Double Circuit Evaporator Shell Tube Heat Exchanger With R134a Refrigerant

Double Circuit Evaporator Shell and Tube

Heat Exchanger for Central Air Conditioning

 
Due to the internal and external fluid temperature is different, so the heat  exchanger shell and tube
 
bundle temperature is also different. If the temperature difference between the two, the heat exchanger
 
will produce a lot of thermal stress, resulting in pipe bending, fracture, or from the tube board pull.
 
Therefore, when the tube and the shell temperature difference exceeds 50 ℃, the need to take
 
appropriate compensation measures to eliminate or reduce thermal stress. According to
 
the compensation measures adopted, shell and tube heat exchanger can be divided into the following
 
main types:
 
① fixed tube plate heat exchanger tube at both ends of the tube plate and the shell into one, simple
 
structure, but only for hot and cold fluid temperature difference is not, and the shell does not need
 
mechanical cleaning when the heat transfer operation. When the temperature difference is slightly larger
 
and the shell pressure is not too high, the elastic compensation ring can be installed on the housing to
 
reduce the thermal stress.
 
(2) The tube sheet at the end of the tube bundle of the floating head heat exchanger can float freely and
 
completely eliminate the thermal stress; and the whole tube bundle can be extracted from the casing for
 
easy mechanical cleaning and maintenance. Floating head heat exchanger is widely used, but the
 
structure is more complex, higher cost.
 
③ U-tube heat exchanger each tube are bent into U-shaped, both ends were fixed in the same tube board
 
upper and lower areas, with the help of the box within the partition into the import and export of two rooms.
 
This heat exchanger completely eliminates thermal stress, the structure is simpler than the floating head,
 
but the pipe is not easy to clean.
 
④ eddy current hot film heat exchanger vortex hot film heat exchanger using the latest vortex heat film
 
heat transfer technology, by changing the fluid movement state to increase the heat transfer effect, when
 
the media through the vortex tube surface, the strong erosion of the pipe surface, Thermal efficiency. Up
 
to 10000W / m2 ℃. At the same time this structure to achieve a corrosion-resistant, high temperature,
 
high pressure, anti-fouling function. Other types of heat exchanger fluid channel for the fixed direction of
 
the flow form, the formation of heat transfer tube surface flow, convective heat transfer coefficient
 
decreases.