Waste heat recycling device of pulverized coal flue gas furnace

Abstract

The utility model belongs to the field of waste heat recovery, and relates to a waste heat recycling device of a pulverized coal flue gas furnace, which can recycle exhausted heat from a mixing chamber of the flue gas furnace to an inlet of a mill and slow down the surface oxidation speed of a pipeline at the position. According to the technical scheme, the device comprises a waste heat recoverer, a pulverized coal preheating device and a pulverized coal preheating oil pump. The waste heat recoverer is fixed on a mixed flue gas pipeline between a mixing chamber of a flue gas furnace and an inlet of a coal injection mill, and the waste heat recoverer is configured to recover heat on the outer surface of the mixed flue gas pipeline. The oil inlet of the pulverized coal preheating and heating device is further communicated with the oil outlet of the waste heat recoverer, and the oil outlet of the pulverized coal preheating and heating device is further communicated with the oil inlet of the waste heat recoverer. And the pulverized coal preheating oil pump is communicated with a pipeline between the oil outlet of the pulverized coal preheating heating device and the oil inlet of the waste heat recoverer.

Description

Technical Field

[0001] This utility model belongs to the field of waste heat recovery and relates to a waste heat recovery and utilization device for pulverized coal flue gas furnace. Background Technology

[0002] The pulverized coal injection flue gas furnace is divided into a combustion chamber and a mixing chamber. The furnace temperature of the combustion chamber is 1000-1200℃, the furnace temperature of the mixing chamber is 900-1000℃, the flue gas temperature from the mixing chamber to the mill inlet is about 300℃, and the surface temperature of the pipe from the mixing chamber to the mill inlet is 270-290℃, with severe oxidation on the pipe surface.

[0003] Currently, the industry has not utilized direct radiation to exhaust the heat from the flue gas mixing chamber to the mill inlet, resulting in energy waste. Furthermore, at high temperatures, the pipe surface undergoes severe oxidation, affecting its service life. Utility Model Content

[0004] To overcome the deficiencies in the aforementioned related technologies, this utility model proposes a waste heat recovery and utilization device for pulverized coal flue gas furnace, which can recover and utilize the exhaust heat from the mixing chamber of the flue gas furnace to the mill inlet, thereby slowing down the oxidation rate of the pipeline surface in this area.

[0005] To achieve the above technical objectives, this utility model provides a waste heat recovery and utilization device for a pulverized coal flue gas furnace. The device includes a waste heat recovery unit, a pulverized coal preheating device, and a pulverized coal preheating oil pump. The waste heat recovery unit is fixed to the mixed flue gas pipeline between the flue gas furnace mixing chamber and the inlet of the pulverized coal mill, and is configured to recover heat from the outer surface of the mixed flue gas pipeline. The oil inlet of the pulverized coal preheating device is also connected to the oil outlet of the waste heat recovery unit, and vice versa. The pulverized coal preheating oil pump is connected to the pipeline between the oil outlet of the pulverized coal preheating device and the oil inlet of the waste heat recovery unit.

[0006] The waste heat recovery unit includes: multiple sets of serpentine coils, an outer pipe, an oil inlet box, and an oil outlet box. The serpentine coils are bent into a spiral structure and are fitted to the outer surface of the mixed flue gas duct. The oil inlet and outlet of the serpentine coils are positioned opposite each other on both sides of the mixed flue gas duct. The outer pipe is fitted around the outside of the multiple sets of serpentine coils and shares a centerline with the mixed flue gas duct. An oil inlet box is fixed to the outer pipe, and the oil inlets of the multiple sets of serpentine coils are all connected to the oil inlet box. The oil outlet of the pulverized coal preheating device is also connected to the oil inlet box. Similarly, an oil outlet box is fixed to the outer pipe, and the oil outlets of the multiple sets of serpentine coils are all connected to the oil outlet box. The oil inlet of the pulverized coal preheating device is also connected to the oil outlet box.

[0007] Preferably, the waste heat recovery unit further includes an inner tube, which is disposed inside the plurality of serpentine coils and fitted onto the mixed flue gas duct.

[0008] Preferably, the waste heat recovery and utilization device for the pulverized coal flue gas furnace further includes: a first shut-off valve, a first regulating valve, a second shut-off valve, a second regulating valve, and a third shut-off valve. The first shut-off valve is installed on the pipeline between the pulverized coal preheating oil pump and the pulverized coal preheating device. The first regulating valve is installed on the pipeline between the first shut-off valve and the pulverized coal preheating device. The second shut-off valve is installed on the pipeline between the pulverized coal preheating device and the waste heat recovery unit. The second regulating valve is installed on the pipeline between the second shut-off valve and the pulverized coal preheating device. The third shut-off valve is installed on the pipeline between the waste heat recovery unit and the pulverized coal preheating device.

[0009] Preferably, the waste heat recovery and utilization device for pulverized coal flue gas furnace further includes: a blast furnace hot blast stove flue gas preheating device, wherein the blast furnace hot blast stove flue gas preheating device is connected to the oil outlet of the pulverized coal preheating device, and the blast furnace hot blast stove flue gas preheating device is also connected to the oil inlet of the pulverized coal preheating device.

[0010] Preferably, a fourth shut-off valve and a fourth regulating valve are sequentially installed on the pipeline between the oil outlet of the pulverized coal preheating device and the flue gas preheating device of the blast furnace hot blast stove. A fifth shut-off valve is installed on the pipeline between the flue gas preheating device of the blast furnace hot blast stove and the oil inlet of the pulverized coal preheating device.

[0011] Preferably, the pulverized coal preheating device includes a pulverized coal preheating heat exchanger, which comprises a shell and an oil pipe. The shell has two connection ports, upper and lower. The oil pipe is wound around the shell, with one end connected to the pulverized coal preheating oil pump, the oil outlet of the waste heat recovery unit, and the oil outlet of the blast furnace hot blast stove flue gas preheating device. The other end of the oil pipe is also connected to the oil inlet of the waste heat recovery unit and the oil inlet of the blast furnace hot blast stove flue gas preheating device.

[0012] The beneficial effects of this utility model are as follows:

[0013] This utility model employs a waste heat recovery device. On the one hand, it wraps the mixed flue gas pipeline between the flue gas furnace mixing chamber and the inlet of the pulverized coal mill to reduce contact with oxygen and moisture in the air and slow down the oxidation rate. On the other hand, it recovers the heat radiated by the mixed flue gas pipeline between the flue gas furnace mixing chamber and the inlet of the pulverized coal mill, which helps to increase the temperature and preheating rate of fly ash in the pulverized coal preheating device. This has the advantages of extending equipment life and reducing energy consumption. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a structural diagram of the present invention;

[0016] Figure 2 This is a cross-sectional view of the waste heat recovery device of this utility model;

[0017] Figure 3 This is a structural diagram of the multiple sets of serpentine coils of this utility model. Detailed Implementation

[0018] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0019] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0020] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0021] like Figures 1 to 3As shown, some embodiments of this utility model provide a waste heat recovery and utilization device for a pulverized coal flue gas furnace. The waste heat recovery and utilization device includes: a waste heat recovery unit 1, a pulverized coal preheating device 2, and a pulverized coal preheating oil pump 3. The waste heat recovery unit 1 is fixed on the mixed flue gas pipeline 4 between the flue gas furnace mixing chamber and the inlet of the pulverized coal mill, and is configured to recover heat from the outer surface of the mixed flue gas pipeline 4. The oil inlet of the pulverized coal preheating device 2 is also connected to the oil outlet of the waste heat recovery unit 1, and the oil outlet of the pulverized coal preheating device 2 is also connected to the oil inlet of the waste heat recovery unit 1. The pulverized coal preheating oil pump 3 is connected to the pipeline between the oil outlet of the pulverized coal preheating device 2 and the oil inlet of the waste heat recovery unit 1.

[0022] The waste heat recovery unit 1 includes: multiple sets of serpentine coils 11, an outer pipe 12, an oil inlet box 13, and an oil outlet box 14. The serpentine coils 11 are bent into a spiral structure and are fitted to the outer surface of the mixed flue gas duct 4. The oil inlet and outlet of the serpentine coils 11 are positioned opposite each other on both sides of the mixed flue gas duct 4. The outer pipe 12 is fitted onto the outside of the multiple sets of serpentine coils 11 and shares a common centerline with the mixed flue gas duct 4. An oil inlet box 13 is fixed to the outer pipe 12, and the oil inlets of the multiple sets of serpentine coils 11 are all connected to the oil inlet box 13. The oil outlet of the pulverized coal preheating device 2 is also connected to the oil inlet box 13. Similarly, an oil outlet box 14 is fixed to the outer pipe 12, and the oil outlets of the multiple sets of serpentine coils 11 are all connected to the oil outlet box 14. The oil inlet of the pulverized coal preheating device 2 is also connected to the oil outlet box 14.

[0023] The waste heat recovery unit 1 also includes an inner tube, which is disposed inside the multiple sets of serpentine coils 11 and is fitted onto the mixed flue gas duct 4.

[0024] The waste heat recovery and utilization device for the pulverized coal flue gas furnace further includes: a first shut-off valve Q1, a first regulating valve T1, a second shut-off valve Q2, a second regulating valve T2, and a third shut-off valve Q3. The first shut-off valve Q1 is installed on the pipeline between the pulverized coal preheating oil pump 3 and the pulverized coal preheating heating device 2. The first regulating valve T1 is installed on the pipeline between the first shut-off valve Q1 and the pulverized coal preheating heating device 2. The second shut-off valve Q2 is installed on the pipeline between the pulverized coal preheating heating device 2 and the waste heat recovery unit 1. The second regulating valve T2 is installed on the pipeline between the second shut-off valve Q2 and the pulverized coal preheating heating device 2. The third shut-off valve Q3 is installed on the pipeline between the waste heat recovery unit 1 and the pulverized coal preheating heating device 2.

[0025] The waste heat recovery and utilization device for pulverized coal flue gas furnace further includes: a blast furnace hot blast stove flue gas preheating device 5, which is connected to the oil outlet of the pulverized coal preheating device 2 and is also connected to the oil inlet of the pulverized coal preheating device 2.

[0026] A fourth shut-off valve Q4 and a fourth regulating valve T4 are sequentially installed on the pipeline between the oil outlet of the pulverized coal preheating device 2 and the flue gas preheating device 5 of the blast furnace hot blast stove. A fifth shut-off valve Q5 is installed on the pipeline between the flue gas preheating device 5 of the blast furnace hot blast stove and the oil inlet of the pulverized coal preheating device 2.

[0027] The pulverized coal preheating device 2 includes a pulverized coal preheating heat exchanger, which comprises a shell and an oil pipe. The shell has two connection ports, one at the top and one at the bottom. The oil pipe is wound around the shell, with one end connected to the pulverized coal preheating oil pump 3, the oil outlet of the waste heat recovery unit 1, and the oil outlet of the blast furnace hot blast stove flue gas preheating device 5. The other end of the oil pipe is also connected to the oil inlet of the waste heat recovery unit 1 and the oil inlet of the blast furnace hot blast stove flue gas preheating device 5.

[0028] The application methods of this utility model are as follows:

[0029] The oil inlet of the pulverized coal preheating oil pump 3 is also connected to the oil tank. The pulverized coal preheating oil pump 3 is used to replenish the heat exchange oil in the waste heat recovery unit 1, the pulverized coal preheating device 2 and the blast furnace hot blast stove flue gas preheating unit. The heat exchange oil can be QB300 or QC320. When the heat exchange oil in the waste heat recovery unit 1, the pulverized coal preheating device 2 and the pulverized coal preheating heat exchanger is full, the first shut-off valve Q1 and the first regulating valve T1 are closed. After the heat exchange oil is heated in the blast furnace hot blast stove flue gas preheating unit, it enters the pulverized coal preheating heat exchanger under the action of heat, thus forming a heat exchange oil circulation and recovering the waste heat of the blast furnace hot blast stove flue gas to heat the pulverized coal.

[0030] Similarly, after the heat exchange oil flows out of the pulverized coal preheating heat exchanger, it can also enter the waste heat recovery unit 1. After the heat exchange oil in the waste heat recovery unit 1 is heated, it enters the pulverized coal preheating heat exchanger under the action of heat, thus forming a heat exchange oil circulation, and recovering the waste heat in the pipeline between the flue gas furnace mixing chamber and the mill inlet to heat the pulverized coal.

[0031] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0032] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A waste heat recovery and utilization device for pulverized coal flue gas furnace, characterized in that, include: A waste heat recovery unit is fixed on the mixed flue gas duct between the flue gas furnace mixing chamber and the inlet of the pulverized coal mill, and the waste heat recovery unit is configured to recover heat from the outer surface of the mixed flue gas duct. A pulverized coal preheating device, wherein the oil inlet of the pulverized coal preheating device is also connected to the oil outlet of the waste heat recovery device, and the oil outlet of the pulverized coal preheating device is also connected to the oil inlet of the waste heat recovery device; A pulverized coal preheating oil pump, wherein the pulverized coal preheating oil pump is connected to the oil outlet of the pulverized coal preheating heating device and the oil inlet of the waste heat recovery unit via pipelines; The waste heat recovery unit includes: Multiple sets of serpentine coils are bent into a spiral structure and are attached to the outer surface of the mixing flue gas duct. The oil inlet and oil outlet of the serpentine coils are arranged opposite each other on both sides of the mixing flue gas duct. The outer pipe is fitted around the outside of multiple sets of serpentine coils and shares a common centerline with the mixed flue gas duct. An oil inlet box is fixed on the outer tube, and the oil inlets of multiple sets of serpentine coils are all connected to the oil inlet box. The oil outlet of the pulverized coal preheating device is connected to the oil inlet box. An oil outlet box is fixed on the outer tube, and the oil outlets of multiple sets of serpentine coils are all connected to the oil outlet box. The oil inlet of the pulverized coal preheating device is connected to the oil outlet box.

2. The waste heat recovery and utilization device for pulverized coal flue gas furnace according to claim 1, characterized in that, The waste heat recovery unit also includes an inner tube, which is disposed inside the multiple sets of serpentine coils and is fitted onto the mixed flue gas duct.

3. The waste heat recovery and utilization device for pulverized coal flue gas furnace according to claim 2, characterized in that, The waste heat recovery and utilization device for pulverized coal flue gas furnace also includes: A first shut-off valve is installed on the pipeline between the pulverized coal preheating oil pump and the pulverized coal preheating heating device. A first regulating valve is installed on the pipeline between the first shut-off valve and the pulverized coal preheating device. The second shut-off valve is installed on the pipeline between the pulverized coal preheating device and the waste heat recovery device. The second regulating valve is installed on the pipeline between the second shut-off valve and the pulverized coal preheating device. The third shut-off valve is installed on the pipeline between the waste heat recovery unit and the pulverized coal preheating device.

4. The waste heat recovery and utilization device for pulverized coal flue gas furnace according to claim 3, characterized in that, The waste heat recovery and utilization device for pulverized coal flue gas furnace further includes: a blast furnace hot blast stove flue gas preheating device, which is connected to the oil outlet of the pulverized coal preheating device, and the blast furnace hot blast stove flue gas preheating device is also connected to the oil inlet of the pulverized coal preheating device.

5. The waste heat recovery and utilization device for pulverized coal flue gas furnace according to claim 4, characterized in that, A fourth shut-off valve and a fourth regulating valve are sequentially installed on the pipeline between the oil outlet of the pulverized coal preheating device and the flue gas preheating device of the blast furnace hot blast stove. A fifth shut-off valve is installed on the pipeline between the blast furnace hot blast stove flue gas preheating device and the oil inlet of the pulverized coal preheating device.

6. The waste heat recovery and utilization device for pulverized coal flue gas furnace according to claim 5, characterized in that, The pulverized coal preheating device includes a pulverized coal preheating heat exchanger, which comprises: The outer casing has two connection ports, one at the top and one at the bottom. An oil pipe is wound around the outer shell. One end of the oil pipe is connected to the oil outlet of the pulverized coal preheating oil pump, the oil outlet of the waste heat recovery unit, and the oil outlet of the blast furnace hot blast stove flue gas preheating device. The other end of the oil pipe is also connected to the oil inlet of the waste heat recovery unit and the oil inlet of the blast furnace hot blast stove flue gas preheating device.

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