COMPOSITIONS AND METHODS FOR LUBRICATING ENGINE COMPONENTS

Abstract

A lubricant oil, the use of a lubricant oil as an additive, and a method of lubricating parts in an engine are described herein. The lubricant oil is characterized as having one or more components with each of the components having a minimum evaporation rate when experiencing conditions within a combustion cylinder of the engine. The minimum evaporation rate is configured so that when at least a portion of the lubricant oil evaporates in combustion cylinder and locally mixes with the air fuel mixture around it, the concentration of the combustible components in that mixture is greater than the net upper flammability limit of the particular components of the combustible mixture. Thus, in some examples, when the pressure and/or temperature of the combustion cylinder volume are increased, such as during a compression cycle, the probability of a portion of the lubricant oil combusting or auto-igniting is preferably decreased.

Claims

1. A lubricant oil, comprising: a first component comprising carbon molecules having a first molecular weight between C20 and C42; and a second component comprising carbon molecules having a second molecular weight between C20 and C42, wherein the first molecular weight and the second molecular weight are different, and wherein the first molecular weight and the second molecular weight are within a molecular weight distribution band of ten or less carbon numbers, wherein: the first component and the second component exhibit an evaporation rate deviation of approximately ten percent (10%) to maintain a first concentration of an evaporated portion of the first component greater than a first upper flammability limit of the first component when subjected to conditions within a combustion cylinder of an engine, and a second concentration of a second evaporated portion of the second component greater than a second upper flammability limit of the second component when subjected to the conditions within the combustion cylinder, and the conditions within the combustion cylinder are characterized by: a temperature between approximately 700K and 1300K, and a pressure between approximately 30 bar and 150 bar.

2. The lubricant oil of claim 1, wherein at least one of the first molecular weight or the second molecular weight comprises carbon molecules between C32 and C34.

3. The lubricant oil of claim 1, wherein at least one of the first molecular weight or the second molecular weight comprises carbon molecules between C30 and C36.

4. The lubricant oil of claim 1, wherein the combustion cylinder comprises a combustion cylinder of the engine, and the conditions within the combustion cylinder comprise conditions during a combustion cycle of the engine.

5. The lubricant oil of claim 1, wherein combustion cylinder comprises a combustion cylinder of the engine, and the conditions within the combustion cylinder comprise at least a portion of a combustion cycle of the combustion cylinder of the engine.

6. The lubricant oil of claim 1, wherein the engine comprises a diesel engine or a gasoline engine.

7. The lubricant oil of claim 1, wherein the engine comprises a natural gas engine or a hydrogen engine.

8. The lubricant oil of claim 1, further comprising a third component comprising carbon molecules having a third molecular weight between C20 and C42, wherein the first molecular weight, the second molecular weight, and the third molecular weight are different.

9. A lubricant oil composition, comprising: a first volume of a base oil; and a second volume of an additive, the second volume comprising: a first component comprising carbon molecules having a first molecular weight between C20 and C42; a second component comprising carbon molecules having a second molecular weight between C20 and C42, wherein the first molecular weight and the second molecular weight are different, and wherein the first molecular weight and the second molecular weight are within a molecular weight distribution band of ten or less carbon numbers; wherein the first component and the second component exhibit an evaporation rate deviation of approximately ten percent (10%) to maintain a first concentration of an evaporated portion of the first component greater than a first upper flammability limit of the first component subjected to conditions within a combustion cylinder of an engine and a second concentration of a second evaporated portion of the second component greater than a second upper flammability limit of the second component subjected to the conditions within the combustion cylinder of the engine; and wherein the conditions within the combustion cylinder are characterized by: a temperature between approximately 700K and 1300K; and a pressure between approximately 30 bar and 150 bar.

10. The lubricant oil composition of claim 9, wherein at least one of the first molecular weight or the second molecular weight comprises carbon molecules between C32 and C34.

11. The lubricant oil composition of claim 9, wherein at least one of the first molecular weight or the second molecular weight comprises carbon molecules between C30 and C36.

12. The lubricant oil composition of claim 9, wherein the conditions within the combustion cylinder comprise conditions during a combustion cycle of the engine.

13. The lubricant oil composition of claim 9, wherein combustion cylinder comprises a combustion cylinder of the engine, and the conditions within the combustion cylinder comprise at least a portion of a combustion cycle of the combustion cylinder of the engine.

14. The lubricant oil composition of claim 9, wherein the first volume comprises a total volume of the lubricant oil composition in a range of 20 percent to 90 percent of the total volume of the lubricant oil composition, in a range of 40 percent to 80 percent of the total volume of the lubricant oil composition, or in a range 50 percent to 60 percent of the total volume of the lubricant oil composition.

15. The lubricant oil composition of claim 9, wherein the base oil comprises a diesel engine oil, natural gas engine oil, or one or more combinations of engine oils used for internal combustion engine applications.

16. The lubricant oil composition of claim 9, wherein the additive further comprises a third component comprising carbon molecules having a third molecular weight between C20 and C42, wherein the first molecular weight, the second molecular weight, and the third molecular weight are different.

17. A method for lubricating moving parts in an engine, the method comprising: providing a lubricant oil comprising a first component and a second component, wherein: the first component comprises carbon molecules having a first molecular weight between C20 and C42; and the second component comprises carbon molecules having a second molecular weight between C20 and C42, wherein the first molecular weight and the second molecular weight are different, and wherein the first molecular weight and the second molecular weight are within a molecular weight distribution band of ten or less carbon numbers; and wherein the first component and the second component exhibit an evaporation rate deviation of approximately ten percent (10%) to maintain a first concentration of an evaporated portion of the first component greater than a first upper flammability limit of the first component subjected to conditions within a combustion cylinder and a second concentration of a second evaporated portion of the second component greater than a second upper flammability limit of the second component subjected to the conditions within the combustion cylinder; and lubricating a surface of the engine by adding the lubricant oil to the engine.

18. The method of claim 17, wherein the conditions within the combustion cylinder are characterized by: a temperature between approximately 700K and 1300K; and a pressure between approximately 30 bar and 150 bar.

19. The method of claim 17, further comprising providing a base oil to the engine.

20. The method of claim 17, wherein the first molecular weight or the second molecular weight comprises carbon molecules between C32 and C34 or between C30 and C36.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0010] FIG. 1 is a cross-sectional view of a combustion cylinder in which a lubricant oil is used, in accordance with one or more examples of the present disclosure.

[0011] FIG. 2 is an example graph illustrating the concentration of the lubricant oil being maintained above the upper flammability limit, in accordance with one or more examples of the present disclosure.

[0012] FIG. 3 is a method of using a lubricant oil used to lubricate parts in an engine, the lubricant oil having a minimum evaporation rate when experiencing cylinder conditions during a compression cycle, in accordance with one or more examples of the present disclosure.

DETAILED DESCRIPTION

[0013] Wherever possible, the same reference numbers will be used throughout the drawings to refer to same or like parts. Referring to FIG. 1, there is shown a cross-sectional view 100 of a engine 101 and a portion of a combustion cylinder 102 illustrating the mass diffusion of a lubricant oil 104 in which a concentration of the lubricant oil 104 in a cylinder volume 106 is maintained above an upper flammability limit, in accordance with one or more examples of the present disclosure. In some examples, the engine 101 can include but is not limited to a natural gas engine that uses natural gas as a fuel, a hydrogen engine that uses hydrogen as a fuel, a diesel fuel engine that uses diesel as a fuel, a gasoline fuel engine that uses gasoline as a fuel, or engines that use methanol. Dimethyl ether (DME), and ethanol as fuels. The present disclosure is not limited to any particular type of engine. In some examples, the engine 101 may be used to power additional equipment such as a generator 103 used to provide electrical energy, although it should be understood that the engine 101 may be used to power other machines such as, but not limited to, drivetrains for vehicles and work machines. The present disclosure is not limited to any particular machine the engine 101 is used for. The lubricant oil 104 has a minimum evaporation rate when the lubricant oil 104 is experiencing compression cycle conditions within the combustion cylinder 102. In some examples, the lubricant oil 104 is a lubricant oil composition comprising one or more components, described in more detail below. Within the combustion cylinder 102 there is a piston 108 that moves during various cycles of the engine 101 (not shown) in which the combustion cylinder 102 may be used. For example, in a four-stroke engine, the combustion cylinder 102 may move along axis AB towards A during the compression and intake cycles and towards B during the intake and combustion cycles.

[0014] To maintain compression within the cylinder volume 106 during the compression cycle and to utilize the expansion of gases during the combustion cycle, the piston 108 is sealed against an inner cylinder wall 110 of the combustion cylinder 102 using compression rings 112A and 112B. The compression rings 112A and 112B each include an outer surface 114A and 114B, respectfully, that is compressed against the inner cylinder wall 110, forming a fluidic seal. As the compression rings 112A and 112B move along the inner cylinder wall 110, heat from friction is generated. To remove the heat and to lubricate the interface between the compression rings 112A and 112B and the inner cylinder wall 110, the lubricant oil 104 is used. The lubricant oil 104 is moved up the inner cylinder wall 110 along the axis AB towards A by the movement of the piston 108. It should be noted that the movement of the lubricant oil 104 is merely an example, as other methods of lubricating the inner cylinder wall 110 and other components of the combustion cylinder 102 may be used and are considered to be within the scope of the present disclosure. In some examples, to remove a portion of the lubricant oil 104 from the inner cylinder wall 110 as the piston 108 moves along the axis AB towards B, the piston 108 may further include an oil scraper 116.

[0015] During the use of the combustion cylinder 102, various surfaces may experience wear due to the movement of those surfaces against other surfaces. For example, the movement of the compression rings 112A and 112B along the inner cylinder wall 110 may result in one or more gaps or spaces between the compression rings 112A, 112B and the inner cylinder wall 110. Along with potentially reducing the compression of the gases within the cylinder volume 106, such gaps may allow for the movement of the lubricant oil 104 along the inner cylinder wall 110 and into the cylinder volume 106. Thus, during a compression cycle, the cylinder volume 106 may include both the lubricant oil 104 and a fuel-air mixture containing fuels such as natural gas, hydrogen, diesel or gasoline or other gaseous fuels. In some examples, if the lubricant oil 104 auto-ignites during the compression stroke due to the increased pressure and temperature during the compression stroke, abnormal and uncontrolled combustion may occur. Not only can the auto-ignition of the lubricant oil 104 reduce the power output of the engine, because the ignition occurs while the piston 108 is moving along the axis AB towards A, the sudden increase in pressure due to rapid combustion of an air-fuel mixture caused by the uncontrolled auto-ignition of the lubricant oil 104 repeatedly over a few engine cycles can damage various components such as a crankshaft 118, the compression rings 112A and 112B, and the piston 108 itself.

[0016] In some examples, to reduce the probability of the lubricant oil 104 ignition during a compression cycle, the concentration of the combustible mixture of fuel and evaporated components, or evaporated portion, of the lubricant oil 104 in the air forming the mixture 120, sometimes referred herein as evaporated lubricant oil) are maintained above the net upper flammability limit of the components of the mixture 120. The conditions within the cylinder volume 106 of the combustion cylinder 102 may vary, but in some examples, are characterized by temperatures between approximately 700K and 1300K and pressures between approximately 30 bar and 150 bar. As used herein, the upper flammability limit may be defined as the highest concentration of a vapor (e.g., the evaporated lubricant oil 120) in air at which ignition of the vapor is possible in the presence of an ignition source, such as the heat of the engine or the heat generated by the compression of the mixture 120 of air, fuel, and evaporated lubricant oil 104 during the compression cycle. If the concentration of the gaseous fuel and evaporated lubricant oil 104 is maintained above the net upper flammability limit of that mixture 120, the probability of the auto-ignition of the lubricant oil 104 or that mixture 120 of fuel and lubricant oil vapor is reduced.

[0017] In some examples, the lubricant oil 104 may include a base oil and an additive, whereby in some examples the additive includes a first component of carbon molecules having a first molecular weight between C20 and C42 and a second component of carbon molecules having a second molecular weight between C20 and C42. In these and other examples, the first molecular weight and the second molecular weight may be different. In still further examples, the first molecular weight and the second molecular weight are within a molecular weight distribution band of ten or less carbon numbers. The base oil may be an oil designed for general use in diesel engines, an oil designed for general use in gasoline engines, or an oil designed for general use in natural gas engines, hydrogen engines or any gaseous fuel engines. In some examples, the base oil and or the lubricant oil 104 may be one or more oils, including combinations thereof, used for internal combustion engine applications. In some examples, the base oil may comprise the larger volume percent of the total volume of the lubricant oil 104. In some additional examples, the base oil may comprise a smaller volume percent of the total volume of the lubricant oil 104. For example, the base oil may be a volume percent of the total volume percent of the lubricant oil 104 in a range of 20 percent to 90 percent of the total volume of the lubricant, in a range of 40 percent to 80 percent of the total volume of the lubricant, or in a range of 50 percent to 60 percent of the total volume of the lubricant.

[0018] In some examples, in order to maintain the concentration of the evaporated lubricant oil 120 above the upper flammability limit, the one or more components of the lubricant oil 104 composition have a minimum evaporation rate when subjected to the conditions within the combustion cylinder 102 during the compression cycle. It should be noted that in some example, other factors such as viscosity and heat removal capabilities may also be considered. In some examples, the lubricant oil 104 comprises one or more components comprising saturated carbon molecules having a molecular weight distribution band between C20 and C42 using the following formula (1) to designate the saturated hydrocarbon:

C.sub.NH.sub.2N+2 (1)

[0019] where C is carbon and H is hydrogen. In some examples, the one or more components of the lubricant oil 104 composition may range from Icosane (C20H42) to Dotetracontrane (C42H86). It should be noted that the presently disclosed subject matter is not limited to that specific range, as molecules having different carbon numbers may be used and are considered to be within the scope of the present disclosure. In some examples, the molecular weight distribution band may be 10 or less carbon numbers. In these examples, the one or more components of the lubricant oil 104 may be in a range from Dotricantane (C32H66) to Triacontane (C30H62). In some examples, the lubricant oil 104 comprises one or more components comprising unsaturated carbon molecules having a molecular weight distribution band between C20 and C42. In some further examples, the one or more components of the lubricant oil 104 are at or within a deviation of approximately ten percent (10%), meaning the highest evaporation rate of one of the components of the lubricant oil 104 is within 10% of the lowest evaporation rate of other components of the lubricant oil 104. In some examples, there is a potential that if a molecular band is smaller, a relatively bulk (or consistent) evaporation rate occurs within the cylinder volume 106 during the compression cycle. The result may be a high radial discharge vapor velocity because droplet vapor flow rate is high. This may result in an improved diffusion of the evaporated lubricant oil 120, reducing the probability of auto-ignition of the evaporated lubricant oil 120. FIG. 2 illustrates how a particular evaporation rate may maintain the concentration of the evaporated lubricant oil 120 above an upper flammability limit.

[0020] FIG. 2 is an example graph 200 illustrating the concentration of the lubricant oil being maintained above the upper flammability limit, in accordance with one or more examples of the present disclosure. The graph 200 in FIG. 2 includes as an X-axis indicating vapor concentration and the Y-axis indicating the pressure/temperature conditions within the cylinder volume 106 during a compression cycle up to the combustion cycle. Moving from the origin in which the compression cycle starts, where the vapor concentration is zero and the combustion cylinder is at or slightly below atmospheric pressure, the cylinder volume 106 experiences an increase in pressure and temperature due to the compression of the vapors within the cylinder volume 106, including the evaporated lubricant oil 120, as the piston 108 compresses the vapors. During the combustion cycle, either a spark plug ignites the vapors (e.g., a spark ignition engine such as a gasoline engine) or the pressure of the vapor ignites the vapors (e.g., a compression ignition engine such as a diesel engine). It should be understood that graph 200 is illustrated assuming that the upper flammability limit (UFL) increases with an increase in pressure/temperature.

[0021] The graph 200 illustrates example in-cylinder characteristics of two types of oils: component #1 and a conventional lubricant oil. As illustrated in FIG. 2, the conventional lubricant oil evaporates but does not exhibit a high enough evaporation rate to maintain the concentration of the conventional lubricant oil above the upper flammability limit of the conventional lubricant oil. At the critical point, where the concentration of the vapors of the conventional lubricant oil is at or below the upper flammability limit of the conventional lubricant oil, if sufficient heat exists within the combustion cylinder, the conventional lubricant oil may auto-ignite before the compression cycle is completed. In a different manner, the lubricant oil 104 comprised of component #1 has an evaporation rate that during the combustion cycle maintains the concentration of the evaporated component #1 above the upper flammability limit of the component #1. Because the concentration of the evaporated component #1 is above the upper flammability limit of the component #1, conditions are not present within the cylinder volume 106 for combustion (or auto-ignition) of the component #1. As noted above, the composition of the lubricant oil 104 may be comprised of multiple components in some examples. The additional components may further have evaporation rates that maintain the concentration of vapors of the evaporated components above their respective upper flammability limit.

[0022] In some examples, the lubricant oil 104 may be added as an additive to a base lubricant oil, such as the conventional lubricant oil to reduce the probability of the auto-ignition of the conventional lubricant oil. In some examples, the base lubricant oil may have a lower evaporation rate than the lubricant oil 104. During the compression cycle, because of their higher evaporation rates, the evaporated lubricant oil 120 may increase the vapor pressure experienced by the base lubricant oil. This may reduce the rate of evaporation of the base lubricant oil, thereby reducing the amount of the base lubricant oil that may potentially experience auto-ignition. Further, in some examples, the vapor pressure experienced by the base lubricant oil may be sufficient to reduce the evaporation rate of the base lubricant oil to a rate that maintains the concentration of the evaporated base lubricant oil below the lower flammability limit of the base lubricant oil, further reducing the probability of the auto-ignition of the base lubricant oil.

[0023] FIG. 3 is a method of using a lubricant oil 104 used to lubricate parts in an engine, the lubricant oil having a minimum evaporation rate when experiencing cylinder conditions during a compression cycle, in accordance with one or more examples of the present disclosure. The method 300 and other processes described herein are illustrated as example flow graphs. The order in which the operations are described is not intended to be construed as a limitation, and any number of the described operations can be combined in any order and/or in parallel to implement the processes.

[0024] The method 300 commences at step 302 by providing a first component of the lubricant oil 104 comprising carbon molecules having a first molecular weight between C20 and C42. The first component has an evaporation rate high enough so that when the first component experiences compression cycle conditions within the combustion cylinder 102 of the engine 101, the concentration of the vapors of the evaporated lubricant oil 120 is above the upper flammability limit of the first component.

[0025] At step 304, the method 300 continues by providing a second component of the lubricant oil 104 having a second molecular weight different than the first molecular weight of the first component. In a manner similar to the first component, the second component has an evaporation rate high enough so that when the second component experiences compression cycle conditions within the combustion cylinder 102 of the engine 101, the concentration of the vapors of the second component of the evaporated lubricant oil 120 is above the upper flammability limit of the second component. In some examples, the first molecular weight or the second molecular weight comprises carbon molecules between the range of between C20 and C42, the range of C32 and C34, or the range between C30 and C36. As noted above, in some examples, the lubricant oil 104 may include only one component or more than two components. In some examples, the first component and the second component have evaporation rates within ten percent (10%) of each other as the first component and the second component experiences compression cycle conditions within the combustion cylinder 102 of an engine.

[0026] At step 306, the lubricant oil 104 is used to lubricate one or more components of an engine by adding the lubricant oil 104 to the engine. As noted above, the lubricant oil 104 may be used as the only lubricant oil or may be combined with another lubricant oil as an additive.

INDUSTRIAL APPLICABILITY

[0027] The present disclosure relates generally to the use of a lubricant oil in engines, the lubricant oil having a minimum evaporation rate when the lubricant oil experiences compression cycle conditions within a combustion cylinder. The lubricant oil 104 can be used to reduce the probability of the autoignition of oil that leaks into the combustion cylinder due to wear and tear of the cylinder rings. A conventional oil that leaks into the combustion cylinder and autoignites prior to the combustion cycle can damage engine parts. Example lubricant oils of the present disclosure reduce the probability of engine damage by having an evaporation rate that is significant enough so that the concentrations of the vapors of the components of the lubricant oil are greater than the upper flammability limit of the components of the lubricant oil. By reducing the probability of the lubricant oil ignition, an engine may experience less wear and tear and have an extended lifetime of use. Further, in some examples, the lubricant oil may be used as an additive to a base lubricant oil to reduce the probability of autoignition of the base lubricant oil in the combustion cylinder. Although not required, in some examples, the evaporation rate of the components are within ten percent (10%) of each other. In some examples, the components of the lubricant oil are carbon molecules having a molecular weight distribution in the range between C20 and C42, the range between C32 and C34, or the range between C30 and C36.

[0028] Unless explicitly excluded, the use of the singular to describe a component, structure, or operation does not exclude the use of plural such components, structures, or operations or their equivalents. As used herein, the word or refers to any possible permutation of a set of items. For example, the phrase A, B, or C refers to at least one of A, B, C, or any combination thereof, such as any of: A; B; C; A and B; A and C; B and C; A, B, and C; or multiple of any item such as A and A; B, B, and C; A, A, B, C, and C; etc.

[0029] While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.