CN210891741U

CN210891741U - Composite heat exchanger for corrosion resistance and high heat exchange efficiency

Info

Publication number: CN210891741U
Application number: CN201921643151.3U
Authority: CN
Inventors: 刘佳
Original assignee: Shenyang Yichen Technology Co ltd
Current assignee: Shenyang Yichen Technology Co ltd
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2020-06-30
Anticipated expiration: 2029-09-29

Abstract

The utility model belongs to the field of heat exchanger equipment, and provides a composite heat exchanger for corrosion resistance and high heat exchange efficiency, which comprises a box body and a composite pipe arranged in the box body, wherein the composite pipe is formed by compounding an outer corrosion-resistant high-heat-conducting pipe and an inner high-pressure water delivery pipe; a first medium is communicated between the internal high-pressure water delivery pipe and the outer corrosion-resistant high-heat-conducting pipe, and is used for transferring heat absorbed by the outer corrosion-resistant high-heat-conducting pipe to the internal high-pressure water delivery pipe; the medium II is communicated with the inside of the internal high-pressure water conveying pipe and used for taking away heat absorbed by the internal high-pressure water conveying pipe. The device has the characteristics of corrosion resistance and high heat exchange efficiency, and is used for recovering the waste heat of low-temperature flue gas.

Description

Composite heat exchanger for corrosion resistance and high heat exchange efficiency

Technical Field

The utility model belongs to heat exchanger equipment field, in particular to a compound heat exchanger of corrosion-resistant high heat exchange efficiency that is used for coal fired boiler heat exchanger for waste heat recovery.

Background

In the operation process of the coal-fired industrial boiler, the heat loss of exhaust gas is the largest item of heat loss, the exhaust gas temperature of a domestic boiler unit in long-term operation is generally higher than a design value and generally ranges from 160 ℃ to 180 ℃, a large amount of waste heat is taken away by exhaust gas, most industrial boilers do not fully utilize the waste heat resources in the production process, and if the waste heat can be recovered, the energy-saving effect is very considerable. The boiler efficiency is improved by about 1% when the exhaust gas temperature is reduced by 15 ℃. The low-temperature waste heat recovery is an energy-saving technology widely applied to the domestic and foreign coal-fired power generation industry, and is popularized and applied rapidly in China in recent years. In the aspect of low-temperature waste heat recovery, a low-temperature heat exchanger is additionally arranged behind an air preheater to heat boiler return water or boiler make-up water, so that the boiler feed water temperature is increased, the coal consumption is reduced, and the boiler efficiency is improved. The waste heat of the boiler exhaust smoke belongs to low-grade waste heat resources, two problems of poor heat transfer performance and low-temperature dew point corrosion exist in recycling, the recycling difficulty and the reconstruction and maintenance cost of the waste heat of the boiler exhaust smoke are increased due to the two problems, and the popularization and the use of the low-temperature heat exchanger are limited to a great extent. Therefore, how to improve the heat exchange coefficient of the low-temperature heat exchanger and improve the corrosion condition of the heat exchange element in the low-temperature waste heat recycling process are two major problems to be solved urgently at present, and the problem is related to whether the low-temperature waste heat recycling can be popularized and used.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a heat exchanger for coal fired boiler waste heat recovery, it can solve the technical limitation that coal fired boiler low temperature flue gas waste heat recovery medium and low temperature acid dew point corrodes seriously, life is short well. Absorb the flue gas heat through outer graphite pipe, the heat conduction of leading to water of inside tubular metal resonator combines together, has solved the graphite pipe and can not bear high-pressure rivers, the poor problem of tubular metal resonator corrosion resistance for low temperature heat exchanger's heat transfer performance and life can improve by a wide margin, have the characteristics that corrosion-resistant heat exchange efficiency is high, are used for low temperature flue gas waste heat recovery, have fine social and economic benefits, and industrial application and popularization potentiality are huge.

The utility model discloses technical scheme as follows:

the application provides a corrosion-resistant high-heat-exchange-efficiency composite heat exchanger, which comprises a box body and a plurality of composite pipes arranged in the box body, wherein the composite pipes are arranged in the box body;

the composite pipe is formed by compounding an outer-layer corrosion-resistant high-heat-conducting pipe and an inner high-pressure water delivery pipe, wherein the outer-layer corrosion-resistant high-heat-conducting pipe is arranged on the outer layer, and the inner high-pressure water delivery pipe is positioned in the outer-layer corrosion-resistant high-heat-conducting pipe;

a first medium is communicated between the internal high-pressure water delivery pipe and the outer corrosion-resistant high-heat-conducting pipe, and is used for transferring heat absorbed by the outer corrosion-resistant high-heat-conducting pipe to the internal high-pressure water delivery pipe; a second medium is introduced into the internal high-pressure water delivery pipe and used for taking away heat absorbed by the internal high-pressure water delivery pipe;

the length of the internal high-pressure water delivery pipe is greater than that of the external corrosion-resistant high-heat-conducting pipe; the two ends of the internal high-pressure water pipe are provided with outer side plates perpendicular to the internal high-pressure water pipe, the two ends of the outer corrosion-resistant high-heat-conducting pipe are provided with inner side plates perpendicular to the external corrosion-resistant high-heat-conducting pipe, and the space formed by the inner side plates and the outer side plates is communicated with the outer corrosion-resistant high-heat-conducting pipe and is not communicated with the internal high-pressure water pipe.

Furthermore, the outer layer corrosion-resistant high-heat-conducting pipe adopts a graphite impregnated pipe, and the excellent corrosion resistance and high heat-conducting property of the graphite impregnated pipe are utilized to absorb the heat of high-temperature flue gas.

Further, the internal high-pressure water delivery pipe is a metal pipe.

Further, both the first medium and the second medium adopt fluid; preferably, both media one and media two are water.

Further, the pressure intensity of the medium I is smaller than that of the medium II, namely the medium I is low-pressure water, and the medium II is high-pressure water.

Further, a flange and a sealing ring are arranged at the joint of the internal high-pressure water delivery pipe and the outer side plate; a flange and a sealing ring are also arranged at the joint of the outer corrosion-resistant high-heat-conducting pipe and the inner side plate;

wherein, the flange presses the sealing ring through the screw rod, makes the sealing ring tightly laminate the junction, realizes sealedly.

Furthermore, the composite pipe is in a high-temperature corrosion environment, in order to avoid corrosion of the flange and the screw rod, the sealing ring is made of corrosion-resistant polytetrafluoroethylene, and polytetrafluoroethylene coatings are arranged on the surfaces of the flange and the screw rod.

Furthermore, the two ends of the outer corrosion-resistant high heat-conducting pipe are respectively provided with a step-shaped structure, and the step-shaped structures can be fixed with the inner side plate to prevent the outer corrosion-resistant high heat-conducting pipe from moving.

After the technical scheme, the utility model discloses effect below having:

firstly, the outer layer corrosion-resistant high heat conduction pipe adopts a graphite pipe, and the graphite pipe has excellent sulfuric acid dew point corrosion resistance and long service life; the heat conductivity coefficient of the graphite pipe is 3 times that of carbon steel, and the graphite pipe is in contact with high-temperature flue gas, so that the graphite pipe is corrosion-resistant and can exchange heat.

Secondly, the internal high-pressure water delivery pipe adopts a metal pipe, so that the defect that the graphite pipe cannot bear high pressure can be overcome; and a large amount of heat which can be absorbed by the outer-layer graphite tube is led into the inner-layer metal tube for utilization.

And a low-pressure liquid heat-conducting medium is introduced between the outer-layer corrosion-resistant high-heat-conducting pipe and the inner high-pressure water delivery pipe, so that the problem of material fatigue caused by the difference of thermal expansion due to different materials of the inner and outer layers of pipes can be solved, and the service life of the heat exchanger is long.

The utility model discloses coal fired boiler is heat exchanger for waste heat recovery has overcome effectively among the prior art because low temperature flue gas heat transfer warm-pressing is little, the heat transfer performance that the acid gas condensation leads to is not good, low temperature corrosion is serious, life is short, manufacturing operation cost is high and the great scheduling drawback of application limitation, helps improving whole job stabilization nature, satisfies environmental protection, energy-conserving requirement and ensures that heat exchanger safety and stability moves the utility model discloses the purpose, therefore, obviously have rational in infrastructure and science, reliable operation and stable and energy-conservation, have very strong practicality and considerable market perspective.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic structural view of a composite pipe.

Reference numerals:

an internal high-pressure water delivery pipe-1; medium two-11; medium one-12; the outer layer is a corrosion-resistant high heat-conducting pipe-2; an outer panel-3; an inner side plate-4; flange-5; through a screw-7; and a sealing ring-6.

Detailed Description

Example 1

According to the composite heat exchanger for corrosion resistance and high heat exchange efficiency, the composite pipe is formed by compounding an outer-layer corrosion-resistant high-heat-conducting pipe 2 and an inner high-pressure water conveying pipe 1, the outer-layer corrosion-resistant high-heat-conducting pipe 2 is arranged on the outer layer, and the inner high-pressure water conveying pipe 1 is located in the outer-layer corrosion-resistant high-heat-conducting pipe 2; the internal high-pressure water pipe 1 is sealed in a mode that the flange 5 compresses the sealing ring 6, an inclined plane is processed on the outer side plate 3 at the contact position of the sealing ring 6 and the outer side plate 3, and the internal high-pressure water pipe 1 is extruded to form sealing when the sealing ring 6 is compressed by the flange 5. Outer corrosion-resistant high heat pipe 2 is spacing by the board that has the notch cuttype structure at both ends, prevents outer corrosion-resistant high heat pipe 2's drunkenness, and outer corrosion-resistant high heat pipe 2's sealed also adopts the mode that the tight sealing washer 6 of blue pressure 5 is sealed, processes out the inclined plane on the board in the place of sealing washer 6 and 4 board contacts of interior side, and sealing washer 6 extrudees outer corrosion-resistant high heat pipe 2 formation when being compressed tightly by the flange and seals. The outer corrosion-resistant high heat-conducting pipe 2 is in a high-temperature corrosion environment, and in order to avoid corrosion of the flange 5 and the screw 7, the flange 5 and the screw 7 are coated with polytetrafluoroethylene on the surfaces.

A medium I12 is communicated between the internal high-pressure water delivery pipe and the outer corrosion-resistant high-heat-conducting pipe, and the medium I12 is used for transferring heat absorbed by the outer corrosion-resistant high-heat-conducting pipe 2 to the internal high-pressure water delivery pipe 1; a second medium 11 is introduced into the internal high-pressure water delivery pipe 1, and the second medium 11 is used for taking away heat absorbed by the internal high-pressure water delivery pipe 1;

the working process is that the corrosive low-temperature flue gas vertically passes through the composite tubes of the heat exchanger in rows and exchanges heat on the surface of the outer-layer corrosion-resistant high-heat-conducting tube 2. After the low-temperature flue gas with high temperature contacts with the outer corrosion-resistant high heat conduction pipe 2 with low temperature, the heat is released and condensed into sulfuric acid and air, and after the outer corrosion-resistant high heat conduction pipe 2 absorbs the heat of the flue gas, the heat is transferred to the middle layer medium I12 with lower temperature. The middle layer is not corrosive, absorbs the heat conducted by the outer corrosion-resistant high-heat-conducting pipe 2 and then conducts the heat to the medium II 11 through the internal high-pressure water conveying pipe 1. Thus, the heat of the low-temperature flue gas is transferred to the medium II 11 through several heat transfers.

Compared with the prior art, the graphite tube is adopted in the high-temperature section, so that the graphite tube has excellent corrosion resistance and can operate for a long time in corrosive atmosphere; the low-temperature section adopts a metal pipe which has high strength and can be filled with large-flow cooling water. The strength of the graphite pipe is not high, and high-pressure cooling water cannot be introduced. The metal pipe has corrosion performance inferior to that of the graphite pipe, but has high strength and good shaping performance, and can be filled with high-pressure cooling water. The effects of corrosion resistance and high heat exchange efficiency can be simultaneously realized after the two are compounded.

The utility model is not the best known technology.

The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose of the embodiments is to enable people skilled in the art to understand the contents of the present invention and to implement the present invention, which cannot limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered by the protection scope of the present invention.

Claims

1. The utility model provides a compound heat exchanger for corrosion-resistant high heat exchange efficiency, includes the box, and sets up at the inside compound pipe of box, its characterized in that: the composite pipe is provided with a plurality of pipes;

the composite pipe is formed by compounding an outer-layer corrosion-resistant high-heat-conducting pipe (2) and an inner high-pressure water delivery pipe (1), wherein the outer-layer corrosion-resistant high-heat-conducting pipe (2) is arranged on the outer layer, and the inner high-pressure water delivery pipe (1) is positioned inside the outer-layer corrosion-resistant high-heat-conducting pipe (2);

a medium I (12) is communicated between the internal high-pressure water pipe (1) and the outer-layer corrosion-resistant high-heat-conducting pipe (2), and the medium I (12) is used for transferring heat absorbed by the outer-layer corrosion-resistant high-heat-conducting pipe (2) to the internal high-pressure water pipe (1); a second medium (11) is introduced into the internal high-pressure water delivery pipe (1), and the second medium (11) is used for taking away heat absorbed by the internal high-pressure water delivery pipe (1);

the length of the internal high-pressure water delivery pipe (1) is greater than that of the external corrosion-resistant high-heat-conducting pipe (2); outer side plates (3) perpendicular to the inner high-pressure water delivery pipe (1) are arranged at two ends of the inner high-pressure water delivery pipe, inner side plates (4) perpendicular to the outer corrosion-resistant high-heat conduction pipe (2) are arranged at two ends of the outer corrosion-resistant high-heat conduction pipe (2), and a space formed by the inner side plates (4) and the outer side plates (3) is communicated with the outer corrosion-resistant high-heat conduction pipe (2) and is not communicated with the inner high-pressure water delivery pipe (1).

2. A composite heat exchanger for corrosion resistance and high heat exchange efficiency according to claim 1, characterized in that: the outer layer corrosion-resistant high heat-conducting pipe (2) adopts a graphite impregnated pipe.

3. A composite heat exchanger for corrosion resistance and high heat exchange efficiency according to claim 1, characterized in that: the internal high-pressure water delivery pipe (1) is a metal pipe.

4. A composite heat exchanger for corrosion resistance and high heat exchange efficiency according to claim 1, characterized in that: the first medium (12) and the second medium (11) both adopt fluids.

5. A composite heat exchanger for corrosion resistance and high heat exchange efficiency according to claim 1, characterized in that: a flange (5) and a sealing ring (6) are arranged at the joint of the internal high-pressure water delivery pipe (1) and the outer side plate (3); a flange (5) and a sealing ring (6) are also arranged at the joint of the outer-layer corrosion-resistant high-heat-conducting pipe (2) and the inner side plate (4);

wherein the flange (5) presses the sealing ring (6) through the screw rod (7).

6. The composite heat exchanger for corrosion resistance and high heat exchange efficiency according to claim 5, characterized in that: the sealing ring (6) is made of polytetrafluoroethylene, and polytetrafluoroethylene coatings are arranged on the surfaces of the flange (5) and the screw (7).