System and method for extending oil life in an engine

Abstract

A system is provided. The system includes a reciprocating engine configured to consume oil at or less than 0.25 g / kw-hr and use makeup oil. The reciprocating engine includes an engine oil sump. The system is configured to maintain the oil volume in the reciprocating engine during operation such that the residence time of the oil in the reciprocating engine is at or less than 1000 hours.

Description

Technical Field

[0001] The subject matter disclosed herein relates to reciprocating engines, and more particularly to extending oil life for reciprocating engines. Background Art

[0002] Reciprocating engines (e.g., reciprocating internal combustion engines) that burn carbon-containing fuels (such as gasoline or diesel) distribute lubricating oil to the engine's moving components to minimize friction and wear. Engine owners and operators attempt to reduce total oil usage and maintenance costs by increasing the time between repairs by increasing oil life. Oil usage is not only composed of the oil changes required at the end of the oil life, but also by the oil consumption during operation. Increasing oil life increases engine availability, which also improves profitability for engine owners. Oil life can be extended by increasing the total oil volume, but this does not reduce total oil usage and includes practical limitations for remote facilities. Higher refueling rates associated with intentionally increasing the oil consumption rate can be used to extend oil life, which increases the freshening ratio, but this increases total oil usage. In addition, oil additives used to delay oil degradation can be effective in increasing oil life, but this also increases the cost of the oil. Therefore, it is necessary to extend maintenance intervals while reducing oil usage and costs. Summary of the Invention

[0003] The subject matter of the present application is a system and method for reducing oil costs associated with the operation of a reciprocating engine by substantially extending the oil life of a reduced oil volume (compared to known oil volumes used in reciprocating engines today) and without increasing the oil consumption of the reciprocating engine.

[0004] Summarized below are certain embodiments corresponding in scope to the originally claimed subject matter. These embodiments are not intended to limit the scope of the claimed subject matter, but rather, these embodiments are intended only to provide a brief summary of possible forms of the subject matter. Indeed, the subject matter may encompass a wide variety of forms that may be similar to or different from the embodiments set forth below.

[0005] In a first embodiment, a system is provided. The system includes a reciprocating engine configured to consume oil at or below 0.25 g / kw-hr and use makeup oil. The reciprocating engine includes an engine oil sump. The system is configured to maintain the oil volume in the reciprocating engine during operation such that the residence time of the oil in the reciprocating engine is at or below 1000 hours.

[0006] In a second embodiment, an oil system coupled to circulate a volume of stored oil through a reciprocating engine is provided. The system includes an engine sump configured to receive the volume of stored oil after circulation through the reciprocating engine. The system also includes an oil reconditioning circuit coupled to the engine sump and configured to receive the volume of stored oil exiting the engine sump before circulating the stored oil through the reciprocating engine during operation, the oil reconditioning circuit including a deaerator for degassing the stored oil. The system further includes a supply device that supplies a volume of make-up oil separate from the volume of stored oil and coupled to associate the make-up oil with consumption of the volume of stored oil during operation of the reciprocating engine, wherein the reciprocating engine is configured to consume oil at or below 0.25 g / kw-hr, and the oil system is configured to maintain a residence time of the oil in the reciprocating engine of 1000 hours or less.

[0007] In a third embodiment, a method for circulating oil in a reciprocating engine using makeup oil is provided. The method includes operating the reciprocating engine at an oil consumption of 0.25 g / kw-hr or less. The method also includes maintaining the oil volume in the reciprocating engine during operation and using the makeup oil to maintain the oil volume, wherein the residence time of the oil in the reciprocating engine is 1000 hours or less. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features, aspects, and advantages of the present subject matter will become better understood upon reading the following detailed description with reference to the accompanying drawings, wherein like characters represent like parts throughout, and wherein:

[0009] Figure 1 is a schematic block diagram of an embodiment of a portion of a reciprocating engine system;

[0010] Figure 2 is a cross-sectional view of an embodiment of a piston positioned within a cylinder;

[0011] Figure 3 is a graphical representation of the effect of tank oil volume on oil degradation / freshness;

[0012] Figure 4 is a graphical representation of the effect of tank oil volume on oil degradation over time;

[0013] Figure 5 is a schematic diagram of an embodiment of an oil replenishment system for a reciprocating engine;

[0014] Figure 6 is a schematic diagram of an embodiment of an engine oil sump (e.g., with a pickup located at the bottom);

[0015] Figure 7 is a schematic diagram of an embodiment of an engine oil sump (e.g., having a groove);

[0016] Figure 8 is a schematic diagram of an embodiment of a reciprocating engine system having a main oil circuit and an auxiliary circuit (eg, having the auxiliary circuit coupled to the main oil circuit);

[0017] Figure 9 is a schematic diagram of an embodiment of a reciprocating engine system having a main oil circuit and an auxiliary circuit (eg, with a bidirectional bleed / safety line); and

[0018] Figure 10 is a schematic diagram of an embodiment of a reciprocating engine system having a main oil circuit and an auxiliary circuit (eg, having the auxiliary circuit separate from the main oil circuit). DETAILED DESCRIPTION

[0019] One or more specific embodiments of the present subject matter will be described below. In order to provide a concise description of these embodiments, not all features of an actual implementation may be described in the specification. It will be appreciated that in the development of any such actual implementation, as in any engineering or design project, many implementation-specific decisions must be made to achieve the developer's specific goals, which may vary from implementation to implementation, such as compliance with system-related and business-related constraints. Furthermore, it will be appreciated that such development efforts may be complex and time consuming, but to one of ordinary skill having the benefit of this disclosure, such development efforts will be no more than a routine task of design, fabrication, and manufacturing.

[0020] When introducing elements of various embodiments of the present subject matter, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0021] Embodiments of the present disclosure can achieve extended oil life for reciprocating engines (e.g., reciprocating internal combustion engines). In the disclosed embodiments, the total oil volume is significantly reduced (e.g., relative to the recommended oil volume or normal oil volume typically utilized by the same engine) to minimize the oil residence time to 1000 hours or less to extend oil life. Oil life can be extended to achieve infinite oil life (i.e., the asymptote of oil degradation is less than the oil's scrap limit). In particular, when minimizing the total oil volume utilized, the change in concentration between the steady-state oil concentration and the replenishment oil concentration is less than the oil's scrap limit. Reducing the total oil volume and minimizing the oil residence time results in a proportional increase in the replenishment oil rate, which increases the freshness rate, thereby enabling extended oil life. In certain embodiments, the total volume of oil (e.g., stored oil) in an engine's sump or oil pan is reduced (e.g., relative to the sump oil volume capacity) without reducing the head height (sometimes also referred to as drop or reservoir height) of the stored oil above the pickup in the engine sump (which provides oil to the engine). In certain embodiments, the stored oil can be continuously conditioned (deaerated) before being recirculated through the engine. For example, an auxiliary circuit (e.g., an oil reconditioning circuit) can be coupled to the engine sump, including a deaerator and a pump (e.g., an auxiliary pump). In some embodiments, the auxiliary circuit can be coupled to a main circuit (e.g., a main oil circuit) having an oil pump (e.g., operating at a higher pressure than the auxiliary pump), wherein oil can be supplied from the auxiliary circuit to the main circuit and subsequently to the engine. In other embodiments, the auxiliary circuit can be separated from the main circuit, with the stored oil recirculated between the deaerator and the engine sump. Minimizing the total oil volume extends oil life, reduces oil usage, extends maintenance intervals, and provides potential utilization for other reconditioning measures that can further extend oil life.

[0022] In the following discussion, makeup oil is defined as unused oil provided to a reciprocating engine from a location external to the reciprocating engine (eg, a makeup oil tank). Storage oil is defined as the oil present in the engine sump.

[0023] Go to the attached figure, Figure 1A block diagram of an embodiment of a portion of an engine-driven power generation system 8 is illustrated. As described in detail below, system 8 includes an engine 10 (e.g., a reciprocating internal combustion engine) having one or more combustion chambers 12 (e.g., 1, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 18, 20, or more combustion chambers 12). In certain embodiments, engine 10 is configured to consume oil (i.e., lose oil) at or below 0.25 g / kw-hr and use supplemental oil. For example, engine 10 may consume oil at or below 0.25, 0.20, 0.15, 0.10, or 0.5 g / kw-hr. An air supply 14 is configured to provide a pressurized oxidant 16, such as air, oxygen, oxygen-enriched air, oxygen-reduced air, or any combination thereof, to each combustion chamber 14. The combustion chambers 12 are also configured to receive fuel 18 (e.g., liquid and / or gaseous fuel) from a fuel supply 19, and the fuel-air mixture ignites and combusts within each combustion chamber 12. The hot, pressurized combustion gases cause a piston 20 adjacent to each combustion chamber 12 to move linearly within a cylinder 26, converting the pressure exerted by the gas into rotational motion, which causes a shaft 22 to rotate. Furthermore, the shaft 22 may be coupled to a load 24, which provides power via the rotation of the shaft 22. For example, the load 24 may be any suitable device that can generate power via the rotational output of the system 10, such as a generator. Furthermore, although the following discussion refers to air as the oxidant 16, any suitable oxidant may be used with the disclosed embodiments. Similarly, the fuel 18 may be any suitable gaseous fuel, such as natural gas, associated petroleum gas, propane, biogas, sewage gas, landfill gas, or coal mine gas, for example.

[0024] The system 8 disclosed herein can be suitable for use in fixed applications (e.g., in industrial power generation engines) or in mobile applications (e.g., in cars or airplanes). The engine 10 can be a two-stroke engine, a three-stroke engine, a four-stroke engine, a five-stroke engine, or a six-stroke engine. The engine 10 can also include any number of combustion chambers 12, pistons 20, and associated cylinders (e.g., 1-24). For example, in certain embodiments, the system 8 can include a large industrial reciprocating engine having 4, 6, 8, 10, 16, 24, or more pistons 20 that reciprocate in the cylinder. In some such cases, the cylinder 26 and / or the piston 20 can have a diameter between about 13.5 and 34 centimeters (cm). In certain embodiments, the cylinder 26 and / or the piston 20 can have a diameter between about 10 and 40 cm, 15 and 25 cm, or about 15 cm. In certain embodiments, the piston 20 can be a steel piston or an aluminum piston, wherein a Ni-resistant ring insert is present in the top ring groove of the piston 20. System 8 can generate power in the range of from 10kW to 10MW. In some embodiments, engine 10 can operate at less than about 1800 revolutions per minute (RPM). In some embodiments, engine 10 can operate at less than about 2000RPM, 1900RPM, 1700RPM, 1600RPM, 1500RPM, 1400RPM, 1300RPM, 1200RPM, 1000RPM, 900RPM or 750RPM. In some embodiments, engine 10 can operate between about 750-2000RPM, 900-1800RPM or 1000-1600RPM. In some embodiments, engine 10 can operate at about 1800RPM, 1500RPM, 1200RPM, 1000RPM or 900RPM. For example, exemplary engine 10 may include a Waukesha engine (e.g., Waukesha VGF, VHP, APG, 275GL). For example, exemplary engine 10 may include a Jenbacher engine (eg, Jenbacher Type 2, Type 3, Type 4, Type 6, Type 9).

[0025] Figure 2is a side cross-sectional view of an embodiment of a piston assembly 25 having a piston 20 disposed within a cylinder block 26 (e.g., an engine block) of a reciprocating engine 10. The cylinder block 26 has an inner annular wall 28 defining a cylindrical cavity 30 (e.g., a bore). The piston 20 can be defined by an axial axis or direction 34, a radial axis or direction 36, and a circumferential axis or direction 38. The piston 20 includes a top portion 40 (e.g., a top land) and a top annular groove 42 (e.g., a top groove, a topmost groove, or a top compression ring groove) extending circumferentially (e.g., along a circumferential direction 38) around the piston 20. A top ring 44 (e.g., a top piston ring or a top compression ring) can be positioned in the top groove 42.

[0026] The top ring 44 is configured to project radially outward from the top groove 42 to contact the inner annular wall 28 of the cylinder block 26. The top ring 44 generally prevents the fuel 18 and air 16, or fuel-air mixture 82, from escaping the combustion chamber 12 and / or facilitates maintaining a suitable pressure to enable the expanding hot combustion gases to cause reciprocating motion of the piston 20. Additionally, for example, the top ring 44 may be configured to facilitate scraping of oil that coats the inner annular wall 28 and controls heat and / or friction within the engine 10.

[0027] As shown, the piston 20 includes a bottom annular groove 46 (e.g., a bottom ring groove, a bottommost groove, or an oil ring groove) extending circumferentially around the piston 20. A bottom ring 48 (e.g., a bottom piston ring or an oil ring) is disposed within the bottom groove 46. The oil ring 48 may project radially outward from the bottom groove 46 to contact the inner wall 28 of the cylinder 26. The oil ring 48 is generally configured to scrape off oil that forms a layer on the inner wall 28 of the cylinder 26 and control oil flow within the cylinder 26.

[0028] In some embodiments, one or more additional annular grooves 50 (e.g., additional annular grooves or additional compression ring grooves) may extend circumferentially around the piston 20 between the top groove 42 and the bottom groove 46. In some embodiments, one or more additional rings 52 (e.g., additional rings or additional compression rings) may be disposed within each of the one or more additional annular grooves 50. The additional rings 52 may be configured to prevent blowby and / or to scrape oil from the inner annular wall 28 of the cylinder 26.

[0029] As shown, the piston 20 is attached to a crankshaft 54 ​​via a connecting rod 56 and a pin 58. The crankshaft 54 ​​converts the reciprocating linear motion of the piston 20 into rotational motion. As discussed above, as the piston 20 moves, the crankshaft 54 ​​rotates to provide the load 24 (in Figure 1) provides power. A sump or oil pan 59 is disposed below or around the crankshaft 54. The sump 59 is a wet sump having an oil reservoir (e.g., for storing oil). As shown, the combustion chamber 12 is positioned adjacent to the top land 80 of the piston 20. A fuel injector 60 provides fuel 18 to the combustion chamber 12, and an intake valve 62 controls the delivery of air 16 to the combustion chamber 14. An exhaust valve 64 controls the discharge of exhaust gases from the engine 10. However, it should be understood that any suitable elements and / or techniques for providing fuel 18 and air 16 to the combustion chamber 12 and / or for discharging exhaust gases may be utilized. In operation, the combustion of the fuel 18 with the air 16 in the combustion chamber 12 causes the piston 20 to move in a reciprocating manner (e.g., back and forth) along the axial direction 34 within the cavity 30 of the cylinder 26.

[0030] The present embodiment includes operating engine 10 while minimizing or reducing the total oil volume (e.g., relative to the recommended or normal oil volume typically utilized by the same engine) to minimize the oil residence time in engine 10 to 1,000 hours or less to extend oil life. In certain embodiments, the total oil volume in engine 10 can be reduced to one-third, one-half, or one-quarter (or another fraction) of the normal or recommended total oil volume utilized in the same engine 10. Due to the smaller total oil volume utilized in engine 10, less stored oil is present in sump 59. Dashed line 66 represents the typical volume of stored oil in sump 59, while line 68 represents the reduced volume of stored oil in sump 59. Reducing the total oil volume and minimizing the oil residence time results in a proportional increase in the oil replenishment rate, which increases the freshness rate (i.e., the ratio of fresh oil to degraded oil; where freshness is defined as the process of mixing fresh, non-degraded oil with degraded oil to improve oil properties without increasing oil consumption (i.e., oil loss), thereby enabling extended oil life.

[0031] Figure 3 FIG7 is a graphical representation 70 of the effect of sump oil volume on oil degradation / freshness. The y-axis 72 represents oil degradation (e.g., via oxidation), and the x-axis 74 represents oil time for a representative engine 10. The dashed line and symbols 76 represent data for a representative engine 10 utilizing one-quarter of the normal sump oil volume (e.g., 40 liters of oil), and the solid line and symbols 78 represent data for a representative engine 10 utilizing the normal sump oil volume (e.g., 162 liters of oil). When utilizing both the reduced sump oil volume and the normal sump oil volume for engine 10, supplemental oil is also utilized. For both lines and symbols 76 and 78, the symbols represent measured data, and the lines represent modeled data. As shown in the graphical representation 70, utilizing a reduced oil volume results in a proportionally greater reduction in oil degradation rate and a corresponding increase in freshness.

[0032] Oil life can be extended to achieve infinite oil life (i.e., the asymptote of oil degradation is less than the oil's end-of-life limit). Specifically, when minimizing the total oil volume utilized, the change in concentration between the steady-state oil concentration and the makeup oil concentration is less than the oil's end-of-life limit. The concentration of degraded oil is C. Defining a control volume around the entire engine 10, the differential equation for oil degradation is as follows:

[0033]

[0034] Note that the volume inflow is the replenishment oil, the volume outflow is the oil consumption, and Q inflow (Q 流入 )=Q outflow (Q 流出 ) = Q. Note that the total oil volume is V oil .therefore,

[0035]

[0036] In steady state, Solving for the concentration at steady state results in:

[0037]

[0038] Here, the residence time of the oil in the engine 10 is defined as the ratio of the total oil volume divided by the volumetric oil replenishment flow rate As noted above, to achieve unlimited oil life with a small total oil volume in engine 10, the residence time of the oil in engine 10 is at or less than 1000 hours. In certain embodiments, the residence time of the oil in engine 10 is at or less than 900 hours, at or less than 800 hours, at or less than 700 hours, at or less than 600 hours, or at or less than 500 hours.

[0039] Figure 480 is a graphical representation of the effect of sump oil volume on oil degradation over time. The y-axis 82 represents oil degradation (e.g., via oxidation), and the x-axis 84 represents oil time in a representative engine 10. A dashed line 88 represents the scrap line for the oil. A solid line 90 represents data for utilizing a normal sump oil volume in the representative engine 10 at normal fuel consumption. A thin solid line 91 represents data for utilizing one-half the normal sump oil volume in the representative engine 10 at normal fuel consumption. A dash-dotted line 92 represents data for utilizing one-quarter the normal sump oil volume in the representative engine 10 at normal fuel consumption. A dash-dotted line 94 represents data for utilizing one-quarter the normal sump oil volume in the representative engine 10 at increased fuel consumption. As shown in the graphical representation 80, when utilizing a normal sump oil volume in the representative engine 10, the oil degradation level (as shown by line 90) continuously increases over time until the oil degradation level exceeds the scrap limit 88. In contrast, when a reduced sump oil volume is utilized in the representative engine 10, the oil degradation level (as shown by lines 92 and 94) initially increases at a higher rate and approaches the scrap limit 88, but then flattens (i.e., levels off) and never exceeds the scrap limit 88 (i.e., the asymptote for oil degradation is less than the oil's scrap limit). Conventional wisdom suggests that oil life is increased by increasing the total oil volume due to a reduced initial degradation rate. Contrary to conventional wisdom, reducing the total oil volume to shorten the residence time to at or below 1000 hours reduces the asymptotic degradation level to below the scrap limit for the oil, thereby enabling unlimited oil life despite a higher initial degradation rate. The reduced total oil volume reduces the amount of oil replaced during oil changes, which further reduces oil costs. It should be noted that oil degradation and scrap rates can be based on different measurements besides oxidation (e.g., nitration or total acid number). It should be noted that for most oil metrics (e.g., oxidation, nitration, TAN), degradation below the scrap limit is desirable. However, for certain metrics (eg, TBN), it is desirable that the metric remain above the scrap limit. In certain embodiments, for oil metrics (eg, viscosity), it is desirable to be within an acceptable range.

[0040] Figure 5FIG1 is a schematic diagram of an oil replenishment system 95 for a reciprocating engine 10. The engine 10 is coupled to a main oil circuit 96 that provides oil to the engine 10. The main oil circuit 96 includes a pickup 98 located in the sump 59 for obtaining oil from the sump 59 and a pump 105 (e.g., a main oil pump) for moving the oil along the circuit 96 to the engine 10. Because the sump 59 contains relatively little oil, it is desirable to maintain the oil level at an upper elevation 102 above the pickup 98 in the sump 59. The upper elevation 102 is the distance or oil level above the inlet 104 maintained by replenishment oil provided to the sump 59 from a replenishment tank 106 external to the engine 10. In certain embodiments, to reduce the volume of oil in the sump 59 without lowering the upper elevation 102, one or more objects or substitutes 108 may be placed in the sump 59 to displace the oil in the sump 59, maintaining the oil level at least at the upper elevation 102. In certain embodiments, stored oil that would normally be in the sump (if the engine 10 were operated at a normal sump oil volume) can be located in the supplemental oil tank 106 and utilized for freshening (i.e., replenishing the oil in the engine 10). Thus, the same amount of oil can be used for a normally available engine 10.

[0041] One or more sensors 110 may be disposed in or adjacent to sump 59 to measure the amount of stored oil in sump 59. One or more sensors 110 may include a level gauge or an optical sensor. In certain embodiments, sensor 110 may communicate with an operably coupled engine control module (ECM) or engine control unit (ECU) 112 (e.g., a controller) to communicate with engine 10 and oil replenishment system 95. In certain embodiments, based on feedback from one or more sensors 110, ECU 112 may provide a control signal for providing replenishment oil from replenishment tank 106 to sump 59 to maintain the stored oil level in sump 59 at upper elevation 102. In certain embodiments, if there is a problem replenishing sump 59, ECU 112 may modify the operation of engine 10 (e.g., operating engine 10 at a reduced speed, reduced load, or reduced power, or shutting down engine 10).

[0042] The ECU 112 includes a processor 114 operably coupled to a non-transitory computer readable medium or memory 116. The computer readable medium 116 may be removable in whole or in part from the ECU 112. The computer readable medium 116 contains instructions used by the processor 114 to perform one or more of the methods described herein. More specifically, the memory 116 may include volatile memory such as random access memory (RAM) and / or non-volatile memory such as read-only memory (ROM), an optical drive, a hard drive, or a solid-state drive. In addition, the processor 114 may include one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), one or more general-purpose processors, or any combination thereof. Furthermore, the term processor is not limited to those integrated circuits referred to as processors in the art, but broadly refers to computers, processors, microcontrollers, microcomputers, programmable logic controllers, application-specific integrated circuits, and other programmable circuits. The ECU 112 may receive one or more input signals (input 1 ... input 2) such as from sensors, actuators, and other components. n ), and one or more output signals (output 1... output n ) such as outputs to sensors, actuators, and other components.

[0043] In order to be able to operate the engine with a minimum oil level, the oil pick-up can be modified. For example, Figure 6 As shown in FIG, the inlet 104 of the pickup 98 may be located at the bottom 118 of the sump 59. Alternatively, as Figure 7 , the sump 59 may be shallow but include a deep recess 120 located on (e.g., extending away from) the bottom 118 of the sump 59. The recess includes a greater depth relative to the remainder of the engine oil sump 59. The inlet 104 of the pickup 98 may be positioned within the recess 120 adjacent to the bottom of the sump 59 to maximize the stored oil level around the inlet 104 of the pickup 98.

[0044] As the oil volume decreases, oil aeration increases because the residence time of the oil in the sump 59 decreases (e.g., when the sump oil volume is reduced to one-quarter of the normal level, the residence time in the sump 59 may also be reduced to one-quarter of the normal residence time with a normal sump oil volume). Figure 8-10An oil reconditioning system 133 is provided in the drawings. Specifically, the oil reconditioning system 133 may include an auxiliary circuit 124 (e.g., an oil reconditioning circuit) for degassing (e.g., continuously degassing) the stored oil before it is recirculated through the engine 10. In certain embodiments, the auxiliary circuit 124 may be selectively utilized. Degassing the stored oil enables the utilization of a lower total oil volume in the engine 10 and extends oil life. While degassing is discussed, other forms of reconditioning the oil (e.g., adding additives) may be incorporated along the auxiliary circuit 124 or form part of a separate circuit.

[0045] Figure 8 is a schematic diagram of an embodiment of a reciprocating engine system 8 having a main oil circuit 96 and an auxiliary circuit 124. As described above, the main oil circuit 96 includes a main oil pump 100, which is arranged along the main oil circuit 96 to provide oil to the engine 10. The auxiliary circuit 124 includes a pump 126 (e.g., an auxiliary pump) and a degasser 128 arranged along the circuit 124. The pump 100 operates at a greater pressure than the pump 126. The auxiliary circuit 124 is coupled to the main oil circuit 96 or connected in series with the main oil circuit 96. As depicted, the degasser 128 is a degassing cyclone separator. In some embodiments, another device (e.g., having an impeller) may be utilized for the degasser 128. As depicted, the stored oil is pumped to the degasser 128 along the circuit 124 via the pump 126. Pump 126 can receive oil from sump 59 at atmospheric pressure and discharge the oil to deaerator 128 at a pressure slightly above atmospheric pressure (e.g., approximately 5 psi (34.5 kPa) above atmospheric pressure). In certain embodiments, deaerator 128 can be utilized to deaerate the stored oil to an oil gas content of less than approximately 20% (plus or minus 1%). Deaerator 128 includes an exhaust port 130 that discharges air back to sump 59 via line 132. Deaerator 128 discharges oil along the main oil circuit 96 at atmospheric pressure. Oil pump 100 receives oil at atmospheric pressure and discharges it to engine 10 at a higher pressure (e.g., approximately 60 psi (413.7 kPa) above atmospheric pressure). In certain embodiments, one or more sensors can be positioned at various points along circuits 96, 124 to measure the oil gas content, as indicated by arrow 133. The sensors can communicate with ECU 112. In certain embodiments, the ECU 112 may regulate degassing of the storage oil.

[0046] Figure 9 is a schematic diagram of an embodiment of a reciprocating engine system 8 having a main oil circuit 96 and an auxiliary circuit 124 with a two-way drain / safety line 134. The main oil circuit 96 and the auxiliary circuit 124 are as described above in Figure 8, with one exception. The reciprocating engine system 8 includes a two-way bleed / safety line 134 extending between the sump 59 and the junction between the circuits 96 and 124. In certain embodiments, when conditions warrant not utilizing the auxiliary circuit 124 (e.g., when there is a problem with the pump 126 and / or the breather processor 128), the reserve oil can be provided directly to the main oil circuit 96 upstream of the pump 100 via the two-way bleed / safety line 134. In certain embodiments, in the event of a problem with the engine 10 or the pump 100, the degassed oil can be recirculated back to the sump 59 via the two-way bleed / safety line 134.

[0047] Figure 10 1 is a schematic diagram of an embodiment of a reciprocating engine system 8 having a main oil circuit 96 and an auxiliary circuit 124, wherein the auxiliary circuit 14 is separate from the main oil circuit 96. The main oil circuit 96 and the auxiliary circuit 124 are as described above in Figure 8 As described in , there is one exception. The auxiliary circuit 124 is separated from the main oil circuit 96. Therefore, the degassed storage oil is discharged from the degasser 128 along the auxiliary circuit 124 to the sump 59.

[0048] Oil scrap limits vary based on engine manufacturer and engine type (e.g., gasoline, diesel, natural gas). Scrap limits are typically based on metrics for oxidation, nitration, total base number (TBN), total acid number (TAN), and viscosity. Representative scrap limits for oils are shown in Table 1 below:

[0049] Table I

[0050]

[0051] Oil gas content is defined as the total gas contained in the oil. The gas content is composed of both entrained gas (i.e., dissolved gas) and free gas (i.e., bubbles). The gas content is defined as the total gas volume measured at a pressure of 105 Pa and a temperature of 273 K based on the Henry-Dalton law using a Bunsen coefficient of 0.10 for oil.

[0052] The technical effects of the disclosed embodiments include providing a system and method for extending the oil life of a reciprocating engine (e.g., a reciprocating internal combustion engine) that consumes oil at or below 0.25 g / kw-hr and utilizes make-up oil. In the disclosed embodiments, the total oil volume is significantly reduced (e.g., relative to the recommended oil volume, normal oil volume, or oil volume capacity typically utilized by the same engine) to minimize the oil residence time to 1000 hours or less to extend oil life. Reducing the total oil volume and minimizing the oil residence time results in a proportional increase in the make-up oil rate, which improves the freshness rate, thereby enabling extended oil life. In certain embodiments, the stored oil can be continuously conditioned (degassed) before being recirculated through the engine. Minimizing the total oil volume to extend oil life reduces oil usage, extends maintenance intervals, and provides potential utilization using other reconditioning measures that can further extend oil life. This can result in cost savings for the engine operator and benefit the environment.

[0053] This written description uses examples to disclose the subject matter, including the best mode, and also to enable any person skilled in the art to practice the subject matter, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

[0054] The technology presented and claimed herein is cited and applied to substantial objects and specific examples of a practical nature that arguably improve the art and are therefore not abstract, intangible, or purely theoretical. Moreover, if any claim appended to the end of this specification contains one or more elements designated as "means for [performing] ... [function]" or "steps for [performing] ... [function]," it is intended that such elements will be interpreted under 35 U.S.C. 112(f). However, for any claim containing elements designated in any other manner, it is intended that such elements will not be interpreted under 35 U.S.C. 112(f).

Claims

1. A system for reducing oil costs associated with the operation of a reciprocating engine, comprising: A reciprocating engine configured to consume oil at or less than 0.25 g / kw-hr and use make-up oil, wherein the reciprocating engine includes an engine oil sump, wherein the system is configured to maintain the volume of oil in the reciprocating engine during operation such that the total oil volume in the reciprocating engine is reduced relative to a normal total oil volume utilized in the same engine such that the residence time of oil in the reciprocating engine is at or less than 1000 hours.

2. The system of claim 1 , comprising an oil reconditioning circuit coupled to the reciprocating engine and configured to degas the stored oil in the engine sump prior to recirculating the stored oil through the reciprocating engine, wherein The oil reconditioning circuit is coupled to the engine oil sump and includes a deaerator for degassing the stored oil.

3. The system according to claim 2, wherein: The degasser is configured to degas the stored oil to less than 20% oil gas content during operation of the reciprocating engine.

4. The system according to claim 1, wherein: The degradation of the oil has a steady level that does not exceed the waste limit of the oil.

5. The system according to claim 1, wherein: The total oil volume in the reciprocating engine is reduced to one-half the normal total oil volume utilized in the same engine.

6. The system according to claim 1, wherein: The total oil volume in the reciprocating engine is reduced to one-third of the normal total oil volume utilized in the same engine.

7. The system according to claim 1, wherein: The total oil volume in the reciprocating engine is reduced to one-fourth of the normal total oil volume utilized in the same engine.

8. An oil system for circulating a volume of stored oil through a reciprocating engine, comprising: an engine oil sump configured to receive the volume of stored oil after circulating through the reciprocating engine; an oil reconditioning circuit connected to the engine sump and configured to receive the volume of stored oil exiting the engine sump prior to circulating the stored oil through the reciprocating engine during operation, the oil reconditioning circuit including a deaerator for degassing the stored oil; as well as a supply device that supplies a volume of make-up oil separate from the volume of stored oil and is connected to the engine oil sump to correlate the volume of make-up oil with consumption of the volume of stored oil during operation of the reciprocating engine, wherein the reciprocating engine is configured to consume oil at a rate of 0.25 g / kw-hr or less, and wherein the oil system is configured to reduce a total oil volume in the reciprocating engine relative to a normal total oil volume utilized in the same engine such that a residence time of oil in the reciprocating engine is at or less than 1000 hours.

9. The system of claim 8, comprising a primary circuit coupled to the engine sump and configured to enable flow of stored oil to the reciprocating engine, wherein The main circuit includes a main oil pump arranged along the main circuit.

10. The system according to claim 9, wherein: The main circuit is connected to the engine sump separately from the connection of the oil reconditioning circuit to the engine sump.

11. The system according to claim 9, wherein: The primary circuit is coupled in series with the oil reconditioning circuit to the engine oil sump.

12. The system of claim 11, comprising a bypass circuit coupled to the main circuit, wherein: The bypass circuit is configured to selectively open the flow of the reserve oil from the engine sump directly to the main circuit.

13. The system according to claim 9, wherein: The oil system includes an auxiliary pump for pumping the storage oil from the engine sump to the deaerator.

14. The system according to claim 13, wherein: The main oil pump is configured to operate at a higher pressure than the auxiliary pump.

15. The system according to claim 8, wherein The degradation of the oil has a steady level that does not exceed the waste limit of the oil.

16. The system according to claim 8, wherein The degasser is configured to degas the stored oil to less than 20% oil gas content during operation of the reciprocating engine.

17. The system according to claim 8, wherein: The total oil volume in the reciprocating engine is reduced to one-half the normal total oil volume utilized in the same engine.

18. The system according to claim 8, wherein The total oil volume in the reciprocating engine is reduced to one-third of the normal total oil volume utilized in the same engine.

19. The system according to claim 8, wherein: The total oil volume in the reciprocating engine is reduced to one-fourth of the normal total oil volume utilized in the same engine.

20. A method for circulating oil through a reciprocating engine, comprising: operating the reciprocating engine at a fuel consumption at or less than 0.25 g / kw-hr; as well as Maintaining an oil volume in the reciprocating engine during operation, wherein the total oil volume in the reciprocating engine is reduced relative to a normal total oil volume utilized in the same engine, and using make-up oil to maintain the oil volume such that the residence time of the oil in the reciprocating engine is at or less than 1000 hours.

21. The method according to claim 20, wherein Operating the reciprocating engine includes operating the reciprocating engine with less stored oil in the engine sump than a sump volume capacity of the engine sump without reducing an upper level of the stored oil above a pickup in the engine sump.

22. The method of claim 20, comprising transferring stored oil in an engine sump of the reciprocating engine through an oil reconditioning circuit coupled to the engine sump, wherein: The oil reconditioning circuit includes a deaerator for degassing the stored oil.

23. The method of claim 22, comprising degassing the stored oil to less than 20% oil gas content via the degasser.

24. The method of claim 22, comprising transferring the stored oil from the engine sump of the reciprocating engine through a primary circuit coupled to the reciprocating engine, wherein The main circuit includes a main oil pump arranged along the main circuit.

25. The method of claim 24, comprising transferring the reserve oil from the engine sump directly to the reciprocating engine via the main circuit separate from the oil reconditioning circuit.

26. The method of claim 24, comprising transferring the reserve oil from the engine sump directly to the reciprocating engine via the primary circuit coupled to the oil reconditioning circuit.

27. The method according to claim 20, wherein The total oil volume in the reciprocating engine is reduced to one-half the normal total oil volume utilized in the same engine.

28. The method according to claim 20, wherein The total oil volume in the reciprocating engine is reduced to one-third of the normal total oil volume utilized in the same engine.

29. The method according to claim 20, wherein The total oil volume in the reciprocating engine is reduced to one-fourth of the normal total oil volume utilized in the same engine.

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