Radial sealing device for cold end of rotary air preheater

Abstract

The utility model discloses a cold-end radial sealing device of a rotary air preheater, which is applied between a rotor and a cold-end sector plate of the rotary air preheater and comprises a curtain-type soft sealing element, one end of the curtain-type soft sealing element is fixed on a modulus bin grid of the rotor, and the other end of the curtain-type soft sealing element is fixed on a cold-end sector plate of the rotary air preheater. The length D of the curtain type soft sealing element exceeding the modulus bin grid is greater than the vertical distance d between the modulus bin grid and the cold-end sector plate, and a balancing weight is fixed at the free end of the curtain type soft sealing element. The rotary preheater can adapt to thermal deformation of the preheater under different loads, and the air leakage rate of the rotary preheater can be effectively reduced, so that the purposes of reducing the power consumption of a fan and reducing the smoke exhaust heat loss of a boiler are achieved. And the air leakage rate of the air pre-heater can be effectively reduced for a unit in medium and low load for a long time.

Description

Technical Field

[0001] This utility model belongs to the technical field of rotary air preheaters, specifically relating to a radial sealing device for the cold end of a rotary air preheater. Background Technology

[0002] The working principle of a rotary air preheater: Metal heat storage elements, machined with special corrugations, are tightly placed within the fan-shaped compartments of a rotor. The rotor rotates at a certain speed, with its left and right halves serving as flue gas and air passages, respectively. The air side is further divided into primary and secondary air passages. When flue gas flows through the rotor, it releases heat to the heat storage elements, lowering its temperature. When the heat storage elements rotate to the air side, they release heat to the air, raising its temperature. This cycle repeats continuously, achieving heat exchange between the flue gas and the air.

[0003] Rotary air preheaters are typically located at the outlet of the denitrification unit or the economizer outlet. The inlet flue gas temperature is generally above 350℃, while the outlet flue gas temperature is generally below 170℃. Cold air is typically heated from 20℃ to above 300℃. This equipment reduces the boiler exhaust temperature and improves boiler efficiency. As a rotating machine, the rotor undergoes a mushroom-shaped deformation when hot, creating a gap between the rotating rotor and the stationary casing. Because the air side of the preheater is under positive pressure while the flue gas side is under negative pressure, this pressure difference causes some air to leak into the flue gas through the gap at the interface between the air and flue gas sides.

[0004] Preheater air leakage consists of two components: direct leakage and carryover leakage. Due to the structural design of rotary preheaters, carryover leakage is unavoidable. Therefore, reducing the preheater's leakage rate and minimizing direct leakage is crucial, with radial leakage being the primary form of direct leakage, especially under low load conditions. Reducing air preheater leakage not only lowers the power consumption of the forced draft fan (including primary air fan) and induced draft fan but also reduces some of the flue gas heat loss caused by hot air leakage. Excessive leakage can cause the forced draft fan and induced draft fan to reach their output limits, and in severe cases, can lead to fan surge, preventing the boiler from operating at full load. Utility Model Content

[0005] To address the aforementioned issues, this invention provides a radial sealing device for the cold end of a rotary air preheater. This device can adapt to the thermal deformation of the preheater under different loads, effectively reducing the air leakage rate of the rotary preheater, thereby reducing fan power consumption and boiler flue gas heat loss. For units operating at medium to low loads for extended periods, it can effectively reduce the air preheater leakage rate.

[0006] The embodiments of this utility model are achieved through the following technical solutions:

[0007] A radial sealing device for the cold end of a rotary air preheater is applied between the rotor and the cold end sector plate of the rotary air preheater. The radial sealing device includes a curtain-type flexible seal, one end of which is fixed to the modular compartment of the rotor. The length D of the curtain-type flexible seal extending beyond the modular compartment is greater than the vertical distance d between the modular compartment and the cold end sector plate. A counterweight is fixed to the free end of the curtain-type flexible seal.

[0008] In one embodiment of this utility model, the curtain-type flexible seal is a polymer flexible material seal.

[0009] In one embodiment of this utility model, the side of the curtain-type flexible seal that contacts the cold end fan-shaped plate is the sealing working surface, and the counterweight is located on the sealing working surface.

[0010] In one embodiment of this utility model, the counterweight is provided with several blocks spaced apart.

[0011] The technical solution of this utility model has at least the following advantages and beneficial effects:

[0012] This invention reduces the leakage rate of a rotary preheater by tightly fitting a curtain-type flexible seal against a sector plate during rotor rotation. After passing the sector plate, the curtain-type flexible seal returns to its original position under gravity. This design adapts to the thermal deformation of the preheater under different loads, effectively reducing the leakage rate and thus lowering fan power consumption and boiler flue gas heat loss. For units operating at medium to low loads for extended periods, it effectively reduces air preheater leakage. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of a rotary air preheater cold end radial sealing device according to the present invention;

[0015] Figure 2 This is a front view of the curtain-type soft sealing component of this utility model;

[0016] Figure 3 This is a schematic diagram showing the relative positions of the rotor and the cold-end sector plate in a rotary air preheater.

[0017] Icons: 1- Modular compartment, 2- Cold end fan-shaped plate, 3- Curtain-type soft seal, 4- Counterweight block. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this utility model, it should be noted that if terms such as "inner" or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0022] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "configure," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of 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.

[0023] A radial sealing device for the cold end of a rotary air preheater is applied between the rotor and the cold end sector plate 2 of the rotary air preheater. The radial sealing device includes a curtain-type flexible seal 3, one end of which is fixed to the modular compartment 1 of the rotor. The length D of the curtain-type flexible seal 3 extending beyond the modular compartment 1 is greater than the vertical distance d between the modular compartment 1 and the cold end sector plate 2. A counterweight 4 is fixed to the free end of the curtain-type flexible seal 3.

[0024] The following embodiments are further elaborated based on the above solutions.

[0025] Example 1

[0026] Please refer to Figure 1-3 This embodiment provides a radial sealing device for the cold end of a rotary air preheater, applied between the rotor and the cold end sector plate 2 of the rotary air preheater. The radial sealing device includes a curtain-type flexible seal 3, which is a high-polymer flexible material seal, such as polyurethane or silicone rubber. In use, one end of the curtain-type flexible seal 3 is riveted to the modular compartment 1 of the rotor, and a counterweight 4 is fixed to the free end of the curtain-type flexible seal 3. When the cold end sector plate 2 passes through the curtain-type flexible seal 3, the curtain-type flexible seal 3 can return to its initial upright state under the action of gravity. Moreover, the length D of the curtain-type flexible seal 3 extending beyond the modular compartment 1 is greater than the vertical distance d between the modular compartment 1 and the cold end sector plate 2. When the cold end sector plate 2 passes through the curtain-type flexible seal 3, the curtain-type flexible seal 3 can seal the gap between the modular compartment 1 and the cold end sector plate 2, thereby reducing the air leakage rate.

[0027] In this embodiment, the side of the curtain-type flexible seal 3 that contacts the cold-end sector plate 2 is designated as the sealing working surface. A counterweight 4 is installed on this sealing working surface, and several counterweights 4 are spaced apart. The counterweights 4 are made of steel plates or other heavy materials. For a single curtain-type flexible seal 3, when the cold-end sector plate 2 first contacts the curtain-type flexible seal 3, i.e., during the process of the curtain-type flexible seal 3 changing from upright to bent, the cold-end sector plate 2 contacts and rubs against the counterweight 4, preventing the cold-end sector plate 2 from causing extensive wear to the curtain-type flexible seal 3. When the cold-end sector plate 2 is in complete contact with the curtain-type flexible seal 3, i.e., the curtain-type flexible seal 3 has completed bending, the gap between the sealing module compartment 1 and the cold-end sector plate 2 is reduced. When the cold-end sector plate 2 disengages from the curtain-type flexible seal 3, the curtain-type flexible seal 3 can return to its initial upright state under the action of gravity.

[0028] This invention reduces the leakage rate of a rotary preheater by tightly fitting a curtain-type flexible seal 3 against a sector-shaped plate 2 during rotor rotation. After passing the sector-shaped plate 2, the curtain-type flexible seal 3 returns to its original position under gravity. Because the curtain-type flexible seal 3 is made of a flexible polymer material, it can adapt to the thermal deformation of the preheater under different loads, effectively reducing the leakage rate of the rotary preheater. This, in turn, reduces fan power consumption and boiler flue gas heat loss. For units operating at medium to low loads for extended periods, it effectively reduces the air preheater leakage rate.

[0029] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A rotary air preheater cold end radial seal apparatus applied between a rotor and a cold end sector plate of a rotary air preheater, characterized in that, The radial sealing device comprises a curtain type soft sealing element, one end of which is fixed to a module compartment of the rotor, the length D of the curtain type soft sealing element beyond the module compartment is greater than the vertical distance d between the module compartment and the cold end sector plate, and a counterweight is fixed to the free end of the curtain type soft sealing element.

2. A cold end radial seal for a rotary air preheater as defined in claim 1 wherein, The curtain type soft sealing element is a high polymer soft sealing element.

3. A cold end radial seal for a rotary air preheater as defined in claim 1 wherein, One side of the curtain type soft sealing element in contact with the cold end sector plate is a sealing working surface, and the counterweight is located on the sealing working surface.

4. A cold end radial seal for a rotary air preheater as defined in claim 1 wherein, A plurality of counterweights are arranged at intervals.

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