Q: In scenarios where chloride-containing cooling water exchanges heat with process materials, why should the tube-side and shell-side medium characteristics be differentiated when selecting the GCH-150 shell-and-tube heat exchanger?
A: The media contacting the tube side and shell side of a shell-and-tube heat exchanger are different, and the corrosion risks also differ. If selection is based only on a unified choice of main material without separately assessing the medium characteristics of the tube side and shell side, galvanic corrosion cells are likely to form locally under chloride-containing conditions, causing pitting corrosion or stress corrosion. During the selection stage of the GCH-150, the chloride ion concentration, temperature, and flow velocity of the media on both sides should be separately identified, and the materials and corrosion allowances for the tube side and shell side should be determined accordingly, rather than covering all flow passages with a single material.
Q: How should design pressure, design temperature, and heat transfer area be matched with on-site operating conditions during selection?
A: Design pressure and design temperature should cover the highest possible operating parameters at the site and include a reasonable margin; the heat transfer area must be calculated based on heat duty, log mean temperature difference, and heat transfer coefficient, as insufficient area will cause the outlet temperature to deviate from the design value. Nozzle diameters should match the on-site piping system to avoid aggravated erosion from excessively high flow velocity. Allowable pressure drop is also a verification item; exceeding the permitted pressure drop range will affect system flow distribution.
Q: When designers compare different options, how should the order of parameter focus be arranged?
A: First verify design pressure and design temperature to confirm the equipment's pressure-bearing and temperature-resistant boundaries; then verify the tube-side and shell-side medium characteristics to clarify materials and corrosion allowances; subsequently calculate the heat transfer area and allowable pressure drop to validate heat transfer capability and system resistance; finally confirm the compatibility of nozzle diameters with on-site piping. This order helps prioritize the elimination of options that do not meet operating conditions during scheme comparison.
