Electromechanical coupling power generation device based on engine exhaust turbine kinetic energy and design method

Abstract

The application provides a kind of electromechanical coupling power generation device based on engine exhaust turbine kinetic energy and its design method, the power generation device includes second stage turbine, second stage turbine end regulating valve, control module, motor speed monitoring module, generator device, motor damping device, overrunning clutch, planetary reducer and floating ring bearing;Wherein, the second stage turbine is used to connect the first stage turbine exhaust port of engine, and the second stage turbine end regulating valve is connected in parallel at both ends of the second stage turbine;The vortex shaft rotor of second stage turbine is supported by floating ring bearing, and is connected to planetary transmission through end spline, and the planetary transmission is connected to generator through overrunning clutch.The power generation device of the application can solve the problem of fully utilizing the kinetic energy of exhaust gas of vehicle internal combustion engine exhaust, and can adapt to different altitudes.

Description

Technical Field

[0001] This invention belongs to the field of power generation device design technology, and specifically refers to an electromechanical coupling power generation device based on the kinetic energy of an engine exhaust turbine and its design method. Background Technology

[0002] The existing design schemes for engine exhaust turbine power generation devices proposed at home and abroad have the following problems: (1) In some exhaust turbine power generation device designs proposed by experts, scholars and inventors, the motor rotor is directly connected to the ultra-high speed turbine rotor, which causes the support bearing of the power generation device to overheat due to high-speed friction and fail to work properly, and the motor control system also cannot work properly in the ultra-high speed range; (2) Other exhaust turbine power generation device designs proposed by experts, scholars and inventors are too complicated, which makes the transmission system prone to rotor system resonance in the ultra-high speed range and unable to work properly. Therefore, it is urgent to research and develop a green power generation technology with simple electromechanical structure that can make full use of the kinetic energy of internal combustion engine exhaust. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and to solve the problem of fully utilizing the kinetic energy of exhaust gas from vehicle internal combustion engines. It proposes an electromechanical coupling power generation device based on the kinetic energy of engine exhaust turbines and its design method.

[0004] The method of this invention is achieved through the following technical solution:

[0005] On one hand, an electromechanical coupling power generation device based on the kinetic energy of an engine exhaust turbine includes a second-stage turbine, a second-stage turbine end regulating valve, a control module, a motor speed monitoring module, a generator unit, a motor vibration damping device, an overrunning clutch, a planetary reducer, and a floating ring bearing; wherein, the second-stage turbine is used to connect to the exhaust port of the first-stage turbine of the engine, the second-stage turbine end regulating valve is connected in parallel to both ends of the second-stage turbine; the turbine rotor of the second-stage turbine is supported by the floating ring bearing and connected to the planetary reducer through the end spline, the planetary reducer is connected to the generator through the overrunning clutch, and the generator unit is supported by the motor vibration damping device;

[0006] The motor speed monitoring is used to collect motor speed information;

[0007] The control module is used to control the second-stage turbine bypass valve actuator and the second-stage turbine bypass valve based on the speed information, altitude data, and vehicle driving conditions, and based on the preset control rate of the second-stage turbine bypass valve actuator and the venting rate of the second-stage turbine bypass valve.

[0008] Furthermore, the control module of the present invention is used to control the second-stage turbine bypass valve actuator according to the control law. u To achieve control of the actuator;

[0009]

[0010] in, N T The driving torque applied to the second-stage turbine by the exhaust gas emitted from the first-stage turbocharger; J T The moment of inertia of the turbine-turbine shaft; J G The equivalent rotational inertia of the rotating components of the planetary gearbox; J D The moment of inertia of the generator; i The speed ratio between the second-stage turbine rotor shaft speed and the generator rotor speed ( i It can also be expressed as the speed ratio between the angular velocity of the second-stage turbine rotor shaft and the angular velocity of the generator rotor. k 1. k 2 and β As a preset constant, oh Td Target angular velocity of the second-stage turbine rotor shaft e For output error, C T C is the damping coefficient of the floating ring bearing on the second-stage turbine rotor shaft. G This refers to the gyroscopic force coefficient of the second-stage turbine rotor shaft. C mesh is the damping coefficient of the meshing motion of the planetary gear transmission gears. C D is the rotor rotation damping coefficient of the motor.

[0011] Furthermore, the control module of the present invention is used to determine the exhaust rate of the second-stage turbine bypass valve. To control the bypass valve:

[0012]

[0013] in, H Represents altitude, n This represents the engine speed.

[0014] On the other hand, a design method for an electromechanical coupling power generation device based on the kinetic energy of an engine exhaust turbine is provided. The power generation device designed using this method is applicable to different altitudes. Specific steps include:

[0015] A thermodynamic model of the engine was built using system simulation software;

[0016] Obtain the relationship between engine exhaust flow rate and vehicle operating conditions at different altitudes, and calculate the relevant parameters of the first-stage turbine under different vehicle driving conditions based on the relationship;

[0017] Based on the relevant parameters of the first-stage turbine, the second-stage turbine, floating ring bearing and planetary gearbox are designed.

[0018] The control module presets the control rate of the second-stage turbine bypass valve actuator and the venting rate of the second-stage turbine bypass valve.

[0019] The design of the electromechanical coupling power generation device is completed by constructing a second-stage turbine, a second-stage turbine end regulating valve, the control module, a motor speed monitoring module, a generator unit, a motor vibration damping device, an overrunning clutch, the planetary reducer, and the floating ring bearing.

[0020] Furthermore, the control law of the second-stage turbine bypass valve actuator of the present invention u Designed as follows:

[0021]

[0022] in, N T The driving torque (i.e. turbine output power) applied to the exhaust gas from the first-stage turbocharger to the second-stage turbine. J T The moment of inertia of the second-stage turbine and turbine rotor shaft; J G The equivalent rotational inertia of the rotating components of the planetary gearbox; J D The moment of inertia of the generator; i This is the speed ratio between the second-stage turbine rotor shaft speed and the generator rotor speed. k 1. k 2 and β As a preset constant, oh Td Target angular velocity of the turbine rotor shaft e For output error, C T The damping coefficient of the floating ring bearing for the second-stage turbine rotor shaft; C G This refers to the gyroscopic force coefficient of the second-stage turbine rotor shaft. C mesh is the damping coefficient of the meshing motion of the planetary gear transmission gears. C D is the rotor rotation damping coefficient of the motor.

[0023] Furthermore, the exhaust rate of the second-stage turbine bypass valve of the present invention... Designed as follows:

[0024]

[0025] in, H Represents altitude, n This represents the engine speed.

[0026] Furthermore, the present invention designs the turbine rotor shaft and floating ring bearing based on the power transmitted by the second-stage turbine and the maximum speed.

[0027] Furthermore, the present invention designs a planetary gearbox device based on the rotor shaft's transmitted torque and maximum speed.

[0028] Beneficial effects

[0029] First, the second-stage turbine of the power generation device of the present invention uses the kinetic energy of the exhaust gas generated by the first-stage turbocharger to drive its turbine rotor shaft to rotate; at the same time, the sun gear of the planetary gearbox fixed at the other end of the turbine rotor shaft drives the connecting rod of the planetary gearbox to rotate through gear meshing, and transmits the power to the generator through the overrunning clutch to realize the power generation function; the power generation device is suitable for turbomechanical-electrical coupling generator devices at various altitudes, and has a simple and compact structure, light weight, and low vibration and noise.

[0030] Secondly, the second-stage turbine of the power generation device of the present invention uses the kinetic energy of the exhaust gas generated by the first-stage turbocharger to drive its turbine rotor shaft to rotate, thus achieving the requirements of low carbon, green and environmentally friendly operation.

[0031] Third, by designing the control rate of the preset second-stage turbine bypass valve actuator and the venting rate of the second-stage turbine bypass valve, the present invention can enable the power generation device to operate stably.

[0032] Fourth, the generator device developed using this invention can be used directly by making only minor modifications to motor vehicles at different altitudes in my country. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of a mechanically-electrically coupled generator device based on the turbine kinetic energy of vehicle engine exhaust gas according to an embodiment of the present invention.

[0035] Among them, 1-second stage turbine; 2-second stage turbine end regulating valve; 3-first stage turbocharger turbine; 4-first stage turbocharger turbine bypass valve; 5-engine; 6-first stage turbocharger intercooler; 7-first stage turbocharger compressor; 8-control module; 9-motor speed monitoring module; 10-generator unit; 11-generator vibration damping device; 12-overrunning clutch; 13-planetary reducer; 14-floating ring bearing.

[0036] Figure 2 Design flow for a turbomechanical-electrical coupled generator device based on exhaust gas turbine kinetic energy;

[0037] Figure 3 The curves show the second-stage turbine intake volume at different altitudes. Detailed Implementation

[0038] The embodiments of the method of the present invention will be described in detail below with reference to the accompanying drawings.

[0039] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0040] It should be noted that, in the absence of conflict, the following embodiments and features can be combined with each other; and, based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0041] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0042] On the one hand, embodiments of this application provide an electromechanical coupling power generation device based on the kinetic energy of an engine exhaust turbine, such as... Figure 1 As shown, it includes a second-stage turbine 1, a second-stage turbine end regulating valve 2, a control module 8, a motor speed monitoring module 9, a generator unit 10, a motor vibration damping device 11, an overrunning clutch 12, a planetary reducer 13, and a floating ring bearing 14. Figure 1 The first-stage turbocharger turbine 3, the first-stage turbocharger turbine bypass valve 4, the engine 5, the first-stage turbocharger intercooler 6, and the first-stage turbocharger compressor 7 are components already present on the motor vehicle.

[0043] The second-stage turbine 1 is used to connect to the exhaust port of the first-stage turbine of the engine. The second-stage turbine end regulating valve 2 is connected in parallel to both ends of the second-stage turbine 1. The turbine rotor shaft of the second-stage turbine 1 is supported by a floating ring bearing 14 and connected to a planetary transmission 13 through an end spline. The planetary transmission 13 is connected to a generator 10 through an overrunning clutch 12.

[0044] The generator speed monitoring 9 is used to collect generator speed (or angular velocity) information;

[0045] The control module 8 is used to, based on the speed information, altitude data, and vehicle driving conditions, and according to the preset control law of the second-stage turbine bypass valve actuator, determine the control parameters. u and the exhaust rate of the second-stage turbine bypass valve It controls the second-stage turbine bypass valve actuator and the second-stage turbine bypass valve.

[0046] In this embodiment, the second-stage turbine 1 uses the exhaust gas kinetic energy generated by the first-stage turbocharger to drive its turbine rotor shaft to rotate; at the same time, the planetary gearbox sun gear fixed to the other end of the turbine rotor shaft drives the planetary gearbox tie rod to rotate through gear meshing, and transmits power to the generator through the overrunning clutch to realize the power generation function; this power generation device is suitable for turbomechanical-electrical coupling generator devices at various altitudes, and has a simple and compact structure, light weight, and low vibration and noise.

[0047] In yet another embodiment of this application, the control module 8 is based on the control law of the second-stage turbine bypass valve actuator. u To achieve control of the actuator;

[0048]

[0049] in, N T The driving torque (i.e. turbine output power) applied to the exhaust gas from the first-stage turbocharger to the second-stage turbine. J T The moment of inertia of the second-stage turbine-turbine rotor shaft; J G The equivalent rotational inertia of the rotating components of the planetary gearbox; J D The moment of inertia of the generator; i This is the speed ratio between the second-stage turbine rotor shaft speed and the generator rotor speed. k 1. k 2 and β As a preset constant, oh Td Target angular velocity of the turbine rotor shaft eFor output error, C T is the damping coefficient of the floating ring bearing for the turbine rotor shaft; C G This refers to the gyroscopic force coefficient of the turbine rotor shaft. C mesh is the damping coefficient of the meshing motion of the planetary gear transmission gears. C D is the rotor rotation damping coefficient of the motor.

[0050] In yet another embodiment of this application, the control module 8 determines the exhaust rate based on the second-stage turbine bypass valve. To control the bypass valve:

[0051]

[0052] in, H Represents altitude, n This represents the engine speed.

[0053] On the other hand, embodiments of this application provide a design method for an electromechanical coupling power generation device based on the kinetic energy of an engine exhaust turbine. The power generation device designed by this method can be applied to different altitudes. Specific steps include:

[0054] A thermodynamic model of the engine was built using system simulation software;

[0055] Obtain the relationship between engine exhaust flow rate and engine speed (i.e. vehicle operating conditions) at different altitudes, and calculate the relevant parameters of the first-stage turbine under different vehicle driving conditions based on the relationship;

[0056] Based on the relevant parameters of the first-stage turbine, design the second-stage turbine, floating ring bearing and planetary gearbox, or select a suitable second-stage turbine, floating ring bearing and planetary gearbox.

[0057] The control law for the second-stage turbine bypass valve actuator is preset in the control module. u and the exhaust rate of the second-stage turbine bypass valve ;

[0058] A power generation device is constructed, comprising a second-stage turbine, a second-stage turbine end regulating valve, the control module, a motor speed monitoring module, a generator unit, a motor vibration damping device, an overrunning clutch, the planetary reducer, and the floating ring bearing, thus completing the design of the electromechanical coupling power generation device.

[0059] In this embodiment, by obtaining the relationship between engine exhaust flow and engine speed (i.e. vehicle operating conditions) at different altitudes, relevant engine parameters are obtained based on this relationship to support the design of key components of the power generation device, thereby enabling it to be applicable to different altitudes.

[0060] In yet another embodiment of this application, the control law of the second-stage turbine bypass valve actuator... u Designed as follows:

[0061]

[0062] in, N T The driving torque (i.e. turbine output power) applied to the exhaust gas from the first-stage turbocharger to the second-stage turbine. J T The moment of inertia of the second-stage turbine-turbine shaft; J G The equivalent rotational inertia of the rotating components of the planetary gearbox; J D The moment of inertia of the generator; i This is the speed ratio between the second-stage turbine rotor shaft speed and the generator rotor speed. k 1. k 2 and β As a preset constant, oh Td Target rotational speed of the turbine rotor shaft e For output error, C T is the damping coefficient of the floating ring bearing for the turbine rotor shaft; C G This refers to the gyroscopic force coefficient of the turbine rotor shaft. C mesh is the damping coefficient of the meshing motion of the planetary gear transmission gears. C D is the generator rotor rotation damping coefficient.

[0063] In this embodiment, the characteristics and / or interrelationships of the first-stage turbine, the second-stage turbine, the planetary gearbox, etc., are fully considered, which can ensure the stable operation of the power generation device.

[0064] In yet another embodiment of this application, the exhaust rate of the second-stage turbine bypass valve... Designed as follows:

[0065]

[0066] in, H Represents altitude, n Represents engine speed.

[0067] In designing the venting rate of the second-stage turbine bypass valve, this embodiment fully considers the influence of altitude on the venting rate, making the power generation device designed in this embodiment applicable to different altitudes.

[0068] In another embodiment of this application, the turbine rotor shaft and floating ring bearing are designed according to the power transmitted by the second-stage turbine and the maximum speed.

[0069] In another embodiment of this application, a planetary gearbox device is designed based on the rotor shaft's transmitted torque and maximum speed.

[0070] Example:

[0071] Based on fundamental thermodynamic theorems, conservation of mechanical energy, and principles of mass and energy balance, an exhaust gas turbine-generator system was constructed. This generator utilizes the kinetic energy of the engine's exhaust turbine and is suitable for mechanical-electrical coupling at different altitudes. The specific design process is as follows: Figure 1 As shown.

[0072] Step 1: Use GT-POWER software to establish a thermodynamic simulation model of the vehicle engine.

[0073] Step 2: Based on the input altitude parameters and vehicle engine parameters, the intake and exhaust mass flow rates of the vehicle engine under different altitudes and driving conditions can be calculated.

[0074] (1) Relationship between engine intake airflow and altitude:

[0075] (1)

[0076] in, Engine intake air volume, kg / h; Engine speed, in r / min.

[0077] (2) The relationship between engine exhaust flow rate and altitude, such as Figure 3 As shown:

[0078] (2)

[0079] in, Engine displacement, kg / h; n Engine speed, in r / min.

[0080] Step 3: Using the above-mentioned thermodynamic simulation model of the vehicle engine, calculate the parameters such as exhaust pressure (i.e., exhaust gas pressure), exhaust flow rate (exhaust gas flow), and exhaust density (i.e., exhaust gas density) of the first-stage turbine under different vehicle driving conditions; based on the above parameters, complete the design of the second-stage turbine, including: (1) calculation of the main thermodynamic parameters of the turbine; (2) calculation of the main operating parameters of the turbine. The main calculation formulas are as follows:

[0081] (1) Calculation formulas for the main thermodynamic parameters of the second-stage turbine;

[0082] 1) Isentropic work of the turbine:

[0083] (3)

[0084] in: L TS For the turbine's isentropic work, L CS The isentropic compression work of the compressor. or TC This refers to the overall efficiency of the turbocharger.

[0085] 2) Turbine temperature drop:

[0086] (4)

[0087] in: R The gas constant is... k 3 represents the isentropic index.

[0088] 3) Turbine expansion ratio :

[0089] (5)

[0090] in: π c The compressor pressure ratio; T 4 represents the exhaust gas temperature after the turbine; T 3 represents the exhaust gas temperature before the turbine; κ3 represents the overall efficiency of the turbocharger, and κ3 represents the turbine isentropic index.

[0091] 4) Ientropic work of turbine nozzle L n :

[0092] (4)

[0093] in: C 1 represents the airflow velocity at the turbine nozzle exit.

[0094] 5) Turbine output power N T :

[0095] (5)

[0096] in: Turbine mass flow rate; p 4 represents the exhaust gas pressure after the turbine; p 3 represents the exhaust gas pressure before the turbine; R It is the gas constant; k 3 represents the turbine isentropic index.

[0097] (2) Calculation of main operating parameters of the second-stage turbine

[0098] 1) Turbine geometric flow section A T :

[0099] (6)

[0100] in: m T The speed of the turbine's circumference; r 3 represents the exhaust gas density before the turbine; other parameters are explained as before.

[0101] 2) Calculation of turbine impeller parameters:

[0102] ① Transmission ratio

[0103] (7)

[0104] in: L n For the isentropic work of the turbine nozzle, L TS This is the isentropic work of the turbine.

[0105] ②Isentropic work done by the working wheel:

[0106] (8)

[0107] ③ Relative velocity of the impeller inlet:

[0108] (9)

[0109] in: α 1 represents the turbine nozzle outlet airflow angle. β 1 represents the relative airflow angle at the impeller inlet.

[0110] ④ Average diameter of the impeller outlet:

[0111] (10)

[0112] in: d T The wheel diameter ratio, D 1 represents the inlet diameter of the working wheel.

[0113] ⑤ Relative speed at the exit of the working wheel:

[0114] (11)

[0115] in: L S For the isentropic work done by the working wheel, w 1 represents the relative velocity of the impeller inlet. u 1 represents the inlet circumferential speed of the working wheel.

[0116] ⑥ Axial velocity component of airflow at the impeller outlet:

[0117] (12)

[0118] in: G T This refers to the engine's displacement. c 2 represents the gas density at the outlet of the impeller. F l2 This refers to the export area of ​​the working wheel.

[0119] ⑦ Circumferential velocity at the average radius of the airflow at the impeller outlet:

[0120] (13)

[0121] in: d T The ratio of the working wheel diameter, u 1 represents the inlet circumferential speed of the working wheel.

[0122] ⑧ Axial velocity component at the average radius of the airflow at the impeller outlet:

[0123] (14)

[0124] in: β 2 represents the relative velocity airflow angle at the outlet of the impeller.

[0125] ⑨ Airflow velocity at the impeller outlet:

[0126] (15)

[0127] ⑩ Loss of isentropic work in the working round:

[0128] (16)

[0129] in: w 2 represents the relative velocity at the exit of the working wheel; g It is the acceleration due to gravity; f It is a constant, taken as 0.92.

[0130] Step 4: Calculate the second-stage turbine intake volume and the initial bleed rate of the bypass valve under different altitudes and vehicle driving conditions.

[0131] (1) Initial venting rate curve of the second-stage turbine bypass valve:

[0132] (17)

[0133] in, This represents the initial venting rate of the second-stage turbine bypass valve. nEngine speed, in r / min.

[0134] (2) Second-stage turbine intake volume curve:

[0135] (18)

[0136] in, The second-stage turbine intake volume is kg / s; n Engine speed, in r / min.

[0137] Step 5: Based on the power transmitted by the second-stage turbine and its maximum speed, design the parameters of the turbine rotor shaft, floating ring bearing, etc.

[0138] (1) The main parameters of the turbine rotor shaft include:

[0139] 1) Total length of rotor L / mm; 2) Turbine diameter D T / mm; 3) Turbine length L T / mm; 4) Rotor shaft diameter d / mm;

[0140] (2) The main parameters of the floating ring bearing include:

[0141] 1) Length of floating ring bearing L F / mm; 2) Gap between inner and outer oil films of the floating ring bearing C i and C o / mm; 3) Lubricating oil viscosity m / pa.s; 4) Inner diameter of floating ring bearing R i / mm; 5) Outer diameter of floating ring bearing R o / mm; 6) Floating ring bearing quality m L / kg.

[0142] Step 6: Design the planetary gearbox based on the torque and maximum speed transmitted by the turbine rotor shaft;

[0143] The main parameters of the planetary gearbox are: (1) number of teeth, module, normal pressure angle, helix angle and tooth width of the sun gear, and pitch circle diameter of the sun gear. d f / mm, mass of the sun gear of the planetary gearbox m C / kg; (2) Number of planetary gears, number of teeth, module, normal pressure angle, helix angle and tooth width; (3) Number of teeth of the gear ring, module, normal pressure angle, helix angle and tooth width; (4) Mass of the connecting rod or planetary carrier.

[0144] Step 7: Use software such as TurboDyn (RotorDynamic) to establish a dynamic model of the second-stage turbine-turbine rotor shaft-floating ring bearing-planetary reducer sun gear rotor, calculate the critical speed, and optimize the relevant parameters.

[0145] Step 8: Use ADAMS multibody dynamics software to establish a dynamic model of the planetary gearbox sun gear-planet gear-ring gear-bearing system, complete vibration simulation, and optimize relevant parameters.

[0146] Step 9: Establish an electromagnetic model of the generator unit using MAXWELL software, simulate the motor characteristics, and predict the generator characteristics under different altitudes and vehicle operating conditions. Furthermore, use MAXWELL software to simulate the copper losses, stator and rotor iron losses, and permanent magnet eddy current losses that cause temperature rise in the motor windings under different speeds and plateau environments or altitude boundary conditions. Fit the relationship between motor winding temperature and motor output power. P Generator rotor angular velocity oh m Motor electromagnetic torque N e and altitude of the plateau H Parameter relationship surface:

[0147] T = T ( P , oh m , N e , H (19)

[0148] Step 10: Using a sliding mode control algorithm, determine the control law for the motor or turbine rotor shaft speed under different altitude conditions; and apply the control law to the second-stage turbine intake volume or the initial venting rate of the bypass valve determined in Step 4 through the controller to complete the control of motor speed and the venting rate of the second-stage turbine bypass valve.

[0149] The specific implementation process is as follows:

[0150] (1) Using the lumped mass method, a set of dynamic equations for the coupling of the second-stage turbine-turbine rotor shaft, gearbox, and motor rotor is established:

[0151] (20)

[0152] in:J T The moment of inertia of the second-stage turbine and rotor shaft; oh T This refers to the angular velocity of the second-stage turbine rotor shaft. N T The driving torque (i.e. turbine output power) applied to the exhaust gas from the first-stage turbocharger to the second-stage turbine. ( n , H ) is a function of the venting rate of the second-stage turbine bypass valve; N G This refers to the interaction torque between the planetary transmission and the rotor shaft of the second-stage supercharger turbine. C T The damping coefficient of the floating ring bearing for the second-stage turbine rotor shaft; C G This is the gyroscopic force coefficient of the second-stage turbine rotor shaft; J G The equivalent rotational inertia of the rotating components of the planetary gearbox; oh G This is the equivalent angular velocity of the planetary gearbox; C mesh is the damping coefficient of the meshing motion of the planetary gear transmission gears; J D The moment of inertia of the generator; oh m This refers to the angular velocity of the generator rotor. N D The driving torque applied to the generator by the planetary gearbox; N e For the electromagnetic torque of the motor, N e =1.5 p n P f i q , P f For permanent magnets, i q The stator current component on the quadrature axis, p n This represents the number of pole pairs of the motor. C D is the generator rotor rotation damping coefficient.

[0153] Turbine rotor shaft angular velocity oh T With the angular velocity of the generator rotor oh m There exists a definite transmission ratio relationship, that is

[0154] oh T = yes m (twenty one)

[0155] By using the mechanical energy equivalence method, the system of equations (20) can be equivalent to the following single-degree-of-freedom motion equations:

[0156] (twenty two)

[0157] (2) Sliding mode control rate:

[0158] First, the system speed error is designed according to the control target. From formula (21), it can be seen that the second-stage turbine rotor shaft angular velocity... oh T With the angular velocity of the generator rotor oh m There is a definite relationship between them. The target angular velocity of the turbine rotor shaft is set as follows: oh Td The output error is then

[0159] e = oh T - oh Td (twenty three)

[0160] In the formula: e This represents the output error.

[0161] To control the bleed rate or opening amount of the second-stage turbocharger bypass valve, the system input is designed as follows:

[0162] u = ( n , H )(twenty four)

[0163] Put the above formula u Substituting into equation (22), we obtain the system state equation:

[0164] (25)

[0165] The characteristics of the slip surface are designed as follows:

[0166] (26)

[0167] in: k 1. k 2 and β It is a constant, and β >0, s for.

[0168] The stability of the control system is determined by selecting the Lyapunov function, i.e.

[0169] (27)

[0170] (28)

[0171] because β Since the value is greater than 0, equation (28) clearly holds, satisfying the reachability condition for sliding mode control, and therefore the system is stable. From equations (25) and (26), the system input is derived. u That is, the control law of the second-stage turbine bypass valve actuator:

[0172] (29)

[0173] (3) Bypass valve venting rate:

[0174] The formula for the exhaust rate of the second-stage turbine bypass valve can be obtained from formula (28):

[0175]

[0176] In the formula:

[0177] H Represents altitude, 0≤ H ≤6km;

[0178] n Represents engine speed, 800 r / min ≤ n ≤2600r / min;

[0179] Indicates the bypass valve venting rate. .

[0180] Step 11: Complete the design of the axially or radially arranged generator and its vibration isolation device. This completes / realizes the design challenge of a turbomachinery-electrical coupling generator system based on exhaust gas turbine kinetic energy and applicable to different altitudes.

[0181] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An electromechanical coupling power generation device based on the kinetic energy of an engine exhaust turbine, characterized in that, The system includes a second-stage turbine, a second-stage turbine end regulating valve, a control module, a motor speed monitoring module, a generator unit, a motor vibration damping device, an overrunning clutch, a planetary gearbox, and floating ring bearings. The second-stage turbine connects to the exhaust port of the first-stage turbine on the engine, and the second-stage turbine end regulating valve is connected in parallel to both ends of the second-stage turbine. The turbine shaft rotor of the second-stage turbine is supported by floating ring bearings and connected to the planetary gearbox via an end spline. The planetary gearbox is connected to the generator unit via an overrunning clutch, and the generator unit is supported by the motor vibration damping device. The motor speed monitoring module is used to collect motor speed information; The control module is used to control the second-stage turbine bypass valve actuator and the second-stage turbine bypass valve based on the speed information, altitude data and vehicle driving conditions, and based on the preset control law of the second-stage turbine bypass valve actuator and the venting rate of the second-stage turbine bypass valve. The control module is used to control the actuator according to the control law u of the second-stage turbine bypass valve actuator; in, u For control laws; N T The driving torque applied to the second-stage turbine by the exhaust gas emitted from the first-stage turbocharger; J T The moment of inertia of the turbine-turbine shaft; J G The equivalent rotational inertia of the rotating components of the planetary gearbox; J D The moment of inertia of the generator; i This is the speed ratio between the second-stage turbine rotor shaft speed and the generator rotor speed; k 1. k 2 and β This is a preset constant; This represents the actual angular velocity of the second-stage turbine rotor shaft. ω Td The target angular velocity of the second-stage turbine rotor shaft; e The formula for calculating the generator rotor angular velocity error of the output control target system is as follows: ; C T is the damping coefficient of the floating ring bearing for the turbine rotor shaft; C G This refers to the gyroscopic torque coefficient of the turbine rotor shaft; C mesh is the damping coefficient of the meshing motion of the planetary gear transmission gears; C D is the rotor rotation damping coefficient of the motor.

2. A design method applicable to the electromechanical coupling power generation device based on engine exhaust turbine kinetic energy as described in claim 1, characterized in that, The specific steps include: A thermodynamic model of the engine was built using system simulation software; Obtain the relationship between engine exhaust flow rate and vehicle operating conditions at different altitudes, and calculate the relevant parameters of the first-stage turbine under different vehicle driving conditions based on the relationship; Based on the relevant parameters of the first-stage turbine, the second-stage turbine, floating ring bearing and planetary gearbox are designed. The control law for the second-stage turbine bypass valve actuator and the venting rate of the second-stage turbine bypass valve are preset in the control module. The design of the electromechanical coupling power generation device is completed by constructing a second-stage turbine, a second-stage turbine end regulating valve, the control module, a motor speed monitoring module, a generator unit, a motor vibration damping device, an overrunning clutch, the planetary gearbox, and the floating ring bearing.

3. The design method for an electromechanical coupling power generation device based on the kinetic energy of an engine exhaust turbine according to claim 2, characterized in that, The turbine rotor shaft and floating ring bearing are designed based on the power transmitted by the second-stage turbine and its maximum speed.

4. The design method for an electromechanical coupling power generation device based on the kinetic energy of an engine exhaust turbine according to claim 2, characterized in that, A planetary gearbox is designed based on the torque transmitted by the rotor shaft and its maximum speed.

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