  Despite tremendous investigations, a quantum spin liquid state realized in
spin-1/2 kagome Heisenberg antiferromagnet remains largely elusive. In
herbertsmithite ZnCu$_3$(OH)$_6$Cl$_2$, a quantum spin liquid candidate on the
perfect kagome lattice, precisely characterizing the intrinsic physics of the
kagome layers is extremely challenging due to the presence of interlayer Cu/Zn
antisite disorder within its crystal structure. Here we measured the specific
heat and thermal conductivity of single crystal herbertsmithite in magnetic
fields with high resolution. Our results are highlighted by the excellent
scaling collapse of the intrinsic magnetic specific heat contribution arising
from the kagome layers as a function of $T/H$ (temperature/magnetic field). In
addition, no residual linear term in the thermal conductivity
$\kappa/T(T\rightarrow 0)$ is observed in zero and applied magnetic fields,
indicating the absence of itinerant gapless excitations. These results suggest
a new picture for a quantum spin liquid state of the kagome layers of
herbertsmithite, wherein localized orphan spins arise and interact with random
exchanges in conjunction with a non-itinerant quantum spin liquid.
