Method for reducing power consumption of circular cooling blower

Abstract

The invention belongs to the technical field of high-temperature sintering energy consumption, and particularly relates to a method for reducing power consumption of an annular cooling air blower, which comprises the following specific steps: S1, transforming a motor control system of the annular cooling air blower into a variable-frequency control mode; s2, thermocouples are installed on a hot air cover and an air duct of the annular cooling air blower, and a dynamic temperature field monitoring system is established; s3, flow meters are installed at all air outlets of the annular cooling air blower, and the air volume and the motor power under different frequencies are detected; s4, according to the sintered ore temperature change trend and the ore discharge temperature change trend, a system linkage relation with the frequency change range of the annular cooling air blower is established; and S5, according to the actual ore removal amount, the air volume needed for cooling the sintered ore is calculated, according to the field temperature and the temperature change, the operation frequency of an annular cooling air blower is measured and calculated, and the minimum operation current of a motor is controlled to be 25-35 A. According to the method, the required cooling air quantity is simulated in combination with the material temperature change, and the lowest current of the motor is controlled and the energy consumption is reduced by adjusting the frequency conversion control mode of the annular cooling air blower.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature sintering energy consumption, and in particular relates to a method for reducing the power consumption of a ring cooling blower. Background Art

[0002] Under normal sintering production conditions, the temperature of the sinter cake discharged from the tail of the sintering machine is about 700℃, and the temperature at the entrance of the ring cooling blower is about 600℃ after a short transfer through the single-roller tooth crusher and the distribution chute. In order to use the rubber belt conveyor to further transport the sintered ore and provide the sintered ore with uniform particle size to the blast furnace, the high-temperature sinter cake needs to be cooled and granulated to meet the requirements of the next process, and the sensible heat of the sintered ore needs to be recovered. For example, the implementation of technologies such as hot air sintering and waste heat power generation can improve the efficiency of energy use.

[0003] Usually, the sintered ore is cooled quickly by forced ventilation with an annular cooling blower to achieve the purpose of cooling. The cooling process mainly uses conduction heat transfer (internal heat of the sintered ore diffuses to the outside) and convection heat transfer (heat on the surface of the sintered ore is exchanged with the surrounding cold air). The cooling capacity is mainly affected by the particle size of the sintered ore, the cooling time and the cooling air volume. The first two are mainly determined by the control and process design of the sintering process. The cooling air volume can be controlled according to the actual material temperature. The cooling air volume is mainly affected by the number of cooling fans and the speed of the motor. It is an effective measure to implement energy saving on site.

[0004] Large sintering machine (400m 2 The above) are generally equipped with 5-7 ring cooling blowers to meet the cooling needs of sintered ore. The installed capacity of cooling blowers accounts for about 20% of the entire sintering system. The power consumption of daily operation accounts for about 25% of the system power consumption. It has high energy consumption and is the second most power-consuming system after the main exhaust fan. Summary of the invention

[0005] The purpose of the present invention is to provide a method for reducing the power consumption of a ring cooling blower, so as to solve the problem of high energy consumption of a cooling blower in a large sintering machine.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: A method for reducing power consumption of an annular cooling blower, the specific steps are as follows: S1: 7 ring cooling blowers are configured. The motor control system of the ring cooling blower is transformed into variable frequency control mode. The operating frequency of the ring cooling blower is 0-50HZ. The air volume of the ring cooling blower is controlled by adjusting the frequency change range of the ring cooling blower. S2: The ring-cooling blowers are in a ring shape and there are 20-28 wind boxes corresponding to the bottom of the 7 ring-cooling blowers. A thermocouple is installed on the hot air cover corresponding to the upper part of each wind box, and a thermocouple is installed on the air duct to detect the wind temperature changes in the entire range in real time, respond to the temperature changes in real time, and establish a dynamic temperature field monitoring system; S3: Install flow meters at each air outlet of the ring cooling blower, adjust the air volume by adjusting the motor frequency and speed, and detect the air volume and motor power at different frequencies; S4: According to the sintering temperature change trend and the discharge temperature change trend, establish a system linkage relationship with the frequency change range of the ring cooling blower. If the temperature is higher than the daily value, increase the operating frequency of the blower, increase the blowing volume, and improve the cooling intensity; when the temperature is lower than the daily temperature, reduce the cooling intensity, reduce the operating frequency of the blower, reduce the load of the motor, and reduce power consumption; S5: Calculate the air volume required for sinter cooling based on the actual ore output, and calculate the operating frequency of the ring cooling blower based on the on-site sinter temperature and temperature changes. When the air volume required for sinter cooling is met, control the minimum operating current of the motor to be 25A-35A.

[0007] Preferably, the frequency variation range of the ring cooling blower in step S1 is 0-35HZ.

[0008] Preferably, the air volume of the ring cooling blower in step S1 is 30000-650000Nm 3 .

[0009] Preferably, the air volume required for cooling the sintered ore per ton of ore in step S5 is 2500±500m 3 .

[0010] Compared with the prior art, the present invention has the following beneficial effects: (1) The required cooling air volume is simulated by the change of sinter material temperature to avoid the generation of excessive air volume, which will cause rapid cooling of the sinter and affect the quality of the sinter. At the same time, the power consumption of the motor is reduced and energy consumption is reduced. A temperature monitoring system is established by combining the hot air hood ring of the ring cooling blower and the thermocouples installed on the air duct. The cooling intensity is adjusted by temperature comparison. The motor load is reduced by adjusting the variable frequency control mode of the ring cooling blower. (2) The energy consumption of the motor is proportional to the square of the current. By adjusting the required cooling air volume, the motor current can be kept at the minimum to save energy. (3) Adjust the motor frequency variation range to achieve precise process control, increase equipment life and reduce power consumption. DETAILED DESCRIPTION

[0011] The technical solution of the present invention is described clearly and completely below in conjunction with the embodiments.

[0012] The cooling area of ​​the sintering ring cooling blower in a certain factory is 715m 2 , the cooling method is blast cooling.

[0013] A method for reducing power consumption of an annular cooling blower, the specific steps are as follows: S1: Equipped with 7 ring-cooling blowers with a power of 1400kw, the 3#-7# ring-cooling blowers are transformed into variable frequency speed regulation. By adjusting the frequency change range of the ring-cooling blower 0-50HZ, the air volume of the ring-cooling blower is controlled to 30000-650000Nm 3 ; S2: 56 pairs of thermocouples are installed on the hot air hood ring and air duct of the ring cooling blower to detect the wind temperature changes in the entire range in real time, respond to temperature changes in real time, and establish a dynamic temperature field monitoring system; S3: Install flow meters at each air outlet of the ring cooling blower, and detect the air volume and motor power at different frequencies when adjusting the air volume by adjusting the frequency and speed of the ring cooling blower; S4: Tracking the ring cooling blower at the corresponding area of ​​the increased temperature change, it was found that the sintering material temperature at the 4# and 5# ring drum positions had large temperature fluctuations; S5: Under normal circumstances, during production, the average material temperature at the 3# and 4# blowers is about 350°C, the temperature of the 7# blower measured by the infrared thermometer is about 120°C, the cooling air volume per ton of ore = 3.2 × fluctuating temperature, the actual ore output = - 13.70 + 465.8 × sintering machine speed, and the corrected air volume = 1486.4 × fluctuating temperature × current machine speed.

[0014] The sintering machine speed is controlled at 2.4m / min, the ring cooling blower speed ratio is set to 0.7, the sintering machine material layer thickness is controlled at 820mm, the mixed material moisture content is controlled at 7.5±0.2%, the alkalinity centerline is 2.16, and the difference between the continuous average of the 18#, 19#, and 20# thermocouples near the 4# blower and 250℃ is used as the main basis for adjusting the blower frequency. The sum of the 4#, 5#, and 6# blower frequencies = [temperature value at time - 250) + 95, and the actual air volume is adjusted: according to: , Where: Q is the amount of cooling air required to cool 1 ton of sintered ore, m 3 / t; T1 is the average temperature of hot sintered ore, generally 750℃; T2 is the average temperature of cold sintered ore, generally 100℃; T1 / is the exhaust gas temperature, blast cooling is 200℃; T2 / is the cold air temperature, generally 20℃; C1 is the average specific heat of hot sintered ore, taken as 0.85 kJ / (kg·℃); C2 is the average specific heat of cold sintered ore, taken as 0.55 kJ / (kg·℃); C / is the average specific heat of air, which is 1.302 kJ / (m 3 ·℃); K is the heat exchange coefficient.

[0015] During normal production, the temperature fields of 3# and 4# blowers are 360±30℃, and the temperature field of 6#-7# blowers is 120±20℃; cooling air volume per ton of ore = 3.2×temperature change (ideal 360℃-detected temperature). The air volume is adjusted according to the steps, and the operating frequencies of 4#, 5#, 6#, and 7# ring cooling blowers are calculated to be 35HZ, 30HZ, 30HZ, and 0HZ.

Claims

1. A method for reducing power consumption of a ring cooling blower, characterized in that: The specific steps are as follows: S1: 7 ring cooling blowers are configured. The motor control system of the ring cooling blower is transformed into variable frequency control mode. The operating frequency of the ring cooling blower is 0-50HZ. The air volume of the ring cooling blower is controlled by adjusting the frequency change range of the ring cooling blower. S2: The ring-cooling blowers are in a ring shape and there are 20-28 wind boxes corresponding to the bottom of the 7 ring-cooling blowers. A thermocouple is installed on the hot air cover corresponding to the upper part of each wind box, and a thermocouple is installed on the air duct to detect the wind temperature changes in the entire range in real time, respond to the temperature changes in real time, and establish a dynamic temperature field monitoring system; S3: Install flow meters at each air outlet of the ring cooling blower, adjust the air volume by adjusting the motor frequency and speed, and detect the air volume and motor power at different frequencies; S4: According to the sintering temperature change trend and the discharge temperature change trend, establish a system linkage relationship with the frequency change range of the ring cooling blower. If the temperature is higher than the daily value, increase the operating frequency of the blower, increase the blowing volume, and improve the cooling intensity; when the temperature is lower than the daily temperature, reduce the cooling intensity, reduce the operating frequency of the blower, reduce the load of the motor, and reduce power consumption; S5: Calculate the air volume required for sinter cooling based on the actual ore output, and calculate the operating frequency of the ring cooling blower based on the on-site sinter temperature and temperature changes. When the air volume required for sinter cooling is met, control the minimum operating current of the motor to be 25A-35A.

2. A method for reducing power consumption of a ring cooling blower according to claim 1, characterized in that: The frequency variation range of the ring cooling blower in step S1 is 0-35HZ.

3. A method for reducing power consumption of a ring cooling blower according to any one of claims 1 or 2, characterized in that: The air volume of the ring cooling blower in step S1 is 30000-650000Nm 3 .

4. A method for reducing power consumption of a ring cooling blower according to claim 3, characterized in that: The air volume required for cooling the sintered ore per ton of ore in step S5 is 2500±500m 3 .