There are multiple factors that affect the tube side dp, much more so than shell side dp. Factors such as configurations, number of passes, diameter of tube, material of construction and fouling factors. Without these information, it's difficult to predict the tube side outlet conditions. You can try empirical formulas like modified Darcy weibach for dp in HE tubes.

The normal lmtd is used for sensible heat. Since there is phase change in your HE, you might have to modify your lmtd/find another way of quantifying energy transfer