When a finned tube heat exchanger is used for waste heat recovery or process cooling, the definition of the fin-side working conditions directly affects the heat exchange area and fan energy consumption. Taking a drying line waste heat recovery project as an example, the required air temperature difference between inlet and outlet is not less than 25°C, the ambient temperature is -20 to +60°C, and the relative humidity is less than 80%. Design and selection personnel need to first determine whether the fin-side medium is clean air, the dust content, and whether it contains corrosive components, and then determine the fin spacing and number of tube rows accordingly.
Purchasing personnel should provide four parameters: medium composition, flow rate, inlet and outlet temperatures, and allowable pressure drop, for the supplier to perform thermal calculations. If any one of these is missing, the heat exchange area and tube diameter selection may deviate from the actual operating conditions.
The GCSF-55 finned tube heat exchanger has a design air volume range of 2000 to 12000 m³/h on the fin side, a working pressure on the tube side not exceeding 1.6 MPa, and a design temperature range of -20 to +200°C. The fin material can be carbon steel, stainless steel, or copper according to the medium composition. Fin spacing is available in three specifications: 2.5 mm, 3.2 mm, and 4.0 mm, to adapt to airflow conditions with different dust contents. The tube-side connection specifications are DN25 to DN80, which can be selected according to the on-site piping configuration.
When the required air temperature difference between inlet and outlet is not less than 25°C, the corresponding relationship between the face velocity and the number of tube rows must be checked. If the air velocity is too high, the pressure drop will increase; if the air velocity is too low, the utilization rate of the heat exchange area will decrease. During the selection stage, the allowable pressure drop should be taken as one of the constraints and checked together with the temperature difference requirement.
Dust accumulation on the fin side will reduce heat exchange efficiency. Under dusty airflow conditions, it is recommended to install a filtration device and regularly clean the fin surface. If the flow rate on the tube side is insufficient, check the opening of the pipeline valves and the operating status of the pump unit to avoid a decrease in heat exchange capacity caused by low flow velocity. If the equipment operating ambient temperature exceeds the range of -20 to +60°C, it should be stated in advance so that corresponding adjustments can be made in material and structure.
Maintenance space should be reserved at the equipment installation location, and the fin surface should face the side that is easy to clean. When connecting pipelines, pay attention to keeping the inlet and outlet directions consistent with the design flow direction to avoid heat exchange performance deviation caused by reverse flow.
