1、 Working principle









A scroll compressor is a type of rotary compressor. It was invented in 1905, but it was not until the early 1980s that it was applied to the fields of refrigeration and air conditioning in Japan. Therefore, it is currently a relatively new type of refrigeration compressor.
The vortex compressor is mainly composed of two vortex discs that are 180 degrees apart^oFormed in opposition, one is a fixed vortex disk and the other is a rotating vortex disk, which contact and form a series of crescent shaped volumes along several straight lines (or points in cross-section). The rotating scroll is driven by a crankshaft with a small eccentricity, and it moves around the fixed scroll in translation. The contact line between the two moves along the vortex surface during operation. The relative position between them is ensured by the cross slip ring installed between the rotating scroll and the fixed components.
The working process of the vortex compressor is shown in the following figure

The suction port is located on the outer side of the fixed vortex disk. Due to the rotation of the crankshaft (clockwise), gas is sucked in from the edge and enclosed in the crescent shaped area. As the contact line advances along the vortex surface towards the center, the crescent shaped area gradually shrinks and compresses the gas. The high-pressure gas is discharged through the axial center hole on the fixed vortex disk. The following figure (a) shows the position where the suction is exactly completed, the figure (b) shows the suction process at the periphery of the vortex, the compression process in the middle, and the exhaust process at the center, and the figures (c, d) show the continuous and simultaneous suction and compression processes. In each rotation of the crankshaft, a new suction volume is formed, so the above process is repeated and completed in sequence.







2、 Structure









At present, there are only two types of models: small fully enclosed and open. Both use Freon as the working fluid, mainly applied in automotive air conditioning and 2.2-4.4kW household heat pump air conditioners




3、 Characteristics
From the perspective of structure and working principle, small scroll compressors have the following characteristics:
1) The high-efficiency vortex compressor operates continuously in one direction for suction, compression, and exhaust, with direct suction, resulting in less harmful overheating of the inhaled gas; Without the expansion process of gas in the clearance volume, the gas transmission coefficient is high
2) The vortex compressor has small torque changes, low vibration, and low noise. The compression process is slow and can perform two or three compression processes simultaneously. The machine runs smoothly and the crankshaft rotation torque changes little; Secondly, the gas flows continuously and the suction and exhaust pressure fluctuations are small.
3) Simple structure, small size, light weight, and few moving parts; There are no suction or exhaust valves, fewer vulnerable parts, and good reliability. Compared with piston compressors, vortex compressors are 40% smaller in volume, 15% lighter in weight, 10% more efficient, and 5dB lower in noise (A).

4、 The main factors affecting the performance of scroll compressors
（1） Motor input power
The main factors affecting the performance of vortex compressors are: 1. Mechanical friction 2. Fluid resistance

（2） Gas Leakage 1. Types of Gas Leakage 2. Leakage Channels
（3） Inhalation preheating