A load distribution control method for the air supply and power generation system of a large blast furnace

Abstract

The present invention provides a load distribution control method for the air supply and power generation system of a large blast furnace, wherein the recovered power of the gas turbine is 80% - 120% of the power consumption of the 4# axial flow compressor. In order to avoid the unit interlocking shutdown caused by excessive vibration value of the first gearbox and affect the normal production of the 2# blast furnace, the first gearbox needs to continuously transmit power in the forward direction or in the reverse direction for a long time; in the air supply and power generation system of the large blast furnace, it is necessary to adjust the loads of the 4# axial flow compressor and the 5# axial flow compressor, change the power consumption of the 4# axial flow compressor and the 5# axial flow compressor during normal operation, so that the recovered power of the gas turbine is always lower than the power consumption of the 4# axial flow compressor at 100% or always higher than the power consumption of the 4# axial flow compressor at 100%, to ensure that the first gearbox transmits power in the forward direction or in the reverse direction for a long time, avoid the unit interlocking shutdown caused by excessive vibration value of the first gearbox, and improve the safety and reliability of the normal production of the blast furnace.

Description

Technical Field

[0001] The invention belongs to the technical field of large-scale blast furnace metallurgy, relates to an air supply and power generation system, and specifically relates to a load distribution control method for an air supply and power generation system of a large-scale blast furnace. Background Art

[0002] In the field of blast furnace metallurgy, users usually use an axial flow compressor unit to supply air to the blast furnace, such as Figure 1 As shown, the steam turbine drives the axial flow compressor unit (main fan unit). At the same time, in order to avoid the situation where the blast furnace cannot be supplied with air for a long time due to the failure of the main fan unit, the user will also provide a set of axial flow compressors of the same model as a backup fan to supply air to the blast furnace, such as Figure 2 As shown, the motor drives the axial compressor unit (standby unit). The coal gas with waste heat and waste pressure produced by blast furnace smelting is used to generate electricity through the gas turbine. Figure 3 As shown, a gas turbine generator set.

[0003] Figure 1 The axial compressor and Figure 2 The axial compressors in the standby units are the same, all of which are AV100 axial compressors with an air volume of 9562Nm3 / min. During normal operation, the main air unit supplies air to the blast furnace, and the standby unit is not put into use and is in a shutdown state.

[0004] Figure 3 The gas turbine drives the motor to generate electricity. Under normal circumstances, the gas turbine uses the waste heat and waste pressure of blast furnace gas to do work and recover power. Figure 1 The axial flow compressor 2 consumes 40% to 60% of the power.

[0005] However, in large blast furnace projects in the Indian metallurgical market, considering the limited project investment, the owners are eager to seek a more economical and technologically advanced air supply system while efficiently utilizing the waste heat and pressure energy of blast furnace gas. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a load distribution control method for the air supply and power generation system of a large blast furnace, so as to solve the technical problem that the units in the prior art are prone to interlocking shutdown.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0008] The invention discloses a load distribution control method for an air supply and power generation system of a large blast furnace. The method adopts the air supply and power generation system of the large blast furnace.

[0009] The air supply and power generation system of the large blast furnace includes a first motor, a first gearbox, a 4# axial flow compressor, a variable speed clutch and a gas turbine connected in sequence; it also includes a steam turbine and a 5# axial flow compressor connected in sequence; the 4# axial flow compressor and the 5# axial flow compressor are respectively connected to the 2# blast furnace to supply air.

[0010] This control method includes:

[0011] The recovered power of the gas turbine is equivalent to 80% - 120% of the power consumption of the 4# axial flow compressor. In order to prevent the first gearbox from causing the unit to trip due to excessive vibration value and affecting the normal production of the 2# blast furnace, the first gearbox needs to continuously transmit power in the forward direction or in the reverse direction for a long time.

[0012] In the air supply and power generation system of the large blast furnace, it is necessary to adjust the loads of the 4# axial flow compressor and the 5# axial flow compressor, change the power consumption of the 4# axial flow compressor and the 5# axial flow compressor during normal operation, so that the recovered power of the gas turbine is always lower than the power consumption of the 4# axial flow compressor of 100% or always higher than the power consumption of the 4# axial flow compressor of 100%, in order to ensure that the first gearbox transmits power in the forward direction or in the reverse direction for a long time, avoid the unit interlock shutdown caused by excessive vibration value of the first gearbox, and improve the safety and reliability of the normal production of the blast furnace.

[0013] The present invention also has the following technical features:

[0014] The air supply and power generation system of the large blast furnace further includes a second motor, a second gearbox and a 1# axial flow compressor connected in sequence.

[0015] The air supply and power generation system of the large blast furnace further includes a third motor, a third gearbox and a 2# axial flow compressor connected in sequence.

[0016] The air supply and power generation system of the large blast furnace further includes a fourth motor, a fourth gearbox and a 3# axial flow compressor connected in sequence.

[0017] The 1# axial flow compressor, the 2# axial flow compressor and the 3# axial flow compressor are respectively connected to the 1# blast furnace to supply air.

[0018] The 1# axial flow compressor, the 2# axial flow compressor and the 3# axial flow compressor are respectively connected to the 2# blast furnace to supply air through air distribution valves.

[0019] The 1# blast furnace and the 2# blast furnace are connected by a blast air valve.

[0020] Check valves, anti-blocking valves, electric air supply valves and flow meters are respectively arranged in sequence between the 1# axial flow compressor, the 2# axial flow compressor, the 3# axial flow compressor and the 1# blast furnace.

[0021] Between the described No. 1 axial flow compressor, No. 2 axial flow compressor and No. 3 axial flow compressor and the air distribution valve, a check valve, an anti-blocking valve, an electric air supply valve and a flow meter are sequentially arranged respectively.

[0022] Isolation valves are arranged on both sides of the described air deflecting valve.

[0023] This control method further includes:

[0024] The described No. 1 axial flow compressor and No. 2 axial flow compressor jointly supply air to the No. 1 blast furnace, the No. 4 axial flow compressor and No. 5 axial flow compressor jointly supply air to the No. 2 blast furnace, and the No. 3 axial flow compressor can simultaneously serve as a standby unit for both the No. 1 blast furnace and the No. 2 blast furnace.

[0025] The described No. 1 blast furnace and No. 2 blast furnace can supplement air supply through the air deflecting valve.

[0026] Compared with the prior art, the present invention has the following technical effects:

[0027] (Ⅰ) The control method of the present invention solves the problem that the power is alternately transmitted in the forward and reverse directions in a short time in the prior art in the gearbox, avoids the unit interlock shutdown caused by excessive vibration of the gearbox, will not cause the air supply volume of the blast furnace to be halved, and will not affect the normal production of the blast furnace.

[0028] (Ⅱ) The standby fan model of the present invention is smaller, reducing the user's investment. In projects with tight investment, the advantages of this scheme are very obvious.

[0029] (Ⅲ) Since the probability of simultaneous failure of two axial flow compressors in the present invention is extremely low, the system scheme will not cause accidents such as stock collapse and slag pouring in the blast furnace due to the inability of all axial flow compressors to supply air, greatly improving the safety of blast furnace smelting.

[0030] (Ⅳ) In the present invention, the gas turbine utilizes the waste heat and pressure energy of the blast furnace gas to do work, and the recovered power is 80% - 120% of the power consumed by the axial flow compressor, greatly reducing the output of the first motor, and the excess power can be directly used for power generation for other equipment in the factory. Greatly improving the user's benefits. Description of the Drawings

[0031] Figure 1 It is a schematic diagram of a steam turbine-driven axial flow compressor (main blower unit).

[0032] Figure 2 It is a schematic diagram of an electric motor-driven axial flow compressor (standby unit).

[0033] Figure 3 It is a schematic diagram of a gas turbine-driven electric motor for power generation.

[0034] Figure 4 It is a schematic diagram of a large blast furnace metallurgy air supply and power generation system of the present invention.

[0035] Figure 5 It is a schematic diagram of another air supply and power generation system for large blast furnace metallurgy of the present invention.

[0036] The meanings of each label in the figure are as follows: 1 - the first motor, 2 - the first gearbox, 3 - the 4# axial flow compressor, 4 - the variable speed clutch, 5 - the gas turbine, 6 - the steam turbine, 7 - the 5# axial flow compressor, 8 - the 2# blast furnace, 9 - the second motor, 10 - the second gearbox, 11 - the 1# axial flow compressor, 12 - the third motor, 13 - the third gearbox, 14 - the 2# axial flow compressor, 15 - the fourth motor, 16 - the fourth gearbox, 17 - the 3# axial flow compressor, 18 - the 1# blast furnace, 19 - the check valve, 20 - the anti-blocking valve, 21 - the electric air supply valve, 22 - the flowmeter, 23 - the air distribution valve, 24 - the air diversion valve, 25 - the isolation valve.

[0037] The following further elaborates on the specific content of the present invention in conjunction with embodiments. Specific Embodiments

[0038] It should be noted that all components and equipment in the present invention, unless otherwise specified, all adopt the components and equipment known in the prior art.

[0039] The following gives specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent transformations made on the basis of the technical solutions of the present application fall within the protection scope of the present invention.

[0040] Embodiment 1:

[0041] This embodiment provides a load distribution control method for the air supply and power generation system of a large blast furnace, and this method adopts the air supply and power generation system of a large blast furnace as shown in Figure 4 the figure.

[0042] The air supply and power generation system of the large blast furnace includes a first motor 1, a first gearbox 2, a 4# axial flow compressor 3, a variable speed clutch 4, and a gas turbine 5 connected in sequence; it also includes a steam turbine 6 and a 5# axial flow compressor 7 connected in sequence; the 4# axial flow compressor 3 and the 5# axial flow compressor 7 are respectively connected to the 2# blast furnace 8 to supply gas.

[0043] This control method includes:

[0044] The recovered power of the gas turbine 5 is equivalent to 80% - 120% of the power consumption of the 4# axial flow compressor 3. In order to avoid the unit interlock shutdown caused by the excessive vibration value of the first gearbox 2 and affect the normal production of the 2# blast furnace 8, the first gearbox 2 needs to continuously transmit power in the forward direction or in the reverse direction for a long time.

[0045] In the air supply and power generation system of a large blast furnace, it is necessary to adjust the loads of the 4# axial flow compressor 3 and the 5# axial flow compressor 7, and change the power consumption of the 4# axial flow compressor 3 and the 5# axial flow compressor 7 during normal operation, so that the recovered power of the gas turbine 5 is always lower than 100% of the power consumption of the 4# axial flow compressor 3 or always higher than 100% of the power consumption of the 4# axial flow compressor 3, so as to ensure that the first gearbox 2 transmits power in the forward direction or in the reverse direction for a long time, avoiding the unit interlock shutdown caused by excessive vibration value of the first gearbox 2, and improving the safety and reliability of the normal production of the 2# blast furnace 8.

[0046] In this embodiment, specifically:

[0047] As Figure 4 shown, the air supply and power generation system of a large blast furnace can also be called a two-machine air supply and power generation device. Figure 4 The models of the 4# axial flow compressor 3 and the 5# axial flow compressor 7 in Figure 4 are the same, both are AV80 axial flow compressors, and the air volume is 4781 Nm3 / min for each. The two AV80 axial flow compressors jointly supply air to one 2# blast furnace 8, and the total air volume is 9562 Nm3 / min. Figure 1 The flow rate and power consumption of the 4# axial flow compressor 3 in Figure 4 are half of the flow rate and power consumption of the axial flow compressor in Figure 4 . Therefore, Figure 4 the recovered power of the gas turbine 5 using the waste heat and pressure of the blast furnace gas to do work in Figure 4 is 80% - 120% of the power consumption of the 4# axial flow compressor 3 in

[0048] Figure 4 . When Figure 2 the recovered power of the gas turbine 5 in Figure 4 is 80% - 100% of the power consumption of the 4# axial flow compressor 3, the first motor 1 still needs to output 0% - 20% of the power to jointly drive the 4# axial flow compressor 3 to supply air to the 2# blast furnace 8. When

[0049] Figure 4 Figure 2 the recovered power of the gas turbine 5 in Figure 4 is 100% - 120% of the power consumption of the 4# axial flow compressor 3, at this time the motor does not need to output power anymore and switches to the power generation state. The excess 0% - 20% of the power of the gas turbine 5 is directly used for power generation.

[0048] Figure 4 In the two-machine air supply and power generation device in Figure 2 the model of the 4# axial flow compressor 3 is an AV80 axial flow compressor, so the model of the standby fan is also an AV80 axial flow compressor. Compared with Figure 4 the axial flow compressor model in the standby unit in

[0049] Figure 4 which is an AV100 axial flow compressor, Figure 4 the standby unit model of the two-machine air supply and power generation device is smaller and more economical. In projects with tight investment, the advantages of this solution are very obvious.

[0049] Figure 4One of the AV100 axial flow compressors in it supplies air to the No. 2 blast furnace 8 alone. Once the axial flow compressor unit suddenly fails and can no longer supply air to the No. 2 blast furnace 8, the blast furnace is prone to pressure loss and material collapse, resulting in a slag pouring accident, causing huge economic losses to users. And Figure 4 In the two-machine air supply device, even if one AV80 axial flow compressor fails and can no longer supply air to the No. 2 blast furnace 8, the other AV80 axial flow compressor will still continue to supply air to the No. 2 blast furnace 8, the pipeline network pressure is normal, and there will be no material collapse or slag pouring accident, greatly improving the safety of the blast furnace operation.

[0050] As Figure 4 shown, the gas turbine 5 utilizes the waste heat and pressure energy of the blast furnace gas to do work, and the recovered power is 80% - 120% of the power consumed by the axial flow compressor 2, greatly reducing the output of the first motor 1, and the excess power can be directly used for power generation for other equipment in the factory. Greatly improving the user's income.

[0051] Embodiment 2:

[0052] This embodiment provides a load distribution control method for the air supply and power generation system of a large blast furnace, which is based on the load distribution control method for the air supply and power generation system of a large blast furnace given in Embodiment 1. Specifically, in this embodiment, a new two-machine air supply and power generation device is installed for a user in India, and the specific parameters are as follows.

[0053] The power of each unit in the system is balanced, and the parameters of the design point of the axial flow compressor and the design point of the gas turbine are taken.

[0054] Unit 1: First motor 1 + First gearbox 2 + 4# axial flow compressor 3 + Variable speed clutch 4 + Gas turbine 5.

[0055] Table 1 Power balance of Unit 1

[0056]

[0057] The power descriptions of each device in Table 1 are as follows:

[0058] The power of the variable speed clutch 4 = the power of the gas turbine 5.

[0059] The power of the first motor 1 = the power of the first gearbox 2 = the power of the gas turbine 5 - the power of the 4# axial flow compressor 3.

[0060] The power recovery rate of the gas turbine 5 = the power of the gas turbine 5 ÷ the power of the 4# axial flow compressor 3

[0061] The motor power is "+", indicating that the motor is in the power generation state.

[0062] The motor power is "-", indicating that the motor outputs power and is in the driving state.

[0063] When the power of the gearbox is "+", it means the gearbox transmits power in the reverse direction.

[0064] When the power of the gearbox is "-", it means the gearbox transmits power in the forward direction.

[0065] Unit 2: Steam turbine 6 + 5# axial flow compressor 7

[0066] Table 2 Power balance of Unit 2

[0067]

[0068] The power descriptions of each device in Table 2 are as follows:

[0069] Power of steam turbine 6 = Power of 5# axial flow compressor 7.

[0070] Power of 4# axial flow compressor 3 in Unit 1 = Power of 5# axial flow compressor 7 in Unit 2.

[0071] To ensure that the first gearbox 2 continuously transmits power in the reverse direction, it is necessary to control the loads of the axial flow compressors in the above two units. Adjust the load of the 4# axial flow compressor 3 in Unit 1 to 40% of the total load of the two axial flow compressors, and the load of the 5# axial flow compressor 7 in Unit 2 to 60% of the total load of the two axial flow compressors, and the power balance of the two units is as follows.

[0072] Table 3 Power balance of Unit 1

[0073]

[0074] Table 4 Power balance of Unit 2

[0075]

[0076] It can be seen from the power balance table of Unit 1 that the power of the motor is "+", and it is in the power generation state; the power of the gearbox is "+", and the gearbox has been in the state of transmitting power in the reverse direction. This ensures that the gearbox will not vibrate due to the alternating transmission of power in the forward and reverse directions, causing the interlock shutdown of Unit 1, and guarantees the normal production of the 2# blast furnace 8.

[0077] Similarly, the first gearbox 2 can also be made to continuously transmit power in the forward direction by adjusting the loads of the axial flow compressors in the two units. The specific method is as follows.

[0078] Adjust the load of the 4# axial flow compressor 3 in Unit 1 to 60% of the total load of the two axial flow compressors, and the load of the 5# axial flow compressor 7 in Unit 2 to 40% of the total load of the two axial flow compressors, and the power balance of the two units is as follows.

[0079] Table 5 Power balance of Unit 1

[0080]

[0081] Table 6 Power balance of unit 2

[0082]

[0083] It can be seen from the power balance table of unit 1 that the motor power is "-", which is in the driving state; the gearbox power is "-", and the gearbox is always in the forward power transmission state. This ensures that the gearbox will not vibrate due to the alternating forward and reverse power transmission, causing the interlocking shutdown of unit 1, ensuring the normal production of No. 2 blast furnace 8.

[0084] Based on the above-mentioned embodiment 1 and embodiment 2, as Figure 4 As shown in the figure, a two-machine air supply and power generation device for large blast furnace metallurgy has the following advantages:

[0085] First, the backup fan is smaller, which reduces the user's investment. In projects with tight investment, the advantages of this solution are very obvious.

[0086] Second, since the probability of two axial flow compressors failing at the same time is extremely low, this system solution will not cause blast furnace collapse or slag filling accidents due to the inability of all axial flow compressors to supply air, greatly improving the safety of blast furnace smelting.

[0087] Third, the gas turbine uses the waste heat and waste pressure of blast furnace gas to do work, and the recovered power is 80% to 120% of the power consumed by the axial compressor, which greatly reduces the output of the motor. The excess power can be directly used to generate electricity for other equipment in the factory, greatly improving user benefits.

[0088] However, there is a problem that needs to be solved urgently in the control of the unit. Figure 4In the first gearbox 2, it can operate safely and stably under the forward power transmission of the first motor 1, and can also operate safely and stably under the reverse power transmission of the gas turbine 5. However, it is difficult for the first gearbox 2 to transmit power forward and then reverse within a short period of time. When this situation occurs, the vibration value of the first gearbox 2 often exceeds the normal value greatly, triggering the interlock shutdown of the unit composed of the first motor 1 + the first gearbox 2 + the 4# axial flow compressor 3 + the variable speed clutch 4 + the gas turbine 5, resulting in a halving of the blast volume supplied to the blast furnace and affecting the normal production of the blast furnace. Since the waste heat and pressure of the blast furnace gas are not stable, the power recovered by the gas turbine 5 by using the blast furnace gas with waste heat and pressure to do work is not stable. Generally, the power recovered by the gas turbine 5 is equivalent to 80% - 120% of the power consumed by the 4# axial flow compressor 3. When the power recovered by the gas turbine 5 is equivalent to 80% - 100% of the power consumed by the 4# axial flow compressor 3, the first gearbox 2 transmits power forward; when the power recovered by the gas turbine 5 is equivalent to 100% - 120% of the power consumed by the 4# axial flow compressor 3, the first gearbox 2 transmits power in reverse. Considering that the parameters of the blast furnace gas are not stable, within a short period of time, the work done by the gas turbine 5 will continuously change within the range of 80% - 120% of the power consumed by the 4# axial flow compressor 3. At this time, the first gearbox 2 will vibrate greatly, thereby triggering the interlock shutdown of the unit composed of the first motor 1 + the first gearbox 2 + the 4# axial flow compressor 3 + the variable speed clutch 4 + the gas turbine 5, halving the blast volume supplied to the blast furnace and affecting the normal production of the blast furnace.

[0089] Based on the above-mentioned Figure 4 defects in the control of the device as shown, the following Embodiment 3 further provides a load distribution control method for the air supply and power generation system in large blast furnace smelting, which solves the Figure 4 problem that the forward and reverse power transmissions of the gearbox occur alternately within a short period of time, avoiding the interlock shutdown of the unit composed of the first motor 1 + the first gearbox 2 + the 4# axial flow compressor 3 + the variable speed clutch 4 + the gas turbine 5 due to excessive vibration of the gearbox, halving the blast volume supplied to the blast furnace and affecting the normal production of the blast furnace.

[0090] Embodiment 3:

[0091] This embodiment provides a load distribution control method for the air supply and power generation system of a large blast furnace. This method uses the air supply and power generation system of a large blast furnace as shown in Figure 5 the figure.

[0092] Based on the system given in Embodiment 1, the air supply and power generation system of the large blast furnace further includes a second motor 9, a second gearbox 10 and a 1# axial flow compressor 11 connected in sequence.

[0093] The air supply and power generation system of the large blast furnace further includes a third motor 12, a third gearbox 13 and a 2# axial flow compressor 14 connected in sequence.

[0094] The air supply and power generation system of the large blast furnace further includes a fourth motor 15, a fourth gearbox 16, and a No. 3 axial flow compressor 17 that are connected in sequence.

[0095] The No. 1 axial flow compressor 11, the No. 2 axial flow compressor 14, and the No. 3 axial flow compressor 17 are respectively connected to the No. 1 blast furnace 18 to supply air.

[0096] The No. 1 axial flow compressor 11, the No. 2 axial flow compressor 14, and the No. 3 axial flow compressor 17 are respectively connected to the No. 2 blast furnace 8 through air distribution valves 23 to supply air.

[0097] The No. 1 blast furnace 18 and the No. 2 blast furnace 8 are connected by a blast air valve 24. It is realized that the blower sets between the No. 1 blast furnace 18 and the No. 2 blast furnace 8 can be used as standby units for each other.

[0098] As a preferred solution of this embodiment, check valves 19, anti-blocking valves 20, electric air supply valves 21, and flow meters 22 are respectively arranged in sequence between the No. 1 axial flow compressor 11, the No. 2 axial flow compressor 14, the No. 3 axial flow compressor 17 and the No. 1 blast furnace 18.

[0099] As a preferred solution of this embodiment, check valves 19, anti-blocking valves 20, electric air supply valves 21, and flow meters 22 are respectively arranged in sequence between the No. 1 axial flow compressor 11, the No. 2 axial flow compressor 14, the No. 3 axial flow compressor 17 and the air distribution valve 23.

[0100] As a preferred solution of this embodiment, isolation valves 25 are respectively arranged on both sides of the blast air valve 24.

[0101] On the basis of the control method given in Embodiment 1, this control method further includes:

[0102] The No. 1 axial flow compressor 11 and the No. 2 axial flow compressor 14 jointly supply air to the No. 1 blast furnace 18, the No. 4 axial flow compressor 3 and the No. 5 axial flow compressor 7 jointly supply air to the No. 2 blast furnace 8, and the No. 3 axial flow compressor 17 can be used as a standby unit for both the No. 1 blast furnace 18 and the No. 2 blast furnace 8 at the same time. One set of standby unit is reduced, saving investment for users.

[0103] The No. 1 blast furnace 18 and the No. 2 blast furnace 8 can supplement air supply through the blast air valve 24, ensuring that the air supply pipe networks of the No. 1 blast furnace 18 and the No. 2 blast furnace 8 will not suddenly lose pressure and collapse, causing slag pouring accidents.

[0104] Specifically in this embodiment, if the user has more than two blast furnaces, a Figure 5 new type of air supply and power generation system for large blast furnace metallurgy in

[0105] Generally, if the furnace volumes of BF No. 1 18 and BF No. 2 8 are close, both being blast furnaces of about 5000 m³, only one set of AV80 standby fans is required for the two sets of air supply devices supporting BF No. 1 18 and BF No. 2 8.

[0106] In extreme cases, if the two sets of AV80 axial flow compressors supplying air to BF No. 2 8 suddenly fail simultaneously, the isolation valve 25 and the air diversion valve 24 can be quickly opened, and the air supply system of BF No. 1 18 can supply air with a certain flow rate and pressure to BF No. 2 8, ensuring that the air supply pipe network of BF No. 2 8 will not suddenly lose pressure and cause stock collapse, resulting in a slag pouring accident. Similarly, if the two sets of AV80 axial flow compressors supplying air to BF No. 1 18 suddenly fail simultaneously, the isolation valve 25 and the air diversion valve 24 can still be quickly opened, and the air supply system of BF No. 2 8 can supply air with a certain flow rate and pressure to BF No. 1 18, ensuring that the air supply pipe network of BF No. 1 18 will not suddenly lose pressure and cause stock collapse, resulting in a slag pouring accident.

Claims

1. A load distribution control method for the air supply and power generation system of a large blast furnace, characterized in that, this method adopts the air supply and power generation system of a large blast furnace; the air supply and power generation system of the large blast furnace includes a first motor (1), a first gearbox (2), a 4# axial flow compressor (3), a variable speed clutch (4) and a gas turbine (5) connected in sequence; it also includes a steam turbine (6) and a 5# axial flow compressor (7) connected in sequence; the 4# axial flow compressor (3) and the 5# axial flow compressor (7) are respectively connected to the 2# blast furnace (8) for air supply; this control method includes: the recovered power of the gas turbine (5) is equivalent to 80% - 120% of the power consumption of the 4# axial flow compressor (3); in order to avoid the unit interlock shutdown caused by excessive vibration value of the first gearbox (2) and affect the normal production of the 2# blast furnace (8), the first gearbox (2) needs to continuously transmit power in the positive direction or transmit power in the reverse direction for a long time; in the air supply and power generation system of the large blast furnace, it is necessary to adjust the loads of the 4# axial flow compressor (3) and the 5# axial flow compressor (7), change the power consumption of the 4# axial flow compressor (3) and the 5# axial flow compressor (7) during normal operation, so that the recovered power of the gas turbine (5) is always lower than the power consumption of the 4# axial flow compressor (3) with 100% or always higher than the power consumption of the 4# axial flow compressor (3) with 100%, to ensure that the first gearbox (2) transmits power in the positive direction or transmits power in the reverse direction for a long time, avoiding the unit interlock shutdown caused by excessive vibration value of the first gearbox (2), and improving the safety and reliability of the normal production of the blast furnace (8).

2. The load distribution control method for the air supply and power generation system of a large blast furnace according to claim 1, characterized in that, the air supply and power generation system of the large blast furnace further includes a second motor (9), a second gearbox (10) and a 1# axial flow compressor (11) connected in sequence; the air supply and power generation system of the large blast furnace further includes a third motor (12), a third gearbox (13) and a 2# axial flow compressor (14) connected in sequence; the air supply and power generation system of the large blast furnace further includes a fourth motor (15), a fourth gearbox (16) and a 3# axial flow compressor (17) connected in sequence; the 1# axial flow compressor (11), the 2# axial flow compressor (14) and the 3# axial flow compressor (17) are respectively connected to the 1# blast furnace (18) for air supply; the 1# axial flow compressor (11), the 2# axial flow compressor (14) and the 3# axial flow compressor (17) are respectively connected to the 2# blast furnace (8) for air supply through air distribution valves (23); the 1# blast furnace (18) and the 2# blast furnace (8) are connected through a blast diversion valve (24).

3. The load distribution control method for the air supply and power generation system of a large blast furnace according to claim 2, characterized in that, check valves (19), anti-blocking valves (20), electric air supply valves (21) and flow meters (22) are respectively arranged in sequence between the 1# axial flow compressor (11), the 2# axial flow compressor (14) and the 3# axial flow compressor (17) and the 1# blast furnace (18).

4. The load distribution control method for the air supply and power generation system of a large blast furnace according to claim 2, characterized in that, a check valve (19), an anti-blocking valve (20), an electric air supply valve (21) and a flow meter (22) are sequentially arranged between the 1# axial flow compressor (11), the 2# axial flow compressor (14) and the 3# axial flow compressor (17) and the air distribution valve (23).

5. The load distribution control method for the air supply and power generation system of a large blast furnace according to claim 2, characterized in that, isolation valves (25) are respectively arranged on both sides of the air diversion valve (24).

6. The load distribution control method for the air supply and power generation system of a large blast furnace according to claim 2, characterized in that, the control method further includes: the 1# axial flow compressor (11) and the 2# axial flow compressor (14) jointly supply air to the 1# blast furnace (18), the 4# axial flow compressor (3) and the 5# axial flow compressor (7) jointly supply air to the 2# blast furnace (8), and the 3# axial flow compressor (17) can simultaneously serve as a standby unit for both the 1# blast furnace (18) and the 2# blast furnace (8); the 1# blast furnace (18) and the 2# blast furnace (8) can supplement air supply through the air diversion valve (24).

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