US 2022/0077474 A1 · METHOD FOR FORMING FLOW CHANNEL ON METAL BIPOLAR PLATE OF FUEL CELL

Abstract

A method for forming a flow channel on a metal bipolar plate of a fuel cell includes: pre-treating a metal polar plate; subjecting the metal polar plate to low-temperature heating; forming a flow channel on the metal polar plate by rolling; cutting an inlet and outlet for gas and cooling liquid on the metal polar plate; performing surface treatment on the metal polar plate; bonding two metal polar plates to form a metal bipolar plate; and trimming the metal bipolar plate. The flow channel is formed by two pre-forming and one truing, and design parameters of punches and dies of the rollers used are determined by calculation models.

A method for forming a flow channel on a metal bipolar plate of a fuel cell, comprising:

pre-treating a metal polar plate;
subjecting the metal polar plate to low-temperature heating;
forming a flow channel on the metal polar plate by rolling;
cutting a gas inlet, a gas outlet, a cooling liquid inlet and a cooling liquid outlet on the metal polar plate;
subjecting the metal polar plate to surface treatment;
bonding the metal polar plate with another metal polar plate treated by the above steps to form a metal bipolar plate;
and
trimming the metal bipolar plate;
wherein the step of “forming a flow channel on the metal polar plate by rolling” is performed through steps of:
performing pre-forming twice on the metal polar plate sequentially using a pair of first rollers and a pair of second rollers;
and
performing truing once using a pair of truing rollers to form the flow channel on the metal polar plate;
and
design parameters of a first punch and a first die of each of the pair of first rollers used in a first pre-forming and design parameters of a second punch and a second die of each of the pair of second rollers used in a second pre-forming are determined through the following steps:
(1) determining an inclination length l11, a draft angle β11 and a depth h11 of the first punch by a first calculation model:
{
l
1
⁢
1
=
(
r
1
⁢
1
+
k
1
⁢
t
)
⁢
tan
⁢
α
1
⁢
1
2
β
1
⁢
1
=
90
⁢
°
-
α
1
⁢
1
h
1
⁢
1
=
r
1
⁢
1
⁡
(
1
-
cos
⁢
α
1
⁢
1
)
+
(
r
1
⁢
1
+
k
1
⁢
t
)
⁢
tan
⁢
α
1
⁢
1
2
×
sin
⁢
α
1
⁢
1
;
wherein r11 is an arc radius of the first punch;
α11 is half of an arc included angle of the first punch;
t is a thickness of the metal polar plate;
and k1 is a ratio of a thickness of the metal polar plate after the first pre-forming to a thickness of the metal polar plate before the first pre-forming, and 0<k1<1;
and
determining an inclination length l12, a draft angle β12, a depth h12 and a horizontal length l1 of the first die by a second calculation model:
{
l
1
⁢
2
=
(
r
1
⁢
2
+
k
1
⁢
t
)
⁢
tan
⁢
α
1
⁢
2
2
β
1
⁢
2
=
90
⁢
°
-
α
1
⁢
2
h
1
⁢
2
=
r
1
⁢
2
⁡
(
1
-
cos
⁢
α
1
⁢
2
)
+
(
r
1
⁢
2
+
k
1
⁢
t
)
⁢
tan
⁢
α
1
⁢
2
2
×
sin
⁢
α
1
⁢
2
l
1
=
2
⁢
(
r
1
⁢
2
+
k
1
⁢
t
)
⁢
tan
⁢
α
1
⁢
2
2
;
wherein r12 is an arc radius of the first die;
α12 is an arc included angle of the first die;
t is the thickness of the metal polar plate;
and k1 is the ratio of the thickness of the metal polar plate after the first pre-forming to the thickness of the metal polar plate before the first pre-forming, and 0<k1<1;
and
(2) determining an inclination length l21, an arc radius r21, a draft angle fill and a depth h21 of the second punch by a third calculation model:
{
r
2
⁢
1
=
k
1
⁢
α
1
⁢
1
k
2
⁢
α
2
⁢
1
×
(
r
1
⁢
1
+
k
1
⁢
t
2
)
-
k
2
⁢
t
2
l
2
⁢
1
=
(
r
2
⁢
1
+
k
2
⁢
t
)
⁢
tan
⁢
α
2
⁢
1
2
β
2
⁢
1
=
90
⁢
°
-
α
2
⁢
1
h
2
⁢
1
=
r
2
⁢
1
⁡
(
1
-
cos
⁢
α
2
⁢
1
)
+
(
r
2
⁢
1
+
k
2
⁢
t
)
⁢
tan
⁢
α
2
⁢
1
2
×
sin
⁢
α
2
⁢
1
;
wherein r11 is the arc radius of the first punch;
α11 is half of the arc included angle of the first punch;
α21 is half of an arc included angle of the second punch;
t is the thickness of the metal polar plate;
k1 is the ratio of the thickness of the metal polar plate after the first pre-forming to the thickness of the metal polar plate before the first pre-forming, and 0<k1<1;
and k2 is a ratio of a thickness of the metal polar plate after the second pre-forming to the thickness of the metal polar plate after the first pre-forming, and 0<k2<1;
and
determining an inclination length l22, an arc radius r22, a draft angle β22, a depth h22 and a horizontal length l1 of the second die by a fourth calculation model:
{
r
2
⁢
2
=
k
1
⁢
α
1
⁢
2
k
2
⁢
α
2
⁢
2
×
(
r
1
⁢
2
+
k
1
⁢
t
2
)
-
k
2
⁢
t
2
l
2
⁢
2
=
(
r
2
⁢
2
+
k
2
⁢
t
)
⁢
tan
⁢
α
2
⁢
2
2
β
2
⁢
2
=
90
⁢
°
-
α
2
⁢
2
h
2
⁢
2
=
r
2
⁢
2
⁡
(
1
-
cos
⁢
α
2
⁢
2
)
+
(
r
2
⁢
2
+
k
2
⁢
t
)
⁢
tan
⁢
α
2
⁢
2
2
×
sin
⁢
α
2
⁢
2
l
2
=
2
⁢
(
r
2
⁢
2
+
k
2
⁢
t
)
⁢
tan
⁢
α
2
⁢
2
2
;
wherein r12 is the arc radius of the first die;
α12 is the arc included angle of the first die;
α22 is an arc included angle of the second die;
t is the thickness of the metal polar plate;
k1 is the ratio of the thickness of the metal polar plate after the first pre-forming to the thickness of the metal polar plate before the first pre-forming, and 0<k1<1;
and k2 is the ratio of the thickness of the metal polar plate after the second pre-forming to the thickness of the metal polar plate after the first pre-forming, and 0<k2<1.

506 more elements

Method for forming flow channel on metal bipolar plate of fuel cell

Life of this patent

Method for forming flow channel on metal bipolar plate of fuel cell

Life of this patent

Abstract

Claims3