Molten salt heat exchanger and modularized molten salt multi-stage heat exchange device

Abstract

The utility model provides a molten salt heat exchanger and modularization molten salt multistage heat exchange device, including shell and be provided the heat exchange unit in the shell, one end of shell is provided with the molten salt hot end inlet and feed water hot end outlet, the other end of shell is provided with the molten salt cold end outlet and feed water cold end inlet, one end of heat exchange unit is communicated with the feed water cold end inlet, and the other end of heat exchange unit is communicated with the feed water cold end inlet. The other end of the heat exchange unit is communicated with a water supply hot end outlet, the heat exchange unit comprises a plurality of heat exchange pipe assemblies arranged in parallel, each heat exchange pipe assembly comprises a plurality of U-shaped pipes connected in series, a plurality of baffle plates are arranged in the shell, the baffle plates are sequentially arranged in a staggered mode in the direction from a molten salt hot end inlet to a molten salt cold end outlet, and the baffle plates correspond to the U-shaped pipes one to one. One end of each baffle plate is fixedly connected with the inner wall of the shell, and a fused salt flowing rotation channel is formed between the other end of each baffle plate and the inner wall of the shell. The molten salt-feed water heat exchange efficiency of the molten salt heat exchanger is improved.

Description

Technical Field

[0001] This utility model relates to a heat exchanger, specifically a molten salt heat exchanger and a modular molten salt multi-stage heat exchange device, belonging to the field of molten salt energy storage technology. Background Technology

[0002] Molten salt energy storage systems, as a highly efficient renewable energy storage technology, play an increasingly important role in the modern energy field. In these systems, the molten salt-water heat exchanger is a key component, and its performance affects the overall system efficiency and economy. Traditional molten salt-water heat exchangers typically employ a straight-tube bundle design, with molten salt flowing on the shell side and water flowing inside the tubes. The straight-tube structure limits the heat exchange area per unit volume, making it difficult to meet the requirements of high-efficiency heat exchange. Furthermore, in existing heat exchanger structures, the uneven distribution of molten salt flow on the shell side also reduces heat exchange efficiency. Given these problems, improving the performance of molten salt-water heat exchangers and increasing their heat exchange efficiency is a pressing technical issue that needs to be addressed in this field. Utility Model Content

[0003] Based on the above background, the purpose of this utility model is to provide a molten salt heat exchanger and a modular molten salt multi-stage heat exchange device to improve the heat exchange efficiency of the molten salt heat exchanger.

[0004] To achieve the above-mentioned objectives, this utility model provides the following technical solution:

[0005] A molten salt heat exchanger includes a shell and a heat exchange unit disposed within the shell. One end of the shell has a molten salt hot-end inlet and a feedwater hot-end outlet, and the other end of the shell has a molten salt cold-end outlet and a feedwater cold-end inlet. One end of the heat exchange unit is connected to the feedwater cold-end inlet, and the other end of the heat exchange unit is connected to the feedwater hot-end outlet. The heat exchange unit includes several parallel heat exchange tube assemblies, each heat exchange tube assembly including multiple U-shaped tubes connected in series. Several baffles are disposed inside the shell. The baffles are arranged alternately from the molten salt hot-end inlet to the molten salt cold-end outlet, and the baffles correspond one-to-one with the U-shaped tubes. One end of each baffle is fixedly connected to the inner wall of the shell, and the other end of the baffle forms a molten salt flow rotation channel with the inner wall of the shell. The U-shaped closed end of each U-shaped tube is located within a molten salt flow rotation channel.

[0006] Preferably, the U-shaped pipe includes two straight pipe segments and an arc-shaped pipe segment disposed between the two straight pipe segments, and the inner wall of the straight pipe segments is provided with internal threads.

[0007] Preferably, the outer walls of both the straight section pipe fitting and the curved section pipe fitting are smooth outer walls.

[0008] Preferably, the vertical distance between the baffle plate and the two straight segments of the corresponding U-shaped tube is the same.

[0009] Preferably, the baffles are arranged at uniform intervals, and the vertical distance between adjacent baffles is the same.

[0010] Preferably, the housing is a horizontal box.

[0011] Preferably, the hot end outlet and the cold end inlet of the water supply are both located at the top of the horizontal tank, and the hot end inlet of the molten salt and the cold end outlet of the molten salt are both located on the side adjacent to the top of the horizontal tank.

[0012] A modular molten salt multi-stage heat exchange device includes multiple molten salt heat exchangers as described above, and the multiple molten salt heat exchangers are connected in series through pipes.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] This invention discloses a molten salt heat exchanger that increases the heat exchange area per unit volume within the shell by using heat exchange units composed of U-shaped tubes. Multiple staggered baffles, corresponding one-to-one with the U-shaped tubes, enhance the turbulence effect of the molten salt on the shell side. The combined effect of these two elements significantly improves the molten salt-feedwater heat exchange efficiency. Furthermore, the baffles optimize the flow distribution of the molten salt, reducing dead zones and extending its residence time within the shell, ensuring sufficient heat transfer between the molten salt and the feedwater. This invention also discloses a modular molten salt multi-stage heat exchange device that achieves cascaded heat exchange between molten salt and feedwater through multiple molten salt heat exchangers connected in series. Adjusting the number of molten salt heat exchangers allows for flexible adaptation to heat exchange requirements under different operating conditions. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the internal structure of a molten salt heat exchanger according to this utility model;

[0017] Figure 2 This is a partial structural schematic diagram of the U-shaped tube in this utility model;

[0018] Figure 3 yes Figure 2 A partial enlarged view of part A in the middle;

[0019] In the diagram: 1. Shell; 2. Heat exchanger tube assembly; 101. Molten salt hot end inlet; 102. Feedwater hot end outlet; 103. Molten salt cold end outlet; 104. Feedwater cold end inlet; 105. Baffle plate; 106. Molten salt flow rotation channel; 201. U-shaped tube; 2011. Straight section fitting; 2012. Arc-shaped section fitting; 2013. Internal thread. Detailed Implementation

[0020] The technical solution of this utility model will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of this utility model is not limited to the following embodiments, and any modifications and / or alterations made to this utility model will fall within the protection scope of this utility model.

[0021] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the field. Unless otherwise specified, the methods in the following embodiments are conventional methods in the field. Unless otherwise specified, the components or equipment in the following embodiments are general standard parts or components known to those skilled in the art, and their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0022] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following detailed description, many specific details are set forth to facilitate explanation and provide a comprehensive understanding of the embodiments of the present invention. However, one or more embodiments may be practiced by those skilled in the art without these specific details.

[0023] like Figure 1 As shown, an embodiment of this utility model discloses a molten salt heat exchanger, including a shell 1 and a heat exchange unit disposed within the shell 1. One end of the shell 1 is provided with a molten salt hot-end inlet 101 and a feedwater hot-end outlet 102, and the other end of the shell 1 is provided with a molten salt cold-end outlet 103 and a feedwater cold-end inlet 104. One end of the heat exchange unit is connected to the feedwater cold-end inlet 104, and the other end of the heat exchange unit is connected to the feedwater hot-end outlet 102. The heat exchange unit includes multiple heat exchange tube assemblies 2 arranged in parallel, and each heat exchange tube assembly 2 includes multiple U-shaped tubes 201 connected in series. Multiple baffles 105 are provided inside the shell 1, and the baffles 105 are arranged alternately from the molten salt hot-end inlet 101 to the molten salt cold-end outlet 103, and the baffles 105 correspond one-to-one with the U-shaped tubes 201. One end of each baffle 105 is fixedly connected to the inner wall of the housing 1, and the other end of the baffle 105 forms a molten salt flow rotation channel 106 between the inner wall of the housing 1 and the baffle 105. The U-shaped closed end of each U-tube 201 is located in a molten salt flow rotation channel 106.

[0024] The tube bundle structure using U-shaped tubes 201 and multiple staggered baffles 105 within the shell 1 offers significant advantages over existing technologies. Firstly, the U-shaped tube arrangement increases the heat transfer area per unit volume, while the multi-baffle design enhances the turbulence effect of the molten salt on the shell side; the combined effect of these two factors significantly improves heat transfer efficiency. Secondly, the multi-baffle design optimizes the flow distribution of the molten salt, creating a serpentine flow path within the shell 1. This reduces dead zones in the molten salt flow and extends its residence time within the shell 1, ensuring sufficient heat transfer between the molten salt and the feedwater.

[0025] Specifically, such as Figure 2 and Figure 3 As shown, the U-shaped pipe 201 includes two straight pipe segments 2011 and an arc-shaped pipe segment 2012 located between the two straight pipe segments 2011. The inner wall of the straight pipe segment 2011 is provided with an internal thread 2013. The outer walls of both the straight pipe segment 2011 and the arc-shaped pipe segment 2012 are smooth pipe walls.

[0026] The design advantages of the aforementioned U-shaped tube 201 are as follows: Due to the good fluidity of water, the internal threads 2013 on the inner wall of the straight section of the tube 2011 increase the turbulence of the water flow, breaking the boundary layer and enhancing the heat transfer effect on the water side inside the tube. Simultaneously, the smooth inner wall of the curved section of the tube 2012 ensures a smooth transition of the water when it changes direction inside the tube, controlling the pressure drop. Since the fluidity of molten salt is lower than that of water, making the outer wall of the U-shaped tube 201 smooth facilitates the flow of molten salt on the shell side and reduces the risk of scaling and corrosion.

[0027] Specifically, the vertical distance between the baffle 105 and the two straight segments 2011 of the corresponding U-shaped tube 201 is the same. The baffles 105 are evenly spaced, and the vertical distance between adjacent baffles 105 is the same. The purpose of this design is to ensure the uniformity of molten salt flow.

[0028] Specifically, the shell 1 is a horizontal box. The hot end outlet 102 and the cold end inlet 104 of the water supply are both located at the top of the horizontal box, while the hot end inlet 101 and the cold end outlet 103 of the molten salt are both located on the side adjacent to the top of the horizontal box.

[0029] An embodiment of this utility model also discloses a modular molten salt multi-stage heat exchange device, including multiple molten salt heat exchangers connected in series by pipes, thereby realizing cascade heat exchange between molten salt and feed water. Furthermore, by adjusting the number of molten salt heat exchangers, the heat exchange requirements under different operating conditions can be flexibly met.

[0030] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A molten salt heat exchanger, characterized in that: The molten salt heat exchanger includes a shell (1) and a heat exchange unit disposed within the shell (1). One end of the shell (1) is provided with a molten salt hot end inlet (101) and a feedwater hot end outlet (102), and the other end of the shell (1) is provided with a molten salt cold end outlet (103) and a feedwater cold end inlet (104). One end of the heat exchange unit is connected to the feedwater cold end inlet (104), and the other end of the heat exchange unit is connected to the feedwater hot end outlet (102). The heat exchange unit includes several parallel heat exchange tube assemblies (2), and each heat exchange tube assembly (2) includes multiple U-shaped tubes connected in series. (201) The shell (1) is provided with several baffles (105). The baffles (105) are arranged alternately from the hot end inlet (101) of the molten salt to the cold end outlet (103) of the molten salt. The baffles (105) correspond one-to-one with the U-shaped tubes (201). One end of each baffle (105) is fixedly connected to the inner wall of the shell (1), and the other end of the baffle (105) forms a molten salt flow rotation channel (106) between the baffle (105) and the inner wall of the shell (1). The U-shaped closed end of each U-shaped tube (201) is located in a molten salt flow rotation channel (106).

2. A molten salt heat exchanger according to claim 1, characterized in that: The U-shaped pipe (201) includes two straight pipe segments (2011) and an arc-shaped pipe segment (2012) located between the two straight pipe segments (2011). The inner wall of the straight pipe segment (2011) is provided with an internal thread (2013).

3. A molten salt heat exchanger according to claim 2, characterized in that: The outer walls of both the straight section pipe fitting (2011) and the curved section pipe fitting (2012) are smooth outer walls.

4. A molten salt heat exchanger according to claim 2, characterized in that: The vertical distance between the baffle (105) and the two straight segments (2011) of the corresponding U-shaped pipe (201) is the same.

5. A molten salt heat exchanger according to claim 1, characterized in that: The baffles (105) are arranged at uniform intervals, and the vertical distance between adjacent baffles (105) is the same.

6. A molten salt heat exchanger according to claim 1, characterized in that: The shell (1) is a horizontal box.

7. A molten salt heat exchanger according to claim 6, characterized in that: The hot end outlet (102) and the cold end inlet (104) of the water supply are both located on the top of the horizontal tank, and the hot end inlet (101) of the molten salt and the cold end outlet (103) of the molten salt are both located on the side adjacent to the top of the horizontal tank.

8. A modular molten salt multi-stage heat exchanger, characterized in that: The modular molten salt multi-stage heat exchanger includes a plurality of molten salt heat exchangers as described in any one of claims 1-7, and the plurality of molten salt heat exchangers are connected in series via pipes.

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