Test results of indigenously developed cryogenic 3-stream plate-fin heat exchanger

The helium refrigerator plant being developed at IPR, Gandhinagar, Gujarat has a 3-stream (He/He/He) plate-fin heat exchanger of Al-alloy, designed and fabricated indigenously. It is designed for nominal operational temperature range of 27 to 15 K. Before using it in the plant, it is necessary to test the thermos-hydraulic performance of the heat exchanger. This heat exchanger is designed for a helium flow rate of ∼ 30 g/s for low pressure cold stream (∼1.2 bar) and same helium flow rate is there for two hot streams in counter-flow. During the operation of helium liquefaction plant, the pressure drop and effectiveness of heat transfer in the heat exchanger are important criteria to determine the plant performance. To test these performances, a closed-loop helium circulation system for generating 80 K helium gas flow has been developed. Necessary instruments like helium flow meter, pressure transmitters, differential pressure transmitters, temperature sensors have been used. Pressure test and helium leak tests have been done at room temperature and 80 K. The thermos-hydraulic test results are also compared with the results obtained from ASPENTECH software analysis. The details of these test results will be discussed in this paper. (author)