I was just trying to simulate a system that has large amount of solvent molecules.
However, as you know, explicit solvent particles are compute-consuming,
My question is does lammps offer any ways to calculate implicit solvent effects.
If you mean do a simulation with implicit solvent,
then see the pair_style lj/charmm/coul/charmm/implicit
command. Several other pair styles can also be
used in implicit mode (just don't put solvent molecules
in your model), assuming you parameterize them
correctly. E.g. use a coarse-grain model. See the
USER-CG-CMM package for example.