Exergy analysis on the simulation of a small-scale hydrogen liquefaction test rig with a multi-component refrigerant refrigeration system
✍ Scribed by Songwut Krasae-in; Jacob H. Stang; Petter Neksa
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 791 KB
- Volume
- 35
- Category
- Article
- ISSN
- 0360-3199
No coin nor oath required. For personal study only.
✦ Synopsis
This study investigates the simulation of a proposed small-scale laboratory liquid hydrogen plant with a new, innovative multi-component refrigerant (MR) refrigeration system. The simulated test rig was capable of liquefying a feed of 2 kg/h of normal hydrogen gas at 21 bar and 25 C to normal liquid hydrogen at 2 bar and À250 C. The simulated power consumption for pre-cooling the hydrogen from 25 C to À198 C with this new MR cycle was 2.07 kWh/kg GH2 from the ideal minimum of 0.7755 kWh per kilogram of feed hydrogen gas. This was the lowest power consumption available when compared to today's conventional hydrogen liquefaction cycles, which are approximately 4.00 kWh/ kg GH2 . Hence, the MR cycle's exergy efficiency was 38.3%. Exergy analysis of the test rig's cycle, which is required to find the losses and optimize the proposed MR system, was evaluated for each component using the simulation data. It was found that the majority of the losses were from the compressors, heat exchangers, and expansion valves. Suggestions are provided for how to reduce exergy in each component in order to reduce the exergy loss. Finally, further improvements for better efficiency of the test rig are explained to assist in the design of a future large-scale hydrogen liquefaction plant.