A two-stage energy-saving air compressor with adjustable pressure ratio

Abstract

The invention discloses a compression ratio adjustable two-stage energy-saving air compressor. The compression ratio adjustable two-stage energy-saving air compressor comprises two stages of compression main engines; oil-gas separation and air cooling are carried out between stages; an oil-gas separation barrel which is internally provided with an oil fine separator is arranged behind the second-stage compression main engine; an oil-gas separation barrel is additionally arranged behind the first-stage compression main engine; the two stages of compression main engines are in direct-linking transmission by adopting a shaft coupler; a frequency conversion control system of each stage of compression main engine can be used for reasonably distributing a rotary speed of each stage of compression main engine according to exhausting pressure of the second-stage compression main engine to obtain an optimal compression ratio; a top gas outlet of the first-stage oil-gas separation barrel is connected with a gas inlet valve of the second-stage compression main engine through a pressure sustaining valve via a heat exchanger; a top gas outlet of the second-stage oil-gas separation barrel is connected with a gas inlet of an oil-gas cooler through the pressure sustaining valve; a gas outlet of the oil-gas cooler is connected with an evaporator of a freezing dryer, a gas-water separator and the heat exchanger in sequence. By adopting the compression ratio adjustable two-stage energy-saving air compressor, the volumetric efficiency of the whole main engine is improved and the overall efficiency is optimized; the utilization efficiency of compressed air is increased.

Description

technical field [0001] The invention belongs to the technical field of mechanical equipment and relates to a two-stage energy-saving air compressor with adjustable pressure ratio. Background technique [0002] The existing two-stage screw air compressor mainly has the following defects: [0003] (1) The existing two-stage screw air compressor mainly adopts closed gear transmission to drive the primary and secondary male rotors to rotate. Once the transmission ratio is confirmed, the internal pressure ratio between the primary and secondary will not be fixed. changed, basically tending to equal pressure ratio compression. Although the reduction of the compression ratio of each stage reduces the leakage and improves the volumetric efficiency of each stage of compression, the adjustment flexibility of this equal-pressure ratio compression is poor, and whether it is the best pressure ratio is only based on theoretical calculations and a small amount of experimental data. Confi...

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Problems solved by technology

Although the reduction of the compression ratio of each stage reduces the leakage and improves the volumetric efficiency of each stage of compression, the adjustment flexibility of this equal-pressure ratio compression is poor, and whether it is the best pressure ratio is only based on theoretical calculations and a small amount of experimental data. Confirm big changes

However, when the frequency is changed, the pressure ratio of the primary and secondary will change continuously, and the efficiency of the main engine will change, so it cannot always work at the best efficiency point.

[0004] (2) This kind of integrated two-stage screw compressor main engine will undergo interstage oil injection cooling after primary compression, and the oil will also be mixed with air to enter the secondary compression. Since only the interstage oil is cooled, the primary compressed air Without heat exchanger cooling and oil-gas separation, too high temperature and too much oil will greatly affect the volumetric efficiency of the two-stage compressor host

[0005] (3) The lateral force generated by the gear transmission will adversely affect the life of the main engine bearing. At the same time, in the prior art, the motor drives the first-stage compression main engine and the second-stage compression main engine through a gear box at one end, and the transmission There is a loss of efficiency

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