A test device and test method for lubricating oil coking

Abstract

The application discloses a kind of lubricating oil coking carbon deposition test device and test method, including flame jet module, temperature control module and injection module;The flame jet module simulates in-cylinder combustion scene, and the lubricating oil of carbon deposition piece on carbon deposition plate is baked at preset flame temperature, and flame jet can be adjusted under the action of bracket along three directions of xyz axis Flame jet direction;The heating furnace in the temperature control module is used to simulate the high-temperature environment in the cylinder of diesel engine, and the carbon deposition plate is processed with multiple carbon deposition grooves, one test carbon deposition piece is placed in each carbon deposition groove, the first temperature sensor is located above the carbon deposition plate for measuring the high-temperature gas temperature of lubricating oil combustion, and the second temperature sensor is located inside the carbon deposition plate for measuring the temperature of the carbon deposition plate;Using the test method, the carbon deposition piece under different flame temperature of different flame section under the same heating plate temperature can be obtained to observe the coking carbon deposition state of lubricating oil.

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 diesel engine cylinders. This mixture firmly adheres to and accumulates on components such as the cylinder head, valves and injectors, pistons, piston rings, cylinder liners, and exhaust pipes, affecting the proper operation of the diesel engine and causing a reduction in power. Because the coking state of lubricating oil in the cylinder of a diesel engine cannot be directly observed during operation, platform testing is required to study the coking process of lubricating oil in the cylinder.

[0003] CN107525911B discloses a test bench and testing method for simulating the formation of oil carbon deposits. The test bench includes a heating device, an oil dripping device, an oil drop counter, an oil recovery device, and an oil fume treatment device. The test bench can quantify the amount of oil dripped during the test, thereby quantitatively comparing the amount of carbon deposits generated by different oils. It can also accurately and intuitively observe the heating temperature when the oil carbon deposits form and adjust the flow rate of the oil on the aluminum foil during the test. Summary of the Invention

[0004] The purpose of the present invention is to provide a testing device and 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 at different flame sections and different flame temperatures under the same heating plate temperature can be tested synchronously to observe the coking and carbon deposition status of the lubricating oil.

[0005] The purpose 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 scenario and includes a flame injector and a bracket. The flame injector can adjust the fuel equivalence ratio to bake the lubricating oil on the carbon deposited plate at a preset flame temperature. The flame injector can also arbitrarily adjust the flame injection direction along the xyz axis under the action of the bracket.

[0008] The temperature control module includes 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 diesel engine cylinder, 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 piece is placed in each carbon deposition groove, so that a single test can realize the effect of different flame section temperatures on lubricating oil coking and carbon deposition; each first temperature sensor is located above each carbon deposition piece and is used to measure the high-temperature gas temperature of lubricating oil combustion, and the first temperature sensor can contact the carbon deposition piece and its contact is exposed to the air, and the second temperature sensor is located inside the carbon deposition plate and is used 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 piece 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 plate is slightly concave to better accommodate lubricating oil; particularly preferably, the concave of the carbon deposition plate is 0.027mm -1 curvature.

[0012] Furthermore, 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, there is a heating base plate on the top of the heating furnace, the heating base 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 a first weight of the carbon deposit sheet to be tested after removing water;

[0017] During the test, the flamethrower bracket was adjusted as required to adjust the XYZ axis position of the flamethrower so that the flame ejected by the flamethrower formed an angle of 30°-45° with the horizontal plane. The flamethrower 3 was rotated at preset intervals to eject each carbon deposit piece. The flamethrower sprayed a 1000-1200°C flame onto the carbon deposit piece to simulate the combustion scene in the cylinder. At the same time, the heating base plate heated the top surface of the carbon deposit piece to 500-600°C to simulate the high temperature environment in the diesel engine cylinder. The carbon deposit pieces were obtained at different flame sections and different flame temperatures at the same heating plate temperature to observe the coking and carbon deposition status of the lubricating oil.

[0018] The cooled coked carbon deposit 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 deposit. The first weight and the third weight are subtracted to simultaneously obtain the carbon deposit weight of each carbon deposit sheet at different flame sections and different flame temperatures.

[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 deposit grooves are provided on the carbon deposit plate. Therefore, the carbon deposit sheet under different flame sections and different flame temperatures can be tested simultaneously under the same heating plate temperature to observe the coking and carbon deposition status of the lubricating oil.

[0021] The flamethrower 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 test requirements to adjust the position of the flamethrower XYZ axis, thereby obtaining the coking state under different flame sections in one test. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is 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 Schematic diagram of the structure of the flamethrower bracket.

[0026] In the picture:

[0027] 1: temperature controller; 21: first temperature sensor; 22: second temperature sensor; 3: flamethrower;

[0028] 4: Carbon deposition plate; 5: Heating furnace; 6: Heating base plate; 7: Injection pipe; 8: Moving device; 9: Injection pump;

[0029] 10: Carbon deposit groove; 11: First carbon deposit piece; 12: Second carbon deposit piece; 13: Third carbon deposit piece. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions, beneficial effects and significant improvements of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are 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.

[0031] 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 tank for combustion.

[0032] The flame spray module includes a flame sprayer and a flame sprayer bracket. The fuel in the flame sprayer is methane. A methane gas tank is connected to the flame sprayer through a pipeline. The flame sprayer 3 is used to spray the lubricating oil on the carbon deposited sheet 4 with flames. The flame sprayer bracket can arbitrarily adjust the position of the flame spray in the three directions of the xyz axis, thereby controlling the distance between the flame and the lubricating oil film. The flame sprayer bracket is a mechanical XYZ three-axis adjustment device. As long as the xyz axis direction can be adjusted mechanically, the actual structure is not limited. As an example, Figure 3 As shown, the flamethrower bracket includes a base, on which is mounted a vertical column perpendicular to the base. The column can slide along the length of the base (i.e., the X-axis) and be fixed at any position along the length, thereby enabling the flamethrower to move along the X-axis. A first slider is mounted on the upper portion of the column. The first slider is fixedly connected to one end of a crossbar, which is parallel to the base and perpendicular to the column. The first slider can slide up and down along the column and rotate circumferentially along the column and be fixed at any position along the column, thereby enabling the flamethrower to move along the Y-axis and Z-axis. The other end of the crossbar is fixedly connected to a flamethrower 3, which can move along the length of the crossbar, i.e., along the X-axis. The flamethrower 3 is located on the flamethrower bracket, with its nozzle facing the carbon deposition plate 4. The flamethrower 3 can adjust the fuel equivalence ratio, thereby controlling the flame temperature to a certain extent.

[0033] 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 2 The carbon plate 4 is a 15mm thick metal sheet simulating an engine block. Its top surface is machined with an inward groove, 5mm deep. Within the groove are multiple circular carbon deposit grooves 10, each 3-5mm deep. These grooves contain 30mm micro-concave carbon deposit sheets for directional lubricant dripping. The size of these carbon deposit sheets is less than or equal to the inner diameter of the carbon deposit grooves 10. The first and second temperature sensors 21, 22 are K-type thermocouple temperature sensors connected to the temperature controller 1. Each first temperature sensor 21 at least partially contacts the top of each carbon deposit sheet to measure the high-temperature gas temperature of the lubricant combustion in each sheet, with its contacts exposed to air. The second temperature sensor 22 is located within the carbon plate 4 (through a punched hole placed in the middle of the plate). Since the second temperature sensor 22 measures the temperature of the carbon plate, and the heating temperature of each position on the carbon plate in the heating furnace is the same, only one second temperature sensor is required. The flame from the flamethrower 3 sprays the upper surface of the carbon plate 4 at an angle of 30-45° (i.e., the angle between the injector's position and a plane parallel to the horizontal plane). The lower surface is located on the top surface of the heating base plate 6 of the heating furnace 5. A 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 plate to the temperature controller 1. A second temperature sensor 22 is used to measure and transmit the internal temperature of the carbon plate 4 (i.e., the temperature received by the electric heating furnace) to the temperature controller 1. The heating furnace 5 is topped with a heating base plate 6 made of far-infrared microcrystalline and with a heating temperature of 100-600°C. The carbon plate 4 is placed on top of the heating base plate 6, simulating the high-temperature environment inside a diesel engine cylinder to heat the bottom of the carbon plate. The temperature controller 1 adjusts the flame spray module, heating furnace power, and injection module based on the upper and internal carbon plate temperatures transmitted by temperature sensors 21 and 22.

[0034] The injection module includes a moving device 8 and an injection pump 9. The moving device 8 is a slide. 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 slide 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.

[0035] The testing method of the lubricating oil coking and carbon deposition testing device includes:

[0036] Step 1: Preparing

[0037] 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 using the injection pump 9; the flamethrower 3 is mounted on the flamethrower bracket, and the position of the XYZ axis of the flamethrower bracket is adjusted so that the nozzle of the flamethrower 3 is at a 30° angle to 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, a 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, a 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 furnace is preheated to a preset temperature of 580°C;

[0038] Step 2: Testing phase

[0039] A flame injector 3 is used to spray a 1200°C flame onto the carbon deposit 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 deposit 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 deposit pieces from right to left in sequence (i.e., from the third carbon deposit piece 13 to the position of the first carbon deposit piece 11), and finally the injector is tilted to 45°. The flame injector sprays from the right side at a direction of 30-45° to the leftmost carbon deposit groove of the carbon deposit flat 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 deposit plate 4 to the temperature controller 1; the flame temperature or the temperature of the electric 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 deposit plate 4 under the test conditions, and obtain the test flame temperature and the carbon deposit plate 4 with coking of the lubricating oil at the carbon deposit plate temperature.

[0040] According to the test, the flamethrower was fired at a 30-45° angle from the Figure 2 The third carbon deposit sheet 13 on the right side of the carbon plate is sprayed onto the first carbon deposit sheet 11 on the far left of the carbon plate. This demonstrates the effect of different flame temperatures in different flame sections on lubricant coking and carbon deposition. The coking state at different flame temperatures is tested at the same heating plate temperature. Each carbon deposit groove is 5 mm apart. The temperatures measured by the three first temperature sensors represent the high-temperature gas temperatures of the lubricant combustion in different sections. The right side has the highest temperature, the middle has the second highest temperature, and the left side has the lowest temperature.

[0041] Step three: Carbon deposit amount calculation

[0042] After heating for a period of time, the oil film will generate soluble and insoluble solids, and the coke plate 4 is cooled and weighed to obtain the second weight m2 (using an analytical balance, the mass accuracy is 0.00001g), at this time the second weight m2 itself is not all carbon deposit, but also other substances except carbon deposit;

[0043] The cooled coke plate 4 is soaked in pure n-heptane for 12 hours, then dried and weighed again to obtain the third weight m3 of the remaining solid product, at this time the third weight m3 is the weight of the carbon deposit plate 4 plus the carbon deposit; Then execute:

[0044] m3-m1= weight of carbon deposit

[0045] The obtained carbon deposit mass is accurate, and the high-temperature gas temperature of the lubricating oil combustion and the carbon deposit plate temperature under different conditions are recorded by the first and second temperature sensors, so that the lubricating oil coking state is established with the wall temperature and the flame temperature, thereby providing important support for reducing the related improvement design of the lubricating oil coking carbon deposit in the diesel engine cylinder.

[0046] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it. Although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features, 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 application. The non-essential improvements and adjustments or replacements made by those skilled in the art according to the content of the present application are within the scope of the present application.

Claims

1. A testing device for lubricating oil coking and carbon deposition, characterized in that: Includes flame spray module, temperature control module and injection module; The flame injection module simulates the combustion scene in the cylinder, and includes a flame injector and a bracket thereof. The flame injector 3 can adjust the equivalence ratio of the fuel and bake the lubricating oil of the carbon deposit sheet on the carbon deposit plate (4) at a preset flame temperature. 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 processed in the groove, and a test carbon deposition piece 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 first temperature sensor (21) is located above each carbon deposition piece and is used to measure the high temperature gas temperature of lubricating oil combustion, and the first temperature sensor can contact the carbon deposition piece and its contact is exposed to 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 heating furnace power 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 for dripping 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 tank (10), and is capable of controlling the dripping acceleration to calculate the amount of dripping, thereby ensuring that the oil film thickness 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 lubricating oil coking and carbon deposition testing device 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 lubricating oil coking and carbon deposition testing device 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: A heating base plate (6) is provided on the top of the heating furnace (5). The heating base plate (6) is made of far-infrared microcrystals, and the heating temperature is 100-600°C.

7. The lubricating oil coking and carbon deposition testing device according to claim 1, characterized in that: The flame of the flame injector (3) is sprayed onto the upper surface of the carbon deposition 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 a 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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