The steam heat exchanger is now in operation
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What are the principles to follow when putting a steam heat exchanger into operation? What is the difference between introducing the hot medium first and then the cold medium, and introducing the cold medium first and then the hot medium?
Regarding the startup sequence of the heat exchanger system, the cooler should be fed with the cold medium first, and the same applies to the heat exchanger; this is because introducing the hot medium first will cause rapid thermal expansion of the various components, while introducing the cold medium later will cause rapid contraction of those same components. This temperature difference stress causes leakage at the seal points. Therefore, hot media is not allowed to be introduced at the start of operation. Conversely, when shutting down, the heat medium should be stopped first, followed by the cold medium.
For advanced cold media, remember to open the steam valve slowly when introducing steam to prevent water hammer.