Mixed flow heat exchange device for outputting hot water

Abstract

The invention provides a mixed flow heat exchange device for outputting hot water, which is characterized in that the connecting line of the vertexes of the section of a jet pipe is a square, a pipe wall is formed between the adjacent vertexes of the square, the pipe wall is bent, the bending direction of the bend faces the center of the square, and jet holes for jetting from the inside of the jet pipe to the outside of the jet pipe are formed in the pipe wall. The invention provides a heat exchange device adopting a novel square jet pipe, so that the mixing heat exchange effect of two fluids is better and more uniform, and the heat exchange efficiency is improved.

Description

Technical Field

[0001] This invention relates to the technical field of energy-saving steam-water mixing heat exchange, specifically to a mixed-flow heat exchange device for outputting hot water in a hotel. Background Technology

[0002] A heat exchanger, also known as a heat exchange device, is a device that transfers part of the heat from a hot fluid to a cold fluid. Heat exchangers play an important role in chemical, petroleum, power, food, and many other industrial production processes. In chemical production, heat exchangers can be used as heaters, coolers, condensers, evaporators, and reboilers, and their applications are widespread. Currently, heat exchangers are commonly used to heat water. In various shell-and-shell and plate heat exchangers, the two fluids flow through different channels, exchanging heat through good conductors. The water flow channels are generally coiled and tortuous to increase the contact area with steam, allowing it to be fully heated. However, this design suffers from drawbacks such as complex structure, slow heating speed, high vibration and noise, and low thermal efficiency. Although installing silencers can reduce noise to some extent, it is necessary to limit the steam flow rate and velocity, and the slow heating speed and low thermal efficiency still persist. Existing direct contact heat exchangers, in situations where direct mixing of cold and hot fluids is permissible, such as steam and water, are recognized as the most efficient heat exchange method.

[0003] CN118347317A discloses a steam heat exchange system, including a municipal steam pipeline connected to the inlet of a tee fitting; a steam pipeline connected to the steam outlet of the tee fitting; a condensate drain pipeline connected to the condensate outlet of the tee fitting; a steam-water mixing energy-saving device, including a steam interface, a condensate drain interface, and a heat exchange device interface, the steam interface and the condensate drain interface being connected to the steam pipeline and the condensate drain pipeline, respectively; and a heat exchange device connected to the steam-water mixing energy-saving device through the heat exchange device interface. This invention, based on steam heat exchange, adds a condensate drain pipeline to utilize the condensate in the municipal steam for heat exchange. On the one hand, this avoids excessive condensate in the municipal steam causing heat energy waste and improves the heat utilization rate of the municipal steam; on the other hand, the steam-water mixing energy-saving device further filters and removes impurities from the steam and condensate entering the heat exchange device, improving the quality of the heat source entering the heat exchange device, thereby mitigating scaling and extending the service life of the heat exchange device.

[0004] CN119983903A discloses a steam jet pipe and its steam-water mixing heat exchange device. The jet pipe includes a pipe body and spiral flow channel plates disposed outside the pipe body. One end of the jet pipe is open for steam to flow in, and the other end is closed. Steam outlet holes are provided on the pipe body between the spiral flow channel plates, and the steam inside the jet pipe flows out through the steam outlet holes. In this invention, the steam flows along the spiral flow channel and mixes thoroughly with the externally flowing liquid, enhancing the turbulence effect of steam-liquid mixing and improving the steam-liquid heat exchange effect.

[0005] CN204787976U discloses a mixing water heater, including a shell and a core tube. The shell has a cold water inlet and a hot water outlet on its two end faces, respectively, and a steam inlet in the middle of the shell. Packing material is placed between the core tube and the shell to form a steam zone. The core tube is placed inside the shell, and its portion corresponding to the steam inlet forms a mixing and heating zone. A nozzle is placed on the side wall of the core tube and is arranged rotatably along the axial direction. This mixing water heater has high heat exchange efficiency, small size, and simple structure, while also reducing equipment and related costs, resulting in low cost.

[0006] CN206803799U provides a direct steam-water mixing heat exchanger, including a shell. The upper part of the shell has a steam inlet and a condensate outlet, while the lower part has a steam outlet and a cold fluid inlet. Multiple tubes are arranged inside the shell, and an inner liner is provided within the shell, forming a heat exchange cavity between the inner liner and the shell. The tubes are arranged in a circular pattern within both the inner liner and the heat exchange cavity. The lower end of the inner liner is connected to the cold fluid inlet, and the upper end of the inner liner has a condensate outlet connected to the heat exchange cavity. This invention improves the heat exchange effect and reduces heat loss through secondary heat exchange between the condensate and circulating water between the inner liner and the shell.

[0007] Currently, hot water used in hotels, bathhouses, and similar establishments is typically obtained by mixing high-temperature steam from a boiler with cold water from a tap. However, this method of hot water supply has several drawbacks, such as a single jet tube, a small heat exchange area for mixing the steam and liquid, and uneven mixing of the two fluids. This application adopts a novel jet tube structure and layout, expanding the heat exchange area, increasing the mixing zone, and resulting in a more uniform mixing of the two fluids. Summary of the Invention

[0008] In order to overcome the defects and deficiencies in the existing technology, the present invention provides a mixed flow heat exchange device for hot water output in hotels, which can increase the heat exchange area, increase the mixing zone, and make the two fluids mix more evenly, thereby effectively improving the heat transfer efficiency.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows: A mixed-flow heat exchanger for outputting hot water includes a shell, a jet pipe, a cold water inlet pipe, an inlet header, and an outlet header. A steam inlet pipe is mounted on the shell. A cold water inlet pipe and a hot water outlet pipe are respectively mounted on the inlet header and outlet header. An inlet tube sheet is mounted between the inlet header and the shell, and an outlet tube sheet is mounted between the outlet header and the shell. The jet pipe is disposed within the shell, with its first and second ends fixedly connected to the inlet tube sheet and the outlet tube sheet, respectively. The first end communicates with the inlet header, while the second end is not connected to the outlet header. The outlet tube sheet has a through hole connecting the shell and the outlet header. The jet pipe's cross-section is characterized by forming a square with the lines connecting the vertices of the cross-section. A pipe wall is formed between adjacent vertices of the square, and the pipe wall is curved, with the curvature pointing towards the center of the square. Jet holes are formed on the pipe wall to allow water to flow from inside the jet pipe to the outside.

[0010] As an improvement, the curved shape is a parabola or a circular arc.

[0011] As an improvement, the curvature of the four walls of the jet tube is equal.

[0012] As an improvement, the centers of four adjacent jet tubes form a square, and the focal points of the bends of the opposing tube walls of two adjacent jet tubes are at one point.

[0013] As an improvement, the extension line of the jet direction of the jet orifice is oriented towards the center of the square.

[0014] As an improvement, the heat exchange device is used for hotel hot water output, with steam coming from a steam generating device and cold water coming from a tap water pipe.

[0015] As an improvement, the output hot water is used for bathing.

[0016] As an improvement, the steam generating device includes one or more of the following: gas-fired boiler, electric heating boiler, and solar water heater.

[0017] As an improvement, the heat exchanger has a horizontal structure with the jet tubes arranged horizontally.

[0018] As an improvement, the vertex position is set as a curved surface, which curves outward.

[0019] Compared with the prior art, the present invention has the following advantages: 1. The heat exchange device of the present invention increases the heat exchange area by modifying the square tube into an inwardly curved shape; and 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, thereby making the overall sprayed fluid uniform.

[0020] 2. This application improves the square tube by making it bend 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.

[0021] 3. This application improves the mixing effect and heat exchange efficiency by using a square distribution of jet tubes in the heat exchange device, with the corresponding square shape of the jet tubes and the focal point of the relative bends between adjacent jet tubes at one point. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the shell-type heat exchanger of the present invention; Figure 2 This is a schematic cross-sectional view of the jet tube structure of the heat exchange device of the present invention; Figure 3 This is a three-dimensional schematic diagram of the jet tube structure of the heat exchange device of the present invention; Figure 4 This is a three-dimensional schematic diagram of the jet tube structure of the heat exchange device of the present invention; Figure 5 This is a three-dimensional schematic diagram of the jet tube structure of the heat exchange device of the present invention; Figure 6 This is a schematic diagram of the jet tube arrangement of the heat exchange device of the present invention; Figure 7 This is a partial schematic diagram of the jet tube arrangement of the heat exchange device 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] Unless otherwise specified, in this article, " / " represents division, and "×" and "*" represent multiplication.

[0025] Figure 1-7 The heat exchange device of the present invention is shown. For example... Figure 1 As shown, a heat exchange device for a square jet tube is disclosed. The heat exchange device includes a shell 1, a jet tube 2, a cold water inlet pipe 3, an inlet header 4, and an outlet header 5. The steam inlet pipe 3 is disposed on the shell 1. The inlet header 4 and the outlet header 5 are respectively provided with a cold water inlet pipe 6 and a hot water outlet pipe 7. An inlet tube sheet 8 is disposed between the inlet header and the shell, and an outlet tube sheet 9 is disposed between the outlet header and the shell. The jet tube 2 is disposed in the shell 1. The first end 24 and the second end 25 of the jet tube 2 are respectively fixedly connected to the inlet tube sheet and the outlet tube sheet, wherein the first end 21 is connected to the inlet header, and the second end 22 is not connected to the outlet header. The outlet tube sheet is provided with a through hole 10 connecting the shell and the outlet header.

[0026] The cold water enters the jet pipe 2 through the header 4 from the cold water inlet pipe 6, and then exits through the jet hole 23 of the jet pipe 1. Because the second end of the jet pipe 2 is a closed structure, the cold water cannot directly enter the outlet header 5 through the second end, and therefore must flow out through the jet hole 23. Steam flows in from the steam inlet pipe 3, and then mixes and exchanges heat directly with the cold water flowing out of the jet hole 23 inside the outer shell 1. The heat-exchanged hot water enters the outlet header through the through holes of the outlet pipe plate, and then flows out from the hot water outlet pipe.

[0027] As an improvement, the heat exchange device is used for hotel hot water output, with steam coming from a steam generating device and cold water coming from a tap water pipe.

[0028] As an improvement, the output hot water is used for bathing.

[0029] As an improvement, the steam generating device includes one or more of the following: gas-fired boiler, electric heating boiler, and solar water heater.

[0030] As an improvement, such as Figure 1-5 As shown, the jet tube is a square jet tube 2. The cross-section of the jet tube is square, that is, the line connecting the vertices of the cross-section of the jet tube forms a square. A tube wall 22 is formed between adjacent vertices 21 of the square. The tube wall is curved, and the curvature of the tube wall is towards the center of the square. Jet holes 23 are formed on the tube wall to spray from the inside of the jet tube to the outside of the tube.

[0031] The heat exchange device 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, thereby making the overall sprayed fluid uniform.

[0032] 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.

[0033] As an improvement, the curved shape is a parabola or a circular arc.

[0034] Preferably, the curvature of the four walls of the jet tube is equal. For example, in the case of circular arcs, the diameters of the four arcs of the jet tube are the same, and the curvatures of the four arcs are the same. This arrangement ensures that the circumferential jet volume is uniform.

[0035] Preferably, the curved shape is an arc, and the jet tube is configured as multiple segments along the direction from the shell-side inlet to the outlet, each segment having a different arc radius. Preferably, the arc radius of the different segments gradually decreases along the direction from the shell-side inlet to the outlet. By decreasing the arc radius, the flow area within the jet tube increases, thereby gradually reducing the flow resistance towards the outlet, resulting in more fluid flowing towards the outlet and a relatively balanced amount of fluid ejected throughout the jet tube, thus promoting heat transfer. Preferably, the rate of decrease in arc radius of the different segments gradually increases along the direction from the shell-side inlet to the outlet. This variation in the rate of decrease in arc radius further ensures a relatively balanced amount of fluid ejected throughout the jet tube, further promoting heat transfer.

[0036] As a preferred option, such as Figure 6 , 7 As shown, the jet tubes are arranged in a square pattern, with the centers of four adjacent jet tubes forming a square, and the focal points of the curved tube walls of two adjacent jet tubes converging at a single point. This application, through the square distribution of the jet tubes within the heat exchange device, combined with the corresponding square shape of the jet tubes, and the convergence of the curved tube walls between two adjacent jet tubes at a single point, achieves better mixing and improves heat exchange efficiency. The square tubes and square arrangement of this invention are mutually complementary and inseparable; their combined effect optimizes the mixing and heat exchange performance.

[0037] Preferably, the extension line of the jet orifice's spray direction points towards the center of the square. This arrangement ensures more uniform spraying from the center of the jet pipe outwards, including better heat exchange with the fluid outside the pipe.

[0038] Preferably, the shell-type heat exchanger is a horizontal shell-type heat exchanger. The distribution density of the jet holes varies at different locations in the jet tube, increasing from bottom to top. Because steam has a low density, it tends to accumulate in the upper part of the tube as it flows. Therefore, by increasing the density of the jet holes in the upper jet tube, the amount of cold water sprayed at the top increases, allowing more fluid to mix and exchange heat with the upper steam. This optimizes the overall heat exchange effect and improves the mixing heat exchange efficiency.

[0039] Preferably, the distribution density of the jet holes in different jet tubes increases progressively from bottom to top. This arrangement further optimizes the overall heat exchange effect and improves the mixing heat exchange efficiency.

[0040] Preferably, the density of jet holes increases from the middle of the curved pipe wall towards both sides. This is because research has shown that the fluid jet volume is highest in the middle section. By adjusting the density of the jet holes, the overall jetting can be made more uniform, thus improving the mixing and heat exchange efficiency.

[0041] Preferably, the distribution density of the jet holes increases progressively from the center of the curved tube wall towards both sides. This arrangement further optimizes the overall heat exchange effect and improves the mixing heat exchange efficiency.

[0042] Preferably, the pipe wall is an arc. The arc angle is 20-70°. Preferably, the arc angle is 40-50°. The above-mentioned arc angle is the optimal arc angle obtained through a large number of numerical simulations and experimental studies. With the above-mentioned arc angle, the mixing and heat exchange effect of the two fluids inside and outside the pipe can be maximized, achieving the best heat exchange effect.

[0043] As an improvement, such as Figure 5 As shown, the vertex position is set as a curved surface, and the curved surface bends outward. Jet holes are provided on the curved surface. By setting the vertex to an outward curved shape, the internal fluid flow can be more evenly distributed. Furthermore, by setting the jet holes at fixed points, the jet direction can be distributed around the perimeter of the pipe, resulting in a more uniform distribution of the jet fluid and achieving better heat exchange.

[0044] As an improvement, the extension line of the jet direction of the jet orifice on the apex curved surface passes through the center of the square. As another improvement, the focal point of the curved surface is located at the center of the square. With these settings, the distribution of the jet fluid can be further made more uniform.

[0045] As an improvement, the curved surface at the vertex is either a circular arc or a parabola.

[0046] As an improvement, both the apex and the pipe wall are circular arcs. The arc radius of the apex is 1.9-2.7 times that of the pipe wall arc radius, preferably 2.2-2.4 times. The aforementioned arc radius is the optimal arc radius obtained through extensive numerical simulations and experimental studies. This arc radius ensures the most uniform mixing and heat exchange effect between the two fluids inside and outside the pipe, achieving the best heat exchange performance.

[0047] Preferably, multiple baffles are provided inside the shell, including a lower baffle located at the bottom of the shell and an upper baffle located at the top of the shell, with the lower and upper baffles spaced apart. By setting up the baffles, the cold water flows in a tortuous manner, improving the heat exchange effect.

[0048] Preferably, the spacing between adjacent baffles gradually increases from the shell-side inlet to the outlet. This is because the flow rate of the fluid in the shell-side continuously increases from the inlet to the outlet as mixing and heat transfer proceed. If the spacing remains constant, the flow velocity will increase, causing scouring of the shell-side outlet and increasing flow resistance. By increasing the spacing, the flow velocity remains relatively stable, thus ensuring a relatively balanced resistance throughout the flow process and preventing a decline in heat transfer efficiency due to increased downstream resistance.

[0049] Preferably, the spacing between adjacent baffles gradually increases from the shell-side inlet to the outlet. This increasing spacing further ensures a relatively balanced resistance throughout the flow process.

[0050] 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 mixed-flow heat exchanger for outputting hot water, the heat exchanger comprising a shell, a jet pipe, a cold water inlet pipe, an inlet header, and an outlet header; a steam inlet pipe is disposed on the shell; a cold water inlet pipe and a hot water outlet pipe are respectively disposed on the inlet header and the outlet header; an inlet tube sheet is disposed between the inlet header and the shell; an outlet tube sheet is disposed between the outlet header and the shell; the jet pipe is disposed in the shell; a first end and a second end of the jet pipe are respectively fixedly connected to the inlet tube sheet and the outlet tube sheet, wherein the first end communicates with the inlet header, and the second end is not communicated with the outlet header; the outlet tube sheet has a through hole communicating with the shell and the outlet header, characterized in that... The lines connecting the vertices of the jet tube cross section form a square, and a tube wall is formed between adjacent vertices of the square. The tube wall is curved, and the curvature of the tube wall is toward the center of the square. Jet holes are formed on the tube wall to spray from the inside of the jet tube to the outside.

2. The heat exchange device as described in claim 1, characterized in that, The curved shape is either a parabola or a circular arc.

3. The heat exchange device as described in claim 1, characterized in that, The curvature of the four walls of the jet tube is equal.

4. The heat exchange device as described in claim 3, characterized in that, The centers of four adjacent jet tubes form a square, and the focal points of the bends in the opposite walls of two adjacent jet tubes are at one point.

5. The heat exchange device as described in claim 1, characterized in that, The extension line of the jet orifice's spray direction points toward the center of the square.

6. The heat exchange device as described in claim 1, characterized in that, The heat exchange device is used to output hot water for the hotel, steam comes from a steam generator, and cold water comes from a tap water pipe.

7. The heat exchange device as described in claim 6, characterized in that, The hot water output is used for bathing.

8. The heat exchange device as described in claim 6, characterized in that, Steam generating devices include one or more of the following: gas-fired boilers, electric boilers, and solar water heaters.

9. The heat exchange device as described in claim 1, characterized in that, The heat exchanger is a horizontal structure with the jet tubes arranged horizontally.

10. The heat exchange device as described in claim 1, characterized in that, The vertex position is set as a curved surface, and the curved surface of the vertex curves outward.

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