Daikin Industries, Ltd.

Yume Inokuchi

Katsumi Sakitani

Michio Moriwaki

Yoshinari Sasaki

Tetsuya Okamoto

Eiji Kumakura

Ikuhiro Iwata

Masakazu Okamoto

A positive displacement expander includes a volume change mechanism () for changing the volume of a first fluid chamber () of an expansion mechanism (). The expansion mechanism () includes a first rotary mechanism () and a second rotary mechanism () each having a cylinder () containing a rotor (). The first fluid chamber () of the first rotary mechanism () and a second fluid chamber () of the second rotary mechanism () are in fluid communication with each other to form an actuation chamber (). Meanwhile, the first fluid chamber () of the first rotary mechanism () is smaller than the second fluid chamber () of the second rotary mechanism (). The volume change mechanism () includes an auxiliary chamber () fluidly communicating with the first fluid chamber () and an auxiliary piston () for changing the volume of the auxiliary chamber (). The auxiliary chamber () is in fluid communication with the first fluid chamber () of the first rotary mechanism ().

Expander

A first and a second expansion and compression machine () having different volume ratios (Vc/Ve) are connected in parallel to a refrigerant circuit () of a refrigeration apparatus. Expanders () of the expansion and compression machines () are connected in parallel. Compressors () of the expansion and compression machines () are also connected in parallel. Upon variation in the operating condition of the refrigeration apparatus, the ratio of rotation speed between the expansion and compression machines () is controlled by a controller (). This, as a result, allows the refrigeration apparatus to operate at a COP close to an ideal condition.

Refrigeration apparatus

An outdoor heat exchanger (), an indoor heat exchanger (), a compression/expansion unit (), and other circuit components are connected in a refrigerant circuit (). The compression/expansion unit () includes a compression mechanism (), an electric motor (), and an expansion mechanism (). In addition, the refrigerant circuit () has an injection pipeline (). When an injection valve () is opened, a portion of high pressure refrigerant after heat dissipation flows into the injection pipeline () and is introduced into an expansion chamber () of the expansion mechanism () in the process of expansion. In the expansion mechanism (), power is recovered from both high pressure refrigerant introduced into the expansion chamber () from an inflow port () and high pressure refrigerant introduced into the expansion chamber () from the injection pipeline ().

Refrigeration apparatus with expander control for improved coefficient of performance

Growing community of inventors

Osaka, Japan

Yume Inokuchi