Engine cooling system early warning diagnosis method and system

Abstract

The application relates to an engine cooling system early warning diagnosis method and system, engine operation data are acquired, a MAP curve corresponding to a rotating speed-torque and a temperature is obtained through screened data, and a water outlet temperature threshold value under each working condition is preset; when the acquired water outlet temperature exceeds the threshold value corresponding to different working conditions, early warning is issued, and the direction of an over-temperature fault occurrence is determined according to the difference between the current temperature and the stable temperature before the early warning. According to the MAP curve, the water outlet temperature threshold value of the engine under all working conditions is preset, data are collected in real time through a temperature sensor and compared with the threshold value, early warning is given when the set threshold value is exceeded, and fault diagnosis is realized according to the related water temperature, oil temperature and intake air temperature and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engine control technology, in particular to an engine cooling system early warning diagnosis method and system. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] The heat generated by the engine during operation can be dissipated by air cooling or water cooling. Some engines used in equipment operating near the sea environment can use seawater as a cooling source to cool the engine, such as ship engines or engines used in offshore platforms. Such engines can directly use the cooler to cool the oil circuit, gas circuit, etc. of the engine by sucking seawater into the cooler, but considering the corrosion of seawater and the maintenance cost of the engine, in most cases, seawater is used to cool freshwater, and then freshwater is used as a cooling circulating medium to further cool the oil circuit, gas circuit, etc. of the engine. In this way, the problem of excessively high freshwater outlet temperature is common. High temperature of freshwater can cause engine cylinder pulling, engine failure to operate normally, etc. In the prior art, only one maximum outlet temperature limit of freshwater is usually set. When the outlet temperature of freshwater exceeds the limit, an over-temperature warning is issued. However, the working conditions of the engine are complex, and the set maximum outlet temperature limit of freshwater is not always suitable for all working conditions. In some short-term special working conditions, the outlet temperature of freshwater may exceed the set limit for a short time, thereby triggering a false warning. SUMMARY

[0004] To solve the technical problems in the background art, the present application provides an engine cooling system early warning diagnosis method and system. According to the MAP curve, the outlet temperature threshold of the engine under all working conditions is preset. The data is collected in real time by the temperature sensor and compared with the threshold. When the set threshold is exceeded, an early warning is given, and fault diagnosis is realized according to the related water temperature, oil temperature, and intake air temperature.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] The first aspect of the present application provides an engine cooling system early warning diagnosis method, comprising the following steps:

[0007] Obtain engine operation data, and obtain the MAP curve corresponding to the speed-torque and temperature by screening the data, and preset the outlet temperature threshold under each working condition;

[0008] When the obtained outlet temperature exceeds the threshold corresponding to different working conditions, an early warning is given, and the direction of the over-temperature fault is determined according to the difference between the current temperature and the stable temperature before the warning, specifically:

[0009] obtaining a difference between the current temperature and the stable temperature before the warning, including a water temperature difference ΔTw, an oil temperature difference ΔTo, and an intake air temperature difference ΔTa;

[0010] when ΔTw < n*ΔTo and ΔTa < m*ΔTw, the fault is a fresh water system fault;

[0011] when ΔTw < n*ΔTo and ΔTa ≥ m*ΔTw, the fault is a sea water system fault;

[0012] when n*ΔTw < ΔTo, the fault is a lubrication system fault;

[0013] wherein n and m are both set coefficients.

[0014] Further, the screened data is specifically: extracting engine operation data in which the speed fluctuation rate and the torque fluctuation rate in a set time period are not more than corresponding set values.

[0015] Further, the speed-torque and temperature corresponding MAP curve is obtained by using an experimental or simulation method.

[0016] Further, the water outlet temperature threshold value under each working condition is less than the maximum allowable limit value of the engine.

[0017] Further, the stable temperature before the warning is specifically: the temperature data fluctuation rate in a set time period before the warning signal is sent is less than a set percentage of the temperature value.

[0018] Further, the engine cooling system has a sea water system, a fresh water system and a lubrication system, the sea water system reduces the temperature of the cooling medium in the fresh water system through sea water, and the cooling medium in the fresh water system is used to cool the oil in the lubrication system.

[0019] Further, the fresh water system fault sends a reminder signal of “checking the antifreeze liquid level, the fresh water pump and the thermostat”.

[0020] Further, the sea water system fault sends a reminder signal of “checking the sea water pump and the sea water filter”.

[0021] Further, the lubrication system fault sends a reminder signal of “checking the oil pan oil and the cylinder friction pair”.

[0022] The second aspect of the application provides a system for implementing the engine cooling system warning diagnosis method described above, comprising:

[0023] a temperature threshold unit configured to: obtain engine operation data, obtain a speed-torque and temperature corresponding MAP curve through screened data, and preset a water outlet temperature threshold value under each working condition.

[0024] The over-temperature early warning unit is configured to issue a warning when the obtained outlet water temperature exceeds the threshold value corresponding to different working conditions, and determine the direction of over-temperature fault occurrence according to the difference between the current temperature and the stable temperature before the warning; specifically:

[0025] The difference between the current temperature and the stable temperature before the warning includes a water temperature difference Tw, an oil temperature difference To, and an intake air temperature difference Ta;

[0026] When Tw < n*To and Ta < m*Tw, it is a freshwater system fault;

[0027] When Tw < n*To and Ta >= m*Tw, it is a seawater system fault;

[0028] When n*Tw < To, it is a lubrication system fault;

[0029] Wherein, n and m are both set coefficients.

[0030] Compared with the prior art, the above one or more technical solutions have the following beneficial effects:

[0031] 1. According to the MAP curve, the outlet water temperature threshold value of the engine under different working conditions can be preset, and early warning can be performed when the outlet water temperature deviates from the normal range under different working conditions, so as to avoid the occurrence of torque limitation or parking when the water temperature is too high, and to avoid affecting the safe operation of the engine and the normal operation of the user. Compared with the current method of setting only one over-temperature limit, the heat dissipation of the engine under different working conditions is considered, and the frequency of false warning signals is reduced.

[0032] 2. By considering the change of the engine mechanism and the change of each related parameter, and by data analysis experience, when over-temperature warning occurs, the inspection direction related to the fault is determined according to the related water temperature, oil temperature and intake air temperature, so as to improve the fault elimination efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0033] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the specification explain the application, and do not constitute an improper limitation on the present application.

[0034] Figure 1 is an engine cooling system early warning diagnosis flowchart provided by one or more embodiments of the present application. DETAILED DESCRIPTION

[0035] The present application will be further described below in conjunction with the drawings and embodiments.

[0036] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs unless otherwise specifically defined herein.

[0037] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It is also to be understood that the terms "comprising," "including," and "having" can be used interchangeably.

[0038] Terminology:

[0039] MAP curve, MAP curve is a visual representation of engine performance, which usually takes speed, torque and another key parameter (such as fuel consumption rate, exhaust temperature, intake temperature, etc., temperature in this invention) as coordinate axes, and represents the performance index under different parameter combinations through different colors or contour lines. MAP curve can be determined by bench test or simulation.

[0040] Engine with seawater cooling system, through seawater as cooling medium, effectively take away the heat generated in the process of engine operation, to ensure the normal operation of the engine.

[0041] Take large equipment such as ships as an example, introduce the main components. It should be noted that this part is only related to the introduction of the invention, and is not used to limit the invention. In actual application, the structure of the seawater cooling system of the engine is complex and diverse, which is only introduced by way of example here.

[0042] Seawater pump: responsible for sucking seawater from the outside of the ship body and pressurizing and delivering it to each part of the cooling system. The selection and configuration of seawater pump need to be determined according to the power of engine and cooling demand.

[0043] Seawater filter: set after the seawater pump, used to filter impurities in seawater, prevent impurities from entering the cooling system and causing blockage or corrosion.

[0044] Cooler: including oil cooler and fresh water cooler, etc. Oil cooler is used to cool engine lubricating oil to prevent high oil temperature from affecting engine performance; fresh water cooler is used to cool fresh water so that it can be circulated for further cooling of the engine. In some systems, seawater directly enters the oil cooler or cylinder water cooler as a cooling medium for cooling.

[0045] Three-way temperature control valve: used to control the flow path and temperature of cooling water. When the seawater temperature is lower than the set value, the three-way temperature control valve will guide the seawater back to the seawater inlet to increase the seawater temperature; when the seawater temperature reaches the set value, it allows the seawater to enter the cooler for cooling.

[0046] Fresh water circulation system: in a closed cooling system, fresh water is circulated within the system. Fresh water is pressurized by the fresh water pump and sent to the cylinder liner, cylinder head and other components of the engine for cooling, and then returned to the fresh water cooler for re-cooling. The fresh water circulation system also includes accessories such as expansion tank, etc., for adjusting the water temperature and pressure in the system.

[0047] The working principle is as follows:

[0048] The seawater pump sucks seawater from the outside of the ship body, filters it through the seawater filter, and pressurizes it to deliver it to various parts of the cooling system.

[0049] The seawater first enters the oil cooler or cylinder water cooler for preliminary cooling, and then may enter the fresh water cooler for further cooling. In a closed cooling system, fresh water is circulated within the fresh water circulation system, constantly absorbing heat generated by the engine and releasing it to seawater through the fresh water cooler.

[0050] The three-way temperature control valve automatically adjusts the flow path and temperature of the cooling water according to the seawater temperature, ensuring that the cooling system always operates in the best state.

[0051] The temperature gauge, pressure gauge and other auxiliary equipment in the cooling system monitor the operating status and performance parameters of the system in real time, providing necessary reference information for the operator.

[0052] Other auxiliary equipment: such as temperature gauge, pressure gauge, observation window, etc., for monitoring the operating status and performance parameters of the cooling system.

[0053] As introduced in the background art, in the prior art, only one maximum fresh water outlet temperature limit is usually set, and an over-temperature warning is issued when the fresh water outlet temperature exceeds the limit. However, the engine has to deal with complex working conditions, and the set maximum fresh water outlet temperature limit is not always suitable for all working conditions. In some short-term special working conditions, the fresh water outlet temperature may exceed the set limit for a short period of time, triggering a false warning.

[0054] Therefore, the following embodiments give an engine cooling system early warning and diagnosis method and system, which pre-sets the fresh water outlet temperature threshold for all working conditions of the engine according to the MAP curve, compares the real-time data collected by the temperature sensor with the threshold, and gives an early warning when the set threshold is exceeded, and realizes fault diagnosis according to the related water temperature, oil temperature and intake air temperature parameters.

[0055] Example 1:

[0056] As Figure 1 shown in the figure, the engine cooling system early warning diagnosis method comprises the following steps:

[0057] Obtain engine operation data.

[0058] Screening steady-state data, specifically: extracting engine operation data with a speed fluctuation rate <5‰ and a torque fluctuation rate <5‰ within 5 minutes in the operation data.

[0059] Using the obtained steady-state data, determine the corresponding outlet water temperature MAP threshold based on different speed-torque conditions.

[0060] In this embodiment, the outlet water temperature MAP threshold refers to the outlet water temperature threshold preset at each condition based on engine speed and torque after obtaining the MAP curve corresponding to speed-torque and temperature using steady-state data through experimental or simulation methods, etc. The threshold is stricter than the maximum allowable limit of the engine (i.e. the temperature threshold is less than the maximum allowable limit of the engine), achieving early warning when an anomaly occurs.

[0061] In this embodiment, the outlet water temperature refers to the outlet water temperature of the engine cooling circulating medium. In an engine with a seawater cooling system, seawater is used to cool the engine cooling circulating medium, and the engine cooling circulating medium cools the engine's air path, oil path, and other facilities. Since the composition of the engine cooling circulating medium is mainly freshwater, it is referred to as outlet water temperature.

[0062] When the obtained outlet water temperature exceeds the threshold corresponding to different conditions, an early warning is issued.

[0063] Obtain the difference between the current temperature and the stable temperature before the warning, including the water temperature difference ΔTw, the oil temperature difference ΔTo, and the intake air temperature difference ΔTa.

[0064] In this embodiment, the current temperature refers to the real-time value of the obtained temperature data.

[0065] In this embodiment, the stable temperature before the warning refers to the temperature data fluctuation rate being less than a set percentage within a set time period before the warning signal is issued.

[0066] When the water temperature appears a warning, automatically diagnose the fault system according to the differences in outlet water temperature, oil temperature, and intake air temperature, and push the inspection direction; specifically:

[0067] Case 1: water temperature difference ΔTw < 1.5 times oil temperature difference ΔTo, and intake air temperature difference ΔTa < 0.5 times water temperature difference ΔTw, then it is a freshwater system fault, and the antifreeze liquid level, freshwater pump, and thermostat components need to be checked;

[0068] Case 2: water temperature difference ΔTw<1.5 times of oil temperature difference ΔTo, and intake air temperature difference ΔTa≥0.5 times of water temperature difference ΔTw, which is a seawater system failure, and the seawater pump and seawater filter and other components need to be checked;

[0069] Case 3: 1.5 times of water temperature difference ΔTw<oil temperature difference ΔTo, which is a lubricating system failure, and the oil pan oil and cylinder friction pair and other components need to be checked.

[0070] When the outlet water temperature deviates from the normal range, early warning can be realized, early troubleshooting can be realized, and high temperature limit torque and parking failure can be avoided, and the engine safety can be protected.

[0071] The above process presets the outlet water temperature threshold of the engine under all working conditions according to the MAP curve, and early warning can be performed when the outlet water temperature deviates from the normal range, so as to avoid high water temperature, limit torque or parking, affect the safe operation of the engine, and affect the normal operation of the user.

[0072] Through real-time collection of data by common components such as temperature sensors, early warning is performed when the set threshold is exceeded, and the checking direction related to the failure is determined according to the related water temperature, oil temperature and intake air temperature and other parameters, the engine mechanism and the change of each related parameter are considered, and the data analysis experience is improved. The failure elimination efficiency is improved.

[0073] The temperature sensor required for collecting temperature data is a common component in the engine, and the whole process can form a model programmed and implanted into ECU or cloud, and the background automatically analyzes the failure and can timely remind the next step disposal. The engine outlet water temperature failure can be timely and accurately located.

[0074] Embodiment two:

[0075] The system for realizing the engine cooling system early warning diagnosis method in embodiment one comprises:

[0076] The temperature threshold unit is configured to: obtain engine operation data, obtain the MAP curve corresponding to the speed-torque and temperature through the screened data, and preset the outlet water temperature threshold under each working condition;

[0077] The over-temperature early warning unit is configured to: when the obtained outlet water temperature exceeds the threshold corresponding to different working conditions, issue a warning, and determine the direction of over-temperature failure occurrence according to the difference between the current temperature and the stable temperature before the warning, specifically:

[0078] The difference between the current temperature and the stable temperature before the warning is obtained, including water temperature difference ΔTw, oil temperature difference ΔTo, and intake air temperature difference ΔTa;

[0079] When ΔTw<n*ΔTo, and ΔTa<m*ΔTw, it is a freshwater system failure;

[0080] when ΔTw < n*ΔTo and ΔTa ≥ m*ΔTw, it is a seawater system failure;

[0081] when n*ΔTw < ΔTo, it is a lubrication system failure;

[0082] wherein n and m are both set coefficients.

[0083] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Various modifications and changes can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of early diagnosis of an engine cooling system, characterized in that, The method comprises the following steps: obtaining engine operation data, obtaining a MAP curve corresponding to the speed-torque and temperature through the screened data, and presetting a water outlet temperature threshold value under each working condition; when the obtained water outlet temperature exceeds the threshold value corresponding to different working conditions, issuing a warning, and determining the direction of the over-temperature fault occurrence according to the difference between the current temperature and the stable temperature before the warning, specifically: obtaining the difference between the current temperature and the stable temperature before the warning, including the water temperature difference ΔTw, the oil temperature difference ΔTo, and the intake air temperature difference ΔTa; when ΔTw < n*ΔTo and ΔTa ≥ m*ΔTw, it is a freshwater system fault; when ΔTw < n*ΔTo and ΔTa ≥ m*ΔTw, it is a seawater system fault; when n*ΔTw < ΔTo, it is a lubrication system fault; wherein n and m are both set coefficients.

2. The engine cooling system early warning diagnostic method of claim 1 wherein, The screened data is specifically: extracting engine operation data in which the speed fluctuation rate and the torque fluctuation rate within a set time period do not exceed the corresponding set values.

3. The engine cooling system early warning diagnostic method of claim 1 wherein, The MAP curve corresponding to the speed-torque and temperature is obtained through the screened data using experimental or simulation methods.

4. The engine cooling system early warning diagnostic method of claim 1 wherein, The water outlet temperature threshold value under each working condition is less than the maximum allowable limit value of the engine.

5. The engine cooling system early warning diagnostic method of claim 1 wherein, The stable temperature before the warning is specifically: the temperature data fluctuation rate within a set time period before the warning signal is issued is less than the set percentage of the temperature value.

6. The engine cooling system early warning diagnostic method of claim 1 wherein, The engine cooling system has a seawater system, a freshwater system, and a lubrication system. The seawater system lowers the temperature of the cooling medium in the freshwater system through seawater, and the cooling medium in the freshwater system cools the oil in the lubrication system.

7. The engine cooling system early warning diagnostic method of claim 1 wherein, The freshwater system fault issues a reminder signal to "check the antifreeze level, freshwater pump, and thermostat".

8. The engine cooling system early warning diagnostic method of claim 1 wherein, The seawater system fault issues a reminder signal to "check the seawater pump and seawater filter".

9. The engine cooling system early warning diagnostic method of claim 1 wherein, The lubrication system fault issues a reminder signal to "check the oil pan oil and cylinder friction pair".

10. A system for implementing the early diagnostic method of the cooling system of the engine according to any one of claims 1 to 9, characterized in that, It comprises: a temperature threshold unit configured to obtain engine operation data, obtain a MAP curve corresponding to the speed-torque and temperature through the screened data, and preset a water outlet temperature threshold value under each working condition; an over-temperature warning unit configured to issue a warning when the obtained water outlet temperature exceeds the threshold value corresponding to different working conditions, and determine the direction of the over-temperature fault occurrence according to the difference between the current temperature and the stable temperature before the warning.

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