Method for selecting lubricating oil for hybrid engine

Abstract

The invention discloses a method for selecting lubricating oil of a hybrid power engine, and relates to the technical field of lubricating oil performance detection. The method comprises the following steps: obtaining at least one kind of candidate lubricating oil, and carrying out an emulsification maintaining stability test on the obtained at least one kind of candidate lubricating oil; selecting at least one kind of candidate lubricating oil of which the emulsification maintaining stability test result is qualified as the lubricating oil of the hybrid power engine; the invention further discloses a method for testing the emulsification maintaining stability of the candidate lubricating oil. According to the selection method for the lubricating oil of the hybrid power engine, reference is provided for engine oil selection of the hybrid power automobile.

Description

Technical Field

[0001] The present application relates to the technical field of lubricating oil performance detection, and in particular to a method for selecting lubricating oil for a hybrid engine. Background Art

[0002] Engine oil is a liquid lubricant used in engines. It can play important roles in lubrication, cooling, protection, sealing and cleaning. It can effectively reduce the mechanical friction of internal engine components and protect machinery and processed parts.

[0003] With the gradual promotion of new energy vehicles, the market share of hybrid vehicles has increased significantly, and higher requirements have been placed on the stability of the engine oil of hybrid vehicle engines. However, the operating conditions of hybrid vehicle engines are different from those of traditional internal combustion engines, with characteristics such as short engine operation time, frequent start and stop, and low oil temperature. These operating conditions make the engine oil of hybrid vehicle engines more susceptible to fuel dilution and water contamination from combustion byproducts. These contaminations will cause oil stratification, and water will be deposited at the bottom of the oil pan, which will affect the lubrication effect, aggravate the wear of mechanical parts, and seriously affect the engine performance and life in the long run.

[0004] Therefore, the engine oil used in hybrid vehicles needs to have good emulsification retention ability to cope with water and fuel contamination. However, there is currently no method in the field that can detect the emulsification retention stability of engine oil, resulting in no clear standard to refer to when selecting lubricants for hybrid engines. Summary of the invention

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

[0006] This application specifically adopts the following technical solutions: A method for selecting lubricating oil for a hybrid engine, comprising: Obtaining at least one candidate lubricant oil, and performing an emulsion retention stability test on the at least one candidate lubricant oil obtained; At least one candidate lubricant oil having a qualified emulsion retention stability test result is selected as the lubricant oil for the hybrid engine; The method for testing the emulsification stability of the candidate lubricant includes: The candidate lubricating oil, fuel oil and water are uniformly mixed in a mass ratio of 8:1:1 to obtain a mixed liquid; Adding equal masses of the mixed liquid into two first containers respectively, and then placing the two first containers in a first temperature environment and a second temperature environment respectively, wherein the first temperature is higher than the second temperature, and the first temperature and the second temperature are both lower than zero degrees Celsius; After standing, pour out the mixed liquid in the two first containers until no liquid flows out of the two first containers; respectively obtaining the masses of the residual liquids of the mixed liquids in the two first containers; Calculating the percentage of ice mass of the mixed liquid in the first temperature environment and the second temperature environment respectively according to the mass of residual liquid of the mixed liquid in the two first containers; In response to the absolute value of the difference between the ice mass percentage of the mixed liquid in the first temperature environment and the second temperature environment being less than or equal to a first threshold, determining that the emulsion retention stability test result of the candidate lubricant is qualified; In response to the absolute value of the difference between the ice mass percentage of the mixed liquid in the first temperature environment and the second temperature environment being greater than the first threshold, it is determined that the emulsion retention stability test result of the candidate lubricant is unqualified.

[0007] Optionally, the method further comprises: In response to at least two of the candidate lubricants having qualified test results in the emulsion retention stability test, the candidate lubricant having the smallest absolute value of difference in the emulsion retention stability test is selected as the lubricant for the hybrid engine.

[0008] Optionally, the method further comprises: In response to the absolute value of the difference between the percentage of ice mass of the mixed liquid in the first temperature environment and the second temperature environment being less than or equal to a second threshold, determining that the emulsion retention stability test result of the candidate lubricant is 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 ice mass percentage of the mixed liquid 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, determining that the emulsion retention stability test result of the candidate lubricant is good; When selecting a lubricant for a hybrid engine, preference is given to candidate lubricants with excellent emulsion retention stability test results.

[0009] Optionally, the ice mass percentage of the mixed liquid is calculated according to the following formula: ω=(1-M1 / M0)×100% Wherein, ω is the percentage of frozen mass of the mixed liquid, M1 is the mass of the residual liquid of the mixed liquid in the first container, and M0 is the mass of the mixed liquid added to the first container.

[0010] Optionally, pouring out the mixed liquid in the two first containers comprises: pouring the mixed liquid in the two first containers into two second containers respectively; The method further comprises: obtaining a first mass of the mixed liquid poured into the second container; The mass of the residual liquid of the mixed liquid in the first container is calculated according to the mass of the mixed liquid added to the first container and the first mass.

[0011] Optionally, pouring out the mixed liquid in the two first containers until no liquid flows out of the two first containers comprises: For each mixed solution in the first container, pour the mixed solution through a filter with a pore size of 30 microns; In response to no liquid dripping through the filter screen within a first period of time, it is determined that no liquid flows out of the first container.

[0012] Optionally, the method further comprises: Obtaining the sum of the masses of the first container and the filter as the second mass; Weighing the sum of the masses of the first container and the filter screen containing the residual liquid of the mixed liquid when no liquid flows out of the first container as the third mass; The mass of the residual liquid of the mixed liquid in the first container is calculated based on the second mass and the third mass.

[0013] Optionally, the first temperature is -20°C and the second temperature is -30°C.

[0014] The method for selecting lubricating oil for a hybrid engine provided in the embodiment of the present application, for at least one candidate lubricating oil, mixes the candidate lubricating oil with fuel and water in a certain mass ratio, and then leaves the mixture to stand for a period of time under different temperature environments, which well simulates the scene of the lubricating oil being contaminated under the operating conditions of the engine of a hybrid vehicle. Subsequently, by pouring the mixture after standing under two temperature environments out of the container, and comparing the ice mass proportion of the remaining mixture in the container under different temperature environments, it can intuitively reflect the emulsification retention of the candidate lubricating oil under different temperature conditions, that is, the method can realize the detection of the stability of the emulsification ability of the candidate lubricating oil under different temperature environments, so that when selecting lubricating oil for a hybrid engine, the candidate lubricating oil with qualified test results can be selected as the lubricating oil of the hybrid engine to ensure that the lubricating oil can maintain good lubrication performance for the internal parts of the engine under the operating conditions of the hybrid engine. Therefore, the method for selecting lubricating oil for a hybrid engine provided in the embodiment of the present application provides a reference for the selection of hybrid engine oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 This is a flow chart of a method for selecting lubricating oil for a hybrid engine provided in an embodiment of the present application.

[0017] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0020] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0021] The present application embodiment provides a method for selecting lubricating oil for a hybrid engine (i.e., the engine of a hybrid vehicle), Figure 1 is a flowchart of this method, see Figure 1 , the method comprising: S100, obtaining at least one candidate lubricant oil, and performing an emulsification stability test on the obtained at least one candidate lubricant oil.

[0022] It should be noted that the emulsion stability emphasizes whether the emulsion can maintain its dispersed state under specific conditions. For example, in the embodiments of the present application, the emulsion stability test of lubricating oil is mainly used to test the stability of the emulsion of lubricating oil under different temperature conditions.

[0023] The performance of the emulsion obtained after mixing the candidate lubricant, fuel and water obtained according to the above preset proportions is extremely similar to the lubricant emulsion under actual engine operating conditions, which is conducive to more accurately simulating the lubricant emulsion under actual engine operating conditions, and then facilitating accurate detection of the emulsification stability of the candidate lubricant.

[0024] The method of conducting an emulsion retention stability test on each candidate lubricant oil may include the following S110-S160.

[0025] S110, for each candidate lubricant, uniformly mix the candidate lubricant, fuel oil and water in a mass ratio of 8:1:1 to obtain a mixed liquid.

[0026] Before step S110 , the method may include: acquiring candidate lubricating oil, fuel oil and water according to the above mass ratio.

[0027] The operating conditions of the engine of a hybrid vehicle are characterized by short operating time, frequent start and stop, and low lubricating oil temperature. Such operating conditions easily lead to more fuel and water being mixed into the engine lubricating oil, thus causing fuel dilution, contamination of the lubricating oil, and formation of emulsion.

[0028] In the detection method provided in the embodiment of the present application, 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 referred to to obtain candidate lubricating oil, fuel and water with the same ratio.

[0029] Optionally, the mass ratio of the candidate lubricant, fuel and water is candidate lubricant: fuel: water = 8: 1: 1. That is, in all the samples obtained, the mass of the candidate lubricant accounts for 80%, the mass of the fuel accounts for 10%, and the mass of water accounts for 10%.

[0030] The performance of the emulsion obtained after mixing the candidate lubricant, fuel and water obtained according to the above preset proportions is extremely similar to the lubricant emulsion under actual engine operating conditions, which is conducive to more accurately simulating the lubricant emulsion under actual engine operating conditions, and then facilitating accurate detection of the emulsification stability of the candidate lubricant.

[0031] In the embodiment of the present application, the candidate lubricant may be an engine oil suitable for a hybrid engine, and the fuel may be, for example, gasoline, diesel or other types of fuel that can be burned in the engine to provide energy.

[0032] In some embodiments, an agitator may be used to mix the candidate lubricant, fuel, and water to achieve a more uniform mixing effect and improve mixing efficiency.

[0033] Exemplarily, during implementation, the candidate lubricants, fuel oils and water of corresponding mass ratios obtained can all be poured into a blender, and the blade speed of the blender can be set to 10,000 r / min and the blending time to 1 minute, so that the candidate lubricants, fuel oils and water are fully mixed, and the resulting mixed liquid is an emulsion.

[0034] Among them, the blade speed and stirring time of the agitator can be adjusted according to actual needs, and the embodiments of the present application are not limited to this.

[0035] S120, adding equal masses of the mixed liquid into the two first containers respectively, and then placing the two first containers in a first temperature environment and a second temperature environment respectively.

[0036] The two first containers are generally the same type of containers, having the same or similar properties. The material of the first container should ensure that it will not chemically react with the components in the mixed liquid. For example, the first container can be made of glass.

[0037] Moreover, the first container should also have good sealing properties, so as to prevent the mixed liquid from volatilizing or oxidizing during the static process, avoid external pollution sources from entering the mixed liquid, and maintain the stability of the internal environment of the container. For example, the first container can be a glass bottle with a sealing stopper.

[0038] To ensure a single variable, the same first container should be used, and the mixed liquid added to the two first containers should be of equal mass. For example, the prepared mixed liquid can be divided into two equal parts, and then added to the two first containers respectively. For another example, a portion of the prepared mixed liquid can be taken out, and then the taken out portion of the mixed liquid can be divided into two equal parts, and then added to the two first containers respectively.

[0039] It should be understood that the “same” first container described in the embodiment of the present application means that the performance parameters and size parameters of the two first containers are the same or substantially the same, for example, the same model of first containers can be used.

[0040] The two first containers containing the mixed liquid are respectively placed in the first temperature environment and the second temperature environment for the same time. For example, the two first containers containing the mixed liquid are respectively placed in the first temperature environment and the second temperature environment and are placed for a second time.

[0041] The first temperature and the second temperature are not equal, for example, the first temperature is higher than the second temperature; and the second time duration is greater than zero.

[0042] Generally speaking, in a low-temperature environment, the engine runs for a short time and the operating temperature is low. Emulsification is more likely to occur during cold start and low-speed driving. Therefore, the lower the temperature, the worse the emulsification performance of the engine oil of a hybrid vehicle. It is relatively more representative to detect the emulsification stability of the candidate lubricant in a low-temperature environment. Therefore, in some embodiments of the present application, both the first temperature and the second temperature can be lower than zero degrees Celsius. For example, the first temperature is -20°C and the second temperature is -30°C.

[0043] Optionally, the two first containers containing the mixed liquid may be placed in two low-temperature freezers set at a first temperature and a second temperature respectively for standing.

[0044] In some embodiments, the second period of time 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.

[0045] In some embodiments, before placing the two first containers in the first temperature environment and the second temperature environment respectively, the two first containers may be placed in a normal temperature environment for a third period of time.

[0046] Among them, the normal temperature environment refers to an environment with a temperature range of 20-25°C, for example, a 20°C environment; the third time length is 40-80 minutes, for example, 40, 50, 60, 70 or 80 minutes.

[0047] Exemplarily, after the mixed liquid is poured into the two first containers, it is first allowed to stand at 20°C for 1 hour, and then the two first containers containing the mixed liquid are placed in -20°C and -30°C environments respectively, and allowed to stand for 24 hours for sufficient freezing.

[0048] S130, after standing still, pour out the mixed liquid in the two first containers until no liquid flows out of the two first containers.

[0049] After the two first containers containing the mixed liquid are placed in a -20°C environment and a -30°C environment for a second period of time, the mixed liquid in the two first containers is poured out until no liquid flows out of the two first containers.

[0050] After the standing is completed, a part of the mixed liquid may change in properties, thereby remaining in the first container and unable to be poured out; and / or a part of the mixed liquid may adhere to the inner wall of the first container due to the change in physical state, thereby unable to be poured out, so there will always be a part of the mixed liquid remaining in the first container and unable to be poured out. It should be noted that the residual mixed liquid (i.e., the residual liquid of the mixed liquid) does not necessarily exist in the form of pure liquid, but may also exist in the form of solid, or in the form of a solid-liquid mixture.

[0051] In some embodiments, for the mixed liquid in each first container after low-temperature standing, the mixed liquid can be directly poured from the first container into the second container, or the mixed liquid can be filtered into the second container through a filter screen with a pore size of 30 microns until no liquid flows out of the first container.

[0052] Among them, "no liquid flows out of the first container" means that no liquid flows out of the first container after the first time period. Specifically, when pouring the mixed liquid in the first container into the second container, the mixed liquid in the first container generally flows down in streams first, and then gradually changes to continuous dripping in the form of droplets. If no other droplets fall within the first time period after one droplet falls, then it can be considered that the droplet is the last droplet, and the condition that no liquid flows out of the first container is met.

[0053] In the case where the mixed liquid is filtered into the second container through a filter screen with a pore size of 30 microns, in response to no liquid dripping through the filter screen within the first time period, it can be determined that no liquid flows out of the first container.

[0054] Optionally, the filter screen is mounted on the first container, and the liquid in the mixed liquid is filtered out through the filter screen when pouring. The mixed liquid filtered out through the filter screen generally also satisfies the filtering mode of first flowing down in streams and then gradually changing into continuous dripping in the form of droplets. If within a first time period after one droplet drips through the filter screen, no other droplets drip through the filter screen, then the droplet can be considered to be the last droplet, satisfying the condition that no liquid flows out of the first container.

[0055] It should be noted that, in the embodiment of the present application, the mixed liquid in the two first containers can be poured into two second containers respectively, or poured into the same second container.

[0056] S140, respectively obtaining the mass of the residual liquid of the mixed liquid in the two first containers.

[0057] In some embodiments, the emulsion maintenance stability of the candidate lubricating oil may be determined based on the mass of the residual liquid of the mixed liquid in the two first containers.

[0058] Furthermore, the mass difference of the residual liquid of the mixed liquid in the two first containers can be obtained to determine the emulsification stability of the candidate lubricating oil.

[0059] When the mixed liquids in the two first containers are poured into the two second containers respectively, the first mass of the mixed liquid poured into the second container can be obtained first, and then the mass of the residual liquid of the mixed liquid in the first container can be calculated based on the first mass and the mass of the mixed liquid added to the first container in step S120.

[0060] In some embodiments, the first mass of the mixed liquid poured into the second container can be obtained based on the mass of the container and the liquid on the second container side.

[0061] One exemplary method includes: obtaining the third mass of the second container and the fourth mass of the second container into which the mixed liquid is poured, and using the difference between the fourth mass and the third mass as the first mass of the mixed liquid poured into the second container. The third mass and the fourth mass can be obtained by weighing using a weighing instrument.

[0062] Another exemplary method includes: placing the second container on a weighing instrument and peeling it; pouring the mixed liquid in the first container into the second container until no liquid flows out of the first container, at which time the data displayed by the weighing instrument is the first mass.

[0063] In other embodiments, the mass of the residual liquid of the mixed liquid in the first container may also be directly obtained based on the mass of the container and the liquid on the first container side.

[0064] Exemplarily, when the mixed liquid in the first container is directly poured into the second container, obtaining the mass of the residual liquid of the mixed liquid in the first container includes: Obtain the container weight of the first container as the fifth mass; obtaining the mass of the first container having residual liquid of the mixed liquid when no liquid flows out of the first container as the sixth mass; The difference between the sixth mass and the fifth mass is taken as the mass of the residual liquid of the mixed liquid in the first container.

[0065] The fifth mass and the sixth mass can be obtained by weighing using a weighing instrument.

[0066] When the mixed liquid in the first container is filtered out into the second container through the filter screen, obtaining the mass of the residual liquid of the mixed liquid in the first container includes: Obtaining the sum of the masses of the first container and the filter as the second mass; Obtaining the sum of the masses of the first container and the filter screen containing the residual liquid of the mixed liquid when no liquid flows out of the first container as the third mass; The mass of the residual liquid of the mixed liquid in the first container is calculated based on the third mass and the second mass.

[0067] The second mass and the third mass can be obtained by weighing using a weighing instrument.

[0068] S150, calculating the ice mass proportion of the mixed liquid in the first temperature environment and the second temperature environment respectively according to the mass of the residual liquid of the mixed liquid in the two first containers.

[0069] Optionally, the ice mass percentage of the mixed liquid can be calculated according to the following formula: ω=(1-M1 / M0)×100% Wherein, ω is the percentage of frozen mass of the mixed liquid, M1 is the mass of the residual liquid of the mixed liquid in the first container, and M0 is the mass of the mixed liquid added to the first container.

[0070] S160. Determine the emulsification stability test result of the candidate lubricant according to the ice mass ratio of the mixed liquid in the first temperature environment and the second temperature environment.

[0071] In response to the absolute value of the difference between the ice mass percentages of the mixed liquid in the first temperature environment and the second temperature environment being less than or equal to the first threshold, it is determined that the emulsification retention stability test result of the candidate lubricant is qualified.

[0072] In response to the absolute value of the difference between the ice mass percentages of the mixed liquid in the first temperature environment and the second temperature environment being greater than a first threshold, it is determined that the emulsion retention stability test result of the candidate lubricant is unqualified.

[0073] In the embodiment of the present application, the first threshold value is set by a person skilled in the art according to actual needs. Generally speaking, if the absolute value of the difference between the ice mass percentage of the mixed liquid in the first temperature environment and the second temperature environment is less than the first threshold value, it means that the emulsification stability of the candidate lubricant being tested is good, and its dispersion state can be maintained in a low temperature environment. When the candidate lubricant is applied to the engine of a hybrid vehicle, even if it is contaminated by fuel and water, it can maintain a good lubrication effect. On the contrary, if the absolute value of the difference between the ice mass percentage of the mixed liquid in the first temperature environment and the second temperature environment is greater than the first threshold value, it means that the emulsification stability of the candidate lubricant being tested is poor, it is difficult or impossible to maintain its dispersion state in a low temperature environment, and oil-water stratification is prone to occur. When the candidate lubricant is applied to the engine of a hybrid vehicle, it is more susceptible to fuel dilution and combustion by-product water contamination, thereby seriously weakening its lubrication effect on the engine parts, and easily affecting the engine performance and life. 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.

[0074] S200, selecting at least one candidate lubricant oil that has a qualified emulsification retention stability test result as the lubricant oil for the hybrid engine.

[0075] In summary, the method for selecting lubricating oil for a hybrid engine provided in the embodiment of the present application, for at least one candidate lubricating oil, mixes the candidate lubricating oil with fuel and water in a certain mass ratio, and then leaves the mixture to stand for a period of time under different temperature environments, which well simulates the scene of the lubricating oil being contaminated under the operating conditions of the engine of a hybrid vehicle. Subsequently, by pouring the mixture after standing under two temperature environments out of the container, and comparing the ice mass proportion of the remaining mixture in the container under different temperature environments, it can intuitively reflect the emulsification retention of the candidate lubricating oil under different temperature conditions, that is, the method can realize the detection of the stability of the emulsification ability of the candidate lubricating oil under different temperature environments, so that when selecting lubricating oil for a hybrid engine, the candidate lubricating oil with qualified test results can be selected as the lubricating oil of the hybrid engine, so as to ensure that the candidate lubricating oil can maintain good lubrication performance for the internal parts of the engine under the operating conditions of the hybrid engine. Therefore, the method for selecting lubricating oil for a hybrid engine provided in the embodiment of the present application provides a reference for the selection of hybrid engine oil.

[0076] In some embodiments of the present application, the method for selecting the lubricant for the hybrid engine may also include: when the test results of the emulsion retention stability test of more than one candidate lubricant 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.

[0077] The "absolute value of the difference" in the emulsification stability test of the lubricating oil reflects the emulsification stability of the lubricating oil under different temperature conditions. The two are negatively correlated, that is, the smaller the absolute value of the difference, the better the emulsification stability of the lubricating oil under different temperature conditions.

[0078] When the emulsification retention stability test results of multiple candidate lubricants are qualified, it means that these candidate lubricants can basically adapt to the operating conditions of the hybrid engine and can maintain good lubrication performance under the operating conditions. In this case, the "absolute value of difference" of these candidate lubricants in the emulsification retention stability test can be further compared. The candidate lubricant with the smallest "absolute value of difference" has better emulsification 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.

[0079] In some embodiments of the present application, when the emulsification stability of the candidate lubricant is qualified, the method may further include: In response to the absolute value of the difference between the ice mass percentage of the mixed liquid in the first temperature environment and the second temperature environment being less than or equal to a second threshold, determining that the emulsion retention stability test result of the candidate lubricant is 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 ice mass percentage of the mixed liquid 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, determining that the emulsion retention stability test result of the candidate lubricant is good; When selecting a lubricant for a hybrid engine, preference is given to candidate lubricants with excellent emulsion retention stability test results.

[0080] The first threshold and the second threshold are set by those skilled in the art according to actual needs. Generally speaking, the smaller the absolute value of the difference between the ice mass percentage of the mixed liquid in the first temperature environment and the second temperature environment, the better the emulsification stability of the lubricating oil being tested; the larger the absolute value of the difference between the ice mass percentage of the mixed liquid in the first temperature environment and the second temperature environment, the worse the emulsification stability of the lubricating oil being tested.

[0081] Compared with the candidate lubricant with a good test result, the candidate lubricant with an excellent test result has better emulsification stability under different temperature conditions. In this way, the candidate lubricant with an excellent test result is preferably selected as the lubricant of the hybrid engine, which can ensure a relatively better and longer-lasting stable lubrication effect under the operating conditions of the hybrid engine.

[0082] Based on the above method steps, including the detection of the emulsification stability of the lubricating oil, when selecting engine oil for a hybrid vehicle, the contents included in the method provided in the embodiment of the present application can be used as a reference to select an engine oil with a qualified (or excellent) emulsification stability test result, or select an engine oil with the highest emulsification stability among a variety of engine oils, so that the selected engine oil can ensure a good and stable lubrication effect on the hybrid engine, thereby effectively reducing the mechanical friction of the internal components of the engine and protecting the machinery and processed parts.

[0083] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the present application disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only.

[0084] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for selecting lubricating oil for a hybrid engine, characterized in that: The method comprises: Obtaining at least one candidate lubricant oil, and performing an emulsion retention stability test on the at least one candidate lubricant oil obtained; At least one candidate lubricant oil having a qualified emulsion retention stability test result is selected as the lubricant oil for the hybrid engine; The method for testing the emulsification stability of the candidate lubricant includes: The candidate lubricating oil, fuel oil and water are uniformly mixed in a mass ratio of 8:1:1 to obtain a mixed liquid; Adding equal masses of the mixed liquid into two first containers respectively, and then placing the two first containers in a first temperature environment and a second temperature environment respectively, wherein the first temperature is higher than the second temperature, and the first temperature and the second temperature are both lower than zero degrees Celsius; After standing, pour out the mixed liquid in the two first containers until no liquid flows out of the two first containers; respectively obtaining the masses of the residual liquids of the mixed liquids in the two first containers; Calculating the percentage of ice mass of the mixed liquid in the first temperature environment and the second temperature environment respectively according to the mass of residual liquid of the mixed liquid in the two first containers; In response to the absolute value of the difference between the percentage of ice mass of the mixed liquid 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 lubricant is determined to be qualified; in response to the absolute value of the difference between the percentage of ice mass of the mixed liquid in the first temperature environment and the second temperature environment being greater than the first threshold, the emulsification retention stability test result of the candidate lubricant is determined to be unqualified.

2. The method according to claim 1, characterized in that The method further comprises: When the test results of the emulsion retention stability test of more than one of the candidate lubricants are qualified, the candidate lubricant with the smallest absolute value of difference in the emulsion retention stability test is selected as the lubricant for the hybrid engine.

3. The method according to claim 1 or 2, characterized in that: The method further comprises: In response to the absolute value of the difference between the percentage of ice mass of the mixed liquid in the first temperature environment and the second temperature environment being less than or equal to a second threshold, determining that the emulsion retention stability test result of the candidate lubricant is 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 ice mass percentage of the mixed liquid 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, determining that the emulsion retention stability test result of the candidate lubricant is good; When selecting a lubricant for a hybrid engine, preference is given to candidate lubricants with excellent emulsion retention stability test results.

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

5. The method according to claim 1, characterized in that The pouring out of the mixed liquid in the two first containers comprises: pouring the mixed liquid in the two first containers into two second containers respectively; The method further comprises: obtaining a first mass of the mixed liquid poured into the second container; The mass of the residual liquid of the mixed liquid in the first container is calculated according to the mass of the mixed liquid added to the first container and the first mass.

6. The method according to claim 1, characterized in that The pouring out of the mixed liquid in the two first containers until no liquid flows out of the two first containers comprises: For each mixed solution in the first container, pour the mixed solution through a filter with a pore size of 30 microns; In response to no liquid dripping through the filter screen within a first period of time, it is determined that no liquid flows out of the first container.

7. The method according to claim 6, characterized in that The method further comprises: Obtaining the sum of the masses of the first container and the filter as the second mass; Weighing the sum of the masses of the first container and the filter screen containing the residual liquid of the mixed liquid when no liquid flows out of the first container as the third mass; The mass of the residual liquid of the mixed liquid in the first container is calculated based on the second mass and the third mass.

8. The method according to claim 1, characterized in that The first temperature is -20°C, and the second temperature is -30°C.

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