Hi Chucheep Cahipoon,
no, you are mistaken. The only difference between a linear sRGB/Rec.709 EXR file and an ACES EXR (2065-1 or ACEScg) file is how it must be interpreted do be able to display it correctly. Both files just store RGB pixel- and metadata. I was sharing an article about that topic here on ACESCentral.
The view transform then makes the difference in the look of the images at the end. As you are using Nuke just open two instances and set one to Nuke-Default and the other to OCIO with a view transform set to ACES(sRGB).
I find it helpful to start playing around with a simple ramp like I was doing this here on my website and the previous page.
it might be helpful to read some more background information that you can find on the website from Chris Brejon.
Best
Daniel