heatFlux item in controdict of packedBed case

hello developer,
I am interested in the function item heatFlux in the controdict file in the folder - cfdemSolverPisoScalarCase_shared/packedBedTemp/CFD/system.
======================================================
libs ("libOpenFOAM.so""libgroovyBC.so""libsimpleFunctionObjects.so""libsimpleSwakFunctionObjects.so""libswakFunctionObjects.so");
functions
(

// simpleFunctionObjects
heatFlux
{
type patchHeatFlux;
functionObjectLibs
(
"libsimpleFunctionObjects.so"
);
verbose true;
patches
(
inlet
outlet
);
fields // name of temp field
(
T
);
cp 1007; // cp in [J/(kg*K)]
factor 1.188; // density for incomp solvers!
}

an error occurred when running the solver even through swak4Foam is installed in the system, it tells me that the "type patchHeatFlux" is not available in simpleFunctionObjects library.
I can't find any description related to this function in the topic of simpleFunctionObject on openfoamwiki forum.
perhaps it has the same function as the utility "wallHeatFlux" in OF?
could you give me some hints about this?
BTW: if I want to calculate the heat flux through the wall in the fluidized bed, the only modification is to add the patch name into "parthes" item?
Best Regards
S.L