CN202470794U - Equipment special for waste heat cascade utilization and dust removal of high-temperature alternation fume of electric furnace - Google Patents

Abstract

Special equipment for cascade utilization of high temperature alternating flue gas waste heat and dust removal of electric furnace, including settling chamber, heat storage homogenizer, high temperature heat pipe evaporator, medium and low temperature waste heat exchange room, dust collector, main fan, exhaust pipe, characterized in that: all The settling chamber is sequentially connected with a heat storage homogenizer, a high-temperature heat pipe evaporator, a medium-low temperature waste heat exchange chamber, a dust collector, a main fan, and an exhaust pipe. The heat storage homogenizer includes a heat storage body, a dust removal device and an ash hopper, and the dust removal device is arranged between the heat storage bodies. The high-temperature heat pipe evaporator is connected to a steam drum through a pipeline, and the steam drum is connected to a steam heat accumulator. The medium-low temperature waste heat exchange chamber is equipped with an evaporator, one end of the evaporator is connected to the working fluid circulation pump, the other end is connected to the steam turbine, one end of the steam turbine is connected to the condenser, and the other end is connected to the generator. It is characterized in that: R245fa is used as the circulating organic working fluid. The utility model can realize cascaded utilization of waste heat of electric furnace flue gas, and convert heat energy in flue gas into high-grade electric energy to the greatest extent.

Description

Cascade utilization of waste heat of electric furnace high temperature alternating flue gas and special equipment for dust removal

technical field

The utility model relates to a waste heat utilization device, in particular to a cascade utilization of high-temperature alternating flue gas waste heat of an electric furnace and special equipment for dust removal, which belongs to the technical field of flue gas dust removal and waste heat power generation.

Background technique

The iron and steel industry consumes a large amount of energy every year, and the high-temperature flue gas generated during the smelting process and the heat dissipation of equipment take away a large amount of energy. Due to the high temperature of the electric furnace steelmaking flue gas, the temperature entering the pipeline after being captured is generally around 1250°C, the dust concentration reaches 18g/Nm ³ , and the dust less than 8um accounts for more than 75% of the total dust, and the dust volume is large, and Sticky and thin. Moreover, the flue gas temperature fluctuates violently and the dust content is large. It is difficult for ordinary water tube waste heat boilers to be used for waste heat recovery of electric furnace flue gas. At present, the heat pipe heat exchanger has been successfully used in the waste heat recovery of the flue gas of the electric furnace. The popularization still faces many problems.

Because the flue gas contains a large amount of dust, the sticky and fine dust will accumulate dust and clog the heat exchange elements, which not only affects the heat exchange efficiency, but also causes insufficient steam production of the waste heat boiler, and more seriously, the waste heat boiler is blocked by dust , the system was unstable, causing the smelting production to be unable to proceed normally, and was forced to stop production for maintenance.

At the same time, because the flue gas temperature of the electric furnace fluctuates violently and has a large amplitude, the waste heat recovery device must be designed to be large enough to ensure that the high-temperature flue gas can be effectively cooled. However, the actual steam output is far lower than the maximum evaporation capacity of the waste heat recovery device, resulting in a situation of large horses and small carts. This relatively reduces the economic value of the waste heat recovery device and increases the investment of the waste heat recovery device.

Contents of the invention

The utility model aims at the problems existing in the prior art, and provides a waste heat cascade utilization device with a heat storage homogenizer that can effectively reduce the fluctuating range of the flue gas temperature of an electric furnace. The heat energy is converted into high-grade electric energy, and the dust removal fan is driven to reduce the discharge temperature of the flue gas, improve the dust removal ability, and obtain a good dust removal effect. The dust emission concentration is less than 5mg/Nm3.

The technical scheme adopted by the utility model is as follows: electric furnace high temperature alternating flue gas waste heat cascade utilization and dust removal special equipment, including combustion settling chamber, heat storage homogenizer, high temperature heat pipe evaporator, medium and low temperature waste heat exchange chamber, dust collector, main The fan and the exhaust tube are characterized in that: the combustion and settling chamber is sequentially connected to a heat storage homogenizer, a high-temperature heat pipe evaporator, a medium and low temperature waste heat exchange room, a dust collector, a main fan, and an exhaust tube through pipelines, and the heat storage The thermostat includes a carbon-ceramic composite regenerator, a shock wave cleaning device and an ash hopper. The shock wave cleaning device is arranged between the carbon-ceramic composite regenerator in sections. The high-temperature heat pipe evaporator passes The steam drum is connected, and the steam drum is connected to the steam heat accumulator through pipelines. A primary surface evaporator is installed in the medium and low temperature waste heat exchange chamber, the inlet end of the primary surface evaporator is connected to the high-pressure outlet end of the working fluid circulation pump, and the outlet end of the primary surface evaporator is connected to the upper flange interface of the steam turbine through a pipeline , the lower interface of the low-boiling-point working medium steam turbine is connected to the air inlet of the shell-and-tube condenser through a pipe, and the liquid-phase outlet of the shell-and-tube condenser is connected to the low-pressure inlet of the working medium circulating pump through a pipeline. The low-boiling point working medium steam turbine It is connected with a three-phase generator, one end of the shell-and-tube condenser is connected to a flange interface with a water pump, the other end of the shell-and-tube condenser is connected to a cooling tower, and the cooling tower is connected to a water pump to form a circuit.

It is further characterized in that: R245fa is used as the circulating organic working fluid.

Since the flue gas temperature of the electric furnace fluctuates violently and the peak value of the flue gas temperature is high, when the flue gas is treated by the heat storage homogenizer of the utility model, the fluctuation range of the flue gas temperature can be greatly reduced, and the peak value of the flue gas temperature is also reduced. The flue gas passing through the heat storage homogenizer enters the high-temperature heat pipe evaporator. Since the peak temperature of the flue gas is reduced, the investment of the high-temperature heat pipe evaporator can be reduced; the fluctuating range of the flue gas temperature is reduced, which is conducive to improving the stability of the high-temperature heat pipe evaporator. Extended service life.

The utility model has the advantages of:

1. Use a high-temperature heat pipe evaporator to recover the waste heat of the high-temperature flue gas of the electric furnace, and a low-boiling-point working medium organic Rankine cycle waste heat power generation to recover the waste heat of the low-temperature flue gas in the electric furnace, and realize the cascade utilization of the waste heat of the electric furnace flue gas;

2. It can alleviate the sudden rise and fall of flue gas temperature, and solve the problem of thermal expansion and cold contraction;

3. The primary surface evaporator does not accumulate dust and is not blocked;

4. Extend the service life of the equipment;

5. Improve the efficiency of waste heat power generation device;

6. Reduce investment in waste heat power generation equipment;

7. It can reduce the amount of mixed cold air and save the energy consumption of dust removal.

Description of drawings

Fig. 1 is a schematic diagram of the device structure of the present invention.

In the figure, 1. Electric furnace, 2. Water-cooled sliding sleeve, 3. Combustion and settling chamber, 4. Heat storage homogenizer, 5. High temperature heat pipe evaporator, 6. Medium and low temperature waste heat exchange chamber, 7. Dust collector, 8. Main Fan, 9. Exhaust cylinder, 10. Carbon-ceramic composite heat storage body, 11. Shock wave ash cleaning device, 12. Ash hopper, 13. Steam drum, 14. Steam heat accumulator, 15. Primary surface evaporator, 16. Low boiling point working medium steam turbine, 17. Three-phase generator, 18. Working medium circulating pump, 19. Water pump, 20. Shell-and-tube condenser, 21. Cooling tower.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described.

The special equipment for cascade utilization of high temperature alternating flue gas waste heat of electric furnace and dust removal in the utility model includes combustion settling chamber 3, heat storage homogenizer 4, high temperature heat pipe evaporator 5, medium and low temperature waste heat exchange chamber 6, dust collector 7, and main fan 8 . Exhaust cylinder 9, characterized in that: the combustion settling chamber 3 is sequentially connected to the heat storage homogenizer 4, the high-temperature heat pipe evaporator 5, the medium and low temperature waste heat exchange chamber 6, the dust collector 7, the main fan 8, the exhaust cylinder 9, the heat storage homogenizer 4 includes a carbon-ceramic composite material regenerator 10, a shock wave cleaning device 11 and an ash hopper 12, and the shock wave cleaning device 11 is arranged in sections of the carbon-ceramic composite material heat storage Between body 10. The high-temperature heat pipe evaporator 5 is connected to a steam drum 13 through a pipeline, and the steam drum 13 is connected to a steam heat accumulator 14 through a pipeline. A primary surface evaporator 15 is installed in the medium and low temperature waste heat exchange chamber 6, the inlet end of the primary surface evaporator 15 is connected to the high-pressure outlet end of the working medium circulation pump 18, and the outlet end of the primary surface evaporator 15 is connected to the low The upper flange interface of the boiling point working medium steam turbine 16 is connected, the lower interface of the low boiling point working medium steam turbine 16 is connected with the air inlet of the shell-and-tube condenser 20 through a pipeline, and the liquid phase outlet of the shell-and-tube condenser 20 is connected with the working medium through a pipeline. The low-pressure inlet port of the mass circulation pump 18 is connected, the low-boiling-point working medium steam turbine 16 is connected with the three-phase generator 17, one end flange interface of the shell-and-tube condenser 20 is connected with the water pump 19, and the other end of the shell-and-tube condenser 20 One end is connected to the cooling tower 21, and the cooling tower 21 is connected with the water pump 19 to form a circuit.

The low boiling point working medium is R245fa, the working medium pressure entering the low boiling point working medium steam turbine is 1.8MPa, when the working medium pressure after expansion is 0.25MPa, the output electric power of the system is 1000KW, and the Rankine cycle efficiency is 17.5%. The exhausted flue gas temperature is 70°C.

The working process of the utility model: 100t/h electric furnace 1 flue gas flow rate 28×10 ⁴ Nm ³ /h, temperature 1250 ℃, dust concentration 18g/Nm ³ is discharged from the fourth hole, mixed with cold air through the water-cooled sliding sleeve 2, and burned The carbon monoxide gas enters the combustion settling chamber 3; the function of the combustion settling chamber 3 is to reduce the flow rate of the flue gas, settle the large particles of dust carried in the flue gas, and mix it with the cold air properly, and finally burn the carbon monoxide gas and come out of the combustion settling chamber 3 The flue gas enters the heat storage homogenizer 4, and after passing through the carbon-ceramic composite regenerator 10 in the heat storage homogenizer 4 to heat and equalize the heat storage of the high-temperature flue gas, the flue gas enters the high-temperature heat pipe evaporator 5, and the steam drum The water in 13 absorbs the waste heat of high-temperature flue gas in the high-temperature heat pipe evaporator 5 to generate steam that enters the steam drum 13, and the steam in the steam drum 13 enters the steam accumulator 14 through the pipeline. After adjustment, the external supply is stable and continuous, and the parameters meet The steam requested by the user is used to generate electricity. After the high-temperature flue gas is heat-exchanged by the high-temperature heat pipe evaporator 5, it becomes medium-low temperature flue gas and enters the medium-low temperature waste heat exchange chamber 6. The medium-low temperature flue gas releases heat and the temperature drops to 70°C, and enters the dust collector 7. After dust removal The dust concentration is 5mg/Nm ³ , which is pressed into the exhaust pipe 9 by the main fan 8 and discharged into the atmosphere. At the same time, the low-boiling-point working fluid is driven by the working fluid pump 18, and first absorbs the heat of the flue gas waste heat carrier in the primary surface evaporator 15 installed in the medium-low temperature waste heat exchange chamber to become saturated steam. After passing through the pressure regulating valve, the working fluid The steam expands in the low-boiling-point working medium steam turbine 16 to perform work, and drives the three-phase generator 17 to generate electricity. The working medium steam discharged from the low-boiling point working medium steam turbine 16 is condensed into a saturated liquid by the shell-and-tube condenser 20, and then the working medium liquid is pressurized by the working medium pump 18 and then sent to the primary surface evaporator 15 to start a new cycle. cycle. The circulating water from the shell-and-tube condenser 20 is cooled by the cooling tower 21, and then sent into the shell-and-tube condenser 20 through the water pump 19 to start a new round of circulation. The electric energy generated by the system is a three-phase alternating current with a rated voltage of 380V. After voltage regulation, it is incorporated into the power grid in the factory, or directly sent to the electrical equipment for use.

Since the heat storage homogenizer 4 can cut the peak and fill the valley of the flue gas temperature, reduce the maximum temperature of the flue gas, reduce the fluctuation range of the flue gas temperature, and alleviate the sudden rise and fall of the flue gas temperature, thus reducing the waste heat cascade utilization device investment, improve the stability of waste heat cascade utilization devices, and safely configure various types of waste heat utilization equipment.

The biggest feature of this device is that it adopts high-temperature heat pipe evaporator to recover the waste heat of high-temperature flue gas from electric furnace, and low-boiling-point working fluid organic Rankine cycle waste heat power generation to recover the waste heat of low-temperature flue gas in electric furnace, so as to realize cascade utilization of waste heat of electric furnace flue gas. Taking 100t/h steelmaking electric furnace waste heat utilization and dust removal process as an example, the utility model device is compared with the conventional device, and the description is as follows:

Note: Calculated on the basis of 330 working days per year.

It can be seen that the utility model has low smoke and dust emission concentration, low device investment, low operating energy consumption and good purification effect.

The utility model can realize cascaded utilization of the waste heat of the electric furnace flue gas, recover the heat energy in the flue gas to the greatest extent and convert it into high-grade electric energy, and can also achieve a good environmental protection effect.

Claims (5)

1. electric furnace high temperature alternation fume afterheat cascade utilization and dust-removing device special; Comprise combustion settling chamber, heat-accumulating and temperature-equalizing device, high-temperature heat pipe evaporimeter, middle-low temperature heat switch room, deduster, main air blower, aiutage, it is characterized in that: said combustion settling chamber is through pipeline be linked in sequence heat-accumulating and temperature-equalizing device, high-temperature heat pipe evaporimeter, middle-low temperature heat switch room, deduster, main air blower, aiutage.

2. electric furnace high temperature alternation fume afterheat cascade utilization according to claim 1 and dust-removing device special; It is characterized in that: said heat-accumulating and temperature-equalizing device comprises carbon ceramic composite material heat storage, shock wave deashing device and ash bucket, and the segmentation of said shock wave deashing device is arranged between the carbon ceramic composite material heat storage.

3. electric furnace high temperature alternation fume afterheat cascade utilization according to claim 1 and dust-removing device special is characterized in that: said high-temperature heat pipe evaporimeter connects drum through pipeline, and drum connects steam accumulator through pipeline.

4. electric furnace high temperature alternation fume afterheat cascade utilization according to claim 1 and dust-removing device special; It is characterized in that: said middle-low temperature heat is equipped with the one-time surface evaporimeter in the switch room; The entrance point of one-time surface evaporimeter is connected with the high-pressure outlet end of working medium circulating pump, and the port of export of one-time surface evaporimeter is connected with the upper flange interface of steam turbine behind pipeline, and the bottom interface of low boiling working fluid steam turbine is connected with the air inlet of shell-and-tube cooler through pipeline; The liquid phase outlet of shell-and-tube cooler is connected with the low pressure inlet end of working medium circulating pump through pipeline; The low boiling working fluid steam turbine is connected with threephase generator, and an end flange interface of shell-and-tube cooler is connected with water pump, and another end of shell-and-tube cooler connects cooling tower; Cooling tower is connected with water pump, constitutes a loop.

5. electric furnace high temperature alternation fume afterheat cascade utilization according to claim 4 and dust-removing device special is characterized in that: adopting R245fa is the circulation organic working medium.

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