Oil emulsification prevention control method for gas compressor of urban rail vehicle

Abstract

The invention relates to an oil-proof emulsification control method and system for an air compressor of an urban rail vehicle, and solves the problem of lubricating oil emulsification caused by insufficient working efficiency of the air compressor and environment humidity change by constructing a comprehensive control system comprising the compressor, an oil-proof emulsification device and a controller. The system monitors lubricating oil temperature and environment humidity in real time through a temperature sensor and a humidity sensor; the working rate of the air compressor is accurately calculated, wherein the vehicle operation time t2 takes the operation speed larger than 10 km / h as the calculation starting point; the controller comprehensively judges whether the oil-proof emulsification device is started or not based on temperature, humidity and working rate data, and the control strategy comprises the step of dynamically adjusting the working rate judgment node according to the real-time temperature and humidity. According to the method, accurate and reliable control over the oil-proof emulsification process is achieved, emulsification of the lubricating oil is effectively prevented, and energy consumption and maintenance cost can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressors, in particular to a control method for preventing oil emulsification of an air compressor of an urban rail vehicle. BACKGROUND

[0002] The braking system of urban rail transit usually uses compressed air as the working medium, and the air supply system mainly adopts two technical routes: oil-filled compressors and oil-free compressors. In the working process of oil-filled compressors, lubricating oil plays a key role in lubrication and cooling, ensuring that compressed air can safely and effectively enter the braking system. However, during the air compression process, water vapor in the air will condense into water, which will mix with the lubricating oil. When the compressor is not working for a long time, the temperature of the lubricating oil decreases, and the water cannot evaporate in time, resulting in the formation of an oil-water mixture and emulsification.

[0003] The industry has explored various methods to solve the problem of lubricating oil emulsification. Mainly including increasing the start-up time of the air compressor to promote oil-water separation, thereby eliminating emulsification. Specific technical means include: increasing the air compressor load rate, the traditional method is to artificially discharge compressed gas to the atmosphere to increase the working time of the air compressor unit, increase the temperature of the lubricating oil, and promote the evaporation of water. Some technical solutions propose to install an electric heating element inside or outside the air compressor oil tank, control the temperature of the lubricating oil with a temperature controller, and evaporate the water to prevent emulsification.

[0004] Despite the above-mentioned various technical solutions, in actual application, the control of oil emulsification of the air compressor of the urban rail vehicle still faces challenges: the calculation of the existing vehicle air compressor working rate may not be accurate enough, and it is difficult to accurately reflect its actual working state, leading to incomplete analysis of the reasons for lubricating oil emulsification. The control strategy of the air compressor working rate adjustment device is relatively simple, and most of them do not fully consider the changes in environmental conditions, and many existing solutions rely on manual tracking and intervention, such as regular inspection of oil conditions, manual forced air compressor operation or replacement of dryer components, which increases the workload and cost of daily maintenance.

[0005] In summary, although the control technology of oil emulsification of the air compressor of the urban rail vehicle has made some progress, there is still a need for further research and improvement in terms of control accuracy, environmental adaptability, energy efficiency optimization, system impact, and intelligent level. SUMMARY

[0006] The purpose of the present application is to realize intelligent and adaptive control of the oil emulsification prevention device by comprehensively monitoring the ambient temperature, humidity and calculating the accurate air compressor working rate. The method effectively prevents lubricating oil emulsification while ensuring the safety of the brake system air supply, and reduces energy waste and avoids affecting passenger comfort through optimized control strategy. The urban rail vehicle air compressor oil emulsification prevention control method of the present application is realized by the following technical scheme, which comprises an oil emulsification prevention control system comprising a compressor, an oil emulsification prevention device and a controller, wherein the oil emulsification prevention device comprises an exhaust pipeline, the exhaust pipeline comprises a plug valve, a first electromagnetic valve; acquire the temperature during the operation of the compressor through a temperature sensor; acquire the humidity during the operation of the compressor through a humidity sensor; acquire the compressor start-up time t1, acquire the vehicle operation time t2, and obtain the working rate according to the compressor start-up time and the vehicle operation time, wherein the vehicle running speed is greater than 10 km / h, which is the starting point for calculating the vehicle operation time; determine whether to start the oil emulsification prevention device according to the temperature, humidity and working rate.

[0007] In one embodiment, a second electromagnetic valve is further provided on the oil emulsification prevention device, the second electromagnetic valve is connected in series with the first electromagnetic valve, and the second electromagnetic valve is controlled by a time period control unit to open only within a preset time range.

[0008] In one embodiment, a manual pipeline is further provided on the oil emulsification prevention device, the manual pipeline comprises a third electromagnetic valve, the third electromagnetic valve is connected in parallel with the first electromagnetic valve, and the third electromagnetic valve is opened by a manual control unit for manual control.

[0009] In one embodiment, a pressure sensor is further provided, and the exhaust pipeline further comprises an overflow valve, which is closed when the total air pressure is less than 7.9 bar.

[0010] In one embodiment, the working rate judgment node is dynamically adjusted according to the humidity and temperature data, and whether to start the oil emulsification prevention device is determined according to the calculated working rate and the adjusted judgment node.

[0011] In one embodiment, the exhaust pipeline further comprises a choke valve, and the flow rate of the choke valve is adjusted according to the humidity and temperature data.

[0012] In one embodiment, different humidities during operation are segmented and sorted, the working rate judgment node is adjusted lower when the humidity gradually increases, and the working rate judgment node is adjusted higher when the humidity gradually decreases.

[0013] In one of the embodiments, the oil emulsification prevention device is started when the humidity change is greater than 50% in the next operation.

[0014] In one of the embodiments, the working rate of the oil emulsification prevention device is set to 30%, and the working rate determination value is reduced when the relative humidity is greater than 90%.

[0015] In one of the embodiments, a kinetic energy recovery device is further included.

[0016] Compared with the prior art, the present application has the following beneficial effects: The temperature sensor and the humidity sensor are used to obtain the lubricating oil temperature and the environmental humidity data during the operation of the compressor in real time, and the accurate working rate calculation is combined with the vehicle operation speed greater than 10 km / h as the calculation starting point, so that the judgment of the working state of the compressor is more accurate. On this basis, the system can dynamically adjust the working rate discrimination node according to the real-time temperature and humidity data, so that the start-stop control of the oil emulsification prevention device is more in line with the actual working condition requirements, the oil emulsification prevention effect is improved, and compared with the traditional single time or pressure control method, the control precision and reliability are improved.

[0017] An overflow valve is arranged in the exhaust pipeline of the oil emulsification prevention device, and the total air pressure is monitored in real time by a pressure sensor. When the total air pressure is lower than 7.9 bar (790 kPa), the overflow valve is automatically closed to ensure that the brake system air is not affected, meet the highest priority requirement of brake safety in the field of rail transit, and the train brake air pressure is maintained within the safety range. By introducing a second electromagnetic valve in series and managed by a time period control unit, the forced exhaust operation of the oil emulsification prevention device can be limited to a preset time range, avoiding the additional start of the compressor due to forced exhaust during peak operation period, thereby reducing energy waste and negative impact on passenger comfort.

[0018] A third electromagnetic valve operated by a manual control unit and a manual pipeline are arranged in parallel with the first electromagnetic valve, so that maintenance personnel can intervene flexibly in special circumstances (such as sensor failure or extreme weather), and directly manually control the start-stop of the oil emulsification prevention device. This manual / automatic dual-mode design improves the redundancy and ability to respond to unexpected situations of the system, and reduces the maintenance difficulties caused by system rigidity.

[0019] In summary, the urban rail vehicle air compressor oil emulsification prevention control method provided by the present application integrates environmental perception, intelligent decision-making, safety protection, and multi-mode operation, etc. Technical features, while effectively preventing and treating lubricating oil emulsification, taking into account brake safety, energy efficiency and operation and maintenance cost, the comprehensive technical effect is good. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1is a flowchart of a control method in an embodiment of the present application; Fig. 2 is a structural diagram of an oil emulsification prevention device in an embodiment of the present application.

[0021] Legend: 100, plug valve; 200, first electromagnetic valve; 300, second electromagnetic valve; 400, third electromagnetic valve; 500, overflow valve; 600, muffler. DETAILED DESCRIPTION

[0022] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that only the parts related to the present application are shown in the drawings, not all the structures. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0023] The terms "comprising" and "having" and any variations thereof in the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0024] In this document, the term "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it independent or alternative to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0025] The urban rail vehicle air compressor oil emulsification prevention control method of the present application will be described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the protection scope of the present application. Those skilled in the art can make various improvements and modifications on the basis of the concept of the present application, and these improvements and modifications should also be considered to fall within the protection scope of the present application. The present application provides an urban rail vehicle air compressor oil emulsification prevention control method, which is characterized by multi-parameter sensing and intelligent decision-making to realize precise control of the oil emulsification prevention device, thereby effectively preventing compressor lubricating oil emulsification while ensuring the absolute safety of the braking system, and taking into account energy efficiency and operation and maintenance requirements. Please refer to Figs. 1-2As shown, the oil emulsification control method for the air compressor of the urban rail vehicle in the preferred embodiment of the present application comprises providing an oil emulsification control system comprising a compressor, an oil emulsification device, and a controller, wherein the oil emulsification device comprises an exhaust pipeline, the exhaust pipeline comprises a plug valve 100 and a first electromagnetic valve 200, the temperature of the compressor during operation is obtained through a temperature sensor, the humidity of the compressor during operation is obtained through a humidity sensor, the compressor start-up time t1 is obtained, the vehicle operation time t2 is obtained, the working rate is obtained according to the compressor start-up time and the vehicle operation time, when the vehicle running speed is greater than 10 km / h, the vehicle operation time t2 is taken as the starting point of calculation, and whether to start the oil emulsification device is determined according to the temperature, the humidity, and the working rate.

[0026] The oil emulsification control method for the air compressor of the urban rail vehicle of the present application solves the problem of lubricating oil emulsification caused by insufficient working rate of the air compressor and change of environmental humidity in the field of rail transit by constructing a comprehensive control system comprising a compressor, an oil emulsification device, and a controller. The oil emulsification device comprises an exhaust pipeline, the pipeline is provided with key components such as a plug valve 100 and a first electromagnetic valve 200, and the core function is to indirectly increase the working load of the compressor through controllable exhaust operation, to improve the temperature of the lubricating oil, thereby promoting the evaporation of water, and preventing the formation of an emulsion phenomenon of the oil-water mixture.

[0027] Firstly, regarding the multi-parameter sensing and collecting system, the temperature of the lubricating oil during the operation of the compressor is obtained in real time through a temperature sensor, and the environmental humidity data during the operation of the compressor is obtained through a humidity sensor, to provide a decision basis for the control system. The environmental humidity is one of the important factors leading to lubricating oil emulsification, and the temperature of the lubricating oil directly affects the evaporation efficiency of water. Through real-time monitoring of these two parameters, the system can more accurately evaluate the risk level of lubricating oil emulsification, to provide a data basis for subsequent judgment.

[0028] Secondly, regarding the accurate calculation of the working rate, the present method defines the ratio of the compressor start-up time t1 to the vehicle operation time t2 as the working rate, and particularly provides that the vehicle running speed greater than 10 km / h is taken as the starting point of calculation of the vehicle operation time t2. The technical feature is to overcome the calculation error of t2 (vehicle power-on time) caused by continuous power supply after the vehicle returns to the depot in the traditional calculation of the working rate, so that the calculation result of the working rate can more truly reflect the load condition of the compressor under the actual operation condition. The working rate is a key index for judging whether the compressor is likely to cause oil temperature to be too low due to insufficient working time, and thus to cause emulsification. The optimization of the calculation method improves the accuracy of state evaluation.

[0029] Regarding the intelligent decision and control logic, the controller makes a comprehensive decision on whether to start the oil emulsification prevention device based on the real-time collected temperature, humidity, and calculated working rate. For example, when the humidity is high, the system can appropriately lower the working rate threshold for triggering the oil emulsification prevention device (e.g., below 30% to trigger), because the emulsification risk is higher in a high-humidity environment; and when it is monitored that the humidity is expected to change significantly (e.g., a change of more than 50%), the system can intervene in advance to cope with the upcoming high-risk working condition. Compared with the control method in the prior art, which only relies on a single parameter (such as working rate or simple humidity threshold), this multi-parameter fusion judgment-based logic can more finely and efficiently manage the anti-emulsification process, start the exhaust at the necessary time, avoid energy waste and unnecessary wear and tear of equipment, and also avoid affecting passenger comfort (such as avoiding frequent exhaust during peak operating periods) when unnecessary.

[0030] Finally, regarding the specific structure and safety protection of the oil emulsification prevention device, the plug valve 100 and the first electromagnetic valve 200 arranged in the exhaust pipeline constitute the exhaust execution mechanism. The plug valve 100 can be used for maintenance isolation, and the first electromagnetic valve 200 receives instructions from the controller to realize the opening and closing of the pipeline. Further, in some embodiments, the exhaust pipeline can further include an overflow valve 500, which cooperates with a pressure sensor to ensure the safety of the brake system when the system monitors that the total air pressure is lower than a safety value.

[0031] A preferred embodiment further relates to the optimization of the specific structure of the oil emulsification prevention device, in which a second electromagnetic valve 300 is arranged on the oil emulsification prevention device, the second electromagnetic valve 300 is connected in series with the first electromagnetic valve 200, and a time period control unit is configured, which is set to control the second electromagnetic valve 300 to be opened only within a preset time range. The second electromagnetic valve 300 and the first electromagnetic valve 200 are connected in series in the exhaust pipeline, forming a double control loop. This design means that only when both electromagnetic valves receive an opening instruction, the exhaust pipeline will be turned on and exhaust. The "preset time range" is usually set according to the train operation timetable and passenger flow regularity. For example, it can be set to the low-peak period of 21:00 to 23:00 at night. By managing the opening and closing of the second electromagnetic valve 300 through the time period control unit, it is ensured that the forced exhaust operation of the oil emulsification prevention device actively avoids the daytime peak operating period, which can effectively reduce the potential impact on passenger comfort caused by exhaust noise or frequent start-stop of the compressor.

[0032] A manual pipeline is added to the oil emulsification prevention device, which includes a third electromagnetic valve 400, and the third electromagnetic valve 400 is connected in parallel with the first electromagnetic valve 200 in the main exhaust pipeline, and a manual control unit is configured to manually trigger and open the third electromagnetic valve 400 under certain conditions, thereby realizing a manual control mode of the oil emulsification prevention device. Specifically, the manual pipeline serves as an additional physical channel independent of the automatic control circuit (i.e., a circuit in which the first electromagnetic valve 200 is automatically controlled by the controller according to temperature, humidity, work rate, and other parameters), and its core function is to provide a direct human intervention control means that is independent of automatic sensors and control algorithms. The third electromagnetic valve 400, as the execution element of the manual pipeline, is usually a normally closed electromagnetic valve, which is initially closed and only gets power on when the manual control unit sends an explicit opening instruction. The third electromagnetic valve 400 can be connected to the second electromagnetic valve 300 and the overflow valve 500, i.e., it is controlled by the second electromagnetic valve 300 and the overflow valve 500, and is normally closed. When the second electromagnetic valve 300 is opened, the third electromagnetic valve 400 is also opened, and when the second electromagnetic valve 300 is closed, the third electromagnetic valve 400 is also closed. When the overflow valve 500 is opened, the third electromagnetic valve 400 is also opened, and when the overflow valve 500 is closed, the third electromagnetic valve 400 is also closed. The manual control unit can be a dedicated button / switch set in the driver's cabin or vehicle equipment cabinet, or it can be integrated into the human-machine interface (HMI) of the train control system (TCMS) and accessed and operated by maintenance personnel after password or permission verification. When it is activated, it bypasses the automatic decision logic of the controller and directly sends an opening signal to the third electromagnetic valve 400 to forcibly open the manual pipeline, so that the compressed air in the total air cylinder is discharged to the atmosphere through the pipeline, thereby artificially increasing the air consumption of the system.

[0033] The air compressor oil emulsification prevention control method claimed in the present application ensures that the exhaust operation of the oil emulsification prevention device does not further reduce the total air pressure by integrating a pressure sensor and an overflow valve 500 in the exhaust pipeline of the oil emulsification prevention device and setting the overflow valve 500 to be closed when the total air pressure is below 7.9 bar (790 kPa), monitoring the total air pressure in real time through the pressure sensor, and immediately closing the overflow valve 500 when the pressure is detected to be below 7.9 bar. This design prioritizes the air demand of the braking system, meeting the core requirement of safety in the field of rail transportation. The closing action of the overflow valve 500 under low air pressure conditions avoids the frequent starting of the air compressor caused by continuous exhaust when the total air pressure is insufficient. This not only reduces unnecessary power consumption (avoiding the waste of converting electrical energy into compressed air energy and then directly discharging it), but also reduces the mechanical wear of the air compressor and related components (such as the dryer) caused by frequent start-stop or long-term operation, helping to extend the service life of the equipment.

[0034] The pressure sensor is used in conjunction with the overflow valve 500, enabling the system to dynamically adjust the start-stop of the oil emulsification prevention function according to the actual wind pressure state. This mechanism enhances the adaptability of the system under different working conditions, such as during the off-peak period of passenger flow (low total wind consumption) or in a high-humidity environment, the system can intelligently determine whether to start the anti-emulsification program while ensuring wind pressure safety, avoiding the misoperation or insufficient response that may be caused by single parameter control.

[0035] According to the real-time monitoring of environmental humidity data and compressor lubricating oil temperature data, the working rate judgment node (i.e. trigger threshold) for determining whether to start the oil emulsification prevention device is dynamically adjusted, and based on the comparison result of the calculated actual working rate and the above dynamically adjusted judgment node, it is comprehensively determined whether to start the oil emulsification prevention device. The fixed working rate trigger threshold (e.g. uniformly set to 30%) may not be optimal under certain working conditions, for example, in a high-humidity environment, even if the working rate is not lower than 30%, the emulsification risk may significantly increase; conversely, in a low-humidity and high-oil-temperature environment, it may be allowed to temporarily allow the working rate to be slightly lower than the conventional threshold without immediately triggering the anti-emulsification action. The specific implementation usually relies on an algorithm module integrated in the control system, which processes real-time data from humidity sensors (usually installed at the bottom of the train or near the air compressor inlet, for monitoring environmental humidity) and temperature sensors (usually monitoring lubricating oil temperature or related part temperature). Its dynamic adjustment logic can include one or more of the following strategies, such as "receiving ambient humidity information and determining whether the air compressor is in a high-humidity environment or a low-humidity environment", the system can preset multiple humidity intervals (e.g. relative humidity <60% is low humidity, 60%-80% is medium humidity, >80% is high humidity). When it is monitored that the environmental humidity continues to rise or is in a high-humidity interval, the control algorithm will automatically adjust the working rate judgment node (e.g. up to 35%), which means that the system is more sensitive to emulsification risk under the same working rate and will start the oil emulsification prevention device earlier. Conversely, when the humidity decreases or is in a low-humidity interval, the working rate judgment node can be appropriately adjusted downward (e.g. from the default 30% to 25% or 20%), to avoid unnecessary intervention and energy consumption.

[0036] The lubricating oil temperature directly affects the water evaporation capacity. If the real-time oil temperature is lower than a certain preset ideal value (for example, 70°C or 88°C), it indicates that the water evaporation condition is not good, and the system can adjust the high working rate judgment node to compensate for the higher emulsification risk due to low temperature. If the oil temperature is continuously higher than the ideal value, the judgment node can be appropriately adjusted lower. By introducing the two key parameters of ambient humidity and lubricating oil temperature, the control system no longer relies solely on the working rate for judgment, but realizes intelligent decision-making of multi-parameter fusion. This makes the start-stop control of the oil emulsion prevention device more accurately reflect the actual emulsification risk, improves the fineness of control and adaptability to different climate conditions and different operating lines (such as seaside projects and plum rain areas), avoids unnecessary actions in low-risk situations, and timely intervention in high-risk situations. This feature embodies the evolution from fixed logic control to adaptive intelligent control. The system can adjust the strategy according to the real-time working condition, reduce the dependence on fixed threshold setting of artificial experience, reduce the risk of control failure due to unreasonable parameter setting, and improve the overall reliability and intelligent level of the system.

[0037] One preferred embodiment further relates to the fine flow control structure of the oil emulsion prevention device. The exhaust pipeline further comprises a contraction valve (or throttle contraction), and the controller is configured to be able to dynamically adjust the channel diameter or its equivalent flow area of the contraction valve according to the real-time monitored ambient humidity data and compressor lubricating oil temperature data, so as to realize accurate control of the exhaust flow size, which is based on the consideration of the required optimal exhaust amount under different working conditions in the oil emulsion prevention process. As mentioned above, in the exhaust device configured on the total air pipeline, the throttle contraction (adjustable diameter) is used to realize control of air consumption, and different diameters of the throttle contraction can provide different air consumption values. The contraction valve can be a variable-diameter throttling device. Its specific implementation can be a valve core structure driven by a stepper motor or a micro motor, which continuously or steplessly changes the cross-sectional area of the flow passage by changing the relative position between the valve core and the valve seat; or it can be a combination of multiple parallel fixed throttle holes with different diameters and a selection solenoid valve, which obtains different equivalent flow areas by controller selecting different branches. The output signal (such as PWM wave or on-off signal) of the controller drives the adjustment mechanism to act. Further, a silencer 600 can also be provided.

[0038] By fine-tuning and adaptive control of exhaust flow, the system can more accurately match the minimum necessary exhaust volume required to eliminate the risk of emulsification under different environmental conditions. Compared with fixed orifice throttling devices or simple on-off exhaust, this method avoids excessive energy consumption of exhaust under low-risk working conditions, and can provide sufficient exhaust capacity under high-risk working conditions, achieving a better balance between anti-emulsification effect and energy efficiency. By dynamically adjusting the flow according to the actual temperature and humidity, the same set of oil emulsification prevention system can better adapt to a variety of operating environments, improving the versatility and scope of application of the system.

[0039] Further, different humidity during work is segmented and sorted, and the work rate judgment node is lowered when the humidity gradually increases, and the work rate judgment node is raised when the humidity gradually decreases. The system can define multiple humidity intervals (Levels) in advance, such as a low humidity interval (e.g., relative humidity < 60%), a medium humidity interval (60% ≤ RH ≤ 80%), and a high humidity interval (RH > 80%). The humidity data monitored by the controller in real time will be classified into the corresponding interval and sorted and compared in time sequence to determine whether its change trend is "gradually increasing" or "gradually decreasing". When the humidity gradually increases, if the system identifies that the humidity data continuously or in multiple sampling periods falls into a higher level interval, or the calculated humidity change slope is greater than zero and exceeds a predetermined value, it is determined that the emulsification risk increases. At this time, the controller will automatically raise the work rate judgment node (e.g., from 25% to 30% or higher). When the humidity gradually decreases: if the system identifies that the humidity data continuously falls back to a lower level interval, or the change slope is negative, it is determined that the environment tends to be dry, and the emulsification risk decreases. At this time, the controller can gradually lower the work rate judgment node (e.g., from the default 30% to 25% or even 20%). By quantifying the environmental humidity level and tracking its change trend, the system can more accurately assess the current and near-term lubricating oil emulsification risk, rather than relying solely on the instantaneous absolute value or a single work rate threshold. This makes the control decision more in line with the actual working condition requirements, achieving a transition from "passive response" to "active adaptation" and even "forward-looking prediction", which helps to take targeted measures at the early stage of risk emergence, improving the prevention and control effect.

[0040] One preferred embodiment further involves the predictive and proactive control strategy of the system to the environmental humidity changes, which is technically characterized in that: the system is configured to be able to predict the humidity changes during the future operation period, and to automatically start the oil emulsification prevention device when the predicted humidity change amplitude at the next operation is greater than 50%. The data sources for the system to predict humidity changes can be multifaceted. One of them can be derived from the weather forecast information received by the train network system, especially the humidity prediction data in the next few hours; the second can be based on the historical humidity data recorded by the train's own sensors (for example, the final environmental humidity at this time and the environmental humidity before the next time) to make simple calculations and trend extrapolation; the third, in some more advanced implementation schemes, can consider combining GPS positioning information, when the system predicts that the train is about to enter a known high-humidity area (such as crossing water, canyon or specific climate zone), make a judgment in advance. The "humidity change greater than 50%" is an empirical threshold value summarized from practice. For example, if the current environmental relative humidity is 40%, and the predicted humidity at the next operation will rise to more than 60% (a change of 50%), it is determined to be a significant change. The setting of this threshold value aims to filter out normal humidity fluctuations and only trigger preventive action when a significant change that may significantly affect the state of lubricating oil is expected.

[0041] Once the controller calculates that the predicted humidity change amplitude exceeds the above-mentioned threshold value (> 50%) based on the obtained information, it will start the oil emulsification prevention device (such as opening the electromagnetic valve on the exhaust pipe for forced exhaust) in advance at the start of the next vehicle operation, or under the premise of meeting other safety conditions (such as total air pressure higher than the safety value), actively increase the working load of the air compressor, so that the temperature of its lubricating oil is raised in advance to cope with the upcoming high-humidity environment and enhance the anti-interference ability of the system.

[0042] One preferred embodiment further specifies the starting conditions of the oil emulsification prevention device, and the working rate of the oil emulsification prevention device is set to 30%, and the relative humidity is greater than 90%, and the working rate determination value is reduced. Relative humidity greater than 90% is defined as a high-risk humidity condition. When the humidity sensor monitors that the environmental relative humidity continuously exceeds this threshold value, the controller determines that the current working condition is prone to emulsification. At this time, the control algorithm will automatically lower the working rate determination value for determining whether to start the oil emulsification prevention device. For example, the working rate determination value of the emulsification prevention device is increased from 30% to 40%, 45% or even higher. This means that in a high-humidity environment, the system is less tolerant of insufficient working rate and will still trigger the oil emulsification prevention device (such as opening the exhaust) when the actual working rate of the air compressor is higher (but may still be lower than the original benchmark of 30%).

[0043] One preferred embodiment further relates to the optimized design of energy recovery and utilization, which is technically characterized in that the system further comprises a kinetic energy recovery device configured to recover and reuse the energy of the compressed air released by the oil emulsion prevention device exhaust pipeline. The kinetic energy recovery device can include a pneumatic motor and a generator connected thereto. Specifically, the pneumatic motor can be connected in series or parallel to the exhaust pipeline of the oil emulsion prevention device. When the oil emulsion prevention device is started and exhausts, the compressed air with certain energy drives the pneumatic motor to rotate, which in turn drives the generator to generate electricity. The generated electricity can be stored in the auxiliary battery of the vehicle, or directly used to supply the low-voltage electrical equipment of the vehicle (such as lighting, control system, etc.), thereby realizing energy recovery.

[0044] Turbine / wind turbine recovery path, such as the disclosed compressor gas kinetic energy recovery device, which uses a gear-chain transmission mechanism to transfer gas kinetic energy to a wind turbine. In this application, a turbine or wind turbine can also be used at the outlet or a specific section of the exhaust pipeline to generate electricity by using the kinetic energy of the exhaust gas flow. This solution is suitable for conditions with low exhaust pressure but large flow rate.

[0045] By recovering and utilizing the kinetic energy carried by the compressed air that is originally directly discharged into the atmosphere, the system converts part of the energy consumption that is inevitable in the oil emulsion prevention process into useful electricity or gas source, reducing the net energy loss of the system and helping to reduce the operating energy consumption cost of the vehicle. The traditional exhaust-only method means pure energy waste. The introduction of the kinetic energy recovery device recovers part of the energy, which to some extent offsets the additional energy cost caused by the execution of the oil emulsion prevention function. In a further technical solution, a set of systems can be used to recover energy from multiple trains.

[0046] As described above, the present application provides a city rail vehicle air compressor oil emulsion prevention control method and system. This method solves the problem of lubricating oil emulsification caused by insufficient air compressor duty rate and environmental humidity changes by building a comprehensive control system including a compressor, an oil emulsion prevention device, and a controller.

[0047] The core is to use multi-parameter perception and intelligent decision-making: real-time monitoring of lubricating oil temperature and environmental humidity through temperature and humidity sensors; accurate calculation of air compressor duty rate (duty rate = compressor start-up time t1 / vehicle operation time t2), where the vehicle operation time t2 is calculated from the running speed greater than 10 km / h, overcoming the error of traditional calculation methods; the controller determines whether to start the oil emulsion prevention device based on temperature, humidity, and duty rate data.

[0048] The oil-proof emulsification device comprises an exhaust pipeline, and is provided with an obturator, a first electromagnetic valve and other actuators. The preferred solution further comprises: a second electromagnetic valve and a time period control unit connected in series, which limits the exhaust operation to a preset time period (such as a low passenger flow period at night); a third electromagnetic valve and a manual control unit connected in parallel, which provides an emergency manual operation mode; and a pressure sensor cooperating with an overflow valve, which closes the overflow valve when the total air pressure is lower than 7.9 bar, thereby preferentially ensuring the safety of the air for the braking system.

[0049] The further optimization of the control strategy comprises: dynamically adjusting the working rate determination node (trigger threshold) according to real-time temperature and humidity, thereby realizing adaptive control; setting a contraction valve in the exhaust pipeline, and adjusting the exhaust flow according to the temperature and humidity data; segmenting and sorting the humidity and tracking the trend, and lowering the determination node when the trend is rising, and vice versa; predicting the next humidity change (such as according to weather forecasts or historical data), and starting the device in advance when the change is more than 50%; setting a reference working rate threshold of 30%, but automatically lowering the threshold when the relative humidity is greater than 90% to cope with extremely high humidity conditions. Some embodiments can further be provided with a kinetic energy recovery device to recover and utilize the exhaust energy.

[0050] In summary, the method described in the present application realizes precise, reliable, safe and efficient control of the oil-proof emulsification process through improvements in multiple parameters, accurate calculation, intelligent determination, structural optimization and safety protection, effectively prevents and controls lubricating oil emulsification, and helps to reduce energy consumption and maintenance costs.

[0051] The above is only one specific embodiment of the present application, and any improvement made on the basis of the concept of the present application is considered to be within the protection scope of the present application.

Claims

1. A method for preventing oil emulsification in an air compressor of an urban rail vehicle, characterized in that, The invention includes an oil-resistant emulsification control system comprising a compressor, an oil-resistant emulsification device, and a controller, wherein the oil-resistant emulsification device includes an exhaust pipe, and the exhaust pipe includes a plug valve and a first solenoid valve. The temperature during compressor operation is obtained using a temperature sensor; The humidity level during compressor operation is obtained using a humidity sensor; Obtain the compressor start-up time t1 and the vehicle operation time t2. Calculate the duty cycle based on the compressor start-up time and the vehicle operation time. The vehicle operation time is calculated starting when the vehicle speed is greater than 10km / h. The decision to activate the anti-oil emulsification device is based on temperature, humidity, and operating rate.

2. The method for preventing oil emulsification in urban rail vehicle gas compressors according to claim 1, characterized in that, It also includes a second solenoid valve installed on the oil-preventing emulsification device. The second solenoid valve is connected in series with the first solenoid valve. The second solenoid valve is controlled by a time period control unit and is opened only within a preset time range.

3. The method for preventing oil emulsification in urban rail vehicle gas compressors according to claim 1, characterized in that, It also includes a manual pipeline on the oil-preventing emulsification device, the manual pipeline including a third solenoid valve, the third solenoid valve being connected in parallel with the first solenoid valve, and the third solenoid valve being opened by a manual control unit for manual control.

4. The method for preventing oil emulsification in the gas compressor of urban rail vehicles according to any one of claims 1-3, characterized in that, It also includes a pressure sensor, and the exhaust pipe also includes an overflow valve that closes when the total air pressure is less than 7.9 bar.

5. The method for preventing oil emulsification in the gas compressor of urban rail vehicles according to claim 1, characterized in that, Based on humidity and temperature data, the working rate judgment node is dynamically adjusted. Based on the calculated working rate and the adjusted judgment node, it is determined whether to activate the anti-oil emulsification device.

6. The method for preventing oil emulsification in the gas compressor of urban rail vehicles according to claim 5, characterized in that, The exhaust pipe also includes a constriction valve, which adjusts the flow rate based on humidity and temperature data.

7. The method for preventing oil emulsification in urban rail vehicle gas compressors according to claim 5, characterized in that, The working period is divided into different humidity levels and sorted. When the humidity gradually increases, the working rate judgment node is lowered, and when the humidity gradually decreases, the working rate judgment node is raised.

8. The method for preventing oil emulsification in urban rail vehicle gas compressors according to claim 7, characterized in that, It also includes anticipating humidity changes and activating the anti-oil emulsification device when the humidity change is greater than 50% during the next operation.

9. The method for preventing oil emulsification in the gas compressor of urban rail vehicles according to claim 5, characterized in that, The operating rate of the oil-proof emulsification device is set to 30%. When the relative humidity is greater than 90%, the operating rate judgment value is reduced.

10. The method for preventing oil emulsification in the gas compressor of urban rail vehicles according to claim 6, characterized in that, It also includes kinetic energy recovery devices.

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