A6-02 R&D On Heat Pumps With Natural Working Fluids In Japan- E.Hihara (Japan)
The conventional refrigerant R22 has been replaced by hydro-fluorocarbons, and the recovery and destruction system for fluorocarbons began operation in Japan. However, for future global warming prevention, it is said that conversion to natural working fluids will be required. In this paper, the overview of the research on the heat pumps using the natural working fluids in Japan is summarized. The carbon dioxide systems for mobile air conditioners and water heaters are actively researched. The heat pump water heaters operated in midnight were put on the market, and the spread is expected. Hydrocarbon heat pumps for air conditioning are not on the market from a viewpoint of safety. Only a small amount of refrigerators operated with isobutene is sold in Japan. Although the ammonia refrigerators are the ripened and reliable technology, the law requires expensive safety facilities, and therefore they are only used for the low-temperature warehouse or for the industrial use.