18 May 2017

O.3.4.1 Development of centrifugal chiller and heat pump using low GWP refrigerant

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.