Heat exchange core body of stepped corrugated tube air pre-heater

Abstract

The utility model discloses a step corrugated tube air pre-heater heat exchange core body which comprises a cabinet body, the interior of the cabinet body is divided into three spaces through partition plates, the three spaces are divided into a high-temperature section heat exchange tube set, a medium-temperature section heat exchange tube set and a low-temperature section heat exchange tube set from top to bottom, and flow guide cover plates are arranged on the two sides of the cabinet body respectively. A plurality of corrugated tube array tubes are arranged in the high-temperature section heat exchange tube group, the medium-temperature section heat exchange tube group and the low-temperature section heat exchange tube group; the corrugated tube structure of the heat exchange tube set enhances turbulent flow on the smoke side and the air side at the same time, and particularly improves the flowing heat transfer coefficient on the smoke side in the tube, so that the heat transfer efficiency is greatly enhanced; the low-temperature section heat exchange tube group adopts small-amplitude and large-pitch corrugated tubes, so that the heat transfer coefficient is improved, the flow area of flue gas is ensured, the flow resistance is reduced, and the occurrence of ammonium bisulfate adhesion and ash deposition blockage is reduced; the heat transfer area of unit volume is increased through the wave node structure of the heat exchange tube set, so that the structure of the air pre-heater is more compact, and the volume of the air pre-heater is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a boiler flue gas waste heat recovery energy -conserving equipment technical field, concretely is a kind of ladder wave tube air preheater heat exchange core body. BACKGROUND

[0002] Air preheater is the heat exchange equipment using boiler exhaust heat to heat the air required for combustion.The current air preheater of coal-fired power plant mainly has rotary type and pipe type.The rotary type air preheater is widely applied to 600MW and above coal-fired generating units because of its compact structure,light weight,adopting counterflow heat exchange and other advantages,But the rotary type air preheater also faces many unavoidable problems,Such as high leakage rate,has rotary mechanism,convenient for maintenance and so on.

[0003] Pipe type air preheater has the following advantages compared with rotary type air preheater:(1) simple structure,without rotating mechanism;(2) simple manufacturing,lower cost;(3) easy to repair and maintain.Therefore pipe type air preheater is still widely applied to 200MW and below coal-fired generating units and various industrial boilers,Its existing problems are: lower heat exchange efficiency,smoke gas in straight passage in pipe,short of disturbing component,low surface heat transfer coefficient;low-temperature section heat exchange pipe group is prone to blockage: rotary type air preheater is arranged after denitrification, before dust collector,In addition to containing a large amount of dust in flue gas,SO2 produced by fuel combustion is converted into SO3 under the action of catalyst when passing through denitrification device,reacts with ammonia escaped in denitrification process to generate NH4HSO4,NH4HSO4 starts to become liquid at temperature lower than 200 DEG C,has very high viscosity,its adhesion in pipe type air preheater low-temperature section heat exchange pipe inner surface combines with fly ash in flue gas to cause flow passage blockage.

[0004] Therefore, the utility model provides an improved ladder wave tube air preheater heat exchange core body, which can improve the heat exchange efficiency of the pipe type air preheater and reduce the possibility of blockage in the low-temperature section. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a ladder wave tube air preheater heat exchange core body to solve the problems in the above background technology.

[0006] To achieve the above object, the utility model provides the following technical scheme: a ladder wave tube air preheater heat exchange core body, comprising a cabinet body, the cabinet body is divided into three spaces by a partition plate inside, the three spaces are divided into high-temperature section heat exchange pipe group, medium-temperature section heat exchange pipe group and low-temperature section heat exchange pipe group from top to bottom, the cabinet body both sides are respectively equipped with flow guide cover plate, the high-temperature section heat exchange pipe group, medium-temperature section heat exchange pipe group and low-temperature section heat exchange pipe group are equipped with a plurality of wave tube column pipes.

[0007] Preferably, the wave tube column tube in the high-temperature section heat exchange pipe group is a wave tube with large amplitude and small pitch, the wave tube column tube in the low-temperature section heat exchange pipe group is a wave tube with small amplitude and large pitch, and the wave tube column tube in the medium-temperature section heat exchange pipe group has an amplitude and a pitch size between those of the wave tube column tubes in the high-temperature section heat exchange pipe group and the low-temperature section heat exchange pipe group.

[0008] Preferably, one side of the cabinet body is fixedly connected with one side of the high-temperature section heat exchange pipe group and the medium-temperature section heat exchange pipe group, and the other side of the cabinet body is fixedly connected with one side of the medium-temperature section heat exchange pipe group and the low-temperature section heat exchange pipe group.

[0009] Preferably, the upper and lower surfaces of the cabinet body and the internal partition plate are each provided with a plurality of through holes, and the two surfaces of the cabinet body connected with the flow guide cover plate are each open.

[0010] Compared with the prior art, the beneficial effects of the present application are as follows: the wave tube structure of the heat exchange pipe group enhances the disturbance of the flue gas side and the air side, especially improves the flow heat transfer coefficient of the flue gas side in the pipe, and greatly enhances the heat transfer efficiency; the low-temperature section heat exchange pipe group adopts a wave tube with small amplitude and large pitch, which improves the heat transfer coefficient, ensures the flue gas flow area, reduces the flow resistance, and reduces the occurrence of ammonium bisulfate adhesion and dust accumulation; the wave tube structure of the heat exchange pipe group increases the heat transfer area per unit volume, makes the air preheater structure more compact, and reduces the volume of the air preheater. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0012] Figure 2 It is a schematic diagram of the internal structure of the cabinet body of the present application.

[0013] In the figure: 1, cabinet body; 2, high-temperature section heat exchange pipe group; 3, medium-temperature section heat exchange pipe group; 4, low-temperature section heat exchange pipe group; 5, flow guide cover plate; 6, wave tube column tube. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0015] Please refer to 1-2, the utility model provides an embodiment: a kind of cascade wave tube air preheater heat exchange core, including cabinet 1, three spaces are divided by partition in cabinet 1 inside, three spaces are divided into high-temperature section heat exchange tube group 2, medium-temperature section heat exchange tube group 3 and low-temperature section heat exchange tube group 4 from top to bottom, cabinet 1 both sides are equipped with flow guide cover plate 5 respectively, high-temperature section heat exchange tube group 2, medium-temperature section heat exchange tube group 3 and low-temperature section heat exchange tube group 4 are all equipped with several wave tube column pipe 6, flue gas moves from the upper portion of cabinet 1 downwards, needs to pass wave tube column pipe 6 in high-temperature section heat exchange tube group 2, medium-temperature section heat exchange tube group 3 and low-temperature section heat exchange tube group 4 in turn, air from outside enters from the side of low-temperature section heat exchange tube group 4, and it is operated to the side of high-temperature section heat exchange tube group 2 by flow guide cover plate 5, flue gas and air are mixed flow heat exchange in counterflow and cross flow.

[0016] The wave tube column pipe 6 in the high-temperature section heat exchange tube group 2 is a wave tube with large amplitude and small pitch, the wave tube column pipe 6 in the low-temperature section heat exchange tube group 4 is a wave tube with small amplitude and large pitch, and the wave tube column pipe 6 in the medium-temperature section heat exchange tube group 3 has an amplitude and a pitch size between those of the wave tube column pipes 6 in the high-temperature section heat exchange tube group 2 and the low-temperature section heat exchange tube group 4; each heat exchange tube group is composed of wave tubes with different sizes welded on corresponding frames and end plates, the wave tube in the high-temperature section heat exchange tube group 2 has high amplitude and small pitch, has obvious disturbance effect, can significantly improve flue gas side flow, and improve heat transfer efficiency, the wave tube in the low-temperature section heat exchange tube group 4 has low amplitude and large pitch, can prevent flue gas side ash deposition, and avoid ash deposition blockage, and the wave tube in the medium-temperature section heat exchange tube group 3 has amplitude and pitch parameters between those of the high-temperature section and the low-temperature section, and plays a transition role.

[0017] The flow guide cover plate 5 on one side of the cabinet 1 is fixedly connected to one side of the high-temperature section heat exchange tube group 2 and the medium-temperature section heat exchange tube group 3, and the flow guide cover plate 5 on the other side is fixedly connected to one side of the medium-temperature section heat exchange tube group 3 and the low-temperature section heat exchange tube group 4, the incoming air is guided by the flow guide cover plate 5, so as to facilitate entering the cabinet 1 and heat exchange.

[0018] The upper and lower surfaces of the cabinet 1 and the internal partition plate are all provided with a plurality of through holes, the two surfaces of the cabinet 1 connected to the flow guide cover plate 5 are both open, flue gas enters from the upper surface of the cabinet 1, moves downwards through the through holes, passes through the wave tube column pipes 6 in the high-temperature section heat exchange tube group 2, the medium-temperature section heat exchange tube group 3 and the low-temperature section heat exchange tube group 4 in turn, and heat exchange is realized.

[0019] Working principle: in use, the high-temperature flue gas from the upper end surface of the high-temperature section heat exchange pipe group 2 flows in, in turn through the high-temperature section heat exchange pipe group 2, the medium-temperature section heat exchange pipe group 3, the low-temperature section heat exchange pipe group 4, and then flows out from the lower end surface of the low-temperature section heat exchange pipe group 4, the flue gas temperature is reduced, the low-temperature air flows in from the side surface of the low-temperature section heat exchange pipe group 4, through the turning effect of the flow guide cover plate 5, the air flows in turn through the low-temperature section heat exchange pipe group 4, the medium-temperature section heat exchange pipe group 3, the high-temperature section heat exchange pipe group 2, and then flows out from the side surface of the high-temperature section heat exchange pipe group 2, the air temperature is raised, the flue gas and the air flow and mix in counterflow and crossflow, the flow guide cover plate 5 and the heat exchange pipe group can be sealed by welding or bolted to realize the detachability of the joint, which is helpful for the transportation, installation and maintenance of the air preheater.

Claims

1. A stepped wave tube air preheater heat exchange core, comprising a cabinet (1), characterized in that: The inside of the cabinet (1) is divided into three spaces by a partition, the three spaces are divided into high-temperature section heat exchange pipe group (2), medium-temperature section heat exchange pipe group (3) and low-temperature section heat exchange pipe group (4) from top to bottom, the cabinet (1) is respectively provided with flow guide cover plate (5) on both sides, the high-temperature section heat exchange pipe group (2), medium-temperature section heat exchange pipe group (3) and low-temperature section heat exchange pipe group (4) are all provided with a plurality of wave tube column pipes (6).

2. The stepped wave tube air preheater heat exchange core according to claim 1, characterized in that: The wave tube column pipes (6) in the high-temperature section heat exchange pipe group (2) are large-amplitude and small-pitch wave tubes, the wave tube column pipes (6) in the low-temperature section heat exchange pipe group (4) are small-amplitude and large-pitch wave tubes, and the wave amplitude and pitch size of the wave tube column pipes (6) in the medium-temperature section heat exchange pipe group (3) are between those of the wave tube column pipes (6) in the high-temperature section heat exchange pipe group (2) and the low-temperature section heat exchange pipe group (4).

3. The stepped wave-solenoidal air preheater core according to claim 1, characterized in that: The flow guide cover plate (5) on one side of the cabinet (1) is fixedly connected with one side of the high-temperature section heat exchange pipe group (2) and the medium-temperature section heat exchange pipe group (3), and the flow guide cover plate (5) on the other side is fixedly connected with one side of the medium-temperature section heat exchange pipe group (3) and the low-temperature section heat exchange pipe group (4).

4. The stepped wave-slug heat exchanger core of claim 1, wherein: The upper and lower surfaces of the cabinet (1) and the internal partition are all provided with a plurality of through holes, and the two surfaces of the cabinet (1) connected with the flow guide cover plate (5) are both open.

Images