Three-box heat exchanger and heat exchange method thereof

Abstract

The invention provides a three-box heat exchanger which comprises a box body, an upper horizontal plate and a lower horizontal plate which are transversely arranged are arranged in the box body, the upper wall and the side wall of the box body and the upper horizontal plate form an upper box body of the heat exchanger, and the upper horizontal plate, the lower horizontal plate and the side wall of the box body form a middle box body. And the lower wall, the side wall and the lower horizontal plate of the box body form a lower box body of the heat exchanger. The three box bodies for fluid to flow transversely and longitudinally are arranged, so that the flowing direction of the fluid can be continuously changed, meanwhile, the flowing tube pass or shell pass is continuously changed, and the overall heat exchange effect is improved.

Description

Technical Field

[0001] This invention relates to a shell-and-tube heat exchanger, and more particularly to a three-box heat exchanger. Background Technology

[0002] Shell-and-tube heat exchangers are widely used in industries such as chemical, petroleum, refrigeration, nuclear power, and energy. Due to the global energy crisis, the demand for heat exchangers in industrial production is increasing, and the quality requirements for heat exchangers are also becoming more stringent. In recent decades, although compact heat exchangers (plate, plate-fin, and welded plate heat exchangers, etc.), heat pipe heat exchangers, and direct contact heat exchangers have developed rapidly, shell-and-tube heat exchangers still dominate in terms of production and usage due to their high reliability and wide adaptability. According to relevant statistics, shell-and-tube heat exchangers still account for about 70% of all heat exchangers used in industrial plants.

[0003] Traditional shell-and-tube heat exchangers involve a single flow of fluid within either the tubes or shell, in a unidirectional direction. Alternatively, flow direction can be altered by adding components such as baffles within the shell. These structures all employ a single flow pattern, are complex, and offer only mediocre heat exchange efficiency. To address these shortcomings, a simple, high-efficiency shell-and-tube heat exchanger has been developed, improving heat exchange performance and meeting the needs for energy conservation and emission reduction. Summary of the Invention

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] A three-box heat exchanger includes a box body containing a horizontally arranged upper and lower horizontal plate. The upper wall, side walls, and upper horizontal plate of the box body constitute the upper box body. The upper horizontal plate, lower horizontal plate, and side walls of the box body constitute the middle box body. The lower wall, side walls, and lower horizontal plate of the box body constitute the lower box body. A left vertical wall and a right vertical wall are provided within the upper box body. The left and right vertical walls, respectively, form a left header and a right header between the upper horizontal plate, side walls, and upper wall. An upper heat exchange tube is fixedly connected between the left and right vertical walls. The middle box body includes a middle heat exchange tube, and the upper and lower horizontal plates are fixedly connected... The middle heat exchange tube is connected; the lower box is provided with a left vertical wall and a right vertical wall. The left vertical wall and the right vertical wall are respectively connected to the horizontal plate, the side wall and the lower wall of the box to form the left header and the right header. The lower heat exchange tube is fixedly connected between the left vertical wall and the right vertical wall; the upper wall of the upper box between the left vertical wall and the right vertical wall is provided with a first fluid inlet and outlet. The lower wall of the lower box between the left vertical wall and the right vertical wall is provided with a first fluid inlet and outlet. The upper wall of the right header and the lower wall of the left header of the upper box and the lower box are respectively provided with a second fluid inlet and outlet, or the upper wall of the left header and the lower wall of the right header of the upper box and the lower box are respectively provided with a second fluid inlet and outlet.

[0006] As an improvement, a horizontal baffle is installed inside the middle chamber, through which the central heat exchange tube passes.

[0007] As an improvement, the baffle includes a left baffle extending from the left and a right baffle extending from the right, and the left baffle and the right baffle are alternately arranged in the vertical direction.

[0008] As an improvement, the upper and lower heat exchange tubes are arranged horizontally, while the middle heat exchange tube is arranged vertically.

[0009] As an improvement, the height of the middle box is smaller than the height of the upper and lower boxes.

[0010] As an improvement, a horizontal baffle is installed inside the upper housing, extending from the left and right vertical walls towards the middle; the left and right baffles are alternately arranged.

[0011] As an improvement, a first fluid inlet is provided on the upper wall of the upper housing, a first fluid outlet is provided on the lower wall of the lower housing, a second fluid outlet is provided on the upper wall of the right header of the upper and lower housings, and a second fluid inlet is provided on the lower wall of the left header of the upper and lower housings respectively.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] This invention employs a three-chamber structure (upper, middle, and lower) to continuously change the positions of the first and second fluids in the tube and shell sides. This variation in the tube and shell sides further enhances heat transfer. Furthermore, by continuously altering the flow direction, it changes the previous single flow pattern in the tube and shell sides or a single flow direction, thus further enhancing heat transfer. In addition, by incorporating multiple heat exchange chambers within the heat exchanger, this invention extends the residence time of the heat exchange fluids, allowing for thorough heat exchange between the two fluids and improving heat exchange efficiency. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the three-box heat exchanger of the present invention. Detailed Implementation

[0015] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0016] A three-box heat exchanger, such as Figure 1 As shown, the heat exchanger includes a housing 1. An upper horizontal plate 2 and a lower horizontal plate 3 are horizontally arranged inside the housing 1. The upper wall 11, side walls 12, and upper horizontal plate 2 of the housing constitute the upper housing 4 of the heat exchanger. The upper horizontal plate 2, lower horizontal plate 3, and side walls 12 of the housing constitute the middle housing 5. The lower wall 13, side walls 12, and lower horizontal plate 3 of the housing constitute the lower housing 6 of the heat exchanger. A left vertical wall 41 and a right vertical wall 42 are arranged inside the upper housing 4. The left vertical wall 41 and right vertical wall 42, together with the upper horizontal plate 2, side walls 12, and upper wall 11, respectively, form a left header 7 and a right header 8. An upper heat exchange tube 43 is fixedly connected between the left vertical wall 41 and right vertical wall 42. The middle housing 5 includes a middle heat exchange tube 51, and the upper horizontal plate 2 and lower horizontal plate 3 are fixedly connected. A central heat exchange tube 51 is fixedly connected; a left vertical wall 61 and a right vertical wall 62 are provided inside the lower box 6. The left vertical wall 61 and the right vertical wall 62 form a left header 9 and a right header 10 with the lower horizontal plate 3, the side wall 12 and the lower wall 13 of the box, respectively. A lower heat exchange tube 63 is fixedly connected between the left vertical wall 61 and the right vertical wall 62; a first fluid inlet / outlet 14 is provided on the upper wall of the box between the left vertical wall and the right vertical wall of the upper box; a first fluid inlet / outlet 15 is provided on the lower wall of the box between the left vertical wall and the right vertical wall of the lower box; a second fluid inlet / outlet 16-19 is provided on the upper wall of the right header and the lower wall of the left header of the upper box and the lower box, respectively.

[0017] As an improvement, the first fluid flows from top to bottom, and the second fluid flows from bottom to top.

[0018] The flow paths of the fluids are described as follows: the first fluid flows from top to bottom, and the second fluid flows from bottom to top. In this invention, the first fluid enters from the upper inlet, then enters the shell side of the upper chamber, exchanges heat with the second fluid in the upper heat exchange tubes, then enters the tube side of the middle chamber after passing through the upper horizontal plate, then enters the shell side of the lower chamber, and finally flows out from the lower outlet 15. Simultaneously, the second fluid flows in from the lower inlet 19, then enters the tube side of the lower chamber through the left header of the lower chamber, exchanges heat with the first fluid in the shell side of the lower chamber, then flows upward through the right header of the lower chamber into the shell side of the middle chamber, exchanges heat with the first fluid in the middle chamber, then enters the left header of the upper chamber through the inlet 17 on the upper horizontal plate, then enters the tube side of the upper chamber, and finally exits through the outlet 16 of the right header of the upper chamber.

[0019] In this invention, the first fluid flows through the shell side of the upper chamber, the tube side of the middle chamber, and the shell side of the lower chamber, while the second fluid flows through the tube side of the lower chamber, the shell side of the middle chamber, and the tube side of the upper chamber for heat exchange. By adopting a three-chamber structure (upper, middle, and lower), the positions of the first and second fluids in the tube and shell sides are constantly changed. This variation in the tube and shell sides further enhances heat transfer. Furthermore, by continuously changing the flow direction, the previous single flow in the tube and shell sides or a single flow direction is altered, further enhancing heat transfer. In addition, by setting multiple heat exchange chambers within the heat exchanger, this invention extends the residence time of the heat exchange fluids within the heat exchanger, allowing for sufficient heat exchange between the two fluids and improving heat exchange efficiency.

[0020] As an improvement, the first fluid is Cistanche deserticola extract, and the second fluid is a cold source used to cool the Cistanche deserticola extract.

[0021] As an improvement, a horizontal baffle 52 is installed inside the middle housing 5, through which the central heat exchange tube 51 passes and is fixed. By installing the baffle, the fluid can flow in a tortuous manner, avoiding short-circuiting of the heat exchange.

[0022] As an improvement, such as Figure 1 As shown, the baffle includes a left baffle extending from the left and a right baffle extending from the right, and the left baffle and the right baffle are alternately arranged in the vertical direction.

[0023] As an improvement, the upper and lower heat exchange tubes are arranged horizontally, while the middle heat exchange tube is arranged vertically.

[0024] As an improvement, the height of the middle box is smaller than the height of the upper and lower boxes.

[0025] As an improvement, horizontal baffles are provided in the upper and / or lower housing, with the baffles extending from the left and right vertical walls toward the middle; the left and right baffles are alternately arranged.

[0026] As an improvement, a first fluid inlet is provided on the upper wall of the upper housing, a first fluid outlet is provided on the lower wall of the lower housing, a second fluid outlet is provided on the upper wall of the right header of both the upper and lower housings, and a second fluid inlet is provided on the lower wall of the left header of both the upper and lower housings. This enables the countercurrent flow of the two fluids.

[0027] Within the intermediate chamber, the first fluid flows from top to bottom, and the second fluid flows from bottom to top. As an improvement, along the top-to-bottom direction of the intermediate chamber, the spacing between adjacent baffles continuously increases from the upper horizontal plate 2 to the midpoint of the chamber's height. Then, from the midpoint of the chamber's height to the lower horizontal plate 3, the spacing between adjacent baffles continuously decreases. This is because during the counter-flow of the two fluids within the intermediate chamber, the heat transfer per unit length along the fluid flow path is relatively uniform in both the shell and tube sides, resulting in the best overall heat transfer effect. However, experiments and simulations revealed that the heat transfer at the midpoint is significantly greater than that at the tube inlet and outlet. Therefore, by varying the baffle spacing, the heat transfer area between the tube-side and shell-side fluids within the baffles also changes. This area variation compensates for the uneven heat transfer, thereby further improving heat transfer efficiency.

[0028] As an improvement, along the middle chamber from top to bottom, from the upper horizontal plate 2 to the midpoint of the middle chamber height, the spacing between adjacent baffles increases progressively. Then, from the midpoint of the middle chamber height to the lower horizontal plate, the spacing between adjacent baffles decreases progressively. This variation in spacing makes the heat transfer per unit length of the entire fluid flow more uniform, further improving heat transfer efficiency.

[0029] As an improvement, fins are installed on the exterior of the upper heat exchange tubes. Multiple heat exchange tubes are arranged along the vertical direction. As an improvement, the fin density of the different upper and / or lower heat exchange tubes varies along the flow direction of the first fluid within the upper and / or lower housing. The fin distribution density on the upper and / or lower heat exchange tubes increases progressively along the flow direction of the first fluid within the upper and / or lower housing. Because the fluid in the upper and lower housings flows vertically, not purely counter-currently, increasing the fin density increases the heat exchange area of ​​the fins, thus making the heat exchange capacity of different heat exchange tubes increasingly stronger along the flow direction of the first fluid. This arrangement ensures that the heat exchange capacity of each heat exchange tube is essentially the same, achieving uniform heat exchange and thus achieving a technical effect similar to counter-current heat exchange.

[0030] As an improvement, along the flow direction of the first fluid within the upper and / or lower casing, the fin distribution density on the upper and / or lower heat exchange tubes increases significantly. This configuration further enhances heat exchange uniformity, more closely resembling the effect of counter-current heat exchange.

[0031] As an improvement, multiple heat exchange tubes are arranged along the vertical direction. As another improvement, the spacing between the upper and / or lower heat exchange tubes decreases progressively along the flow direction of the first fluid within the upper and / or lower casing. Because the fluid in the upper and lower casing flows vertically, not purely counter-currently, increasing the spacing between the heat exchange tubes increases the heat exchange area, thus making the heat exchange capacity of different heat exchange tubes increasingly stronger along the flow direction of the first fluid. This arrangement ensures that the heat exchange capacity of each heat exchange tube is essentially the same, achieving uniform heat exchange and thus achieving a technical effect similar to counter-current heat exchange.

[0032] As an improvement, along the flow direction of the first fluid within the upper and / or lower casings, the spacing between the upper and / or lower heat exchange tubes gradually decreases and increases. This configuration further enhances heat exchange uniformity, more closely resembling the effect of counter-current heat exchange.

[0033] 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 three-box heat exchanger, the heat exchanger comprising a box body, wherein an upper horizontal plate and a lower horizontal plate are disposed within the box body, the upper wall, side walls, and upper horizontal plate of the box body constitute the upper box body of the heat exchanger, the upper horizontal plate, lower horizontal plate, and side walls of the box body constitute the middle box body, and the lower wall, side walls, and lower horizontal plate of the box body constitute the lower box body of the heat exchanger; a left vertical wall and a right vertical wall are disposed within the upper box body, the left vertical wall and the right vertical wall respectively forming a left header and a right header with the upper horizontal plate, the side walls of the box body, and the upper wall, and an upper heat exchange tube is fixedly connected between the left vertical wall and the right vertical wall; the middle box body includes a middle heat exchange tube, and the upper horizontal plate and the lower horizontal plate are fixedly connected. The middle heat exchange tube; the lower box is provided with a left vertical wall and a right vertical wall, which together with the lower horizontal plate, the side wall of the box and the lower wall form a left header and a right header, respectively. The lower heat exchange tube is fixedly connected between the left vertical wall and the right vertical wall; the upper wall of the upper box between the left vertical wall and the right vertical wall is provided with a first fluid inlet and outlet, and the lower wall of the lower box between the left vertical wall and the right vertical wall is provided with a first fluid inlet and outlet. The upper wall of the right header and the lower wall of the left header of the upper box and the lower box are each provided with a second fluid inlet and outlet, or the upper wall of the left header and the lower wall of the right header of the upper box and the lower box are each provided with a second fluid inlet and outlet.

2. The heat exchanger as described in claim 1, characterized in that, A horizontal baffle is installed inside the middle chamber, and the middle heat exchange tube passes through the baffle.

3. The heat exchanger as described in claim 2, characterized in that, The baffle plate includes a left baffle plate extending from the left and a right baffle plate extending from the right, and the left baffle plate and the right baffle plate are alternately arranged in the vertical direction.

4. The heat exchanger as described in claim 1, characterized in that, The upper and lower heat exchange tubes are arranged horizontally, while the middle heat exchange tube is arranged vertically.

5. The heat exchanger as described in claim 1, characterized in that, The height of the middle box is less than the height of the upper and lower boxes.

6. The heat exchanger as described in claim 1, characterized in that, A horizontal baffle is installed inside the upper chamber, extending from the left and right vertical walls toward the middle; the left and right baffles are alternately arranged.

7. The heat exchanger as claimed in claim 1, characterized in that, A first fluid inlet is provided on the upper wall of the upper housing, a first fluid outlet is provided on the lower wall of the lower housing, a second fluid outlet is provided on the upper wall of the right header of the upper and lower housings, and a second fluid inlet is provided on the lower wall of the left header of the upper and lower housings respectively.

8. A heat exchange method for a heat exchanger as described in any one of claims 1-7, characterized in that, The first fluid flows from the upper inlet, then into the shell side of the upper chamber, where it exchanges heat with the second fluid in the upper heat exchange tubes. After passing through the upper horizontal plate, it enters the tube side of the middle chamber, then the shell side of the lower chamber, and finally exits from the lower outlet. Simultaneously, the second fluid flows in from the lower inlet, then through the left header of the lower chamber into the tube side of the lower chamber, where it exchanges heat with the first fluid in the shell side of the lower chamber. After passing through the right header of the lower chamber, it flows upward into the shell side of the middle chamber, exchanges heat with the first fluid in the middle chamber, then enters the left header of the upper chamber through the inlet on the upper horizontal plate, then enters the tube side of the upper chamber, and finally exits through the outlet of the right header of the upper chamber.

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