CN110617713B

CN110617713B - High-temperature flue gas heat exchange device of cement kiln

Info

Publication number: CN110617713B
Application number: CN201910935235.2A
Authority: CN
Inventors: 何华斌; 尚海涛; 李明凯; 李永亮; 张建
Original assignee: Jidong Cement Chongqing Hechuan Co ltd
Current assignee: Jidong Cement Chongqing Hechuan Co ltd
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2021-01-19
Anticipated expiration: 2039-09-29
Also published as: CN110617713A

Abstract

The invention belongs to the technical field of energy recovery, and particularly relates to a high-temperature flue gas heat exchange device of a cement kiln, which comprises a shell and a heat exchange mechanism positioned in the shell, wherein the shell is provided with a flue gas inlet, a flue gas outlet, a fluid inlet and a fluid outlet; the heat exchange mechanism comprises a gas flow channel and a plurality of heat exchange tube units which are communicated with each other, the plurality of heat exchange tube units form a heat exchange channel, and the heat exchange channel is positioned in the gas flow channel; one end of the heat exchange channel is communicated with the fluid inlet, and the other end of the heat exchange channel is communicated with the fluid outlet; one end of the gas flow channel is communicated with the smoke inlet, and the other end of the gas flow channel is positioned in the shell; the flow direction of the high-temperature flue gas is opposite to that of the fluid to be heated; one end of each heat exchange tube unit is connected with a drain pipe extending out of the shell, and a valve is arranged on each drain pipe. The heat exchange efficiency of the fluid can be adjusted according to actual needs by using the scheme, so that the temperature of the fluid is more in line with the use requirement.

Description

High-temperature flue gas heat exchange device of cement kiln

Technical Field

The invention belongs to the technical field of energy recovery, and particularly relates to a high-temperature flue gas heat exchange device of a cement kiln.

Background

In the production process of cement clinker, a large amount of high-temperature flue gas is generated at the head and the tail of a cement kiln, the temperature of the high-temperature flue gas is about 350 ℃, and the high-temperature flue gas can account for about 35% of the total heat consumption of clinker burning. In order to effectively recycle the resources, heat exchange devices are usually installed at the head and tail of the cement kiln. The heat exchanger is an energy-saving equipment for transferring heat between two or more kinds of fluid at different temperatures, and is used to transfer heat from the fluid with higher temperature to the fluid with lower temperature to make the temperature of the fluid reach the index specified by the flow so as to meet the requirement of technological conditions, and is also one of the main equipments for improving the utilization rate of energy.

The heat exchange devices arranged at the head and the tail of the cement kiln transfer the heat of the high-temperature flue gas to the cold fluid, so that the cold fluid can be heated to a fixed temperature. Although the existing high-temperature flue gas heat exchange device can better recover heat energy, once formed, the heat exchange efficiency is constant and cannot be freely adjusted according to actual conditions.

Disclosure of Invention

The invention aims to provide a high-temperature flue gas heat exchange device for a cement kiln, and aims to solve the problem that the heat exchange efficiency of the existing high-temperature flue gas heat exchange device cannot be adjusted according to actual conditions.

In order to achieve the purpose, the scheme of the invention is as follows: the high-temperature flue gas heat exchange device for the cement kiln comprises a shell and a heat exchange mechanism positioned in the shell, wherein the shell is provided with a flue gas inlet, a flue gas outlet, a fluid inlet and a fluid outlet; the heat exchange mechanism comprises a gas flow channel and a plurality of heat exchange tube units which are communicated with each other, the plurality of heat exchange tube units form a heat exchange channel, and the heat exchange channel is positioned in the gas flow channel; one end of the heat exchange channel is communicated with the fluid inlet, and the other end of the heat exchange channel is communicated with the fluid outlet; one end of the gas flow channel is communicated with the smoke inlet, and the other end of the gas flow channel is positioned in the shell; the flow direction of the high-temperature flue gas is opposite to that of the fluid to be heated; one end of each heat exchange tube unit is connected with a drain pipe extending out of the shell, and a valve is arranged on each drain pipe.

The working principle and the beneficial effects of the scheme are as follows: the fluid with lower temperature (water is a common fluid, and water is taken as the fluid of the scheme for explanation) enters the heat exchange channel through the fluid inlet and flows in the heat exchange channel. High-temperature flue gas gets into the gas flow path through the flue gas import in, the high-temperature flue gas at this moment encircles the outer wall at heat transfer passageway, can give the water in the heat transfer passageway with heat transfer through the outer wall of heat transfer passageway, heats water, makes its temperature rise. The water temperature in different heat exchange tube units is different, the temperature of the heat exchange tube units is higher as the heat exchange tube units are closer to the fluid outlet, when water flows along the heat exchange channel and is finally discharged from the fluid outlet, the temperature of the water flowing out is highest as the flowing channel of the water is long enough and can be fully in heat transfer with high-temperature flue gas. When the temperature of the water to be discharged is approximately in a certain temperature range, the valve on one water discharge pipe can be reasonably determined to be opened according to the water temperatures in different heat exchange pipe units (the valves on the other water discharge pipes are kept closed), and at the moment, one part of the water flowing in from the fluid inlet is discharged through the water discharge pipe, and the other part of the water continues to flow along the heat exchange channel. The temperature of the water discharged from the water discharge pipe meets the actual use requirement, the water continuously flowing forwards makes full use of the high-temperature flue gas to carry out heat transfer, the temperature is continuously increased, and the resource waste caused by the fact that the heat of the high-temperature flue gas cannot be fully utilized is avoided.

In the scheme, the flow path of part of water can be controlled according to the water temperature of actual needs, and the heat exchange efficiency of the part of water is controlled, so that the discharge temperature of the water meets the use requirements. However, no matter what water temperature is needed, the whole heat exchange channel is always kept in a water flowing state, and the problem that the heat of high-temperature flue gas cannot be fully utilized due to the fact that part of heat exchange tube units do not contain water is avoided, and energy is wasted.

The high-temperature flue gas entering the gas flow channel from the flue gas inlet flows along the gas flow channel and then is discharged into the shell at the tail end of the gas flow channel, and the part of the high-temperature flue gas flows in the shell and is finally discharged through the flue gas outlet. The temperature of the high-temperature flue gas exhausted from the gas flow channel is higher than that of the outside air, and the high-temperature flue gas is firstly introduced into the shell instead of being directly exhausted into the outside, so that the inside of the shell can keep a relatively high temperature, and the heat-preserving effect is achieved.

Optionally, the inner wall of the shell is provided with preheating pipes distributed around the inner wall of the shell; the heat exchange channel is communicated with the fluid inlet through a preheating pipe.

The low-temperature water firstly enters the preheating pipe through the fluid inlet and flows along the preheating pipe, and the low-temperature water can be preheated by high-temperature flue gas in the shell in the flowing process of the low-temperature water along the preheating pipe, so that the temperature of the low-temperature water is gradually increased. When water flows into the heat exchange channel, the temperature is raised, and then the temperature of the part of water is raised to a fixed temperature, so that the energy consumption is reduced, and the energy of high-temperature flue gas is fully utilized.

Optionally, the valve comprises a fixed seat and a spherical valve core rotatably connected in the fixed seat, and a through hole capable of communicating the drain pipe with the heat exchange pipe unit is formed in the spherical valve core; a flow adjusting rod which is rotationally connected with the fixed seat is fixed on the spherical valve core.

With a uniform diameter of the flow passage, the flow of water discharged through the drain pipe is much greater than the flow of water discharged from the fluid outlet. In order to better adjust the water flow discharged from different positions, the flow adjusting rod can be rotated according to actual conditions, and the opening size of the through opening is controlled.

Optionally, the heat exchange tube unit is provided with 3. Through the experiment, set up 3 heat exchange tube units and just can be better satisfy the demand to the heat exchange efficiency.

Optionally, the device further comprises a dust removal mechanism, the dust removal mechanism comprises a shell and a plurality of pieces of filter cloth which are positioned in the shell and used for filtering high-temperature flue gas, and the shell is provided with a gas inlet and a gas outlet communicated with the flue gas inlet. The high-temperature flue gas has a lot of dust, directly lets in heat transfer mechanism can make heat transfer mechanism pile up the dust not handling, influences its heat transfer effect. The dust removal unit is arranged, and dust in the high-temperature flue gas is filtered through the filter cloth, so that the condition can be effectively avoided.

Optionally, a partition plate for dividing the interior of the shell into an upper cavity and a lower cavity is arranged in the shell, a rotating plate is hinged to the partition plate, and the weight of one side of a hinge point of the rotating plate is greater than that of the other side of the hinge point of the rotating plate; one end of the filter cloth is fixed on the upper wall of the shell, and the other end of the filter cloth is fixed on one side of the rotating plate with larger weight; dust falling ports are formed in the rotating plates between the adjacent filter cloth; the shell is internally provided with a limiting part which limits the downward movement of the side with larger weight of the rotating plate.

In general, the rotating plate is attached to the partition plate, and high-temperature flue gas introduced from the gas inlet is filtered by the filter cloth and then discharged from the gas outlet. After the filter cloth is used for a period of time, a large amount of dust can be adhered to the surface of the filter cloth, and the filtering effect of the filter cloth is greatly influenced. In the actual use process, when the filter cloth is used for a period of time, the dust removal mechanism is cleaned, and the specific cleaning steps are as follows: the rotating plate is reciprocated to drive the filter cloth to be loosened and tensioned continuously, dust adhered to the filter cloth is shaken out, most of the dust falls down along the dust falling port, and the dust shaken out by the filter cloth close to one side of the hinge point falls down along the rotating plate and falls into the lower cavity.

Optionally, a dust falling plate is fixed in the lower cavity, and a strip-shaped through hole allowing dust to fall is formed in the lower end of the dust falling plate. The dust falling from the filter cloth falls on the dust falling plate firstly, then falls down along the dust falling plate under the action of gravity, and finally falls on the bottom of the shell through the strip-shaped through hole. The dust falling plate is arranged, so that high-temperature smoke can be prevented from lifting dust at the bottom of the shell to a great extent.

Optionally, a lifting unit capable of driving the rotating plate to rotate is fixed in the housing; the lifting unit is a telescopic column which is positioned below one side of the rotating plate with larger weight, the telescopic column comprises a fixed rod penetrating through the dust falling plate and a sliding rod connected in the fixed rod in a sliding manner, and an elastic piece is connected between the fixed rod and the sliding rod; the fixed rod is provided with a pressure relief valve which can communicate the outside with the inside of the fixed rod; the flue gas outlet is connected with a three-way pipe, and the three-way pipe is provided with a three-way valve; one end of the three-way pipe is communicated with the fixed rod through a pipeline.

When the dust adhered to the filter cloth needs to be removed, the three-way valve is rotated, so that high-temperature smoke discharged from the smoke outlet can enter the fixed rod through the pipeline, and the sliding rod slides upwards under the action of the high-temperature smoke. The sliding rod starts to contact with the side with the larger weight of the rotating plate, upward acting force is applied to the rotating plate on the side, the rotating plate rotates along the hinge point, the side with the larger weight of the rotating plate is lifted upwards, and the filter cloth is in a loose state at the moment. And the three-way valve is adjusted to close a passage between the smoke outlet and the fixed rod, at the moment, under the action of the elastic piece, the sliding rod has a downward sliding trend, the sliding rod compresses gas in the fixed rod, the pressure in the fixed rod is increased, and when the preset value of the pressure release valve is reached, the pressure release valve is opened to discharge redundant gas in the fixed rod. After the telescopic column is reset, the rotating plate is also restored to the original position under the action of the gravity of the rotating plate, and the filter cloth is tensioned again at the moment. The three-way valve is controlled, so that the filter cloth can be loosened and tensioned repeatedly, most of dust adhered to the filter cloth is shaken out, the dust is convenient to clean, the dust removing mechanism does not need to be disassembled for cleaning, and the operation process is greatly simplified.

Optionally, a pull rope is connected to the upper part of the sliding rod, and a steel ball capable of colliding with the dust falling plate is connected to the free end of the pull rope. In the process that the sliding rod slides up and down, the sliding rod drives the steel ball to move up and down together through the pull rope, and the steel ball collides with the dust falling plate in the moving process, so that dust on the dust falling plate can move downwards along the dust falling plate. Meanwhile, the gravity action of the steel ball is also beneficial to accelerating the reset of the sliding rod.

Optionally, a baffle plate obliquely arranged towards one side of the strip-shaped through hole is fixed on the lower surface of the dust falling plate, and a gap allowing dust to fall is reserved between the baffle plate and the inner wall of the shell. When high-temperature flue gas is introduced into a flue gas inlet of the dust removal mechanism, a small part of high-temperature flue gas can enter the bottom of the shell through the dust falling port, dust at the bottom of the shell can be raised, and the baffle is arranged to be favorable for preventing the dust from escaping.

Drawings

FIG. 1 is a sectional view of a high-temperature flue gas heat exchange device of a cement kiln according to an embodiment of the invention;

FIG. 2 is a sectional view of a high-temperature flue gas heat exchange device of a cement kiln in the second embodiment of the invention.

Detailed Description

The following is further detailed by way of specific embodiments:

reference numerals in the drawings of the specification include: the device comprises a shell 10, a fluid inlet 11, a flue gas outlet 12, a flue gas inlet 13, a heat exchange channel 20, a gas flow channel 30, a preheating pipe 40, a water discharge pipe 50, a through hole 51, a spherical valve core 52, a shell 60, a dust falling plate 61, a gas inlet 62, a partition plate 70, a rotating plate 71, a dust falling port 711, filter cloth 72, a limiting member 73, a fixed rod 80, a sliding rod 81, an elastic member 82, a pressure release valve 83, a strip-shaped through hole 84, a steel ball 85 and a three-way valve 90.

Example one

This embodiment is substantially as shown in fig. 1: the cement kiln high-temperature flue gas heat exchange device comprises a shell 10 and a heat exchange mechanism, wherein the heat exchange mechanism is arranged in the shell 10; the shell 10 is provided with a flue gas inlet 13, a flue gas outlet 12, a fluid inlet 11 and a fluid outlet respectively.

The heat exchange mechanism comprises a preheating pipe 40, a gas flow channel 30 and 3 communicating pipe units which are communicated with each other, the 3 heat exchange pipe units are connected with each other to form a heat exchange channel 20, the heat exchange channel 20 is arranged in the gas flow channel 30, a gap is formed between the outer wall of the heat exchange channel 20 and the outer wall of the gas flow channel 30 to form a flow channel, and high-temperature flue gas flows in the flow channel. The preheating pipe 40 is fixedly wound on the inner wall of the casing 10, one end of the preheating pipe 40 is communicated with the fluid inlet 11, the other end is communicated with the right lower end of the heat exchange passage 20, the other end of the heat exchange passage 20 is communicated with the fluid outlet, and the low-temperature fluid entering through the fluid inlet 11 is preheated in the preheating pipe 40 and is conveyed into the heat exchange passage 20 after being preheated. The left end of the gas flow channel 30 is communicated with the flue gas inlet 13, the other end is positioned in the shell 10 and is communicated with the gas in the shell 10, and the flow direction of the introduced high-temperature flue gas is opposite to the flow direction of the fluid to be heated.

Each heat exchange pipe unit is connected with a drain pipe 50 extending out of the casing 10, and a valve is mounted on the drain pipe 50. The valve comprises a fixed seat arranged in the drain pipe 50 and a spherical valve core 52 rotatably connected in the fixed seat, and a through hole 51 capable of communicating the drain pipe 50 and the heat exchange pipe unit is formed in the spherical valve core 52; the ball valve core 52 is fixed with a flow adjusting rod which is rotatably connected with the fixed seat, and the opening size of the through hole 51 can be controlled by rotating the flow adjusting rod according to actual conditions.

A fluid with a lower temperature (water is a common fluid, and water is taken as the fluid of the present embodiment for illustration) enters the preheating pipe 40 through the fluid inlet 11 and flows along the preheating pipe 40, and the low-temperature water can be preheated by the high-temperature flue gas in the housing 10 during the flowing along the preheating pipe 40, and the temperature gradually rises. The preheated water enters the heat exchange channel 20 and flows in the heat exchange channel 20. The high-temperature flue gas enters the gas flow channel 30 through the flue gas inlet 13, and the high-temperature flue gas at the moment surrounds the outer wall of the heat exchange channel 20, so that heat can be transferred to water in the heat exchange channel 20 through the outer wall of the heat exchange channel 20 to heat the water, and the temperature of the water is increased. The water temperature in different heat exchange tube units is different, the temperature of the heat exchange tube units is higher as the heat exchange tube units are positioned closer to the fluid outlet, when water flows along the heat exchange channel 20 and is finally discharged from the fluid outlet, the flowing channel of the water is long enough in the process, the water can be fully in heat transfer with high-temperature flue gas, and the temperature of the discharged water is highest. When the temperature of the water to be discharged is within a certain temperature range, it is reasonably determined that the valve of one of the water discharge pipes 50 is opened (the valves of the other water discharge pipes 50 are kept closed) according to the temperature of the water in the different heat exchange pipe units, and then a part of the water flowing in from the fluid inlet 11 is discharged through the water discharge pipe 50, and the other part of the water continues to flow along the heat exchange channel 20. The temperature of the water discharged from the water discharge pipe 50 meets the actual use requirement, the water continuously flowing forwards makes full use of the high-temperature flue gas for heat transfer, the temperature is continuously increased, and the resource waste caused by the fact that the heat of the high-temperature flue gas cannot be fully utilized is avoided. In order to better regulate the water flow discharged from different positions, the flow regulating rod can be rotated according to actual conditions, and the opening size of the through hole 51 can be controlled.

Example two

The difference between the present embodiment and the first embodiment is that, as shown in fig. 2, the heat exchange device for high-temperature flue gas in a cement kiln further includes a dust removal mechanism, the dust removal mechanism includes a housing 60 and a plurality of filter cloths 72 located in the housing 60, and the filter cloths 72 are used for filtering the high-temperature flue gas. The upper part of the shell 60 is provided with an air inlet 62 and an air outlet, the air inlet 62 is arranged opposite to the filter cloth 72, and the air outlet is communicated with the smoke inlet 13 of the shell 10.

A partition plate 70 is fixed in the housing 60, the partition plate 70 divides the interior of the housing 60 into an upper cavity and a lower cavity, a rotating plate 71 is hinged on the partition plate 70, the weight of the left side of the hinged point of the rotating plate 71 is larger than that of the right side by taking the hinged point of the rotating plate 71 as a boundary, a limiting member 73 positioned on the left side of the rotating plate 71 is fixed at the bottom of the partition plate 70, and the limiting member 73 is arranged to limit the movement of the left side of the rotating plate 71, so that the rotating plate. The upper ends of the filter cloths 72 are fixed to the upper wall of the housing 60, the lower ends are fixed to the left side of the rotating plate 71, and dust falling ports 711 are formed in the rotating plate 71 between the adjacent filter cloths 72. A dust falling plate 61 which is obliquely arranged towards the left side is fixed in the lower cavity of the shell 60, and the oblique angle of the dust falling plate 61 is 15 degrees in the embodiment; the lower end of the dust falling plate 61 is provided with a strip-shaped through hole 84 for allowing dust to fall. A baffle (not shown) inclined toward the strip-shaped through hole 84 is fixed to the lower surface of the dust falling plate 61, and a gap for allowing dust to fall is left between the baffle and the inner wall of the housing 60.

The lifting unit capable of driving the rotating plate 71 to rotate is fixed in the shell 60, the lifting unit is a telescopic column, and the telescopic column is located below the left side of the rotating plate 71. The flexible post includes dead lever 80 and slide bar 81, and the dead lever 80 welds in the bottom of shell 60 and passes dust fall board 61, has seted up the cavity in the dead lever 80, and slide bar 81 slides and sealing connection is in the cavity, and specific connected mode is: the inner wall of the fixed rod 80 is provided with a strip-shaped groove distributed along the height direction, and the sliding rod 81 is fixed with a bulge clamped in the strip-shaped groove. An elastic member 82 is connected between the fixed rod 80 and the bottom of the sliding rod 81, and the elastic member 82 is a spring in this embodiment. The upper part of the sliding rod 81 is connected with a pull rope, the free end of the pull rope is connected with a steel ball 85, and the steel ball 85 can collide with the dust falling plate 61 in the process of moving up and down along with the sliding rod 81. The fixed rod 80 is provided with a pressure release valve 83, when the pressure in the cavity reaches a preset value of the pressure release valve 83, the pressure release valve 83 is opened, and at the moment, the cavity can be communicated with the outside. The flue gas outlet 12 is connected with a three-way pipe, the three-way pipe is provided with a three-way valve 90, and one end of the three-way pipe is communicated with the fixed rod 80 through a pipeline.

In general, the rotating plate 71 is attached to the partition plate 70, and the high-temperature flue gas introduced from the gas inlet 62 is filtered by the plurality of filter cloths 72 and then discharged from the gas outlet. After the filter cloth 72 is used for a period of time, a large amount of dust can adhere to the surface of the filter cloth 72, and the filtering effect of the filter cloth 72 is greatly influenced. When dust adhered to the filter cloth 72 needs to be removed, the three-way valve 90 is rotated, so that high-temperature flue gas discharged from the flue gas outlet 12 can enter the fixing rod 80 through the pipeline, and the sliding rod 81 slides upwards under the action of the high-temperature flue gas. The sliding rod 81 applies an upward acting force to the left rotating plate 71 in the upward movement process, so that the rotating plate 71 rotates along the hinge point, the left side of the rotating plate 71 is lifted upwards, and the filter cloth 72 is in a loose state. The three-way valve 90 is adjusted to close the passage between the smoke outlet 12 and the fixed rod 80, at this time, under the action of the spring, the sliding rod 81 tends to slide downwards, the sliding rod 81 compresses the gas in the fixed rod 80, the pressure in the fixed rod 80 is increased, and when the preset value of the pressure release valve 83 is reached, the pressure release valve 83 is opened to discharge the redundant gas in the fixed rod 80. After the telescopic column is reset, the rotating plate 71 is also restored to the original position under the action of the self gravity, and the filter cloth 72 is tensioned again at the moment. The three-way valve 90 is controlled to loosen, tension, loosen and tension the filter cloth 72, most of dust adhered to the filter cloth 72 is shaken out, and the dust shaken out of the filter cloth 72 falls on the dust falling plate 61 first, then slides down along the dust falling plate 61 under the action of gravity, and finally falls on the bottom of the shell 60 through the strip-shaped through hole 84.

In the process that the sliding rod 81 slides up and down, the sliding rod 81 drives the steel ball 85 to move up and down together through the pull rope, and the steel ball 85 collides with the dust falling plate 61 in the moving process, so that the dust on the dust falling plate 61 can move downwards along the dust falling plate 61.

The foregoing is merely an example of the present invention and common general knowledge of known specific structures and features of the embodiments is not described herein in any greater detail. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the present invention.

Claims

1. Cement kiln high temperature flue gas heat transfer device, its characterized in that: the device comprises a shell and a heat exchange mechanism positioned in the shell, wherein the shell is provided with a flue gas inlet, a flue gas outlet, a fluid inlet and a fluid outlet; the heat exchange mechanism comprises a gas flow channel and a plurality of heat exchange tube units which are communicated with each other, the plurality of heat exchange tube units form a heat exchange channel, and the heat exchange channel is positioned in the gas flow channel; one end of the heat exchange channel is communicated with the fluid inlet, and the other end of the heat exchange channel is communicated with the fluid outlet; one end of the gas flow channel is communicated with the smoke inlet, and the other end of the gas flow channel is positioned in the shell; the flow direction of the high-temperature flue gas is opposite to that of the fluid to be heated; one end of each heat exchange tube unit is connected with a drain pipe extending out of the shell, and a valve is arranged on each drain pipe; the dust removal mechanism comprises a shell and a plurality of pieces of filter cloth which is positioned in the shell and is used for filtering high-temperature smoke, and the shell is provided with an air inlet and an air outlet communicated with the smoke inlet; a partition plate for dividing the interior of the shell into an upper cavity and a lower cavity is arranged in the shell, a rotating plate is hinged to the partition plate, and the weight of one side of the hinged point of the rotating plate is greater than that of the other side; one end of the filter cloth is fixed on the upper wall of the shell, and the other end of the filter cloth is fixed on one side of the rotating plate with larger weight; dust falling ports are formed in the rotating plates between the adjacent filter cloth; the shell is internally provided with a limiting part which limits the downward movement of the side with larger weight of the rotating plate.

2. The cement kiln high-temperature flue gas heat exchange device according to claim 1, characterized in that: the inner wall of the shell is provided with preheating pipes distributed around the inner wall of the shell; the heat exchange channel is communicated with the fluid inlet through a preheating pipe.

3. The cement kiln high-temperature flue gas heat exchange device according to claim 2, characterized in that: the valve comprises a fixed seat and a spherical valve core which is rotatably connected in the fixed seat, and a through hole which can communicate the drain pipe with the heat exchange pipe unit is formed in the spherical valve core; a flow adjusting rod which is rotationally connected with the fixed seat is fixed on the spherical valve core.

4. The cement kiln high-temperature flue gas heat exchange device according to claim 3, characterized in that: the number of the heat exchange tube units is 3.

5. The cement kiln high-temperature flue gas heat exchange device according to claim 1, characterized in that: a dust falling plate which is obliquely arranged is fixed in the lower cavity, and the lower end of the dust falling plate is provided with a strip-shaped through hole allowing dust to fall.

6. The cement kiln high-temperature flue gas heat exchange device according to claim 5, characterized in that: a lifting unit capable of driving the rotating plate to rotate is fixed in the shell; the lifting unit is a telescopic column which is positioned below one side of the rotating plate with larger weight, the telescopic column comprises a fixed rod penetrating through the dust falling plate and a sliding rod connected in the fixed rod in a sliding manner, and an elastic piece is connected between the fixed rod and the sliding rod; the fixed rod is provided with a pressure relief valve which can communicate the outside with the inside of the fixed rod; the flue gas outlet is connected with a three-way pipe, and the three-way pipe is provided with a three-way valve; one end of the three-way pipe is communicated with the fixed rod through a pipeline.

7. The cement kiln high-temperature flue gas heat exchange device according to claim 6, characterized in that: the upper part of the sliding rod is connected with a pull rope, and the free end of the pull rope is connected with a steel ball which can collide with the dust falling plate.

8. The cement kiln high-temperature flue gas heat exchange device according to claim 7, characterized in that: the lower surface of the dust falling plate is fixedly provided with a baffle which is obliquely arranged towards one side of the strip-shaped through hole, and a gap for allowing dust to fall is reserved between the baffle and the inner wall of the shell.