Method for testing alcohol resistance of methanol engine oil

Abstract

This invention discloses a method for testing the alcohol resistance of methanol engine oil. The method involves performing a long-term wear test on the engine oil to obtain its initial long-term wear value (X0). The engine oil and methanol are added to a test tube, and the mixture is heated to 40°C–75°C and stirred. After stirring, the mixture is allowed to stand for a certain period and then centrifuged. The upper layer of oil in the test tube is then extracted for a long-term wear test, and the final long-term wear value (X1) is obtained. The decrease in long-term wear value (X0) is then subtracted from the final long-term wear value (X1) to obtain the reduction in long-term wear. If the reduction in long-term wear (X) is ≤0.12, the engine oil's alcohol resistance meets the requirements. This method for testing the alcohol resistance of methanol engine oil can accurately detect its performance.

Description

Technical Field

[0001] This invention belongs to the field of engine oil testing technology, specifically relating to a method for testing the alcohol resistance of methanol engine oil. Background Technology

[0002] With the advancement of energy conservation and emission reduction policies and marine emission regulations at home and abroad, the use of new clean energy fuels to replace traditional fuels has become an important trend. Currently, methanol fuel, with its advantages of 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.

[0003] Major international OEMs all produce methanol-fueled engines, and the domestic methanol engine market, primarily driven by companies like Zibo Diesel Engine Co., Ltd., has also commenced production. The future market prospects for methanol engine oil applications are enormous. During engine operation, methanol inevitably leaks into the lubricating oil. This methanol decomposes some of the lubricating oil additives, leading to a loss of anti-wear properties. Therefore, assessing the alcohol resistance of methanol engine oils is crucial. However, existing engine oil simulation methods are still based on traditional fuels and lack specific simulation methods for methanol engine oils. Traditional methods are insufficient to objectively and effectively evaluate the degradation of anti-wear properties after methanol contamination. Summary of the Invention

[0004] The purpose of this invention is to provide a method for testing the alcohol resistance of methanol engine oil, which can accurately test the alcohol resistance of methanol engine oil.

[0005] The technical solution adopted in this invention is a method for testing the alcohol resistance of methanol engine oil. The method involves conducting a long-term wear test on the engine oil to be tested to obtain the long-term wear value X0 before the test. The engine oil to be tested and methanol are added to a test tube, and the mixed solution is heated to 40℃~75℃ and stirred. After the stirred solution has been allowed to stand for a certain period of time, it is centrifuged. The upper layer of oil in the test tube is extracted for a long-term wear test, and the long-term wear value X1 after the test is obtained. The long-term wear reduction value X1 is obtained by subtracting the long-term wear value X0 before the test from the long-term wear value X1 after the test. If the long-term wear reduction value X≤0.12, the alcohol resistance of the engine oil meets the requirements.

[0006] The invention is further characterized in that,

[0007] The engine oil and methanol added to the test tube are calculated by volume percentage, with methanol accounting for 2% to 15% of the total volume percentage and the remainder being engine oil.

[0008] Use a stirring paddle when stirring, keeping the paddle 2.5mm to 3.5mm away from the bottom of the test tube.

[0009] The stirring speed is 2500 r / min to 4500 r / min, and the stirring time is 25 s to 35 s.

[0010] Let the stirred liquid stand for 1 to 3 minutes.

[0011] The centrifugal force for centrifugation is 500N to 900N, and the centrifugation time is 1.5h to 2h.

[0012] Taking the upper layer of solution from the test tube refers to taking 22mL to 28mL of the upper layer.

[0013] The beneficial effects of this invention are:

[0014] (1) The alcohol resistance test method of the present invention simulates the actual operating conditions of methanol engine and examines the degree of wear resistance degradation of oil through the "long grinding method" and performs alcohol resistance test on methanol engine oil. The test results are more targeted and accurate.

[0015] (2) The alcohol resistance test method of the present invention is simple and portable, and can be tested in the laboratory. Detailed Implementation

[0016] The present invention will now be described in detail with reference to specific embodiments.

[0017] This invention discloses a method for testing the alcohol resistance of methanol engine oil. The method involves performing a long-term wear test on the engine oil to be tested to obtain the initial long-term wear value X0. The engine oil and methanol are added to a test tube, and the mixture is heated to the actual operating temperature of the methanol engine before stirring. After the mixture has been stirred and allowed to stand for a certain period, it is centrifuged. The upper layer of oil in the test tube is then extracted for a long-term wear test to obtain the final long-term wear value X1. The final long-term wear value X1 is then subtracted from the initial long-term wear value X0 to analyze the decrease in long-term wear. If the decrease in long-term wear X ≤ 0.12, the alcohol resistance of the engine oil meets the requirements.

[0018] The specific steps are as follows:

[0019] Step 1: Before the experiment, perform a long-term wear test on the engine oil to be tested to obtain the long-term wear value X. Add the engine oil to be tested and methanol to the test tube. The added engine oil and methanol are calculated by volume percentage. Methanol accounts for 2% to 15% of the total volume percentage, and the remainder is the engine oil to be tested.

[0020] Step 2: Heat the mixed solution in the test tube from Step 1 to 40℃~75℃ to simulate the actual operating temperature of a methanol engine. Then, stir the mixed solution with a stirrer, adjusting the height of the stirrer to 2.5mm~3.5mm from the bottom of the test tube. Stir the mixed liquid at a speed of 2500r / min~4500r / min for 25S~35S.

[0021] Step 3: Let the mixed liquid from Step 2 stand for 1 to 3 minutes. At the same time, remove the stirring paddle from the test tube and suspend it above the test tube so that the liquid on the surface of the stirring paddle falls back into the test tube. Then put the test tube into a centrifuge for centrifugation. The centrifugal force is 500 N to 900 N and the centrifugation time is 1.5 h to 2 h.

[0022] Step 4: Take 22mL to 28mL of the upper layer solution from the test tube for a long-term wear test to obtain the long-term wear value X1. Then, calculate the long-term wear reduction value of the engine oil to be tested using the following formula:

[0023] X = X1 - X0

[0024] Where X is the long-term wear reduction value, X1 is the long-term wear value measured in step 4, and X0 is the long-term wear value measured in step 1;

[0025] Example 1

[0026] Step 1: Perform a long-term wear test on engine oil a to obtain the long-term wear value X. Add engine oil a and methanol to a test tube. The amount of engine oil a and methanol added is calculated by volume percentage, with methanol accounting for 2% of the total volume percentage and the remainder being engine oil a.

[0027] Step 2: First, heat the mixed liquid in the test tube to 40°C, then adjust the height of the stirring paddle 2 to 2.5 mm from the bottom of the test tube, and stir the mixed liquid at a speed of 2500 r / min for 35 seconds.

[0028] Step 3: Let the mixed liquid from Step 2 stand for 1 minute. At the same time, remove the stirrer from the test tube and suspend it above the test tube so that the liquid on the surface of the stirrer falls back into the test tube. Then put the test tube into a centrifuge for centrifugation at a centrifugal force of 500N for 2 hours.

[0029] Step 4: Take 22 mL of the upper layer solution in the test tube for long-term wear test and obtain the long-term wear value X1. The long-term wear reduction value is calculated as X = X1 - X0 = 0.61 - 0.53 = 0.08.

[0030] Example 2

[0031] Step 1: Perform a long-term wear test on engine oil b to obtain the long-term wear value X. Add engine oil b and methanol to a test tube. The amount of engine oil b and methanol added is calculated by volume percentage, with methanol accounting for 8% of the total volume percentage and the remainder being engine oil b.

[0032] Step 2: First, heat the mixed liquid in the test tube to 55°C, then adjust the height of the stirrer to 3mm from the bottom of the test tube, and stir the mixed liquid at 3500r / min for 30 seconds.

[0033] Step 3: Let the mixed liquid from Step 2 stand for 2 minutes. At the same time, remove the stirrer from the test tube and suspend it above the test tube so that the liquid on the surface of the stirrer falls back into the test tube. Then put the test tube into a centrifuge for centrifugation at a centrifugal force of 700N for 1.8 hours.

[0034] Step 4: Take 25 mL of the upper layer solution in the test tube for long-term wear test and obtain the long-term wear value X1. The long-term wear reduction value is calculated as X = X1 - X0 = 0.59 - 0.54 = 0.05.

[0035] Example 3

[0036] Step 1: Perform a long-term wear test on engine oil c to obtain the long-term wear value X. Add engine oil c and methanol to a test tube. The amount of engine oil c and methanol added is calculated by volume percentage, with methanol accounting for 15% of the total volume percentage and the remainder being engine oil c.

[0037] Step 2: First, heat the mixed liquid in the test tube to 75°C, then adjust the height of the stirrer to 3.5 mm from the bottom of the test tube, and stir the mixed liquid at 4500 r / min for 25 seconds.

[0038] Step 3: Let the mixed liquid from Step 2 stand for 3 minutes. At the same time, remove the stirrer from the test tube and suspend it above the test tube so that the liquid on the surface of the stirrer falls back into the test tube. Then put the test tube into a centrifuge for centrifugation at a centrifugal force of 900N for 1.5 hours.

[0039] Step 4: Take 28 mL of the upper layer solution in the test tube for long-term wear test and obtain the long-term wear value X1. The long-term wear reduction value is calculated as X = X1 - X0 = 0.64 - 0.54 = 0.1.

[0040] Comparative Example 1

[0041] Step 1: Perform a long-term wear test on the engine oil d to obtain the long-term wear value X. Add engine oil d and methanol to the test tube. The amount of engine oil d and methanol added is calculated by volume percentage, with methanol accounting for 2% of the total volume percentage and the remainder being engine oil d.

[0042] Step 2: First, heat the mixed liquid in the test tube to 40°C, then adjust the height of the stirrer to 2.5 mm from the bottom of the test tube, and stir the mixed liquid at a speed of 2500 r / min for 35 seconds.

[0043] Step 3: Let the mixed liquid from Step 2 stand for 1 minute. At the same time, remove the stirrer from the test tube and suspend it above the test tube so that the liquid on the surface of the stirrer falls back into the test tube. Then put the test tube into a centrifuge for centrifugation at a centrifugal force of 500N for 2 hours.

[0044] Step 4: Take 22 mL of the upper layer solution in the test tube for long-term wear test and obtain the long-term wear value X1. The long-term wear reduction value is calculated as X = X1 - X0 = 0.72 - 0.54 = 0.18.

[0045] Comparative Example 2

[0046] Step 1: Perform a long-term wear test on engine oil e to obtain the long-term wear value X. Add engine oil e and methanol to a test tube. The amount of engine oil e and methanol added is calculated by volume percentage, with methanol accounting for 15% of the total volume percentage and the remainder being engine oil e.

[0047] Step 2: First, heat the mixed liquid in the test tube to 75°C, then adjust the height of the stirring paddle to 3.5 mm from the bottom of the test tube and stir the mixed liquid at a speed of 4500 r / min for 25 seconds.

[0048] Step 3: Let the mixed liquid from Step 2 stand for 3 minutes. At the same time, remove the stirrer from the test tube and suspend it above the test tube so that the liquid on the surface of the stirrer falls back into the test tube. Then put the test tube into a centrifuge for centrifugation at a centrifugal force of 900N for 1.5 hours.

[0049] Step 4: Take 28 mL of the upper layer solution in the test tube for long-term wear test and obtain the long-term wear value X1. The long-term wear reduction value is calculated as X = X1 - X0 = 0.54 - 0.41 = 0.13.

[0050] Engine oils a, c, d, and e from Examples 1, 3, and Comparative Examples 1 and 2 were subjected to bench wear resistance tests under the same operating conditions using a Zibo Diesel marine inline six-cylinder four-stroke direct injection turbocharged marine engine. After the experiment, the cleanliness of the cylinder liner and piston rings was observed. It was clearly evident that engine oils a and c had good cylinder liner and piston ring cleanliness and less sludge. This demonstrates that the engine oils with a long-term wear reduction value ≤0.12 obtained by the alcohol resistance test method of this invention meet the alcohol resistance requirements of methanol engine oils.

Claims

1. A method for testing the alcohol tolerance of a methanol engine oil, characterized in that, The engine oil to be tested is subjected to a long-term wear test to obtain the long-term wear value X0 before the test. The engine oil to be tested and methanol are added to a test tube, and the mixed solution is heated to 40℃~75℃ and stirred. After the mixed solution is stirred and allowed to stand for a certain period of time, it is centrifuged. The upper layer of oil in the test tube is extracted for a long-term wear test to obtain the long-term wear value X1 after the test. The long-term wear value X1 after the test is subtracted from the long-term wear value X0 before the test to obtain the long-term wear reduction value of the engine oil. If the long-term wear reduction value X≤0.12, the alcohol resistance of the engine oil meets the requirements. The extraction of the upper layer of oil from the test tube refers to extracting 22mL to 28mL of the upper layer solution from the test tube.

2. The method for testing the methanol resistance of engine oil according to claim 1, characterized in that, The engine oil and methanol added to the test tube are calculated by volume percentage, with methanol accounting for 2% to 15% of the total volume percentage and the remainder being engine oil.

3. The method of claim 1, wherein the methanol engine oil alcohol tolerance performance test is characterized by, Use a stirring paddle when stirring, keeping the paddle 2.5mm to 3.5mm away from the bottom of the test tube.

4. The method of claim 1, wherein the methanol engine oil alcohol tolerance performance test is characterized by, The stirring speed is 2500r / min~4500r / min, and the stirring time is 25s~35s.

5. The method of claim 1, wherein the methanol engine oil alcohol tolerance performance test is characterized by, Let the stirred liquid stand for 1 to 3 minutes.

6. The method of claim 1, wherein the methanol engine oil alcohol tolerance performance test is characterized by, The centrifugal force for the centrifugation process is 500N~900N, and the centrifugation time is 1.5h~2h.