Forough, I tried it, but the deviation is considerable

What is the composition, operating conditions, the unit operations through which fluid goes and other related information? 

The composition varies, temperature and pressure varies throughout the plant, to give an estimate, the temperature won't go ever 200 C nor less than 30 C. The pressure is also limited to 2 to 20 bars. but the composition is very different.

EES provides a lot tabular data. If I could implement these data in Hysys the result would be much more reliable.

You can adjust the fluidpackage parameters so that it fits your data. I am sure that there is a solution for it in ASPEN. However, I am not sure about Hysys. I have not installed it on my PC right now. I should consult my colleagues about this.

For now, try NRTL or UNQUACK for liquid phase and RK or SRK for gas phase.  You can also adjust binary coefficients in binary tab of fluidpackage window. 

What was the result with my suggestions?

I consulted with my colleagues, they had the same experience with water/ammonia mixture and their industrial data were fitted well with Peng-Robbinson EOS. Also try this. 

If this does not fix the problem, you must use data fit option. It is not available in Hysys. However you can adjust the binary parameters of a fluid package in data fit tool of Aspen. This tool adjust binary parameters of fluid package based on the your experimental data (EES). Then you can insert adjusted parameters into Hysys and do you simulation. Give me an email address to send you a file that describes data fit in Aspen. 

Thanks Hamidreza

PR yet has worked best but I think more improvement is possible yet. [email protected]

Best Regards

PRSV should be able to handle your case or you could try any of the non ideal activity models such as uniquac or nrtl

Amine package is used for this kind of situation and in case you dont have licence for this LKP can be used. it predicts good properties except viscosty.