A system for utilizing process waste heat of a casting machine

Abstract

The application relates to the technical field of waste heat recovery, and particularly provides a cast iron machine process waste heat utilization system which comprises a first heat collecting area, a first heat collecting pipeline, a second heat collecting pipeline, a second heat collecting area, a first storage tank, a coal economizer and a second storage tank; the first heat collecting pipeline is arranged in the first heat collecting area, the second heat collecting pipeline is arranged in the second heat collecting area, the first end of the first heat collecting pipeline and the first end of the second heat collecting pipeline are respectively connected with the inlet end of the first storage tank through first pipelines, the outlet end of the first storage tank is connected with the inlet end of a heat transfer channel in the coal economizer, the outlet end of the heat transfer channel is connected with the inlet end of the second storage tank, and the outlet end of the second storage tank is connected with the second end of the first heat collecting pipeline and the second end of the second heat collecting pipeline through second pipelines; a third pipeline is in communication between the second pipelines and the first pipelines, and a valve is assembled on the third pipeline, so that the waste heat released in the high-temperature cast iron cooling process of the cast iron machine can be efficiently recovered.

Description

Technical Field

[0001] This application relates to the field of waste heat recovery technology, and in particular to a waste heat utilization system for a cast iron machine process. Background Technology

[0002] Traditional iron casting machines employ an open structure, where molten iron at approximately 1200°C enters the casting machine through a pouring system. Under the combined effects of natural cooling and water spray cooling, the temperature gradually decreases to approximately 600°C. While this process effectively cools and shapes the cast iron, the heat is primarily lost through air convection, radiation, and water spray evaporation, failing to be effectively recovered and utilized.

[0003] Because the cast iron production line has no waste heat recovery device, a large amount of sensible and latent heat released by the high-temperature molten iron and billets during the cooling process is directly discharged into the environment, resulting in extremely low energy utilization.

[0004] With the development trend of energy conservation, emission reduction and green manufacturing, the high energy consumption problem of traditional open-type casting iron process is becoming increasingly prominent. How to efficiently recover the waste heat of casting iron machines and use it for waste heat air, power generation or heating has become a technical problem that the industry urgently needs to solve. Utility Model Content

[0005] To address the aforementioned issues, this application provides a waste heat recovery system for a cast iron machine. Through a two-stage heat extraction structure with a first heat extraction zone and a second heat extraction zone, combined with the heat transfer channel in the economizer, the system achieves efficient recovery of waste heat released during the high-temperature cooling process of the cast iron machine.

[0006] To achieve the objectives of this application, the following technical solution is provided:

[0007] In a first aspect, this application provides a waste heat utilization system for a casting iron machine, comprising: a first heat extraction zone, a first heat extraction pipe, a second heat extraction pipe, a second heat extraction zone, a first storage tank, an economizer, and a second storage tank;

[0008] The first heat extraction pipe is located in the first heat extraction zone, and the second heat extraction pipe is located in the second heat extraction zone. The first end of the first heat extraction pipe and the first end of the second heat extraction pipe are respectively connected to the inlet end of the first storage tank through the first pipe. The outlet end of the first storage tank is connected to the inlet end of the heat transfer channel in the economizer. The outlet end of the heat transfer channel is connected to the inlet end of the second storage tank. The outlet end of the second storage tank is respectively connected to the second end of the first heat extraction pipe and the second end of the second heat extraction pipe through the second pipe.

[0009] A third pipe is connected between the second pipe and the first pipe, and a valve is installed on the third pipe.

[0010] In some implementations, a conveying device is also included, which includes a conveyor belt and a heat shield. The heat shield extends along the conveying path of the conveyor belt, and the two ends of the heat shield are respectively provided with an inlet for the conveyor belt to enter and an outlet for it to exit. The opening size of the inlet and outlet matches the cross-section of the conveyor belt.

[0011] The space inside the heat insulation cover is divided into a first heat extraction zone and a second heat extraction zone along the conveyor belt's conveying direction. The first heat extraction pipe and the second heat extraction pipe are disposed inside the heat insulation cover and above the conveyor belt, and are respectively located in the first heat extraction zone and the second heat extraction zone.

[0012] In some implementations, the economizer includes a shell device with an inner cavity and a heat exchange tube bundle located in the inner cavity. The space between the inner cavity of the shell device and the heat exchange tube bundle forms the heat transfer channel. The inlet end of the heat exchange tube bundle is located on the same side as the outlet end of the heat transfer channel, and the outlet end of the heat exchange tube bundle is located on the same side as the inlet end of the heat transfer channel, forming a reverse heat exchange structure.

[0013] In some implementations, the outlet end of the heat transfer channel is connected to the inlet end of the second storage tank via a water pump mechanism; the water pump mechanism includes two water pumps connected in parallel, and each water pump is equipped with a first valve.

[0014] The waste heat recovery system for iron casting machines provided in this application adopts a two-stage heat recovery structure with a first heat recovery zone and a second heat recovery zone. Combined with the heat transfer channel in the economizer, it can efficiently recover the waste heat released during the high-temperature cooling process of cast iron. This recovered waste heat can directly replace coal gas for heating the economizer, while simultaneously enabling the recycling of heat transfer water in the system, significantly improving energy efficiency. Furthermore, by installing a third pipeline equipped with valves, the temperature inside the first storage tank at the front end of the economizer can be adjusted according to the actual heat storage requirements of the economizer, avoiding adverse effects on the economizer's operation due to excessively high temperatures. Attached Figure Description

[0015] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.

[0016] Figure 1 This is a schematic diagram of a waste heat recovery system for a casting machine according to an embodiment of this application;

[0017] Illustration: 10. Heat insulation cover; 11. First heat extraction zone; 12. Second heat extraction zone; 21. First heat extraction pipe; 22. Second heat extraction pipe; 23. First pipe; 24. Second pipe; 25. Third pipe; 31. First storage tank; 32. Second storage tank; 33. Economizer; 331. Heat transfer channel; 332. Heat exchange tube bundle; 40. Water pump mechanism; 41. Water pump; 42. First valve. Detailed Implementation

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

[0019] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[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 application, unless otherwise stated, "multiple" means two or more.

[0021] The following is combined Figure 1 The following embodiments illustrate the technical solutions of this application.

[0022] Figure 1 This application illustrates a schematic diagram of a waste heat recovery system for a casting machine, as shown in an embodiment. Figure 1 As shown in the figure, this application provides a waste heat utilization system for a casting machine, comprising: a first heat extraction zone 11, a first heat extraction pipe 21, a second heat extraction pipe 22, a second heat extraction zone 12, a first storage tank 31, an economizer 33, and a second storage tank 32. Specifically:

[0023] The first heat extraction pipe 21 is located in the first heat extraction zone 11, and the second heat extraction pipe 22 is located in the second heat extraction zone 12. The first end of the first heat extraction pipe 21 and the first end of the second heat extraction pipe 22 are respectively connected to the inlet end of the first storage tank 31 through the first pipe 23. The outlet end of the first storage tank 31 is connected to the inlet end of the heat transfer channel 331 in the economizer 33. The outlet end of the heat transfer channel 331 is connected to the inlet end of the second storage tank 32. The outlet end of the second storage tank 32 is respectively connected to the second end of the first heat extraction pipe 21 and the second end of the second heat extraction pipe 22 through the second pipe 24.

[0024] A third pipe 25 connects the second pipe 24 and the first pipe 23, and a valve is installed on the third pipe 25. The third pipe 25 allows the low-temperature water after heat exchange to flow into the first pipe 23.

[0025] For example, the second pipe 24 and the first pipe 23 have holes along their length for sealing connections with both ends of the third pipe 25. The first end of the third pipe 25 is connected to the second pipe 24 between the second end of the second heat-extracting pipe 22 and the outlet end of the second storage tank 32, and the second end of the third pipe 25 is connected to the first pipe 23 between the first end of the second heat-extracting pipe 22 and the inlet end of the first storage tank 31. Alternatively, the second end of the third pipe 25 is connected to the second pipe 24 between the first end of the first heat-extracting pipe 21 and the outlet end of the first storage tank 31.

[0026] For example, the second pipe 24 and the first pipe 23 have holes along their length for sealing connections with both ends of the third pipe 25. The first end of the third pipe 25 is connected to the second pipe 24 between the second end of the first heat-extracting pipe 21 and the outlet end of the second storage tank 32, and the second end of the third pipe 25 is connected to the first pipe 23 between the first end of the second heat-extracting pipe 22 and the inlet end of the first storage tank 31. Alternatively, the second end of the third pipe 25 is connected to the second pipe 24 between the first end of the first heat-extracting pipe 21 and the outlet end of the first storage tank 31.

[0027] like Figure 1 As shown, Figure 1 The straight lines with arrows in the diagram indicate the flow direction of the fluid medium in the waste heat recovery system. In this system, the fluid medium absorbs heat in two heat exchange zones via the first heat exchange pipe 21 and the second heat exchange pipe 22, and then collects in the first storage tank 31. Subsequently, the high-temperature medium flows into the heat transfer channel 331 of the economizer 33, transferring heat to the fluid medium within the heat exchange tube bundle 332, thus achieving energy recovery. The low-temperature medium, after heat exchange, enters the second storage tank 32 and returns to the first heat exchange pipe 21 and the second heat exchange pipe 22 via pipelines, forming a closed-loop cycle. This process achieves a continuous operation mode of "heat absorption-heat exchange-heat absorption" for the fluid medium. An exemplary fluid medium is water.

[0028] Meanwhile, to ensure the efficient operation of the economizer 33, the waste heat utilization system strictly limits the inlet water temperature of the heat transfer channel 331 in the economizer 33: the inlet water temperature must be controlled below 70℃, and the outlet water temperature must be maintained above 50℃. When the temperature of the flowing medium in the first storage tank 31 exceeds the set threshold, the valve of the third pipe 25 is opened, allowing the low-temperature medium flowing from the second storage tank 32 to be mixed into the first storage tank 31 sequentially through the second pipe 24, the third pipe 25, and the first pipe 23, quickly reducing the temperature of the flowing medium in the first storage tank 31 to a reasonable range. This dynamic adjustment mechanism ensures both the thermal efficiency of the economizer 33 and the stability of the system operation.

[0029] In some embodiments, the waste heat recovery system further includes a conveying device, which includes a conveyor belt and a heat insulation cover 10. The heat insulation cover 10 extends along the conveying path of the conveyor belt, and the two ends of the heat insulation cover 10 are respectively provided with an inlet for the conveyor belt to pass through and an outlet for the conveyor belt to pass through. The opening size of the inlet and the outlet matches the cross-section of the conveyor belt.

[0030] The space inside the heat insulation cover 10 is divided into a first heat-extracting zone 11 and a second heat-extracting zone 12 along the conveyor belt direction. The first heat-extracting pipe 21 and the second heat-extracting pipe 22 are disposed inside the heat insulation cover 10 and above the conveyor belt, and are respectively located in the first heat-extracting zone 11 and the second heat-extracting zone 12.

[0031] Specifically, if the length of the conveying device is designed to be 80m, then the corresponding heat exchange hood will also be 80m long, 6m wide, and 2m high. In actual production, the casting temperature in the first heat exchange zone 11 is approximately 1000℃. After the cast iron passes through the 80m long conveying device to the second heat exchange zone 12, the casting temperature drops to approximately 600℃. Therefore, the temperature difference between the first heat exchange zone 11 and the second heat exchange zone 12 is approximately 400℃. This satisfies the cooling rate requirement of the iron casting, preventing it from cracking due to excessive cooling, while also meeting the inlet water temperature requirement of the heat transfer channel 331 in the economizer 33.

[0032] Furthermore, the heat shield of the casting machine can isolate the harmful fumes generated during the casting cooling process within the space of the heat shield 10, thereby improving the atmospheric environment of the factory and the working environment for workers. At the same time, it also facilitates the periodic centralized absorption and treatment of harmful fumes by a harmful gas treatment device.

[0033] In some embodiments, the economizer 33 includes a shell device with an inner cavity and a heat exchange tube bundle 332 located within the inner cavity. The space between the inner cavity of the shell device and the heat exchange tube bundle 332 forms a heat transfer channel 331. The inlet end of the heat exchange tube bundle 332 is located on the same side as the outlet end of the heat transfer channel 331, and the outlet end of the heat exchange tube bundle 332 is located on the same side as the inlet end of the heat transfer channel 331. Figure 1The arrowed curves in the diagram are used to indicate the flow direction of the medium within the heat exchanger tube bundle.

[0034] Specifically, the heat-absorbing flowing medium enters the first storage tank 31 and then flows into the heat transfer channel 331 of the economizer 33, where it exchanges heat with the flowing medium in the heat exchange tube bundle 332 in a counter-current flow. This structural design allows the high-temperature flowing medium in the heat transfer channel 331 to form convection with the low-temperature flowing medium in the heat exchange tube bundle 332, fully transferring heat, avoiding heat loss, and improving heat exchange efficiency.

[0035] In some embodiments, the outlet end of the heat transfer channel 331 is connected to the inlet end of the second storage tank 32 via a water pump 41 system; the water pump 41 system includes two water pumps 41 connected in parallel, and each of the two water pumps 41 is equipped with a first valve 42.

[0036] Specifically, for ease of maintenance, a water pump 41 system is connected to the first storage tank 31. When one of the water pumps 41 fails, the first valve 42 connected to that water pump 41 can be closed for maintenance, while the first valve 42 of the other water pump 41 is opened to ensure that the preheating utilization system can work normally.

[0037] Valves are installed at both ends of the first heat extraction pipe 21 and the second heat extraction pipe 22. When a water leakage accident occurs in the heat extraction pipe, the waste heat utilization system can be stopped by closing the valves at both ends of the heat extraction pipe, which facilitates maintenance.

[0038] After calculation, a 450m 3 The waste heat recovery system of the casting machine process described in this application, used in conjunction with two casting machine production lines, generates the following benefits for a blast furnace with an annual output of 500,000 tons: 8970 MJ of heat can be recovered per hour. This results in annual savings of approximately 160 million standard cubic meters of blast furnace gas, 1832 tce of carbon consumption, a reduction of 302 t of carbon dioxide emissions, and a reduction of 120,000 tons of industrial water consumption.

[0039] The beneficial effects achievable by the embodiments of this application are as follows: The waste heat recovery system for iron casting machines provided by this application adopts a two-stage heat recovery structure with a first heat recovery zone and a second heat recovery zone. Combined with the heat transfer channel in the economizer, it can efficiently recover the waste heat released by the iron casting machine during the high-temperature cooling process of the cast iron. This recovered waste heat can directly replace coal gas for heating the economizer, while simultaneously enabling the recycling of heat transfer water in the system, significantly improving energy efficiency. Furthermore, by setting up a third pipeline equipped with valves, the temperature inside the first storage tank at the front end of the economizer can be adjusted according to the actual heat storage requirements of the economizer, avoiding adverse effects on the economizer's operation due to excessively high temperatures.

[0040] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0041] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A waste heat recovery system for a casting iron machine, characterized in that, include: The first heat extraction zone, the first heat extraction pipeline, the second heat extraction pipeline, the second heat extraction zone, the first storage tank, the economizer, and the second storage tank; The first heat extraction pipe is located in the first heat extraction zone, and the second heat extraction pipe is located in the second heat extraction zone. The first end of the first heat extraction pipe and the first end of the second heat extraction pipe are respectively connected to the inlet end of the first storage tank through the first pipe. The outlet end of the first storage tank is connected to the inlet end of the heat transfer channel in the economizer. The outlet end of the heat transfer channel is connected to the inlet end of the second storage tank. The outlet end of the second storage tank is respectively connected to the second end of the first heat extraction pipe and the second end of the second heat extraction pipe through the second pipe. A third pipe is connected between the second pipe and the first pipe, and a valve is installed on the third pipe.

2. The waste heat recovery system for casting iron machines according to claim 1, characterized in that, It also includes a conveying device, which includes a conveyor belt and a heat shield. The heat shield extends along the conveying path of the conveyor belt, and the two ends of the heat shield are respectively provided with an inlet for the conveyor belt to enter and an outlet for it to exit. The opening size of the inlet and outlet matches the cross-section of the conveyor belt. The space inside the heat insulation cover is divided into a first heat extraction zone and a second heat extraction zone along the conveyor belt's conveying direction. The first heat extraction pipe and the second heat extraction pipe are disposed inside the heat insulation cover and above the conveyor belt, and are respectively located in the first heat extraction zone and the second heat extraction zone.

3. The waste heat recovery system for casting iron machines according to claim 1, characterized in that, The economizer includes a shell device with an inner cavity and a heat exchange tube bundle located in the inner cavity. The space between the inner cavity of the shell device and the heat exchange tube bundle forms the heat transfer channel. The inlet end of the heat exchange tube bundle is located on the same side as the outlet end of the heat transfer channel, and the outlet end of the heat exchange tube bundle is located on the same side as the inlet end of the heat transfer channel, forming a reverse heat exchange structure.

4. The waste heat recovery system for casting iron machines according to claim 1, characterized in that, The outlet end of the heat transfer channel is connected to the inlet end of the second storage tank via a water pump mechanism; the water pump mechanism includes two water pumps connected in parallel, and each water pump is equipped with a first valve.

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