The actual operating conditions of the air compressor v […]
The actual operating conditions of the air compressor vary with the needs of the process or gas consumption equipment so that the method of selecting the air compressor according to the maximum volume flow required by the device or system is not suitable. When the air consumption is less than the air compressor displacement, it is necessary to air compressor air volume adjustment, so that the air compressor displacement to meet the requirements of air consumption, and maintain the pressure in the pipe network stability. Here we have a conventional air compressor, for example, describes the commonly used air volume adjustment method:
1. Speed adjustment
Speed adjustment that is by changing the air compressor speed to adjust the displacement. The advantages of this adjustment is continuous gas, less power than the power consumption, air compressor pressure ratio at all levels remain unchanged, air compressor does not need a special adjustment mechanism; but it is only widely used in the drive for the internal combustion engine and steam turbine Of the compressor, if the drive for the motor, you need to configure the inverter, because high-power, high-voltage inverter is expensive, and requires a lot of maintenance, maintenance work, therefore, the current motor-driven reciprocating air compressor rarely Using this method. In addition, variable speed adjustment may have an adverse effect on the work of the air compressor, such as valve flutter, component wear, vibration increases, inadequate lubrication, etc., also limits the wide application of the method.
2. clearance chamber adjustment
In the air compressor cylinder, in addition to the fixed clearance volume, the other without a certain cavity, adjust the access to the cylinder working chamber, the air compressor clearance volume increases, the volume coefficient decreases, the displacement is reduced, This is the working principle of the clearance chamber adjustment. In accordance with the subsidy volume access to different ways, but also divided into continuous, graded into the intermittent adjustment, and more for large-scale process air compressor. The main drawback of this adjustment is: usually manual adjustment, and slow response, the general need to use with other adjustment methods. Although the method of connecting the variable subsidy clearance volume can in principle achieve 0% 100% adjustment, but the system reliability is poor, more vulnerable parts, difficult to maintain.
3. Press the inlet valve to adjust
According to the length of the intake valve is pressed, the method is divided into two ways: the whole stroke is forced into the intake valve and the partial stroke is forced into the intake valve. For the whole stroke to adjust the intake valve adjustment, in the process of inhalation, the gas is sucked into the cylinder, in the compression process, because the intake valve is fully open, the inhaled gas is fully pushed out of the cylinder. The full stroke of the intake valve to adjust the larger adjustment for thick adjustment. Part of the stroke to open the inlet valve adjustment principle and the whole stroke of the inlet valve is similar, but it controls the return time of the intake valve in the compressor, control the amount of return gas, which can achieve continuous adjustment of gas, Almost proportional to the amount of displacement to reduce, so there is a high operating economy
4. Bypass adjustment
The exhaust pipe is connected with the intake pipe through the bypass pipe and the bypass valve. When the bypass valve is opened, some of the exhaust gas is returned to the intake pipe. This adjustment method is more flexible, and simple, coupled with the automatic control system adjustment accuracy is relatively high, but because the excess gas of all the compression work are lost, so the economy is poor, so this method is suitable for occasional adjustment or adjustment Small range of occasions.