Spinning machine frequency conversion application energy saving cost reduction

I. Introduction

The spinning machine is a spinning device that drafts, twists, and winds semi-finished rovings or slivers into finished yarns for spinning. It is the main equipment in the cotton spinning industry. The yield and quality of the spun yarn determine the overall quality of each process in the entire spinning process.

The production unit of a spinning machine is a spindle, and the production level of a spinning machine is generally measured in terms of the production volume per thousand spindles. The spinning mill production scale is expressed in terms of the total number of spindles that own a spinning frame. The spinning machine is the most energy-consuming machine in spinning production.

Therefore, efforts to increase the production efficiency of the spinning frame, reduce the breakage rate of the spinning frame, reduce the energy consumption, and increase the level of automation control have become a means for the cotton mills to increase production, reduce consumption, and increase profitability. At the same time, they are also used for motor transmission and automation applications. Bring new opportunities.

Second, the spinning machine work characteristics

Spinning machine Luoding motor and speed control system, there are the following several ways:

2.1. Multi-pole motor + power frequency power supply relay control: By changing the number of motor poles to achieve the adjustment of the process speed, the narrow speed range, can not meet the requirements of process improvement, and the system maintenance workload is relatively large.

2.2. AC asynchronous motor + frequency converter: Through frequency control, speed regulation is more convenient, wide speed range, but the asynchronous motor there is a certain slip, roller speed will have a certain degree of fluctuation, speed response is also slightly slower. In addition, the efficiency and power factor of ordinary asynchronous motors are not too high, and there is a certain power loss.

2.3. Permanent Magnet Synchronous Motor + Permanent Magnet Special Inverter: Through frequency control, convenient speed control, and wide speed range, permanent magnet motors have high efficiency, high power factor, stable speed, and low reactive power loss.

In contrast, the third drive system is the best for the spinning machine, with high production efficiency and energy saving. However, the relative investment in equipment is relatively high. Therefore, most textile companies use the second AC asynchronous motor + inverter control scheme. .

Third, the spinning frame inverter design requirements and features

3.1. Due to the poor environment of the textile site, there will be a phenomenon that the fan is blocked by the cotton wool during the use of the inverter, causing damage to the fan and causing the inverter to overheat. Based on PI500's high-performance vector inverter, Pu Chuan Technology has developed a PI500 XXXG3N series inverter. This inverter has no cooling fan and is cooled by the wind provided by the on-site air duct. , The product has been field verified that the temperature rise meets the design criteria and the operating results meet the customer's needs.

3.2. Characteristics of PI500 XXXG3N Series Inverters

DSP-based control unit is adopted to achieve high-speed and high-performance control. Three speed control modes: V/F control, vector control without PG, vector control with PG. Support vector control of asynchronous motors and permanent magnet synchronous motors, accurate motor parameter self-learning. Under the non-induction vector, low-frequency 0.5HZ/150% torque output can be realized, low-speed and high-torque, and small torque ripple. The simple PLC function can realize up to sixteen speed control. Advanced thermal management technology, fanless design, adapt to 40°C ambient temperature. Flange installation, easy installation and maintenance. Built-in 485 communication interface, easy-to-use PC software, network communication with the host computer, support for multiple communications. Three anti-paint coating treatment to adapt to a variety of harsh environments.

3.3.PI500 XXXG3N inverter pictures

Fourth, the scene test situation and application picture

4.1. Field test results

The test results confirm that the equipment operating current is very stable and fluctuates little. At the same time, the temperature rise effect is also

Ideally, it fully meets the needs of the site.

4.2. Live Application Picture:

Fifth, the field application effect

5.1. Increased production. Although the speed is reduced by 5%-8% in the case of small yarns and large yarns (the purpose is to reduce the breakage rate), the middle yarn is increased by 5%-15% according to the condition of the vehicle, while the length of the middle yarn accounts for the entire yarn. The 80% of the length increases the overall spinning speed by nearly 10%, greatly increasing the effective running time of the spindle and increasing the production efficiency and yield of the spinning frame. Production also increased by nearly 10%.

5.2. Improve product quality. The use of frequency converters to control speed fluctuations, thereby reducing the end of the head rate, due to the reduction in the end of the break can be used to save time for the cleaning work to reduce the number of unexpected yarn defects, improve product quality.

5.3. Saving raw materials. After the decapitation is reduced, the number of flowers in the joints is reduced, and the number of rolls on the rolls is also reduced. This means that raw materials that are wasted on rework are saved.

5.4. Change process is convenient. Improve the degree of automation, reduce labor intensity When changing the product or adjusting the speed, without replacing the belt pulley, directly modify the inverter parameters can be achieved.

5.5. For some types of spinning, such as strong twist yarn, core yarn, hemp yarn, and high-grade combed products, the best point of the production process can be selected through variable speed, which can maximize the yield and reduce the breakage.

5.6. The use of frequency converter + asynchronous motor drive method, the maximum potential to tap the reactive power of the motor, make full use of and improve the power factor, so as to achieve the purpose of saving electricity. Increasing the power factor of the spinning machine from the original 0.71 to 0.92 reduces reactive current, reduces line losses, and saves power.

5.7. Decrease in yarn breakage, value-added lathes can increase the number of stands, reduce the number of labor, and save labor costs.

5.8. The equipment failure rate is reduced, and the loss caused by equipment failures caused by stoppages and shutdowns is reduced, which relatively increases the output and reduces the equipment maintenance costs.

5.9. Inverter has no cooling fan management, which reduces the chance of the inverter malfunction due to fan failure and improves the working efficiency of the equipment.