Wind turbine mold B-surface heating and cooling using vacuum bag with fluid channels
Devices, systems, and methods of improving heat transfer between a composite wind turbine blade surface are provided to reduce cure time. The assembly includes molds having heating wires disposed proximate the mold surface for delivering heat to the composite blade during layup and/or resin cure. Additionally, the vacuum bag disposed on top of the composite part includes a plurality of fluid channels for distributing a thermal fluid (e.g. heated/cooled water, air or oil) across the composite surface (opposite the mold surface).
1. An apparatus for forming a composite wind turbine blade comprising:
a first turbine blade half comprising a first shell;
a second turbine blade half comprising a second shell;
a first mold half in an open configuration, comprising a first mold surface corresponding to the first shell;
a second mold half in an open configuration, comprising a second mold surface corresponding to the second shell;
a first vacuum bag overlaid on a spar cap on a B-surface of the first shell; and
a second vacuum bag overlaid on a spar cap on a B-surface of the second shell, the first vacuum bag distinct from the second vacuum bag;
wherein the first vacuum bag includes a first series of fluid channels for heating fluid and a second series of fluid channels for cooling fluid, each of the first and second series of fluid channels disposed on an outer surface of the first vacuum bag, at least a portion of each of the first and second series of fluid channels disposed proximate the first shell; and
wherein the second vacuum bag includes a third series of fluid channels for heating fluid and a fourth series of channels for cooling fluid, each of the third and fourth series of fluid channels disposed on an outer surface of the second vacuum bag, at least a portion of each of the third and fourth series of fluid channels disposed proximate the second shell;
wherein each of the first and second vacuum bags comprises a root region and a tip region, the root region having a first density of fluid channels and the tip region having a second density of fluid channels; and wherein
the first density of fluid channels is greater than the second density of fluid channels;
wherein the first density of fluid channels has a greater surface area in contact with the B-surfaces of the wind turbine blade than the density of second fluid channels;
an inlet fluid channel;
an outlet fluid channel,
wherein each of the inlet fluid channel and the outlet fluid channel are configured with a greater cross section than fluidly coupled first, second, third and fourth series of fluid channels.
2. The apparatus of claim 1 , wherein the first mold half includes a heating element disposed proximate the first mold surface.
3. The apparatus of claim 1 , wherein the second mold half includes a heating element disposed proximate the second mold surface.
4. The apparatus of claim 1 , wherein at least one of the fluid channel extends along the entire span of the blade.
5. The apparatus of claim 1 , wherein at least one of the fluid channel extends from a leading edge to a trailing edge of the blade.
6. The apparatus of claim 1 , wherein the fluid channels are configured for unidirectional flow.
7. The apparatus of claim 1 , wherein a first fluid channel of the first or second series of fluid channels has a greater surface area in contact with the surface of the first shell than a second fluid channel of the first or second series of fluid channels.
8. The apparatus of claim 1 , wherein the cooling fluid travels from the root region towards the tip region of at least one of the first and second vacuum bags and into a heat exchanger.
9. The apparatus of claim 1 , wherein at least one of the first series or the second series of fluid channels is disposed on top of the first shell in a pattern reflecting the spar cap and at least one of the third series or the fourth series of fluid channels is disposed on top of the second shell in a pattern reflecting the spar cap.