A constant temperature controlled wind power lubrication system

Abstract

The application discloses a constant-temperature-controlled wind power lubricating system, and belongs to the field of wind power fluid equipment. The system comprises a gear box, an electric pump group, a filter, a radiator and a control end. The gear box is connected with the electric pump group through a pipeline. The electric pump group is connected with the filter through a pipeline. The filter is connected with the radiator through a pipeline. The radiator is connected with the gear box through a pipeline, so that oil circulation is completed. The radiator adopts an axial flow fan form. A fan impeller driven by a variable frequency motor generates air volume, carries away heat released by a finned heat exchanger, and achieves the purpose of heat dissipation and cooling. The control end is configured to complete variable frequency motor control in the radiator based on collected radiator inlet and outlet oil temperatures and a preset control algorithm, so that radiator outlet oil temperature control is realized. The application effectively solves the problem of excessive fluctuation of oil temperature range under the existing control logic, and also solves the problem of low-temperature heat dissipation failure.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of general machinery and the field of wind power fluid equipment, and particularly relates to a constant-temperature control wind power lubricating system. BACKGROUND

[0002] At present, the gear box of a wind power generator is mainly cooled by a matched lubricating system. The structure of the matched lubricating system generally comprises an electric pump set, a filter, a radiator, and matched pipelines. The electric pump set is mainly driven by a three-phase asynchronous motor to provide power for the lubricating system to establish flow and pressure. The three-phase asynchronous motor has two speed levels, i.e., high speed and low speed, which correspond to 4 levels and 8 levels of the motor respectively. The structure of the radiator belongs to the form of an axial flow fan. The three-phase asynchronous motor drives the fan impeller to generate air volume to take away the heat released by the finned heat exchanger, so as to achieve the purpose of cooling.

[0003] The control logic of the electric pump set is shown in Figure 1 . The electric pump is controlled at high speed and low speed. The main reason is that the oil viscosity is large at low temperature, and direct high-speed starting requires too much power for the motor. However, the actual working condition does not require such high power, and the power redundancy of the motor is too large, causing cost waste. Specifically, when the oil temperature of the gear box is greater than or equal to 5℃, the motor is started to be in low speed mode; when the oil temperature of the gear box is greater than or equal to 35℃, or the high-speed bearing temperature of the gear box is greater than 70℃, the motor is in high speed mode; when the oil temperature of the gear box is less than or equal to 30℃, and the high-speed bearing temperature of the gear box is less than or equal to 65℃, the motor is switched from high speed mode to low speed mode; when the oil temperature of the gear box is less than or equal to 0℃, the motor pump is closed.

[0004] The control logic of the radiator is shown in Figure 2 . The radiator motor is started at high speed and low speed. The main reason is to consider energy saving. When the fan is not running at full power, the heat generation power of the gear box is low, and the air volume of the radiator running at low speed can meet the cooling demand. Specifically, when the oil pool temperature of the gear box is greater than 60℃ or the high-speed bearing temperature of the gear box is greater than 70℃, the radiator motor is started to be in low speed mode; when the oil pool temperature of the gear box is greater than 65℃ or the high-speed bearing temperature of the gear box is greater than 80℃, the radiator motor is started to be in high speed mode; when the oil pool temperature of the gear box is less than or equal to 58℃ and the high-speed bearing temperature of the gear box is less than or equal to 72℃, the radiator motor is switched from high speed mode to low speed mode; when the oil pool temperature of the gear box is less than or equal to 50℃ and the high-speed bearing temperature of the gear box is less than or equal to 65℃, the radiator motor is switched from low speed mode to the closed state.

[0005] The current control logic has the following problems:

[0006] Temperature control is not accurate, and the oil temperature fluctuation range is large. Because the oil storage capacity of the wind turbine gearbox is 500-1000L+, the heat inertia brought by such oil quantity is large, and the circulating heat dissipation needs time. When the sensor tests the control point temperature, the actual oil temperature of the entire lubrication system is often much higher or lower than the control point temperature. The best working temperature range of the lubricating oil of the rolling bearing of the wind turbine gearbox is 50-75℃, and due to the first reason, the actual temperature range adjusted by the current control logic is beyond this range. When the gearbox runs for a long time beyond the best temperature range of the oil, the oil film thickness at the bearing and gear friction pair of the gearbox is not enough, the lubrication is poor, excessive wear is generated, the gearbox is damaged, the wind turbine stops running, and the power generation is affected, which causes great economic loss. When the heat sink is running in an extremely low temperature environment (usually less than-20℃), the current control logic starts the fan when the oil temperature is greater than 60℃. Due to the large temperature difference between the two heat exchange media (air temperature and oil temperature), the oil temperature of the lubrication system will decrease rapidly, and the oil will be "frozen" in a short time after passing through the heat sink. The lubricating oil of the gearbox of the wind turbine is VG320 type oil, and the lower the oil temperature, the greater the viscosity. In this working condition, the heat sink will be blocked, the heat exchange capacity will be completely lost, and the oil temperature of the gearbox will be out of control, which will directly stop the machine.

[0007] The purpose of the present application is to overcome the problems of the prior art, and disclose a constant temperature control wind power lubrication system. The heat sink is controlled by control logic and control algorithm to start, stop and run, so that the oil temperature is controlled near the ideal target temperature point. The problem of large oil temperature range fluctuation under the existing control logic can be effectively solved, and the problem of low temperature heat dissipation failure can also be solved.

[0008] The purpose of the present application is achieved by the following technical scheme:

[0009] A constant temperature control wind power lubrication system comprises a gearbox, an electric pump group, a filter, a heat sink and a control end. The gearbox is connected with the electric pump group through a pipeline, the electric pump group is connected with the filter through a pipeline, the filter is connected with the heat sink through a pipeline, and the heat sink is connected with the gearbox through a pipeline, so as to complete oil circulation.

[0010] The heat sink adopts an axial flow fan form, a fan impeller driven by a variable frequency motor generates air volume, and the heat released by the flow through the finned heat exchanger is taken away to achieve the purpose of heat dissipation and cooling.

[0011] The control end is configured to complete the control of the variable frequency motor in the radiator based on the collected radiator inlet and outlet oil temperature and a preset control algorithm, so as to realize the control of the radiator outlet oil temperature.

[0012] According to a preferred embodiment, when the radiator inlet oil temperature is greater than or equal to a preset temperature, the algorithm controller in the control end and the radiator variable frequency motor are started;

[0013] When the radiator outlet oil temperature is maintained in a preset temperature range, the algorithm controller controls the radiator variable frequency motor in real time based on a preset algorithm, and when the radiator outlet oil temperature is lower than a threshold value, the radiator variable frequency motor is stopped.

[0014] According to a preferred embodiment, the algorithm controller completes the control of the radiator variable frequency motor based on the following control logic, which comprises:

[0015] S1: heat load calculation, based on the radiator inlet oil temperature, flow rate, specific heat, and radiator outlet target temperature, the heat release amount of the heat fluid in the radiator is calculated,

[0016] S2: heat exchange balance calculation, based on the calculated heat release amount of the heat fluid, the flow rate of the cold fluid is calculated;

[0017] S3: speed calculation, based on the calculated flow rate of the cold fluid, the speed of the radiator variable frequency motor is calculated;

[0018] S4: motor control frequency calculation, based on the obtained speed and the type of motor, the motor control frequency is calculated;

[0019] S5: obtaining a control signal, completing the control of the radiator variable frequency motor.

[0020] According to a preferred embodiment, in step S1, the heat release amount calculation process of the heat fluid in the radiator comprises:

[0021]

[0022] wherein, represents the heat release amount of the heat fluid, represents the specific heat capacity of the heat fluid, represents the mass of the heat fluid, represents the radiator inlet oil temperature, represents the radiator outlet oil temperature / target temperature.

[0023] According to a preferred embodiment, in step S1, the mass of the heat fluid is:

[0024]

[0025] wherein, represents the heat fluid density, represents the heat fluid flow rate.

[0026] According to a preferred embodiment, in step S2, the heat sink corresponding heat balance is: , represents the heat fluid heat release amount, represents the cold fluid heat absorption amount, Q represents the heat exchange amount;

[0027] Thus, based on the cold fluid heat absorption amount:

[0028]

[0029] and the cold fluid mass:

[0030]

[0031] the cold fluid flow rate is obtained:

[0032]

[0033] wherein, represents the cold fluid specific heat capacity, represents the cold fluid mass, represents the cold fluid inlet temperature, represents the cold fluid outlet temperature, the cold fluid density.

[0034] According to a preferred embodiment, in step S3, based on the heat sink heat exchange structure parameter acquisition, the heat exchange amount is obtained through repeated iterative operation, and the cold fluid heat absorption amount is further obtained:

[0035]

[0036] wherein, K represents the total heat transfer coefficient, A represents the total heat transfer area, represents the logarithmic mean temperature difference, represents the temperature difference correction factor.

[0037] According to a preferred embodiment, in step S3, the fan curve equation is established, which is expressed as:

[0038]

[0039] wherein, P represents the fan static pressure, represents the air volume, which also corresponds to the cold fluid flow rate obtained in step S2, ​​is a constant, determined by the fan structure form, measured by experiment, is a function related to the flow, obtained by fitting the data measured by experiment.

[0040] According to a preferred embodiment, in step S3, the rotating speed is:

[0041]

[0042] wherein the fan static pressure P is obtained based on the radiator cooling fin structure parameters and the cold fluid physical property parameters.

[0043] According to a preferred embodiment, the control logic further comprises: S6: modifying the control signal, the modification process comprising:

[0044] based on the radiator inlet oil temperature and the target temperature, performing inertia calculation to obtain an inertia compensation amount, and converting to obtain a corresponding compensation signal,

[0045] based on the compensation signal and the control signal obtained in S5, performing control signal integration, and outputting a signal to complete the radiator variable frequency motor control.

[0046] The foregoing main scheme of the present application and each further selected scheme thereof can be freely combined to form multiple schemes, all of which are the schemes that can be adopted and claimed by the present application. Those skilled in the art can understand that there are multiple combinations according to the existing technology and common knowledge after understanding the schemes of the present application, all of which are the technical schemes claimed by the present application, and are not listed here.

[0047] The beneficial effects of the present application are:

[0048] 1. The output temperature of the radiator is accurately controlled within the optimal temperature range of the gearbox;

[0049] 2. The output temperature of the radiator is constantly controlled around a target temperature point;

[0050] 3. Within the optimal temperature range of the gearbox, the film thickness of the gearbox bearing and gear oil is appropriate, the lubrication is sufficient, the transmission wear is minimized, the service life of the gearbox is effectively prolonged, and the whole life cycle operation and maintenance cost is reduced.

[0051] 4. The failure condition that the oil temperature of the lubrication system rapidly decreases, the oil is frozen in a short time after passing through the radiator, the radiator is blocked, the heat exchange capacity is completely lost, the oil temperature of the gearbox is out of control, and the gearbox is directly stopped is effectively solved when the radiator operates in an extremely low temperature environment due to the large temperature difference between the two heat exchange media (air temperature and oil temperature), the stability, compatibility and adaptability of the lubrication system are improved, the product value is maximized, and the economic benefit of the fan is improved. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 is a schematic diagram of the control logic of the electric pump group;

[0053] Figure 2 is a schematic diagram of the control logic of the radiator;

[0054] Figure 3 is a schematic diagram of the system structure of the present application;

[0055] Figure 4 is a schematic diagram of the control method of the present application;

[0056] Figure 5 is a schematic diagram of the algorithm logic of the present application;

[0057] Figure 6 is a schematic diagram of the control signal correction logic of the present application. DETAILED DESCRIPTION

[0058] The specific embodiments of the present application will be described below with reference to the drawings, and other advantages and effects of the present application can be easily understood by those skilled in the art from the contents disclosed in the specification. The present application can also be implemented or applied in other different specific embodiments, and various modifications or changes can be made to the details of the specification based on different views and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0059] It should be noted that similar reference numerals and letters refer to similar items in the following drawings, and therefore, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0060] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third", and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0061] In addition, the terms "horizontal", "vertical", "overhanging", and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that it is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0062] In the description of the present application, it also needs to be explained that, unless otherwise explicitly specified and limited, the terms "set", "install", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0063] In addition, it should be pointed out that, in the present application, unless the specific structure, connection relationship, positional relationship, power source relationship, etc. are specifically written, the structure, connection relationship, positional relationship, power source relationship, etc. involved in the present application are all known by those skilled in the art on the basis of the prior art without creative labor.

[0064] Embodiment 1

[0065] Reference Figures 3 to 6 As shown in the figure, a constant temperature control wind power lubrication system is shown, the constant temperature control wind power lubrication system comprises: a gear box, an electric pump group, a filter, a radiator and a control end, the gear box is connected with the electric pump group through a pipeline, the electric pump group is connected with the filter through a pipeline, the filter is connected with the radiator through a pipeline, and the radiator is connected with the gear box through a pipeline, so as to complete oil circulation.

[0066] Among them, the radiator adopts the form of axial flow fan, the fan impeller is driven by variable frequency motor to produce air volume, and the heat released by the flow through the finned heat exchanger is taken away to achieve the purpose of heat dissipation and cooling; the control end is configured to complete the control of the variable frequency motor in the radiator based on the collected radiator inlet and outlet oil temperature and the preset control algorithm, so as to realize the control of the radiator outlet oil temperature.

[0067] Preferably, when the radiator inlet oil temperature is greater than or equal to the preset temperature, the algorithm controller in the control end and the radiator variable frequency motor are started; when the radiator outlet oil temperature is maintained in the preset temperature interval, the algorithm controller controls the radiator variable frequency motor in real time based on the preset algorithm, and when the radiator outlet oil temperature is lower than the threshold value, the radiator variable frequency motor stops, as shown in Figure 4 .

[0068] Preferably, as shown in Figure 5 , the algorithm controller completes the control of the radiator variable frequency motor based on the following control logic, including the following steps.

[0069] Step S1: heat load calculation, based on the radiator inlet oil temperature, flow, specific heat and radiator outlet target temperature, the heat release of the radiator heat fluid is calculated.

[0070] Specifically, the heat load calculation includes:

[0071] Heat released by the heat fluid:

[0072] (1)

[0073] Cold fluid absorbs heat:

[0074] (2)

[0075] Mass of thermal fluid:

[0076] (3)

[0077] Cold fluid mass:

[0078] (4)

[0079] Hot fluid flow rate:

[0080] (5)

[0081] In the formula: Heat release of a hot fluid (unit: kcal / h) c: Heat absorbed by cold fluid (unit: Kcal / h), d: Specific heat capacity (unit: Joules / kg℃ J / kg℃), m: Mass flow rate (unit: ... ), Radiator inlet oil temperature (unit: °C). Radiator outlet oil temperature / target temperature (unit: °C). : Cold fluid inlet temperature (unit: °C) : Cold fluid outlet temperature (unit: °C) Thermofluid density (unit: kg / ) ), Flow rate (unit: / h), Displacement (unit: mL / r) Rotational speed (unit: r / min). In this application, hot fluid corresponds to lubricating oil, and cold fluid corresponds to air medium.

[0082] Different fluid systems The flow rate can be determined through the design flow rate of the fluid system. Taking a gearbox lubrication system as an example, the design displacement of the oil pump is known, the high and low speeds of the oil pump drive motor are known, and the switching logic of the high and low speeds of the oil pump drive motor is known, so the theoretical flow rate can be calculated.

[0083] Step S2: Heat exchange balance calculation, based on the heat release of the hot fluid, to complete the cold fluid flow rate calculation.

[0084] The ideal state of heat exchange equilibrium is:

[0085] = = (6)

[0086] in, Heat exchange (unit: Kcal / h).

[0087] Cold fluid flow rate calculate:

[0088] From equation (2), we can obtain:

[0089] (7)

[0090] From equation (4), we can obtain:

[0091] (8)

[0092] By combining the equations, we can obtain:

[0093] (9)

[0094] Cold fluid flow rate (unit: Generally speaking, The assumption method is used to determine this; the algorithm program can pre-determine the assumptions. By setting numerical segments to reduce the amount of iterative calculations, we can obtain the result from equation (6). .

[0095] Q is calculated through iterative iterations in the following heat exchange series calculations. Achieving balance, and thus complete determination .

[0096] Heat exchange calculation

[0097] (10)

[0098] Where: K: Overall heat transfer coefficient (unit: W / ( •K), A: Total heat transfer area (unit: K) ), Logarithmic mean temperature difference (unit: °C).

[0099] Since the temperature difference does not change linearly during the heat exchange process, the arithmetic mean method cannot accurately calculate the actual temperature difference generated by the heat exchange. The logarithmic mean temperature difference calculation method is closer to the actual working conditions.

[0100] Logarithmic mean temperature difference:

[0101] (11)

[0102] in, : Hot side inlet temperature (unit: degrees Celsius °C) : Hot side outlet temperature (unit: degrees Celsius °C) Cold side inlet temperature (unit: degrees Celsius °C). Cold side outlet temperature (unit: degrees Celsius °C).

[0103] The logarithmic mean temperature difference calculation formula here is an idealized mean temperature difference (pure counterflow (or pure coflow)). In reality, plate-fin heat exchangers are usually cross-flow or more complex flow arrangements, so a temperature difference correction factor F needs to be introduced. F can be calculated by referring to charts or empirical formulas, and the final determination depends on the type of heat exchanger selected for the system.

[0104] Overall heat transfer coefficient calculation:

[0105] (12)

[0106] Among them, the convective heat transfer coefficient of the hot fluid (unit: ), cold fluid convective heat transfer coefficient (unit: Thermal conductivity of the partition material (unit: ), fin efficiency .

[0107] (1) Determination of radiator fin structure parameters

[0108] Structural parameters: fin height (Unit: mm), fin thickness (Unit: mm), fin spacing P (unit: mm), partition thickness (Unit: mm), effective fin width B, number of fin channel layers n, effective fin channel length L.

[0109] Note: Fin structure parameters are generally calculated using an assumption method, which is highly efficient. In selecting radiators for fluid systems, the fin height is typically determined based on commonly used fin types. ,thickness Spacing P, partition thickness The effective fin width B, the number of fin channel layers n, and the effective fin channel length L are determined through an iterative method, balancing cost and heat exchange requirements to achieve the desired actual calculated area. That's all.

[0110] (2) Calculation of equivalent diameter D

[0111] (13)

[0112] (3) Calculation of convective heat transfer coefficient h

[0113] Reynolds number:

[0114] (14)

[0115] Flow velocity v (unit: ) is calculated by flow rate and fin channel cross-sectional area; fluid dynamic viscosity (unit: ), Nusselt number (taking turbulent flow as an example):

[0116] (15)

[0117] Applicable conditions: turbulent flow (Re>10,000), , z=0.4 when the fluid is heated, and z=0.3 when the fluid is cooled.

[0118] Convective heat transfer coefficient h:

[0119] (16)

[0120] Fin thermal conductivity (unit: ).

[0121] (4) Fin efficiency Calculation

[0122] (17)

[0123] (18)

[0124] Simultaneous equations (10)-(18) are iterated to obtain Q, and the Q value is substituted into equation (9) to obtain the cold fluid flow rate .

[0125] Step S3: Speed calculation, based on the calculated cold fluid flow rate, complete the calculation of the speed of the frequency conversion motor of the radiator .

[0126] Specifically, step S3 includes: establishing a curve equation.

[0127] Generally: , .

[0128] The curve equation can be expressed as:

[0129] (19)

[0130] Where, fan static pressure P (unit: Pa), air volume (unit: ), is a constant, determined by the fan structure, measured by experiment, is a function related to the flow, mainly in the form of a polynomial, usually can be fitted by experimental data.

[0131] Calculate the speed :

[0132] (20)

[0133] Since the fan static pressure P in the actual operation process can be obtained by introducing the heat sink cold measurement fin structure parameters and cold fluid physical parameters, it is not further listed here.

[0134] Step S4: motor control frequency calculation, based on the obtained speed and motor type to complete the motor control frequency calculation.

[0135] Specifically, in step S4, the motor control frequency f calculation (for example, asynchronous motor):

[0136] (21)

[0137] Where, is the synchronous speed (unit: ), is the slip rate (look up table or ask the supplier or test available).

[0138] (22)

[0139] Where, is the power frequency (unit: Hz), p is the number of magnetic pole pairs of the motor.

[0140] Equation (21) (22) together

[0141] (23)

[0142] So far, the motor control frequency can be obtained.

[0143] Step S5: obtain the control signal, complete the radiator variable frequency motor control.

[0144] Step S6: correct the control signal.

[0145] Generally, the heat source (gearbox) oil storage capacity is often a single minute cycle oil volume of 8-15 times or so (may have deviation, but the relationship is correct), the whole system in the initial stage of control algorithm (estimated within 20 minutes), due to the foregoing reasons, the oil storage capacity will bring great thermal inertia to the system during the temperature rise, system inertia may cause control delay, and then produce control error, so processing this situation, the control signal correction needs to be proposed.

[0146] The correction process includes: based on the radiator inlet oil temperature and the target temperature, inertia calculation is carried out to obtain inertia compensation, and the corresponding compensation signal is obtained, based on the compensation signal and the control signal obtained in S5, the control signal integration is carried out, and the output signal completes the radiator variable frequency motor control, as shown in Figure 6

[0147] Through the present application, the following is achieved: the radiator output temperature is accurately controlled within the optimal temperature range of the gearbox; the radiator output temperature is constantly controlled near a target temperature point; within the optimal temperature range of the gearbox, the gearbox bearing and gear oil film thickness are suitable, the lubrication is sufficient, the transmission wear is minimized, the gearbox life is effectively prolonged, and the whole life cycle operation and maintenance cost is reduced.

[0148] Moreover, the following is effectively solved: when the radiator operates in an extremely low temperature environment, due to the large temperature difference between the two heat exchange media (air temperature and oil temperature), the oil temperature of the lubrication system will rapidly decrease, the oil will be "frozen" after passing through the radiator in a short time, the radiator will be blocked, the heat exchange capacity will be completely lost, the gearbox oil temperature will be out of control, and the failure of direct shutdown will occur, the lubrication system stability, compatibility and adaptability are improved, the product value is maximized, and the economic benefit of the fan is improved.

[0149] The above only describes the preferred embodiments of the present application and does not limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.​

Claims

1. A thermostatically controlled wind turbine lubrication system, characterized in that, The constant-temperature controlled wind power lubrication system comprises a gear box, an electric pump group, a filter, a radiator and a control end, the gear box is connected with the electric pump group through a pipeline, the electric pump group is connected with the filter through a pipeline, the filter is connected with the radiator through a pipeline, and the radiator is connected with the gear box through a pipeline, so as to complete oil circulation; The radiator adopts an axial flow fan form, a fan impeller driven by a variable frequency motor generates air volume, and the heat released by the flow through the finned heat exchanger is taken away, so that the purpose of heat dissipation and cooling is achieved. The control end is configured to complete the control of the variable frequency motor in the radiator based on the collected radiator inlet and outlet oil temperatures and a preset control algorithm, so as to realize the control of the radiator outlet oil temperature. When the radiator inlet oil temperature is greater than or equal to the preset temperature, the algorithm controller in the control end and the radiator variable frequency motor are started; When the radiator outlet oil temperature is maintained in the preset temperature range, the algorithm controller controls the radiator variable frequency motor in real time based on the preset algorithm, and when the radiator outlet oil temperature is lower than the threshold value, the radiator variable frequency motor is stopped. The algorithm controller completes the control of the radiator variable frequency motor based on the following control logic, which comprises: S1: heat load calculation, based on the radiator inlet oil temperature, flow rate, specific heat and radiator outlet target temperature, the heat release amount of the radiator heat fluid is calculated, S2: heat exchange balance calculation, based on the calculated heat release amount of the heat fluid, the cold fluid flow rate is calculated; S3: Rotational speed calculation, based on the calculated cold fluid flow to complete the radiator variable frequency motor rotational speed Calculation; S4: Motor control frequency calculation, based on obtained rotational speed and motor type complete motor control frequency calculation; S5: obtaining a control signal to complete the control of the radiator variable frequency motor.

2. The thermostatically controlled, wind-driven lubricating system of claim 1, wherein, In step S1, the heat release amount calculation process of the radiator heat fluid comprises: wherein, represents the heat fluid heat release amount, represents the heat fluid specific heat capacity, represents the heat fluid mass, represents the radiator inlet oil temperature, represents the radiator outlet oil temperature / target temperature.

3. The thermostatically controlled, wind-driven lubrication system of claim 2, wherein, In step S1, the heat fluid mass: wherein, represents the hot fluid density, represents the hot fluid flow rate.

4. The thermostatically controlled, wind-driven lubricating system of claim 2, wherein, In step S2, the heat balance of the heat sink is: = = , represents the heat release amount of the hot fluid, represents the heat absorption amount of the cold fluid, and Q represents the heat exchange amount; Thus, based on the heat absorption amount of the cold fluid: And the mass of the cold fluid: The flow rate of the cold fluid is obtained: wherein, represents the specific heat capacity of the cold fluid, represents the mass of the cold fluid, represents the inlet temperature of the cold fluid, represents the outlet temperature of the cold fluid, represents the density of the cold fluid.

5. The thermostatically controlled, wind-driven lubrication system of claim 4, wherein, In step S3, based on the acquisition of the heat dissipation structure parameter, the heat exchange amount is obtained through repeated iteration operation , and then the cold fluid heat absorption amount is obtained. where K represents the total heat transfer coefficient, A represents the total heat transfer area, represents the logarithmic mean temperature difference, represents the temperature difference correction factor.

6. The thermostatically controlled, wind-driven lubrication system of claim 5, wherein, In step S3, the fan is established The curve equation is expressed as: where P represents the fan static pressure, represents the air volume, also corresponds to the cold fluid flow calculated in step S2 , is a constant, determined by the fan structure form, measured by experiment, is a function related to the flow, obtained by fitting the experimental data.

7. The thermostatically controlled, wind-driven lubrication system of claim 6, wherein, In step S3, the rotational speed for: Wherein, the fan static pressure P is obtained based on the radiator cooling fin structure parameters and the cold fluid physical property parameters.

8. The thermostatically controlled, wind power lubrication system of claim 1, wherein, The control logic further comprises: S6: correcting the control signal, the correction process comprises: Based on the radiator inlet oil temperature and the target temperature, the inertia calculation is performed to obtain an inertia compensation amount, and the corresponding compensation signal is obtained by conversion, Based on the compensation signal and the control signal obtained in S5, the control signal integration is performed, and the output signal completes the control of the radiator variable frequency motor.

Images