Recently organized by the Department of Science and Technology of Guangdong Province, Prof. Zhu Dongsheng of the School of Chemical Engineering and Energy, South China University of Technology, Deputy Dean of Yang Yuanzheng of Guangdong University of Technology, Professor Zhu Jinji of Sun Yat-sen University, Prof. Li Wei of Jinan University, etc. The application of aluminum alloy new energy-saving and environmental-friendly heat exchange materials in gas water heaters and the industrialization of new technology achievements have been technically appraised. The results of the appraisal show that the technology meets the relevant national standards, ensuring the service life of water heaters and achieving the effect of energy saving and environmental protection. At the same time, the product fills the domestic gap and the technology is at the leading domestic level. The identification of this achievement will promote the technical upgrading of gas water heater heat exchangers in the field of energy conservation and environmental protection, ease the current situation of China's lack of copper resources, and achieve sustainable development of the water heater industry. It is reported that as early as 2005, Wanhe has begun to study aluminum alloy as a new material for gas water heater heat exchangers, successfully developed a prototype of the product, and conducted more than one year of suitability test and type experiment, and obtained a large number of experimental data. . And applied for two invention patents and four utility model patents during the development process. The invention patents are: Application for invention patent in July 2006: 200610036587.7 Aluminium/aluminum alloy heat exchanger unit for gas water heater; Patent application for invention patent in July 2007: 200710029215.6 Cavity aluminum heat exchanger for gas water heater. It lays a good foundation for the industrialization of aluminum alloy as a heat exchanger for gas water heaters. In September 2007, Wanhe Group and Guangdong Hisense Kelon Electrical Appliance Co., Ltd., Guangdong Shenling Air Conditioning Equipment Co., Ltd. and the State Key Laboratory of Metal Materials Strength and Welding Research Institute of Xi'an Jiaotong University jointly tendered key breakthroughs in the key areas of Guangdong and Hong Kong. The project “New Energy-Saving Heat Exchanger and System for White Appliances†won the bid and received special financial support from Guangdong Provincial Department of Finance and Guangdong Provincial Department of Science and Technology. In order to ensure the safety and reliability of aluminum alloy heat exchangers, in addition to routine tests such as thermal efficiency and temperature rise, Wanhe has also achieved reliable resistance to cold and heat shocks, salt spray tests, heavy load durability, and high water pressure. Sex test, the number of experiments reached more than 400 times. Before the deadline, Wanhe's trial-produced aluminum alloy heat exchanger gas water heater products passed the inspection of the national gas appliance product quality supervision and inspection center, and all the test results were in line with the "Fast Water Heater for Domestic Gas Water Heaters" and "Fast Water Heater for Domestic Gas Fast Water Heaters". And "home gas fast water heater and gas heating water heater energy efficiency limit value and energy efficiency rating" standard, in addition, also passed the National Daily Quality Supervision and Inspection Center for metal products inspection. In order to verify the excellent performance of aluminum alloy heat exchangers, to master the use conditions and product life of different gas sources and water quality conditions in different parts of China, in August 2008, Wanhe commissioned the College of Urban Construction and Environmental Engineering of Chongqing University to conduct experiments in the Institute. The chamber was tested for endurance life of 2 sets of products equipped with aluminum alloy heat exchangers. After 96 days of continuous full-load work (if calculated according to household use 45 minutes per day, which is equivalent to more than eight years), the test results show that the thermal efficiency of the water heater and the CO content in the flue gas remain basically unchanged, the waterway structure And the strength design meets the actual needs, and there is no leakage phenomenon. The effluent quality meets the requirements of GB5749-2006 "Living Water Standard", and the corresponding aluminum alloy heat exchanger has no obvious oxidation corrosion and discoloration deformation. In September 2009, Tsinghua University School of Aeronautics and Astronautics compared the heat transfer performance of Wanhe gas water heater copper/aluminum high temperature heat exchanger and concluded that if the copper heat exchanger welding process is not improved, the actual heat exchange process The total heat exchange capacity of the aluminum heat exchanger is greater than that of the copper heat exchanger, and the unit mass heat exchange capacity is much larger than that of the copper heat exchanger, and the higher surface temperature may be comparable to or even smaller than the copper heat exchanger. According to the scientific and technological achievements appraisal report, the solder used in the aluminum alloy heat exchanger is aluminum-silicon, and the Japanese imported fully-integrated soldering furnace ensures that the fins and the water pipe are tightly combined, thereby improving the overall heat exchange of the aluminum alloy heat exchanger. The ability to make aluminum gas water heaters more energy-efficient than traditional water heaters, thermal efficiency of 88%, in line with the national energy efficiency standards. At the same time, the melting point of aluminum alloy material reaches 650 degrees to 700 degrees, which is much higher than the national standard and can fully meet the high temperature use environment of gas water heaters. In terms of corrosion resistance, aluminum alloys generate a dense oxide film (or passivation film) at high temperatures, protecting the substrate from oxidation and corrosion. In addition, in order to ensure the strength of the aluminum alloy heat exchanger, Wanhe increased the thickness of the water pipe and tank shell and the heat exchange sheet of the aluminum alloy heat exchanger by 40% to 60%. For Wanhe’s newer technological achievements, Liu Runfeng, deputy secretary-general of the China National Hardware Association and the general manager of the gas appliance division, said that aluminum alloy is currently one of many materials used in gas water heater heat exchangers, and enterprises should comply with the requirements of national standards. , Adhere to the principle of quality first for product development. The association encourages technological innovation of enterprises, and the industry must jointly create a healthy ecological environment for gas water heaters.
