  Tidal disruption events (TDEs) may occur in supermassive black holes (SMBHs)
surrounded by clouds. TDEs can generate ultrafast and large opening-angle
outflow with a velocity of $\sim$ 0.01--0.2 c, which will collide with clouds
with time lags depending on outflow velocity and cloud distances. Since the
fraction of the outflow energy transferred into cloud's radiation is
anti-correlated with the cloud density, high density clouds was thought to be
inefficient in generating radiation. In this work, we studied the radiation
from the outflow-cloud interactions for high density clouds, and found that
thermal conduction plays crucial roles in increasing the cloud's radiation. Up
to 10\% of the bow shock energy can be transferred into clouds and gives rise
to X-ray emission with equivalent temperature of $10^{5-6}$ Kelvins due to the
cooling catastrophe. The inverse Compton scattering of TDE UV/optical photons
by relativistic electrons at bow shock generates power-law X-ray spectra with
photon indices $\Gamma\sim 2-3$. This mechanism may account for some TDE
candidates with delayed X-ray emission, and can be examined by delayed radio
and gamma-ray emissions.
