Blast furnace gas energy recovery system

Abstract

The utility model discloses a blast furnace gas energy recovery system which comprises a blast furnace, a gas turbine, a blast furnace blower and a hot blast stove, a turbine rotating shaft is arranged in the gas turbine in a penetrating mode, and an air blower rotating shaft is arranged in the blast furnace air blower in a penetrating mode. The air blower rotating shaft is in transmission connection with a motor, the air blower rotating shaft, the turbine rotating shaft and a generator are coaxially arranged, a first clutch is installed between the turbine rotating shaft and the air blower rotating shaft, and a second clutch is installed between the turbine rotating shaft and the generator. And the generator and the power supply unit are electrically connected with a power supply unit. According to the utility model, by controlling the opening and closing of the first clutch and the second clutch, the output of the recovered energy of the gas turbine can be adjusted, and the output path of the recovered energy of the gas turbine can be changed, so that the energy can be saved to the maximum extent by adjusting the output path of the recovered energy under different working conditions.

Description

Technical Field

[0001] The utility model relates to the technical field of iron-making blast furnaces, in particular to a blast furnace gas energy recovery system. Background Art

[0002] During the blast furnace smelting process, hot air and rich oxygen are sent into the furnace from the tuyere. The hot air and rich oxygen react with the raw materials in the furnace through a series of chemical reduction reactions to generate CO and CO 2 , H 2 、N 2 , SO2, SO3, H2S and other gases, which are collectively referred to as blast furnace gas. The acidic components (such as SO2, SO3, H2S, HCl, etc.) in blast furnace gas are high in content and highly corrosive. In order to recycle the energy carried by blast furnace gas, a blast furnace energy recovery device (Blast Furnace Power Recovery Turbine, referred to as BPRT) is often installed. The BPRT unit connects the gas turbine and the blast furnace blower coaxially, and uses the energy recovered by the gas turbine to directly drive the blower; specifically, after the blast furnace gas is output, it is sent to the gas turbine after gravity dust removal and dry dust removal. The gas sent to the gas turbine drives the moving and stationary blades of the gas turbine, drives the rotating shaft of the gas turbine and the coaxially connected blast furnace blower to rotate, thereby realizing energy recovery and utilization.

[0003] Under the existing BPRT unit, in the relationship between the coaxial connection of the gas turbine and the blast furnace blower, the roles of the two devices and the relationship of the energy realized are closely related to the rotation speed of the gas turbine. For example, when the amount of blast furnace gas is large and the blast furnace gas drives the gas turbine to rotate faster, the gas turbine drives the blast furnace blower and serves as the power of the blast furnace blower. At this time, energy recovery is achieved. However, if the gas turbine itself fails, or the furnace condition is not smooth, the wind is stopped, or the amount of gas is small, resulting in a slow rotation speed of the gas turbine or even no rotational power, the gas turbine not only cannot drive the blast furnace blower, but the energy of the gas turbine cannot be recovered. On the contrary, due to the coaxial connection relationship, the gas turbine still needs to be driven by the blast furnace blower, becoming a load of the blast furnace blower, increasing the energy consumption of the blast furnace blower. This makes the recovery rate of blast furnace gas energy low, and energy cannot be recovered to a greater extent.

[0004] Moreover, after gravity dust removal and dry dust removal, the temperature of blast furnace gas gradually decreases, especially after entering the gas turbine, the outlet temperature of the gas turbine can drop to 12.2℃, or even as low as the water vapor dew point. On the one hand, once the temperature drops to the water vapor dew point, condensed water will precipitate, and the acidic gas in the blast furnace gas will dissolve in water to form a strong acid solution, causing equipment corrosion; on the other hand, some complex components in blast furnace gas, such as ammonium chloride, will precipitate in solid form and adhere to the moving and stationary blades and equipment of the gas turbine when the temperature is lower than the dew point of its compound (about 80-90℃) and dust, forming a scale layer. The formation of the scale layer will not only increase the load of the moving and stationary blades and reduce the energy recovery rate, but also cause uneven shedding of the scale layer, which will cause unbalanced operation of the gas turbine and affect the service life of the gas turbine. Utility Model Content

[0005] The utility model aims to provide a blast furnace gas energy recovery system.

[0006] The technical solution to achieve the purpose of the utility model is: a blast furnace gas energy recovery system, comprising a blast furnace, a gravity dust removal device, a dry dust removal device, a gas turbine, a blast furnace blower and a hot blast furnace; the blast furnace is provided with a hot blast port and a gas port; a turbine shaft is provided in the gas turbine, a turbine gas inlet and a turbine gas outlet are provided on the gas turbine; a blower shaft is provided in the blast furnace blower, and a blower air supply port is provided on the blast furnace blower;

[0007] The air outlet of the blower, the hot blast furnace and the hot blast outlet of the blast furnace are sequentially connected through a hot blast pipe, and the gas outlet of the blast furnace, the gravity dust removal device, the dry dust removal device and the gas inlet of the turbine are sequentially connected through a gas pipe;

[0008] The blower shaft is drivingly connected to an electric motor, and the blower shaft, the turbine shaft and a generator are coaxially arranged. The turbine shaft is located between the blower shaft and the generator, a first clutch is installed between one end of the turbine shaft and the blower shaft, and a second clutch is installed between the other end of the turbine shaft and the generator, and the generator and the power supply unit are respectively electrically connected to the same power supply unit.

[0009] Furthermore, a heat exchanger is installed on the gas pipe, and the heat exchanger is located between the dry dust removal device and the gas inlet of the turbine, and the heat exchanger is provided with a high-temperature steam inlet and a low-temperature steam outlet. During operation, high-temperature steam is introduced into the heat exchanger from the high-temperature steam inlet, and the high-temperature steam entering the heat exchanger exchanges heat with the low-temperature gas in the gas pipe to increase the gas temperature of the gas pipe; after the temperature of the gas pipe is increased, the gas enters the gas turbine for energy conversion. The heat exchanger is set to increase the temperature of the gas entering the gas turbine, avoid the temperature in the gas turbine being too low, prevent the acidic gas in the blast furnace gas from dissolving in water to form a strong acidic solution, and corrode the equipment, and can also effectively reduce the formation of scale layers inside and outside the gas turbine, reduce the load of the gas turbine, improve the energy recovery rate of the gas turbine, and make the gas turbine run more stably, extending the service life of the gas turbine.

[0010] Furthermore, the heat exchanger is any one of a plate heat exchanger, a shell and tube heat exchanger, and a plate heat exchanger.

[0011] Furthermore, a gas branch pipe is connected between the dry dust removal device and the gas outlet of the turbine, and a pressure regulating valve is installed on the gas branch pipe. The arrangement of the pressure regulating valve on the gas branch pipe can be used to adjust the top pressure of the blast furnace, making the blast furnace production more flexible.

[0012] The utility model blast furnace gas energy recovery system, after the blower shaft is coaxially arranged on one end side of the turbine shaft, the generator is coaxially arranged on the other end side of the turbine shaft, so as to increase the output path of the gas turbine energy recovery. In the case of the two output paths of the blast furnace blower and the generator, the first clutch is installed between the turbine shaft and the blower shaft, and the second clutch is installed between the turbine shaft and the generator, so that the output of the gas turbine energy recovery can be adjusted by controlling the opening and closing of the first clutch and the second clutch, and the output path of the gas turbine energy recovery can be changed, so that the utilization of the gas turbine energy recovery can be more flexible, and thus it is convenient to adjust the energy recovery output path under different working conditions, so that the energy recovery can have the best processing method. For example, if the amount of blast furnace gas is large and the speed of the turbine shaft is high, the first clutch is controlled to close and the second clutch is disconnected, and the turbine shaft directly transfers its kinetic energy to the blower shaft, and drives the blower shaft together with the motor. At this time, the speed of the turbine shaft is high, which can drive the blower shaft and serve as the power of the blower shaft. After the turbine shaft directly transfers its kinetic energy to the blower shaft, the energy loss in the intermediate conversion link is saved, and the utilization rate of energy recovery of the gas turbine is high. If the amount of blast furnace gas is small and the speed of the turbine shaft is low, the first clutch is controlled to be disconnected and the second clutch is closed, and the turbine shaft drives the generator, which converts kinetic energy into electrical energy and stores it in the power supply unit for use by the motor. At this time, on the one hand, the turbine shaft is separated from the blower shaft and will not become the load of the blast furnace blower, reducing the power expenditure of the motor; on the other hand, the turbine shaft with a low speed but still kinetic energy drives the generator, which can realize the conversion and utilization of this part of energy. This "one minus one plus" can greatly improve the utilization rate of the energy recovered by the gas turbine. In this way, the utilization rate of blast furnace gas energy recovery can be ultimately improved, and energy saving can be maximized. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of a blast furnace gas energy recovery system of the utility model. DETAILED DESCRIPTION

[0014] The following is a detailed description of the preferred implementation of the blast furnace gas energy recovery system of the utility model in conjunction with the accompanying drawings:

[0015] like Figure 1As shown, a blast furnace gas energy recovery system comprises a blast furnace 1, a gravity dust removal device 2, a dry dust removal device 3, a gas turbine 4, a blast furnace blower 5 and a hot blast furnace 6; the blast furnace 1 is provided with a hot blast port 11 and a gas port 12; a turbine shaft 40 is provided inside the gas turbine 4, and a turbine gas inlet 41 and a turbine gas outlet 42 are provided on the gas turbine 4; a blower shaft 50 is provided inside the blast furnace blower 5, and a blower air supply port 51 is provided on the blast furnace blower 5;

[0016] The blower air outlet 51, the hot blast furnace 6 and the hot blast outlet 11 of the blast furnace 1 are sequentially connected through a hot blast pipe 101, and the gas outlet 12 of the blast furnace 1, the gravity dust removal device 2, the dry dust removal device 3 and the turbine gas inlet 41 are sequentially connected through a gas pipe 102;

[0017] The blower shaft 50 is transmission-connected to an electric motor 7. The blower shaft 50, the turbine shaft 40 and a generator 8 are coaxially arranged. The turbine shaft 40 is located between the blower shaft 50 and the generator 8. A first clutch 91 is installed between one end of the turbine shaft 40 and the blower shaft 50, and a second clutch 92 is installed between the other end of the turbine shaft 40 and the generator 8. The generator 8 is electrically connected to a power supply unit 10 for generating electrical energy and storing the generated electrical energy in the power supply unit 10. The power supply unit 10 is electrically connected to the electric motor 7 for supplying power to the electric motor 7.

[0018] The utility model blast furnace gas energy recovery system, the blast furnace 1 has a hot blast port 11 and a gas port 12, the blast furnace 1 is used for iron ore reaction; during the operation of the blast furnace 1, hot blast needs to be sent into the blast furnace 1 by the hot blast port 11; after the iron ore reacts in the blast furnace 1, gas is generated, and the gas is output from the gas port 12. The hot blast furnace 6 is burned to provide hot blast for the blast furnace 1; the blast furnace blower 5 is used to provide power for the hot blast from the hot blast furnace 6 to the blast furnace 1. The gravity dust removal device 2 and the dry dust removal device 3 are used to remove and purify the coal gas output from the blast furnace 1. The turbine shaft 40 is passed through the gas turbine 4. The gas turbine 4 is provided with the turbine gas inlet 41 and the turbine gas outlet 42. The gas enters the gas turbine 4 through the turbine gas inlet 41 and exits the turbine gas outlet 42. The gas entering the gas turbine 4 pushes the turbine shaft 40, driving the turbine shaft 40 to rotate, so as to convert the energy in the gas for recovery.

[0019] In the blast furnace gas energy recovery system of the utility model, when the blast furnace 1 is working, the hot blast furnace 6 burns, and under the power of the blast furnace blower 5, hot air is continuously provided to the blast furnace 1 along the gas pipe 102 through the hot blast port 11 to promote the reaction of iron ore in the blast furnace 1. The iron ore reacts in the blast furnace 1 to form a large amount of coal gas, which enters the gas pipe 102 through the gas port 12, and then enters the gravity dust removal device 2 and the dry dust removal device 3 in sequence along the gas pipe 102, and is successively dusted and purified by the gravity dust removal device 2 and the dry dust removal device 3; the dust-removed and purified coal gas is sent to the gas turbine 4 along the gas pipe 102 and the turbine gas inlet 41, driving the turbine shaft 40 of the gas turbine 4 to rotate, and the turbine shaft 40 converts and recovers the energy in the coal gas, and the coal gas in the gas turbine 4 is output from the turbine gas outlet 42.

[0020] In the blast furnace gas energy recovery system of the utility model, the blower shaft 50 of the blast furnace blower 5 is not only connected to the motor 7, but also connected to the turbine shaft 40 of the gas turbine 4 through the first clutch 91, and driven by the turbine shaft 40 and the motor 7 at the same time. One end of the turbine shaft 40 of the gas turbine 4 can be connected to the blower shaft 50 through the first clutch 91, and directly transfer the kinetic energy to the blower shaft 50; the other end of the turbine shaft 40 can be connected to the generator 8 through the second clutch 92, and drive the generator 8, so that the generator 8 can convert the kinetic energy into electrical energy, which is stored in the power supply unit 10, and the power supply unit 10 is used by the motor 7.

[0021] In the blast furnace gas energy recovery system of the utility model, during operation, when the amount of blast furnace gas is large and the rotation speed of the turbine shaft 40 is high, the first clutch 91 is controlled to be closed and the second clutch 92 is disconnected, and the turbine shaft 40 directly transfers its kinetic energy to the blower shaft 50, and drives the blower shaft 50 together with the motor 7, so as to complete the gas energy recovery in the form of driving the blower shaft 50. When the amount of blast furnace gas is small and the rotation speed of the turbine shaft 40 is low, the first clutch 91 is controlled to be disconnected and the second clutch 92 is controlled to be closed, and the turbine shaft 40 drives the generator 8, and the generator 8 converts the kinetic energy into electrical energy, which is stored in the power supply unit 10 for use by the motor 7. In this way, the gas energy recovery is completed in the form of converting kinetic energy into electrical energy and then converting electrical energy into kinetic energy.

[0022] The utility model blast furnace gas energy recovery system, after the blower shaft 50 is coaxially arranged on one end side of the turbine shaft 40, the generator 8 is coaxially arranged on the other end side of the turbine shaft 40, so as to increase the output path of the gas turbine 4 to recover energy. In the case of the two output paths of the blast furnace blower 5 and the generator 8, the first clutch 91 is installed between the turbine shaft 40 and the blower shaft 50, and the second clutch 92 is installed between the turbine shaft 40 and the generator 8, so that the output of the recovered energy of the gas turbine 4 can be adjusted by controlling the opening and closing of the first clutch 91 and the second clutch 92, and the output path of the recovered energy of the gas turbine 4 can be changed, so that the utilization of the recovered energy of the gas turbine 4 can be more flexible, and then it is convenient to adjust the recovered energy output path under different working conditions, so that the recovered energy can have the best processing method. For example, when the amount of blast furnace gas is large and the rotation speed of the turbine shaft 40 is relatively high, the first clutch 91 is controlled to be closed and the second clutch 92 is disconnected, and the turbine shaft 40 directly transfers its kinetic energy to the blower shaft 50, and drives the blower shaft 50 together with the motor 7. At this time, the rotation speed of the turbine shaft 40 is high, which can drive the blower shaft 50 and serve as the power of the blower shaft 50. After the turbine shaft 40 directly transfers its kinetic energy to the blower shaft 50, the energy loss in the intermediate conversion link is saved, and the utilization rate of the recovered energy of the gas turbine 4 is high. If the amount of blast furnace gas is small and the speed of the turbine shaft 40 is low, the first clutch 91 is controlled to be disconnected and the second clutch 92 is closed, and the turbine shaft 40 drives the generator 8, and the generator 8 converts kinetic energy into electrical energy, which is stored in the power supply unit 10 for use by the motor 7. At this time, on the one hand, the turbine shaft 40 is separated from the blower shaft 50 and will not become the load of the blast furnace blower 5, reducing the power expenditure of the motor 7; on the other hand, the turbine shaft 40 with a low speed but still kinetic energy drives the generator 8, and the conversion and utilization of this part of energy can be realized. This "one minus one plus" can greatly improve the utilization rate of the energy recovered by the gas turbine 4. In this way, the utilization rate of blast furnace gas energy recovery can be finally improved, and energy saving can be maximized.

[0023] In the blast furnace gas energy recovery system of the utility model, preferably, a heat exchanger 20 is installed on the gas pipe 102, the heat exchanger 20 is located between the dry dust removal device 3 and the turbine gas inlet 41, and the heat exchanger 20 is provided with a high-temperature steam inlet 201 and a low-temperature steam outlet 202. During operation, high-temperature steam is introduced into the heat exchanger 20 from the high-temperature steam inlet 201, and the high-temperature steam entering the heat exchanger 20 exchanges heat with the low-temperature gas in the gas pipe 102, thereby increasing the gas temperature of the gas pipe 102; after the temperature of the gas pipe 102 is increased, the gas enters the gas turbine 4 for energy conversion. The heat exchanger 20 is configured to increase the temperature of the gas entering the gas turbine 4, avoid the temperature in the gas turbine 4 being too low, and prevent the acidic gas in the blast furnace gas from dissolving in water to form a strong acidic solution, thereby corroding the equipment. At the same time, it can also effectively reduce the formation of scale layers inside and outside the gas turbine 4, reduce the load of the gas turbine 4, increase the energy recovery rate of the gas turbine 4, and make the gas turbine 4 run more stably, thereby extending the service life of the gas turbine 4.

[0024] In the blast furnace gas energy recovery system of the utility model, the heat exchanger 20 is any one of a slab-type heat exchanger, a shell-and-tube heat exchanger, and a plate-type heat exchanger.

[0025] In the blast furnace gas energy recovery system of the utility model, preferably, a gas branch pipe 103 is connected between the dry dust removal device 3 and the turbine gas outlet 42, and a pressure regulating valve 104 is installed on the gas branch pipe 103. The arrangement of the pressure regulating valve 104 on the gas branch pipe 103 can be used to adjust the blast furnace top pressure, making the blast furnace production more flexible.

[0026] In the blast furnace gas energy recovery system of the utility model, the power supply unit 10 may be a battery pack.

[0027] For ordinary technicians in the technical field to which the utility model belongs, the utility model can make several simple deductions or substitutions without departing from the concept of the utility model, which should be regarded as falling within the protection scope of the utility model.

Claims

1. A blast furnace gas energy recovery system, comprising a blast furnace, a gravity dust removal device, a dry dust removal device, a gas turbine, a blast furnace blower and a hot blast furnace; the blast furnace is provided with a hot blast inlet and a gas inlet; a turbine shaft is provided in the gas turbine, a turbine gas inlet and a turbine gas outlet are provided in the gas turbine; a blower shaft is provided in the blast furnace blower, and a blower air outlet is provided on the blast furnace blower; the characteristics are: The blower air outlet, the hot blast stove and the hot blast outlet of the blast furnace are connected in sequence through a hot blast pipe, and the gas outlet of the blast furnace, the gravity dust removal device, the dry dust removal device and the turbine gas inlet are connected in sequence through a gas pipe; the blower shaft is drivingly connected to an electric motor, the blower shaft, the turbine shaft and a generator are coaxially arranged, the turbine shaft is located between the blower shaft and the generator, a first clutch is installed between one end of the turbine shaft and the blower shaft, and a second clutch is installed between the other end of the turbine shaft and the generator, and the generator and the electric motor are respectively electrically connected to the same power supply unit.

2. The blast furnace gas energy recovery system according to claim 1, characterized in that: A heat exchanger is installed on the gas pipe. The heat exchanger is located between the dry dust removal device and the gas inlet of the turbine. A high-temperature steam inlet and a low-temperature steam outlet are provided on the heat exchanger.

3. The blast furnace gas energy recovery system according to claim 2, characterized in that: The heat exchanger is any one of a plate heat exchanger, a shell and tube heat exchanger, and a plate heat exchanger.

4. The blast furnace gas energy recovery system according to claim 1, characterized in that: A gas branch pipe is connected between the dry dust removal device and the turbine gas outlet, and a pressure regulating valve is installed on the gas branch pipe.

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