阅读说明：本技术 一种高效解冻装置 (High-efficient thawing apparatus ) 是由 李艺维 赵京 牛雷 江文峰 谢大为 谢龙 于 2019-10-23 设计创作，主要内容包括：本发明提供了一种高效解冻装置,包括蒸发区、汽管路、冷凝区、液管路、储液器、传热工质、支架,所述蒸发区、冷凝区包括若干块翅片板并排拼接设置而成；所述翅片板的上下两端分别连通汽管路、液管路；所述汽管路、液管路为中部设有空腔的空心管体,其管体两端密封；所述翅片板的上下两端分别穿设于汽管路、液管路的条形插孔之内；所述翅片板上设有若干竖直阵列布置微通道,微通道上下两端分别连通汽管路、液管路的空腔；装置整体组成两相流体回路,所述传热工质设于两相流体回路内。本发明的高效解冻装置,其有效导冷面积大、底层传热技术传热能力强,因此导冷能力强,可有效提升解冻板的解冻速度。(The invention provides a high-efficiency unfreezing device which comprises an evaporation area, a steam pipeline, a condensation area, a liquid pipeline, a liquid storage device, a heat transfer working medium and a bracket, wherein the evaporation area and the condensation area comprise a plurality of fin plates which are spliced side by side; the upper end and the lower end of the fin plate are respectively communicated with a steam pipeline and a liquid pipeline; the steam pipeline and the liquid pipeline are hollow pipes with cavities in the middle, and two ends of each pipe are sealed; the upper end and the lower end of the fin plate are respectively arranged in the strip-shaped jacks of the steam pipeline and the liquid pipeline in a penetrating way; the fin plate is provided with a plurality of vertical array-arranged micro-channels, and the upper end and the lower end of each micro-channel are respectively communicated with cavities of a steam pipeline and a liquid pipeline; the device integrally forms a two-phase fluid loop, and the heat transfer working medium is arranged in the two-phase fluid loop. The efficient thawing device has the advantages of large effective cold conduction area and strong heat transfer capacity of the bottom layer heat transfer technology, so that the cold conduction capacity is strong, and the thawing speed of the thawing plate can be effectively increased.)

1. The utility model provides a high-efficient thawing apparatus which characterized in that: comprises an evaporation area, a steam pipeline, a condensation area, a liquid pipeline, a liquid storage device, a heat transfer working medium and a bracket,

the evaporation zone and the condensation zone comprise a plurality of fin plates which are spliced side by side;

the upper end and the lower end of the fin plate are respectively communicated with a steam pipeline and a liquid pipeline;

the steam pipeline and the liquid pipeline are hollow pipes with cavities in the middle, and two ends of each pipe are sealed; the outer wall of the lower bottom surface of the steam pipeline is provided with a plurality of strip-shaped jacks, and the outer wall of the upper surface of the liquid pipeline is provided with a plurality of strip-shaped jacks;

the upper end and the lower end of the fin plate are respectively arranged in the strip-shaped jacks of the steam pipeline and the liquid pipeline in a penetrating way;

the fin plate is provided with a plurality of vertical array-arranged micro-channels, and the upper end and the lower end of each micro-channel are respectively communicated with cavities of a steam pipeline and a liquid pipeline;

the device integrally forms a two-phase fluid loop, and the heat transfer working medium is arranged in the two-phase fluid loop;

the reservoir is arranged in the liquid pipeline.

2. The high-efficiency thawing apparatus according to claim 1, wherein: the support is fixedly arranged on the steam pipeline.

3. The high-efficiency thawing apparatus according to claim 2, wherein: the support is hollow body, the steam pipeline wears to locate the hollow portion of support, and the support border is riveted with fin board top.

4. A high efficiency thawing apparatus according to any of claims 1 to 3, wherein: the heat transfer working medium comprises propylene, difluoromethane, acetylene and nano silicon carbide powder.

5. The efficient thawing apparatus according to claim 4, wherein: is prepared from 10-15 parts of propylene, 30-45 parts of difluoromethane, 40-55 parts of acetylene and 1-5 parts of nano silicon carbide powder.

6. The efficient thawing apparatus according to claim 4, wherein: the section caliber of the micro-channel is rectangular.

7. The efficient thawing apparatus according to claim 4, wherein: the cross section of the micro-channel is elliptical or circular.

8. The efficient thawing apparatus according to claim 6, wherein: the dimension specification is 60mm multiplied by 2mm or 32mm multiplied by 2mm or 25.4mm multiplied by 2 mm.

9. The efficient thawing apparatus according to claim 4, wherein: the fin plate is a micro-channel fin plate or a blown fin plate.

10. The efficient thawing apparatus according to claim 4, wherein: the included angle between the fin plate and the horizontal plane is 2-6 degrees.

Technical Field

The invention belongs to the technical field of unfreezing devices, and particularly relates to a high-efficiency unfreezing device.

Background

Meat products are generally preserved by freezing and are thawed before use. The common natural thawing speed is slow, bacteria are bred, nutrition loss and taste influence are caused when the food is soaked in water for thawing, and the food is cooked outside and frozen inside and damaged when the food is thawed by microwaves. The unfreezing plate is utilized to carry out quick natural unfreezing, and the unfreezing mode is the healthiest unfreezing mode.

The unfreezing plate transmits the cold energy of the frozen food to the environment to realize quick unfreezing, and the larger the transmitted cold energy is, the faster the unfreezing speed is. The thawing rate is mainly determined by the heat transfer capability of the underlying heat transfer technology and the effective cold conducting area.

The traditional unfreezing plate is a pure aluminum plate or a low-temperature gravity heat pipe filled with alcohol, on one hand, the pure aluminum plate is made of pure materials for heat conduction, the heat conduction coefficient is about 200W/(m.K), and the heat transfer capacity of the low-temperature gravity heat pipe is not high as well; on the other hand, the effective cold conducting area is small due to the poor heat conducting capability of the bottom layer. Therefore, the traditional defrosting plate has limited cold conduction capability, and the defrosting speed of the defrosting plate is directly limited. The invention provides an efficient thawing device, which aims to solve the problem of poor cold conducting capability of a traditional extruded aluminum profile or low-temperature gravity heat pipe thawing plate.

For the purposes of understanding the principles of operation of the present application, a highly efficient passive heat transfer technique based on a temperature difference driven self-circulating two-phase fluid loop is described in detail herein. The high-efficiency passive heat transfer technology refers to a heat transfer technology having a high heat transfer capability, requiring no external power (i.e., having high reliability).

The heat exchange carried out by the phase change latent heat is several orders of magnitude larger than the heat transferred by a single relative flow system in a sensible heat mode, and meanwhile, the efficient passive heat transfer technology is usually constructed on the basis of the phase change heat exchange without external power.

The high-efficiency passive heat transfer technology has wide engineering application scenes.

In a heat utilization scene, the method relates to the field of efficient utilization of cold quantity, such as cold conduction of a semiconductor refrigerator, cold conduction of a Stirling refrigerator, LNG (liquefied natural gas) cold quantity transmission, a thawing plate and the like; and the fields of high-efficiency utilization of heat, such as high-efficiency utilization of solar energy, utilization of low-grade heat energy of ground source/water source/air source, utilization of industrial waste heat, thermoelectric generation, IH-like electric cooker inner containers and the like.

In a thermal control scene, the heat dissipation field of electronic devices is related, such as 5G equipment, LEDs, lasers, phased array radar T/R components, CPUs (home computers/servers/mobile phones), IGBTs (frequency converters/photovoltaic inverters/extra-high voltage direct current transmission), semiconductor refrigerators, power batteries, proton exchange membrane fuel cells and the like; and the field of heat exchange of closed spaces, such as base stations, data centers, power cabinets, naval vessel engine cabins and the like.

1. Principle of system

The fundamental idea of strengthening the phase change heat exchange is to increase the phase change heat exchange quantity in unit time, namely, to increase the product of the phase change rate and the phase change latent heat.

On one hand, the whole phase change period covers the whole process of bubble nucleation, bubble growth, bubble detachment and bubble polymerization rise; on the other hand, the phase transition rate and the phase transition latent heat are closely related parameters on the physical aspect, so the improvement of the product of the two parameters needs to be based on the comprehensive analysis of the bubble nucleation and the kinetic characteristics of the phase transition complete cycle.

2. Intensification of the phase transition Rate

2.1 bubble nucleation theory

The vapor bubbles in the boiling process all develop from the core of vaporization (i.e., the tiny vapor bubbles).

The vaporization core of the volume boiling is generated spontaneously, and is caused by fluctuation of the density of each part of the liquid around the average value due to the energy distribution nonuniformity of liquid molecules (according to the molecular motion theory, the energy of each molecule in the liquid is unequal and is distributed according to a certain rule, the nonuniformity of the molecular energy distribution enables the density of each part of the liquid to fluctuate around the average value, temporary local tiny low-density areas are formed due to the random aggregation of activated molecules with larger energy, and the small low-density areas are considered to be tiny vapor bubbles with certain radius and molecular number, which is the formation process of tiny vapor saturated cores in the liquid phase), and the degree of superheat of hundreds is needed.

The vaporization cores of the boiling in the pool are provided outside and are pits, slits and cracks on the heating wall surface (firstly, the liquid in the slits on the heating surface is influenced by much more heating than the same amount of liquid on the plane, and is easy to vaporize to generate steam, and secondly, the gas in the slits is easy to remain, and the gas naturally becomes the vaporization cores for generating bubbles), and the superheat degree is smaller.

As shown in FIG. 1, a container is provided, the bottom surface of which is heated and the upper surface of which is provided with a pressure p_sCorresponds to t_sE.g. with a bubble in the middle, with internal pressure p_vTemperature t_vAmbient fluid corresponds to p_l、t_l。

The conditions under which the bubbles are stable are thermal equilibrium and force equilibrium:

(1) heat balance: t is t_l＝t_v

If t_l＜t_vThen the bubbles transfer heat to the fluid, the steam in the bubbles condenses, and the bubbles collapse;

if t_l＞t_vThen the fluid transfers heat to the vapor bubble, the vapor in the vapor bubble expands, and the vapor bubble grows up.

(2) Force balance: p is a radical of_v-p_l＝2γ/R

If p is_v-p_lIf the pressure difference between two sides of the steam bubble is less than 2 gamma/R, the pressure difference between two sides of the steam bubble is not enough to resist surface tension, steam in the steam bubble is condensed, and the steam bubble is collapsed;

if p is_v-p_lIf the pressure difference is more than 2 gamma/R, the pressure difference of two sides of the steam bubble is more than the surface tension, the steam in the steam bubble expands, and the steam bubble grows up.

For the force balance condition, without considering the static pressure,

p_l＝p_s

then there is a change in the number of,

is the rate of change of pressure on a vapor-liquid two-phase saturation line with temperature, and is constant for a certain pressure. According toThe relation between the pressure variation along with the temperature on the saturation line and each parameter of the saturation state, the Clausius-Clabairon proposes the following calculation formula:

wherein r is the latent heat of vaporization at saturation temperature, ρ_vAnd rho_lRespectively the density of the vapor and liquid within the bubble. When boiling away from the critical point, ρ_v＜＜ρ_lThen, the above formula is simplified as follows:

the substitution above can result in:

in the case of boiling, the liquid has a maximum superheat at the wall, Δ t ═ t_v-t_s＝t_w-t_sTherefore, the bubble generation condition is satisfied at the wall surface first, and the minimum radius of the wall surface when the bubble nucleus is generated is as follows:

the above formula shows that under certain conditions of p and delta t, the primary bubble nucleus can grow continuously only when the radius of the primary bubble nucleus is larger than the value, and the above formula is the minimum radius of the primary bubble nucleus for standing the foot.

If the vaporized core in the pit can not grow any more, the pit is an inactive pit, i.e., an inactive nucleation site. The vaporization core in the pit grows until the vaporization core grows to expose the opening of the pit, and the radius of a small vapor bubble exposing the opening (which can be approximately regarded as the radius of the opening of the pit) is larger than or equal to the critical radius of the vapor bubble corresponding to the superheat degree of a given liquid, so that the vaporization core can continue to grow, and the pit is called an activation pit, namely an activation nucleation point.

Critical activation nucleation point radius r_mCritical core of vaporization R_min＝2γT_s/rρ_vΔ T, where γ is the surface tension coefficient of the working fluid, T_sIs the saturation temperature at local pressure, r is the latent heat of vaporization at saturation temperature, ρ_vIs the saturated steam density, Δ t ═ t_w-t_sThe superheat degree of the liquid working medium on the wall surface. The boiling heat exchange intensity (or phase change rate) on the wall surface depends on the total number of activated nucleation points on the heating wall surface, and the size distribution density of pits on the heating wall surface is approximate to a normal distribution function N with the origin as the starting point_rThus total number of activated nucleation sites

I.e. the radius r of the heating wall surface is larger than the critical activation nucleation point_mThe pits of (a) are all activation nucleation sites. Thus, the ways to increase the total number of activated nucleation sites N fall into two categories: firstly, a layer of porous structure is formed on the heating wall surface, and the normal distribution function N is increased_rThe expectation and standard deviation of the activation nucleation sites N can be multiplied by the method; secondly, the phase change working medium is modified at a certain saturation temperature T_sAnd the critical activation nucleation point radius r is reduced under the condition of the wall surface superheat degree delta t_mThis method can increase the total number of activated nucleation sites N by several orders of magnitude.

2.2 gas dynamic theory

The dynamics of the vapor bubble mainly researches the growth and movement rule of the vapor bubble in the liquid.

(1) The bubble grows, the vaporization core formed on the activation nucleation point can grow continuously under various forces. The early stage is a dynamic control stage, the growth of the bubbles is mainly governed by internal thermal inertia force and external surface tension, and the growth rate of the bubbles is very high; the latter is a heat transfer control stage, which is extended for a longer time, with the bubble growth rate being dominated by the heat transfer capacity from the heated liquid to the vapor bubble, the bubble growth rate being slower when the liquid is saturated liquid and faster when the liquid is superheated liquid (discussed at point (2.3)).

(2) In the bubble-disengaging period of time,diameter D of detachment of bubbles from heating wall surface_dThe smaller the detachment frequency f, the higher the phase transition rate. Wherein the bubble detachment diameter D_dThe influencing factors comprise that the system pressure is reduced along with the increase of the system pressure, the proportional relation of the system pressure and the gravity acceleration is proportional to the power of-1/3 times, and the influence of inertia force is mainly caused under the condition of negative pressure (the pressure is lower than the atmospheric pressure); the bubble disengagement frequency f has a relationship

For the kinetic control phase, the index n is 2, and for the heat transfer control phase, the index n is 1/2. Therefore, the bubble separation diameter D can be reduced by modifying the working medium_dMeanwhile, the bubble separation frequency f is increased, and the phase change rate is further enhanced.

(3) In the bubble polymerization rising period, the heat exchange between the bubbles and the liquid in the rising process can reach very high strength (discussed at (2.3)), so that the effective discharge of the bubbles can improve the critical heat flow density under the working condition of high heat flow density, the polymerization and rising movement of the bubbles are very complex, and the bubbles are related to complex gas-liquid two-phase turbulence, and the current research is in the initial stage. But a reasonable bubble discharge structure can be designed to effectively discharge bubbles, thereby strengthening the phase change rate.

The method integrates (1) and (2) nub analysis, modifies the phase change working medium based on the phase change characteristic of the phase change full cycle, and reduces the radius r of the critical activation nucleation point from the physical property level_mTo increase the total number of activated nucleation sites N; reducing the bubble separation diameter D from the physical layer_dIncreasing the bubble separation frequency f to further enhance the phase change rate.

2.3 theory of superheated boiling

In the boiling process, in the heat transfer control stage at the later stage of bubble growth, the bubble growth rate is mainly governed by the heat transfer capacity from liquid to vapor bubble, and the superheat degree of the liquid determines the growth rate of the bubbles; in the rising stage of bubble polymerization, the superheat degree of the liquid determines the heat exchange strength between the vapor bubble and the liquid in the rising process. The bubble growth rate can be enhanced by designing the liquid working medium as superheated liquid.

The boiling state when the temperature of the liquid main body reaches the saturation temperature is saturated boiling, and bubbles can grow slowly in the liquid after being separated from the wall surface; the boiling state that the main body temperature of the liquid is lower than the saturation temperature is supercooling boiling, and the bubbles can disappear in the liquid after separating from the wall surface; the boiling state in which the bulk temperature of the liquid exceeds the saturation temperature is superheated boiling, and bubbles grow rapidly in the liquid after leaving the wall surface. Therefore, the liquid working medium is designed to be an overheat liquid, namely, an overheat boiling state is established.

For heterogeneous boiling on the overheating wall surface, the temperature of the liquid working medium is from the heating of the overheating wall surface, the liquid body is difficult to obtain larger superheat degree in a wall surface heating mode, therefore, the boiling point of the working medium is required to be reduced in a mode of reducing boiling interface pressure, and the overheating boiling is realized under the condition that the liquid working medium obtains heat only through the wall surface heating.

In order to reduce the boiling interface pressure, a phase change cycle must be constructed. The complete two-phase fluid loop comprises an evaporator, a steam pipeline, a condenser, a liquid pipeline and a liquid storage device, the two-phase fluid loop is driven by temperature difference to carry out self circulation, and the circulating power can be gravity or capillary force.

(1) The pressure-temperature diagram of a two-phase fluid loop thermodynamic cycle when the cycle power is gravity is shown in figure 2.

Wherein the content of the first and second substances,

1: an evaporation interface within the evaporator;

1 → 2: the steam is continuously heated in the evaporator to form superheated steam-delta P_eva；

2 → 3: steam flows in the steam line-delta P_vap；

3 → 4: cooling steam in the condenser;

4 → 5: condensing steam in the condenser;

5 → 6: supercooling of liquid in condenser-total of the three items Δ P_con；

6 → 8: liquid flowing in the liquid pipe-delta P_liq；

7: a reservoir;

gravity pressure difference delta P as circulating power_gTotal flow pressure loss Δ P_total＝ΔP_eva+ΔP_vap+ΔP_con+ΔP_liq。

(2) When the circulation power is capillary force, the pressure-temperature diagram of the thermodynamic circulation of the two-phase fluid loop is similar to the upper diagram, and the flow pressure difference delta P in the capillary core is increased in the circulation_wic。

Corresponding to capillary pressure difference DeltaP as circulation power_cTotal flow pressure loss Δ P_total＝ΔP_eva+ΔP_vap+ΔP_con+ΔP_liq+ΔP_wicIf the evaporator is in the antigravity working condition, the capillary wick correspondingly provides the total flow resistance delta P_totalAnd gravity head Δ P_gThe circulating power of (2). During thermal equilibrium of the system, the radius of the meniscus in the evaporator is automatically adjusted to match the flow resistance of the fluid circuit, which is the heat transfer capacity limit of the system when the radius of the meniscus is equal to the capillary aperture.

Under any circulating power condition, the boiling interface temperature of the two-phase fluid loop is T₁Pressure of P₈The boiling environment at this time is lower than the saturation pressure + the saturation temperature, that is, the superheated boiling state.

In an overheat boiling state, the liquid working medium is overheat liquid, and in a heat transfer control stage at the later stage of bubble growth, the overheat liquid transfers heat to the vapor bubble in a large amount, and the growth rate of the bubble is high; in the bubble polymerization rising stage, the superheated liquid also transfers a large amount of heat to the bubbles, and the heat exchange strength between the bubbles and the liquid is higher, so that the phase change rate is enhanced.

By integrating the summary analysis of (2.1) - (2.3), the critical activation nucleation point radius r can be reduced from the physical property level by modifying the phase change working medium_mTo increase the total number N of activation nucleation points and to decrease the bubble separation diameter D from the physical aspect_dIncreasing the bubble separation frequency f to ensure that the heat transfer working medium has higher phase change rate in the bubble nucleation and bubble separation process of the phase change full period, thereby strengthening the phase change rate; the vapor-liquid separation is realized by designing a two-phase fluid loop and by a capillary structure, a liquid pool structure and a height difference structure, so that the phase change interface pressure of a heat transfer working medium in the evaporator is reduced, and further the hot boiling is constructedThe state of the heat transfer medium increases the heat exchange strength between the vapor heat transfer medium and the liquid heat transfer medium in the process of bubble growth and bubble polymerization in the whole phase change period, thereby enhancing the phase change rate.

3. Intensification of latent heat of phase change

The latent heat of phase change refers to the heat absorbed or released by the working medium of unit mass in the phase change process when the temperature is unchanged. The latent heat of phase change comprises an internal work part for overcoming the interaction potential energy between molecules to do work and an external work part for overcoming the atmospheric pressure to do work. The internal work is a main component, and the potential energy of intermolecular interaction includes intermolecular forces such as van der waals force and hydrogen bond. Van der waals' force is a weakly basic electrical attraction, also called intermolecular force, that exists between neutral molecules or between inert gas atoms; hydrogen bonds exist between nonmetal atoms with large electronegativity and small atomic radius such as F, O and N and hydrogen, and molecules with hydrogen bonds include HF and H₂O and NH₃And the like.

The intermolecular forces of working media with similar physical shapes in the same temperature zone are not different greatly, for example, water, ethanol and acetone are all liquid at normal temperature and normal pressure, and the intermolecular forces are different by only a few times. That is, the latent heat of phase change between different working mediums in a certain temperature area is usually only several times different.

Therefore, when the product of the phase change rate and the phase change latent heat is comprehensively considered in the enhanced phase change heat exchange, the phase change rate enhanced by several orders of magnitude can be realized, and the phase change latent heat with the difference of several times in the same temperature region is considered.

4. System components

The high-efficiency passive heat transfer technology based on the temperature difference driven self-circulation two-phase fluid loop is designed by combining the analysis of the enhanced phase change rate and the enhanced phase change latent heat, mainly comprises an evaporator, a steam pipeline, a condenser, a liquid pipeline, a liquid storage device and a modified heat transfer working medium, the system is a closed loop, the product of the phase change rate and the phase change latent heat of the system is large, the phase change heat exchange capacity is strong, and the high-efficiency passive heat transfer technology is ideal.

Disclosure of Invention

The invention aims to provide an efficient unfreezing device to solve the problem that a traditional extruded aluminum profile or low-temperature gravity heat pipe unfreezing plate is poor in cold conducting capacity.

In order to solve the technical problems, the invention adopts the technical scheme that:

the high-efficiency thawing apparatus includes evaporation zone (or evaporator), steam pipeline, condensation zone (or condenser), liquid pipeline, liquid storage, heat transfer working medium and support, and the system is formed into two-phase fluid loop.

Wherein evaporation zone and condensation zone set up to same part, and the microchannel that constitutes this part is vertical array and arranges (the interior channel of inflation board is the vertical arrangement of level from top to bottom, the middle is vertical when adopting the inflation board, arranges for vertical array when adopting the extrusion aluminium alloy), and the condensation zone is that frozen food places the face, and the condensation zone sets up in the upper and middle optional position of evaporation zone. The liquid storage device and the liquid pipeline are arranged as the same part, when the storage temperature of the product is overhigh, if the heat transfer working medium is still in a two-phase state, the volume of the liquid working medium is increased, and redundant liquid working medium is stored in the liquid storage device; if the temperature of the heat transfer working medium is supercritical, the liquid storage device plays a role in buffering and reducing pressure, and the cold guide assembly is maintained at a reasonable pressure level. The bracket makes the unfreezing plate have an inclination angle of about 3 degrees for effectively discharging unfreezing water.

The evaporation area and the condensation area adopt a micro-channel process, a blowing process or an aluminum profile extrusion process, and the integral forming adopts a brazing process; the support adopts an aluminum profile extrusion process, a flanging process or an injection molding process, and the support is installed by adopting processes such as riveting, screwing, clamping and the like.

Preferably, the cross-sectional caliber of the microchannel is rectangular, and the dimension specification is 60mm × 2mm (width × thickness), 32mm × 2mm, 25.4mm × 2mm and the like;

the sizes and volumes of functional parts of the evaporator, the steam pipeline, the condenser, the liquid pipeline and the liquid storage device need to be matched and designed based on the technical requirements of working medium physical properties and heat transfer capacity of a working temperature zone.

The working principle is as follows:

the bottom layer heat transfer technology is an efficient passive heat transfer technology based on a temperature difference driven self-circulation two-phase fluid loop, and achieves an efficient heat transfer effect by strengthening phase change heat exchange.

The fundamental idea of strengthening the phase change heat exchange is to increase the phase change heat exchange quantity in unit time, namely, to increase the product of the phase change rate and the phase change latent heat. On one hand, the whole phase change period covers the whole process of bubble nucleation, bubble growth, bubble detachment and bubble polymerization rise; on the other hand, the phase transition rate and the phase transition latent heat are closely related parameters on the physical aspect, so the improvement of the product of the two parameters needs to be based on the comprehensive analysis of the bubble nucleation and the kinetic characteristics of the phase transition complete cycle.

By modifying the phase change working medium, the critical activation nucleation point radius r is reduced from the physical property level_mTo increase the total number N of activation nucleation points and to decrease the bubble separation diameter D from the physical aspect_dIncreasing the bubble separation frequency f to ensure that the heat transfer working medium has higher phase change rate in the bubble nucleation and bubble separation process of the phase change full period, thereby strengthening the phase change rate; by designing a two-phase fluid loop and realizing vapor-liquid separation through a height difference structure, the phase change interface pressure of the heat transfer working medium in an evaporation area is reduced, and further a hot boiling state is established, so that the heat exchange strength of the vapor heat transfer working medium and the liquid heat transfer working medium is increased in the processes of bubble growth and bubble polymerization in a phase change full period, and the phase change rate is further enhanced.

The invention has the beneficial effects that:

on one hand, the invention adopts a micro-channel process, a blowing process or aluminum profile extrusion, the internal flow channels of the micro-channel, the blowing plate or the aluminum profile are fully distributed with heat transfer working media, the effective cold conducting area is approximately equal to the whole area of the evaporation zone, and the cold conducting area is large.

On the other hand, the bottom layer heat transfer technology is an efficient passive heat transfer technology based on a temperature difference driven self-circulation two-phase fluid loop, and the product of the phase change rate and the phase change latent heat is comprehensively enhanced based on the bubble nucleation and the dynamic characteristics of the phase change full period. The technology has the characteristics of large heat/high heat flow density heat transfer capacity, high heat transfer speed, long heat transfer distance, small system thermal resistance and high reliability. Compared with the traditional aluminum profile or low-temperature gravity heat pipe, the heat transfer capacity is greatly improved.

In conclusion, the efficient unfreezing device has the advantages of large effective cold conducting area and strong heat transfer capacity of the bottom layer heat transfer technology, so that the cold conducting capacity is strong, and the unfreezing speed of the unfreezing plate can be effectively increased.

Drawings

FIG. 1 is a background art illustration;

FIG. 2 is a background art illustration;

FIG. 3 is a schematic structural diagram of the high-efficiency thawing apparatus of the present invention;

FIG. 4 is a side view of the reservoir of the high efficiency thawing apparatus of the present invention;

FIG. 5 is a schematic cross-sectional view of a microchannel of the high efficiency thawing apparatus of the present invention;

FIG. 6 is an illustration of a final product made by the evaporation zone and the condensation zone using a blown-up process;

FIG. 7 is an exemplary diagram of the evaporation zone and the condensation zone formed by an aluminum profile extrusion process.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As shown in fig. 3-5, a high-efficiency thawing device comprises an evaporation zone 1, a steam pipeline 2, a condensation zone 3, a liquid pipeline 4, a liquid storage device, a heat transfer working medium 6 and a bracket 7,

the evaporation zone 1 and the condensation zone 3 comprise a plurality of fin plates 8 which are spliced side by side;

the upper end and the lower end of the fin plate 8 are respectively communicated with the steam pipeline 2 and the liquid pipeline 4;

the steam pipeline 2 and the liquid pipeline 4 are hollow pipes with cavities in the middle, and two ends of each pipe are sealed; the outer wall of the lower bottom surface of the steam pipeline 2 is provided with a plurality of strip-shaped jacks, and the outer wall of the upper surface of the liquid pipeline 4 is provided with a plurality of strip-shaped jacks;

the upper end and the lower end of the fin plate 8 are respectively arranged in the strip-shaped jacks of the steam pipeline 2 and the liquid pipeline 4 in a penetrating way;

a plurality of vertical array-arranged micro-channels 81 are arranged on the fin plate 8, and the upper end and the lower end of each micro-channel 81 are respectively communicated with the cavities of the steam pipeline 2 and the liquid pipeline 4;

the device integrally forms a two-phase fluid loop, and the heat transfer working medium 6 is arranged in the two-phase fluid loop (namely in the evaporation zone 1, the steam pipeline 2, the condensation zone 3, the liquid pipeline 4 and the liquid reservoir). The reservoir is arranged in the liquid pipeline.

The support 7 is fixedly arranged on the steam pipeline 2, preferably, the support 7 is a hollow pipe body, the steam pipeline 2 penetrates through the hollow part of the support 7, and the edge of the support 7 is riveted with the top of the fin plate 8;

the support 7 makes the unfreezing plate have an inclination angle of about 2-6 degrees for effectively discharging unfreezing water, i.e. the inclination angle of the fin plate 8 is about 2-6 degrees with the horizontal plane.

Preferably, the heat transfer working medium 6 comprises propylene, difluoromethane, acetylene and nano silicon carbide powder;

preferably, the heat transfer working medium is prepared from 10-15% of propylene, 30-45% of difluoromethane, 40-55% of acetylene and 1-5% of nano silicon carbide powder, or is prepared from 10-15 parts of propylene, 30-45 parts of difluoromethane, 40-55 parts of acetylene and 1-5 parts of nano silicon carbide powder.

As shown in fig. 6 and 7, the evaporation zone 1 and the condensation zone 3 adopt a microchannel 81 process, a blowing process or an aluminum profile extrusion process, and the integral forming adopts a brazing process; the support 7 adopts an aluminum profile extrusion process, a flanging process or an injection molding process, and the support 7 is installed by adopting processes such as riveting, screwing, clamping and the like.

Preferably, the cross-sectional diameter of the microchannel 81 is rectangular, and the dimension thereof is 60mm × 2mm (width × thickness), 32mm × 2mm, 25.4mm × 2mm, or the like.

The fin plate 8 is a microchannel fin plate or a blown fin plate.

The working process is as follows:

the evaporation area 1 in the two-phase fluid loop absorbs the environmental heat, the internal liquid working medium 6 is evaporated at the phase change interface, the vapor working medium is transmitted to the condensation area 3 through the vapor pipeline 2, the vapor working medium in the condensation area 3 is firstly cooled, then condensed and finally supercooled, and the liquid working medium is supplemented to the evaporation area 1 for continuous evaporation. The circulating power of the fluid loop is gravity, and the working medium 6 in the two-phase fluid loop flows in a self-circulation mode along the path of the evaporation area 1 → the condensation area 3 under the driving of temperature difference.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, and the scope of protection is still within the scope of the invention.