Integrated air-fuel gas integrated preheating device

Abstract

An integrated air-fuel gas integrated preheating device is composed of an air preheating unit and a fuel gas preheating unit, wherein the air preheating unit and the fuel gas preheating unit are arranged in an inner cavity of the same preheater shell in an up-down nested mode. The air preheating unit is arranged in the center of an inner cavity of the preheater shell. The air preheating unit comprises an air heat exchanger, a cold air collector ring and a hot air collector ring. The fuel gas preheating unit is arranged around the outer side of the air preheating unit and comprises a hot fuel gas collecting tank, a fuel gas heat exchange pipe and a fuel gas collecting pipe; a flue gas isolating ring plate which is relatively isolated and has a through function is arranged between the fuel gas preheating unit and the air preheating unit, so that the fuel gas preheating unit and the air preheating unit form a preheating system which is relatively independent and can locally communicate with each other; and a hot fuel gas collecting tank is arranged at the top of the inner cavity of the preheater shell.

Description

TECHNICAL FIELD

[0001] The utility model relates to an air-gas integrated preheating device and preheating method, belong to industrial flue gas waste heat recovery technical field. BACKGROUND

[0002] It is an important means of energy saving and emission reduction in industrial production to preheat combustion air or gas by high-temperature flue gas waste heat, and it is also a conventional configuration in industrial furnace equipment. At present, most industrial furnaces are equipped with combustion air preheating devices to preheat combustion air to 300-500 DEG C (regenerative combustion can preheat combustion air to 800-1000 DEG C), and some industrial furnaces are provided with combustion air and gas double preheating devices to achieve the purpose of maximum recovery of flue gas waste heat, energy saving and emission reduction and reduction of production cost.

[0003] Generally, when the gas heat value is low (gas heat value ≦8000kJ / Nm 3 ), the gas-air double preheating mode is mostly used. The commonly used method is to arrange the combustion air preheater and the gas preheater in series, that is, the high-temperature flue gas is used to preheat the combustion air first, and then the gas is preheated. This arrangement has the following shortcomings:

[0004] 1) the preheater needs a large space;

[0005] 2) the connecting part of the two preheaters must have insulation facilities, and the connecting flange is easy to be damaged.

[0006] However, if the space of the industrial furnace area is small, the air-gas double preheating cannot be realized, resulting in waste of a large amount of flue gas waste heat, and the fuel combustion effect of the furnace is also poor.

[0007] Therefore, how to solve the difficulty of realizing air-gas double preheating in a small space and improve the heat exchange efficiency of the preheater is still one of the problems to be solved in the field, INVENTION CONTENTS

[0008] The utility model discloses a kind of integrated air-gas double preheating devices, solve the difficult problem of realizing air-gas double preheating in a small space, not only make the preheater volume greatly reduce, improve the heat exchange efficiency of preheater, and can save the investment cost of preheater equipment.

[0009] The above-mentioned utility model invention purpose is realized by the following technical scheme:

[0010] The integrated air-gas integrated preheating device is characterized in that: it is composed of an air preheating unit and a gas preheating unit which are arranged in a nested manner in the inner cavity of the same preheater shell 7; the air preheating unit is arranged at the center position of the inner cavity of the preheater shell 7, and the air preheating unit includes an air heat exchanger 11, a cold air collecting ring 18 and a hot air collecting ring 5; the gas preheating unit is arranged around the outside of the air preheating unit, and the gas preheating unit includes a hot gas collecting tank 14, a gas heat exchanger 9 and a gas collecting pipe 12; a flue gas isolation ring plate 10 is arranged between the gas preheating unit and the air preheating unit, which is relatively isolated and can also play a through role, so that the two become a preheating system which is relatively independent and can be partially communicated; the hot gas collecting tank 14 is arranged at the top of the inner cavity of the preheater shell 7.

[0011] Further, the air heat exchanger 11 is composed of a plurality of air heat exchanger pipes 11.1 which are arranged in a ring shape at the central part of the vertical direction of the inner cavity of the integrated preheater shell, each of the air heat exchanger pipes 11.1 is in communication with the inner cavity of the cold air collecting ring 18 arranged at the upper part, and the lower part of each air heat exchanger pipe is in communication with the inner cavity of the hot air collecting ring 5 arranged at the bottom of the inner cavity of the integrated preheater shell; the cold air collecting ring 18 forms a combustion air inlet 19 through the pipe body extending out of the preheater shell 7.

[0012] Further, the gas heat exchanger 9 is composed of gas heat exchanger pipes 9.1 which are arranged in a ring shape outside the ring-shaped air heat exchanger pipes 11.1, the upper end of each gas heat exchanger pipe 9.1 is in communication with the inner cavity of the hot gas collecting tank 14 arranged at the top of the inner cavity of the preheater shell 7, and the lower end is in communication with the cold gas descending channel 8 arranged on the inner wall of the preheater shell 7.

[0013] Further, the hot gas collecting tank 14 is composed of a circular gas isolation plate 24 and a preheater upper cover arranged at the top of the inner cavity of the preheater shell 7 and a heat preservation layer 16, the upper part of each gas heat exchanger pipe 9.1 is in communication with the inner cavity of the hot gas collecting tank 14, and a hot gas outlet 15 is arranged on one side of the hot gas collecting tank 14 to provide heated gas outwardly.

[0014] Further, the cold gas descending channel 8 is a space sandwiched layer arranged on the inner wall of the preheater shell 7, the lower part is in communication with each ring-shaped gas heat exchanger pipe 9.1 in the gas preheating unit through a through hole, and the upper part is in communication with the gas collecting pipe 12 arranged outside the preheater shell 7 at this position through the gas inlet hole 13 arranged on the preheater shell 7; the gas collecting pipe 12 is provided with a cold gas inlet 20 which is in communication with a gas supply source.

[0015] Further, the height of the flue gas isolation ring plate 10 is lower than the height of the air heat exchange pipe 11.1 in the air preheating unit, and the lower part of the flue gas isolation ring plate 10 is fixed on the inner bottom of the preheater bottom plate 2, and the upper part of the flue gas isolation ring plate 10 is fixed on the inner wall of the preheater shell 7 through the flue gas isolation ring plate support rod 23 arranged outside the flue gas isolation ring plate.

[0016] Further, the hot air collection ring 5 extends out of the preheater shell 7 through the horizontally arranged hot air input pipe to form the hot air outlet 6.

[0017] Further, the hot air collection ring 5 is connected with the preheater bottom plate 2 through the hot air collection ring support legs 4 connected with the bottom of the hot air collection ring 5.

[0018] Further, the preheater bottom plate 2 is annular, and the annular inner ring edge is provided with a flue gas upward passage partition wall 3, the upper part of which is sealingly connected with the bottom of the hot air collection ring 5 to form a flue gas upward passage connected with the high-temperature flue gas inlet 1.

[0019] Further, the bottom of the preheater shell 7 is provided with a high-temperature flue gas inlet 1, which is directly connected with the space surrounded by the hot air collection ring 5, the air heat exchanger 11, the flue gas upward passage partition wall 3 and the flue gas isolation ring plate 10 to form a high-temperature flue gas upward passage from bottom to top.

[0020] Further, the cylindrical cavity surrounded by the air heat exchange pipe 11.1 is provided with a plurality of tapered flue gas guide plates 22 in the form of V-shaped cone bodies penetrating and sleeving the air heat exchange pipes around the periphery, and the outer periphery of the tapered flue gas guide plate 22 is fixedly connected with the flue gas isolation ring plate 10 to form a layered flue gas horizontal diffusion structure from bottom to top.

[0021] Further, the upper part of the preheater shell 7 is provided with a hot gas outlet 15 on the shell for providing high-temperature combustion gas outwardly, and the hot gas outlet 15 is in communication with the hot gas collection box 14 in the inner cavity of the upper part of the preheater shell 7; and the lower part of the other side of the preheater shell 7 is provided with a flue gas discharge port 21 in communication with the lower part of the preheater shell 7.

[0022] Further, the top of the preheater shell 7 is provided with a group of preheater lifting rings 17 for installing the integrated air-gas integrated preheating device.

[0023] When in use, the integrated preheating device is connected to the flue gas discharge channel of the industrial furnace, the high-temperature flue gas inlet 1 is connected to the high-temperature flue gas outlet of the industrial furnace, and the flue gas discharge port 21 of the integrated preheating device is connected to the flue gas discharge pipeline connected with the flue gas fan or flue gas chimney; the combustion-supporting air inlet 19 and the cold fuel gas inlet 20 are respectively connected to the cold air source and the cold fuel gas inlet air source.

[0024] When in use, the integrated preheating device is connected to the flue gas discharge channel of the industrial furnace, the high-temperature flue gas inlet 1 is connected to the high-temperature flue gas outlet of the industrial furnace, and the flue gas discharge port 21 of the integrated preheating device is connected to the flue gas discharge pipeline connected with the flue gas fan or flue gas chimney; the combustion-supporting air inlet 19 and the cold fuel gas inlet 20 are respectively connected to the cold air source and the cold fuel gas inlet air source.

[0025] The preheating process is as follows:

[0026] 1) When the high-temperature flue gas enters the preheater center from the high-temperature flue gas inlet 1 at the lower part of the integrated preheating device, it moves upward along the channel formed by the flue gas isolation ring plate 10 under the guidance of the conical flue gas guide plate 22, fully contacts each air heat exchange pipe 11.1 of the air heat exchanger 11 arranged in the intermediate columnar space of the preheater shell 7, and preheats the air passing through the heat exchanger pipe bundle area; at the same time, the rising high-temperature flue gas moves downward along the outer side of the flue gas isolation ring plate, fully contacts each flue gas heat exchanger 9 pipe bundle in the flue gas heat exchange unit during the downward movement, and heats the flue gas in the lumen of the flue gas heat exchanger 9 pipe bundle, while the downward flue gas continues to move along the outer circle of the flue gas isolation ring plate 10, and is discharged from the flue gas discharge port 21 at the lower part of the preheater;

[0027] 3) At the same time, the external cold air enters the cold air collection ring 18 through the combustion-supporting air inlet 19, is uniformly distributed into each air heat exchange pipe 11.1 of the cold air heat exchanger 11, moves downward along the lumen of each air heat exchange pipe 11.1 of the air heat exchanger 11, and exchanges heat with the rising high-temperature flue gas from the flue gas inlet 1 arranged at the lower part of the preheater shell 7 in countercurrent; the preheated air in the pipe is collected into the lower hot air collection ring 5, and then is supplied to the burner of the use device through the hot air outlet 6 connected with the hot air collection ring 5;

[0028] 4) At the same time, the cold gas enters the gas collecting pipe 12 through the cold gas inlet 20, and then the gas is uniformly distributed into the cold gas descending channel 8 through the descending channel hole 13 between the shell wall of the preheater shell 7 and the cold gas descending channel 8, moves downwards along the inner wall of the preheater shell 7, and enters the inner cavity of each gas heat exchange pipe 9.1 bundle constituting the gas heat exchange unit through the lower part of the cold gas descending channel 8, moves upwards, and realizes countercurrent heat exchange with the high-temperature flue gas descending along the outer side of the flue gas isolation ring plate 10; the preheated in-pipe gas rises into the hot gas collecting tank 14, and is supplied to the use device-burner through the hot gas outlet 15.

[0029] The integrated air-gas integrated preheating device has the following advantages:

[0030] 1) The volume of the air-gas double preheating device is greatly reduced, and air-gas double preheating can be realized in a small space, and the energy consumption is greatly reduced.

[0031] 2) The comprehensive heat exchange coefficient of the preheater is 30-40 W / (m 2 .℃), which is greater than the heat exchange coefficient of a conventional preheater, and the heat exchange efficiency of the preheater is greatly improved.

[0032] 3) When the inlet flue gas temperature is 900-1050℃, the air preheating temperature can reach 460-550℃, and the gas preheating temperature can reach 420-500℃.

[0033] 4) The preheater adopts the mode that the cold gas flows downwards along the inner wall of the preheater shell, so that the preheater shell does not heat up. The preheater shell reduces or does not use heat insulation materials.

[0034] 5) The preheater is easy to disassemble, and when the dust is seriously accumulated in the preheater after being used for a certain period of time, the gas preheating part and the air preheating part can be separated to clean the dust. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0036] Figure 2 It is an A-A sectional view of the integrated preheater;

[0037] Figure 3 It is a lower plan view of the integrated air-gas integrated preheating device;

[0038] Figure 4 It is a schematic diagram of the gas, flue gas and air inlet and outlet distribution of the utility model.

[0039] In the drawings:

[0040] 1-high temperature flue gas inlet; 2-preheater bottom plate; 3-flue gas rising passage partition wall;

[0041] 4-hot air collecting ring support leg; 5-hot air collecting ring; 6-hot air outlet;

[0042] 7-preheater shell; 8-cold flue gas descending passage; 9-flue gas heat exchanger;

[0043] 9.1-flue gas heat exchange pipe; 10-flue gas isolation ring plate; 11-air heat exchanger;

[0044] 11.1-air heat exchange pipe; 12-flue gas collecting pipe;

[0045] 13-flue gas entering descending passage hole; 14-hot flue gas collecting tank;

[0046] 15-hot flue gas outlet; 16-preheater upper cover and insulation layer; 17-preheater lifting ring;

[0047] 18-cold air collecting ring; 19-combustion air inlet; 20-cold flue gas inlet;

[0048] 21-flue gas discharge port; 22-conical flue gas guide plate;

[0049] 23-flue gas isolation ring plate support rod. DETAILED DESCRIPTION

[0050] The integrated air-gas integrated preheating device according to the above technical scheme, the core idea of which is that the air-gas double preheating units are arranged in the same preheater cavity, so that the whole device is greatly reduced in size and greatly improved in heat exchange efficiency, and can be used not only in the field of industrial furnace flue gas waste heat recovery but also in the high-temperature flue gas waste heat recovery of other industries.

[0051] The utility model will be further described below in combination with embodiments and specific embodiments of the utility model are given.

[0052] The integrated air-gas integrated preheating device is characterized in that: it is composed of an air preheating unit and a gas preheating unit which are arranged in a nested manner in the inner cavity of the same preheater shell 7; the air preheating unit is arranged at the center position in the inner cavity of the preheater shell 7, and the air preheating unit includes an air heat exchanger 11, a cold air collector ring 18 and a hot air collection ring 5; the gas preheating unit is arranged around the outside of the air preheating unit, and the gas preheating unit includes a hot gas collection tank 14, a gas heat exchanger 9 and a gas collector pipe 12; a flue gas isolation ring plate 10 is arranged between the gas preheating unit and the air preheating unit, which is relatively isolated and can also play a through role, so that the two become a preheating system which is relatively independent and can be communicated with each other locally; the hot gas collection tank 14 is arranged at the top of the inner cavity of the preheater shell 7.

[0053] The air heat exchanger 11 is composed of a plurality of air heat exchange pipes 11.1 which are arranged in a ring shape at the central part of the vertical direction of the inner cavity of the integrated preheater shell, each air heat exchange pipe 11.1 is in communication with the inner cavity of the cold air collection ring 18 arranged at the upper part, and the lower part of each air heat exchange pipe is in communication with the inner cavity of the hot air collection ring 5 arranged at the bottom of the inner cavity of the integrated preheater shell; the cold air collection ring 18 forms a combustion air inlet 19 through the pipe body extending out of the preheater shell 7. The cold air flows downward through the air heat exchange pipe 11.1 bundle and performs countercurrent heat exchange with the upward high-temperature flue gas, the preheated air enters the hot air collection ring 5, and the collected hot air is sent to the using device through the hot air outlet 6.

[0054] The gas heat exchanger 9 is composed of a plurality of gas heat exchange pipes 9.1 which are arranged in a ring shape outside the ring-shaped air heat exchange pipe 11.1, the upper end of each gas heat exchange pipe 9.1 is in communication with the inner cavity of the hot gas collection tank 14 arranged at the top of the inner cavity of the preheater shell 7, and the lower end is in communication with the cold gas descending channel 8 arranged on the inner wall of the preheater shell 7.

[0055] The gas heat exchange pipe 9 is composed of a plurality of "J" type metal elbow pipes along the circumferential direction of the preheater, the lower elbow of the metal pipe is communicated with the lower part of the cold gas descending channel 8, and the upper end is communicated with the hot gas collection tank 14, thereby forming a flue gas and gas heat exchange channel.

[0056] The cold gas descending channel 8 is a space sandwiched layer arranged on the inner wall of the preheater shell 7, the lower part is communicated with each ring-shaped gas heat exchange pipe 9.1 in the gas preheating unit through a through hole, and the upper part is communicated with the gas collector pipe 12 arranged outside the preheater shell 7 at this position through the gas inlet hole 13 arranged on the preheater shell 7; the gas collector pipe 12 is provided with a cold gas inlet 20 which is communicated with a gas supply source.

[0057] The gas collecting pipe 12 is composed of a metal "C" type or rectangular plate and a part of the preheater shell 7, the gas collecting pipe 12 is fixed on the preheater shell 7, and a plurality of gas inlet holes 13 are opened on the part of the preheater shell 7 to communicate the gas collecting pipe 12 with the cold gas descending channel 8.

[0058] The cold gas entering through the cold gas inlet 20 is distributed to the cold gas descending channel 8 through the gas inlet descending channel hole 13 of the cold gas collecting pipe 12. The cold gas enters the gas heat exchanger 9 through the lower part of the cold gas descending channel 8, and is collected in the hot gas collecting tank 14 after being reversely heat-exchanged with the downward high-temperature flue gas, and is sent to the using device (burner) through the hot gas outlet 15. The high-temperature flue gas enters the preheater through the high-temperature flue gas inlet 1, flows upward from the center of the preheater, is heat-exchanged with the air heat exchanger 11, and then turns over the flue gas isolation ring plate 10 to continue heat-exchange with the gas heat exchanger 9, and is discharged from the flue gas discharge port 21.

[0059] A plurality of conical flue gas guide plates 22 are arranged on the central channel of the preheater to guide the high-temperature flue gas around the tube bundle of the air heat exchanger 11. The conical flue gas guide plate 22 is made of a conical heat-resistant steel plate, and a plurality of conical flue gas guide plates 22 (two in the case) are arranged from bottom to top in the preheater, and the periphery of each conical flue gas guide plate 22 is provided with 4-6 flue gas isolation ring plate support rods 23 to be fixed on the preheater shell 7.

[0060] The height of the flue gas isolation ring plate 10 is lower than the height of the annularly distributed air heat exchange tube 11 in the air preheating unit, and the lower part of the flue gas isolation ring plate 10 is fixed on the inner bottom of the preheater bottom plate 2, and the upper part of the flue gas isolation ring plate 10 is fixed on the inner wall of the preheater shell 7 through the flue gas isolation ring plate support rod 23 arranged outside the flue gas isolation ring plate. The flue gas isolation ring plate 10 is composed of a cylindrical steel plate, the lower part of which is fixed on the preheater bottom plate 2, and the upper end is located at about 200 mm below the lower part of the cold air collecting ring 18. The cold air collecting ring 18 is located at the upper part of the preheater, and is a ring pipe with a rectangular or circular cross section. The combustion air inlet 19 is arranged on the side of the cold air collecting ring 18. The lower part of the cold air collecting ring 18 is communicated with the tube bundle of the air heat exchanger 11.

[0061] The hot air collecting ring 5 is composed of a hot air input pipe arranged in a horizontal direction and extending out of the preheater shell 7 to form the hot air outlet 6.

[0062] The hot air collection ring 5 is connected with the preheater bottom plate 2 through several hot air collection ring support legs 4 connected with the bottom of the hot air collection ring 5. The hot air collection ring 5 is located at the lower part of the preheater, and can be in the shape of a rectangular ring or a circular ring. The lower part of the hot air collection ring 5 is fixed on the preheater bottom plate 2 by the hot air collection ring support legs 4, and is communicated with the flue gas rising passage partition wall 3. The upper part of the hot air collection ring 5 is communicated with the air heat exchanger 11 tube bundle.

[0063] The preheater bottom plate 2 is in the shape of a ring, and the inner ring edge of the ring is provided with a ring-shaped flue gas rising passage partition wall 3. The upper part of the flue gas rising passage partition wall 3 is sealingly connected with the bottom of the hot air collection ring 5, and forms a flue gas rising passage.

[0064] The integrated air-gas preheater has a circular high-temperature flue gas inlet 1 at the center of the bottom, and the hot air collection ring 5 is fixed on the preheater bottom plate 2 through the hot air collection ring support legs 4. The hot air outlet 6 is arranged on the hot air collection ring 5. The cold air collection ring 18 is located above the hot air collection ring 5, and the cold air collection ring 18 and the hot air collection ring 5 are connected. The combustion air inlet 19 is arranged on the cold air collection ring 18.

[0065] The preheater shell 7 is provided with a high-temperature flue gas inlet 1 at the bottom, so that the high-temperature flue gas is directly communicated with the space surrounded by the air heat exchange tube 11, the flue gas rising passage partition wall 3 and the flue gas partition ring plate 10 through the inner ring of the hot air collection ring 5, and forms a high-temperature flue gas rising passage from bottom to top.

[0066] The preheater shell 7 is provided with a gas collection pipe 12 at the upper part, and the cold gas inlet 20 is arranged on the gas collection pipe 12. A plurality of gas inlet descending passage holes 13 are arranged on the circumference of the preheater shell 7 where the gas collection pipe 12 is located. The holes communicate the gas collection pipe 12 with the cold gas descending passage 8. The lower part of the cold gas descending passage 8 is connected with the lower part of the gas heat exchange tube 9, the upper part of the gas heat exchange tube 9 is communicated with the hot gas collection tank 14, and the hot gas collection tank 14 is located above the cold air collection ring 18. The upper part of the hot gas collection tank 14 is the preheater upper cover and the heat preservation layer 16. The preheater upper cover and the heat preservation layer 16 are provided with a preheater lifting ring 17.

[0067] The integrated preheater composed of the above components can greatly reduce the volume of the air-gas double preheating device and greatly improve the heat exchange efficiency. It can not only be used in the field of industrial furnace flue gas waste heat recovery, but also be used in the high-temperature flue gas waste heat recovery of other industries.

[0068] The flue gas partition ring plate 10 is composed of a cylindrical steel plate. The lower part of the cylindrical steel plate is fixed on the preheater bottom plate 2, and the upper end is located at about 200 mm below the lower part of the cold air collection ring 18. The flue gas partition ring plate support rod 23 is arranged on the upper part of the flue gas partition ring plate 10, and is fixed on the preheater shell 7.

[0069] The upper part of the hot gas collecting box 14 is the preheater upper cover and the heat preservation layer 16, and the lower part is connected with the tube bundle of the gas heat exchanger 9. The hot gas outlet 15 is arranged on the side of the hot gas collecting box 14.

[0070] The integrated air-gas integrated preheater further comprises a high-temperature flue gas inlet 1, so that the high-temperature flue gas enters the preheater from bottom to top. The preheater upper cover and the heat preservation layer 16 are provided with a preheater lifting ring 17 for lifting and moving the preheater.

[0071] The preheating process of the integrated air-gas integrated preheater is as follows:

[0072] The integrated air-gas preheater is connected to the industrial furnace flue gas passage, that is, the lower high-temperature flue gas inlet 1 is connected to the high-temperature flue gas discharged from the industrial furnace, and the flue gas discharge port 21 is connected to the flue gas duct (connected with a flue gas fan or a flue gas chimney).

[0073] The high-temperature flue gas enters the central part of the preheater from the lower high-temperature flue gas inlet 1, moves upward along the flue gas isolation ring plate 10 in the channel of the flue gas isolation ring plate 10 under the guidance of the conical flue gas guide plate 22, fully contacts the air heat exchanger 11 tube bundle, and preheats the air in the air heat exchanger 11 tube bundle. The high-temperature flue gas reaches the upper part of the flue gas isolation ring plate 10, turns over the flue gas isolation ring plate 10 and moves downward, fully contacts the gas heat exchanger 9 tube bundle, and preheats the gas in each tube bundle of the gas heat exchanger 9. After two heat exchanges, the flue gas moves along the outer circle of the flue gas isolation ring plate 10 and is discharged from the lower flue gas discharge port 21 of the preheater;

[0074] The cold air enters the cold air collecting ring 18 from the combustion air inlet 19 and is uniformly distributed to the air heat exchanger 11 tube bundle, moves downward along the air heat exchanger 11, and performs heat exchange with the rising high-temperature flue gas in counterflow. The preheated air is collected in the hot air collecting ring 5 and is supplied to the use device (burner) through the hot air outlet 6.

[0075] The cold gas enters the gas collecting pipe 12 from the cold gas inlet 20, is uniformly distributed to the cold gas descending channel 8 through the gas descending channel hole 13, moves downward along the inner wall of the preheater shell 7, enters the gas heat exchanger 9 tube bundle at the lower part of the cold gas descending channel 8, moves upward, and exchanges heat with the descending high-temperature flue gas in counterflow. The preheated gas enters the hot gas collecting box 14 and is supplied to the use device (burner) through the hot gas outlet 15.

[0076] The preheater fundamentally solves the problem that air-gas double preheating cannot be realized in a small space, greatly improves the flue gas waste heat recovery efficiency, and is a device for high-efficiency energy saving, emission reduction and production cost reduction.

[0077] The above is only the basic implementation of the utility model according to the technical scheme, and any improvement without substantial creativity made by any ordinary technical personnel in the industry with reference to the technical scheme should be considered as falling within the protection scope of the utility model.

Claims

1. An integrated air-fuel integrated preheating device, characterized by: It is composed of air preheating unit and gas preheating unit which are arranged in the same preheater shell (7) cavity in a top and bottom stacked manner; the air preheating unit is arranged at the center position of the preheater shell (7) cavity, which includes air heat exchanger (11), cold air collection ring (18) and hot air collection ring (5); the gas preheating unit is arranged around the outside of the air preheating unit, which includes hot gas collection tank (14), gas heat exchanger (9), gas collection pipe (12); the gas preheating unit and the air preheating unit are provided with a flue gas isolation ring plate (10) which is relatively isolated and can also play a through role, so that the two become a preheating system which is relatively independent and can be communicated with each other; the hot gas collection tank (14) is arranged at the top of the preheater shell (7) cavity.

2. An integrated air-fuel integrated preheating device as claimed in claim 1, characterized in that: The air heat exchanger (11) is composed of a plurality of air heat exchanger pipes (11.1) which are arranged in a ring shape at the central part of the vertical direction of the integrated preheater cavity, each air heat exchanger pipe (11.1) is individually connected with the inner cavity of the cold air collection ring (18) arranged at the upper part, and the lower part of each air heat exchanger pipe is connected with the inner cavity of the hot air collection ring (5) arranged at the lower part of the integrated preheater shell cavity; the cold air collection ring (18) forms a combustion air inlet (19) by extending out of the preheater shell (7) pipe body.

3. An integrated air-fuel integrated preheating device as set forth in claim 1, characterized by: The gas heat exchanger (9) is arranged in a ring shape outside the air heat exchanger pipe (11.1) which is also arranged in a ring shape, the upper end of each gas heat exchanger pipe (9.1) is connected with the inner cavity of the hot gas collection tank (14) arranged at the top of the preheater shell (7) cavity, and the lower end is connected with the cold gas descending channel (8) arranged on the inner wall of the preheater shell (7).

4. An integrated air-fuel integrated preheating device as set forth in claim 1, characterized by: The hot gas collection tank (14) is composed of a circular gas isolation plate (24) and a preheater upper cover and insulation layer (16) arranged at the top of the preheater shell (7) cavity, the upper part of each gas heat exchanger pipe (9.1) is connected with the inner cavity of the hot gas collection tank (14), and a hot gas outlet (15) is arranged on one side of the hot gas collection tank (14) to provide heated gas outward.

5. An integrated air-fuel integrated preheating device as set forth in claim 3, characterized by: The cold gas descending channel (8) is a space sandwiched layer arranged on the inner wall of the preheater shell (7), the lower part is connected with each ring-shaped gas heat exchanger pipe (9.1) in the gas preheating unit through a through hole, and the upper part is connected with the gas collection pipe (12) arranged outside the preheater shell (7) at this position through the gas inlet hole (13) arranged on the preheater shell (7); the gas collection pipe (12) is provided with a cold gas inlet (20) which is connected with the gas supply source.

6. An integrated air-fuel integrated preheating device as set forth in claim 1, characterized by: The height of the smoke isolation ring plate (10) is lower than the height of the air heat exchange pipe (11.1) in the air preheating unit; and the lower part of the smoke isolation ring plate (10) is fixed on the inner bottom of the preheater bottom plate (2), and the upper part of the smoke isolation ring plate (10) is fixed on the inner wall of the preheater shell (7) through the smoke isolation ring plate support rod (23) arranged outside the smoke isolation ring plate.

7. An integrated air-fuel integrated preheating device as set forth in claim 2, characterized by: The hot air collection ring (5) extends out of the preheater shell (7) through a horizontally arranged hot air input pipe to form a hot air outlet (6).

8. An integrated air-fuel integrated preheating device as set forth in claim 7, characterized by: The hot air collection ring (5) is connected with the preheater bottom plate (2) through a plurality of hot air collection ring support legs (4) connected with the bottom of the hot air collection ring.

9. An integrated air-fuel integrated preheating device as set forth in claim 8, characterized by: The preheater bottom plate (2) is annular, and an annular flue gas rising passage partition wall (3) is arranged at the edge of the inner ring of the preheater bottom plate (2), and the upper part of the flue gas rising passage partition wall (3) is sealingly connected with the bottom of the hot air collection ring (5) to form an upward passage connected with the high-temperature flue gas inlet (1).

10. An integrated air-fuel integrated preheating device as set forth in claim 1, characterized by: The bottom of the preheater shell (7) is provided with a high-temperature flue gas inlet (1) to directly communicate with the space surrounded by the air heat exchanger (11), the flue gas rising passage partition wall (3), and the smoke isolation ring plate (10) through the inner ring of the hot air collection ring (5), thereby forming a high-temperature flue gas upward passage.

11. An integrated air-fuel integrated preheating device as set forth in claim 6, characterized by: A conical flue gas guide plate (22) with a V-shaped cone in the middle is arranged in the cylindrical cavity surrounded by the air heat exchange pipe (11.1), and the outer periphery of the conical flue gas guide plate (22) is fixedly connected with the smoke isolation ring plate (10) to form a multi-layer flue gas horizontal diffusion structure from bottom to top.

12. An integrated air-fuel integrated preheating device as set forth in claim 1, characterized by: A hot gas outlet (15) for providing high-temperature combustion gas outward is arranged on one side of the upper part of the preheater shell (7), and the hot gas outlet (15) is in communication with the hot gas collection box (14) in the inner cavity of the upper part of the preheater shell (7); a flue gas discharge port (21) in communication with the lower part of the preheater shell (7) is arranged on the other side of the lower part of the preheater shell (7).

13. An integrated air-fuel integrated preheating device as set forth in claim 1, characterized by: A group of preheater lifting rings (17) for installing the integrated air-gas integrated preheating device are arranged on the top outer shell of the preheater shell (7).

14. An integrated air-fuel integrated preheating device as set forth in claim 9, characterized by: The high-temperature flue gas inlet (1) is connected with the high-temperature flue gas outlet of an industrial furnace, and the flue gas discharge port (21) of the integrated preheating device is connected with the flue gas discharge pipeline connected with a flue gas fan or a flue gas chimney; the combustion air inlet (19) and the cold gas inlet (20) are respectively connected with a cold air source and a cold gas inlet source.

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