TA-23-C097 – Refrigeration System Design Exploration for a Heavy-Duty Hydrogen Refueling Station PDF

Due to the structural integrity of the hydrogen tank in a vehicle, high pressure hydrogen needs to be cooled down below -22°F (-30°C) before entering a dispenser and requires an efficient refrigeration system. Especially for a heavy-duty vehicle application, the design and selection of an appropriate refrigeration system is a challenging duty considering its large capacity and short charging time requirements. The purpose of this study is to design various available refrigeration systems and develop a baseline to select the most cost-effective solution. For a fixed ambient temperature and hydrogen inlet condition, diverse refrigeration systems are designed. Considered variables are the difference between the temperatures of the cold and hot streams, the number of compressors, refrigerants, the composition ratio of refrigerant mixtures, and the type of refrigeration system. Several refrigeration options, such as conventional vapor compression cycles, cascaded systems, auto-cascading cycles having mixed refrigerants, reverse Brayton cycles, and a vortex tube system are investigated considering the required hydrogen operating temperature. Refrigeration system characteristics are described in terms of coefficients of performance, relative heat exchanger cost, and heat exchanger size. The drawbacks and limitations of each refrigeration system are also presented.