18 May 2017
The manufacture of HFCs has been restricted by increasingly stringent regulations, with the aim of reducing global warming.
There is a need for low GWP refrigerants that can be used in air-conditioning and refrigeration equipment. The refrigerant R-
1233zd (E) has low toxicity, non-flammable, and a GWP of approximately 1, and these characteristics make it suitable for
use in centrifugal chillers and heat pumps. We have developed a centrifugal chiller using R-1233zd (E). It is required that the
compressor, heat exchanger, and other components are optimized, and the size of the chiller is minimized, but the specific gas
volume of R-1233zd (E) is much larger than that of R-134a. We have designed a chiller whose size was almost the same as
that of an R-134a chiller of between 150 and 700 tons. A COP 2% higher than that of the R-134a chiller was achieved. We
also have been developing a centrifugal heat pump system using a low GWP refrigerant to heat pressurized hot water to
200°C, with a COP of 3.5. The most important criteria for refrigerant selection are low GWP, toxicity, flammability, and
stability at high temperature. We will distribute a practical high temperature heat pump by 2023.