Seeking advice on heat exchanger design and material selection
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I need help with the design of the heat exchanger’s structure and materials selection. Please refer to the process design parameters shown in the images. I would appreciate advice on how to proceed with the design, or if anyone else has experience designing heat exchangers for such extreme operating conditions , please share.
It’s not extreme; it’s common in places where liquid nitrogen is used. Is it to recover the cold energy? Choose aluminum or seamless stainless steel tubes.
I’m not sure I understand your process description correctly. Liquid nitrogen enters the water cooler, then the liquid nitrogen vaporizer, and is subsequently fed into the nitrogen pipeline? 1. At a pressure of 5–6 Mpa, liquid nitrogen is in a supercritical state; you need to consult a pressure-enthalpy diagram to understand the various properties and characteristics of this supercritical state ； 2. Heat exchange between liquid nitrogen and water is feasible, but attention must be paid to the flow rate of water to ensure that its kinetic energy parameters reach a certain value and remain stable ； The flow rate cannot be too slow, otherwise freezing is likely to occur ； 3. Here is a reference value for you: the overall heat transfer coefficient K for supercritical liquid nitrogen and water is approximately 165 W/㎡·K (this value is for reference only). For this, it’s necessary to clarify the parameters and calculate step by step; that’s the proper approach ； I hope this helps you.
I’ve learned it; this cold energy can still be recovered
Is a DN40 material outlet sufficient?
It is more reasonable to start with a dry bath before moving on to a wet bath
That’s right; the area of the vacuum vaporizer needs to be much larger, or one unit should be used while another serves as a backup!