Question About the Sign of the Energy Source Term Using the Schrage Model

[srzhang90s]

Dear developers,
Thank you for sharing this fantastic framework. However, I have a question regarding the Schrage model that I haven't been able to understand. When the source terms for both TL and TV in the energy equation are placed on the left side of the equation,

    fvScalarMatrix TLEqn
    (
        fvm::ddt(rhoCpL,TL)
        + fvm::div(rhoCpLPhi,TL)
	    - fvm::Sp(fvc::ddt(rhoCpL) + fvc::div(rhoCpLPhi), TL)
        - fvm::laplacian(kappaLEff,TL)
        + phaseChange.TSource1()
            ==
        fvOptions(rhoCpL, TL)
    );  
    // energy equation
    fvScalarMatrix TVEqn
    (
        fvm::ddt(rhoCpV,TV)
        + fvm::div(rhoCpVPhi,TV)
	    - fvm::Sp(fvc::ddt(rhoCpV) + fvc::div(rhoCpVPhi), TV)
        - fvm::laplacian(kappaVEff,TV)
        - dpdt*alpha2
        + phaseChange.TSource2()
            ==
        fvOptions(rhoCpV, TV)
    );

shouldn't the expression of the source term have the opposite sign? Or does the applicability of the Schrage model to two temperature fields really meet its physical meaning?
tmp<fvScalarMatrix> T1Source(fvm::Sp(TSource,T1) - TSource*TSat);
tmp<fvScalarMatrix> T2Source(fvm::Sp(TSource,T2) - TSource*TSat);

Could you please help me understand it at your earliest convenience? Thank you!

Best regards,
Shawn