Temperature Control Device and Method for Impact Turbine Bearings Based on Magnetohydrodynamic Intelligent Control

Abstract

This invention discloses a temperature control device and method for impulse turbine bearings based on magnetohydrodynamic (MHD) intelligent control, belonging to the field of hydraulic machinery and thermal management technology. It includes an impulse turbine generator, a magnetohydrodynamic intelligent heat dissipation module, and a remote monitoring and control module. During operation, the impulse turbine generator is driven to rotate by external water flow, which in turn drives a connected micro-generator to generate electricity. In the MHD intelligent heat dissipation module, a high thermal conductivity magnetohydrodynamic (MHD) fluid is used as the cooling medium, sealed within an organic glass cylindrical structure. The outer wall is surrounded by controllable electromagnets. When the MHD fluid is heated, a temperature sensor array senses and feeds back the temperature in real time. Based on temperature changes, the on / off frequency and combination of the electromagnets are automatically adjusted to guide the MHD fluid to flow orderly within the cylinder, forming a periodic circulating heat dissipation path. The temperature control device and method provided by this invention offer a practical new solution for the intelligent, efficient, and stable operation of impulse turbines.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic machinery and thermal management, and in particular to a Francis turbine bearing temperature control device and method based on magnetic fluid intelligent control. BACKGROUND

[0002] At present, as a mature, stable and reliable renewable energy, hydropower plays an important role in energy structure adjustment. In the hydropower project on the lower reaches of the Yarlung Zangbo River approved at the end of 2024, the Francis turbine has a wide application potential in the project due to its suitability for high water head hydraulic environment.

[0003] However, the existing traditional Francis turbine is prone to high temperature of the motor bearing due to friction and high-speed rotation during operation, thereby affecting the power generation efficiency and equipment life. In addition, the existing heat dissipation measures such as lubricating oil cooling system, water cooling system, material optimization, air natural convection and forced ventilation have problems such as low heat dissipation efficiency and insufficient cooling capacity. Therefore, how to improve the heat dissipation performance of the Francis turbine while considering intelligent control has become a key challenge for current hydropower technology optimization. SUMMARY

[0004] The purpose of the present application is to provide a Francis turbine bearing temperature control device and method based on magnetic fluid intelligent control, to solve the problem of overheating failure of the Francis turbine under high water head and high speed operation conditions due to long-term friction heating of the bearing, to realize active capture, directional transport and intelligent heat dissipation control of the bearing area heat by introducing Fe3O4 magnetic fluid material and electromagnetic field regulation mechanism, to break through the technical bottleneck of traditional passive heat dissipation mode, and to improve the system operation stability and life.

[0005] To achieve the above purpose, the present application provides a Francis turbine bearing temperature control device based on magnetic fluid intelligent control, which comprises a Francis turbine generator and a magnetic fluid intelligent heat dissipation module.

[0006] The Francis turbine generator is composed of an inlet cavity, a Francis turbine impeller, a rotating shaft and a micro generator. The Francis turbine impeller is externally provided with a transparent glass cover, and the lower part of the transparent glass cover is provided with a bottom support. The micro generator is connected with the bottom support through a support frame. The two ends of the rotating shaft are respectively connected with the bearing inside the Francis turbine impeller and the micro generator. The inlet cavity is connected with the side wall of the transparent glass cover.

[0007] The magnetic fluid intelligent heat dissipation module is composed of a plexiglass cylinder, magnetic fluid, an annular electromagnet array, and a temperature sensor array; one end of the plexiglass cylinder is connected with a transparent glass cover, and the other end is connected with a micro generator; a rotating shaft is located inside the plexiglass cylinder, and the temperature sensor array is used for monitoring the dynamic bearing temperature; the magnetic fluid is packaged in a cavity between the plexiglass cylinder and the rotating shaft, and the annular electromagnet array is composed of electromagnets arranged at both ends of the outside of the plexiglass cylinder.

[0008] The magnetic fluid is composed of Fe3O4 nanoparticles and oil-based liquid, has a thermal conductivity greater than 0.6 W / m·K, and a saturation magnetization strength matching the electromagnetic regulation frequency required by the system.

[0009] Preferably, one end of the rotating shaft away from the bearing is a bearing heat dissipation area, and the other end close to the bearing is a bearing heating area.

[0010] Preferably, the inner diameter of the transparent cylinder is 10-20 mm, and the wall thickness is 2-3 mm.

[0011] Preferably, a spiral flow guide is arranged on the rotating shaft to optimize the flow trajectory of the magnetic fluid, reduce dead zone heat accumulation, and improve heat exchange efficiency.

[0012] Preferably, the intelligent control unit receives temperature data of the bearing heating area monitored by the temperature sensor array, and generates control instructions according to the comparison result of the temperature data and the set threshold value, adjusts the working period and on-off combination of the annular electromagnet array, so as to drive the magnetic fluid to circulate between the bearing heating area and the bearing heat dissipation area, and realize intelligent temperature control.

[0013] Preferably, the magnetic fluid circulation period is composed of magnetic fluid heat absorption time, transmission time, and heat dissipation time:

[0014] (1)

[0015] Wherein, each time parameter is determined by the electromagnetic driving frequency and the device geometric parameters.

[0016] Preferably, the flow velocity of the magnetic fluid is related to the magnetic field strength of the electromagnet as follows:

[0017]

[0018] (2)

[0019] Wherein, N is the number of turns of the single-sided electromagnet coil outside the device, I is the current flowing through the coil inside the electromagnet, R is the radius of the electromagnet coil. is the average distance of the magnetic fluid from the coil center, is the magnetic susceptibility, is the magnetic fluid dynamic viscosity;

[0020] According to formula (2), the transmission time of the magnetic fluid in the organic glass cylinder can be calculated:

[0021] (3)

[0022] wherein, is the overall length of the organic glass cylinder.

[0023] Preferably, the device further comprises a remote monitoring and control module for real-time monitoring of bearing temperature and remotely adjusting electromagnetic control parameters through wireless communication.

[0024] The application also provides a magnetic fluid intelligent control based bearing temperature control method for impulse water turbines, comprising the following steps:

[0025] Step 1, real-time acquisition of bearing heating area temperature signal;

[0026] Step 2, the intelligent control unit adjusts the switching frequency and combination mode of the annular electromagnet array according to the temperature signal;

[0027] Step 3, under the driving of the magnetic field, the magnetic fluid circulates in the heating area and the heat dissipation area;

[0028] Step 4, dynamically optimize the magnetic field strength and flow path according to the operating conditions to keep the bearing within the safe temperature range.

[0029] Therefore, the application adopts the above-mentioned magnetic fluid intelligent control based bearing temperature control device and method for impulse water turbines, which has the following beneficial effects:

[0030] (1) Improve the heat dissipation efficiency: innovatively apply nano-sized ferroferric oxide magnetic fluid as the heat conducting medium, which has a thermal conductivity greater than 0.6 W / m·K and good heat transfer characteristics and fast magnetic response, which can realize efficient heat dissipation of the impulse water turbine bearing, and the heat dissipation effect is better than that of the traditional water cooling device and other heat dissipation measures;

[0031] (2) Avoid local overheating problems: through the intelligent control unit, the on-off frequency and combination mode of the electromagnet are adjusted according to the temperature change, and the magnetic fluid is guided to form a periodic circulating heat dissipation path in the cylinder, which can effectively avoid the problems of local heat accumulation and overheating, mechanical wear and energy efficiency reduction, etc.

[0032] (3) Realize intelligent temperature control: The integrated high sensitivity temperature sensor array can monitor bearing temperature in real time, and the intelligent control unit dynamically optimizes the magnetic field strength and magnetic fluid flow path according to the temperature data, keeps the bearing in the safe temperature range, and realizes intelligent regulation and control.

[0033] (4) Adapt to complex working conditions: The overall design follows the principles of modularity, high integration and high adaptability, and takes into account the actual operating environment of high water head, high humidity and high strength, and is suitable for the thermal management system of high water head and high speed hydroelectric generating set.

[0034] The technical solutions of the present application will be described in further detail below with the help of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the impact water turbine bearing temperature control device based on the magnetic fluid intelligent control of the present application;

[0036] Figure 2 It is a side view of the impact water turbine bearing temperature control device based on the magnetic fluid intelligent control of the present application;

[0037] Figure 3 It is a magnetic fluid heat dissipation module diagram of the embodiment of the present application;

[0038] Figure 4 It is a magnetic fluid intelligent heat dissipation module working cycle flow chart of the embodiment of the present application, wherein (a) is the magnetic fluid heat dissipation process, and (b) is the process of returning to the heating area after heat dissipation is completed;

[0039] Figure 5 It is a working flow chart of the impact water turbine bearing temperature control device based on the magnetic fluid intelligent control of the embodiment of the present application;

[0040] REFERENCE NUMERALS:

[0041] 1, water inlet cavity; 2, impact water turbine impeller; 3, organic glass cylinder; 4, bearing heat dissipation area; 5, cavity; 6, bearing heating area; 7, micro generator; 8, annular electromagnet; 9, magnetic fluid; 10, transparent glass cover; 11, bottom support; 12, rotating shaft. DETAILED DESCRIPTION

[0042] The following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0043] The following will be described in conjunction with Figure 1 — Figure 5The working manner of the present application is described.

[0044] As shown in Figure 1 and Figure 2 , a kind of bearing temperature control device of impulse water turbine based on magnetic fluid intelligent control, the overall structure of device is composed of impulse water turbine generator and magnetic fluid intelligent heat dissipation module, impulse water turbine generator is composed of water inlet cavity 1, impulse water turbine impeller 2, rotating shaft 12 and micro generator 7;Impulse water turbine impeller 2 is provided with transparent glass cover 10 outside, the bottom support 11 of transparent glass cover 10 is provided with the bottom support 11 below, micro generator 7 is connected with bottom support 11 by support frame, the both ends of rotating shaft 12 are connected with the bearing inside impulse water turbine impeller 2 and micro generator 7 respectively, water inlet cavity 1 is connected with the side wall of transparent glass cover 10;Wherein water inlet cavity 1 and impulse water turbine impeller 2 are made of corrosion-resistant stainless steel material, suitable for high water head flow field, water flow enters after high-speed impact impulse water turbine impeller 2 from water inlet cavity 1, and impulse water turbine impeller 2 rotates and drives micro generator 7 to work.Water inlet structure design adopts horn mouth diffusion structure to improve inflow efficiency and avoid cavitation phenomenon.Water flow enters water inlet cavity 1 and impacts impulse water turbine impeller 2 to make it rotate, and the power generation module is composed of magnetic induction type micro generator 7 connected with rotating shaft 12, and mechanical energy is transmitted to micro generator 7 by rotating shaft 12, and magnetic fluid 9 starts to work.

[0045] Magnetic fluid intelligent heat dissipation module is composed of organic glass cylinder 3, magnetic fluid 9, annular electromagnet array and temperature sensor array;One end of organic glass cylinder 3 is connected with transparent glass cover 10, the other end is connected with micro generator 7;Rotating shaft 12 is located inside organic glass cylinder 3, and temperature sensor array is used for monitoring bearing temperature dynamic;Magnetic fluid 9 is packaged in cavity 5 between organic glass cylinder 3 and rotating shaft 12, and annular electromagnet array is composed of annular electromagnet 8 arranged at both ends of the outer side of organic glass cylinder.

[0046] As shown in Figure 3 and Figure 4 , a plurality of annular electromagnets 8 are arranged outside organic glass cylinder 3, magnetic potential gradient is formed by space displacement, and magnetic fluid is guided to make directional circulation.Magnetic fluid 9 flows to bearing heat dissipation area 4 after absorbing heat from bearing heating area 6, completes heat release process, and returns to bearing heating area 6, to form continuous heat dissipation circulation. Figure 2 and Figure 3The middle arrow indicates the direction of the movement of the magnetic fluid 9 under the drive of the annular electromagnet 8. The circulation period of the magnetic fluid is composed of the heat absorption time, the transmission time and the heat dissipation time of the magnetic fluid, and meets the following control period function:

[0047]

[0048] Wherein, each time parameter is determined by the electromagnetic drive frequency and the device geometric parameters.

[0049] Based on the above device, the time parameter of the directional transmission of the magnetic fluid 9 in the control period can be calculated by establishing the mathematical model of the flow speed of the magnetic fluid 9 and the magnetic field strength of the annular electromagnet 8. The flow speed of the magnetic fluid 9 is The relationship between the magnetic field strength

[0050]

[0051]

[0052] Wherein, is the number of turns of the single-sided electromagnet coil outside the device, is the current flowing through the coil inside the electromagnet, is the radius of the electromagnet coil, is the average distance of the magnetic fluid from the center of the coil, is the magnetic susceptibility, is the dynamic viscosity of the magnetic fluid.

[0053] Accordingly, the transmission time of the magnetic fluid in the cylindrical heat dissipation device is calculated by the following formula:

[0054]

[0055] Wherein, is the overall length of the cylinder.

[0056] Based on the above device, the time required for the magnetic fluid 9 to absorb and release heat can be intelligently controlled to achieve the best control effect of the bearing temperature, and the overall working frequency of the electromagnet is adjusted. The temperature rise model is established as follows:

[0057] The heat conduction of the bearing to the magnetic fluid 9 is:

[0058] ;

[0059] Wherein, represents the thermal conductivity of the magnetic fluid, represents the effective contact area between the magnetic fluid and the bearing heating area, represents the temperature.

[0060] The heat dissipation of the magnetic fluid to the heat dissipation material is:​

[0061] ;

[0062] wherein, represents the thermal conductivity of the magnetic fluid, represents the effective contact area of the magnetic fluid and the heat dissipation material, represents the temperature.

[0063] For the magnetic fluid itself, the temperature rise model is established as follows:

[0064] .

[0065] Figure 5 The working flowchart of the magnetic fluid intelligent control based bearing temperature control device of the impulse water turbine of the embodiment is shown in the figure. The overall working steps are divided into the following four steps:

[0066] S1: The water flow impacts the impeller 2 of the impulse water turbine, so that the impeller 2 rotates, thereby driving the micro generator 7 to generate electricity.

[0067] S2: The temperature sensor monitors the temperature change of the bearing in real time, and transmits the data to the intelligent control unit.

[0068] S3: The intelligent control unit generates control instructions by algorithm analysis according to the temperature data, and adjusts the working frequency of the annular electromagnet 8, so as to change the working state of the magnetic fluid heat dissipation device.

[0069] S4: The magnetic fluid heat dissipation device utilizes the rapid magnetic response and high-efficiency heat transfer characteristics of the nanoscale Fe3O4 magnetic fluid 9 under the control of the electromagnet, quickly conducts and dissipates the heat generated by the bearing, and realizes periodic heat dissipation cycle.

[0070] Therefore, the magnetic fluid intelligent control based bearing temperature control device of the impulse water turbine is adopted, the nanoscale Fe3O4 magnetic fluid is first introduced as a functionalized heat conduction medium into the bearing heat dissipation system of the impulse water turbine, and the efficiency bottleneck of the traditional passive heat conduction method is broken. Through accurate regulation and control of the external magnetic field parameters, the dual regulation and control mechanism of the ordered arrangement and directional flow of the magnetic fluid microstructure is realized, and the multi-physical field coupled heat transfer process of the bearing contact surface is effectively strengthened. The innovative method not only fully utilizes the high thermal conductivity and rapid magnetic response characteristics of the magnetic fluid, but also establishes a dynamic adjustable active heat dissipation new paradigm through the synergistic effect of the magnetic field-flow field-temperature field.

[0071] It should be pointed out finally that the above examples are only used to illustrate the technical solutions of the present application but not to limit it, and although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can still be modified or replaced equivalently, and these modifications or equivalent replacements should not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. The bearing temperature control device of the impulse water turbine based on the intelligent control of the magnetic fluid, characterized in that, The application relates to a magnetic fluid intelligent heat dissipation module and an impact water turbine generator. The impact water turbine generator is composed of a water inlet cavity, an impact water turbine impeller, a rotating shaft and a micro generator; the impact water turbine impeller is externally provided with a transparent glass cover, the lower portion of the transparent glass cover is provided with a bottom support, the micro generator is connected with the bottom support through a supporting frame, the two ends of the rotating shaft are respectively connected with the impact water turbine impeller and a bearing in the micro generator, and the water inlet cavity is connected with the side wall of the transparent glass cover. The magnetic fluid intelligent heat dissipation module is composed of an organic glass cylinder, magnetic fluid, an annular electromagnet array and a temperature sensor array; one end of the organic glass cylinder is connected with the transparent glass cover, and the other end is connected with the micro generator; the rotating shaft is located in the organic glass cylinder, and the temperature sensor array is used for monitoring the bearing temperature dynamic; the magnetic fluid is packaged in a cavity between the organic glass cylinder and the rotating shaft, and the annular electromagnet array is composed of electromagnets arranged at the two ends outside the organic glass cylinder. The magnetic fluid is composed of Fe3O4 nanoparticles and oil-based liquid, the thermal conductivity of the magnetic fluid is greater than 0.6 W / m*K, and the saturation magnetization intensity matches the electromagnetic control frequency required by the system.

2. The bearing temperature control device for the impeller hydraulic turbine based on the magnetofluid intelligent control according to claim 1, characterized in that: The end of the rotating shaft far away from the bearing is a bearing heat dissipation area, and the end close to the bearing is a bearing heating area.

3. The bearing temperature control device for the impeller hydraulic turbine based on the magnetofluid intelligent control according to claim 1, characterized in that: The inner diameter of the transparent cylinder is 10-20 mm, and the wall thickness is 2-3 mm.

4. The bearing temperature control device for the impeller hydraulic turbine based on the magnetofluid intelligent control according to claim 1, characterized in that: Spiral flow guide vanes are arranged on the rotating shaft and used for optimizing the flow trajectory of the magnetic fluid.

5. The bearing temperature control device for the impeller hydraulic turbine based on the magnetofluid intelligent control according to claim 2, characterized in that: The application further comprises an intelligent control unit. The intelligent control unit receives the temperature data of the bearing heating area monitored by the temperature sensor array, generates a control instruction according to the comparison result of the temperature data and a set threshold value, adjusts the working period and on-off combination of the annular electromagnet array, and drives the magnetic fluid to circulate between the bearing heating area and the bearing heat dissipation area, so that intelligent temperature control is realized.

6. The bearing temperature control device for the impeller hydraulic turbine based on the magnetofluid intelligent control according to claim 5, characterized in that, Magnetic fluid circulation period By the magnetic fluid heat absorption time, transmission time and heat dissipation time The application further comprises an intelligent control unit. （1） The time parameters are determined by the electromagnetic driving frequency and the geometric parameters of the device.

7. The bearing temperature control device for the impeller hydraulic turbine based on the magnetofluid intelligent control according to claim 6, characterized in that, Flow velocity of the magnetic fluid The relationship between the magnetic field intensity of the electromagnet is: （2） wherein, N is the number of turns of the coil of the external single-sided electromagnet, I is the magnitude of the current flowing through the coil of the electromagnet, R is the radius of the coil of the electromagnet, D is the average distance of the magnetic fluid from the center of the coil, χ is the magnetic susceptibility, η is the magnetic fluid dynamic viscosity; The transmission time of the magnetic fluid in the organic glass cylinder is calculated according to formula (2): （3） wherein, is the overall length of the plexiglass cylinder.

8. The bearing temperature control device for the impeller hydraulic turbine based on the magnetofluid intelligent control according to claim 1, characterized in that: The device further comprises a remote monitoring and control module for monitoring the bearing temperature in real time and remotely adjusting the electromagnetic control parameters through wireless communication.

9. The bearing temperature control method for the impulse water turbine based on the magnetofluid intelligent control, applied to the bearing temperature control device for the impulse water turbine based on the magnetofluid intelligent control in any one of claims 1-8, characterized in that, The application comprises the following steps: Step 1, collecting the bearing heating area temperature signal in real time; Step 2, the intelligent control unit adjusts the switching frequency and combination mode of the annular electromagnet array according to the temperature signal; Step 3, under the driving of the magnetic field, the magnetic fluid circulates between the heating area and the heat dissipation area; Step 4, the magnetic field strength and flow path are dynamically optimized according to the operation condition, and the bearing is kept in a safe temperature range.

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