Vapor-liquid heat exchanger with uniformly distributed steam

Abstract

The steam-liquid heat exchanger is characterized in that two steam inlets are formed in the first inlet and the second inlet of the opposite left side and right side of a box body respectively, a steam pipe is divided into two parts including the first steam pipe and the second steam pipe, the first steam pipe is communicated with the first inlet, and the second steam pipe is connected with the second inlet; wherein the multiple first steam pipes extend from the left side to the right side of the box body, the multiple second steam pipes extend from the right side to the left side of the box body, the steam outlet holes are distributed in the extending direction of the multiple steam pipes, and the second steam pipes extend to the positions between every two adjacent first steam pipes; the first steam pipes extend to the positions between the two adjacent second steam pipes. The first steam pipes and the second steam pipes are distributed at intervals, so that steam in the box body is uniformly distributed on the whole, and the heat exchange effect can be improved on the whole.

Description

Technical Field

[0001] This invention belongs to the field of heat exchangers, and particularly relates to a vapor-liquid heat exchanger with uniform steam distribution. Background Technology

[0002] A heat exchanger is an energy-saving device that facilitates heat transfer between two or more fluids at different temperatures. It transfers heat from a higher-temperature fluid to a lower-temperature fluid, bringing the fluid temperature to the specified parameters to meet process requirements. It is also one of the key devices for improving energy efficiency. The heat exchanger industry involves nearly 30 sectors, including HVAC, pressure vessels, wastewater treatment equipment, chemicals, and petroleum, forming interconnected industrial chains.

[0003] Vapor-liquid mixing heat exchangers, as a common type of heat exchanger, are now widely used in systems for heating domestic and industrial hot water, as well as in hot water heating and thermal deaeration. Vapor-liquid mixing heaters can directly mix waste heat steam from the production processes of steel plants, chemical plants, and thermal power plants with water to heat it. This hot water can meet the requirements of some industrial processes such as printing and dyeing, food processing, building HVAC, and daily residential use. The application of vapor-liquid mixing heaters effectively utilizes waste heat from industrial processes, reduces the consumption of fossil fuels by heat energy users, lowers production and operating costs, and correspondingly reduces emissions of greenhouse gases such as carbon dioxide. It is an effective way to rationally utilize energy and reduce environmental pollution.

[0004] In the prior art, CN103090693A discloses a continuous vapor-liquid mixer, which includes a water collection tank. The water collection tank is provided with a cold water inlet, a hot water outlet, and a steam inlet. The steam inlet is connected to a steam pipe, and the steam pipe is provided with at least one small hole. This invention has a simple structure and is easy to use. The densely distributed small holes serve to reduce noise, ensuring that the continuous vapor-liquid mixer does not generate noise during operation.

[0005] CN106017133A discloses a vapor-liquid mixing device, including an inner pipe, at least one outer pipe, a connecting pipe, an end cover plate, an annular sealing plate, and a flange. Each of the outer pipes is sequentially fitted over the inner pipe. One end of each outer pipe and one of the inner pipes is fixedly connected to and closed by the end cover plate. The other end of each inner pipe is connected to one end of the connecting pipe, and the other end of the connecting pipe is fixedly connected to the flange. The flange is used to connect to a flange on a steam conveying pipeline. The annular sealing plate is fitted over the connection between the inner pipe and the connecting pipe and is fixedly connected to and closed by the other ends of each outer pipe. The inner pipe and the end cover plate form a closed enclosure. The inner section is formed by the innermost outer tube, the inner tube, the end cover plate, the annular sealing plate, and the adjacent outer tubes, which enclose at least one outer section. The inner tube and each outer tube have a plurality of steam outlets on their side walls. The inner tube and each outer tube are placed in a container holding liquid. Steam enters the connecting pipe through a steam conveying pipe and enters the inner section. The steam in the inner section is depressurized through the steam outlets and enters the adjacent outer section. The pressure is gradually reduced and finally enters the container through the outermost steam outlet, where it mixes with the liquid and exchanges heat.

[0006] CN108267029A discloses a novel pipeline vapor-liquid mixing heater, comprising a shell and a core tube. The core tube is composed of at least two concentric reducers connected in a stacked manner. The connection between two adjacent concentric reducers is as follows: the smaller diameter end of one reducer is inserted into the larger diameter end of another reducer, and the connection is fixed, with a gap connecting the inside and outside of the core tube. Hot steam enters the vicinity of the core tube after passing through the outer shell pipe. Under the action of steam pressure, the steam enters the core tube along the gap between the shells, following the direction of the diameter reduction of the shells, and comes into contact with and mixes with the cold liquid inside the core tube.

[0007] CN1959323A discloses a liquid ejector steam mixing heater, which consists of a cold liquid inlet connector, a converging nozzle, a porous vapor-liquid mixing heating pipe, a steam header pipe, a steam interface, a diffuser pipe, and a hot liquid outlet connector. The cold liquid outlet connector is connected to the inlet of the porous vapor-liquid mixing heating pipe. The porous vapor-liquid mixing heating pipe has a smooth inner wall with 4 to 20,000 holes of diameter Φ1 to Φ20 mm that connect the inner and outer walls. The outlet of the porous vapor-liquid mixing heating pipe is connected to the small end of the diffuser pipe, while the large end of the diffuser pipe is connected to the hot liquid outlet connector. One end of the steam header pipe is fixed to the outer side of the outlet end of the converging nozzle, and the other end is fixed to the outer side of the inlet end of the diffuser pipe. The porous vapor-liquid mixing heating pipe is placed inside the steam header pipe. The centerlines of the converging nozzle, the porous vapor-liquid mixing heating pipe, the steam header pipe, and the diffuser pipe are all on the same axis. A hole is opened in the middle of the steam header pipe and connected to the steam interface.

[0008] In existing technologies, steam in vapor-liquid mixing heat exchangers enters from one direction and flows along the pipe. However, during the flow process, as steam is continuously ejected, the amount of steam ejected further away from the inlet decreases, resulting in uneven distribution of steam ejection from the inlet to the outlet, thus affecting the overall heat exchange effect.

[0009] To address the aforementioned problems, this invention improves the heat exchanger by setting two steam inlets at relatively opposite positions and distributing the steam pipes to achieve uniform steam injection and improve heat exchange efficiency. Summary of the Invention

[0010] This invention provides a novel vapor-liquid heat exchanger structure, thereby solving the aforementioned technical problems.

[0011] To achieve the above objectives, the technical solution of the present invention is as follows: A vapor-liquid heat exchanger with uniform steam distribution includes a housing and steam pipes. The housing has a liquid inlet and a mixed fluid outlet. The steam pipes are disposed within the housing and have steam outlets. Steam flows out of the steam outlets and exchanges heat with a cold source entering the housing. The steam pipes are connected to steam inlets. The steam inlets are two inlets, respectively located on opposite left and right sides of the housing as a first inlet and a second inlet. The steam pipes are divided into two parts: a first steam pipe and a second steam pipe. The first steam pipe connects to the first inlet, and the second steam pipe connects to the second inlet. Multiple first steam pipes extend from the left side of the housing to the right, and multiple second steam pipes extend from the right side of the housing to the left. Steam outlets are distributed along the direction of the multiple steam pipes. The second steam pipes extend between two adjacent first steam pipes, and the first steam pipes extend between two adjacent second steam pipes.

[0012] As an improvement, it also includes a first manifold and a second manifold installed inside the housing, with a first inlet connected to the first manifold, the first manifold connected to multiple first steam pipes, a second inlet connected to the second manifold, and the second manifold connected to multiple second steam pipes.

[0013] As an improvement, the second steam pipe extends between two adjacent first steam pipes, and the first steam pipe extends between two adjacent second steam pipes.

[0014] As an improvement, no steam outlet is provided in the first and second manifolds.

[0015] As an improvement, no connecting hole is provided at the position of the first steam pipe near the first manifold, and no connecting hole is provided at the position of the second steam pipe near the second manifold.

[0016] As an improvement, the depth of the second steam pipe extending between two adjacent first steam pipes shall not exceed 80% of the length of the first manifold, and the depth of the first steam pipe extending between two adjacent second steam pipes shall not exceed 80% of the length of the second manifold.

[0017] As an improvement, no steam outlet is provided on the first steam pipe from the first manifold to the position of the second steam pipe extending between the two first steam pipes; and no steam outlet is provided on the second steam pipe from the second manifold to the position of the first steam pipe extending between the two second steam pipes.

[0018] As an improvement, the liquid is cold water, the steam is water vapor, and the mixed fluid is hot water.

[0019] As an improvement, the hydraulic diameters of the first and second steam pipes are the same, and the distance between the second steam pipes of adjacent first steam pipes is 2.5-4.5 times the hydraulic diameter.

[0020] As an improvement, the end of the first steam pipe furthest from the first manifold is a closed structure, and the end of the second steam pipe furthest from the second manifold is a closed structure.

[0021] Compared with the prior art, the present invention has the following advantages: This invention provides steam inlets on opposite sides of the housing. Multiple steam pipes connecting the first and second inlets are arranged at intervals, allowing adjacent first and second steam pipes to cooperate. The position of a larger steam injection volume in the first steam pipe corresponds to a position of a smaller steam injection volume in the second steam pipe, and vice versa. This complementary injection volume of the first and second steam pipes achieves balanced injection volume along the overall length of the steam pipes, thereby improving the overall heat exchange effect. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the heat exchanger structure of the present invention; Figure 2 This is a schematic cross-sectional view of the heat exchange tube of the present invention; Figure 3 This is a schematic diagram of the improved cross-sectional structure of the heat exchanger tube of the present invention. Detailed Implementation

[0023] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0024] In this article, unless otherwise specified, when formulas are involved, " / " represents division, and "×" and "*" represent multiplication. The left and right references in this invention are relative positions and are not required to be set horizontally.

[0025] Figure 1 A vapor-liquid heat exchanger with uniform steam distribution is disclosed. For example... Figure 1 As shown, the heat exchanger includes a housing 1 and a steam pipe 2. The housing is equipped with a liquid inlet 3 and a mixed fluid outlet 4. The steam pipe 2 is located inside the housing 1 and has a steam outlet 21. Steam flows out from the steam outlet 21 and mixes with the liquid entering the housing 1 for heat exchange. The steam pipe 2 connects to steam inlets 5 and 6. There are two steam inlets, located on opposite left and right sides of the housing: a first inlet 5 and a second inlet 6. The steam pipe is divided into two parts: a first steam pipe 22 and a second steam pipe 23. The first steam pipe 22 connects to the first inlet 5, and the second steam pipe 23 connects to the second inlet 6. Figure 1 As shown, multiple first steam pipes are provided extending from the left side to the right side of the housing 1, and multiple second steam pipes are provided extending from the right side to the left side of the housing 1. Steam outlets 21 are distributed along the direction of the multiple steam pipes. The second steam pipe 23 extends between two adjacent first steam pipes 22, and the first steam pipe 22 extends between two adjacent second steam pipes 23.

[0026] This invention provides steam inlets on opposite sides of the housing. Multiple steam pipes connecting the first and second inlets are arranged at intervals, allowing adjacent first and second steam pipes to cooperate. The position of a larger steam injection volume in the first steam pipe corresponds to a position of a smaller steam injection volume in the second steam pipe, and vice versa. This complementary injection volume of the first and second steam pipes achieves balanced injection volume along the overall length of the steam pipes, thereby improving the overall heat exchange effect.

[0027] As an improvement, a first manifold 7 and a second manifold 8 are also provided inside the chamber. The first inlet 5 is connected to the first manifold 7, the first manifold 7 is connected to multiple first steam pipes 22, the second inlet 6 is connected to the second manifold 8, and the second manifold 8 is connected to multiple second steam pipes 23. Steam can be introduced into multiple steam pipes through the manifold, and the heat exchange area between steam and liquid inside the chamber can be increased through the manifold, thereby improving the heat exchange effect.

[0028] As an improvement, the second steam pipe extends to the middle of two adjacent first steam pipes, and the first steam pipe extends to the middle of two adjacent second steam pipes. By placing them in the middle position, the steam distribution can be made more even.

[0029] As an improvement, the first manifold 7 and the second manifold 8 do not have steam outlets. Because the steam at the inlet has a certain pressure and temperature, direct injection would generate significant noise. This invention eliminates steam outlets in the first manifold 7 and the second manifold 8, employing indirect heat exchange via partitioned heat exchange tubes at the location of highest steam temperature and pressure. This reduces the steam pressure and temperature, allowing the steam to cool and depressurize before entering the steam pipe for injection, thus reducing steam injection noise. Furthermore, as the steam flows, its temperature decreases, and the temperature difference between the steam and the liquid decreases, resulting in a gradual reduction in heat exchange efficiency along the steam's direction of movement. This application employs a combination of indirect and direct heat exchange, using indirect heat exchange at high steam temperatures and direct heat exchange at low steam temperatures. Because direct heat exchange is more efficient than indirect heat exchange, it ensures relatively uniform heat exchange along the entire heat exchange tube direction, avoiding localized uneven heat exchange.

[0030] As an improvement, no steam holes are provided on the first steam pipe near the first manifold, and no steam holes are provided on the second steam pipe near the second manifold. The absence of steam holes in certain sections of the first and second steam pipes allows for indirect heat exchange through a partition wall, thereby reducing steam temperature and pressure, minimizing noise, and ensuring uniform overall heat exchange.

[0031] As an improvement, the length of the steam pipe without an outlet is between one-sixth and one-quarter of the total length of the steam pipe. Preferably, it is one-fifth. This arrangement ensures sufficient heat exchange efficiency while minimizing noise.

[0032] As an improvement, the depth of the second steam pipe extending between two adjacent first steam pipes shall not exceed 80% of the length of the first manifold, and the depth of the first steam pipe extending between two adjacent second steam pipes shall not exceed 80% of the length of the second manifold. These dimensions ensure maximum steam distribution balance and achieve maximum heat exchange efficiency.

[0033] As an improvement, no steam outlet is provided on the first steam pipe from the first manifold to the second steam pipe extending between the two first steam pipes; similarly, no steam outlet is provided on the second steam pipe from the second manifold to the first steam pipe extending between the two second steam pipes. This arrangement reduces noise, achieves uniform heat exchange, and ensures overall uniform steam distribution. If steam outlets were provided at these locations, the steam distribution at those outlets would be uneven compared to other locations. This arrangement achieves a complementary and uniform steam distribution between the first and second steam pipes.

[0034] As an improvement, the liquid is cold water, the steam is water vapor, and the mixed fluid is hot water.

[0035] As an improvement, the first and second steam pipes have the same hydraulic diameter, and the distance between adjacent first and second steam pipes is 2.5-4.5 times the hydraulic diameter, preferably 3-4 times. The spacing should not be too large or too small. If it is too large or too small, it will result in too much or too little steam distribution at the steam injection point, and it will also result in the heated water temperature being too high or too low. Moreover, it will not be able to cooperate with the preceding indirect heat exchange to achieve uniform heat exchange overall, thus reducing the overall heat exchange effect.

[0036] As an improvement, the end of the first steam pipe furthest from the first manifold is a closed structure, and the end of the second steam pipe furthest from the second manifold is also a closed structure. By sealing off the other end of the steam pipe, steam is prevented from being ejected from the other end, allowing steam to be ejected from the middle position for direct mixing and heat exchange, while indirect heat exchange occurs on both sides, thereby improving the overall heat exchange effect.

[0037] As an improvement, the heat exchange tube has a square cross-section.

[0038] As an improvement, the lines connecting the vertices of the heat exchange tube cross section form a square, and a tube wall is formed between adjacent vertices of the square. The tube wall is parabolic, and the bending direction of the tube wall is towards the center of the square. A connecting hole 31 is formed on the tube wall.

[0039] The heat exchange tube of the present invention increases the heat exchange area by modifying the square tube into an inwardly curved shape; moreover, because of the inwardly curved tube wall, the fluid inside the tube flows more from the center of the tube to the apex of the tube, thereby increasing the corner pressure. Compared with other shapes, it reduces the flow dead zone and avoids uneven spraying caused by uneven fluid distribution at different positions, thus making the overall sprayed fluid uniform.

[0040] This application improves the shape of the square tube wall by making it curved inward, which increases the flow area of ​​the external fluid and the mixing area and mixing time of the two fluids, thereby making the mixing more uniform and the heat exchange effect better.

[0041] While the present invention has been disclosed above with reference to preferred embodiments, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A vapor-liquid heat exchanger with uniform steam distribution, the heat exchanger comprising a housing and a steam pipe, the housing having a liquid inlet and a mixed fluid outlet, the steam pipe being disposed within the housing, the steam pipe having a steam outlet hole, steam flowing out from the steam outlet hole exchanging heat with a cold source entering the housing; the steam pipe being connected to a steam inlet; characterized in that, The steam inlet is configured as two, located on opposite left and right sides of the housing as the first and second inlets, respectively. The steam pipe is divided into two parts: a first steam pipe and a second steam pipe. The first steam pipe connects to the first inlet, and the second steam pipe connects to the second inlet. Multiple first steam pipes extend from the left side of the housing to the right, and multiple second steam pipes extend from the right side of the housing to the left. Steam outlets are distributed along the direction of the multiple steam pipes. The second steam pipe extends between two adjacent first steam pipes, and the first steam pipe extends between two adjacent second steam pipes.

2. The vapor-liquid heat exchanger as described in claim 1, characterized in that, It also includes a first manifold and a second manifold installed inside the housing. The first inlet is connected to the first manifold, the first manifold is connected to multiple first steam pipes, the second inlet is connected to the second manifold, and the second manifold is connected to multiple second steam pipes.

3. The vapor-liquid heat exchanger as described in claim 1, characterized in that, The second steam pipe extends between two adjacent first steam pipes, and the first steam pipe extends between two adjacent second steam pipes.

4. The vapor-liquid heat exchanger as described in claim 1, characterized in that, No steam outlet is provided in the first and second manifolds.

5. The vapor-liquid heat exchanger as described in claim 4, characterized in that, No connecting hole is provided at the position of the first steam pipe near the first manifold, and no connecting hole is provided at the position of the second steam pipe near the second manifold.

6. The vapor-liquid heat exchanger as described in claim 1, characterized in that, The depth of the second steam pipe extending between two adjacent first steam pipes shall not exceed 80% of the length of the first manifold, and the depth of the first steam pipe extending between two adjacent second steam pipes shall not exceed 80% of the length of the second manifold.

7. The vapor-liquid heat exchanger as described in claim 6, characterized in that, From the first manifold to the position of the second steam pipe extending between the two first steam pipes, no steam outlet is provided on the first steam pipe; from the second manifold to the position of the first steam pipe extending between the two second steam pipes, no steam outlet is provided on the second steam pipe.

8. The vapor-liquid heat exchanger as described in claim 1, characterized in that, The liquid is cold water, the steam is water vapor, and the mixed fluid is hot water.

9. The vapor-liquid heat exchanger as described in claim 1, characterized in that, The first and second steam pipes have the same hydraulic diameter, and the distance between adjacent first and second steam pipes is 2.5-4.5 times the hydraulic diameter.

10. The vapor-liquid heat exchanger as described in claim 1, characterized in that, The end of the first steam pipe furthest from the first manifold is a closed structure, and the end of the second steam pipe furthest from the second manifold is a closed structure.

Images