Why there are two pumps on each side?
There are 2 pumps on each side and I don't know de diference between this case and if there is only one pump on the left side with variable speed. Are they hydraulic or heat pumps?
I also don't know the difference between pumps with variable speed and pumps with constant speed.
@raquel.collado it looks like your image didn't attach correctly. You should have enough karma points now to try again.
Also, what simulation tool are you using? Please mention it in the title or body of your post, as well as add a tag so that others can provide better help.