Blast furnace slag water waste heat refrigeration for blast dehumidification energy-saving system

Abstract

The utility model relates to a kind of blast dehumidification energy-saving system for blast furnace slag flushing water waste heat refrigeration, the energy-saving system, including filtering unit, lithium bromide absorption refrigerating unit and blast dehumidification unit, blast furnace slag flushing water flows into the heat source side loop of the generator of lithium bromide absorption refrigerating unit after filtering unit, as driving heat source preparation chilled water;The evaporator of lithium bromide absorption refrigerating unit and the chilled water circuit of surface cooler of blast dehumidification unit are communicated by pipeline, and the chilled water generated by evaporator provides cold source for blast to carry out condensation dehumidification.Directly use the low-grade slag flushing water waste heat of waste as driving energy, completely replace or greatly reduce the energy consumption of traditional electric refrigeration or steam refrigeration.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery and industrial energy conservation technology, specifically to a blast furnace slag flushing water waste heat cooling system for blast dehumidification and energy conservation. Background Technology

[0002] The slag flushing water from blast furnaces in the steel industry contains abundant low-grade waste heat resources, with temperatures typically between 65 and 95°C. Currently, the utilization of this waste heat is relatively limited, mainly used for preheating air or heating domestic water. This results in problems such as low waste heat recovery rates and a mismatch between the heat energy grade and energy demand, ultimately leading to a significant waste of heat energy.

[0003] In the process of blast furnace blasting in industries such as steel, water vapor in the air enters the blast furnace with the blast air, which lowers the theoretical combustion temperature and increases the coke ratio. At the same time, the humidity of the blast air changes constantly with atmospheric conditions, causing fluctuations in the flame temperature in front of the tuyeres, which is detrimental to smooth furnace operation. Using dehumidification technology for blast furnace blast air can not only reduce the metallurgical coke ratio but also stabilize blast furnace conditions and reduce temperature fluctuations, and its application in large blast furnace blasting is becoming increasingly widespread.

[0004] Traditional blower dehumidification processes mainly rely on electric or steam-driven chillers, consuming large amounts of high-grade electricity or steam, resulting in high operating costs. Although solution dehumidification technology can also be applied, its solution regeneration process also requires an external heat source, making it still highly dependent on energy.

[0005] In recent years, some studies have attempted to utilize industrial waste heat (such as boiler flue gas and circulating cooling water waste heat) to drive dehumidification systems in order to reduce energy consumption. However, applying blast furnace slag flushing water waste heat to blast dehumidification still faces significant challenges: Large fluctuations in heat source: Changes in blast furnace production load cause frequent fluctuations in the temperature and flow rate of slag flushing water. Traditional lithium bromide units have high requirements for the stability of heat source temperature, and fluctuations can lead to a decrease in refrigeration efficiency or even shutdown.

[0006] Poor water quality: The flushing water contains a large amount of suspended solids, calcium and magnesium ions, and other impurities, exhibiting strong abrasiveness, scaling, and corrosiveness. Current technology involves installing an intermediate heat exchanger to prevent the flushing water from directly entering the waste heat to drive the chiller unit. However, the intermediate heat exchanger causes a drop in the temperature of the heat source entering the unit, thereby reducing the system's energy efficiency.

[0007] Low system integration: Existing technologies make it difficult to achieve dynamic matching and efficient coordination between the waste heat side and the dehumidification side under varying operating conditions, resulting in poor overall system energy efficiency and economy.

[0008] Therefore, developing a system that can adapt to fluctuations in the quality and temperature of slag flushing water and achieve efficient and stable dehumidification is of great significance for tapping the energy-saving potential of steel enterprises and reducing carbon emissions. Utility Model Content

[0009] To address the above problems, this utility model provides a blast furnace slag flushing water waste heat cooling system for blast dehumidification and energy saving. It can directly utilize slag flushing water that has not undergone intermediate heat exchange, solving the technical bottlenecks caused by heat source fluctuations and poor water quality, and achieving low energy consumption and high efficiency blast dehumidification.

[0010] The technical solution adopted in this utility model is: a blast furnace slag flushing water waste heat cooling and blower dehumidification energy-saving system, including a filter unit, a lithium bromide absorption chiller unit, and a blower dehumidification unit connected in sequence by pipelines. The blast furnace slag flushing water flows into the heat source side loop of the generator of the lithium bromide absorption chiller unit after passing through the filter unit, serving as the driving heat source to produce chilled water. The evaporator of the lithium bromide absorption chiller unit is connected to the chilled water loop of the surface cooler of the blower dehumidification unit through pipelines. The chilled water produced by the evaporator provides a cold source for the blower for condensation and dehumidification. This system directly utilizes the waste heat of low-grade slag flushing water as the driving energy, completely replacing or significantly reducing the energy consumption of traditional electric or steam refrigeration.

[0011] Preferably, a water flow buffer unit is connected in parallel between the filtration unit and the lithium bromide absorption chiller. The water flow buffer unit includes a storage tank. One path of the filtration unit is directly connected to the generator heat exchange tube of the lithium bromide absorption chiller, and the other path connects to the generator heat exchange tube of the lithium bromide absorption chiller after passing through the storage tank. When the flushing water flow rate increases, the electric valve on the water flow buffer unit side is opened, and a portion of the flushing water enters the storage tank of the water flow buffer unit for storage. When the flushing water flow rate decreases, the electric valve is closed, and simultaneously, the water pump on the storage tank side is turned on, allowing the flushing water stored in the storage tank to replenish the inlet pipe of the lithium bromide absorption chiller, thus reducing the impact of fluctuations in the flushing water flow rate.

[0012] Preferably, the heat exchange tubes of the generator are made of metal materials that are resistant to slag and water abrasion and corrosion. By using special anti-corrosion materials to manufacture the core heat exchange components of the generator and optimizing their structure, the risks of corrosion and scaling of the equipment are fundamentally solved, the system is simplified, and heat loss caused by indirect heat exchange is avoided.

[0013] Preferably, a chilled water pump is provided between the evaporator of the lithium bromide absorption chiller unit and the chilled water circuit of the surface cooler of the blower dehumidification unit. The chilled water produced by the evaporator is sent to the surface cooler of the blower dehumidification unit by the chilled water pump, where it exchanges heat and moisture with the process blower that needs to be dehumidified. The air is cooled, and the water vapor in it condenses and precipitates out, flowing through the demister and into the condensate tank, thereby achieving the purpose of dehumidification.

[0014] Preferably, the condensate tank is connected to the water collection tray of the cooling tower via a condensate pump, and the cooling tower is connected to the cooling pipes of the lithium absorption chiller unit via a cooling water pump.

[0015] Preferably, the condensate tank is connected to the chilled water expansion tank via a condensate pump, and the chilled water expansion tank is connected to the chilled water circuit of the surface cooler of the blower dehumidification unit.

[0016] Preferably, the heat exchange tubes of the surface cooler are made of T2 copper tubes, and the fins are made of rust-proof aluminum.

[0017] Preferably, the demister is a wire mesh type.

[0018] Preferably, the filtration unit includes a sand remover and an auger filter arranged in series for filtering suspended particulate matter in the flushing water.

[0019] The beneficial effects achieved by this utility model are: 1. High efficiency and energy saving, significantly reduced costs: It directly utilizes the waste heat from low-grade slag flushing water as the driving energy, completely replacing or significantly reducing the energy consumption of traditional electric or steam refrigeration. Calculations show that the operating cost per unit of dehumidified water volume can be reduced by 20%~30% compared to traditional electric chillers / steam refrigeration dehumidification. 2. Innovative direct utilization and anti-corrosion technology: Breaking through the traditional thinking that slag flushing water cannot be directly introduced into precision units, the core heat exchange components of the generator are manufactured using special anti-corrosion materials and optimized in structure, which fundamentally solves the risk of corrosion and scaling of the equipment, simplifies the system, and avoids heat loss caused by indirect heat exchange. 3. Strong adaptability to heat source fluctuations: Through the intelligent control unit, dynamic matching between the lithium bromide unit and fluctuating heat sources is achieved; the system can automatically adapt to temperature changes within the range of 65~95℃ and flow fluctuations of ±20%, ensuring stable dehumidification effect and broadening the application scenarios of the technology. 4. Resource recycling and outstanding environmental benefits: The "waste heat" in the steel production process is transformed into a valuable "cold source" for energy conservation and consumption reduction in the production process. This realizes the cascade utilization of energy, which is in line with the policy orientation of circular economy and carbon emission reduction, and creates good economic and environmental benefits for enterprises. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of the present invention; The components include: 1. Filter unit; 2. Water flow buffer unit; 21. Energy storage tank; 22. Electric valve; 23. Make-up water pump; 3. Lithium bromide absorption chiller; 4. Cooling water pump; 5. Cooling tower; 6. Chilled water pump; 7. Expansion tank; 8. Surface cooler; 9. Demister; 10. Condensate tank; 11. Condensate pump. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, this utility model discloses a blast furnace slag flushing water waste heat cooling and dehumidification energy-saving system, comprising a filtration unit 1, a lithium bromide absorption chiller unit 3, and a dehumidification unit. The hot water circuit (heat source side circuit) of the generator of the lithium bromide absorption chiller unit 3 is directly connected to the slag flushing water pipeline after filtration unit 1, allowing the slag flushing water to flow directly through the generator as a driving heat source. Inside the generator of the lithium bromide absorption chiller unit 3, the heat of the slag flushing water concentrates the dilute lithium bromide solution, and the generated refrigerant vapor condenses into refrigerant water in the condenser, simultaneously transferring heat to the cooling water. The refrigerant water is then throttled and evaporates in the evaporator, absorbing heat from the chilled water to produce low-temperature chilled water (7°C outlet). The heat from the cooling water absorber and condenser in the lithium bromide absorption chiller unit 3 is dissipated to the cooling tower 5 by the cooling water pump 4.

[0023] The evaporator of the lithium bromide absorption chiller unit 3 is connected to the chilled water circuit of the surface cooler 8 of the blower dehumidification unit via pipelines. The chilled water produced by the evaporator provides a cold source for the blower to condense and dehumidify. It directly utilizes the waste heat of the low-grade slag flushing water as the driving energy, completely replacing or significantly reducing the energy consumption of traditional electric or steam refrigeration.

[0024] In this embodiment, a water flow buffer unit 2 is connected in parallel between the filter unit 1 and the lithium bromide absorption chiller unit 3. The water flow buffer unit 2 includes an energy storage tank 21. One path of the filter unit 1 is directly connected to the generator heat exchange tube of the lithium bromide absorption chiller unit 3, and the other path is connected to the generator heat exchange tube of the lithium bromide absorption chiller unit 3 after passing through the energy storage tank 21. When the flushing water flow rate increases, the electric valve 22 on the side of the water flow buffer unit 2 is opened, and a portion of the flushing water enters the energy storage tank 21 of the water flow buffer unit 2 for storage. When the flushing water flow rate decreases, the electric valve 22 is closed, and the replenishment water pump 23 on the side of the energy storage tank 21 is turned on, so that the flushing water stored in the energy storage tank 21 is replenished to the inlet pipe of the lithium bromide absorption chiller unit 3, thereby reducing the impact of fluctuations in the flushing water flow rate.

[0025] In this embodiment, the heat exchange tubes of the generator in the lithium bromide absorption chiller unit 3 are made of a metal material resistant to slag water abrasion and corrosion. Furthermore, they are made of corrosion-resistant special stainless steel or titanium alloy. By using special anti-corrosion materials to manufacture the core heat exchange components of the generator and optimizing their structure, the risks of corrosion and scaling of the equipment are fundamentally solved, the system is simplified, and heat loss caused by indirect heat exchange is avoided.

[0026] In this embodiment, a chilled water pump 6 is provided between the evaporator of the lithium bromide absorption chiller unit 3 and the chilled water circuit of the surface cooler of the blower dehumidification unit. The produced chilled water is sent to the surface cooler 8 of the blower dehumidification unit by the chilled water pump 6, where it exchanges heat and moisture with the process blower that needs to be dehumidified. The air is cooled, and the water vapor in it condenses and precipitates out, flowing through the demister 9 and into the condensate tank 10, thereby achieving the purpose of dehumidification.

[0027] Condensate flows through condensate pump 11, one path into chilled water expansion tank 7, and the other path into cooling tower 5 collection basin, serving as a makeup water source for chilled water and cooling water, and is recycled.

[0028] In this embodiment, the heat exchange tubes of the surface cooler are made of T2 copper tubes, and the fins are made of rust-proof aluminum; preferably, the demister is a wire mesh type.

[0029] In this embodiment, the filtration unit 1 includes a sand remover and an auger filter arranged in series, used to filter suspended particulate matter in the flushing water.

[0030] In this embodiment, both the chilled water pump 6 and the cooling water pump 4 adopt an integrated delivery unit, which includes a variable frequency pump, a zero-resistance filter, and a low-resistance check valve.

[0031] This utility model's blast furnace slag flushing water waste heat cooling system is a blower dehumidification energy-saving system. The control unit monitors in real time the temperature and flow rate of the slag flushing water entering the generator, as well as the air temperature and humidity parameters at the inlet and outlet of the blower dehumidification unit. Based on the monitored data parameters, the system dynamically matches the cooling capacity and dehumidification load by adjusting the solution circulation volume of the lithium bromide absorption chiller unit 3, the refrigerant water pump frequency, the working mode of the water flow buffer unit 2, and the pump frequencies of the chilled water pump 6 and the cooling water pump 4.

[0032] The specific control methods include the following steps: 1. Large suspended solids are removed from the blast furnace slag flushing water through filtration unit 1; 2. The filtered flushing water enters the water flow buffer unit 2 to reduce fluctuations in the flushing water flow. 3. The flushing water from the water flow buffer unit 2 directly enters the generator of the lithium bromide absorption chiller unit 3, serving as a driving heat source to heat the lithium bromide solution and generate refrigerant vapor. 4. After the refrigerant vapor is condensed in the condenser, it is throttled and evaporated in the evaporator, absorbing heat to produce chilled water; 5. The produced chilled water is transported to the surface cooler 8 of the blower dehumidification unit to cool and dehumidify the process blower.

[0033] 6. The control unit dynamically adjusts the operating parameters (solution pump frequency, refrigerant water pump frequency), working mode (heat storage and heat release) of the water flow buffer unit 2, and pump frequencies of the chilled water pump 6 and cooling water pump 4 based on the real-time monitored inlet temperature and flow rate of the slag flushing water, as well as the inlet and outlet air temperature and humidity parameters of the blower dehumidification unit, to ensure that the system can still operate stably and efficiently under heat source fluctuations.

[0034] When the temperature and humidity of the air at the outlet of the dehumidification unit are detected to rise, the control unit increases the solution circulation rate and refrigerant evaporation rate of the lithium absorption chiller 3 to increase the cooling capacity, and correspondingly increases the operating frequency of the chilled water pump 6 and the cooling water pump 4 to adapt to the load change; when the temperature and humidity of the air at the outlet of the dehumidification unit are detected to drop, the above control variables are reduced accordingly.

[0035] When the flushing water flow rate increases, the electric valve 22 on the side of the water flow buffer unit 2 is opened, and a portion of the flushing water enters the energy storage tank 21 of the water flow buffer unit 2 for storage. When the flushing water flow rate decreases, the electric valve 22 is closed, and the replenishment water pump 23 on the side of the energy storage tank 21 is turned on, so that the flushing water stored in the energy storage tank 21 is replenished into the inlet pipe of the lithium bromide absorption chiller unit 3, thereby reducing the impact of the fluctuation in the flushing water flow rate.

[0036] The foregoing has shown and described the basic principles and main structural features of this utility model. This utility model is not limited to the above examples; various changes and modifications can be made without departing from the spirit and scope of this utility model, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A blast furnace slag flushing water waste heat cooling and dehumidification energy-saving system, characterized in that: The system includes a filter unit (1), a lithium bromide absorption chiller (3), and a blower dehumidification unit connected in sequence by pipes. The blast furnace slag flushing water flows into the heat source side circuit of the generator of the lithium bromide absorption chiller (3) after passing through the filter unit (1), and serves as a driving heat source to produce chilled water. The evaporator of the lithium bromide absorption chiller (3) is connected to the chilled water circuit of the surface cooler (8) of the blower dehumidification unit through a pipeline. The chilled water generated by the evaporator provides a cold source for the blower to condense and dehumidify.

2. The blast furnace slag flushing water waste heat cooling and dehumidification energy-saving system according to claim 1, characterized in that: A water flow buffer unit (2) is connected in parallel between the filter unit (1) and the lithium bromide absorption chiller (3). The water flow buffer unit (2) includes an energy storage tank. One path of the filter unit (1) is directly connected to the generator heat exchange tube of the lithium bromide absorption chiller (3), and the other path flows through the energy storage tank and is connected to the generator heat exchange tube of the lithium bromide absorption chiller (3).

3. The blast furnace slag flushing water waste heat cooling and dehumidification energy-saving system according to claim 1, characterized in that: The heat exchange tubes of the generator are made of metal materials that are resistant to slag water abrasion and corrosion.

4. The blast furnace slag flushing water waste heat cooling and dehumidification energy-saving system according to claim 1, characterized in that: A chilled water pump (6) is provided between the evaporator of the lithium bromide absorption chiller unit (3) and the chilled water circuit of the surface cooler (8) of the blower dehumidification unit. The chilled water generated by the evaporator is sent to the surface cooler (8) of the blower dehumidification unit after passing through the chilled water pump (6), and exchanges heat and moisture with the process blower that needs to be dehumidified. The air is cooled, and the water vapor in it is condensed and precipitated, flowing through the demister (9) and entering the condensate tank (10), thereby achieving the purpose of dehumidification.

5. The blast furnace slag flushing water waste heat cooling and dehumidification energy-saving system according to claim 4, characterized in that: The condensate tank (10) is connected to the water collection tray of the cooling tower (5) via the condensate pump (11), and the cooling tower (5) is connected to the cooling pipe of the lithium absorption chiller (3) via the cooling water pump (4).

6. The blast furnace slag flushing water waste heat cooling and dehumidification energy-saving system according to claim 4, characterized in that: The condensate tank (10) is connected to the chilled water expansion tank (7) via the condensate pump (11), and the chilled water expansion tank (7) is connected to the chilled water circuit of the surface cooler (8) of the blower dehumidification unit.

7. The blast furnace slag flushing water waste heat cooling and dehumidification energy-saving system according to claim 4, characterized in that: The heat exchange tubes of the surface cooler (8) are made of T2 copper tubes and the fins are made of rust-proof aluminum.

8. The blast furnace slag flushing water waste heat cooling and dehumidification energy-saving system according to claim 4, characterized in that: The demister (9) is a wire mesh type.

9. The blast furnace slag flushing water waste heat cooling and dehumidification energy-saving system according to claim 1, characterized in that: The filtration unit (1) includes a sand remover and an auger-type dirt remover arranged in series.

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