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CN-122015510-A - Industrial furnace step-based efficient waste heat recovery process method and system

CN122015510ACN 122015510 ACN122015510 ACN 122015510ACN-122015510-A

Abstract

The invention discloses a technological method and a system for step efficient waste heat recovery based on an industrial furnace, and belongs to the technical field of industrial waste heat recovery. The method comprises the steps of obtaining high-temperature flue gas of the industrial furnace, introducing a step heat exchanger through a flue gas recovery module to perform two-stage heat exchange to obtain high-temperature hot water and low-temperature hot water, utilizing the high-temperature hot water to drive a steam generator to produce steam, respectively conveying the steam, the high-temperature hot water and the low-temperature hot water to corresponding terminals for use, aiming at multiple working conditions, regulating various temperature section operation parameters in real time through an intelligent control system to ensure that the exhaust temperature, the steam pressure and the water temperature are stably matched, and converting the waste heat of the industrial furnace into steam, the high-temperature hot water and the low-temperature hot water to meet the energy requirements for life and production of factories.

Inventors

  • HE QUNWEI

Assignees

  • 苏州何洛清洁能源科技研究院有限公司

Dates

Publication Date
20260512
Application Date
20260126

Claims (10)

  1. 1. The technological method for recovering the waste heat based on the industrial furnace step is characterized by comprising the following steps of: obtaining high-temperature flue gas generated in the production process of an industrial furnace; Introducing the high-temperature flue gas into a cascade heat exchanger module through a high-temperature flue gas recovery module to perform cascade heat exchange; In the cascade heat exchanger module, a high-temperature heat exchange unit and a low-temperature heat exchange unit are utilized to conduct two-stage heat exchange on the high-temperature flue gas, and high-temperature hot water and low-temperature hot water are respectively prepared; storing the high-temperature hot water in a high-temperature hot water storage tank, and storing the low-temperature hot water in the low-temperature hot water storage tank; The stored high-temperature hot water is conveyed to a steam generator, pure water is converted into steam by utilizing heat of the high-temperature hot water, and the steam is supplied to a main steam pipeline of a user or stored in a steam storage tank; the stored high-temperature hot water and low-temperature hot water are respectively supplied to water terminals corresponding to temperature requirements through a high-temperature hot water supply pipeline and a low-temperature hot water supply pipeline; The intelligent control terminal is used for collecting system temperature, pressure and flow data in real time, and the running state of the equipment is automatically adjusted based on the collected data so as to maintain the smoke discharging temperature in a set range, the steam pressure is stable and the hot water temperature is matched with the terminal requirement.
  2. 2. The industrial furnace cascade high-efficiency waste heat recovery-based process method according to claim 1, wherein the step of obtaining the high-temperature flue gas generated in the industrial furnace production process comprises the following steps: a bypass air pipe is arranged on an original main air pipe of the industrial furnace, and comprises a circulating front air pipe passage and a circulating rear air pipe passage; the opening and closing of the cut-off valve is controlled by the PLC, and the bypass air pipe is intelligently cut in or cut out; and starting an induced draft fan, sucking the high-temperature flue gas into the bypass air pipe and guiding the high-temperature flue gas into the cascade heat exchanger module.
  3. 3. The industrial furnace cascade high-efficiency waste heat recovery-based process method according to claim 2, wherein in the cascade heat exchanger module, the high-temperature flue gas is subjected to two-stage heat exchange by using a high-temperature heat exchange unit and a low-temperature heat exchange unit, and high-temperature hot water and low-temperature hot water are respectively prepared, and the process method comprises the following steps: The high-temperature flue gas firstly enters a high-temperature heat exchange unit and exchanges heat with cold water in a pipeline for one time, so that the temperature of the cold water is raised to 150-190 ℃ to become high-temperature hot water, and the temperature of the flue gas is reduced to below 150 ℃; the cooled flue gas enters a low-temperature heat exchange unit and carries out secondary heat exchange with cold water in a pipeline, so that the cold water is heated to 50-80 ℃ to become low-temperature hot water; wherein, the flue gas after heat exchange is discharged through the smoke outlet.
  4. 4. The industrial furnace cascade high-efficiency waste heat recovery process method according to claim 3, wherein a temperature sensor and an electric auxiliary heating device are arranged in the high-temperature hot water storage tank, and a liquid level sensor and a water supplementing device are arranged in the low-temperature hot water storage tank.
  5. 5. The industrial furnace cascade high efficiency waste heat recovery based process of claim 4, wherein said delivering high temperature hot water to a steam generator comprises: introducing high-temperature hot water into a steam generator from a high-temperature hot water storage tank; Supplying pure water in the pure water tank to the steam generator; Heating pure water by using high-temperature hot water to generate saturated steam of 0.8-1.2 MPa; After steam is separated by a steam drum, the steam is conveyed to a steam storage tank or a main steam pipeline of a user.
  6. 6. The industrial furnace cascade high-efficiency waste heat recovery-based process method according to claim 5, wherein the supplying the high-temperature hot water and the low-temperature hot water to the water terminals corresponding to the temperature demands through the high-temperature hot water supply pipeline and the low-temperature hot water supply pipeline, respectively, comprises: Introducing steam in a steam storage tank into a preheater at the front end of a high-temperature hot water storage tank to preheat cold water entering the high-temperature hot water storage tank; The constant temperature valve, the flow controller, the filtering device and the pressure stabilizing valve are respectively arranged on the high-temperature hot water supply pipeline and the low-temperature hot water supply pipeline so as to stabilize the outlet water temperature.
  7. 7. The industrial furnace cascade high-efficiency waste heat recovery-based process method according to claim 1, wherein the regulation and control are performed through an intelligent control terminal, and the industrial furnace cascade high-efficiency waste heat recovery-based process method comprises the following steps: Collecting flue gas inlet temperature, flue gas exhaust temperature, steam pressure, hot water temperature and flow data in real time; when the temperature of the flue gas is lower than the temperature required by high-temperature hot water heat exchange, the flue gas is controlled to directly enter a low-temperature hot water heat exchange unit or directly discharge into a chimney; The running states of the cut-off valve, the induced draft fan and the thermostatic valve are automatically adjusted, the temperature of discharged smoke is ensured to be stabilized at 110-120 ℃, the steam pressure is ensured to be stabilized at 0.8-1.2MPa, and the temperature of hot water is matched with the terminal requirement.
  8. 8. The industrial furnace step-based efficient waste heat recovery process method according to claim 1, wherein the process method further comprises a safety protection step, specifically: the system is monitored through a safety valve, a pressure alarm device, an exhaust valve, an overtemperature protection device, a dry burning prevention device and a fireproof valve; When the temperature and the pressure of the system exceed the set threshold values, an alarm is automatically triggered and emergency shutdown or pressure relief operation is executed.
  9. 9. The industrial furnace cascade high-efficiency waste heat recovery process method according to claim 1, wherein the cascade heat exchanger module adopts a heat pipe type heat exchange structure, the material is ND steel, the heat exchange area of the high-temperature heat exchange unit is 100-150m < 2 >, and the heat exchange area of the low-temperature heat exchange unit is 80-120m < 2 >.
  10. 10. An industrial furnace cascade high-efficiency waste heat recovery-based system for realizing the industrial furnace cascade high-efficiency waste heat recovery process method according to any one of claims 1 to 9, characterized by comprising: The system comprises a high-temperature flue gas recovery module, a cascade heat exchanger module, a steam-hot water preparation module, a water supply module, an intelligent control terminal and a safety protection module; the high-temperature flue gas recovery module is connected with an original main air pipe of the industrial furnace and is used for leading out high-temperature flue gas generated by the industrial furnace; the cascade heat exchanger module is connected with the high-temperature flue gas recovery module and comprises a high-temperature heat exchange unit and a low-temperature heat exchange unit which are sequentially arranged along the flow direction of the flue gas, and the cascade heat exchanger module is used for carrying out two-stage heat exchange on the high-temperature flue gas to respectively generate high-temperature hot water and low-temperature hot water; The steam-hot water preparation module is connected with the cascade heat exchanger module and comprises a steam generator, a high-temperature hot water storage tank and a low-temperature hot water storage tank, wherein the steam generator is used for receiving the high-temperature hot water as a heat source and converting pure water into steam; The water supply module is respectively connected with the high-temperature hot water storage tank, the low-temperature hot water storage tank and the steam output end of the steam-hot water preparation module and is used for distributing the high-temperature hot water, the low-temperature hot water and the steam to corresponding water terminals; the intelligent control terminal is respectively and electrically connected with the high-temperature flue gas recovery module, the step heat exchanger module, the steam-hot water preparation module and the water supply module, and is used for collecting system operation parameters and automatically adjusting the operation state of each module; the safety protection module is integrated on key pipelines and equipment of the system and is used for executing safety protection operation under the conditions of overtemperature, overpressure or abnormal working conditions.

Description

Industrial furnace step-based efficient waste heat recovery process method and system Technical Field The invention relates to a technological method and a system for step efficient waste heat recovery based on an industrial furnace, and belongs to the technical field of industrial waste heat recovery and utilization. Background Industrial furnaces (such as aluminum alloy solution heat treatment furnaces, forging heating furnaces and the like) are key equipment in the metal processing industry, and the industrial furnaces are heated by fuel gas and the like in the working process to meet the process requirements, and a large amount of high-temperature flue gas is generated in the heating process, and the flue gas temperature is usually 300-1000 ℃. At present, most enterprises directly discharge the high-temperature flue gas of the industrial furnace through a chimney, so that not only is a great deal of heat energy wasted, but also the energy consumption cost of the enterprises is increased, and meanwhile, the direct discharge of the high-temperature flue gas also increases the environmental heat pollution. On the other hand, domestic water (such as hot water in a bathroom of workers, water for kitchen, clean water and the like) in the factory area and surrounding communities of enterprises is usually heated and prepared by a gas boiler, an electric heater and the like, and the mode has high energy consumption and high operation cost and has certain potential safety hazard. In the prior art, although part of industrial flue gas waste heat recovery devices exist, the special waste heat recovery system for the industrial furnace flue gas with high-temperature smoke exhaust and trace metal oxide dust containing characteristics is less, and the part of waste heat recovery system can influence the production of a user industrial furnace if in fault maintenance or maintenance, so that the following defects generally exist: 1) The waste heat recovery efficiency is low, most of the waste heat is subjected to single-stage heat exchange, only part of high-temperature waste heat can be recovered, and the middle-low-temperature waste heat is not effectively utilized; 2) The protection structure is not designed according to the characteristics that the flue gas of the industrial furnace contains trace metal oxide dust and is easy to cause the blockage and corrosion of a heat exchanger, and the service life of equipment is short; 3) And for discontinuous periodicity, intermittent maintenance industrial furnaces, the heat characteristics cannot be matched accurately. 4) Lack of accurate temperature and pressure control systems is prone to dew point corrosion (when the exhaust gas temperature is too low) or unstable hot water/steam supply; 5) The waste heat recovered can not be supplied in a grading manner according to different temperature requirements of domestic water, and the adaptability is poor. Disclosure of Invention The invention aims to overcome the defects in the prior art, and provides a process method and a system for recovering waste heat based on industrial furnace steps, which are used for converting the recovered waste heat into high-temperature hot water, low-temperature hot water and steam so as to meet the requirements of domestic water and steam. In order to achieve the above purpose, the invention is realized by adopting the following technical scheme: In a first aspect, the invention provides a process method based on industrial furnace cascade high-efficiency waste heat recovery, which comprises the following steps: obtaining high-temperature flue gas generated in the production process of an industrial furnace; Introducing the high-temperature flue gas into a cascade heat exchanger module through a high-temperature flue gas recovery module to perform cascade heat exchange; In the cascade heat exchanger module, a high-temperature heat exchange unit and a low-temperature heat exchange unit are utilized to conduct two-stage heat exchange on the high-temperature flue gas, and high-temperature hot water and low-temperature hot water are respectively prepared; storing the high-temperature hot water in a high-temperature hot water storage tank, and storing the low-temperature hot water in the low-temperature hot water storage tank; The stored high-temperature hot water is conveyed to a steam generator, pure water is converted into steam by utilizing heat of the high-temperature hot water, and the steam is supplied to a main steam pipeline of a user or stored in a steam storage tank; the stored high-temperature hot water and low-temperature hot water are respectively supplied to water terminals corresponding to temperature requirements through a high-temperature hot water supply pipeline and a low-temperature hot water supply pipeline; The intelligent control terminal is used for collecting system temperature, pressure and flow data in real time, and the running state of the equipment is automatically adju