Patent ID: 11879786
Assignee: SHANDONG UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A heat flux sensor, comprising:
a ceramic heat sink;
a sensitive element fixed to the ceramic heat sink through a thermally conductive and electrically insulative adhesive, the sensitive element being made of a single-crystal material with high thermal conductivity and high electrical conductivity, and the single-crystal material having a resistivity of less than or equal to 0.02 Ω·cm at room temperature and a thermal conductivity of larger than or equal to 270 Wm−1K−1 at room temperature, there being an included angle θ between c axis and normal of the single-crystal material, where 0.1°<θ<45°;
a heat absorption layer arranged on an upper surface of the sensitive element; and
metal electrodes, comprising:
a first metal electrode and a second metal electrode, which are arranged on the upper surface of the sensitive element, the first metal electrode and the second metal electrode being arranged at two ends of the heat absorption layer, a voltage signal between the first metal electrode and the second metal element being a transverse voltage Ux, and an approximate expression of the transverse voltage Ux is expressed as: Ux=l*(Sab−Sc)*∇Tz*sin(2θ)/2, where Sab is a thermoelectric coefficient in an ab plane of the single-crystal material, Se is a thermoelectric coefficient along a c-axis direction of the single-crystal material, ∇Tz is a temperature gradient in a thickness direction, that is, a z-axis direction, of the single-crystal material and/is a distance between the first metal electrode and the second metal electrode;
a third metal electrode arranged on the upper surface of the sensitive element and a fourth metal electrode arranged on a lower surface of the sensitive element, the third metal electrode and the fourth metal electrode being arranged opposite to each other, a voltage signal between the third metal electrode and the fourth metal electrode being a longitudinal voltage Uz, and an approximate expression of the longitudinal voltage Uz is expressed as: ∪z=(Sab sin2(θ)+Sccon2(θ))*Δ Tz, where Δ Tz is a temperature difference between an upper surface and an lower surface in the thickness direction of the single-crystal material; the third metal electrode being spaced apart from the first metal electrode, and the third metal electrode and the second metal electrode being fixed at two ends of the upper surface of the sensitive element; and
a fifth metal electrode arranged on an upper surface of the ceramic heat sink and bonded to the fourth metal electrode, the fourth metal electrode being larger than the third metal electrode in size.