When medium temperature fluctuates frequently during selection, how should seals be considered to avoid early failure? This is a common question encountered by design and selection personnel when determining the specifications of hot and cold heat exchangers.
Under operating conditions with frequent medium temperature fluctuations, the thermal expansion and contraction and aging rate of sealing materials will accelerate. It is recommended to select sealing materials with better matching resistance according to the temperature cycling range, and to confirm the rebound performance of the seals at the highest and lowest temperatures. For occasions with large fluctuation amplitudes, consider increasing the frequency of seal replacement inspections and reserving space for easy maintenance in the structural design.
Providing the medium name, inlet and outlet temperatures, flow rate, allowable pressure drop, and on-site space dimensions is the basis for determining the heat exchanger specifications. Missing parameters may cause the heat exchange area or interface dimensions to be inconsistent with the actual operating conditions, affecting operational stability.
Cast aluminum heat exchangers are suitable for medium- and low-temperature uniform heating applications such as plastic machinery, die heads, and water heaters, with relatively low cost; cast copper heat exchangers have better thermal conductivity and high mechanical strength, and are often used in chemical pipelines, alloy die-casting machines, and high-requirement molds. During daily maintenance, the cleanliness of the heat exchange surface and the sealing condition should be checked regularly to avoid reduced heat exchange efficiency due to fouling or seal aging.
During installation, ensure reliable interface connections to avoid seal loosening caused by vibration. During operation, pay attention to pressure drop changes, and promptly investigate blockage or scaling when the pressure drop rises significantly.
