Enterprise Guide-Purchase Air Compressor Pre-test
1. The feasibility of power saving transformation of air compressor
The energy consumption of air compressors during use is obvious to all. The Zhongtian high-pressure fan power saver developed by okmarts.com based on the principle of frequency conversion can save electricity for all motor-driven air compressors. The overall power saving effect is remarkable, with a power saving rate of 20-50%.
Now take the actual transformation of okmarts.com as an example to illustrate as follows:
The electric company currently has 4 fully automatic production lines and another 80 injection molding machines. The compressed air required is provided by a set of compressors. The plant's gas supply system has four 380V compressors, of which two 37KW always work, and the other 55KW and 45KW are put into use in different time periods according to the gas supply situation. Due to the lack of compressor design and uncertain factors in the production process, this air compression system has the following defects:
Waste electrical energy. The working pressure of compressed air on the production line is required to be 3kgf/cm2, and the pressure on the main gas pipeline is kept at 3.2kgf/cm2. Since the air cannot be constant, in fact, the operation of two 37KW air compressors can basically meet the requirements, and the operation of three air compressors will cause frequent emptying and deflation, which is a serious waste of electricity. Moreover, the system pressure often fluctuates in a wide range of 3kgf/cm2-4kgf/cm2, which affects the product quality of certain processes to a certain extent.
loud noise. When the air compressor is automatically vented and deflated, the noise is very loud, causing environmental pollution.
The grid has a big impact. Since the three air compressors all start and run at industrial frequency, the starting current z* of the machine is as high as 630A, which has an impact on the power grid.
Fluctuations in air supply. Since the system cannot automatically adjust the air supply, fluctuations in the air supply have a certain impact on the quality of the product.
To sum up, the air compressor energy-saving system can be used to carry out technical transformation of the existing air compression system, and the PID control frequency conversion technology can be used to establish a constant pressure air supply system, so as to save electricity, reduce noise, reduce equipment wear, and reduce power grid Impact, improve power factor, stabilize product quality and other effects.
Principles of Power Saving Reformation of Air Compression System
1. Introduction to power saving principle
The energy-saving controller adopts frequency conversion technology and the latest PID control technology. It uses pressure sensor signals and related electrical control signals to control the motor speed of the air compressor according to the set compressed gas pressure value to maintain the air pressure at the required pressure value. The energy that does not have to be consumed is saved, so as to achieve the purpose of saving electricity.
The system adopts continuous program control, there is no large current impact phenomenon during frequent startup, and it can effectively protect the power grid.
2. Modification requirements
There are four compressors in the factory's air supply system, two of which are 37KW always working, and the other 55KW and 45KW are put into use in different time periods according to the air supply situation. According to the requirements of the factory, the air supply of the air compressor should be at a constant pressure, and the air supply pressure range is 0～1MPa; in addition to the two 37KW air compressors working at full frequency (power frequency), the other 55KW and 45KW can be switched into operation. The operating frequency is controlled according to the required air pressure.
3. Control method
The working principle diagram of the control system is shown in the figure below.
It can be seen from the figure that there are 1 55KW air compressor (1# pump), 1 45KW compressor (2# pump), and 2 37KW compressors (3#, 4# pump) included in the system operation. Two of them are operated at 37KW industrial frequency and cannot be adjusted in speed, and the other two are adjusted by frequency converters. According to the specific conditions of the air compressor in the factory, the motor drive equipment inverter uses a 55KW inverter, which can be adapted to two air compressors of 55KW and 45KW.
In order to realize the constant pressure gas supply on the gas pipeline, a pressure transmitter is installed on the gas pipeline to transform the pressure in the pipeline network into a 4-20mA signal and send it to an intelligent self-tuning PID regulator. The PID regulator changes its input 4-20mA signal into a 0-10VDC electrical signal, and controls the output frequency and output voltage of the inverter, thereby changing the speed of the motor. When the system is working, pumps 3# and 4# run at power frequency. If the pipe network pressure is not enough, the frequency converter controls the 2# pump to start working. If the pipe network pressure is still not enough when working at the power frequency state, the frequency converter will
