Lubrication methods for large slow-speed marine diesel engines.

Abstract

The present invention provides a method for lubricating a large, slow-operating marine diesel engine having at least one cylinder with a piston having a ring pack. Lubricant injection is performed through an injection unit for each cylinder. Each injection unit is controlled by a control unit having multiple lubrication routines stored in memory. The control unit receives input from an input station or from one or more sensors. The input can determine the implementation of one of multiple possible lubrication routines, each lubrication routine being distinguished by duration, dosage adjustment as a percentage of the total lubricant required, and two or more distinct injection phases relative to piston position. Each of the two or more distinct injection phases injects a quantity of lubricant expressed as a percentage of the total amount of lubricant injected.

Description

[Technical field]

[0001] The present invention relates to a method for lubricating a large slow-running marine diesel engine, the diesel engine having at least one cylinder within which a piston moves, the piston having a ring pack, injection of lubricating oil is provided by a plurality of injection units corresponding to a multiple of the number of cylinders in the engine, the lubricating oil being supplied by a combination of injection of at least two portions of lubricating oil, the at least two portions of lubricating oil being delivered at two different piston positions, the at least two different piston positions being selected from piston positions of injection before, during and after the passage of the piston through the injection unit, and the lubricating oil being supplied by injection directly onto the ring area of ​​the wall of the cylinder. [Background technology]

[0002] Various systems exist in the art for lubricating large marine diesel engines, both two-stroke and four-stroke, to minimize wear and tear between the moving piston and the cylinder wall. Currently, three different methods are used for cylinder lubrication.

[0003] The first method is the conventional cylinder lubrication method. In this method, a system is used with a mechanical lubricator that is driven directly via the engine's chain drive. The lubricator and the engine operate synchronously. Such a system usually consists of a mechanical lubricator with a piston pump and an associated check valve. The outlet of the lubricator is provided with a check valve, which is connected to an injection unit (injector / check valve) via a lubricant tube. In this type of system, the lubricant is delivered to the cylinder just before the top piston ring of the piston passes the injection unit. The lubricant is usually delivered to the cylinder with every stroke of the engine.

[0004] In these conventional cylinder lubrication systems, primarily for large two-stroke diesel engines, two or more central lubrication systems are used, each lubricating a single or multiple cylinder locations by supplying portions of oil under pressure through respective connecting lines to the various locations to be lubricated at appropriate time intervals. These appropriate time intervals may usually be when the piston rings are presented against the appropriate lubrication locations during the compression stroke when the piston is moving upwards.

[0005] The second method for cylinder lubrication is found in modern engines and is called high speed cylinder lubrication. For this purpose, instead of a mechanical chain drive, a hydraulic lubricator is used, timed by a timing sensor attached directly to the flywheel of the marine engine. This type of cylinder lubrication usually also uses a piston pump. In this type of system, the oil is fed into the cylinder as the piston passes, with the majority of the oil being fed directly between the top and bottom piston rings of the piston.

[0006] If the oil is fed between the piston rings, it is expected that the piston rings will better retain the oil and then the piston will distribute the oil along its path of travel. There are also systems that use a hydrostatic drive, as disclosed, for example, in WO 2008 / 009291, in which the amount and timing of the oil injection can be adjusted.

[0007] The lubricant is supplied intermittently such that the amount of oil injected is adjusted based on the working period of the piston pump when the stroke of the piston pump is constant. The lubricant is supplied by these systems through injection units including conventional check valves, injectors or spray valves. Examples of this technology are disclosed, for example, in Danish Patent No. 173512 or German Patent No. 10149125.

[0008] There are variations on this high speed lubrication. Thus, a system is provided that does not use the piston pump method. Instead, the amount of lubricant injected is controlled by controlling the opening and closing times. An example of this technology is known, for example, from EP 1 426 571 A1.

[0009] Injection may occur with the upward or downward passage of the piston. If it occurs during the downward movement, the oil is distributed over the cylinder surface from the lubrication point to under the cylinder lining. However, it is preferred to inject during the upward movement of the piston into the hot end of the cylinder where the need for lubrication is greatest.

[0010] The conventional method of distributing oil across a cylinder surface is to provide two angled grooves or slots at each location on the cylinder surface to be lubricated, both of which originate at the lubrication point and point away from the top of the cylinder. As a piston ring passes through such a slot, a pressure drop occurs across the piston ring and in the slot, which displaces the lubricating oil away from the lubrication point. However, these and other methods are considered inadequate because of the substantial variability in the wear that actually occurs along the circumference of the cylinder.

[0011] The development of engines towards greater use has led to increased mechanical and thermal loads on the cylinder lining and piston rings, which are traditionally countered by increasing the dosage of lubricating oil. However, it has been found that if the dosage is increased beyond a certain, not clearly defined limit, the velocity of the lubricating oil, when injected into the cylinder with the above-mentioned traditional lubrication methods, is so high that instead of remaining on the cylinder surface, a jet is formed in the cylinder cavity, which then disappears. If the dosage is carried out as desired while the piston rings are placed against the lubrication unit, it is not so critical, but if the dosage is carried out outside of this period, there is no benefit from part of the lubricating oil that has been dosed.

[0012] The above two methods can also be said to relate to systems in which lubrication is established by piston dispersion of the lubricating oil. A third method of cylinder lubrication uses a system that delivers lubricant directly into the cylinder and to the cylinder walls before the piston passes.

[0013] The system uses an injector that delivers the lubricant either in the form of a spray or in the form of one or more dense jets. Either a conventional mechanically driven lubricating system or a hydraulic system is used to deliver the lubricant to the injector. The advantage of this method is that the lubricant is already widely distributed on the cylinder wall before the piston passes through. With this method, the lubricant is distributed to the top of the cylinder before the piston arrives, and it is expected that the piston will carry the lubricant downwards into the cylinder during the expansion stroke. Examples of this technology are disclosed, for example, in WO 00028194, EP 1350929, or DK 176129.

[0014] EP 1 350 929 A1 describes a method in which a jet of lubricant (with maximum prevention of atomization of the lubricant) can be delivered to the cylinder surface by injection before, during and / or after the passage of the piston, which means that the entire amount of lubricant is injected onto the cylinder surface in at least two portions, as indicated at the beginning.

[0015] Since the cylinder walls are supplied with oil before the piston passes, timing is less critical with this third method than with the first two systems, which strictly supply lubricant for a very short period of time when the piston rings are positioned against the lubricator.

[0016] Cylinder lubrication, so-called SIP lubrication, as disclosed in WO 0028194, has been found to provide the greatest oil film thickness in the cylinder where wear is greatest, corresponding to the region of the topmost piston and topmost piston ring, whereas conventional or high speed lubrication has been found to provide a thicker oil film on the rest of the moving surfaces. SIP lubrication requires pressure to obtain the desired atomization in the lubricant line between the pump and the nozzle, which is higher than that of conventional lubrication methods that operate at a pressure of a few bar. SIP valves operate at set pressures of up to 60 bar, typically 35 to 40 bar.

[0017] In addition, the oil supply has the purpose of neutralizing the acidic effect on the cylinder walls, which occurs due to the combustion of sulfur-containing fuels, and which is well counteracted by supplying the oil directly to the top of the cylinder. Measurements show that SIP lubrication results in less wear. In fact, corrosive wear appears to be the most important factor in cylinder service life.

[0018] A drawback of conventional or high speed lubrication, which primarily utilizes the piston to distribute the lubricant, is that it requires some over-lubrication to ensure sufficient lubricant at the top of the cylinder, particularly on the piston, which requires an increased amount of lubricant relative to the sulfur content of the fuel to achieve satisfactory cylinder conditions.

[0019] Thus, lubrication with systems in which the lubricant is directly applied to the cylinder wall has the disadvantage that, if sufficient lubricant is applied to avoid corrosive wear, an insufficient amount of lubricant is applied to the bottom of the cylinder. This is because the piston rings, in addition to their distribution function, produce a certain scraping effect. Measurements have shown that SIP lubrication produces less scraping of lubricant than lubrication with lubricant distributed by the piston.

[0020] The difference between a system where the lubricant is fed directly to the cylinder wall and a lubricant distributed by the piston is the resulting amount of lubricant that descends in the cylinder. Thus, the scavenging oil of SIP lubrication (according to WO 0028194) is to some extent less than a piston-distributed lubrication system where the lubricant is distributed only by the piston. This means that the one parameter used to evaluate the cylinder condition (measurement of the Fe content in the scavenging oil) cannot be directly used for the comparison of the cylinder condition, since the same Fe content will be in different concentrations depending on the lubrication method.

[0021] The scavenging air openings of a longitudinally scavenged two-stroke diesel engine are arranged so that, as the gases move upwards in the cylinder during scavenging, the gas mixture starts to move in a rotating motion and exits through the exhaust valve at the top of the cylinder. Thus, the gases in the cylinder follow a spiral path or swirl on their way from the scavenging air opening to the exhaust valve. Due to centrifugal force, any oil particles in this swirling flow that are small enough will be forced against the cylinder wall and will eventually deposit on the wall. This effect is exploited by introducing the oil fraction into the cylinder as a mist of oil particles of suitable size sprayed through a nozzle. By adjusting the nozzle size, the oil ejection speed and pressure in front of the nozzle, the average size of the oil droplets in the oil mist can be controlled. If the oil particles or droplets are too small, they will "float" in the gas stream for a long time and will eventually be expelled by the scavenging air without colliding with the cylinder wall. If the oil particles or droplets are too large, they will move too far from their initial path due to inertia and will be overtaken by the piston and positioned at the top of the piston, so that they will not reach the cylinder wall.

[0022] The nozzle can be oriented relative to the flow in the cylinder so that the interaction between the individual droplets and the gas flow in the cylinder ensures that the oil droplets impinge on the cylinder wall over an area that corresponds primarily to the circumferential distance between two lubrication points. In this way, the oil is more or less uniformly distributed over the cylinder surface before passing the piston ring. Furthermore, the nozzle can be adjusted so that the oil impinges on the cylinder wall at a higher position than the nozzle. In this way, the oil is not only well distributed over the cylinder surface before being introduced into the cylinder, but also on the cylinder surface near the top of the cylinder where the need for lubrication is greatest. The result is improved oil utilization with an improved relationship between cylinder life and oil consumption.

[0023] The supply of lubricant to the cylinder surfaces is carried out in regulated portions, much like the two conventional systems described above. The supply means can be a conventional lubrication system, but other supply means having corresponding characteristics are also envisaged. To prevent cylinder pressure from returning to the oil line, a check valve is usually placed at the end of the lubrication line just before the inner cylinder lining. The check valve allows lubricating oil to flow from the oil line to the cylinder lining but prevents gas from flowing in the opposite direction. Check valves usually have a moderate opening pressure (a few bar).

[0024] The characteristics of the above three cylinder lubrication methods are: - Lubrication timing: during which engine cycle should lubrication oil be applied? -Feed rate: how to adjust the relative injection rate? -Pump characteristics: how and at what rate does it deliver lubricant? It is.

[0025] This relates to finding ways to minimise lubricant consumption by providing improved cylinder lubrication in large diesel engines, such as marine engines. From WO 2010 / 149162 it is known to combine the above three methods, in which the lubricant is supplied by a combination of injection of a first part of the lubricant onto the ring area of ​​the cylinder wall just above the piston before the piston passes, and injection of a second and / or a third part of the lubricant, the second part of the lubricant being injected directly onto the piston during its passage and the third part of the lubricant being injected directly onto the ring area of ​​the cylinder wall below the piston after the piston passes.

[0026] When a combination of multiple portions of lubricant is used, the control is adjusted so that an algorithm is generated based on the injection of multiple partial amounts of lubricant at different lubrication times. This combination allows a combination of prior art methods for cylinder lubrication to be applied, obtaining the advantages of each method while avoiding their disadvantages. Direct supply to the ring area can be in the form of atomized or dense oil jets. The lubricant is supplied via lubricant injectors which form part of the injection system and are provided in the cylinder wall.

[0027] When determining how to lubricate the cylinder walls to reduce wear and corrosion, it is important to consider a variety of factors, including, for example, the sulfur content of the fuel used, the load at which the engine is operated, the widely varying temperatures within the cylinder, the type of lubricant, and the method of application of the lubricant to the internal cylinder walls. All of these factors, and many more, are addressed by a variety of different systems and methods in the art.

[0028] One such example is disclosed in WO 2008 / 009291, where the amount of lubricant injected as well as the timing of the lubricant delivery can be adjusted. Further similar devices are disclosed in DK 173512, DE 10149125 and EP 1426571. The concept common to all these conventional systems is the fact that it is possible to vary the amount of lubricant and the timing at which it is injected into the cylinder.

[0029] The method described by way of introduction is an advanced system disclosed in the applicant's WO 2010 / 149162. This system allows the lubricant to be injected at different times during the revolution of the engine, taking into account other factors as well. In this way, by placing the injection nozzles in the right positions, it is possible to distribute the lubricant at the right time and in the most desirable position, minimizing the use of lubricant while at the same time achieving sufficient and optimal lubrication. Another example of a more advanced lubrication system is disclosed in DE 10112691, where the amount of lubricant is adjusted according to the sulphur content of the fuel. Sulphur in fuel is known to be very corrosive, and the addition of extra lubricant due to the high sulphur content in the fuel makes it possible to neutralize the sulphuric acid generated during combustion.

[0030] The system is regulated by a sulphur regulation algorithm, which adjusts the amount of lubricant using input from a sensor that detects the sulphur content in the fuel. In addition, the FE content is monitored and used as an indicator of wear. This wear is compared to the allowable wear amount and an alarm is triggered in case of an unacceptable deviation.

[0031] This relates to finding a way to more effectively minimize the consumption of lubricant in the cylinder lubrication of large diesel engines, such as marine engines, by allowing the distribution of the lubricant to be varied over time, taking into account many parameters and which may also include regulating the amount of lubricant. [Prior art documents] [Patent documents]

[0032] [Patent Document 1] International Publication No. 2008 / 009291 [Patent Document 2] Danish Patent No. 173512 [Patent Document 3] German patent no. 10149125 [Patent Document 4] European Publication No. 1426571 [Patent Document 5] International Publication No. 00028194 [Patent Document 6] European Publication No. 1350929 [Patent Document 7] Danish Patent No. 176129 Summary of the Invention [Problem to be solved by the invention]

[0033] As is evident from the above description of the prior art, various attempts have been made to improve the lubrication of the cylinder walls while at the same time minimizing the amount of lubricant required. It is apparent that the overall principle is to provide sufficient lubrication to the cylinder walls so that under all circumstances the piston does not cause unnecessary tearing or wear to the cylinder walls through mechanical wear. None of the above examples fully address many of the uncertainties that exist for different engines operating under different conditions at different loads. As a result, there is a need to provide a system that addresses all the needs and circumstances to which a large, slow-speed operating marine diesel engine may be exposed. [Means for solving the problem]

[0034] The present invention, as mentioned by way of introduction and as defined in the preamble of claim 1, aims to address this need by providing a method for lubricating large slow-speed operating marine diesel engines, wherein each injection unit is controlled by a control unit having a plurality of lubrication routines stored in its memory, the control unit receiving input either from an input station or from one or more sensors, which input is capable of determining the implementation of one of a plurality of possible lubrication routines, each lubrication routine being differentiated by one or more different injection phases relative to duration, amount of lubricant and / or piston position, each of the one or more different injection phases injecting a quantity of lubricant expressed as a percentage of the total amount of lubricant injected.

[0035] Although the amount is expressed as a percentage of the total amount of lubricant, the present invention will also cover situations where the amount injected is expressed as a fraction of the total amount, or any other expression that can be converted to an expression as a percentage of the total amount. It should be understood that in accordance with the present invention, a lubrication routine may include only one injection per revolution, which may be the case, for example, for a cleaning routine.

[0036] Thus, lubrication in some separate routines may only involve the supply of one injection of only one portion of lubrication oil for such separate routine, whereas the overall lubrication of a large slow-running marine diesel engine comprises many more lubrication routines over a given period of time, which may be, for example, a 24 hour period, or any other period of time that is found suitable for establishing a desired number of possible lubrication routines for implementing the method according to the invention.

[0037] Thus, the primary advantage is the ability to dispense lubricating oil based on parameters such as time, temperature, sulfur content in the fuel, oil film thickness in the cylinder, and other parameters that are important to in-cylinder conditions in large, slow-running marine diesel engines.

[0038] This change can be made based on engine load and condition, and directly or indirectly on parameters important to the cylinder condition (e.g. rpm, cylinder temperature, engine load, amount of fuel injected, lubricant quality, lubricant viscosity, TBN content of the lubricant, analysis of the scavenging exhaust (residual TBN, Fe content, etc.)). The amount of oil can also be adjusted depending on the parameters used by the control device when determining the distribution of lubricant. The method according to the invention can be considered as a further development of the Applicant's WO 2010 / 149162, the disclosure of which is therefore incorporated herein by reference.

[0039] According to a further embodiment of the invention, the lubrication routine is further differentiated by controlling the frequency of injection with respect to engine speed, thereby allowing one or more separate injection phases to be each at different frequencies to optimize lubrication to handle all operating conditions that a slow running marine diesel may experience.

[0040] If SIP lubrication is only used, the area of ​​the cylinder below the injector is typically lubricated less than desired. This results in higher than acceptable wear. The reason is that the engine at low loads - Experience has shown that the area of ​​the cylinder wall above the injector receives a relatively small amount of lubricant with SIP lubrication, since the amount of lubricant can be significantly reduced without increasing wear. - The piston rings play only a secondary role in distributing the lubricant, with all the lubricant being supplied directly to the cylinder wall; - Fuel and lubricant quality may contribute to a situation where the amount of lubricant remaining due to being "pulled down the cylinder" becomes too low if not enough lubricant is added; This is thought to be the reason.

[0041] To compensate for this, the amount of lubricant can be increased, or it can be injected directly onto the piston, as experience shows that conventional lubrication increases the distribution of lubricant on the cylinder surface below the injector. By combining different timings, it is possible to reduce the amount of lubricant while at the same time improving the wear condition of the cylinder surface below the injector.

[0042] Extensive testing and development have shown that three parameters in particular are very important to accommodate all the operating conditions that a slow-speed marine diesel engine may be subjected to. These three parameters are typically the distribution of the total amount of lubricant in the cylinder, the feed regulation, i.e. the minimum amount and location of lubricant required for adequate lubrication of the cylinder walls, and finally the duration for which the set of parameters is maintained.

[0043] In an algorithm or multiple possible lubrication cycles according to the present invention, these three parameters can be varied to take into account multiple factors, such as the sulfur content of the fuel, the base number of the particular lubricant, the engine operating speed and load, input and output changes, the total number of hours the engine is operating, relative humidity, and the ambient air temperature and humidity in combination with the engine temperature.

[0044] Base number, often referred to as BN, is a characteristic characteristic of engine lubricants. Base number can be defined as the ability of a lubricant to neutralize acids generated during combustion. The higher the base number of a lubricant, the more acids it can neutralize during use. Usually, the price of a lubricant depends to some extent on the base number, and it is desirable to use as little lubricant as possible and to use the right lubricant at the right time. It is well known that large slow-running marine diesel engines use different types of fuel oil depending on various conditions, such as how close to land they are or if they are operating in a harbor. The quality of the fuel oil is often reflected in the BN number, which is an important factor in determining the proper lubrication of the cylinder walls. Thus, this is one of many factors that the multiple lubrication routines of the present invention take into account and are reflected in the method. To select the appropriate lubrication routine, the control unit receives input from an input station or from one or more centers. The input station can be, for example, a keyboard or other electronic input device, allowing the selection of the appropriate routine (or a person operating the input device) depending on the ambient conditions. Alternatively, sensors may be arranged so that load, operating speed, sulfur content of fuel, or any other sensor-detectable parameter may be used as an input for selecting an appropriate lubrication routine.

[0045] Every lubrication routine is differentiated by duration, dosage adjustment, and two or more distinct injection phases. Duration is the time that a particular setting and distribution of lubricant to the various nozzles is maintained before the lubrication routine transitions to another phase.

[0046] The dosage adjustment represents a factor that indicates how the total lubricant amount can be reduced or increased relative to the optimal amount of lubricant required, so as to adapt the lubricant usage to the specific situation for which the lubrication routine is programmed. As is evident from further embodiments, the dosage adjustment can vary between -30% and +30% of the optimal amount of lubricant required. As is evident from the above description, the conditions in the cylinders may vary greatly due to external and internal factors that affect the operation of the engine, so that the actual amount of oil also varies, and the average amount may not be sufficient in all conditions and may be too much in others. The dosage adjustment takes this into account, so that the right amount of lubricant is delivered during the appropriate duration of that particular phase.

[0047] Furthermore, a third parameter included in the above-mentioned method according to the invention is the fact that it includes two or more separate injection phases, where part of the required amount of lubricant is injected at one time and another part at another time. The specific injection timing is understood in relation to the position of the piston. The piston usually has three positions: the lowest position, where the piston is as far away as possible from the top of the cylinder before the compression stroke, the highest position, where the piston is as close as possible to the top of the cylinder, and an intermediate position, where the piston reserves space above the piston to achieve lubrication of the cylinder wall in a swirl injection manner, in which the lubricant is introduced into the cylinder in the form of a spray and rotates / swirls in the cylinder due to the turbulence during scavenging caused by the combustion, so that the lubricant is distributed almost uniformly on the cylinder wall surface between the top of the piston and the top of the cylinder. In particular, depending on the position of the piston and the ring pack provided on the piston, the injection timing can be adjusted and the lubricant distributed between the various positions to optimize the lubrication.

[0048] Thus, the method of the present invention as described above is capable of accommodating all operating conditions of a slow-running marine diesel engine, with multiple lubrication routines that can be stored in memory and executed by the control unit.

[0049] In a further advantageous embodiment of the invention, two or more separate injection phases are selected which inject an amount of lubricant expressed as a percentage of the total amount of lubricant, this percentage being variable between 0% and 100% depending on the selected lubrication routine. In this embodiment, it is foreseen, for example, that one injection phase can inject 0% of the oil that is not required during the operation of the engine. Thus, lubricant is saved, resulting in good economy. In another injection phase, in one injection, 100% of the lubricant that may be required during the operation of the engine can be injected. It is also foreseen, in an embodiment, that the amount of lubricant can be distributed between two or more, typically three, separate injection phases, whereby it is for example possible to inject lubricant at the position of the ring pack during the compression stroke, but also to inject lubricant in the cylinder in SIP mode. Further embodiments are also described below.

[0050] In a further embodiment of the invention, the separate injection phases also include a frequency relative to engine revolutions such that two or more separate injection phases injecting a portion of the lubricant expressed as a percentage of the total amount of lubricant injected are actuated corresponding to the engine revolutions, the number of revolutions between which each separate injection timing is achieved can vary between 1 and 15.

[0051] Also, the injection of a portion of the lubricant may not have to occur with every revolution of the engine, and thus one or more separate injection phases each injecting a quantity of lubricant may be used at different frequencies to optimize lubrication.

[0052] In a further embodiment of the invention, the lubrication strategy for a given time period comprises a plurality of lubrication routines, Each routine or window within a given period has a duration that is a specific portion of the given period, such that the total duration of the number of routines covers the given period; Each of the routines has a delivery rate, which can be adjusted with an adjustment being the amount of change in the amount delivered to the cylinder during that particular routine; Each of the doses is provided by a distribution key that includes one or more distinct injection phases.

[0053] In a further embodiment of the invention, the lubrication strategy for a given time period comprises a plurality of lubrication routines, at least a first lubrication routine having a duration of a first portion of a given period, a negative feed rate adjustment, and one to three distinct injection phases; at least a second lubrication routine has a duration of the second portion of the given period, a dosage adjustment of 0%, and one to three distinct injection phases; at least a third lubrication routine having a duration of a third portion of the given period, a positive feed rate adjustment, and one to three distinct injection phases; Possible further lubrication routines have a duration of further parts of a given period, possible supply amount adjustments, one to three separate injection phases, - the total time of that portion of a given period of all lubrication routines covers the period, The routine is repeated until the lubrication strategy is changed.

[0054] In a more detailed embodiment of the present invention, the lubrication routine is provided as a 24-hour lubrication strategy including a plurality of lubrication routines, - a first lubrication routine having a duration of 11 hours, a -15% feed rate adjustment, three separate injection phases, a first timing for injecting 30% of the lubricant amount at the ring pack during the compression stroke of the piston, a second timing for injecting 60% of the lubricant amount above the piston, and a third timing for injecting 10% of the lubricant amount at the ring pack during the combustion stroke of the piston, with the amount of lubricant being 30% at the first timing; a second lubrication routine having a duration of 1 hour, 0% feed rate modulation, three separate injection phases, a first timing for injecting 40% of the lubricant volume at the ring pack during the compression stroke of the piston, a second timing for injecting 50% of the lubricant volume above the piston, and a third timing for injecting 10% of the lubricant volume at the ring pack during the combustion stroke of the piston; a third routine having a duration of 11 hours 30 minutes, a -15% feed rate adjustment, three separate injection phases, a first timing for injecting 30% of the lubricant volume at the ring pack during the compression stroke of the piston, a second timing for injecting 60% of the lubricant volume above the piston, and a third timing for injecting 10% of the lubricant volume at the ring pack during the combustion stroke of the piston; a fourth lubrication routine having a duration of 30 minutes, a +20% feed rate adjustment, three separate injection phases, a first timing for injecting 50% of the lubricant volume at the ring pack during the compression stroke of the piston, a second timing for injecting 40% of the lubricant volume above the piston, and a third timing for injecting 10% of the lubricant volume at the ring pack during the combustion stroke of the piston; The first, second, third and fourth routines are repeated until the lubrication strategy is changed.

[0055] This lubrication scheme, consisting of four windows, assumes that most of the time the feed adjustment is set to -15% and a significant portion of the lubricant is saved, while in two windows, namely the middle hour of the scheme and the last 30 minutes of the scheme, a lot of lubricant is fed to the cylinder. In detail, the last 30 minutes, when the feed adjustment is increased to +20%, is used as a cleaning program, where a large amount of lubricant is added to the cylinder in order to flush out any contaminants and wear particles, so that a thorough and practically complete cleaning of the cylinder is achieved at least once every 24 hours, so that the normal operating scheme and windows allow for optimal lubrication with a minimum of lubricant.

[0056] If the fuel oil contains more sulfur, it may be advantageous to increase the amount of lubricating oil delivered in the second injection phase using a swirl injection method so that residues and acids are effectively removed from the cylinder during each revolution of the engine, as will be further explained below with reference to specific examples.

[0057] In a further embodiment of the invention, the lubrication routine includes the first, second or subsequent timing being achieved every revolution up to 14 revolutions of the engine, with no two separate timings being achieved in the same engine revolution. A number of timings different from 14 can be used. For example, the number may vary between 10 and 20.

[0058] In a further embodiment of the present invention, a lubrication routine is provided, the lubrication routine can include a first timing being achieved every second through fifth revolutions of the engine, a second timing being achieved every third or more revolutions of the engine, and a third timing being achieved every fifth through fourteenth revolutions of the engine.

[0059] A further advantage is that lubrication can be optimized by injecting lubricant only at intervals where lubrication is needed, which are not coincident with engine revolutions. The frequency of injection can be different for different lubrication routines.

[0060] In a further embodiment of the invention, Delta-timing injection sequence using HJ SIP method, Injection between the piston rings on the upward stroke, and Injection occurs between the piston rings on the downward stroke, A jetting sequence is used, and an automatic cleaning sequence is performed if the feed rate is increased.

[0061] In a further embodiment of the invention, the supply is increased in an amount between 1.0 and 2 g / kWh, preferably about 1.5 g / kWh, for 30 minutes every 12 hours. In a further embodiment of the invention there is an average supply of between 0.8 and 1.6 g / kWh, preferably around 1.02 g / kWh.

[0062] In a further embodiment of the present invention, the multi-timing algorithm allows for multiple injection angles per cylinder, the injection angles being: Angle by swirl injection method (SIP), Angle for lubrication of the ring pack during the compression stroke of the piston, angle for ring pack lubrication during the piston's combustion stroke, To be chosen between,

[0063] The method according to the invention makes it possible to obtain three new lubrication strategies: -Multi-timing -Automatic cleaning sequence -Delta Timing It is.

[0064] The Moore adjustment algorithm can be used in the method according to the invention. An example of the algorithm is as follows: - RMP-RA (RPM Adjustment Algorithm): In RPM-RA, the stroke length is constant. The delivery volume varies with the fuel index. - MEP-RA (Mean Effective Pressure Regulation Algorithm): In MEP-RA, the supply is constant at a given speed. The lubricant flow rate over time is proportional to the fuel index. -LCD (Load Change Dependence): Increases the supply of cylinder lubricant oil when the main engine load changes significantly. -LDT (Load Dependent Timing): Some engines have exhaust valves with variable timing. The optimum SIP timing depends on the exhaust valve closing. If this changes, the SIP timing must also change to achieve the optimum timing. As the exhaust valve timing changes with load variations, the timing of the SIP injection becomes load dependent. -S-RA (Sulfur Adjustment Algorithm): When the sulfur content of the fuel oil and the BN of the cylinder lubricant are entered into the system, the system will automatically correct the sulfur / BN balance by adjusting the supply of cylinder lubricant. All these algorithms can be combined with each other in the method according to the invention.

[0065] With regard to SIP injection, the engine speed is an important parameter for regulating the amount of lubricant given that the predetermined angle for SIP injection is the closing time of the injection. The engine speed is the parameter that determines the timing of the start of injection depending on the amount of lubricant injected.

[0066] Three new lubrication strategies explained The examples given below use the feed rate instead of the feed rate coefficient or the adaptive cylinder control (ACC) coefficient used in the sulfur adjustment algorithm (S-RA). S-RA can also be used in combination with the strategies described. For further explanations, the applicant's publications can be consulted. For more information on S-RA and ACC, see "How to Successfully Run HJ SIP 920166-10".

[0067] Multi Timing Multi-timing means injecting fresh cylinder lubricant into the cylinder at multiple crankshaft positions. The algorithm supports injection at up to four different crankshaft positions during each cylinder revolution. A ratio of the amount is set at each position, called the distribution key. The sum of the four amounts is the set delivery amount, so multiple injections per revolution do not increase the total amount of cylinder lubricant injected.

[0068] The use of Multi-Timing ensures that cylinder lubricant is introduced exactly where it is needed, every revolution. By controlling the distribution of cylinder lubricant, optimal cylinder lubrication can be achieved at every revolution. Ensuring optimal distribution allows optimal cylinder conditions while reducing cylinder lubricant consumption.

[0069] FIG. 5 shows examples of crankshaft positions for the three optimal injection windows. The multi-timing algorithm allows multiple injection angles to be set for each cylinder. Typical angles are: -Swirl injection method (SIP) angle, - angle for ring pack lubrication during the piston compression stroke, -Angle for ring pack lubrication during the piston's combustion stroke, It is. The angles used in FIG. 5 are engine specific and cannot be generally applied.

[0070] SIP injection occurs on the liner surface above the piston during the compression stroke. When injecting by SIP, the favorable window is relatively large. Tests have shown that the entire window is about 30° of crankshaft rotation. The actual injection does not last 30°, but a target injection angle is selected so that both the start and end of injection are within the 30° window.

[0071] When injecting into a ring pack, the injection window is much narrower than with SIP, so both timing accuracy and injection duration are very important. The distribution key is set for each angle. A part of the total amount is sprayed at each angle according to the distribution key. The sum of all sprayed amounts during a full rotation is equal to the set delivery amount.

[0072] If already operating with HJ SIP, it is recommended that when starting multi-timing, the current feed rate setpoint be reduced by 10%. Multi-timing recommendations when operating with high sulfur fuels (>0.5%) are shown in Table 2. Multi-timing recommendations when operating with low sulfur fuels (≦0.5%) are shown in Table 3.

[0073] Table 2: Multi-Timing Recommendations for HSFO (>0.5%) TIFF0007645908000001.tif31145 Table 3: Multi-timing recommendations for HSFO (≤0.5%) TIFF0007645908000002.tif31145 An immediate reduction of 10% compared to normal HJ SIP is recommended. Further optimization is possible. Reduce the feed amount further based on the recommendations in the above publication. See "920166-10 How to make HJ SIP successful".

[0074] example Using the original LSFO supply of 0.6g / kWh, reduce the supply to 0.54g / kWh and set the multi-timing algorithm to 60% according to SIP and 20% each on the compression stroke and combustion stroke of the piston. This results in an effective supply injected according to SIP of 0.324g / kWh, and 0.108g / kWh on the compression stroke and combustion stroke. See Table 4 below for an overview of this setting.

[0075] Automatic Cleaning Sequence A cleaning sequence may also be thought of as a cleaning routine. When operating at low or very low feed rates, certain functions of the cylinder lubricant may not function as intended. Experience has shown that cleaning can be an issue when the cylinder lubricant feed rate is low, particularly when using cylinder lubricants with low base number (BN). This is because the low detergency of low BN lubricants impairs the ability of the lubricant to clean combustion residues and wear particles from the cylinder liner, pistons and piston rings. A continuous cleaning function is not necessary, intermittent cleaning can provide good results.

[0076] Table 4: Example of multi-timing using LSFO. TIFF0007645908000003.tif36146

[0077] The automatic cleaning cycle results in improved piston and cylinder cleanliness while providing low feed rates, resulting in improved cylinder condition and reduced wear. This method has been tested with very good results in terms of cylinder condition. An automatic flush cycle can facilitate low-flow flushing by periodically increasing the flow of cylinder lubricant, allowing low or very low flow rates for most of the operation, with short periods of increased flow to react with and flush away wear and combustion particles.

[0078] The automatic cleaning cycle can be set to multiple intervals of various durations. It is recommended to set the current feed rate to be reduced by 10% when starting an automatic cleaning cycle and to increase the feed rate by 30% during the cleaning cycle. Two 30-minute cleaning cycles are recommended every 24 hours. See Table 5 and Figure 6. The feed rate is further reduced as recommended in the above publication "920166-10 How to Successfully Perform HJ SIP".

[0079] When optimizing the consumption of cylinder lubricant, it is recommended to first reduce the supply amount at long intervals, and after finding the optimal supply amount at long intervals, reduce the supply amount again at short intervals. Table 5: Automatic Cleaning Cycle Recommendations TIFF0007645908000004.tif31142 TIFF0007645908000005.tif10135 FIG. 6 is a visual representation of the time distribution of recommended cleaning cycles over a 24 hour period.

[0080] example For example, consider a vessel that is unable to achieve a delivery below 0.60g / kWh due to cleaning issues. By using the automatic cleaning sequence, a delivery of 0.54g / kWh during normal operation and 0.90g / kWh for two 30 minute periods every 24 hours can be achieved, resulting in a 24 hour average of 0.555g / kWh. See Table 6 and Figure 7 for an overview of this configuration.

[0081] Table 6: Example of an automated cleaning sequence TIFF0007645908000006.tif31142 TIFF0007645908000007.tif12157 FIG. 7 is a visual representation of the 24-hour time distribution of a further example cleaning sequence.

[0082] Delta Timing Delta Timing combines multi-timing with automatic cleaning sequences to provide the ultimate in flexibility. When using delta timing, the extra cylinder lubricant injected during the cleaning sequence can be placed directly on the ring pack where the cleaning effect is greatest. The delta timing algorithm allows optimal distribution and amount in every case. Fully automatic control of when and how much cylinder lubricant is introduced into the cylinder is possible. Using delta timing guarantees an overall optimal distribution of cylinder lubricant.

[0083] Fully automatic control of cylinder lubricant distribution and quantity -Optimal top liner lubrication - Optimal neutralization of sulfuric acid -Optimal ring pack lubrication -Optimal piston ring cleaning This achieves an overall optimum cylinder condition with the lowest possible cylinder lubricant supply. By ensuring an optimal supply, cylinder conditions can be optimized while minimizing cylinder lubricant consumption.

[0084] Delta timing allows for a change of multi-timing dispense key each cycle, not just the volume. Delta timing can also be implemented to simply change multi-timing dispense keys periodically without changing the volume. This can facilitate a cleaning sequence without increasing the volume.

[0085] The delta timing algorithm allows a minimum quantity to be set for each injection window to ensure the proper cylinder lubricant quantity per injection. This means that the frequency of injections relative to the main engine (ME) revolutions can be varied. For example, the minimum quantity can be set so that the quantity injected into the ring pack during an injection is 100% of the set delivery quantity at 100% ME load. If the total quantity in the ring pack is set to 10% of the total average lubricant quantity per revolution, with a minimum of 100% of the set delivery quantity at 100% ME load, the injection rate will be 1 injection per 10 revolutions at 100% ME load. See the example in Table 7 below, where the quantity is set to 10% and the minimum quantity is set to 100% of the set delivery quantity at 100% ME load.

[0086] Table 7: Example delta timing distribution TIFF0007645908000008.tif21119 A minimum quantity of 0% means that injection takes place at every revolution. In the following, the minimum quantity always relates to the set delivery quantity at 100% ME load. In any period, the delta timing algorithm can use any combination of quantity and distribution key.

[0087] When using delta timing, a reduction in cylinder lubricant consumption of approximately 22% is expected from a SIP-optimized feed rate. The recommended values ​​vary depending on the sulfur content of the fuel oil. Injection according to SIP is recommended every revolution to ensure fresh lubricant and additives at every revolution, at the top of the cylinder where the high temperatures and pressures are the most hostile environment. I will.

[0088] Table 8: Delta Timing HSFO Recommended Values TIFF0007645908000009.tif83148 TIFF0007645908000010.tif10133

[0089] Figure 8 is a visual representation of the delta timing time distribution of supply over a 24-hour period. Figure 9 shows a visual representation of the delta timing time distribution of the quantity distribution key over a 24-hour period. The order is SIP, ring pack compression stroke, and ring pack combustion stroke. The distribution key is set in four windows: 11 hours, 1 hour, 11.5 hours and 0.5 hours. In the two normal operating windows of 11 hours and 11.5 hours, the feed rate must be immediately adjusted to obtain 25% less cylinder lubricant compared to normal HJ SIP lubrication. The settings in Tables 8 and 9 immediately reduce the average age by 22.4%. Further optimization is possible. Following the recommendations in the above publication "920166-10 How to Successfully Run HJ SIP", the feed rate can be further reduced

[0090] Please see Table 8, Figures 8 and 9 above for recommended values ​​for HSFO, and Table 9, Figures 10 and 11 below for recommended values ​​for LSFO. Table 9: Delta Timing LSFO Recommended Values TIFF0007645908000011.tif78139 TIFF0007645908000012.tif10133

[0091] FIG. 10 is a visual representation of the delta timing time distribution of supply over a 24 hour period. Figure 11 is a visual representation of the delta timing time distribution of the quantity distribution key over a 24-hour period. The order is SIP, ring pack compression stroke, and ring pack combustion stroke. The difference between HSFO and LSFO is the distribution key.

[0092] example When operating LSFO, the vessel cannot achieve less than 0.60g / kWh. Using delta timing, the following can be achieved: 0.45g / kWh of 60% SIP, 30% compression stroke, and 10% combustion stroke in normal operation on the distribution key; 0.60g / kWh of 45% SIP, 45% compression stroke, and 10% combustion stroke in 1 hour of every 24 hours on the distribution key; and 0.90g / kWh of 30% SIP, 60% compression stroke, and 10% combustion stroke in 30 minutes of every 24 hours on the distribution key.

[0093] Table 10: Delta Timing LSFO Recommended Values TIFF0007645908000013.tif125144 TIFF0007645908000014.tif10133

[0094] FIG. 11 is a visual representation of the delta timing time distribution of supply over a 24 hour period. Figure 12 is a visual representation of the time distribution of the delta timing of the mass distribution keys over a 24-hour period, listed in the order SIP, ring pack compression stroke, and ring pack combustion stroke. For an overview of the setup using LSFO, see Table 10, Figure 11, and Figure 12. The above presents an explanation of the concepts of multi-timing and delta-timing and how the injection frequency can be set for each desired injection angle.

[0095] Alternatively, it should be understood that a minimum amount can be set for each injection instead of the fixed injection frequency described above. The minimum amount is determined to ensure that a sufficient amount of lubricant is provided to achieve proper injection atomization. This will have an impact on the system. So, for example, if the minimum amount is determined to be 100 mg per injection, and the actual feed rate and distribution of the lubricant creates a situation where only 30 mg is injected per injection, the control unit algorithm will "count together" until the amount of lubricant exceeds the minimum amount. In such a case, an injection will occur at that injection angle approximately every 3 revolutions of the engine.

[0096] Abbreviations used ACC: Applied cylinder control BN: Base number HJ SIP: Hans Jensen Swirl Injection Method HJL: Hans Jensen Lubrication A / S HSFO: High sulfur fuel oil LSFO: Low Sulfur Fuel Oil ME: Main engine SIP: Swirl injection method S-RA: Sulfur Adjustment Algorithm

[0097] Further advantages are obtained with the embodiments disclosed in the further dependent claims. The invention will now be described in more detail with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0098] [Figure 1] 1 shows a schematic cross-sectional view of a cylinder into which a first portion of lubricating oil is injected; [Diagram 2] 2 shows a cross-sectional view corresponding to FIG. 1, in which a second portion of the lubricating oil is injected into the cylinder. [Diagram 3] 2 shows a cross-sectional view corresponding to FIG. 1, in which a third portion of the lubricating oil is injected into the cylinder. [Figure 4] FIG. 1 shows a schematic diagram of a system having multiple lubrication devices for use in the method according to the invention. [Diagram 5] Examples of crankshaft positions for three optimal injection windows are shown. [Figure 6]4 shows a visual representation of different time distributions in a method according to the invention; [Figure 7] 4 shows a visual representation of different time distributions in a method according to the invention; [Figure 8] 4 shows a visual representation of different time distributions in a method according to the invention; [Figure 9] 4 shows a visual representation of different time distributions in a method according to the invention; [Figure 10] 4 shows a visual representation of different time distributions in a method according to the invention; [Figure 11] 4 shows a visual representation of different time distributions in a method according to the invention; [Figure 12] 4 shows a visual representation of different time distributions in a method according to the invention; [Figure 13] 4 shows a visual representation of different time distributions in a method according to the invention; [Figure 14] The test results of the automatic cleaning sequence implementation are summarized below. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0099] Figures 1 to 4 correspond to Figures 1 to 3 and Figure 12 of the Applicant's WO 2010 / 149162. 1 to 3 show a cross-sectional view of a cylinder 51 with a piston 52 and a number of injection units 53 arranged in a ring area 54 of the cylinder wall 55 and connected to a lubrication device (not shown).

[0100] 1, the piston 52 is in a lower position. An injection of lubricating oil 58 is made from each injection unit directly into the ring area 54 of the cylinder wall 55. The injection occurs at a position above the piston 52 just before the piston passes the ring area 54 during its upward movement.

[0101] 2, the piston 52 is shown in an intermediate position with the injection units 53 located at a position between the upper piston ring 56 and the lower piston ring 57. A jet of lubricating oil 58 from each injection unit is delivered directly onto the piston 52 between the upper piston ring 56 and the lower piston ring 57 via the ring area 54 during the upward movement of the piston.

[0102] 3, the piston 52 is in the upper position. An injection of lubricating oil 59 is provided from each injection unit directly into the ring area 54 of the cylinder wall 55. Injection occurs at a lower position of the piston 52 just before the upwardly moving piston passes through the ring region 54 .

[0103] In FIG. 4, two different lubrication times are shown depending on whether it is SIP lubrication or conventional lubrication. In either case, lubricant is supplied into the cylinder during the upward movement of the piston, i.e., between bottom dead center (BDC) and top dead center (TDC). The "window" timed by SIP occurs before the piston passes the oil injector. The "window" used in conventional lubrication is narrower and is simply stated to occur after the piston top passes the oil injector.

[0104] 4 shows diagrammatically four cylinders 250 and eight injection nozzles 251 present on each cylinder. The lubricating systems 252 are typically connected to a central computer 253 with local control units 254 for each single lubricating system 252. The central computer 253 is connected in parallel to another control unit 255 which serves as a backup for the central computer. In addition, a monitoring unit 256 is provided to monitor the pumps, a monitoring unit 257 to monitor the load, and a monitoring unit 258 to monitor the crankshaft position.

[0105] The upper part of Fig. 4 shows a hydraulic station 259 with a motor 260 driving a pump 261 in a tank 262 of hydraulic oil. The hydraulic station 259 further includes a cooler 263 and a filter 264. The oil of the system is pumped through a supply line 265 to the lubricator via a valve 220. The hydraulic station is further connected to a return line 266, which is also connected to the lubricator via a valve. 268 is an interface between the control unit 254 and the monitoring units 256, 257, 258.

[0106] Lubricating oil is delivered from a lubricating oil supply tank (not shown) via line 267 to the lubricating system 252. Lubricating oil is delivered from the lubricating system to the injection nozzle 251 via line 110.

[0107] The local control unit allows adjustment of the lubricant quantity (in the form of frequency and stroke) and the injection timing. Adjustments of the injection time and quantity can be made automatically in response to changes in operating conditions based on various lubricant adjustment algorithms (e.g. load-dependent lubricant reduction) and injection time distribution keys (resulting in a change of the ratio between the first, second and third parts of the supply). These changes can be made directly or indirectly based on engine load and condition or on parameters important for the cylinder condition (e.g. rpm, cylinder lining temperature, engine load, injected fuel quantity, lubricant quality, lubricant viscosity, lubricant TBN content, scavenging exhaust oil analysis results (residual TBN, Fe content, etc.)).

[0108] FIG. 5 is an explanatory diagram of three injection angle windows according to different injection methods. - Swirl injection method (SIP) -By lubricating the ring pack during the compression stroke of the piston -By lubricating the ring pack during the combustion stroke of the piston It is. The angles used in Figure 5 are engine specific and cannot be generally applied. In other engines, these three angles may be larger or smaller.

[0109] Regarding figures 6 to 13, please refer to the above explanations regarding these figures. Every figure shows a different visual representation of the time distribution of different cleaning sequences over a 24-hour period. According to the above-mentioned methods, the various embodiments of the method can be combined into a lubrication regime. An example of such a regime is shown in Table 1.

[0110] [Table 1] TIFF0007645908000015.tif78139 TIFF0007645908000016.tif10133 The "Cycle" column lists multiple windows with a particular duration, e.g., the first window is 0-11 hours, the second window is 11-12 hours, the third window is 12-23.5 hours, and the fourth window is 23.5-24 hours in duration. The term "window" is another word for routine. It is clear that in other embodiments of the invention, more or fewer windows can be provided so that the duration of the various windows can be adjusted accordingly. Also, the duration of each window can be selected to be different. Typically, one regime consists of a total duration of 24 hours, and then this regime is repeated as many times as necessary. For example, in the case of a ship traveling long distances over days or weeks, the same regime can be operated after the ship leaves port and is at normal running speed until it arrives at its destination and prepares to move to a new port. In such a case, the same lubrication regime can be maintained by repeating the windows, e.g., as shown in Table 1, as many times as necessary.

[0111] The second column with "Feed Adjustment" shows the change in the amount of lubricant fed to the cylinder during a particular window of the scheme. For example, in the first window from 0-11 hours, -15% of the average lubricant content needs to be fed. It is clear that the savings in lubricant needs to be offset by a distribution of lubricant such that sufficient lubrication of the cylinder walls is achieved during operation of the marine engine. This is achieved by injecting the amount of lubricant in three different and separate injection phases per revolution of the engine, where 60% of the amount of lubricant is injected according to the SIP scheme. This is explained in the top row of the first window, where the amount column is 60%, the frequency is 1 / 1 and the timing is SIP, i.e. swirl injection scheme. This translates to 60% of the required amount of lubricant to be injected during the first window from 0-11 hours being injected per revolution of the engine by the SIP injector, which means that the piston is removed from the top of the cylinder so that most of the cylinder wall is exposed. The SIP approach is discussed and patented in the applicant's European Patent No. 1129275. The second and third injection phases coincide with the piston's ring pack being positioned adjacent to the injection nozzle so that the lubricant is injected directly onto the piston and ring pack. The ring pack helps the lubricant to be properly distributed along the cylinder wall while at the same time removing any debris and contaminants that may be lodged near the cylinder wall. In the first separate injection phase, 30% of the lubricant is injected, which needs to be injected every 3 revolutions of the engine. From the third row of the first window of 0-11 hours, it is clear that the third injection phase consists of a 10% amount of lubricant injected every 10 revolutions of the engine. Thus, it can be inferred that substantially less lubricant is used compared to injecting 100% of the lubricant every revolution of the engine. As a result, the approach shown in Table 1 results in an overall lubricant saving of -13.6% as shown immediately below the table. However, due to the distribution of the injections at various timings and positions, complete and sufficient lubrication is achieved.

[0112] In the fourth window, called the "cleaning cycle," the excess oil is injected in a specific distribution such that 40% of the amount is injected by the SIP for every revolution of the engine, 50% of the desired oil is injected into the ring pack during the compression stroke for every revolution of the engine, and only 10% of the oil is injected into the ring pack during the combustion stroke for every 10 revolutions of the engine.

[0113] The four window schemes with predetermined distribution of lubricant quantity, dosage adjustment and frequency shown in Table 1 are to be taken merely as examples, but many other variations of lubrication schemes may be contemplated within the scope of the claims. Typically, a suitable scheme may be selected depending on various factors such as the sulfur content of the fuel, the base number of the lubricant, the load and speed of the engine, the variations in the load and speed of the engine, the age of the engine, the type of engine, the relative humidity temperature of the engine, the air temperature, etc. Furthermore, the control unit may also apply different lubrication schemes to different cylinders of the same engine, since some cylinders may be refurbished and therefore require different lubrication than older cylinders, or vice versa.

[0114] Figure 14 summarizes the results of field testing of the introduction of automatic cleaning sequences. The field test was carried out for one year (February 2020 to February 2021) to demonstrate the effectiveness of the automatic cleaning sequence. It was decided to carry out the field test on a container ship equipped with RTA62U engines, due to issues with engine cleanliness and deposits caused by the switchover to LSFO.

[0115] During the field test the engine was operated with LSFO, 40BN lubricant and a feed rate of 1.0g / kWh. The condition of the main engine was assessed by a scavenge port inspection. For this particular vessel it was decided to solve the cleanliness issue using the following injection sequence: TIFF0007645908000017.tif36147

[0116] The results during the study period are summarized in Figure 14. The results show that the cleanliness of the main engine is greatly improved by the multiple injection and automatic cleaning sequence of cylinder lubricating oil. It can be seen that the top land, piston ring and ring area deposits have been removed.

[0117] In addition, the increased frequency of the lube oil injection and washing process also prevents the production of high levels of black lube oil sludge (seen before the upgrade). Black sludge is a sticky and viscous mixture formed of insoluble products from lubricating oils, combustion by-products, wear debris, and the like. Problems caused by excessive black lube oil sludge include engine blackening, under crown deposits, piston head corrosion, base number loss, plugging of lube oil scraper rings, and increased piston deposits, which are eliminated by the method of the present invention.

Claims

1. 1. A method of lubricating a large slow-speed marine diesel engine, the diesel engine having at least one cylinder (51) in which a piston (52) moves, the piston having a ring pack (56, 57), injection of lubricating oil is performed via a number of injection units (53) corresponding to a multiple of the number of cylinders of the engine, the lubricating oil being supplied as a combination of injections of at least two portions of the lubricating oil, the at least two portions of the lubricating oil being delivered at at least two different piston positions, the at least two different piston positions being selected from piston positions for injection before, during and after the passage of the piston (52) by the injection unit (53), the lubricating oil being supplied by direct injection onto the ring area (54) of the wall (55) of the cylinder, each of the injection units (53) is controlled by a control unit (254), a plurality of lubrication routines are stored in a memory in the control unit, the control unit receives inputs either from an input station or from one or more sensors, the inputs being capable of determining the implementation of one of a plurality of possible lubrication routines, each of the lubrication routines being differentiated by one or more distinct injection phases relative to the duration, amount of lubricant and / or position of the piston (52), each of the one or more distinct injection phases injecting an amount of lubricant expressed as a percentage of the total amount of lubricant injected in the respective lubrication routine, the timing being performed as delta timing combining multi-timing and automatic cleaning sequences.

2. 10. The method of claim 1, wherein the lubrication routine is further differentiated by controlling a frequency of injection relative to revolutions of the engine.

3. 2. The method of claim 1, wherein the lubrication routine can include an injection of an amount of lubricant only once for each revolution, such as a cleaning routine.

4. 4. The method according to claim 1 or 3, wherein each of the one or more different injection phases injecting an amount of lubricant expressed as a percentage of the total amount of lubricant is selected such that the percentage varies between 0% and 100% depending on the lubrication routine selected.

5. 2. The method of claim 1, wherein the distinct injection phases also include a frequency relative to the revolutions of the engine, such that the one or more distinct injection phases of injecting a portion of the lubricant expressed as a percentage of the total amount of lubricant injected are performed as a function of the engine revolutions, which can vary between 1 and 15 revolutions when each distinct injection timing occurs.

6. A method according to any one of claims 1 to 5, wherein the supply amount adjustment in proportion to the total amount of lubricant injected is selected between -30% and +30% of the total amount of lubricant injected.

7. The lubrication strategy for a given time period includes a number of lubrication routines; each routine or window within said given period has a duration that is a particular portion of said given period, such that the total duration of said number of routines covers said given period; each of said routines has a delivery rate that can be adjusted by varying the amount of fuel delivered to the cylinder during a particular routine; A method according to any of claims 1 to 6, wherein each of said feed amounts is provided with a distribution key comprising one or more distinct injection phases.

8. at least a first lubrication routine having a duration of a first portion of said given period, a negative feed rate adjustment, and one to three distinct injection phases; at least a second lubrication routine has a duration of a second portion of said given period, a dosage adjustment of 0%, and one to three distinct injection phases; at least a third lubrication routine having a duration of a third portion of said given period, a positive dosage adjustment, and one to three distinct injection phases; a further lubrication routine having a duration of a further portion of said given period, a dosage adjustment, one to three separate injection phases, The method of claim 7, wherein the total time of the relevant portion of all lubrication routines in the given period covers the given period, the routines are repeated until the lubrication strategy is changed, and the supply adjustments represent factors that indicate how the overall lubricant amount can be reduced or increased relative to the optimal amount of lubricant required.

9. 9. The method of claim 1, wherein in a lubrication routine, a first, second or subsequent timing is achieved every revolution up to 14 revolutions of the engine, and no two separate timings are achieved in the same engine revolution.

10. A delta-timing injection sequence using Hans Jensen swirl injection. Injection between the piston rings (56, 57) on the upward stroke; and Injection between the piston rings (56, 57) on the downward stroke; The injection sequence is used:

7. The method according to claim 1, wherein an automatic cleaning sequence is performed when the feed rate is increased.

11. 11. The method of claim 10, wherein the feed rate is increased in an amount between 1.0 and 2 g / kWh, preferably about 1.5 g / kWh, for 30 minutes every 12 hours.

12. A method as described in claim 10 or 11, wherein the average supply amount is between 0.8 and 1.6 g / kWh, preferably about 1.02 g / kWh.

13. a multi-timing algorithm allows multiple injection angles per cylinder (51), said injection angle being indicative of a crankshaft angle; Angle by swirl injection method (SIP), Angle for ring pack lubrication during the compression stroke of the piston (52), and Angle for ring pack lubrication during the combustion stroke of the piston (52); The method according to any one of claims 1 to 12, wherein the method is selected between:

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