Combined thermodynamic power and cryogenic refrigeration system using binary working fluid

摘要

A combined thermodynamic power and cryogenic refrigeration system using a first and second (binary) working fluid has a low-temperature closed bottoming cycle and either a closed or open topping cycle. In the bottoming cycle a mixture of a first gas such as helium or hydrogen and a low temperature liquid such as liquefied nitrogen is isothermally compressed and then the liquid content is separated. The separated first gas is heated using heat from a second gas or ambient air expanded in the topping cycle and then the heated first gas is adiabatically expanded and supercooled while performing useful work and thereafter is mixed with the separated liquid to serve as a coolant and facilitate rejection of adiabatic heat and to supplement the cool gas/liquid fed to the compressor and thus completes the bottoming cycle. The bottoming cycle functions to cool the second gas during its compression in the topping cycle. The topping cycles are closed or open modified Brayton cycles. The closed topping cycle uses heat of the ambient air or other low temperature heat source to simultaneously produce cool refrigerated air and power and may function as a heat pump for warming cool ambient air. The open topping cycle may use a low temperature heat source, or a high temperature heat source with regeneration, to simultaneously produce power and cool refrigerated air with high thermal efficiency.