Methanol engine oil acid resistance testing device and testing method
By designing a testing device and method for the acid resistance of methanol engine oil, the problem of the lack of simulation devices in the existing technology is solved, and the corrosion and alkalinity decay of methanol engine oil in acidic environment are detected, providing an accurate laboratory testing method.
Patent Information
- Application Number
- CN202311216153.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-20
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2043-09-20
AI Technical Summary
Existing technologies lack simulation devices and performance testing methods for methanol engine oil operating conditions, and cannot effectively test the corrosion and alkali retention performance of methanol engine oil in acidic environments.
A device for testing the acid resistance of methanol engine oil was designed, including a sample tube, a thermocouple, and a bundle of test pieces. By simulating the internal temperature and air flow rate of an engine, the device detects the effects of combustion byproducts such as formic acid and water on methanol engine oil. Corrosion tests are conducted using lead, copper, tin, and phosphor bronze test pieces.
It enables accurate detection of the corrosion performance and base number degradation of methanol engine oil in acidic environments, provides a simple experimental method, can simulate actual working conditions in the laboratory, and provides targeted test results.
Smart Images
Figure CN119666708B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of engine oil testing technology, and relates to a device for testing the acid resistance of methanol engine oil. This invention also relates to a testing method using the device. Background Technology
[0002] Currently, the replacement of traditional fuels with new clean energy fuels has become an important trend. Methanol fuel, with its advantages such as wide availability, low production cost, strong anti-knock ability, and large latent heat of gasification, is expected to become one of the main clean energy sources in the future. Therefore, the application market prospects of methanol engine oil in the engine field are huge.
[0003] However, during engine operation, the mixture of combustion byproducts such as formic acid and water produced by methanol fuel combustion can easily cause corrosion of engine cylinder liners and piston rings, as well as affect the alkalinity retention performance of lubricating oil. Therefore, it is very necessary to analyze and study the acid resistance of methanol engine oil. However, current simulation devices for engine oil operating conditions and engine oil performance testing methods are still based on research on traditional fuels, and there are no simulation devices or performance testing methods specifically for methanol engine oil operating conditions. Therefore, traditional methods cannot objectively and effectively detect the metal corrosion and alkalinity retention performance degradation of oil after formic acid is mixed in. Summary of the Invention
[0004] The purpose of this invention is to provide a device for testing the acid resistance of methanol engine oil, which solves the problem of the lack of a device for simulating the operating conditions of methanol engine oil in the prior art.
[0005] Another object of the present invention is to provide a method for testing the acid resistance of methanol engine oil using the above-described apparatus.
[0006] The first technical solution adopted in this invention is a methanol engine oil acid resistance testing device, including a sample tube, an air tube and a thermocouple respectively disposed inside the sample tube, a sample tube cap disposed at the top of the sample tube, a condenser tube installed on the sample tube cap, a bundle of test pieces sleeved on the wall of the air tube, a connecting tube disposed at the top of the air tube, the connecting tube passing through the sample tube cap and connected to an air source device, and the thermocouple passing through the sample tube cap and connected to a power supply device.
[0007] The first technical solution of this invention is further characterized by:
[0008] The sample bundle includes a sleeve, and several hooks are evenly distributed around the outer wall of one end of the sleeve. Each hook does not contact the sample tube wall.
[0009] The second technical solution adopted in this invention is a method for testing the acid resistance of methanol engine oil, using a methanol engine oil acid resistance testing device, and the specific method is as follows:
[0010] Three identical test pieces were selected and suspended on test piece bundles in three sample tubes. Methanol engine oil was added to each of the three sample tubes, and anhydrous formic acid, water, and a mixture of anhydrous formic acid and water were added to the three sample tubes respectively. The samples were preheated, and then air of equal flow rate was continuously introduced into the three sample tubes through air tubes. Finally, the samples in the three sample tubes were sampled and analyzed at different time periods.
[0011] The second technical solution of the present invention is further characterized by:
[0012] The above-mentioned method for testing the acid resistance of methanol engine oil shall be implemented according to the following steps:
[0013] Step 1: Select three sample tubes and label them sample tube a, sample tube b, and sample tube c.
[0014] Step 2: Hang the three identical test pieces on the hooks of the test piece bundles in sample tubes a, b, and c, respectively.
[0015] Step 3: Add methanol engine oil to sample tubes a, b and c respectively, add anhydrous formic acid to sample tube a, add water to sample tube b, and add a mixture of anhydrous formic acid and water to sample tube c.
[0016] Step 4: Place sample tubes a, b, and c in a heating bath for preheating. Use thermocouple 5 to control the internal temperature of sample tubes a, b, and c within the range of 69.5℃-135.5℃. Use an air source device to continuously introduce air of equal flow rate into sample tubes a, b, and c respectively.
[0017] Step 5: Take 20 ml of each of the samples a, b, and c from sample tubes a, b, and c in step 4 at different time intervals. Analyze the acid resistance of the methanol engine oil by detecting various indicators in samples a, b, and c.
[0018] In step 2, the test pieces are composed of lead, copper, tin, and phosphor bronze, and each test piece in sample tube a, sample tube b, and sample tube c is not in contact with the tube wall of its respective sample tube and is suspended independently.
[0019] The specific steps for adding methanol engine oil in step 3 are as follows:
[0020] The amount of methanol engine oil added to sample tubes a, b, and c was the same, and the liquid level of the methanol engine oil in sample tubes a, b, and c was higher than the position of the sample bundle 8 in each sample tube.
[0021] In step 3, the volume percentage of anhydrous formic acid, water, and the mixture of anhydrous formic acid and water added is 2%-10% of the volume of methanol engine oil added, and the mixing ratio of anhydrous formic acid and water in the mixture is 1:1.
[0022] In step 4, the immersion depth of sample tubes a, b, and c in the heating bath is less than the liquid level height inside sample tubes a, b, and c.
[0023] In step 4, the rate of air introduction is 5-20 L / h.
[0024] In step 5, the different time periods are 120h-144h, 144h-216h, and greater than 216h. The specific indicators are kinematic viscosity, alkalinity, and corrosion elements, with the corrosion elements being Cu, Sn, and Pb.
[0025] The beneficial effects of this invention are:
[0026] (1) The methanol engine oil acid resistance test device of the present invention simulates the actual working environment of methanol engine oil by means of sample tube, thermocouple and test strip bundle, which solves the problem of lack of a methanol engine oil working condition simulation device in the prior art.
[0027] (2) The method for testing the acid resistance of methanol engine oil of the present invention can detect the degree of alkalinity decay of methanol engine oil by combustion byproducts such as formic acid and water, as well as the corrosion performance on engine metal, and thus test the acid resistance of methanol engine oil. The test results are more targeted.
[0028] (3) The method for testing the acid resistance of methanol engine oil of the present invention is simple and portable to operate and can be tested in the laboratory. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of the structure of the methanol engine oil acid resistance testing device of the present invention;
[0030] Figure 2 This is a schematic diagram of the test piece bundle in the methanol engine oil acid resistance testing device of the present invention.
[0031] In the figure, 1. Sample tube, 2. Sample tube cap, 3. Condenser, 4. Air tube, 5. Thermocouple, 6. Air source device, 7. Power supply device, 8. Sample bundle, 9. Hook, 10. Sleeve. Detailed Implementation
[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0033] This invention provides a device for testing the acid resistance of methanol engine oil, such as... Figure 1 As shown, the apparatus includes a sample tube 1, inside which are an air tube 4 and a thermocouple 5. A sample tube cap 2 is located at the top of the sample tube 1, and a condenser tube 3 is installed on the sample tube cap 2. Cooling water is circulated through the condenser tube 3 to prevent the formic acid in the sample tube 1 from evaporating. A bundle of test pieces 8 is attached to the wall of the air tube 4, and a connecting tube is located at the top of the air tube 4. The connecting tube passes through the sample tube cap 2 and is connected to an air source device 6. Clean and dry air is circulated into the air tube 4 through the air source device 6 to accelerate the oxidation of methanol engine oil, thereby accelerating the experimental process. Thermocouple 5 passes through the sample tube cap 2 and is connected to a power supply device 7. Heating the methanol engine oil in the sample tube 1 through thermocouple 5 can simulate the internal temperature of an engine and ensure the accuracy of the experiment.
[0034] Test bundle 8, such as Figure 2 As shown, the sample bundle 8 includes a sleeve 10. Several hooks 9 are evenly distributed around the outer wall of one end of the sleeve 10. Each hook 9 does not contact the wall of the sample tube 1. The sample bundle 8 is used to suspend metal samples to simulate the metal material of the engine itself.
[0035] This invention also provides a method for testing the acid resistance of methanol engine oil, using the aforementioned methanol engine oil acid resistance testing device, and the specific method is as follows:
[0036] Three identical test pieces were selected and suspended on test piece bundles (8) in three sample tubes (1). Methanol engine oil was added to each of the three sample tubes (1), and anhydrous formic acid, water, and a mixture of anhydrous formic acid and water were added to each of the three sample tubes (1) respectively. The samples were preheated, and then air of equal flow rate was continuously introduced into each of the three sample tubes (1) through an air tube (4). Finally, the samples in the three sample tubes (1) were sampled and analyzed at different time periods.
[0037] The method for testing the acid resistance of methanol engine oil is implemented according to the following steps:
[0038] Step 1: Select three sample tubes 1 and label them sample tube a, sample tube b, and sample tube c respectively;
[0039] Step 2: Hang the three identical test pieces on the hooks 9 of the test piece bundle 8 in sample tubes a, b, and c, respectively.
[0040] In step 2, the test pieces are composed of lead, copper, tin, and phosphor bronze. Each test piece in sample tube a, sample tube b, and sample tube c is not in contact with the tube wall of its respective sample tube and is suspended independently to ensure uniform oxidation and corrosion of the test pieces and to ensure the accuracy of the experiment.
[0041] Step 3: Add methanol engine oil to sample tubes a, b, and c respectively. Add anhydrous formic acid to sample tube a, add water to sample tube b, and add a mixture of anhydrous formic acid and water to sample tube c. By adding anhydrous formic acid, water, and a mixture of anhydrous formic acid and water to the three sample tubes respectively, a control group can be formed to more clearly reflect the acid resistance of methanol engine oil.
[0042] The specific steps for adding methanol engine oil in step 3 are as follows:
[0043] The amount of methanol engine oil added to sample tubes a, b, and c was the same, and the liquid level of the methanol engine oil in sample tubes a, b, and c was higher than the position of the sample bundle 8 in each sample tube.
[0044] In step 3, the volume percentage of anhydrous formic acid, water, and the mixture of anhydrous formic acid and water added is 2%-10% of the volume of methanol engine oil added, and the mixing ratio of anhydrous formic acid and water in the mixture is 1:1.
[0045] Step 4: Place sample tubes a, b, and c in a heating bath for preheating. Use thermocouple 5 to control the internal temperature of sample tubes a, b, and c within the range of 69.5℃-135.5℃. This temperature range is the internal temperature of the engine when it is working normally, as measured in the simulation experiment. Use air source device 6 to continuously introduce air of equal flow rate into sample tubes a, b, and c respectively.
[0046] In step 4, the immersion depth of sample tubes a, b, and c in the heating bath is less than the liquid level height inside sample tubes a, b, and c.
[0047] During the test run, the rate at which air of equal flow rate was introduced in step 4 was 5-20 L / h.
[0048] Step 5: Take 20 ml of each of the samples a, b, and c from sample tubes a, b, and c in step 4 at different time intervals. Analyze the acid resistance of the methanol engine oil by detecting various indicators in samples a, b, and c.
[0049] Step 5 involves different operating time periods: 120h-144h, 144h-216h, and greater than 216h. The specific indicators are kinematic viscosity, base number, and corrosion elements. Corrosion elements are specifically Cu, Sn, and Pb. The degree of base number decay of the methanol engine oil due to combustion byproducts such as formic acid and water is tested. Kinematic viscosity is measured using GB / T 265 (Determination of Kinematic Viscosity of Petroleum Products), and base number is measured using GB / T 0251 (Determination of Base Number of Petroleum Products). Simultaneously, the corrosion performance of engine metals is tested, and consequently, the acid resistance of the methanol engine oil is tested. When the oil test indicators exceed the oil change indicators in Table 1 below, the test can be stopped, and new oil should be used. See Table 1 for details.
[0050] Table 1 Oil Change Indicators for Inspection Items
[0051]
[0052] Specific embodiments of the method for testing the acid resistance of methanol engine oil according to the present invention are as follows:
[0053] Example 1
[0054] (1) Adjust the temperature inside sample tube 1 to 75℃;
[0055] (2) Adjust the air flow rate of the air source device to 10L / h;
[0056] (3) Add 200g of methanol engine oil and a pre-prepared mixture of anhydrous formic acid, water, and anhydrous formic acid and water to sample tubes a, b, and c respectively. Stir manually with a glass rod until well mixed, then introduce clean and dry air into the air tube and start timing.
[0057] (4) After 120 hours, 20 mL of sample was taken for analysis. The kinematic viscosity, alkalinity, Cu, Sn, and Pb were measured. The specific results are shown in Table 2 below:
[0058] Table 2. Test results of methanol engine oil after 120 hours of experiment.
[0059]
[0060]
[0061] Example 2
[0062] (1) Adjust the temperature inside sample tube 1 to 85℃;
[0063] (2) Adjust the air flow rate of the air source device to 10L / h;
[0064] (3) Add 200g of methanol engine oil and a pre-prepared mixture of anhydrous formic acid, water, and anhydrous formic acid and water to sample tubes a, b, and c respectively. Stir manually with a glass rod until well mixed, then introduce clean and dry air into the air tube and start timing.
[0065] (4) After 144 hours, 20 mL of sample was taken for analysis. Kinematic viscosity, alkalinity, Cu, Sn, and Pb were measured. The specific results are shown in Table 3 below:
[0066] Table 3. Test results of methanol engine oil after 144 hours of experiment.
[0067]
[0068]
[0069] Example 3
[0070] (1) Adjust the temperature inside sample tube 1 to 135℃;
[0071] (2) Adjust the air flow rate of the air source device to 10L / h;
[0072] (3) Add 200g of methanol engine oil and a pre-prepared mixture of anhydrous formic acid, water, and anhydrous formic acid and water to sample tubes a, b, and c respectively. Stir manually with a glass rod until well mixed, then introduce clean and dry air into the air tube and start timing.
[0073] (4) After 216 hours, 20 mL of sample was taken for analysis. Kinematic viscosity, alkalinity, Cu, Sn, and Pb were measured. The specific results are shown in Table 4 below:
[0074] Table 4. Test results of methanol engine oil after 216 hours of experiment.
[0075]
[0076]
[0077] The testing indicators involved in Examples 1, 2, and 3 above include kinematic viscosity, base number, Cu content, Sn content, and Pb content. Kinematic viscosity (at 100°C) is the core indicator of engine oil lubrication performance. Base number indicates the content of alkaline substances in the lubricating oil, representing its acid neutralization ability. When the kinematic viscosity is less than -20% or greater than +25% of the new oil's value, or when the base number is less than 50% of the new oil's value, the test should be stopped and the oil replaced. Cu, Pb, and Sn elements simulate components from the bushings and bearings of the engine's friction pairs. When impurities such as formic acid and water are mixed into the lubricating oil, the proportion of corrosive elements in the lubricating oil is measured through a long-term oxidation test, simulating engine operating conditions, to assess the degree of corrosion and wear of each component.
Claims
1. A method for testing the acid resistance of methanol engine oil, characterized in that, A methanol engine oil acid resistance testing device was used. The methanol engine oil acid resistance testing device includes a sample tube (1), an air tube (4) and a thermocouple (5) are respectively installed inside the sample tube (1), a sample tube cap (2) is installed on the top of the sample tube (1), a condenser tube (3) is installed on the sample tube cap (2), a test strip bundle (8) is sleeved on the wall of the air tube (4), a connecting tube is installed at the top of the air tube (4), the connecting tube passes through the sample tube cap (2) and is connected to the air source device (6), and the thermocouple (5) passes through the sample tube cap (2) and is connected to the power supply device (7). The sample bundle (8) includes a sleeve (10), and a number of hooks (9) are evenly distributed around the outer wall of one end of the sleeve (10). Each hook (9) does not contact the wall of the sample tube (1). The specific method is as follows: Three identical test pieces were selected and suspended on test piece bundles (8) in three sample tubes (1). Methanol engine oil was added to each of the three sample tubes (1), and anhydrous formic acid, water, and a mixture of anhydrous formic acid and water were added to each of the three sample tubes (1) respectively. The tubes were preheated, and then air of equal flow rate was continuously introduced into each of the three sample tubes (1) through an air tube (4). Finally, the samples in the three sample tubes (1) were sampled and analyzed at different time periods. The specific steps are as follows: Step 1: Select three sample tubes (1) and label them as sample tube a, sample tube b and sample tube c respectively; Step 2: Hang the three identical test pieces on the hooks (9) of the test piece bundle (8) in sample tubes a, b and c respectively; Step 3: Add methanol engine oil to sample tubes a, b and c respectively, add anhydrous formic acid to sample tube a, add water to sample tube b, and add a mixture of anhydrous formic acid and water to sample tube c. Step 4: Place sample tubes a, b and c in a heating bath for preheating. Use thermocouples (5) to control the temperature inside sample tubes a, b and c within the range of 69.5℃-135.5℃. Use an air source device (6) to continuously introduce air of equal flow rate into sample tubes a, b and c respectively. Step 5: Take 20 ml of each of the samples a, b, and c from sample tubes a, b, and c in step 4 at different time intervals, and analyze the acid resistance of methanol engine oil by detecting various indicators in samples a, b, and c. The test piece described in step 2 is composed of lead, copper, tin, and phosphor bronze, and each of the test pieces in sample tubes a, b, and c is not in contact with the tube wall of its respective sample tube and is suspended independently. The specific steps for adding methanol engine oil in step 3 are as follows: The amount of methanol engine oil added to sample tubes a, b and c is the same, and the liquid level of methanol engine oil in sample tubes a, b and c is higher than the position of the sample bundle (8) in each sample tube. In step 3, the amount of anhydrous formic acid, water, and the mixture of anhydrous formic acid and water added accounts for 2%-10% of the volume of methanol engine oil added, and the mixing ratio of anhydrous formic acid and water in the mixture is 1:
1. In step 4, the immersion depth of sample tubes a, b, and c in the heating bath is less than the liquid level height inside sample tubes a, b, and c. In step 4, the rate of air introduction is 5-20 L / h; The different time periods mentioned in step 5 are specifically 120h-144h, 144h-216h, and greater than 216h. The various indicators are specifically kinematic viscosity, alkalinity, and corrosion elements, and the corrosion elements are specifically Cu, Sn, and Pb.