The benefits of plate heat exchangers in steel enterprises

1.Application of plate heat exchangers in steel enterprises

Plate heat exchangers are widely used in steel enterprises, mainly involving efficient heat exchange, energy saving and consumption reduction, and process optimization. The following are its main application scenarios:

1.1. Blast furnace system

Blast furnace blast heating: used to preheat blast furnace blast, increase furnace temperature, and enhance smelting efficiency.

Gas heat exchange: used for blast furnace gas and converter gas waste heat recovery to improve energy utilization.

1.2. Steel rolling system

Emulsion cooling: During the steel rolling process, the emulsion is used for lubrication and cooling, and needs to be cooled to a suitable temperature through a plate heat exchanger.

Process water cooling: such as rolling mill cooling water, continuous casting cooling water, etc., are cooled through plate heat exchangers to ensure stable production.

1.3. Steelmaking and continuous casting system

Secondary cooling of molten steel: During the continuous casting process, a plate heat exchanger is used to control the cooling water temperature to ensure the quality of the ingot.

Electric furnace cooling water system: used to cool key components such as electric furnace water jackets and electrodes to prevent overheating damage.

1.4. Waste heat recovery and energy utilization

Flue gas waste heat recovery: Use plate heat exchangers to recover high-temperature flue gas heat, heat water or air, and improve energy utilization.

Steam condensation system: Used for steam condensers to improve heat recovery efficiency and reduce energy loss.

1.5. Environmental protection treatment system

Wastewater and waste gas treatment: During sewage treatment, plate heat exchangers are used for heat exchange to improve sewage treatment efficiency.

Pickling liquid heating or cooling: Used to control the temperature of the pickling liquid to ensure the pickling effect and extend the life of the equipment.

2.Advantage analysis

High heat exchange efficiency, turbulence between plates, and improved heat transfer efficiency.

Compact structure, small footprint, suitable for complex working conditions in steel enterprises.

Easy to disassemble and maintain, reduce downtime, and improve production efficiency.

Energy saving and consumption reduction, improve waste heat utilization, and reduce energy costs.

3.How can plate heat exchangers achieve energy saving and consumption reduction in steel enterprises?

The energy saving and consumption reduction of plate heat exchangers in steel enterprises are mainly achieved through efficient heat exchange, waste heat recovery, reduced energy consumption, and reduced water waste. The following are detailed energy saving and consumption reduction measures and their specific applications:

3.1. Improve heat exchange efficiency and reduce energy waste

3.1.1 Use efficient heat exchange structure

Turbulence enhances heat transfer: The internal flow channel of the plate heat exchanger is a corrugated structure, and turbulence is formed when the fluid passes through, which improves the heat transfer efficiency. Compared with traditional shell and tube heat exchangers, the heat exchange efficiency is increased by more than 30%.

Thin plate material optimizes heat conduction: The plate thickness is usually 0.5mm~0.8mm, the heat transfer resistance is small, and the heat conduction efficiency is higher.

3.1.2 Application case: emulsion cooling of steel rolling

Problem: During the steel rolling process, the emulsion is used for lubrication and cooling, and it needs to maintain a suitable temperature (30-40℃), otherwise it will affect the rolling quality.

Solution: Use plate heat exchangers to exchange heat with cooling water to keep the emulsion temperature stable.

Energy-saving effect:

The accuracy of emulsion temperature control is improved by ±1℃, reducing heat energy waste.

Reduce the frequency of emulsion replacement and reduce emulsifier consumption by 20%-30%.

3.2. Waste heat recovery to improve energy utilization

3.2.1 Waste heat recovery of blast furnace gas

Problem: The temperature of blast furnace gas is as high as 400-500℃, and direct discharge will waste a lot of heat energy.

Solution: Use plate heat exchangers to recover the heat of high-temperature gas and heat boiler feed water or air.

Energy-saving effect:After waste heat recovery, the boiler feed water temperature increases by 30-50℃, saving 10%-15% of coal.

After the gas temperature is reduced, the energy consumption of the water cooling system is reduced by 15%.

3.2.2 Waste heat recovery of continuous casting cooling water

Problem: Continuous casting cooling water takes away a lot of heat, and the traditional method of direct discharge wastes energy.

Solution: The heat of hot water is transferred to the low-temperature return water through the plate heat exchanger, so that it is preheated and enters the heating system.

Energy-saving effect:

Recover heat for plant heating or process heat, reducing steam consumption by 20%-25%.

Reduce the drop in cooling water temperature and reduce water replenishment demand by 15%-20%.

3.3. Reduce energy consumption and improve fuel utilization

3.3.1 Energy saving of converter flue gas cooling

Problem: The flue gas temperature generated during converter smelting is as high as 800-1000℃, and the traditional water cooling method is inefficient.

Solution: Use plate heat exchangers to transfer flue gas heat to hot water or steam systems.

Energy-saving effect:

Reduce flue gas temperature to 300-400℃ and reduce cooling water consumption by 20%.

Waste heat recovery can be used for plant heating or hot water production, reducing boiler load by 10%-15%.

3.3.2 Heat recovery of steel rolling

Problem: During steel rolling, the temperature of the billet is as high as 1000℃, and the cooling water takes away a lot of heat.

Solution: The plate heat exchanger recovers the heat of cooling water for preheating air or process water.

Energy-saving effect:

Preheating the lubricating oil or process water of the rolling mill can improve the utilization rate of thermal energy by 30%.

Reduce the amount of supplementary cooling water by 25% and save water resources.

3.4. Reduce water waste and optimize the cooling system

3.4.1 Closed-loop cooling to reduce new water consumption

Problem: The cooling water consumption of steel enterprises is large, and the traditional direct discharge system wastes a lot of water resources.

Solution: Use plate heat exchangers to establish a closed-loop system to improve the reuse rate of water.

Energy-saving effect:

The reuse rate of cooling water is increased to 90%, and the amount of new water replenishment is reduced by 50%-70%.

Reduce the consumption of water treatment chemicals and reduce operating costs by 15%-20%.

3.4.2 Pickling liquid temperature control to reduce acid consumption

Problem: Too high a temperature in the pickling process will accelerate the volatilization of the acid and increase the acid consumption.

Solution: Use a plate heat exchanger to accurately control the temperature of the pickling liquid (maintained at 40-70℃). Energy-saving effect:

Acid consumption is reduced by 10%-15%, reducing the cost of waste liquid treatment.

The pickling uniformity is improved, and the rework rate is reduced by 5%-8%.

3.5. Comprehensive energy-saving optimization to improve overall efficiency

3.5.1 Heating system optimization

Problem: The heating and hot water supply systems in the steel plant area have high energy consumption.

Solution: Use plate heat exchangers to recover waste heat and replace part of the boiler heating.

Energy-saving effect:

The heating system saves 15%-20% energy and reduces boiler fuel consumption.

Reduce carbon dioxide emissions by 10%-12%, meeting environmental protection requirements.

3.5.2 Intelligent control and optimization

Problem: Traditional heat exchange systems lack intelligent regulation and are prone to energy waste.

Solution: Cooperate with the automatic control system to accurately adjust the flow and temperature of the heat exchanger.

Energy-saving effect:

Improve heat exchange efficiency by 10%-15% and reduce energy loss.

The operating life of the equipment is extended by 20%, reducing maintenance costs.

4.Summary:

Energy-saving and consumption-reducing measures of plate heat exchangers in steel enterprises

Measures	Energy-saving and consumption-reducing effects
Improve heat exchange efficiency	Improve heat transfer efficiency by 30% and reduce energy waste.
Waste heat recovery	Save fuel consumption by 10%-25%, reduce flue gas emissions
Reduce cooling water consumption	Increase cooling water utilization to 90%, reduce water replenishment demand by 50%
Optimize the pickling system	Reduce acid consumption by 10%-15%, reduce waste liquid treatment costs
Intelligent control system	Energy efficiency increased by 10%-15%, equipment life extended by 20%

5.Conclusion:

Plate heat exchangers, with their high-efficiency heat exchange, compact structure, and easy maintenance, achieve energy conservation and consumption reduction in multiple links of steel enterprises such as blast furnaces, steelmaking, rolling, heating, and environmental protection, providing important guarantees for enterprises to reduce costs, improve energy utilization, and reduce environmental pollution.

 

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