Study of a low temperature refrigeration system based on Linde Hampson cycle

In the recent past, the cryogenic system has become significant because of its extensive applications across various industries, including liquefaction, medical imaging, aerospace, etc There are many thermodynamic cycles used to achieve ultra-low temperatures, but the Linde-Hampson cycle is known for its simplicity compared to other complex cycles, such as the Claude or Kapitza cycles. The present study focuses on the design and development of a cryocooler using the Linde-Hampson refrigeration cycle to achieve ultra-low temperatures. A thermodynamic analysis of the Linde-Hampson cryogenic refrigeration cycle has been carried out using an isenthalpic expansion via a Joule-Thomson (JT) valve. The study investigates the behavior and performance of four different working gases: nitrogen, oxygen, methane, and air. Simulations were carried out using Engineering equation Solver (EES) to evaluate each gas under actual operating conditions. The work input, COP, liquefaction fraction, exergy efficiency, and efficiency are identified as key performance metrics for assessing system performance. Nitrogen and oxygen exhibited higher liquefaction efficiencies; however, methane shows more refrigeration potential. Further, an experimental setup has been developed to achieve ultra-low temperatures with certain limitations of the compressor. Experiments were conducted using air and water as a secondary fluid in the evaporator to carry the refrigeration. The water medium showed a higher COP than air. These findings help to improve the efficiency and viability of gas liquefaction operations by providing a better understanding of gas-specific thermodynamic behaviour.