Fan control method, cooling system and vehicle

Abstract

The invention belongs to the technical field of vehicles, and discloses a fan control method, a cooling system and a vehicle. The cooling system comprises an engine, a retarder, a thermostat and a fan, the actual state of the thermostat is considered in the fan control method, and when the water temperature of the thermostat does not reach the initial starting temperature of the thermostat, the fan does not respond even if the hydraulic retarder is in the working state; the actual braking power of the hydraulic retarder and the vehicle deceleration are considered, when the braking power is small and the vehicle deceleration is large, the lower fan rotating speed is set, when the braking power is large or the vehicle deceleration is small, the higher fan rotating speed is set, and the actual heat dissipation requirement of the retarder is fully considered; under certain working conditions, the fan does not enter a full-meshing state, the full-meshing time of the fan is greatly shortened, noise is effectively reduced, user experience is improved, and oil consumption is effectively reduced.

Description

Technical Field

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

[0002] The hydraulic retarder is a device that uses liquid damping to produce a retarding effect. When the hydraulic retarder is working, it stirs the oil on the vehicle's drive shaft to produce damping, thereby achieving a braking effect. The stirring of the oil by the hydraulic retarder will generate a large amount of heat. Usually, as long as the hydraulic retarder is working, the fan will be required to rotate at full speed to ensure the heat dissipation needs of the entire vehicle. However, this setting will not only cause loud noises, but also due to the long disengagement time of the fan clutch after turning off the hydraulic retarder, the engine fan will continue to fully engage and rotate for a period of time, resulting in unnecessary increase in power consumption and increase in fuel consumption of the entire vehicle.

[0003] In order to solve the above problems, the fan control method disclosed in the invention patent "CN116025455A" determines whether the fan is rotating at full speed according to the engine cooling water temperature and the retarder heat dissipation power. While ensuring the heat dissipation demand, it can reasonably control the engine cooling water temperature to ensure that the engine is in the best working state, and can reduce the power consumption when the fan is disconnected from the engine; the vehicle fan control method disclosed in the invention patent "CN118640181A" can determine the target speed of the fan considering the vehicle operation information when the heat generation of the hydraulic retarder is low, so as to control the fan rotation, which can effectively reduce the fan speed, reduce the noise in the cab, ensure driving comfort and reduce fuel consumption. The fan in the first fan control method only has two working conditions: full speed rotation and no rotation, and has poor adaptability. The second fan control method only takes into account the heat generation of the retarder, and the adjustment is relatively simple.

[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 object 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. The adjustment is more flexible, fully considers the actual heat dissipation requirements of the retarder, reduces the full engagement time of the fan, and thus reduces fuel consumption.

[0006] To achieve this object, 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 optional technical solution, the S33A specifically includes:

[0019] 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 outlet temperature T2 and the ambient temperature T3, to obtain the target speed N of the fan; if not, proceeding to S332;

[0020] S332A, query retarder water outlet temperature-ambient temperature-speed MAP table 3 according to the retarder water outlet temperature T2 and the ambient temperature T3 to obtain the target speed N of the fan.

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

[0022] S31B, comparing the temperature T2 of the retarder water outlet 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;

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

[0024] S33B, 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;

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

[0026] 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 S33B specifically includes:

[0027] The target speed N of the fan is calculated 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 optional technical solution, the S34B specifically includes:

[0031] S341B, comparing the deceleration a of the vehicle with the first preset deceleration a1 to determine whether a≥a1, and if so, calculating the target speed N of the fan according to the following formula:

[0032] N = n*i*α2;

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

[0034] If not, proceed to S342B;

[0035] S342B, calculating the target speed N of the fan according to the following formula:

[0036] N = n*i*α3;

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

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

[0039] The actual speed of the fan is compared with the target speed N to obtain the difference between the target speed N and the actual speed, and then the duty cycle of the solenoid valve of the fan clutch is adjusted so that the actual speed of the fan is the target speed N.

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

[0041] A cooling system for dissipating heat from a power system, the power system comprising an engine and a retarder, the retarder being arranged downstream of the engine, the cooling system adopting the fan control method as described above, the cooling system comprising 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 being transmission-connected to the engine, one end of the first cooling pipeline being connected to a water outlet of the engine, the other end of the first cooling pipeline being connected to a water inlet of the retarder, one end of the second cooling pipeline being connected to a water outlet of the retarder, the other end of the second cooling pipeline being connected to an inlet of the thermostat, the first outlet of the thermostat being connected to a water inlet of the radiator, the second outlet of the thermostat being connected to a water inlet of the engine, and the water outlet of the radiator being connected to a water inlet of the engine; the first temperature sensor being arranged at the thermostat, and the second temperature sensor being arranged 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 1is a schematic structural diagram of a cooling system according to an embodiment of the present invention;

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

[0051] Figure 3 is a flow chart of a 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. Oil cooling channel. DETAILED DESCRIPTION

[0054] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0055] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0057] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0058] Example 1

[0059] like Figure 1 As shown, a cooling system is provided in this embodiment for dissipating heat from a power system, the power system comprising an engine 1, a gearbox 2, and a retarder 3, the cooling system comprising 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 is transmission-connected to the gearbox 2, the retarder 3 is arranged at the output end of the gearbox 2, the fan 4 is transmission-connected to the engine 1, one end of the first cooling pipeline 7 is connected to the water outlet of the engine 1, and the other end of the first cooling pipeline 7 is connected to the water inlet of the retarder 3 One end of the second cooling pipeline 8 is connected to the water outlet of the retarder 3, and 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; 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, the first temperature sensor is arranged on the thermostat 5, and the second temperature sensor 9 is arranged at the water outlet of the retarder 3. Specifically, in this embodiment, when the thermostat 5 is closed, the inlet of the thermostat 5 is connected to the second outlet, and the coolant circulates between the engine 1 and the retarder 3 to form a small cycle. When the thermostat 5 is fully opened, the inlet of the thermostat 5 is connected to the first outlet, and the coolant passes through the engine 1, the retarder 3, the thermostat 5 and the radiator 6 in sequence to cool and form a large cycle.

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

[0061] Specifically, in this embodiment, the first temperature sensor is arranged 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 arranged at the water outlet of the retarder 3, and can obtain the temperature at the water outlet of the retarder 3 in real time, and then accurately judge the temperature at the retarder 3, and adjust the speed of the fan 4 according to the temperature, which can ensure the performance of the retarder 3 to the greatest extent.

[0062] Furthermore, the cooling system also includes an oil cooling channel 10 , and two ends of the oil cooling channel 10 are connected to the engine 1 and the thermostat 5 respectively.

[0063] A vehicle is also provided in this embodiment, which includes a power system and the above-mentioned cooling system. The cooling system dissipates heat from the power system. By setting up the cooling system, the vehicle can adjust the speed of the fan 4 according to actual working conditions, thereby reducing the full engagement time of the fan 4, effectively reducing noise, reducing fuel consumption, and improving user experience.

[0064] Based on the above cooling system, such as Figure 2 As shown, this embodiment also provides a fan control method 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, enter S20.

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

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

[0069] S20, comparing the initial opening temperature T0 of the coolant in the thermostat 5 with the real-time temperature T1 of the coolant at the thermostat 5, and determining whether T1>T0, if so, proceeding 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 be opened, and the temperature at the retarder 3 will not increase significantly. Even if the hydraulic retarder 3 is in working state, the fan 4 will not respond, thereby effectively reducing energy consumption.

[0071] S30 . Determine a target rotation 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 rises and the radiator 6 needs to intervene to cool it down, so 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] Wherein, t is the real-time torque of the retarder 3 , and n is the real-time rotation speed of the engine 1 .

[0076] In this embodiment, the formula is used to calculate the braking power of the retarder 3 for a specific scenario, and the real-time torque t of the retarder 3 and the real-time speed n of the engine 1 can be directly obtained from the controller without adding hardware layout, effectively reducing costs.

[0077] Furthermore, S30 specifically includes the following contents.

[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, and whether the fan 4 needs to rotate needs to be determined based on the deceleration of the vehicle. This can not only ensure the normal operation of the retarder 3, but also improve the flexibility of the fan 4 control, avoid increased fuel consumption and noise, and affect the user experience.

[0080] S32A, compare the vehicle's deceleration a with the first preset deceleration a1 to determine whether a≥a1, if so, the fan 4 does not work; if not, obtain the 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.

[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 work subsequently, so no additional heat dissipation is required, so the fan 4 does not work 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 hydraulic braking gear, and the fan 4 needs to work to take away the heat generated by the retarder 3 to ensure the normal operation of the retarder 3 afterwards.

[0082] In this process, the target speed N of the fan 4 is obtained according to the temperature T2 of the water outlet of the retarder 3 and the ambient temperature T3, which specifically includes: querying the retarder water outlet temperature-ambient temperature-speed MAP table 1 according to the temperature T2 of the water 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 1 can be obtained through calculation or experiment.

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

[0086] 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.

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

[0088] S331A, compare the vehicle's deceleration a with the first preset deceleration a1 to determine whether a≥a1. If so, query 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, enter S332.

[0089]

[0090] S332, query the retarder outlet temperature-ambient temperature-speed MAP table 3 according to the retarder 3 outlet temperature T2 and the ambient temperature T3, and 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 is required to work to ensure the normal operating temperature range of the retarder 3. On this basis, by increasing the deceleration a of the vehicle for comparison with the first preset deceleration a1, when the deceleration of the whole vehicle is small, considering that the driver may continue to increase the hydraulic braking gear, a larger target speed N of the fan 4 is set at this time; when the deceleration of the whole vehicle is large, a smaller target speed N of the fan 4 is set, so that the controllability of the fan 4 speed is increased, the full engagement time of the fan 4 is greatly reduced, the fuel consumption is effectively reduced, and the economy is improved.

[0093] Specifically, in the present embodiment, the determination of the rotation speed of the fan 4 takes into account the change in ambient temperature, and avoids the problem that the heat dissipation capacity of the cooling system changes greatly at different ambient temperatures, resulting in the fan 4 still entering full engagement when the ambient temperature is cold, causing increased power consumption due to the setting of the heat dissipation power threshold being too small and the duration being too short; and effectively avoids the problem that the performance of the hydraulic retarder 3 is affected when the ambient temperature is hot due to the setting of the heat dissipation power threshold being too high and the duration being too long.

[0094] Specifically, in this embodiment, the retarder water outlet temperature-ambient temperature-speed MAP table 2 and the retarder water outlet temperature-ambient temperature-speed MAP table 3 can be obtained by calculation or experiment.

[0095] S40, controlling the fan 4 to rotate according to the target speed N.

[0096] Specifically, in the present embodiment, this fan control method does not respond when the ambient temperature is low or the outlet temperature of the hydraulic retarder 3 is low; when the ambient temperature is higher and the outlet temperature 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 taking into account the ambient temperature, the coolant temperature at the thermostat 5 and the coolant temperature at the outlet of the retarder 3 at the same time, the actual heat dissipation demand of the retarder 3 is fully considered, and the fan 4 is not allowed to enter the full meshing state under certain working conditions, thereby greatly reducing the full meshing time of the fan 4.

[0097] Example 2

[0098] This embodiment discloses a cooling system, a vehicle, and a fan cooling method based on the cooling system. The cooling system and the vehicle in this embodiment are the same as the cooling system and the vehicle in Embodiment 1. Figure 3 As shown, the fan cooling method in this embodiment is different from the fan cooling method in Embodiment 1 in that the specific content of S30 is different.

[0099] Specifically, S30 includes the following contents.

[0100] S31B, compare 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.

[0101] Specifically, in this embodiment, the temperature T2 of the water outlet of the retarder 3 is included in the judgment basis for the speed control of the fan 4, which can ensure the accuracy of the speed regulation of the fan 4, and further ensure that the temperature at the retarder 3 can be within the temperature range most suitable for the retarder 3 to work, thereby ensuring 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, which will not be described in detail here.

[0103] S32B, compare the braking power P of the retarder 3 with the first preset power P1 to determine whether P≤P1, if so, enter S32B; if not, 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 relatively small at this time, and whether the fan 4 needs to rotate needs to be determined based on the deceleration of the vehicle. This can not only ensure the normal operation of the retarder 3, but also improve the flexibility of the fan 4 control, avoid increased fuel consumption and noise, and affect 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 is, the higher the corresponding first preset power P1 is.

[0106] S33B, compare the vehicle's deceleration a with the first preset deceleration a1 to determine whether a≥a1, if so, the fan 4 does not work; if not, obtain the 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.

[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 no additional heat dissipation is required, so the fan 4 does not work 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 hydraulic braking gear, and the fan 4 needs to work to take away the heat generated by the retarder 3 to ensure the normal operation of the retarder 3 afterwards.

[0108] Further, the target speed N of the fan 4 is obtained according to the temperature T2 of the water outlet of the retarder 3 and the ambient temperature T3. Specifically, the target speed N of the fan 4 is calculated 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 of 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 of 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 great influence 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 of the water outlet of the retarder 3 and the ambient temperature T3, thereby ensuring the operating temperature of the retarder 3 and improving the performance of the retarder 3.

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

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

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

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

[0116] α1=ΔT*(β1+γ1);

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

[0118] This calculation formula can further improve the calculation accuracy of the target rotation speed N of the fan 4, thereby improving the control accuracy of the rotation speed of the fan 4, which is further beneficial to improving the temperature control accuracy of the retarder 3 and ensuring the working performance of the retarder 3.

[0119] S34B, obtaining the 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.

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

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

[0122] N = n*i*α2;

[0123] Among them, 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.

[0124] If not, go to 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 temperature value of the environment measured by the vehicle, and A2, B2 and C2 can be obtained based on 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 using other formulas, which will not be elaborated here.

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

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

[0129] α2=ΔT*(β2+γ2);

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

[0131] This calculation formula can further improve the calculation accuracy of the target rotation speed N of the fan 4, and then improve the control accuracy of the rotation speed of the fan 4, which is further beneficial to the temperature control of the retarder 3 and ensures 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] Among them, 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.

[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 temperature value of the environment measured by the vehicle, and A3, B3 and C3 can be obtained based on experiments or calculations, which will not be elaborated here.

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

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

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

[0139] α3=ΔT*(β3+γ3);

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

[0141] This calculation formula can further improve the calculation accuracy of the target rotation speed N of the fan 4, and then improve the control accuracy of the rotation speed of the fan 4, which is further beneficial to the temperature control of the retarder 3 and ensures the working performance of the retarder 3.

[0142] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in 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 rotation speed N.

2. The fan control method according to claim 1, characterized in that: The S30 further 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.

3. The fan control method according to claim 2, 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).

4. The fan control method according to claim 3, 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).

5. The fan control method according to claim 1, characterized in that: 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.

6. The fan control method according to claim 5, 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.

7. The fan control method according to claim 5, 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.

8. 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.

9. 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 8, 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.

10. A vehicle, comprising a power system, characterized in that: The vehicle further comprises a cooling system as claimed in claim 9, wherein the cooling system is used to dissipate heat from the power system.

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