Test device and control method for thermodynamic state parameters of cooling oil chamber in engine piston

Abstract

The present invention relates to the technical field of thermodynamic analysis of the inner cooling oil cavity of an engine piston, and discloses a thermodynamic state parameter testing device and control method of the inner cooling oil cavity of an engine piston, including a cylinder wall and a valve arranged on the inner side of an engine body, an ECU, a water cooler, a thermocouple and a battery, wherein the thermocouple includes a first thermocouple, a second thermocouple, a third thermocouple, a fourth thermocouple, a fifth thermocouple, a sixth thermocouple and a seventh thermocouple. The method monitors and analyzes the temperature data from the piston and the inner cooling oil cavity and the lubricating oil pressure data at the lubricating oil nozzle through the ECU, obtains the optimal control strategy, controls the lubricating oil pressure by controlling the lubricating oil pump and controls the water cooler to change the flow rate of the cooling water according to the optimal MAP data of all working conditions, so as to achieve the purpose of controlling the piston temperature, and solves the problem that the piston temperature is difficult to control in real time.

Description

Technical Field

[0001] The invention relates to the technical field of thermodynamic analysis of a cooling oil cavity in an engine piston, and in particular to a device and a control method for testing thermodynamic state parameters of a cooling oil cavity in an engine piston. Background Art

[0002] With the increasing demand for engine applications in national defense science and technology and civilian fields, the degree of engine strengthening is constantly improving. High-strength engines can provide greater output power, and increasing output power will inevitably require engine components to bear greater mechanical and thermal loads, and the reliability of its components faces more severe tests. As one of the most critical components in the engine, the piston directly bears the combined effects of fuel gas pressure and high-temperature gas. When it is subjected to a large heat load for a long time, it is prone to problems such as piston head ablation, pin seat cracks, and ring groove scorching, which directly affect the reliability of the engine. Therefore, monitoring and obtaining the thermodynamic state parameters of the piston and the inner cooling oil cavity, and real-time control of the piston temperature based on the monitored parameters is one of the very necessary key technologies for the engine;

[0003] Regarding the cooling of piston temperature, the current conventional technologies are mainly: 1. Piston inner cavity direct injection lubricating oil cooling technology. Use a lubricating oil nozzle to spray lubricating oil directly into the piston inner cavity for cooling. Because the lubricating oil pressure at the lubricating oil nozzle is fixed, the cooling effect of this cooling method is unchanged; 2. Conventional inner cooling oil cavity cooling technology. The conventional inner cooling oil cavity cooling technology uses a nozzle connected to the lubrication system in the engine, and relies on the lubricating oil pressure of the lubrication system to spray lubricating oil into the inner cooling oil cavity through the nozzle to achieve cooling of the piston. Because the piston reciprocates rapidly in the body when the engine is running, it is very difficult to monitor the temperature of the piston and the inner cooling oil cavity, which makes it very difficult to achieve real-time control of the piston temperature. Therefore, the current conventional technology cannot achieve real-time control of the piston temperature; Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a device and a control method for testing the thermodynamic state parameters of the cooling oil chamber in an engine piston, which has the advantages of accurate control and solves the above-mentioned technical problems.

[0006] (II) Technical solution

[0007] To achieve the above-mentioned object, the present invention provides the following technical solutions: a device for testing thermodynamic state parameters of a cooling oil cavity in an engine piston, comprising a cylinder wall and a valve arranged inside an engine body, an ECU, a water cooler, a thermocouple and a battery, wherein the thermocouple comprises a first thermocouple, a second thermocouple, a third thermocouple, a fourth thermocouple, a fifth thermocouple, a sixth thermocouple and a seventh thermocouple;

[0008] A piston is arranged on the inner side of the cylinder wall, a first heat insulation box and a second heat insulation box are arranged on the inner side of the piston skirt, a third thermocouple, a fourth thermocouple and a fifth thermocouple are arranged inside the piston and close to the upper surface, an inner cooling oil cavity is arranged inside the piston, a second thermocouple and a sixth thermocouple are arranged on the inner side surface of the inner cooling oil cavity, a first thermocouple is arranged at the outlet of the inner cooling oil cavity, and a seventh thermocouple is arranged at the inlet of the inner cooling oil cavity, a data acquisition circuit is encapsulated in the first heat insulation box, and a high temperature resistant battery is arranged in the second heat insulation box;

[0009] A crankshaft is arranged on the lower side of the piston, a first magnetic induction charging module is arranged on the inner side of the cylinder wall on the right side of the piston, a second magnetic induction charging module is arranged on the right side of the piston skirt, a lubricating oil nozzle is arranged on the bottom of the cylinder wall, the lubricating oil outlet of the lubricating oil nozzle is opposite to the inlet of the internal cooling oil chamber, a lubricating oil pressure sensor is arranged on the mounting base of the lubricating oil nozzle, the sensing head of the lubricating oil pressure sensor is in contact with the lubricating oil, a Bluetooth receiving module is arranged on the inner side of the engine body on the right side of the cylinder wall, and a lubricating oil pump connected with the oil circuit and the lubricating oil nozzle is arranged at the bottom of the engine body.

[0010] As a preferred technical solution of the present invention, the thermocouple is circuit-connected to the data acquisition circuit, and the piston temperature data collected by the thermocouple is transmitted to the data acquisition circuit. After processing the temperature signal collected by the thermocouple, the data acquisition circuit transmits the signal to the Bluetooth receiving module in the form of a Bluetooth transmission signal, and transmits the signal to the ECU.

[0011] As a preferred technical solution of the present invention, one side of the high temperature resistant battery is connected to the second magnetic induction charging module through a circuit, and the other side is connected to the data acquisition circuit through a circuit.

[0012] As a preferred technical solution of the present invention, the second magnetic induction charging module and the first magnetic induction charging module are arranged at intervals, and the second magnetic induction charging module and the first magnetic induction charging module are composed of an induction coil and a circuit control chip, and are used for charging high temperature resistant batteries.

[0013] As a preferred technical solution of the present invention, the thermocouple is a K-type thermocouple, and its temperature measurement range is -20 to 600°C.

[0014] The present invention also provides a method for controlling the thermodynamic state parameters of a cooling oil cavity in an engine piston, using the above-mentioned device for testing the thermodynamic state parameters of a cooling oil cavity in an engine piston, comprising the following steps:

[0015] S1, obtaining a third temperature value of the third thermocouple, a fourth temperature value of the fourth thermocouple, and a fifth temperature value of the fifth thermocouple, and taking the largest value among the third temperature value, the fourth temperature value and the fifth temperature value as the piston temperature D1;

[0016] S2, obtaining a first temperature value of the first thermocouple, a second temperature value of the second thermocouple, a sixth temperature value of the sixth thermocouple, and a seventh temperature value of the seventh thermocouple, and performing comprehensive evaluation to obtain internal cooling oil chamber temperature data D2;

[0017] S3, obtaining a first pressure value of a lubricating oil pressure sensor as lubricating oil pressure data D3;

[0018] S4. The influencing factors are determined to be EGR rate, fuel injection pressure, fuel injection timing, multiple fuel injections, lubricating oil pump speed, and cooling water circulation speed through the three-dimensional combustion model and the finite element analysis and thermodynamic coupling calculation model. The output targets are effective fuel consumption rate, maximum explosion pressure and pressure rise rate, piston temperature peak value, piston thermal-mechanical coupling stress / strain peak value, and the correlation analysis is performed between the influencing factors and the output targets.

[0019] S5. After obtaining the design samples using Latin hypercube sampling, a Transformer proxy model is established, and a multi-objective optimization algorithm is used for multi-objective collaborative optimization to obtain the optimal combination of control parameters of the piston inner cooling oil chamber;

[0020] S6. Taking effective fuel consumption rate, maximum burst pressure and pressure rise rate as the main weights, and piston temperature peak value and piston thermal engine coupling stress / strain peak value as the secondary weights, an optimization algorithm is used to obtain the optimal MAP data for all working conditions;

[0021] S7. Write the optimal MAP data for all operating conditions into the ECU. The ECU obtains the optimal control strategy based on the monitored piston temperature data D1, the internal cooling oil chamber temperature data D2, the lubricating oil pressure data D3, and the optimal MAP data for all operating conditions, and sends instructions from the ECU to the water cooler and the lubricating oil pump to control the piston temperature.

[0022] Compared with the prior art, the present invention provides a device and a control method for testing the thermodynamic state parameters of the cooling oil cavity in the engine piston, which has the following beneficial effects:

[0023] 1. The present invention monitors and analyzes the temperature data from the piston and the inner cooling oil cavity and the lubricating oil pressure data at the lubricating oil nozzle through the ECU to obtain the optimal control strategy. According to the optimal MAP data of all working conditions, the lubricating oil pump is controlled to change the lubricating oil pressure and the water cooler is controlled to change the flow rate of cooling water to achieve the purpose of controlling the piston temperature, thereby solving the problem that the piston temperature is difficult to control in real time.

[0024] 2. The present invention uses multi-objective optimization technology to analyze a large amount of data obtained from three-dimensional combustion models and finite element analysis and thermodynamic coupling calculation models, and finally obtains the optimal MAP data for all working conditions for controlling piston temperature, providing data support for achieving real-time control of piston temperature.

[0025] 3. The piston and inner cooling oil cavity data monitored by the monitoring device of the present invention provide more realistic boundary conditions for constructing a three-dimensional engine combustion model with better predictability and higher prediction accuracy and a finite element analysis and thermodynamic coupling calculation model of the piston inner cooling oil cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the device of the present invention;

[0027] Figure 2 This is a general schematic diagram of the thermocouple installation of the present invention;

[0028] Figure 3 This is a partial enlarged schematic diagram of the thermocouple installation of the present invention;

[0029] Figure 4 It is a schematic diagram of the combination of a thermocouple and a bolt of the present invention;

[0030] Figure 5 A schematic diagram of optimal MAP data for all operating conditions obtained by multi-objective optimization of the present invention;

[0031] Figure 6 Schematic diagram of the control strategy of the present invention.

[0032] Among them: 1. Engine body; 2. Crankshaft; 3. Data acquisition circuit; 4. First insulation box; 5. Cylinder wall; 6. First thermocouple; 7. Second thermocouple; 8. Internal cooling oil chamber; 9. Third thermocouple; 10. Piston; 11. Valve; 12. Fourth thermocouple; 13. Sixth thermocouple; 14. Fifth thermocouple; 15. Seventh thermocouple; 16. Second insulation box; 17. High temperature resistant battery; 18. Second magnetic induction charging module; 19. First magnetic induction charging module; 20. Lubricating oil nozzle; 21. Lubricating oil pressure sensor; 22. Bluetooth receiving module; 23. ECU; 24. Battery; 25. Lubricating oil pump; 26. Water cooler; 30. Bolt; 31. Thermocouple; 32. Thermocouple wire; 33. Thermocouple protective cover. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figure 1-6 , a device for testing thermodynamic state parameters of a cooling oil cavity in an engine piston, comprising a cylinder wall 5 and a valve 11 arranged on the inner side of an engine body 1, and further comprising an ECU 23, a water cooler 26, a thermocouple 31 and a battery 24, wherein the thermocouple 31 comprises a first thermocouple 6, a second thermocouple 7, a third thermocouple 9, a fourth thermocouple 12, a fifth thermocouple 14, a sixth thermocouple 13 and a seventh thermocouple 15;

[0035] A piston 10 is arranged on the inner side of the cylinder wall 5, a first heat-insulating box 4 and a second heat-insulating box 16 are arranged on the inner side of the skirt of the piston 10, a third thermocouple 9, a fourth thermocouple 12 and a fifth thermocouple 14 are arranged inside the piston 10 and close to the upper surface, an inner cooling oil chamber 8 is arranged inside the piston 10, a second thermocouple 7 and a sixth thermocouple 13 are arranged on the inner side of the inner cooling oil chamber 8, a first thermocouple 6 is arranged at the outlet of the inner cooling oil chamber 8, a seventh thermocouple 15 is arranged at the inlet of the inner cooling oil chamber 8, a data acquisition circuit 3 is encapsulated in the first heat-insulating box 4, and a high-temperature resistant battery 17 is arranged in the second heat-insulating box 16;

[0036] A crankshaft 2 is arranged on the lower side of the piston 10, a first magnetic induction charging module 19 is arranged on the inner side of the cylinder wall 5 on the right side of the piston 10, a second magnetic induction charging module 18 is arranged on the right side of the skirt of the piston 10, a lubricating oil nozzle 20 is arranged at the bottom of the cylinder wall 5, the lubricating oil outlet of the lubricating oil nozzle 20 is opposite to the inlet of the internal cooling oil chamber 8, a lubricating oil pressure sensor 21 is arranged on the mounting base of the lubricating oil nozzle 20, the sensing head of the lubricating oil pressure sensor 21 is in contact with the lubricating oil, a Bluetooth receiving module 22 is arranged on the inner side of the engine body 1 on the right side of the cylinder wall 5, and a lubricating oil pump 25 whose oil circuit is connected to the lubricating oil nozzle 20 is arranged at the bottom of the engine body 1.

[0037] Furthermore, the thermocouple 31 is circuit-connected to the data acquisition circuit 3, and the piston temperature data collected by the thermocouple 31 is transmitted to the data acquisition circuit 3. After processing the temperature signal collected by the thermocouple, the data acquisition circuit 3 transmits the signal to the Bluetooth receiving module 22 in the form of a Bluetooth transmission signal, and transmits the signal to the ECU 23.

[0038] Furthermore, one side of the high temperature resistant battery 17 is connected to the second magnetic induction charging module 18 through a circuit, and the other side is connected to the data acquisition circuit 3 through a circuit.

[0039] Furthermore, the second magnetic induction charging module 18 and the first magnetic induction charging module 19 are arranged at intervals. The second magnetic induction charging module 18 and the first magnetic induction charging module 19 are composed of an inductor coil and a circuit control chip, and are used for charging the high temperature resistant battery 17.

[0040] Furthermore, the thermocouple 31 is a K-type thermocouple, and its temperature measurement range is -20 to 600°C.

[0041] The thermocouple 31 is fixed on the thermocouple protection sleeve 33, and the thermocouple protection sleeve 33 is integrated with the bolt 30. The thermocouple 31 also has a thermocouple wire 32 at the end, and the thermocouple wire 32 is connected to the line for transmitting the temperature signal. The installation method of the thermocouple 31 is as follows: Figure 2 and Figure 3 As shown, the bolt 30 with the thermocouple fixed inside is fixed on the piston 10 through threads, and finally the purpose of fixing the thermocouple 31 on the piston is achieved.

[0042] The battery 24 is preferably a battery made based on lithium iron phosphate technology. The battery 24 is connected to the first magnetic induction charging module 19 through a circuit to supply power to the first magnetic induction charging module 19. The battery 24 is also connected to the lubricating oil pump 25 through a circuit to supply power to the lubricating oil pump 25.

[0043] The water cooler 26 is a cooler with adjustable cooling effect. One side of the water cooler 26 is connected to the lubricating oil pump 25 through an oil circuit, and the other side is connected to the lubricating oil nozzle 20 through an oil circuit. The water cooler 26 is placed outside the engine body 1 and mainly cools the lubricating oil;

[0044] The present invention also provides a method for controlling the thermodynamic state parameters of a cooling oil cavity in an engine piston, using the above-mentioned device for testing the thermodynamic state parameters of a cooling oil cavity in an engine piston, comprising the following steps:

[0045] S1, obtaining a third temperature value of the third thermocouple 9, a fourth temperature value of the fourth thermocouple 12, and a fifth temperature value of the fifth thermocouple 14, and taking the largest value among the third temperature value, the fourth temperature value and the fifth temperature value as the piston temperature D1;

[0046] S2, obtaining a first temperature value of the first thermocouple 6, a second temperature value of the second thermocouple 7, a sixth temperature value of the sixth thermocouple 13, and a seventh temperature value of the seventh thermocouple 15, and performing comprehensive evaluation to obtain the internal cooling oil chamber temperature data D2;

[0047] The calculation expression of comprehensive evaluation is as follows:

[0048]

[0049] η1+η2=1

[0050] Wherein, T7 is the seventh temperature value, T1 is the first temperature value, T6 is the sixth temperature value, T2 is the second temperature value, η1 and η2 are coefficients;

[0051] S3, obtaining the first pressure value of the lubricating oil pressure sensor 21 as lubricating oil pressure data D3;

[0052] S4. A three-dimensional combustion model of the engine with better predictability and higher prediction accuracy and a finite element analysis and thermodynamic coupling calculation model of the cooling oil cavity in the piston 10 are constructed by monitoring the first temperature value, the second temperature value, the third temperature value, the fourth temperature value, the fifth temperature value, the sixth temperature value, the seventh temperature value, and the first pressure value. The influencing factors are determined to be EGR rate, fuel injection pressure, fuel injection timing, multiple fuel injections, lubricating oil pump speed, and cooling water circulation speed through the three-dimensional combustion model and the finite element analysis and thermodynamic coupling calculation model. The output targets are effective fuel consumption rate, maximum explosion pressure and pressure rise rate, piston temperature peak value, and piston thermal engine coupling stress / strain peak value, and a correlation analysis is performed on the influencing factors and the output targets.

[0053] S5. After obtaining the design samples by using Latin hypercube sampling, a Transformer proxy model is established (the Transformer proxy model is an algorithm for expanding the samples, which will not be described in detail here), and a multi-objective optimization algorithm is used to perform multi-objective collaborative optimization to obtain the optimal combination of control parameters of the cooling oil chamber in the piston 10;

[0054] The design samples are specifically: EGR rate, fuel injection pressure, fuel injection timing, fuel multiple injections, lubricating oil pump speed, cooling water circulation speed, effective fuel consumption rate, maximum burst pressure and pressure rise rate, piston temperature peak, piston thermal-mechanical coupling stress / strain peak values;

[0055] Multi-objective collaborative optimization here means: taking EGR rate, fuel injection pressure, fuel injection timing, multiple fuel injections, lubricating oil pump speed, cooling water circulation speed as influencing factors, multi-objective collaborative optimization is performed on targets such as effective fuel consumption rate, maximum burst pressure and pressure rise rate, piston temperature peak, piston thermal engine coupling stress / strain peak, etc.

[0056] S6. Taking effective fuel consumption rate, maximum burst pressure and pressure rise rate as the main weights, and piston temperature peak value and piston thermal engine coupling stress / strain peak value as the secondary weights, an optimization algorithm is used to obtain the optimal MAP data for all working conditions;

[0057] S7, writing the optimal MAP data of all working conditions into the ECU 23, the ECU 23 obtains the optimal control strategy according to the monitored piston temperature data D1, the internal cooling oil chamber temperature data D2, the lubricating oil pressure data D3, and the optimal MAP data of all working conditions, and sends the command from the ECU to the water cooler 26 and the lubricating oil pump 25 to control the temperature of the piston 10;

[0058] The process of ECU executing strategy / command is as follows:

[0059] Obtain piston temperature data D1, internal cooling oil chamber temperature data D2, and lubricating oil pressure data D3;

[0060] According to the optimal MAP data of all working conditions corresponding to the piston temperature data D1, the internal cooling oil chamber temperature data D2, and the lubricating oil pressure data D3, the Y1 optimal water cooler cooling water flow rate and lubricating oil pump speed strategy is executed;

[0061] According to the optimal MAP data of all working conditions corresponding to the piston temperature data D1, the internal cooling oil chamber temperature data D2, and the lubricating oil pressure data D3, the Y2 optimal water cooler cooling water flow rate and lubricating oil pump speed strategy is executed;

[0062] …

[0063] According to the optimal MAP data of all working conditions corresponding to the piston temperature data D1, the internal cooling oil chamber temperature data D2, and the lubricating oil pressure data D3, the Yn optimal water cooler cooling water flow rate and lubricating oil pump speed strategy is executed;

[0064] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for testing thermodynamic state parameters of a cooling oil cavity in an engine piston, comprising a cylinder wall (5) and a valve (11) arranged inside an engine body (1), characterized in that: The device also includes an ECU (23), a water cooler (26), a thermocouple (31) and a battery (24), wherein the thermocouple (31) includes a first thermocouple (6), a second thermocouple (7), a third thermocouple (9), a fourth thermocouple (12), a fifth thermocouple (14), a sixth thermocouple (13) and a seventh thermocouple (15); A piston (10) is arranged on the inner side of the cylinder wall (5), a first heat insulation box (4) and a second heat insulation box (16) are arranged on the inner side of the skirt of the piston (10), a third thermocouple (9), a fourth thermocouple (12) and a fifth thermocouple (14) are arranged inside the piston (10) and close to the upper surface, an inner cooling oil chamber (8) is arranged inside the piston (10), a second thermocouple (7) and a sixth thermocouple (13) are arranged on the inner side surface of the inner cooling oil chamber (8), a first thermocouple (6) is arranged at the outlet of the inner cooling oil chamber (8), and a seventh thermocouple (15) is arranged at the inlet of the inner cooling oil chamber (8), a data acquisition circuit (3) is encapsulated in the first heat insulation box (4), and a high temperature resistant battery (17) is arranged in the second heat insulation box (16); A crankshaft (2) is arranged at the lower side of the piston (10), a first magnetic induction charging module (19) is arranged at the inner side of the cylinder wall (5) on the right side of the piston (10), a second magnetic induction charging module (18) is arranged at the right side of the skirt of the piston (10), a lubricating oil nozzle (20) is arranged at the bottom of the cylinder wall (5), the lubricating oil outlet of the lubricating oil nozzle (20) is directly opposite to the inlet of the inner cooling oil chamber (8), a lubricating oil pressure sensor (21) is arranged at the mounting base of the lubricating oil nozzle (20), the sensing head of the lubricating oil pressure sensor (21) is in contact with the lubricating oil, a Bluetooth receiving module (22) is arranged at the inner side of the engine body (1) on the right side of the cylinder wall (5), and a lubricating oil pump (25) connected with the lubricating oil nozzle (20) is arranged at the bottom of the engine body (1).

2. The device for testing thermodynamic state parameters of the cooling oil chamber in the engine piston according to claim 1, characterized in that: The thermocouple (31) is electrically connected to the data acquisition circuit (3), and the piston temperature data collected by the thermocouple (31) is transmitted to the data acquisition circuit (3). After the data acquisition circuit (3) processes the temperature signal collected by the thermocouple, the signal is transmitted to the Bluetooth receiving module (22) in the form of a Bluetooth transmission signal, and the signal is transmitted to the ECU (23).

3. The device for testing thermodynamic state parameters of the cooling oil chamber in the engine piston according to claim 1, characterized in that: One side of the high temperature resistant battery (17) is connected to the second magnetic induction charging module (18) through a circuit, and the other side is connected to the data acquisition circuit (3) through a circuit.

4. The device for testing thermodynamic state parameters of the cooling oil chamber in the engine piston according to claim 1, characterized in that: The second magnetic induction charging module (18) and the first magnetic induction charging module (19) are arranged at intervals, and the second magnetic induction charging module (18) and the first magnetic induction charging module (19) are composed of an induction coil and a circuit control chip, and are used for charging the high temperature resistant battery (17).

5. The device for testing thermodynamic state parameters of the cooling oil cavity in the engine piston according to claim 1, characterized in that: The thermocouple (31) is a K-type thermocouple, and its temperature measurement range is -20 to 600°C.

6. A method for controlling the thermodynamic state parameters of the cooling oil chamber in an engine piston, using a device for testing the thermodynamic state parameters of the cooling oil chamber in an engine piston as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: S1, obtaining a third temperature value of the third thermocouple (9), a fourth temperature value of the fourth thermocouple (12), and a fifth temperature value of the fifth thermocouple (14), and taking the largest value among the third temperature value, the fourth temperature value and the fifth temperature value as the piston temperature D1; S2, obtaining a first temperature value of the first thermocouple (6), a second temperature value of the second thermocouple (7), a sixth temperature value of the sixth thermocouple (13), and a seventh temperature value of the seventh thermocouple (15), and performing comprehensive evaluation to obtain internal cooling oil chamber temperature data D2; S3, obtaining a first pressure value of a lubricating oil pressure sensor (21) as lubricating oil pressure data D3; S4. The influencing factors are determined to be EGR rate, fuel injection pressure, fuel injection timing, multiple fuel injections, lubricating oil pump speed, and cooling water circulation speed through the three-dimensional combustion model and the finite element analysis and thermodynamic coupling calculation model. The output targets are effective fuel consumption rate, maximum explosion pressure and pressure rise rate, piston temperature peak value, piston thermal-mechanical coupling stress / strain peak value, and the correlation analysis is performed between the influencing factors and the output targets. S5, after obtaining the design samples by Latin hypercube sampling, a Transformer proxy model is established, and a multi-objective optimization algorithm is used to perform multi-objective collaborative optimization to obtain the optimal combination of control parameters of the cooling oil chamber inside the piston (10); S6. Taking effective fuel consumption rate, maximum burst pressure and pressure rise rate as the main weights, and piston temperature peak value and piston thermal engine coupling stress / strain peak value as the secondary weights, an optimization algorithm is used to obtain the optimal MAP data for all working conditions; S7. The optimal MAP data for all operating conditions is written into the ECU (23). The ECU (23) obtains an optimal control strategy based on the monitored piston temperature data D1, the internal cooling oil chamber temperature data D2, and the lubricating oil pressure data D3, and the optimal MAP data for all operating conditions, and sends instructions from the ECU (23) to the water cooler (26) and the lubricating oil pump (25) to control the temperature of the piston (10).

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