Intelligent temperature control device for online viscosity measurement of high-temperature lubricating oil of engine and online viscosity measurement method

Abstract

The invention relates to the technical field of engine lubricating oil state monitoring, in particular to an intelligent temperature control device for on-line viscosity measurement of engine high-temperature lubricating oil and an on-line viscosity measurement method, and the intelligent temperature control device comprises a module tool installed between an engine oil pump and a main engine oil filter element; the intelligent cooling module comprises a semiconductor chilling plate; the heat dissipation module is thermally coupled with the hot end of the semiconductor chilling plate; the temperature sensor is arranged on the sampling flow path; and the controller is electrically connected with the temperature sensor and the semiconductor chilling plate, and is configured to adjust the current of the TEC through a PID control algorithm according to a feedback signal of the temperature sensor, so that the temperature of the lubricating oil flowing through the temperature sensor is stabilized at a preset target value. According to the invention, the technical bottleneck that an on-line viscosity sensor cannot stably work in a high-temperature environment of 100 DEG C or above is successfully broken through by a composite heat dissipation scheme of integrating a semiconductor chilling plate and an engine coolant system and cooperating with intelligent PID temperature control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine lubricating oil state monitoring, in particular to an intelligent temperature control device for online viscosity measurement of high-temperature lubricating oil of an engine and an online viscosity measurement method. BACKGROUND

[0002] In engine lubricating oil bench special tests, in order to evaluate the performance of lubricating oil under harsh conditions such as high temperature, high speed and high load, especially the oxidation resistance and high temperature stability, it is usually necessary to continuously monitor the viscosity and other key indicators of lubricating oil. Viscosity change is an important parameter reflecting the aging degree and lubricating performance of lubricating oil, which directly affects the operation reliability and service life of the engine.

[0003] At present, the measurement of lubricating oil viscosity mainly relies on offline detection method, that is, after periodic sampling, the kinematic viscosity of lubricating oil at 40℃ and 100℃ is measured respectively in laboratory environment. The disadvantage of this method is that it cannot reflect the dynamic change of lubricating oil in the actual running process of the engine. Especially in the aging process of lubricating oil, the viscosity may change suddenly, if it is not found in time, the lubricating oil will lose its lubricating protection function, and then cause engine failure.

[0004] Although some online viscosity sensors have been developed and applied to industrial monitoring, such as vibration type viscosity sensors based on quartz tuning fork or vibration rod principle, the long-term working temperature of the core piezoelectric element and electronic element is usually lower than 100℃, and the best working range is below 80℃. However, the temperature of lubricating oil in the main oil way of modern high-performance engine is often higher than 100℃, even reaching 120℃ to 130℃ under high speed and high load conditions. In lubricating oil special tests, the oil way temperature is also controlled at 120℃ to 130℃ for hundreds of hours. This high temperature environment poses a severe challenge to existing online viscosity sensors, which is manifested in the following aspects: The sensor cannot be installed directly: high temperature will damage the precise electronic elements inside the sensor, causing the sensor to fail; Measurement accuracy decreases: even if the sensor can withstand high temperature for a short time, the key parameters such as resonance frequency will drift due to the increase of its own temperature, causing serious distortion of viscosity measurement results; Data loss: unable to obtain real state data of lubricating oil under high temperature working conditions, such as high temperature high shear (HTHS) viscosity, oxidation decay trend, fuel dilution degree and other key information. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides an intelligent temperature control device for online viscosity measurement of high-temperature lubricating oil of an engine and an online viscosity measurement method.

[0006] To achieve the above object, the present application is implemented by the following technical solutions: an intelligent temperature control device for online viscosity measurement of high-temperature lubricating oil of an engine, comprising: A module tool is installed between an oil pump and a main oil filter element to form a bypass sampling flow path; An intelligent cooling module is arranged on the sampling flow path, and the intelligent cooling module comprises a semiconductor thermoelectric cooler (TEC); A heat dissipation module is thermally coupled to the hot end of the semiconductor thermoelectric cooler (TEC), and the heat dissipation module is integrated into the cooling liquid circulation system of the engine to dissipate heat from the hot end of the TEC by using the engine cooling liquid; A temperature sensor is arranged on the sampling flow path and located downstream of the intelligent cooling module; A controller is electrically connected to the temperature sensor and the semiconductor thermoelectric cooler (TEC) and is configured to adjust the current of the TEC according to the feedback signal of the temperature sensor by a PID control algorithm to stabilize the temperature of the lubricating oil flowing through the temperature sensor at a preset target value.

[0007] Preferably, the heat dissipation module is a liquid-cooled heat exchanger, and the liquid-cooled heat exchanger is internally provided with a channel for the engine cooling liquid to flow through.

[0008] Preferably, the preset target temperature is 40℃±5℃ or 100℃±5℃.

[0009] Preferably, the controller is further configured to switchably control the oil temperature to circulate between 40℃ and 100℃ and receive the kinematic viscosity values at the corresponding temperatures measured by the online viscosity sensor.

[0010] Preferably, the controller further comprises a calculation module configured to calculate and output the viscosity index of the lubricating oil according to the kinematic viscosity values at 40℃ and 100℃.

[0011] Preferably, the outlet of the sampling flow path is connected to the online viscosity sensor, and the measured oil sample is returned to the engine oil sump through the oil filter.

[0012] The present application also discloses an engine high-temperature lubricating oil online viscosity measurement method using the device, comprising the following steps: High-temperature lubricating oil is led out from the outlet of the engine oil pump to form a bypass sampling flow; The high-temperature lubricating oil flows through the intelligent cooling module and is actively cooled by the cold end of the semiconductor thermoelectric cooler (TEC); The hot end of the TEC is continuously cooled by the engine cooling liquid circulation system; The temperature of the cooled lubricating oil is monitored in real time; Based on the monitored temperature, the current of the TEC is dynamically adjusted by the PID controller to precisely control the lubricating oil temperature at the preset target value; The lubricating oil, after being kept at a constant temperature, is fed into an online viscosity sensor for measurement.

[0013] Preferably, the method further includes the step of: controlling the oil temperature to switch periodically between 40°C and 100°C, and obtaining the kinematic viscosity values ​​at the two temperatures respectively.

[0014] Preferably, the method further includes the step of: obtaining the viscosity index of the lubricating oil by means of a lookup table or a calculation program based on the obtained kinematic viscosity values ​​at 40℃ and 100℃, and displaying its changing trend over time in real time.

[0015] The beneficial effects of this invention are as follows: Compared with the prior art, this invention, through a composite heat dissipation scheme integrating a semiconductor cooling chip and an engine coolant system, combined with intelligent PID temperature control, successfully overcomes the technical bottleneck that online viscosity sensors cannot work stably in high-temperature environments above 100°C. It achieves real-time, accurate, and online monitoring of lubricating oil viscosity under harsh high-temperature conditions, and has significant advantages such as fast response, compact structure, intelligent control, and high reliability, providing key technical support for engine oil condition monitoring and life assessment. Attached Figure Description

[0016] Figure 1 This is a block diagram of the overall structure of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0022] Reference Figure 1 The system structure diagram shown illustrates that tooling 1 is directly screwed into the engine oil filter mounting position via a standard threaded interface on its housing (e.g., the same thread specification as the oil filter base), thus integrating into the engine's lubrication system. For oil circuit connections, the oil inlet of tooling 1 utilizes the existing engine oil passage and connects to the oil pump outlet, while the oil outlet connects to the inlet of the online viscosity sensor. For cooling circuit connections, the coolant inlet and outlet of the existing miniature heat exchanger 2 are connected in parallel to the engine's existing coolant circulation pipeline via quick-connect couplings. The cold end of the thermoelectric cooler 3 is attached to tooling 1, and the hot end is coupled to the heat dissipation module (miniature heat exchanger), which is integrated into the engine 4's coolant circulation system, utilizing the engine coolant to dissipate heat from the hot end of the entire device. The electrical components, including the controller 5, are connected to the vehicle power supply (12V or 24V DC) and a host computer or engine ECU via wiring harnesses.

[0023] The semiconductor cooling chip (TEC) is model TEC1-12706, with a rated operating voltage of 12VDC, compatible with vehicle power supply, and a maximum temperature difference ΔTmax of over 67℃, which can meet the requirement of cooling high-temperature oil at 130℃ to below 70℃.

[0024] The tooling that is in close contact with the cold end of the TEC is made of T2 copper with high thermal conductivity. The heat dissipation module that is in contact with the hot end of the TEC is a compact copper alloy liquid cooling plate with a multi-channel structure inside to maximize the heat exchange efficiency with the engine coolant (typically around 90°C).

[0025] A PT1000 platinum resistance temperature sensor 7, with a measurement accuracy of ±0.1℃, is installed at the oil flow channel outlet, just before entering the online viscosity sensor 6. The sensor signal is connected to a digital PID controller based on an STM32 series microcontroller. The controller, based on the set target temperature (e.g., 40℃) and the actual temperature fed back by the PT1000, uses a PID algorithm to adjust the magnitude and direction of the current output to the TEC in real time (achieving either cooling or heating), ultimately stabilizing the oil temperature entering the viscosity sensor precisely within the target range of ±0.5℃.

[0026] The workflow of this invention is as follows: When the engine is running, the high-temperature lubricating oil (potentially reaching 120-130℃) in the oil pan is driven by the oil pump 8 and enters the intelligent cooling module of this device via a bypass sampling stream. The oil first flows through a copper flow channel coupled to the cold end of the TEC (Dynamic Cooling Device), undergoing primary active cooling, resulting in a significant temperature reduction. The heat generated by the hot end of the TEC is rapidly carried away by the closely attached liquid cooling plate and continuously dissipated into the engine cooling system by the engine coolant flowing through the liquid cooling plate.

[0027] After initial cooling, the oil flows to the outlet and is monitored in real time by a PT1000 temperature sensor. This temperature signal is transmitted to a PID controller, which dynamically adjusts the drive current of the TEC to achieve precise constant temperature control of the oil. Finally, the oil, with its temperature stabilized at a set value (e.g., 40°C), enters the downstream online viscosity sensor (e.g., a vibratory viscometer). The sensor performs high-precision measurements at its optimal operating temperature and outputs a viscosity signal. The measured oil sample can then be returned to the engine oil pan via the return line and oil filter 9, achieving oil recycling.

[0028] As a preferred implementation, a program can be preset in the host computer software to allow the controller to automatically switch the target temperature between 40°C and 100°C at fixed time intervals (e.g., every minute). The system then controls the TEC to maintain the oil at these two temperature points, and the viscosity sensor measures the corresponding kinematic viscosity values. The controller's built-in calculation program then calculates the viscosity index (VI) of the lubricating oil using standard algorithms such as ASTM D2270, based on the kinematic viscosity values ​​at 40°C and 100°C, thereby achieving a more comprehensive real-time online assessment of oil quality.

[0029] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A smart temperature control device for online viscosity measurement of high temperature lubricating oil of an engine, characterized in that, The application relates to a lubricating oil temperature control system for an engine, comprising: a module tool installed between an oil pump and a main engine oil filter element to form a bypass sampling flow path; an intelligent cooling module arranged on the sampling flow path, wherein the intelligent cooling module comprises a semiconductor thermoelectric cooler (TEC); a heat dissipation module coupled with a hot end of the semiconductor thermoelectric cooler (TEC), wherein the heat dissipation module is integrated into a cooling liquid circulation system of the engine and uses engine cooling liquid to dissipate heat from the hot end of the TEC; a temperature sensor arranged on the sampling flow path and located downstream of the intelligent cooling module; and a controller electrically connected with the temperature sensor and the semiconductor thermoelectric cooler (TEC) and configured to adjust the current of the TEC through a PID control algorithm according to the feedback signal of the temperature sensor so as to stabilize the temperature of lubricating oil flowing through the temperature sensor at a preset target value.

2. The intelligent temperature control device of claim 1, wherein, The heat dissipation module is a liquid-cooled heat exchanger, and a channel for the engine cooling liquid to flow through is arranged in the heat exchanger.

3. The intelligent temperature control device of claim 1 or 2, wherein, The preset target temperature is 40 DEG C + / - 5 DEG C or 100 DEG C + / - 5 DEG C.

4. The intelligent temperature control device of claim 1 or 2, wherein, The controller is further configured to switchably control the oil temperature to circulate between 40 DEG C and 100 DEG C and receive the kinematic viscosity values at the corresponding temperatures measured by an online viscosity sensor.

5. The intelligent temperature control device of claim 4, wherein, The controller further comprises a calculation module configured to calculate and output the viscosity index of the lubricating oil according to the kinematic viscosity values at 40 DEG C and 100 DEG C.

6. The intelligent temperature control device of claim 1, wherein, An outlet of the sampling flow path is connected to the online viscosity sensor, and the measured oil sample is returned to an engine oil sump through an oil filter.

7. An on-line viscosity measurement method of high temperature lubricating oil of an engine using the apparatus according to any one of claims 1 to 6, characterized by, The application further relates to a lubricating oil temperature control method for an engine, comprising the following steps: high-temperature lubricating oil is led out from an outlet of an engine oil pump to form a bypass sampling flow; the high-temperature lubricating oil is caused to flow through an intelligent cooling module and is actively cooled by a cold end of a semiconductor thermoelectric cooler (TEC); the hot end of the TEC is continuously cooled by an engine cooling liquid circulation system; the temperature of the cooled lubricating oil is monitored in real time; the current of the TEC is dynamically adjusted by a PID controller according to the monitored temperature so as to accurately control the temperature of the lubricating oil at a preset target value; and the constant-temperature lubricating oil is sent to an online viscosity sensor for measurement.

8. The method of claim 7, wherein, The method further comprises the steps of: controlling the oil temperature to periodically switch between 40 DEG C and 100 DEG C and obtaining the kinematic viscosity values at the two temperatures respectively.

9. The method of claim 8, wherein, The method further comprises the steps of: obtaining the viscosity index of the lubricating oil through a table lookup method or a calculation program according to the obtained kinematic viscosity values at 40 DEG C and 100 DEG C and displaying the change trend of the viscosity index with time in real time.

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