Device and method for testing coking and carbon deposition of lubricating oil

Abstract

The invention discloses a device and a method for testing coking and carbon deposition of lubricating oil. The device comprises a flame jet module, a temperature control module and an injection module, the flame jetting module simulates a combustion scene in a cylinder, lubricating oil of a carbon deposition sheet on a carbon deposition plate is baked at a preset flame temperature, and a flame jetting device can adjust the jetting direction of flames in the x-axis direction, the y-axis direction and the z-axis direction under the action of a support. A heating furnace in the temperature control module is used for simulating a high-temperature environment in a diesel engine cylinder, a plurality of carbon deposition grooves are machined in a carbon deposition plate, a carbon deposition sheet for testing is placed in each carbon deposition groove, and a first temperature sensor is located above the carbon deposition plate and used for measuring the temperature of high-temperature fuel gas generated by combustion of lubricating oil. The second temperature sensor is located in the carbon deposition plate and used for measuring the temperature of the carbon deposition plate. By utilizing the testing method, the carbon deposition plate at the same heating plate temperature and different flame temperatures in different flame sections can be obtained, so that the coking and carbon deposition state of the lubricating oil can be observed.

Description

Technical Field

[0001] The invention belongs to the field of engine testing, and in particular relates to a testing device and a testing method for lubricating oil coking and carbon deposition. Background Art

[0002] Carbon deposits are a mixture of asphalt, oil coke and carbon formed by incomplete combustion of fuel and lubricating oil in the cylinder of a diesel engine. These mixtures firmly adhere to and accumulate on parts such as the cylinder head, valves and injectors, pistons, piston rings, cylinder liners, exhaust pipes, etc., affecting the normal operation of the diesel engine and causing its power to drop. Since the coking state of the lubricating oil in the cylinder cannot be directly observed when the diesel engine is working, it is necessary to study the coking process of the lubricating oil in the cylinder through platform testing methods.

[0003] CN107525911B discloses a test bench and a test method for simulating the generation of carbon deposits in engine oil. The test bench for simulating the generation of carbon deposits in engine oil includes a heating device, an engine oil dripping device, an oil drop counter, an engine oil recovery device, and an oil fume treatment device. The test bench can quantify the amount of engine oil dripping in the test, thereby quantitatively comparing the amount of carbon deposits generated by different engine oils, accurately and intuitively observing the heating temperature when the engine oil generates carbon deposits, and adjusting the flow rate of the engine oil on the aluminum foil in the test. Summary of the invention

[0004] The purpose of the present invention is to provide a testing device and a testing method for lubricating oil coking and carbon deposition. The testing device has a simple structure. The flame of the injection module simulates the combustion scene in the cylinder, the temperature control module simulates the high temperature environment in the diesel engine cylinder, and multiple carbon deposition grooves are arranged on the carbon deposition plate, so that the carbon deposition sheets under different flame temperatures in different flame sections at the same heating plate temperature can be tested synchronously to observe the coking and carbon deposition state of the lubricating oil.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A testing device for lubricating oil coking and carbon deposition, comprising a flame spray module, a temperature control module and an injection module;

[0007] The flame injection module simulates the in-cylinder combustion scene, and includes a flame injector and a bracket thereof. The flame injector can adjust the fuel equivalence ratio, bake the lubricating oil of the carbon deposited sheet on the carbon deposited plate at a preset flame temperature, and the flame injector can arbitrarily adjust the injection direction of the flame along the three directions of the xyz axis under the action of the bracket;

[0008] The temperature control module comprises a temperature controller, a heating furnace, a carbon deposition plate, a plurality of first temperature sensors and a second temperature sensor; the heating furnace is used to simulate the high temperature environment in the cylinder of a diesel engine, the carbon deposition plate is placed on the top of the heating furnace, and the carbon deposition plate is processed with an inward groove, and the groove is also processed with a plurality of carbon deposition grooves, and a test carbon deposition sheet is placed in each carbon deposition groove, so that one test can realize the influence of different flame section temperatures on the coking and carbon deposition of lubricating oil; each of the first temperature sensors is located above each carbon deposition sheet to measure the temperature of the high-temperature fuel gas of the combustion of the lubricating oil, and the first temperature sensor can contact the carbon deposition sheet and its contact is exposed to the air, and the second temperature sensor is located inside the carbon deposition plate to measure the temperature of the carbon deposition plate; the temperature controller is used to adjust the position and angle of the flame injection module and the power of the heating furnace according to the upper surface and internal temperature of the carbon deposition sheet transmitted in real time by the first temperature sensor and the second temperature sensor;

[0009] The injection module is used to drip lubricating oil into the carbon deposit groove, and includes a moving device and an injection pump. The moving device is arranged on the side wall of the heating furnace along the length direction of the heating furnace. The injection pump is slidably connected to the moving device, and the injection port of the injection pump can slide along the length direction of the heating furnace. The injection pump is used to provide lubricating oil to the designated carbon deposit groove, and can control the dripping acceleration to calculate the dripping amount, thereby ensuring that the oil film thickness is controllable.

[0010] Furthermore, the carbon deposition groove in the carbon deposition plate is a circular groove with a depth of 3-5 mm.

[0011] Preferably, the carbon deposition plate is provided with 3-4 carbon deposition grooves, and the carbon deposition grooves are arranged side by side; particularly preferably, the upper surface of the carbon deposition sheet is slightly concave to better accommodate lubricating oil; particularly preferably, the concave of the carbon deposition sheet is 0.027mm -1 Curvature.

[0012] Further, the first temperature sensor and the second temperature sensor are K-type thermocouple temperature sensors, and are respectively connected to the temperature controller;

[0013] Furthermore, a heating bottom plate is provided on the top of the heating furnace, the heating bottom plate is made of far-infrared microcrystals, and the heating temperature is 100-600°C.

[0014] Furthermore, the flame of the flamethrower is sprayed onto the upper surface of the carbon deposited plate at an angle of 30-45 degrees.

[0015] The testing method of the lubricating oil coking and carbon deposition testing device comprises:

[0016] Obtaining in advance the first weight of the carbon deposit sheet to be tested after removing water;

[0017] During the test, the flamethrower bracket is adjusted as required to adjust the XYZ axis position of the flamethrower, so that the flame sprayed by the flamethrower forms an angle of 30°-45° with the horizontal plane, and the flamethrower 3 is rotated at a preset interval to spray each carbon deposit sheet; the flamethrower sprays a 1000-1200°C flame to the carbon deposit sheet to simulate the combustion scene in the cylinder, and at the same time, the bottom plate is heated to heat the top surface of the carbon deposit sheet at a temperature of 500-600°C to simulate the high temperature environment in the diesel engine cylinder; the carbon deposit sheets at different flame temperatures in different flame sections under the same heating plate temperature are obtained to observe the coking and carbon deposition state of the lubricating oil;

[0018] The cooled coked carbon deposited plate is soaked in pure n-heptane for 12 hours and then dried. The remaining solid product is weighed to obtain the third weight of the carbon deposits. The first weight is subtracted from the third weight to simultaneously obtain the carbon deposit weight of each carbon deposited sheet at different flame temperatures in different flame sections.

[0019] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0020] The test device of the present invention has a simple structure. The flame of the injection module simulates the combustion scene in the cylinder, the temperature control module simulates the high temperature environment in the diesel engine cylinder, and multiple carbon deposition grooves are arranged on the carbon deposition plate, so that the carbon deposition sheets at different flame temperatures in different flame sections under the same heating plate temperature can be tested synchronously to observe the coking and carbon deposition state of the lubricating oil.

[0021] The flame injector in the test device can adjust the fuel equivalence ratio and the flame temperature according to the test requirements;

[0022] The testing method can adjust the flamethrower support according to the testing requirements to adjust the position of the flamethrower XYZ axis so as to obtain the coking state under different flame sections in one test. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A structural diagram of a testing device for lubricating oil coking and carbon deposition according to the present invention;

[0024] Figure 2 is a schematic diagram of the carbon deposition plate;

[0025] Figure 3 It is a structural schematic diagram of the flamethrower bracket. In the figure: 1: temperature controller; 21: first temperature sensor; 22: second temperature sensor; 3: flamethrower; 4: Carbon deposition plate; 5: Heating furnace; 6: Heating bottom plate; 7: Injection pipe; 8: Moving device; 9: Injection pump; 10: carbon deposit groove; 11: first carbon deposit sheet; 12: second carbon deposit sheet; 13: third carbon deposit sheet. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution, beneficial effects and significant progress of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described below in conjunction with the drawings provided in the examples of the present invention. Obviously, all the described embodiments are only partial embodiments of the present invention, rather than all embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] like Figure 1 As shown, a testing device for lubricating oil coking and carbon deposition includes a flame spray module, a temperature control module and an injection module. The flame spray module simulates the combustion scene in the cylinder, the temperature control module simulates the high temperature environment in the diesel engine cylinder, and the injection module drips lubricating oil on the carbon deposition groove to burn.

[0028] The flame spray module includes a flamethrower and a flamethrower bracket. The fuel in the flamethrower is methane. A methane gas tank is connected to the flamethrower through a pipeline. The flamethrower 3 is used to spray the lubricating oil on the carbon deposited sheet 4 to bake the carbon deposited sheet with flame. The flamethrower bracket can arbitrarily adjust the position of the flame spray in the three directions of the xyz axis, so as to control the distance between the flame and the lubricating oil film. The flamethrower bracket is a mechanical XYZ three-axis adjustment device. As long as the xyz axis direction can be adjusted mechanically, there is no limitation on the actual structure. As an example, Figure 3 As shown, the flamethrower bracket includes a base, a column perpendicular to the base is arranged on the base, and the column can slide along the length direction of the base (i.e., the X-axis direction) and be fixed at any position in the length direction, so that the flamethrower moves along the X-axis direction; a first slider is arranged on the upper part of the column, the first slider is fixedly connected to one end of a crossbar, so that the crossbar is parallel to the base and perpendicular to the column, the first slider can slide up and down along the column and rotate along the circumference of the column and be fixed at any position of the column, so that the flamethrower can move along the Y-axis and Z-axis directions; the other end of the crossbar is fixedly connected to a flamethrower 3, and the flamethrower 3 can move along the length direction of the crossbar, that is, move along the X-axis direction. The flamethrower 3 is located on the flamethrower bracket and the flamethrower's injection port faces the carbon deposition plate 4. The flamethrower 3 can adjust the equivalent ratio of the fuel and control the temperature of the flame to a certain extent.

[0029] The temperature control module includes a temperature controller 1, a heating furnace 5, a carbon deposition plate 4, a plurality of first temperature sensors 21 and a second temperature sensor 22; Figure 2The carbon deposition plate 4 shown is a metal sheet simulating an engine cylinder block, with a thickness of 15 mm, and an inward groove processed on its upper surface, the groove depth of which is 5 mm, and a plurality of circular carbon deposition grooves 10 with a depth of 3-5 mm are also processed in the groove, and a 30 mm micro-concave carbon deposition sheet is placed inside for directional dripping of lubricating oil, and the size of the carbon deposition sheet is less than or equal to the inner diameter of the carbon deposition groove 10. The first temperature sensor 21 and the second temperature sensor 22 are k-type thermocouple temperature sensors, which are connected to the temperature controller 1, and each first temperature sensor 21 at least partially contacts the top of each carbon deposition sheet to measure the high-temperature gas temperature of the lubricating oil combustion of each carbon deposition sheet, and the contact of the first temperature sensor is exposed to the air; the second temperature sensor 22 is located inside the carbon deposition plate 4 (put into the middle position of the carbon deposition plate by punching a hole), because the second temperature sensor 22 measures the temperature of the carbon deposition plate, and the heating temperature of each position of the carbon deposition plate on the heating furnace is the same, so only one second temperature sensor is required. The flame of the flame injector 3 is injected at an angle of 30-45° (i.e., the angle between the position of the injector and the plane parallel to the horizontal plane) onto the upper surface of the carbon deposition plate 4, and the lower surface is located on the top surface of the heating bottom plate 6 of the heating furnace 5. The first temperature sensor 21 is used to measure and transmit the temperature of the high-temperature gas burning above the upper lubricating oil of each carbon deposition plate to the temperature controller 1, and the second temperature sensor 22 is used to measure and transmit the internal temperature of the carbon deposition plate 4 (i.e., the temperature of the electric heating furnace received) to the temperature controller 1. The heating bottom plate 6 is provided on the top of the heating furnace 5. The heating bottom plate 6 is made of far-infrared microcrystals, and the heating temperature is 100-600°C. The carbon deposition plate 4 is placed on the top surface of the heating bottom plate 6, so as to simulate the high-temperature environment in the diesel engine cylinder to heat the bottom of the carbon deposition plate. The temperature controller 1 adjusts the flame injection module, the heating furnace power and the injection module according to the upper surface and internal temperature of the carbon deposition plate transmitted by the temperature sensors 21 and 22.

[0030] The injection module includes a moving device 8 and an injection pump 9. The moving device 8 is a slideway. The sliding device 8 is fixed on the side wall of the heating furnace and extends a certain distance from the end of the heating furnace. The injection pump 9 has a slider at the bottom that can slide along the slideway of the moving device 8. The injection port of the injection pump 9 has an injection pipe extending from the injection port. When in use, as needed, the injection pump 9 is slid along the moving device 8 so that the outlet of the injection pipe 7 is aligned with the carbon deposition groove 10 of the carbon deposition plate 4 to be dripped. The injection pump 9 is used to provide lubricating oil, and the lubricating oil is dripped into the carbon deposition groove 10 of the carbon deposition plate, and the injection pump 9 can control the dripping speed to calculate the dripping amount, thereby ensuring that the oil film thickness is controllable.

[0031] The testing method of the lubricating oil coking and carbon deposition testing device comprises:

[0032] Step 1: Preparing

[0033] Place the three slightly concave carbon deposits in a drying oven at 150°C for 5 minutes to remove moisture, and then weigh them to obtain the first weight m1 of the three carbon deposits as the weight of the carbon deposits; place the carbon deposit plate 4 on the heating bottom plate 6 at the top of the heating furnace 5, as shown in FIG. Figure 2 As shown, the first carbon deposition sheet 11, the second carbon deposition sheet 12 and the third carbon deposition sheet 13 are placed in the corresponding carbon deposition grooves from left to right; 0.05 ml of lubricating oil is dripped onto the carbon deposition sheets on the carbon deposition groove of the carbon deposition plate 4 one by one by using the injection pump 9; the flame injector 3 is mounted on the flame injector bracket, and the position of the XYZ axis of the flame injector bracket is adjusted, so that the injection port of the flame injector 3 is at an angle of 30° with the third carbon deposition sheet 13 on the carbon deposition plate 4 and the vertical distance from the carbon deposition plate 4 is about 0.3 m; the flame is best sprayed on the third carbon deposition sheet 13 on the far right; at the same time, the first temperature sensor 21 is arranged above each carbon deposition sheet and at least part of the first temperature sensor 21 contacts the lubricating oil on the carbon deposition sheet, the second temperature sensor 22 is arranged inside the carbon deposition plate 4, and each temperature sensor is connected to the temperature controller 1; the electric heating furnace is preheated to a preset temperature of 580°C;

[0034] Step 2: Testing Phase

[0035] A flame injector 3 is used to spray a 1200°C flame onto the carbon deposition plate 4 to simulate the combustion scene in the cylinder, and at the same time, the bottom plate 6 is heated to 500°C to heat the top surface of the carbon deposition plate 4 to simulate the high temperature environment in the diesel engine cylinder; the angle of the injection port of the flame injector 3 is rotated at intervals of thirty seconds (i.e., adjusted along the Z-axis direction) to spray the carbon deposition plates from right to left in sequence (i.e., from the third carbon deposition plate 13 to the position of the first carbon deposition plate 11), and finally the injector is tilted to 45°, and the flame injector sprays from the right side surface at a direction of 30-45° to the leftmost carbon deposition groove of the carbon deposition plate, and the first temperature sensor 21 and the second temperature sensor 22 transmit the monitored high-temperature gas temperature of the lubricating oil combustion and the temperature of the carbon deposition plate 4 to the temperature controller 1; the flame temperature or the temperature of the electric heating furnace is adjusted according to the test needs, and the first and second temperature sensors record the high-temperature gas temperature of the lubricating oil combustion and the temperature of the carbon deposition plate 4 under the test conditions, and the carbon deposition plate 4 with coking of the lubricating oil under the test flame temperature and the carbon deposition plate temperature is obtained.

[0036] According to the test, the flamethrower was fired at a 30-45° angle from Figure 2 The third carbon deposition sheet 13 on the right is sprayed onto the first carbon deposition sheet 11 on the leftmost side of the carbon deposition plate to realize the influence of different flame temperatures in different flame sections on the coking and carbon deposition of lubricating oil, and test the coking state of different flame temperatures under the same heating plate temperature. The distance between each carbon deposition groove is 5mm, and the temperatures measured by the three first temperature sensors are the high-temperature gas temperatures of the lubricating oil combustion in different parts. The temperature on the right is the highest, the middle is the second, and the temperature on the left is the lowest.

[0037] Step 3: Calculation of carbon deposits

[0038] After heating for a period of time, the oil film will generate soluble substances and insoluble solids. After the coked carbon deposit plate 4 is cooled, it is weighed to obtain a second weight m2 (using an analytical balance with a mass accuracy of 0.00001g). At this time, the second weight m2 itself is not entirely carbon deposits, but also contains other substances besides carbon deposits.

[0039] After the coked carbon deposit plate 4 is cooled, it is soaked in pure n-heptane for 12 hours and then dried. The remaining solid product is weighed to obtain the third weight m3 of carbon deposits. At this time, the third weight m3 is the weight of the carbon deposit plate 4 plus the carbon deposits. Then, the following is executed:

[0040] m3-m1=weight of carbon deposits

[0041] The obtained carbon deposit quality is accurate, and the first and second temperature sensors are used to record the high-temperature gas temperature and the carbon deposit plate temperature of the lubricating oil combustion under different conditions. In this way, the coking state of the lubricating oil is linked to the wall temperature and the flame temperature, thereby providing important support for the related improved design to reduce the coking and carbon deposits of the lubricating oil in the diesel engine cylinder.

[0042] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. The non-essential improvements, adjustments or replacements made by those skilled in the art based on the contents of this specification are all within the scope of protection required by the present invention.

Claims

1. A testing device for lubricating oil coking and carbon deposition, characterized in that: It includes flame spray module, temperature control module and injection module; The flame injection module simulates the combustion scene in the cylinder, and comprises a flame injector and a bracket thereof. The flame injector 3 can adjust the equivalent ratio of the fuel, bake the lubricating oil of the carbon deposited sheet on the carbon deposited plate (4) at a preset flame temperature, and the flame injector can arbitrarily adjust the injection direction of the flame along the three directions of the xyz axis under the action of the bracket; The temperature control module comprises a temperature controller (1), a heating furnace (5), a carbon deposition plate (4), a plurality of first temperature sensors (21) and a second temperature sensor (22); the heating furnace (5) is used to simulate a high temperature environment in a diesel engine cylinder, the carbon deposition plate (4) is placed on the top of the heating furnace (5), and the carbon deposition plate (4) is processed with an inward groove, and a plurality of carbon deposition grooves (10) are also processed in the groove, and a carbon deposition sheet for testing is placed in each carbon deposition groove (10), so that one test can realize the influence of different flame section temperatures on lubricating oil coking and carbon deposition; each of the first temperature sensors (21) is located above each carbon deposition sheet and is used to measure the temperature of high-temperature fuel gas during lubricating oil combustion, and the first temperature sensor can contact the carbon deposition sheet and its contact is exposed to the air, and the second temperature sensor (22) is located inside the carbon deposition plate; the temperature controller (1) is used to adjust the position and angle of the flame injection module and the power of the heating furnace according to the upper surface and internal temperature of the carbon deposition plate (4) transmitted in real time by the first temperature sensor (21) and the second temperature sensor (22); The injection module is used to drip lubricating oil into the carbon deposition tank, and comprises a moving device (8) and an injection pump (9), wherein the moving device (8) is arranged on the side wall of the heating furnace along the length direction of the heating furnace, and the injection pump (9) is slidably connected to the moving device (8), so that the injection port of the injection pump can slide along the length direction of the heating furnace; The injection pump (9) is used to supply lubricating oil to the designated carbon deposition groove (10), and can control the dripping acceleration to calculate the amount of dripping, thereby ensuring that the thickness of the oil film is controllable.

2. The lubricating oil coking and carbon deposition testing device according to claim 1, characterized in that: The carbon deposition groove (10) in the carbon deposition plate (4) is a circular groove with a depth of 3-5 mm.

3. The testing device for lubricating oil coking and carbon deposition according to claim 2, characterized in that: The carbon deposition plate (4) is provided with 3-4 carbon deposition grooves (10), and the carbon deposition grooves (10) are arranged side by side.

4. The lubricating oil coking and carbon deposition testing device according to claim 3, characterized in that: The upper surface of the carbon deposit sheet is slightly concave.

5. The testing device for lubricating oil coking and carbon deposition according to claim 1, characterized in that: The first temperature sensor (21) and the second temperature sensor (22) are K-type thermocouple temperature sensors.

6. The lubricating oil coking and carbon deposition testing device according to claim 1, characterized in that: The top of the heating furnace (5) is provided with a heating bottom plate (6), the material of the heating bottom plate (6) is far-infrared microcrystals, and the heating temperature is 100-600°C.

7. The testing device for lubricating oil coking and carbon deposition according to claim 1, characterized in that: The flame of the flame injector (3) is sprayed onto the upper surface of the carbon deposited plate (4) at an angle of 30-45 degrees.

8. The testing method of the lubricating oil coking and carbon deposition testing device according to claim 1, comprising: Obtaining in advance the first weight of the carbon deposit sheet to be tested after removing water; During the test, the flamethrower bracket is adjusted as required to adjust the XYZ axis position of the flamethrower (3), so that the flame sprayed by the flamethrower (3) forms an angle of 30°-45° with the horizontal plane, and the flamethrower (3) is rotated at a preset time interval to spray each carbon deposit piece; the flamethrower (3) sprays a 1000-1200°C flame to the carbon deposit plate (4) to simulate the combustion scene in the cylinder, and at the same time, the heating base plate (6) heats the top surface of the carbon deposit plate (4) at a temperature of 500-600°C to simulate the high temperature environment in the diesel engine cylinder; the carbon deposit pieces at different flame temperatures in different flame sections under the same heating plate temperature are obtained to observe the coking and carbon deposition state of the lubricating oil; The cooled coked carbon deposit plate (4) is soaked in n-heptane for 12 hours and then dried. The remaining solid product is weighed to obtain the third weight of the carbon deposit. The first weight and the third weight are subtracted to simultaneously obtain the carbon deposit weight of each carbon deposit plate at different flame stages and different flame temperatures.

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