CN102252549A - Liquid separating condensation pipe of capillary structure - Google Patents

Abstract

The invention belongs to the technical field of enhanced heat transfer, and relates to a capillary structure liquid-separating condenser tube. The outside of the capillary structure section on the wall is fixed on the ordinary condensation heat exchange tube. The liquid collection cavity and the capillary structure section on the wall form a capillary strengthening structural component. The end extending to the ordinary condensing heat exchange tube is connected to it. When the steam flows through the condensation tube and undergoes a phase change, the condensate in the tube is separated in time under the action of the surface tension of the liquid through the capillary structure of the wall, and is automatically sucked to the end of the condensation tube through the liquid collection chamber and the catheter tube. The present invention fundamentally It breaks through the technical bottleneck of condensation heat transfer that forms a thick liquid film along the length of the tube and deteriorates heat transfer. It is suitable for ordinary condensation heat transfer and occasions where steam condensation exists, and can also be extended to condensation heat transfer under microgravity conditions.

Description

Capillary structure liquid separation condenser

technical field

The invention belongs to the technical field of heat transfer enhancement, and in particular relates to a capillary structure liquid-separating condenser tube.

Background technique

Due to the high efficiency of phase change heat transfer, condensing phase change heat exchangers are widely used in refrigeration, air conditioning, power generation, petrochemical and other fields. In some applications, such as using a low-grade heat source to drive the ORC cycle, it is necessary to reduce the temperature and pressure in the condenser in the Rankine cycle as much as possible, so that the condenser is in a small temperature difference (the temperature difference between the organic working medium in the tube and the air outside the tube or cooling water is small) Driven to work, resulting in an increase in heat transfer area and investment costs. At the same time, in refrigeration, air conditioning, petrochemical and other fields, further improving the efficiency of condensing heat exchange can greatly reduce costs and have significant economic and social benefits. This places significant demands on the design, manufacture and operation of efficient condensers.

Condensation phase change is an important phase change process in the two-phase flow science. During the continuous evolution of the condensation process in the tube from the vapor state to the condensed liquid state, the vapor-liquid content gradually changes, making the process from the full vapor state to the full liquid state appear Wet steam flow, annular flow, stratified flow, slug flow, plug flow, bubble flow and other flow patterns. At the same time, due to the continuous appearance and accumulation of condensate, the liquid gradually forms a thin liquid film on the wall surface, a thick liquid film on the wall surface, a liquid bridge, and finally a full liquid state in the condenser tube from small droplets at the beginning. If it is said that the formation of a thin liquid film of condensate on the wall during annular flow increases the heat transfer coefficient between vapor and solid; then this liquid film with a certain thermal resistance must have an optimal thickness value. According to the reports of domestic and foreign researchers, and a consensus has been reached, the annular flow in the thin liquid film state has the highest heat transfer efficiency, that is, as the flow pattern changes from annular flow to stratified flow and slug flow during the entire condensation process , plug flow, the liquid film on the wall is gathered from a thin liquid film to a thick liquid film or even to a liquid bridge state, and the thermal resistance of the liquid film increases significantly, which leads to a gradual decrease in the heat transfer coefficient during the condensation process and a significant deterioration in the heat transfer effect. Therefore, the evolution of the flow pattern during the condensation process is the root cause of the deterioration and attenuation of the heat transfer efficiency of the condenser tube.

At present, various forms of strengthening tubes are mainly used in strengthening condensation heat exchange at home and abroad, such as micro-finned tubes, grooved tubes, corrugated tubes, and strengthening tubes with inserts. In terms of the strengthening effect, the micro-finned tube can enhance the mixing of the condensate film and cause the disturbance of the fluid in the tube. Generally, the strengthening effect of the micro-finned tube is more obvious than that of the grooved tube, and can increase the condensation heat transfer coefficient of the smooth tube by 80-180%. For grooved tubes with different inclination angles, and the strengthening effect is affected by the mass flow velocity, the greater the mass velocity, the faster the condensate is exported, and the more obvious the strengthening effect is. Generally, the corrugated tube can increase the heat transfer coefficient of the smooth tube by 50%. In addition, the reinforced tube with double helix structure inserted into the tube can also significantly strengthen the condensation heat transfer in the vertical tube. However, the currently used condensation enhancement tubes fail to pay attention to the change of the condensation flow pattern, and proceed from the fundamental evolution of the flow pattern, but only cause the center fluid to replace the tube wall fluid by causing the swirling flow and the secondary flow, destroying the flow pattern. A boundary layer develops, which intensifies condensation inside the tube. They have the following things in common: (1) The fine structure of the inner wall mainly changes the flow and heat transfer performance of the near wall area, and cannot regulate the flow pattern as a whole. (2) Although the strengthening structure of the inner wall has a strengthening effect, it does not solve the evolution characteristics of the heat transfer performance decay in the long direction of the condenser tube. (3) The strengthening tube increases the manufacturing difficulty and increases the cost of the condenser.

In 2007, Professor Peng Xiaofeng of Tsinghua University's Phase Change and Interface Transfer Laboratory approximated the condensation in the entire tube as thin liquid film condensation, and based on Nusselt's laminar flow and film condensation analysis, he knew that the thickness of the condensed heat exchange liquid film is 1/ of the tube length It is directly proportional to the 4th power, and the average surface heat transfer coefficient is inversely proportional to the 1/4 power of the entire tube length, which quantitatively reveals the objective fact that the condensation heat transfer coefficient decays with the increase of the length of the heat exchange tube; and the use of short tubes effect, abandoning the subsequent low heat transfer flow pattern of the condensation heat exchange tube, and retaining the high heat transfer performance flow pattern in the initial process; at the same time, the vapor phase obtained by separating the vapor and liquid at the outlet of the short tube enters the next short tube to continue to condense, so that The method that the condensing flow pattern is always maintained in the annular flow significantly improves the heat transfer efficiency of the condensing heat exchange tube. Based on the understanding of the heat transfer performance of each flow pattern of condensation, it strengthens the heat transfer from the perspective of the scientific process of condensation; but its starting point is to directly avoid the flow pattern with poor heat transfer effect and shorten the length of the heat exchange tube; The method of liquid separation makes the design of the condenser must be different under different inclination angle heat exchangers, and the application under microgravity conditions has certain limitations.

To sum up, to significantly improve the heat transfer efficiency of condensation, we must start from the physical process of condensation and control the flow pattern in order to fundamentally improve its heat transfer performance and solve the current situation of its deterioration along the length of the tube. A process based on the evolution of the flow pattern is required The method and technology of high-efficiency condensing heat exchange tubes that fundamentally improve the efficiency of condensing heat transfer through the scientific control of the flow pattern and the characteristics of thickened liquid film and increased thermal resistance.

Contents of the invention

The purpose of the present invention is to change the situation of ignoring the flow pattern and heat transfer separation in the traditional heat transfer enhancement method, solve the key problem of the gradual deterioration of the condensation phase change heat transfer process, and provide a capillary structure liquid separation type condenser, which is characterized in that, The capillary structure liquid-separating condenser tube is composed of ordinary condensation heat exchange tube 1, wall capillary structure section 2, liquid collection chamber 3 and liquid guide tube 4, and its structure is to connect in series 2~ 5 wall capillary structure sections 2, the liquid collection cavity 3 surrounds the outside of the wall surface capillary structure section 2 and is fixedly connected to the ordinary condensation heat exchange tube 1, the liquid collection cavity 3 and the wall surface capillary structure section 2 form a capillary strengthening structural assembly, each group of capillary structure The liquid collection chamber 3 of the reinforced structural component is connected with the liquid guide tube 4, and the end of the liquid guide tube 4 is connected with the end of the condensation tube.

The common condensing heat exchange tube 1 is a bare tube, a finned tube with an extended heating surface, a grooved tube or a corrugated tube, and realizes steam condensation in the tube by exchanging heat with the working medium outside the tube.

The axial section of the liquid collection chamber 3 is rectangular or semicircular.

The wall capillary structure section 2, the position and area of the wall capillary structure section are determined by the distribution and length of annular flow, semi-annular flow, slug flow or plug flow in the flow pattern evolution law when the working fluid condenses and phase changes , the wall capillary structure segment 2 of the first group of capillary strengthening structure components is set at the thick liquid film before the end of the annular flow in the tube, starting from the second group, the wall capillary structure segment 2 of the adjacent group of capillary strengthening structure components is in the axial direction The distance is the length of the slug flow or plug-like flow bomb to eliminate or weaken the liquid bridge thermal resistance of the slug flow, regulate the flow pattern, and enhance heat transfer; the circumferential direction of the capillary structure is determined by the amount of liquid that needs to be derived locally Distribution, for example, because the capillary strengthening structure components of the second group and subsequent groups need to lead out the liquid of the whole liquid bridge, so the number of capillary pores in the wall capillary structure section 2 of the first group of capillary strengthening structure components is less than that of the second group and subsequent groups Set of Capillary Strengthening Structural Components Wall Capillary Segment 2 Capillary Number.

The capillary diameter or equivalent diameter of the wall capillary structure of the wall capillary structure section 2 is calculated by the following formula:

$\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 1.83</span>}\sqrt{\frac{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; )</span>}}<span\; class="notranslate">\; ,</span>$

Among them, σ is the surface tension of the condensate, g is the acceleration of gravity, ρ _f is the density of the condensate, and ρ _g is the density of the vapor phase, that is, the surface tension of the condensing working medium is large, and the diameter of the capillary is slightly larger, otherwise it is slightly smaller, such as water, capillary The diameter of the hole is between 1 and 2mm, and the capillary diameter corresponding to different working fluids and mixtures can be compared.

The wall capillary structure of the wall capillary structure section 2 is a wall microporous structure, a wall slit 205 structure, a porous foam structure or a wall wire mesh structure.

The wall surface micropores 201 of the wall surface microporous structure of the wall surface capillary structure section 2 are circular holes or square holes with different apertures arranged uniformly or non-uniformly, and the circumferential distribution density of the wall surface micropores 201 of the first section is smaller than that of the second section. The circumferential distribution density of micropores 201 on the walls of the first section and subsequent sections.

The wall surface slits 205 of the wall surface slit structure of the wall surface capillary structure section 2 are parallel, staggered or intersecting slits with the same or different widths, and the circumferential distribution density of the wall surface slits in the first section is smaller than that in the second section And the circumferential distribution density of the wall slits of each section.

The porous foam structure of the wall surface capillary structure section 2 is a porous foam ring 204, and the length of the first segment of the porous foam ring is less than the length of the second segment and subsequent segments of the porous foam ring.

The material of the porous foam ring 204 is metal foam or ceramic foam.

The wall screen structure of the wall surface capillary structure section 2 is composed of a round hole 202 opened on the tube wall of the common condensation heat exchange tube 1 and a wire mesh 203 coated outside the round hole. The round hole of the first section The number in the circumferential direction is less than the number in the circumferential direction of the circular holes in the second section and subsequent sections.

The invention is a new type of condensation-enhanced tube for enhancing the heat transfer of the condensing phase. Starting from the physical process of condensation and the control of the flow pattern, the efficiency of the condensation phase change heat transfer is greatly improved, and the complete condensation is improved based on the control of the condensation heat transfer flow pattern. The new idea of heat transfer flow and heat transfer performance provides a new type of capillary structure liquid separation condenser tube which is different from the short tube effect and gravity separation described in the background technology. The capillary structure liquid-separating condenser tube is to set a wall capillary structure section on the local wall of the ordinary condensation heat exchange tube, and set a liquid collection chamber and a catheter around the wall capillary structure section to store and timely transport the condensate separated by the porous structure. , so as to thin the liquid film, reduce the thermal resistance of the liquid film, and even convert the stratified flow and slug flow condensation flow into an efficient heat transfer annular flow, thereby fundamentally improving the performance of condensation phase change heat transfer. Its working process is that the condensate near the capillary structure section of the wall is separated out of the condensation tube in time under the action of surface tension through structures such as micropores or slits, and automatically passes through the liquid collection chamber and the catheter tube of the capillary structure component. It is sucked to the end of the condensing tube, and the excessive condensate in the thick liquid film area or liquid bridge area is led away from the heat exchange wall in time by setting the position and area of the capillary structure section on the wall, so as to control the flow pattern to ensure that the entire tube length direction is uniform. The annular heat transfer of the thin liquid film achieves the purpose of fundamentally improving the condensation heat transfer efficiency.

The effects of the present invention are: (1) By arranging wall porous structures, liquid collecting chambers and liquid guide tubes at local positions of ordinary heat exchange tubes according to flow patterns, a large amount of condensate in the condensation process can be separated in time, so that the thick liquid in the condensation tubes The film flow pattern and the slug flow or plug flow containing the liquid bridge are converted into the annular flow of the thin liquid film heat transfer, thereby regulating the flow pattern and strengthening the condensation heat transfer; the present invention starts from the basic physical process of condensation, from the scientific Angle solves the problem of condensation heat transfer deterioration along the tube length direction, fundamentally breaks through the technical bottleneck that condensation heat transfer forms a thick liquid film along the tube length direction and makes heat transfer worse; (2) the surface of capillary structure and liquid is utilized in the present invention The tension leading out of the liquid is a passive process that does not require energy consumption, and its effect is not affected by gravity, that is, it is not limited by the inclination angle of the heat exchange tube. Extended to condensation heat transfer under microgravity conditions. Therefore, the heat transfer efficiency of the condensing phase change heat pipe can be significantly improved without increasing the resistance.

Description of drawings

1 is a schematic diagram of the overall structure of a capillary structure liquid separation type condenser;

Fig. 2 (a) is the axial cross-sectional view of the capillary-strengthened structural assembly of the wall microporous type;

Fig. 2 (b) is the circumferential sectional view of the microporous capillary-strengthened structural component on the wall;

Fig. 3 (a) is the axial sectional view of the capillary strengthening structure assembly of the wall mesh type;

Fig. 3 (b) is the circumferential sectional view of the capillary reinforced structural component of the wall mesh type;

Fig. 4 (a) is the axial cross-sectional view of the capillary strengthening structural component of porous foam type;

Fig. 4 (b) is the circumferential cross-sectional view of the porous foam-type capillary-reinforced structural component;

Fig. 5 (a) is the axial cross-sectional view of the wall surface slit type capillary strengthening structure assembly;

Figure 5(b) is a circumferential cross-sectional view of a wall slit-type capillary-reinforced structural component;

Fig. 6 is a structural schematic diagram of an embodiment of a condensation tube with a semicircular cross-section of the liquid collecting chamber.

In the figure, 1--ordinary condensing heat exchange tube, 2--wall capillary structure section, 3--collecting chamber, 4--drain tube, 5--flow direction of condensing working medium, 201--wall micropore , 202--round hole, 203--wire mesh, 204--porous foam ring, 205--wall slit.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific examples.

Figure 1 is a schematic diagram of the overall structure of the capillary structure liquid separation type condenser tube. The capillary structure liquid separation type condenser tube is composed of an ordinary condensation heat exchange tube 1, a wall capillary structure section 2, a liquid collection chamber 3 and a liquid guide tube 4. From the condenser tube From the head end to the end, 2 to 5 wall capillary structure sections 2 are connected in series in the common condensation heat exchange tube 1 at intervals along the tube length direction of the common steam condensing tube 1, and the wall capillary structure section 2 surrounded by the liquid collection chamber 3 is fixedly connected to the common steam condensing tube 1. On the condensing heat exchange tube 1, the liquid collection chamber 3 and the wall capillary structure section 2 form a capillary strengthening structural component, and the liquid guide tube 4 communicates the liquid collecting chambers 3 of each group of capillary strengthening structural components with each other, and the liquid guide tube 4 extends to the common condensation The ends of the heat exchange tubes 1 are connected thereto. The common condensing heat exchange tube 1 is a bare tube, and the steam inside the tube is condensed by exchanging heat with the working medium outside the tube. The axial section of the liquid collecting chamber 3 is rectangular. The condensed working fluid flows from the head end of the condensing tube to the end according to the flow direction 5 of the condensed working fluid shown in the figure.

Wall capillary structure section 2, the position and area of the wall capillary structure section are determined by the distribution and length of annular flow, semi-annular flow, slug flow or plug flow in the flow pattern evolution law when the working fluid condenses and phase changes, No. The wall capillary structure section 2 of a group of capillary strengthening structure components is arranged at the thick liquid film before the end of the annular flow in the tube, starting from the second group, the wall capillary structure section 2 of the adjacent group of capillary strengthening structure components is in the axial distance is the length of the slug flow or plug flow steam bomb to eliminate or weaken the liquid bridge thermal resistance of the slug flow, regulate the flow pattern, and enhance heat transfer; its circumferential distribution is determined by the amount of liquid that needs to be derived locally, because the first The capillary strengthening structure components of the second and subsequent groups need to export the liquid of the entire liquid bridge, so the number of capillary pores in the wall capillary structure section 2 of the second and subsequent groups of capillary strengthening structure components is more than that of the first group.

The capillary diameter or equivalent diameter of the wall capillary structure section 2 is calculated by the following formula:

$\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 1.83</span>}\sqrt{\frac{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; )</span>}}<span\; class="notranslate">\; ,</span>$

Where σ is the surface tension of the condensate, g is the acceleration of gravity, ρ _f is the density of the condensate, and ρ _g is the density of the vapor phase, that is, the surface tension of the condensing working fluid is large, and the diameter of the capillary is slightly larger, and vice versa; for water, the capillary The diameter of the hole is between 1 and 2mm, and the capillary diameter corresponding to different working fluids and mixtures can be compared.

As shown in Fig. 2 to Fig. 5, in the capillary strengthening structure component, the wall capillary structure of the wall capillary structure section 2 is a wall microporous structure, a wall slit structure, a porous foam structure or a wall mesh structure.

Fig. 2(a) and Fig. 2(b) are the axial sectional view and the circumferential sectional view of the capillary strengthening structural assembly of the microporous wall type respectively, and the microporous structure on the wall surface is formed directly on the tube wall of the common condensing heat exchange tube 1. The micropores 201 on the wall surface can be seen from the axial sectional view of Fig. 2 (a) along the pipe length direction, and 5 groups of micropores 201 on the wall surface are distributed in the liquid collecting chamber 3, while the circumferential sectional view of Fig. 2 (b) It can be seen that 8 wall micropores 201 are evenly distributed in each group of wall micropores in the circumferential direction, and the condensed liquid can directly enter the liquid collection chamber 3 through the wall micropores 201, so as to be separated in time through the catheter 4 to the end of the condensation tube. The circumferential distribution density of micropores on the wall of the first wall capillary structure section 2 is smaller than the circumferential distribution density of micropores on the wall of the second and subsequent sections.

Fig. 3(a) and Fig. 3(b) are the axial sectional view and the circumferential sectional view of the capillary reinforced structural assembly of the wall mesh type respectively. A group of larger circular holes 202 on the tube wall of the tube 1 and a wire mesh 203 covering the circular holes 202 are composed, as shown in Figure 3(b), 8 circular holes 202 are evenly distributed in the circumferential direction , the condensed liquid can directly enter the liquid collection chamber 3 through the circular hole 202 and the wire mesh 203, so as to be separated in time through the catheter 4 to the end of the condensing tube. The circumferential number of round holes in the first wall capillary structure section 2 is smaller than the circumferential number of round holes in the second section and subsequent sections.

Fig. 4(a) and Fig. 4(b) are the axial sectional view and the circumferential sectional view of the capillary reinforced structural assembly of the porous foam type respectively, and the wall capillary structure section 2 is processed by the porous foam material of foam metal or foam ceramics The porous foam ring 204 is connected in series in the common condensing heat exchange tube 1 along the tube length direction by a bracket or welding method. Or the calculation result of the equivalent diameter selects the mesh number of the foam holes, and the condensed liquid can directly enter the liquid collection chamber 3 through the porous foam ring 204, so as to be separated in time through the catheter 4 to the end of the condensation pipe. The length of the porous foam ring in the first wall capillary structure segment 2 is smaller than the length of the porous foam ring in the second segment and subsequent segments.

Fig. 5(a) and Fig. 5(b) are the axial sectional view and the circumferential sectional view of the wall slit-type capillary-strengthening structural assembly respectively, and the wall slit-type structure is on the tube wall of the common condensing heat exchange tube 1 Directly process uniform and parallel wall slits 205. It can be seen from the axial sectional view of Fig. 5 (a) that the length of the wall slit 205 is the same as that of the liquid collection chamber 3. 205 has 12 wall surface slits 205 evenly distributed in the circumferential direction. The condensed liquid can directly enter the liquid collecting chamber 3 through the slit 205 on the wall surface, so as to be separated in time through the catheter 4 to the end of the condensing tube. The circumferential distribution density of wall slits in the first wall surface capillary structure section 2 is smaller than the circumferential distribution density of wall slits in the second and subsequent sections.

Example

Fig. 6 is a structural schematic diagram of an embodiment of a condensation tube with a semicircular cross-section of the liquid collecting chamber. In this embodiment, the wall capillary structure of the wall capillary structure section 2 is a wall microporous structure, and the axial section of the liquid collecting chamber 3 is a semicircular capillary structure liquid-separating condenser tube. The entire capillary structure liquid-separating condenser tube is Two sets of capillary strengthening structural components are distributed along the tube length direction, and the catheter tube 4 is connected to the liquid collection chamber 3 of the two sets of capillary strengthening structural components, and the end is directly connected to the end of the condensation tube.

12mm×1mm的铜管作为普通冷凝换热管1；制作第一组毛细强化结构组件，在距离冷凝管的首端，即工质入口50mm的壁面位置，周向均匀分布打4个

2mm的壁面微孔201，管外侧利用

5mm×1mm的半圆铜管包围全部壁面微孔201并与换热管焊接密封做成集液腔3；制作第二组毛细强化结构组件，在距离冷凝管的首端120mm处，轴向分布两圈，圈距为3mm，周向均匀分布打8个2mm的壁面微孔201，同样利用9mm×1mm的半圆铜管在管外侧焊接加工成集液腔3；最后将2个集液腔3用

2mm的导液管4连通，在换热管尾部240mm处，导液管4的末端与换热管连通，该段换热管已全部成为冷凝液体的主管道，从而获得具有强化冷凝相相变功能的毛细结构分液式冷凝管。The preparation process of this embodiment is: use a 2.5m long

The 12mm×1mm copper tube is used as the ordinary condensing heat exchange tube 1; the first group of capillary strengthening structural components is made, and 4 pieces are evenly distributed in the circumferential direction at the wall position 50mm away from the head end of the condensing tube, that is, the inlet of the working fluid

2mm microholes 201 on the wall, the outer side of the tube is used

A 5mm×1mm semicircular copper tube surrounds all the micropores 201 on the wall and is welded and sealed with the heat exchange tube to form a liquid collection chamber 3; a second group of capillary strengthening structural components is made, and two axially distributed Circle, the circle distance is 3mm, 8 circles are evenly distributed in the circumferential direction The wall microholes 201 of 2mm also utilize A 9mm×1mm semicircular copper tube is welded on the outside of the tube to form a liquid collection chamber 3; finally, the two liquid collection chambers 3 are used

The 2mm liquid guide tube 4 is connected. At the end of the heat exchange tube 240mm, the end of the liquid guide tube 4 is connected with the heat exchange tube. This section of the heat exchange tube has all become the main pipe of the condensed liquid, thereby obtaining a phase change with enhanced condensation phase. Functional capillary structure liquid separation condenser.

The present invention is applicable to any occasion that requires steam condensation, and can be used in a single tube, multiple tubes in parallel, or assembled into a condenser; due to the capillary structure, the vapor-liquid separation outside the condenser tube is not affected by gravity by using surface tension The condensation heat transfer coefficient can be significantly improved both on the ground and in microgravity environments. The invention is not only applicable to common condensation heat transfer and occasions where steam condensation exists, but also can be extended to condensation heat transfer under microgravity conditions.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (11)

1. A capillary structure liquid separation type condenser tube is characterized in that the capillary structure liquid separation type condenser tube is composed of common condensation heat exchange tube (1), wall surface capillary structure section (2), liquid collection cavity (3) and liquid guide 2 to 5 wall capillary structure sections (2) are connected in series along the tube length direction of the ordinary steam condensing tube 1, and the liquid collection chamber (3) surrounds the outside of the wall surface capillary structure section (2) and is fixed on the On the ordinary condensing heat exchange tube (1), the liquid collecting cavity (3) and the wall capillary structure section (2) constitute the capillary strengthening structural component, and the liquid collecting cavity (3) and the liquid guide tube (4) of each group of capillary strengthening structural components Connected, the end of the catheter (4) is connected to the end of the condenser tube. 2. A kind of capillary structure liquid-separating condenser tube according to claim 1, characterized in that, the common condensation heat exchange tube (1) is a bare tube, a finned tube with an extended heating surface, a grooved tube or corrugated tube. 3. A capillary structure liquid separation type condenser according to claim 1, characterized in that the axial section of the liquid collecting chamber (3) is rectangular or semicircular. 4. a kind of capillary structure liquid separation type condensing tube according to claim 1, is characterized in that, described wall surface capillary structure section (2), by the evolution law of flow pattern when condensation of working fluid phase changes, it is characterized in that annular flow, The distribution and length of the semi-annular flow, slug flow or plug flow determine the position and area of the wall capillary structure segment, the wall capillary structure segment (2) of the first group of capillary strengthening structural components is arranged before the end of the annular flow in the tube At the thick liquid film place, starting from the second group, the axial distance between the wall capillary structure segments (2) of adjacent groups of capillary strengthening structure components is the length of the slug flow or plug flow gas bomb. 5. a kind of capillary structure liquid separation type condenser according to claim 1, is characterized in that, the capillary diameter or equivalent diameter of the wall surface capillary structure of described wall surface capillary structure section (2) is determined by following formula calculation: $\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 1.83</span>}\sqrt{\frac{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; )</span>}}<span\; class="notranslate">\; ,</span>$ Among them, σ is the surface tension of the condensate, g is the acceleration of gravity, ρ _f is the density of the condensate, and ρ _g is the density of the vapor phase, that is, the surface tension of the condensing working fluid is large, and the diameter of the capillary is slightly larger, and vice versa. 6. A kind of capillary structure liquid separation type condenser according to claim 1, is characterized in that, the wall surface capillary structure of described wall surface capillary structure section (2) is wall surface microporous structure, wall surface slit type structure, porous Foam type structure or wall mesh type structure. 7. A kind of capillary structure liquid separation type condenser according to claim 1 or 6, is characterized in that, the wall surface micropore (201) of the wall surface microporous structure of described wall surface capillary structure section (2) is uniform arrangement Or non-uniform arrangement of round or square holes with different hole diameters. 8. A kind of capillary structure liquid separation type condenser according to claim 1 or 6, is characterized in that, the wall surface slit (205) of the wall surface slit type structure of described wall surface capillary structure section (2) is parallel, Slits with the same or different slit widths are distributed in a staggered or cross pattern. 9. A capillary structure liquid-separating condenser tube according to claim 1 or 6, characterized in that the porous foam structure of the wall surface capillary structure section (2) is a porous foam ring (204). 10. A capillary structure liquid separation type condenser according to claim 9, characterized in that the material of the porous foam ring (204) is metal foam or ceramic foam. 11. A kind of capillary structure liquid separation type condensing tube according to claim 1 or 6, it is characterized in that, the wall surface screen type structure of described wall surface capillary structure section (2) is opened in common condensing heat exchange tube (1 ) on the pipe wall of the hole (202) and coated in the metal wire mesh (203) outside the hole.

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