Condenser tube for testing aviation lubricating oil

Abstract

The present application relates to aviation lubricating oil testing device technical field, disclose a kind of aviation lubricating oil testing condenser tube, including inner tube, outer tube and sleeve, the outer tube is peripherally arranged in inner tube and with the inner tube between first interlayer is formed;The first interlayer inside is the cavity for cooling fluid flow;The outer tube upper side is equipped with liquid outlet, and the outer tube lower side is equipped with liquid inlet;The upper and lower ends of inner tube are equipped with baffle;The sleeve is peripherally arranged in outer tube and with the outer tube between second interlayer is formed;The second interlayer inside is the cavity for test gas flow;The sleeve upper side is equipped with gas outlet, and the sleeve lower side is equipped with gas inlet.The present application is suitable for the test scene that needs to carry out long time condensation reflux, environment humidity is higher or environment temperature difference is greater, help to improve test accuracy.

Description

Technical Field

[0001] This invention relates to the technical field of aviation lubricating oil testing devices, and specifically to a condenser tube for testing aviation lubricating oil. Background Technology

[0002] A condenser is a laboratory device used to facilitate condensation in the distillation of liquids or the preparation of organic compounds. It is a glass instrument that uses the principle of heat exchange to cool and condense condensable gases into liquids. It typically consists of two glass tubes, one inside and one outside, with the smaller tube passing through the larger one, as shown in the attached image. Figure 1 As shown.

[0003] In aviation lubricant performance testing, condenser tubes are frequently used. For example, in the oxidation and corrosion performance test of aviation lubricants, a condenser tube is placed above the test tube, which contains a metal plate and the oil sample to be tested. During the test, the test tube is heated in a constant-temperature bath. During this process, the oil sample in the test tube evaporates and is condensed and refluxed through the condenser tube, preventing oil sample evaporation and facilitating accurate measurement of oil performance. Furthermore, in existing aviation lubricant performance testing, most condenser tubes used are conventional ones with inner and outer tubes. While these condenser tubes are simple in structure and easy to operate, they are still relatively susceptible to the effects of ambient temperature and humidity, affecting the condensation effect and even the test process. Summary of the Invention

[0004] The present invention aims to provide a condenser tube for testing aviation lubricating oil, which is suitable for test scenarios that require long-term condensation and reflux, and helps to improve the accuracy of the test.

[0005] The basic solution provided by this invention is as follows: a condenser tube for testing aviation lubricating oil, comprising an inner tube and an outer tube, wherein the outer tube is sleeved around the inner tube and forms a first interlayer between the outer tube and the inner tube; the interior of the first interlayer is a cavity for coolant flow; the upper side of the outer tube is provided with a liquid outlet, and the lower side of the outer tube is provided with a liquid inlet; both the upper and lower ends of the inner tube are provided with joints; and a sleeve is also included; the sleeve is sleeved around the outer tube and forms a second interlayer between the outer tube and the outer tube; the interior of the second interlayer is a cavity for test gas flow; the upper side of the sleeve is provided with a gas outlet, and the lower side of the sleeve is provided with a gas inlet.

[0006] The working principle and advantages of this invention are as follows: During the use of the condenser tube, due to the temperature difference between the first jacket containing the coolant and the external environment, for conventional condenser tubes with only a first jacket, this temperature difference causes frost to condense on the outer wall of the outer tube. After the frost melts into water, it flows down the tube wall. In conventional tests, since the impact of such droplets on the test seems insignificant, no additional testing costs are usually incurred to treat these droplets; this is also the case in existing aviation lubricant performance testing. However, this solution has made a breakthrough by discovering that such droplets actually have many negative impacts on the test and has designed a corresponding structure to effectively eliminate these negative impacts.

[0007] Specifically, if the droplets formed here continue to flow downwards, they can easily enter the test tube along the inner tube joint, affecting the quality of the oil sample. Furthermore, there is a possibility that direct contact between oil and water at high temperatures could cause the test tube to crack. This phenomenon has not been addressed in existing aviation lubricant performance testing because the testing environment and temperature conditions are unique, and the testing time is long. For example, in corrosion performance testing, the temperature environment of the test tube is around 200℃ (e.g., 175℃, 204℃), the coolant temperature is 18℃±2.5℃, and the laboratory room temperature is typically above 21℃. The standard test time is 72 hours. Under these conditions, the room temperature and coolant temperature are not significantly different. Although frost may form on the outer wall of the outer tube, it is relatively small, making it difficult to detect the risk immediately. During long-term testing, this small frost will form droplets, but due to the high temperature environment of the test tube, the droplets are easily evaporated during the dripping process, making the droplets themselves difficult to detect. However, the droplets still have an impact on the experiment, such as evaporation inside the test tube, affecting the accuracy of oil test data. This effect is more severe when the temperature difference is greater.

[0008] This solution addresses this phenomenon by adding a sleeve around the outer tube, creating a second interlayer for the flow of test gas. By introducing the test gas into the cavity of this second interlayer through the inlet, it effectively prevents the formation of accumulated droplets on the outer wall of the outer tube, fundamentally eliminating the potential risks associated with the condenser tube. The condenser tube provided by this solution is well-suited for testing scenarios requiring prolonged condensation and reflux, and in complex temperature and experimental environments. It reduces the risk of test tube breakage while improving experimental accuracy.

[0009] Furthermore, compared to existing condenser tubes with insulation layers, although these can handle droplets on the outer tube to some extent, the solid insulation layer can easily obstruct the observation of coking phenomena. Some insulation layers are designed to create a vacuum environment, but in practice, absolute vacuum cannot be achieved within the insulation layer, and the condenser tube risks cracking as the test tube temperature increases. In contrast, the second interlayer in this solution is transparent and maintains gas flow within it, facilitating the observation of coking phenomena while eliminating the risk of condenser tube cracking. It also provides superior handling of droplets on the outer tube. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of a conventional condenser tube structure;

[0011] Figure 2 This is a schematic diagram of the overall structure of an embodiment of a condenser tube for testing aviation lubricating oil according to the present invention. Detailed Implementation

[0012] The following detailed explanation illustrates the specific implementation methods:

[0013] The markings in the accompanying drawings of the instruction manual include: inner tube 1, connector 11, outer tube 2, liquid inlet 21, liquid outlet 22, sleeve 3, air inlet 31, and air outlet 32.

[0014] The basic implementation examples are as follows: Figure 2 As shown: A condenser tube for testing aviation lubricating oil includes an inner tube 1, an outer tube 2, and a sleeve 3.

[0015] The outer tube 2 is sleeved around the inner tube 1 and forms a first interlayer between them; the interior of the first interlayer is a cavity for the flow of coolant; the upper side of the outer tube 2 is provided with an outlet 22, and the lower side of the outer tube 2 is provided with an inlet 21; both the upper and lower ends of the inner tube 1 are provided with joints 11. The inner tube 1 is used for the condensation and reflux of aviation lubricating oil vapor.

[0016] The sleeve 3 is sleeved around the outer tube 2 and forms a second interlayer with the outer tube 2; the interior of the second interlayer is a cavity for the flow of test gas; the upper side of the sleeve 3 is provided with an air outlet 32 ​​and the lower side of the sleeve 3 is provided with an air inlet 31.

[0017] Specifically, the cavity thickness of the second interlayer is 5mm-10mm. The test gas is introduced into the second interlayer through the inlet 31 at a rate of 50ml / s-100ml / s. Under this condition, the flow of the test gas in the cavity is more stable, and it can more evenly purge any droplets that may condense on the outer wall of the outer tube 2. The inlet 31 is located below the liquid inlet 21, and the outlet 32 ​​is located above the liquid outlet 22. Under this structural condition, the purging area of ​​the test gas can cover the entire coolant flow section, ensuring thorough purging.

[0018] The dew point of the test gas is below -30°C. In this embodiment, the test gas used is compressed air, and the temperature of the test gas is 15°C–35°C. This type of gas does not readily interact with ambient temperature, the temperature of the first interlayer, etc., and has a good purging effect when purging the outer wall of the outer tube 2, effectively preventing the formation of water droplets on the outer wall of the outer tube 2.

[0019] In practical applications, such as in the oxidation and corrosion performance test of aviation lubricating oil, a condenser tube for aviation lubricating oil testing is installed above the test tube, connecting the inner tube 1 (connection 11) to the test tube. The inlet 21 and outlet 22 of the outer tube 2 are connected to the coolant inlet and outlet pipes, respectively. The inlet 31 and outlet 32 ​​of the sleeve 3 are connected to the air inlet and outlet pipes, respectively, to facilitate the flow of coolant and test gas. During the test, test gas and coolant are injected into the second and first jackets, respectively, through the air inlet 31 and inlet 21. The inner tube 1 and outer tube 2 then work together to complete condensation and reflux; the test gas in the sleeve 3 continuously purges the outer wall of the outer tube 2, preventing the formation of droplets on the outer wall. Furthermore, during a long-term test of 72 hours, or in environments with large temperature differences, this condenser tube can ensure that the outer wall of the outer tube 2 remains relatively dry and does not form droplets.

[0020] This embodiment provides a condenser tube for testing aviation lubricating oil, which features an additional sleeve 3 to construct a second interlayer. Test gas flows through this second interlayer, effectively mitigating the condensation phenomenon of the outer tube 2 itself and preventing its impact on the test. This design is compatible with aviation lubricating oil performance testing and can meet the needs of complex test scenarios requiring prolonged condensation reflux and varying temperature and testing environments, thus contributing to improved test accuracy.

[0021] Notably, the condenser tube in this design is used in a unique scenario—in aviation lubricant testing. As an aviation-grade oil, aviation lubricant requires more specialized testing methods and environments compared to conventional samples. For example, in its oxidation corrosion performance test, the oil needs to be kept at approximately 200°C for 72 hours. The condenser tube is connected to the test tube containing the oil to condense and reflux the oil vapor generated at high temperatures. During this process, the test tube is actually situated within a specific temperature environment. The condenser tube itself has an internal and external temperature difference (the first temperature difference), and its outer tube 2 also has a temperature difference with the external environment (the second temperature difference). In condenser tube applications, testers often only focus on the first temperature difference, neglecting the potential impact of droplets generated by the second temperature difference on the test: 1) Droplets flow into the test tube along the tube wall, affecting the test results; 2) Droplets flow to the outer tube 2 wall, posing a risk of test tube breakage and potentially damaging the test environment.

[0022] This study identified the impact of droplets on the outer tube 2 of the condenser on the experiment and proposed an effective improvement plan. However, existing improvement plans for the condenser do not specifically address the structural modifications to handle droplets on the outer tube 2. The reasons for this are as follows: in current experiments, the condensation process of droplets on the outer tube 2 is slow, making them difficult to observe and leaving no trace. The second temperature difference is often overlooked, and researchers are unaware of this impact. Furthermore, even under conditions of large temperature differences, the droplets are more noticeable, and current methods involve periodically inspecting the experimental setup to manage the condensation. This approach requires significant manpower. Other structural solutions include increasing the friction of the condenser joint 11 and adding an insulation layer. However, the former is inconvenient to operate, and disassembling the condenser and test tube is difficult; the latter is effective for a certain period, but the solid insulation layer structure can obstruct the observation of coking phenomena, and insulation layers designed for a vacuum environment cannot achieve absolute vacuum, posing a risk of test tube breakage.

[0023] In the double-layer structure of this design, a gas flow rate of 50ml / s–100ml / s is maintained in the second interlayer. Within this second interlayer, which has a preset thickness of 5mm–10mm, a new and stable temperature layer is constructed surrounding the outer tube 2 of the condenser. This ensures a long-term, uniform, and stable temperature environment for the outer tube 2. Furthermore, the airflow continuously purges the outer tube 2, effectively preventing droplet formation. Moreover, the properly controlled thickness of the second interlayer minimizes the increase in the volume of the condenser, ensuring it does not interfere with the placement of other equipment during the experiment. The overall design is convenient to handle and use.

[0024] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics of the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, based on the guidance provided in this application, improve and implement this solution in conjunction with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method for using a condenser tube for testing aviation lubricating oil, characterized in that, The aviation lubricating oil testing condenser tube includes an inner tube, an outer tube, and a sleeve. The outer tube is sleeved around the inner tube, forming a first interlayer between them. The interior of the first interlayer is a cavity for coolant flow. The upper side of the outer tube has an outlet, and the lower side has an inlet. Both the upper and lower ends of the inner tube have joints. The sleeve is sleeved around the outer tube, forming a second interlayer between them. The interior of the second interlayer is a cavity for test gas flow. The upper side of the sleeve has an outlet, and the lower side has an inlet. The inlet is located below the inlet, and the outlet is located above the outlet. During the test, the test gas is introduced into the second jacket from the inlet at a rate of 50 ml / s to 100 ml / s; the test gas in the sleeve is kept blowing on the outer wall of the outer tube to prevent the formation of droplets on the outer wall of the outer tube; The dew point of the test gas is below -30°C; the air temperature of the test gas is 15°C to 35°C; the inner tube is used for condensation and reflux of aviation lubricating oil vapor.

2. The method of using a condenser tube for testing aviation lubricating oil according to claim 1, characterized in that, The test gas was compressed air.

3. The method of using a condenser tube for testing aviation lubricating oil according to claim 1, characterized in that, The cavity thickness of the second interlayer is 5 mm to 10 mm.

4. The method of using a condenser tube for testing aviation lubricating oil according to claim 1, characterized in that, The inner tube is a spherical inner tube.

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