11.01.17
Being a specialist in the field, Power Products International will be called upon to create or improve a piece of equipment designed to a very particular circumstance. The following is a brief case study of such an event; outlining the steps taken to fulfil the request of one particular client who wanted the most cost effective liquid cooled plate design for temperature control of an electric vehicle battery system.
The cost target would rule out many of the most temperature efficient options such as a machined & drilled plates, or more complex machining of 2 piece systems assembled using controlled atmosphere brazing.
The concept design was initially defined as an extruded base plate with provision for an adaptable inlet/outlet configuration. The first task was to model a system that would meet the client’s thermal conduction performance target, within a given set of dimensions.
Optimising the thermal transfer from the system, through the plates into the liquid, and achieving a stable flow would help to define the design for the channels through the extrusion. The plate thickness was not to exceed 10mm leaving just 5mm usable height for the liquid channel.
The plate footprint was largely determined by the dimensions of the battery packs which would be mounted directly onto the plates. This would also allow the plate dimensions to be standardised and used in multiple stacks, as a modular design.
The optimum channel arrangement was determined to be 11 channels running through the plate, 5mm high by 25mm wide. This design was validated by computer simulation to confirm the thermal conduction performance would be sufficient to meet the system requirement.
Optimising the heat transfer via the liquid flow from inlet to outlet would involve directing the liquid through the channels in the most efficient way. The design of the inlet/outlet manifolds could be trialled and the configuration modified until the best performance was achieved. One example of the designs considered was to pass the liquid through the plate in 3 sections simultaneously – two sections of 4 channels and one of 3 channels.
Keeping the assembly simple and cost effective, the manifolds would be welded to the extrusion, and fitted with suitable connectors. This would allow relatively fast assembly using standardised parts, and requiring only two 360° welds. The final assembly cost came within the target requested by the client, with a one-off tooling charge for the custom extrusion.
The design shown would provide a flow through the cooling plate as illustrated, dependent upon the position selected for the end cap plugs:
Other options available include assemblies designed around Controlled Atmosphere Brazing, where application-specific machined halves can be mated to provide a highly efficient cooling system, or gun-drilled assemblies, which are most cost effective where small numbers are involved, particularly for proof of concept and prototyping.
Power Products are the sole UK partner for MeccAl s.r.l, a major supplier of aluminium extrusions and complex thermal management systems. Our in house sales team can provide assistance with design issues, and have direct access to the MeccAl technical support team. We are ready to assist with all of your power system requirements.
If you would like to know more or have a specific request or design enquiry; be sure to contact Power Products International and discover all the options available to you. Get in touch by calling us on 01732 866424 or email us at [email protected]
