Cooling bed waste heat recovery system

Abstract

The invention relates to the technical field of cooling bed waste heat recovery, in particular to a cooling bed waste heat recovery system which comprises a heat supply unit, a circulation unit, a refrigeration unit and a control unit, and the heat supply unit is connected with the circulation unit and used for providing a second working medium for the circulation unit; the circulating unit is connected with the refrigerating unit and used for outputting a fourth working medium after the second working medium makes full contact with a third working medium provided by the refrigerating unit and outputting a fifth working medium to the heat supply unit; the control unit is electrically connected with the heat supply unit, the circulation unit and the refrigeration unit so as to control supply of the second working medium according to the first temperature of the second working medium contained in the circulation unit and control output of the fifth working medium according to the second temperature of the fifth working medium contained in the circulation unit.

Description

Technical Field

[0001] The present application relates to the technical field of cooling bed waste heat recovery, and in particular to a cooling bed waste heat recovery system. Background Art

[0002] Industrial waste heat recovery is an important task in my country's energy conservation and emission reduction. When the metallurgical industry produces rolled steel products such as bars and steel sections, they must enter the cooling process after the rolling process. Specifically, the rolled pieces are sent to the cooling bed for natural cooling through transmission devices such as rollers, so that the rolled pieces are reduced from more than 950℃ before cooling to less than 250-350℃ when they are on the cooling bed. In this process, the rolled pieces release a large amount of sensible heat into the air, causing energy waste and worsening the high temperature working environment of the workshop.

[0003] In the existing technology, it is difficult to achieve long-term continuous production of steel rolling due to the influence of production scheduling, maintenance, and product replacement. The utilization value of unstable waste heat resources will be greatly reduced, and the utilization of low-grade waste heat such as sensible heat of steel is too limited. It is usually only used to produce low-temperature saturated steam with low added value. In addition, since the rolled pieces are gradually cooled on the cooling bed, the temperature of each section of the cooling bed is also different. The temperature of the high-temperature section can reach 600-800℃, and the temperature of the low-temperature section is 80-100℃, resulting in unstable heat sources. At present, the industry has not taken effective measures to collect and utilize this part of the lost heat energy. The heat released by the cooling of the rolled pieces is concentrated and dissipated into the environment, resulting in high temperature and poor environment in the working space of the operators.

[0004] In view of this, this application is specially filed. Summary of the invention

[0005] The present application provides a cooling bed waste heat recovery system to solve the problem of how to improve the recovery efficiency of cooling bed waste heat.

[0006] The present application provides a cooling bed waste heat recovery system, comprising: a heating unit, a circulation unit, a refrigeration unit and a control unit; wherein: The heat supply unit is connected to the circulation unit and is used to provide a second working medium to the circulation unit; The circulation unit is connected to the refrigeration unit, and is used to make the second working fluid fully contact with the third working fluid provided by the refrigeration unit, and then output a fourth working fluid, and output a fifth working fluid to the heating unit; The control unit is electrically connected to the heating unit, the circulation unit, and the refrigeration unit, respectively, to control the replenishment of the second working fluid according to the first temperature of the second working fluid set in the circulation unit, and to control the output of the fifth working fluid according to the second temperature of the fifth working fluid set in the circulation unit.

[0007] In some embodiments, the heating unit comprises: A heat collecting pipeline, used for accommodating a first working medium, wherein the heat collecting pipeline encloses a plurality of first installation areas and second installation areas alternately arranged along a steel passing direction of the cooling bed; The heat collecting cover accommodates the heat collecting pipeline and is used to receive the heat source provided by the cooling bed and heat the first working fluid to output the second working fluid.

[0008] In some embodiments, the heating unit further comprises: A mirror device is arranged in the first installation area and the second installation area, connected to the heat collecting cover, and is used to reflect infrared rays generated by the cooling bed heat source to the heat collecting pipeline to heat the first working medium.

[0009] In some embodiments, the mirror device comprises: A first reflector having a first reflective surface facing the heat collection pipeline; The second reflector is connected to the first reflector and has a second reflective surface facing away from the first reflective surface and toward the heat collection pipeline; wherein: The first reflector and the second reflector are arranged alternately along the steel passing direction of the cooling bed; and The first reflecting surface is inclined relative to the working surface of the cooling bed along a first direction, and the first reflecting surface and the working surface of the cooling bed form a first angle; The second reflecting surface is inclined relative to the cooling bed along a second direction, and the second reflecting surface forms a second angle with the working surface of the cooling bed; The first reflecting surface and the second reflecting surface form a third angle.

[0010] In some embodiments, the first angle ranges from 0 to 90°; the second angle ranges from 0 to 90°; and the third angle ranges from 0 to 180°.

[0011] In some embodiments, the heating unit further comprises: Sliding brackets are arranged at intervals on a side of the heat collecting cover close to the cooling bed along the steel passing direction of the cooling bed; A rolling element is arranged at one end of the sliding bracket away from the heat collecting cover.

[0012] In some embodiments, including: a first delivery pipeline, through which the heat supply unit provides the second working medium to the circulation unit; A first return pipeline, through which the circulation unit provides the fifth working medium to the heat supply unit.

[0013] In some embodiments, the control unit comprises: A first sensor, disposed on the first delivery pipeline, for detecting a first temperature of the second working fluid; A first control component is arranged on the first conveying pipeline; The control unit controls the amount of the second working fluid provided by the heat supply unit to the circulation unit through a first control component based on the first temperature detected by the first sensor.

[0014] In some embodiments, the control unit further comprises: a second sensor, disposed on the second return pipeline, for detecting a second temperature of the fifth working fluid; A second control component is arranged on the first return pipeline; The control unit controls the amount of the fifth working fluid output by the second storage tank to the heat supply unit through the second control component based on the second temperature detected by the second sensor.

[0015] After adopting the above technical scheme, the present application has the following beneficial effects compared with the prior art: the cooling bed waste heat recovery system in the present invention is provided with a heating unit, a circulation unit, a refrigeration unit and a control unit, the heating unit is connected to the circulation unit, and is used to provide the second working fluid to the circulation unit; the circulation unit is connected to the refrigeration unit, and is used to make the second working fluid fully contact with the third working fluid provided by the refrigeration unit, and then output the fourth working fluid, and output the fifth working fluid to the heating unit; the control unit is electrically connected to the heating unit, the circulation unit, and the refrigeration unit respectively, so as to control the supply of the second working fluid according to the first temperature of the second working fluid in the circulation unit, and control the output of the fifth working fluid according to the second temperature of the fifth working fluid in the circulation unit. By setting a temperature measuring point and a valve between the circulation unit and the heating unit, the supply of the second working fluid to the circulation unit is controlled according to the first temperature of the second working fluid, which can greatly improve the quality and output efficiency of the fourth working fluid, i.e., steam; and the output of the fifth working fluid to the heating unit is controlled according to the second temperature of the fifth working fluid, so that the molten salt enters the heating unit again for heating, thereby ensuring that the molten salt in the heat collection section reaches the first preset temperature before entering the circulation unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of the cooling bed waste heat recovery system in the embodiment of the present application; Figure 2 is a schematic structural diagram of a heat collecting device in an embodiment of the present application; Figure 3 yes Figure 2 Schematic diagram of the internal structure of the solar collector; Figure 4 yes Figure 3 Schematic diagram of the assembly of the middle mirror device; Figure 5 yes Figure 3 Another assembly diagram of the middle mirror device.

[0017] In the figure: 100, heating unit; 110, cooling bed; 111, heat collecting pipeline; 114, heat collecting cover; 120, mirror device; 121, first reflector; 121a, first reflective surface; 122, second reflector; 122a, second reflective surface; 123, first pivot member; 124, second pivot member; 130, sliding bracket; 131, rolling member; 140, first delivery pipeline; 141, first movable pipeline; 150, first return pipeline; 151, second movable pipeline ; 160, valve; 200, circulation unit; 210, first storage tank; 211, electric heater; 220, second storage tank; 230, superheater; 240, second delivery pipeline; 250, second return pipeline; 300, refrigeration unit; 310, convection pipeline; 320, preheater; 330, steam drum; 340, evaporator; 400, control unit; 410, first sensor; 420, first control component; 430, second sensor; 440, second control component. DETAILED DESCRIPTION

[0018] The technical solution of the present application will be described clearly and completely below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0019] The present application provides a cooling bed waste heat recovery system based on molten salt heat storage. For the specific structure of the cooling bed waste heat recovery system, please refer to Figures 1 to 5 , which includes: a heating unit 100, a circulation unit 200, a refrigeration unit 300 and a control unit 400. The heating unit 100 is connected to the circulation unit 200, and is used to provide the second working fluid b to the circulation unit 200. The circulation unit 200 is connected to the refrigeration unit 300, and is used to output a fourth working fluid d after the second working fluid b is fully contacted with the third working fluid c provided by the refrigeration unit 300, and output a fifth working fluid e to the heating unit 100; the control unit 400 is electrically connected to the heating unit 100, the circulation unit 200, and the refrigeration unit 300, respectively, to control the supply of the second working fluid b according to the first temperature of the second working fluid b in the circulation unit 200, and to control the output of the fifth working fluid e according to the second temperature of the fifth working fluid in the circulation unit 200.

[0020] The following, combined Figure 1 The structure of the heating unit 100 is described in detail.

[0021] In some of the embodiments, the heating unit 100 includes a heat collecting pipeline 111 , a heat collecting cover 114 , a mirror device 120 , and a sliding bracket 130 .

[0022] In some embodiments, the heat collecting cover 114 covers the top of the cooling bed 110. The heat collecting cover 114 contains a heat collecting pipeline 111, which is used to receive the heat source provided by the cooling bed 110 and heat the first working medium a. The heat collecting pipeline 111 is used to accommodate the first working medium a, and the heat collecting pipeline 111 encloses a plurality of heat collecting pipes along the first direction. A The first installation area and the second installation area are arranged alternately; wherein the first direction A The cooling bed 110 passes the product direction.

[0023] In some embodiments, the mirror device 120 is disposed in the first installation area and the second installation area, and the mirror device 120 is connected to the heat collection cover 114, and the specific connection method is welding. The mirror device 200 is used to reflect the infrared rays generated by the heat source provided by the cooling bed 110 to the heat collection pipeline 111 to heat the first working medium a. The mirror device 120 includes a first reflector 121 and a second reflector 122. The first reflector 121 has a first reflective surface 121a facing the heat collection pipeline 111; the second reflector 122 is connected to the first reflector 121, and the second reflector 122 has a second reflective surface 122a away from the first reflective surface 121a and facing the heat collection pipeline 111; wherein the first reflector 121 and the second reflector 122 are arranged along the first direction A That is, the cooling beds are arranged alternately in the direction of passing the steel; and the first reflecting surface 121a is arranged along the second direction B The first reflecting surface 121a is inclined relative to the working surface of the cooling bed 110, and a first angle is formed between the first reflecting surface 121a and the inner wall of the heat collecting cover 114 located on one side of the cooling bed 110. α The second reflecting surface 122a is along the third direction C The second reflecting surface 122a is tilted relative to the cooling bed 110, and a second angle is formed between the second reflecting surface 122a and the inner wall of the heat collecting cover 114 located on one side of the cooling bed 110. β A third angle is formed between the first reflecting surface 121a and the second reflecting surface 122a γ , that is, the second direction B With third parties C The third angle γ The first angle α、 The second angle β、 The third angle γ The value is adjustable.

[0024] In some embodiments, the first angle α The range is 0~90°; and / or, the second angle β The range is 0~90°; and / or, the third angle γ The range is 0~180°.

[0025] In some embodiments, such as Figures 3 to 5 As shown, the first reflector 121 or the second reflector 122 is connected to the heat collecting cover 114 through at least two pivot structures, and the two adjacent pivot structures are connected along the first direction. A The pivot structure is used to adjust the first reflective surface 121a along the second direction B and a first angle formed between the first reflecting surface 121a and the inner wall of the heat collecting cover 114 located on one side of the cooling bed 110. α Alternatively, the pivot structure is used to adjust the second reflective surface 122a along the third direction. C The second angle formed between the second reflecting surface 122a and the inner wall of the heat collecting cover 114 located on one side of the cooling bed 110 is β The pivot structure includes a first pivot member 123 and a second pivot member 124 which are hinged to each other. The first pivot member 123 is installed on the inner wall of the heat collecting cover 114 located on one side of the cooling bed 110, and the second pivot member 124 is installed on the side of the first reflector 121 away from the first reflective surface 121a, or the second pivot member 124 is installed on the side of the second reflector 122 away from the second reflective surface 122a.

[0026] A heat collecting cover 114 is provided above the front end of the cooling bed 110, and a heat collecting pipeline 111, i.e., a molten salt coil, a first reflector 121, and a second reflector 122 are arranged in the heat collecting cover 114. The first reflector 121 and the second reflector 122 are fixed in the cover of the heat collecting cover 114 by bolts. The inclination angles of the first reflector 121 and the second reflector 122 relative to the working surface of the cooling bed 100 or the inner wall of the heat collecting cover 114 can be adjusted during installation. The first reflecting surface 121a and the second reflecting surface 122a are used to directionally reflect infrared rays to increase the heat collecting capacity of the heat collecting pipeline 111, i.e., the molten salt pipe. At the same time, an infrared coating layer is sprayed in the heat collecting cover 114 to further improve the heating capacity of the molten salt.

[0027] In some embodiments, the heating unit 100 further includes a sliding bracket 130, the sliding bracket 130 is moved along the first direction A That is, the cooling bed is arranged at intervals on the side of the heat collecting cover 114 close to the cooling bed 110 in the steel passing direction; the sliding bracket 130 is provided with a rolling member 131 at one end away from the heat collecting cover 114, which can also be set as a sliding member, and a brake pad is also provided to brake the rolling member 131 when needed.

[0028] In the embodiment of the present invention, the heat collection device includes the above-mentioned heat collection cover 114, heat collection pipeline 111, mirror device 120, and sliding bracket 130. The heat collection device absorbs the heat of the high-temperature rolled material on the cooling bed 110 through thermal radiation. The surface of the heat collection cover 114 is coated with a high-temperature infrared paint layer to increase diffuse reflection and improve the shell blackness of the heat collection cover 114, forming a high-emissivity radiation layer. At the same time, a first reflector 121 and a second reflector 122 are installed between the heat collection pipeline 111. The first reflector 121 and the second reflector 122 are fixedly connected to the heat collection cover 114 through a pivot structure. The infrared rays radiated outward by the high-temperature rolled material on the cooling bed 110 are reflected to the heat collection pipeline 111 through the mirror device 120, thereby enhancing the heat collection of the heat collection pipeline 111.

[0029] The following combination Figure 1 The structures of the circulation unit 200 and the refrigeration unit 300 are described in detail. Figure 1 As shown, the refrigeration unit 300 includes: a convection pipeline 310, a preheater 320, a drum 330 and an evaporator 340. The refrigeration unit 300 is connected to the circulation unit 200 through the convection pipeline 310 and provides the third working medium c to the circulation unit 200. The preheater 320 is used to pass the third working medium c into the convection pipeline 310. The drum 330 is connected to the preheater 320 and the circulation unit 200 through the convection pipeline 310; the evaporator 340 is connected to the drum 330.

[0030] The circulation unit 200 includes: a first storage tank 210, a second storage tank 220, a superheater 230, a second delivery pipeline 240, and a second return pipeline 250. The first storage tank 210 is used to accommodate the second working medium b; the second storage tank 220 is used to accommodate the fifth working medium e; the superheater 230 is connected to the preheater 320 through the convection pipeline 310. The first storage tank 210, the superheater 230, the preheater 320, and the second storage tank 220 are sequentially connected to the second delivery pipeline 240. Among them, the superheater 230 is used to make the second working medium b provided by the first storage tank 210 fully contact with the third working medium c provided by the preheater 320 to output the fourth working medium d, and output the sixth working medium f to the preheater 320. The second storage tank 220 is connected to the preheater 320 through the second return line 250. The preheater 320 is used to mix the sixth working medium f with the third working medium c and output the fifth working medium e to the second storage tank 220. The second storage tank 220 outputs the fifth working medium e to the heating unit 100 through the first return line 150.

[0031] In the embodiment of the present invention, the first working fluid a is low-temperature molten salt; the second working fluid b is high-temperature molten salt; the third working fluid c is desalted water; the fourth working fluid d is superheated steam; the fifth working fluid e is low-temperature molten salt or cold salt; the sixth working fluid f is hot molten salt. Molten salt is used as a heat absorption and heat storage medium, and the characteristics of high heat capacity, high stability and wide temperature range of molten salt are used for thermodynamic cycle. In order to match the system steam production temperature with the freezing point of molten salt, low melting point ternary salt or mixed quaternary nitrate is selected as molten salt.

[0032] The cooling bed waste heat recovery system of the present invention is designed with a first storage tank 210 and a second storage tank 220. When the system is running, when the second temperature of the fifth working fluid e, i.e., the low-temperature molten salt, contained in the second storage tank 220 is lower than the second preset temperature, the control unit 300 controls the pump body of the second control component 440 to open so as to transport it to the heat collecting cover 114. The heat collecting pipeline 111, i.e., the molten salt pipeline, which is heated by high-intensity thermal radiation in the heat collecting cover 114, heats the molten salt. It should be supplemented that a bypass is also arranged outside the heat collecting cover 114 to realize cyclic heating. The bypass is arranged between the first conveying pipeline 140 and the first return pipeline 150. A pump body and a valve are arranged on the bypass. When the second working fluid b in the first conveying pipeline 140 is heated to about the second preset temperature, the control unit 400 controls the pump body and the valve of the second control component 440 to open so as to transport the second working fluid, i.e., the high-temperature molten salt, to the first storage tank 210.

[0033] In some embodiments of the present invention, the hot molten salt in the second delivery pipeline 240 flows from the first storage tank 210 through the molten salt pump through the superheater 230, the evaporator 340, and the preheater 320 in sequence, and continuously exchanges heat and cools down with the third working medium c in the convection pipeline 310 of the refrigeration unit 300. When the temperature of the final output fifth working medium e is lower than the second preset temperature, the fifth working medium e returns to the second storage tank 220, and the third working medium c passes through the preheater 320, the steam drum 330, and the superheater 230 in sequence to produce a high-quality fourth working medium d, i.e., superheated steam.

[0034] An electric heater 211 is provided in the first storage tank 210. When the temperature of the second working fluid b contained in the first storage tank 210 is low, the electric heater 211 can be started to supplement the heat for the second working fluid b. The enterprise can also take advantage of the difference in regional peak and valley electricity prices and directly use the electric heater 211 to supplement the heat for the second working fluid b during the valley electricity period when the electricity price is lower, and store the heated second working fluid b, i.e., high-temperature salt, in the second storage tank 220. During the peak electricity period when the electricity price is higher, the superheater 230 outputs the fourth working fluid d to generate electricity. The cold bed waste heat recovery system can play the role of an energy storage device.

[0035] In addition, the first delivery pipeline 140 is provided with a first movable pipeline 141, the first return pipeline 150 is provided with a second movable pipeline 151, and a valve is provided between the first movable pipeline 141 and the second movable pipeline 151. The heat collecting cover 114 is connected to the circulation unit 200 through a movable flange. When it is necessary to shut down for maintenance, it is only necessary to turn off the pump body, and the high-temperature molten salt in the second delivery pipeline 240, i.e., the molten salt pipe, flows back to the first storage tank 210 by its own gravity. At this time, it is only necessary to disassemble the movable flange to disconnect the heat collecting cover 114 and the circulation unit 200, and the sliding bracket 130 can be used to easily move the heat collecting section to free up maintenance space.

[0036] In order to reduce the risk of molten salt leakage, the heat collecting pipeline 111, the first conveying pipeline 140, the first return pipeline 150, the second conveying pipeline 240, the second return pipeline 250, and the convection pipeline 310 of the entire cooling bed waste heat recovery system are welded as much as possible to reduce the use of flange connections. The outlet pipeline part of the heat collecting device uses a section of flange-connected pipeline as the movable section, namely the first movable pipeline 141 and the second movable pipeline 151 mentioned above, which can cooperate with the heat collecting cover 114 and the sliding bracket 130 to quickly disassemble and assemble the cooling bed waste heat system. , which does not affect the maintenance of the cooling bed 110; a rolling member 131 or a sliding member is provided at the bottom of the sliding bracket 130, and the rolling member 131 can be a roller with a braking function. The other end of the sliding bracket 130 is welded to the heat collecting cover 114, supporting the entire heat collecting cover 114 to span and cover the top of the cooling bed 110. The height can be adjusted according to the supercooling bed product. After disconnecting the first movable pipeline 141 and the second movable pipeline 151, the entire heat collecting device can be slid forward and backward to avoid the maintenance space, and can be lifted away from the cooling bed area by a crane when necessary.

[0037] In order to achieve the first temperature of the second working medium b, the amount of the second working medium b provided by the heating unit 100 to the circulation unit 200 is controlled, such as Figure 1 As shown, the control unit 400 includes a first sensor 410 and a first control component 420. The first sensor 410 is arranged on the first delivery pipeline 140 to detect the first temperature of the second working fluid b; the first control component 420 is arranged on the first delivery pipeline 140; the control unit 400 controls the heating unit 100 to provide the amount of the second working fluid b to the circulation unit 200 through the first control component 420 based on the first temperature detected by the first sensor 410.

[0038] In order to control the amount of the fifth working fluid e output by the circulation unit 200 to the heating unit 100 according to the second temperature of the fifth working fluid e, the control unit 400 also includes a second sensor 430 and a second control component 440, and the second sensor 430 is arranged on the first return pipe 150; the control unit 400 controls the amount of the fifth working fluid e output by the circulation unit 200 to the heating unit 100 through the second control component 440 based on the second temperature of the fifth working fluid e detected by the second sensor 430.

[0039] like Figure 1 As shown, the first control component 420 includes a pump body and a valve. When the first temperature of the outlet of the heating unit 100 on the first delivery pipeline 140 reaches or exceeds the first preset temperature, the control unit 400 controls the opening and closing of the pump body and the valve of the first control component 420 to replenish the second working fluid b to the circulation unit 200, and the second working fluid b is delivered to the first storage tank 210.

[0040] In the embodiment of the present application, the first preset temperature is 400°C.

[0041] The second control assembly 440 includes a pump body and a valve. When the second temperature of the outlet of the heating unit 100 on the first return line 150 reaches or is lower than the second preset temperature, the control unit 400 controls the pump body and the opening and closing of the valve of the second control assembly 440 to output the fifth working fluid e to the heating unit 100, and the fifth working fluid e is stored in the second storage tank 210. In this embodiment, the main control method of the control unit 400 on the supply unit 100, the circulation unit 200 and the refrigeration unit 300 is described in detail as follows. In the embodiment of the present invention, the second preset temperature is 150°C.

[0042] like Figure 1 As shown, the control unit 400 controls the amount of the second working fluid b provided to the first storage tank through the first control component 420 on the first delivery pipeline based on the first temperature detected by the first sensor 410, and controls the amount of the fifth working fluid e output to the second storage tank 220 through the second control component 420 on the first return pipeline 150.

[0043] The first storage tank 210 is used as a hot salt tank, and the second storage tank 220 is used as a cold salt tank, to realize the cold and hot salt dual storage tank design, and a high-power electric heater 211 is added to the first storage tank 210. The first storage tank 210 and the second storage tank 220 are both made of aluminum silicate insulation material, which can ensure that the temperature drop of the storage tank is less than or equal to 2°C / day. The extremely low heat dissipation loss can store high-temperature molten salt for a long time, ensuring the energy storage efficiency of the cold bed waste heat recovery system. On the basis of the waste heat of the cold bed, low-cost electricity such as valley price electricity period can be used to heat the molten salt, and the molten salt is concentrated in the peak price electricity period to produce steam and generate electricity, thereby improving the economic benefits of the company's waste heat utilization.

[0044] By setting a circulation unit 200 at the outlet section of the heat collecting cover 114, the circulation unit 200 is provided with a temperature measuring point, i.e., a measuring point for testing the first temperature, and a regulating valve. When the outlet temperature of the heat collecting cover 114 does not meet the process requirements, the valve is adjusted to allow the molten salt to re-enter the heat collecting cover 114 for circulation, ensuring that the molten salt in the heat collecting section reaches the design temperature, i.e., the first preset temperature, before entering the first storage tank 210, i.e., the hot salt tank.

[0045] The cooling bed waste heat recovery system of the present invention can switch to multiple modes according to production conditions. If the peak-valley price difference is high in the place where the enterprise is located, the electric heater 211 can be used to heat the molten salt during the valley price period, and the high-temperature molten salt can be used to produce steam during the peak price period. It can also operate even if the steel rolling mill is shut down for maintenance. Taking a 5,000-ton / day steel rolling bar production line as an example, assuming that the temperature of the cooling bed on the bar is 950°C, and the heat is dissipated to about 350°C in 15 minutes, the area of ​​the heat collection pipeline 111 in the heat collection cover 114, i.e., the molten salt pipeline, is 4*6=24m 2 The heat released by natural cooling can provide 5000*0.46*103*(950-350)=1380GJ / day of heat. The waste heat resources available for utilization are huge. Considering only the effective recovery of 30% of the sensible heat resources, about 6.4t / h of steam can be produced.

[0046] Therefore, the beneficial effect of the cooling bed waste heat recovery system of the present invention is that the waste heat of the cooling bed 100 can be recovered through the molten salt medium to avoid energy waste, and the high heat capacity of the molten salt and the heat collecting cover 114 with the mirror device 120 can be used to improve the heat absorption efficiency and temperature upper limit of the molten salt. Different from the low-temperature waste heat recovery to produce hot water, the cooling bed waste heat recovery system of the present invention can greatly improve the quality of steam production and improve energy conversion efficiency. The first storage tank 210, the second storage tank 220, and the electric heating device 211 are used to store and release heat. The molten salt has a higher temperature after multiple cycles, and high-quality superheated steam can be generated through the steam drum 330, the superheater 230, etc., to improve the waste heat utilization efficiency. The design of the second storage tank 220, the first storage tank 210 and the electric heater 211 inside it enables the cooling bed waste heat recovery system to have the function of peak-shifting energy storage, and can operate independently when the steel rolling mill is shut down. The first storage tank 210 and the second storage tank 220 are made of aluminum silicate insulation material, which can ensure that the temperature drop of the storage tank does not exceed 2°C every day. The extremely low heat loss can store high-temperature molten salt for a long time. On the basis of the waste heat of the cooling bed, low-cost electricity such as valley-price electricity period can be used to heat the molten salt, and the molten salt is concentrated in the peak-price electricity period to produce steam and generate electricity, thereby improving the economic benefits of the waste heat utilization of the enterprise. In addition, the design of the first movable pipeline 141, the second movable pipeline 151 and the sliding bracket 130 greatly improves the flexibility of the system structure. When the cooling bed 110 has an emergency such as steel jumping or unplanned maintenance, the heat collecting cover 114 can be quickly disconnected and moved away.

[0047] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0048] In addition, the terms "above" and "below" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "above" and "below" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0049] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0051] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A cooling bed waste heat recovery system, characterized in that: include: A heating unit, a circulation unit, a refrigeration unit and a control unit; wherein, The heat supply unit is connected to the circulation unit and is used to provide a second working medium to the circulation unit; The circulation unit is connected to the refrigeration unit, and is used to make the second working fluid fully contact with the third working fluid provided by the refrigeration unit, and then output a fourth working fluid, and output a fifth working fluid to the heating unit; The control unit is electrically connected to the heating unit, the circulation unit, and the refrigeration unit, respectively, to control the replenishment of the second working fluid according to the first temperature of the second working fluid set in the circulation unit, and to control the output of the fifth working fluid according to the second temperature of the fifth working fluid set in the circulation unit.

2. The waste heat recovery system according to claim 1, characterized in that: The heating unit comprises: A heat collecting pipeline, used for accommodating a first working medium, wherein the heat collecting pipeline encloses a plurality of first installation areas and second installation areas alternately arranged along a steel passing direction of the cooling bed; The heat collecting cover accommodates the heat collecting pipeline and is used to receive the heat source provided by the cooling bed and heat the first working fluid to output the second working fluid.

3. The waste heat recovery system according to claim 2, characterized in that: The heating unit also includes: A mirror device is arranged in the first installation area and the second installation area, connected to the heat collecting cover, and is used to reflect infrared rays generated by the cooling bed heat source to the heat collecting pipeline to heat the first working medium.

4. The waste heat recovery system according to claim 3, characterized in that: The mirror device comprises: A first reflector having a first reflective surface facing the heat collection pipeline; The second reflector is connected to the first reflector and has a second reflective surface facing away from the first reflective surface and toward the heat collection pipeline; wherein: The first reflector and the second reflector are arranged along the steel passing direction of the cooling bed A Alternately arranged; and The first reflective surface is along a first direction B The first reflecting surface is inclined relative to the working surface of the cooling bed, and the first reflecting surface forms a first angle with the working surface of the cooling bed. α ; The second reflective surface is along a second direction C The second reflecting surface is inclined relative to the cooling bed, and the second reflecting surface forms a second angle with the working surface of the cooling bed. β ; The first reflecting surface and the second reflecting surface form a third angle γ .

5. The waste heat recovery system according to claim 4, characterized in that: The first angle ranges from 0 to 90°; the second angle ranges from 0 to 90°; and the third angle ranges from 0 to 180°.

6. The waste heat recovery system according to claim 2, characterized in that: The heating unit also includes: Sliding brackets are arranged at intervals on a side of the heat collecting cover close to the cooling bed along the steel passing direction of the cooling bed; A rolling element is arranged at one end of the sliding bracket away from the heat collecting cover.

7. The waste heat recovery system according to claim 2, characterized in that: The first working fluid is a low melting point ternary salt or a mixed quaternary nitrate.

8. The cooling bed waste heat recovery system according to claim 1, characterized in that: include: a first delivery pipeline, through which the heat supply unit provides the second working medium to the circulation unit; A first return pipeline, through which the circulation unit provides the fifth working medium to the heat supply unit.

9. The cooling bed waste heat recovery system according to claim 8, characterized in that: The control unit comprises: A first sensor, disposed on the first delivery pipeline, for detecting a first temperature of the second working fluid; A first control component is arranged on the first conveying pipeline; The control unit controls the amount of the second working fluid provided by the heat supply unit to the circulation unit through a first control component based on the first temperature detected by the first sensor.

10. The cooling bed waste heat recovery system according to claim 9, characterized in that: The control unit also includes: a second sensor, disposed on the second return pipeline, for detecting a second temperature of the fifth working fluid; A second control component is arranged on the first return pipeline; The control unit controls the amount of the fifth working fluid output by the second storage tank to the heat supply unit through the second control component based on the second temperature detected by the second sensor.

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