INCREASING THE SPEED OF MEASUREMENT OF NON-STATIONARY HEAT FLUX IN TIME. Russian patent published in 2023 - IPC G01K17/08 

FIELD: measuring technology.

SUBSTANCE: invention relates to measuring technology, to the field of thermometry when measuring non-stationary heat flux through the surface. The proposed method for measuring non-stationary heat flow can be used in the study of heat transfer, for measuring heat transfer from surfaces, in the manufacture of metal heat-insulating screens, in the development and optimization of cooling systems for radio-electronic equipment, for measuring heat flow leakage through enclosing surfaces in construction, metallurgy and energy. A method for determining a non-stationary heat flux is proposed, which includes measuring the difference in the temperature change of the directed heat flux on the surface of the heat meter and in its cross sections. The electrodes are preliminarily placed on the receiving surface of the heat meter, which is a thin electrically conductive plate located in the path of the heat flow. By passing electric current through the electrodes at frequencies ω₁ and ω₂ (ω₁ > ω₂) in the near-surface layer and in the volume of the heat meter, electric skin layers are formed, respectively, with a thickness of δ₁ and δ₂ (δ₁ < δ ₂), significantly smaller thicknesses h of the heat meter. The impedances Z₁[j ω₁, T₁(δ₁,t)] and Z₂[j ω₂, T₂(δ₂,t)] of the skin layers are measured at the corresponding frequencies on the receiving side of the heat meter and in its volume, by which the electrical resistances R₁[ω₁, T₁(δ₁,t)] and R₂[ω₂, T₂(δ₂,t)] of the skin layers, taking into account the preliminary calibration of the temperature dependence of the resistances R₁= f(ω₁, T₁(δ₁)) and R₂= f(ω₂,T2(δ₂)) of the heat meter. At given frequencies ω₁ and ω₂ (ω₁ > ω₂) for a specific material of the heat meter, and according to the electrical resistances R₁[ω₁,T₁(δ₁,t)] and R₂[ω₂,T₂(δ₂,t)] of heat meter skin layers determine the values of non-stationary temperatures T₁(δ₁,t) and T₂(δ₂,t), corresponding to thicknesses δ₁ and δ₂, and determine the non-stationary heat flux q(t) as the ratio of the temperature difference ΔT=T₁(δ₁,t)-T₂(δ₂,t) to the difference in skin layer thicknesses Δδ=δ₂-δ₁ according to the formula:

,

where is the coefficient of proportionality determined in the process of initial calibration of the heat meter.

EFFECT: improving the accuracy of determining the non-stationary heat flux.

1 cl, 2 dwg