Industry News

What are the energy-saving effects of Ingersoll Rand inverter air compressors, regret it late?

Author : Runningway

Update time : 2019-04-30 13:54:24

What are the energy-saving effects of Ingersoll Rand's variable frequency air compressors? Do you regret that it is late? After the Ingersoll Rand inverter air compressor is energy-saving, it is not correct to say that the air compressor has no empty car status. Use the inverter to adjust the motor speed to achieve energy savings. As the output frequency of the inverter is reduced, the air compressor compression mechanism reduces the gas production, so that the air compressor is operated as much as possible in the loading state, and the utilization rate of the air compressor is improved. When the gas terminal is used to stop the gas, or the gas is used to reach the pressure requirement, the air compressor enters the empty state. In order to save costs, most of the air compressors we have modified use the original three-phase asynchronous motor instead of replacing it with a variable frequency motor. Then, in order to ensure the heat dissipation of the ordinary three-phase asynchronous motor, the motor torque is ensured. The loading frequency must not be lower than 20Hz. The unloading frequency can't be lower than 15Hz. Otherwise, the motor is very likely to be overheated and damaged. On the other hand, the air compressor motor speed is too low, affecting the oil pressure system. If the internal pressure is too low, it is easy to make the air compressor head high temperature and increase the possibility of oil running oil.

Such motors are also not suitable for overclocking, with a maximum frequency of 50 Hz. That is to say, after the air compressor is modified, the dynamic frequency conversion range of the motor is between 20Hz and 50Hz. In addition, after the frequency conversion transformation of the air compressor, the air pressure machine sets three pressure control points: loading point, constant pressure point, and unloading point. At the loading point, the motor runs at full frequency of 50Hz. When the pressure is close to the constant voltage set point, the frequency converter runs down frequency, the frequency changes around the pressure value, and under the condition of constant gas demand, find the appropriate constant voltage frequency. Stable, then the inverter will have unstable frequency changes. At the same time, when the inverter runs at the lowest frequency of 20 Hz, the gas production can still make the pressure reach the unloading pressure value, and the air compressor will enter the unloading state. The air compressor is empty, the pressure drops to the loading point pressure, and the air compressor enters the loading state again, repeating the above process. This is why the air pressure opportunity enters the empty state. After the air compressor frequency conversion energy-saving transformation, the statement that there is no empty car is wrong.

Ingersoll-Rand inverter air compressor adopts inverter PID constant voltage control system, the frequency conversion speed control system takes the pipe network pressure as the control object, and the pressure transmitter installed in the gas storage tank converts the pressure of the gas storage tank into electricity. The signal is transmitted to the PID regulator inside the controller, compared with the pressure set value, and according to the magnitude of the difference, the operation is performed according to the predetermined PID control mode, and a control signal is generated to control the output voltage and the inverter frequency of the inverter, and the adjustment is performed. The speed of the motor, so that the actual pressure is always maintained at the set pressure, resulting in a constant air pressure. The inverter is used for the impact of current and equipment when the main motor starts. The optimized SPWM algorithm is used to make the motor start smoothly, increase the starting torque, and reduce the interference of the inrush current to other equipment. The advanced multi-point is adopted in the acceleration process. The acceleration curve reduces the wear of the bearing and the main screw of the head due to the quick start, which can greatly increase the service life of the equipment and the maintenance period of the mechanical equipment.

energy saving effect

The 250kW ordinary unit runs 8759 hours a year, with a loading time of 2442 hours, an unloading time of 6317 hours, and an electricity bill of 0.7 yuan/kWh.

Load loss:

Unloading time × no-load current loss (1.732×0.38×175×0.85)×6317 hours/year=618442 kWh generated during unloading; however, considering that the screw air compressor can ensure lubrication without leakage at low frequency, it is generally required The frequency limit of the frequency conversion is set to 30 Hz, and the power consumption of the frequency conversion is 618442×40%=247377 degrees.

Differential pressure loss:

1. The screw unit can't run in direction. When changing, you must pay attention to the running direction of the motor.

2, need to pay attention to the lubrication problem of the air compressor, the lower the speed of the air compressor, the smaller the consumption of lubricating oil, the worse the lubrication effect.

3, need to pay attention to the heat dissipation problem of the motor, the motor uses frequency conversion to adjust the speed, the speed is reduced, and the heat dissipation effect of the motor fan is also reduced.

Previous : Do you know the knowledge of Ingersoll Rand air compressor factory maintenance and management?

Next : Do you know the oil cleaning and maintenance methods for screw air compressors?