According to the relevant requirements of GB/T 151 and JB/T 4756, the thermal calculation of finned tube heat exchangers requires four prerequisite data: medium composition, flow rate, inlet and outlet temperatures, and allowable pressure drop. If any one of these is missing during the design and selection stage, the deviation between the calculation results and actual operation may exceed the allowable range, resulting in insufficient heat exchange area or excessive pressure drop.
When the medium composition is not clearly defined, the corrosive components and their content must be confirmed to determine the tube and fin materials; flow rate data should distinguish between normal and maximum operating conditions for checking flow velocity and heat transfer coefficient; inlet and outlet temperatures determine the logarithmic mean temperature difference and directly affect the heat exchange area; the allowable pressure drop constrains the fin spacing and tube pass arrangement. Once the above parameters are complete, structural selection can be completed in combination with on-site space and nozzle orientation.
The GCH-72 model is suitable for waste heat recovery, process gas cooling, and air heating or cooling in HVAC systems. Under operating conditions with lower flue gas temperature and better medium cleanliness, a higher fin density can be used to reduce equipment volume; when the medium contains dust or is prone to scaling, the fin spacing should be appropriately increased and maintenance space reserved.
During the commissioning stage, after adjusting the temperature knob to the required value, observe whether the signal lamp displays normally; if an abnormality is found, first record the operating parameters, then arrange a shutdown inspection to avoid expanding the scope of damage by running with a fault. Regularly check fin dust accumulation and tube bundle corrosion, and adjust the maintenance cycle according to actual operating data.
