The EDR and HTRI calculation results differ greatly; I don’t understand it~
Thread Content
Design conditions: mass flow rate of 35 t/h, temperature reduction from 95°C to 65°C, ambient temperature of 33°C; horizontal air coolers are used for cooling； Verification calculations were carried out using both EDR and HTRI. With the same air cooler configuration, the difference between the two methods was as much as 60%. The difference lay in the effective logarithmic heat transfer temperature difference: it was 22.88°C for EDR, with a heat transfer coefficient of 562.8 W/(m2·K), whereas for HTRI it was 33.4°C, with a heat transfer coefficient of 701.4 W/(m2·K). The difference is so large; I went through the data again, and input errors can probably be ruled out. I have worked on many projects, most of which were designed using EDR. From previous comparisons, the values calculated by EDR tend to be more conservative compared to HTRI; generally, they are 5-15% higher than those of HTRI ； I think all of these are reasonable, but the difference is too large. Please, experts, analyze it for me~
I can’t upload the calculation file; please send a PDF version
I’ve said it many times, more than 10 times. EDR is unreliable, which is recognized in engineering practice. However, since running training courses is profitable, it is much easier to make money by offering EDR training courses, especially with universities rushing to offer such courses for profit. That software that allows one to charge for training courses is “good”.
Moreover, EDR often yields large errors and completely distorted results when calculating heat exchangers with phase changes.
This post was last edited by wiseboy on 2019-1-12 at 17:50. It’s simply that students and teachers are using EDR; whether it’s right or wrong doesn’t matter. Engineers should use EDR cautiously.
Why do I say that? I have been using EDR all along, and only using HTRI for verification. It still seems that the Aspench results are reliable
This post was last edited by wiseboy on 2019-1-13 at 14:48. To reiterate: engineers should use EDR with caution, as practice and engineering mistakes have proven this. Especially in cases of phase changes, such as in multi-component fractional condensers, the probability of EDR errors is extremely high.
Send over the calculation files; I already noticed something seems off in the calculation sheet, but it’s better if you still send the calculation files.
Sending files of this type is prohibited. Otherwise, I’ll try compressing them; something isn’t right with that part. Please help me point it out
Contains EDR calculation files and HTRI calculation files
You know a lot about this industry; I’m not aware of these things. I usually use it to calculate air-cooler equipment. Based on past comparative designs, air coolers designed using the EDR method are approximately 10% larger than those designed using the HTRI method. I can’t say anything else, but when it comes to air-cooler equipment, the designs developed by EDR tend to be conservative; in such situations, I usually opt for a larger size rather than a smaller one. Based on past bidding experiences, the equipment is basically the same, with differences only in motor power. Please help me figure out what’s wrong with these two calculation results of mine. Thank you for your support