  We study a system composed of two quantum dots connected in series between
two leads at different temperatures, in the limit of large intratomic
repulsion. Using the non-crossing approximation, we calculate the spectral
densities at both dots $\rho_i(\omega)$, the thermal and thermoelectric
responses, thermopower and figure of merit in different regimes. The
interatomic repulsionleads to finite heat transport even if the hopping between
the dots $t=0$. The thermopower can be very large compared to single-dot
systems in several regimes. The changes in sign of the thermoelectric current
can be understood from the position and magnitude of the Kondo and
charge-transfer peaks in $\rho_i(\omega)$. The figure of merit can reach values
near 0.7. The violation of the Wiedemann-Franz law is much more significant
than in previously studied nanoscopic systems. An analysis of the widths of
$\rho_i(\omega)$ indicates that the dots are at effective temperatures $T_i$
intermediate between those of the two leads, which tend to be the same for
large $T$.
