CN111121508A - Low-temperature flue gas waste heat recovery device of acid-resistant enamel heat pipe - Google Patents

Abstract

The invention discloses a low-temperature flue gas waste heat recovery device of an acid-resistant enamel heat pipe, which comprises a plurality of mutually independent heat exchange units, wherein each heat exchange unit comprises a plurality of mutually independent heat pipes, the heat pipes are arranged on a pipe plate, so that the bottom ends of the heat pipes extend into a flue, and the top ends of the heat pipes take away heat in the heat pipes through a two-loop coolant, wherein an acid-resistant enamel layer is enameled on the outer wall surface of each heat pipe, the heat pipes are hermetically arranged on the pipe plate through annular bosses and sealing gaskets, the service life of the heat pipes is prolonged, the two-loop coolant channel is formed by a plurality of sequentially connected U-shaped pipes which are inverted outside the heat pipes, the circulation speed of the two-loop coolant is increased, and the heat exchange capacity and the pressure-bearing capacity are improved.

Description

Low-temperature flue gas waste heat recovery device of acid-resistant enamel heat pipe

Technical Field

The invention relates to the field of energy conservation and environmental protection, in particular to a low-temperature flue gas waste heat recovery device for an acid-resistant enamel heat pipe.

Background

China is a large industrial country, has huge energy consumption and is now the first carbon dioxide emitting country in the world. The reduction of carbon dioxide emission is a current important task in China and is a key for fulfilling the promise of the Tokyo protocol, so that energy conservation and emission reduction are important points of work.

Because the energy in China is mainly coal, 2.64 tons of carbon dioxide and other pollutants can be produced by burning 1 ton of standard coal. The combustion of a large amount of coal in an industrial kiln discharges carbon dioxide which has great influence on the environment, in addition, the combustion of the coal is also a great main cause of the coal combustion for heating, particularly, the natural gas heating with low pollution is carried out in the trial point in the northern area of China, but the coal combustion is still required for heating in the mainstream at present, and the necessary coal burning activities required by production and life all cause the coal burning quantity and the carbon dioxide discharge quantity of China to be high.

The standard of the smoke discharged by coal-fired boilers in China is 160 ℃, and the smoke discharged by coal-fired boilers in China generally exceeds the national standard in actual operation, even reaches more than 200 ℃.

Too high exhaust gas temperature makes a large amount of heat energy discharge to the atmosphere along with the flue gas, makes boiler efficiency reduce, causes very big energy waste. The emission of carbon dioxide is increased while resources are wasted, and the normal and safe operation of environmental protection facilities (such as a dust remover and desulfurization equipment) at the rear part of the boiler is influenced.

Therefore, the effective reduction of the smoke exhaust temperature of the coal-fired boiler and the utilization of the waste heat of the smoke exhaust are problems to be solved urgently in the existing coal-fired boiler (industrial kiln), the coal-fired efficiency can be improved more by recovering more waste heat of the smoke exhaust, the coal consumed by the same heat supply requirement is naturally decelerated, and the core value of energy conservation and emission reduction is realized.

At present, some equipment schemes for recycling exhaust smoke waste heat exist in the market, and although the equipment schemes can also play a basic waste heat recycling role, the existing technical schemes have various defects, such as the service life problem which is most concerned by users, the service life of the existing waste heat recycling equipment is often lower than the expected service life, and larger problems can be caused within half a year of actual work, such as dust accumulation blockage is difficult to clean, metal pipelines are corroded and leaked, and the like; in addition, the existing equipment is huge in size and high in cost, and the installation price and the maintenance cost of the equipment are hard to bear by most enterprises under the condition that the service life of the equipment is not optimistic.

For the above reasons, the present inventors have made intensive studies on the existing waste heat recovery apparatus, and have awaited designing a new waste heat recovery device capable of solving the above problems.

Disclosure of Invention

In order to overcome the problems, the inventor of the invention makes an intensive study and designs a low-temperature flue gas waste heat recovery device of an acid-resistant enamel heat pipe, the recovery device comprises a plurality of heat exchange units which are independent from each other, each heat exchange unit comprises a plurality of heat pipes which are independent from each other, the heat pipes are arranged on a pipe plate, so that the bottom ends of the heat pipes extend into a flue, and the top ends of the heat pipes take away heat in the heat pipes through a two-loop coolant, wherein an acid-resistant enamel layer is burnt on the outer wall surface of the heat pipes, the heat pipes are hermetically arranged on the pipe plate through an annular boss and a sealing gasket, the service life of the heat pipes is prolonged, the two-loop coolant channel is formed through a plurality of U-shaped pipes which are sequentially connected and are inverted outside the heat pipes, the circulation speed of the two-loop coolant is increased, and.

Specifically, the invention aims to provide an acid-resistant enamel heat pipe low-temperature flue gas waste heat recovery device, which comprises a heat exchange unit 1, wherein the heat exchange unit 1 comprises a plurality of heat pipes 11 which are independent from each other, the heat pipes 11 are all arranged on a pipe plate 12, pipe sections of the heat pipes, which are positioned below the pipe plate 12, all extend into a flue 2 for flue gas to pass through, and pipe sections of the heat pipes, which are positioned above a pipe 21, are in contact with a two-loop coolant, so that heat in the heat pipes is taken away through the two-loop coolant.

The invention has the advantages that:

(1) the acid-resistant enamel heat pipe low-temperature flue gas waste heat recovery device provided by the invention solves the problems of acid corrosion and ash deposition abrasion of the metal heat exchange pipe in low-temperature coal-fired flue gas, prolongs the service life of the heat exchanger, has high heat exchange efficiency, greatly improves the production efficiency of the coal-fired boiler, reduces the coal consumption, and has reasonable design of all components and optimized system;

(2) the acid-resistant enamel heat pipe low-temperature flue gas waste heat recovery device provided by the invention has the advantages of exquisite structure, easiness in disassembly and assembly, convenience in installation and transportation, and convenience in overhaul and maintenance.

Drawings

FIG. 1 is a schematic structural diagram of a heat pipe and a pipe plate in an acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device according to a preferred embodiment of the invention;

FIG. 2 is a schematic diagram showing the position relationship of an annular boss and a sealing gasket in the acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device according to a preferred embodiment of the invention;

FIG. 3 is a schematic structural diagram of the bottom surface of a tube plate in the acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device according to a preferred embodiment of the invention;

FIG. 4 is a schematic structural diagram of a U-shaped pipe in the low-temperature flue gas waste heat recovery device of the acid-proof enamel heat pipe according to a preferred embodiment of the invention;

FIG. 5 is a schematic structural diagram of a heat exchange unit in the acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device without a protective cover according to a preferred embodiment of the invention;

FIG. 6 is a schematic structural diagram of a heat exchange unit in the acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device after a protective cover is installed;

FIG. 7 is a schematic structural diagram of a unit frame in the acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device according to a preferred embodiment of the invention;

FIG. 8 is a schematic diagram illustrating the overall structure of a heat exchange unit in the acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device according to a preferred embodiment of the invention;

FIG. 9 is a schematic structural diagram of an annular notch on a supporting member in the acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device according to a preferred embodiment of the invention;

FIG. 10 shows a partial cross-sectional view at a tube plate of a heat exchange unit in the acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device according to a preferred embodiment of the invention;

FIG. 11 is a schematic structural diagram of a partition plate in the acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device according to a preferred embodiment of the invention;

FIG. 12 is a schematic diagram illustrating the overall structure of an acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device according to a preferred embodiment of the invention;

fig. 13 shows a schematic structural diagram of a diffuser section and an internal flue gas guide plate in the acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device according to a preferred embodiment of the invention.

The reference numbers illustrate:

1-Heat exchange Unit

11-Heat pipe

111-ring boss

112-sealing gasket

12-tube plate

121-via hole

122-annular projection

13-U-shaped tube

131-straight pipe section

132-bend section

14-protective cover

141-hanging ring

15-unit frame

151-column

152-support

1521 circular groove

153-grid plate

1531-grid through hole

2-flue

21-diffusion section

211-flue gas guide plate

2111-connecting sleeve

212-rotating shaft

213-slideway

22-narrowing section

23-flue support frame

231-manhole

24-cigarette ash collecting box

Detailed Description

The invention is explained in more detail below with reference to the figures and examples. The features and advantages of the present invention will become more apparent from the description.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The general process of low-temperature flue gas waste heat recovery is to arrange a flue so that flue gas passes along the flue, arrange heat exchange devices in the flue, transfer heat in the flue to the heat exchange devices, and then transfer the heat in the heat exchange devices to other media for utilization through secondary heat exchange in real time; coal-fired flue gas often contains a certain amount of oxysulfide and nitric oxide and a certain amount of water vapor, so that acidic substances are inevitably generated when the flue gas exchanges heat with the heat exchanger, and most of the heat exchanger can be corroded and damaged in a long-time and high-temperature environment; the heat exchanger arranged in the flue is contacted with the flue gas for a long time, and impurities such as particles in the flue gas can be gradually accumulated on the surface of the heat exchanger, and the flue is blocked finally; meanwhile, the temperature of the flue gas is not high particularly and is generally not more than 200 ℃, in a short time when the flue gas passes through a flue, in order to exchange heat from the flue gas as much as possible, the contact area between the flue gas and a heat exchanger needs to be increased, the number of the heat exchanger needs to be increased, and the heat transfer speed of heat exchange of the two loops needs to be increased. Such prior structural arrangements have resulted in a number of problems including large size, short service life, inconvenient maintenance, high cost, low heat recovery efficiency, etc.

The low-temperature flue gas waste heat recovery device for the acid-resistant enamel heat pipe can solve the problems, and comprises heat exchange units 1, wherein each heat exchange unit 1 can independently operate and can transfer heat in flue gas to two loops of coolant, even if part of the heat exchange units fail or break down, other heat exchange units can still normally work, normal production and life cannot be influenced, and time can be scheduled for unified maintenance.

In a preferred embodiment, the heat exchange unit 1 comprises a plurality of heat pipes 11 which are independent from each other, the heat pipes are all installed on a pipe plate 12, as shown in fig. 1, the pipe sections of the heat pipes below the pipe plate 12 all extend into a flue 2 for flue gas to pass through, as shown in the figure, the pipe sections of the heat pipes above the pipe plate are in contact with a secondary heat exchange medium, and heat in the heat pipes is taken away through the secondary heat exchange medium. The tube section of the heat pipe below the tube plate 12 is called an evaporation section, and the tube section of the heat pipe above the tube plate 12, especially above the annular boss, is called a condensation section.

Wherein, heat pipe 11 is long rod-shaped, and its inside cavity is used for sealed heat transfer medium, and this heat transfer medium is low boiling point material, can be alcohol, or the mixture of alcohol and water, or other medium, can realize in this application the heat transfer requirement can, do not limit to this in this application in particular.

The outer side of the heat pipe 11 is a regular round bar with a uniform cross-sectional dimension, and an annular boss 111 protruding outwards is arranged at the upper position of the outer side of the heat pipe, as shown in fig. 2, the annular boss and the heat pipe can be fixedly connected into a whole in a welding mode, and the connection is firm enough to ensure that the heat pipe does not fall off after long-time working.

The tube plate is a metal flat plate with a certain thickness and can bear the heat pipe, the strength of the tube plate is enough, and the tube plate is ensured not to be deformed after the heat pipe is arranged on the tube plate; the tube plate is provided with a plurality of through holes 121 according to a predetermined rule, and the through holes can enable the heat pipe to be clamped on the tube plate.

The inner diameter of the through hole is slightly larger than the outer diameter of the heat pipe 11, so that the pipe plate can be conveniently inserted into the pipe plate from top to bottom, and the size of the through hole is smaller than the outer diameter of the annular boss 111, so that when the heat pipe is installed from top to bottom, the annular boss 111 can be clamped above the pipe plate, and the heat pipe is clamped and installed on the pipe plate.

Preferably, an annular sealing gasket 112 is further disposed between the annular boss 111 and the tube plate, as shown in fig. 2, before the heat pipe is installed, the sealing gasket 112 is first placed on the tube plate or sleeved on the heat pipe, so that after the heat pipe is inserted into the through hole of the tube plate, the sealing gasket 112 can be located between the tube plate and the annular boss 111, and because the heat pipe has a certain weight, under the action of the gravity of the heat pipe, the annular boss downwardly presses the sealing gasket 112, so that the sealing gasket 112 can deform, thereby sealing a gap possibly existing between the annular boss and the tube plate, and ensuring that smoke below the tube plate cannot overflow from the gap.

The structure is convenient for the installation, the disassembly and the replacement of the heat pipe, and can also reduce the construction cost and simplify the structure of the heat pipe under the condition of ensuring the safety.

Further preferably, an acid-resistant enamel layer is enamel-fired on the outer wall surface of the heat pipe, and the acid-resistant enamel layer is completely wrapped outside the heat pipe, is free from leakage and comprises an area where the annular boss is located. The acid-resistant enamel layer is an acid-resistant glaze material formed by adding raw materials such as cobalt oxide and iron oxide into main raw material silicon dioxide and firing, the acid-resistant glaze material and a steel heat exchange element are fired into a composite material formed by steel and inorganic materials, namely the material of the heat pipe in the application, the firing method and the material are all technologies in the field, and the material is not particularly limited in the application and can be completely coated outside the heat pipe including the annular boss.

The interior of the heat pipe is vacuum and is lower than the standard atmospheric pressure, so the wall surface of the heat pipe needs to have high enough strength, and from the viewpoint of material heat exchange coefficient and cost, for large-scale application, only common metal materials can be selected for preparation, such as low-carbon steel seamless steel pipes and the like, and meanwhile, in order to deal with corrosion of sulfide, nitride and other substances in flue gas, a corrosion-resistant coating needs to be arranged on the surface of the heat pipe. In order to ensure the firmness of the coating, the heat pipe must be subjected to high-temperature firing under special working conditions, that is, the surface corrosion-resistant coating must be processed before the heat pipe is installed on the pipe plate, however, the existing connection relationship between the heat pipe and the pipe plate is basically welding, if the surface of the heat pipe is covered by the corrosion-resistant coating, the welding may be difficult to perform, and even if the welding is forced, the coating at the welding position is damaged, so that in many low-temperature flue gas waste heat recovery devices which are operated at present, the area on the heat pipe adjacent to the pipe plate does not have the corrosion-resistant coating, or the corrosion-resistant coating is damaged in the welding process, so that the area is often the area on the heat pipe which is damaged by corrosion firstly, and is also a critical constraint factor for the short service life of the heat pipe in the low-temperature. The heating section in condensation segment and the flue passes through the tube sheet separately in this application to adopt mechanical seal and mechanical fastening mode to connect, thereby guaranteed that condensation segment and flue gas separate, also avoided the adverse factor that the welding brought, so can know that the shorter problem of heat pipe life can perfectly be solved to the scheme that this application provided.

Preferably, since the acid-resistant enamel layer is provided for the purpose of preventing low-temperature coal-fired flue gas from corroding the heat pipe, the acid-resistant enamel layer may not be provided on the outer surface of the heat pipe section in the region where flue gas cannot reach.

Preferably, the plurality of through holes 121 formed in the tube plate are arranged in a staggered manner with respect to each other, as shown in fig. 3, so that the heat pipes are also arranged in a staggered manner with respect to each other, so that the flue gas passing through the heat exchange unit is sufficiently contacted with the heat pipes.

Among the present low temperature flue gas waste heat recovery equipment, set up big water tank on the heat pipe condensation segment outside, some still set up the baffle in the water tank, structures such as guide plate, so that increase the flow distance of cooling water, increase the contact time and the area of contact of cooling water and heat pipe, but still have a large amount of cooling water and do not have the chance and the heat pipe contact, can not direct convection heat transfer, in addition, current water tank all is square structure, its inside bearing capacity is less strong, so the velocity of flow of cooling water wherein can not be too fast, restrict its improvement heat transfer ability naturally.

In a preferred embodiment, an inverted U-shaped tube 13 is disposed above the tube plate, an open end of the U-shaped tube 13 faces downward and faces the direction of the tube plate, the U-shaped tube 13 includes a straight tube section 131 and a bent tube section 132, as shown in fig. 4, 5 and 10, a length dimension of the straight tube section 131 is slightly greater than or substantially equal to a length dimension of a condensation section on the heat pipe, so that the U-shaped tube 13 can be buckled outside the condensation sections of the two heat pipes, that is, the condensation section of each heat pipe is externally sleeved with one straight tube section 131, and at most one condensation section is disposed inside each straight tube section 131.

The inner diameter of the U-shaped pipe 13 is 5-10 mm larger than the outer diameter of the condensation section of the heat pipe, so that after the U-shaped pipe 13 is buckled outside the condensation sections of the two heat pipes, a channel between the inner wall of the U-shaped pipe 13 and the outer wall of the condensation section is narrow and about 2-5 mm, when two loops of cooling agents flow through the channel, the flow speed of the two loops of cooling agents is high, and under the condition of the same flow, the contact area between the two loops of cooling agents and the heat pipe is larger, so that the heat exchange capacity of the two loops of cooling agents is higher.

A plurality of the inverted U-shaped tubes 13 are arranged above the tube plate, and the inverted U-shaped tubes 13 are connected through a pipeline to form a two-loop coolant channel passing through each condensation section in sequence. The two-loop coolant in the two-loop coolant channel can flow at high speed, the contact time between the coolant and the heat pipe is long, the whole contact area is large, and the heat transfer efficiency is high.

Through setting up the circulation passageway that U type pipe regarded as two return circuits coolants in this application, utilize the stronger characteristic of arc structure bearing capacity, can make two return circuits coolant's velocity of flow faster, the flowing passageway just can be done littleer, so formed around two return circuits coolant passageways outside in this application around the condensation segment.

Preferably, the bottom end surface of the straight tube section 131 abuts against the annular boss 111 and is fixedly connected with the annular boss 111, so that the U-shaped tube is not in direct contact with the tube plate, and the problem that the axis of a through hole of the tube plate inclines due to overlarge stress on the tube plate and the far ends of the heat pipes are in contact/interference with each other is avoided.

In addition, the tube plate is used as a force-bearing device with higher precision requirement, the processing requirement and the processing difficulty are high, if the U-shaped tube/straight tube section 131 is directly and fixedly installed on the tube plate, the overall maintenance of the device becomes extremely difficult, and the time and the cost for replacing the tube plate are higher.

Preferably, the straight tube section 131 and the annular boss 111 are consolidated into an integral structure by welding. More preferably, the outer diameter of the annular boss 111 is substantially the same as the outer diameter of the straight tube section 131, so as to facilitate welding.

Further preferably, the height dimension of the straight pipe section 131 is slightly larger than that of the heat pipe condensation section, so that the straight pipe section 131 can be cut off and repaired for multiple times, and the maintenance cost is reduced.

In a preferred embodiment, the heat exchange unit 1 further includes a protective cover 14 disposed above the tube sheet, as shown in fig. 6, a bottom of the protective cover 14 abuts against the tube sheet, an inside of the protective cover is hollow, the condensation section of the heat pipe and the inverted U-shaped tubes 13 are both located inside the protective cover 14, and in the inside of the protective cover 14, heat preservation and insulation filler is filled between the plurality of inverted U-shaped tubes 13, and the heat preservation and insulation filler may be selected from heat preservation and insulation fillers commonly used in the art, which can achieve the functions described in this application, and this application is not limited thereto.

Through setting up this protection casing 14 and the thermal-insulated filler that insulates against heat wherein, can greatly slow down the speed of heat loss to in the air in the condensation segment to give two return circuits coolant with more heat transfer, improve the utilization ratio of heat energy, in addition, because the inside packing of protection casing 14 has the thermal-insulated filler that insulates against heat that keeps warm, the surface temperature of protection casing is lower relatively, is difficult to scald the operator to the device, improve equipment's security.

In addition, inside the protection casing 14, be provided with flue gas sensor and smoking material layer in the position that closes on the tube sheet, when seal ring 112 department is not sealed tight, the flue gas in the flue can be followed in this department escapes the protection casing to in time inform the operator through flue gas sensor, under the double-deck effect of smoking material layer and protection casing 14, a small amount of flue gas is revealed in the short time, can not lead to the flue gas to spill over from the protection casing, does not have the macroscopic flue gas promptly, thereby can guarantee in time accurately to discover the trouble problem that probably appears, also can improve user's application experience.

Correspondingly, inside the protection casing 14, be provided with humidity transducer and water-absorbing material layer in the position department that is close to U type pipe 13, can in time discover when U type pipe 13 has the leakage to two return circuits coolant that come the absorption seepage through water-absorbing material layer, reduce the harmful effects that the leakage brought, the life of extension equipment.

Furthermore, the protective cover is fixedly connected with the tube plate into a whole, and can be fixedly connected through bolts in a screwing mode or a welding mode. A hanging ring 141 is provided on the top of the shield to facilitate the vertical movement of the heat exchange unit 1 by the hanging ring, as shown in fig. 6.

Two return circuits cooling water route settings are as for the flue outside in this application, realize the separation of smoke and water, have ensured the security of boiler flue gas emission operation, have especially guaranteed the security of boiler rear portion equipment.

In a preferred embodiment, the heat exchange unit 1 further comprises a unit frame 15, the unit frame comprises a vertical column 151 and a supporting beam installed on the top of the vertical column,

the number of the upright columns 151 is at least 4, the upright columns are vertically arranged, the supporting beams are also horizontally arranged, the supporting beams are sequentially connected end to form an annular supporting piece 152, the supporting piece 152 is used for supporting a tube plate, namely the tube plate drives heat pipes arranged on the tube plate to be placed on the supporting piece together, and the heat pipes are all embedded below the supporting piece and located among the upright columns 151, as shown in fig. 7 and 8.

Preferably, as shown in fig. 3, 9 and 10, the upper surface of the support beam is provided with a notch, and the notches on the plurality of support beams are communicated with each other to form an annular notch, that is, the upper surface of the annular support member 152 is provided with an annular notch 1521, correspondingly, the bottom of the tube plate is provided with an annular protrusion 122 protruding downwards, when the tube plate is placed on the support member, the annular protrusion 122 is inserted into the annular notch 1521, and a sealing gasket is pre-installed in the annular notch, so as to complete the sealing between the tube plate and the support beam 152.

Further preferably, the height of the annular protrusion 122 is slightly smaller than the depth of the notch 1521, so that the bottom surface of the annular protrusion 122 cannot abut against the bottom surface of the notch 1521, the inner side wall of the notch 1521 abuts against the bottom surface of the tube plate, and due to the arrangement, the bottom of the notch 1521 can be provided with a sealing gasket, and the sealing gasket can be pressed by the tube plate, so that the sealing gasket is in full contact with the tube plate, the sealing gasket can deform greatly enough, and the sealing effect of temperature is ensured.

Preferably, the side edges of the support member 152 extend outward to form overlapping surfaces for overlapping the support member 152 and the tube plate heat pipe thereon to be mounted on the smoke box.

In a preferred embodiment, a grid 153 is further disposed on the unit frame 15, as shown in fig. 7, 8 and 11, the grid 153 is located directly below the supporting member 152, and is located between the plurality of columns 151 at a position close to the lowest portion of the heat pipe, a plurality of grid through holes 1531 are formed on the grid, each bottom of the heat pipe is inserted into one grid through hole 1531, the number of the grid through holes 1531 is greater than the number of the heat pipes, and preferably, the number of the grid through holes 1531 is more than two times or more than 2 of the number of the heat pipes.

Preferably, the through holes 1531 of the grid 153 are rectangular holes, that is, the cross-sectional shape of the holes is rectangular, and the side length of the rectangle is substantially equal to or slightly larger than the outer diameter of the heat pipe, so as to facilitate the insertion of the heat pipe into the through holes of the grid and prevent the bottom end of the heat pipe from shaking or shifting. Because this grid through-hole is the rectangular hole, must leave certain space between its and the cross-section for the circular shape heat pipe, in addition, because the quantity that grid through-hole 1531 set up is more, does not have the heat pipe to pass in a lot of grid through-holes 1531, so can make things convenient for the solid particle thing of carrying in the flue gas to pass the grid from last to down, and then collect the clearance.

In a preferred embodiment, the heat exchange unit 1 is provided with one or more, and when the heat exchange unit is provided with a plurality of heat exchange units, the lower ends of the plurality of heat exchange units, namely the parts below the tube plates, are all positioned in the flue 2 and are independent of each other; the circulation channels of the two-loop coolant of the heat exchange units are mutually connected in parallel, namely when one heat exchange unit fails and can not work normally, other heat exchange units are not affected and can work normally.

Preferably, the grid plate is arranged 10-20 mm away from the bottommost end of the heat pipe.

In a preferred embodiment, the device further comprises a flue 2, one end of the flue is connected with a smoke exhaust pipeline of equipment such as a boiler, and the other end of the flue is connected with environmental protection equipment such as a desulfurizing tower and a dust remover, the flue 2 comprises a diffusion section 21 located in a smoke inlet direction and a narrowing section 22 located in a smoke outlet direction, a flue support frame 23 is arranged between the diffusion section 21 and the narrowing section 22, as shown in fig. 12, the diffusion section 21 and the narrowing section 22 are fixedly mounted on the flue support frame 23, the heat exchange unit 1 is connected to the flue support frame 23 from top to bottom in series, a support member 152 of the heat exchange unit 1 is fixed to the top of the flue support frame 23 in an overlapping manner, and a sealing ring is arranged between the top of the flue support frame 23 and the support member 152 to ensure sealing connection of the flue support frame 23 and the support member.

When being provided with a plurality of heat exchange unit 1, seal each other between a plurality of heat exchange unit 1, prevent that the flue gas in the flue from overflowing from the contact position, particularly, be provided with sealed the pad at the lateral part of two adjacent supporting piece 152 to press from both sides tight each heat exchange unit from the side and can realize the sealed between each heat exchange unit.

The heat exchange units 1 can be independently disassembled and assembled and also can be independently transported and maintained, so that the installation and transportation cost of the equipment can be reduced, the time is saved, and the maintenance and replacement of vulnerable devices are facilitated.

In a preferred embodiment, when the heat exchange units 1 are installed on the smoke box, the heat exchange units are arranged side by side and all face the smoke inlet direction, that is, the smoke flowing through the expanding section basically contacts with each heat exchange unit at the same time, so that the heat obtained by each heat exchange unit is basically equal, but in actual operation, the smoke flowing through the heat exchange unit located in the middle and facing the center of the expanding section is more, and the heat obtained by the heat exchange unit is also more. Such situation lasts for a long time, so that the working efficiency of each heat exchange unit is different, the service life of the heat exchange unit is shortened, and the resource waste is also caused.

Preferably, the diffusion section 21 is provided with a flue gas guide plate 211, as shown in fig. 13, the flue gas guide plate 211 has at least two pieces, which are vertically arranged, and the flue gas guide plate 211 can swing back and forth under the action of flowing flue gas to automatically adjust the flow rate of flue gas in each area in the flue, so that the flow rate of flue gas flowing through each heat exchange unit 1 is substantially the same.

A rotating shaft 212 vertically installed is arranged in the diffusion section 21, and a connecting sleeve 2111 sleeved on the rotating shaft 212 is arranged at the side part of the flue gas guide plate 211, so that the guide plate can swing around the rotating shaft 212 in a reciprocating manner; preferably, the area size of guide plate makes the guide plate can not collide each other at the swing in-process, also can not collide the inner wall of smoke box, prevents that the guide plate from damaging, avoids noise pollution.

Preferably, the diffuser section 21 is further provided with two slideways 213, the slideways are respectively located at the top and the bottom of the diffuser section 21, and the top and the bottom of the rotating shaft 212 are embedded into the slideways 213, so that the rotating shaft 212 can move along the slideways 213, the distance between two adjacent deflectors 211 can be increased or decreased, and the flue gas flow distribution in the flue can be adjusted.

Preferably, as shown in fig. 12, the front end surface of the flue supporting frame 23 is fixedly connected with the diffusion section 21, the rear end surface of the flue supporting frame 23 is fixedly connected with the narrowing section 22, sealing plates are arranged on two side wall surfaces of the flue supporting frame 23, and a manhole 231 is optionally arranged on the sealing plates for observing and maintaining the heat exchange unit inside; the top of the flue supporting frame 23 is provided with a heat exchange unit, the flue supporting frame is lap-sealed with the supporting member 152, the bottom of the flue supporting frame 23 is provided with an ash collecting box 24 for collecting particulate matters accumulated and falling at the heat pipe, and the ash collecting box 24 is provided with an ash discharging door for regularly cleaning the ash accumulated therein.

In a preferred embodiment, two loops of coolant piping on the plurality of heat exchange units are arranged in parallel with each other, the two loops of coolant preferably being water;

the outlet on the two-loop coolant pipeline of each heat exchange unit is provided with a flowmeter and a thermometer, the inlet is provided with a flow regulating valve for monitoring the heat exchanged from the smoke box of each heat exchange unit in real time, and the distribution condition of the smoke in the flue is regulated according to the heat value, so that each heat exchange unit works according to the same heat exchange power as much as possible, and the service life of part of the heat exchange units is prevented from being reduced due to overlarge working load.

Particularly, through the position of flue gas guide plate 211 in the adjustment diffuser section 21, adjust the flue gas flow through heat transfer unit, when the temperature of two return circuit coolant pipe outlets was too high on heat transfer unit, the pivot 212 of control guide plate 211 slided to this heat transfer unit the place ahead along slide 213 to the flue gas of reposition of redundant personnel process in this heat transfer unit the place ahead, make the flue gas flow that finally flows into this heat transfer unit reduce.

The actuating mechanism for the relative movement between the rotating shaft 212 and the sliding channel 213 can be selectively set according to the size, cost, moving frequency and other conditions of the flue, for example, the rotating shaft 212 is pushed/stretched by a telescopic rod, or a plurality of rotating shafts 212 are fixed on one or more cross beams, and the rotating shaft is moved by pulling the cross beams.

Preferably, when the temperature of the coolant at the outlet of the two-circuit coolant pipeline of the heat exchange unit 1 is too high, the flow rate of the coolant at the inlet of the two-circuit coolant pipeline can be increased, the heat exchange capacity is improved by increasing the heat exchange medium, and more heat is taken away in time.

The present invention has been described above in connection with preferred embodiments, but these embodiments are merely exemplary and merely illustrative. On the basis of the above, the invention can be subjected to various substitutions and modifications, and the substitutions and the modifications are all within the protection scope of the invention.

Claims (10)

1. The low-temperature flue gas waste heat recovery device of the acid-resistant enamel heat pipe is characterized by comprising a heat exchange unit (1),

the heat exchange unit (1) comprises a plurality of mutually independent heat pipes (11), the heat pipes (11) are all arranged on a pipe plate (21),

the pipe sections of the heat pipes, which are positioned below the pipe plate (21), extend into the flue (2) for smoke to pass through, the pipe sections of the heat pipes, which are positioned above the pipe plate (21), are in contact with the two-loop coolant, and heat in the heat pipes is taken away through the two-loop coolant.

2. The acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device of claim 1,

an annular boss (111) protruding outwards is arranged at the middle upper part of the outer side of the heat pipe (11),

a plurality of through holes (211) are formed in the tube plate (21), and the heat pipe (11) is clamped and installed on the tube plate (21) through the through holes (211).

3. The acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device of claim 1,

an annular sealing gasket (112) is arranged between the annular boss (111) and the tube plate (21).

4. The acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device of claim 1,

an acid-resistant enamel layer is enamel-fired on the outer wall surface of the heat pipe (11).

5. The acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device of claim 1,

a plurality of inverted U-shaped tubes (13) are arranged above the tube plate, each U-shaped tube (13) comprises a straight tube section (131) and a bent tube section (132), the straight tube sections (131) are sleeved outside the condensation sections of the heat tubes, and the inverted U-shaped tubes (13) are connected through a pipeline to form two-loop coolant channels passing through each condensation section in sequence.

6. The acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device of claim 1,

the heat exchange unit (1) also comprises a protective cover (14) arranged above the tube plate,

the condensation section and the inverted U-shaped tubes (13) of the heat pipe are positioned inside the protective cover (14), heat-insulating filler is filled between the inverted U-shaped tubes (13) inside the protective cover (14),

and a hanging ring (141) is arranged at the top of the protective cover.

7. The acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device of claim 1,

the heat exchange unit (1) further comprises a unit frame (15), the unit frame comprises a vertical column (151) and a supporting piece (152) installed at the top of the vertical column, and the tube plate (21) is supported through the supporting piece (152).

8. The acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device of claim 1,

an annular notch (1521) is arranged on the upper surface of the supporting piece (152),

an annular bulge (212) protruding downwards is arranged at the bottom of the tube plate,

when the tube plate is placed on the supporting piece, the annular protrusion (212) is embedded into the annular groove (1521), and the sealing gasket is pre-installed in the annular groove.

9. The acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device of claim 1,

the flue (2) comprises a diffusion section (21) positioned in the smoke inlet direction and a narrowing section (22) positioned in the smoke outlet direction, and a flue support frame (23) is arranged between the diffusion section (21) and the narrowing section (22); the diffusion section (21) and the narrowing section (22) are fixedly arranged on a flue supporting frame (23).

10. The acid-proof enamel heat pipe low-temperature flue gas waste heat recovery device of claim 1,

the heat exchange units (1) are arranged in parallel.

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