Method for utilizing the residual heat of a belt sintering machine body

Abstract

The application discloses a belt sintering machine body waste heat recovery method, belongs to the technical field of industrial waste heat recovery, and aims to solve the problem that sensible heat of a sintering machine return trolley is not effectively utilized. Firstly, according to the measured temperature, the return path is divided into a high-temperature zone (>= 300 DEG C), a medium-temperature zone (150-300 DEG C) and a low-temperature zone (< 150 DEG C). Subsequently, a radiation heat exchange device is arranged above the trolley body in each temperature zone, the lower surface of the device keeps a small gap of 2mm to 40mm with the moving trolley, and heat exchange safety is ensured without interference. Waste heat utilization is divided into two levels: the heat exchange device in the high-temperature and medium-temperature zones is connected to an economizer or an evaporation section of a waste heat boiler, a steam-water cycle is formed to produce steam, and the steam is used for power generation or process heating; the heat exchange device in the medium-temperature end and the low-temperature zone forms an independent hot water circulation system, and the output hot water is used for preheating of sintering mixture, heating of a factory area and life facilities. The application opens up a new source of sintering waste heat, and through a cascade utilization mode, remarkable energy saving and consumption reduction and economic benefits are realized.

Description

Technical Field

[0001] A method for utilizing the waste heat of a belt sintering machine. This invention belongs to the field of industrial waste heat recovery and utilization technology, specifically relating to a method for the efficient recovery and graded utilization of sensible heat carried by the high-temperature trolley body of a belt sintering machine during its return journey. Background Technology

[0002] In the sintering process of the iron and steel metallurgical industry, the belt sintering machine is the core equipment. After the sintered ore completes the ignition and sintering process on the belt sintering machine, the incandescent sintered ore is crushed by a single-roll crusher at the tail end of the machine and unloaded into the annular cooler. However, the temperature of the main structure of the sintering machine, including the trolleys, grates, and beams (hereinafter referred to as "trolley body"), remains extremely high, typically exceeding 350°C. This high-temperature trolley body will travel with the belt sintering machine into the return stroke (i.e., the unloaded stroke from the tail end back to the head end). The large amount of sensible heat it carries is mainly dissipated into the environment during the return stroke through radiation and convection, resulting in significant energy waste. Currently, mature waste heat recovery technologies in the industry mainly focus on the recovery of waste heat from sintering flue gas and the recovery and utilization of cooling exhaust gas from the annular cooler (i.e., the sensible heat of the sintered ore), for example, for generating steam or power generation. However, existing technologies have not yet effectively and systematically recovered this high-quality waste heat resource carried by the main structure of the belt sintering machine (especially the return trolley). Developing a simple, efficient method for recovering waste heat from the trolley body that does not affect the normal operation of the belt sintering machine is of great significance for tapping the energy-saving potential of the sintering process, reducing process energy consumption, and reducing carbon emissions. Summary of the Invention

[0003] The technical problem this invention aims to solve is to address the gaps and deficiencies in existing technologies by providing a method for utilizing the waste heat of a belt sintering machine. This method can safely and efficiently recover the sensible heat carried by the return trolley of the belt sintering machine, converting it into steam or hot water for utilization, thereby achieving waste heat resource recovery and realizing energy conservation, consumption reduction, and lower production costs. To achieve the above objectives, this invention adopts the following technical solution: A method for utilizing the waste heat of a belt sintering machine, applicable to the recovery and utilization of waste heat from the return trolley during the production process of a belt sintering machine. Its core lies in: based on the temperature distribution in different sections of the return path of the belt sintering machine, arranging heat exchange devices at specific locations above the trolley, recovering heat through radiation and convection heat exchange, and utilizing the recovered heat in a graded manner according to its quality.

[0004] Specifically, the method includes the following steps: S1: Temperature zone division. Based on the measured temperature, the return path of the belt sintering machine from the tail to the head is divided into three temperature zones: high temperature zone (temperature ≥ 300℃), medium temperature zone (150℃ ≤ temperature < 300℃), and low temperature zone (temperature < 150℃).

[0005] S2: Heat Exchanger Arrangement. A radiant heat exchanger, such as a heat exchanger composed of finned tube arrays, is arranged above the trolley body located in the high-temperature zone of the return path. The heat exchanger can be installed in single or multiple layers, with its lower surface maintaining a gap of 2mm to 40mm from the upper surface (i.e., the reverse side) of the moving trolley body below, to ensure no scraping of the equipment and to avoid affecting the normal operation of the belt sintering machine. The size and arrangement of the heat exchanger can be flexibly designed according to the trolley width and site space.

[0006] S3: High-quality waste heat recovery. Heat exchangers located in the high-temperature and medium-temperature zones are connected to the economizer or evaporation section of a waste heat boiler (or steam generator) via a piping system, forming a closed-loop steam-water circulation system. The working fluid (water) is heated in the heat exchangers and then enters the waste heat boiler or steam generator, where stable medium-to-low pressure saturated steam or superheated steam is generated and supplied externally for power generation, driving equipment, or process heating.

[0007] S4: Low-quality waste heat recovery. Heat exchangers, either located at the end of the medium-temperature zone and the low-temperature zone, or independently installed in these zones, are connected to form a hot water circulation system via pipelines. The hot water produced by this system (typically below saturation temperature) can be directly used for purposes such as factory bathhouses, winter heating, and supplementary water preheating in the sintering mixing process. Preheating the mixture increases the material temperature, helping to reduce solid fuel consumption.

[0008] 3. Beneficial effects Compared with the prior art, the present invention has the following significant beneficial effects: (1) It opens up a new high-efficiency waste heat source: The present invention is the first to systematically propose and realize the large-scale recycling and utilization of waste heat of the main structure of the belt sintering machine, tapping a high-quality waste heat resource that has been neglected in the sintering process for a long time, and providing a brand-new technical path for energy conservation and carbon reduction in the steel industry.

[0009] (2) Significant energy saving and economic benefits: The steam generated from the recovery of waste heat can be used for power generation or to replace part of the purchased steam, directly creating economic benefits; the hot water generated is used to preheat the sintering mixture, which can effectively reduce the fuel consumption of sintering solids and reduce the energy consumption of the process from the source. Both bring direct cost reduction benefits.

[0010] (3) Simple to implement and safe and reliable: The method only requires the installation of a heat exchange device in the space above the return section of the belt sintering machine, without changing the main structure and production process of the belt sintering machine, making construction convenient. By precisely controlling the installation gap, it ensures that there is no interference with moving equipment, making operation safe and reliable, and maintenance simple.

[0011] (4) Realize the cascade utilization of energy: According to the grade of waste heat (high, medium and low), it is used for steam production and hot water production respectively, realizing the principle of "high energy for high use and low energy for low use" in the scientific cascade utilization of energy, and improving the overall energy utilization efficiency. Attached Figure Description

[0012] Figure 1 Schematic diagram of the heat exchanger installation location.

[0013] Figure 2 Schematic diagram of waste heat boilers or steam generating equipment and hot water users.

[0014] In the diagram: 1-Belt sintering machine; 2-Sintering machine tail wheel; 3-High temperature zone heat exchange device; 4-Medium temperature zone heat exchange device; 5-Low temperature zone heat exchange device; 6-Sintering machine head wheel; 7-Waste heat boiler or steam generating equipment; 8-Connecting pipe for the first heat exchange device; 9-Steam pipe; 10-User adding water; 11-Connecting pipe for the second heat exchange device; 12-Connecting pipe for the third heat exchange device; 13-Bathhouse user.

[0015] Detailed Description of Embodiments: The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited to the content described.

[0016] This invention is implemented above the return section of a belt sintering machine. During normal operation, the high-temperature belt sintering machine 1 returns from the tail pulley 2 to the head pulley 6. Approximately one-third of the return length from the tail pulley is a high-temperature zone, where the temperature of the trolley bottom exceeds 300°C. A high-temperature zone heat exchanger 3 is installed directly above this zone. This device consists of multiple rows of finned tubes, with the lower edge of the tube rows 20mm from the trolley bottom. After all heat exchange tubes are connected in parallel, they are connected to the inlet first heat exchanger connection pipe 8 of a vertical waste heat boiler or steam generator via a water supply pipeline. The heated working fluid generates 0.8MPa saturated steam in the waste heat boiler or steam generator 7, which is then sent to the plant's low-pressure steam network via the steam output pipeline 9.

[0017] In the next intermediate temperature zone (approximately 150-300℃), an intermediate temperature zone heat exchange device 4 is installed. Its front end is connected in parallel with the high temperature zone heat exchange device 3 to the same waste heat boiler or steam generator 7 system to jointly produce steam. Its rear end independently forms a closed hot water circulation system, producing 85℃ hot water, which is supplied to a mixing water user 10 in the sintering workshop through a second hot water heat exchange device and connecting pipe 11 for preheating the mixture.

[0018] In the low-temperature zone (temperature below 150℃) near the star wheel 6 at the machine head, a low-temperature zone heat exchange device 5 is arranged to produce hot water at 50-60℃, which is supplied to the users 13 of the factory's domestic bathhouse through another third heat exchange device connected to the pipeline 12.

[0019] All heat exchange units are mounted on the belt sintering machine's wind box frame or the plant structure via a robust support structure, without a rigid connection to the moving trolley. During installation, it must be ensured that the gaps at each point are within permissible limits, and safety monitoring devices must be installed.

[0020] The above embodiments are only used to illustrate the technical concept of the present invention, and are not intended to limit it. Any modifications or variations made to the above embodiments by those skilled in the art without departing from the design concept of the present invention will fall within the protection scope of the claims of the present invention.

Claims

1. A method for utilizing the waste heat of a belt sintering machine body, characterized in that... By utilizing the temperature distribution in different sections of the sintering machine's return path, a heat exchange device is arranged at a specific location above the trolley to recover heat through radiation and convection heat exchange.

2. The method for utilizing the waste heat of a belt sintering machine body according to claim 1, characterized in that... The heat exchange device maintains a gap of 2mm to 40mm between its lower surface and the upper surface (i.e., the reverse side) of the moving trolley body below, to ensure that it does not scratch the equipment and does not affect the normal operation of the sintering machine.

3. The method for utilizing the waste heat of a belt sintering machine body according to claim 1, characterized in that... Based on the measured temperature, the return path of the sintering machine from the tail to the head is divided into three temperature zones: high temperature zone (temperature ≥ 300℃), medium temperature zone (150℃ ≤ temperature < 300℃) and low temperature zone (temperature < 150℃).

4. The method for utilizing the waste heat of a belt sintering machine body according to claim 1, characterized in that... The recovered heat is graded and utilized according to its quality.

5. A method for utilizing the waste heat of a belt sintering machine body according to claim 1, characterized in that... The heat exchange device is arranged above the trolley body located in the high-temperature zone of the return path. It is a radiative heat exchange device, which is a heat exchanger composed of finned tube heat exchange tube arrays or radiative heat exchange structures.

6. A method for utilizing the waste heat of a belt sintering machine body according to claim 1, characterized in that... The medium inside the radiative heat exchanger can be demineralized water.

7. A method for utilizing the waste heat of a belt sintering machine body according to claim 1, characterized in that... The heat exchange device can be configured as a single layer or multiple layers.

8. A method for utilizing the waste heat of a belt sintering machine body according to claim 1, characterized in that... The heat exchange device has pipes on both sides that connect to a boiler or steam generating equipment or to a hot water user.

9. A method for utilizing the waste heat of a belt sintering machine body according to claim 1, characterized in that... The size and arrangement of the heat exchange device can be flexibly designed according to the width of the trolley and the available space.

10. A method for utilizing the waste heat of a belt sintering machine body according to claim 1, characterized in that... The heat exchange devices located in the high-temperature and medium-temperature zones are connected to the economizer or evaporation section of the waste heat boiler or steam generator through a pipeline system to form a closed steam-water circulation system.

11. A method for utilizing the waste heat of a belt sintering machine body according to claim 1, characterized in that... The working fluid (water) is heated in the heat exchange device and then enters the waste heat boiler or steam generator, where stable medium and low pressure saturated steam or superheated steam is generated and supplied to the outside for power generation, driving equipment or process heating.

12. A method for utilizing the waste heat of a belt sintering machine body according to claim 3, characterized in that... The heat exchange devices located at the end of the medium-temperature zone and the low-temperature zone, or the heat exchange devices set up independently in this zone, are connected to a hot water circulation system via water pumps and pipelines.

13. A method for utilizing the waste heat of a belt sintering machine body according to claim 12, characterized in that... The hot water produced by the regional heat exchanger (usually below saturation temperature) can be directly used for factory bathhouses, winter heating, and supplementary water preheating in the sintering mixing process.

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