High-temperature air flows in the tube side, while water flows in the shell side. Is the convective heat transfer coefficient on the tube side around 50?
Thread Content
High-temperature air flows in the tube side, while water flows in the shell side. Is the convective heat transfer coefficient on the tube side around 50?
Textbooks on chemical engineering principles will indicate the general range
50 is possible, and 10 is also possible. Calculate each specific problem individually; guessing like this is meaningless and pointless. “It is a definite conclusion that “lookup tables, recommendations, and experience values” are all shoddy in quality.
The K value of a heat exchanger depends on: type of fluid (2 factors), fluid flow rate (2 factors), temperature (4 factors), shell diameter, heat exchange tube diameter, spacing between heat exchange tubes, arrangement pattern of the tubes, presence of baffles, spacing between baffles, size of gaps in the baffles, material of the heat exchange tubes, number of tube passes...... Therefore, there are hardly any empirical values that can correspond to your specific conditions! ! ! Any experience value is unreliable, unless it matches exactly the situations listed above!
Natural air convection: 5-25 W/m2·°C. Forced convection: 20-100 W/m2·°C. Natural convection refers to the natural movement of air driven by the principles of airflow (hot air rising, cold air falling, natural winds, etc.). So-called forced convection refers to the use of fans, heating (or cooling) equipment, and specially designed air ducts (or pipes) to move air within a specific environment. Forced convection generally involves some element of human intervention. Generally speaking, natural convection places very low demands on the equipment and is the most basic form of convection; in some special situations, such as in enclosed environments, forced convection is often required to enhance air flow.