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Talking About The Safety Precautions Of Heat Exchanger Design
- Sep 11, 2017 -

Talking about the safety precautions of Heat Exchanger design
In the development process, pay attention to the safety of plate Heat Exchangers or now must be concerned about:
 1, design indicators. The design parameters of the Heat Exchanger include the type of working fluid and its flow, inlet and outlet temperature, working pressure and Heat Exchanger efficiency. Aerospace Heat Exchangers should also include permissible pressure drop, size and quality.
 2, the overall arrangement. The overall layout of the Heat Exchanger first selects the type and structure of the Heat Exchanger, the form of fluid flow and the material used, and then heats the type of heat transfer surface. To consider operating temperature and pressure.
 3, thermal design. Thermal design of the Heat Exchanger includes heat transfer calculation, flow resistance calculation and determination of size. In addition to technical performance indicators, but also need to have the characteristics of heat transfer (including heat transfer characteristics, flow resistance characteristics and structural parameters) and the fluid and material thermal properties of the parameters can be used to optimize the technology applied to the Heat Exchanger thermal design , According to the design goals, for the selected variety of Heat Exchanger form and heat transfer surface, through different angles to optimize the analysis, to provide several options.
 4, structural design. The mechanism design of the Heat Exchanger includes the following:
 (1) According to the maximum working temperature and maximum working pressure, as well as thermal design and resistance calculation results, determine the material and size of each part to ensure the performance of the heat transfer in stable operation.
 (2) According to the working temperature, pressure and fluid properties, choose welding methods and sealing materials.
 (3) To ensure the uniformity of fluid distribution as the goal, the head, header, take over and partition design.
 (4) to meet the thermal and resistance performance of the structural design, the main components to be strength check to avoid the extreme working conditions due to lack of strength, resulting in damage or selection of too thick and cause waste.
 (5) to consider maintenance (including cleaning, maintenance and maintenance, etc.) and transport requirements.
  For some Heat Exchangers operating under special conditions, some have to calculate the thermal stresses during start-up and stop periods, calculate structural vibrations due to fluid flow, or calculate flow rates in order to reduce corrosion and structure. In short, structural design and thermal design have the same importance, the design of Heat Exchangers need to take into account both, and should be coordinated with each other.
 5, design options. After the Heat Exchanger thermal design and structural design is completed, the structure is available for the option, and then the designer according to the evaluation criteria. Consider the specific conditions for the final choice. The choice of conditions for qualitative, such as mold manufacturing conditions, brazing furnace size, transport restrictions, delivery date, company policy and competitive strength will all affect the final choice. The evaluation criteria can be used to quantify the measured indicators such as weight, dimensions, pumped fluid consumption, initial investment and life expectancy
 Now Heat Exchangers have been used in all walks of life, and the effect is obvious, the so-called favorable and vulgar, Heat Exchangers are also shortcomings, such as Heat Exchangers are easy to scale, which is a common problem of Heat Exchangers. But also very troublesome, today to analyze the next, why the Heat Exchanger scaling, and scaling is how to deal with.
     First look at why the Heat Exchanger scaling, the reason is very simple, the first point, the Heat Exchanger equipment is running, where the environment is a big reason for the formation of scaling. For example, some Heat Exchangers installed in the workshop, the workshop dust, a long time to become a scale, there are Heat Exchangers installed in the water, a long time, suspended solids in the water is also easy to scale. The situation will produce scaling. Look at the common types of dirt it,
     1) Particulate soil: the accumulation of solid particles suspended in the heat on the surface of the Heat Exchanger. This dirt also includes the deposition of large precipitates of precipitated soils and other colloidal particles on the horizontal heat transfer surface due to the action of gravity.
     2) Crystalline fouling: The deposits formed by crystallization of the inorganic salts dissolved in the fluid on the surface of the Heat Exchanger usually occur during supersaturation or cooling. Typical fouling such as cooling water side of calcium carbonate, calcium sulfate and silica fouling layer.