Waste heat coupling recovery system for steel rolling cooling bed and heating furnace

Abstract

The utility model provides a steel rolling cooling bed and heating furnace waste heat coupling recovery system which comprises a liquid storage tank, a low-grade waste heat exchange module, a deaerator and a cooling bed waste heat exchange module. The input end of the low-grade waste heat exchange module communicates with the output end of the liquid storage tank, and the low-grade waste heat exchange module is used for recovering heat of smoke exhausted by the steel rolling heating furnace through a heat exchange medium. The input end of the deaerator communicates with the output end of the low-grade waste heat exchange module, and the deaerator is used for removing dissolved oxygen in a heat exchange medium; the input end of the cooling bed waste heat exchange module communicates with the output end of the deaerator, and the cooling bed waste heat exchange module is used for recovering heat of the steel rolling cooling bed through a heat exchange medium. According to the waste heat coupling recovery system for the steel rolling cooling bed and the heating furnace, the system efficiency can be improved through low-grade waste heat of smoke exhausted out of the steel rolling heating furnace, the quality of finally formed steam is improved, and the service life of equipment is prolonged.

Description

Technical Field

[0001] This application relates to the field of rolling steel processing, and particularly to a waste heat coupling recovery system for a rolling steel cooling bed and a heating furnace. Background Art

[0002] In the hot rolling production process of iron and steel enterprises, steel billets need to be heated to a high temperature of 1100 - 1250 °C, then rolled through multiple passes, and finally cooled after rolling to obtain finished products. During the cooling process of the rolled pieces, natural cooling is usually carried out on the cooling bed, so that the temperature of the rolled pieces drops from 800 - 950 °C before cooling to about 100 °C when leaving the cooling bed. Therefore, a large amount of heat is usually lost, which not only causes waste of energy but also causes thermal pollution and deteriorates the working environment of the workshop.

[0003] In the prior art, a waste heat recovery device for the rolling steel cooling bed is usually used to recover the waste heat of the rolling steel cooling bed. For example, the utility model patent with the publication number CN216297529U and the name "A waste heat recovery and utilization device for a hot rolling seamless steel pipe cooling bed" collects the waste heat of the cooling bed through a steam drum and a heat exchange seamless steel pipe and outputs it in the form of steam. However, the utilization rate of the waste heat of the rolling steel production system by this device is low, and the heat exchange equipment is also easily corroded by dissolved oxygen and other gases in the water. Another example is the invention patent with the publication number CN115789605A and the name "A waste heat recovery and utilization system for a rolling steel cooling bed", which outputs the recovered waste heat in the form of steam through a heat exchange tube and a steam drum. However, similarly, the utilization rate of the waste heat of the rolling steel production system by this device is low, and the heat exchange equipment is also easily corroded by dissolved oxygen and other gases in the water. Utility Model Content

[0004] In view of the above problems, this application provides a waste heat coupling recovery system for a rolling steel cooling bed and a heating furnace, which can utilize the low-grade waste heat of the exhaust gas from the rolling steel heating furnace to improve the system efficiency, improve the quality of the finally formed steam, and extend the service life of the equipment.

[0005] To achieve the purpose of this application, the following technical solutions are provided in this application:

[0006] This application provides a waste heat coupling recovery system for a rolling steel cooling bed and a heating furnace, including: a liquid storage tank, a low-grade waste heat heat exchange module, a deaerator, and a cooling bed waste heat heat exchange module;

[0007] The input end of the low-grade waste heat heat exchange module is communicated with the output end of the liquid storage tank, and is used to recover the heat of the exhaust gas from the rolling steel heating furnace through a heat exchange medium;

[0008] The input end of the deaerator is communicated with the output end of the low-grade waste heat heat exchange module, and is used to remove the dissolved oxygen in the heat exchange medium;

[0009] The input end of the cooling bed waste heat exchange module is communicated with the output end of the deaerator, and is used to recover the heat of the rolling cooling bed through a heat exchange medium.

[0010] In a possible implementation manner, the rolling cooling bed and the heating furnace waste heat coupling recovery system, the low-grade waste heat exchange module includes: a low-grade waste heat exchanger;

[0011] The input end of the heat exchange side of the low-grade waste heat exchanger is communicated with the output end of the liquid storage tank, the output end of the heat exchange side is communicated with the input end of the deaerator, and the input end of the heat source side is communicated with the flue gas output end of the rolling heating furnace.

[0012] In a possible implementation manner, the low-grade waste heat exchange module further includes: a first branch for directly communicating the liquid storage tank with the deaerator.

[0013] In a possible implementation manner, the rolling cooling bed and the heating furnace waste heat coupling recovery system, the cooling bed waste heat exchange module includes: a steam drum and a high-efficiency radiation heat exchange device;

[0014] The liquid input end of the steam drum is communicated with the output end of the deaerator, and the steam input end is communicated with the output end of the high-efficiency radiation heat exchange device;

[0015] The high-efficiency radiation heat exchange device is arranged on the rolling cooling bed, and the input end is communicated with the liquid output end of the steam drum.

[0016] In a possible implementation manner, the rolling cooling bed and the heating furnace waste heat coupling recovery system, the low-grade waste heat exchanger has a first valve at the input end and a second valve at the output end; the first branch has a third valve.

[0017] In a possible implementation manner, the output end of the liquid storage tank has a first water pump, and the output end of the deaerator has a second water pump.

[0018] In a possible implementation manner, the liquid output end of the steam drum has a third water pump.

[0019] In a possible implementation manner, the high-efficiency radiation heat exchange device includes: a bracket, a slide rail, and a heat exchange component;

[0020] The heat exchange component is arranged on the cooling bed and is slidably connected to the slide rail through the bracket;

[0021] The slide rail is arranged on both sides of the cooling bed.

[0022] In a possible implementation manner, the steam output end of the steam drum is also communicated with the input end of the deaerator to provide heat for the deaerator.

[0023] In a possible implementation, the third water pump has a frequency conversion module for adjusting the circulation ratio of the heat exchange medium in the cold bed waste heat exchange module.

[0024] Beneficial effects:

[0025] Through a waste heat coupling recovery system for a rolling mill cooling bed and a heating furnace provided by the present application, the low-grade waste heat of the flue gas discharged from the rolling mill heating furnace can be utilized to provide heat source for the thermal deaerator, improving the thermal recovery efficiency of the rolling mill production system. After on-site implementation, the steam production per unit can be increased by 2.2 - 6.5%; and the dissolved oxygen and other gases in the raw water for generating steam are removed through the thermal deaerator, improving the quality of the finally formed steam, avoiding the corrosion of the equipment by dissolved oxygen, and extending the service life of the equipment. Description of the drawings

[0026] The drawings are used to provide further understanding of the present application and form a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation to the present application.

[0027] Figure 1 It is a schematic structural diagram of a waste heat coupling recovery system for a rolling mill cooling bed and a heating furnace provided by an embodiment of the present application;

[0028] Figure 2 It is a schematic structural diagram of an efficient radiation heat exchange device provided by an embodiment of the present application.

[0029] Reference numerals:

[0030] 1 - liquid storage tank; 2 - first water pump; 3 - first valve; 4 - low-grade waste heat exchanger; 5 - second valve; 6 - third valve; 7 - deaerator; 8 - second water pump; 9 - steam drum; 10 - third water pump; 11 - second valve;

[0031] 12 - efficient radiation heat exchange device, 121 - cooling bed, 1211 - cooling bed output roller table, 1212 - cooling bed input roller table, 122 - main pipeline, 123 - steam drum, 124 - support, 125 - slide rail, 126 - heat exchange component. Detailed implementation manners

[0032] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below with reference to the drawings in the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present application belong to the scope of protection of the present application.

[0033] 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 quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features; in the description of this application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0034] Embodiment 1

[0035] Figure 1-2 A waste heat coupling recovery system for a rolling mill cooling bed and a heating furnace provided by an embodiment of this application includes:

[0036] A liquid storage tank 1, a low-grade waste heat heat exchange module, a deaerator 7, and a cooling bed waste heat heat exchange module;

[0037] The input end of the low-grade waste heat heat exchange module is connected to the output end of the liquid storage tank 1 and is used to recover the heat of the flue gas discharged from the rolling mill heating furnace through a heat exchange medium;

[0038] The input end of the deaerator 7 is connected to the output end of the low-grade waste heat heat exchange module and is used to remove the dissolved oxygen in the heat exchange medium;

[0039] The input end of the cooling bed waste heat heat exchange module is connected to the output end of the deaerator 7 and is used to recover the heat of the rolling mill cooling bed through a heat exchange medium.

[0040] Among them, the cooling bed waste heat heat exchange module outputs high-temperature steam after heat exchange, which can be connected to the high-temperature steam supply pipeline to realize heat utilization.

[0041] Optionally, the heat exchange medium is demineralized water, and the liquid storage tank is a soft water storage tank for storing demineralized water as the heat exchange medium. Adopting this implementation method can slow down the corrosion rate of the inner wall of the pipeline.

[0042] Optionally, the pipeline in the waste heat coupling recovery system for the rolling mill cooling bed and the heating furnace has a heat insulation layer. Adopting this implementation method can reduce the heat loss during the operation of the heat exchange medium.

[0043] In a possible implementation manner, for the waste heat coupling recovery system for the rolling mill cooling bed and the heating furnace, the low-grade waste heat heat exchange module includes: a low-grade waste heat heat exchanger 4;

[0044] The input end of the heat exchange side of the low-grade waste heat heat exchanger 4 is connected to the output end of the liquid storage tank 1, the output end of the heat exchange side is connected to the input end of the deaerator 7, and the input end of the heat source side is connected to the flue gas output end of the rolling mill heating furnace.

[0045] Optionally, the low-grade waste heat heat exchanger is any one or more of a shell-and-tube heat exchanger, a plate heat exchanger, and a finned-tube heat exchanger.

[0046] In a possible implementation, the low-grade waste heat heat exchange module further includes: a first branch for directly connecting the liquid storage tank 1 to the deaerator 7. Adopting this implementation can ensure the supply of the heat exchange medium to the cooling bed waste heat heat exchange module during the maintenance or replacement of the low-grade waste heat heat exchanger.

[0047] In a possible implementation, for the rolling mill cooling bed and reheating furnace waste heat coupling recovery system, the cooling bed waste heat heat exchange module includes: a steam drum 9 and a high-efficiency radiation heat exchange device 12;

[0048] The liquid input end of the steam drum 9 is connected to the output end of the deaerator 7, and the steam input end is connected to the output end of the high-efficiency radiation heat exchange device 12;

[0049] The high-efficiency radiation heat exchange device 12 is arranged on the rolling mill cooling bed, and the input end is connected to the liquid output end of the steam drum 9. Adopting this implementation can enable the heat exchange medium to circulate in the cooling bed waste heat heat exchange module. The high-temperature gaseous heat exchange medium is output through the steam output end of the steam drum 9, and the high-temperature liquid heat exchange medium circulates in the cooling bed waste heat heat exchange module.

[0050] In a possible implementation, for the rolling mill cooling bed and reheating furnace waste heat coupling recovery system, the low-grade waste heat heat exchanger 4 has a first valve 3 at the input end and a second valve 5 at the output end; the first branch has a third valve 6. Adopting this implementation can close the first valve 3 and the second valve 5 and open the third valve 6 for the replacement or maintenance of the low-grade waste heat heat exchanger 4; during normal use, open the first valve 3 and the second valve 5 and close the third valve 6 to directly supply the heat exchange medium to the deaerator.

[0051] In a possible implementation, the output end of the liquid storage tank 1 has a first water pump 2, and the output end of the deaerator 7 has a second water pump 8. Adopting this implementation can provide the operating power for the heat exchange medium in the pipeline.

[0052] In a possible implementation, the liquid output end of the steam drum 9 has a third water pump 10.

[0053] In a possible implementation, the high-efficiency radiation heat exchange device 12 includes: a bracket 124, a slide rail 125, and a heat exchange component 126;

[0054] The heat exchange component 126 is arranged on the cooling bed 121 and is slidably connected to the slide rail 125 through the bracket 124;

[0055] The slide rail 125 is arranged on both sides of the cooling bed 121.

[0056] Optionally, the heat exchange assembly 126 includes a plurality of heat exchangers, and the support 124 includes a plurality of support units respectively corresponding to each heat exchanger one by one. Pulley wheels are provided at the ends of the support units for sliding the support on the slide rail 125, so as to facilitate the adjustment of the position of a single heat exchanger relative to the cooling bed.

[0057] Among them, multiple groups of the high-efficiency radiation heat exchange devices operate in parallel, and multiple heat exchange assemblies 126 in each group operate in series, and can be flexibly designed according to the width of the cooling bed and the distribution of the temperature field of the cooling bed.

[0058] Optionally, a regulating pump is provided at the input end of the heat exchange assembly 126 for regulating the water volume entering each heat exchange assembly to keep the water volume of each heat exchange assembly consistent.

[0059] In a possible implementation manner, the steam output end of the steam drum 9 is also communicated with the input end of the deaerator 7 for providing heat to the deaerator 7.

[0060] Optionally, a fourth valve is provided on the pipeline connecting the steam output end of the steam drum 9 and the deaerator 7.

[0061] In a possible implementation manner, the third water pump 10 has a frequency conversion module for regulating the circulation ratio of the heat exchange medium in the waste heat exchange module of the cooling bed.

[0062] Working principle:

[0063] The first heat exchange medium is output from the liquid storage tank 1 by the first water pump 2 and enters the low-grade waste heat exchanger 4. According to the temperature of the flue gas discharged from the steel rolling heating furnace, the flue gas flow is adjusted to raise the temperature of the first heat exchange medium to 40 °C to 60 °C to obtain the second heat exchange medium.

[0064] The second heat exchange medium enters the deaerator 7 and is heated to above 104 °C to obtain the third heat exchange medium.

[0065] The third heat exchange medium is then passed into the steam drum 9 through the second water pump 8, and then enters the high-efficiency radiation heat exchange device 12 from the steam drum 9 for heat exchange. The third heat exchange medium is heated to a high-temperature gas-liquid mixture state and then returned to the steam drum 9; the saturated steam at 170 °C to 180 °C in the steam drum 9 is output from the steam output end of the steam drum.

[0066] The output high-temperature steam can be passed into the deaerator 7 to provide heat, or can be supplied to other equipment for operation.

[0067] In several embodiments provided by the present application, it should be understood that the disclosed systems, modules, and methods can be implemented in other ways. For example, the module embodiments described above are merely illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling, direct coupling, or communication connection between each other can be an indirect coupling or communication connection through some interfaces, modules, or units, and can be in electrical, mechanical, or other forms.

[0068] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. The present application is not limited to the exact structures described above and illustrated in the drawings, and it cannot be determined that the specific implementation of the present application is only limited to these descriptions. For those of ordinary skill in the technical field to which the present application belongs, without departing from the concept of the present application, various changes and deformations made should be regarded as falling within the protection scope of the present application.

Claims

1. A steel rolling cooling bed and heating furnace waste heat coupling recovery system, characterized in that: include: Liquid storage tank (1), low-grade waste heat heat exchange module, deaerator (7), cooling bed waste heat heat exchange module; The input end of the low-grade waste heat heat exchange module is connected to the output end of the liquid storage tank (1) and is used to recover the heat of the exhaust gas from the steel rolling heating furnace through the heat exchange medium; The input end of the deaerator (7) is connected to the output end of the low-grade waste heat heat exchange module, and is used to remove dissolved oxygen in the heat exchange medium; The input end of the cooling bed waste heat exchange module is connected to the output end of the deaerator (7) and is used to recover the heat of the steel rolling cooling bed through a heat exchange medium.

2. The steel rolling cooling bed and heating furnace waste heat coupling recovery system according to claim 1 is characterized in that: The low-grade waste heat heat exchange module comprises: a low-grade waste heat heat exchanger (4); The input end of the heat exchange side of the low-grade waste heat exchanger (4) is connected to the output end of the liquid storage tank (1), the output end of the heat exchange side is connected to the input end of the deaerator (7), and the input end of the heat source side is connected to the flue gas output end of the steel rolling heating furnace.

3. The steel rolling cooling bed and heating furnace waste heat coupling recovery system according to claim 2 is characterized in that: The low-grade waste heat heat exchange module further comprises: a first branch, used to connect the liquid storage tank (1) directly to the deaerator (7).

4. The steel rolling cooling bed and heating furnace waste heat coupling recovery system according to claim 1 is characterized in that: The cooling bed waste heat exchange module comprises: a steam drum (9), and a high-efficiency radiation heat exchange device (12); The liquid input end of the steam drum (9) is in communication with the output end of the deaerator (7), and the steam input end is in communication with the output end of the high-efficiency radiation heat exchange device (12); The high-efficiency radiation heat exchange device (12) is arranged on the steel rolling cooling bed, and its input end is connected to the liquid output end of the steam drum (9).

5. The steel rolling cooling bed and heating furnace waste heat coupling recovery system according to claim 3 is characterized in that: The low-grade waste heat exchanger (4) has a first valve (3) at the input end and a second valve at the output end; and a third valve is provided on the first branch.

6. The steel rolling cooling bed and heating furnace waste heat coupling recovery system according to claim 1 is characterized in that: The output end of the liquid storage tank (1) is provided with a first water pump (2), and the output end of the deaerator (7) is provided with a second water pump (8).

7. The steel rolling cooling bed and heating furnace waste heat coupling recovery system according to claim 4 is characterized in that: The liquid output end of the steam drum (9) is provided with a third water pump (10).

8. The steel rolling cooling bed and heating furnace waste heat coupling recovery system according to claim 4 is characterized in that: The high-efficiency radiation heat exchange device (12) comprises: a bracket (124), a slide rail (125), and a heat exchange component (126); The heat exchange component (126) is arranged on the cooling bed (121) and is slidably connected to the slide rail (125) via the bracket (124); The slide rails (125) are arranged on both sides of the cooling bed (121).

9. The steel rolling cooling bed and heating furnace waste heat coupling recovery system according to claim 4 is characterized in that: The steam output end of the steam drum (9) is also connected to the input end of the deaerator (7) for providing heat to the deaerator (7).

10. The steel rolling cooling bed and heating furnace waste heat coupling recovery system according to claim 7, characterized in that: The third water pump (10) has a frequency conversion module for adjusting the circulation rate of the heat exchange medium in the cooling bed waste heat exchange module.

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