Self-deashing low-temperature economizer

Abstract

The utility model belongs to the technical field of economizers, and discloses a self-ash-cleaning low-temperature economizer which comprises a tube bundle, the tube bundle is arranged in a snake shape, and the outer surface of the tube bundle is plated with a gradient composite coating. The outer surface of the tube bundle is wrapped with a dust collecting bin, a plurality of nozzles are arranged above the tube bundle and located in the dust collecting bin, the nozzles are communicated with an external high-pressure air supply system through air inlet channels, a lower dust collecting hopper is arranged below the tube bundle and installed on the bottom wall of an inner cavity of the dust collecting bin, and a dust discharging device is installed at the bottom of the dust collecting bin. The tube bundle adopts an asymmetric reducing design, the tube diameter of the flue gas inlet end of the tube bundle is larger than that of the outlet end of the tube bundle, and the gradient composite coating comprises a nickel base alloy layer, a silicon carbide enhancement layer and a hydrophobic ceramic layer which are sequentially arranged from inside to outside. According to the utility model, ash of the economizer can be conveniently removed, the tube wall is not damaged, and the tube bundle can be prevented from being corroded, so that the service life of the tube bundle is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of economizer technology, and in particular to a self-cleaning low-temperature economizer. Background Technology

[0002] An economizer is a device installed at the bottom of the boiler flue to recover the waste heat of the exhaust gas. It heats the boiler feedwater to saturated water at the pressure of the steam drum. Because it absorbs the heat of the high-temperature flue gas, it reduces the exhaust temperature of the flue gas, saves energy, and improves efficiency, hence the name economizer.

[0003] Existing low-temperature economizers generally suffer from flue gas ash accumulation. Ash adheres to the surface of heat exchange tubes, leading to a decrease in heat transfer efficiency and requiring frequent shutdowns for manual cleaning, which affects the continuous operation of the system. Traditional mechanical rapping cleaning is prone to damaging the tube wall. At the same time, uneven ash distribution leads to increased local thermal resistance and exacerbates the risk of tube bundle corrosion. Therefore, we propose a self-cleaning low-temperature economizer. Utility Model Content

[0004] In order to overcome the defects of the prior art mentioned above, the inventors conducted in-depth research and, after a great deal of creative work, completed this utility model.

[0005] Specifically, the technical problem to be solved by this utility model is to provide a self-cleaning low-temperature economizer to solve the technical problems of easy damage to the tube wall and uneven ash distribution exacerbating the risk of tube corrosion caused by traditional mechanical vibration cleaning.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A self-cleaning low-temperature economizer includes a tube bundle arranged in a serpentine pattern, and the outer surface of the tube bundle is coated with a gradient composite coating.

[0008] The outer surface of the tube bundle is covered with a dust collection bin. Several nozzles are arranged above the tube bundle and are located inside the dust collection bin. The nozzles are connected to an external high-pressure air supply system through an air inlet channel. A lower dust collection hopper is arranged below the tube bundle and is installed on the bottom wall of the inner cavity of the dust collection bin. A dust discharge device is installed at the bottom of the dust collection bin and is connected to the lower dust collection hopper.

[0009] As an improved technical solution, the tube bundle adopts an asymmetric variable diameter design, and the diameter of the flue gas inlet end of the tube bundle is larger than the diameter of the outlet end of the tube bundle.

[0010] As an improved technical solution, the gradient composite coating includes a nickel-based alloy layer, a silicon carbide reinforcement layer, and a hydrophobic ceramic layer, wherein the nickel-based alloy layer, the silicon carbide reinforcement layer, and the hydrophobic ceramic layer are arranged sequentially from the inside to the outside.

[0011] As an improved technical solution, the air intake channel consists of a hollow disc and an air intake pipe. Several nozzles are installed at the bottom of the hollow disc and the two are connected. One end of the air intake pipe passes through the top of the ash collection bin and the extended part is connected to the hollow disc. The other end of the air intake pipe is connected to an external high-pressure air supply system.

[0012] As an improved technical solution, several of the nozzles are equidistantly arranged along the length and width directions of the hollow disk.

[0013] As an improved technical solution, the nozzle is embedded with a Venturi accelerator tube.

[0014] As an improved technical solution, the ash discharge device includes a high-pressure air pump, a fixed base is installed on the outer surface of the high-pressure air pump, the fixed base is installed at the bottom of the ash collection hopper, an ash inlet pipe is installed at the input end of the high-pressure air pump, the ash inlet pipe passes through the bottom of the ash collection hopper, and the extended part is connected to the lower ash collection hopper, and an ash discharge pipe is installed at the output end of the high-pressure air pump.

[0015] After adopting the above technical solution, the beneficial effects of this utility model are:

[0016] 1. This utility model, by activating the external high-pressure air supply system, allows high-pressure gas to enter the nozzle through the inlet pipe and hollow disc, and finally be ejected through the nozzle, cleaning the dust on the tube bundle. At the same time, the fixed high-pressure air pump is activated. The input end of the high-pressure air pump draws dust and escaping dust from the lower ash hopper into the high-pressure air pump through the ash inlet pipe, and then discharges it through the ash discharge pipe on the output end of the high-pressure air pump, thereby achieving the cleaning of the economizer, which facilitates the cleaning of the economizer without damaging the tube wall.

[0017] 2. This utility model, by setting a gradient composite coating composed of a nickel-based alloy layer, a silicon carbide reinforcement layer and a hydrophobic ceramic layer, can prevent tube corrosion and extend the service life of the tube bundle.

[0018] 3. This utility model, through the asymmetric variable diameter tube bundle design, can reduce flue gas resistance and improve the heat transfer coefficient. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0020] Figure 1 This is a schematic diagram of the main structure of this utility model.

[0021] Figure 2 For the present utility model Figure 1 Enlarged structural diagram at point A in the middle.

[0022] Figure 3 This is a side view of the structure of this utility model.

[0023] Figure 4 This is a cross-sectional structural diagram of the present invention.

[0024] Explanation of reference numerals in the attached figures:

[0025] In the figure: 1. Tube bundle; 101. Silicon carbide reinforcing layer; 102. Hydrophobic ceramic layer; 2. Ash collection bin; 3. Nozzle; 4. Hollow disc; 5. Air inlet pipe; 6. High-pressure air pump; 7. Fixing base; 8. Ash inlet pipe; 9. Lower ash collection hopper; 10. Ash discharge pipe. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0028] Meanwhile, the meaning of "and / or" or "and / or" appearing throughout the text is that it includes three options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0029] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0030] Reference Figures 1-4 A self-cleaning low-temperature economizer is provided. The self-cleaning low-temperature economizer includes a tube bundle 1, which is arranged in a serpentine manner, and the outer surface of the tube bundle 1 is coated with a gradient composite coating.

[0031] The outer surface of the tube bundle 1 is covered with a dust collection bin 2. Several nozzles 3 are arranged above the tube bundle 1 and are located inside the dust collection bin 2. The nozzles 3 are connected to an external high-pressure air supply system through an air inlet channel. A lower dust collection hopper 9 is arranged below the tube bundle 1 and is installed on the bottom wall of the inner cavity of the dust collection bin 2. A dust discharge device is installed at the bottom of the dust collection bin 2 and is connected to the lower dust collection hopper 9.

[0032] Reference Figures 1-3 Tube bundle 1 adopts an asymmetric variable diameter design, and the diameter of the flue gas inlet end of tube bundle 1 is larger than the diameter of the outlet end of tube bundle 1. The asymmetric variable diameter design of tube bundle 1 can reduce flue gas resistance and improve heat transfer coefficient.

[0033] Reference Figure 1 and Figure 2 The gradient composite coating includes a nickel-based alloy layer, a silicon carbide reinforcement layer 101, and a hydrophobic ceramic layer 102, arranged sequentially from the inside to the outside, in order to prevent corrosion of the tube bundle 1 and extend the service life of the tube bundle 1.

[0034] Reference Figure 3 and Figure 4 The air intake channel consists of a hollow disc 4 and an air intake pipe 5. Several nozzles 3 are installed at the bottom of the hollow disc 4 and the two are connected. One end of the air intake pipe 5 passes through the top of the ash collection bin 2 and the extended part is connected to the hollow disc 4. The other end of the air intake pipe 5 is connected to the external high-pressure air supply system to facilitate the cleaning of dust on the tube bundle 1.

[0035] Reference Figure 3 and Figure 4 Several nozzles 3 are evenly spaced along the length and width of the hollow disk 4 to facilitate the cleaning of dust on the tube bundle 1.

[0036] Reference Figure 3 and Figure 4 The nozzle 3 has an embedded venturi tube to increase the fluid velocity.

[0037] Reference Figure 3 and Figure 4 The ash removal device includes a high-pressure air pump 6, a fixed base 7 installed on the outer surface of the high-pressure air pump 6, the fixed base 7 being installed at the bottom of the ash collection hopper 2, an ash inlet pipe 8 installed at the input end of the high-pressure air pump 6, the ash inlet pipe 8 penetrating the bottom of the ash collection hopper 2, and the protruding part being connected to the lower ash collection hopper 9, and an ash discharge pipe 10 installed at the output end of the high-pressure air pump 6. In application, by starting the high-pressure air pump 6, the dust and loose dust in the lower ash collection hopper 9 are drawn into the high-pressure air pump 6 through the ash inlet pipe 8, and then discharged through the ash discharge pipe 10 at the output end of the high-pressure air pump 6, thereby facilitating the discharge of dust and loose dust in the lower ash collection hopper 9.

[0038] In actual use, when it is necessary to clean the dust on the tube bundle 1, the external high-pressure air supply system is started. At this time, the high-pressure gas enters the nozzle 3 through the air inlet pipe 5 and the hollow plate 4, and finally sprays out through the nozzle 3 to clean the dust on the tube bundle 1. At the same time, the high-pressure air pump 6 fixed on the fixed base 7 is started. At this time, the input end of the high-pressure air pump 6 is drawn into the high-pressure air pump 6 through the ash inlet pipe 8 and the dust and scattered dust in the lower ash hopper 9, and then discharged through the ash discharge pipe 10 on the output end of the high-pressure air pump 6 to achieve the cleaning of the economizer, thus facilitating the cleaning of the economizer without damaging the tube wall.

[0039] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. Furthermore, it should be understood that after reading the technical description of this utility model, those skilled in the art can make various alterations, modifications, and / or variations to this utility model, and all such equivalent forms also fall within the scope of protection defined by the appended claims.

Claims

1. A self-cleaning low-temperature economizer, characterized by: The application relates to a heat exchange tube bundle (1) with a gradient composite coating. The outer surface of the tube bundle (1) is provided with a dust collecting bin (2), the upper portion of the tube bundle (1) is provided with a plurality of nozzles (3), the nozzles (3) are located in the dust collecting bin (2), the nozzles (3) are connected with an external high-pressure gas supply system through a gas inlet channel, the lower portion of the tube bundle (1) is provided with a lower dust collecting hopper (9), the lower dust collecting hopper (9) is arranged on the bottom wall of the inner cavity of the dust collecting bin (2), a dust discharging device is arranged on the bottom of the dust collecting bin (2) and is connected with the lower dust collecting hopper (9).

2. The self-coking low-temperature economizer according to claim 1, characterized in that: The tube bundle (1) is designed in an asymmetric variable-diameter mode, and the diameter of the flue gas inlet end of the tube bundle (1) is larger than the diameter of the outlet end of the tube bundle (1).

3. The self-coking low-temperature coal economizer according to claim 1, characterized in that: The gradient composite coating comprises a nickel-based alloy layer, a silicon carbide reinforced layer (101) and a hydrophobic ceramic layer (102), and the nickel-based alloy layer, the silicon carbide reinforced layer (101) and the hydrophobic ceramic layer (102) are arranged from inside to outside.

4. The self-cleaning low-temperature economizer of claim 1, wherein: The gas inlet channel is composed of a hollow disc (4) and a gas inlet pipe (5), a plurality of nozzles (3) are arranged on the bottom of the hollow disc (4) and are connected with the hollow disc (4), one end of the gas inlet pipe (5) penetrates through the top of the dust collecting bin (2) and is connected with the hollow disc (4), and the other end of the gas inlet pipe (5) is connected with the external high-pressure gas supply system.

5. The self-cleaning low-temperature coal economizer according to claim 4, characterized in that: A plurality of nozzles (3) are arranged at equal intervals along the length and width directions of the hollow disc (4).

6. The self-cleaning low-temperature coal economizer according to claim 4, characterized in that: The nozzles (3) are embedded with Venturi accelerating tubes.

7. The self-cleaning low-temperature economizer of claim 1, wherein: The dust discharging device comprises a high-pressure gas pump (6), the outer surface of the high-pressure gas pump (6) is provided with a fixing seat (7), the fixing seat (7) is arranged on the bottom of the dust collecting bin (2), the input end of the high-pressure gas pump (6) is provided with a dust inlet pipe (8), the dust inlet pipe (8) penetrates through the bottom of the dust collecting bin (2) and is connected with the lower dust collecting hopper (9), and the output end of the high-pressure gas pump (6) is provided with a dust discharging pipe (10).

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