Device and method for detecting acid resistance of methanol engine oil

Abstract

The invention discloses a methanol engine oil acid resistance detection device which comprises a sample tube, an air tube and a thermocouple are arranged in the sample tube, a sample tube cover is arranged at the top of the sample tube, a condensation tube is mounted on the sample tube cover, a test piece bundle is sleeved on the tube wall of the air tube, and the top end of the air tube is connected with an air source device. And the thermocouple is connected with the power supply device. The device solves the problem of lack of a methanol engine oil working condition simulation device in the prior art. The invention also discloses a method for detecting the acid resistance of the methanol engine oil, which comprises the following steps of: respectively suspending three same test pieces on the test piece bundles in the three sample tubes, adding the methanol engine oil into the three sample tubes, correspondingly adding anhydrous formic acid, water and a mixed solution of the anhydrous formic acid and the water, preheating, introducing air, and finally sampling and analyzing, so as to obtain the acid resistance of the methanol engine oil. The method can be used for detecting the alkali number decay degree of combustion byproducts such as formic acid and water on methanol engine oil and the corrosion performance of the combustion byproducts on engine metal, so that the acid resistance is detected.

Description

Technical Field

[0001] The invention belongs to the technical field of engine oil detection, and relates to a device for detecting the acid resistance of methanol engine oil. The invention also relates to a detection method using the device. Background Art

[0002] At present, it has become an important trend for new clean energy fuels to replace traditional fuels. Methanol fuel is expected to become one of the main clean energy sources in the future due to its wide sources, low production cost, strong anti-knock ability, and large latent heat of gasification. Therefore, the application market prospect of methanol engine oil in the engine field is huge.

[0003] However, during engine operation, a mixture of formic acid, water and other combustion by-products produced by the combustion of methanol fuel can easily cause corrosion of the engine cylinder liner and piston ring, and affect the alkali retention performance of the lubricating oil. Therefore, it is very necessary to analyze and study the acid resistance of methanol engine oil. However, the current simulation devices for engine oil working conditions and engine oil performance detection methods are still based on research on traditional fuels. There are no special simulation devices for methanol engine oil working conditions and performance detection methods. Therefore, traditional methods cannot objectively and effectively detect metal corrosion and alkali retention performance decay after formic acid is mixed into the oil. Summary of the invention

[0004] The purpose of the present invention is to provide a device for detecting the acid resistance of methanol engine oil, which solves the problem of lack of a device for simulating the working condition 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 device.

[0006] The first technical solution adopted by the present invention is a methanol engine oil acid resistance testing device, comprising a sample tube, an air tube and a thermocouple are respectively arranged inside the sample tube, a sample tube cover is arranged on the top of the sample tube, a condenser is installed on the sample tube cover, a test piece bundle is sleeved on the wall of the air tube, a connecting tube is arranged on the top of the air tube, the connecting tube passes through the sample tube cover and is connected to an air source device, and the thermocouple passes through the sample tube cover and is connected to a power supply device.

[0007] The first technical solution of the present invention is also characterized in that:

[0008] The test piece bundle comprises a sleeve, and a plurality of hooks are evenly distributed along the outer wall of one end of the sleeve, and each hook 9 does not contact the wall of the sample tube.

[0009] The second technical solution adopted by the present invention is a method for detecting the acid resistance of methanol engine oil, using a device for detecting the acid resistance of methanol engine oil. The specific method is as follows:

[0010] Three identical test pieces were selected and hung on the test piece bundles in three sample tubes respectively. Methanol engine oil was added to the three sample tubes. Anhydrous formic acid, water, and a mixture of anhydrous formic acid and water were added to the three sample tubes respectively for preheating. Then, an equal flow of air was continuously introduced into the three sample tubes through the 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 also characterized in that:

[0012] The above-mentioned method for testing the acid resistance of methanol engine oil is specifically implemented according to the following steps:

[0013] Step 1, select three sample tubes and record them as sample tube a, sample tube b and sample tube c respectively;

[0014] Step 2, hang three identical test pieces on the hooks of the test piece bundle in sample tube a, sample tube b and sample tube c respectively;

[0015] Step 3, adding methanol engine oil into sample tube a, sample tube b and sample tube c respectively, adding anhydrous formic acid into sample tube a, adding water into sample tube b, and adding a mixture of anhydrous formic acid and water into sample tube c;

[0016] Step 4, placing the sample tube a, the sample tube b and the sample tube c in a heating bath for preheating, controlling the internal temperature of the sample tube a, the sample tube b and the sample tube c within the range of 69.5° C.-135.5° C. by means of a thermocouple 5, and continuously passing equal flow of air into the sample tube a, the sample tube b and the sample tube c respectively through an air source device;

[0017] Step 5. Take out 20 ml of each of the samples a, b and c in the sample tubes a, b and c in step 4 at different time periods, and analyze the acid resistance of the methanol engine oil by testing various indicators in the 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 does not contact the tube wall of the sample tube in which it is located and is suspended independently.

[0019] The specific operation of adding methanol engine oil in step 3 is:

[0020] The amounts of methanol engine oil added to sample tube a, sample tube b and sample tube c are the same, and the liquid levels of the methanol engine oil in sample tube a, sample tube b and sample tube c are all higher than the position of the test piece bundle 8 in each sample tube.

[0021] In step 3, the added amount of anhydrous formic acid, water, and the mixture of anhydrous formic acid and water accounts for 2%-10% of the added amount of methanol engine oil by volume, and the mixing ratio of anhydrous formic acid and water in the mixture of anhydrous formic acid and water is 1:1.

[0022] In step 4, the immersion depth of sample tube a, sample tube b and sample tube c in the heating bath is less than the liquid level in sample tube a, sample tube b and sample tube c.

[0023] The rate of introducing air in step 4 is 5-20 L / h.

[0024] The different time periods 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.

[0025] The beneficial effects of the present invention are:

[0026] (1) The device for testing the acid resistance of methanol engine oil of the present invention simulates the actual working condition of methanol engine oil through a sample tube, a thermocouple and a test piece bundle, thereby solving the problem of the lack of a device for simulating the working condition of methanol engine oil 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 caused by combustion by-products such as formic acid and water, as well as its corrosion performance to engine metals, thereby testing the acid resistance of methanol engine oil, and 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 a laboratory. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a device for testing the acid resistance of methanol engine oil according to the present invention;

[0030] Figure 2 It is a schematic diagram of the structure of the test piece bundle in the device for testing the acid resistance of methanol engine oil of the present invention.

[0031] In the figure, 1. sample tube, 2. sample tube cover, 3. condenser, 4. air tube, 5. thermocouple, 6. air source device, 7. power supply device, 8. test piece bundle, 9. hook, 10. sleeve. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] The present invention provides a device for testing the acid resistance of methanol engine oil. Figure 1 As shown, it includes a sample tube 1, an air tube 4 and a thermocouple 5 are respectively arranged inside the sample tube 1, a sample tube cover 2 is arranged on the top of the sample tube 1, a condenser 3 is installed on the sample tube cover 2, cooling water is introduced into the condenser 3, and formic acid in the sample tube 1 can be prevented from volatilizing, a test piece bundle 8 is sleeved on the wall of the air tube 4, a connecting pipe is arranged on the top of the air tube 4, the connecting pipe passes through the sample tube cover 2 and is connected to the air source device 6, clean and dry air is introduced into the air tube 4 through the air source device 6, the oxidation of methanol engine oil can be accelerated, and then the experimental process is accelerated, the thermocouple 5 passes through the sample tube cover 2 and is connected to the power supply device 7, the methanol engine oil in the sample tube 1 is heated by the thermocouple 5, the internal temperature of the engine can be simulated, and the accuracy of the experiment is ensured.

[0034] Test piece bundle 8, such as Figure 2 As shown, the test piece bundle 8 includes a sleeve 10, and a plurality of hooks 9 are evenly distributed along the outer wall at one end of the sleeve 10, and each hook 9 does not contact the wall of the sample tube 1. The test piece bundle 8 is used to hang metal test pieces, thereby simulating the metal material of the engine itself.

[0035] The present invention also provides a method for testing the acid resistance of methanol engine oil. The method adopts the above-mentioned device for testing the acid resistance of methanol engine oil. The specific method is as follows:

[0036] Three identical test pieces are selected and hung on test piece bundles (8) in three sample tubes (1), methanol engine oil is added to the three sample tubes (1), and anhydrous formic acid, water, and a mixture of anhydrous formic acid and water are added to the three sample tubes (1) respectively, and preheated. Then, an equal flow of air is continuously introduced into the three sample tubes (1) through the air tube (4), and finally, the samples in the three sample tubes (1) are sampled and analyzed at different time periods.

[0037] The method for testing the acid resistance of methanol engine oil is specifically implemented according to the following steps:

[0038] Step 1, select three sample tubes 1 and record them as sample tube a, sample tube b and sample tube c respectively;

[0039] Step 2, hang three identical test pieces on the hooks 9 of the test piece bundle 8 in the sample tube a, the sample tube b and the sample tube c respectively;

[0040] 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 does not contact the tube wall of the sample tube in which it is located and is independently suspended to ensure that the degree of oxidation corrosion of the sample is uniform and the accuracy of the experiment is ensured.

[0041] Step 3, methanol engine oil is added to sample tube a, sample tube b and sample tube c respectively, and anhydrous formic acid is added to sample tube a, water is added to sample tube b, and a mixture of anhydrous formic acid and water is added to sample tube c. By adding anhydrous formic acid, water, and a mixture of anhydrous formic acid and water to the three sample tubes 1 respectively, a control group is formed, and the acid resistance of the methanol engine oil can be more clearly reflected;

[0042] The specific operation of adding methanol engine oil in step 3 is:

[0043] The amounts of methanol engine oil added to sample tube a, sample tube b and sample tube c are the same, and the liquid levels of the methanol engine oil in sample tube a, sample tube b and sample tube c are all higher than the position of the test piece bundle 8 in each sample tube.

[0044] In step 3, the added amount of anhydrous formic acid, water, and the mixture of anhydrous formic acid and water accounts for 2%-10% of the added amount of methanol engine oil by volume, and the mixing ratio of anhydrous formic acid and water in the mixture of anhydrous formic acid and water is 1:1.

[0045] Step 4, placing the sample tube a, the sample tube b and the sample tube c in a heating bath for preheating, and controlling the internal temperature of the sample tube a, the sample tube b and the sample tube c within the range of 69.5°C-135.5°C through the thermocouple 5, which is the internal temperature of the engine when it is working normally measured in the simulation experiment, and continuously passing equal flow of air into the sample tube a, the sample tube b and the sample tube c respectively through the air source device 6;

[0046] In step 4, the immersion depth of sample tube a, sample tube b and sample tube c in the heating bath is less than the liquid level in sample tube a, sample tube b and sample tube c.

[0047] During the test run, the rate of introducing equal flow air in step 4 is 5-20L / h.

[0048] Step 5. Take out 20 ml of each of the samples a, b and c in the sample tubes a, b and c in step 4 at different time periods, and analyze the acid resistance of the methanol engine oil by testing various indicators in the samples a, b and c.

[0049] In step 5, the different operating time periods are specifically 120h-144h, 144h-216h and greater than 216h, and the various indicators are specifically kinematic viscosity, alkalinity and corrosion elements. The corrosion elements are specifically Cu, Sn and Pb. The degree of decay of the alkalinity of the methanol engine oil by combustion byproducts such as formic acid and water, kinematic viscosity, kinematic viscosity is measured by GB / T 265 method (method for determination of kinematic viscosity of petroleum products), and alkalinity is measured by GB / T 0251 method (method for determination of alkalinity of petroleum products). At the same time, the corrosion performance of the engine metal is detected, and then the acid resistance of the methanol engine oil is detected. When the oil test index exceeds the oil change index in Table 1 below, the test can be stopped and new oil can be replaced, as shown in Table 1 below.

[0050] Table 1 Oil change indicators for inspection items

[0051]

[0052] The specific embodiment of the method for testing the acid resistance of methanol engine oil of the present invention is as follows:

[0053] Example 1

[0054] (1) Adjust the temperature in sample tube 1 to 75°C;

[0055] (2) Adjust the air flow rate of the air source device to 10 L / h;

[0056] (3) Add 200 g of methanol engine oil and a pre-prepared mixture of anhydrous formic acid, water, and anhydrous formic acid and water into sample tube a, sample tube b, and sample tube c, respectively, stir them evenly with a glass rod, introduce clean, dry air into the air tube, and start timing;

[0057] (4) After 120 hours, 20 mL of sample was taken for analysis to determine kinematic viscosity, base number, Cu element, Sn element, and Pb element. The specific results are shown in Table 2 below:

[0058] Table 2 Test results of methanol engine oil after 120h experiment

[0059]

[0060]

[0061] Example 2

[0062] (1) Adjust the temperature in sample tube 1 to 85°C;

[0063] (2) Adjust the air flow rate of the air source device to 10 L / h;

[0064] (3) Add 200 g of methanol engine oil and a pre-prepared mixture of anhydrous formic acid, water, and anhydrous formic acid and water into sample tube a, sample tube b, and sample tube c, respectively, stir them evenly with a glass rod, introduce clean, dry air into the air tube, and start timing;

[0065] (4) After 144 hours, 20 mL of sample was taken for analysis to determine kinematic viscosity, base number, Cu element, Sn element, and Pb element. The specific results are shown in Table 3 below:

[0066] Table 3 Test results of methanol engine oil after 144h experiment

[0067]

[0068]

[0069] Example 3

[0070] (1) Adjust the temperature in sample tube 1 to 135°C;

[0071] (2) Adjust the air flow rate of the air source device to 10 L / h;

[0072] (3) Add 200 g of methanol engine oil and a pre-prepared mixture of anhydrous formic acid, water, and anhydrous formic acid and water into sample tube a, sample tube b, and sample tube c, respectively, stir them evenly with a glass rod, introduce clean, dry air into the air tube, and start timing;

[0073] (4) After 216 hours, 20 mL of sample was taken for analysis. The kinematic viscosity, base number, Cu element, Sn element, and Pb element were determined. The specific results are shown in Table 4 below:

[0074] Table 4 Test results of methanol engine oil after 216h of experiment

[0075]

[0076]

[0077] The inspection indicators involved in the above-mentioned embodiment 1, embodiment 2 and embodiment 3 include kinematic viscosity, alkalinity, Cu element content, Sn element content and Pb element content, among which kinematic viscosity (100°C) is the core indicator of the lubricating performance of the engine oil, and the alkalinity indicates the index of the content of alkaline substances in the lubricating oil, indicating the acid neutralization ability of the lubricating oil. When the kinematic viscosity is less than -20% of the new oil or greater than +25% of the new oil, or the alkalinity is less than 50% of the new oil, the test should be stopped and the new oil should be replaced. Among them, the Cu, Pb and Sn elements all simulate the bushings and bearing components from the engine friction pair. When impurities such as formic acid and water are mixed into the lubricating oil, the proportion of the content of corrosive elements in the lubricating oil is measured by simulating the engine operating conditions, that is, after a long-term oxidation test, to measure the corrosion and wear degree of each component.

Claims

1. A methanol engine oil acid resistance testing device, characterized in that: The invention comprises a sample tube (1), wherein an air tube (4) and a thermocouple (5) are respectively arranged inside the sample tube (1), a sample tube cover (2) is arranged on the top of the sample tube (1), a condenser (3) is installed on the sample tube cover (2), a test piece bundle (8) is sleeved on the tube wall of the air tube (4), a connecting tube is arranged on the top of the air tube (4), the connecting tube passes through the sample tube cover (2) and is connected to an air source device (6), and the thermocouple (5) passes through the sample tube cover (2) and is connected to a power supply device (7).

2. The device for detecting the acid resistance of methanol engine oil according to claim 1, characterized in that: The test piece bundle (8) comprises a sleeve (10), one end of which is provided with a plurality of hooks (9) uniformly distributed along the outer wall, and each of the hooks (9) does not contact the wall of the sample tube (1).

3. A method for testing the acid resistance of methanol engine oil, characterized in that: Using the methanol engine oil acid resistance testing device as claimed in claim 2, the specific method is as follows: Three identical test pieces are selected and hung on test piece bundles (8) in three sample tubes (1), methanol engine oil is added to the three sample tubes (1), and anhydrous formic acid, water, and a mixture of anhydrous formic acid and water are added to the three sample tubes (1) respectively, and preheated. Then, an equal flow of air is continuously introduced into the three sample tubes (1) through the air tube (4), and finally, the samples in the three sample tubes (1) are sampled and analyzed at different time periods.

4. The method for testing the acid resistance of methanol engine oil according to claim 3, characterized in that: Follow the steps below to implement it: Step 1, select three sample tubes (1) and record them as sample tube a, sample tube b and sample tube c respectively; Step 2, hang three identical test pieces on the hooks (9) of the test piece bundle (8) in sample tube a, sample tube b and sample tube c respectively; Step 3, adding methanol engine oil into sample tube a, sample tube b and sample tube c respectively, adding anhydrous formic acid into sample tube a, adding water into sample tube b, and adding a mixture of anhydrous formic acid and water into sample tube c; Step 4, placing the sample tube a, the sample tube b and the sample tube c in a heating bath for preheating, controlling the internal temperature of the sample tube a, the sample tube b and the sample tube c within the range of 69.5° C.-135.5° C. through a thermocouple (5), and continuously introducing equal flow of air into the sample tube a, the sample tube b and the sample tube c respectively through an air source device (6); Step 5. Take out 20 ml of each of the samples a, b and c in the sample tubes a, b and c in step 4 at different time periods, and analyze the acid resistance of the methanol engine oil by testing various indicators in the samples a, b and c.

5. The method for testing the acid resistance of methanol engine oil according to claim 4, characterized in that: The test piece in step 2 is composed of lead, copper, tin, and phosphor bronze, and each of the test pieces in sample tube a, sample tube b, and sample tube c does not contact the tube wall of the sample tube in which it is located and is suspended independently.

6. The method for testing the acid resistance of methanol engine oil according to claim 4, characterized in that: The specific operation of adding methanol engine oil in step 3 is: The amounts of methanol engine oil added to the sample tube a, the sample tube b and the sample tube c are all the same, and the liquid levels of the methanol engine oil in the sample tube a, the sample tube b and the sample tube c are all higher than the position of the test piece bundle (8) in each sample tube.

7. The method for testing the acid resistance of methanol engine oil according to claim 4, characterized in that: The added amount of anhydrous formic acid, water, and the mixture of anhydrous formic acid and water in step 3 accounts for 2%-10% of the added amount of methanol engine oil by volume, and the mixing ratio of anhydrous formic acid and water in the mixture of anhydrous formic acid and water is 1:

1.

8. The method for testing the acid resistance of methanol engine oil according to claim 4, characterized in that: The immersion depth of the sample tube a, the sample tube b and the sample tube c in the heating bath in step 4 is less than the liquid level in the sample tube a, the sample tube b and the sample tube c.

9. The method for testing the acid resistance of methanol engine oil according to claim 4, characterized in that: The rate of introducing air in step 4 is 5-20 L / h.

10. The method for testing the acid resistance of methanol engine oil according to claim 4, characterized in that: The different time periods 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.

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