Turbocharger, Turbocharger thermal control system and thermal control method

Abstract

This invention discloses a turbocharger, a turbocharger thermal control system, and a thermal control method, comprising: a turbine housing; a bearing housing connected to the turbine housing; and a heat shield disposed between the turbine housing and the bearing housing. The heat shield has a hollow flow channel and a cooling medium inlet and a cooling medium outlet respectively connected to the hollow flow channel. The cooling medium inlet is used to connect to an external cooling medium supply pipeline, and the cooling medium outlet is used to connect to an external cooling medium return pipeline. By using a hollow heat shield, the cooling medium flows along the hollow flow channel during use, carrying away the heat from the heat shield. This reduces the temperature gradient of the heat shield, blocks heat conduction to the bearing housing, and achieves source cooling by directly introducing the cooling medium into the interior of the heat shield, which is closest to the heat source. This prevents heat conduction to the bearing housing, ensures that the operating temperature of the bearing housing meets requirements, prevents coking of the lubricating oil inside the bearing housing, and prevents key components such as sealing rings and floating bearings from aging and failing due to excessive temperature.

Description

Technical Field

[0001] This invention relates to the field of turbocharger heat transfer technology, and more specifically, to a turbocharger, a turbocharger thermal control system, and a thermal control method. Background Technology

[0002] A turbocharger uses the high-temperature exhaust gas from the engine to drive a turbine, which in turn drives a coaxial compressor impeller to rotate, thereby increasing the intake pressure. During this process, there is a severe heat load. The gas temperature at the turbine housing inlet of the turbocharger can reach 800-1000℃. The turbine housing is connected to the bearing housing through a heat shield. The high temperature of the gas is transferred to the bearing housing through the turbine housing and heat shield. The bearing housing is the core support of the turbocharger rotor. It contains floating bearings and a lubricating oil film. When the temperature of the bearing housing exceeds a certain limit, the lubricating oil inside will coke due to the excessive temperature. The sealing ring will lose its elasticity, causing oil leakage. The strength of the floating bearing material will decrease, accelerating wear and aging.

[0003] To prevent coking of lubricating oil in the bearing housing and failure of sealing rings and floating bearings, related technologies use single or multiple layers of thin metal plates as heat shields to isolate heat radiation. However, after long-term operation, the temperature of the heat shield gradually rises and approaches the turbine housing temperature, becoming a new heat source that radiates heat to the bearing housing.

[0004] Therefore, how to effectively reduce the temperature of the bearing housing is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a turbocharger that can effectively reduce the bearing body temperature.

[0006] Another object of the present invention is to provide a turbocharger thermal control system including the above-described turbocharger, so as to effectively reduce the bearing body temperature.

[0007] Another object of the present invention is to provide a turbocharger thermal control method applied to the above-mentioned turbocharger thermal control system, so as to effectively reduce the bearing body temperature.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A turbocharger, comprising:

[0010] Turbine housing;

[0011] The bearing housing is connected to the turbine housing;

[0012] A heat shield is disposed between the turbine housing and the bearing body. The heat shield has a hollow flow channel and a cooling medium inlet and a cooling medium outlet respectively connected to the hollow flow channel. The cooling medium inlet is used to connect to an external cooling medium supply pipeline, and the cooling medium outlet is used to connect to an external cooling medium return pipeline.

[0013] Optionally, the cooling medium inlet is located at the lower part of the heat insulation cover, and the cooling medium outlet is located at the upper part of the heat insulation cover; and / or,

[0014] The hollow flow channel is arranged in a spiral or serpentine shape.

[0015] Optionally, the heat shield is provided with a sensor inlet, the bearing housing is provided with a first mounting channel, and the turbocharger further includes:

[0016] The first bushing connector is inserted through the first mounting channel and connected to the sensor inlet;

[0017] A temperature sensor is connected to the first bushing joint, and the probe of the temperature sensor passes through the hollow inner cavity of the first bushing joint and contacts the inner wall surface of the heat insulation cover near the turbine housing.

[0018] Optionally, the bearing housing is provided with two second mounting channels, and the turbocharger further includes:

[0019] Two second bushing connectors, one of which passes through one of the second mounting channels and is connected to the cooling medium inlet, and the other of which passes through the other second mounting channel and is connected to the cooling medium outlet.

[0020] Optionally, a preset gap exists between the heat shield and the turbine housing.

[0021] A turbocharger thermal control system, comprising:

[0022] Any of the above turbochargers;

[0023] A coolant circulation pump is connected between the coolant inlet and coolant outlet of the turbocharger to provide power for the circulation of the coolant.

[0024] A cooling fan is used to cool the cooling medium returning from the outlet of the cooling medium;

[0025] The controller is connected to the coolant circulation pump and the cooling fan respectively, and is used to control the operation of the coolant circulation pump and the cooling fan.

[0026] A turbocharger thermal control method is provided, applied to the controller of the aforementioned turbocharger thermal control system, the turbocharger thermal control method comprising:

[0027] Obtain the temperature of the heat shield of the turbocharger in the turbocharger thermal control system;

[0028] The temperature of the heat insulation cover is compared with the preset lower limit and preset upper limit of the preset temperature range, respectively;

[0029] When the temperature of the heat shield exceeds the preset upper limit, the speed of the coolant circulation pump of the turbocharger thermal control system is increased to increase the flow rate, and the speed of the cooling fan of the turbocharger thermal control system is increased to reduce the temperature of the coolant entering the turbocharger.

[0030] When the temperature of the heat shield is lower than the preset lower limit, the speed of the coolant circulation pump is reduced to decrease the flow rate, or the speed of the cooling fan is reduced or stopped to increase the temperature of the coolant entering the turbocharger.

[0031] When the temperature of the heat shield is greater than or equal to the preset lower limit and less than or equal to the preset upper limit, the current control parameters of the coolant circulation pump and the cooling fan remain unchanged.

[0032] Optionally, before comparing the temperature of the heat shield with a preset lower limit and a preset upper limit of a preset temperature range, the method further includes:

[0033] When the temperature of the heat shield is detected to be continuously abnormal or the temperature signal of the heat shield cannot be obtained, a system fault message is issued, and the coolant circulation pump is controlled to operate at a first preset speed, and the cooling fan is controlled to operate at a second preset speed.

[0034] Optionally, after controlling the coolant circulation pump to operate at a first preset speed and controlling the cooling fan to operate at a second preset speed, the method further includes:

[0035] Calculate the rate of temperature change of the heat shield;

[0036] Determine whether the rate of change is greater than a preset rate of change;

[0037] If so, the speed of the coolant circulation pump is increased to increase the flow rate, and the speed of the cooling fan is increased to reduce the temperature of the coolant entering the turbocharger, until the rate of change meets the preset rate of change.

[0038] Optionally, the preset temperature range is obtained by calibration through bench testing. In the bench test, the correspondence between the temperature of the heat shield and the coolant flow rate, the inlet temperature of the cooling medium and the engine operating conditions is determined. Based on the correspondence, the temperature range of nucleation boiling heat transfer is calibrated as the preset temperature range.

[0039] The turbocharger provided by this invention has at least the following beneficial effects:

[0040] A hollow heat shield is used. During operation, the cooling medium inlet is connected to an external cooling medium supply pipe, and the cooling medium outlet is connected to an external cooling medium return pipe. The external cooling medium supply pipe supplies cooling medium into the hollow flow channel of the heat shield, allowing the cooling medium to flow along the channel. When heat from the turbine housing is transferred to the heat shield wall, this heat is promptly carried away by the cooling medium flowing within the hollow channel. The heat-absorbing cooling medium flows out from the cooling medium outlet and is discharged through the external cooling medium return pipe. This cycle continues, carrying away heat from the heat shield and significantly reducing its temperature gradient. This fundamentally blocks heat conduction to the bearing housing. In other words, the heat shield in this embodiment not only... It not only provides conventional heat insulation but also heat dissipation. By directly introducing the cooling medium into the heat shield closest to the heat source (i.e., the turbine housing), it achieves source cooling. A large amount of heat is carried away before it is transferred to the bearing housing, preventing heat conduction to the bearing housing. This significantly reduces the temperature of the bearing housing, ensuring that the operating temperature of the bearing housing meets the requirements and preventing the lubricating oil in the bearing housing from coking due to excessive temperature. At the same time, it improves the operating environment temperature of the sealing ring and floating bearing in the bearing housing, preventing key components such as sealing ring and floating bearing from aging and failing due to excessive temperature. This improves the reliability and service life of the turbocharger under high temperature and high load conditions, meeting the more stringent emission and power requirements of the engine.

[0041] The turbocharger thermal control system provided by the present invention includes the turbocharger described above and has at least the beneficial effects of the turbocharger described above.

[0042] The turbocharger thermal control method provided by the present invention, when applied to the aforementioned turbocharger thermal control system, has at least the beneficial effects of the aforementioned turbocharger. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0044] Figure 1This is a cross-sectional view of a turbocharger provided in a specific embodiment of the present invention;

[0045] Figure 2 This is a cross-sectional view of the heat shield;

[0046] Figure 3 This is a schematic diagram of the end face of the heat shield (partial cross-section).

[0047] Figure 4 This is a schematic diagram of the bearing housing.

[0048] Figure 5 This is a cross-sectional view of the turbocharger from another direction.

[0049] Figure 6 This is a schematic diagram of the structure of the first bushing joint;

[0050] Figure 7 This is a schematic diagram of the second bushing joint.

[0051] Figure 8 This is a flowchart of a turbocharger thermal control method provided in a specific embodiment of the present invention.

[0052] Figure label:

[0053] 1-Turbine housing; 2-Bearing body; 21-First mounting channel; 22-Second mounting channel; 23-Floating bearing; 24-Lubricating oil passage; 25-Flange; 3-Heat insulation cover; 31-Hollow flow channel; 32-Cooling medium inlet; 33-Cooling medium outlet; 34-Sensor inlet; 35-Inner wall surface; 4-First bushing joint; 5-Temperature sensor; 6-Second bushing joint. Detailed Implementation

[0054] 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.

[0055] The core of this invention is to provide a turbocharger that effectively reduces bearing housing temperature. Another core aspect of this invention is to provide a turbocharger thermal control system including the aforementioned turbocharger, thereby effectively reducing bearing housing temperature. Yet another core aspect of this invention is to provide a turbocharger thermal control method applied to the aforementioned turbocharger thermal control system, thereby effectively reducing bearing housing temperature.

[0056] Please refer to Figure 1 , Figure 2 and Figure 3This invention provides a turbocharger, including a turbine housing 1, a bearing body 2, and a heat shield 3. The bearing body 2 is connected to the turbine housing 1. The heat shield 3 is disposed between the turbine housing 1 and the bearing body 2. The heat shield 3 has a hollow flow channel 31 and a cooling medium inlet 32 ​​and a cooling medium outlet 33 respectively connected to the hollow flow channel 31. The cooling medium inlet 32 ​​is used to connect to an external cooling medium supply pipeline, and the cooling medium outlet 33 is used to connect to an external cooling medium return pipeline.

[0057] In other words, this embodiment of the invention uses a hollow heat shield 3. During use, the cooling medium inlet 32 ​​is connected to an external cooling medium supply pipe, and the cooling medium outlet 33 is connected to an external cooling medium return pipe. The external cooling medium supply pipe supplies cooling medium into the hollow flow channel 31 of the heat shield 3, allowing the cooling medium to flow along the hollow flow channel 31. When heat from the turbine housing 1 is transferred to the wall of the heat shield 3, this heat is promptly carried away by the cooling medium flowing within the hollow flow channel 31. The heat-absorbing cooling medium flows out from the cooling medium outlet 33 and is discharged through the external cooling medium return pipe. This cycle continues, carrying away heat from the heat shield 3, significantly reducing the temperature gradient of the heat shield 3 itself, and fundamentally blocking heat conduction to the bearing body 2. That is, this invention... The heat shield 3 in the example not only has a conventional heat insulation function, but also a heat dissipation function. By directly introducing the cooling medium into the interior of the heat shield 3, which is closest to the heat source (i.e., turbine housing 1), source cooling is achieved. A large amount of heat is carried away before it is transferred to the bearing housing 2, avoiding heat conduction to the bearing housing 2. This significantly reduces the temperature of the bearing housing 2, ensuring that the operating temperature of the bearing housing 2 meets the requirements and preventing the lubricating oil in the bearing housing 2 from coking due to excessive temperature. At the same time, it improves the operating environment temperature of the sealing ring and floating bearing 23 in the bearing housing 2, preventing key components such as the sealing ring and floating bearing 23 from aging and failing due to excessive temperature. This improves the reliability and service life of the turbocharger under high temperature and high load conditions, meeting the more stringent emission and power requirements of the engine.

[0058] It should be noted that the embodiments of the present invention do not limit the specific type or state of the cooling medium, as long as the cooling medium can flow within the hollow flow channel 31 to remove the heat from the heat insulation cover 3. The cooling medium can be a coolant or cooled air. When the cooling medium is a coolant, it can be cooling water or other liquid cooling medium. In this case, a coolant circulation pump can be connected between the external cooling medium supply pipeline and the external cooling medium return pipeline to drive the coolant flow. The coolant enters the hollow flow channel 31 from the cooling medium inlet 32, flows along the hollow flow channel 31, flows out from the cooling medium outlet 33, enters the external cooling medium return pipeline, and can finally be recycled after passing through the radiator for heat dissipation.

[0059] In applications where coolant supply is limited, such as commercial vehicles or off-road machinery, cooling air can flow within the hollow channel 31. In this case, the external cooling medium supply pipeline connected to the cooling medium inlet 32 ​​is connected to a compressed air source. The compressed air source can be bleed air from the turbocharger compressor outlet or an independent electric fan, etc. Furthermore, cooling air is suitable for low to medium heat load scenarios.

[0060] It is understood that turbine housing 1 serves as a high-temperature exhaust gas passage, with its inlet end connected to the engine exhaust manifold. A turbine is installed inside turbine housing 1. To facilitate the connection between turbine housing 1 and bearing housing 2, exemplarily, turbine housing 1 has a flange mounting surface on the side near bearing housing 2, and bearing housing 2 has a flange 25 (e.g., ...). Figure 4 As shown), flange 25 is connected to the flange mounting surface by several bolts, thereby achieving a fixed connection between turbine housing 1 and bearing body 2. Additionally, as... Figure 1 As shown, the bearing housing 2 houses a floating bearing 23 and a rotor shaft, and is equipped with a lubrication oil passage 24.

[0061] Furthermore, this embodiment does not limit the specific formation method of the hollow flow channel 31 inside the heat insulation cover 3. For example, the heat insulation cover 3 is made of heat-resistant silicon molybdenum ductile iron casting, and the hollow flow channel 31 is formed inside the heat insulation cover 3 by casting. That is, the structure of the heat insulation cover 3 consists of two shells, an inner and an outer shell, and the two shells are integrally cast to form a closed hollow flow channel 31. In addition, this embodiment does not limit the specific shape of the hollow flow channel 31. In some embodiments, the hollow flow channel 31 is arranged in a spiral or serpentine manner. This structure can increase the contact area and flow path length between the cooling medium and the wall of the heat insulation cover 3, thereby improving the heat exchange efficiency. In addition, the cross-sectional shape of the hollow flow channel 31 can be circular or flat, etc., to adapt to the limited installation space of the heat insulation cover 3.

[0062] Furthermore, such as Figure 2 and Figure 3 As shown, in some embodiments, the cooling medium inlet 32 ​​is located at the lower part of the heat insulation cover 3, and the cooling medium outlet 33 is located at the upper part of the heat insulation cover 3.

[0063] In other words, in this embodiment, the cooling medium inlet 32 ​​is located below the geometric center of the heat insulation cover 3, and the cooling medium outlet 33 is located above the geometric center of the heat insulation cover 3. For example, the cooling medium inlet 32 ​​is located at the bottom of the heat insulation cover 3, and the cooling medium outlet 33 is located at the top of the heat insulation cover 3. That is, the cooling medium flows in a bottom-in, top-out manner. After the cooling medium enters the hollow flow channel 31 from the cooling medium inlet 32, it flows in the direction from bottom to top. Utilizing the physical property that the density of the coolant decreases after being heated and expands, and rises naturally, natural convection is added on the basis of forced circulation to ensure that the coolant can fill the entire cavity and effectively discharge the gas, so that there are no air bubbles trapped in the hollow flow channel 31, thereby improving the heat exchange uniformity and stability.

[0064] In addition, in some embodiments, there is a preset gap between the heat shield 3 and the turbine housing 1.

[0065] It is understandable that the side of the heat shield 3 closest to the turbine housing 1 is the heat-receiving surface, and there is a preset gap between the heat shield 3 and the turbine housing 1 to form an air gap heat insulation layer. Utilizing the air gap as a heat insulation layer slows down heat transfer and further restricts heat transfer from the turbine housing 1 to the bearing body 2. Combined with the heat dissipation of the cooling medium inside the heat shield 3, the temperature control effect is better. In addition, it is understandable that the side of the heat shield 3 closest to the bearing body 2 is the mounting surface, and heat insulation and sealing between the bearing body 2 and the heat shield 3 can be achieved through sealing gaskets and high-temperature sealant.

[0066] Furthermore, such as Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, in some embodiments, the heat shield 3 is provided with a sensor inlet 34, the bearing body 2 is provided with a first mounting channel 21, and the turbocharger also includes a first bushing joint 4 and a temperature sensor 5. The first bushing joint 4 passes through the first mounting channel 21 and is connected to the sensor inlet 34; the temperature sensor 5 is connected to the first bushing joint 4, and the probe of the temperature sensor 5 passes through the hollow inner cavity of the first bushing joint 4 and contacts the inner wall surface 35 of the heat shield 3 near the turbine housing 1.

[0067] In other words, in this embodiment, the temperature sensor 5 is arranged on the heat shield 3 via the first bushing connector 4, so that the temperature sensor 5 can detect the temperature of the inner wall surface 35 of the heat shield 3 near the turbine housing 1 in real time. This position is closest to the heat source and can reflect changes in heat load most quickly and accurately, providing a reliable input for control. This allows for control of the cooling medium temperature based on the real-time temperature value detected by the temperature sensor 5, thereby optimizing the heat exchange efficiency and cooling effect of the heat shield 3. For example, the temperature sensor 5 is connected to a controller to send the real-time temperature detected by the temperature sensor 5 to the controller. The controller can be connected to a coolant circulation pump and a cooling fan to control the coolant flow rate and coolant inlet temperature, thereby regulating the coolant to keep the temperature of the heat shield 3 within a suitable range. The specific control method of the controller can be found in the turbocharger thermal control method described below.

[0068] It should be noted that this embodiment does not limit the specific number and arrangement of the first bushing connector 4 and the temperature sensor 5, as long as the temperature of the heat insulation cover 3 can be detected in real time. For example, there are two first bushing connectors 4 and two temperature sensors 5. Correspondingly, the heat insulation cover 3 has two sensor inlets 34, and the bearing body 2 has two first mounting channels 21. In some embodiments, the bearing body 2 has a flange 25 connected to the turbine housing 1, and each flange 25 has a first mounting channel 21 located near the cooling medium inlet 32 ​​and the cooling medium outlet 33. It can be understood that the two sensor inlets 34 correspond one-to-one with the two first mounting channels 21. The first bushing connector 4 is fixedly installed in the first mounting channel 21 and connected to the corresponding sensor inlet 34. For example, the two sensor inlets 34 are internally threaded, that is, the first bushing connector 4 is threadedly connected to the corresponding sensor inlet 34. Furthermore, exemplarily, high-temperature sealant is applied to the first mounting channel 21 and the sensor inlet 34 respectively to improve the sealing performance of the first bushing connector 4 connected to the first mounting channel 21 and the sensor inlet 34 respectively, and to prevent coolant leakage.

[0069] In some embodiments, the first bushing connector 4 is made of stainless steel and has a hollow metal structure. The first bushing connector 4 is fixed inside the first mounting channel 21 and is used to guide and protect the probe of the temperature sensor 5. The first bushing connector 4 needs to have a suitable length to ensure that after the temperature sensor 5 is inserted, its probe can accurately fit or approach the inner wall surface 35 of the heat shield 3 near the turbine housing 1.

[0070] It should be noted that this embodiment does not limit the specific type and detection principle of the temperature sensor 5. For example, the temperature sensor 5 is a thermocouple or platinum resistance temperature sensor 5, and its measurement temperature range must cover at least -40°C to 300°C.

[0071] In addition, such as Figure 1 , Figure 3 , Figure 4 and Figure 6 As shown, in some embodiments, the bearing housing 2 is provided with two second mounting channels 22, and the turbocharger also includes two second bushing joints 6, one of which passes through one of the second mounting channels 22 and is connected to the cooling medium inlet 32, and the other of which passes through the other second mounting channel 22 and is connected to the cooling medium outlet 33.

[0072] It is understood that the second bushing connector 6 connected to the cooling medium inlet 32 ​​is used to connect to the external cooling medium supply pipeline, and the second bushing connector 6 connected to the cooling medium outlet 33 is used to connect to the external cooling medium return pipeline. That is to say, in this embodiment, by adding the second bushing connector 6, it is convenient to connect the cooling medium inlet 32 ​​to the external cooling medium supply pipeline and the cooling medium outlet 33 to the external cooling medium return pipeline, which is beneficial to achieving a reliable transition of coolant between the static heat shield 3 and the dynamic engine pipeline.

[0073] For example, the flange 25 of the bearing body 2 is provided with a second mounting channel 22 at the positions corresponding to the cooling medium inlet 32 ​​and the cooling medium outlet 33, and one second mounting channel 22 is used to install one second bushing connector 6. In addition, for example, the cooling medium inlet 32 ​​and the cooling medium outlet 33 are threaded holes for corresponding connection with the second bushing connector 6.

[0074] In some embodiments, the second bushing connector 6 is a hollow tubular structure made of stainless steel. One end of the second bushing connector 6 has an external thread for connection to the cooling medium inlet 32 ​​or the cooling medium outlet 33, and the other end has a quick connector or flange for connection to an external cooling medium supply line or an external cooling medium return line. It is understood that the hollow inner diameter of the second bushing connector 6 matches the inner diameter of the external cooling medium supply line or the external cooling medium return line to ensure smooth coolant flow. Additionally, exemplarily, high-temperature sealant is applied to the second mounting channel 22, the cooling medium inlet 32, and the cooling medium outlet 33 to improve the sealing of the second bushing connector 6 connected to the second mounting channel 22, the cooling medium inlet 32, and the cooling medium outlet 33, respectively, preventing coolant leakage.

[0075] In addition to the turbocharger described above, this embodiment of the invention also provides a turbocharger thermal control system. The turbocharger thermal control system includes the turbocharger, coolant circulation pump, cooling fan, and controller disclosed in any of the above embodiments. The coolant circulation pump is connected between the coolant inlet 32 ​​and the coolant outlet 33 of the turbocharger to provide power for the circulation of the coolant. The cooling fan is used to cool the coolant returning from the coolant outlet 33. The controller is connected to the coolant circulation pump and the cooling fan respectively to control the operation of the coolant circulation pump and the cooling fan.

[0076] It is understood that the coolant circulation pump is connected to the turbocharger's coolant inlet 32 ​​via an external coolant supply pipeline, and to the turbocharger's coolant outlet 33 via an external coolant return pipeline. When the coolant circulation pump operates, it circulates the coolant through the coolant inlet 32, the hollow flow channel 31, and the coolant outlet 33. Simultaneously, a cooling fan cools the coolant flowing from the coolant outlet 33 after heat absorption, allowing the cooled coolant to enter the hollow flow channel 31 from the coolant inlet 32. In other words, the temperature of the coolant at the inlet 32 ​​can be controlled by controlling the operation of the cooling fan. In this embodiment, the controller operates the coolant circulation pump and the cooling fan to provide coolant with appropriate flow rate and temperature, achieving active control of the heat shield 3's temperature. This helps the heat shield 3 meet temperature requirements, reduces heat transfer to the bearing housing 2, and ensures the bearing housing 2's operating temperature meets requirements. Therefore, this turbocharger thermal control system possesses at least the aforementioned beneficial effects of a turbocharger, which will not be elaborated further here.

[0077] Furthermore, in some embodiments, the turbocharger thermal control system includes the temperature sensor 5 described above, which is used to detect the wall temperature of the heat shield 3 in real time, thereby enabling the controller to control the operation of the coolant circulation pump and the cooling fan based on the wall temperature of the heat shield 3 detected in real time by the temperature sensor 5.

[0078] It should be noted that this embodiment does not limit the specific method by which the controller controls the operation of the coolant circulation pump and the cooling fan, as long as the cooling effect of the coolant on the heat shield 3 can be controlled by controlling the operation of the coolant circulation pump and the cooling fan. For example, the controller can use the specific steps of the turbocharger thermal control method disclosed in any of the following embodiments to control the coolant circulation pump and the cooling fan.

[0079] Please refer to Figure 8In addition to the turbocharger and turbocharger thermal control system described above, this embodiment of the invention also provides a turbocharger thermal control method. This turbocharger thermal control method is applied to the turbocharger thermal control system disclosed in the above embodiments, and includes steps S1-S5:

[0080] S1: Obtain the temperature of the turbocharger heat shield 3 of the turbocharger thermal control system;

[0081] S2: Compare the temperature of the heat insulation cover 3 with the preset lower limit and preset upper limit of the preset temperature range respectively;

[0082] S3: When the temperature of the heat shield 3 exceeds the preset upper limit, the speed of the coolant circulation pump of the turbocharger thermal control system is increased to increase the flow rate, and the speed of the cooling fan of the turbocharger thermal control system is increased to reduce the temperature of the coolant entering the turbocharger.

[0083] S4: When the temperature of the heat shield 3 is lower than the preset lower limit, control the speed of the coolant circulation pump to reduce the flow rate, or control the speed of the cooling fan to reduce or stop to increase the temperature of the coolant entering the turbocharger.

[0084] S5: When the temperature of the heat shield 3 is greater than or equal to the preset lower limit and less than or equal to the preset upper limit, the current control parameters of the coolant circulation pump and the cooling fan remain unchanged.

[0085] In other words, this embodiment monitors the wall temperature of the heat shield 3 in real time and dynamically adjusts the coolant flow rate and the temperature of the cooling medium inlet 32 ​​to automatically respond to changes in engine operating conditions. It reduces cooling power consumption when the engine is under low load and actively enhances cooling when the engine is under high load, thus achieving on-demand cooling. This keeps the temperature of the heat shield 3 within a suitable range and ensures that the operating temperature of the bearing body 2 is strictly controlled below the thermal stability temperature of the lubricating oil.

[0086] It should be noted that this turbocharger thermal control method can be implemented by the controller's internal program. The temperature sensor 5, as described above, detects the wall temperature of the heat shield 3 in real time. After receiving the wall temperature of the heat shield 3 from the temperature sensor 5, the controller compares the temperature of the heat shield 3 with the preset lower limit and preset upper limit of the preset temperature range. When the temperature of the heat shield 3 is greater than the preset upper limit, it indicates that the current heat load is too high and cooling is insufficient. At this time, the controller increases the speed of the coolant circulation pump to increase the flow rate and increases the speed of the cooling fan to reduce the coolant temperature at the cooling medium inlet 32. By enhancing heat exchange, the wall temperature of the heat shield 3 returns to within the preset temperature range. When the temperature of the heat shield 3 is less than the preset lower limit, it indicates that the current heat load is low and cooling is excessive. At this time, the controller decreases the speed of the coolant circulation pump to reduce the flow rate, or decreases or stops the speed of the cooling fan to increase the coolant temperature at the cooling medium inlet 32, thereby reducing unnecessary power consumption and preventing the wall temperature of the heat shield 3 from becoming too low and affecting engine thermal efficiency. When the temperature of the heat shield 3 is greater than or equal to the preset lower limit and less than or equal to the preset upper limit, it indicates that the current heat exchange range is relatively optimal and the cooling intensity is appropriate. In this case, the current control parameters of the coolant circulation pump and the cooling fan can be kept unchanged.

[0087] For example, controlling the speed of the coolant circulation pump to increase the flow rate and controlling the speed of the cooling fan to increase the coolant temperature at the coolant inlet 32 ​​includes:

[0088] When the current duty cycle of the coolant circulation pump is less than the first maximum allowable duty cycle, the duty cycle of the coolant circulation pump is increased, and the coolant flow rate Q is increased. The first maximum allowable duty cycle can be 100%.

[0089] If the current duty cycle of the cooling fan is less than the second maximum allowable duty cycle, the duty cycle of the cooling fan is increased to reduce the coolant temperature at the cooling medium inlet 32. The second maximum allowable duty cycle can be 100%.

[0090] Additionally, by way of example, controlling the speed of the coolant circulation pump to reduce the flow rate, or controlling the speed of the cooling fan to reduce or stop to increase the coolant temperature at the coolant inlet 32, includes:

[0091] When the current duty cycle of the coolant circulation pump is greater than the first minimum allowable duty cycle, the duty cycle of the coolant circulation pump is reduced according to the PID (Proportional-Integral-Derivative) algorithm or a preset step size, thereby reducing the coolant flow rate Q. The first minimum allowable duty cycle can be 20%.

[0092] When the current duty cycle of the cooling fan is greater than the second minimum allowable duty cycle, the duty cycle of the cooling fan is reduced, allowing the coolant temperature at the cooling medium inlet 32 ​​to rise naturally. The second minimum allowable duty cycle can be 0%.

[0093] Additionally, for example, when the temperature of the heat shield 3 is greater than or equal to a preset lower limit and less than or equal to a preset upper limit, the current control parameters of the coolant circulation pump and cooling fan are kept unchanged, including:

[0094] Keep the current duty cycle of the coolant circulation pump and cooling fan unchanged.

[0095] In addition, in some embodiments, a bypass circuit can be provided in the coolant circulation loop. When the temperature of the heat shield 3 is less than a preset lower limit, the temperature of the coolant at the cooling medium inlet 32 ​​can be increased by opening the bypass circuit to allow the bypass portion of the coolant to pass through.

[0096] In addition, when the cooling medium is cooling air, the temperature of the heat insulator can be controlled by adjusting the cooling air flow rate by controlling the valve opening or the flow rate of the compressed air source.

[0097] Furthermore, in some embodiments, before comparing the temperature of the heat shield 3 with a preset lower limit and a preset upper limit of a preset temperature range, the method further includes:

[0098] When the temperature of the heat shield 3 is detected to be continuously abnormal or the temperature signal of the heat shield 3 cannot be obtained, a system fault message is issued, and the coolant circulation pump is controlled to operate at the first preset speed, and the cooling fan is controlled to operate at the second preset speed.

[0099] like Figure 8 As shown, exemplarily, before comparing the temperature of the heat shield 3 with the preset lower limit and preset upper limit of the preset temperature range, the method further includes:

[0100] S6: Determine whether the temperature sensor 5 used to detect the temperature of the heat insulation cover 3 is working properly;

[0101] S2: If so, compare the temperature of the heat insulation cover 3 with the preset lower limit and preset upper limit of the preset temperature range respectively;

[0102] S7: If not, issue a system fault message, control the coolant circulation pump to operate at the first preset speed, and control the cooling fan to operate at the second preset speed.

[0103] In other words, when the controller detects that the temperature of the heat shield 3 is continuously abnormal, such as rising rapidly and being ineffective in adjustment, or when the temperature signal of the heat shield 3 cannot be obtained, that is, when the temperature sensor 5 signal is lost, the system is determined to be faulty. At this time, a system fault message is issued, for example, the fault indicator light on the instrument panel is lit to remind the user to perform maintenance; at the same time, the protection mode is entered, that is, the coolant circulation pump is controlled to work at the first preset speed, and the cooling fan is controlled to work at the second preset speed, for example, the coolant circulation pump and the cooling fan are driven according to the preset safe duty cycle.

[0104] It should be noted that when the temperature signal of the heat insulation cover 3 returns to normal, it will automatically return to the step of comparing the temperature of the heat insulation cover 3 with the preset lower limit and preset upper limit of the preset temperature range respectively.

[0105] like Figure 8 As shown, further, in some embodiments, after controlling the coolant circulation pump to operate at a first preset speed and controlling the cooling fan to operate at a second preset speed, a safety protection mode is entered, that is, it also includes:

[0106] S8: Calculate the rate of temperature change of the heat shield 3;

[0107] S9: Determine if the rate of change is greater than the preset rate of change;

[0108] S10: If so, control the speed of the coolant circulation pump to increase the flow rate, and control the speed of the cooling fan to reduce the temperature of the cooling medium inlet 32 ​​until the rate of change meets the preset rate of change.

[0109] In other words, when the rate of change of the temperature of the heat insulation cover 3 is greater than the preset rate of change, it indicates that the heat load is rising sharply. At this time, the cooling intensity is temporarily forcibly increased by controlling the speed of the coolant circulation pump to increase the flow rate and controlling the speed of the cooling fan to reduce the temperature of the cooling medium inlet 32, until the rate of change of the temperature of the heat insulation cover 3 drops back to meet the preset rate of change.

[0110] It should be noted that the above embodiments do not limit the specific range of the preset temperature range, that is, the specific values ​​of the preset lower limit and the preset upper limit are not limited, as long as they are conducive to ensuring that the heat insulation cover 3 has a suitable temperature.

[0111] In some embodiments, the preset temperature range is obtained by calibration through bench testing. In the bench test, the correspondence between the temperature of the heat shield 3 and the coolant flow rate, the temperature of the cooling medium inlet 32 ​​and the engine operating conditions is determined. Based on this correspondence, the temperature range of nucleation boiling heat transfer is calibrated as the preset temperature range.

[0112] It should be noted that boiling heat transfer refers to the heat transfer phenomenon that occurs between a liquid and the solid wall it contacts during the boiling process. As the wall superheat increases, it successively undergoes nucleation boiling and film boiling. During nucleation boiling, bubbles are generated, the heat transfer coefficient is high, and the wall temperature is low; during film boiling, a vapor film is formed, and the heat transfer coefficient drops sharply. In this embodiment, the temperature range of nucleation boiling heat transfer is calibrated as a preset temperature range. Within this preset temperature range, the heat transfer coefficient is the highest, the cooling effect is optimal, and the wall temperature is below the coking limit of the lubricating oil. Coking refers to the oxidation and polymerization of lubricating oil at high temperatures, forming gum or carbon deposits on the surface of parts, which can clog oil passages and accelerate wear.

[0113] In other words, this embodiment uses closed-loop control based on the boiling heat transfer principle. The temperature sensor 5 monitors the wall temperature of the heat shield 3 in real time and dynamically adjusts the coolant flow rate and inlet temperature to ensure that the wall temperature is always in the nucleation boiling zone with the highest heat transfer coefficient. Therefore, the system can achieve the best cooling effect with the minimum coolant power consumption, realize the optimal balance between cooling effect and energy consumption, and avoid the risk of overcooling waste at low load and insufficient cooling at high load.

[0114] For example, based on the principle of boiling heat transfer, when the coolant is an ethylene glycol-water mixture with a concentration of 30%-50%, the boiling temperature at atmospheric pressure is 105-110℃. Experiments show that when the wall superheat ΔT (i.e., the difference between the wall temperature and the boiling point of the coolant) is in the range of 5-30℃, the heat transfer is in the nucleus boiling region, with the highest heat transfer coefficient. Therefore, the preset temperature range can be set as follows: the preset lower limit Tmin = 110℃, corresponding to ΔT = 5℃, entering the high-efficiency nucleus boiling region; the preset upper limit Tmax = 135℃, corresponding to ΔT = 30℃, approaching the inflection point from nucleus boiling to film boiling.

[0115] In addition, the preset temperature range can be calibrated and corrected through bench tests when at different altitudes or using different coolants. The calibration method is as follows:

[0116] With the engine operating conditions fixed, the coolant flow rate was gradually increased, and the wall temperature Tw and heat exchange rate Q were recorded.

[0117] Plot the relationship curve between wall temperature Tw and heat transfer Q, and identify the inflection point of the nucleation boiling zone (that is, the point where the heat transfer coefficient begins to decrease) as the preset upper limit value Tmax;

[0118] Take 30-40℃ below the preset upper limit Tmax as the reference value for the preset lower limit Tmin to ensure that the control range is in the middle of the nucleation boiling zone.

[0119] It should also be noted that, in this specification, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0120] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0121] The turbocharger and its temperature control method, as well as the turbocharger thermal control system provided by this invention, have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of this invention.

Claims

1. A turbocharger, characterized in that, include: Turbine housing (1); The bearing body (2) is connected to the turbine housing (1); A heat shield (3) is provided between the turbine housing (1) and the bearing body (2). The heat shield (3) is provided with a hollow flow channel (31) and a cooling medium inlet (32) and a cooling medium outlet (33) respectively connected to the hollow flow channel (31). The cooling medium inlet (32) is used to connect to an external cooling medium supply pipeline, and the cooling medium outlet (33) is used to connect to an external cooling medium return pipeline. The cooling medium inlet (32) is located at the lower part of the heat insulation cover (3), and the cooling medium outlet (33) is located at the upper part of the heat insulation cover (3); The heat shield (3) is provided with a sensor inlet (34), the bearing body (2) is provided with a first mounting channel (21), and the turbocharger further includes: The first bushing connector (4) is inserted through the first mounting channel (21) and connected to the sensor inlet (34); Temperature sensor (5) is connected to the first bushing joint (4), and the probe of the temperature sensor (5) passes through the hollow cavity of the first bushing joint (4) and contacts the inner wall surface (35) of the heat shield (3) near the turbine housing (1). The bearing housing (2) is provided with two second mounting channels (22), and the turbocharger further includes: Two second bushing connectors (6), one of which is inserted through one of the second mounting channels (22) and connected to the cooling medium inlet (32), and the other of which is inserted through the other second mounting channel (22) and connected to the cooling medium outlet (33).

2. The turbocharger according to claim 1, characterized in that, The hollow flow channel (31) is arranged in a spiral or serpentine manner.

3. The turbocharger according to claim 1 or 2, characterized in that, There is a preset gap between the heat shield (3) and the turbine housing (1).

4. A turbocharger thermal control system, characterized in that, include: The turbocharger according to any one of claims 1-3; A coolant circulation pump is connected between the coolant inlet (32) and coolant outlet (33) of the turbocharger to provide power for the circulation of the coolant. A cooling fan is used to cool the cooling medium returning from the cooling medium outlet (33); The controller is connected to the coolant circulation pump and the cooling fan respectively, and is used to control the operation of the coolant circulation pump and the cooling fan.

5. A method for thermal control of a turbocharger, characterized in that, The controller applied to the turbocharger thermal control system of claim 4, wherein the turbocharger thermal control method comprises: Obtain the temperature of the heat shield (3) of the turbocharger in the turbocharger thermal control system; The temperature of the heat insulation cover (3) is compared with the preset lower limit and preset upper limit of the preset temperature range, respectively; When the temperature of the heat shield (3) is greater than the preset upper limit value, the speed of the coolant circulation pump of the turbocharger thermal control system is increased to increase the flow rate, and the speed of the cooling fan of the turbocharger thermal control system is increased to reduce the temperature of the coolant entering the turbocharger. When the temperature of the heat shield (3) is less than the preset lower limit, the speed of the coolant circulation pump is reduced to decrease the flow rate, or the speed of the cooling fan is reduced or stopped to increase the temperature of the coolant entering the turbocharger. When the temperature of the heat shield (3) is greater than or equal to the preset lower limit and less than or equal to the preset upper limit, the current control parameters of the coolant circulation pump and the cooling fan remain unchanged.

6. The turbocharger thermal control method according to claim 5, characterized in that, Before comparing the temperature of the heat shield (3) with the preset lower limit and preset upper limit of the preset temperature range, the method further includes: When the temperature of the heat shield (3) is detected to be abnormal or the temperature signal of the heat shield (3) cannot be obtained, a system fault message is issued, and the coolant circulation pump is controlled to operate at a first preset speed, and the cooling fan is controlled to operate at a second preset speed.

7. The turbocharger thermal control method according to claim 6, characterized in that, After controlling the coolant circulation pump to operate at a first preset speed and the cooling fan to operate at a second preset speed, the method further includes: Calculate the rate of temperature change of the heat shield (3); Determine whether the rate of change is greater than a preset rate of change; If so, the speed of the coolant circulation pump is increased to increase the flow rate, and the speed of the cooling fan is increased to reduce the temperature of the coolant entering the turbocharger, until the rate of change meets the preset rate of change.

8. The turbocharger thermal control method according to any one of claims 5-7, characterized in that, The preset temperature range is obtained by calibration through bench testing. In the bench test, the correspondence between the temperature of the heat shield (3) and the coolant flow rate, the temperature of the cooling medium inlet (32) and the engine operating conditions is determined. The temperature range of nucleation boiling heat transfer is calibrated according to the correspondence, which is the preset temperature range.

Images