Bladeless turbine with adjustable dynamic clearance

Abstract

The invention discloses a dynamic gap adjustable bladeless turbine, and particularly relates to a lightweight bladeless turbine which is adaptive to a vehicle-mounted wind energy recovery system and has a dynamic gap adjusting function. The invention aims to overcome the defects that a traditional blade-free turbine is large in efficiency fluctuation caused by a fixed gap, control lag is caused by low sensing precision, and the structure is heavy and cannot adapt to a vehicle-mounted scene. A main body part, a connecting part, a disc group, a sensing system and a gap adjusting system are arranged in a shell of the dynamic gap-adjustable bladeless turbine.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of turbine technology, more particularly to a dynamic gap adjustable bladeless turbine. Especially for the scene of vehicle-mounted bladeless turbine wind energy recovery system, it can effectively solve the problems of large efficiency fluctuation, heavy structure and poor overall adaptability of traditional fixed gap turbine. BACKGROUND

[0002] The bladeless turbine, also known as Tesla turbine, is driven by the viscous shear force between the discs. The disc gap is the core parameter that determines the energy conversion efficiency: when the gap is too small, the fluid friction resistance increases and the power loss is significant; when the gap is too large, the fluid leakage increases and the efficiency decreases significantly.

[0003] However, the existing technology has many key defects:

[0004] 1. Fixed gap cannot be adjusted: the mainstream technology uses copper alloy or rubber gasket to fix the gap, such as a certain existing patent which fixes the gap to a certain value, which cannot adapt to the flow fluctuation caused by vehicle speed change in vehicle-mounted scene. The flow difference can reach 3 times, and the efficiency fluctuation range is large ± 15%;

[0005] 2. Insufficient sensing accuracy: the accuracy of traditional temperature sensor is low, only ± 0.5℃, and the accuracy of speed sensor is poor, ± 10rpm, which cannot accurately capture the real-time changes of SMA gasket temperature and turbine speed, resulting in long control lag time over 100ms, further aggravating the efficiency fluctuation;

[0006] 3. Conflict between structural stability and lightweight: the discs are usually made of carbon fiber or alloy, with large parallelism deviation often exceeding 0.02mm, which is prone to vibration during operation, and the failure rate is high over 20% after long-term operation; the shell has poor heat dissipation performance, and the performance of SMA gasket decays quickly in high temperature environment; the existing adjustable gap technology such as a certain foreign patent uses servo motor to adjust, which has complex structure and large size, increasing the volume of traditional turbine by 40%, and cannot adapt to the lightweight demand of vehicle-mounted.

[0007] Therefore, it is urgent to design a dynamic gap adjustable bladeless turbine, which realizes real-time and accurate adjustment of disc gap through the synergistic effect of shape memory alloy SMA gasket, high-precision sensor and intelligent control system, and improves the efficiency stability and system response speed. SUMMARY

[0008] The present application provides a dynamic gap adjustable bladeless turbine to solve the problems in the prior art.

[0009] To achieve the above object, the embodiment of the present application provides a bladeless turbine with adjustable dynamic gap, comprising: a shell, the inside of which is coaxially assembled with a main body, a connecting part and a disc set, and is provided with a sensing system, a gap adjusting system and a control system;

[0010] The main body comprises a generator shaft, a stator coaxially sleeved on the generator shaft, permanent magnets, a rotor and a rotor support sequentially assembled along the axial direction of the generator shaft on both sides of the stator, and a bearing sleeved on the end portion;

[0011] The connecting part comprises a planetary bridge and a gear set, which are used for realizing power transmission between the main body and the disc set;

[0012] The disc set comprises a turbine shaft, a plurality of discs and SMA gaskets staggered along the axial direction of the turbine shaft, and the turbine shaft is positioned by a nut and a bearing at both ends; the SMA gasket is of an annular structure, the inner diameter of which is matched with the turbine shaft, and the outer diameter of which is matched with the disc;

[0013] The sensing system comprises a high-precision temperature sensor and a Hall-type rotating speed sensor; the temperature sensor has an accuracy of ±0.1℃ and a short response time, and is installed in the middle of the disc set; the rotating speed sensor has an accuracy of ±3rpm and a measurement range covering the normal working interval of the turbine, and is installed at the end of the generator shaft;

[0014] The gap adjusting system comprises a fuzzy PID controller, which is connected with the sensing system and realizes closed-loop control of the gap of the disc set based on temperature and rotating speed signals;

[0015] The control system comprises a high-performance microprocessor and an H-bridge driving circuit, the microprocessor runs an optimized fuzzy PID algorithm, outputs a PWM current to adjust the temperature of the SMA gasket, and realizes accurate control of the disc gap.

[0016] Preferably, the shell is provided with an air inlet corresponding to the position of the disc set, which is used for inputting working airflow to the disc set; the inside of the shell is further provided with an interface, which is used for assembling a fixed or externally connected pipeline.

[0017] Preferably, the SMA gasket is made of a nickel-titanium shape memory alloy, has a phase transition temperature interval of 40-80℃, and has a number N≥2, which is uniformly and interval distributed along the axial direction of the disc set.

[0018] Preferably, the parameters of the fuzzy PID controller are configured as follows: when the rotating speed deviation of the generator shaft is greater than 50rpm, the proportional coefficient Kp is 2.7; when the rotating speed deviation is less than or equal to 50rpm and the temperature of the SMA gasket is greater than 60℃, the proportional coefficient Kp is 2.3 and the integral time constant Ti is 0.8s.

[0019] Preferably, the control system outputs precise PWM current through the H-bridge drive circuit, adjusts the temperature of the SMA gasket based on the signals collected by the sensing system, and maintains the disc gap within the preset range, with a control error of ≤1.5%.

[0020] Preferably, after the cold and hot cycle test of the nickel-titanium SMA gasket under the extreme temperature of-40℃-120℃, the cumulative deformation attenuation rate is ≤3%.

[0021] Preferably, the algorithm parameters of the fuzzy PID controller range from: proportional coefficient Kp=2.3-2.7, integral time Ti=0.5s-1.2s, and differential time Td=0.1s-0.3s, with a sampling frequency of ≥100Hz.

[0022] Preferably, the control system has overheat protection and overload protection functions: when the temperature of the SMA gasket exceeds 80℃, the PWM current automatically decreases below the safety threshold; when the speed of the generator shaft exceeds the preset safety threshold, the controller outputs a stop signal.

[0023] Preferably, the coaxiality of the disc set is ≤0.02mm; the surface roughness Ra of the generator shaft is ≤0.8μm; and the wall thickness of the shell is 3-10mm, meeting the balance requirements of structural rigidity and light weight.

[0024] The application also includes a control method for the bladeless turbine, comprising the following steps:

[0025] S1: The sensing system collects the temperature signals of the SMA gasket and the speed signals of the generator shaft in real time at a frequency of ≥100Hz, and transmits them to the microprocessor;

[0026] S2: The microprocessor determines the working condition according to the speed signals, and outputs corresponding PWM current to adjust the disc gap: when the speed is higher than the preset high-speed threshold, a higher current is outputted to adjust the gap to a larger preset value; when the speed is in the preset medium-speed interval, a medium current is outputted to adjust the gap to a medium preset range; and when the speed is lower than the preset low-speed threshold, a lower current is outputted to adjust the gap to a smaller preset value; the high-speed threshold, medium-speed interval, and low-speed threshold are preset according to the rated working parameters of the turbine.

[0027] S3: The microprocessor monitors the temperature of the SMA gasket in real time, and automatically reduces the current below the safety threshold if the temperature exceeds 80℃ to prevent overheating of the SMA gasket; and S4: The microprocessor calculates the actual disc gap based on the speed and temperature signals, compares it with the target gap, and corrects the PWM current output through the fuzzy PID algorithm to make the control error ≤1.5%.

[0028] Compared with the prior art, the application has the following advantages:

[0029] 1. Efficiency stability significantly improved: In the common vehicle speed range of 50-180km / h, the energy conversion efficiency can be stabilized at a high level, with a fluctuation range controlled within ±2%, which is significantly better than the traditional fixed-gap turbine with a fluctuation range of ±5%, meeting the core requirements of "high efficiency and stability" for vehicle-mounted wind energy recovery;

[0030] 2. Fast response speed: The gap adjustment response time is extremely short, which is significantly improved compared to the traditional servo motor adjustment of >150ms, and can adapt to sudden changes in vehicle speed such as sudden acceleration and sudden deceleration in real time;

[0031] 3. Compact and lightweight structure: Lightweight materials such as aluminum alloy shell and titanium alloy disc are used, which significantly reduces the overall weight compared to traditional steel shell turbines, and the installation size meets the space limitations of vehicle-mounted space and can be adapted to the front bumper or grille area;

[0032] 4. Strong long-term stability: After the SMA gasket is subjected to multiple cold and hot cycle simulations of vehicle-mounted high and low temperature environments, the deformation attenuation is extremely small; the disc parallelism deviation is controlled within a very small range, and there is no vibration failure after 2000 hours of continuous operation, reducing the failure rate to a low level;

[0033] 5. Intelligent protection is perfect: It has overheat protection, flow reduction when the temperature is too high, overload protection, shutdown when the speed is too high, sensor fault tolerance, and backup algorithm function when a single sensor fails, improving the operation reliability in complex working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, a brief introduction will be given below to the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and those skilled in the art can obtain other drawings according to the provided drawings without creating any inventive labor.

[0035] Fig. 1 The drawing is an exploded view of the present application.

[0036] Fig. 2 The drawing is a sectional view of the present application.

[0037] Fig. 3 The drawing is a schematic diagram of the disc set structure of the present application.

[0038] Reference signs: 1, rotor support; 2, permanent magnet; 3, stator; 4, air inlet; 5, rotor; 6, generator shaft; 7, gear set; 8, main body; 9, disc set; 10, connecting part; 11, planetary bridge; 12, turbine shaft; 13, disc; 16, SMA gasket; 17, shell; 20, interface. DETAILED DESCRIPTION

[0039] In the description of the present patent, it needs to be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present patent.

[0040] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present patent, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0041] In the present patent, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; 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; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present patent can be understood according to the specific circumstances.

[0042] Please refer to the drawings Figs. 1-3 A dynamic gap adjustable bladeless turbine is disclosed in the present application, which adopts a highly integrated design, and the core structure is entirely contained in a complete shell 17. The shell 17 serves as the support and protection body of the entire device, and its internal space is reasonably planned into three functional areas: the main body part 8, the connecting part 10 and the turbine working area where the disc set 9 is located. The inner diameter and length of the shell 17 are accurately calculated to adapt to the overall size of the disc set 9 and the generator shaft 6; its wall thickness is analyzed and optimized through simulation, meeting the structural rigidity requirements while considering the lightweight design goal. In terms of material selection, the shell 17 adopts high-strength aluminum alloy and is subjected to heat treatment and surface anodizing treatment, so that it has a relatively high heat dissipation coefficient, thereby providing reliable structural protection and support for the equipment, while ensuring good heat dissipation performance.

[0043] The generator shaft 6 is the core component of the power output, which bears the important torque transmission function. The stator 3 is fixedly sleeved on the generator shaft 6, and the permanent magnet 2 and the rotor 5 are arranged on both sides of the stator 3, respectively. The end is sleeved with a bearing, and the whole rotor assembly is stably supported by the rotor support 1. This design constitutes a compact permanent magnet generator, which can efficiently convert mechanical energy into electrical energy.

[0044] The turbine shaft 12 is a key component of the rotating system, and its diameter is set to a reasonable size to meet the structural rigidity, and its length is adapted to the overall layout of the disc set 9 and the shell 17. The turbine shaft 12 is made of high-strength alloy material, and is subjected to quenching and tempering treatment to improve its fatigue resistance, and the surface is subjected to chrome plating treatment to enhance the wear resistance, thereby providing stable rotating support for the equipment and ensuring the reliability and durability of long-term operation.

[0045] The connecting part 10 is an important hub of power transmission, which contains necessary bearings, a planetary bridge 11 and a set of gear sets 7. The connecting part 10 contains a set of high-precision angular contact ball bearings, a planetary bridge 11 and a set of multi-stage gear sets 7, which together constitute a power transmission chain. The planetary bridge 11 is fixedly connected to the end of the turbine shaft 12 through spline or interference fit, and receives high-speed rotating power. The input stage of the gear set 7 is linked with the planetary bridge 11, and the output stage is connected with the generator shaft 6, so as to realize the power transmission of speed reduction and torque increase. The gear set 7 contains sun gear, planetary gear and ring gear which are meshed with each other, and the power is transmitted to the generator shaft 6 after speed reduction and torque increase, so as to realize the speed matching and efficient power coupling between the main part 8 and the disc set 9.

[0046] The disc set 9 is a core functional module for realizing wind energy capture and conversion, which includes a turbine shaft 12, on which a plurality of discs 13 and SMA gaskets 16 are installed in an interleaved manner. The SMA gasket 16 is designed as an annular structure, and its inner diameter and outer diameter are accurately calculated to match the sizes of the turbine shaft 12 and the disc 13, respectively. The two ends of the turbine shaft 12 are supported on the shell 17 through bearings, and are axially locked by nuts, thereby forming a complete rotor system.

[0047] Specifically, the disc set 9 is composed of N pieces of carbon fiber or alloy discs 13 and multiple SMA gaskets 16 which are alternately stacked. The diameter and thickness of the disc 13 are adapted to the power demand of the turbine, and the parallelism deviation is controlled within a very small range. The disc 13 is made of high-performance titanium alloy material, which is forged and precisely milled, and the surface is subjected to anodic oxidation treatment to improve wear resistance, so as to realize effective fluid viscous shear driving, while having the characteristics of light weight and high wear resistance. Its excellent parallelism helps to reduce system vibration.

[0048] The SMA gasket 16 adopts a ring structure, the inner diameter and the outer diameter of which match the sizes of the generator shaft 6 and the disc set 13 respectively, and the thickness is set to a reasonable value suitable for the clearance adjustment requirement. The SMA gasket 16 is made of a nickel-titanium shape memory alloy, and is subjected to rolling, laser cutting and vacuum annealing treatment, and the phase transition temperature interval thereof is set within a range suitable for the vehicle working condition, so that the SMA gasket 16 can realize dynamic adjustment of the clearance through temperature driving, and ensure the stability and sufficient deformation amount of the phase transition process.

[0049] In order to realize intelligent clearance adjustment, the device is equipped with a high-precision sensing system. The system includes a temperature sensor with an accuracy of ±0.1°C and an extremely short response time, which is directly installed in the middle of the disc set for accurately monitoring the working temperature of the SMA gasket 16. At the same time, a Hall type speed sensor with an accuracy of ±3 rpm is installed at the end of the turbine shaft 12 for real-time monitoring of the running speed of the system, and the measurement range completely covers the normal working interval of the turbine.

[0050] The clearance adjustment system is based on the above-mentioned sensing system and is composed of a fuzzy PID controller. The fuzzy PID controller is connected with the sensor signal to form a closed-loop control system. In a preferred embodiment, the control rule of the fuzzy PID controller is as follows: when the deviation of the monitored turbine speed from the target value is greater than 50 rpm, the proportional coefficient of the controller is 2.7; when the speed deviation is less than or equal to 50 rpm and the temperature of the SMA gasket 16 is higher than 60°C, the proportional coefficient is 2.3, and the integral time constant is 0.8 seconds. This control strategy effectively ensures that the clearance adjustment process of the disc set 9 has both rapid response and running stability.

[0051] The control system is realized by high-performance microprocessors and H-bridge driving circuit hardware. The microprocessor runs an optimized fuzzy PID algorithm inside, which is based on the temperature and speed signals collected by the sensing system in real time, and outputs precise PWM pulse width modulation current. The current is used to adjust the temperature of the SMA gasket 16, and then changes the thickness of the SMA gasket 16 by using the shape memory effect of SMA material, finally realizes the accurate and closed-loop control of the clearance between the discs 13 within the preset range, and stabilizes the control error at ≤1.5%.

[0052] In the specific control process, the signal acquisition system collects temperature and speed signals at a frequency of 100 Hz and transmits them to the microprocessor. The system executes corresponding control strategies according to different speed working conditions:

[0053] When the speed is greater than 3000 rpm, output 3A-5A current, heat the SMA pad 16 to 60-80℃, make it produce 0.8-1mm deformation, so as to adjust the gap to 0.8-1mm;

[0054] When the speed is 1500-3000 rpm, output 1.5A-3A current, temperature control at 40-60℃, deformation 0.3-0.8mm, gap adjustment 0.5-0.8mm;

[0055] When the speed is less than 1500 rpm, output 0.5A-1.5A current, temperature maintained at 40-50℃, deformation 0.2-0.3mm, gap adjustment 0.2-0.5mm;

[0056] When the temperature of the SMA pad 16 is detected to be greater than 80℃, the system automatically reduces the current to 0.5A to prevent performance degradation due to overheating of the material.

[0057] The parameters of the fuzzy PID controller are experimentally set, the proportional coefficient is 2.3-2.7, the integral time constant is 0.5-1.2s, and the differential time constant is 0.1-0.3s, and the finally realized gap control error is less than or equal to ±0.02mm.

[0058] The temperature sensor probe is small in size to fit into the limited installation space, and its measurement range covers the phase transition temperature range of the SMA pad 16. The sensor uses high-precision platinum resistance and has very short response time. It is fixed by threads in the middle of the disc set 9 and can accurately and real-time monitor the temperature of the SMA pad 16, providing reliable temperature feedback for the control system. The measurement range of the speed sensor covers the speed range of the turbine in normal operation, and its output signal is suitable for the sampling requirements of the microprocessor. The sensor uses Hall principle and is installed at the end of the generator shaft 6. The sampling frequency meets the real-time monitoring requirements and can accurately and real-time monitor the turbine speed, providing accurate speed feedback for system condition judgment. The main frequency of the controller meets the high-performance processing requirements, and the built-in fuzzy PID algorithm is optimized. The system uses high-performance microprocessors and is equipped with H-bridge driving circuit. Its output current range covers the heating requirements of the SMA pad 16, realizes closed-loop control of the entire gap adjustment process, adjusts the temperature of the SMA pad 16 by outputting accurate current, and ensures the accuracy of gap adjustment.

[0059] To further improve the function, a special air inlet 4 is provided on the shell 17 outside the disc set 9 for guiding airflow into the turbine. The shell 17 also integrates an electrical interface 20 inside for easy connection with external circuits.

[0060] The material of the SMA gasket 16 is preferably a nickel-titanium shape memory alloy, and its phase transition temperature range is set between 40°C and 80°C, which can well adapt to the working temperature of the vehicle environment. The number of the gaskets is N, which is uniformly distributed along the axial direction of the disc set 9 to ensure the uniformity and stability of the gap adjustment. Through multiple cold and hot cycle tests simulating the extreme temperature of the vehicle, the deformation of the nickel-titanium SMA gasket 16 is very small, which shows excellent fatigue life and long-term working stability.

[0061] The algorithm parameters of the fuzzy PID controller are set through experiments, and the core parameter range is: proportional coefficient 2.3-2.7, integral coefficient 0.7-0.9, and differential coefficient 0.25-0.35. The system performs signal acquisition and control operation at a sampling frequency of not less than 100Hz, ensuring the real-time and accuracy of the control.

[0062] The control system also integrates perfect protection functions, including overheat protection and overload protection. When the system detects that the temperature of the SMA gasket 16 exceeds 80°C, the heating current will be automatically reduced to the minimum level to prevent the material from failing due to overheating; when the rotating speed of the turbine shaft 12 exceeds the preset safety threshold, the controller will immediately output a shutdown signal to protect the entire device from damage.

[0063] In terms of manufacturing precision, the overall coaxiality of the disc set 9 is strictly controlled to be ≤0.02mm, and the surface of the generator shaft 6 is finished with a low roughness. The wall thickness of the housing 17 is simulated and optimized to a reasonable value that can balance the structural rigidity and lightweight design requirements.

[0064] Based on the above device, the control method specifically includes the following steps:

[0065] Step S1: The sensing system collects the temperature of the SMA gasket 16 and the rotating speed signal of the generator shaft 6 in real time at a frequency of not less than 100Hz, and transmits them to the microprocessor immediately.

[0066] Step S2: The microprocessor determines the current working condition according to the received real-time rotating speed signal. If the rotating speed is higher than the preset high-speed threshold, a higher current is output to adjust the disc gap 13 to a larger preset value; if the rotating speed is in the preset medium-speed range, a medium current is output to adjust the gap to a medium preset range; if the rotating speed is lower than the preset low-speed threshold, a lower current is output to adjust the gap to a smaller preset value.

[0067] Step S3: The microprocessor continuously monitors the temperature of the SMA pad 16 in real time while adjusting the gap. Once the temperature is detected to exceed 80℃, the current is automatically reduced to the minimum level to prevent the performance degradation of the SMA pad 16 due to overheating.

[0068] Step S4: Dynamic correction of current output is performed by a fuzzy PID algorithm. The algorithm calculates the current approximate actual gap based on real-time speed and temperature, compares it with the target gap, and finally stabilizes the overall control error of the system within ≤1.5%.

[0069] Manufacturing and assembly process:

[0070] 1. Disc 13 manufacturing: Titanium alloy ingot is forged at high temperature, then milled into a disc of predetermined size, processed to a small parallelism deviation ≤0.01mm by high-precision double-sided grinding machine, and finally anodized to form an oxide film of predetermined thickness to improve wear resistance.

[0071] 2. SMA pad 16 processing: SMA alloy bar stock is rolled into a sheet of predetermined thickness, laser cut into a ring-shaped pad, and annealed in a vacuum annealing furnace to eliminate internal stress. The phase transition temperature range is tested to ensure compliance with design requirements.

[0072] 3. Generator shaft 6 processing: High-strength alloy bar stock is quenched and tempered after heat treatment, then numerically controlled turned into a generator shaft 6 of predetermined size, chrome plated to improve wear resistance, and the surface roughness is reduced to a low level.

[0073] 4. Housing 17 processing: Aluminum alloy sheet is heat treated by solid solution and aging, then pressure cast into a housing blank, numerically controlled milled to a predetermined size, and surface anodized to improve heat dissipation performance and corrosion resistance. The heat dissipation coefficient is tested to ensure that it meets the design requirements.

[0074] 5. Assembly and debugging:

[0075] ① Assembly: High-precision angular contact ball bearings are press-fitted on both ends of the turbine shaft 12 and fixed in the bearing seats of the housing 17.

[0076] ② Disc set 9 assembly: Discs 13 and SMA pads are alternately stacked and fitted on the turbine shaft 12, ensuring that the disc coaxiality is controlled within ≤0.02mm.

[0077] ③ Sensor installation: The temperature sensor is fixed by threads in the middle of the disc set 9, and the speed sensor is installed by a bracket at the end of the turbine shaft 12, ensuring accurate installation position.

[0078] (4) Control system integration: The microprocessor and H-bridge drive circuit are integrated on the control board. The sensor and SMA heating loop are connected through wires. The control logic is debugged to ensure that the gap adjustment response time is less than or equal to 70 ms.

[0079] 6. Performance test

[0080] Medium speed test in the drum test bench: Under the condition of simulating medium speed in the inlet wind speed, the turbine speed reaches the preset range, the controller outputs medium current, the SMA temperature enters the phase change intermediate interval, the disc gap is adjusted to the intermediate preset value, the system energy conversion efficiency reaches a high level, and the pressure loss is controlled in a small range.

[0081] High and low temperature cycle test: After simulating the vehicle extreme temperature environment and multiple high and low temperature cycle tests, the deformation of the SMA gasket 16 is small, and the friction coefficient changes little.

[0082] Continuous running durability test: Under the condition of medium speed for more than 2000 hours, the system gap deviation is small, the efficiency is stable, and no vibration, abnormal sound and other faults occur.

[0083] Sudden acceleration test: The vehicle speed rises from low speed to medium and high speed in a short time, the turbine speed is quickly increased, the controller completes current adjustment in a very short time, and the gap is quickly adjusted from a small value to an intermediate value. The system efficiency fluctuation range is very small.

[0084] 7. Comparison experiment with traditional fixed gap turbine and existing adjustable gap product

[0085] Under the same test conditions, different vehicle speeds and environmental temperatures are covered. The core performance indicators of the product of the application and the traditional fixed gap turbine and the existing adjustable gap product such as servo motor adjustment type are compared as follows:

[0086] 1. Efficiency: The average efficiency of the application in the whole vehicle speed range is obviously improved compared with the traditional product, and has certain advantages over the existing adjustable product;

[0087] 2. Efficiency fluctuation: The efficiency fluctuation range of the application is much smaller than that of the traditional product and the existing adjustable product;

[0088] 3. Response time: The gap adjustment response time of the application is much faster than that of the existing adjustable product, and the traditional product has no adjustment function;

[0089] 4. Weight: The overall weight of the application is much lighter than that of the traditional product, and has obvious advantages over the existing adjustable product;

[0090] 5. Long-term stability: The deformation attenuation and failure rate of the application after multiple thermal cycles are much lower than those of the existing adjustable product, and the vibration failure rate of the traditional product is high.

[0091] The application discloses a dynamic gap adjustable bladeless turbine based on shape memory alloy (SMA), through integrated design of "high-precision sensing + intelligent closed-loop control + SMA driving", precise and rapid adjustment of disc disc gap in a preset range is realized, common vehicle speed range is adapted, energy conversion efficiency is improved to a high level, and meanwhile, compact structure and light weight are ensured.

[0092] The various embodiments are described in the specification by way of progression, each building on the last to facilitate ease of understanding. Likewise, the same reference numerals are used throughout the drawings and specification and denote like features and steps. The drawings are kept to a minimum and are for purposes of clarity only.

[0093] The foregoing description of the disclosed embodiments enables one skilled in the art to accomplish or use the present application. Numerous modifications to these embodiments can be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not to be limited to the implementations described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bladeless turbine with dynamically adjustable clearance, characterized in that, include: The housing 17 contains a main body 8, a connecting part 10, and a disc assembly 9 coaxially assembled inside, and is equipped with a sensing system, a gap adjustment system, and a control system. The main body 8 includes a generator shaft 6, on which a stator 3 is coaxially mounted. Permanent magnets 2, rotors 5 and rotor supports 1 are sequentially assembled on both sides of the stator 3 along the axial direction of the generator shaft 6, and bearings are sleeved at the ends. The connecting part 10 includes a planetary bridge 11 and a gear set 7, which are used to realize the power transmission between the main body 8 and the disc assembly 9. The disc assembly 9 includes a turbine shaft 12, on which a plurality of discs 13 and SMA gaskets 16 are arranged axially in a staggered manner. The two ends of the turbine shaft 12 are positioned by nuts and bearings. The SMA gasket 16 has an annular structure, with its inner diameter adapted to the turbine shaft 12 and its outer diameter adapted to the discs 13. The sensing system includes a high-precision temperature sensor and a Hall-effect speed sensor; the temperature sensor has an accuracy of ±0.1℃ and a short response time, and is installed in the middle of the disc group 9; the speed sensor has an accuracy of ±3rpm, and its measurement range covers the normal operating range of the turbine, and is installed at the end of the generator shaft 6. The gap adjustment system includes a fuzzy PID controller, which is connected to the sensor system and realizes closed-loop control of the gap of the disc group 9 based on temperature and speed signals. The control system includes a high-performance microprocessor and an H-bridge drive circuit. The microprocessor runs an optimized fuzzy PID algorithm and outputs PWM current to adjust the temperature of the SMA pad 16, thereby achieving precise control of the gap between the discs 13.

2. The bladeless turbine with dynamically adjustable clearance according to claim 1, characterized in that, The housing 17 has an air inlet 4 at the position corresponding to the disc assembly 9, which is used to input working airflow into the disc assembly 9; the housing 17 also has an interface 20 inside, which is used for assembling and fixing or external piping.

3. The bladeless turbine with dynamically adjustable clearance according to claim 1, characterized in that, The SMA gasket 16 is made of nickel-titanium shape memory alloy, with a phase transition temperature range of 40℃-80℃, and the quantity N≥2, which are evenly distributed along the axial direction of the disc group 9.

4. The bladeless turbine with dynamically adjustable clearance according to claim 1, characterized in that, The parameters of the fuzzy PID controller are configured as follows: when the speed deviation of generator shaft 6 is >50rpm, the proportional coefficient Kp is 2.7; when the speed deviation is ≤50rpm and the temperature of SMA gasket 16 is >60℃, the proportional coefficient Kp is 2.3 and the integral time constant Ti is 0.8s.

5. The bladeless turbine with dynamically adjustable clearance according to claim 1, characterized in that, The control system outputs a precise PWM current through the H-bridge drive circuit and adjusts the temperature of the SMA pad 16 based on the signal collected by the sensor system, so that the gap of the disc 13 is maintained within a preset range and the control error is ≤1.5%.

6. The bladeless turbine with dynamically adjustable clearance according to claim 3, characterized in that, After undergoing a thermal cycling test at extreme vehicle temperatures of -40℃ to 120℃, the cumulative deformation attenuation rate of the nickel-titanium SMA gasket 16 is ≤3%.

7. The bladeless turbine with dynamically adjustable clearance according to claim 4, characterized in that, The algorithm parameters of the fuzzy PID controller are: proportional coefficient Kp = 2.3-2.7, integral time Ti = 0.5s-1.2s, derivative time Td = 0.1s-0.3s, and sampling frequency ≥ 100Hz.

8. The bladeless turbine with dynamically adjustable clearance according to claim 1, characterized in that, The control system has overheat protection and overload protection functions: when the temperature of SMA gasket 16 exceeds 80°C, the PWM current automatically drops below the safety threshold; when the speed of generator shaft 6 exceeds the preset safety threshold, the controller outputs a shutdown signal.

9. The bladeless turbine with dynamically adjustable clearance according to claim 1, characterized in that, The coaxiality of the disc assembly 9 is ≤0.02mm; the surface roughness Ra of the generator shaft 6 is ≤0.8μm; and the wall thickness of the housing 17 is 3-10mm, satisfying the requirements for balancing structural rigidity and lightweight design.

10. The control method for a bladeless turbine according to any one of claims 1-9, characterized in that, Includes the following steps: S1: The sensing system acquires the temperature signal of the SMA gasket 16 and the speed signal of the generator shaft 6 in real time at a frequency of ≥100Hz and transmits them to the microprocessor. S2: The microprocessor determines the operating condition based on the speed signal and outputs a corresponding PWM current to adjust the gap of disc 13: When the speed is higher than the preset high-speed threshold, a higher current is output to adjust the gap to a larger preset value. When the rotational speed is within the preset medium speed range, a medium current is output, and the gap is adjusted to the middle preset range; when the rotational speed is below the preset low speed threshold, a lower current is output, and the gap is adjusted to a smaller preset value; the high speed threshold, medium speed range, and low speed threshold are preset according to the rated operating parameters of the turbine. S3: The microprocessor monitors the temperature of the SMA gasket 16 in real time. If the temperature exceeds 80°C, it automatically reduces the current to below the safe threshold to prevent the SMA gasket 16 from overheating. S4: The microprocessor calculates the actual disc gap based on the rotation speed and temperature signals. After comparing it with the target gap, it corrects the PWM current output through a fuzzy PID algorithm to make the control error ≤1.5%.

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