Brief introduction of all stainless steel brazed h

Introduction to all stainless steel brazed heat exchanger

market background

in the late 1970s, Alfa Laval invented the copper brazed plate heat exchanger, which brought a revolution to the design concept of HVAC and refrigeration. After that, the copper brazed plate heat exchanger became popular and quickly occupied the territory of many traditional heat exchangers with its high efficiency, compactness and sealing. But on the road of expansion, it also encountered some gaps. For example, in many fields where heat exchangers are used, copper cannot be used, so it is also a forbidden area for the use of copper brazed plate heat exchangers

as an alternative, nickel brazed plate heat exchanger was born. However, because the affinity between nickel and stainless steel is far less than that of copper, the pressure of nickel brazed plate heat exchanger is low, and its service life is short under high pressure or temperature fluctuation, which restricts its application. Moreover, nickel brazing is difficult to process and the cost remains high, which has never become the mainstream. The existing laser welded plate heat exchanger has good performance (especially the excellent frost resistance of Alfa Laval's laser semi welded heat exchanger). However, under the condition of small load, it feels that it is overqualified and underused

manufacturing process

the all stainless steel plate heat exchanger with highly reliable performance (hereinafter referred to as alfanova) is based on a new fusion welding technology - alfafusion, which has been applied in its production and manufacturing process. Alfafusion fusion welding technology is the crystallization of years of research in the field of materials and welding technology. These efforts are to meet the market demand for compact heat exchange solutions - higher mechanical strength, stronger corrosion resistance and higher hygiene level

AlfaFusio3. The material changes the resolution and dynamic performance (bandwidth) of the experimental machine and selects n process

product performance

after years of research and test, the result is that the reliability of alfanova has passed the verification, including Alfa fusion process certification, burst inspection certification, pressure fatigue test, temperature fatigue test, heat transfer performance test and corrosion test

1. Mechanical strength

the improved mechanical strength means that compared with the traditional brazed heat exchanger, alfanova has higher design pressure and stronger mechanical and thermal fatigue resistance (for example, in the 0 ~ 3Mpa mechanical fatigue test, alfanova's life is 10 times that of copper brazed heat exchanger and 2 orders of magnitude higher than that of nickel brazed heat exchanger!), Alfanova can withstand temperatures up to 550 ℃

2. Corrosion resistance

alfanova's 100% stainless steel structure can ensure its high resistance to corrosion. Thus, alfanova is a major technological breakthrough for refrigeration systems (such as evaporators, economizers, oil coolers, etc.) that need to use natural working fluids such as ammonia, or other media systems that are corrosive to copper

3. Compact design

compared with the traditional shell and tube heat exchanger, alfanova has a very compact structure. Such a compact structure makes it highly flexible. In any application system, people can incorporate it into their own equipment and give full play to the overall efficiency

alfanova's unique channel can ensure the best distribution of fluid. The specially designed corrugated plate can provide the best heat exchange effect and only need less charge, which is of great significance for refrigerants such as ammonia. For example, according to en378 standard, when the direct system is installed in the plant with trained personnel, the allowable NH3 filling amount shall not exceed 10kg at most. If alfanova is used, the refrigerating capacity can reach 340kw

alfanova's cost performance is unparalleled. In fact, alfanova equipment has enough strength to replace other large and bulky heat exchangers in a variety of practical applications

4. Higher hygiene level

in many countries, the hygienic indicators of some heat exchangers are becoming an increasingly stringent legislative theme. 1. Pointer tensile testing machine: this kind of traditional tensile testing machine has low test accuracy. This kind of application includes clean water cooler in refrigeration system, tap water heating system, and a long list of other sanitary applications. For such practical applications, alfanova made of all stainless steel, combined with its excellent mechanical strength, will undoubtedly become the winner in the future when challenging shell and tube heat exchangers and other types of heat exchangers

5. Tightness

although the rubber seal of semi welded plate heat exchanger has been reduced by more than 90% by laser welding, and ammonia is not easy to leak, from the microscopic point of view, the only two ammonia sealing rings are rubber products, and ammonia will penetrate outward through molecular movement

Application

1. Application of ammonia refrigeration system

in refrigeration system, brazed heat exchanger is widely used. However, most of them were used in Freon system before, because there is no suitable brazed heat exchanger for ammonia system. Nowadays, people pay more and more attention to environmental protection, and many synthetic media have been or will be eliminated. Since the natural medium does not destroy the natural balance, ammonia begins to regain its luster. Alfanova can show its talents. Evaporator, condenser, oil cooler and economizer can all be used. Because of its compactness, it promotes the standardization and modularization of the unit

1) evaporator: in the past, the filling capacity of industrial cooling equipment of gravity liquid supply full liquid evaporation system was up to 1000g NH3/kW, but if plate heat exchanger was used, the filling capacity could be reduced to 29g NH3/kW

in the relatively small load system, the direct expansion system is undoubtedly a better choice in terms of refrigerant charge. In this case, in addition to adding a distributor to ensure the uniform distribution of two-phase ammonia between each flow channel, suction-x system is more innovative. In the past, in DX system, part of the evaporator was usually superheated area to ensure safety, but it caused waste. After adding suction-x system, all plates are used for evaporation, which improves the COP value

alfanova for DX system

2) condenser: if in areas with water shortage, air-cooled system can be connected in series to make the condensate circulate in a closed circuit; If there are water sources (such as river water, lake water, groundwater and even seawater), an ordinary gasket plate heat exchanger can be connected in series, just like the boiler water system which is very common in the heating system of buildings. In this way, even the worst water quality can be solved

2. Other applications

alfanova is also an ideal solution for high-temperature gas applications and other high-temperature operations, absorption systems, industrial cooling, and a wide range of industrial heating and cooling operations. (E has a large number of new customers in the western region through this platform nd)