Device for determination of thermal exchange coefficient and associated method
AssigneeCommissariat A L'energie Atomique Et Aux Energies Alternatives
InventorOlivier Braillard
Life of this patent
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Abstract
A device for determining the thermal exchange coefficient between a fluid and a wall at a point PN of a surface of the wall in contact with the fluid, including a measuring device (DT) which measures at least two temperature values TC1 and TC2 of the wall and a temperature value TF of the fluid, and a computer for calculating, from the temperature values TC1 and TC2, a temperature value Tp of the wall and a thermal flow Φ given by the following equation: Φ=−λgrad (TC1−TC2), where λ is the thermal conductivity of the wall, and for calculating, from the fluid temperature TF, the average temperature TP and the thermal flow φ the thermal exchange coefficient h in the following form: h=Φ/(TF−TP).
Claims10
A device for determining the thermal exchange coefficient between a fluid (F) and a wall (P) at a point PN of a surface of the wall (P) in contact with the fluid (F), characterized in that it includes:
- a temperature-measuring device (DT) which includes:
- two wall temperature sensors (D1, D2), with a first temperature sensor (D1) measuring a first temperature value TC1 of the wall at a point P1 and a second temperature sensor (D2) measuring a second temperature value TC2 of the wall at a point P2 which is roughly aligned with point P1 in a straight line normal to the surface at point PN, and where point P1 is the closer to the surface of the wall, and
- a fluid temperature sensor (DF) measuring a temperature value TF of the fluid at a point PF of the fluid roughly aligned with points P1 and P2, and
- a computer (C) which includes:
- first means for calculating, from the temperature values TC1 and TC2, a temperature value Tp of the wall and a thermal flow Φ given by the following equation:
- Φ=−λgrad (TC1−TC2),
- where λ is the thermal conductivity of the wall,
- and second means for calculating, from fluid temperature TF, temperature TP and thermal flow Φ the thermal exchange coefficient h in the following form:
- h=φ/(TF−TP).
A method for determining the thermal exchange coefficient between a fluid (F) and a wall (P) at a point PN of a surface of the wall (P) in contact with the fluid (F), characterized in that it includes:
- a measurement of a first temperature value TC1 of the wall at a point P1,
- a measurement of a second temperature value TC2 of the wall at a point P2 roughly aligned with point P1 in a straight line normal to the surface at the point PN, where point P1 is closest to the surface of the wall,
- a measurement of a temperature value TF of the fluid at a point PF of the fluid roughly aligned with points P1 and P2,
- a calculation of an average temperature TP of the wall from the temperature values TC1 and TC2,
- a calculation of thermal flow Φ such that:
- Φ=−λgrad (TC1−TC2),
- where λ is the thermal conductivity of the wall, and
- a calculation of the thermal exchange coefficient h such that:
- h=Φ/(TF−TP)
Dependencies are inferred from the claim text.