CN220793969U - Heat exchange device and aluminum electrolysis cell flue gas waste heat recovery device - Google Patents

Abstract

The application discloses a heat transfer device and aluminum electrolysis cell flue gas waste heat recovery device solves the technical problems that a heat exchanger in the prior art is complex in structure and high in assembly difficulty. The heat exchange device comprises a shell, a first heat exchange assembly and a second heat exchange assembly, wherein the shell is provided with a heat exchange channel, a flue gas inlet and a flue gas outlet; the first heat exchange assembly comprises a cooling box and a plurality of heat exchange pipes, the cooling box is connected to the outside of the shell, the cooling box is provided with a cooling inlet and a cooling outlet, the plurality of heat exchange pipes are arranged at intervals along the vertical direction, the lower ends of the heat exchange pipes are provided with gaps with the inner wall of the heat exchange channel, and the upper ends of the heat exchange pipes extend out of the heat exchange channel and are positioned in the cooling box; the second heat exchange assembly is located in the heat exchange channel and is close to the flue gas outlet, and the second heat exchange assembly comprises radial heat pipes for cooling a medium to be cooled, and the radial heat pipes extend in the horizontal direction. The heat exchange device that this application provided, heat exchange efficiency is high, and dew point corrosion risk is low, and the structure is few, simple structure, easy assembly.

Description

Heat exchange device and aluminum electrolysis cell flue gas waste heat recovery device

Technical Field

The application belongs to the technical field of heat exchange, and particularly relates to a heat exchange device and an aluminum electrolysis cell flue gas waste heat recovery device.

Background

The heat exchanger can transfer the heat in the high-temperature flue gas to the low-temperature medium, and the heated low-temperature medium is applied to air or boiler water preheating, urban building heating, engineering refrigeration or low-temperature power generation and the like, so that the energy consumption of other links is reduced, and the purpose of energy conservation is achieved. Common heat exchangers include tubular heat exchangers, plate heat exchangers, heat pipe heat exchangers, direct contact heat exchangers, and the like. The heat pipe heat exchanger is generally composed of heat pipe bundles, and the heat pipes which are the constituent units of the heat pipe bundles are efficient phase-change heat exchange elements and can transfer quite large heat flow under the condition of small temperature difference. The heat pipe is formed by filling a certain amount of phase change working medium into a closed metal pipe for pumping non-condensable gas, and the principle is that the working medium phase change is utilized for heat exchange and heat transfer, and the heat transfer efficiency and the heat exchange capacity of the heat pipe type heat exchanger are far higher than those of a single-phase temperature difference heat exchanger due to the severe boiling action of the working medium phase change and the huge enthalpy difference between two phases.

The heat pipe bundle used in industry at present mainly has two structures of axial heat pipes and radial heat pipes, wherein the axial heat pipes are also called gravity heat pipes, and the heat pipes realize phase change medium backflow by gravity. Compared with the axial heat pipe, the radial heat pipe extends along the horizontal direction, and the area of the hot side is far larger than that of the cold side, so that the radial heat pipe has high isothermal performance, and the influence of non-condensable gas on the radial heat pipe is very small.

The pipe body of gravity heat pipe includes evaporation zone and condensation segment, and the condensation segment adopts the sleeve pipe condensation, and the sleeve pipe is located outside the condensation segment, arranges such a plurality of axial heat pipes (gravity heat pipe) in the heat exchanger, leads to the structure of heat exchanger complicacy, and the assembly degree of difficulty is big.

Disclosure of Invention

In order to solve the technical problems of complex structure and high assembly difficulty of the conventional heat exchanger, the application provides a heat exchange device and an aluminum electrolysis cell flue gas waste heat recovery device.

In a first aspect of the present application, there is provided a heat exchange device comprising:

the shell is provided with a heat exchange channel for the medium to be cooled to circulate, and a flue gas inlet and a flue gas outlet which are communicated with the heat exchange channel;

the first heat exchange assembly is close to the flue gas inlet and comprises a cooling box for containing cooling liquid and a plurality of heat exchange pipes for containing phase change media, the cooling box is connected to the outside of the shell and is provided with a cooling inlet and a cooling outlet, the plurality of heat exchange pipes are arranged at intervals vertically, the lower ends of the heat exchange pipes are positioned in the heat exchange channels, and the upper ends of the heat exchange pipes extend out of the heat exchange channels and are positioned in the cooling box;

the second heat exchange assembly is positioned in the heat exchange channel and is close to the flue gas outlet, and comprises radial heat pipes for cooling the medium to be cooled, and the radial heat pipes extend along the horizontal direction.

In some embodiments, the radial heat pipe comprises an outer pipe and an inner pipe for allowing the cooling liquid to circulate, the inner pipe is movably sleeved in the outer pipe, a heat exchange cavity for containing a phase change medium is formed between the inner pipe and the outer pipe, one end of the inner pipe is communicated with the cooling inlet, and the other end of the inner pipe is communicated with a cooling liquid source.

In some embodiments, the radial heat pipes are provided with a plurality of radial heat pipes, the radial heat pipes are sequentially arranged at intervals along the flowing direction of the medium to be cooled or along the vertical direction, both ends of the inner pipes extend out of the outer pipe and are positioned outside the heat exchange channel, and the inner pipes arranged at intervals are sequentially communicated, are positioned in two inner pipes at the outermost side, one of the two inner pipes is communicated with the cooling inlet, and the other one of the two inner pipes is communicated with the cooling liquid source.

In some embodiments, the housing includes a high temperature section and a low temperature section sequentially arranged along a circulation direction of the medium to be cooled, the lower end of the heat exchange tube and the radial heat pipe are respectively positioned in the high temperature section and the low temperature section, and a cross-sectional dimension of the high temperature section perpendicular to the circulation direction of the medium to be cooled is larger than that of the low temperature section.

In some embodiments, heat exchange fins are arranged on the outer side of the outer tube and the outer side of the heat exchange tube, and the heat exchange fins are located in the heat exchange channels.

In some embodiments, the flue gas inlet, the flue gas outlet, the cooling inlet and the cooling outlet are each provided with a temperature sensor for detecting temperature and a pressure sensor for detecting pressure.

In some embodiments, the heat exchange device comprises a plurality of baffles positioned between the heat exchange tube and the flue gas inlet, a plurality of baffles being spaced apart, the baffles being positioned within the heat exchange channel.

In some embodiments, the outer wall of the baffle tube is provided with a wear layer; the outer wall of the heat exchange tube is provided with a wear-resistant layer; and the outer wall of the radial heat pipe is provided with a corrosion-resistant layer.

In some embodiments, the heat exchange device comprises two air ejector pipes for removing dust on the surfaces of the heat exchange pipes and the radial heat pipes respectively, and the two air ejector pipes are positioned between the first heat exchange assembly and the second heat exchange assembly.

In a second aspect of the present application, there is provided an aluminium electrolysis cell flue gas waste heat recovery device comprising:

an aluminum electrolysis cell;

in the heat exchange device, the flue gas inlet is communicated with the aluminum electrolysis cell through the flue gas collecting structure.

The heat exchange device comprises a shell, a first heat exchange assembly and a second heat exchange assembly, wherein the shell is provided with a heat exchange channel for a medium to be cooled to circulate, and a flue gas inlet and a flue gas outlet which are communicated with the heat exchange channel; the first heat exchange assembly is close to the flue gas inlet and comprises a cooling box for containing cooling liquid and a plurality of heat exchange pipes for containing phase change media, the cooling box is connected to the outside of the shell and is provided with a cooling inlet and a cooling outlet, the plurality of heat exchange pipes are arranged at intervals vertically, the lower ends of the heat exchange pipes are positioned in the heat exchange channels, and the upper ends of the heat exchange pipes extend out of the heat exchange channels and are positioned in the cooling box; the second heat exchange assembly is located in the heat exchange channel and is close to the flue gas outlet, and the second heat exchange assembly comprises radial heat pipes for cooling a medium to be cooled, and the radial heat pipes extend in the horizontal direction.

The heat exchange tube and the radial heat tube are sequentially arranged along the running direction of the medium to be cooled, namely the flue gas, and the temperature of the heat exchange tube in the axial direction of the heat exchange tube is not uniform, but the heat exchange tube is positioned in a high-temperature section of the flue gas, so that the temperature of the outer wall of the heat exchange tube is still above the dew point temperature of corrosive gas in the flue gas, and dew point corrosion is not easy to occur; the radial heat pipe has good temperature uniformity along the axis direction, is arranged in a low-temperature section, and ensures that the temperature of the outer wall of the radial heat pipe is above the dew point temperature of the corrosive gas of the flue gas, and dew point corrosion is not easy to occur. The combined layout of the axial heat exchange tubes and the radial heat tubes not only realizes flue gas cooling and ensures heat exchange efficiency, but also is not easy to cause dew point corrosion. Meanwhile, the cooling boxes are arranged outside the shell, so that the upper ends of the heat exchange tubes extend into the cooling boxes, and only one cooling box is needed to be matched with a plurality of heat exchange tubes, so that the cooling box is simple in structure and easy to assemble.

Drawings

Fig. 1 shows a top cross-sectional view of a heat exchange device in an embodiment of the present application.

Fig. 2 shows a front cross-sectional view of the heat exchange device of fig. 1.

Fig. 3 shows a schematic structural view of a second heat exchange assembly in the heat exchange device of fig. 1.

Reference numerals illustrate:

100-shell, 110-low temperature section, 120-high temperature section, 130-flue gas inlet, 140-flue gas outlet, 200-first heat exchange component, 210-cooling box, 211-cooling inlet, 212-cooling outlet, 220-heat exchange tube, heat exchange fin of 230-heat exchange tube, 300-second heat exchange component, 310-radial heat tube, 311-inner tube, 312-outer tube, heat exchange fin of 320-radial heat tube, 400-baffle tube; 500-gas jet tube, 600-phase change medium, 700-temperature sensor and 800-pressure sensor.

Detailed Description

In order to make the present application more clearly understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

An embodiment of a first aspect of the present application provides a heat exchange device, which has a simple structure and is easy to assemble.

Referring to fig. 1 and 2, the heat exchange device provided in the embodiment of the present application includes a housing 100, a first heat exchange assembly 200 and a second heat exchange assembly 300, where the housing 100 is provided with a heat exchange channel through which a medium to be cooled flows, and a flue gas inlet 130 and a flue gas outlet 140 which are communicated with the heat exchange channel; the first heat exchange assembly 200 is close to the flue gas inlet 130, and comprises a cooling box 210 for containing cooling liquid and a plurality of heat exchange tubes 220 for containing a phase change medium 600, wherein the cooling box 210 is connected to the outside of the shell 100, the cooling box 210 is provided with a cooling inlet 211 and a cooling outlet 212, the plurality of heat exchange tubes 220 are vertically arranged at intervals, the lower ends of the heat exchange tubes 220 are positioned in the heat exchange channels, and the upper ends of the heat exchange tubes 220 extend out of the heat exchange channels and are positioned in the cooling box 210; the second heat exchange assembly 300 is located in the heat exchange channel, close to the flue gas outlet 140, and the second heat exchange assembly 300 comprises radial heat pipes 310 for cooling the medium to be cooled, the radial heat pipes 310 extending in a horizontal direction.

The casing 100 is a casing of a heat exchange device, and a heat exchange channel therein is used for circulating and exchanging heat of a medium to be cooled, such as high-temperature flue gas generated by aluminum electrolysis, and when the heat exchange device works, the medium to be cooled at a high temperature enters from the flue gas inlet 130 and is discharged from the flue gas outlet 140 after running along the heat exchange channel. The shell 100 is made of carbon steel or stainless steel, the inner wall of the shell 100 is provided with a heat insulating coating, and the heat insulating coating can be made of aluminum silicate, sepiolite, opal, perlite powder, titanium dioxide and the like, and the thickness of the heat insulating coating is 2-8mm.

The heat exchange tube 220 of the first heat exchange assembly 200 accommodates the phase change medium 600, i.e. the phase change working medium, the volume of the phase change medium 600 is smaller than the inner cavity volume of the heat exchange tube 220, and since the heat exchange tube 220 is arranged vertically, the heat exchange tube 220 comprises an evaporation section and a condensation section which are connected, both ends of the heat exchange tube 220 are blocked, so that the phase change medium 600 in the heat exchange tube 220 is concentrated at the lower end of the heat exchange tube 220, i.e. the evaporation section, and the phase change medium 600 is positioned in the heat exchange channel so as to exchange heat with the medium to be cooled, and the phase change medium 600 is in a liquid state at low temperature, forms gas after heat exchange, and rises to the upper end of the heat exchange tube 220, i.e. the condensation section. The condensing section of the heat exchange tube 220 is located in the cooling tank 210, so that the gas in the condensing section can exchange heat with the cooling liquid in the cooling tank 210, so that the gas condenses into liquid which slides down to the lower end of the heat exchange tube 220 along the inner wall of the heat exchange tube 220 to participate in heat exchange again. Because the plurality of heat exchange tubes 220 can realize condensation of phase medium steam in the heat exchange tubes 220 only by arranging one cooling box 210, each heat exchange tube 220 is not required to be provided with a condensation sleeve, and therefore, the heat exchange tube has a simple structure and is easy to assemble. The heat exchange tubes 220 distributed axially are distributed at a position close to the flue gas inlet, here the high temperature section 120, and even if the heat exchange tubes 220 are distributed unevenly along the axial direction of the heat exchange tubes, the temperature of the outer wall of the heat exchange tubes 220 is not locally reduced below the dew point temperature of the corrosive flue gas. The welding position of the heat exchange tube 220 and the shell 100 is the outer side of the shell 100, so that the welding seam is prevented from being directly exposed to the electrolytic aluminum smoke environment to be corroded. In some embodiments, the outer wall of the heat exchange tube 220 is provided with a wear-resistant layer, i.e. the evaporation section of the heat exchange tube 220 is provided with a wear-resistant layer, to improve the wear resistance of the windward end; the wear-resistant layer can be aluminum nitride, silicon carbide, tungsten and the like, and the thickness of the wear-resistant layer is 1-5mm.

The second heat exchange assembly 300 includes the radial heat pipes 310, and the radial heat pipes 310 are close to the flue gas outlet 140, so that the radial heat pipes 310 are located behind the first heat exchange assembly 200, i.e. in the low temperature section 110 of the housing 100, and the radial heat pipes 310 have high isothermal performance, so that the temperature uniformity in the axial direction of the radial heat pipes 310 is high, and therefore, the temperatures of all parts of the radial heat pipes 310 can be ensured to be higher than the dew point temperature of corrosive gases such as sulfur dioxide, hydrogen fluoride and the like in the aluminum electrolysis flue gas, and dew point corrosion cannot occur. If the low temperature section 110 adopts an axial heat pipe, the phase change medium 600 approaches to the lower end of the axial heat pipe, so that a temperature distribution rule of low lower temperature and high upper temperature of the axial heat pipe occurs along the axial direction of the axial heat pipe, and a mixture liquid drop of sulfur dioxide and hydrogen fluoride may occur on the outer wall of a part of the axial heat pipe with the temperature lower than the dew point range of corrosive gas, thereby corroding the axial heat pipe.

The heat exchange tube 220 and the radial heat tube 310 are sequentially arranged along the running direction of the medium to be cooled, namely the flue gas, and the temperature of the heat exchange tube 220 in the axial direction of the heat exchange tube is not uniform, but is positioned in the high-temperature section 120 of the flue gas, so that the temperature of the outer wall of the heat exchange tube 220 is still above the dew point temperature of corrosive gas in the flue gas, and dew point corrosion is not easy to occur; the radial heat pipe 310 has good temperature uniformity along the axis direction, and is arranged in the low-temperature section 110, so that the temperature of the outer wall of the radial heat pipe 310 is above the dew point temperature of the corrosive gas of the flue gas, and dew point corrosion is not easy to occur. The combined layout of the axial heat exchange tube 220 and the radial heat tube 310 not only realizes flue gas cooling and ensures heat exchange efficiency, but also is not easy to generate dew point corrosion. Meanwhile, the cooling boxes 210 are arranged outside the shell 100, so that the upper ends of the heat exchange tubes 220 extend into the cooling boxes 210, only one cooling box 210 is needed to be matched with a plurality of heat exchange tubes 220, and the structure is simple and the assembly is easy.

In some embodiments, referring to fig. 3, the radial heat pipe 310 includes an outer pipe 312 and an inner pipe 311 for circulating cooling liquid, the inner pipe 311 is movably sleeved in the outer pipe 312, a heat exchange cavity for accommodating the phase change medium 600 is formed between the inner pipe 311 and the outer pipe 312, one end of the inner pipe 311 is communicated with the cooling inlet 211, and the other end of the inner pipe 311 is communicated with the cooling liquid source. The phase change medium 600 in the gap between the outer tube 312 and the inner tube 311 performs secondary heat exchange with the flue gas after primary cooling, the phase change medium 600 heats to form steam, the steam rises to exchange heat with the cooling liquid in the inner tube 311, so that the steam cools to form liquid drops, and drops along the inner wall of the outer tube 312 to the bottom wall of the outer tube 312 to continuously participate in the next heat exchange; the cooling liquid runs in the inner pipe 311 to take away the heat of the steam, so that the steam is cooled to form liquid drops. In some embodiments, the inner tube 311 and the outer tube 312 may be coaxially arranged, wherein the axial directions of the inner tube 311 and the outer tube 312 are parallel to each other, and the axial direction of the inner tube 311 is higher than that of the outer tube 312, namely, the eccentric structure radial heat tube 310, so as to prolong the service life of the heat exchange device.

Since corrosive gases such as sulfur dioxide and hydrogen fluoride contained in the aluminum electrolysis flue gas may form droplets at low temperature, the droplets are more corrosive than the gases, and in some embodiments, the outer wall of the radial heat pipe 310 is provided with a corrosion-resistant layer, specifically, the outer wall of the outer pipe 312 is provided with a corrosion-resistant layer, so as to improve the corrosion resistance of the low temperature end. The corrosion-resistant layer can be silicon carbide, tungsten and the like, and the thickness of the corrosion-resistant layer is 2-5 mm. The corrosion-resistant layer may be coated on the outer wall of the outer tube 312 or may be wrapped on the outer wall of the outer tube 312.

In some embodiments, referring to fig. 1 and 2, a plurality of radial heat pipes 310 are provided, the plurality of radial heat pipes 310 are sequentially arranged at intervals along the flowing direction of the medium to be cooled or along the vertical direction, two ends of the inner pipe 311 extend out of the outer pipe 312 and are positioned outside the heat exchange channel, the plurality of inner pipes 311 arranged at intervals are sequentially communicated, one of the two inner pipes 311 positioned at the outermost side is communicated with the cooling inlet 211, and the other is communicated with the cooling liquid source. The inner tubes 311 of the radial heat pipes 310 are sequentially communicated and then are communicated with an external cooling liquid source, so that the structure is simplified. The cooling liquid flows into the plurality of inner pipes 311 arranged at intervals, flows into the cooling box 210, and is discharged from the cooling outlet 212 of the cooling box 210, and the radial heat pipes 310 are positioned in a low-temperature region, so that the cooling liquid has low temperature after flowing through the inner pipes 311, still has cooling value, and is reused as the cooling liquid of the heat exchange pipes 220 positioned in a high-temperature region. Because the temperature of the aluminum electrolysis flue gas is not high, the temperature of the cooling liquid is about 100 ℃ when the cooling liquid exits the inner tube 311 of the radial heat pipe 310, and steam is not formed yet, so that a vaporization cooler is not required, the structure is simpler, and the aluminum electrolysis flue gas heat recovery device is suitable for aluminum electrolysis flue gas heat recovery.

In some embodiments, referring to fig. 1 and 2, the housing 100 includes a high temperature section 120 and a low temperature section 110 sequentially arranged along a flowing direction of a medium to be cooled, the lower ends of the heat exchange tubes 220 and the radial heat pipes 310 are respectively located in the high temperature section 120 and the low temperature section 110, and a cross-sectional dimension of the high temperature section 120 perpendicular to the flowing direction of the medium to be cooled is larger than that of the low temperature section 110. As the medium to be cooled is cooled, the temperature and the volume thereof are reduced, the section size of the high-temperature section 120 perpendicular to the running direction of the electrolytic aluminum flue gas is larger, the section size of the low-temperature section 110 perpendicular to the running direction of the electrolytic aluminum flue gas is smaller, the section size of the low-temperature section is suitable for the low-temperature flue gas, and the space is saved.

In some embodiments, referring to fig. 1 and 3, the outer tube 312 and the outer side of the heat exchange tube 220 are provided with heat exchange fins 230, 320, and the heat exchange fins 230, 320 are located in the heat exchange channels. The arrangement of the heat exchange fins 230 and 320 increases the heat exchange area, thereby improving the heat exchange efficiency of the electrolytic aluminum flue gas and the phase change medium 600. The outer tube 312 and the heat exchange fins 230, 320 of the heat exchange tube 220 are provided in plurality, and the plurality of heat exchange fins 230, 320 are arranged at intervals. The heat exchange fins 230, 320 may extend in a vertical direction, may extend in a horizontal direction, and may be disposed obliquely.

In some embodiments, referring to fig. 1 and 2, a temperature sensor 700 for detecting temperature and a pressure sensor 800 for detecting pressure are provided at each of the flue gas inlet 130, the flue gas outlet 140, the cooling inlet 211, and the cooling outlet 212. The temperature sensors 700 are respectively arranged at the flue gas inlet 130 and the flue gas outlet 140 so as to monitor the flue gas temperatures of the flue gas inlet 130 and the flue gas outlet 140 in real time, and the temperature sensors 700 are respectively arranged at the cooling inlet 211 and the cooling outlet 212 so as to monitor the temperatures of the cooling liquid entering the cooling box 210 and exiting the cooling box 210 in real time. Similarly, the pressure sensors 800 are respectively arranged at the flue gas inlet 130 and the flue gas outlet 140 to monitor the flue gas pressure of the flue gas inlet 130 and the flue gas outlet 140 in real time, and the pressure sensors 800 are respectively arranged at the cooling inlet 211 and the cooling outlet 212 to monitor the pressure of the cooling liquid entering the cooling box 210 and exiting the cooling box 210 in real time.

In some embodiments, referring to fig. 1 and 2, the heat exchange device includes a plurality of baffle pipes 400 between the heat exchange pipe 220 and the flue gas inlet 130, the plurality of baffle pipes 400 are spaced apart, and the baffle pipes 400 are located in the heat exchange channel. The flue gas carries particulate matters, such as dust particles and impurities, and the running speed of the high-temperature flue gas is very fast, and the baffle pipe 400 can intercept dust and the like containing alumina and cryolite powder carried in the flue gas and enable the dust to fall to the bottom wall of the shell 100 under the action of gravity, so that the high-speed particulate matters are prevented from flushing the heat exchange pipe 220 and the radial heat pipe 310, and the service lives of the heat exchange pipe 220 and the radial heat pipe 310 are prolonged. Meanwhile, the baffle pipes 400 can also enable the distribution of the flue gas to be more uniform to a certain extent, and the heat exchange efficiency of the heat exchange pipes 220 and the radial heat pipes 310 at the rear end is improved.

In some embodiments, referring to fig. 1 and 2, the baffle tube 400 may extend in a vertical direction, and the baffle tube 400 and the heat exchange tube 220 are parallel to each other. In certain embodiments, the baffle 400 corresponds to the position of the heat exchange tube 220. The baffle tube 400 can be inserted into the shell 100 from top to bottom for installation, and can be pulled out from the top end of the shell 100 when the baffle tube 400 is severely worn, and then a new baffle tube 400 can be put in, so that the installation is simple and the operation is convenient.

In some embodiments, the outer wall of the baffle 400 is provided with a wear-resistant coating to increase the service life of the baffle 400.

The wear-resistant coating can be made of the same material as the wear-resistant layer on the outer wall of the heat exchange tube 220, and can be any one of chromium carbide, tungsten carbide and nano ceramic, and the thickness of the wear-resistant coating is 1-5mm. In some embodiments, a plurality of baffle pipes 400 are provided, and the plurality of baffle pipes 400 are arranged in a matrix, and the baffle pipes 400 are staggered along the running direction of the aluminum electrolysis flue gas.

In some embodiments, referring to fig. 2, the heat exchange device includes two gas nozzles 500 for removing dust from surfaces of the heat exchange tubes 220 and the radial heat pipes 310, respectively, and both gas nozzles 500 are located between the first heat exchange assembly 200 and the second heat exchange assembly 300. The air ejector 500 can blow off dust on the outer side of the evaporation section of the heat exchange tube 220 and the surface of the outer tube 312, so as to improve the heat exchange effect.

In some embodiments, the heat exchange device comprises a guide rail and a screw, the guide rail and the screw both extend along the vertical direction and are arranged at intervals, the air ejector 500 is connected with a sliding block, the sliding block is in threaded connection with the screw, the sliding block is in sliding connection with the guide rail, and the screw rotates to drive the sliding block to reciprocate along the direction of the sliding rail, so that the air ejector 500 moves along the vertical direction to improve the purging range.

In some embodiments, the air lance 500 is rotatably coupled to the slider to achieve 360 ° blowing. The pipe body of the air jet pipe 500 is provided with a plurality of jet holes, one end of the air jet pipe 500 is plugged, and the other end of the air jet pipe extends out of the heat exchange channel to be communicated with an external wind source.

In some embodiments, the housing 100 is provided with dust removal holes communicating with the heat exchange channels, the dust removal holes being located between the heat assembly and the second heat exchange assembly 300, below the air lance 500, and being capable of discharging dust blown off by the air lance 500.

In this application, all hookup location's welding all is outside the heat exchanger, avoids the welding seam direct exposure in electrolytic aluminum flue gas environment, reduces the corruption to the heat exchanger body because of acid dew point, prolongs the life of heat exchanger.

In a second aspect of the present utility model, there is provided an aluminum electrolysis cell flue gas waste heat recovery device, comprising an aluminum electrolysis cell and the heat exchange device of the first aspect, wherein a flue gas inlet 130 of the heat exchange device is communicated with a flue gas collection structure of the aluminum electrolysis cell.

The high-temperature cooling liquid discharged from the cooling outlet 212 in the heat exchange device contains a large amount of heat and can be used for preheating boiler water, heating urban buildings, engineering refrigeration or low-temperature power generation, and the like, so that the energy consumption of other links is reduced, and the purpose of energy conservation is achieved.

The phase change medium 600 (working medium) in the application can be at least one of R23, R134a, R410a and R407c, and the heat transfer efficiency and the heat exchange quantity of the heat pipe heat exchanger are far higher than those of single-phase temperature difference heat exchange due to the severe boiling action of the phase change of the working medium and the huge enthalpy difference between two phases. The heat medium is adopted to transfer heat, and the heat exchange media are mutually separated, so that the heat exchange medium has unique safety characteristics. The cooling liquid may be cooling water.

The working procedure of the heat exchange device is illustrated below:

the electrolytic aluminum flue gas with the temperature of 100-180 ℃ enters the heat exchange channel from the flue gas inlet, the flue gas flow is 25 kilocubic meters per hour, the baffle pipe 400 collides with the flue gas, part of particles in the flue gas fall under the action of the baffle pipe 400, the flue gas continuously runs and exchanges heat with the phase change medium 600 in the evaporation section of the heat exchange pipe 220, the temperature of the flue gas is reduced to 125 ℃, the temperature of the phase change medium 600 rises, the flue gas after primary cooling continuously runs and exchanges heat with the phase change medium 600 in the outer pipe 312 of the radial heat pipe 310, the temperature of the outer pipe 312 is 95 ℃, the temperature is higher than the dew point temperature of 91 ℃, the temperature of the flue gas is secondarily cooled to 100 ℃, and then the flue gas is discharged from the flue gas outlet 140. The temperature of external cooling water is 70 ℃, the cooling water enters the radial heat pipe to exchange heat with the flue gas, then is heated to 100 ℃ and is discharged into the cooling box, water vapor with the temperature of 120 ℃ is formed after heat exchange with the condensation section in the cooling box and is discharged from the cooling outlet to be heated by the boiler, the building is heated, and the cooled cooling water is circulated and enters the radial heat pipe to continue to participate in heat exchange.

The heat exchange device and the aluminum electrolysis cell flue gas waste heat recovery device provided by the embodiment of the application have the following advantages:

(1) The heat exchange tubes 220 (axial heat tubes) and the radial heat tubes 310 are arranged in a sectional manner along the running direction of the aluminum electrolysis flue gas, so that the risk of dew point corrosion can be reduced when the high-efficiency heat exchange requirement under the working condition of the aluminum electrolysis low-temperature flue gas is met.

(2) The condensing sections of the plurality of heat exchange tubes 220 share one cooling tank 210, so that the structure is simpler and the installation is easy.

(3) The heat exchange tube 220 is provided with a wear-resistant layer, so that the wear resistance of the windward end is improved, and the corrosion resistance of the low-temperature end is improved by arranging a corrosion-resistant layer outside the outer tube 312 of the radial heat tube 310; the inner wall of the shell 100 is provided with a heat insulating coating, so that the heat insulation effect is achieved, and the heat exchange efficiency is improved.

(4) The waste heat of the aluminum electrolysis flue gas recovered by the device can be used for preparing hot water and steam, is used for bath, heating and industrial use in factories, and realizes energy conservation and consumption reduction of electrolytic aluminum enterprises.

In this application, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other by way of additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present application, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise" indicate or positional relationships are based on the positional relationships shown in the drawings, merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

In the present application, unless explicitly specified and limited otherwise, the terms "coupled," "secured," and the like are to be construed broadly, and for example, "secured" may be either permanently attached or removably attached, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In addition, descriptions such as those related to "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated in this application. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. A heat exchange device, comprising:

the shell is provided with a heat exchange channel for the medium to be cooled to circulate, and a flue gas inlet and a flue gas outlet which are communicated with the heat exchange channel;

the first heat exchange assembly is close to the flue gas inlet and comprises a cooling box for containing cooling liquid and a plurality of heat exchange pipes for containing phase change media, the cooling box is connected to the outside of the shell and is provided with a cooling inlet and a cooling outlet, the plurality of heat exchange pipes are arranged at intervals vertically, the lower ends of the heat exchange pipes are positioned in the heat exchange channels, and the upper ends of the heat exchange pipes extend out of the heat exchange channels and are positioned in the cooling box;

the second heat exchange assembly is positioned in the heat exchange channel and is close to the flue gas outlet, and comprises radial heat pipes for cooling the medium to be cooled, and the radial heat pipes extend along the horizontal direction.

2. The heat exchange device according to claim 1, wherein the radial heat pipe comprises an outer pipe and an inner pipe for circulating the cooling liquid, the inner pipe is movably sleeved in the outer pipe, a heat exchange cavity for accommodating a phase change medium is formed between the inner pipe and the outer pipe, one end of the inner pipe is communicated with the cooling inlet, and the other end of the inner pipe is communicated with a cooling liquid source.

3. The heat exchange device according to claim 2, wherein the plurality of radial heat pipes are provided, the plurality of radial heat pipes are sequentially arranged at intervals along the circulation direction of the medium to be cooled or along the vertical direction, both ends of the inner pipes extend out of the outer pipe and are positioned outside the heat exchange channel, the plurality of inner pipes which are arranged at intervals are sequentially communicated, one of the two inner pipes which are positioned at the outermost side is communicated with the cooling inlet, and the other is communicated with the cooling liquid source.

4. A heat exchange device according to any one of claims 2 to 3, wherein the housing comprises a high temperature section and a low temperature section which are arranged in sequence along the flow direction of the medium to be cooled, the lower ends of the heat exchange tubes and the radial heat pipes are respectively positioned in the high temperature section and the low temperature section, and the cross-sectional dimension of the high temperature section perpendicular to the flow direction of the medium to be cooled is larger than that of the low temperature section.

5. The heat exchange device of claim 4 wherein the outer tube and the outer side of the heat exchange tube are both provided with heat exchange fins, the heat exchange fins being located within the heat exchange channels.

6. A heat exchange device according to any one of claims 1-3, wherein the flue gas inlet, the flue gas outlet, the cooling inlet and the cooling outlet are provided with temperature sensors for detecting temperature and pressure sensors for detecting pressure.

7. A heat exchange device according to any one of claims 1 to 3, comprising a plurality of baffles between the heat exchange tube and the flue gas inlet, a plurality of baffles being spaced apart, the baffles being located within the heat exchange channel.

8. The heat exchange device of claim 7, wherein the outer wall of the baffle tube is provided with a wear layer; the outer wall of the heat exchange tube is provided with a wear-resistant layer; the outer wall of the radial heat pipe is provided with a corrosion-resistant layer; the inner wall of the shell is provided with a heat insulation coating.

9. A heat exchange device according to any one of claims 1-3, comprising two gas nozzles for removing dust from the surfaces of the heat exchange tubes and the radial heat tubes, respectively, both of the gas nozzles being located between the first heat exchange assembly and the second heat exchange assembly.

10. An aluminum electrolysis cell flue gas waste heat recovery device is characterized by comprising:

an aluminum electrolysis cell;

the heat exchange device of any one of claims 1-9, the flue gas inlet being in communication with the aluminum electrolysis cell via a flue gas collection structure.