Aspen HX-NET heat exchange network design
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I used ASpen HX-NET to design the heat exchange network. There are two pinch points, and matching them is a bit complicated. I have tried several options. In the process of determining which one is better, there are several indicators that I am not particularly clear about. For example, what is the concept of cost index, and what does the brackets of Total Cost (cost/s) mean? In addition, I found that the flow streams matched in HX-NET can exchange heat to a certain temperature, but when I used ASpen plus to simulate the calculation, it was wrong. The discrepancy was still a bit large. I don’t know why. Which one is more accurate? Also, some of the heat exchange area data obtained there are only about 10 square meters, and some are almost thousands of square meters. I wonder whether those area data are highly referable. Looking forward to your advice, thank you!
What do the brackets in Total Cost (cost/s) mean? answer: How much does it cost per second? . . . It seems that I have encountered the same problem. The data is wrong.
I think it's a ratio, but I don't know what it is.
Is Total Cost (cost/s) the rate of heat loss? It seems that the key is to understand the specific meaning of this cost. What is the concept of cost index? Unfortunately, I don’t know! I look forward to experts and learn by the way.*
Cost should be operating costs, operating costs, capital (fixed costs), and cost/s should be operating costs per unit time. I don’t know if my understanding is correct. I hope it is useful to you.
Oh, okay, thank you very much for your answer.
If you have any questions, you can discuss them. Goodbye.
HX-NET and Aspen Plus are not software specifically designed to calculate heat exchangers. They calculate the inlet and outlet temperatures of the heat exchanger, which mainly depends on the stream specific heat, temperature difference, and flow rate input by the user, and is obtained by conversion. I don’t know how big the difference is in the temperature of your process. I think it may be due to the different conditions you gave, otherwise it won’t be very big.
cost/s is the unit of cost index per time, s is seconds
5# Knowledge Hunter answered it right, cost index per time, s is seconds. hehe