What makes the fully controllable vortex triple-wheel impeller technology advanced?
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Carbon dioxide centrifugal compressors are key equipment in large-scale urea production plants. Since the 1970s, our country has introduced more than 30 sets of urea production plants with an annual capacity of 520,000 tons from abroad, most of which use fully centrifugal compressors manufactured by General Electric and Albemarle in the United States, or those produced using their technology. After the 1990s, the West **stopped supplying technology for carbon dioxide centrifugal compressors to our country in order to monopolize the market, and instead sold finished products. To this end, our country has not only spent a large amount of foreign exchange, but also faced numerous problems with centrifugal compressors abroad; failures resulting from these compressors account for nearly 40% of all shutdowns in large fertilizer production facilities, posing a serious challenge for China’s fertilizer industry. In 1973, Professor Wang Shangjin began research on the three-dimensional flow theory of centrifugal compressors. Three years later, a design method for fully controllable vortex triangular impellers of radial and mixed-flow types was developed, resolving for the first time both domestically and internationally the conflict between fluid condition control within the impeller and the smoothness and machinability of the blades. Using this method, comparative tests were conducted between the basic stage of a fully controllable vortex three-stage centrifugal compressor and similar products from the United States; the results showed superior energy-saving performance as well as better performance under varying operating conditions, and this technology was thus awarded an **Invention Prize. In December 1985, the Department of Power Machinery Engineering at Xi’an Jiaotong University suggested to the former **Economic and Trade Commission that the fully controllable vortex technology be adopted in large-scale fertilizer production facilities across the country; the former **Economic and Trade Commission issued a special directive urging prompt implementation of this idea. I hope the above text will serve as a starting point to discuss the research, development, application, and effects of three-phase flow technology
Firstly, the flow within the impeller is three-dimensional. In three-dimensional flow design, the pressure distribution across the blades is specified first, and then the blade profiles are determined accordingly. There are currently many methods for three-dimensional flow design, but the basic approach remains similar: an initial condition is given, and equations are solved. Current methods for three-dimensional flow design include those based on ruled surfaces and those using arbitrary surfaces. Among the software tools I’m familiar with, such as ANSYS CCD and CFTURBO, the design is carried out using ruled surfaces. This method is convenient for manufacturing impellers, but it is relatively less efficient. To date, the highest efficiency achievable with three-dimensional flow impellers is 96%; I have not yet found a specific design method that can achieve this level of efficiency. To gain a thorough understanding of the theories and methods behind three-dimensional flow design, one must master concepts related to fluid dynamics, tensors, numerical computation, etc. Additionally, a great deal of experience is required to develop such designs. Of course, it is also necessary to be proficient in a programming language, as programs need to be written
It can be said that gas dynamics is better, as it enables higher compression efficiency.