Mitsubishi Electric Corporation

Ryo Tsukiyama

Takuya Matsuda

Kimitaka Kadowaki

Masahiro Ito

So Nomoto

Naoki Kato

Satoru Yanachi

Toshiro Abe

Tomotaka Ishikawa

Yusuke Arii

Tomoyoshi Oobayashi

An air conditioning device has: a refrigerant circuit that includes a compressor, a switching valve, a cascade heat exchanger, an expansion valve and an outdoor heat exchanger connected to one another by a first pipe through which a refrigerant flows, and that performs a defrosting operation in which the refrigerant discharged from the compressor is introduced into the outdoor heat exchanger; a heat-transfer medium circuit that includes a pump, the cascade heat exchanger, and the indoor heat exchanger connected to one another by a second pipe through which a heat-transfer medium flows; and a control device that controls the compressor and the pump. When an amount of heat storage of the heat-transfer medium is less than a threshold, the control device reduces the heating capability of the indoor heat exchanger when the air conditioning device transitions from a heating operation to the defrosting operation.

Air conditioning device

Each of plural temperature adjustment apparatuses variably adjusts the amount of heat exchange between an inflow medium, which is a liquid medium supplied to a corresponding indoor heat exchanger, and an outflow medium, which is a liquid medium discharged from the corresponding indoor heat exchanger. Each of the plural temperature adjustment apparatuses reduces the heat exchanging capacity of the corresponding indoor heat exchanger by increasing the amount of heat exchange between the inflow medium and the outflow medium when the heat exchanging capacity of the corresponding indoor heat exchanger is larger than the indoor load. When there is no temperature adjustment apparatus in which the amount of heat exchange between the inflow medium and the outflow medium is set to the minimum, the heat source apparatus reduces the heating capacity or the cooling capacity for changing the temperature of the liquid medium.

Air conditioning system

A temperature adjustment apparatus adjusts a temperature of a heating medium that exchanges heat with air in an indoor heat exchanger connected to a heat source apparatus. It includes a first and second pipes through which the heating medium flows, the second pipe being branched into a first and second branch pipes which are thereafter merged, a second heat exchanger in which heat is exchanged between the heating medium in the first branch pipe and the heating medium in the first pipe, and a flow rate regulator that changes a flow rate of the heating medium in the first branch pipe and a flow rate of the heating medium in the second branch pipe. The second pipe supplies the heating medium from the heat source apparatus to the indoor heat exchanger. The first pipe returns the heating medium from the indoor heat exchanger to the heat source apparatus.

Temperature adjustment apparatus, intermediary apparatus, load apparatus, and refrigeration cycle apparatus

An air-conditioner includes: a refrigerant circuit through which a refrigerant flows, the refrigerant circuit being formed of a compressor, a switching valve, a first heat exchanger, an expansion valve, and a second heat exchanger connected to one another by a first pipe; a heat-transfer medium circuit through which a heat-transfer medium flows, the heat-transfer medium circuit being formed of a pump, the first heat exchanger, and a third heat exchanger connected to one another by a second pipe; and control device that controls the compressor and the pump. In an operation of the air-conditioner performed before entering a defrosting operation, the control device increases a frequency of the compressor, as compared to the frequency of the compressor in a heating operation, and reduces a rotational speed of the pump, as compared to the rotational speed of the pump in the heating operation.

Air-conditioner that prevents degradation in heating capability during defrosting operation

A refrigeration device includes a refrigerant circuit sequentially connecting a compressor, a condenser, a reservoir, and a subcooling coil via refrigerant pipes in series, an injection circuit configured to inject part of refrigerant flowing from the condenser to an intermediate pressure part of the compressor, and an injection expansion valve configured to reduce a pressure of refrigerant branched on a downstream side of the subcooling coil. The refrigeration device includes a temperature measurement unit, a pressure measurement unit, and a controller configured to identify a type of refrigerant on the basis of a measured value of the temperature measurement unit and a measured value of the pressure measurement unit, and control at least one of an operating frequency of the compressor, a rotation frequency of a condenser fan, and an opening degree of the injection expansion valve.

Growing community of inventors

Tokyo, Japan

Ryo Tsukiyama