Owing to the large volumetric expansion ratio of the subcritical refrigerant and the geometrical restriction of the positive displacement machine, investigations on expanders in subcritical vapor refrigeration systems are relatively few in the literature. In this paper, a radial inflow turbo...

Carbon dioxide is a promising natural working fluid that can be used in transcritical Rankine cycles due to environmental and safety concerns. However, the high operation pressure has to be reduced and the relatively low efficiency of the system has to be increased. Traditional working fluids...

This paper provides an energy efficiency study of transcritical carbon dioxide systems by comparing six cycles with and without an expressor (expander–compressor), which serves as an assistant compressor or the main compressor. Several different expander–compressor arrangements in the system...

As a natural refrigerant, carbon dioxide is safe, economic and environmentally sustainable which can be used in heat pump and refrigeration systems especially in transcritical cycles. From the early 1990s, in which the carbon dioxide transcritical cycle began, theoretical and experimental...

Improving the efficiency of trans-critical CO2 heat pump systems becomes one of the investigative focuses of the development of refrigeration technologies. The use of expander can improve the efficiency of trans-critical CO2 cycles, and make it near to that of traditional refrigeration systems....

The study we present here analyzes the status of the water chiller energy efficiency standard in China. The national standard, GB19577-2004, which sets the grade and scale of water chiller energy efficiency, has been implemented for five years and has produced achievements in energy-saving and...

China is a big agricultural country and one of the most abundant straw resources in the world, producing more than 620 million tons of straw in 2002, and representing about 33-45% of energy consumption for livelihood in rural areas. Utilization of straw as energy with high efficiency and...