Plate heat exchanger is an efficient, compact heat transfer equipment, 1880s, first as a continuous successful development of low-temperature sterilization, to the beginning of the last century, 20 years **** used in the food industry. Since the plate heat exchanger in the manufacture and use has some unique features. Therefore, the current plate heat exchangers are widely used in petroleum, chemical industry, light industry, electric power, metallurgy, machinery, energy, heat exchangers family became very competitive varieties. Our country is from the beginning of the last century, 60 years of production **** plate heat exchangers, plate heat exchanger has many areas in our country have been widely used.
In the refrigeration technique, the heat exchanger of the refrigeration equipment is indispensable, a condenser, an evaporator, the heat recovery unit and the intercooler heat exchange equipment, etc., not only in terms of weight, volume, and accounted for 50% of the total metal consumption of the refrigerating apparatus or more, and the cooling performance will have a significant impact. Therefore, strengthening the refrigeration heat exchanger to reduce the weight and volume, reduce metal consumption in refrigeration technology has been the development direction, now there is a new, all-welded plate heat exchangers in refrigeration technology in applications, and exhibit strong growth potential. Compared with the refrigeration shell and tube heat exchanger, in addition to the general characteristics of plate heat exchangers, plate heat exchanger cooling also has the following characteristics. Refrigerant small amount, in favor of environmental protection and reduce the volume of the shell side and tube side of the running costs of shell and tube heat exchangers are large, to make the cooling system to work properly, the refrigerant must be filling a lot, but also may cause environmental pollution. The small plate heat exchanger on the one hand, on the other hand pitch size is also small. Less tendency to freeze, frost resistance due to high water at low flow rates can be a highly turbulent flow in the plate heat exchanger, the temperature distribution is very uniform, thereby reducing the tendency to freeze chilled water. Even if a freeze occurs, and better able to withstand the pressure generated by the freeze, rather than shell and tube heat exchanger pipe bursting as easy to make, and can continue to be used after freezing. Completely evaporated, the refrigerant at high economic evaporated refrigerant in the plate heat exchanger, it is not easy to achieve complete evaporation of the liquid to reach the degree, so in most cases, the cooling system gas-liquid separator need not be provided. And easily achieve a unit, easy to install, maintain and transport can save costs and reduce costs.
As compared with the conventional shell and tube heat exchangers, plate heat exchanger cooling has a very significant development advantages, since the beginning of the last century, 70 years **** been applied in the refrigeration unit, has been increasing attention has been paid , especially in many developed countries, such as Europe, America, Australia and so very great importance to the cooling plate heat exchanger research and applications. In the beginning of the last century, 80 years of research **** cooling plate heat exchanger and used in refrigeration equipment, and good economic benefits, some of the world famous companies such as refrigeration York, Carrier, Hitachi, also have the the refrigerating apparatus used in a plate heat exchanger. After entering the 1990s, the cooling plate heat exchanger has been further developed, used in ammonia refrigeration systems capable of plate heat exchangers in Sweden Stael company successfully developed. This new modular plate heat exchanger plate and frame combines style and brazing characteristics. Compared with freon refrigeration system, using this plate heat exchanger ammonia refrigeration system is not only on the unit material volume weight has obvious advantages, but also higher coefficient of performance 10% to 20%. Currently, this system has been formed the eight products, cooling capacity from 10kw ~ 1000kw. ammonia successful development of plate heat exchangers, plate heat exchangers not only broadens the range of applications in refrigeration technology, but also for the protection of atmospheric ozone, protecting the environment has important significance, but also will promote the further development of refrigeration technology. China since the early 1960s began to produce plate heat exchanger, to 1994, with energy-saving products targeted manufacturers of plate heat exchanger, which amounts to 15, and some manufacturers also studied plate evaporator and heat transfer characteristics work, however, is limited to the production of these manufacturers plate and frame heat exchanger (DHE).
In China, the cooling plate heat exchanger applications is still in its infancy, before many refrigeration manufacturers have their products used in refrigeration plate heat exchanger, and its products are widely favored by the users. It can be expected that with the use of plate heat exchangers for refrigeration knowledge and understanding, plate heat exchanger with high efficiency, compact, energy-saving materials and environmentally friendly features, etc., will more and more widely used in refrigeration devices. Plate heat exchanger is a compact and efficient heat transfer equipment, its use in almost all industrial sectors, and its type, structure and scope are still evolving. In recent years, welded plate heat exchanger is compact, light weight, good cooling performance, low operating cost advantages have been increasingly recognized. As China's economic development, the development of future refrigeration technology ambitious, especially various large industrial refrigeration equipment and air-conditioning refrigeration unit rapid development, which for a variety of refrigeration applications with plate heat exchanger provides a broad market.
