CN201363970Y - Sectional-type vapor-liquid phase-change heat exchanger - Google Patents

Abstract

The utility model relates to a segmented vapor-liquid phase change heat exchanger, which is characterized in that it comprises at least one set of heat exchange tubes, and the two ends of the heat exchange tubes are respectively connected with straight-through headers. A number of leaking liquid vapor blocking devices are arranged staggeredly in the header to separate the two headers into a plurality of sequentially connected liquid separation spaces. The above-mentioned liquid-distributing space is connected in parallel with a liquid outlet pipe, and at least one main hole and several auxiliary holes are arranged on the liquid-leakage vapor-blocking device. When the utility model is used, when there is less condensed liquid, the liquid will form a layer of water film on the surface of the main hole and the auxiliary hole to prevent the gas from flowing out from the main hole and the auxiliary hole; The large main hole will seep first; when the amount of separated liquid is large, the pressure of the liquid will destroy the liquid film covering the surface of the auxiliary hole, and seep from the auxiliary hole, which is equivalent to increasing the number of drains. The liquid pipe discharges liquid, which solves the problem that the liquid discharge volume is limited in the prior art.

Description

A segmented vapor-liquid phase change heat exchanger

technical field

The utility model relates to a vapor-liquid phase change heat exchanger, in particular to a segmented vapor-liquid phase change heat exchanger.

Background technique

Vapor-liquid phase change heat exchangers are widely used in energy systems, power engineering, chemical and petrochemical industries, automotive industries, etc., such as air condensers in thermal power stations, air conditioning engineering, vehicle air conditioning, and evaporation and condensers in chemical processes.

The traditional air-cooled vapor-liquid phase change heat exchanger mostly adopts the serpentine tube process, relying on air convection heat exchange outside the tube, and the working fluid condenses or evaporates inside the tube. In the condensation heat transfer in the tube, as the condensation progresses, the condensate on the wall gradually increases, and then the film formation hinders the contact between the steam and the wall, which is the main thermal resistance of the condensation heat transfer. During the condensation process, the liquid film gradually thickens, and in the long-term later, it will be a complex two-phase flow in which the liquid gradually increases, the thermal resistance will gradually increase, and the condensation effect will deteriorate seriously; at the same time, with the condensation of the steam, the amount of steam will gradually decrease. The steam flow rate in the tube drops significantly, the condensation effect degrades sharply, and the heat transfer coefficient decreases; the condensation process in a single tube process also leads to complex vapor-liquid two-phase flow, which has great impact on system operation stability, flow resistance and system regulation. negative effect. On the air side, due to the increase in the thermal resistance of condensation heat transfer in the tube, the temperature of the outer tube wall decreases, resulting in a decrease in the utilization rate of the fins. In order to solve the above-mentioned problems, traditional air-cooled condensers increase the heat exchange area to meet the demand for heat exchange, but the volume and weight are large, and the production and operation costs are high. There is a similar problem with evaporators.

The applicant's patent number is ZL200610113304.4, the name is "separation type air condenser" (as shown in Figure 1), and the patent application number is 200710064952.X, the name is "multi-stage cooling intermediate liquid separation type air condenser" In the utility model patent of "device" (as shown in Figure 2), the technical scheme of adopting multi-stage steam condensation, automatic vapor-liquid separation and liquid drainage in the middle, and centralized accumulation of condensate for supercooling is proposed, so as to ensure that each tube pass is powered by pure steam It enters and is cooled, which effectively reduces the thickness of the liquid film during the condensation process and eliminates the unfavorable two-phase flow pattern; makes full use of the short heat exchange tubes, so that each tube can be in the short tube beads or unstable thin liquid film condensation , or through the influence of steam on the liquid film to promote the instability and breakage of the liquid film, forming a stream-like condensation in which the film-like condensation and bead-like condensation coexist, enhance the heat transfer effect of the film-like condensation, and increase the condensation heat transfer coefficient in the tube.

The headers 2 in the above two patents all use a single discharge pipe as the leaking liquid vapor blocking device 30. This thinner discharge pipe can better prevent the gas separated in the header from leaking from the discharge pipe, but This structure also brings the following problems: firstly, the diameter of the liquid discharge pipe is smaller than that of the header, the flow range of the condensate is greatly restricted, and sometimes the problem of poor liquid discharge occurs. Although a liquid dispensing device (as shown in FIG. 3 ) consisting of a solid top cover 31, a porous core body 32 and a discharge pipe wall 33 is adopted in the latter patent, since the upper surface of the liquid dispensing device adopts a solid top cover, During the operation of the condenser, the contact surface between the condensate and the liquid separator is the side surface of the porous medium, so the liquid separation driving force of the liquid separator is mainly the capillary suction force of the porous core, and the suction force is determined by the selected porous medium. It is determined by the structural parameters of the system, and the self-adjusting ability is weak. When the amount of condensate is large, there may be a problem of insufficient suction force, which affects the effect of liquid separation; Production and subsequent installation work pose certain difficulties.

Contents of the invention

In view of the above problems, the purpose of this utility model is to provide a segmented vapor-liquid phase change heat exchanger capable of more effectively separating vapor-liquid.

In order to achieve the above object, the utility model adopts the following technical solutions: a segmented vapor-liquid phase change heat exchanger, which is characterized in that it includes at least one set of heat exchange tubes, and the two ends of the heat exchange tubes are respectively connected to the The two headers are interleaved with a number of liquid leakage and vapor barrier devices, which divide the two headers into a plurality of sequentially connected liquid separation spaces, and the first stage of the liquid separation space is connected to The steam pipe is connected with a liquid outlet pipe in parallel with the liquid separation space at the bottom of both ends, and at least one main hole and several auxiliary holes are arranged on the liquid leakage and steam blocking device.

The liquid leakage vapor barrier device is a substrate that can be embedded in the header, and the substrate is provided with at least one main hole with an equivalent diameter of 2-5 mm and several auxiliary holes with an equivalent diameter of less than 2 mm.

The main hole and the auxiliary hole on the substrate are straight holes with the same upper and lower equivalent diameters respectively.

The main hole and the auxiliary hole on the substrate are respectively truncated cone holes, and may also be through holes with variable cross-sections.

Several auxiliary holes on the base plate intersect with the edge of the main hole to form an integral quincunx-shaped hole.

Several independent auxiliary holes are provided between the integral quincunx-shaped hole and the edge of the substrate.

A porous medium core is arranged in the main hole and the auxiliary hole.

The material of the substrate is metal material.

The material of the substrate is a porous medium material.

Because the utility model adopts the above technical scheme, it has the following advantages: 1. The utility model is provided with straight-through headers at both ends of a group of heat exchange tubes, and the two headers are connected by the embedded liquid leakage gas blocking device in the header. Separated into multiple liquid separation spaces connected in sequence, and at least one main hole and several auxiliary holes are arranged on the base plate of the liquid leakage and gas barrier device, so when the condensed liquid generated in the heat exchange tube upstream of the heat exchanger header is less , the liquid separated from the header will form a layer of water film on the surface of the main hole and the auxiliary hole, preventing the gas from flowing out from the main hole and the auxiliary hole; when the liquid volume increases slightly, the main hole with a larger pore size will First of all, seepage, which is equivalent to the discharge of a single drain pipe in the prior art; when the amount of separated liquid is large, the pressure of the liquid will destroy the liquid film covering the surface of the auxiliary hole, and seep out from the auxiliary hole , which is equivalent to increasing the drainage of multiple drainage pipes, which solves the problem of limited drainage in the prior art. 2. Since the utility model is provided with a plurality of holes that can leak liquid on the substrate, and the equivalent diameter of the holes can be changed according to the design requirements, although the equivalent diameter of each hole is relatively small, the total amount of liquid leakage Larger, especially the setting of holes with different equivalent apertures can automatically adjust the number of leaking apertures according to the change of liquid volume, and the structural design is very ingenious. 3. Due to the large number of openings on the substrate of the utility model, the equivalent pore size can be smaller, and the smaller equivalent pore size distribution can generate a larger surface tension, thus effectively ensuring the vapor barrier ability of the utility model, and at the same time, the porous The base plate also has obvious advantages in solving the oil clogging liquid core in the system. 4. Since the utility model is provided with a porous medium core in the main hole and the auxiliary hole, even if the flow rate of the condensate is very small, the smaller pore structure of the porous medium core can be used to ensure the vapor resistance of the pore structure. The new type fills the porous medium core without changing the pore structure, which can effectively enhance the surface tension of the pores and enhance the vapor barrier ability. At the same time, due to the suction effect of the porous medium core, the circulation of condensate can be better ensured, and the liquid separation function under small refrigerant flow rate can be realized. 5. The utility model directly embeds the liquid leakage and steam blocking device in the header. Compared with the existing technology, it has its advantages in terms of early processing, operation stability and later maintenance, and is suitable for the requirements of industrialized module production. . 6. When the utility model is applied to a traditional air-cooled vapor-liquid phase change heat exchanger or evaporator, it can significantly improve the separation effect of the heat exchanger for liquid leakage and vapor-liquid separation. The utility model can be widely used in energy systems, power engineering, Chemical and petrochemical, automobile industry and other industries, such as air condensers in thermal power plants, air conditioning engineering and chemical systems, vapor-liquid phase change heat exchangers for vehicle air conditioners, etc.

Description of drawings

Fig. 1 is the liquid separation type air condenser of prior art

Fig. 2 is the air condenser of prior art multi-stage condensation, intermediate liquid separation

Fig. 3 is a structural schematic diagram of the leakage liquid vapor arresting device in Fig. 2

Figure 4 and Figure 5 are schematic diagrams of the installation of the liquid leakage and steam blocking device of the present invention in the headers on the left and right sides

Fig. 6 and Fig. 7 are front and top view schematic diagrams of Embodiment 1 of the present utility model

Fig. 8 and Fig. 9 are the schematic diagrams of front view and top view of Embodiment 2 of the present utility model

Fig. 10 and Fig. 11 are front and top view schematic diagrams of Embodiment 3 of the present utility model

Fig. 12 and Fig. 13 are front and top view schematic diagrams of Embodiment 4 of the present utility model

Fig. 14 and Fig. 15 are front and top view schematic diagrams of Embodiment 5 of the present utility model

Fig. 16 and Fig. 17 are the schematic diagrams of front view and top view of Embodiment 6 of the present utility model

Fig. 18 and Fig. 19 are front and top view schematic diagrams of Embodiment 7 of the present utility model

Fig. 20 and Fig. 21 are schematic diagrams of front view and top view of Embodiment 8 of the present utility model

Fig. 22 is the liquid separation type air condenser adopting the utility model method

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in detail.

As shown in Figure 4, the heat exchanger of the present invention includes at least one set of heat exchange tubes 1 arranged up and down, and a header connected to the upper and lower sides of the heat exchange tubes 1 is respectively provided at the left and right ends of the heat exchange tubes 1. 2. A number of liquid leakage and steam arresting devices 10 are installed at intervals in the two headers 2, and the positions of the liquid leakage and vapor arresting devices 10 in the two headers 2 are arranged in a staggered shape, so that the two headers 2 form a plurality of sequentially connected left and right Dispensing space, the size of each dispensing space gradually decreases according to the change of dispensing volume. If the heat exchanger of the present utility model is used as a condenser, a steam inlet pipe 3 is connected to the first cascade box space (the left side in the figure, but not limited to this), and a liquid outlet is connected in parallel to the bottom of the header box 2 on both sides. The tube 4 and the heat exchange tube 1 are provided with fins 5 . The liquid leaking vapor arresting device 10 of the present invention includes a base plate 11 embedded in the header 2, and at least one main hole with an equivalent diameter of 2-5 mm and several auxiliary holes with an equivalent diameter of less than 2 mm are arranged on the base plate. The following is an embodiment of the liquid leakage vapor arresting device 10 of the present invention.

Example 1:

As shown in Fig. 6 and Fig. 7, the liquid leakage and steam arresting device 10 of the present utility model includes a base plate 11 having the same cross-sectional size as the heat exchanger header 2, and the center of the base plate 11 has an equivalent diameter of 2 to 5 mm and the same aperture. The main hole 12 is evenly arranged around the main hole 12 with a circle of auxiliary holes 13 having an equivalent diameter less than 2 mm and the same equivalent hole diameter. When the condensed liquid generated in the heat exchange tube 1 upstream of the heat exchanger 2 is less, the liquid separated from the header 2 will form a layer of liquid film on the surface of the main hole 12 and the auxiliary hole 13 of the substrate 11, preventing liquid and vapor The solid flows out from the main hole 12 and the auxiliary hole 13; when the liquid volume increases slightly, the main hole 12 with a larger aperture will seep first, which is equivalent to the drainage of a single drain pipe in the prior art. When the amount of separated liquid is large, the pressure of the liquid will destroy the liquid film covering the surface of the auxiliary hole 13, and seep out from the auxiliary hole 13, which is equivalent to increasing the drainage of multiple drain pipes, solving the problem of The problem that the liquid discharge volume is limited in the prior art is solved.

Example 2:

As shown in Fig. 8 and Fig. 9, the size range of the main hole 12 and the auxiliary hole 13 in this embodiment is similar to that of embodiment 1, the difference is that the main hole 12 and the auxiliary hole 13 are frustum holes with variable equivalent apertures. The aperture can be large at the top and small at the bottom; it can also be small at the top and large at the bottom, and it can also be in any form of variable cross-sectional area. This structure can make both the main hole 12 and the auxiliary hole 13 able to carry a certain amount of condensate, and when the amount of condensate in the main hole is relatively low, it can also ensure the continuous drainage and prevent steam from passing through; the auxiliary hole 13 The condensate in the pores can improve its steam resistance ability and prevent steam from passing through. It can also improve the steam resistance ability and accelerate liquid discharge according to the hole type.

Example 3:

As shown in Fig. 10 and Fig. 11, the main hole 12 and the auxiliary hole 13 in this embodiment intersect with each other, presenting a "plum blossom" hole structure. The intersecting plum-blossom hole structure can be regarded as an extended structure of the main hole. Compared with the single main hole 12 structure, its flow equivalent diameter is increased, which can effectively strengthen the condensate flow capacity of the main hole 12, while the auxiliary hole 13 Intersecting with the main hole 12 can adhere a certain amount of condensate through surface tension when the amount of liquid is relatively small, which strengthens the vapor resistance and liquid sealing ability of the device.

Example 4:

As shown in Fig. 12 and Fig. 13, the auxiliary hole 13 in this embodiment intersects with the main hole 12 to form a "plum blossom" hole structure, and an auxiliary hole 13 not intersecting with the main hole 12 is also provided. This is a combination of the above-mentioned structures, which ensures that the liquid leakage and vapor resistance device has the ability to adjust in a larger flow range while the flow area is enlarged.

The function of the above structure is mainly to strengthen the steam-blocking ability and liquid flow regulation ability of the liquid-leakage vapor-arresting device by combining different equivalent pore diameters from the pore structure. The hole 13 ensures the liquid flow adjustment capability of the leaking liquid vapor blocking device, and blocks the flow of steam through the liquid seal when the liquid volume is small. Directly adopting the above-mentioned substrate 11 with a porous structure has obvious advantages in solving the clogging of the substrate 11 by oil in the heat exchanger system.

Example 5:

As shown in FIGS. 14 and 15 , in this embodiment, the porous medium core 4 is provided in the main hole 12 and the auxiliary hole 13 provided on the manufactured substrate 11 . In a heat exchanger with a small refrigerant flow rate, due to the small condensate flow rate, a smaller pore structure is required to ensure the vapor resistance of the pore structure. Filling the porous medium core 4 can be achieved without changing the pore structure. Enhance the effect of pore surface tension and enhance the vapor barrier ability. At the same time, the suction effect of the porous medium core 4 can also ensure the circulation of the condensate, and realize the liquid separation effect under the small refrigerant flow rate.

Embodiment 6:

As shown in Figures 16 and 17, in this embodiment, a porous medium core 4 is provided in the aperture where the main hole and the auxiliary hole intersect to present a "plum blossom" hole structure. This structure can be based on the characteristics of the above-mentioned embodiment 3. The steam resistance effect of the device is enhanced.

Embodiment 7:

As shown in Figures 18 and 19, in this embodiment, when the main hole 12 and the auxiliary hole 13 intersect to present a "plum blossom" hole-shaped structure, the auxiliary hole 13 that does not intersect the main hole is also provided. A porous media core 4 is provided. This structure is a combination of the structures described in Embodiment 4 above, which ensures that the leaking liquid vapor barrier device has the ability to adjust in a larger flow range while increasing the flow area, and at the same time ensures the vapor barrier effect of the device.

Embodiment 8:

As shown in Figures 20 and 21, this embodiment is similar to Embodiment 1, but the porous dielectric material is used as the substrate 11, and the structure of the main hole 12 and the auxiliary hole 13 is used to ensure the vapor barrier capability through the porous structure of the porous dielectric material itself. The through-hole structure ensures the ability to divert liquid leakage.

In each of the above-mentioned embodiments, the liquid leakage and vapor barrier device 10 uses the same solid material or solid porous medium as the substrate 11 in the cross section of the header 2, generally a metal material, under the premise of ensuring no leakage and close contact with the header , other materials can also be used. The substrate is directly embedded in the determined position in the header, and the metal substrate is generally fixed by welding, which greatly simplifies the structure. The holes on the perforated plate can be composed of holes with different equivalent pore diameters and structures. Each pore structure can be variable equivalent pore size or the same equivalent pore size. The porous medium can be porous medium or silk screen made by sintering powder particles.

Embodiment 9: The utility model can be applied in various refrigeration and heating equipment.

As shown in Figure 22, this embodiment is an application in a liquid-separated air condenser, and the header 2 equipped with a liquid-leakage vapor-proof device 10 replaces the liquid-separating pipe and the header in the original liquid-separated air condenser Structure, the header 2 on one side is connected to the header 2 on the other side through heat exchange tubes, the left and right headers 2 are staggeredly inlaid and fixed with multiple liquid leakage and vapor resistance devices 10, and the headers 2 on both sides are divided into left and right A plurality of vapor-liquid separation spaces connected in sequence, the first cascade box 2 is connected to a liquid inlet pipe 3, the bottom of the bottommost header box 2 on both sides is connected in parallel to a liquid outlet pipe 4, and the heat exchange tube 1 is provided with fins 5 .

When the utility model is in use, the condensate produced by the heat exchange of the heat exchange tube 1 will gather in the header 2 to the upper part of the leaking liquid vapor blocking device 10 due to the action of gravity. With the continuous accumulation of the condensate, the condensate will It will first be drained by the main hole 12 with a larger diameter, and the auxiliary hole 13 with a smaller diameter will be sealed by a liquid film formed by a small amount of condensate, effectively preventing the passage of steam. The condensate accumulated on the upper part of the vapor barrier device 10 increases, the thickness of the liquid layer increases, the pressure head generated by gravity increases, and the flow capacity of the small-diameter auxiliary hole 13 is activated, which can effectively reduce the excessive flow of condensate on the upper part of the liquid separator. gather. The flow capacity experiment of the hole shows that under the condition of a certain liquid level, the condensate flow rate of the through hole is roughly proportional to the flow area of the through hole. Therefore, the flow capacity of the leaking liquid vapor barrier device 10 is characterized by defining the parameter porosity S,

S＝A _p /A _t

Among them, A _{p and At} are respectively the sum of the flow areas of each hole and the surface area of the substrate. The parameter S is determined by the circulation flow of the condenser system, which is roughly 20-50% of this.

The utility model can also be used in other refrigeration and heating heat exchangers, which will not be repeated here. Any improvement and equivalent transformation based on the principles and technical solutions of the utility model should not be excluded from the protection of the utility model. out of range.

Claims (11)

1, a kind of segmented liquid-gas phase transition heat exchanger, it is characterized in that: it comprises at least one group of heat exchanger tube, be communicated with a straight-through header respectively at the two ends of described heat exchanger tube, in two described headers, be staggeredly equipped with some leakage resistance vapour devices, two described headers are divided into a plurality of minutes liquid spaces that order is communicated with, described minute liquid space of the first order connects a steam inlet pipe, described minute liquid space of the two ends bottommost drain pipe that is connected in parallel, leakage resistance vapour device is provided with at least one main aperture and several via holes.

2, a kind of segmented liquid-gas phase transition heat exchanger as claimed in claim 1, it is characterized in that: described leakage resistance vapour device is one can be inlaid into the substrate in the described header, and described substrate is provided with main aperture that at least one equivalent diameter is 2～5mm and several equivalent diameters via hole less than 2mm.

3, a kind of segmented liquid-gas phase transition heat exchanger as claimed in claim 2 is characterized in that: the described main aperture on the described substrate is respectively the identical straight type hole of upper and lower equivalent diameter with via hole.

4, a kind of segmented liquid-gas phase transition heat exchanger as claimed in claim 2, it is characterized in that: main aperture on the described substrate and via hole are respectively one of frustum hole and variable cross-section hole.

5, as claim 2 or 3 or 4 described a kind of segmented liquid-gas phase transition heat exchangers, it is characterized in that: some via holes on the described substrate and described main aperture edge intersect, and form holistic plum blossom shape hole.

6, as claim 2 or 3 or 4 described a kind of segmented liquid-gas phase transition heat exchangers, it is characterized in that: between the edge of the plum blossom shape hole of described integral body and described substrate, be provided with some independently via holes.

7, a kind of segmented liquid-gas phase transition heat exchanger as claimed in claim 5 is characterized in that: be provided with some independently via holes between the edge of the plum blossom shape hole of described integral body and described substrate.

8, as claim 2 or 3 or 4 or 7 described a kind of segmented liquid-gas phase transition heat exchangers, it is characterized in that: described substrate is a metal material, is provided with the porous media core in described main aperture and the via hole.

9, a kind of segmented liquid-gas phase transition heat exchanger as claimed in claim 5, it is characterized in that: described substrate is a metal material, is provided with the porous media core in described main aperture and the via hole.

10, a kind of segmented liquid-gas phase transition heat exchanger as claimed in claim 6, it is characterized in that: described substrate is a metal material, is provided with the porous media core in described main aperture and the via hole.

11, as claim 2 or 3 or 4 or 7 described a kind of segmented liquid-gas phase transition heat exchangers, it is characterized in that: the material of described substrate is a porous media material.

Images