KR20160055230A - Lubricating device and method - Google Patents

Abstract

The present invention relates to a method and system for lubricating a diesel engine operating with a sulfur-containing fuel. The feed of lubricating oil is supplied to the cylinder of the diesel engine and is regulated based on the humidity of the intake air of the engine.

Description

[0001] LUBRICATING DEVICE AND METHOD [0002]

The present invention relates to the lubrication of compression ignition (diesel) engines. In particular, and not exclusively, the present invention is directed to regulating the cylinder lube oil supply in low and medium speed diesel engines such as those used in, for example, ships, railroads or static applications.

Low speed diesel engines typically operate at a high maximum power output per cylinder, for example in the range of 2000 to 6000 kW per cylinder, in the range of less than about 300 rpm, for example in the range of about 50 to 250 rpm. A low speed diesel engine is typically a two stroke engine and may be, for example, a direct connected and directly reversed crosshead construction. Typically, such an engine includes a separator, such as a diaphragm and a stuffing box, which separates the power cylinder from the crankcase to prevent the combustion products entering the crankcase and mixing with the crankcase oil. Low speed diesel engines tend to use significant amounts of sulfur-containing fuels such as residual fuel oil.

Medium duty diesel engines operate in the range of about 300 to 1000 rpm and can provide a medium maximum high power output per cylinder, for example up to about 2000 kW per cylinder. Such an engine may be a four-stroke or two-stroke engine and may also operate as a sulfur-containing fuel such as residual fuel oil.

Cylinders of low or medium speed diesel engines are lubricated by cylinder lubricant. In order to counteract corrosion by acidic sulfur species, the cylinder lube oil is defined as the total base number (TBN), expressed in mg KOH / g, and the alkali reserve measured in accordance with ASTM D2896 reserve. For example, a low-speed two-stroke compression ignition engine is provided with a cylinder lubricating oil having a TBN in the range of 40 to 100 mg KOH / g, and such a TBN is achieved through the inclusion of an additive in a lubricating oil reference stock.

In low or medium speed engines, engine operating temperatures and pressures tend to destroy the lubrication film on the inner wall of the engine cylinder, which can lead to increased wear. Therefore, the cylinder lube oil is supplied substantially continuously with the lube oil supply rate. The lube oil feed rate is generally expressed as a function of g / kWh, i.e., the engine power output.

In addition to power output, it is known to regulate the cylinder lubricant supply rate of large diesel engines in response to engine load conditions, sulfur content in the fuel, or specific engine designs. This allows the lubricating oil supply to be optimized for better engine performance.

U.S. Patent Application 2003/0196632 Al discloses a method of using a device that causes a variation in the fluid flow rate or characteristics in response to actual engine conditions. The method regularly monitors one or more engine parameters for a device such as XRF to determine metal wear or IR for base number measurement. The measured engine parameters are used to calculate the lubrication supply rate for the engine.

It is also known that the sulfur content of the fuel can also affect the lubricating requirements. Combustion of higher sulfur fuel often results in the emission of more sulfur oxides, nitrogen oxides and particulate matter such as soot and metal oxides. With low sulfur content fuels, low or medium speed diesel engines can operate at reduced lubricant supply rates and / or lower TBN. In such cases, excess unreacted compounds in additive packages that provide TBN, such as over-based detergents, can contribute to the formation of sediments. Thus, it is known to change the TBN of the cylinder lubricant to match the sulfur content of the fuel.

   Adjustment to the lubricating composition can be made according to periodic or continuous review of the board.

 US 2003/0159672 A1 discloses a system for periodically monitoring one or more engine parameters of an all-loss lubricating system and for adding to the basic lubricant to produce a modified basic lubricant applied to the engine during operation Lt; RTI ID = 0.0 > a < / RTI > amount of secondary fluid required to be calculated from engine parameters.

US 2006/0068995 discloses a method for producing cylinder oil, the method comprising determining TBN (s) for at least one initial fluid, determining the preferred TBN of the cylinder oil and contacting at least one initial fluid with a suitable additive (S) by modifying the TBN (s) of the at least one initial fluid by mixing the at least one initial fluid with the at least one initial fluid.

US 2008/0318818 A1 discloses a method of monitoring the performance characteristics of an engine, comprising preparing an appropriate lubricant composition by in-situ mixing at least two different fluids comprising an additive package with a detergent Disclosed is a method for lubricating a marine diesel two-stroke engine.

Despite their advances, operational problems related to cylinder lubrication such as scuffing or excessive corrosive wear, which have not been described so far, have been continuously caused.

It is an object of the present invention to provide an improved solution for lubricating diesel engines operating with sulfur-containing fuels, in particular low speed and medium speed diesel engines and / or to solve at least one problem associated with the prior art.

According to a first aspect of the present invention there is provided a method for lubricating a diesel engine operating with a sulfur-containing fuel, the method comprising the steps of supplying a lubricating oil feed to a cylinder of a diesel engine, And is adjusted based on the humidity of the intake air of the engine.

It has been found that the degree of humidity of the intake air for the combustion of the sulfur-containing fuel in the diesel engine affects the exhaustion of the TBN of the lubricating oil supplied to the cylinder of such engine.

The humidity of the intake air of the engine may be determined or deduced in any suitable manner, and the method may include measuring or monitoring the humidity accordingly. Humidity can be absolute humidity or relative humidity. In one embodiment of the invention, the lubricating oil supply is adjusted based on the absolute humidity. In another embodiment of the invention, the lubricating oil supply is regulated on the basis of a relative humidity, especially at a defined air temperature. Any measurement indicating intake air humidity can be used to control the supply of lubricant. Conveniently, the humidity of the intake air can be measured or monitored by a humidity sensor. For a certain precision, the humidity of the intake air can be advantageously measured or monitored in the scavenge air space of the engine.

The lubricating oil supply can be adjusted over the entire range of relative humidity (0-100%) or absolute humidity of the intake air measured at any particular inlet air temperature (占 폚).

In an embodiment, the humidity-based conditioning is calibrated by one or more previous measurements of the drained oil sample. For example, the method may include a preliminary step of measuring the TBN and / or metal content of the endosperm sample at a plurality of humidities to calibrate the humidity-based regulation.

Periodic measurements may require monitoring, estimation, or reasoning of humidity over a period of time, such as at least 5 minutes, at least 10 minutes, at least 1 hour, or at least one day.

As can be seen from the non-limiting example illustrated in Figure 1, the relationship between exhaustion of the alkali reserve (base water) and intake air humidity at a given engine load, constant sulfur content in fuel and constant lubricant supply rate, , Where a lower alkali reserve (base water) is observed at higher humidity.

The present invention allows the lubricant supply to be optimized for better performance by taking into account the humidity factors of the intake air. However, the supply of lubricating oil can also be adjusted based on other factors besides the humidity of the intake air. In an embodiment, the method is based on one or more factors selected from the engine and / or the power output of each cylinder, the engine load, the sulfur content of the fuel used in the engine, the TBN of the lubricant, wear, deposits, and / Thereby adjusting the lubricating oil supply.

 In an embodiment, the lubricating oil supply is regulated (or maintained) as a function of the humidity of the intake air for a period of time, such as at least 5 minutes, at least 10 minutes, at least 1 hour, or at least one day.

 The lubricating oil supply can be adjusted by varying the feed rate and / or composition of the feed. Thus, the feed rate is a function of the humidity of the intake air.

In an embodiment, the feed rate is regulated within the range of about 0.50 to about 1.4 g / kWh (i.e., g / h per kW of engine power). In an embodiment, the feed rate is adjusted within the range of about 0.50 to 1.2, about 0.5 to 1.1, about 0.6 to 1.4, about 0.6 to 1.2, or about 0.6 to 1.1 g / kWh. The level of supply at a particular level will depend on the engine type and other factors, for example those listed above.

 In one embodiment, the feed rate is adjusted to a trend toward a higher feed rate as the humidity of the intake air increases. In one embodiment, the feed rate is adjusted to a trend towards a lower feed rate as the humidity of the intake air is reduced. The term "trend towards" reflects that other factors, such as those described above, can also optionally be used to adjust the supply rate and thus affect overall regulation. The specific weight given to the humidity of the intake air to optimize performance may depend on the engine type.

In one embodiment, the feed may be additionally or alternatively controlled by altering its composition or content. In an embodiment, the concentration of the additive providing the alkali reserve can be varied in the feed.

A blend on board system may be used to effect a change in the content of the feed. An example of a mixed-mount system is described in US 2006/0068995 A1.

In an embodiment, the method comprises the steps of: (1) monitoring the humidity of the intake air for the engine; (2) by in-situ controlled mixing of at least (i) an additive providing an alkaline reserve, and optionally other performance additives, and (ii) a base oil with a lubricating viscosity to modify the performance characteristics of the engine Selecting a prepared lubricating oil; And (3) supplying the lubricating oil prepared in the step (2) above to the engine.

Control mixing can be performed by any known mixing process known in the art, provided that the amount of additive is metered to provide the required lubricating composition.

In an embodiment, the additive comprises at least one over-basic detergent and / or at least one neutral detergent as described below.

In an embodiment, the lubricating oil is prepared by mixing more than two different base oils, additives, fluids or components. In an embodiment, the number of base oils, additives, fluids or ingredients ranges from 2 to 8, from 2 to 6, from 2 to 4, from 3 to 8, from 3 to 6, or from 3 to 4. In an embodiment, the number of additives, fluids or components is three.

The specific number, nature and concentration of additives, fluids or components may be selected to achieve the desired properties of the lubricant feed. For example, the nature, number and concentration of additives, fluids or components may be selected to provide a lubricant feed as described herein.

In one embodiment, the concentration of the additive that provides the alkali reserve is adjusted to a trend towards higher TBN in the feed as the humidity of the intake air increases. In one embodiment, as the humidity of the intake air decreases, the concentration of the additive is adjusted to a trend towards lower TBN in the feed. The term "trend towards" reflects that other factors, such as those described above, can also optionally be used to adjust the concentration of the additive and thus affect overall control. The specific weight given to the humidity of the intake air to optimize performance will depend on the engine type.

In principle, the benefits of the present invention can be expected to be broadly applied to any diesel engine operating with a sulfur-containing fuel. However, the present invention has been contemplated in the context of a marine diesel engine that tends to operate on a residual fuel flow path with a high sulfur content and can be exposed to significant humidity changes. An advantage of the present invention may be particularly significant and advantageous in embodiments where the engine is a low or medium speed diesel engine as described or defined above, for example. In the embodiment, the engine is a two-stroke diesel engine, in particular a marine two-stroke diesel engine. In an embodiment, one or more cylinders of the engine are total-loss lubricated by the lubricant feed.

Diesel engines operate as sulfur-containing fuels. Such an operation may occur simultaneously with the adjustment of the lubricant feed, but the present invention also encompasses a method wherein such operation occurs prior to or after adjustment of the feed, for example during a period of 24 hours or 48 hours after the start or end of adjustment . In particular, the present invention encompasses a method wherein a substantially sulfur-free fuel or a fuel having a sulfur content lower than that of the sulfur-containing fuel is used temporarily, for example when the marine engine enters the port or inland water. An example of a relevant category of fuel is specified below.

The sulfur-containing fuel may in principle be any fuel which contains at least a detectable amount, for example greater than 1 ppm of sulfur. In an embodiment, the fuel comprises a distillate and / or residue. In an embodiment, the sulfur-containing fuel comprises at least 0.0001% w / w sulfur. Such levels can even be found in very low sulfur fuels such as ultra low sulfur gas oil (ULSMGO). In another embodiment, the fuel comprises at least 0.001% w / w sulfur. Such levels can even be found in low sulfur fuels such as low sulfur marine gas oil (LSMGO). In yet another embodiment, the fuel comprises at least 0.1% w / w sulfur, or even at least 0.5% w / w sulfur, or at least 1.0% w / w sulfur, or at least 2% sulfur, or at least 3% sulfur. Such levels can be found, for example, in low sulfur intermediate fuel oil (e.g., LS 180 or LS 380). In yet another embodiment, the fuel comprises at least 3.5% w / w sulfur. Such a level can be found, for example, in an intermediate fuel oil (e. G., IFO 380). Generally, fuels with a high sulfur content are lower in cost. The present invention is particularly advantageous in engines operating at lower cost of fuel. The effect of intake air humidity on lubricant performance is considered to be particularly significant when a fuel with a higher level of sulfur is used. Thus, the present invention advantageously enables a solution so far recognized to achieve a balance between cost and corrosion.

The lubricating oil can be any lubricating oil suitable for lubricating the engine, particularly the engine cylinder. Lubricants in the examples are defined elsewhere in WO 99/64543 Al, the contents of which are incorporated herein by reference.

In an embodiment, the lubricating oil is SAE 40 grade or SAE 50 grade or SAE 60 grade lubricating oil.

As mentioned above, the lubricating oil can be pre-mixed or mixed by on-board or in-situ combination. In an embodiment, the lubricating oil comprises at least one base oil and at least one additive capable of constituting an additive package. The base oil may optionally also contain one or more pre-mixed additives.

In an embodiment, the base oil or combination of base oils has a viscosity ranging from 2 mm 2 / s to 40 mm 2 / s or from 2 mm 2 / s to 50 mm 2 / s (at 100 ° C). Suitably, the base oil is selected from the group consisting of new (fresh or unused) system oil, system oil used (also referred to as lightweight neutralizer stream), heavy neutral base oil, bright stock, Or mixtures thereof. Such oils include oils derived from neutral and synthetic oils, hydrocracking, hydrogenation, and hydrofinishing, untreated, refined and re-refined oils, and mixtures thereof. In addition to hydrotreated naphthenic oils, oils prepared by Fischer-Tropsch gas-to-liquid synthesis procedures and oils prepared by other gas-to-liquid oils are also known and can be used.

As described above, the additive or additive package may comprise one or more overbased detergents and / or one or more neutral detergents.

In an embodiment, the lubricating oil supplied to the cylinder has a TBN in the range of 20 to 100 (mg KOH / g). In an embodiment, the lubricating oil has a TBN of 20 to 80, 20 to 70, 30 to 100, 30 to 80, 30 to 70, 40 to 100, 40 to 80,

In an embodiment, the overbased detergent has a TBN of at least 200. In an embodiment, the overbased detergent has a TBN of at least 230 or at least 300. In an embodiment, the overbased detergent has a TBN of up to 600, 550 or 500. Examples of ranges of TBN for an overbased detergent include 200 to 600, 200 to 550, 200 to 500, 230 to 600, 230 to 550, 230 to 500, 300 to 600, 300 to 550, and 300 to 500 .

In an embodiment, the neutral detergent has a TBN of less than 200. In an embodiment, the neutral detergent has a TBN of less than 175. Examples of ranges of TBN for neutral detergents include 1 to 200, 1 to 175, 20 to 200, and 20 to 175. [

In an embodiment, the at least one overbased detergent or at least one neutral detergent comprises a salicylate, a sulfonate, a calcium carbonate or a mixed substrate detergent. The mixed substrate cleaner may, for example, optionally comprise a complex / hybrid of a sulfonate and a carbonate in the presence of a salicylate.

In the examples, other additives are also present in the lubricating oil feed. In an embodiment, the lubricating oil feed comprises a polymer thickener or viscosity index improver. Polymer thickeners include, for example, styrene-butadiene rubbers, ethylene-propylene copolymers, hydrogenated styrene-isoprene polymers, hydrogenated radical isoprene polymers, poly (meth) acrylate esters, polyalkylstyrenes, polyolefins , Polyisobutylene), polyalkyl methacrylates, and esters of styrene maleic anhydride styrene copolymers.

In an embodiment, the polymer thickener has a weight average molecular weight (Mw) of at least 8000, at least 8400, at least 10,000, at least 12,000, at least 15,000, at least 20,000, at least 25,000, at least 30,000, or at least 35,000. Polymer thickeners generally do not have an upper limit on Mw, but in embodiments Mw is less than 2,000,000, less than 500,000, less than 300,000, less than 150,000, or less than 75,000.

In an embodiment, the lubricating oil applied to the engine is selected from metal deactivators, dispersants, antioxidants, antiwear agents, corrosion inhibitors, anti-scuffing agents, extreme pressure agents, foam inhibitors, demulsifiers, At least one performance additive selected from the group consisting of a friction modifier, a pour point depressant, and mixtures thereof.

In an embodiment, the lubricating oil comprises a wear-resistant agent such as, for example, a metal hydrocarbyl dithiophosphate. An example of a metal hydrocarbyl dithiophosphate includes zinc dihydrocarbyldithiophosphate (often referred to as ZDDP, ZDP, or ZDTP). Examples of suitable zinc hydrocarbyl dithiophosphate compounds include butyl / pentyl, heptyl, octyl, nonyl dithiophosphoric acid zinc salts or mixtures thereof.

In an embodiment, the wear-resistant agent is ashless, i.e. the wear-resistant agent is metal-free. In an embodiment, the metal-free antiwear agent is an amine salt. The ashless wear resistant agent may contain atoms including sulfur, phosphorus, boron or mixtures thereof.

In an embodiment, the lubricating oil comprises a dispersing agent. The dispersant may be a batch-containing dispersant or a non-ash-type dispersant, and the ashless-form dispersant is so named because it does not contain the metal forming the sulfuric acid ash before it is combined with the other components of the lubricant. After compounding, they can acquire metal ions from other components, but they are still commonly referred to as "ashless dispersants ". The dispersant may be used alone or in combination with other dispersants. In an embodiment, the ashless dispersant does not contain ash-forming metal. The ashless dispersant is characterized by a polar group attached to a relatively high molecular weight hydrocarbon chain. The ashless dispersant may comprise an N-substituted long chain hydrocarbon succinimide such as alkenyl succinimide. Examples of N-substituted long chain hydrocarbonsuccinimides include polyisobutylene esters having a number average molecular weight of polyisobutylene substituents of, for example, 350 to 5000, 350 to 3000, 500 to 5000, or 500 to 3000 Meade. Succinimide dispersants and their preparation are disclosed, for example, in US 4234435. A succinimide dispersant is typically an imide formed from a polyamine, typically a poly (ethyleneamine).

In embodiments, the lubricating oil feed includes antioxidants such as, for example, diphenylamine, hindered phenol, molybdenum dithiocarbamate, sulphurised olefin, and mixtures thereof. In alternative embodiments, the lubricating oil has no antioxidant.

In an embodiment, the lubricating oil feed may also contain other performance additives such as corrosion inhibitors such as, for example, octylamine octanoate; Condensates of dodecenyl succinic acid or anhydride and fatty acids such as oleic acid and polyamines; Metal deactivators including derivatives of benzotriazole, 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole or 2-alkyldithiobenzothiazole; A wadding agent comprising a copolymer of ethyl acrylate and 2-ethylhexyl acrylate and optionally vinyl acetate; Demulsifiers comprising trialkyl phosphates, polyethylene glycols, polyethylene oxides, polypropylene oxides and (ethylene oxide-propylene oxide) polymers; A pour point depressant comprising an ester of maleic anhydride styrene, polymethacrylate, polyacrylate or polyacrylamide; And / or other performance additives such as amines, esters, epoxides, parthimidazolines, condensates of carboxylic acids with polyalkylene-polyamines, and fatty acid derivatives such as amine salts of alkylphosphoric acids can do.

The total combined amount of the additives present may be, for example, from 0 to 25, from 0 to 20, from 0 to 15, from 0 to 10, from 0.01 to 25, from 0.01 to 20, from 0.01 to 15, from 0.01 to 10, from 0.05 to 25 , 0.05 to 20, 0.05 to 15, 0.05 to 10, 0.1 to 25, 0.1 to 20, 0.1 to 15, 0.1 to 10, 0.5 to 25, 0.5 to 20, 0.5 to 15, or 0.5 to 10 wt% .

 From the second aspect, the present invention relates to a lubrication system for a diesel engine operating with a sulfur-containing fuel,

A humidity sensor for sensing the humidity of the intake air of the engine;

A supply regulating unit for controlling supply of lubricating oil to one or more cylinders of the engine; And

And an engine control unit configured to control the supply control unit based on the humidity sensed by the humidity sensor.

In this second aspect of the invention, the humidity of the intake air may be the absolute humidity or relative humidity of the intake air.

In an embodiment, the feed conditioning unit comprises a unit for controlling the feed rate of the lubricating oil and / or a mixing unit for controlling the composition of the lubricating oil.

In an embodiment, the system may be configured and tailored to perform the method according to the first aspect of the present invention.

From a third aspect, the invention is directed to a computer-readable medium comprising programming instructions that enable a computer processor to perform the steps of the method according to the first aspect of the present invention.

From the fourth aspect, the invention relates to a computer-readable medium according to the third aspect of the present invention, and (ii) a cylinder lubricant as defined somewhere in the present invention, for example (i) To a kit comprising one or more of the systems according to the embodiments. Advantageously, the computer-readable medium of such kits can be tailored to the system of lubricants and / or kits. A kit may be provided as a bundle of instructions for a combined use, or the components thereof may be separately sold, but the component has instructions for combinational use.

From the fifth aspect, the present invention relates to a method for countering the increase of corrosion and / or sediment in a cylinder of a diesel engine operating with a sulfur-containing fuel, wherein the increase in corrosion and / (I. E., Increase or decrease) of the intake air, the method comprising adjusting the supply of lubricating oil supplied to the cylinder based on the humidity of the intake air of the engine. In this fifth aspect of the invention, the humidity of the intake air may be the absolute humidity of the intake air or the relative humidity of the intake air.

In a sixth aspect, the present invention relates to the use of an amount of alkali reserve in a lubricating oil for the purpose of adjusting the lubricating oil to compensate for the intake air humidity in the engine in which the lubricating oil is to be used or in which the lubricating oil is to be used. In this sixth aspect of the invention, the intake air humidity may be absolute humidity or relative humidity.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words such as "comprising" and "comprises" ) "Means" including but not limited to, " and does not exclude other portions, additions, components, integers, or steps. In addition, singular forms include plural forms unless the context requires otherwise, and in particular when indefinite articles are used, the present specification will be understood to include singular forms as well as plural forms unless the context requires otherwise.

The preferred features of each aspect of the invention may be described in connection with any of the other aspects. Generally speaking, the present invention extends to any novel or any novel combination of features disclosed herein (including any appended claims and drawings). Thus, any chemical moiety or group described in connection with a feature, integer, feature, compound, particular aspect, an embodiment or example of the invention, or any other matter described in the present invention, Embodiment, or example of the present invention. Furthermore, unless stated otherwise, any feature disclosed herein may be replaced by alternative features that serve the same or similar purposes.

In the case where the upper limit and the lower limit are presented for the characteristic, ranges of numerical values defined by a combination of any of the upper limits and the lower limits can also be included.

In this specification, references to the properties of the components - unless otherwise stated - refer to temperatures under ambient conditions, i.e., atmospheric pressure and 16-22 or 25 ° C, or 18-22 or 25 ° C, .

The present invention will now be further described with reference to the following non-limiting examples, and the accompanying exemplary drawings.

1 is a graph showing the effect of humidity variation in the intake air for combustion of sulfur-containing fuel in a large two-stroke marine diesel engine when TBN of cylinder lubricant is exhausted;
2 is a schematic diagram of a lubrication system according to an embodiment of the present invention.

Example 1 - Influence of Humidity of Engine Intake Air on TBN

Investigations were conducted on a commercially available 70 TBN cylinder oil (Shell Alexia 50).

Alkaline reservoir depletion is a function of the absolute humidity contained in the intake air (at various temperatures) to evacuate the engine load in the 65 to 85% MCR range in a 96 cm cylinder bore two-stroke marine diesel engine at two different levels of fuel sulfur .

As is common in the art, the absolute feed rate of the lubricant was continuously adjusted based on the engine load. The feed rate to the engine load was kept constant at 0.9 g / kwh.

It can be seen that the relative humidity of the intake air influenced the depletion of the TBN of the lubricating oil, as can be seen in Table 1 and Fig.

According to the present invention, the cylinder lubricating oil feed rate is further optimized for better performance if the humidity of the intake air for combustion is considered for control of the feed rate (typically with sulfur content, load, and any other special engine characteristics) .

Example 2 - Control of lubricant supply based on humidity

2, the lubrication system 1 for the two-stroke marine diesel engine 2 comprises an engine control unit 4, a humidity sensor 6, an on-board lubricating oil mixing system 8 And a supply controller 10.

The two-stroke marine diesel engine 2 is a conventional low speed diesel engine. The humidity sensor 6 is installed in a space of the engine for measuring the humidity of the intake air of the engine.

The humidity sensor is connected to the engine control unit 4 programmed to control the operation of the engine, but such control can also be performed by a separate unit if desired. The engine control unit 4 may include or be connected to a user interface (not shown) for displaying the engine operating state and / or accepting input of a user. The engine control unit can also be configured to control the engine output, engine load, sulfur content of the fuel used by the engine, TBN of the lubricant, wear, deposition (e.g., , And / or additional information regarding corrosion.

The engine control unit 4 includes a microprocessor. The engine control unit controls the operation of the mounting mixer system 8 in fluid communication with the base oil 12 and the sources (e.g., tanks) of the first and second additives 14,16. The first additive 14 comprises an overbased detergent. The second additive is optional and includes a performance additive package. Based on an instruction from the engine control unit 4, the mixing system 8 mixes the base oil and optionally one or more additives 14,16 to provide the cylinder lubricating oil 18.

The supply controller 10 receives the lubricating oil 18 mixed by the mixing system 8 and supplies the lubricating oil 18 to the engine control unit 4 based on the command from the engine control unit 4, And supplies it to the cylinder of the engine 2 as a feed 20 having a feed rate.

In operation, the system 1 is set to deliver the lubricant composition 18 to the cylinder of the engine at a feed rate. The humidity sensor (6) continuously monitors the humidity of the intake air and supplies this information to the engine control unit (4).

When an increase in humidity is detected by the sensor 6, the engine control unit is programmed to perform one or both of the following by providing appropriate commands to the supply control unit 10 and / or the mixing system 8 :

 (I) increasing the TBN of the lubricating oil 18 by increasing the concentration of the alkali reserve additive 14 in the lubricating oil 18;

 (Ii) increase the feed rate of the feed 20 of the lubricating oil 18;

When a decrease in humidity is detected by the sensor 6, the engine control unit is programmed to perform one or both of the following:

 (I) reducing the TBN of the lubricating oil 18 by reducing the concentration of the alkali reserve additive 14 in the lubricating oil 18;

 (Ii) reducing the feed rate of the feed 20 of the lubricating oil 18;

In a variant of this embodiment, the engine control unit controls the mixing system 8 and the feed controller 10 such that the power output of the engine or each cylinder, the engine load, the sulfur content of the fuel used by the engine, Of TBN, abrasion, deposition, and / or corrosion.

In a further variant of this embodiment the mixing system 8 is omitted.

Claims (17)

A lubrication method for lubricating a diesel engine operating with sulfur-containing fuel,
Supplying a supply of lubricating oil to the cylinder of the diesel engine,
Wherein the feed is regulated based on the humidity of the intake air of the diesel engine. The method according to claim 1,
Wherein the humidity is absolute humidity. The method according to claim 1,
Wherein the humidity is a relative humidity, especially at a given air temperature. 4. The method according to any one of claims 1 to 3,
Wherein the humidity of the intake air is measured by a humidity sensor in a space of the engine. 5. The method according to any one of claims 1 to 4,
Wherein the feed of lubricating oil is adjusted based on at least one factor selected from the power output of the engine, the engine load, the sulfur content of the fuel used by the engine, and the TBN of the lubricating oil. 6. The method according to any one of claims 1 to 5,
Wherein the feed is regulated by changing the lubricant feed rate and / or the composition of the lubricant feed. 7. The method according to any one of claims 1 to 6,
Wherein the feed rate is adjusted to a trend toward a higher feed rate as the humidity of the intake air increases and toward a lower feed rate as the humidity of the intake air decreases. 8. The method according to any one of claims 1 to 7,
The composition of the lubricating oil feed is adjusted by providing an alkaline reserve to the feed to change the concentration of the additive and the concentration of the additive is adjusted to increase the TBN in the feed as the humidity of the intake air increases To the tendency of the feed air to be lower and to a lower TBN in the feed when the humidity of the intake air decreases. 9. The method according to any one of claims 1 to 8,
Wherein the engine is a two-stroke marine diesel engine operating with fuel comprising at least 1.0% w / w sulfur. 10. The method according to any one of claims 1 to 9,
Wherein the lubricating oil is a SAE 40 or 50 or 60 grade lubricating oil. A lubrication system for a diesel engine operating with a sulfur-containing fuel,
A humidity sensor for sensing the humidity of the intake air of the engine,
A feed regulation unit for controlling the feed of lubricating oil to one or more cylinders of the engine,
And an engine control unit configured to control the feed regulation unit based on the humidity sensed by the humidity sensor. 12. The method of claim 11,
Wherein the feed conditioning unit comprises a unit for controlling the supply rate of the lubricating oil and / or a mixing unit for controlling the composition of the lubricating oil. 13. The method according to claim 11 or 12,
Wherein the engine control unit is configured to perform the lubrication method according to any one of claims 1 to 10. 11. A computer-readable medium comprising programming instructions that cause a computer processor to perform the steps of a lubricating method according to any one of claims 1 to 10. A kit comprising at least one of a computer-readable medium according to claim 14, and a lubricating system according to any one of claims 11 to 13. A method for countering the increase in corrosion and / or deposits in the cylinder of a diesel engine operating with a sulfur-containing fuel,
The increase in corrosion and / or sediment results from fluctuations in the humidity of the intake air of the engine,
Comprising the step of adjusting the feed of lubricating oil supplied to the cylinder based on the humidity of the intake air of the engine. The use of an amount of alkali reserve in the lubricating oil for the purpose of adjusting the lubricating oil to compensate for the intake air humidity in the engine in which the lubricating oil is to be used or in which the lubricating oil is to be used.

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