Use of a fatty amine for reducing and/or controlling the abnormal combustion of gas in a marine engine

Abstract

The invention relates to the use of one or more fatty amines that are soluble in a lubricant composition comprising at least one detergent in order to reduce and/or control the abnormal combustion of gas in a marine engine, the amine/detergent weight 1-1 ratio being between 0.01 and 0.5. The invention also relates to a process for reducing and/or controlling the abnormal combustion of gas in a marine engine in which the gas is in contact with one or more fatty amines that are soluble in a lubricant composition comprising at least one detergent, the amine/detergent weight ratio being between 0.01 and 1, preferably between 0.01 and 0.9, more preferentially between 0.02 and 0.8, for example between 0.03 and 0.8, in particular between 0.01 and 0.5, preferably between 0.01 and 0.4, for el example between 0.02 and 0.4.

Claims

1. A method for reducing and/or controlling abnormal gas combustion in a marine engine, comprising using one or more fatty amines soluble in a lubricant composition comprising at least one detergent to reduce and/or control abnormal gas combustion in a marine engine, wherein said lubricant composition has a amine/detergent weight ratio of between 0.01 and 1, and wherein the fatty amine is selected from a mixture of fatty polyalkylamines comprising one or more polyalkylamines of formulas (III) and/or (IV): ##STR00003## where: R, the same or different, is a linear or branched alkyl group having 8 to 22 carbon atoms; n and z are each independently 0, 1, 2 or 3; and when z is higher than 0, o and p are each independently 0, 1, 2 or 3, said mixture comprising at least 3 weight % of branched compounds such that at least one of n or z is 1 or higher, or the derivatives thereof.

2. The method according to claim 1, wherein the fatty amine represents from 0.1 to 10 weight % relative to the total weight of the lubricant composition.

3. The method according to claim 1, wherein the composition comprises at least one dispersant.

4. The method according to claim 1, wherein said method is used to reduce and/or control abnormal gas combustion in a marine pure gas or dual fuel engine, two-stroke or four-stroke.

5. The method according to claim 1, wherein said method is used to reduce and/or control abnormal gas combustion in a marine engine caused by autoignition of the lubricant composition.

6. The method according to claim 1 wherein said method is used with any type of gas.

7. A method for reducing and/or controlling abnormal gas combustion in a marine engine, comprising lubrication of the engine with a lubricant composition comprising: at least one base oil; at least one fatty amine; at least one detergent, the amine/detergent weight ratio being between 0.01 and 1; wherein the fatty amine is selected from a mixture of fatty polyalkylamines comprising one or more polyalkylamines of formulas (III) and/or (IV): ##STR00004## where: R, the same or different, is a linear or branched alkyl group having 8 to 22 carbon atoms; n and z are each independently 0, 1, 2 or 3; and when z is higher than 0, o and p are each independently 0, 1, 2 or 3, said mixture comprising at least 3 weight % of branched compounds such that at least one of n or z is 1 or higher, or the derivatives thereof.

8. The method according to claim 7, wherein the fatty amine represents from 0.1 to 10 weight % relative to the weight of the lubricant composition.

9. The method according to claim 7, wherein the detergent represents from 4 to 30 weight % relative to the weight of the lubricant composition.

10. The method according to claim 7, further comprising a dispersant.

11. The method according to claim 7, wherein said method is used for reducing and/or controlling abnormal combustion of gas in a pure gas or dual fuel marine engine, two stroke or four stroke.

12. The method according to claim 7, wherein said method is used to reduce and/or control abnormal gas combustion in a marine engine caused by autoignition of the lubricant composition.

Description

(1) FIG. 1 translates percentage pre-ignition by the lubricant as a function of the admission temperature.

(2) FIG. 2 translates the frequency of abnormal combustion as a function of admission temperature.

(3) FIG. 3 translates the time to autoignition as a function of temperature at the top dead centre.

EXAMPLE 1

Experimental Protocol for Measuring the Frequency of Initiated Pre-Ignition by the Lubricant Before the Ignition Command of the Single-Cylinder Gas Engine, and the Frequency of Abnormal Combustion Generated by Pre-Ignition of the Lubricant

(4) To determine the effect of the lubricant on the phenomenon of abnormal combustion, the frequency of initiated pre-ignition was measured on the single-cylinder gas engine due to the lubricant before the main ignition command of the engine, and the frequency of pre-ignition by the lubricant generating a rise in cylinder pressure corresponding to abnormal combustion.
To determine the frequency of initiated pre-ignition due to the lubricant, the law of heat release rate was measured for each combustion cycle. The ignition command was set in repeatable manner at −4° crankshaft angle before the top dead centre. Therefore, for each cycle, each rise in energy release starting before a crankshaft angle of −6° was counted as abnormal pre-ignition generated by the lubricant before the main engine ignition command. The test was started at an admission temperature of the air-gas premix at about 55° C. Throughout the test, the temperature was gradually increased until the pre-ignition event was observed. All these abnormal events in relation to all the 15 000 combustion events recorded during the 30 minutes of each test gave the frequency of abnormal pre-ignition generated by the lubricant before the main engine ignition command.
To determine the frequency of pre-ignition by the lubricant generating a rise in cylinder pressure corresponding to abnormal combustion, the maximum pressure reached in the cylinder for each cycle was measured. The test was started at an admission temperature of the air-gas premix set at about 55° C. Throughout the test, the temperature was gradually increased until the pre-ignition event was observed. The operating point of the single-cylinder gas engine was fixed and generated a normal maximum cylinder pressure of 80 bar. In the event of abnormal combustion, it was considered that the maximum cylinder pressure in the combustion chamber must exceed the limit of 120 bar so that the cycle could be counted as abnormal ignition generated by the lubricant. All these abnormal events in relation to all the 15 000 combustion events recorded during the 30 minutes of each test gave the frequency of abnormal pre-ignition generated by the lubricant.
This test inter alia allows evidencing of the effect of the lubricant on resistance to the phenomenon of pre-ignition of the air-gas mixture due to autoignition of the lubricant before the normal ignition command, and the effect of the lubricant on the intensity of the maximum cylinder pressure peaks in the event of abnormal combustion, representing the energy released by abnormal combustion.
The lubricant compositions in Table 1 were tested. The fatty amines used in these compositions are the following:
Fatty amine 1: mixture of amines (III) and (IV)

(5) TABLE-US-00002 TABLE 1 1 Formulation (control) 2 3 Base oil 88.9 88.4 81.1 (weight %) Detergents 11.1 9.6 18.4 (weight %) Fatty amine 1 — 2.0 0.5 (weight %) Weight ratio 0 0.21 0.03 amine/ detergent

(6) The results given in FIG. 1 were generated from temperature conditions in which a phenomenon of abnormal combustion was initiated, and translate the intensity of the abnormal combustion phenomenon.

(7) The results given in FIG. 2 translate the temperature conditions on and after which the phenomenon of abnormal combustion occurred, and the frequencies of onset of this phenomenon over a given cycle.

(8) In FIG. 2, the frequency was measured of initiated pre-ignition due to the lubricant as a function of the admission temperature of the air-gas premix. It can be seen that this frequency is reduced for the compositions of the invention i.e. the frequency of initiated pre-ignition also called abnormal combustion starts at a higher temperature contrary to the comparative composition.

(9) In addition, it is also observed that at one same admission temperature of the air-gas premix, the frequency of initiated pre-ignition due to the lubricant is lower for the compositions of the invention contrary to the comparative composition.

(10) In FIG. 2, the frequency was measured of pre-ignition by the lubricant generating a rise in cylinder pressure corresponding to abnormal combustion as a function of the admission temperature of the air-gas premix. It can be seen that this frequency is reduced for the compositions of the invention i.e. the frequency of pre-ignition by the lubricant generating a rise in cylinder pressure corresponding to abnormal combustion starts at a higher temperature contrary to the comparative composition.

(11) In addition, it is also observed that at one same admission temperature of the air-gas premix, the frequency of pre-ignition by the lubricant generating a rise in cylinder pressure corresponding to abnormal combustion is lower for the compositions of the invention contrary to the comparative composition.

(12) Therefore, following from the results in FIGS. 1 and 2, it is observed that the compositions of the invention allow both limiting of the onset of the abnormal combustion phenomenon and limiting of the intensity thereof, contrary to the comparative composition.

EXAMPLE 2

Experimental Protocol for Measuring the Time to Ignition of Abnormal Combustion Generated by Pre-Ignition of the Lubricant

(13) The objective here was to evaluate the reduction in the phenomenon of abnormal gas combustion in a marine engine when the gas is contacted with the compositions of the invention contained in a lubricant composition.

(14) For this purpose, different lubricant compositions were prepared from the following compounds:

(15) a lubricant base oil comprising a mixture of Group 1 and/or II mineral oils, in particular oils of Brightstock type, a détergent package, fatty amine 1: mixture of amines (III) and (IV), fatty amine 2: fatty diamine (I)

(16) Composition 4 of the invention and two reference lubricant compositions 5 and 6 are described in Table 2; the percentages given are weight percentages.

(17) TABLE-US-00003 TABLE 2 5 6 Formulations 4 (reference) (reference) Base oil 83.6 93.2 94.4 Detergents 8.9 2.1 5.6 Fatty amine 1 7.5 0 0 Fatty amine 2 0 4.7 0 Weight Ratio 0.8 2.2 0 amine/ detergent

(18) The test for measuring time-to-ignition of gas combustion when the gas is in contact with a lubricant composition was conducted in a rapid compression machine (RCM) comprising a combustion chamber with bore of 80.4 mm and stroke of 95 mm respectively. The piston motion speed in the RCM corresponded to engine rotation of 600 rpm. The RCM also comprised a cylinder head device with quartz insert allowing visualisation of gas combustion in the combustion chamber by means of a rapid acquisition camera (30 000 fps).

(19) Prior to the test to measure abnormal gas combustion in a RCM combustion chamber, a mixture was prepared formed of gas having a methane number equivalent to 70% and air containing nitrogen and oxygen in an excess air ratio (air-gas) of 1.5 relative to the stoichiometric ratio used for gas combustion.

(20) Under a pressure of 19 MPa using a piezoelectric-controlled injector, 0.1 mg of lubricant composition was injected into the RCM. The air-gas mixture was previously heated to a temperature of between 60 and 80° C. and injected under pressure varying between 100 kPa and 270 kPa into the cylinder and compressed at a compression rate ε varying between 7.4 and 11.5.

(21) This test inter alia allows evidencing of the effect of the lubricant on autoignition of the air-gas mixture.

(22) Following the above protocol, the released pressure and released energy were measured during gas combustion when in contact with compositions 4, 5 and 6 respectively. The time-to-ignition of abnormal combustion was also measured in FIG. 3.

(23) It can be seen in FIG. 3 that the time to pre-ignition after autoignition of the lubricant composition of the invention (lubricant composition 4) is longer than the time to pre-ignition after autoignition of the reference lubricant compositions (lubricant compositions 5 and 6).

(24) Since the time to pre-ignition through autoignition of lubricant composition 4 is optimised compared with the reference lubricant compositions 5 and 6, it is therefore observed that the phenomenon of abnormal combustion is decreased in the presence of lubricant composition 4 containing one or more fatty amines of the invention, compared with the reference lubricant compositions 5 and 6.

(25) It follows that the lubricant composition of the invention is shown to reduce and/or control abnormal gas combustion in a marine engine.