Localization and goals
Over the past 20 years, in the research and development of 300,000-ton/year ethylene complete sets of equipment, the localization of major key equipment in large-scale ethylene plants has been well established.
Ethylene cracking furnace
At present, the international production scale has reached 150,000 to 200,000 tons/year, and the technology is developing toward large-scale, low investment, low raw material consumption, low energy consumption, long operating cycle, advanced control technology, and simulation design. The furnace type is developed from a single furnace single row tube to single furnace multiple row tubes, double hearth furnace single row tubes or misaligned tubes; radiant section furnace tubes are developed from multiple passes to two passes or one pass, and a large number of special-shaped furnace tubes are used. The material develops in the direction of better resistance to creep, resistance to carburization, and high temperature durability; the furnace section of the convection section develops in the direction of widening, modularization, and arrangement of heat transfer tubes; the technology of quenching boilers from single inlet to linear The development of quenching boilers, multi-feed quench boilers, and rapid quenching boilers is developing. The burners are developing toward low nitrogen oxides, high capacity, and combustion air preheating and energy conservation. Domestically, ethylene cracking furnaces have made unremitting efforts to design and manufacture 20,000-ton/year, 40,000-ton/year, 60,000-ton/year CBL furnaces and 100,000 tons/year SL furnaces, and have applied them. In the old device technology reform. In order to meet the needs of 1 million tons of ethylene production, domestic companies are currently cooperating with foreign countries to develop 150,000-200,000 tons of large-scale ethylene cracking furnaces.
Gas compressor set
Large-scale ethylene plants have many gas compressors, the most important being ethylene “three machinesâ€, namely cracked gas compressors, propylene compressors, ethylene compressors (or three-way refrigeration compressors). They are the "heart" equipment of the ethylene cracker. The total price of the "three machines" is more than 300 million yuan. The international technology development trend is that the compressor has a larger processing capacity and a higher operating characteristic parameter; it adopts early fault diagnosis control and noise control and control technology; the overall machine efficiency is more than 82%, and it can continuously operate without failure for more than 3 years. After more than 20 years of digestion and absorption and continuous innovation, Shengu Group has made major breakthroughs in compressor gas dynamics, rotor dynamics, and heat transfer. Especially in the late 1990s, Shengu began the development of a 300,000-ton/year ethylene “three-machine†and has so far successfully developed 480,000 tons/year in Daqing, 720,000 tons/year in Shanghai, and 1 million tons/year in Maoming. Cracking gas compressors for ethylene renovation projects. The refrigerating compressors and ethylene compressors developed by Shengu have been applied to Daqing, Yangzi, Yanshan, Shanghai and Maoming ethylene renovation projects. It can be seen that at present, China has developed a technological basis for the development of a large-scale ethylene "three-machine" of 800,000 to 1 million tons per year. However, due to the large size of the compressor, it is necessary to develop thermodynamic software program for the compressor, software program for dynamic analysis of the rotor, real-world gas flow analysis software, ternary impeller design and flow field analysis program, and efficient basic-level cell technology development. More work on the development of new materials such as housings, spindles, and impellers.
The development of reciprocating labyrinth seal compressors in polyethylene and polypropylene plants is only a matter of recent years in China. The labyrinth seal compressors jointly developed by Lanzhou Tianhua Chemical Machinery Research & Design Institute, Jiangyin Compressor Factory, and Wuxi Compressor Factory have been used in 70,000 to 100,000 tons/year polyethylene units. To meet the needs of millions of tons of large-scale ethylene, they are developing large 4-row labyrinth sealed compressors that can be used in 200,000 to 450,000 tons/year polypropylene and polyethylene units.
The secondary compressor in the low-density polyethylene plant is the highest-pressure ultrahigh-pressure reciprocating compressor currently used in China. It cannot be designed and manufactured on its own in China, and research and development need to be accelerated.