The hottest screw and piston compressor compete fo

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Screw and piston compressors are competing for supremacy. Core tip: semi closed piston compressors are most widely used in the low-temperature market. However, with the advent of open and semi closed screw compressors, the low-temperature market of semi closed piston compressors is gradually eroded. Compared with screw machine, the advantages of piston machine are dwarfed. According to the interview, at present, the application of piston machine in the low-temperature market is much wider than that of screw machine. General manager Wang of Yantai ice wheel said that the piston machine has a long history and is highly accepted by consumers, while the screw machine has too high technical content and high cost, which restricts its development. However, the screw machine has developed rapidly in recent years, and the future development trend is obvious

the low temperature market is dominated by semi closed piston compressors

in the low temperature market, semi closed piston compressors dominate half of the country. The main characteristics of the piston machine are as follows: first, it can adapt to a wider pressure range and refrigeration capacity requirements; 2、 It has higher thermal efficiency and less unit power consumption, especially the pendulum impact tester of the air valve. The analysis of the experimental process makes the deviation from the design working condition more obvious; 3、 Its 5.5 hydraulic system parts have low requirements for materials at the joint. Ordinary steel materials are mostly used, so it is easier to process and the cost is relatively low; 4、 It is technically mature and has accumulated rich experience in production and use; 5、 The device system is relatively simple. These characteristics of piston machine have laid the foundation for its position in the low temperature market. It has large refrigerating capacity and low price. Interviewed several enterprises such as Xuemei, Lixi and Shenyang Dahua, they all said that the semi closed piston compressor is currently developing well in the low temperature market and occupies a large market share. President Wang of Lixi said that the low temperature market has grown rapidly in the past two years. Semi closed piston compressors with a capacity of more than 40p have sold well. The key lies in the quality of the products. As long as the quality is good, we are not afraid that the products will not sell. When it comes to the impact of screw machines on piston machines, President Wang said that there is not much impact at present, mainly because screw machines are relatively expensive and are mainly used in large cold storage. Zhu General of Jiangsu Xuemei answers this question from another level. President Zhu said that the type of compressor to be used depends on the size of the project

screw compressors are designed for low temperature.

since the advent of screw compressors in 1934, after decades of technological improvements, screw compressors have been widely used, especially in refrigeration. Because the screw includes "2015 Symposium on the use of rubber and plastic and innovative materials in automobiles", "2015 Symposium on the use of rubber and plastic and innovative materials in electronic product design" and "2015 Symposium on the use of rubber and plastic and innovative materials in medical products", compared with the piston refrigeration compressor, the refrigeration compressor has the advantages of simple structure, less vulnerable parts, long maintenance cycle, high volumetric efficiency, low exhaust temperature It is insensitive to liquid hammer and can realize stepless adjustment of refrigeration capacity, so screw refrigeration compressors are more and more appreciated by users; It is widely used in various sectors of the national economy where artificial refrigeration is needed, such as the production of industrial products such as petroleum, chemical industry, light industry, medicine, low-temperature experiments in scientific research, low-temperature processing and storage of food and aquatic products, and air conditioning of large buildings such as public places

the first oil injected screw refrigeration compressor was jointly designed and produced in China in 1976. At present, Yantai ice wheel group Co., Ltd., Dalian refrigerator Co., Ltd., Wuhan new world refrigeration industry Co., Ltd. and other manufacturers have been able to produce screw refrigeration compressors. The nominal diameter of rotors ranges from 91mm to 315mm, and the refrigerating capacity under standard working conditions (-15 ℃/30 ℃) ranges from 38KW to 2470kw [1]. Two series of screw refrigeration compressors, open and semi closed, have been formed

the advantages of screw compressor mainly include: first, less parts, less vulnerable parts and high reliability; 2、 Convenient operation and maintenance; 3、 There is no unbalanced inertia force, the operation is stable and safe, and the vibration is small; 4、 It has the characteristics of forced gas transmission, and the exhaust volume is hardly affected by the exhaust pressure, so it has strong adaptability to working conditions; 5、 The rotor tooth surface of screw compressor actually has clearance, so it is insensitive to wet stroke and resistant to liquid hammer;; 6、 The exhaust temperature is low, and it can operate under high-pressure bide conditions; 7、 It can realize stepless adjustment of refrigeration, and adopts slide valve mechanism, so that the refrigerating capacity can be stepless adjusted from 15% to 100%, saving operating costs; 8、 It is easy to realize automation and remote communication. The excellent characteristics of screw compressor determine its potential in the low temperature market. According to the interview, the application of screw compressor in the low temperature market is gradually heating up. President Wang of Yantai ice wheel told that the current market of screw compressors is good, reaching a growth rate of more than 30%. At the same time, bizel's relevant staff also said that the screw compressor has developed rapidly in recent years, the research and development level has reached a new level, and many technical problems have been overcome, so the market awareness is also getting higher and higher

will the rise of screw compressors pose a threat to semi closed piston compressors? When interviewing the heads of relevant enterprises, most of them just laughed off meaningfully, and some people said that it was sooner or later for screw machines to replace piston machines. President Zeng of Fusheng said that the future of screw machines is entirely determined by the market, and the market is always moving forward, and the survival of the fittest is the law of market development

expert comments

experts in the large market of air conditioning and refrigeration believe that the semi closed piston compressor originated the earliest, and the market is relatively mature, with various shutdown controllers and computers; The interfaces on the controller are corresponding one by one, and the technical experience is also very mature. It is not so difficult to repair after it breaks down. Moreover, the channel is relatively deep and the acceptance of end users is high. Therefore, it is impossible to completely withdraw from the stage of history at once. The development history of screw compressor is relatively short, and the market is not mature enough. Because the rotor tooth surface is a spatial curved surface, it needs to use special tools to process on expensive equipment. There are also high requirements for the machining accuracy of body parts, which requires the use of high-precision equipment, resulting in high production costs. In terms of channel, it is not as good as piston machine. The key is that the awareness of end users is not high enough, and the acceptance of price is not high enough. These constitute factors restricting the development of screw machine. Of course, this is only from the overall situation. Every new thing has a process from immature to mature. Therefore, according to the interview results of those companies that produce screw compressors, screw compressors are currently in the stage of advancing in twists and turns. Despite the heavy market resistance, some people still recognize its advantages in the low-temperature market, such as simple device, almost no maintenance, long service life and so on

in addition, from the perspective of cost, the one-time investment cost of screw compressor is slightly higher than that of piston machine, but there are many vulnerable parts of piston machine, and parts are replaced and repaired frequently. Large piston machine requires more people to maintain. On the whole, its cost is higher than that of screw machine. From the perspective of market conditions, president Zhu of Jiangsu Xuemei said that the application of compressors is determined by terminals, and the development of terminals will greatly affect the market trend of compressors. Since this year, the state has attached great importance to food safety, and food quality has also become a hot issue of concern to the whole society, which has promoted the development of cold chain cold storage, especially the development of large cold storage. Large refrigerators are the most suitable for screw compressors, so the growth of screw compressors largely depends on the trend of policies and the trend of the end market

source: Global appliances

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