Method of a heat transfer of a non-metallic or metallic item

Patent metadata

Field	Value
Publication number	US-11118091-B2
Application number	US-201616064808-A
Country	US
Kind code	B2
Filing date	Dec 20, 2016
Priority date	Dec 22, 2015
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

A method of heat treatment of a non-metallic or metallic item is provided. The method includes at least one step A) of heat transfer between the item and a heat transfer fluid A′ including a fluid medium and nanoparticles. The heat transfer fluid has a heat transfer coefficient above the heat transfer coefficient of water. The method also includes at least one step B) of heat transfer between the item and a heat transfer fluid B′ including a fluid medium and nanoparticles. The heat transfer fluid B′ has a heat transfer coefficient different from the heat transfer coefficient of A′ and above the heat transfer coefficient of water. The heat transfer fluids A′ and B′ are different.

First claim

What is claimed is:

1. A method of heat treatment of a non-metallic or metallic item comprising:
a first cooling step comprising transferring heat, in a laminar or turbulent regime flow, between a non-metallic or metallic item and a heat transfer fluid A′ including a fluid medium and nanoparticles, the heat transfer fluid A′ having a heat transfer coefficient above a heat transfer coefficient of water; and
a second cooling step comprising transferring heat, in a laminar regime flow or a turbulent regime flow, between the item and a heat transfer fluid B′ including a fluid medium and nanoparticles, the heat transfer fluid B′ having a heat transfer coefficient different from the heat transfer coefficient of the heat transfer fluid A′ and above the heat transfer coefficient of water;
the second cooling step performed before or after the first cooling step;
the heat transfer fluids A′ and B′ being different;
the heat transfer enhancement between the heat transfer coefficient of each of the heat transfer fluid A′ and B′ and the heat transfer coefficient of water being:
in the laminar flow, proportional to the thermal conductivity, and
in the turbulent flow regime, satisfying the following formula:

h
nf

h
bf

=

(

k
nf

k
bf

)

3
/
5

⁢

(

ρ
nf

ρ
bf

)

4
/
5

⁢

(

C

p
,
nf

C

p
,
bf

)

2
/
5

⁢

(

μ
nf

μ
bf

)

-
2

/
5

wherein h nf is heat transfer coefficient of the heat transfer fluid (J/s·K·m 2 ), h bf is heat transfer coefficient of water (J/s·K·m 2 ), k nf is thermal conductivity of the heat transfer fluid measured at room temperature (J/s·K·m), ρ nf is density of the heat transfer fluid (kg/m 3 ), C p,nf is heat capacity of the heat transfer fluid (J/kg·K) and μ nf is viscosity of the heat transfer fluid (kg/s·m).

2. The method according to claim 1 , further comprising the step of:
transferring heat between the item and a heat transfer fluid C′ including a fluid medium and nanoparticles, the heat transfer fluid C′ having a heat transfer coefficient below the heat transfer coefficient of water;
the heat transfer enhancement between the heat transfer coefficient of the heat transfer fluid C′ and the heat transfer coefficient of water being:
in the laminar flow, proportional to the thermal conductivity, and
in the turbulent flow regime, satisfying the following formula:

h
nf

h
bf

=

(

k
nf

k
bf

)

3
/
5

⁢

(

ρ
nf

ρ
bf

)

4
/
5

⁢

(

C

p
,
nf

C

p
,
bf

)

2
/
5

⁢

(

μ
nf

μ
bf

)

-
2

/
5

wherein h nf is heat transfer coefficient of the heat transfer fluid (J/s·K·m 2 ), h bf is heat transfer coefficient of water (J/s·K·m 2 ), k nf is thermal conductivity of the heat transfer fluid measured at room temperature (J/s·K·m), ρ nf is density of the heat transfer fluid (kg/m 3 ), C p,nf is heat capacity of the heat transfer fluid (J/kg·K) and μ nf is viscosity of the heat transfer fluid (kg/s·m).

Assignees

• Arcelormittal

Inventors

• CABANAS CORRALES Maria
• NORIEGA PEREZ David

Classifications

• C21D1/667

  for spray quenching · CPC title

• C21D1/60

  Aqueous agents · CPC title

• C21D1/56

  characterised by the quenching agents · CPC title

• C21D1/00

  General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering · CPC title

• C09K5/10 Primary

  Liquid materials · CPC title