Stress-free riser coil heat exchanger filled with mixed-state heat-conducting medium

Abstract

The utility model relates to an unstressed riser coil heat exchanger filled with a mixed-state heat-conducting medium, and belongs to the technical field of coke oven waste heat recovery. According to the technical scheme, the upper end of an inner barrel (1) is connected with an upper flange (3) through an inner barrel expansion joint (5), a spiral pipe is wound around the outer wall of the inner barrel (1), the two ends of the spiral pipe are connected with a water inlet pipe (10) and a water outlet pipe (13) respectively, and water pipe expansion joints (12) are arranged at the positions, extending out of an outer barrel (4), of the two ends; the space between the inner cylinder and the outer cylinder is filled with a mixed-state heat-conducting medium, the space between the inner cylinder and the spiral pipe is filled with heat-conducting cement (18), and the space between the heat-conducting cement and the inner wall of the outer cylinder is filled with liquid-state heat-conducting sand (19). The heat exchanger has the advantages that liquid heat conduction sand can be automatically filled in gaps between the heat conduction cement and the inner barrel and the spiral pipe, and it is guaranteed that the heat removal capacity of the heat exchanger is not attenuated; expansion joints are arranged at the inner cylinder, the water inlet pipe and the water outlet pipe, so that thermal stress is effectively released, the steam yield is increased, and coking is reduced.

Description

Technical Field

[0001] The utility model relates to a stress-free riser coil heat exchanger filled with a mixed heat-conducting medium, belonging to the technical field of coke oven waste heat recovery. Background Art

[0002] The waste heat recovery of raw gas from coke ovens usually adopts an external coil heat exchanger. When installing the external coil heat exchanger, the original straight section of the riser is replaced and installed between the riser base and the bridge pipe. When the high-temperature raw gas of 600℃-800℃ passes through the internal channel of the external coil heat exchanger, it exchanges heat with the spiral tube circulating water inside the external coil heat exchanger, thereby realizing waste heat recovery.

[0003] The existing coke oven gas waste heat recovery external coil heat exchanger has the following technical problems during use:

[0004] 1) The reliability of the heat exchanger is poor. The space between the spiral tube and the inner tube is filled with thermal conductive paste, which solidifies and hardens after being heated and dried. During the heat extraction process of the heat exchanger, gaps will appear between the hardened thermal conductive paste and the inner tube and spiral tube, and the heat extraction capacity of the heat exchanger will be attenuated; the unreasonable structural design of the heat exchanger leads to the ineffective release of thermal stress, resulting in stress failure; the root of the heat exchanger is close to the carbonization chamber, and the temperature is too high during the drying process, exceeding the material limit temperature, causing root burns.

[0005] 2) Insufficient steam production. The inner tube of the outer coil heat exchanger is only in contact with the raw gas around the inner tube, and the temperature of the raw gas above and below the inner tube of the heat exchanger is also different. The existing structure takes less heat.

[0006] 3) Since the raw gas contains complex chemical components, unreasonable heat extraction during the external coil heat exchanger will cause coking on the inner wall and adhere to the inner tube of the heat exchanger, thereby affecting the heat extraction effect of the heat exchanger and causing smoke and other effects. Utility Model Content

[0007] The utility model aims to provide a stress-free riser coil heat exchanger filled with a mixed heat-conducting medium, wherein a mixed heat-conducting medium composed of heat-conducting clay and fluid heat-conducting sand is filled between an inner tube and an outer tube to ensure that the heat-taking capacity of the heat exchanger is not attenuated; expansion joints are arranged at the inner tube and the water inlet and outlet pipes to effectively release thermal stress; a protective layer is arranged at the root of the outer coil heat exchanger to protect the root from burning damage; the steam production is increased, the generation of coking is reduced, and the problems existing in the background technology are solved.

[0008] The technical solution of the utility model is:

[0009] A stress-free riser coil heat exchanger filled with a mixed heat-conducting medium comprises an inner tube, a lower flange, an upper flange and an outer tube, wherein the inner tube is arranged inside the outer tube, the two are arranged concentrically, the upper flange and the lower flange are respectively arranged at the upper end and the lower end of the outer tube, and the lower end of the inner tube is welded to the lower flange; the special feature of the invention is that the upper end of the inner tube is connected to the upper flange through an inner tube expansion joint, the upper end and the lower end of the inner tube are respectively provided with an outlet pipe and an inlet pipe, a spiral tube is wound around the outer wall of the inner tube, the two ends of the spiral tube are respectively connected to the inlet pipe and the outlet pipe, and water pipe expansion joints are provided at both ends where the two ends extend out of the outer tube; a mixed heat-conducting medium is filled between the inner tube and the outer tube, the mixed heat-conducting medium is composed of heat-conducting clay and liquid heat-conducting sand, the heat-conducting clay is filled between the inner tube and the spiral tube, and the liquid heat-conducting sand is filled between the heat-conducting clay and the inner wall of the outer tube.

[0010] A plurality of fins are evenly arranged vertically in the inner cylinder along the circumferential direction, and the inner surface of the inner cylinder is lined with ceramic glaze.

[0011] A protective layer is provided at the lower part of the inner cylinder, and the protective layer is made of tortoise shell mesh and high-temperature castable material.

[0012] An expansion joint sheath is arranged inside the inner tube expansion joint to protect the inner tube expansion joint.

[0013] The number of the spiral tubes is two groups, namely spiral tube one and spiral tube two. Spiral tube one and spiral tube two are arranged in parallel. Spiral tube one and spiral tube two have small pitches in the lower part of the inner cylinder and are arranged closely, and the rest of the parts have large pitches and are arranged sparsely.

[0014] The water inlet pipe and the water outlet pipe are connected to the water inlet flange and the water outlet flange respectively.

[0015] The outer side of the outer cylinder is provided with a heat-insulating filler and a heat-insulating outer skin.

[0016] The spiral tube 1 and the spiral tube 2 are fixed by intermittent welding or by using clips.

[0017] The particle size of the liquid thermal conductive sand is 50-300 meshes.

[0018] The pitch of the inner cylinder welded fins is 50-80 mm in arc length, 6-8 mm in fin thickness, and 50-100 mm in width.

[0019] The beneficial effects of the utility model are as follows: liquid heat-conducting sand can be automatically filled into the gaps between the heat-conducting mortar and the inner tube and the spiral tube, thereby ensuring that the heat-taking capacity of the heat exchanger is not attenuated; expansion joints are arranged at the inner tube and the water inlet pipe and the water outlet pipe, thereby effectively releasing thermal stress; a protective layer is arranged at the root of the heat exchanger to protect the root from burning damage; heat extraction is more reasonable, more heat is extracted from the lower part with more heat, and less heat is extracted from the place with less heat, thereby increasing steam production and reducing coking. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a cross-sectional view of the utility model;

[0021] Figure 2 It is a top view of the utility model;

[0022] Figure 3 for Figure 1 A magnified view of part I;

[0023] Figure 4 It is a schematic diagram of the structure of the utility model;

[0024] In the figure: inner tube 1, lower flange 2, upper flange 3, outer tube 4, inner tube expansion joint 5, expansion joint jacket 6, fin 7, thermal insulation skin 8, thermal insulation filler 9, water inlet pipe 10, water inlet flange 11, water pipe expansion joint 12 water outlet pipe 13, water outlet flange 14, spiral tube 15, spiral tube 2 16, protective layer 17, thermal conductive paste 18, liquid thermal conductive sand 19. DETAILED DESCRIPTION

[0025] The present invention will be further described below through examples in conjunction with the accompanying drawings.

[0026] A stress-free riser coil heat exchanger filled with a mixed heat-conducting medium comprises an inner tube 1, a lower flange 2, an upper flange 3 and an outer tube 4, wherein the inner tube 1 is arranged inside the outer tube 4, the two are arranged concentrically, the upper flange 3 and the lower flange 2 are respectively installed on the upper end face and the lower end face of the outer tube 4, and the lower end of the inner tube 1 is welded to the lower flange 2; the special features thereof are as follows: the upper end of the inner tube 1 is connected to the upper flange 3 through an inner tube expansion joint 5, the upper end and the lower end of the inner tube 1 are respectively provided with an outlet pipe 13 and an inlet pipe 10, a spiral tube is wound around the outer wall of the inner tube 1, the two ends of the spiral tube are respectively connected to the inlet pipe 10 and the outlet pipe 13, and water pipe expansion joints 12 are provided at both ends extending out of the outer tube 4; a mixed heat-conducting medium is filled between the inner tube 1 and the outer tube 4, the mixed heat-conducting medium is composed of a heat-conducting paste 18 and liquid heat-conducting sand 19, the heat-conducting paste 18 is filled between the inner tube 1 and the spiral tube, and the liquid heat-conducting sand 19 is filled between the heat-conducting paste 18 and the inner wall of the outer tube 4.

[0027] A plurality of fins 7 are vertically and uniformly welded inside the inner tube 1 along the circumferential direction, and the inner surface of the inner tube 1 is lined with ceramic glaze.

[0028] The lower part of the inner tube 1 within the range of 100-300 mm is covered with a protective layer 17, which is composed of a tortoise shell mesh and a high-temperature castable material and is used to protect the root and prevent burning.

[0029] An expansion joint sheath 6 is provided inside the inner tube expansion joint 5 to protect the inner tube expansion joint.

[0030] Two groups of spiral tubes are wound within the height range of the outer wall L2 of the inner tube 1, namely spiral tube 1 15 and spiral tube 2 16. The spiral tube 1 15 and spiral tube 2 16 are intermittently welded or fixed with clips. The spiral tube 1 15 and spiral tube 2 16 are arranged in parallel. The spiral tube 1 15 and spiral tube 2 16 adopt small pitch and are closely arranged in the lower L1 section of the inner tube, and adopt large pitch and are sparsely arranged in the rest of the section. The relationship between the L1 section and the total length section L2 is: L1 = (1 / 3-1 / 2) * L2. The pitch of the spiral tube in the L1 section is 1 / 3-1 / 2 of the pitch of the spiral tube in the rest of the section. The spiral tube 1 and spiral tube 2 are respectively connected with the outlet pipe and the inlet pipe at the upper and lower ends of the inner tube. The inlet pipe 10 and the outlet pipe 13 are respectively connected with the inlet flange 11 and the outlet flange 14. The spiral tube 1 15 and the spiral tube 2 16 are respectively provided with water pipe expansion joints 12 at the outer tube to eliminate the influence of thermal deformation.

[0031] The outer side of the outer cylinder 4 is provided with a heat-insulating filler 9 and a heat-insulating outer skin 8, and the outer cylinder plays a load-bearing supporting role.

[0032] The mixed heat-conducting medium filled between the inner tube 1 and the outer tube 4 is specifically as follows: a heat-conducting paste 18 is applied between the inner tube 1 and the spiral tube, and the heat-conducting paste 18 fully fills the gap between the spiral tubes, and preferably the spiral tubes are not exposed after smoothing. The space between the heat-conducting paste 18 and the inner wall of the outer tube 4 is filled with liquid heat-conducting sand 19, and the particle size of the liquid heat-conducting sand 19 is 50-300 meshes.

[0033] The spacing of the welded fins 7 of the inner tube 1 is 50-80 mm in arc length, 6-8 mm in fin thickness, and 50-100 mm in width.

[0034] The utility model can realize the automatic filling of the gap between the heat-conducting mortar and the inner tube and the spiral tube with liquid heat-conducting sand, so as to ensure that the heat-collecting capacity of the heat exchanger is not attenuated; expansion joints are arranged at the inner tube and the water inlet and outlet pipes, so that the places where the heat exchanger may be deformed are in a floating state, and the thermal stress is effectively released; a protective layer is arranged at the root of the outer coil heat exchanger, which can effectively block the heat from entering the root of the heat exchanger and protect the root from burning damage; the inner wall of the inner tube is evenly distributed with vertical heat-conducting fins to increase the heat exchange area; the spiral tube coiled on the outer wall of the inner tube adopts a variable pitch double spiral tube, the lower part of the heat exchanger is dense and the upper part is sparse, so that the heat collection is more reasonable. More heat is collected in the lower part with more heat, and less heat is collected in the place with less heat, thereby increasing the steam production and reducing the generation of coking; the sintered enamel glaze of the inner tube can enhance the smoothness and further reduce the adhesion of tar.

Claims

1. A stress-free riser coil heat exchanger filled with a mixed heat-conducting medium, comprising an inner tube (1), a lower flange (2), an upper flange (3) and an outer tube (4), wherein the inner tube (1) is arranged inside the outer tube (4), the two being arranged concentrically, the upper flange (3) and the lower flange (2) being arranged at the upper and lower ends of the outer tube (4), respectively, and the lower end of the inner tube (1) being welded to the lower flange (2); characterized in that: The upper end of the inner tube (1) is connected to the upper flange (3) via an inner tube expansion joint (5); a water outlet pipe (13) and a water inlet pipe (10) are respectively provided at the upper and lower ends of the inner tube (1); a spiral tube is wound around the outer wall of the inner tube (1); both ends of the spiral tube are respectively connected to the water inlet pipe (10) and the water outlet pipe (13); and water pipe expansion joints (12) are provided at both ends where the ends extend out of the outer tube (4); a mixed heat-conducting medium is filled between the inner tube (1) and the outer tube (4); the mixed heat-conducting medium is composed of heat-conducting paste (18) and liquid heat-conducting sand (19); the heat-conducting paste (18) is filled between the inner tube (1) and the spiral tube; and the liquid heat-conducting sand (19) is filled between the heat-conducting paste (18) and the inner wall of the outer tube (4).

2. The stress-free riser coil heat exchanger filled with a mixed heat-conducting medium according to claim 1, characterized in that: A plurality of fins (7) are evenly arranged vertically in the circumferential direction inside the inner cylinder (1), and the inner surface of the inner cylinder (1) is lined with a ceramic glaze.

3. A stress-free riser coil heat exchanger filled with a mixed heat-conducting medium according to claim 1 or 2, characterized in that: A protective layer (17) is provided at the lower part of the inner tube (1), and the protective layer (17) is made of tortoise shell mesh and high-temperature castable material.

4. A stress-free riser coil heat exchanger filled with a mixed heat-conducting medium according to claim 1 or 2, characterized in that: An expansion joint sheath (6) is provided on the inner side of the inner tube expansion joint (5).

5. A stress-free riser coil heat exchanger filled with a mixed heat-conducting medium according to claim 1 or 2, characterized in that: The number of the spiral tubes is two groups, namely spiral tube one (15) and spiral tube two (16). The spiral tube one (15) and spiral tube two (16) are arranged in parallel. The spiral tube one and spiral tube two have a small pitch at the lower part of the inner tube and are arranged closely, while the remaining part has a large pitch and is sparsely arranged.

6. A stress-free riser coil heat exchanger filled with a mixed heat-conducting medium according to claim 1 or 2, characterized in that: The water inlet pipe (10) and the water outlet pipe (13) are respectively connected to the water inlet flange (11) and the water outlet flange (14).

7. A stress-free riser coil heat exchanger filled with a mixed heat-conducting medium according to claim 1 or 2, characterized in that: The outer side of the outer cylinder (4) is provided with a thermal insulation filler (9) and a thermal insulation outer skin (8).

8. The stress-free riser coil heat exchanger filled with a mixed heat-conducting medium according to claim 5, characterized in that: The spiral tube 1 (15) and the spiral tube 2 (16) are fixed by intermittent welding or by using clips.

9. A stress-free riser coil heat exchanger filled with a mixed heat-conducting medium according to claim 1 or 2, characterized in that: The particle size of the liquid thermal conductive sand (19) is 50-300 mesh.

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