  We construct the QCD equation of state at finite chemical potentials
including net baryon, electric charge, and strangeness based on the results of
lattice QCD simulations and the hadron resonance gas model. The situation of
strangeness neutrality and a fixed charge-to-baryon ratio, which resembles that
of heavy nuclei, is considered for the application to relativistic heavy-ion
collisions. This increases the values of baryon chemical potential compared to
the case of vanishing strangeness and electric charge chemical potentials,
modifying the fireball trajectory in the phase diagram. We perform viscous
hydrodynamic simulations and demonstrate the importance of multiple chemical
potentials for identified particle production in heavy-ion collisions at the
RHIC and SPS beam energy scan energies.
