KR20020081549A - A method for operating a reciprocating piston internal combustion engine as well as a reciprocating piston internal combustion engine - Google Patents

Abstract

PURPOSE: An operation method of a reciprocating piston internal combustion engine and device thereof are provided to improve the efficiency and the stability by regulating the amount of lubricant to cylinders corresponding to fluctuation of sulfur contents, and to increase the safety by warning wear with monitoring iron contents among lubricant. CONSTITUTION: A reciprocating piston internal combustion engine comprises a fuel supply unit(3) including a fuel pipe(5), and a cylinder(1) combined with a lubricant supply unit(7) including a lubricant supply pipe(9) and a lubricant discharge pipe(10). A flow rate regulating unit(11) is combined with the lubricant supply unit. Fuel or lubricant is supplied to the cylinder according to the lubricant quantity directly or indirectly dependent on the sulfur content of the fuel and varied in conjunction with the variation in the fuel sulfur content. The stability is improved, and expenses are reduced by regulating the amount of lubricant according to fluctuation of the sulfur content.

Description

Operation Method of Reciprocating Piston Internal Combustion Engine and Reciprocating Piston Internal Combustion Engine TECHNICAL AS

The present invention relates to a method of operating a reciprocating piston internal combustion engine, more particularly a large two-stroke diesel engine in which fuel and lubricating oil are supplied to a cylinder, and a fuel comprising a reciprocating piston internal combustion engine, more specifically a fuel line. A large two-stroke diesel engine with at least one cylinder associated with a fuel supply device and a lubricant supply device comprising a supply line and an extension line.

There is a constant correlation between the sulfur content in the fuel and the wear of the cylinder bush. Up to a predetermined limit sulfur content, wear increases approximately linearly and relatively gently as the sulfur content increases. After this point it increases rapidly. When the amount of lubricating oil supplied increases under constant load, the limiting sulfur content moves in the higher value direction.

Conventionally, the amount of lubricating oil supplied per unit time is defined as a fixed variable depending on the average degree of wear that has survived a predetermined period. However, there is an unnecessary consumption of lubricating oil here when using fuels with a relatively low sulfur content. In addition, excessive lubricating oil may corrode by reducing the so-called polishing, ie adhesion of the lubricating oil film. Thus, the methods used to date have proved insufficient in terms of economics and safety.

It is therefore an object of the present invention to ensure relatively high cost effectiveness and stability in the method and in the aforementioned type of reciprocating piston internal combustion engine.

In a general method, the object is achieved by varying the sulfur content of the supplied fuel in a direct or indirect function in the same direction as the amount of lubricating oil supplied to each cylinder of the sulfur content.

To this end, in a general reciprocating piston internal combustion engine, a flow metering device is coupled to a lubricating oil supply device, and the amount of lubricating oil that can be supplied to each cylinder by the flow adjusting device is supplied in the same direction as the variation of the sulfur content. The sulfur content of can be varied by direct or indirect function.

These methods according to the invention are preferred for the optimization of lubricating oil supply. Excess lubricant and lack of lubricant are prevented. Thus, by using the method according to the invention the aforementioned disadvantages are completely avoided and a high level of stability and cost effectiveness is ensured.

Preferred embodiments and convenient methods of improvement of the invention are described in the dependent claims. In a simple embodiment, the sulfur content of the fuel used can be predetermined during fuel supply and can be manually entered into the flow regulating device. The same applies to the conversion of one type of fuel to another. However, in the first preferred embodiment of the method of the present invention, it is preferable that the sulfur content of the supplied fuel is continuously measured and the lubricating oil amount is changed as a function of it. As a result, a control device is preferably provided which ensures an automatic operation method and considerable operational convenience. At the same time, fluctuations in sulfur content in the fuel feed load are also known and lubricating oil is supplied accordingly.

Intrinsic properties of another preferred embodiment may consist of continuously monitoring the parameters that are affected by the sulfur content of the supplied fuel and that can be measured in the lubricant used and the amount of lubricant being varied as a function. These methods are preferred for closed-loop contron systems, whereby it is advantageous to provide a high level of precision and stability. In addition, the above modification is advantageous in that the lubricant can be optimally supplied to each specific cylinder.

As another improvement of the method of the present invention, the iron content of the lubricant used can be continuously monitored and the actual wear compared to the allowable wear when the lubricant supply depends on the sulfur content of the fuel, An alarm can be triggered if the allowable deviation is exceeded. In this regard, in addition to the sulfur content of the fuel supplied, there may be other sources of wear that may occur from time to time, such as, for example, water infiltration and contamination of the injected air with sand particles and / or wear particles from the fuel. . It is an advantage that in this case an alarm can be known in advance so that other causes of wear can be recognized in advance, so that remedial measures can also be taken in advance, thus making it possible to obtain particularly high levels of safety.

The flow regulating device is conveniently configured as an automatic open loop control device or an automatic closed loop control device, which inputs a signal combined with the actual value and at least one flow regulating member arranged in front of the cylinder of the lubricating oil pipe. A programmable computer with an output and / or an alarm device. This results in a simple, comprehensive design, high functional reliability and ease of operation.

Other preferred embodiments and convenient improvements of the method of the present invention are described in the remaining dependent claims, which are described in detail below with reference to the accompanying drawings.

1 is a schematic view of a reciprocating piston internal combustion engine with a first device according to the invention for optimizing the lubricating oil supply.

2 is a diagram illustrating a correlation between cylinder bush wear and sulfur content of fuel.

3 is a diagram illustrating the amount of lubricating oil required when a predetermined wear is allowed as a function of the sulfur content of the fuel.

4 is a schematic view of a variant of the apparatus according to FIG. 1.

FIG. 5 is a diagram illustrating a correlation between residual calcium hydroxide in a used lubricant and sulfur content of a fuel.

Figure 6 illustrates the correlation between cylinder bush wear and residual calcium hydroxide in the lubricant used.

FIG. 7 is a diagram illustrating a correlation between variation in the amount of lubricant oil supplied and variation in residual calcium hydroxide in the lubricant used.

The present invention finds application in large engines, more particularly in large two-stroke diesel engines, for example for use in driving ships. Engine configurations of this type and methods of operation thereof are well known and will not be described further herein.

The engine of the type described above, which forms the basis of FIGS. 1 to 4, comprises a plurality of cylinders 1 each having an injection device represented by a combined injection nozzle 2. The injection device combined with the cylinder 1 is supplied with fuel by the fuel supply device 3. The fuel supply device comprises a fuel pipe 5 branched from the tank installation 4 and branched into a tap line 5a coupled with different cylinders 1 in the engine direction. The tank plant 4 comprises a plurality of tanks, in this case two tanks 4a, 4b, which are combined with fuels of different quality, for example heavy oil and light oil, and the selector device 6 ) Can be alternately connected to the fuel pipe.

The cylinder bush of the cylinder 1, which is not illustrated in detail, is provided with a lubricating oil hole in a known manner, which is supplied with a suitable lubricating oil, usually in the form of a lubricating oil, by the lubricating oil supply device 7. The lubricating oil supply device 7 comprises a supply pipe 9 branched from the lubricating oil supply container 8 and branched into a tap tube 9a coupled with different cylinders 1 in the engine direction. The lubricating oil supply device 7 also has an extraction line 10 which is engaged with the different cylinders 1 in the engine direction, branched into the inlet line 10a and used to extract the used lubricating oil. Include. The lubricating oil discharged from the cylinder 1 and extracted through the extraction tube 10 may be injected into an extract container not shown, and may be stored in this container or supplied to a cleaning device not shown, It is cleaned so that it can be reused in the cleaning device and supplied to the lubricating oil supply container 8.

The lubricant supplied to the cylinder 1 is metered as a function of the braking load applied to the engine. The higher the load, the more lubricant is supplied. According to the present invention, the amount of lubricating oil according to the load varies according to the allowable wear rate by the sulfur content of the fuel supplied to the cylinder 1 as a direct and indirect function.

As illustrated in FIG. 2, a tight correlation between the wear produced and the sulfur content of the fuel used is shown. In this respect, the cylinder bush wear is expressed in millimeters per 1000 hours with respect to the sulfur content of fuel per volume percent, and the two curves A and B show different operating states. Curve A is a curve relating to the operation of supplying the lubricant with a relatively small and constant, and curve B is a curve relating to the operation of supplying more and more consistently. In the range with less sulfur content, curves A and B show a very flat and almost linearly rising area, but the area with a higher sulfur content rises more steeply. In the transition region from one region to another, the sulfur content is substantially at the threshold value S _K. The value S _KB is located to the right for the curve B than the value S _KA of the curve A. Thus, the sulfur content threshold moves in the higher value direction when the amount of lubricating oil increases. This shows that the amount of lubricating oil supplied to the cylinder changes as a function of sulfur content.

In order to carry out the above modification, a flow rate adjusting device 11 is provided. The flow regulating device consists of an automatic open-loop control device in FIG. 1 and an automatic closed-loop control device in FIG. 4 which comprises a computer 12 which functions and functions as a control or regulator. do. The computer 12 includes inputs for the actual values required and outputs for the generated control signals. The tap pipe 9a of the lubricating oil supply pipe 9 leading to the cylinder 1 is constituted, for example, by a valve or the like. The signal line 14 of FIG. 1 and the plurality of signal lines 14 of FIG. A flow regulating member 13 which can be actuated via is arranged.

In the embodiment of the flow regulating device 11, which is an open-loop control device forming the basis of FIG. 1, the lubricating oil amount defined by the brake load acting on the engine is determined by the sulfur content of the fuel supplied to the cylinder 1. Directly into a function The relationship between PS-grams of lubricating oil amount required for a given wear rate allowed after taking into account the repair and lubricating oil supply costs and the volume% of the sulfur content of the fuel supplied to the cylinder 1 is illustrated in FIG. 3. The curve forming the basis of FIG. 3 is illustrated to gradually rise in a substantially straight line in the region where the sulfur content is lower, and to rise rapidly after the sulfur content passes a predetermined value. This type of curve is substantially programmed into the computer 12, as illustrated in FIG. 1.

The computer 12 is conveniently configured to first calculate the lubricating oil amount corresponding to each load and the result to vary the sulfur content of the fuel as a function. Computer 12 includes an input 15 coupled with a load signal. The sulfur content of the fuel supplied to the tanks 4a and 4b can be grasped in advance at the time of supply and stored in the computer 12. To this end, the computer 12 may be provided with a suitable store 16 and an input 17 combined with a manual input device. Depending on which tank 4a or 4b is connected to the fuel pipe 5 via the selector 6, one value or the other of the sulfur content forms the calculation criteria. Information on which tanks 4a and 4b operate can also be entered manually. However, for this purpose, it is also possible to connect the selection device 6 to supply a corresponding signal to the computer 12 as indicated by the signal line 18 extending from the selection device 6, which signal line is in this case the computer 12. Can be combined with a suitable input of.

In the embodiment of FIG. 1, the sulfur content is not entered manually but is measured continuously. For this purpose, a sensor 19 connected to the input 21 coupled via the signal line 20 is provided in the fuel line 5 downstream of the selection device 6. By continuously detecting the sulfur content, variation in the sulfur content in the tank can be detected, so that a particularly high level of safety can be ensured.

In each case, the flow regulating member 13 is adjusted in accordance with the mutual relationship shown in FIG. Therefore, the lubricating oil is optimally supplied to the cylinder 1 by an amount that always requires sulfur content depending on the degree of wear tolerance, for example, and does not exceed more. In this way, the operating cost, that is, the estimated repair cost and the lubricant cost can be optimized. Variation in the amount of lubricating oil supplied to the cylinder 1 as a function of the sulfur content in the fuel is conveniently limited within a predetermined range. The upper threshold is located at the point where the normal consumption, ie the lubricant consumption generated without varying the sulfur content as a function of the present invention, does not exceed 50%. Above the threshold is generally more desirable to bear faster wear in terms of high lubricant cost. In each case, the lower threshold is the amount of lubricant required to extract impurities from the running surface of the cylinder bush and to keep the piston ring in proper hydrodynamic lubrication.

Apart from the sulfur content of the fuel supplied to the cylinder 1, other sources of wear, such as water seeping into the cylinder 1 or contaminated air contaminated with dust and / or sand and / or wear particles from the fuel, etc. This can be. In order to solve this case quickly, a monitor apparatus is provided in both the embodiment according to FIGS. 1 and 4. For this purpose, the iron content of the lubricating oil discharged from the cylinder 1 is monitored. For this purpose, at least one sensor 22 is provided in the extraction tube 23, which is connected via the signal line 23 to the combined input 24 of the computer. In the simple case, it is sufficient to couple the iron-sensor located downstream of the mouse of the connecting tube 10a to the extraction tube 10.

However, each of the connecting tubes 10a extending from the cylinder 1 may be conveniently provided with a corresponding sensor 22 connected to the combined input of the computer 12, as further indicated in FIG. 1. In this way, the wear of the cylinder 1 can be measured separately. From the measured iron-values, the computer 12 calculates the actual degree of wear and compares it with the desired, i. If the actual degree of wear is high, this indicates that there is an additional cause of wear. In the above case, an alarm sounds for quick action. For this purpose, an alarm device 25 is provided which is connected via a signal line 26 to the combined output of the computer 12. It may be conceivable to temporarily further increase the supply lubricant.

Unlike the embodiment according to FIG. 1 described above, the embodiment according to FIG. 4 shows not the sulfur content of the fuel directly measured, but a parameter that is affected by the sulfur content of the fuel and can be detected in the lubricating oil. In this way, a closed-loop control system is formed. In this case, the flow regulating device 11 is configured as a closed-loop control device.

A suitable parameter of this type is the neutralizing capacity, ie the neutralizer content, such as the calcium hydroxide content of the lubricant. In the technical field, the calcium hydroxide content per% by volume is expressed as basis number (BN). The BN value of the lubricating oil, that is, the neutralization ability according to calcium hydroxide, is reduced as a function of the sulfur content, ie, the acid content of the fuel supplied to the cylinder 1 as the lubricating oil passes through the reciprocating piston internal combustion engine. The interrelationship in this case is shown in FIG. The residual BN value that can be measured in the lubricating oil discharged from the cylinder 1 decreases as the sulfur content of the fuel supplied to the cylinder 1 increases, that is, the BN value further decreases as the sulfur content of the fuel increases. Thus, as shown in FIG. 6, there is also a constant correlation between the degree of wear and the residual BN content which can be measured in the lubricant discharged from the cylinder 1, ie the lubricant used. The higher the residual content, that is, the smaller the decrease in BN during passage through the cylinder 1, the less the degree of wear. Thus, a correlation similar to that shown in FIG. 2 is generated to reduce the BN value.

If the decrease in the BN value is directly dependent on the sulfur content of the fuel used, as described above, the lubricant consumption according to a certain acceptable degree of wear is in a similar relationship as shown in FIG. The greater the reduction in BN, the higher the lubricant consumption. Since lubricants generally used are relatively expensive, adjustments should always be made between the expected repair and lubricant costs. In addition, the aforementioned threshold of 50% is applied to the amounts necessary for extracting the normal consumption and impurities and maintaining proper fluid dynamics.

These thresholds are shown in FIG. 6 as BN ₁ and BN ₂ . Only in the region between BN ₁ and BN ₂ it is important to vary the amount of lubricating oil supplied to the cylinder 1 as a function of the residual BN content of the used lubricant. Although the degree of wear is very weak above BN ₂ , the amount of lubricating oil required is so high that it is of no economic interest when considering lubricating oil costs. Below BN ₁ , the lubricant flow rate is so low that impurities on the cylinder running surface are no longer transported and the hydrodynamic lubrication state can no longer be maintained. Therefore, the BN value should not fall below the BN ₁ value.

Thus, the computer 12 is programmed such that the predetermined value BN _S resulting from the above trade-off between repair and lubricant costs is selected in the range between BN ₁ and BN ₂ . The value is compared by computer 12 with the residual BN content actually measured in the lubricant used. If the difference is large, that is, if the measured residual BN value is less than or equal to the selected value BN _S , it is necessary to increase the lubricating oil supply to the cylinder 1 or vice versa. This relationship is illustrated in FIG. 7 and programmed into the computer 12 as shown in FIG. 4.

The residual BN content in the used lubricating oil is continuously monitored and compared by the computer 12 with the BN value of the unused lubricating oil, thereby reducing the BN while the lubricating oil passes through the reciprocating piston internal combustion engine. In order to measure the residual BN content, at least one sensor 30 is provided in the extraction tube 10, which is connected to the combined input 32 of the computer 12 via a combined signal line 31. .

Instead of a sensor 30 provided downstream of the mouse 10a of the connector 10a, a corresponding sensor 30 is conveniently provided in each connector 10a region so that the residual BN content is recorded, and the sensor 30 is 4 is connected to each coupled input of the computer 12, as indicated by the dotted signal lines extending from the sensor 30 arranged in the connector 10a. In this way, the BN reduction of each cylinder 1 can be measured separately.

The BN value of the unused lubricant is generally known and can be supplied to the computer 12 via a suitable input 33. In the example of FIG. 4, the BN value of the lubricating oil which is not used is also measured continuously. For this purpose, a sensor 34 is provided in the supply pipe 9 upstream of the tap pipe 9a. The sensor 34 is connected via the combined signal line 35 to the combined input of the computer 12, in this case the input 33 described above.

Since the BN reduction is individually measured for each cylinder 1, the advantage is that the lubricant supplied to the cylinder 1 can also be changed individually. Thus, the flow regulating member 13 is individually connected to the respective combined outputs of the computer 12 via the combined signal lines 14, as shown in FIG.

Since the above description about the BN value and the residual BN value also applies to other neutralizing agent content or residual content, it is generally applied to the neutralizing capacity and the residual capacity of the lubricating oil. In each case, the neutralization capacity is thought to be reduced as a function of the sulfur content of the fuel as it passes through the engine, whereby the reduction can be considered to correlate with the sulfur content.

In order to monitor the overall wear, the iron content in the lubricating oil used is also combined with the combined signal line 26 and the sensor 22 with the computer input 24 coupled with the combined signal line 23 described above and shown in FIG. Can be monitored by an excitation alarm device 25.

The invention can be used to determine the actual wear which the iron content of the lubricating oil can be continuously monitored and the wear protection of the lubricating oil supply can be compared as a function of the sulfur content of the fuel, which alerts in case of leakage. Can ring. In this regard, in addition to the sulfur content of the supplied fuel, there may be other sources of wear that may occur from time to time, such as, for example, water infiltration and contamination of the injected air with sand particles and / or wear particles from the fuel. have. It is an advantage that in this case, by alerting in advance, other causes of wear can be recognized in advance, so that remedial measures can also be taken in advance, so that the remedy can attain particularly high levels of safety.

Claims (17)

In a method of operating a reciprocating piston internal combustion engine, more particularly a large two-stroke diesel engine, supplied with fuel and lubricant to a cylinder, The amount of lubricating oil supplied to each cylinder fluctuates in the same direction as the fluctuation of sulfur content by using the sulfur content of the supplied fuel as a direct and indirect function. Way. The method of claim 1, The amount of lubricating oil supplied to each cylinder fluctuates in the same direction as the load as a function of the load acting on the reciprocating piston internal combustion engine, The lubricating oil amount associated with each load varies in the same direction as the sulfur content by using the sulfur content of the supplied fuel as a direct and indirect function. Way. The method according to claim 1 or 2, Regardless of the sulfur content and load of the fuel supplied, the amount of lubricating oil supplied is not reduced below the minimum required to extract impurities. The method according to any one of claims 1 to 3, Regardless of the sulfur content of the fuel supplied, the amount of lubricating oil supplied does not increase beyond a maximum amount which is approximately 50% of the normal consumption associated with each load. The method according to any one of claims 1 to 4, The sulfur content of the supplied fuel is continuously measured, and the lubricating oil quantity varies as a function of the sulfur content. The method according to any one of claims 1 to 4, Influenced by the sulfur content of the supplied fuel, a parameter that can be detected in the lubricating oil used is continuously monitored, and the lubricating oil quantity varies as a function of the parameter. The method of claim 6, The neutralizing capacity of the lubricating oil, more specifically the decrease in the calcium hydroxide content, which occurs when the lubricating oil passes through the reciprocating piston internal combustion engine is continuously measured, and the lubricating oil amount is increased or decreased as a function of the calcium hydroxide content. Way. The method according to any one of claims 1 to 7, The iron content of the used lubricant is continuously monitored and the actual wear compared to the allowable level of wear is measured according to the iron content and an alarm is sounded if the deviation is out of tolerance. The method of claim 8, The iron content of the already used lubricant and / or the calcium hydroxide reduction of the lubricant which occurs when the lubricant passes through the reciprocating piston internal combustion engine is monitored separately in each cylinder and the amount of lubricant supplied to each cylinder varies individually. . A fuel supply device (3) comprising a fuel pipe (5) and a lubricating oil supply device comprising a supply pipe (9) and an extraction pipe (10), which carry out the method according to any one of claims 1-9. In a reciprocating piston internal combustion engine with at least one cylinder 1 in combination with 7), more particularly in a large two-stroke diesel engine, The flow rate adjusting device 11 is combined with the lubricating oil supply device 7, By the flow rate adjusting device, the amount of lubricating oil that can be supplied to each cylinder 1 can be varied in the same direction as the variation of the sulfur content by using the sulfur content of the supplied fuel as a direct or indirect function. Reciprocating piston internal combustion engine. The method of claim 10, The flow regulating device 11 is composed of an automatic open-loop control device or an automatic closed-loop control device, The flow regulating device is a programmable computer 12 and / or alarm device having a signal input coupled with an actual value and an output for at least one flow regulating member arranged in the lubricating oil supply pipe 9 upstream of the cylinder 1. A reciprocating piston internal combustion engine comprising 25). The method of claim 11, The computer 12 includes a signal input 15 corresponding to a load acting on the reciprocating piston internal combustion engine, the lubricating oil corresponding to the load being programmed to vary individually as a function of the sulfur content of the supplied fuel. Reciprocating piston internal combustion engine. The method according to claim 11 or 12, wherein The fuel supply device 3 comprises a plurality of tanks 4a and 4b which are supplied with different fuels and which can be connected to the fuel pipe 5 alternately by the selection device 6, The reservoir 16 for the sulfur content value of all fuels is combined with a computer 12, which preferably includes an input for signals of the selection device 6, The computer (12) is a reciprocating piston internal combustion engine that is programmed to be used when the stored value corresponding to each of the supplied fuel changes the lubricating oil flow rate. The method according to any one of claims 10 to 12, The fuel pipe (5) region is provided with a sensor (19) for measuring the sulfur content of the supplied fuel and supplying its output signal to the computer (12). The method according to any one of claims 10 to 12, The lubricating oil extraction pipe 10 is provided with at least one sensor 30 for measuring a parameter affected by the sulfur content of the supplied fuel, The output signal of the sensor 30 compares the parameter value measured downstream of the reciprocating piston internal combustion engine with the same parameter value of the unused lubricating oil so as to function the difference in the amount of lubricating oil supplied to the cylinder 1 as a function. A reciprocating piston internal combustion engine supplied to the computer 12 to be varied. The method according to any one of claims 10 to 15, The lubricating oil extraction pipe 10 measures the iron content of the lubricating oil and measures its degree of wear according to the iron content of the lubricating oil used, and compares it with the allowable wear level, and if it is out of the allowable deviation, an alarm device ( A reciprocating piston internal combustion engine supplied to a computer 12 for operating 25). The method according to claim 15 or 16, A parameter sensor 30 and / or an iron content sensor 22, which are affected by the sulfur content of the fuel, is combined with each connecting tube 10a of the extraction tube 10 away from each cylinder 1, The amount of lubricating oil that can be supplied to each cylinder (1) is individually calculated and adjustable by the computer (12).