Ascending pipe waste heat utilization device

Abstract

The utility model relates to an ascending pipe waste heat utilization device which comprises a heated section, a heat release section, a waste heat leading-out pipeline and a working medium leading-in pipeline. The heated section is composed of a lower collecting pipe, heat exchange vertical pipes and an upper collecting pipe, the multiple heat exchange vertical pipes are embedded in the pipe wall of the ascending pipe in the circumferential direction, and fins are arranged on one sides of the heat exchange vertical pipes; the heat release section is arranged in the furnace gas pipeline and consists of a plurality of annular finned tubes; one end of the annular finned tube is connected with the upper collecting tube through a waste heat leading-out pipeline, and the other end is connected with the lower collecting tube through a working medium leading-in pipeline; and a working medium inlet is formed in the waste heat leading-out pipeline close to the heat release section. The waste heat of the raw gas in the ascending pipe is recovered by the circulating working medium and used for heating the gas before entering the coke oven, so that the use amount of the heating gas of the coke oven can be effectively reduced, and the heat efficiency is improved; the ascension pipe waste heat utilization device is simple in structure and safe to use, molten salt is adopted as a working medium, an ultrasonic descaling device is arranged, and the inner wall of the ascension pipe is not prone to scaling.

Description

Technical Field

[0001] This utility model relates to the field of coke oven coking technology, and in particular to a coke oven riser pipe waste heat utilization device. Background Technology

[0002] Heat loss during the coking process in a coke oven mainly includes four parts: sensible heat from the red-hot coke exiting the oven, sensible heat from the raw coke gas, sensible heat from the coke oven flue gas, and heat dissipation from the oven surface. The temperature of the raw coke gas is approximately 650–750℃, and its sensible heat accounts for about 36% of the total heat distribution in the coke oven. Currently, the technology for recovering waste heat from raw coke gas is relatively mature and has significant economic benefits.

[0003] Installing heat exchange devices (such as jackets or coils) on the outer wall of the coke oven riser pipe, and using heat transfer oil, water, or organic working fluids to absorb the heat from the raw coal gas, is called riser pipe waste heat utilization technology. In the practical application of this technology, it is crucial to ensure that the riser pipe heat exchanger has effective measures and a reasonable structure to avoid deformation and leakage. Even if these problems occur, the working fluid should be prevented from entering the coke oven carbonization chamber to ensure the safe and stable operation of coke oven production. Simultaneously, it is necessary to reasonably and effectively control the temperature of the riser pipe's inner wall (typically ≥450℃) to avoid the temperature range where large amounts of tar condense, thus preventing tar buildup and graphitization on the inner wall of the riser pipe, which could lead to blockage and environmental problems (such as smoke).

[0004] On the other hand, the traditional method for treating raw coal gas in the coking industry is to spray circulating ammonia water at 70-75°C into the raw coal gas. As the circulating ammonia water absorbs heat and evaporates, the temperature of the raw coal gas decreases before it enters the subsequent chemical production stage for recovery and treatment. This process results in a significant waste of the sensible heat of the raw coal gas. Summary of the Invention

[0005] This utility model provides a waste heat recovery device for riser pipes. It uses a circulating working fluid to recover the waste heat of raw coal gas in the riser pipes and uses it to heat the coal gas before it enters the coke oven. This can effectively reduce the amount of coal gas used for heating the coke oven and improve thermal efficiency. The waste heat recovery device for riser pipes has a simple structure and is safe to use. It uses molten salt as the working fluid and is equipped with an ultrasonic descaling device, so that scale does not easily form on the inner wall of the riser pipe.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A waste heat recovery device for a riser pipe includes a heating section, a heat release section, a waste heat discharge pipe, and a working fluid inlet pipe. The heating section consists of a lower manifold, a heat exchange riser, and an upper manifold. Both the lower and upper manifolds are annular pipes. The lower manifold is located at the bottom periphery of the riser pipe, and the upper manifold is located at the top periphery of the riser pipe. Multiple heat exchange risers are circumferentially embedded in the riser pipe wall. The heat exchange risers have fins on the side facing inwards from the riser pipe. The lower end of the heat exchange riser is connected to the lower manifold, and the upper end of the heat exchange riser is connected to the upper manifold. The heat release section is located inside the furnace gas pipeline and consists of multiple annular finned tubes. Both ends of the annular finned tubes extend from the furnace gas pipeline. One end is connected to the upper manifold through the waste heat discharge pipe, and the other end is connected to the lower manifold through the working fluid inlet pipe. A working fluid inlet is provided on the waste heat discharge pipe near the heat release section, and a valve is provided at the working fluid inlet.

[0008] The riser consists of a cylinder, flanges, and an insulation layer. Flanges are provided at both ends of the cylinder, and an insulation layer is provided on the outside of the cylinder, which encloses the heat exchange riser. Multiple slits are opened along the circumference of the cylinder, and the heat exchange riser is embedded in the slits and welded to the cylinder. The inner wall of the cylinder is a smooth wall surface.

[0009] The waste heat extraction pipeline is equipped with an outlet valve near the upper manifold; the working fluid introduction pipeline is equipped with an inlet valve near the lower manifold.

[0010] The fins are multiple and arranged radially.

[0011] The heating section, heat release section, waste heat discharge pipe and working fluid introduction pipe are all made of stainless steel, with the heating section made of heat-resistant stainless steel.

[0012] Each heat exchange riser is made from a single seamless steel pipe.

[0013] A device for utilizing waste heat from a riser pipe further includes an ultrasonic descaling device; the ultrasonic descaling device comprises an ultrasonic generator, an ultrasonic transducer, and a high-frequency cable, wherein the ultrasonic generator and the ultrasonic transducer are connected via the high-frequency cable; the ultrasonic transducer is mounted on a waveguide structure, and the waveguide structure is mounted on a flange at the top of the riser pipe.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1) The heating section of the riser waste heat utilization device is made of a whole seamless steel pipe, which is welded to the manifold at both ends, which helps to reduce leakage and extend service life; the heat exchange tubes in the heating section are equipped with fins on the inside, which increases the heat exchange area and improves the heat exchange efficiency.

[0016] 2) All pipes in the riser waste heat recovery device are made of stainless steel, which is corrosion-resistant and not easy to leak; the circulating working fluid is molten salt, which has a high operating temperature, and even if there is a leak, it will not affect the operation of the coke oven, ensuring the stable operation of the coke oven.

[0017] 3) The waste heat of the recovered raw coal gas is exchanged with the coal gas before it enters the coke oven. The waste heat of the raw coal gas is used to indirectly heat the coal gas entering the furnace, thereby increasing the temperature of the coal gas entering the furnace. This helps to reduce the amount of coal gas used during coke oven production and improve thermal efficiency.

[0018] 4) Use an ultrasonic descaling device to remove scale from the inner wall of the riser pipe in a timely manner to ensure the long-term stable operation of the system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the riser pipe waste heat utilization device described in this utility model.

[0020] Figure 2 This is a top view of the heated section described in this utility model.

[0021] Figure 3 This is a schematic diagram of the structure of the heat exchange riser described in this utility model.

[0022] Figure 4 yes Figure 3 AA view in the middle.

[0023] In the diagram: 1. Ascending pipe 101. Cylinder 102. Flange 103. Insulation layer 21. Heat exchange riser 22. Fin 23. Upper manifold 24. Lower manifold 3. Furnace gas inlet pipe 41. Annular finned tube 42. Valve 5. Waste heat outlet pipe 51. Outlet valve 6. Working fluid inlet pipe 61. Inlet valve 7. Ultrasonic descaling device 701. Ultrasonic generator 702. High-frequency cable 703. Ultrasonic transducer 704. Waveguide structure Detailed Implementation

[0024] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings:

[0025] like Figure 1 , Figure 2As shown, the waste heat utilization device for a riser pipe according to this utility model includes a heating section, a heat dissipation section, a waste heat outlet pipe 5, and a working fluid inlet pipe 6. The heating section consists of a lower manifold 24, a heat exchange riser 21, and an upper manifold 23. Both the lower manifold 24 and the upper manifold 23 are annular pipes. The lower manifold 24 is located at the bottom periphery of the riser pipe 1, and the upper manifold 23 is located at the top periphery of the riser pipe 1. Multiple heat exchange risers 21 are circumferentially embedded in the wall of the riser pipe 1, with the heat exchange risers 21 facing inwards towards the riser pipe 1. The heat exchange riser 21 is connected to the lower manifold 24 at its lower end and to the upper manifold 23 at its upper end. The heat release section is located inside the furnace gas pipeline 3 and consists of multiple annular finned tubes 41. Both ends of the annular finned tubes 41 extend from the furnace gas pipeline 3. One end is connected to the upper manifold 23 through the waste heat discharge pipeline 5, and the other end is connected to the lower manifold 24 through the working fluid inlet pipeline 6. A working fluid inlet is provided on the waste heat discharge pipeline 5 near the heat release section, and a valve 42 is provided at the working fluid inlet.

[0026] The riser pipe 1 is composed of a cylinder 101, a flange 102 and an insulation layer 103. The cylinder 101 has flanges 102 at both ends, and an insulation layer 103 is provided on the outside of the cylinder 101, which wraps the heat exchange riser 21. Multiple slits are opened along the circumference of the cylinder 101, and the heat exchange riser 21 is embedded in the slits and welded to the cylinder 101. The inner wall of the cylinder 101 is a smooth wall surface.

[0027] The waste heat discharge pipe 5 is provided with an outlet valve 51 near the upper manifold 23; the working fluid introduction pipe 6 is provided with an inlet valve 61 near the lower manifold 24.

[0028] like Figure 3 , Figure 4 As shown, there are multiple fins 22 arranged radially.

[0029] The heating section, the heat release section, the waste heat discharge pipe 5, and the working fluid introduction pipe 6 are all made of stainless steel, with the heating section made of heat-resistant stainless steel.

[0030] Each heat exchange riser 21 is made from a single seamless steel pipe.

[0031] The present invention provides a waste heat utilization device for a riser pipe, which further includes an ultrasonic descaling device 7. The ultrasonic descaling device 7 consists of an ultrasonic generator 701, an ultrasonic transducer 703, and a high-frequency cable 702. The ultrasonic generator 701 and the ultrasonic transducer 703 are connected through the high-frequency cable 702. The ultrasonic transducer 703 is mounted on a waveguide structure 704, which is mounted on a flange at the top of the riser pipe 1.

[0032] The working process of the riser pipe waste heat utilization device described in this utility model is as follows:

[0033] 1) Weld the two flanges 102 of the riser pipe 1 to the cylinder 101, weld fins 22 to the heat exchange riser 21 in the heating section, and weld the two ends of the heat exchange riser 21 to the upper manifold 23 and the lower manifold 24 respectively; weld the heat exchange riser 21 to the slit opened on the cylinder 101; weld the waveguide structure 704 to the flange at the top of the riser pipe 1; after all welding is completed, perform a pressure test on the assembly, and after the pressure test is qualified, install the insulation layer 103 on the outside of the riser pipe 1.

[0034] 2) Place multiple annular finned tubes 41 of the heat release section inside the furnace gas pipeline 3, perpendicular to the gas flow direction; weld the two ends of the annular finned tubes 41 to the waste heat discharge pipeline 5 and the working fluid inlet pipeline 6 respectively; connect the waste heat discharge pipeline 5 to the upper manifold 23 through the outlet valve 51, and connect the working fluid discharge pipeline 6 to the lower manifold 24 through the inlet valve 61; after the connection is completed, perform a pressure test on the working fluid circulation system; after the pressure test is passed, fill the working fluid using the valve 42 on the waste heat discharge pipeline 5;

[0035] 3) The high-temperature raw coal gas generated during the coke oven production process is discharged through riser pipe 1. The heat absorbed by the heating section is transferred to the working medium inside the pipe through the pipe wall of heat exchange riser 21. After absorbing heat, the working medium boils and evaporates, turning into steam. Under the action of pressure difference, the steam is discharged along the waste heat outlet pipe 5 to reach the heat release section.

[0036] 4) In the heat release section, the steam exchanges heat with the low-temperature coal gas in the furnace gas pipeline 3. The steam condenses and releases the latent heat of gasification. The condensate returns to the heating section through the working medium introduction pipeline 6 under the action of gravity and exchanges heat with the raw coal gas again.

[0037] 5) Steps 3) and 4) are repeated. The waste heat of the high-temperature raw coal gas is recovered by using the working fluid and used to heat the coal gas entering the furnace. The heated coal gas enters the coke oven directly for combustion.

[0038] The working medium is molten salt.

[0039] During the coke oven production process, the ultrasonic descaling device 7 is activated to remove impurities adhering to the inner wall of the riser pipe 1 and prevent graphite formation.

[0040] The waste heat utilization device for a riser pipe described in this utility model comprises stainless steel components for all major parts (including heat exchange riser 21, fins 22, upper manifold 23, lower manifold 24, outlet valve 51, inlet valve 61, waste heat discharge pipe 5, working fluid introduction pipe 6, annular finned tube 41, and valve 42, etc.). The heat exchange riser 21 is made of a single seamless steel pipe (without seams), with both ends welded to the corresponding manifolds to reduce leakage and extend service life. Fins 22 are welded to one side of the heat exchange riser 21 inside the riser pipe 1 (e.g., fins 22). Figure 3 , Figure 4 As shown, the side of the riser pipe 1 also functions as fins, effectively increasing the heat exchange area and improving heat exchange efficiency. The heat exchange element in the heat dissipation section uses annular finned tubes 41 (steel pipes with annular fins). The heated section and the heat dissipation section are connected via the waste heat discharge pipe 5 and the working fluid inlet pipe 6, forming a working fluid circulation system. The working fluid is filled on-site using the valve 42 on the waste heat discharge pipe 5. This valve 42 also allows for vacuuming or extraction of non-condensable gases, enabling on-site regeneration of the working fluid and extending its service life.

[0041] The working medium used in this invention is nitrate or other molten salt.

[0042] The riser pipe 1 of this invention has a seamless steel pipe body 101. Multiple slits are formed along the longitudinal direction of the body 101, the size of which matches the installation dimensions of the heat exchange riser pipe 21, ensuring a smooth inner wall after welding. The flange 102 is welded to the body 101 inside the body 101, and the weld is ground smooth after welding to ensure a smooth weld. Both the flange 102 and the body 101 are made of heat-resistant metal materials because they are in direct contact with the high-temperature raw coal gas.

[0043] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A device for utilizing waste heat from a riser pipe, characterized in that, The system includes a heating section, a heat release section, a waste heat discharge pipe, and a working fluid inlet pipe. The heating section consists of a lower manifold, a heat exchange riser, and an upper manifold. Both the lower and upper manifolds are annular pipes. The lower manifold is located at the bottom periphery of the riser pipe, and the upper manifold is located at the top periphery of the riser pipe. Multiple heat exchange risers are circumferentially embedded in the riser pipe wall. The heat exchange risers have fins on the side facing inwards from the riser pipe. The lower end of the heat exchange riser is connected to the lower manifold, and the upper end is connected to the upper manifold. The heat release section is located inside the furnace gas pipeline and consists of multiple annular finned tubes. Both ends of the annular finned tubes extend from the furnace gas pipeline. One end is connected to the upper manifold through the waste heat discharge pipe, and the other end is connected to the lower manifold through the working fluid inlet pipe. A working fluid inlet is located on the waste heat discharge pipe near the heat release section, and a valve is installed at the working fluid inlet.

2. The waste heat recovery device for riser pipes according to claim 1, characterized in that, The riser pipe consists of a cylinder, flanges, and an insulation layer; flanges are provided at both ends of the cylinder, and an insulation layer is provided on the outside of the cylinder, which wraps the heat exchange riser pipe inside. Multiple slits are opened along the circumference of the cylinder body, and the heat exchange riser is embedded in the slits and welded to the cylinder body. The inner wall of the cylinder body is a smooth wall surface.

3. The waste heat recovery device for riser pipes according to claim 1, characterized in that, The waste heat extraction pipeline is equipped with an outlet valve near the upper manifold; the working fluid introduction pipeline is equipped with an inlet valve near the lower manifold.

4. The waste heat recovery device for riser pipes according to claim 1, characterized in that, The fins are multiple and arranged radially.

5. The waste heat recovery device for riser pipes according to claim 1, characterized in that, The heating section, heat release section, waste heat discharge pipe and working fluid introduction pipe are all made of stainless steel, with the heating section made of heat-resistant stainless steel.

6. The waste heat recovery device for riser pipes according to claim 1, characterized in that, Each heat exchange riser is made from a single seamless steel pipe.

7. The waste heat recovery device for riser pipes according to claim 1, characterized in that, It also includes an ultrasonic descaling device; the ultrasonic descaling device consists of an ultrasonic generator, an ultrasonic transducer and a high-frequency cable, the ultrasonic generator and the ultrasonic transducer are connected by the high-frequency cable; the ultrasonic transducer is mounted on a waveguide structure, and the waveguide structure is mounted on the flange at the top of the riser pipe.

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