Vacuum heat pipe technology low-temperature economizer

Abstract

The utility model relates to the technical fields of flue gas treatment discloses a kind of low-temperature economizers of vacuum heat pipe technology, including flue, the upper portion of the flue is provided with heat exchange channel, the inner surface of the heat exchange channel is fixedly installed with economizer;The economizer includes vacuum heat pipe, the bottom end of the vacuum heat pipe is through heat exchange channel and flue and extends to the inside of flue, the outer surface of the vacuum heat pipe is fixedly installed with assembly frame.The low-temperature economizer of vacuum heat pipe technology, by the low-temperature flue gas flowing in flue, low-temperature flue gas passes through the multiple vacuum heat pipes in assembly frame, the heat in its low-temperature flue gas will be transferred to vacuum heat pipe by pin, and its vacuum heat pipe inside capillary inner container absorbs heat, evaporates water in capillary inner container, moves upward from the hollow position of vacuum heat pipe, steam moves to the top of vacuum heat pipe, and the water in heat exchange channel is absorbed steam heat in vacuum heat pipe when passing through vacuum heat pipe, so that water in heat exchange channel is preheated.

Description

Technical Field

[0001] This utility model relates to the technical field of flue gas treatment, and in particular to a low-temperature economizer based on vacuum heat pipe technology. Background Technology

[0002] An economizer is an energy-saving device installed in the flue gas duct at the tail end of a boiler. Its core function is to utilize the waste heat from the high-temperature flue gas discharged from the boiler to preheat the boiler feedwater. This significantly reduces the flue gas temperature, recovers heat, saves fuel, and improves boiler efficiency. Furthermore, it reduces the temperature difference between the cold water entering the boiler and the high-temperature furnace body, effectively alleviating thermal stress and protecting the boiler equipment. Therefore, it offers both economic and safety benefits.

[0003] Traditional economizers typically use hollow copper tubes for heat exchange, transferring heat from the low-temperature flue gas to cold water for preheating. Boiler water flows directly through the hollow tubes to exchange heat with the low-temperature flue gas. However, this method has low heat exchange efficiency and cannot absorb and utilize more heat from the low-temperature flue gas. At the same time, because the flue gas at the boiler tail contains acidic substances such as sulfur oxides, low-temperature corrosion will occur when the wall temperature of the heated surface is lower than the acid dew point of the flue gas. This can easily lead to leakage of the boiler water system into the flue through the hollow copper tubes, resulting in shutdowns for maintenance and reduced efficiency due to leakage. Utility Model Content

[0004] In view of the problems mentioned above, such as the low heat exchange efficiency of existing economizers in low-temperature flue gas, and the easy corrosion of the flue-side tube wall of the economizer, which causes boiler water to leak from the hollow copper tube into the flue, this utility model is proposed.

[0005] Therefore, the purpose of this utility model is to provide a low-temperature economizer using vacuum heat pipe technology. Its purpose is to use vacuum heat pipes to replace heat exchange and separate the boiler water, so that the heating end is corroded without affecting the boiler water leakage into the flue, and at the same time, it can reduce the accumulation of soot on the heat pipes.

[0006] To solve the above technical problems, this utility model provides the following technical solution: a low-temperature economizer based on vacuum heat pipe technology, including a flue, a heat exchange channel is provided above the flue, and an economizer is fixedly installed on the inner surface of the heat exchange channel; The economizer includes a vacuum heat pipe, the bottom end of which passes through the heat exchange channel and the flue and extends into the interior of the flue. An assembly frame is fixedly installed on the outer surface of the vacuum heat pipe.

[0007] As a preferred embodiment of the low-temperature economizer based on the vacuum heat pipe technology of this utility model, the vacuum heat pipe includes a copper shell, a capillary inner liner is fixedly installed on the inner surface of the copper shell, and an enamel layer is fixedly installed on the outer surface of the copper shell.

[0008] As a preferred embodiment of the low-temperature economizer based on the vacuum heat pipe technology of this utility model, the economizer further includes fins, and the opposite sides of the two fins are connected to the outer surface of the vacuum heat pipe. The fins and the vacuum heat pipe are H-shaped.

[0009] As a preferred embodiment of the low-temperature economizer based on the vacuum heat pipe technology of this utility model, the economizer further includes pins, and the opposite sides of the two pins are fixedly connected to the outer surface of the vacuum heat pipe.

[0010] As a preferred embodiment of the vacuum heat pipe technology low-temperature economizer of this utility model, the economizer further includes a soot blowing pipe, the bottom end of which passes through the flue and the assembly frame and extends to the outside of the assembly frame. A valve is fixedly installed on the outer surface of the soot blowing pipe, and a nozzle is fixedly installed at the bottom of the soot blowing pipe.

[0011] As a preferred embodiment of the low-temperature economizer based on the vacuum heat pipe technology described in this utility model, the installation angle of the vacuum heat pipe is 30 degrees.

[0012] Compared with the prior art, the present invention has at least the following beneficial effects: 1. This utility model incorporates vacuum heat pipe technology. Through the combined use of the flue and vacuum heat pipe with the heat exchanger and economizer, and the copper shell and capillary inner liner with the enamel and assembly frame, the working fluid inside the heat pipe absorbs heat from the flue gas in the heated evaporation section and rapidly evaporates into steam. The steam flows to the cooling section under pressure difference, transferring heat to the water outside the pipe before condensing into liquid. The liquid working fluid then returns to the evaporation section via capillary force. The heat pipes are arranged in a downward-sloping, staggered pattern within the multi-layered flue. This design facilitates the smooth return of the condensed working fluid. Simultaneously, because the phase change temperature of the working fluid inside the heat pipe is relatively stable, it automatically maintains the pipe wall temperature at a relatively high level, helping to mitigate low-temperature corrosion. This continuous liquid-vapor phase change cycle gives the heat pipe extremely high thermal conductivity, far exceeding that of a solid metal rod of the same size. Even if corrosion or wear occurs on the flue-side pipe wall, it will not cause boiler water system leakage into the flue, thus avoiding downtime and efficiency reduction caused by leakage, significantly improving the system's reliability and safety.

[0013] 2. This utility model achieves physical isolation between the flue gas side (heating section) and the working fluid side (cooling section) of the heat pipe through the cooperation of the flue and heat exchange channels with the vacuum heat pipe and the assembly frame. This means that even if the flue wall corrodes or wears, boiler water in the heat exchange channel will not leak into the flue, thus avoiding downtime and efficiency reduction caused by leakage, improving the reliability and safety of the economizer. At the same time, through the cooperation of the soot blowing pipe and valve with the nozzle and heat exchange channel, regular purging can be achieved, which can effectively remove floating ash on the vacuum heat pipe wall and prevent the ash plate from hardening on the vacuum heat pipe, affecting the heat exchange efficiency of the vacuum heat pipe. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the vacuum heat pipe technology low-temperature economizer of this utility model; Figure 2 This is a three-dimensional structural diagram of the economizer of the vacuum heat pipe technology low-temperature economizer of this utility model; Figure 3 This is a partial cross-sectional view of the vacuum heat pipe structure of the low-temperature economizer based on the vacuum heat pipe technology of this utility model; Figure 4 This utility model relates to a low-temperature economizer based on vacuum heat pipe technology. Figure 2 A schematic diagram of the enlarged structure of A.

[0015] Explanation of reference numerals in the attached figures: 1. Flue; 2. Heat exchange channel; 3. Economizer; 31. Vacuum heat pipe; 311. Copper shell; 312. Capillary inner liner; 313. Enameled glass; 32. Assembly frame; 33. Fins; 34. Pins; 35. Soot blowing pipe; 36. Valve; 37. Nozzle. Detailed Implementation

[0016] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Example

[0017] Reference Figures 1-3 This is the first embodiment of the present invention, which provides a low-temperature economizer using vacuum heat pipe technology. The low-temperature economizer using vacuum heat pipe technology includes a flue 1, a heat exchange channel 2 is provided above the flue 1, and an economizer 3 is fixedly installed on the inner surface of the heat exchange channel 2. The economizer 3 includes a vacuum heat pipe 31. The bottom end of the vacuum heat pipe 31 passes through the heat exchange channel 2 and the flue 1 and extends into the interior of the flue 1. An assembly frame 32 is fixedly installed on the outer surface of the vacuum heat pipe 31.

[0018] The vacuum heat pipe 31 includes a copper shell 311, a capillary inner liner 312 fixedly installed on the inner surface of the copper shell 311, and an enamel 313 fixedly installed on the outer surface of the copper shell 311.

[0019] A non-metallic enamel coating is sprayed onto the outer surface of the vacuum heat pipe 31, which can effectively isolate acidic substances from contact with the metal pipe wall, thereby greatly enhancing corrosion resistance.

[0020] The installation angle of vacuum heat pipe 31 is 30 degrees.

[0021] During use, low-temperature flue gas flows through flue 1 and passes through multiple vacuum heat pipes 31 in the assembly frame 32. The heat in the low-temperature flue gas is transferred to the vacuum heat pipes 31 through pins 34. The capillary liner 312 inside the vacuum heat pipes 31 absorbs the heat and evaporates the water inside the capillary liner 312. The steam moves upward from the hollow position of the vacuum heat pipes 31. When the water in the heat exchange channel 2 passes through the vacuum heat pipes 31, it absorbs the heat of the steam in the vacuum heat pipes 31, thus preheating the water in the heat exchange channel 2. The steam in the vacuum heat pipes 31 is condensed by heat exchange, and the water is absorbed by the capillary liner 312 at a 30-degree angle. This cycle is repeated to quickly transfer the heat in the low-temperature flue gas to the water in the heat exchange channel 2. Example

[0022] Reference Figures 1-4 This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the economizer 3 also includes fins 33. The opposite sides of the two fins 33 are connected to the outer surface of the vacuum heat pipe 31. The fins 33 and the vacuum heat pipe 31 are H-shaped.

[0023] It consists of two parallel rectangular fins 33 connected to the base tube (light tube) by welding or mechanical means. From the end face, the base tube and the fins 33 on both sides together form a shape similar to the letter "H".

[0024] The economizer 3 also includes pins 34, with each of the two pins 34 fixedly connected to the outer surface of the vacuum heat pipe 31 on opposite sides.

[0025] The economizer 3 also includes a soot blowing pipe 35, the bottom end of which passes through the flue 1 and the assembly frame 32 and extends to the outside of the assembly frame 32. A valve 36 is fixedly installed on the outer surface of the soot blowing pipe 35, and a nozzle 37 is fixedly installed at the bottom of the soot blowing pipe 35.

[0026] The soot blowing pipe 35 is connected to an external high-pressure air pump. The external high-pressure air pump will inject high-pressure gas into the soot blowing pipe 35, and its valve 36 will control the opening and closing of the soot blowing pipe 35.

[0027] During use, since the vacuum heat pipe 31 and the flue 1 are connected by the assembly frame 32, the corrosion effect of low-temperature flue gas on the contact point between the vacuum heat pipe 31 and the flue 1 is reduced. When dust in the low-temperature flue gas accumulates on the vacuum heat pipe 31, external high-pressure gas will enter the nozzle 37 through the soot blowing pipe 35. Under the control of the valve 36, the high-pressure gas will be continuously sprayed into the flue 1 to blow away the dust accumulated on the vacuum heat pipe 31.

[0028] The remaining structure is the same as that in Example 1.

[0029] Based on embodiments 1-2, the working principle of this utility model is as follows: Low-temperature flue gas flows in the flue 1, passing through multiple vacuum heat pipes 31 within the assembly frame 32. The heat in the low-temperature flue gas is transferred to the vacuum heat pipes 31 via pins 34. The capillary liner 312 inside the vacuum heat pipe 31 absorbs the heat, evaporating the water inside. The steam moves upward from the hollow position of the vacuum heat pipe 31, reaching the top of the vacuum heat pipe 31. When the water in the heat exchange channel 2 passes through the vacuum heat pipe 31, it absorbs the heat from the steam inside the vacuum heat pipe 31, preheating the water in the heat exchange channel 2. The steam inside 31 is condensed by heat exchange, and water is absorbed by the capillary inner liner 312 at a 30-degree angle. This cycle is repeated to quickly transfer the heat from the low-temperature flue gas to the water in the heat exchange channel 2. Since the vacuum heat pipe 31 is connected to the flue 1 by the assembly frame 32, the corrosion effect of the low-temperature flue gas on the contact point between the vacuum heat pipe 31 and the flue 1 is reduced. When dust in the low-temperature flue gas accumulates on the vacuum heat pipe 31, external high-pressure gas will enter the nozzle 37 through the soot blowing pipe 35. Under the control of the valve 36, the high-pressure gas will be continuously sprayed into the flue 1 to blow away the dust accumulated on the vacuum heat pipe 31.

[0030] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A low-temperature economizer using vacuum heat pipe technology, comprising a flue (1), characterized in that: A heat exchange channel (2) is provided above the flue (1), and an economizer (3) is fixedly installed on the inner surface of the heat exchange channel (2). The economizer (3) includes a vacuum heat pipe (31), the bottom end of which passes through the heat exchange channel (2) and the flue (1) and extends into the interior of the flue (1). An assembly frame (32) is fixedly installed on the outer surface of the vacuum heat pipe (31).

2. The low-temperature economizer based on vacuum heat pipe technology according to claim 1, characterized in that: The vacuum heat pipe (31) includes a copper shell (311), a capillary inner liner (312) is fixedly installed on the inner surface of the copper shell (311), and an enamel (313) is fixedly installed on the outer surface of the copper shell (311).

3. The low-temperature economizer based on vacuum heat pipe technology according to claim 1, characterized in that: The economizer (3) also includes fins (33), and the two fins (33) are connected to the outer surface of the vacuum heat pipe (31) on opposite sides. The fins (33) and the vacuum heat pipe (31) are H-shaped.

4. The low-temperature economizer based on vacuum heat pipe technology according to claim 1, characterized in that: The economizer (3) also includes pins (34), and the opposite sides of the two pins (34) are fixedly connected to the outer surface of the vacuum heat pipe (31).

5. The low-temperature economizer based on vacuum heat pipe technology according to claim 1, characterized in that: The economizer (3) also includes a soot blowing pipe (35), the bottom end of which passes through the flue (1) and the assembly frame (32) and extends to the outside of the assembly frame (32). A valve (36) is fixedly installed on the outer surface of the soot blowing pipe (35), and a nozzle (37) is fixedly installed at the bottom of the soot blowing pipe (35).

6. The low-temperature economizer based on vacuum heat pipe technology according to claim 1, characterized in that: The vacuum heat pipe (31) is installed at an angle of 30 degrees.

Images