CN102128552B - Single-sided corrugated plate type pulsating heat pipe - Google Patents

Abstract

Single face wave plate formula pulsating heat pipe includes bottom plate, wave board, first UNICOM's chamber, its characterized in that: the bottom plate is a plane metal plate; one end of the bottom plate is provided with a first communicating cavity which is hermetically connected with the bottom plate, and the section of the wave plate is a continuous triangle, a sine shape or other periodic zigzag; two ends along the extending direction of the wave plate waves are hermetically connected with the bottom plate, one end perpendicular to the extending direction of the wave plate waves is hermetically connected with the first communication cavity, and the other end is hermetically connected with the bottom plate; and a plurality of pulsating channel grooves perpendicular to the extending direction of the wave plate are formed on the bottom plate by welding adjacent wave troughs of the wave plate through spot welding, and the adjacent channel grooves are communicated through micro-seams. The equivalent heat conductivity coefficient of the heat pipe is two orders of magnitude higher than that of an aluminum extruded radiator, is 2-3 times higher than that of a related flat heat pipe, can be horizontally installed, and is particularly suitable for air conditioner ventilation energy recovery and heat dissipation and cooling of electronic components.

Description

Single-sided wavy plate pulsating heat pipe

technical field

The invention discloses a single-sided corrugated plate type pulsating heat pipe. It belongs to the technical field of heat exchange equipment. It is suitable for energy recovery of air-conditioning ventilation and heat dissipation and cooling of electronic devices.

Background technique

With the development of the economy, air conditioners are used more and more widely, but the energy consumption and air quality are increasingly bothering consumers. According to the "Indoor Air Quality Standards", in order to ensure the air quality, it is necessary to exhaust to the outside and send fresh air to the room. The incoming fresh air must be processed by the air conditioning unit to meet the requirements, while the exhaust air is already processed air, both of which consume energy. If the exhaust and fresh air can perform an energy exchange when entering and leaving the room, the load on the air conditioning unit will be greatly reduced and a large amount of energy will be saved. Data show that the fresh air load accounts for 20-30% of the air conditioning load, which shows that the energy consumption of the fresh air load is astonishing. In view of the above situation, it is very necessary and meaningful to recycle the energy of the exhaust air and send it to the fresh air.

At present, air-conditioning ventilation energy recovery technology is divided into several categories: plate type total heat exchanger, rotary wheel heat exchanger, intermediate refrigerant type exchanger, heat pipe heat exchanger. Among them, the heat pipe heat exchanger is widely used in the field of air-conditioning ventilation energy recovery because of its unique advantages such as high heat exchange efficiency, no cross-contamination, no moving parts, and small temperature difference heat transfer. According to the available information, the heat pipes used in air-conditioning ventilation energy recovery are currently limited to traditional gravity heat pipes, new heat pipes such as pulsating heat pipes are rarely used, and the number of published air-conditioning ventilation energy recovery pulsating heat pipes is also very small.

Chips in the field of electronics and microelectronics, thyristors in the electromechanical field, silicon-controlled rectifiers, semiconductor light-emitting diodes (LEDs), large-scale integrated circuits (LSLchips) and other electronic components are widely used in production and life. These components generate a lot of heat when they work, and the heat must be dissipated in time to ensure the safe and stable operation of the equipment. Studies have shown that the operating temperature of the CPU is generally -5 to +70°C. Beyond this range, the reliability of the system will drop by 50% for every 10°C increase in the temperature of a single semiconductor component, and more than 55% of electronic equipment failures are caused by excessive temperature. . It can be seen that the heat dissipation of chips and electronic components is very important.

At present, for the heat dissipation of components, the following two forms of radiators are generally used, namely, aluminum extruded radiators and heat pipe radiators with liquid-absorbing cores.

The heat dissipation principle of the aluminum extruded radiator is that the metal base of the aluminum extruded radiator is in contact with the heating element, and the heat of the component is transferred to the surface of the radiator through heat conduction, and then the fan is used to perform forced convection heat exchange on the radiator, so that the heat transfer to the surrounding atmosphere to realize heat dissipation of components. The heat transfer nature of this method is heat conduction plus convection, which is a relatively low-efficiency heat transfer method.

The heat pipe radiator with a liquid-absorbing core utilizes the heat-absorbing working medium of the heat pipe to change into steam at the hot end, and the steam flows to the cold end to release heat and condense into a liquid, and then returns to the hot end to absorb heat by gravity or the capillary force of the liquid-absorbing core. Circular transfer of heat. Due to the phase change heat transfer, its heat dissipation capacity is greatly improved compared with the aluminum extruded radiator, and it belongs to a higher level of heat dissipation for electronic components.

With the advancement of science and technology, practice shows that the heat dissipation capacity of aluminum extruded heat sinks has reached its limit, and it will be difficult to meet the heat dissipation needs of components in the future. Although the heat pipe radiator with a liquid-absorbing core has a stronger heat dissipation effect than the aluminum extruded radiator, its heat dissipation capability is about to or has already faced a severe test. For example, notebook computers often affect their stable work due to heating, and excessive heating can cause computer crashes, malfunctions, or even damage.

Especially in the field of electronic microelectronics, integrated circuits are developing rapidly in the direction of high density and high power. The heat flux per unit area of the chip is increasing rapidly, and it has reached the order of magnitude of MW/ ^m2 or above. Improvement has become a major bottleneck in the development of electronic and microelectronic technology, and it has become an urgent task to seek a new technology to solve the problem of high heat flux heat dissipation.

The pulsating heat pipe is a new type of high-efficiency heat transfer element proposed in the 1990s. It is especially suitable for heat transfer in the case of small space, small temperature difference, low temperature heat source, and high heat flux. The working mechanism of the pulsating heat pipe is very different from that of the traditional gravity heat pipe. The working process of the traditional gravity heat pipe is a cyclic heat transfer form in which the hot end of the working fluid absorbs heat and evaporates → the steam flows to the cold end to release heat and condenses → the liquid flows back from the cold end to the hot end. The heat transfer cycle process of the pulsating heat pipe is as follows: the hot end of the working fluid absorbs heat and evaporates → when the working fluid flows to the cold end, a vapor-liquid plug randomly occurs and disappears. Hot end recycles. Due to the flow exothermic process in which the vapor-liquid plug randomly occurs and disappears in the pulsating heat pipe, the thermal boundary layer is destroyed during the heat transfer process, the thermal resistance is greatly reduced, and the heat transfer capacity of the heat pipe is greatly enhanced. In addition, the pulsating heat pipe has its own capillary reflux effect, so it still has good heat transfer ability in a horizontal state with an inclination angle of zero, unlike traditional gravity heat pipes that need to use a liquid-absorbent core to complete heat transfer, which simplifies the process and enhances the application. sex, flexibility. As a heat transfer element still in the development stage, there are not many reports on the practical technology and products of pulsating heat pipes. From the currently available information, some research on pulsating heat pipes has been carried out in two directions. One direction is a tubular pulsating heat pipe. The basic structure of the tubular pulsating heat pipe is a serpentine tubular pulsating heat pipe. The processing process is to bend the slender metal thin tube with capillary function into a serpentine shape as required to form a pulsating heat pipe. This type of pulsating heat pipe is mainly used for heat transfer of a fluid medium heat source, and cannot be used for heat transfer or heat dissipation of a solid heat source because it does not have a flat plate structure. Another direction is the plate-shaped pulsating heat pipe. The basic structure of the plate-shaped pulsating heat pipe is a flat container with both sides flat, and the internal arrangement has pulsating channels with capillary left and right. This type of heat pipe can be used for heat transfer of fluid medium heat sources and solid heat sources. It is more applicable than tubular pulsating heat pipes, and it is also convenient for industrial batch production. Therefore, plate pulsating heat pipes are recognized by the engineering community as having high heat transfer performance and the most applicable A pulsating heat pipe in the foreground. However, the inventor of the present invention believes that there are two important defects in this plate structure pulsating heat pipe, which affect the heat transfer performance. Two important defects are respectively: the surface of the heat pipe is all flat, and the channels inside the heat pipe are independent and sealed. For the case where the surface of the heat pipe is all flat, when the air exchanges heat with the heat pipe, since the wall of the heat pipe is all flat, the air will quickly pass over the flat plate, and a thicker thermal boundary layer will be formed between the air and the plane, which increases the heat transfer heat. The resistance is unfavorable to the heat exchange of the air, so that the heat exchange efficiency is not maximized. For the case where the internal channels of the heat pipe are independent and sealed, when the heat pipe is working, the working fluid inside the independent channel will only change according to its corresponding thermal state, and the vapor and liquid plugs with a certain frequency will change randomly under capillary action. Realize the transfer of heat; when the equivalent diameter of the channel is fixed and the type of working fluid is determined, the change frequency of the vapor and liquid plugs is constant. Therefore, the heat transfer performance of the heat pipe cannot be improved by increasing the change frequency of the vapor and liquid plugs. Therefore, the purpose of enhancing heat transfer cannot be achieved.

Chinese patent 200820054984 proposes a pulsating heat pipe type air conditioning exhaust system waste heat recovery device. The core component of the device is a pulsating heat pipe element, and the pulsating heat pipe is formed by bending capillary metal tubes into planar serpentine tube bundles. Although it is a pulsating heat pipe, it is easy to understand that its heat transfer area is smaller than that of a flat heat pipe, and there is no horizontal erosion inside the heat pipe. Chinese patent 200710304125 proposes a thermal energy regeneration device. The core component of the device is the so-called pulsating heat pipe module, which is essentially a serpentine tube bundle bent into a planar shape by capillary metal tubes. There are also the above-mentioned deficiencies in existence.

The electronic device cooling plate heat pipe proposed in Chinese patent 200810119311 has a working principle of non-pulsating heat transfer. The heat pipe frame and the support are integrally brazed, and the channels are independent and sealed, which does not produce enhanced heat transfer between the channels, and the overall brazing will increase the thickness of the entire metal, resulting in an increase in thermal resistance. The plate-shaped heat pipe proposed in Chinese patent 200520011723 has a working principle of non-pulsating heat transfer. In addition, the channel of the heat pipe is square without sharp angles, and the capillary action of the channel is relatively weak. Chinese patent 201010170205 proposes a sintered flat heat pipe, the channel of which is formed by sintering filled metal powder. This method will increase the thickness of the entire shell, increase the thermal resistance, and the powder is difficult to fill densely and uniformly, and the channels are also independent and sealed, so the heat transfer performance of the heat pipe cannot be improved by increasing the frequency of the change of the vapor and liquid plugs. In the flat heat pipe proposed in Chinese patent 200920246791, the channels are circular, and the channels are independent and sealed. The circular shape has weak capillary action. If you want to increase the capillary action, you need to process microgrooves in the circular channel, which is a complicated process. The channels are also independent and sealed from each other, and the heat transfer performance of the heat pipe cannot be improved by increasing the frequency of changing the vapor and liquid plugs.

Judging from the above-mentioned published technical documents, due to the limitations of the working mechanism adopted or the structure of the existing technologies or patents, their heat transfer performance has not yet reached better, and they cannot meet the increasingly stringent requirements. Strict air-conditioning ventilation energy recovery and the need for heat dissipation and cooling of electronic components.

Based on the technical characteristics of the pulsating heat pipe, combined with the current application status of air-conditioning ventilation energy recovery and electronic components heat dissipation, the present invention proposes a single-sided corrugated plate type pulsating heat pipe suitable for air-conditioning ventilation energy recovery and electronic components heat dissipation, in order to form A new, efficient and practical heat exchange element suitable for energy recovery of air-conditioning ventilation and heat dissipation of electronic components, and also provides strong help and support for the progress and development of science and technology in related fields.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, to provide a simple and reasonable structure, small volume, good heat transfer performance, low start-up and working temperature, and small temperature difference heat transfer, which is suitable for air conditioning ventilation energy recovery and electronic components. Single-sided corrugated plate pulsating heat pipe for device heat dissipation.

The present invention is realized by adopting the following technical solutions.

The single-sided corrugated plate type pulsating heat pipe includes a bottom plate, a wave plate, and a first communication cavity, and is characterized in that: the bottom plate is a flat metal plate; one end of the bottom plate is provided with a first communication cavity sealed with the bottom plate, The wave plate is a curved plate composed of a periodic zigzag shape; two ends along the extending direction of the wave plate are sealed with the bottom plate, and one end perpendicular to the extending direction of the wave plate is connected to the second A communication cavity is sealed and connected, and the other end is sealed and connected to the bottom plate; a plurality of pulsating grooves perpendicular to the extension direction of the waves of the wave plate are formed on the bottom plate by spot welding between two adjacent troughs of the wave plate channels, so that micro-slits are connected between adjacent channels; the single-sided wave plate type pulsating heat pipe is evacuated, filled with working fluid, and sealed.

In the single-sided corrugated plate type pulsating heat pipe of the present invention, each of the two ends of the bottom plate is provided with a first communication cavity and a second communication cavity sealedly connected with the bottom plate, and the two ends perpendicular to the extending direction of the waves of the corrugated plate They are respectively sealed and connected with the first communication cavity and the second communication cavity.

In the single-sided corrugated plate type pulsating heat pipe of the present invention, the length of the micro-slits is 5-50 mm, and the width of the micro-slits is 3-30 μm.

In the single-sided corrugated plate type pulsating heat pipe of the present invention, the equivalent diameter of the pulsating channel is 0.5-3.5 mm.

In the single-sided corrugated plate type pulsating heat pipe of the present invention, the cross-section of the periodically zigzag shape of the corrugated plate is one of triangular, trapezoidal and sinusoidal.

In the single-sided corrugated plate type pulsating heat pipe of the present invention, the bottom plate, the corrugated plate, the first communication chamber and the second communication chamber are made of copper alloy, aluminum alloy and stainless steel.

In the single-sided corrugated plate type pulsating heat pipe of the present invention, the working medium is selected from one of distilled water, methanol, absolute ethanol, acetone, R123, and R134a.

The working principle and advantages of the single-sided corrugated plate type pulsating heat pipe of the present invention are briefly described as follows.

The gas-liquid two-phase random distribution of the working medium in the channel, the random generation and disappearance of the vapor-liquid plug, the main body of steam flowing from the evaporating section to the condensing section, and the pulsating flow heat transfer process of the condensate main body flowing from the condensing section to the evaporating section. Part of the working fluid’s lateral movement and heat and mass transfer process exist between the pulsating channels.

Due to the use of corrugated plates, when the air blows over the heat pipe, the wavy surface will disturb the air, making the thermal boundary layer thinner and even destroyed, thereby strengthening the convective heat transfer on the wind side and improving the heat transfer coefficient of the heat pipe.

Due to the use of the corrugated plate, the heat exchange area of the heat pipe is increased, thereby improving the heat exchange capacity of the heat pipe.

Due to the use of micro-slit channels, part of the working fluid moves laterally in the channels when the heat pipe is working, resulting in disturbances between channels, resulting in an increase in the frequency of random bursting of vapor and liquid plugs in the channels, thus making the thermal boundary layer on the inner wall of the channel change. Thin or damaged, improve the heat transfer performance of the heat pipe.

Due to the plate structure with one side being a flat plate and one side being a corrugated plate, the heat pipe is well suited for air conditioning ventilation energy recovery as well as heat dissipation and cooling of electronic components.

There must be at least one of the first communication cavity and the second communication cavity of the heat pipe of the present invention, which is used to communicate with the internal pulsation channel, so that the heat pipe can be vacuumed and filled with liquid more conveniently, and the working medium of each pulsation channel is evenly distributed, which is beneficial to the uniformity of the heat pipe. heat transfer.

The equivalent diameter of the channel in the present invention is between 0.5 and 3.5 mm, and the cross-section has multiple sharp angles, forming a capillary channel. The capillary channel can overcome the traditional gravity without a liquid-absorbing core. It must be greater than the limit of 15°. Even if it is installed horizontally, it still has good heat transfer capability, and it is extremely convenient to install and use.

The invention adopts copper alloy, aluminum alloy and stainless steel, which are good conductors of heat, to process a single-sided corrugated plate type pulsating heat pipe, which can effectively improve the heat transfer efficiency of the heat pipe.

The invention adopts distilled water, methanol, absolute ethanol, acetone, R123 and R134a as working fluids, and has wide source of materials and low price.

The single-sided corrugated plate type pulsating heat pipe of the present invention is suitable for heat transfer when the temperature of the heat source is in the range of 20°C to 120°C.

The present invention breaks through the inertial constraints of the existing pulsating heat pipe research and thinking because one side is a wavy and zigzag surface, the other side keeps the same plane and the micro-slit channel. heat transfer performance. It solves the difficulties of efficient recovery of air-conditioning ventilation energy and poor heat dissipation of electronic components, and provides a new, efficient and practical basic heat transfer system that integrates the four functions of pulsating heat transfer, planarization, capillaryization, and enhanced heat transfer. Heat element----Single-sided corrugated plate type pulsating heat pipe, which is especially suitable for air-conditioning ventilation energy recovery and heat dissipation and cooling of electronic components.

In summary, the single-sided corrugated plate type pulsating heat pipe of the present invention combines pulsating heat transfer, planarization, capillaryization, and enhanced heat transfer in one, and its equivalent thermal conductivity is more than two orders of magnitude higher than that of aluminum extrusion radiators. It is 2 to 3 times higher than the flat heat pipe, and has excellent heat transfer performance. The channel with capillary effect enables it to be installed horizontally and has excellent heat transfer function, and it is extremely convenient to install and use. The originality of its structure makes it an efficient, practical and basic flat-plate heat pipe suitable for air-conditioning ventilation energy recovery and heat dissipation and cooling of electronic components.

Description of drawings

Accompanying drawing 1 is the front view of embodiment 1 of the present invention.

Accompanying drawing 2 is the side view of accompanying drawing 1.

Accompanying drawing 3 is the top view of accompanying drawing 1.

Accompanying drawing 4 is an enlarged view of part I in accompanying drawing 2.

Accompanying drawing 5 is the front view of Embodiment 2 of the present invention.

Accompanying drawing 6 is the left view of accompanying drawing 5.

In the attached drawings: 1-the first communication cavity, 2-the second communication cavity, 3-wave plate, 4-pulsation channel, 5-spot welding node, 6-bottom plate, 7-micro seam.

Detailed ways

The two embodiments will be further described below in conjunction with the accompanying drawings. The examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. After reading the content of the present invention, various changes and modifications made by those skilled in the art to the present invention also belong to the scope of the appended claims of the present invention.

Embodiment one

See accompanying drawing 1,2,3,4. The single-sided corrugated plate type pulsating heat pipe of the present invention includes a bottom plate 6, a wave plate 3, and a first communication cavity 1, and is characterized in that: the bottom plate 6 is a flat metal plate; one end of the bottom plate 6 is provided with a The first communication cavity 1 connected; the wave plate 3 is a curved plate formed by a periodic zigzag shape; the baffle plate is a flat metal plate; the two ends along the extending direction of the waves of the wave plate 3 and the The bottom plate 6 is sealed and connected, one end perpendicular to the extending direction of the wave of the wave plate 3 is sealed and connected with the first communication chamber 1, and the other end is sealed and connected with the bottom plate 6; the wave plate 3 is connected between two adjacent troughs A plurality of pulsating channels 4 perpendicular to the extension direction of the wave plate waves are formed on the bottom plate by spot welding 5, so that micro seams 7 are formed between adjacent channels; the single-sided wave plate type pulsating heat pipe Vacuumize, fill with working medium, and seal.

The cross-sectional shape of the pulsation channel 4 is triangular, and the equivalent diameter is 0.5-1.2mm; the bottom plate 6, the wave plate 3, and the first communication cavity 1 are made of red copper; the length of the micro-slit 7 is 5-50mm, and the width 10 to 30 μm. The working medium is distilled water.

Embodiment two

Referring to accompanying drawings 5 and 6, the single-sided corrugated plate type pulsating heat pipe of the present invention includes a base plate 6, a corrugated plate 3, a first communication cavity 1, and a second communication cavity 2, and it is characterized in that: the base plate 6 is a plane metal plate; Both ends of the bottom plate 6 are respectively provided with a first communication cavity 1 and a second communication cavity 2 which are sealed and connected with the bottom plate 6, and the wave plate 3 is a curved plate formed in a periodic zigzag shape; along the wave plate The two ends of the extension direction of the 3 waves are sealed and connected with the bottom plate 6, one end perpendicular to the extension direction of the waves of the wave plate 3 is sealed and connected with the first communication cavity 1, and the other end is connected with the second communication cavity 2 Sealed connection, the wave plate 3 is welded on the bottom plate by spot welding 5 between two adjacent troughs to form a plurality of pulsating channels 4 perpendicular to the extension direction of the waves of the wave plate, so that between adjacent channels Micro-slits 7 are formed to communicate; the single-sided corrugated plate type pulsating heat pipe is vacuumed, filled with working fluid, and sealed.

The cross-sectional shape of the pulsating channel 4 is triangular, and the equivalent diameter is 0.5-1.5mm; the bottom plate 6, the wave plate 3, the first communication cavity 1, and the second communication cavity 2 are made of stainless steel; the length of the micro-slit 7 is 20 to 50 mm and a width of 20 to 30 μm. The working medium is acetone.

In Embodiment 1 of the present invention, there is only the first communication cavity 1 , and the internal working medium distribution and heat transfer uniformity of the heat pipe are slightly worse than those in Example 2, but the processing and manufacture of the heat pipe can be made easier. In the second embodiment, the first communicating chamber 1 and the second communicating chamber 2 exist simultaneously, and the internal working fluid distribution and heat transfer uniformity of the heat pipe are better when the heat pipe is in operation, but the processing is slightly more complicated. In actual use, it can be selected according to specific conditions.

Claims (7)

1. the board-like pulsating heat pipe of single face wave comprises base plate, wave plate, the first UNICOM chamber, and it is characterized in that: said base plate is a planar metal plate; One end of said base plate is provided with first a UNICOM chamber that is tightly connected with said base plate, and said wave plate is the curved slab that one-period property meander-shaped constitutes; Two ends and said base plate along the bearing of trend of said wave Lamb wave are tightly connected, and are tightly connected perpendicular to an end and the said first UNICOM chamber of the bearing of trend of said wave Lamb wave, and the other end and said base plate are tightly connected; On said base plate, form many pulsation conduits through spot-welded between adjacent two troughs of said wave plate, make and form slit UNICOM between the adjacent conduit perpendicular to the bearing of trend of said wave Lamb wave; The board-like pulsating heat pipe of said single face wave vacuumizes, filling working medium, sealing.

2. the board-like pulsating heat pipe of single face wave according to claim 1; It is characterized in that: the two ends of said base plate respectively are provided with the first UNICOM chamber, the second UNICOM chamber that are tightly connected with said base plate, are tightly connected with the said first UNICOM chamber, the second UNICOM chamber respectively perpendicular to the two ends of the bearing of trend of said wave Lamb wave.

3. the board-like pulsating heat pipe of single face wave according to claim 1 is characterized in that: the length of said slit is 5 ~ 50mm, and the slit width is 3 ~ 30 μ m.

4. the board-like pulsating heat pipe of single face wave according to claim 1 is characterized in that: said pulsation conduit equivalent diameter is 0.5～3.5mm.

5. the board-like pulsating heat pipe of single face wave according to claim 1 is characterized in that: the cross section of the periodicity meander-shaped of said wave plate is a kind of in triangle, trapezoidal, the sinusoidal waveform.

6. the board-like pulsating heat pipe of single face wave according to claim 1 and 2 is characterized in that: a kind of manufacturing in copper alloy, aluminium alloy or the stainless steel is selected in said base plate, wave plate, the first UNICOM chamber, the second UNICOM chamber for use.

7. the board-like pulsating heat pipe of single face wave according to claim 1 is characterized in that: said working medium is selected from a kind of among distilled water, methyl alcohol, absolute ethyl alcohol, acetone, R123, the R134a.

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