing the mixture of gaseous phase fuel and air into a
cylinder of the engine; and
[0023] allowing the atomised liquid phase lubricant to lubricate
components of the cylinder prior to burning the mixture of gaseous
phase fuel and air in the cylinder.
[0024] The method for lubricating a dry fuel internal combustion
engine, wherein the step of injecting an atomised portion of liquid
phase lubricant into a mixture of gaseous phase fuel and air
preferably occurs immediately prior to or during an intake stroke
of the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] To assist in understanding the invention and to enable a
person skilled in the art to put the invention into practical
effect, preferred embodiments of the invention are described below
by way of example only with reference to the accompanying drawings,
in which:
[0026] FIG. 1 is a plan view of a liquid phase lubricant system
according to one embodiment of the invention showing how lubricant
is delivered to an engine;
[0027] FIG. 2 is a plan view of the liquid phase lubricant system
of FIG. 1 showing how the delivery of lubricant is controlled;
[0028] FIG. 3 is a sectional view of the liquid phase lubricant
system of FIG. 1 showing an injector mounting on a wall of an
intake manifold; and
[0029] FIG. 4 is a flow diagram of the method of delivering the
lubricant to the engine.
DETAILED DESCRIPTION OF THE INVENTION
[0030] FIGS. 1 and 2 show a liquid phase lubricant system 10
retrofitted to an existing stationary 20-cylinder diesel V-engine
20 that has been converted to using methane gas.
[0031] The engine 20 includes two rows of cylinders 21. Each
cylinder 21 is operatively connected to an intake manifold 22. An
air intake system 23 and a gaseous phase fuel delivery system 24 is
operatively connected to each cylinder 21 via the intake manifold
22, as known in the prior art.
[0032] The liquid phase lubricant system 10 includes a lubricant
delivery system 30 and a lubricant control system 40. Although the
invention is explained with reference to stationary engines, the
inventor envisages that the invention is also applicable in other
environments such as vehicle engines running on similar `dry`
fuels.
[0033] FIG. 1 shows the lubricant delivery system 30 which delivers
a 10-weight mineral oil to each cylinder 21 of the engine 20.
However, it is to be appreciated that other forms of lubricant may
be used, such as a lightweight synthetic oil. Embodiments of the
lubricant may also include additives such as a combustion enhancer
to improve fuel efficiency and reduce exhaust emissions of the
engine 20. The lubricant delivery system 30 includes a series of
injectors 31, a high pressure pump 32, a reservoir 33, a pressure
regulator 34, and a supply rail 35. Only one side of the engine 20
is shown fluidly connected to the lubricant delivery system 30 for
clarity.
[0034] Each injector 31 is mounted through an intake manifold 22 of
the engine 20 such that a nozzle of the injector 31 points towards
a respective intake valve of each cylinder 21, as will be discussed
in detail later. Alternately, each injector 31 may be mounted
through a cylinder head 23 of the engine 20 such that the nozzle of
the injector is located inside each cylinder 21. An inlet of each
injector 31 is fluidly connected to the supply rail 35 that runs
along the intake manifold 22 adjacent each row of cylinders 21.
[0035] The high pressure pump 32 supplies lubricant from the
reservoir 33 to the supply rail 35 under pressure. An inlet of the
high pressure pump 32 is fluidly connected to the reservoir 33
while an outlet of the high pressure pump 32 is fluidly connected
to an inlet of the supply rail 35. However, it is to be appreciated
that the outlet of the high pressure pump 32 may also be connected
to an inlet of another supply rail to lubricate the other row of
cylinders 21.
[0036] The reservoir 33 is used to store a constant supply of
lubricant to the high pressure pump 32. The reservoir 33 includes a
swirl pot 36 having two inlets and two outlets, a low pressure pump
37, and a supply tank 38. An inlet of the swirl pot 36 is fluidly
connected to the supply tank 38 via the low pressure pump 37. The
other inlet of the swirl pot 36 is fluidly connected to an outlet
of the pressure regulator 34. An outlet of the swirl pot 36 is
fluidly connected to the supply rail 35 via the inlet of the high
pressure pump 32. The other outlet of the swirl pot 36 is fluidly
connected to the supply tank 38. Alternatively, it is to be
appreciated that the reservoir 33 may only comprise the supply tank
38.
[0037] The pressure regulator 34 is used to regulate lubricant
pressure within the supply rail 35. The pressure regulator 34 is
fluidly connected to the outlet of the supply rail 35. A pressure
gauge 39 is included with the pressure regulator 34 to monitor the
pressure of lubricant within the supply rail 35.
[0038] FIG. 2 shows the lubricant control system 40 which controls
the delivery of lubricant to each cylinder 21. The lubricant
control system 40 includes a lubricant control unit (LCU) 41, a
crank pickup 42, and two cam pickups 43.
[0039] The LCU 41 monitors the engine's operating parameters via
each of the crank and cam pickups 42,43 to control the delivery of
lubricant to each cylinder 21. However, it is to be appreciated
that the LCU 41 may be incorporated into an Engine Control Unit
(ECU) of the engine 20 and use a number of other sensors to monitor
the engine's operating parameters, such as air flow, fuel mixture,
engine temperature, exhaust composition, etc. The LCU 41 is
electrically connected to the crank pickup 42, the cam pickup 43,
and each injector 31.
[0040] The crank and cam pickups 42,43 measure the speed of
rotation and/or relative position of each respective crank and cam
shaft. Each of the crank and cam pickups 42,43 comprise a hall
effect sensor 44 fixedly positioned adjacent a sensor wheel 45 that
is mounted on a respective crank and cam pulley 46,47. The sensor
wheel 45 has a number of magnets 48 equally spaced around its
periphery such that when the sensor wheel 45 rotates due to
rotation of the crank and/or cam shafts, the voltage of each pickup
42,43 peaks as each magnet 48 approaches the hall effect sensor 44.
Alternatively, the sensor wheel 45 may comprise a series of
magnetised pointed teeth disposed around its periphery, such that
the point of each tooth is detected as it approaches the hall
effect sensor 44. It is also to be appreciated that optoelectronic
or other forms of pickup devices can be used to measure the speed
of rotation and/or relative position of the crank and cam
shafts.
[0041] FIG. 3 shows an injector mounting 50 on a wall of an intake
manifold 22 allowing the system to be installed in an existing
engine that is operatively connected to an air intake system 24 and
a gaseous phase fuel delivery system 25.
[0042] The injector mounting 50 may be installed on site to reduce
the downtime that the engine is offline and minimise disruption.
The injector mounting 50 includes a threaded boss 51 having an end
52 cut at an angle of 45.degree.. However, it is to be appreciated
that the end 52 of the threaded boss 51 may be cut at other angles
to accommodate each particular injector 31 on the intake manifold
22. The end 52 of the threaded boss 51 is welded to the wall of the
intake manifold 22 such that a nozzle 53 of the injector (not
shown) will point in the general direction of an intake valve 54 in
a cylinder 21. A hole 55 is drilled through the wall of the intake
manifold 22 inside the threaded boss 51. The intake manifold 22 may
be removed from the engine either before or after drilling and
cleaned after drilling to prevent any metal filings from the hole
55 being blown into the cylinder 21.
[0043] FIG. 4 shows a flow diagram of a method 60 of delivering the
lubricant to the engine.
[0044] The method 60 commences at step 61 by injecting an atomised
portion of liquid phase lubricant into a mixture of gaseous phase
fuel and air contained in an intake manifold of the engine. Step 61
preferably occurs immediately prior to or during an intake stroke
of the engine.
[0045] Step 62 involves drawing the mixture of gaseous phase fuel
and air from the intake manifold into a cylinder of the engine.
[0046] Finally, step 63 involves allowing the atomised liquid phase
lubricant to lubricate components of the cylinder prior to burning
the mixture of gaseous phase fuel and air in the cylinder.
[0047] In operation, the low pressure pump 37 supplies lubricant
from the supply tank 38 to the swirl pot 36. The swirl pot 36
remains fully primed with lubricant to provide the high pressure
pump 32 with a constant source of lubricant to prevent cavitation
within the supply rail 35 that can result in pressure fluctuations
in one or more of the injectors 31. The oil pressure regulator 34
allows the pressure of the lubricant within the supply rail 35 to
be controlled and provides a return path for lubricant to return to
the swirl pot 36. The cam pickup 43 measures the position of the
cam shaft allowing the LCU 41 to determine the timing when each
injector 31 should be sequentially fired to deliver the lubricant
immediately prior to or during an intake stroke of its respective
cylinder 21. The crank pickup 42 measures the speed of rotation of
the crankshaft allowing the LCU 41 to determine the duration that
each injector 31 should be fired to deliver an amount of lubricant
that is required by each cylinder 21 under the engine's current
operating parameters. However, it is to be appreciated that other
sensors may be used to calculate the appropriate amount of
lubricant to be injected at each cylinder 21. Furthermore, the LCU
41 may be connected to the high pressure pump 32 and/or the
pressure regulator 34 to monitor and control the pressure of
lubricant in the supply rail 35 allowing the portion of lubricant
delivered by each injector 31 to be further controlled. The firing
of each injector 31 opens a solenoid valve in the injector 31 to
allow lubricant to pass through the nozzle 53 of the injector 31.
The pressure of lubricant contained within the supply rail 35
causes the lubricant to atomise as it passes through the nozzle 53
and into a mixture of gaseous phase fuel and air contained in the
intake manifold 22. As the mixture is drawn into the cylinder 21,
the atomised lubricant is allowed to coat the stem of the intake
valve and cylinder walls.
[0048] The liquid phase lubricant system dramatically improves the
life of `dry` fuel engines by providing lubrication to the
components of the cylinder. The liquid phase lubricant system may
also be retrofitted to existing stationary plant engines that have
been converted to using `dry` fuel and the cost of upgrading the
engine is relatively cheap without causing major disruption. The
invention allows the amount of lubricant delivered to each cylinder
to be measured to comply with engine emission standards. For
example, a test conducted on a 16-valve 4320 cu in V-engine running
at 1800 rpm found that only 0.2 L to 0.7 L per hour of lubricant is
required to keep the cylinders fully lubricated. Furthermore,
atomising lubricant in a localised area of the intake manifold
adjacent each intake valve before drawing it into each cylinder is
more effective than simply adding lubricant to a gas prior to
piping it to the engine. When a lubricant is added to the gas, the
majority of lubricant may not remain in suspension long enough to
reach the cylinders where it is needed. Accordingly, adding the
lubricant at a site immediately adjacent where it is needed ensures
a majority of lubricant stay in suspension long enough to coat the
components of the cylinder. Finally, it is hoped that reduced
engine maintenance costs will encourage the use of land fill gas,
biogas, methane, natural gas, and other gas products as a viable
alternative to using petroleum, coal or nuclear power as a fuel
source for the generation of electricity.
[0049] Words such as "comprises" or "includes" are not used to
define an exclusive set of elements or method steps. Rather, such
words merely define a minimum set of elements or method steps
included in a particular embodiment of the present invention.
[0050] The above description of various embodiments of the present
invention is provided for purposes of description to one of
ordinary skill in the related art. It is not intended to be
exhaustive or to limit the invention to a single disclosed
embodiment. As mentioned above, numerous alternatives and
variations to the present invention will be apparent to those
skilled in the art of the above teaching. Accordingly, while some
alternative embodiments have been discussed specifically, other
embodiments will be apparent or relatively easily developed by
those of ordinary skill in the art. Accordingly, this patent
specification is intended to embrace all alternatives,
modifications and variations of the present invention that have
been discussed herein, and other embodiments that fall within the
spirit and scope of the above described invention.
* * * * *