A system for preventing dry burning of circulating water heat exchangers

Abstract

This utility model relates to the field of heat exchange system technology, and more particularly to an anti-dry-burning system for circulating water heat exchangers, comprising: a heat exchanger and a container; the heat exchanger includes: a shell and heat exchange tubes; the heat exchange tubes are disposed within the shell; an upper cavity is provided at the top of the shell; the upper cavity is connected to the heat exchange tubes; a tube inlet and a tube vent are provided on the upper cavity; a lower cavity is provided at the bottom of the shell; the lower cavity is connected to the heat exchange tubes; a tube outlet is provided on the lower cavity; a shell inlet is provided at the lower part of the shell; the container is connected to the shell outlet via a first pipe; the first pipe has a height limiting section; the height of the height limiting section is higher than the bottom of the upper cavity; the container is connected to the shell vent via a second pipe; a return water port is provided on the container; the height of the return water port is higher than the outlet height of the first pipe within the container. This utility model can prevent the heat exchanger from being partially filled with water, resulting in localized dry burning, and extends the service life of the heat exchanger.

Description

Technical Field

[0001] This utility model relates to the field of heat exchange system technology, and in particular to a system for preventing dry burning of a circulating water heat exchanger. Background Technology

[0002] In polysilicon production processes, especially when using the modified Siemens process, the exhaust gas recovery workshop plays a crucial role. In this high-purity process, a circulating water heat exchanger is commonly used as the core equipment for exhaust gas recovery. For energy conservation and space optimization, the primary heat exchanger is often installed at the top of the production frame, requiring the cooling medium (usually circulating water) to maintain a pressure differential of at least 0.45 MPa. During actual operation, due to the high position of the heat exchanger, insufficient pressure from the circulating water pump can cause water to flow directly from the outlet pipe. In this case, there is no cooling medium at the top baffle of the shell side, leading to dry burning; sometimes this can result in excessive negative pressure suction (the so-called "siphon phenomenon"), which can cause internal damage to the heat exchanger (such as...). Figure 2 If the heat exchanger (displayed area) is not completely filled with cooling water, resulting in insufficient water for heat exchange and protection, it will not be in contact with the working fluid (i.e., circulating water). Continuous operation under high-temperature conditions without effective heat exchange medium coverage will lead to dry burning. Prolonged dry burning will cause the surface of the heat exchanger to overheat abnormally due to lack of necessary cooling, leading to destructive consequences such as oxidation, corrosion, and even melting. Ultimately, this may cause the heat exchanger to burn out or become unusable, shortening its lifespan. Even if the heat exchanger is filled with water, the water in contact with the baffles after the high-temperature material heats them will vaporize over time. If the vapor cannot be discharged in time, the cooling medium will still not be able to completely fill the heat exchanger, creating dead water zones and causing dry burning again. Utility Model Content

[0003] In view of this, the present invention provides a system for preventing dry burning of circulating water heat exchangers, the main purpose of which is to prevent the heat exchanger from being partially dry-burned due to insufficient water filling, and to extend the service life of the heat exchanger.

[0004] To achieve the above objectives, this utility model mainly provides the following technical solutions:

[0005] An embodiment of this utility model provides a circulating water heat exchanger anti-dry-burning system, comprising: a heat exchanger and a container;

[0006] The heat exchanger includes: a shell and heat exchange tubes; the heat exchange tubes are disposed inside the shell;

[0007] The top of the shell is provided with an upper cavity; the upper cavity is connected to the heat exchange tube; the upper cavity is provided with a tube layer inlet and a tube layer exhaust port;

[0008] The bottom of the shell is provided with a lower cavity; the lower cavity is connected to the heat exchange tube; the lower cavity is provided with a tube outlet and a tube drain outlet;

[0009] The lower part of the shell is provided with a shell inlet and a shell drain outlet;

[0010] The upper part of the shell is provided with a shell outlet and a shell exhaust port;

[0011] The container has an opening at the top;

[0012] The container is connected to the shell outlet via a pipe; the pipe has a height-limiting section; the height of the height-limiting section is higher than the bottom of the upper cavity;

[0013] The container is connected to the shell exhaust port via pipe two;

[0014] The container is equipped with a water return port;

[0015] The height of the return water inlet is higher than the outlet height of the pipe inside the container.

[0016] Furthermore, an upper isolation cavity is provided below the upper cavity;

[0017] The lower part of the upper isolation chamber is provided with a diaphragm drain.

[0018] Furthermore, a lower isolation cavity is provided above the lower cavity;

[0019] The lower part of the lower isolation chamber is provided with a second diaphragm drain.

[0020] Furthermore, the container is an open water tank.

[0021] By employing the above technical solution, the anti-dry-burning system for circulating water heat exchangers of this utility model has at least the following advantages:

[0022] It can prevent the heat exchanger from being partially dry-burning due to insufficient water filling, thus extending the service life of the heat exchanger.

[0023] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0024] Figure 1 A schematic diagram of an anti-dry-burning system for a circulating water heat exchanger provided for an embodiment of this utility model;

[0025] Figure 2 This is a schematic diagram showing the location where dry burning occurs in existing heat exchangers.

[0026] As shown in the figure:

[0027] 1 is the heat exchanger, 101 is the upper cavity, 102 is the tube layer inlet, 103 is the tube layer vent, 104 is the lower cavity, 105 is the tube layer outlet, 106 is the tube layer drain outlet, 107 is the upper isolation cavity, 108 is the first isolation cavity drain, 109 is the lower isolation cavity, 110 is the second isolation cavity drain, 111 is the shell layer inlet, 112 is the shell layer drain outlet, 113 is the shell layer outlet, 114 is the shell layer vent, 2 is the container, 201 is the return water inlet, 3 is pipe one, and 4 is pipe two. Detailed Implementation

[0028] To further illustrate the technical means and effects adopted by this utility model to achieve its intended purpose, the specific implementation methods, structures, features, and effects according to this utility model application are described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0029] like Figure 1 As shown in the figure, an embodiment of the present invention provides a circulating water heat exchanger anti-dry-burning system, comprising: a heat exchanger 1 and a container 2; the heat exchanger 1 includes: a shell and heat exchange tubes; the heat exchange tubes are disposed inside the shell; an upper cavity 101 is provided at the top of the shell; the upper cavity 101 is connected to the heat exchange tubes; a tube inlet 102 is provided on the upper cavity 101 for material entry; a tube vent 103 is provided on the upper cavity 101 for maintenance replacement and venting.

[0030] The bottom of the shell is provided with a lower cavity 104; the lower cavity 104 is connected to the heat exchange tubes; the lower cavity 104 is provided with a tube outlet 105 for material output. The lower cavity 104 is provided with a tube drain outlet 106 for maintenance replacement and liquid drainage.

[0031] The lower part of the shell is provided with a shell inlet 111 and a shell drain outlet 112; both the shell inlet 111 and the shell drain outlet 112 are connected to the interior of the shell. The shell drain outlet 112 is used for maintenance replacement and drainage. The upper part of the shell is provided with a shell outlet 113 and a shell vent outlet 114; both the shell outlet 113 and the shell vent outlet 114 are connected to the interior of the shell. The shell vent outlet 114 is used for maintenance replacement and venting.

[0032] Container 2 has an opening at the top; Container 2 can be an open water tank. Container 2 is used to temporarily store circulating media. Container 2 is connected to the shell outlet 113 via pipe 3; pipe 3 has a height limiting section; the height of the height limiting section is higher than the bottom of the upper cavity 101; Container 2 is connected to the shell vent 114 via pipe 4; Container 2 is provided with a return water inlet 201; the height of the return water inlet 201 is higher than the outlet height of pipe 3 inside container 2. In practical applications, container 2 contains circulating water, and the ends of pipes 3 and 4 need to be below the water surface in container 2.

[0033] Heat exchanger 1 is a counter-current heat exchanger. The material flows through the tube layer, entering from the tube layer inlet 102 at the top of heat exchanger 1, and exiting from the tube layer outlet 105 at the bottom of heat exchanger 1 after heat exchange. Circulating water enters from the shell layer inlet 111 at the bottom of heat exchanger 1, and exits from the shell layer outlet 113 at the top of heat exchanger 1 after heat exchange. When the height of the height-limiting section of pipe 1 3 is higher than the bottom of the upper cavity 101, the phenomenon of heat exchanger 1 not being filled can be eliminated. Furthermore, at the tube sheet where the high-temperature material contacts the circulating water, the water will vaporize. At this time, a large amount of gas will accumulate at the highest point of heat exchanger 1. The gas will flow out through pipe 2 4 and be discharged through container 2, ensuring that the cooling medium in heat exchanger 1 can fill heat exchanger 1. This solves the siphon phenomenon and the dry burning phenomenon caused by gas, and reduces the pressure requirements of the circulating water pump.

[0034] Optionally, an upper isolation chamber 107 is provided below the upper cavity 101; the bottom of the upper cavity 101 is a tube layer perforated plate, which is welded and fixed to the upper end of the heat exchange tube; a shell layer perforated plate is provided below the tube layer perforated plate; the shell layer perforated plate is welded and fixed to the heat exchange tube and the shell, and is sealed. The upper isolation chamber 107 is formed between the shell layer perforated plate and the tube layer perforated plate. A partition drain 108 is provided at the lower part of the upper isolation chamber 107. The partition drain 108 is normally open and is used to detect whether the heat exchanger 1 is leaking from the tube layer perforated plate or the shell layer perforated plate. By checking the leaking material, it can be determined whether the heat exchanger 1 is leaking from the material side or the circulating water side.

[0035] Optionally, a lower isolation chamber 109 is provided above the lower cavity 104; the top of the lower cavity 104 is a tube layer perforated plate II, which is welded and fixed to the lower end of the heat exchange tube; a shell layer perforated plate II is provided on the upper side of the tube layer perforated plate II; the shell layer perforated plate II is welded and fixed to the heat exchange tube and the shell, and sealed. The lower isolation chamber 109 is formed between the shell layer perforated plate II and the tube layer perforated plate II. A second isolation chamber drain 110 is provided at the lower part of the lower isolation chamber 109. The second isolation chamber drain 110 is in a normally open state and is used to detect whether the heat exchanger 1 is leaking from the tube layer perforated plate II or the shell layer perforated plate II. By checking the leaking material, it can be determined whether the heat exchanger 1 is leaking from the material side or the circulating water side.

[0036] One embodiment of this utility model discloses an anti-dry-burning system for circulating water heat exchangers, which can prevent the heat exchanger 1 from being partially dry-burning due to insufficient water filling, extend the service life of the heat exchanger 1, and ensure the safe and stable operation of the equipment. It is particularly suitable for high-level circulating water heat exchangers used in polycrystalline silicon tail gas recovery systems.

[0037] To further clarify, while the terms "first," "second," etc., may be used herein to describe various elements, these terms should not limit the elements. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element; these terms are used only to distinguish one element from another. This does not depart from the scope of the exemplary embodiments. Similarly, "element one," "element two," and so on do not represent the order of elements; these terms are used only to distinguish one element from another. As used herein, the term "and / or" includes any and all combinations of one or more associated listed items.

[0038] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0039] All standard parts used in this utility model can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0040] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A system for preventing dry burning of a circulating water heat exchanger, characterized in that, Includes: heat exchangers and containers; The heat exchanger includes: a shell and heat exchange tubes; the heat exchange tubes are disposed inside the shell; The top of the shell is provided with an upper cavity; the upper cavity is connected to the heat exchange tube; the upper cavity is provided with a tube inlet and a tube exhaust port; The bottom of the shell is provided with a lower cavity; the lower cavity is connected to the heat exchange tube; the lower cavity is provided with a tube outlet and a tube drain outlet; The lower part of the shell is provided with a shell inlet and a shell drain outlet; The upper part of the shell is provided with a shell outlet and a shell exhaust port; The container has an opening at the top; The container is connected to the shell outlet via a pipe; the pipe has a height-limiting section; the height of the height-limiting section is higher than the bottom of the upper cavity; The container is connected to the shell exhaust port via pipe two; The container is equipped with a water return port; The height of the return water inlet is higher than the outlet height of the pipe inside the container.

2. The anti-dry-burning system for circulating water heat exchangers according to claim 1, characterized in that, An upper isolation cavity is provided below the upper cavity; The lower part of the upper isolation chamber is provided with a diaphragm drain.

3. The anti-dry-burning system for circulating water heat exchangers according to claim 1, characterized in that, A lower isolation cavity is provided above the lower cavity; The lower part of the lower isolation chamber is provided with a second diaphragm drain.

4. The anti-dry-burning system for circulating water heat exchangers according to claim 1, characterized in that, The container is an open water tank.

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