Fan control method, cooling system and vehicle

Abstract

The present invention belongs to the technical field of vehicles, and discloses a fan control method, a cooling system and a vehicle. The cooling system includes an engine, a retarder, a thermostat and a fan. The fan control method takes into account the actual state of the thermostat. When the water temperature at the thermostat does not reach the initial opening temperature of the thermostat, the fan does not respond even if the hydraulic retarder is in the working state. And considering the actual braking power of the hydraulic retarder and the vehicle deceleration, when the braking power is small and the vehicle deceleration is large, a lower fan speed is set. When the braking power is large or the vehicle deceleration is small, a higher fan speed is set, fully considering the actual heat dissipation requirements of the retarder, preventing the fan from entering the full engagement state under certain working conditions, greatly reducing the time of fan full engagement, effectively reducing noise, improving the user experience, and effectively reducing fuel consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and particularly to a fan control method, a cooling system, and a vehicle. Background Art

[0002] A hydrodynamic retarder is a device that generates a retardation effect by using liquid damping. When the hydrodynamic retarder works, it stirs the oil in the vehicle's drive shaft to generate damping, thereby achieving a braking effect. When the hydrodynamic retarder stirs the oil, a large amount of heat will be generated. Usually, as long as the hydrodynamic retarder works, it is required that the fan rotates at full speed to ensure the heat dissipation requirement of the whole vehicle. However, this setting not only generates a large amount of noise, but also there will be a situation where after the hydrodynamic retarder is turned off, the fan clutch disengages for a long time, and the engine fan will continue to rotate at full engagement for a period of time, resulting in an increase in unnecessary power consumption and an increase in the fuel consumption of the whole vehicle.

[0003] To solve the above problems, the fan control method disclosed in the invention patent "CN116025455A" can determine whether the fan rotates at full speed according to the engine coolant temperature and the heat dissipation power of the retarder, reasonably control the engine coolant temperature while ensuring the heat dissipation requirement, ensure that the engine is in the best working state, and reduce the power consumption when the fan is disengaged from the engine; the vehicle fan control method disclosed in the invention patent "CN118640181A" can consider the vehicle operation information to determine the target speed of the fan when the heat generation of the hydrodynamic retarder is relatively low, and control the rotation of the fan accordingly, which can effectively reduce the fan speed, reduce the noise in the cab, and reduce the fuel consumption while ensuring driving comfort. The fan in the first fan control method only has two working conditions: full-speed rotation and non-rotation, with poor adaptability. The second fan control method only considers the heat generation degree of the retarder, and the adjustment is relatively single.

[0004] Therefore, a fan control method, a cooling system, and a vehicle are needed to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a fan control method, a cooling system, and a vehicle, which can effectively adjust and control the fan speed according to the actual braking power of the retarder and the deceleration of the vehicle, with more flexible adjustment, fully considering the actual heat dissipation requirement of the retarder, reducing the full-engagement time of the fan, and thus reducing the fuel consumption.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] A fan control method is used to control the operation of a fan in a cooling system, wherein the cooling system includes a thermostat, a radiator and a fan, and is used to dissipate heat for a power system, wherein the power system includes an engine and a retarder, wherein the retarder is arranged downstream of the engine, the fan is drivingly connected to the engine, the coolant flows through the engine, the retarder and the thermostat to form a small cycle, and the coolant flows through the radiator, the engine, the retarder and the thermostat to form a large cycle, the thermostat can switch between the small cycle and the large cycle, and the fan is used to cool the coolant flowing through the radiator. The fan control method comprises the following steps:

[0008] S10, determining whether the retarder is working, if so, proceeding to S20;

[0009] S20, comparing the initial opening temperature T0 of the coolant of the thermostat with the real-time temperature T1 of the coolant at the thermostat to determine whether T1>T0, if so, proceeding to S30;

[0010] S30, determining a target speed N of the fan according to a braking power P of the retarder and a deceleration a of the vehicle;

[0011] S40, controlling the fan to rotate according to the target speed N.

[0012] As an optional technical solution, the S30 further includes:

[0013] S31A, comparing the braking power P of the retarder with the first preset power P1, determining whether P≤P1, if so, proceeding to S32A; if not, proceeding to S33A;

[0014] S32A, comparing the deceleration a of the vehicle with the first preset deceleration a1, determining whether a≥a1, if so, the fan does not work; if not, obtaining the target speed N of the fan according to the temperature T2 of the retarder water outlet and the ambient temperature T3;

[0015] S33A, obtaining a target speed N of the fan according to the temperature T2 of the retarder water outlet and the ambient temperature T3.

[0016] As an optional technical solution, obtaining the target speed N of the fan according to the temperature T2 of the retarder water outlet and the ambient temperature T3 in S32A includes:

[0017] According to the retarder water outlet temperature T2 and the ambient temperature T3, the retarder water outlet temperature-ambient temperature-speed MAP table 1 is queried to obtain the target speed N of the fan.

[0018] As an alternative technical solution, the S33A specifically includes:

[0019] S331A. Compare the deceleration a of the vehicle with a first preset deceleration a1 to determine whether a≥a1. If so, query the retarder outlet temperature - ambient temperature - speed MAP table two according to the temperature T2 of the retarder outlet and the ambient temperature T3 to obtain the target speed N of the fan; if not, proceed to S332;

[0020] S332A. Query the retarder outlet temperature - ambient temperature - speed MAP table three according to the temperature T2 of the retarder outlet and the ambient temperature T3 to obtain the target speed N of the fan.

[0021] As an alternative technical solution, the S30 includes:

[0022] S31B. Compare the temperature T2 of the retarder outlet with a first temperature threshold t1 and a second temperature threshold t2. If t1<T2<t2, proceed to S32B; if T2≥t2, proceed to S33B;

[0023] S32B. Compare the braking power P of the retarder with a first preset power P1 to determine whether P≤P1. If so, proceed to S33B; if not, proceed to S34B;

[0024] S33B. Compare the deceleration a of the vehicle with a first preset deceleration a1 to determine whether a≥a1. If so, the fan does not operate; if not, obtain the target speed N of the fan according to the temperature T2 of the retarder outlet and the ambient temperature T3;

[0025] S34B. Obtain the target speed N of the fan according to the temperature T2 of the retarder outlet and the ambient temperature T3.

[0026] As an alternative technical solution, obtaining the target speed N of the fan according to the temperature T2 of the retarder outlet and the ambient temperature T3 in the S33B specifically includes:

[0027] Calculate the target speed N of the fan according to the following formula:

[0028] N=n*i*α1;

[0029] Wherein, n is the real-time speed of the engine, i is the transmission ratio of the fan; α1 = β1 + γ1, β1 is positively correlated with the temperature T2 of the retarder outlet, γ1 is positively correlated with the ambient temperature T3, and 0<α1<1.

[0030] As an alternative technical solution, the S34B specifically includes:

[0031] S341B. Compare the deceleration a of the vehicle with a first preset deceleration a1 to determine whether a ≥ a1. If so, calculate the target speed N of the fan according to the following formula:

[0032] N = n * i * α2;

[0033] where α2 = β2 + γ2; α2 is positively correlated with the temperature T2 at the water outlet of the retarder, γ2 is positively correlated with the ambient temperature T3, and α1 < α2 < 1;

[0034] If not, proceed to S342B;

[0035] S342B. Calculate the target speed N of the fan according to the following formula:

[0036] N = n * i * α3;

[0037] where α3 = β3 + γ3; β3 is positively correlated with the temperature T2 at the water outlet of the retarder, γ3 is positively correlated with the ambient temperature T3, and α2 < α3 ≤ 1.

[0038] As an alternative technical solution, the S40 is specifically:

[0039] Compare the actual speed of the fan with the target speed N to obtain the difference between the target speed N and the actual speed, and then adjust the duty ratio of the solenoid valve of the fan clutch so that the actual speed of the fan is the target speed N.

[0040] The present invention also adopts the following technical solution:

[0041] A cooling system for dissipating heat from the power system, the power system including an engine and a retarder, the retarder being disposed downstream of the engine. The cooling system adopts the fan control method as described above. The cooling system includes a thermostat, a radiator, a fan, a first cooling pipeline, a second cooling pipeline, a first temperature sensor, and a second temperature sensor. The fan is drivingly connected to the engine. One end of the first cooling pipeline communicates with the water outlet of the engine, and the other end of the first cooling pipeline communicates with the water inlet of the retarder. One end of the second cooling pipeline communicates with the water outlet of the retarder, and the other end of the second cooling pipeline communicates with the inlet of the thermostat. The first outlet of the thermostat communicates with the water inlet of the radiator, and the second outlet of the thermostat communicates with the water inlet of the engine. The water outlet of the radiator communicates with the water inlet of the engine; the first temperature sensor is disposed on the thermostat, and the second temperature sensor is disposed at the water outlet of the retarder;

[0042] Wherein, when the thermostat is closed, the inlet of the thermostat is connected to the second outlet, and when the thermostat is fully opened, the inlet of the thermostat is connected to the first outlet.

[0043] The present invention also adopts the following technical solutions:

[0044] A vehicle, the vehicle comprising a power system, the vehicle further comprising the above-mentioned cooling system, the cooling system being used to dissipate heat from the power system.

[0045] Beneficial effects of the present invention:

[0046] The present invention discloses a fan control method, which is used to control the operation of a fan in a cooling system. The cooling system includes an engine, a retarder, a thermostat and a fan. The fan control method includes: judging whether the retarder is working, and if so, comparing the initial opening temperature T0 of the coolant of the thermostat with the real-time temperature T1 of the coolant at the thermostat to judge whether T1>T0, and if so, determining the target speed of the fan according to the braking power P of the retarder and the deceleration a of the vehicle, and controlling the fan to rotate according to the target speed. This fan control method takes into account the actual state of the thermostat. When the water temperature at the thermostat does not reach the initial opening temperature of the thermostat, the fan will not respond even if the hydraulic retarder is in working state. The actual braking power of the hydraulic retarder and the vehicle deceleration are taken into account. When the braking power is small and the vehicle deceleration is large, a lower fan speed is set. When the braking power is large or the vehicle deceleration is small, a higher fan speed is set. The actual heat dissipation needs of the retarder are fully considered. Under certain working conditions, the fan is not allowed to enter the full engagement state, which greatly reduces the time of full engagement of the fan, effectively reduces noise, improves user experience, and effectively reduces fuel consumption.

[0047] The present invention also discloses a cooling system, which is used to cool a power system, wherein the power system includes an engine, a retarder and a fan, wherein the retarder is arranged downstream of the engine, and the cooling system includes a thermostat, a radiator, a fan, a first cooling pipeline, a second cooling pipeline, a first temperature sensor and a second temperature sensor, wherein the fan is connected to the engine by a transmission, and the cooling system adopts the fan control method as described above. This cooling system adjusts the speed of the fan according to the actual working conditions, reduces the full engagement time of the fan, thereby effectively reducing the fan noise and reducing fuel consumption.

[0048] The present invention also discloses a vehicle, which includes a power system and the above-mentioned cooling system, wherein the cooling system is used to dissipate heat from the power system. By setting up the cooling system, the vehicle can adjust the fan speed according to actual working conditions, thereby reducing the full engagement time of the fan, effectively reducing noise, reducing fuel consumption, and improving user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1It is a schematic structural diagram of the cooling system according to an embodiment of the present invention;

[0050] Figure 2 It is a flowchart of the fan control method according to Embodiment 1 of the present invention;

[0051] Figure 3 It is a flowchart of the fan control method according to Embodiment 2 of the present invention.

[0052] In the figure:

[0053] 1. Engine; 2. Gearbox; 3. Retarder; 4. Fan; 5. Thermostat; 6. Radiator; 7. First cooling pipeline; 8. Second cooling pipeline; 9. Second temperature sensor; 10. Engine oil cooling channel. Specific embodiments

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the convenience of description, only the parts related to the present invention rather than all the structures are shown in the drawings.

[0055] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0056] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "above and over", and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "below and under", and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the horizontal height of the first feature is lower than that of the second feature.

[0057] In the description of this embodiment, the orientation or positional relationships such as "upper", "lower", "right", etc. are based on the orientation or positional relationships shown in the drawings. They are only for convenience of description and simplifying operations, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0058] Embodiment 1

[0059] As Figure 1 shown, in this embodiment, a cooling system is provided for dissipating heat from the power system. The power system includes an engine 1, a gearbox 2, and a retarder 3. The cooling system includes a fan 4, a thermostat 5, a radiator 6, a first cooling pipeline 7, a second cooling pipeline 8, a first temperature sensor, and a second temperature sensor 9. The engine 1 and the gearbox 2 are in transmission connection. The retarder 3 is disposed at the output end of the gearbox 2. The fan 4 and the engine 1 are in transmission connection. One end of the first cooling pipeline 7 communicates with the water outlet of the engine 1, and the other end of the first cooling pipeline 7 communicates with the water inlet of the retarder 3; one end of the second cooling pipeline 8 communicates with the water outlet of the retarder 3, and the other end of the second cooling pipeline 8 communicates with the inlet of the thermostat 5. The first outlet of the thermostat 5 communicates with the water inlet of the radiator 6, and the second outlet of the thermostat 5 communicates with the water inlet of the engine 1. The water outlet of the radiator 6 communicates with the water inlet of the engine 1; wherein, when the thermostat 5 is closed, the inlet of the thermostat 5 communicates with the second outlet, and when the thermostat 5 is fully open, the inlet of the thermostat 5 communicates with the first outlet. The first temperature sensor is disposed at the thermostat 5, and the second temperature sensor 9 is disposed at the water outlet of the retarder 3. Specifically, in this embodiment, when the thermostat 5 is closed, the inlet and the second outlet of the thermostat 5 communicate, and the coolant circulates between the engine 1 and the retarder 3 to form a small cycle. When the thermostat 5 is fully open, the inlet and the first outlet of the thermostat 5 communicate, and the coolant sequentially passes through the engine 1, the retarder 3, the thermostat 5, and the radiator 6 for cooling to form a large cycle.

[0060] Specifically, in this embodiment, the fan 4 and the engine 1 are in transmission connection through a silicone oil clutch.

[0061] Specifically, in this embodiment, the first temperature sensor is disposed at the thermostat 5 and can obtain the temperature of the coolant at the thermostat 5 in real time. The second temperature sensor 9 is disposed at the water outlet of the retarder 3 and can obtain the temperature at the water outlet of the retarder 3 in real time, thereby accurately judging the temperature at the retarder 3. By adjusting the rotational speed of the fan 4 according to this temperature, the service performance of the retarder 3 can be guaranteed to the greatest extent.

[0062] Further, the cooling system further includes an engine oil cooling passage 10, and both ends of the engine oil cooling passage 10 are respectively communicated with the engine 1 and the thermostat 5.

[0063] In this embodiment, a vehicle is further provided. The vehicle includes a power system, and the vehicle further includes the above cooling system. The cooling system dissipates heat from the power system. By setting the cooling system, the vehicle can adjust the rotational speed of the fan 4 according to the actual working conditions, thereby reducing the full engagement time of the fan 4, effectively reducing noise, reducing fuel consumption, and enhancing the user experience.

[0064] Based on the above cooling system, as Figure 2 shown, in this embodiment, a fan control method is further provided for controlling the operation of the fan 4 in the cooling system.

[0065] The fan control method includes the following steps.

[0066] S10. Determine whether the retarder 3 is working. If so, proceed to S20.

[0067] Further, S10 further includes: if not, the fan 4 does not work.

[0068] Specifically, in this embodiment, this setting can reduce the noise caused by the fan 4, enhance the user experience, and effectively reduce energy consumption.

[0069] S20. Compare the initial opening temperature T0 of the coolant of the thermostat 5 with the real-time temperature T1 of the coolant at the thermostat 5, and determine whether T1 > T0. If so, proceed to S30.

[0070] Specifically, in this embodiment, considering the actual state of the thermostat 5, when the water temperature at the thermostat 5 has not reached the initial opening temperature of the thermostat 5, the thermostat 5 does not need to open, and the temperature at the retarder 3 will not increase significantly. Even if the hydraulic retarder 3 is in the working state, the fan 4 does not respond, effectively reducing energy consumption.

[0071] S30. Determine the target rotational speed N of the fan 4 according to the braking power P of the retarder 3 and the deceleration a of the vehicle.

[0072] Specifically, if T1 ≤ T0, it indicates that the temperature of the retarder 3 is rising at this time, and the radiator 6 needs to intervene for cooling. Therefore, the fan 4 needs to be started.

[0073] Specifically, in this embodiment, the braking power of the retarder 3 is obtained by the following formula:

[0074] P = (t × n) / 9550

[0075] where t is the real-time torque of the retarder 3 and n is the real-time rotational speed of the engine 1.

[0076] In this embodiment, the braking power of the retarder 3 is calculated using this formula for settings in a specific scenario, and the real-time torque t of the retarder 3 and the real-time speed n of the engine 1 can both be directly obtained from the controller without adding additional hardware arrangements, effectively reducing costs.

[0077] Further, S30 specifically includes the following content.

[0078] S31A. Compare the braking power P of the retarder 3 with the first preset power P1 to determine whether P ≤ P1. If so, proceed to S32A; if not, proceed to S33A.

[0079] Specifically, in this embodiment, when the braking power P of the retarder 3 is less than or equal to the first preset power P1, it indicates that the power of the retarder 3 is relatively small at this time. Whether the fan 4 needs to rotate needs to be determined based on the deceleration of the vehicle, which can not only ensure the normal operation of the retarder 3 but also improve the flexibility of fan 4 control, avoiding increased fuel consumption and noise, and affecting the user experience.

[0080] S32A. Compare the deceleration a of the vehicle with the first preset deceleration a1 to determine whether a ≥ a1. If so, the fan 4 does not operate; if not, obtain the target speed N of the fan 4 based on the temperature T2 at the outlet of the retarder 3 and the ambient temperature T3.

[0081] Specifically, in this embodiment, if the deceleration a of the vehicle is large, it indicates that the vehicle is about to be in a braking state and the retarder 3 does not need to operate subsequently, so no additional heat dissipation is required, and thus the fan 4 does not operate at this time. If the deceleration a of the vehicle is small at this time, it indicates that there is a possibility of further increasing the liquid retarder braking gear, and the fan 4 needs to operate to take away the heat generated by the operation of the retarder 3 to ensure the normal operation of the subsequent retarder 3.

[0082] In this process, obtaining the target speed N of the fan 4 based on the temperature T2 at the outlet of the retarder 3 and the ambient temperature T3 specifically includes: querying the retarder outlet temperature - ambient temperature - speed MAP table one according to the temperature T2 at the outlet of the retarder 3 and the ambient temperature T3 to obtain the target speed N of the fan 4.

[0083]

[0084] Specifically, in this embodiment, the retarder outlet temperature - ambient temperature - speed MAP table one can be obtained through calculation or experiments.

[0085] Specifically, in this embodiment, the first preset power P1 is set according to the performance of the radiator 6.

[0086] S33A. Obtain the target speed N of the fan 4 based on the temperature T2 at the water outlet of the retarder 3 and the ambient temperature T3.

[0087] Specifically, in this embodiment, when the braking power of the retarder 3 is large, the heat generated by the retarder 3 is relatively large. Correspondingly, a higher speed of the fan 4 is required to ensure that the heat of the retarder 3 can be fully dissipated and the service performance of the retarder 3 is ensured.

[0088] S331A. Compare the deceleration a of the vehicle with the first preset deceleration a1 to determine whether a≥a1. If so, query the retarder water outlet temperature - ambient temperature - speed MAP table two based on the temperature T2 at the water outlet of the retarder 3 and the ambient temperature T3 to obtain the target speed N of the fan 4. If not, proceed to S332.

[0089]

[0090] S332. Query the retarder water outlet temperature - ambient temperature - speed MAP table three based on the temperature T2 at the water outlet of the retarder 3 and the ambient temperature T3 to obtain the target speed N of the fan 4.

[0091]

[0092] Specifically, in this embodiment, when the braking power of the retarder 3 is large, the fan 4 needs to operate to ensure the normal operating temperature range of the retarder 3. On this basis, by comparing the deceleration a of the vehicle with the first preset deceleration a1, when the vehicle deceleration is small, considering that the driver may continue to increase the hydraulic retarder braking gear, a larger target speed N of the fan 4 is set at this time; when the vehicle deceleration is large, a smaller target speed N of the fan 4 is set, which increases the controllability of the fan 4 speed, greatly reduces the full engagement time of the fan 4, effectively reduces fuel consumption, and improves economy.

[0093] Specifically, in this embodiment, the determination of the fan 4 speed takes into account the change in ambient temperature, avoiding the problem that when the ambient temperature is cold, the fan 4 still enters full engagement due to the large change in the heat dissipation capacity of the cooling system, resulting in an increase in power consumption due to too small a set heat dissipation power threshold and a short duration; and effectively avoiding the problem that when the ambient temperature is hot, it affects the service performance of the hydraulic retarder 3 due to too high a set heat dissipation power threshold and a long duration.

[0094] Specifically, in this embodiment, both the retarder water outlet temperature - ambient temperature - speed MAP table two and the retarder water outlet temperature - ambient temperature - speed MAP table three can be obtained through calculation or experiment.

[0095] S40. Control the rotation of the fan 4 according to the target speed N.

[0096] Specifically, in this embodiment, when the ambient temperature is low or the temperature of the outlet of the hydraulic retarder 3 is low, the fan 4 does not respond; when the ambient temperature is higher and the temperature of the outlet of the hydraulic retarder 3 is higher, the target speed N of the fan 4 is higher. By calculating the braking power of the retarder 3 and simultaneously considering the ambient temperature, the coolant temperature at the thermostat 5, and the coolant temperature at the outlet of the retarder 3, the actual heat dissipation requirements of the retarder 3 are fully considered, and the fan 4 is not allowed to enter the full engagement state under certain working conditions, significantly reducing the full engagement time of the fan 4.

[0097] Embodiment 2

[0098] This embodiment discloses a cooling system, a vehicle, and a fan cooling method implemented based on the cooling system. The cooling system and the vehicle in this embodiment are the same as those in Embodiment 1. As Figure 3 shown, the difference between the fan cooling method in this embodiment and the fan cooling method in Embodiment 1 lies in the specific content of S30.

[0099] Specifically, S30 specifically includes the following content.

[0100] S31B. Compare the temperature T2 of the outlet of the retarder 3 with a first temperature threshold t1 and a second temperature threshold t2. If t1 < T2 < t2, then enter S32B; if T2 ≥ t2, then enter S33B.

[0101] Specifically, in this embodiment, incorporating the temperature T2 of the outlet of the retarder 3 into the determination basis for the speed control of the fan 4 can ensure the accuracy of the speed adjustment of the fan 4, and further ensure that the temperature at the retarder 3 can be within the temperature range most suitable for the operation of the retarder 3, and further ensure the working performance of the retarder 3.

[0102] Specifically, in this embodiment, the first temperature threshold t1 and the second temperature threshold t2 can be specifically calibrated according to actual use and will not be elaborated here.

[0103] S32B. Compare the braking power P of the retarder 3 with a first preset power P1 to determine whether P ≤ P1. If so, then enter S32B; if not, then enter S33B.

[0104] Specifically, in this embodiment, when the braking power P of the retarder 3 is less than or equal to the first preset power P1, it indicates that the power of the retarder 3 is small at this time. Whether the fan 4 needs to rotate needs to be determined based on the deceleration of the vehicle, which can not only ensure the normal operation of the retarder 3, but also improve the flexibility of the fan 4 control, avoiding increased fuel consumption and noise, and affecting the user experience.

[0105] Specifically, in this embodiment, the first preset power P1 is obtained according to the heat dissipation performance of the radiator 6. The better the heat dissipation performance of the radiator 6, the higher the corresponding first preset power P1.

[0106] S33B. Compare the deceleration a of the vehicle with the first preset deceleration a1 to determine whether a ≥ a1. If so, the fan 4 does not operate; if not, obtain the target speed N of the fan 4 based on the temperature T2 at the water outlet of the retarder 3 and the ambient temperature T3.

[0107] Specifically, in this embodiment, if the deceleration a of the vehicle is large, it indicates that the vehicle is about to be in a braking state, and the retarder 3 does not need to work subsequently, so there is no need for additional heat dissipation. Therefore, the fan 4 does not operate at this time. If the deceleration a of the vehicle is small at this time, it indicates that the vehicle may continue to increase the liquid retarder braking gear, and the fan 4 needs to operate to take away the heat generated by the work of the retarder 3 to ensure the normal operation of the subsequent retarder 3.

[0108] Further, obtaining the target speed N of the fan 4 based on the temperature T2 at the water outlet of the retarder 3 and the ambient temperature T3 is specifically calculating the target speed N of the fan 4 according to the following formula:

[0109] N = n * i * α1;

[0110] Wherein, n is the real-time speed of the engine, i is the transmission ratio of the fan; α1 = β1 + γ1, β1 is positively correlated with the temperature T2 at the water outlet of the retarder 3, γ1 is positively correlated with the ambient temperature T3, and 0 < α1 < 1.

[0111] Specifically, in this embodiment, the temperature T2 at the water outlet of the retarder 3 can better reflect the working temperature of the retarder 3, and the ambient temperature T3 also has a greater impact on the temperature rise of the retarder 3. Therefore, this setting enables the target speed of the fan 4 to be controlled based on the temperature T2 at the water outlet of the retarder 3 and the ambient temperature T3, thereby ensuring the operating temperature of the retarder 3 and improving the operating performance of the retarder 3.

[0112] Specifically, in this embodiment, β1 = A1 * T2, γ1 = B1 * T3 + C1, T2 can be real-time monitored by the second temperature sensor 9, T3 is the real-time ambient temperature value monitored by the vehicle, and A1, B1, and C1 can be obtained according to experiments or calculations, which will not be elaborated here.

[0113] In other embodiments, the relationships between β1 and T2, and γ1 and T3 can also be calculated using other formulas, which will not be elaborated here.

[0114] Specifically, in this embodiment, in order to further improve the accuracy of the target speed N of the fan 4, it is also necessary to consider the slip of the clutch of the fan 4. The slip of the clutch is an inherent property of the fan 4 and will have a certain impact on the speed of the fan 4.

[0115] Therefore, preferably, the calculation formula of α1 is:

[0116] α1 = ΔT * (β1 + γ1);

[0117] Wherein, ΔT is the slip of the clutch of the fan 4.

[0118] This calculation formula can further improve the calculation accuracy of the target speed N of the fan 4, and then improve the control accuracy of the speed of the fan 4, thereby further facilitating the improvement of the temperature control accuracy of the retarder 3 and ensuring the working performance of the retarder 3.

[0119] S34B. Obtain the target speed N of the fan 4 according to the temperature T2 at the water outlet of the retarder 3 and the ambient temperature T3.

[0120] Specifically, in this embodiment, when the braking power of the retarder 3 is large and the heat generated by the retarder 3 is more, correspondingly, the speed of the fan 4 needs to be large to ensure that the heat of the retarder 3 can be fully dissipated and the service performance of the retarder 3 is ensured.

[0121] S341B. Compare the deceleration a of the vehicle with the first preset deceleration a1, and determine whether a ≥ a1. If so, calculate the target speed of the fan 4 according to the following formula:

[0122] N = n * i * α2;

[0123] Wherein, α2 = β2 + γ2; α2 is positively correlated with the temperature T2 at the water outlet of the retarder 3, γ2 is positively correlated with the ambient temperature T3, and α1 < α2 < 1.

[0124] If not, enter S342B.

[0125] Specifically, in this embodiment, β2 = A2 * T2, γ2 = B2 * T3 + C2, T2 can be monitored in real time by the second temperature sensor 9, T3 is the real-time ambient temperature value measured by the vehicle, and A2, B2 and C2 can be obtained according to experiments or calculations, which will not be elaborated here.

[0126] In other embodiments, the relationship between β2 and T2 and the relationship between γ2 and T3 can also be calculated by other formulas, which will not be elaborated here.

[0127] Specifically, in this embodiment, in order to further improve the accuracy of the target speed N of the fan 4, it is also necessary to consider the slip of the clutch of the fan 4. The slip of the clutch is an inherent property of the fan 4 and will have a certain impact on the speed of the fan 4.

[0128] Therefore, preferably, the calculation formula of α2 is:

[0129] α2 = ΔT * (β2 + γ2);

[0130] where ΔT is the slip of the clutch of the fan 4.

[0131] This calculation formula can further improve the calculation accuracy of the target speed N of the fan 4, and then improve the control accuracy of the speed of the fan 4, thus further facilitating the temperature control of the retarder 3 and ensuring the working performance of the retarder 3.

[0132] S342B. Calculate the target speed N of the fan according to the following formula:

[0133] N = n * i * α3;

[0134] where α3 = β3 + γ3; β3 is positively correlated with the temperature T2 at the water outlet of the retarder 3, γ3 is positively correlated with the ambient temperature T3, and α2 < α3 ≤ 1.

[0135] Specifically, in this embodiment, β3 = A3 * T2, γ3 = B3 * T3 + C3, T2 can be monitored in real time by the second temperature sensor 9, T3 is the real-time ambient temperature value measured by the vehicle, and A3, B3, and C3 can be obtained through experiments or calculations, which will not be elaborated here.

[0136] In other embodiments, the relationships between β3 and T2, and γ3 and T3 can also be calculated using other formulas, which will not be elaborated here.

[0137] Specifically, in this embodiment, in order to further improve the accuracy of the target speed N of the fan 4, it is also necessary to consider the slip of the clutch of the fan 4. The slip of the clutch is an inherent property of the fan 4 and will have a certain impact on the speed of the fan 4.

[0138] Therefore, preferably, the calculation formula of α3 is:

[0139] α3 = ΔT * (β3 + γ3);

[0140] where ΔT is the slip of the clutch of the fan 4.

[0141] This calculation formula can further improve the calculation accuracy of the target speed N of the fan 4, thereby improving the control accuracy of the speed of the fan 4, and further facilitating the temperature control of the retarder 3 to ensure the working performance of the retarder 3.

[0142] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A fan control method for controlling the operation of a fan (4) in a cooling system, wherein the cooling system is used to dissipate heat from a power system, characterized in that: The cooling system comprises a thermostat (5), a radiator (6) and a fan (4); the power system comprises an engine (1) and a retarder (3); the retarder (3) is arranged downstream of the engine (1); the fan (4) is drivingly connected to the engine (1); the coolant flows through the engine (1), the retarder (3) and the thermostat (5) to form a small cycle; the coolant flows through the radiator (6), the engine (1), the retarder (3) and the thermostat (5) to form a large cycle; the thermostat (5) is capable of switching between the small cycle and the large cycle; the fan (4) is used to cool the coolant flowing through the radiator (6); and the fan control method comprises the following steps: S10, determining whether the retarder (3) is working, and if so, proceeding to S20; S20, comparing the initial opening temperature T0 of the coolant of the thermostat (5) with the real-time temperature T1 of the coolant at the thermostat (5), and determining whether T1>T0, and if so, proceeding to S30; S30, determining a target rotation speed N of the fan (4) according to a braking power P of the retarder (3) and a deceleration a of the vehicle; S40, controlling the fan (4) to rotate according to the target speed N; Wherein, the S30 includes: S31A, comparing the braking power P of the retarder (3) with the first preset power P1, determining whether P≤P1, if so, proceeding to S32A; if not, proceeding to S33A; S32A, comparing the deceleration a of the vehicle with the first preset deceleration a1, determining whether a≥a1, if so, the fan (4) does not work; if not, obtaining a target speed N of the fan (4) according to the temperature T2 of the water outlet of the retarder (3) and the ambient temperature T3; S33A, obtaining a target rotation speed N of the fan (4) according to the temperature T2 of the water outlet of the retarder (3) and the ambient temperature T3; Or, the S30 includes: S31B, comparing the temperature T2 of the water outlet of the retarder (3) with the first temperature threshold t1 and the second temperature threshold t2, if t1<T2<t2, proceed to S32B; if T2≥t2, proceed to S33B; S32B, comparing the braking power P of the retarder (3) with the first preset power P1, determining whether P≤P1, if so, proceeding to S33B; if not, proceeding to S34B; S33B, comparing the deceleration a of the vehicle with the first preset deceleration a1, determining whether a≥a1, if so, the fan (4) does not work; if not, obtaining a target speed N of the fan (4) according to the temperature T2 of the water outlet of the retarder (3) and the ambient temperature T3; S34B, obtaining a target rotation speed N of the fan (4) according to the temperature T2 of the water outlet of the retarder (3) and the ambient temperature T3.

2. The fan control method according to claim 1, characterized in that: The step S32A of obtaining the target rotation speed N of the fan (4) according to the temperature T2 of the water outlet of the retarder (3) and the ambient temperature T3 comprises: According to the temperature T2 of the water outlet of the retarder (3) and the ambient temperature T3, a retarder water outlet temperature-ambient temperature-rotation speed MAP table 1 is queried to obtain the target rotation speed N of the fan (4).

3. The fan control method according to claim 2, characterized in that: The S33A specifically includes: S331A, comparing the deceleration a of the vehicle with the first preset deceleration a1, determining whether a≥a1, if so, querying the retarder outlet temperature-ambient temperature-speed MAP table 2 according to the retarder (3) outlet temperature T2 and the ambient temperature T3, to obtain the target speed N of the fan (4); if not, proceeding to S332A; S332A, querying the retarder outlet temperature-ambient temperature-speed MAP table 3 according to the retarder (3) outlet temperature T2 and the ambient temperature T3, and obtaining the target speed N of the fan (4).

4. The fan control method according to claim 1, characterized in that: The step S33B of obtaining the target rotation speed N of the fan (4) according to the temperature T2 of the water outlet of the retarder (3) and the ambient temperature T3 specifically includes: The target speed N of the fan (4) is calculated according to the following formula: N=n i α1; Wherein, n is the real-time rotation speed of the engine, i is the transmission ratio of the fan (4); α1=β1+γ1, β1 is positively correlated with the temperature T2 of the water outlet of the retarder (3), γ1 is positively correlated with the ambient temperature T3, and 0<α1<1.

5. The fan control method according to claim 4, characterized in that: The S34B specifically includes: S341B, comparing the deceleration a of the vehicle with the first preset deceleration a1, determining whether a≥a1, and if so, calculating the target speed N of the fan (4) according to the following formula: N=n i α2; Wherein, α2=β2+γ2; α2 is positively correlated with the temperature T2 of the water outlet of the retarder (3), γ2 is positively correlated with the ambient temperature T3, and α1<α2<1; If not, proceed to S342B; S342B, calculating the target speed N of the fan (4) according to the following formula: N=n i α3; Wherein, α3=β3+γ3; β3 is positively correlated with the temperature T2 of the water outlet of the retarder (3), γ3 is positively correlated with the ambient temperature T3, and α2<α3≤1.

6. The fan control method according to claim 1, characterized in that: The S40 is specifically: The actual rotation speed of the fan (4) is compared with the target rotation speed N to obtain a difference between the target rotation speed N and the actual rotation speed, and then the duty cycle of the electromagnetic valve of the clutch of the fan (4) is adjusted so that the actual rotation speed of the fan (4) is equal to the target rotation speed N.

7. A cooling system for dissipating heat from a power system, the power system comprising an engine (1) and a retarder (3), the retarder (3) being arranged downstream of the engine (1), characterized in that: The cooling system adopts the fan control method according to any one of claims 1 to 6, the cooling system comprising a thermostat (5), a radiator (6), a fan (4), a first cooling pipeline (7), a second cooling pipeline (8), a first temperature sensor and a second temperature sensor (9), the fan (4) and the engine (1) are drivingly connected, one end of the first cooling pipeline (7) is connected to a water outlet of the engine (1), the other end of the first cooling pipeline (7) is connected to a water inlet of the retarder (3), and the second cooling pipeline (9) is connected to a water outlet of the engine (1). One end of the second cooling pipeline (8) is connected to the water outlet of the retarder (3), the other end of the second cooling pipeline (8) is connected to the inlet of the thermostat (5), the first outlet of the thermostat (5) is connected to the water inlet of the radiator (6), the second outlet of the thermostat (5) is connected to the water inlet of the engine (1), and the water outlet of the radiator (6) is connected to the water inlet of the engine (1); the first temperature sensor is arranged on the thermostat (5), and the second temperature sensor (9) is arranged on the water outlet of the retarder (3); Wherein, when the thermostat (5) is closed, the inlet of the thermostat (5) is connected to the second outlet, and when the thermostat (5) is fully opened, the inlet of the thermostat (5) is connected to the first outlet.

8. A vehicle, comprising a power system, characterized in that: The vehicle further comprises a cooling system as claimed in claim 7, wherein the cooling system is used to dissipate heat from the power system.

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