Farhani - Assistant professor, Iranian Research Organization for Science and Technology (IROST), Iran
Sarangi - Professor, Indian Institute of Technology (IIT), Kharagpur, India

Performance and economy of a cryogenic system strongly depend on the effectiveness of the heat exchanger(s) used. The matrix heat xchanger (MHE), with high effectiveness and compactness, is ideal for use in these systems. The development process of a matrix heat exchanger consists of design of the exchanger elements (perforated plates, and spacers) of the desired geometry and configuration, fabrication of these elements using an accurate and reproducible technique, and finally bonding of the elements using a suitable method. This paper resents our work for the development and testing of all metal matrix heat exchangers. Photochemical Milling (PCM) technique has been used to produce copper perforated plates and stainless steel spacers of desired geometries and configurations. Bonding of the exchangers was carried out in a vacuum brazing furnace, designed and constructed by the authors. A test apparatus, designed a nd constructed in-house, has been used for the evaluation of heat transfer and flow friction characteristics of these exchangers. Results of tests, carried out on some sample matrix heat exchangers, show good overall performance, suggesting the applicability of the fabrication techniques presented in this paper for similar applications.

cryogenic systems, MHE, perforated plates, spacers, PCM, vacuum brazing