阅读说明：本技术 用于回转式空气预热器的换热板及空气预热器 (Heat exchange plate for rotary air preheater and air preheater ) 是由 王定 刘堃 何俊锋 周昊 齐博阳 倪玉国 于 2020-11-30 设计创作，主要内容包括：本发明公开一种用于回转式空气预热器的换热板,包括空心夹层换热板、电热丝和热电偶；所述空心夹层换热板两层薄板组成,所述电热丝置于空心夹层换热板的夹层中,热电偶嵌于薄钢板中。本发明还公开本发明还提供一种空气预热器,空气预热器内设置有上述的换热板。本发明能够解决空气预热器存在的硫酸氢铵粘结问题,从而实现保持空气预热器换热效率避免频繁冲洗空气预热器等目标。(The invention discloses a heat exchange plate for a rotary air preheater, which comprises a hollow interlayer heat exchange plate, an electric heating wire and a thermocouple, wherein the hollow interlayer heat exchange plate is provided with a hollow interlayer; the heating wire is arranged in the interlayer of the hollow interlayer heat exchange plate, and the thermocouple is embedded in the thin steel plate. The invention also discloses an air preheater, and the heat exchange plate is arranged in the air preheater. The invention can solve the problem of ammonium bisulfate bonding in the air preheater, thereby achieving the aims of keeping the heat exchange efficiency of the air preheater and avoiding frequent flushing of the air preheater.)

1. A heat exchange plate for a rotary air preheater is characterized by comprising a hollow interlayer heat exchange plate (1), an electric heating wire (2) and a thermocouple (3):

the hollow interlayer heat exchange plate is characterized in that the hollow interlayer heat exchange plate (1) is composed of two layers of thin plates, the electric heating wire (2) is arranged in an interlayer of the hollow interlayer heat exchange plate (1), and the thermocouple (3) is embedded in the thin steel plate.

2. The heat exchange plate for a rotary air preheater as recited in claim 1, wherein the thickness of each thin steel plate is 0.4-0.6 mm.

3. A heat exchange plate for a rotary air preheater according to claim 2, wherein the thickness of the hollow interlayer in the middle of the hollow interlayer heat exchange plate (1) is 0.3-0.5 mm.

4. A heat exchange plate for a rotary air preheater according to claim 1, wherein the pitch of the heating wires (2) is 130-170 mm along the heat exchange surface.

5. A heat exchange plate for a rotary air preheater according to claim 1, wherein the thermocouple (3) pitch is 130-170 mm.

6. A heat exchanger plate for a rotary air preheater according to claim 1, wherein two adjacent thermocouples (3) are located in different layers of sheets of the same hollow sandwich heat exchanger plate (1).

7. An air preheater, characterized in that a heat exchanger plate as claimed in any one of claims 1-5 is provided in the air preheater.

8. A heat exchanger plate for a rotary air preheater according to claim 1, wherein the heating wires (2) and the thermocouples (3) are connected to the temperature control device by wires.

Technical Field

The invention belongs to the field of research on heat exchange influence of a tail flue of a power plant boiler, and particularly relates to a heat exchange plate for a rotary air preheater and the air preheater.

Background

In order to meet the increasingly strict environmental requirements of the country and effectively control the content of NOx in the boiler flue gas of the power plant, the coal-fired power plant usually adopts a Selective Catalytic Reduction (SCR) technology to denitrate the flue gas. SCR systems generally employ V₂O₅/TiO₂Based on a catalyst, but the catalyst can reduce part of SO in the flue gas while catalyzing NOx reduction₂By oxidation to SO₃. NH injected into the flue due to temperature fluctuation, catalyst aging, poisoning and other factors₃Will be excessive, resulting in NH₃And (4) leakage. SO formed by oxidation₃And leaked NH₃Under certain conditions, viscous ammonium bisulfate is formed and is accumulated on the surface of the air preheater. The ammonium bisulfate can adsorb ash in the flue gas to generate deposition on the surface of the air preheater, which can lead to the reduction of the heat exchange efficiency of the air preheater and seriously lead to the abnormal shutdown of the unit. Therefore, it is important to reduce and clean the deposits on the surface of the air preheater without shutdown.

At present, the air preheater is mainly treated by high-pressure water flow washing, but has the defects of large workload, time consumption, unsatisfactory cleaning effect and the like. In addition, the alkaline solution can be used for dissolving the adhered ammonium bisulfate and then the high-pressure water flow is used for washing to improve the cleaning effect, but the problems of environmental pollution and the like are easily caused. In addition, in the prior art, publication numbers CN 208269187U and CN 102032587 a also propose two improved technical solutions for the inner heat exchange plate, respectively.

Research and development a novel air heater of inside heating reaches ammonium bisulfate sublimation point through periodic heating heat transfer board to make ammonium bisulfate flow out air heater along with the flue gas, guarantee that heat exchange efficiency has important meaning to the quick clearance of boiler afterbody air preheater deposition.

Disclosure of Invention

The invention aims to solve the problem of ammonium bisulfate bonding in an air preheater by heating the inside of a heat exchange plate of the rotary air preheater, thereby achieving the aims of keeping the heat exchange efficiency of the air preheater and avoiding frequent washing of the air preheater.

A heat exchange plate for a rotary air preheater comprises a hollow interlayer heat exchange plate, an electric heating wire and a thermocouple;

the heating wire is arranged in the interlayer of the hollow interlayer heat exchange plate, and the thermocouple is embedded in the thin steel plate.

In the invention, the thickness of each layer of thin steel plate is 0.4-0.6 mm, and the thickness of the hollow interlayer in the middle of the hollow interlayer heat exchange plate is 0.3-0.5 mm.

Preferably, the distance between the heating wires is 130-170 mm along the direction of the heat exchange surface.

Preferably, the thermocouple interval is 130-170 mm.

Preferably, two adjacent thermocouples are located in different layers of thin plates of the same hollow interlayer heat exchange plate.

The invention also provides an air preheater, and the heat exchange plate is arranged in the air preheater. The air preheater is not limited to a rotary air preheater, and can be other plate preheaters.

In the air preheater, the electric heating wire and the thermocouple are connected with a temperature control device through leads.

Compared with the prior art, the invention has the following remarkable advantages:

1. the rotary air preheater can transfer more heat through a double-layer structure, and improves the heat exchange efficiency of the rotary air preheater;

2. according to the invention, the internal heating wire is used for heating, so that the adhesion of ammonium bisulfate in the flue gas is reduced, and the blockage problem of the preheater is relieved;

3. in the invention, the temperature is measured by the thermocouple embedded in the thin steel plate, which is beneficial to accurately controlling the heating temperature of the electric heating wire.

Drawings

FIG. 1 is a schematic cross-sectional view of a novel heat exchange plate for a rotary air preheater according to the present invention;

in the figure: 1 is the surface of a heat exchange plate of the rotary air preheater, and 2 is an electric heating wire additionally arranged in the heat exchange plate.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments disclosed below. The terms "upper", "lower", "left" and "right" as used herein are set forth with reference to the accompanying drawings, and it is understood that the presence of the terms does not limit the scope of the present invention.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Referring to fig. 1, a heat exchange plate for a rotary air preheater includes a hollow interlayer heat exchange plate 1, heating wires 2, and thermocouples 3; the hollow interlayer heat exchange plate 1 consists of two layers of thin steel plates, the thickness of each layer of thin steel plate is 0.6mm, and the thickness of the middle hollow interlayer is 0.5 mm; the electric heating wire 2 is arranged in the interlayer of the hollow interlayer heat exchange plate 1, the thermocouple 3 is embedded in the thin steel plate, and the electric heating wire and the thin steel plate can rotate and move along with the heat exchange plate 1; the distance between the electric heating wires 2 is 150mm along the direction of the heat exchange surface, and the electric heating wires 2 are connected with a temperature control device through leads; the distance between the thermocouples 3 is 150mm, the thermocouples 3 are connected with a temperature control device through wires, and the two adjacent thermocouples 3 are located in different thin steel plates of the same heat exchange plate 1.

The hollow interlayer heat exchange plate 1 is of a double-layer thin steel plate structure, and can exchange more heat in the rotary air preheater than a common single-layer thin steel plate structure, so that the heat exchange efficiency of the air preheater is improved;

the heating wire 2 can heat the heat exchange plate 1 of the air preheater to enable the temperature of the plate surface to reach the sublimation point of ammonium bisulfate, so that the adhesion of the ammonium bisulfate on the surface of the heat exchange plate is reduced, and the frequent washing of the air preheater can be avoided;

the thermocouple 3 can measure the surface temperature of the heat exchange plate 1 of the air preheater and feed the temperature back to the temperature control device, so that the temperature of the electric heating wire can be controlled more accurately.

In this embodiment, the working process of the novel heat exchange plate for the rotary air preheater is as follows: firstly, hot flue gas passes through a heat exchange plate 1 of a rotary air preheater, a thermocouple 3 measures the surface temperature of the heat exchange plate 1, if the temperature is lower than the sublimation temperature of ammonium bisulfate, the heat exchange plate is heated by a heating wire 2, and low-temperature air flows through the heat exchange plate 1 for heat exchange after a certain time.

Compare with current heat transfer board component, the novel heat transfer board 1 that is used for rotary air heater of this patent can be through more heats of bilayer structure transmission, effectively improves rotary air heater's heat exchange efficiency, heats through 1 inside heating wire 2 of heat transfer board, reduces ammonium bisulfate's in the flue gas adhesion, alleviates the jam problem of pre-heater, measures the temperature through the thermocouple 3 that inlays in the steel sheet simultaneously, does benefit to the heating temperature of accurate control heating wire 2.

In another embodiment, an air preheater is provided with the heat exchange plate with the structure. In the air preheater, the electric heating wire and the thermocouple are connected with a temperature control device through leads.

The above description is only exemplary of the preferred embodiments of the present invention, and is not intended to limit the present invention, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.