CN202254897U - Special equipment for submerged arc furnace flue gas multistage organic Rankine cycle waste heat power generation - Google Patents

Abstract

A special equipment for power generation of waste heat from multi-stage organic Rankine cycle of flue gas from an ore-heating furnace, comprising an ore-heating furnace, a water-cooled flue, a combustion and settling chamber, a main fan, and an exhaust pipe connected in sequence, characterized in that: a high-temperature dust collector and a heat storage chamber are connected in sequence between the combustion and settling chamber and the main fan through a pipeline, a stainless steel filter element is provided in the high-temperature dust collector, a separation sleeve heat pipe heat exchanger is installed in the heat storage chamber, and the hot water outlet of the heat exchanger is connected to a high-pressure evaporator, a medium-pressure evaporator, and a low-pressure evaporator in sequence. One end of the evaporator is connected to a working medium pressure pump, and the other end is connected to an organic turbine with a supplementary steam port, one end of the organic turbine with a supplementary steam port is connected to a condenser, and the other end is connected to a generator. It is further characterized in that R413a is used as a circulating organic working medium. The device can maximize the recovery of heat energy in the flue gas and directly convert it into high-grade electrical energy, and its efficiency is increased by 10-20% compared with a single-stage evaporation organic Rankine, and can also achieve a good environmental protection effect.

Description

Special equipment for submerged arc furnace flue gas multi-stage organic Rankine cycle waste heat power generation

Technical field

The utility model relates to the technical field of multi-stage organic Rankine cycle waste heat power generation of submerged arc furnace flue gas.

Background technique

The flue gas temperature of the submerged arc furnace is very high, and the temperature entering the pipeline after being captured is generally around 1000°C. The dust concentration reaches 35g/Nm ³ , and the dust less than 5um accounts for more than 80% of the total dust. And thin. At present, the method of heat exchange and cooling is usually adopted first (heat exchange and cooling methods include: mechanical cooler heat exchange, spray cooling heat exchange, waste heat boiler heat exchange, etc.) and then dust removal method. There are many disadvantages in the method of heat exchange and cooling before dust removal:

1. Dust removal after heat exchange of the mechanical cooler: the cooling effect is poor, the temperature of the imported flue gas should not be higher than 450°C, the cooling range is limited, and the tube wall of the mechanical cooler is easy to block with ash, resulting in burning cloth bags and the system cannot operate normally.

2. Dust removal after spray cooling and heat exchange: increasing the water content in the flue gas will not only harden the bag, but also easily cause water and dust to bond, resulting in blockage of system equipment.

3. Dust removal after heat exchange of the waste heat boiler: Since the flue gas contains a large amount of dust, the sticky and fine dust will accumulate dust and blockage even on the heat pipe elements of the light pipe. Ash and clogging are more serious. At the same time, in order to prevent ash formation, the fin spacing of heat exchange core components in waste heat utilization facilities is large, which not only affects heat exchange efficiency, but also causes insufficient steam production of waste heat boilers. The unstable operation of the system caused the smelting production to be unable to proceed normally, and was forced to stop production for maintenance.

Due to the above shortcomings, many soot blowing methods are used in the project: such as shock wave soot blowing, steam soot blowing, falling shot cleaning, etc., but because the dust is fine and sticky, and the amount of dust is large, 35kg of dust will be generated for every ton of steel produced. However, these dust removal methods have little effect and cannot fundamentally solve the problem of dust accumulation and blockage.

Contents of the invention

The purpose of this utility model is to provide a multi-stage organic Rankine cycle waste heat power generation equipment for submerged arc furnace flue gas. At the same time, it can reduce the discharge temperature of the flue gas to achieve a good environmental protection effect without affecting the stability and continuity of the production of the submerged arc furnace. It can also obtain a good dust removal effect, and the dust concentration of the discharge is 10mg/Nm ³ .

The technical scheme adopted by the utility model is as follows: the special equipment for multi-stage organic Rankine cycle waste heat power generation of submerged arc furnace flue gas, including submerged arc furnace, water-cooled flue, combustion and settling chamber, main fan, exhaust cylinder, which is characterized in that: a high-temperature dust collector and a regenerator are sequentially connected between the combustion settling chamber and the main fan through pipelines, the high-temperature dust collector is provided with a stainless steel filter element, and a separation filter is installed in the regenerator. In the casing heat pipe heat exchanger, the cold water inlet of the separated casing heat pipe heat exchanger is connected to the heat exchanger feed water pump, and the hot water outlet of the separated casing heat pipe heat exchanger is connected to the hot water inlet of the high-pressure stage evaporator. The cold water outlet of the low-pressure evaporator is connected to the hot water inlet of the medium-pressure evaporator, the cold water outlet of the medium-pressure evaporator is connected to the hot water inlet of the low-pressure evaporator, the cold water outlet of the low-pressure evaporator is connected to the circulating water pool, and the circulating water pool is connected to the water exchange tank. The heater is connected to the water pump to form a loop. The working fluid inlet port of the low-pressure stage evaporator is connected with the high-pressure outlet port of the low-pressure stage working medium pressurization pump, and the working medium outlet port of the low-pressure stage evaporator passes through the pipeline all the way and is connected with the low-pressure steam supply port of the organic turbine with steam supply port. , the other one is connected to the inlet port of the medium-pressure working fluid pressurization pump, the outlet port of the medium-pressure working medium pressurizing pump is connected to the medium-pressure evaporator, and the working medium outlet port of the medium-pressure evaporator passes through the pipeline and then connected to the The medium-pressure steam supply port of the organic turbine with a steam supply port is connected, and the other is connected to the inlet end of the high-pressure working medium pressurization pump, and the outlet end of the high-pressure working medium pressurization pump is connected to the high-pressure stage evaporator, and the high-pressure stage evaporator The outlet end of the working medium is connected to the high-pressure inlet cylinder of the organic turbine with the steam inlet through the pipeline, and the lower interface of the organic turbine with the steam inlet is connected to the inlet of the shell-and-tube condenser through the pipeline, and the shell-and-tube condenser The liquid phase outlet of the condenser is connected to the low-pressure inlet of the low-pressure working medium booster pump through the pipeline, the organic turbine with the steam supply port is connected to the three-phase generator, and the flange interface at one end of the shell-and-tube condenser is connected to the circulating water pump The other end of the shell-and-tube condenser is connected to the cooling tower, and the cooling tower is connected to the circulating water pump to form a loop.

It is further characterized in that: R413a is used as the circulating organic working fluid.

The beneficial effects of the utility model are: since the waste heat power generation device of the utility model is placed behind the high-temperature dust collector, the dust content of the heat source flue gas is low, so the fin spacing of the heat exchange core unit in the heat storage chamber can be designed to be very small; and there is no need to unload Ash, dust cleaning, and dust transportation facilities; the volume is reduced, and the maintenance amount is reduced at the same time, which also prolongs the service life of the separated sleeve heat pipe heat exchanger, and the dust emission concentration is lower. The biggest difference between this power generation equipment and the single-stage single-pressure organic Rankine cycle is that this power generation equipment adopts multi-stage evaporation measures in the high, medium and low organic working fluid evaporators, and uses the low temperature section of hot water (inlet 90 °C, outlet 60°C) to heat the working fluid to produce low-pressure working medium steam, which enters the low-pressure steam inlet of the organic turbine to expand and do work; use the medium temperature section of hot water (inlet 120°C, outlet 90°C) to heat the working medium to produce medium-pressure working medium steam, Entering the medium-pressure steam inlet of the organic turbine to expand and do work; use the high-temperature section of saturated water vapor (inlet 150°C, outlet 120°C) to heat the working medium to generate high-pressure working medium steam, which enters the high-pressure cylinder of the organic turbine to expand and do work; realize waste heat The cascade partial pressure heating of the flow to the organic working medium reduces the unevenness of the heat transfer temperature difference between the waste heat flow and the working medium in the heating surfaces at all levels, and reduces the entropy increase caused by the irreversible heat transfer loss due to the temperature difference. The thermal efficiency of single-stage evaporative organic Rankine cycle can be increased by 10-20%, the emission temperature of flue gas is reduced, the emission concentration is low, and the emission dust concentration can be guaranteed to be 10mg/Nm ³ .

Compared with the prior art, the utility model has the following advantages and economic effects:

1. Maximum recovery of heat energy in flue gas into high-grade electric energy, its thermal efficiency is 10-20% higher than that of single-stage evaporation organic Rankine.

2. Meet the requirements of circular economy and the national policy of energy saving and emission reduction.

3. The separated casing heat pipe heat exchanger does not accumulate dust and is not blocked, and the heat exchange efficiency is increased by 8 to 9 times.

4. The soot blowing system of the heat pipe heat exchanger is omitted, thereby reducing the cost of construction and operation.

5. Adopt high temperature resistant stainless steel material filter element dust collector, the emission concentration is 10mg/Nm ³ .

6. It has a wide range of applications, and can be used for power generation with waste heat from dust removal in submerged arc furnaces.

To sum up, this scheme adopts a device that first removes dust and then generates electricity with waste heat, with low smoke and dust emission concentration, large power generation, stable operation and low energy consumption.

Description of drawings

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

In Figure 1: 1. submerged arc furnace, 2. water-cooled flue, 3. combustion settling chamber, 4. high temperature dust collector, 5. regenerator, 6. main fan, 7. exhaust pipe, 8. separation sleeve Type heat pipe heat exchanger, 9. Heat exchanger feed water pump, 10. Circulating pool, 11. Low-pressure evaporator, 12. Medium-pressure evaporator, 13. High-pressure evaporator, 14. Low-pressure working fluid booster pump , 15. Medium-pressure working medium booster pump, 16. High-pressure working medium booster pump, 17. Organic turbine with steam inlet, 18. Three-phase generator, 19. Circulating water pump, 20. Shell-and-tube condensing 21. Cooling tower.

Detailed ways

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

The special equipment for multi-stage organic Rankine cycle waste heat power generation of submerged arc furnace flue gas in the utility model includes a water-cooled flue 2, a combustion settling chamber 3, a high-temperature dust collector 4, a regenerator 5, a main fan 6, and an exhaust cylinder 7. The combustion settling chamber 3 is sequentially connected to the high-temperature dust collector 4, the regenerator 5, the main fan 6, and the exhaust cylinder 7 through pipelines. The high-temperature dust collector 4 is provided with a stainless steel filter element, and the regenerator 5 is equipped with Separate the sleeve-type heat pipe heat exchanger 8, the cold water inlet of the separate sleeve-type heat pipe heat exchanger 8 is connected to the heat exchanger feed water pump 9, and the hot water outlet of the separate sleeve-type heat pipe heat exchanger 8 is connected to the high-pressure stage evaporator 13 The hot water inlet of the high-pressure evaporator 13 is connected to the hot water inlet of the medium-pressure evaporator 12, the cold water outlet of the medium-pressure evaporator 12 is connected to the hot water inlet of the low-pressure evaporator 11, and the low-pressure evaporator 11 The cold water outlet is connected to the circulating water pool 10, and the circulating water pool 10 is connected with the heat exchanger feed water pump 9 to form a loop. The working medium inlet port of the low-pressure stage evaporator 11 is connected with the high-pressure outlet port of the low-pressure stage working medium pressurization pump 14, and the working medium outlet port of the low-pressure stage evaporator 11 passes through the pipeline all the way and connects with the low-pressure port of the organic turbine 17 with steam supplement port. The steam supply port is connected, and the other is connected with the inlet end of the medium-pressure working medium pressurization pump 15, and the outlet end of the medium-pressure working medium pressurizing pump 15 is connected with the medium-pressure evaporator 12, and the working medium of the medium-pressure evaporator 12 One way of the gas outlet port is connected to the medium-pressure steam inlet port of the organic turbine 17 with a steam inlet port after passing through the pipeline, and the other road is connected to the inlet end of the high-pressure working fluid booster pump 16, and the outlet of the high-pressure working fluid booster pump 16 The end is connected to the high-pressure stage evaporator 13, and the outlet end of the working medium of the high-pressure stage evaporator 13 is connected to the high-pressure inlet cylinder of the organic turbine 17 with a steam supply port through a pipeline, and the lower interface of the organic turbine 17 with a steam supply port is connected to the The air inlet of the shell-and-tube condenser 20 is connected, and the liquid-phase outlet of the shell-and-tube condenser 20 is connected to the low-pressure inlet of the low-pressure working medium booster pump 14 through a pipeline. The generator 18 is connected. One end flange interface of the shell-and-tube condenser 20 is connected to the circulating water pump 19, and the other end of the shell-and-tube condenser 20 is connected to the cooling tower 21, and the cooling tower 21 is connected to the circulating water pump 19 to form a loop.

The low-boiling point organic working fluid is R413a, three-stage evaporation, the evaporation pressure of the low-pressure stage is 0.43MPa, the evaporation pressure of the medium-pressure stage is 0.86MPa, and the evaporation pressure of the high-pressure stage is 1.75MPa. When the working fluid pressure after expansion is 0.31MPa , the output electric power of the system is 2000KW, the Rankine cycle efficiency is 21%, and the temperature of the flue gas discharged from the system is 90°C.

The waste heat power generation device after dust removal is adopted, that is, the high-temperature dusty flue gas enters the stainless steel filter element dust collector for purification. The stainless steel filter element in the dust collector can generally withstand the long-term working temperature of about 600°C, and the highest temperature can withstand 650°C. , and can withstand the erosion of high-temperature large particles, so it can directly purify high-temperature flue gas without any pretreatment. The dust concentration after purification is reduced to 10mg/ ^Nm3 to become clean flue gas, and there is no need to deal with problems such as dust blockage and dust removal.

The working process of the utility model: 25500KVA submerged arc furnace 1 flue gas flow rate 15×10 ⁴ Nm ³ /h, temperature 1000 ℃, dust concentration 35g/Nm ³ is discharged from the furnace, mixed with cold air through the water-cooled flue 2, and burns carbon monoxide The gas enters the combustion settling chamber 3; the function of the combustion settling chamber 3 is to reduce the flue gas flow rate, settle the large particle dust carried in the flue gas, and mix it with the cold air appropriately, finally burn the carbon monoxide gas, and adjust and control the flue gas in the settling chamber The temperature is 600°C, and the flue gas from the combustion and settling chamber 3 enters the high-temperature dust collector 4, and the dust concentration after dust removal is 10 mg/Nm ³ . Then enter the regenerator 5, the high-temperature flue gas releases heat, completes the heat exchange, the temperature drops to 90°C, and is pressed into the exhaust pipe 7 by the main fan 6 and discharged into the atmosphere. At the same time, the circulating water is driven by the heat exchanger feed water pump 9, and enters the separate casing heat pipe heat exchanger 8 installed in the regenerator 4 to absorb the heat of the flue gas to form a steam-water mixture (temperature 150 ° C), and the steam-water mixture Driven by natural circulation force, it enters the high-pressure evaporator 13 to release heat, the temperature drops to 120°C, then enters the medium-pressure evaporator 12 to release heat, the temperature drops to 90°C, and then enters the low-pressure evaporator 11 to release heat. The temperature drops to 60° C. to become low-temperature water, and the low-temperature water flows into the circulating pool 10 to start a new round of circulation.

At the same time, the condensed organic working medium liquid, driven by the low-pressure working medium booster pump 14, first absorbs the heat of the waste heat carrier in the low-pressure evaporator 11, and becomes a low-pressure working medium steam; The steam port of the organic turbine 17 is the low-pressure steam supply port, and the other path is pressurized by the medium-pressure working medium booster pump 15, and then enters the medium-pressure evaporator 12 to absorb the heat of the waste heat carrier, and becomes medium-pressure working medium steam One road enters the medium-pressure steam supply port of the organic turbine 17 with the steam supply port through the pipeline, and the other road enters the high-pressure stage evaporator 13 to absorb the heat of the waste heat carrier after being pressurized by the high-pressure stage working fluid booster pump 16, and becomes The high-pressure working medium steam enters the high-pressure inlet cylinder of the organic turbine 17 with a steam supply port through the pipeline, and the working medium steam expands in the multi-stage organic turbine 17 to perform work and drives the three-phase generator 18 to generate electricity. The working medium steam discharged from the organic turbine 17 with steam supply port is condensed into a saturated liquid by the shell-and-tube condenser 20, and then the working medium liquid is pressurized by the low-pressure stage working medium booster pump 14 and then sent to the low-pressure stage evaporator 11 , start a new cycle. The circulating water from the cooling tower 21 is driven by the circulating water pump 19, enters the shell-and-tube condenser 20 to absorb heat, enters the cooling tower 21 under the force of natural circulation, releases heat, turns into low-temperature water, and starts a new round of circulation . The electric energy generated by the system is three-phase alternating current with a rated voltage of 380V, which can be connected to the power grid in the factory after voltage regulation, or directly sent to the electrical equipment for use.

The biggest feature of this equipment is that it adopts organic Rankine cycle waste heat power generation after dust removal and multi-stage evaporation to recover the waste heat of the flue gas of the submerged arc furnace. Taking the waste heat recovery and dust removal process of 25500KVA submerged arc furnace as an example, the process of this utility model is compared with the dust removal after conventional waste heat utilization, 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 can maximize the recovery of the heat energy in the flue gas and directly convert it into high-grade electric energy. Ash, ash cleaning, and ash transportation facilities prolong the service life of the equipment, and at the same time reduce the discharge temperature of the flue gas, and do not affect the stability and continuity of the steelmaking production of the submerged arc furnace, and can also obtain good environmental protection effects. Concentration 10mg/Nm ³ . The device has low investment and low energy consumption.

Claims (4)

1. A submerged arc furnace flue gas multi-stage organic Rankine cycle waste heat power generation equipment, comprising a submerged arc furnace, a water-cooled flue, a combustion settling chamber, a main blower fan, and an exhaust pipe connected in sequence by pipelines, characterized in that: A high-temperature dust collector and a regenerator are sequentially connected through pipelines between the combustion settling chamber and the main fan. 2. The multi-stage organic Rankine cycle waste heat power generation equipment for submerged arc furnace flue gas according to claim 1, characterized in that: the high temperature dust collector is provided with a stainless steel filter element. 3. The multi-stage organic Rankine cycle waste heat power generation equipment for submerged arc furnace flue gas according to claim 1, characterized in that: a separate casing heat pipe heat exchanger is installed in the regenerator chamber, and the separation casing heat pipe The cold water inlet of the heat exchanger is connected to the feed water pump of the heat exchanger, the hot water outlet of the split-tube heat pipe heat exchanger is connected to the hot water inlet of the high-pressure evaporator, and the cold water outlet of the high-pressure evaporator is connected to the middle-pressure evaporator The hot water inlet, the cold water outlet of the medium-pressure evaporator is connected to the hot water inlet of the low-pressure evaporator, the cold water outlet of the low-pressure evaporator is connected to the circulating water pool, and the circulating water pool is connected to the heat exchanger feed pump to form a loop; the low-pressure evaporator The working fluid inlet port of the low-pressure stage evaporator is connected to the high-pressure outlet port of the low-pressure working medium booster pump, and the working medium outlet port of the low-pressure stage evaporator is connected to the low-pressure steam supply port of the organic turbine with a steam supply port through a pipeline. It is connected to the inlet end of the medium-pressure working medium pressurization pump, and the outlet end of the medium-pressure working medium pressurization pump is connected to the medium-pressure evaporator. One port of the organic turbine is connected to the medium-pressure steam supply port, the other is connected to the inlet end of the high-pressure working medium pressurization pump, and the outlet end of the high-pressure working medium pressurizing pump is connected to the high-pressure stage evaporator. The outlet end is connected to the high-pressure inlet cylinder of the organic turbine with the steam inlet through the pipeline, and the lower interface of the organic turbine with the steam inlet is connected to the inlet of the shell-and-tube condenser through the pipeline, and the liquid of the shell-and-tube condenser The phase outlet is connected to the low-pressure inlet of the low-pressure working medium pressurized pump through pipelines, the organic turbine with supplementary steam port is connected to the three-phase generator, and the flange interface at one end of the shell-and-tube condenser is connected to the circulating water pump. The other end of the shell condenser is connected to the cooling tower, and the cooling tower is connected to the circulating water pump to form a loop. 4. The multi-stage organic Rankine cycle waste heat power generation equipment for submerged arc furnace flue gas according to claim 3, characterized in that: R413a is used as the circulating organic working fluid. the

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