In the field of petrochemical industry, at present, domestic centrifugal compressors can not meet the needs of domestic high-tech and special products. In addition, there is still a gap with foreign countries in terms of technical level, quality and completeness. With the continuous expansion of petrochemical production scale in China, centrifugal compressors will face new problems in large-scale production, but China has no mature experience in designing and manufacturing these large gas compressors.
Centrifugal compressors need to develop to large capacity to meet the requirements of the continuous expansion of petrochemical production scale in China. At the same time, with the development of new technology, the emergence of new gas seals, magnetic bearings and lubrication-free couplings, the development trend of turbocompressors is as follows: (1) continuously develop high-pressure and low-flow products; Further study the three-dimensional flow theory and apply it to the design of impeller and blade diffuser to realize high efficiency unit; Reduce noise, take noise protection and improve the working environment.
In the field of refrigeration and air conditioning, at present, turbocompressors still maintain their advantages in a large refrigeration capacity range. Centrifugal compressor has few and simple moving parts and low manufacturing precision, so the manufacturing cost is relatively low and the reliability is high. Due to the influence of screw compressor and absorption refrigerator, the development of centrifugal refrigeration compressor is relatively slow. Under the current technical conditions, centrifugal refrigeration compressors are mainly used for air conditioning in large buildings, with less demand. In recent years, due to large-scale infrastructure projects, centrifugal refrigeration compressor has become the focus of attention.
2. Reciprocating compressor
In the field of petrochemical industry, reciprocating compressors mainly develop in the direction of large capacity, high pressure, low noise, high efficiency and high reliability. Continuously develop new air valves operating under variable working conditions to improve the service life of air valves; In product design, the performance of compressor under actual working conditions is predicted by comprehensive simulation using thermodynamics and dynamics theory. Strengthen the electromechanical integration of compressor, adopt computer automatic control, and realize optimized energy-saving operation and online operation.
In the field of power, piston compressors currently occupy the main market. However, with the improvement of people's requirements for the use environment, energy consumption and environmental protection, screw and scroll air compressors began to occupy a certain market.
In the field of refrigeration and air conditioning, reciprocating refrigeration compressor, as a traditional refrigeration compressor, is suitable for refrigeration systems with a wide range of refrigeration capacity. Although it is still widely used at present, its market share is gradually decreasing.
At present, the main engine of refrigeration system of refrigerator (including small refrigeration and refrigeration device) is still the former compound compressor. After years of design improvement and technical progress, the efficiency of reciprocating refrigerator compressor has been greatly improved. At the same time, the refrigerant substitution technology closely related to environmental protection has also made gratifying progress. Further improving the efficiency of reciprocating refrigerator compressor and reducing system noise is its main development direction.
(1) Linear compressor Linear compressor is a kind of reciprocating compressor. Because the linear motion of the motor can directly drive the piston to reciprocate, the complexity of the crank-connecting rod mechanism and the resulting mechanical power consumption are avoided. The key technologies of linear compressor are the design of compressor oil system, the effective control of linear displacement limit point of motor and the corresponding anti-collision technology.
(2) The swash plate compressor is also a variant structure of reciprocating compressor, which is mainly used in vehicle air conditioning system. After decades of development, the swash plate compressor has become a very mature model, accounting for more than 70% of the automobile air conditioning compressor market. But its efficiency is lower than that of rotary compressor, and its volume is larger. Due to the maturity of technology and the further improvement of technology, the swash plate automobile air conditioning compressor will still maintain a certain market share in the foreseeable future, but it is inevitable to be gradually replaced within a certain displacement range.
3. Rotary compressor
(1) Rolling rotor compressors At present, rolling rotor compressors are widely used in household air conditioners and refrigerators. This kind of compressor does not need a suction valve and is suitable for variable speed operation, so the system performance can be improved by frequency conversion control. In order to ensure the performance of high-power (motor output 2.2kW (3P)) rolling rotor compressor, domestic double-rotor rolling rotor compressor has been developed since the end of last century, and has been put on the market at present.
In the air conditioner below 2.2kW(3P), there is no better model to replace the rolling rotor compressor for the time being. Therefore, improving the efficiency of the compression process, reducing noise, controlling the motor speed, and adopting new refrigerants such as R4 10A are the research directions of the rolling rotor compressor.
(2) Vane compressor Vane compressor is a kind of rotary compressor, which is mainly used to provide compressed air. The displacement is generally 0.3 ~ 3 m 3/min, and the market share is low. Rotary vane compressor is an improved structure of vane compressor. Because of its good starting performance and small torque change during compression, it is mainly used in air conditioning systems of mini-cars and some small-displacement tool cars. High-speed dynamic characteristics are the main technical research direction of the compressor.
(3) Scroll compressor Scroll compressor has developed rapidly in the past ten years, which constitutes a new bright spot in the development of compressor technology. At present, scroll compressor has an absolute advantage in the field of cabinet air conditioning. In the field of automobile air conditioning, the refrigeration coefficient of scroll compressor has reached 2.0, showing strong competitiveness. The development of scroll compressor lies in expanding its refrigeration capacity range, further improving efficiency, using alternative working fluids and reducing manufacturing costs.
(4) Screw compressor Screw compressor has the characteristics of small volume, light weight and easy maintenance, and it is a kind of refrigeration compressor with rapid development. On the one hand, the design of screw profile and structure has made great progress. On the other hand, the introduction of special milling machine for screw rotor, especially grinder, has improved the machining accuracy and efficiency of this pair of key parts and effectively improved the performance of screw compressor. At present, screw compressors are mainly used for compressed air and medium-sized refrigeration heat pump air conditioning systems. Due to the continuous improvement of working reliability of screw compressor, it has gradually replaced reciprocating compressor in the range of medium refrigeration capacity, and occupied part of the market of centrifugal compressor.
Third, the preliminary market analysis of compressor
1. gas compressor
Commonly used gas compressors are centrifugal gas compressors and reciprocating gas compressors. Over the years, China's compressor manufacturing industry has overcome many difficulties and made major breakthroughs. However, China's centrifugal compressor can't meet the domestic demand in terms of high technology, high parameters, high quality and special products, and about 50% of the products need to be imported. Domestic small and medium-sized reciprocating compressors can basically meet the demand of domestic petrochemical industry, but large reciprocating compressors can not meet the market demand, especially the products with high technical content and special requirements can not meet the domestic demand. It is predicted that the total demand of large and medium-sized compressors during the Eleventh Five-Year Plan period will increase more than that during the Ninth Five-Year Plan period, especially for super-large and special process compressors. According to the current situation forecast, the compressor market will basically grow steadily in the next five years.
2. Domestic air conditioner compressor
At present, the total output of room air conditioning in China has surpassed that of the United States, ranking first in the world. In 2004, the apparent consumption of compressors (sales volume+import volume-export volume) was 42 million units, while the output of air conditioners reached 47.46 million units in the same period, with a gap of nearly 5.5 million units. It is estimated that there will be 6 million gap air-conditioning compressors in 2005, and the supply situation is relatively tight. However, with the expansion of air-conditioning compressor enterprises and the joining of refrigeration and air-conditioning enterprises, the production and sales of air-conditioning compressors in China will reach 70 million units in 2006, and domestic air-conditioning compressors will meet the demand.
3. Automobile air conditioning compressor
At present, although there are many kinds of automobile air-conditioning compressors, the output of swash-plate compressors is the most, and that of rotary compressors is the least. Rotary compressor has few parts and high efficiency, which is an important development direction of automobile air conditioning compressor. Rotary automobile air conditioning compressors mainly include rotary vane compressors and scroll compressor. Rotary vane compressors are mainly manufactured by Matsushita Corporation of Japan and Seiko Seiki Corporation of Japan, and rotary vane compressors are also manufactured by Denso Corporation of Japan and Jack Sell Corporation. Scroll compressors are mainly produced by Sanpower Corporation of Japan, Mitsubishi Heavy Industries Corporation and Denso Corporation. Some domestic enterprises have also begun to set foot in rotary automobile air conditioning compressors.