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CN-122015555-A - Rotary braking energy recovery device based on magnetocaloric effect and use method

CN122015555ACN 122015555 ACN122015555 ACN 122015555ACN-122015555-A

Abstract

A rotary braking energy recovery device based on a magnetocaloric effect and a use method thereof are integrated in a vehicle brake disc assembly. The device comprises an external composite shell, a magnetic excitation unit, an internal energy conversion and medium management module and an axle center fluid conveying assembly. The permanent magnet rotating along with the brake disc generates a periodically moving magnetic field to make the inner magnetocaloric material layer generate a magnetocaloric effect, the Novec low boiling point fluorinated liquid in the sealing cavity is heated together with the braking friction heat to be evaporated into a gas-liquid two-phase flow, the gas-liquid separation is realized through the centrifugal force and the Coriolis guide blade, the gas phase is led out to the external heat exchange system through the central converging flow passage by the axis pipeline to recover heat energy, the condensed liquid flows back to the inside of the device and is precooled by the magnetic material in the demagnetizing and heat absorbing stage, and the cycle is completed. The invention does not need external energy, has compact structure, can efficiently recycle the middle-low temperature braking waste heat, and is suitable for a new energy automobile thermal management system.

Inventors

  • Su huashan
  • WANG SHIYU
  • Han Xuding
  • YU WAN
  • WANG GANG
  • HU TAO

Assignees

  • 三峡大学

Dates

Publication Date
20260512
Application Date
20260128

Claims (10)

  1. 1. The rotary braking energy recovery device based on the magnetocaloric effect is characterized by being integrated in a vehicle brake disc assembly and synchronously rotating along with wheels, and comprises the following functional modules: An outer composite shell (1) which forms a bearing framework and a sealing shell of the device; The magnetic excitation unit (2) is fixedly arranged on the outer composite shell (1) and is used for generating a moving magnetic field which periodically sweeps the inner area in the rotating process; The internal energy conversion and medium management module (3) is coaxially packaged in the external composite shell (1), is internally filled with Novec type fluorinated liquid with low boiling point in a sealing way, is provided with a porous structure containing a magnetic working medium, is used for generating a magneto-caloric effect under the action of the moving magnetic field, and is used for driving the working medium to change phase in cooperation with braking friction heat; And the axle center fluid conveying assembly (4) penetrates through the rotating axle center of the device, one end of the axle center fluid conveying assembly is respectively communicated with the gas phase outlet and the liquid phase inlet of the internal energy conversion and medium management module (3), and the other end of the axle center fluid conveying assembly is connected to an external circulation system through a rotary joint and is used for guiding out high-temperature high-pressure gaseous working media and reinjecting the condensed liquid working media.
  2. 2. The rotary braking energy recovery device based on the magnetocaloric effect according to claim 1, wherein the outer composite housing (1) comprises an upper heat dissipation layer (G1) and a lower heat dissipation layer (G2) which are arranged up and down symmetrically, and each layer surface is provided with heat dissipation fins and turbulence columns extending along non-orthogonal directions for enhancing forced convection heat dissipation during rotation.
  3. 3. A rotational braking energy recovery device based on the magnetocaloric effect according to claim 1, characterized in that the magnetic excitation unit (2) comprises two sector-shaped high-performance permanent magnets (21) respectively fixed to the upper and lower outer surfaces of the outer composite casing (1), whose poles are alternately arranged along the circumferential direction so as to form a continuously swept high-intensity pulsating magnetic field when rotating.
  4. 4. The rotary braking energy recovery device based on the magnetocaloric effect according to claim 1, wherein the internal energy conversion and medium management module (3) is sequentially composed of five concentric functional layers from outside to inside, namely an upper magnetocaloric material layer (G31), an upper gas-liquid separation and diversion layer (G32), a central gas convergence layer (G33), a lower gas-liquid separation and diversion layer (G34) and a lower magnetocaloric material layer (G35), wherein the upper magnetocaloric material layer (G31) and the lower magnetocaloric material layer (G35) are in mirror symmetry.
  5. 5. The rotary braking energy recovery device based on the magnetocaloric effect according to claim 4, wherein the upper magnetocaloric material layer (G31) and the lower magnetocaloric material layer (G35) are both metal or ceramic honeycomb porous substrates with 60% -80% of porosity, and gadolinium-based or lanthanum-iron-silicon series giant magnetocaloric effect alloy particles are filled in the pores.
  6. 6. The rotary braking energy recovery device based on the magnetocaloric effect according to claim 4, wherein the upper layer gas-liquid separation and diversion layer (G32) and the lower layer gas-liquid separation and diversion layer (G34) are respectively provided with an upper coriolis force guide vane (321) and a lower coriolis force guide vane (341), and the curved surfaces thereof are optimized by computational fluid dynamics and are used for superposing coriolis forces on the basis of centrifugal force to realize efficient directional separation of gas-liquid two-phase flow.
  7. 7. The rotary braking energy recovery device based on the magnetocaloric effect according to claim 4, wherein a centripetal converging gas flow channel (331) is arranged in the central gas convergence layer (G33), and the molded surface is a logarithmic spiral surface for efficiently converting the kinetic energy of the tangentially flowing gaseous working medium into the static pressure energy and guiding the static pressure energy to the axial center.
  8. 8. The rotary braking energy recovery device based on the magnetocaloric effect according to claim 1, wherein the axial fluid conveying assembly (4) comprises a central gas output main pipe (41) and a plurality of liquid reflux auxiliary pipes (42), the central gas output main pipe (41) is communicated with a central gas convergence layer (G33) and used for guiding out gaseous Novec fluoride liquid, and the liquid reflux auxiliary pipes (42) are respectively communicated with an upper gas-liquid separation layer, a lower gas-liquid separation layer and a diversion layer and used for reinjection of condensate liquid.
  9. 9. The rotary braking energy recovery device based on the magnetocaloric effect according to claim 1, wherein the Novec fluorinated liquid is a fluorinated ketone or fluorinated ether working medium with a standard boiling point between 40 ℃ and 90 ℃ and is suitable for medium and low-temperature heat energy recovery situations.
  10. 10. The method of using a rotary braking energy recovery device based on the magnetocaloric effect according to any of the claims 1-9, characterized in that it comprises the following steps: s1, activating a cooperative heat source, namely generating heat by friction of a brake disc when a vehicle brakes, and enabling a magnetic working medium to periodically undergo excitation and demagnetization by rotating a magnetic excitation unit along with a device; s2, evaporating the working medium, namely quickly vaporizing the heated liquid working medium in honeycomb pores to form a high-temperature high-pressure gas-liquid two-phase mixed flow; S3, centrifugally driving primary separation, namely enabling the two-phase flow to outwards move under the action of centrifugal force generated by high-speed rotation, then enabling the two-phase flow to enter a gas-liquid separation and diversion layer, enabling the gas phase to deflect towards the axis under the guidance of a Coriolis force guide blade, and enabling the liquid phase to maintain peripheral distribution; S4, gas phase convergence and output, namely enabling the separated gaseous working medium to pass through the diversion holes and enter the central gas convergence layer, accelerating centripetal convergence through the logarithmic spiral flow channels, and guiding out the separated gaseous working medium to an external heat exchange system through a central gas output main pipeline; s5, external condensation and pressurization, namely releasing heat from the led-out steam in an external condenser, converting the heat into low-temperature low-pressure liquid, and lifting the pressure by a booster pump; S6, liquid phase reflux and redistribution, namely injecting the pressurized liquid working medium into an upper gas-liquid separation and diversion layer and a lower gas-liquid separation and diversion layer through a liquid reflux auxiliary pipeline, throwing the liquid working medium towards the periphery again under the action of centrifugal force, and infiltrating the pores of the magnetocaloric material layer; s7, working medium precooling, namely performing heat exchange between the reflux liquid and the magnetic working medium in a demagnetizing and heat absorbing stage, and further cooling to provide low-temperature storage for the next evaporation cycle; s8, heat energy cascade utilization, namely, an external system respectively uses the heat energy recovered in the condensation process for motor preheating, passenger cabin heating or battery pack heat preservation according to the temperature grade, so that high-efficiency recovery and multistage utilization of braking heat energy are realized.

Description

Rotary braking energy recovery device based on magnetocaloric effect and use method Technical Field The invention belongs to the technical field of energy recovery, and particularly relates to a rotary braking energy recovery device based on a magnetocaloric effect and a use method thereof. Background For the recovery of braking heat energy, in recent years, research is attempted to introduce a Phase Change Material (PCM) or a heat pipe technology for heat buffering and export, but such passive schemes only realize heat transfer, and are difficult to realize active extraction and reuse of energy. Another type of active heat recovery system (such as an organic rankine cycle, ORC) can convert waste heat into mechanical or electrical energy, but is complex, bulky, and has a delayed response, and requires additional pumping work and control units, which are difficult to integrate in a hub braking area with limited space and high dynamic response requirements. Meanwhile, the magnetocaloric effect (Magnetocaloric Effect, MCE) is used as a solid-state refrigeration/heating technology, and has great potential in the field of thermal management due to the advantages of high energy efficiency, no moving parts, environmental friendliness and the like. The giant magneto-thermal material (such as Gd-based and La-Fe-Si alloy) can generate remarkable temperature change when a magnetic field is applied or removed, and if the giant magneto-thermal material is combined with a rotary machine, the giant magneto-thermal material is hopeful to realize active heating and cooling of working media by utilizing the periodical magnetic field change generated by the rotary motion under the condition of no external driving. However, the existing magnetocaloric device is mostly used in static refrigeration scenes, and the integrated design of deeply fusing the magnetocaloric device with a vehicle braking system and utilizing the braking friction heat and the magnetocaloric effect to cooperatively drive the working medium to change phase so as to realize energy recovery is not seen. In addition, novecTM fluorinated liquids (such as 3MTM novec (TM) 649 and 7000 series) are used as novel environment-friendly working media, and have the characteristics of incombustibility, low toxicity, low global warming potential (GWP < 1), moderate boiling point (40-90 ℃) and good thermal stability, and are particularly suitable for medium-low temperature heat energy recovery systems. However, in the brake disc environment with high-speed rotation, strong vibration and strict sealing requirements, the phase change process of the magnetic heating effect, friction heat and low-boiling point working medium is efficiently coupled, and the integration of gas-liquid separation, fluid delivery and heat energy output is realized, so that the technology is still blank. In view of the foregoing, there is a need for an energy recovery device that is compact in structure, fast in response, does not require external energy input, and can be highly integrated with a vehicle braking system, so that not only can frictional heat generated in a braking process be effectively captured, but also a rotational motion can be utilized to excite a magnetocaloric effect, and an environment-friendly working medium is cooperatively driven to change phase, thereby realizing efficient extraction, transportation and cascade utilization of braking heat energy. Disclosure of Invention The invention aims to solve the technical problem of providing a rotary braking energy recovery device based on a magnetocaloric effect and a use method thereof. In order to solve the technical problems, the invention adopts the following technical scheme: the utility model provides a rotatory braking energy recuperation device based on magnetocaloric effect, this device is integrated in vehicle brake disc assembly and rotates along with the wheel is synchronous, includes following functional module: An external composite shell, which forms a bearing framework and a sealing shell of the device; the magnetic excitation unit is fixedly arranged on the outer composite shell and is used for generating a moving magnetic field which periodically sweeps the inner area in the rotating process; The internal energy conversion and medium management module is coaxially packaged in the external composite shell, is internally filled with Novec type fluorinated liquid with low boiling point in a sealing way, is provided with a porous structure containing a magnetic working medium, is used for generating a magneto-caloric effect under the action of the moving magnetic field, and is used for driving the working medium to change phase in cooperation with braking friction heat; And the axis fluid conveying assembly penetrates through the rotating axis of the device, one end of the axis fluid conveying assembly is respectively communicated with the gas phase outlet and the liquid phase inlet of the internal energy conversion