Non-metallic, flexible, thin, microchannel heat exchangers made from heat-sealable polyimide films haverecently been developed for refrigeration and air-conditioning applications. In order for these heat exchangers tofunction properly and independently, robust and reliable connectors are needed. The connectors must be easy tomanufacture and assemble, hold high pressures without leaking, resist a pullout force, and have the ability toconnect to standard tubing and piping and different heat exchangers together in series and parallel. Three uniquelydifferent functional prototype connector designs have been developed, manufactured, and tested. The first includesa machined metal connector internally embedded within the heat exchanger that is capable of holding pressures upto 0.83 MPa and 65.5 N of pullout force before failure. The second connector design includes a two-piece polymerassembly containing an o-ring used to seal around the inlet and outlet holes of the heat exchanger. The designincorporates a 10-degree wedge that creates the sealing force when fully assembled with the heat exchanger and hasbeen pressure tested to 1.83 MPa without leaking and 73.6 N of pullout force applied before failure. A variation ofthe design allows multiple heat exchangers to connect in series and in parallel. Finally, the third design contains noadditional parts and connects two heat exchangers together by thermally bonding the inlet of one heat exchanger tothe outlet of another. The thermally bonded connection was able to hold pressures greater than 2.07 MPa. Finally,fatigue testing of the heat exchangers is conducted using an Instron machine to develop a stress amplitude versusnumber of cycles to failure diagram for the zero pressure case.
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