Multi-screw type frequency conversion refrigeration compressor

Abstract

The invention discloses a multi-screw type frequency conversion refrigeration compressor. At least two screw rotors are arranged, and arranged and positioned on a rotating shaft in a sleeving manner in the length direction of the rotating shaft. A screw groove of each screw rotor is defined by a shell inner wall and two star wheels to form two closed cavities. Exhaust passages corresponding to the closed cavities are formed in the shell, correspond to high-pressure exhaust sides of the screw rotors and communicate with an exhaust port. A corresponding exhaust passage is provided with a sliding valve structure capable of adjusting the opening size of the exhaust passage. The two sets of sliding valve structures are arranged. Each sliding valve structure comprises a lead screw and multiple valve blocks. The two lead screws are arranged on the two sides of the rotating shaft in parallel, and the corresponding valve blocks correspond to a bypass opening in one side of each screw rotor. The lead screws are rotationally arranged in a compression side shell. When the lead screws rotate, the valve blocks horizontally move on the lead screws front and back, and the function of adjusting the opening size of the exhaust passages is achieved. The upper limit of the exhaust amount is broken through, the refrigeration effect is improved, and during frequency conversion adjustment, additional acting losses of a compressor cannot be caused.

Description

technical field [0001] The invention relates to a screw type refrigeration compressor, in particular to a multi-screw frequency conversion refrigeration compressor with adjustable discharge pressure. Background technique [0002] With the continuous updating of single-screw refrigeration compressor technology, single-screw compressors have been widely used in the fields of air conditioning, refrigeration, refrigeration and chemical industry. The working principle of the single-screw refrigeration compressor is to drive the screw rotor to rotate through the motor, and compress the refrigerant vapor through the cooperation of the screw rotor and the star wheel, so that the pressure of the refrigerant vapor is increased, and then sent to the condenser through the exhaust port of the compressor middle. The cooling effect of the refrigeration compressor is directly proportional to the displacement of the exhaust port. The higher the displacement, the stronger the cooling effect....

AI Technical Summary

Problems solved by technology

[0004] 1. It is difficult to break through the upper limit of the exhaust volume, which leads to the limitation of the refrigeration effect of the compressor, and it is difficult to meet the higher refrigeration requirements; in order to overcome this deficiency, the conventional method is to increase the volume of the star wheel and the screw rotor of the compressor, However, this method is limited by the processing technology, and the processing is difficult, the processing cost is high, and the reliability is poor, so it is not practical; another method is to set up multiple refrigeration compressors to work together, but this method will lead to high equipment costs , and the equipment occupies a large area;

[0005] 2. The internal volume ratio of the existing single-screw compressor cannot be adjusted, and there are over-compression and under-compression phenomena (when the compression ends, the internal pressure of the compression chamber is lower than the external exhaust pressure, which will cause under-compression, and the gas in the chamber will produce Constant volume compression, increase the pressure in the cavity, and then discharge the compression cavity, resulting in additional power

At this time, the gas in the cavity will expand at a constant volume, and additional wasteful work will be consumed

In an ideal compression process, the pressure at the end of compression is the same as the external back pressure, there is no additional work loss, the compressor consumes the least power, and the energy efficiency ratio is the highest) Whether it is over-compression or under-compression, it will cause additional work loss of the compressor;

[0006] 3. The adjustment of the displacement of the frequency conversion refrigeration compressor is realized by changing the speed of the motor. When the refrigeration compressor is lightly loaded, the required speed may only be 20% of the full load. At this time, the displacement is small, but this time When the exhaust pressure is also reduced, it will not be able to meet the pressure conditions entering the condenser, and the refrigerant vapor in the condenser may even flow back, and flow back into the compressor shell through the compressor exhaust port, increasing the inefficiency of the compressor. The workmanship may cause the compressor to not work normally and stably, or damage the internal components of the compressor

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