Once in the air conditioning industry uproar of aluminum in place of copper, recently renewed at gas-fired water heater industry. Recently, media reports, market part of the water heater quietly "heart" to reduce the cost of copper aluminium generation, resulting in a product security risk. Conditions as reported by? this site reporter has exclusive in-depth investigation.
Focus: aluminum in place of copper and then questioned
Recently, some media reports, the number of years using copper gas water heater water tank that was partly quietly changed into a manufacturer of aluminum. The article claimed that the aluminum properties far inferior to copper, used for water heater core components prone to problems. For example, one expert pointed out that the water heater products now, in the heat exchanger at the entrance to high temperature flue gas temperature has reached 1000 degrees Celsius, and copper melting temperature, much higher than the melting point of pure aluminum. Some of the experts on aluminum heat resistance and heat transfer performance. Some experts noted that, "has not seen any validation on the aluminum, so that the report" "copper heart" water heater from decades of application is secure, reliable, and "Al heart" water heater indicators have yet to be professional identification.
See this and let people have a sense of the familiar. 2007 frozen quarter because of air conditioner industry of copper and aluminum connecting pipe contentions is especially lively.
Quality inspection departments: products have passed the correlation detection
In response to reports of the various questions raised in the relevant quality inspection specialist to journalists a detailed explanation. "What we call the aluminum in place of copper, not what people think of pure aluminum, but joined the titanium alloy. "Chongqing University City construction and environmental engineering Professor Ng Fuk told reporters, because adding material, alloy melting point will change, the materials used in the product, its melting point at 650 ° c to 700 ° c, although no copper melting point is high, but also fully meets the requirements of national standards.
"Heat exchangers entrance to high temperature flue gas temperatures up to 1000 ° c is only a limit. "National gas appliances product quality supervision and inspection Center (Foshan) examination of Minister Zhang mingwei told reporters that national standards for material requirements of heat-resistant 500 degrees Celsius is actually much higher than the actual run-time temperature. Because of the gas water heater is working with water, and therefore their operating temperature of 110 ° c to mostly in 260 degrees Celsius. High temperature flue gas temperature of 1000 degrees Celsius did have reached, however, this was mainly due to product design not reasonable cause stem burn, if this happens, do not say is aluminum, copper, also be shaohua.
Reportedly, at home, gas water heater heat exchanger has been using dip lead-copper materials, gas water heater, easy discharge large amounts of waste containing heavy metals. According to the EU RoHS directive, European non-leaching, lead and copper heat exchanger. But in China, almost the entire unburnt products and most of the strong type products are also used in the materials, only in the high-end products on the use of oxygen-free copper brazing technology. Due to the water tank and external layers are high concentrations of lead packages, and the melting point of lead only to 327 ° c, if aluminum tanks will being burn, then dip lead and copper products more can't stand the test of high temperature.
For materials of heat transfer performance, Zhang mingwei explained that if simply from two materials, aluminium heat conduction performance indeed than copper. However, this problem is by product design and process improvement to solve. He took out two tank heat exchanger broken tablets on the reporter explained that the leaching of lead, copper products, finned tube fin and tube, combustion chamber wall and the coil connection is also the lead through leaching. In between there solder and gaps. While the lead and air of conductivity lower than aluminum, therefore, greatly affects its heat transfer rate. Currently aluminum heat exchanger brazing technology due to improved use, finned tubes and pipes in fin has not gap between, allowing the heat transfer area greatly increase the thermal efficiency is increased.
Department: Science and technology research promotes the aluminum in place of copper
So, gas water heater water tank of copper and aluminum in place of how to have a background of? in Guangdong Province Foshan Shunde science and Technology Bureau, reporters saw a copy of Guangdong science and technology plan project contract — yuecai teach (2008), no. 2, clearly marked with the contract, the project name for white goods new energy-saving heat exchanger heat exchanger materials and systems, project plan category for Guangdong-Hong Kong technology cooperation funding, management unit of the Department of science and technology of Guangdong Province. In addition, there is a report on the release of 2007 production funds (tender) notification yuecai teach (2008), no. 2, notice that the Guangdong-Hong Kong technology cooperation funding scheme in accordance with the relevant procedures have been approved by the provincial leadership and Ministry of education of Guangdong Province, given the combination of special funds of $ 4 million.
Its Deputy Director Guo Qiang told reporters, Guangdong-Hong Kong technology cooperation funding scheme is the people's Government of Guangdong Province and Hong Kong S.A.R. Government jointly decided to a key the two pillars of the industry and generic technology as a point of scientific and technological research, in the "new materials" and "new energy, energy saving and resource-friendly technology," six key areas of joint tender, organized scientific and technological research, achieving breakthroughs in tenders. Gas water heater water tank of copper substitute as one of the items carried out in 2007. According to the provisions of the contract, may 1, 2009-2009-31 October, shall invite the industry expert on product technology, technology, reliability, security and identification. And complete product series, small batch production and marketing. November 1, 2009-2010-31 May, start industrial mass production. 2010-1-2010, December 31, the Organization of project acceptance. But in fact, the aluminum alloy tank of
Issued in 2006 raises, in June 2007 a prototype of the first structure, completed in June 2008 a small batch production.Guo Qiang said inconvenience-to-business competition, however, as the competent authorities, in the hope that the development and progress of science and technology have a fair environment. Energy-saving emission reduction and new materials substitution is always a new issue of the scientific and technological progress, and aluminum in place of copper in multiple areas. This alternative is not a simple concept of Al-Cu, but has a high technology content, in his view this simple negation does not conform to the scientific spirit. But he also said that the alternative results also requires a third-party authority to speak, since there is doubt, the acceptance, will be more strictly and carefully.
Science and technology, Guangdong Province officials also said the project, science and technology project and not a man Pats his head set up, but authoritative experts to discuss the results that are consistent with the Guangdong-Hong Kong technology cooperation funding project purposes.
Expert: bold innovation, careful verification
It is understood that in November 2008, two paragraphs to aluminium titanium alloy heat exchanger gas water heater products through a national gas appliances product quality supervision and inspection Center (Foshan) examination, inspection conclusions: all projects meet GB6932-2001 residential gas water heater, GB20665-2006 "household gas water heater and gas heating hot water boilers limited values of energy efficiency rating, DB44/T402.7-2007" household gas instantaneous water heater heat exchanger on the standards of this type inspection qualified total outsourcing. In March 2009, similar products through a national gas appliances for quality supervision and inspection Center (Tianjin) examination, inspection conclusions as inspection items meet GB6932-2001 "household gas instantaneous water heater" standards requirements (see Figure 1). Also, Chongqing University beginning in August 2008, also on behalf of copper products for 96 days (2304 hours) of durable life simulation test, concluded that: "the use of aluminum heat exchanger water heater structure is reasonable, in simulated user 8 years of using the cycle, the heat exchange efficiency is a good, safe and reliable running. ”
Zhang Wei said, product while in test performance is fine, but China's vast parts of the water, air, there is a very big difference, at the same time, the water heater is a safe product, so that in future long-term marketing, also need to caution, continuously emerging issues. However, regardless of how we should encourage industry of bold innovation, because only then can a scientific and technological progress.
China household electrical appliances Association Vice Director Liu fortunate they said that in recent years, taking into account the impact of the global environment, countries on energy saving and environmental protection products increasingly high demands of standards, new technologies, new materials development and application of the implementation of household electrical appliances from the traditional to the Green primary means of upgrading.
In fact, for household use of material replacement technology, whether producers or consumers, most concerned about is whether alternative materials to ensure product quality is not affected. They believe that Liu is not the product is flawed due to the use of new technologies, new materials, new processes. Well-known enterprises to new technologies, new products to market very carefully, before delivery of the new products will be on new technology, new materials, new processes for repeated experiments, therefore, generally speaking, the new product was able to withstand the test of the market.
Journalists from the national standardization Technical Committee was informed that the household appliances, at present, in more of the new revised standard, household electrical appliances are not material to the product, but for qualified product performance indicators have strict rules, the purpose is to guide the technical innovation of enterprises.
But experts also pointed out that the household electrical appliance enterprises material alternative work is not only working hard, but should be timely so that consumers understand the necessity of alternative materials, learn about the use of alternative materials for authenticity of the product, the only way to really win the trust of consumers, promote home appliance material substitution work smoothly, promote China's household electrical appliance industry in fast and healthy development.
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