Methods for Selecting Lubricating Oil for Hybrid Engines

Abstract

This application discloses a method for selecting lubricating oil for a hybrid power engine, relating to the field of lubricating oil performance testing technology. The method includes: obtaining at least one candidate lubricating oil and performing an emulsion retention stability test on the obtained candidate lubricating oil; selecting the candidate lubricating oil that passes the emulsion retention stability test as the lubricating oil for the hybrid power engine; and a method for performing the emulsion retention stability test on the candidate lubricating oil. The lubricating oil selection method for hybrid power engines disclosed in this application provides a reference for selecting engine oils for hybrid vehicles.

Description

Technical Field

[0001] This application relates to the field of lubricating oil performance testing technology, specifically to a method for selecting lubricating oil for a hybrid engine. Background Technology

[0002] Engine oil is a liquid lubricant used in engines. It plays an important role in lubrication, cooling, protection, sealing, and cleaning, effectively reducing mechanical friction of internal engine components and protecting machinery and machined parts.

[0003] With the gradual promotion of new energy vehicles, the market share of hybrid vehicles has increased significantly, placing higher demands on the oil stability of hybrid vehicle engines. However, the operating conditions of hybrid vehicle engines differ from those of traditional internal combustion engines, characterized by shorter engine running times, frequent start-stop cycles, and lower oil temperatures. These characteristics make hybrid vehicle engine oil more susceptible to fuel dilution and contamination from combustion byproducts such as water. This contamination can lead to oil stratification, with water depositing at the bottom of the oil pan, thus affecting lubrication, accelerating wear on mechanical parts, and ultimately severely impacting engine performance and lifespan.

[0004] Therefore, engine oils used in hybrid vehicles need to have good emulsification retention capabilities to cope with water and fuel contamination. However, there is currently no method in the field to test the emulsification retention stability of engine oils, resulting in a lack of clear standards for selecting lubricants for hybrid engines. Summary of the Invention

[0005] In view of this, this application provides a method for selecting lubricating oil for hybrid engines, providing a reference for the selection of engine oil for hybrid vehicles.

[0006] The specific technical solution adopted in this application is as follows:

[0007] A method for selecting lubricating oil for a hybrid engine, comprising:

[0008] At least one candidate lubricating oil was obtained, and the emulsification retention stability test was performed on each of the at least one candidate lubricating oils obtained.

[0009] At least one candidate lubricant that passed the emulsification stability test was selected as the lubricant for the hybrid engine.

[0010] The method for testing the emulsification stability of the candidate lubricating oil includes:

[0011] The candidate lubricating oil, fuel oil and water are mixed evenly at a mass ratio of 8:1:1 to obtain a mixture.

[0012] Equal masses of the mixture are added to two first containers, and then the two first containers are placed in a first temperature environment and a second temperature environment, respectively, wherein the first temperature is higher than the second temperature, and both the first temperature and the second temperature are below zero degrees Celsius.

[0013] After the settling period, pour out the mixture from the two first containers until no liquid flows out of the two first containers;

[0014] The mass of the residual liquid in the mixture in each of the two first containers was obtained;

[0015] Based on the mass of the residual liquid in the two first containers, calculate the percentage of the mass of the mixture that has frozen in the first temperature environment and the second temperature environment, respectively.

[0016] In response to the absolute value of the difference between the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment being less than or equal to a first threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be qualified;

[0017] If the absolute value of the difference in the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment is greater than the first threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be unqualified.

[0018] Optionally, the method further includes:

[0019] In response to the fact that the emulsion retention stability test results of at least two of the candidate lubricants are qualified, the candidate lubricant with the smallest absolute value of the difference in the emulsion retention stability test is selected as the lubricant for the hybrid engine.

[0020] Optionally, the method further includes:

[0021] In response to the absolute value of the difference between the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment being less than or equal to a second threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be excellent, wherein the second threshold is greater than zero and less than the first threshold;

[0022] In response to the absolute value of the difference between the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment being less than or equal to the first threshold and greater than the second threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be good.

[0023] When selecting lubricating oil for hybrid engines, priority should be given to candidate lubricating oils with excellent emulsification stability test results.

[0024] Optionally, the freezing mass percentage of the mixture is calculated according to the following formula:

[0025] ω=(1-M1 / M0)×100%

[0026] Where ω is the percentage of the mixture that is frozen, M1 is the mass of the residual mixture in the first container, and M0 is the mass of the mixture added to the first container.

[0027] Optionally, pouring out the mixture from the two first containers includes: pouring the mixture from the two first containers into two second containers respectively;

[0028] The method further includes:

[0029] Obtain the first mass of the mixture poured into the second container;

[0030] The mass of the residual liquid in the first container is calculated based on the mass of the mixture added to the first container and the first mass.

[0031] Optionally, the step of pouring out the mixture from the two first containers until no liquid flows out of the two first containers includes:

[0032] For the mixture in each of the first containers, the mixture is poured out through a filter with a pore size of 30 micrometers;

[0033] If no liquid drips through the filter within a first time period, it is determined that no liquid is flowing out of the first container.

[0034] Optionally, the method further includes:

[0035] The sum of the masses of the first container and the filter screen is used as the second mass;

[0036] The mass of the first container and the filter screen containing the residual liquid of the mixture when no liquid flows out of the first container is measured as the third mass;

[0037] The mass of the residual liquid in the mixture in the first container is calculated based on the second mass and the third mass.

[0038] Optionally, the first temperature is -20°C and the second temperature is -30°C.

[0039] The method for selecting lubricating oil for hybrid engines provided in this application embodiment, for at least one candidate lubricating oil, involves uniformly mixing the candidate lubricating oil with fuel and water at a certain mass ratio, and then allowing the mixture to stand for a period of time under different temperature environments. This effectively simulates the scenario of lubricating oil being contaminated under the operating conditions of a hybrid vehicle engine. Subsequently, by pouring the mixture after standing at two temperature environments into containers and comparing the proportion of the frozen mass of the remaining mixture in the containers under different temperature environments, the emulsification retention of the candidate lubricating oil under different temperature conditions can be clearly reflected. In other words, this method can detect the stability of the emulsification ability of the candidate lubricating oil under different temperature environments. Thus, when selecting lubricating oil for a hybrid engine, a candidate lubricating oil with qualified test results can be selected as the lubricating oil for the hybrid engine, ensuring that the lubricating oil can maintain good lubrication performance for the internal components of the engine under the operating conditions of the hybrid engine. Therefore, the method for selecting lubricating oil for hybrid engines provided in this application embodiment provides a reference for the selection of engine oil for hybrid engines. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart illustrating a method for selecting lubricating oil for a hybrid engine, as provided in an embodiment of this application.

[0042] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] In the description of this application, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0046] This application provides a method for selecting lubricating oil for a hybrid power engine (i.e., the engine of a hybrid electric vehicle). Figure 1 This is a flowchart of the method; see [link / reference]. Figure 1 The method includes:

[0047] S100. Obtain at least one candidate lubricating oil and perform emulsification retention stability tests on the obtained at least one candidate lubricating oil.

[0048] It should be noted that emulsion retention stability emphasizes whether the emulsion can maintain its dispersed state under specific conditions. For example, in the embodiments of this application, the emulsion retention stability test of lubricating oil is mainly used to test the stabilization performance of the lubricating oil emulsion under different temperature conditions.

[0049] The emulsion obtained by mixing the candidate lubricating oil, fuel and water according to the above preset ratio has a very high similarity to the lubricating oil emulsion under actual engine operating conditions. Therefore, it is beneficial to more accurately simulate the lubricating oil emulsion under actual engine operating conditions, and thus to accurately detect the emulsion maintenance stability of the candidate lubricating oil.

[0050] The method for testing the emulsification stability of each candidate lubricating oil may include the following steps S110-S160.

[0051] S110. For each candidate lubricating oil, mix the candidate lubricating oil, fuel oil and water in a mass ratio of 8:1:1 to obtain a mixture.

[0052] Prior to step S110, the method may include: obtaining candidate lubricating oil, fuel oil and water according to the above mass ratio.

[0053] Hybrid electric vehicle engines operate under conditions characterized by short running times, frequent start-stop cycles, and low lubricating oil temperatures. These characteristics can easily lead to more fuel and water mixing into the engine lubricating oil, resulting in fuel dilution, oil contamination, and the formation of emulsions.

[0054] In the detection method provided in this application embodiment, in order to more realistically simulate the above-mentioned emulsion, the ratio of lubricating oil, fuel and water in the actual operating conditions of the engine of a hybrid vehicle can be used to obtain candidate lubricating oil, fuel and water in the same proportion.

[0055] Optionally, the mass ratio of candidate lubricating oil, fuel oil, and water is candidate lubricating oil: fuel oil: water = 8:1:1. That is, in all the samples obtained, the mass proportion of candidate lubricating oil is 80%, the mass proportion of fuel oil is 10%, and the mass proportion of water is 10%.

[0056] The emulsion obtained by mixing the candidate lubricating oil, fuel and water according to the above preset ratio has a very high similarity to the lubricating oil emulsion under actual engine operating conditions. Therefore, it is beneficial to more accurately simulate the lubricating oil emulsion under actual engine operating conditions, and thus to accurately detect the emulsion maintenance stability of the candidate lubricating oil.

[0057] In this embodiment of the application, the candidate lubricating oil can be an engine oil suitable for hybrid power engines, and the fuel can be, for example, gasoline, diesel or other types of fuel that can be burned in the engine to provide energy.

[0058] In some embodiments, an agitator can be used to mix candidate lubricating oil, fuel, and water to achieve a more uniform mixing effect and improve mixing efficiency.

[0059] For example, in implementation, the candidate lubricating oil, fuel and water of the corresponding mass ratio can be poured into a mixer, the blade speed of the mixer is set to 10000 r / min and the mixing time is 1 minute, so that the candidate lubricating oil, fuel and water are fully mixed and the resulting mixture is the emulsion.

[0060] The blade speed and stirring time of the agitator can be adjusted according to actual needs, and this application embodiment does not limit this.

[0061] S120. Add equal masses of the mixture to the two first containers respectively, and then place the two first containers in the first temperature environment and the second temperature environment respectively.

[0062] The two primary containers are generally of the same type and have the same or similar properties. The material of the primary container should ensure that it will not chemically react with the components in the mixture. For example, the primary container can be made of glass.

[0063] Furthermore, the first container should have good sealing properties to prevent the mixture from evaporating or oxidizing during the settling process, avoid external contaminants from entering the mixture, and maintain the stability of the internal environment of the container. For example, the first container can be a glass bottle with a sealing plug.

[0064] To ensure a single variable, identical first containers should be used, and the mixture added to both first containers should be of equal mass. For example, the prepared mixture can be divided into two equal portions and then added to the two first containers respectively. Alternatively, a portion of the prepared mixture can be taken out, divided into two equal portions, and then added to the two first containers respectively.

[0065] It should be understood that the "same" first container in the embodiments of this application refers to two first containers having the same or substantially the same performance parameters and size parameters, for example, the same model of first container can be used.

[0066] Two first containers containing the mixture are placed in a first temperature environment and a second temperature environment for the same amount of time, respectively. For example, two first containers containing the mixture are placed in a first temperature environment and a second temperature environment, respectively, and placed for a second period of time.

[0067] Among them, the first temperature and the second temperature are not equal, for example, the first temperature is higher than the second temperature; the second duration is greater than zero.

[0068] Generally speaking, in low-temperature environments, the engine operates for shorter periods and at lower temperatures, making emulsification more likely during cold starts and low-speed driving. Therefore, the lower the temperature, the worse the emulsification performance of the engine oil in hybrid vehicles. Testing the emulsification stability of candidate lubricants in low-temperature environments is relatively more representative. Therefore, in some embodiments of this application, both the first and second temperatures can be below zero degrees Celsius. For example, the first temperature is -20°C and the second temperature is -30°C.

[0069] Optionally, the two first containers containing the mixture can be placed in two low-temperature freezers with set temperatures of a first temperature and a second temperature, respectively, and allowed to stand.

[0070] In some embodiments, the second duration is 18-48 hours, for example 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44 or 48 hours, to ensure that the emulsion is fully frozen in this environment.

[0071] In some embodiments, before placing the two first containers in a first temperature environment and a second temperature environment respectively, the two first containers can be placed in a room temperature environment for a third time.

[0072] Among them, the normal temperature environment refers to an environment with a temperature range of 20-25℃, such as a 20℃ environment; the third duration is 40-80 minutes, such as 40, 50, 60, 70 or 80 minutes.

[0073] For example, after the mixture is poured into two first containers, it is first left to stand at 20°C for 1 hour, and then the two first containers containing the mixture are placed in environments of -20°C and -30°C respectively, and left to stand for 24 hours to be fully frozen.

[0074] S130. After standing, pour out the mixture from the two first containers until no liquid flows out of the two first containers.

[0075] After the two first containers containing the mixture have been left to stand for a second period of time in environments of -20°C and -30°C respectively, the mixture in the two first containers is poured out until no liquid flows out of the two first containers.

[0076] After settling, some of the mixture may change properties and remain in the first container, making it impossible to pour out; and / or, some of the mixture may change its state and adhere to the inner wall of the first container, making it impossible to pour out. Therefore, there will always be some mixture remaining in the first container that cannot be poured out. It should be noted that the remaining mixture (i.e., the residual liquid of the mixture) does not necessarily exist in the form of a pure liquid; it may also exist in the form of a solid or a solid-liquid mixture.

[0077] In some embodiments, for the mixture in each first container after being allowed to stand at low temperature, the mixture can be directly poured from the first container into the second container, or the mixture can be filtered into the second container through a filter with a pore size of 30 micrometers until no liquid flows out of the first container.

[0078] The phrase "no liquid flows out of the first container" means that no liquid flows out of the first container after a first set of time. Specifically, when the mixture in the first container is poured into the second container, the mixture in the first container generally flows down in streams at first, and then gradually becomes continuous droplets. If no other droplets fall within the first set of time after one droplet falls, then that droplet can be considered the last droplet, satisfying the condition that no liquid flows out of the first container.

[0079] If the mixture is filtered into the second container through a filter with a pore size of 30 micrometers, and no liquid drips through the filter within a first time period, then it can be determined that no liquid flows out of the first container.

[0080] Optionally, a filter screen is installed on the first container, and the liquid in the mixture passes through the filter screen during pouring. The mixture filtered through the filter screen generally meets the following filtration pattern: it initially flows down in streams, and then gradually becomes a continuous dripping in the form of droplets. If, within a first time period after one droplet passes through the filter screen, no other droplets fall through the filter screen, then that droplet can be considered the last droplet, satisfying the condition that no liquid flows out of the first container.

[0081] It should be noted that, in the embodiments of this application, the mixture in the two first containers can be poured into the two second containers respectively, or it can be poured into the same second container.

[0082] S140. Obtain the mass of the residual liquid in the two first containers respectively.

[0083] In some embodiments, the emulsification retention stability of the candidate lubricating oil can be determined based on the mass of the residual liquid in the mixture within the two first containers.

[0084] Furthermore, the mass difference between the residual liquid in the two first containers can be obtained to determine the emulsification stability of the candidate lubricating oil.

[0085] When the mixture in the two first containers is poured into the two second containers respectively, the first mass of the mixture poured into the second container can be obtained first. Then, based on the first mass and the mass of the mixture added to the first container in step S120, the mass of the residual liquid in the first container can be calculated.

[0086] In some embodiments, the first mass of the mixture poured into the second container can be obtained based on the container and liquid mass on the second container side.

[0087] One exemplary method includes: obtaining a third mass of the second container and a fourth mass of the second container containing the mixture, and using the difference between the fourth mass and the third mass as the first mass of the mixture poured into the second container. The third and fourth masses can be obtained using a weighing instrument.

[0088] Another exemplary method includes: placing the second container on a weighing instrument and tare it; pouring the mixture from the first container into the second container until no liquid flows out of the first container, at which point the data displayed by the weighing instrument is the first mass.

[0089] In other embodiments, the mass of the residual liquid in the mixture in the first container can also be obtained directly based on the container and liquid mass on the first container side.

[0090] For example, when the mixture in the first container is directly poured into the second container, obtaining the mass of the residual liquid in the first container includes:

[0091] Obtain the self-weight of the first container and use it as the fifth mass;

[0092] The mass of the first container containing the residual liquid of the mixture when no liquid flows out of the first container is taken as the sixth mass;

[0093] The difference between the sixth and fifth masses is taken as the mass of the residual liquid in the first container.

[0094] The fifth and sixth masses can be obtained by weighing using a weighing instrument.

[0095] When the mixture in the first container is filtered through a filter screen into the second container, the mass of the residual liquid in the first container is obtained, including:

[0096] The sum of the masses of the first container and the filter screen is used as the second mass;

[0097] The mass of the first container and the filter screen containing the residual liquid of the mixture when no liquid flows out of the first container is obtained as the third mass;

[0098] Calculate the mass of the residual liquid in the first container based on the third and second masses.

[0099] The second and third masses can be obtained by weighing using a weighing instrument.

[0100] S150. Based on the mass of the residual liquid in the two first containers, calculate the proportion of the mass of the mixture frozen in the first temperature environment and the second temperature environment, respectively.

[0101] Alternatively, the mass percentage of the mixture that freezes can be calculated using the following formula:

[0102] ω=(1-M1 / M0)×100%

[0103] Where ω is the percentage of the mixture that is frozen, M1 is the mass of the residual mixture in the first container, and M0 is the mass of the mixture added to the first container.

[0104] S160. Determine the emulsification retention stability test results of the candidate lubricating oil based on the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment.

[0105] If the absolute value of the difference between the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment is less than or equal to a first threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be qualified.

[0106] If the absolute value of the difference between the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment is greater than a first threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be unqualified.

[0107] In this embodiment, the first threshold is set by those skilled in the art based on actual needs. Generally speaking, if the absolute value of the difference between the proportion of ice-forming mass of the mixture in the first temperature environment and the second temperature environment is less than the first threshold, it indicates that the tested candidate lubricating oil has good emulsification stability and can maintain its dispersion state even in low-temperature environments. When the candidate lubricating oil is applied to the engine of a hybrid vehicle, it can maintain a good lubrication effect even if it is contaminated by fuel and water. Conversely, if the absolute value of the difference between the proportion of ice-forming mass of the mixture in the first temperature environment and the second temperature environment is greater than the first threshold, it indicates that the tested candidate lubricating oil has poor emulsification stability and is difficult or impossible to maintain its dispersion state in low-temperature environments, easily resulting in oil-water separation. When the candidate lubricating oil is applied to the engine of a hybrid vehicle, it is more susceptible to contamination by fuel dilution and combustion byproduct water, thereby severely weakening its lubrication effect on engine components and easily affecting engine performance and lifespan. It should be understood that "absolute value of difference" refers to the absolute value of the difference between two numbers, and the absolute value of the difference is greater than or equal to zero.

[0108] S200. Select at least one candidate lubricant that has passed the emulsification stability test as the lubricant for hybrid engines.

[0109] In summary, the lubricant selection method for hybrid power engines provided in this application, for at least one candidate lubricant, simulates the scenario of lubricant contamination under the operating conditions of a hybrid vehicle engine by uniformly mixing the candidate lubricant with fuel and water at a certain mass ratio and then allowing the mixture to stand for a period of time under different temperature environments. Subsequently, by pouring the mixture out of the container after standing at two temperature environments and comparing the proportion of ice formation in the remaining mixture at different temperature environments, the emulsification retention of the candidate lubricant under different temperature conditions can be clearly reflected. That is, this method can detect the stability of the emulsification ability of the candidate lubricant under different temperature environments. Thus, when selecting lubricant for a hybrid power engine, a candidate lubricant with qualified test results can be selected as the lubricant for the hybrid power engine, ensuring that the candidate lubricant can maintain good lubrication performance for the internal engine components under the operating conditions of the hybrid power engine. Therefore, the lubricant selection method for hybrid power engines provided in this application provides a reference for the selection of engine oil for hybrid engines.

[0110] In some embodiments of this application, the method for selecting the lubricating oil for the hybrid power engine may further include: when the emulsification retention stability test results of more than one of the candidate lubricating oils are qualified, selecting the candidate lubricating oil with the smallest absolute value of the difference in the emulsification retention stability test as the lubricating oil for the hybrid power engine.

[0111] The "absolute value of the difference" in the emulsion retention stability test of lubricating oil reflects the emulsion retention stability of lubricating oil under different temperature conditions. The two are negatively correlated, that is, the smaller the absolute value of the difference, the better the emulsion retention stability of lubricating oil under different temperature conditions.

[0112] When the emulsion retention stability test results of multiple candidate lubricants are qualified, it indicates that these candidate lubricants can basically adapt to the operating conditions of the hybrid engine and maintain good lubrication performance under these conditions. In this case, the "absolute value of the difference" in the emulsion retention stability test of these candidate lubricants can be further compared. The candidate lubricant with the smallest "absolute value of difference" has better emulsion retention stability under different temperature conditions. Therefore, the candidate lubricant with the smallest "absolute value of difference" can be selected as the lubricant for the hybrid engine.

[0113] In some embodiments of this application, if the emulsification stability of the candidate lubricating oil is satisfactory, the method may further include:

[0114] In response to the absolute value of the difference between the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment being less than or equal to the second threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be excellent, wherein the second threshold is greater than zero and less than the first threshold.

[0115] The candidate lubricating oil is determined to have good emulsification retention stability test results if the absolute value of the difference between the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment is less than or equal to the first threshold and greater than the second threshold.

[0116] When selecting lubricating oil for hybrid engines, priority should be given to candidate lubricating oils with excellent emulsification stability test results.

[0117] The first and second thresholds are set by those skilled in the art according to actual needs. Generally speaking, the smaller the absolute value of the difference between the proportion of ice formation in the first and second temperature environments, the better the emulsification stability of the tested lubricating oil; the larger the absolute value of the difference between the proportion of ice formation in the first and second temperature environments, the worse the emulsification stability of the tested lubricating oil.

[0118] Compared to candidate lubricants with good test results, candidate lubricants with excellent test results exhibit better emulsification stability under different temperature conditions. Therefore, prioritizing candidate lubricants with excellent test results as the lubricant for hybrid engines can ensure relatively better and longer-lasting stable lubrication performance under hybrid engine operating conditions.

[0119] Based on the above method steps, including the testing of the emulsion retention stability of lubricating oil, when selecting engine oil for hybrid vehicles, the contents included in the method provided in the embodiments of this application can be used as a reference. Engine oil with a test result of qualified (or excellent) emulsion retention stability can be selected, or the engine oil with the highest emulsion retention stability among a variety of engine oils can be selected, so that the selected engine oil can ensure good and stable lubrication effect for hybrid engines, thereby effectively reducing mechanical friction of internal engine components and protecting machinery and processed parts.

[0120] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only.

[0121] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for selecting lubricating oil for a hybrid power engine, characterized in that, The method includes: At least one candidate lubricating oil was obtained, and the emulsification retention stability test was performed on each of the at least one candidate lubricating oils obtained. At least one candidate lubricant that passed the emulsification stability test was selected as the lubricant for the hybrid engine. The method for testing the emulsification stability of the candidate lubricating oil includes: The candidate lubricating oil, fuel oil and water are mixed evenly at a mass ratio of 8:1:1 to obtain a mixture. The mixture is added in equal mass to two first containers, and then the two first containers are placed in a first temperature environment and a second temperature environment, respectively, wherein the first temperature is higher than the second temperature, and both the first temperature and the second temperature are below zero degrees Celsius, the first temperature is -20°C and the second temperature is -30°C. After settling, the mixture in the two first containers is poured out until no liquid flows out of the two first containers, including: for the mixture in each first container, the mixture is poured out through a filter with a pore size of 30 micrometers; in response to no liquid dripping through the filter within a first time period, it is determined that no liquid flows out of the first container; The method of obtaining the mass of the residual liquid in the two first containers includes: for each first container, obtaining the sum of the mass of the first container and the filter screen as a second mass; weighing the sum of the mass of the first container and the filter screen with the residual liquid of the mixture when no liquid flows out of the first container as a third mass; and calculating the mass of the residual liquid in the first container based on the second mass and the third mass. Based on the mass of the residual liquid in the two first containers, calculate the percentage of the mass of the mixture that has frozen in the first temperature environment and the second temperature environment, respectively. If the absolute value of the difference between the proportion of the freezing mass of the mixture in the first temperature environment and the second temperature environment is less than or equal to a first threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be qualified; if the absolute value of the difference between the proportion of the freezing mass of the mixture in the first temperature environment and the second temperature environment is greater than the first threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be unqualified.

2. The method according to claim 1, characterized in that, The method further includes: When the emulsion retention stability test results of more than one of the candidate lubricating oils are qualified, the candidate lubricating oil with the smallest absolute value of the difference in the emulsion retention stability test will be selected as the lubricating oil for the hybrid engine.

3. The method according to claim 1 or 2, characterized in that, The method further includes: In response to the absolute value of the difference between the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment being less than or equal to a second threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be excellent, wherein the second threshold is greater than zero and less than the first threshold; In response to the absolute value of the difference between the proportion of freezing mass of the mixture in the first temperature environment and the second temperature environment being less than or equal to the first threshold and greater than the second threshold, the emulsification retention stability test result of the candidate lubricating oil is determined to be good. When selecting lubricating oil for hybrid engines, priority should be given to candidate lubricating oils with excellent emulsification stability test results.

4. The method according to claim 1, characterized in that, The mass percentage of the mixture that freezes is calculated according to the following formula: ω=(1-M1 / M0)×100% Where ω is the percentage of the mixture that is frozen, M1 is the mass of the residual mixture in the first container, and M0 is the mass of the mixture added to the first container.

5. The method according to claim 1, characterized in that, The step of pouring out the mixture from the two first containers includes: pouring the mixture from the two first containers into the two second containers respectively; The method further includes: Obtain the first mass of the mixture poured into the second container; The mass of the residual liquid in the first container is calculated based on the mass of the mixture added to the first container and the first mass.

Images