Composite winding pipe type heat exchanger

Abstract

The utility model discloses a composite winding pipe type heat exchanger which comprises a shell, a medium inlet and a medium outlet, wherein the medium inlet and the medium outlet are fixedly connected with the shell through respective pipe plates; an upper partition plate and a lower partition plate are fixedly connected in the shell, a winding tube bundle is arranged in the shell, the two ends of the winding tube bundle are fixedly connected with the two tube plates respectively, and the middle of the winding tube bundle penetrates through and is fixedly connected with the upper partition plate and the lower partition plate. A preheating section inlet and a preheating section outlet are formed in the shell between the medium outlet and the lower partition plate, an evaporation section inlet and an evaporation section outlet are formed in the shell between the upper partition plate and the lower partition plate, and an overheating section inlet and an overheating section outlet are formed in the shell between the medium inlet and the upper partition plate; the device can realize three functions of preheating, evaporation and overheating, has the advantages of compact structure, large heat exchange area per unit volume, high heat transfer efficiency and capability of realizing multi-stream heat exchange, is easy to realize large scale, and can meet the requirement of a thermal power generating unit combined with a fused salt heat storage system to realize deep peak regulation.

Description

Technical Field

[0001] The utility model relates to a tubular heat exchanger, in particular to a composite wound tubular heat exchanger for molten salt heat storage. Background Art

[0002] Molten salt heat storage is currently mainly used in large-scale heat storage systems for solar thermal power generation. It has good economic efficiency, and the evaporation system is an important component. The evaporation system consists of heat exchangers such as preheaters, evaporators, and superheaters. High-temperature molten salt is used to preheat, evaporate, and superheat high-pressure feed water before sending it to the steam turbine for power generation. The heat exchangers of the existing evaporation system mostly use three independent heat exchangers connected by pipes. The structural type of the heat exchanger generally adopts hairpin, U-tube, and serpentine heat exchangers. This type of heat exchanger is not only large in size and floor space, but also has a small heat exchange area per unit volume, resulting in low heat exchange efficiency, which limits the further large-scale solar thermal power generation units and is not conducive to the existing thermal power units combined with molten salt heat storage systems to achieve deep peak regulation. Summary of the invention

[0003] The purpose of the utility model is to provide a composite wound tube heat exchanger in view of the above-mentioned deficiencies in the prior art, which can realize the three functions of preheating, evaporation and superheating, has a compact structure, has the advantages of large heat exchange area per unit volume, high heat transfer efficiency, and can realize multi-stream heat exchange, is easy to realize large-scale, and can meet the needs of thermal power units combined with molten salt heat storage systems to achieve deep peak regulation.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a composite wound tube heat exchanger, comprising a shell, a medium inlet and a medium outlet arranged at both ends of the shell, the medium inlet and the medium outlet are both fixedly connected to the shell through their own tube sheets; the characteristics are: an upper partition and a lower partition are fixedly connected in the shell, a wound tube bundle is arranged in the shell, the two ends of the wound tube bundle are respectively fixedly connected to the tube holes of the two tube sheets, the middle part of the wound tube bundle passes through the upper partition and the lower partition and is fixedly connected by welding; a preheating section inlet and a preheating section outlet are arranged on the shell between the medium outlet and the lower partition, an evaporation section inlet and an evaporation section outlet are arranged on the shell between the upper partition and the lower partition, and a superheating section inlet and a superheating section outlet are arranged on the shell between the medium inlet and the upper partition, and each section inlet is located below its corresponding outlet and is arranged on opposite sides of the shell.

[0005] When the utility model is used, the molten salt flows through the tube side, and the steam and water flow through the shell side. The shell is divided into a preheating section, an evaporation section, and a superheating section through the upper partition and the lower partition. High-pressure feed water, high-temperature feed water and steam are respectively introduced into each section. Each section performs reverse heat exchange with the molten salt in the tube separately. After the high-temperature molten salt preheats, evaporates and superheats the high-pressure feed water, the superheated steam obtained is sent to the steam turbine for power generation. The utility model can realize the three functions of preheating, evaporation and superheating in one machine. It has a compact structure, a large heat exchange area per unit volume, high heat transfer efficiency, and the advantages of being able to realize multi-stream heat exchange. It is easy to realize large-scale and can meet the needs of thermal power units combined with molten salt heat storage systems to realize deep peak regulation. The inlet of each section and the corresponding outlet are arranged on opposite sides of the shell, which can prevent steam and water from short-circuiting and ensure the heat exchange effect.

[0006] As a further improvement of the utility model, a central tube axially passes through the upper baffle and the lower baffle and is fixedly connected to the two plates; the central tube can not only increase the strength and bearing pressure of the upper baffle and the lower baffle, but also prevent the shell medium from colliding in the radial direction, enhance the heat transfer with the heat exchange tube, and further improve the heat exchange effect;

[0007] As a further improvement of the utility model, a wire mesh demister arranged along the cross section of the shell is provided in the shell between the evaporation section inlet and the evaporation section outlet; the demister can remove the foam in the soda and improve the outlet steam quality;

[0008] In summary, the utility model can realize the three functions of preheating, evaporation and superheating. It has a compact structure, a large heat exchange area per unit volume, high heat transfer efficiency, and the ability to realize multi-stream heat exchange. It is easy to realize large-scale operation and can meet the needs of thermal power units combined with molten salt heat storage systems to achieve deep peak regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is the front view of the embodiment of the utility model. DETAILED DESCRIPTION

[0010] The utility model is further described below in conjunction with the accompanying drawings.

[0011] like Figure 1As shown, a composite wound tube heat exchanger of this embodiment comprises a shell 1, a medium inlet 2 and a medium outlet 3 arranged at both ends of the shell, the medium inlet 2 is welded and fixedly connected to the shell 1 through an inlet tube sheet 4, and the medium outlet 3 is welded and fixedly connected to the shell 1 through an outlet tube sheet 5; an upper baffle 6 and a lower baffle 7 are welded and fixedly connected in the shell 1, a central tube 8 axially passes through the upper baffle 6 and the lower baffle 7 and is welded and fixedly connected to the upper baffle 6 and the lower baffle 7; a spiral wound tube bundle 9 is arranged in the shell 1, the two ends of the wound tube bundle 9 are respectively welded and fixedly connected to the tube holes of the inlet tube sheet 4 and the outlet tube sheet 5, and the middle part of the wound tube bundle 9 passes through the upper baffle 6 and the lower baffle 7. The partition 6 and the lower partition 7 are welded and fixedly connected; a preheating section inlet 11 and a preheating section outlet 12 are provided on the shell between the medium outlet 3 and the lower partition, an evaporation section inlet 13 and an evaporation section outlet 14 are provided on the shell between the upper partition 6 and the lower partition 7, a superheating section inlet 15 and a superheating section outlet 16 are provided on the shell between the medium inlet 2 and the upper partition 6, each section inlet is located below its corresponding outlet, and each section inlet and its corresponding outlet are arranged on opposite sides of the shell; a wire mesh demister 17 arranged along the cross section of the shell is provided in the shell between the evaporation section inlet 13 and the evaporation section outlet 14.

[0012] When the utility model is used, the molten salt flows through the tube side, the molten salt is introduced through the medium inlet 2, the steam and water flow through the shell side, and the shell is divided into a preheating section, an evaporation section, and a superheating section through the upper partition 6 and the lower partition 7. The preheating section inlet 11 is introduced into the high-pressure feed water, the evaporation section inlet 13 is introduced into the high-temperature feed water, and the superheating section inlet 15 is introduced into the steam. Each section performs reverse heat exchange with the molten salt in the wound tube bundle 9 separately. After the high-temperature molten salt preheats, evaporates, and superheats the high-pressure feed water, the superheated steam obtained is sent to the steam turbine for power generation. The utility model can realize the three functions of preheating, evaporation, and superheating in one machine, and its structure is compact and has It has the advantages of large heat exchange area per unit volume, high heat transfer efficiency, and can realize multi-stream heat exchange. It is easy to realize large-scale and can meet the needs of thermal power units combined with molten salt heat storage systems to achieve deep peak regulation; the inlet and corresponding outlet of each section are arranged on the opposite sides of the shell to prevent steam-water short circuit and ensure the heat exchange effect; the central tube 8 can not only increase the strength and bearing pressure of the upper partition 6 and the lower partition 7, but also prevent the radial impact of the medium in the shell, enhance the heat transfer with the winding tube bundle 9, and further improve the heat exchange effect; the wire mesh demister 17 can remove the foam in the steam and improve the export steam quality;

[0013] The above embodiments have been described, but it should be understood that the above embodiments are only used for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments.

Claims

1. A composite wound tube heat exchanger, comprising a shell, a medium inlet and a medium outlet arranged at both ends of the shell, wherein the medium inlet and the medium outlet are both fixedly connected to the shell through respective tube sheets; characterized in that: An upper baffle and a lower baffle are fixedly connected in the shell, and a wound tube bundle is arranged in the shell. The two ends of the wound tube bundle are respectively fixedly connected to the tube holes of the two tube sheets, and the middle part of the wound tube bundle passes through the upper baffle and the lower baffle and is fixedly connected by welding; a preheating section inlet and a preheating section outlet are arranged on the shell between the medium outlet and the lower baffle, an evaporation section inlet and an evaporation section outlet are arranged on the shell between the upper baffle and the lower baffle, and a superheating section inlet and a superheating section outlet are arranged on the shell between the medium inlet and the upper baffle. The inlets of each section are located below their corresponding outlets and are arranged on opposite sides of the shell.

2. The composite wound tube heat exchanger according to claim 1, characterized in that: A central tube axially passes through the upper partition plate and the lower partition plate and is fixedly connected to the two plates.

3. The composite wound tube heat exchanger according to claim 1 or 2, characterized in that: A wire mesh demister arranged along the cross section of the shell is arranged in the shell between the inlet and the outlet of the evaporation section.

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