Fluid Parameters:
Flow Rate, Initial and Final Temperatures, and Specific Heat Capacity: These parameters determine the required heat exchange area. A preliminary estimate needs to be made based on the specific conditions of the cold and hot fluids, and an assumed heat transfer coefficient should be used to determine the heat exchanger structure.
Pressure Rating and Operating Temperature:
Pressure Rating: A suitable heat exchanger must be selected based on the pressure requirements of the working system.
Operating Temperature: Ensure the heat exchanger material can withstand the operating temperature of the fluid.
Heat Exchanger Structure:
Diameter and Length: Within the limits of pressure drop and installation conditions, select a smaller diameter but longer heat exchanger to improve efficiency.
Pressure Drop and Flow Rate:
Pressure Drop: The operating pressure drop of the heat exchanger should be strictly controlled between 0.01 and 0.05 MPa to ensure stable operation.
Flow Rate: Select an appropriate flow rate based on the fluid viscosity. For fluids with high viscosity, the flow rate should be maintained below 0.5 to 1.0 m/s; for fluids prone to scaling, the flow rate should be between 0.8 and 1.2 m/s to prevent clogging.
Equipment Cleaning and Maintenance:
Filters: High-temperature water typically requires a filter before entering the heat exchanger to remove impurities that may affect heat exchange efficiency.
System Configuration:
Single vs. Multiple Unit Configuration: The processing capacity of a single heat exchanger should meet part or all of the heating load demand of the heat exchange station. In the design, it is recommended to install at least 2 heat exchangers but no more than 5 to maintain system flexibility and reliability.