A magnetic fluid circulation cooling system

Abstract

The present invention relates to a magnetic fluid circulation cooling system, comprising: a heat source cooler, a connecting pipeline and a radiator, wherein the connecting pipeline comprises a first pipeline and a second pipeline; the outlet of the heat source cooler is connected to the inlet of the radiator through the first pipeline, and the outlet of the radiator is connected to the inlet of the heat source cooler through the second pipeline, thereby forming a closed internal circulation loop, wherein a magnetic fluid is arranged in the internal circulation loop; a magnetic driving layer is arranged on the surface of the heat source cooler, and the magnetic driving layer is used to provide an external magnetic field so that the magnetic fluid has a magnetic field driving force flowing in the internal circulation loop; and further comprises an energized coil, which comprises a DC power supply and a coil, and the coil is wound outside the connecting pipeline, and the energized coil is used to provide a magnetic field driving force from the outlet of the heat source cooler to the inlet of the radiator for the magnetic fluid. The present invention drives the magnetic fluid circulation by jointly driving the internal temperature difference of the system and the external magnetic field, cools the heat source, and plays an energy-saving role while dissipating the heat from the heat source.

Description

Technical Field

[0001] The invention belongs to the technical field of heat source cooling systems, and in particular relates to a magnetic fluid circulation cooling system. Background Art

[0002] The most common loop heat pipe currently is a closed loop heat pipe consisting of an evaporator, a condenser, a liquid reservoir, a steam pipeline, and a liquid phase pipeline. The power that drives the flow of the working fluid in the loop heat pipe is divided into a gravity loop heat pipe (or a thermal siphon loop heat pipe) or a capillary pump loop heat pipe, and no additional power is required from the outside. The gravity loop heat pipe requires a certain height difference between the condenser and the evaporator, and the capillary pump loop heat pipe requires a reasonable capillary structure. The inside of the loop heat pipe is evaporating into a negative pressure state, and a working fluid with a suitable low boiling point is filled in. It evaporates and vaporizes at the evaporator and flows to the condenser. The working fluid condenses in the condenser, and then circulates to the evaporator under the push of capillary force or gravity, continuously cooling the heat source. In the loop heat pipe system, the liquid refluxes through the smooth inner wall pipeline, the flow pressure is significantly reduced, and the heat transfer distance is long, which solves the problem of traditional heat pipes being restricted by direction and length. At the same time, steam and liquid are transmitted in their respective pipelines, eliminating the occurrence of carryover. Therefore, loop heat pipes are widely used in aerospace, military and other industries.

[0003] However, the traditional loop heat pipe has the following disadvantages: 1. The traditional loop heat pipe is prone to the problem of not being able to start normally. There are two main aspects. One is that the evaporation temperature is prone to be too high during startup, exceeding the temperature range allowed by the equipment; on the other hand, some startup methods will cause the working temperature to be high during stable operation, that is, maintaining a high superheated nucleate boiling. The above-mentioned high temperature working state will increase the possibility of heat leakage and further lead to heat dissipation failure. 2. Instability problem. Due to the two-phase circulation cooling in the loop heat pipe, it is easy to cause instability during the operation of the system. The specific manifestations are: temperature hysteresis, temperature fluctuations and liquid phase working medium backflow. 3. Disadvantages of capillary structure. The capillary structure has large resistance and slow startup; the capillary structure is difficult to process and has poor consistency; the liquid flow rate in the capillary structure is small and the heat dissipation capacity is limited; the capillary structure is heavy. 4. During the operation of the gravity loop heat pipe, the condenser needs to be maintained above the evaporator, and its application in aviation and aerospace related equipment is limited. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention proposes a magnetic fluid circulation cooling system.

[0005] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. A magnetic fluid circulation cooling system proposed in the present invention includes: a heat source cooler, a connecting pipeline and a radiator, the connecting pipeline includes a first pipeline and a second pipeline; the outlet of the heat source cooler is connected to the inlet of the radiator through the first pipeline, and the outlet of the radiator is connected to the inlet of the heat source cooler through the second pipeline, so as to form a closed internal circulation loop, and a magnetic fluid is arranged in the internal circulation loop, and the magnetic fluid absorbs the heat emitted by the heat source when passing through the heat source cooler and realizes cooling at the radiator; the surface of the heat source cooler is provided with a magnetic driving layer, and the magnetic driving layer is used to provide an external magnetic field so that the magnetic fluid has a magnetic field driving force to flow in the internal circulation loop; and also includes: an energized coil, the energized coil includes a DC power supply and a coil electrically connected to the DC power supply, the coil is wound outside the connecting pipeline, and the energized coil is used to provide the magnetic fluid with a magnetic field driving force from the outlet of the heat source cooler to the inlet of the radiator; the magnetic field driving force provided by the energized coil and the magnetic field driving force provided by the magnetic driving layer are both conducive to the circulation of the magnetic fluid in the internal circulation loop.

[0006] Furthermore, the magnetic driving layer is a layer of permanent magnet sintered on the surface of the heat source cooler.

[0007] Furthermore, the magnetic fluid is a temperature-sensitive magnetic fluid.

[0008] Furthermore, the temperature-sensitive magnetic fluid is composed of nano-scale temperature-sensitive magnetic particles, a base liquid and a dispersant; wherein the nano-scale temperature-sensitive magnetic particles are manganese-zinc ferrite nanoparticles.

[0009] Furthermore, the energized coil is arranged close to the heat source cooler, and the coil is wound on the first pipeline at the outlet of the heat source cooler.

[0010] Furthermore, the heat sink adopts a micro and small channel cold plate structure.

[0011] Furthermore, the heat dissipation method of the radiator to the environment or the heat sink includes natural heat dissipation, air cooling and external liquid cold plate heat dissipation.

[0012] The present invention drives the magnetic fluid circulation by the temperature difference inside the system and the external magnetic field, cools the heat source, and dissipates the heat to the environment at the radiator. According to the thermomagnetic effect of the temperature-sensitive magnetic fluid, the power provided by the outside can be reduced, and the heat source can be dissipated while the heat source is dissipated. Energy saving is achieved. Since the magnetic fluid does not undergo phase change, the side effects of the cold leakage phenomenon on the stability of the system operation are reduced, and it is not affected by gravity; the high thermal conductivity of the nanoscale magnetic nanofluid is used to improve the cooling capacity of the circulation system. The present invention eliminates the capillary structure used in the prior art, reduces the flow resistance of the cooling medium, and improves the cooling efficiency of the traditional loop heat pipe. In addition, the present invention can provide additional magnetic field drive during the system startup process by setting the energized coil and dynamic voltage to achieve a smooth startup of the system. When the heat flux density at the heat source is large, the circulation flow of the system can be increased by the additional magnetic field provided by the coil, thereby improving the heat dissipation capacity of the entire magnetic fluid circulation system.

[0013] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a schematic diagram of the structure of a magnetic fluid circulation cooling system.

[0015] Figure 2A and Figure 2B All of them are structural schematic diagrams of radiators.

[0016] Figure 3 It is a schematic diagram of the driving principle of the thermomagnetic effect of the temperature-sensitive magnetic fluid in the present invention. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0018] See also Figures 1 to 3A magnetic fluid circulation cooling system comprises a heat source cooler 1, a connecting pipeline and a radiator 2, wherein the connecting pipeline comprises a first pipeline 3 and a second pipeline 4, wherein the outlet of the heat source cooler is connected to the inlet of the radiator 2 through the first pipeline 3, and the outlet of the radiator is connected to the inlet of the heat source cooler through the second pipeline 4, thereby forming a closed internal circulation loop. An energized coil is arranged at a position close to the heat source cooler, wherein the energized coil comprises a DC power supply 5 and a coil 6 electrically connected to the DC power supply, wherein the coil 6 is wound on the first pipeline 3 at the outlet of the heat source cooler, and the two ends of the coil are connected to the two poles of the DC power supply in a one-to-one correspondence. Magnetic fluid is arranged in the connecting pipeline, the flow channel of the heat source cooler and the flow channel of the radiator, that is, magnetic fluid is arranged in the internal circulation loop; the energized coil is used to provide the magnetic fluid with a magnetic field force in the direction from the outlet of the heat source cooler to the inlet of the radiator. A magnetic driving layer 7 is arranged on the surface of the heat source cooler, and the formation of the magnetic driving layer can be achieved by sintering magnetic particles, that is, a layer of permanent magnet is sintered on the surface of the heat source cooler to form an external magnetic field. The heat source to be cooled (such as a chip, a connector or other electronic module) is arranged on the surface of the heat source cooler 1. When the magnetic fluid flows through the heat source cooler, it absorbs the heat of the heat source, thereby increasing the temperature, and the heat source is cooled. The heated magnetic fluid flows through the outlet of the heat source cooler and the first pipeline into the radiator. After the magnetic fluid is cooled in the radiator, it flows back to the heat source cooler through the outlet of the radiator and the second pipeline, thereby realizing the circulation heat dissipation of the heat source.

[0019] Combination Figure 3 The principle of driving the magnetic fluid movement of the magnetic drive layer is as follows: the inlet of the heat source cooler is the low-temperature end, because the magnetic fluid circulating here has been cooled by the radiator; at the low-temperature end of the heat source cooler, the magnetic field strength of the magnetic fluid is large, and the magnetic field driving force it receives is large; the heat source realizes heat exchange by heating the heat source cooler, and the heat source is cooled down, and the magnetic fluid absorbs the heat of the heat source and flows out from the outlet of the heat source cooler, then the outlet of the heat source cooler is the high-temperature end, where the temperature of the magnetic fluid is high; and at the high-temperature end, the magnetic field strength of the magnetic fluid is small, and the magnetic field driving force it receives is small, so that in the magnetic field area provided by the permanent magnet, a magnetic field driving force is formed from the inlet of the heat source cooler to the outlet of the heat source cooler, and the magnetic fluid flows under the action of the magnetic field driving force, so the magnetic fluid can flow from the low-temperature end to the high-temperature end under the combined action of its own temperature difference and the magnetic field provided by the external permanent magnet.

[0020] Furthermore, during the normal cycle of the cooling system, the voltage of the energized coil can be reduced to achieve energy saving. Moreover, even if the output voltage of the energized coil is reduced to weaken the magnetic field force in the right direction, or even the output of the DC voltage is directly cut off, the magnetic fluid can still be Figure 1The system shown in the figure circulates clockwise. Because there must be a high temperature difference at both ends of the heat source cooler, there is a magnetic field force from the heat source cooler inlet to its outlet. Of course, this magnetic field force is greater than the resistance of the connecting pipeline, the flow channel of the heat source cooler and the flow channel of the radiator to the magnetic fluid. Therefore, no external energy is required to realize the circulation of the magnetic fluid in the entire system loop. It can be seen that during the system startup process, in order to avoid the magnetic fluid from being unable to circulate quickly when the heat source is working, the auxiliary startup of the energized coil is very important. When the heat flux density at the heat source is large, the additional magnetic field provided by the DC coil can also increase the system's magnetic fluid circulation flow rate, thereby improving the cooling capacity of the entire magnetic fluid circulation cooling system.

[0021] The DC power supply is controlled by a control module, which is used to adjust the voltage provided by the DC power supply to the coil so that the DC power supply can provide a dynamic voltage. This part is the prior art and will not be described in detail. Of course, the control module can also directly control the on or off of the DC power supply, for example, the on and off control can be achieved by opening and closing a switch element on the wire between the DC power supply and the coil; or the DC voltage uses an existing adjustable DC power supply.

[0022] In this embodiment, the heat source cooler 1 can adopt a heat exchange cold plate structure or other similar structures, which should have a position for arranging a magnetic drive layer and maintaining a sufficient contact area with the heat source; for example, a magnetic drive layer can be set on one side surface of the heat source cooler, and a heat source can be set on the other side surface of the heat source cooler; or, a magnetic drive layer 7 is set on both opposite sides of the heat source cooler, but a cooling surface in contact with the heat source should also be reserved. The extension direction of the flow channel 11 of the heat source cooler should be the same as the direction of the magnetic field driving force provided by the magnetic drive layer 7, so as to avoid the situation where the magnetic fluid appears in the flow channel of the heat source cooler in the opposite direction to the magnetic field driving force, thereby avoiding the magnetic fluid from being affected by the flow direction of the flow channel and reducing the resistance as much as possible.

[0023] In this embodiment, the heat sink 2 can adopt a micro-channel cold plate structure, and the heat dissipation to the environment or the heat sink can be divided into three ways: natural heat dissipation, air cooling and external liquid cold plate heat dissipation. When natural heat dissipation is adopted, fins 21 (such as Figure 1 ), or no fins are provided. When air cooling is used, Figure 2A , a fan 22 can be added to the existing cold plate structure with fins. When using an external liquid cold plate for heat dissipation, such as Figure 2B A liquid cooling plate 23 may be provided on one side of the radiator, or may be provided on multiple side surfaces.

[0024] In this embodiment, the magnetic fluid used as the cooling medium is a temperature-sensitive magnetic fluid. The temperature-sensitive magnetic fluid has nanofluid properties and has a significant thermomagnetic effect due to its low Curie temperature. Figure 3As shown, the temperature-sensitive magnetic fluid will flow from the low-temperature end to the high-temperature end under the conditions of its own temperature difference and external magnetic field. As the heat source heats the heat source cooler and the environment cools the radiator, a temperature difference will be formed inside the magnetic fluid circulation system. According to the principle of thermomagnetic effect, the magnetic drive layer can provide circulation power to the magnetic fluid in the entire system. According to the thermomagnetic effect of the temperature-sensitive magnetic fluid, the power provided by the outside can be reduced, which plays an energy-saving role while dissipating the heat source. The temperature-sensitive magnetic fluid is composed of nano-scale temperature-sensitive magnetic particles, a base liquid and a dispersant; wherein the mass fraction of the temperature-sensitive magnetic particles is between 0.1% and 2%, and the temperature-sensitive magnetic particles can be manganese-zinc ferrite nanoparticles, but not limited to this; the base liquid can be mineral oil or deionized water.

[0025] As an extension, at least one temperature sensor can be set on the heat source, and the temperature sensor is connected to the control module. When the temperature of the heat source is high, the control module can increase the magnetic field force provided by the energized coil according to the temperature feedback from the temperature sensor, thereby increasing the circulation power of the magnetic fluid. When it is detected that the chip temperature drops back to the normal range, the working voltage of the DC coil can be reduced to achieve automatic adjustment.

[0026] In this embodiment, the magnetic fluid is circulated in the clockwise direction as an example for explanation. The direction of the magnetic field force provided by the DC coil is determined by the right-hand screw rule to be consistent with the clockwise circulation of the magnetic fluid; however, in other embodiments, the magnetic fluid can also be circulated in the clockwise direction. Figure 1 The system structure shown performs a counterclockwise cycle. At this time, the winding direction of the coil should be opposite so that the force provided by the energized coil conforms to the counterclockwise movement of the magnetic fluid.

[0027] In other embodiments, a layer of insulator may be sintered on the surface of the heat source cooler, and then a circuit or coil capable of driving the magnetic fluid from the inlet to the outlet of the heat source cooler may be arranged on the insulator to form an electromagnet and an external magnetic field. Similarly, a layer of insulator may be arranged on the surface of the radiator, and a magnetic driving layer capable of driving the magnetic fluid to flow in the inner circulation loop may be arranged on the insulator. The number of energized coils may not be limited to one, but may be two or more, but it should be ensured that the magnetic field driving force provided is consistent with the circulation direction of the magnetic fluid. The energized coils may be evenly distributed in the circumferential direction of the connecting pipeline. The present invention can improve the driving performance of the magnetic fluid by arranging a distributed magnetic field.

[0028] When the present invention is working, the heat source cooler is heated by the heat source and the temperature rises, while the temperature of the radiator is relatively low, and there is a temperature difference in the entire cooling system. When the heat source just starts to heat up or heats up for a short time, in order to timely realize the circulation cooling and normal operation of the heat source, and to avoid the evaporation temperature being too high at startup and exceeding the temperature range allowed by the heat source, the energized coil is started, and the magnetic field driving force is applied to the magnetic fluid in time, so that the magnetic fluid circulates in the cooling system in a clockwise or counterclockwise direction. During the operation of the cooling system, there is a high temperature difference between the two ends of the heat source cooler. The magnetic fluid flows from the low temperature end to the high temperature end under the action of its own temperature difference and the external magnetic field generated by the magnetic drive layer, and the magnetic fluid in the entire system is provided with circulation power through the magnetic drive layer; at this time, the voltage output of the energized coil can be reduced or even cut off. When the temperature at the heat source is high, the voltage output of the energized coil can be increased to increase the circulation flow of the magnetic fluid, thereby realizing the temperature control of the heat source.

[0029] The above description is only a preferred embodiment of the present invention, and the parts not described in detail are all prior art; any simple modification, equivalent changes and modifications made to the above embodiments by any technician familiar with the profession according to the technical essence of the present invention without departing from the scope of the technical solution of the present invention, still fall within the scope of the technical solution of the present invention.

Claims

1. A magnetic fluid circulation cooling system, used in aerospace industry and military industry, characterized by include: A heat source cooler, a connecting pipeline and a radiator, wherein the connecting pipeline includes a first pipeline and a second pipeline; The outlet of the heat source cooler is connected to the inlet of the radiator through a first pipeline, and the outlet of the radiator is connected to the inlet of the heat source cooler through a second pipeline, thereby forming a closed internal circulation loop, in which a magnetic fluid is provided. When passing through the heat source cooler, the magnetic fluid absorbs the heat emitted by the heat source and realizes cooling at the radiator; a magnetic driving layer is provided on the surface of the heat source cooler, and the magnetic driving layer is used to provide an external magnetic field so that the magnetic fluid has a magnetic field driving force to flow in the internal circulation loop; It also includes: an energized coil arranged near the heat source cooler, the energized coil including a DC power supply and a coil electrically connected to the DC power supply, the coil is wound on a first pipeline at the outlet of the heat source cooler, and the energized coil is used to provide a magnetic field driving force for the magnetic fluid from the outlet of the heat source cooler to the inlet of the radiator; a temperature sensor is arranged on the heat source, the temperature sensor is electrically connected to the control module, and the control module is electrically connected to the DC power supply; During the startup of the cooling system, when the heat source just starts to heat up or heats up for a short time, the energized coil assists in the startup, exerting a magnetic field driving force on the magnetic fluid, causing the magnetic fluid to circulate in the cooling system; During the operation of the cooling system, there is a high temperature difference at both ends of the heat source cooler. The magnetic fluid circulates under the action of its own temperature difference and the external magnetic field generated by the magnetic drive layer. At this time, the voltage output of the energized coil is reduced or cut off. When the heat flux density at the heat source is large, the voltage output of the energized coil is increased according to the temperature feedback from the temperature sensor to increase the circulation flow of the magnetic fluid.

2. A magnetic fluid circulation cooling system according to claim 1, characterized in that: The magnetic driving layer is a layer of permanent magnet sintered on the surface of the heat source cooler.

3. A magnetic fluid circulation cooling system according to claim 1, characterized in that: The magnetic fluid is a temperature-sensitive magnetic fluid.

4. A magnetic fluid circulation cooling system according to claim 3, characterized in that: The temperature-sensitive magnetic fluid is composed of nanometer-scale temperature-sensitive magnetic particles, a base liquid and a dispersant; wherein the nanometer-scale temperature-sensitive magnetic particles are manganese-zinc ferrite nanoparticles.

5. A magnetic fluid circulation cooling system according to claim 1, characterized in that: The radiator adopts a micro and small channel cold plate structure.

6. A magnetic fluid circulation cooling system according to claim 5, characterized in that: Ways for the radiator to dissipate heat to the environment or a heat sink include natural cooling, air cooling, and external liquid cold plate cooling.

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