US 12,460,974 B2
Method for ascertaining the temperature of a substance to be measured, and measuring system for this purpose
Mattia Alioli, Binningen (CH); Vivek Kumar, Allschwil (CH); Alfred Rieder, Landshut (DE); and Gerhard Eckert, Grenzach-Wyhlen (DE)
Assigned to Endress+Hauser Flowtec AG, Reinach (CH)
Appl. No. 18/006,437
Filed by Endress+Hauser Flowtec AG, Reinach (CH)
PCT Filed Jun. 21, 2021, PCT No. PCT/EP2021/066756
§ 371(c)(1), (2) Date Jan. 23, 2023,
PCT Pub. No. WO2022/022890, PCT Pub. Date Feb. 3, 2022.
Claims priority of application No. 10 2020 120 054.4 (DE), filed on Jul. 29, 2020.
Prior Publication US 2023/0349771 A1, Nov. 2, 2023
Int. Cl. G01K 1/143 (2021.01); G01F 1/34 (2006.01); G01F 1/84 (2006.01); G01K 13/02 (2021.01)
CPC G01K 1/143 (2013.01) [G01F 1/34 (2013.01); G01F 1/8427 (2013.01); G01K 13/02 (2013.01)] 37 Claims
OG exemplary drawing
 
1. A method for determining a temperature of a medium conducted in a line, wherein the line includes a lumen enclosed by a wall, the method comprising:
flowing the medium through the line in a predetermined flow direction;
measuring a wall temperature value (XTW) representing a temperature of the wall;
determining a density value (Xρ) representing a density of the medium flowing in the line;
determining a viscosity value (Xμ) representing a viscosity of the medium flowing in the line;
determining a thermal conductivity value (Xλ) representing a thermal conductivity of the medium;
determining a heat capacity value (Xcp) representing a specific heat capacity of the medium;
determining a pressure differential value (XΔp) representing a pressure differential established in the medium flowing in the line in the flow direction, wherein the pressure differential is between a first static pressure in the flowing medium and a second static pressure in the flowing medium established downstream of the first static pressure;
calculating a characteristic number value (XV) for a medium characteristic number (V) that characterizes heating of the medium flowing in the line caused by dissipation using the density value, the viscosity value, the pressure differential value, the thermal conductivity value and the heat capacity value, wherein the medium characteristic number is defined by an Eckert number (Ec) of the medium flowing in the line, a Prandtl number (Pr) of the medium flowing in the line, a pressure loss coefficient (ζ) of the line, a line-specific first exponent (a), a line-specific second exponent (b), and a line-specific third exponent (c), as:
V=f(Δp,ρ,μ,λ,cp)=Pra·Ecb·ζc; and
determining a medium temperature value (XTM) representing the temperature of the medium using the characteristic number value and the wall temperature value such that the medium temperature value satisfies a calculation rule.