2015年7月31日星期五

How to choose the air compressor control system?

How to choose the air compressor control system?

The purpose of any air compressor control system are the most efficient way to match the demand and supply of compressed air. The vintage electric pneumatic control being based on the upgrade software of the control of the microprocessor and to be able to optimize the system and control parameters are replaced, but any type of control is a constant speed control or shift control.
Fixed speed compressor control
Name suggests, this method is to let the air compressor speed is constant, the specific speed is determined by the drive function of the transmission ratio of the motor speed and the transmission apparatus, the transmission means can be a gear or triangular belt port and the gas supply amount control based on the modulation control or poppet valve control .













Modulation control
This form of control is adjusted based on the exhaust pressure of the air compressor to the intake valve of the air compressor. When the controller detects that the exhaust pressure increases, it starts to close the intake valve. Although this control is effective, but the efficiency is the lowest. The reason is that an efficiency is inversely proportional to the pressure ratio of the air compressor, the ratio of compression ratio, i.e. the exhaust gas pressure and the intake pressure. The closure of the intake valve at the inlet of the air compressor to generate a vacuum, and the exhaust pressure is relatively constant, this is equivalent to the increased pressure ratio.
Remedial measures is limited modulation control adjustment range Once the output drops to less than about 40%, 60% on the automatic control program into the load / no-load control. Unfortunately, this control can not be applied to multiple machines.
Variable row and Control of
Can change the air compressor displacement control the effective length of the rotor. Mainly on the host plus cone or spiral valves, control the internal bypass. Although the efficiency of such control is better than the modulation control, but the helical valve control in more than 50% to 60% capacity, and this control debugging complex and difficult.
Unload / load control
Such control is simple and effective, the use of fully closing the intake valve when the pressure reaches the upper limit (disconnected) in the compressor discharge pressure at the switch, and to fully open the intake valve when the pressure reaches the lower limit (access). The modulation control difference is that this control air compressor implement internal unload. Pressure ratio decline leads to wasted effort and consumption decline. This type of control can take advantage of the the sequencer (main) controller to easily connect multiple air compressor equipment. On the other hand, the air system will need to install a suitably sized air storage tank.
On / off control
This is the most effective control program. The air compressor is either running at full load or outage, depending on the signal at the mouth of the pressure switch, unfortunately, more than 10hp motor accordance with the requirements of this control often start and off will cause overheating. This control commonly used in small piston compressor installation of storage. This differential pressure of the air compressor is relatively large, up to 15psig to 25 psig.
Variable speed control
The technology of the advanced economies to the air compressor application variable frequency drive technology. The principle sounds simple, precise control air compressor / motor speed according to system requirements. If properly designed, variable frequency control is fine-tuning of the most advanced and energy saving air compressor control port, however, some of the following questions must be given to solve.
Air Compressor host to be designed into the host has a higher efficiency throughout the rev range port efficiency is a function of the speed of the rotor tip line, may be too low or too high speed dropped significantly.
Variable speed drive controller as an additional coupling between the power supply and the drive motor, and must be sufficiently efficient. Mechanical and electrical performance must not drive systems and electric power distortions and the effects of electromagnetic radiation, in order to avoid the computer or other sensitive electronic equipment from electromagnetic interference. The drive motor must handle high speed image processing as efficient low speed, high speed bearing design and cooling problems may be more trouble. Intelligent controller to establish a highly efficient and reliable link between the air pressure, motor and air compressor inlet valve. A well-designed device can accurately control the compressor discharge pressure within 1 Psi And despite the gas fluctuation range. The variable speed control to adjust the compressor running, it allows sequencer / controller in the efficient running parallel air compressor mouth run at full capacity according to the demand part of the air compressor, the rest of the air compressor in the aside standby mouth variable speed control can effectively compensate for the volatility of gas demand.
Yet even the most efficient control system can not compensate for the improper design. A comprehensive system of checks to the air system, so that the control system has the opportunity to achieve efficiency.

4 条评论: