[Ten years of development of chemical equipment] 1042-2021 ultra-low temperature minus 269°C wound tube liquid helium heat exchanger exported overseas

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Chemical science and technology has developed greatly in the past ten years. Praise for China's prosperity and strength in the prosperous age. It will be more lively and exciting with everyone's participation. Everyone is welcome to participate in the forum to exchange and discuss. Pay attention to fire prevention in July------------------------------------------------- In June 2021, the Daqing Petrochemical Company Machinery Factory completed the design and manufacture of a low-temperature liquid helium wound tube condenser. Its design and manufacturing and other technologies have filled domestic gaps. In the field of domestic wound tube heat exchanger manufacturing, it has achieved a breakthrough in designing and manufacturing ultra-low temperature products in accordance with ASME standards for export to the international market. As of the end of May, all 19 cryogenic liquid helium equipment designed and manufactured by the Daqing Petrochemical Company Machinery Factory have been sent to the general contractor. 　　The liquid helium heat exchanger is part of the skid-mounted project of Daqing Petrochemical Company undertaking the external market and exporting liquid helium production to South Africa. Hou Xiaofeng, deputy director of the machinery factory, said that the design and manufacturing of the low-temperature heat exchanger faces two major problems. First, there was no domestic liquid helium production equipment before, and there was no domestic market for liquid helium heat exchangers. Second, the liquid helium heat exchanger manufactured is in the form of a wound tube structure and manufactured according to ASME standards and needs to meet the design working conditions of minus 269°C. This is currently a blank in the country. 　　According to reports, the factory has design and manufacturing experience with the ASME standard "U" stamp, but this is the first time it has undertaken and manufactured a liquid helium heat exchanger. Because there is no liquid helium device in the country, and it is the first time to manufacture a minus 269°C liquid helium wound tube condenser unit for a South African liquid helium device, its ultra-low temperature working conditions, wound tube structure, ultra-low carbon stainless steel material and other particularities require very high manufacturing technology, and there is no experience to draw from. In May last year, our factory established a technical research team and invested energy in developing, designing and manufacturing this equipment. 　For liquid helium equipment, the design temperature of the liquid helium heat exchanger is close to absolute zero, and because it is a skid-mounted equipment, the space requirements are relatively stringent, which makes design and manufacturing very difficult. First, the liquid helium heat exchanger has relatively high requirements on materials and welding technology, especially the low-temperature toughness of materials and welds. Second, due to space constraints, the product structure must be extremely compact, which brings great difficulties to the welding operation. 　The manufacturing plant has conducted a large number of tests since October 2020. Traditionally, when manufacturing wound tube heat exchanger internals, traditional machine tools, presses and other equipment are usually used. However, when manufacturing liquid helium heat exchanger equipment, the manufacturer uses new equipment such as digital laser cutting machines and develops multiple manufacturing tools to ensure the quality and efficiency of assembly and tube-to-tube-sheet welding. Through strict operation training, technical briefing, process execution and other control measures, the entire equipment was 100% qualified in one inspection, and it also accumulated technology and manufacturing experience for the production of ultra-low temperature equipment products.