CN116294301B

CN116294301B - Pump-assisted capillary force driven two-phase fluid heat management system

Info

Publication number: CN116294301B
Application number: CN202211551943.4A
Authority: CN
Inventors: 郭向吉; 张博
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2022-12-05
Filing date: 2022-12-05
Publication date: 2024-05-03
Anticipated expiration: 2042-12-05
Also published as: CN116294301A

Abstract

The invention provides a pump-assisted capillary force driven two-phase fluid thermal management system, comprising: the evaporator, the condenser and the liquid storage tank have the function of controlling the temperature of the system besides the function of supplying liquid to the pump; a compressor for heating and boosting the vapor at the outlet of the evaporator and supplying the vapor to the condenser; the expansion valve is used for reducing the pressure and the temperature of the liquid working medium from the condenser in the high-pressure area; and a pump located in the circulation path for supplying the working medium to the evaporator in a unidirectional circulation mode; in the evaporator, the liquid working medium is provided on the hydrophilic capillary sheet in a cyclone manner and evaporated to form a vapor working medium, so that the liquid is distributed more uniformly in the annular area of the hydrophilic capillary sheet in the cyclone flow channel, and the uniformity of temperature control is facilitated; meanwhile, the compressor is added, so that the temperature and the pressure of the steam at the outlet of the evaporator can be increased, and the steam can be radiated at a higher-temperature cold source, thereby not only improving the upper limit of the use of the system environment, but also carrying out waste heat refrigeration.

Description

Pump-assisted capillary force driven two-phase fluid heat management system

Technical Field

The invention relates to the field of heat dissipation, in particular to a pump-assisted capillary force driven two-phase fluid heat management system, in particular to an evaporator in the system, which adopts a cyclone structure and a film structure, has uniform liquid supply and shortened heat transfer path so as to improve heat exchange efficiency and can intensively recycle waste heat.

Background

With the development of electronic technology, the required information processing amount is also larger and larger, and a data processing module for processing various large-capacity information is also a focus of attention, so that the power of electronic products is larger and larger, and the heat flux is increased. These data processing modules require a constant temperature environment to operate, and the temperature environment for normal operation is set to be relatively low. Thus, when the data processing modules are in a high temperature state, they may cause a malfunction such as a system stop.

In conventional technology, forced air convection and forced liquid cooling systems are commonly used. By conduction cooling, the heat source is cooled by conduction and natural convection of heat into the surrounding air. This cooling method is sufficient for devices of relatively low power and having a relatively large external surface area. However, as power usage/dissipation increases, conductively cooled devices may experience undesirably high surface and device temperatures. The form of a radiator or other radiator of the forced air convection conduction cooling system adds considerable mass to the device. Forced air convection cooling may include air-driven devices, such as fans, to circulate air through the interior of the apparatus, thereby drawing heat out of the device. Air cooling may accommodate moderate power levels, but produces fan noise, requires ventilation openings, requires power to operate the air mover, may be degraded by dust scaling, and may involve discomfort to the user due to surface hot spots at the fan exhaust and due to hot air exhaust to the user.

Accordingly, two-phase fluid heat transfer techniques have been applied to products or environments having high heat flux densities to dissipate heat. In contrast to air-cooled heat dissipation techniques and liquid-cooled heat dissipation techniques, two-phase flow heat dissipation techniques are considered as one of the most promising heat dissipation modes. The traditional two-phase flow heat dissipation technology comprises a heat exchange heat pipe, a pump driven two-phase flow loop, a pump auxiliary capillary force driven two-phase flow loop, a capillary force pumping loop and the like. The pump driving fluid loop system mainly comprises a liquid storage device, a mechanical pump, a preheater, an evaporator, a condenser and a connecting pipeline, and the working principle is that the mechanical pump is used for driving working medium to circulate in the loop system, supercooled working medium firstly flows through the preheater and is heated to a saturated state, then flows through the evaporator, takes heat of the evaporator by utilizing phase change heat absorption, then flows through the condenser and is condensed to the supercooled state, finally the working medium returns to the mechanical pump, so that a complete circulation is formed, and heat collection, transportation and dissipation are realized.

At present, the principle of the hot spot of the thin film evaporation two-phase fluid heat exchange technology, which can accelerate evaporation, is that liquid forms a thin film under the condition of reduced pressure so as to have extremely large evaporation surface area, heat is quickly and uniformly spread, the liquid is directly evaporated into gas, and the thermal failure of a chip can be well prevented by continuously supplementing the liquid to the surface of the chip. The key that the film evaporation can be continuously carried out is that the thickness of a thin liquid film can be stably maintained, and when the liquid supply is uneven, the film is easy to dry and damage electrical equipment.

The invention patent application with publication number of CN111504103A discloses a pump-driven two-phase fluid loop evaporator, which comprises an evaporator shell, a hydrophobic capillary core, an axial liquid channel and an axial steam trunk, wherein the hydrophobic capillary core is arranged in the evaporator shell, a plurality of axial liquid channels are arranged between the evaporator shell and the hydrophobic capillary core, the axial steam trunk is arranged in the hydrophobic capillary core, liquid is supplied to the axial liquid channels through a gear pump and heated by a heat source, the hydrophobic capillary core separates the liquid from generated steam, and the steam is discharged to the axial steam trunk and finally discharged out of the evaporator.

The patent publication No. CN111146167 discloses a heat dissipating device and a heat dissipating method for a third-generation semiconductor electronic device by pumping thin film evaporation, which supply liquid to a central position above the surface of a microstructure of a heat sink by pumping, but working media in the liquid supply mode are easily affected by gravity to cause uneven distribution on the thin film. And dry burning can occur.

Therefore, the conventional evaporator is not uniform in liquid supply to the heat exchange portion, and the long distance from the inlet side to the outlet side is liable to cause drying and uneven temperature control; in addition, for a two-phase fluid evaporator driven by capillary force, excessive thickness of the liquid immersed capillary core can cause extra heat transfer resistance, so that efficient heat transfer is difficult to perform, and the efficiency of liquid evaporation is further affected; furthermore, in order to provide a cold source for the condenser, a refrigeration loop is additionally required to be introduced, so that the waste heat of the system cannot be recycled, and the quality and the complexity of the system are increased; finally, the recovery design of the vapor and the excess liquid generated by the evaporator is not ideal enough, i.e. the vapor-liquid separation characteristics of the evaporator itself need to be more reasonably designed to meet the heat dissipation requirement of high heat flux density.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a pump-assisted capillary force driven rotational flow two-phase fluid heat management system with the advantages of more efficient heat transfer mode leading, uniform liquid supply, high heat exchange efficiency and waste heat refrigeration.

A pump assisted capillary force driven cyclonic two-phase fluid thermal management system comprising: the evaporator, wherein the liquid working medium of the evaporator evaporates and enters the circulation path after receiving heat from the heat source; a condenser that receives the vapor state working medium from the evaporator via a circulation path; the liquid storage tank has a system temperature control function besides a liquid supply function for the pump; a compressor for heating and boosting the vapor at the outlet of the evaporator and supplying the vapor to the condenser; the expansion valve is used for reducing the pressure and the temperature of the liquid working medium from the condenser in the high-pressure area; and a pump located in the circulation path for supplying the working medium to the evaporator in a unidirectional circulation mode; in the evaporator, the liquid working medium is supplied to the hydrophilic capillary sheet in a rotational flow manner and is evaporated under the action of a heat source to form a vapor state working medium.

Preferably, the method further comprises: the liquid storage tank is a liquid storage device for storing cooling working media and has a system temperature control function; the outlet end of the liquid storage tank is connected to the evaporator through a pump, the steam outlet of the evaporator is connected to the inlet of the compressor, the outlet of the compressor is connected to the condenser, the outlet end of the condenser is connected to the liquid storage tank through an expansion valve, and the liquid outlet of the evaporator is connected to the liquid storage tank; the liquid storage tank is connected with a temperature control loop which is used for heating or cooling the working medium in the liquid storage tank so as to control the evaporation temperature of the evaporator, and the temperature control loop can be changed into heating by a heating rod or refrigerating by a semiconductor refrigerating sheet for temperature control; and the liquid storage device is provided with a cooling working medium inlet and a cooling working medium outlet.

Preferably, the evaporator further comprises: a liquid inlet chamber having an annular region and connected to the liquid passage through a liquid inlet; a swirl flow passage having an annular region and located inside the liquid inlet chamber, communicating with the liquid inlet chamber through a liquid swirl inlet; a steam cavity located in the central region and communicating with the steam passage through a steam trunk; hydrophilic capillary sheet, fluid working medium enters the steam cavity from the rotational flow channel through the hydrophilic capillary sheet; the liquid outlet cavity is positioned at the outer side of the cyclone flow channel and is communicated with the cyclone flow channel through a liquid cyclone outlet; the heating surface corresponds to the hydrophilic capillary sheet area in the steam cavity, and the fluid working medium is subjected to film evaporation under the action of the heating surface.

Preferably, the evaporator further comprises: the hydrophilic capillary sheet is positioned at the bottoms of the cyclone flow channel and the steam cavity, after the liquid working medium enters the cyclone flow channel, one part enters the steam cavity through the hydrophilic capillary sheet under the capillary action and is vaporized, and the other part is still discharged from the liquid cyclone outlet to the liquid outlet cavity in a liquid form.

Preferably, the method further comprises: a steam cover plate comprising a steam trunk and a first partition; the first partition plate divides the inner cavity of the cyclone evaporation chamber into a cyclone flow channel and a steam cavity, and the hydrophilic capillary sheet is positioned at the bottom of the inner cavity and communicates the cyclone flow channel with the steam cavity; the outer wall of the cyclone evaporation chamber is also provided with an annular second baffle plate; an inlet cover plate, the inlet cover plate and a second partition plate of the cyclone evaporation chamber defining a liquid inlet chamber; an outlet cover plate, the outlet cover plate and the second partition plate of the cyclone evaporating chamber define a liquid outlet chamber.

Preferably, the method further comprises: the liquid cyclone inlet and the liquid cyclone outlet are both arranged on the side wall of the cyclone evaporation chamber, and the liquid cyclone inlet is positioned above the liquid cyclone outlet.

The beneficial effects of the application are as follows:

1) In the pump-assisted capillary force driven rotational flow two-phase fluid heat management system, because the liquid supply of the capillary core in the thin film evaporation rotational flow two-phase fluid evaporator is mainly subjected to the action of self capillary force, excessive liquid is prevented from entering the hydrophilic capillary sheet and filling the space of the steam cavity, the hydrophilic capillary sheet isolates the steam cavity of the rotational flow channel in the evaporator, namely, the liquid channel and the gas channel are isolated from each other, and the liquid channel and the gas channel are respectively connected with mutually independent pipelines to respectively transmit gaseous working medium and liquid working medium. Because the liquid working medium is fully isolated from the gaseous working medium, a gas-liquid separator is not required to be arranged in front of the inlet of the compressor, and the gaseous working medium can directly enter the compressor and enter the condenser after being compressed, so that the difficulty in installation and arrangement and control of the refrigeration system are greatly reduced, and the stability of the whole system is improved.

2) The method comprises the steps that thin film evaporation spiral-flow type two-phase fluid evaporators are arranged at different heat source positions and used for radiating heat of the heat sources, working media flowing into the evaporators absorb heat, a part of liquid is evaporated to form saturated steam and enters a compressor to be heated and boosted, then enters a condenser to release heat and condense the saturated steam into liquid, the condensed liquid flows through an expansion valve to be depressurized, finally flows into a liquid storage tank, and the liquid working media are pumped to the evaporators again through a gear pump; the other part of the liquid working medium which absorbs heat and is not evaporated returns to the liquid storage tank through the reflux liquid loop of the evaporator, the heat exchanger communicated with the liquid storage tank dissipates heat brought by the reflux liquid, and the heat exchanger plays a role in controlling the temperature of the evaporator at the same time and is used for maintaining the temperature of the liquid working medium in the liquid storage tank, so that the evaporation effect in the evaporator can be controlled better.

3) According to the invention, the compressor is arranged at the steam outlet of the evaporator to heat and boost the pressure of the steam, so that the temperature of a cold source, namely the condensing temperature of a working medium, is improved, the environmental applicability of the system is improved, meanwhile, waste heat can be utilized for refrigeration, and the waste heat is used as the cold source of the condenser to refrigerate the working medium or supply heat to other heat consuming loads, so that the system has good green economy.

4) In the aspect of controlling the temperature of high heat flux density electrical components, a plurality of evaporator loops are connected in parallel in a pump-assisted capillary force driven rotational flow two-phase fluid heat management system, and the loops work relatively independently, so that loop working media of all main loops and branches can be controlled to maintain a stable circulation state, the heat dissipation condition of a multi-point heat source is respectively controlled in a heat management system, and the pressure in the evaporator is adjusted to adjust a gaseous working medium saturation curve, so that the conditions of different heat absorption and phase change occurrence conditions of working media flowing into the evaporator are comprehensively adjusted.

Drawings

FIG. 1 is a schematic perspective view of a thin film evaporation cyclone two-phase fluid evaporator used in the present invention;

FIG. 2 is a schematic diagram showing a second perspective view of a thin film evaporation cyclone two-phase fluid evaporator according to the present invention;

FIG. 3 is a front view of FIG. 1;

FIG. 4 is a sectional view taken along E-E of FIG. 3;

FIG. 5 is a G-G cross-sectional view of FIG. 3;

FIG. 6 is a cross-sectional view in the H-H direction of FIG. 3;

Fig. 7 is a schematic diagram of a pump assisted capillary force driven two-phase fluid thermal management system according to the present invention.

Reference numerals illustrate:

1. a condenser; 2. a compressor; 3. an evaporator; 4. a control valve; 5. a gear pump; 6. a heat exchanger; 7. a liquid storage tank; 10. a liquid supply pipe; 11. a liquid inlet; 12. a liquid inlet chamber; 13. a liquid swirl inlet; 14. a swirl flow channel; 15. a steam chamber; 16. a steam trunk; 17. a liquid outlet chamber; 18. a liquid outlet; 19. a liquid swirl outlet; 20. an inlet cover plate; 21. a swirl evaporation chamber; 22. a first separator; 23. a steam cover plate; 24. a liquid outlet pipe; 25. a heating surface; 26. a seal ring; 27. a second separator; 28. an outlet cover plate; 30. hydrophilic capillary sheets.

Detailed Description

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

Fig. 7 is a schematic block diagram of an exemplary pump assisted capillary force driven two-phase fluid heat management system including evaporator 3, condenser 1, and high heat flux electrical components. Various components are shown for clarity, but may be rearranged, combined, or integrated with one another. In some exemplary embodiments, the components may be arranged in a planar arrangement alongside one another to save vertical space, for example, for applications on devices such as smart terminals. Alternatively, the components may be stacked and/or integrated in a vertical arrangement, for example in an electrical device where relatively more vertical space is available.

The high heat flux electrical components may be processors and/or controllers or other chips, including microchips with variable heat generation/dissipation that can be at idle performance levels most of the time in their devices, but once used for a large number of data processing or communication conditions, the operational performance will be at significantly higher performance levels and rise to extremely high temperatures in a short period of time.

As can be seen from fig. 7, in the pump-assisted capillary force driven two-phase fluid thermal management system, the evaporator 3 is disposed on the high heat flux density electrical components for dissipating heat therefrom. The evaporator 3 can absorb heat generated from the high heat flux electrical components by the evaporation effect of the liquid working medium. The evaporator 3 chamber may contain a liquid working fluid which is evaporated in the evaporator as a result of heat absorption from the high heat flux electrical components to form vapor, which then flows along the coolant circulation path to the condenser 1 and back to the liquid reservoir 7, again into the refrigeration cycle.

The controller establishes a unidirectional circulation pattern along the coolant circulation path. In some exemplary embodiments, the controller includes a valve to direct the coolant directionally, enabling active pumping of the coolant as needed. In fig. 7, the pump-assisted capillary force driving two-phase fluid heat management system using the gear pump 5 as an auxiliary pump for pumping the liquid working medium. The controller may receive and control the flow of liquid coolant formed as condensate in the condenser and of vapor coolant. In this embodiment, the evaporator is a thin film evaporation cyclone type two-phase fluid evaporator, and the capillary force provided by the thin film evaporation is used as the main driving force for the flow of the liquid working medium, which will be described in detail later.

The condenser 1 may take various forms to remove heat from a liquid working medium, i.e., a coolant, such as a radiator, which may be laminated by sheets to form a flow passage for a coolant circulation path. Such a thin profile shape enables the condenser to be integrated into a housing, such as an electronic device, providing an environment that is exposed to a large surface area for use around a heat transfer cooler. The condenser is schematically represented as a block in fig. 7, but may take the form of an elongated tube along a tortuous path, as in a radiator. The form of the condenser is not particularly limited in this embodiment, and is prior art and is not modified here.

The cooling cycle of the liquid working substance in the entire coolant circulation path may flow-circulate based on a two-phase liquid/vapor cycle, and in the vapor chamber 15 of the evaporator 3, capillary force of the hydrophilic capillary sheet drives the liquid working substance to be supplied to a high temperature region and evaporated.

Still include the liquid storage pot, it is the liquid storage device that is used for storing cooling medium, and the exit end of liquid storage pot is connected to the evaporimeter through the pump, and the steam outlet of evaporimeter is connected to the condenser, and the exit end of condenser is connected to the liquid storage pot, and the liquid outlet of evaporimeter is connected to the liquid storage pot, and is provided with cooling medium and adds entry and cooling medium discharge port on the liquid storage device. In addition, the temperature of the working medium in the liquid storage tank can be regulated through a refrigerating loop.

The thin film evaporation rotational flow type two-phase fluid evaporator used in the invention is essentially a rotational flow type two-phase fluid evaporator driven by a pump auxiliary capillary force, which is mainly driven by the capillary force, is assisted by the pump driving, and is used for tangentially feeding and leaving fluid working medium at a certain flow rate. Evaporation is the physical process of converting a liquid state into a gaseous state. In general, a vaporizer, i.e. a body in which a liquid substance is converted into a gas state. There are a large number of evaporators in industry, one of which is the evaporator used in refrigeration systems.

The thin film evaporation rotational flow type two-phase fluid evaporator 3 is arranged at different heat source positions and is used for radiating heat of the heat source, working medium flowing into the evaporator absorbs heat, part of liquid is evaporated to form saturated steam, the saturated steam enters the compressor 2 for heating and boosting, then enters the condenser for heat release and condensation to form liquid, the condensed liquid flows through the expansion valve 8 for depressurization, finally flows into the liquid storage tank 7, and the liquid working medium is pumped to the evaporator again through the gear pump 5; the other part of liquid working medium which absorbs heat and is not evaporated returns to the liquid storage tank 7 through a backflow liquid loop of the evaporator, the heat exchanger 6 communicated with the liquid storage tank 7 dissipates heat brought by backflow liquid, and the heat exchanger 6 plays a role in controlling the temperature of the evaporator 3 at the same time and is used for maintaining the temperature of the liquid working medium in the liquid storage tank 7.

The thin film evaporation rotational flow type two-phase fluid evaporator is mainly driven by capillary force to perform liquid supply, evaporation and heat dissipation, so that when the fluctuation range of heat dissipation capacity of a heat source is not large, an electric valve at the front end of the evaporator can be set as a throttle valve, and instability of a system caused by an electric element is reduced; meanwhile, when the range of the heat dissipation capacity of the heat source is large, the electric valve at the front end of the evaporator can well distribute the flow, and more liquid can be supplied to the branch with large heat dissipation capacity requirement of the heat source so as to meet the temperature control requirement;

when the temperature condition of the heat source changes, the temperature of the working medium in the liquid storage tank 7 is regulated and controlled by the heat exchanger 6 to control the evaporation temperature in the evaporator 3, so that the regulation and control of the temperature of the heat source are realized; when the stable operation of the temperature control system is completed, the heat exchanger 6 still needs to maintain operation to balance the extra heat brought by the reflux liquid loop and the condensed liquid loop, so as to ensure the temperature of the working medium in the liquid storage tank 7.

In fig. 1-6, a two-phase fluid evaporator comprises a vapor cover plate 23, an inlet cover plate 20, a cyclonic evaporation chamber 21, an outlet cover plate 28, and a hydrophilic capillary sheet 30; the hydrophilic capillary sheet 30 is arranged at the inner bottom of the cyclone evaporation chamber 21; the steam cover plate 23 is provided with a steam trunk 16 and a steam cavity 15; a cyclone runner 14 is arranged between the steam cover plate 23 and the cyclone evaporation chamber 21; a liquid inlet chamber 12 is arranged between the inlet cover plate 20 and the cyclone evaporation chamber 21; a liquid outlet chamber 17 is arranged between the outlet cover plate 28 and the cyclonic evaporating chamber 21. When the thin film evaporation cyclone type two-phase fluid evaporator of the embodiment is used, the power of a pump is controlled so as to control the conveying flow and the flow speed of a fluid working medium, the inlet pressure of the fluid working medium at the liquid inlet 11 of the evaporator is adjusted, the fluid working medium of a refrigerating system is connected with the evaporator through the liquid inlet 11, the working medium firstly enters the liquid inlet chamber 12 through the liquid inlet 11 along the tangential direction, the liquid inlet chamber 12 can be regarded as a flow dividing chamber to play a role of uniformly distributing liquid, the liquid enters the cyclone evaporation chamber 21 through a plurality of uniformly distributed liquid cyclone inlets 13, flows in the cyclone flow channel 14, and part of liquid directly flows out of the cyclone evaporation chamber 21 through a plurality of uniformly distributed liquid cyclone outlets 5 and enters the liquid outlet chamber 17 through the liquid cyclone outlet 19 to leave the evaporator; the other part of working medium liquid is sucked into the hydrophilic capillary sheet 30 by capillary force by the hydrophilic capillary sheet 30 arranged at the inner bottom of the cyclone evaporation chamber 21, the bottom of the cyclone evaporation chamber 21 is heated to transfer heat to the hydrophilic capillary sheet 30, the liquid in the sheet is heated to generate film evaporation, so that a large amount of steam is generated, and the generated steam firstly enters the steam cavity 15 and then is discharged out of the evaporator through the steam trunk 16.

Thus, in this embodiment, the fluid working medium is tangentially swirled into the swirling evaporation chamber 21, and the hydrophilic capillary sheet 30 is laid on the bottom surface of the swirling evaporation chamber 21; the fluid working medium whirls on the bottom surface of the whirl evaporating chamber 21 to wash the thin sheet (namely, the liquid suction core), the hydrophilic capillary thin sheet sucks the fluid working medium near the wall surface and at the bottom into the evaporating surface positioned at the center of the evaporator, and the evaporating surface heats the fluid working medium to evaporate; the redundant fluid working medium flows out from the lower part of the cyclone flow channel 14, and the steam is discharged from the upper middle part, so that the film evaporation is realized, the thermal resistance of liquid is reduced as much as possible, the purpose of gas-liquid separation can be achieved, and the design of the whole pump-driven two-phase system is facilitated.

For the materials of each structure of the evaporator, the metal with hydrophilicity is mainly selected, and the bottom of the cyclone evaporation chamber 21 can be in direct contact with a heat source for heat exchange, so that the metal material with good heat conduction performance is preferably prepared; while hydrophilic capillary sheet 30 may be made of any capillary micro-nano structured material selected from metal powder sintering, wire mesh, and the like. The heating surface at the bottom of the cyclone evaporating chamber 21 is generally attached to an electrical component with high heat flux density, for example, a laser diode, a high power sensing chip, etc. for a space communication system, which not only has a high integration level, but also has a heat flux density of hundreds of W/cm ², and has significant instantaneous periodic working characteristics, and also requires good temperature uniformity.

In use, the high heat flux electrical components are mounted in different devices which will sometimes be in hybrid motion, such as on aircraft, spacecraft. The thin film evaporation cyclone type two-phase fluid evaporator of the embodiment can be suitable for high heat flux density electrical components in various motion states. The fluid working medium is forced to be driven by centrifugal force in the evaporator, so that the fluid working medium can adapt to various inclination-angle-changing postures of the aircraft, namely, the fluid working medium in a forced rotational flow state can be stably and uniformly supplied to the liquid suction core; secondly, the circumferential flow of the fluid working medium rotational flow can enable the liquid suction core to uniformly suck liquid, so that uneven local liquid supply is avoided; in addition, aiming at the characteristics of multiple heat sources, different working conditions and the like of a heat load object, the temperature control can be better realized by regulating and controlling the flow rate of a pump and utilizing the centrifugal force of fluid working media to assist the liquid suction of a liquid suction core so as to achieve the purpose of adapting to the density of the heated fluid; finally, the mode of supplying fluid working medium in a cyclone mode forces liquid to flow, is more beneficial to stabilizing the flowing posture, and also enables the design of the evaporator to be more compact.

In the thin film evaporation rotational flow type two-phase fluid evaporator of the embodiment, because the liquid supply of the capillary core is mainly influenced by the capillary force of the capillary core, the influence of gravity or acceleration can be well avoided, and the stability of the liquid supply is ensured; to avoid excessive liquid entering the hydrophilic capillary sheets 30 and filling the vapor chamber 15 space, this can be accomplished by increasing the heat flux density or by appropriately increasing the back pressure of the vapor chamber 15. The hydrophilic capillary sheet 30 isolates the vapor chambers 15 of the cyclone flow channels 14 in the evaporator from each other, i.e., the liquid channels and the gas channels from each other, and connects the mutually independent pipelines to respectively transmit the gaseous working medium and the liquid working medium. The heat of the heat source absorbed by the working medium is vaporized on the surface of the hydrophilic capillary sheet 30 on the gas channel side of the evaporator, and capillary force is formed at the same time. The capillary force can provide driving force for the liquid to permeate the capillary core and the gas working medium to flow along the pipeline, and it is understood that the larger the heat load is, the more the fluid working medium is permeated and vaporized, and the larger the capillary force is formed. Therefore, the system can automatically realize the distribution of cold energy according to the requirement without any regulating valve, and is an evaporator capable of adaptively supplying fluid working media.

In particular structural mounting, the structural body may be constructed according to the inventive concept of the present embodiment, which is not particularly limited.

In this embodiment, the thin film evaporation cyclone two-phase fluid evaporator comprises a steam cover plate comprising a steam trunk and a first partition; the first partition plate divides the inner cavity of the cyclone evaporation chamber into a cyclone flow channel and a steam cavity, and the hydrophilic capillary sheet is positioned at the bottom of the inner cavity and communicates the cyclone flow channel with the steam cavity; the outer wall of the cyclone evaporation chamber is also provided with an annular second baffle plate; an inlet cover plate, the inlet cover plate and a second partition plate of the cyclone evaporation chamber defining a liquid inlet chamber; an outlet cover plate, the outlet cover plate and the second partition plate of the cyclone evaporating chamber define a liquid outlet chamber.

In the present invention the liquid inlet 11 is chosen to enter the evaporator in a tangential manner to ensure a more even distribution of liquid in the liquid inlet chamber 12, while the evenly distributed plurality of swirl inlets 14 and swirl outlets 5 are also arranged in a tangential perforated manner on the swirl evaporation chamber 21; the hydrophilic capillary sheet 30 may be attached to the vapor cover plate 23 by diffusion welding, or may be attached directly to the inner bottom of the cyclonic evaporator 21 and secured by pressing the vapor cover plate 23.

Preferably, the liquid cyclone outlet arranged below the cyclone flow channel 14 is slightly higher than the hydrophilic capillary sheet 30, the cyclone flow channel of the evaporator in the embodiment divides the fluid working medium into two parts, one part is sucked into the steam cavity to be further evaporated by the film under the action of capillary force, the other part still leaves the cyclone flow channel at a higher speed, the fluid working medium can wash the surface of the hydrophilic capillary sheet at the bottom of the cyclone flow channel, and residual impurities on the surface of the hydrophilic capillary sheet can be carried away, so that the excessive accumulation of the residual impurities is prevented, and the driving action of the capillary force of the sheet is influenced. And after the fluid working medium tangentially enters the cyclone flow channel from the liquid inlet chamber at a certain pressure, strong three-dimensional elliptic strong rotary shearing turbulence motion is generated. Impurities in the fluid working medium migrate to the side wall of the cyclone flow channel due to the gravity and centrifugal force of the impurities, namely centrifugal sedimentation occurs, and impurity particles move along the side wall of the cyclone flow channel and are discharged through the liquid cyclone outlet, so that the impurities in the fluid working medium can be prevented from being settled on the film.

In this embodiment, the fluid working medium is any one of freon, alkane, alkene and its halogenated compounds, ammonia, methanol, ethanol and ethylene glycol. In the evaporator 3, the working medium flowing into the evaporator absorbs heat, and a part of the liquid evaporates to form saturated vapor which enters the compressor 2 for heating up and boosting, and in this embodiment, the compressor is arranged behind the evaporator and in front of the condenser. In the conventional type of compressor and the refrigeration system using the same, liquid working medium is not allowed to enter the compressor, otherwise, liquid impact is easily caused to cause damage to the compressor and even the compressor cannot work. In order to prevent the incompletely evaporated circulating working medium from entering the compressor to cause the compressor to fail to work, a gas-liquid separator is arranged in front of the inlet of the compressor to separate the incompletely evaporated circulating working medium. The gas-liquid separator is thus a necessary component of a conventional mass-cooling circuit. However, in this embodiment, since the liquid supply of the capillary core is mainly acted by the capillary force of the capillary core in the thin film evaporation cyclone two-phase fluid evaporator, excessive liquid is prevented from entering the hydrophilic capillary sheet 30 and filling the space of the vapor chamber 15, the vapor chamber 15 of the cyclone flow channel 14 in the evaporator is isolated from each other by the hydrophilic capillary sheet 30, i.e. the liquid channel and the gas channel are isolated from each other, and the liquid channel and the liquid medium are respectively connected with mutually independent pipelines to respectively transmit the gaseous medium and the liquid medium. Therefore, a gas-liquid separator is not required to be arranged in front of the inlet of the compressor, and the gaseous working medium can directly enter the compressor and enter the condenser after being compressed.

According to fig. 7, a plurality of thin film evaporation rotational flow type two-phase fluid evaporators are arranged at different heat source positions, and the exhaust ports of the plurality of evaporators are connected in parallel and then connected in series with the compressor 2, so that the important invention concept of the invention, namely the two-phase fluid heat comprehensive management concept is embodied.

In terms of temperature control of the high heat flux electrical components, the multiple evaporator loop thermal process schematically shown in fig. 7 can be regarded as a superposition of three single loop thermal processes, and the three loops are all operated relatively independently, so that loop working media of each main loop and each branch loop can be controlled respectively to maintain a stable circulation state. The evaporation efficiency or performance of each evaporator in each evaporator loop heat pipe is differentiated due to the difference in heating load, the variability caused by the randomness of the processing of the hydrophilic capillary sheets 30, and the uneven arrangement of the tubes, as compared to the refrigeration loop of a single evaporator. Therefore, the two-phase fluid heat integrated management system can respectively control the heat dissipation conditions of the multi-point heat sources, and adjust the saturation curve of the gaseous working medium by adjusting the pressure in the evaporator, so that the integrated adjustment is carried out on the difference of the heat absorption quantity of the working medium flowing into the evaporator, the difference of the conditions of phase change and the like.

In the aspect of heat utilization of the high heat flux density electrical components, firstly, the heat generated by the high heat flux density electrical components is characterized by high temperature, but the heat generated by the heat source is less, so that the heat generated by the single electrical components is difficult to be recycled as waste heat when the single electrical components are used as the heat source. In addition, the insufficient temperature of condenser heat dissipation also has greatly limited waste heat utilization's field scope.

In order to solve the above-mentioned drawbacks of the waste heat treatment, in this embodiment, the superheated steam generated by the multiple thin film evaporation cyclone two-phase fluid evaporators is collected and concentrated, and after being converged in the same thermal state, the superheated steam is further subjected to the pressure-increasing and temperature-increasing treatment by the compressor 2 and then passes through the condenser. The heat dissipation at the condenser may be supplied to other heat consuming loads while the heat dissipation is at the same time. As shown in fig. 7, the gaseous working medium output by the evaporator 3 is subjected to adiabatic compression by the compressor 2 and then is heated and boosted to become a high-temperature high-pressure gaseous working medium; the high-temperature high-pressure gaseous working medium enters a condenser to be condensed and then is changed into a medium/low-temperature liquid refrigerant, the process releases heat, the released heat comprises exhaust waste heat of a compressor and condensation heat of the working medium, cooling water in a cooling water pipeline matched with the condenser can be used for utilizing the waste heat and is absorbed and transferred into a cooling tower, and the cooling water is released into an external environment through the cooling tower, can also be used for other heat loads, and can also be directly used for refrigerating heat of the system. The medium/low temperature liquid working medium is expanded to low pressure through an expansion valve to become a gas-liquid mixture, and the liquid working medium at low temperature and low pressure absorbs heat of a heat source in an evaporator to be changed into a gaseous working medium again, so that circulation is completed.

In the waste heat application scene, taking a data machine room heat management system as an example, a high heat flux density electric element is taken as a chip, the highest working temperature of the chip is 70 ℃, the corresponding heat management system can control the evaporation temperature to 65 ℃, a host in the data machine room is placed into a layered structure, heat sources are dispersed and have extremely large quantity, and the heat generated by the heat sources alone is insufficient for waste heat utilization. After the parallel evaporator and the serial compressor temperature and pressure rise technology are used, the temperature at the exhaust gas of the compressor can be increased to 90-100 ℃, namely heat collection and temperature rise treatment are carried out, so that a heat source can be provided for a waste heat refrigerating system; if the compressor discharge temperature is increased to 110 ℃ or even 130 ℃, the waste heat source can be supplied to the Organic RANKINE CYCLE (ORC) cycle waste heat power generation. Therefore, the method has very wide industrial application fields and industrial application prospects, can also intensively utilize waste heat when radiating a tiny heat source, and has very high economic value.

Although the present invention is disclosed above, the present invention is not limited thereto. In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be assessed accordingly to that of the appended claims.

Claims

1. A pump assisted capillary force driven two-phase fluid thermal management system comprising:

The evaporator, wherein the liquid working medium of the evaporator evaporates and enters the circulation path after receiving heat from the heat source;

a condenser that receives the vapor state working medium from the evaporator via a circulation path;

an expansion valve that converts the working medium condensed via the condenser into a low-temperature low-pressure state; and

A pump located in the circulation path for supplying the working medium to the evaporator in a unidirectional circulation mode;

The method is characterized in that:

in the evaporator, the liquid working medium is provided on the hydrophilic capillary sheet in a cyclone mode and is evaporated under the action of a heat source to form a steam working medium;

the compressor receives the working medium from the evaporator for absorbing heat and evaporating and sends the vapor after temperature and pressure rise to the condenser for heat dissipation,

The liquid storage tank is a liquid storage device for storing cooling working media and has a system temperature control function; the outlet end of the liquid storage tank is connected to the evaporator through a pump, the steam outlet of the evaporator is connected to the inlet of the compressor, the outlet of the compressor is connected to the condenser, the outlet end of the condenser is connected to the liquid storage tank through an expansion valve, and the liquid outlet of the evaporator is connected to the liquid storage tank;

the evaporator further comprises a liquid inlet chamber (12) having an annular region and being connected to the liquid channel by a liquid inlet (11);

a swirl flow passage (14) having an annular region and located inside the liquid inlet chamber (12) and communicating with the liquid inlet chamber (12) through a liquid swirl inlet (13);

a steam chamber (15) located in the central region and communicating with the steam passage through a steam trunk (16);

a hydrophilic capillary sheet (30), wherein fluid working medium enters the steam cavity (15) from the cyclone flow channel (14) through the hydrophilic capillary sheet (30);

a liquid outlet chamber (17) which is positioned outside the swirl flow channel (14) and is communicated with the swirl flow channel (14) through a liquid swirl outlet (19);

A heating surface (25) corresponding to the area of the hydrophilic capillary sheet (30) in the steam cavity (15), wherein the fluid working medium is subjected to film evaporation under the action of the heating surface (25);

the first partition plate divides the inner cavity of the cyclone evaporating chamber into a cyclone flow channel and a steam cavity, and the hydrophilic capillary sheet is positioned at the bottom of the inner cavity and communicates the cyclone flow channel with the steam cavity;

the working medium flowing into the evaporator absorbs heat, part of liquid is evaporated to form saturated steam, the saturated steam enters the compressor to be heated and boosted, then enters the condenser to release heat, and finally flows into the liquid storage tank; and the other part of the liquid working medium which absorbs heat and is not evaporated returns to the liquid storage tank through a reflux liquid loop of the evaporator.

2. The pump assisted capillary force driven two-phase fluid thermal management system of claim 1, further comprising:

the front end of the compressor does not contain a gas-liquid separation device, and the evaporator directly supplies the steam working medium into the compressor.

3. The pump assisted capillary force driven two-phase fluid thermal management system of claim 2, further comprising:

The liquid storage tank is connected with a temperature adjusting module, the temperature adjusting module heats or cools working medium in the liquid storage tank so as to control the evaporation temperature of the evaporator, and the liquid storage device is provided with a cooling working medium inlet and a cooling working medium outlet.

4. The pump assisted capillary force driven two-phase fluid thermal management system of claim 3, further comprising:

The temperature adjusting module is a temperature control loop and is used for heating or cooling working media in the liquid storage tank; or the temperature is controlled by heating a heating rod or refrigerating a semiconductor refrigerating sheet.

5. The pump assisted capillary force driven two-phase fluid heat management system of claim 2, wherein the evaporator further comprises:

The exhaust ports of the evaporators are connected in parallel and then connected with the compressor in series, and the controller can independently control the working medium flow rotational flow inlet flow and the internal air pressure parameters of each evaporator.