Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Yuji Inoue

Kazuo Nakatani

Noriho Okaza

Yoshikazu Kawabe

Akira Hiwata

Hisashi Kodama

Hirozo Takegawa

Tomoko Kitamura

Shigeyuki Inoue

Hiroyuki Miyamoto

Masami Hayashi

Yoshikimi Tatsumu

It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range. A refrigeration cycle apparatus uses carbon dioxide as refrigerant and has a compressor, anoutdoor heat exchangerevaporator, an expander andan indoor heat exchangera radiator. An injection circuit for introducing high pressure refrigerant is provided in a halfway of an expansion process of said expander.

Refrigeration cycle apparatus

In the case of gas injection, a discharging temperature is not reduced sufficiently, and if an amount of injection is increased, a liquid refrigerant flows into a cylinder and the liquid is compressed, and the reliability can not be ensured. A refrigerator wherein at least a compressor, a radiator, a first throttle apparatus and an evaporator are connected to one another in an annular form to constitute a main circuit of a refrigeration cycle, a refrigerant which can be brought into a supercritical state by the radiator during operation is charged into the refrigeration cycle, the refrigerator comprises an injection pipe for injecting the refrigerant on the side of an outlet of the radiator into a cylinder of the compressor.

Refrigerator

A refrigeration cycle apparatus using carbon dioxide as a refrigerant has a compressor, an outdoor heat exchanger, an expander, an indoor heat exchanger and an auxiliary compressor. The auxiliary compressor is driven by power recover by the expander. When refrigerant flows using the indoor heat exchanger as an evaporator, a discharge side of the auxiliary compressor becomes a suction side of the compressor, and when refrigerant flows using the indoor heat exchanger as a gas cooler, a discharge side of the compressor becomes a suction side of the auxiliary compressor.

It is an object of the invention to provide an inexpensive double-pipe heat exchanger having high performance and comprising an inner pipe and an outer pipe which constitute a double pipe without adding a heat-transfer facilitating material such as an inner fin. In the double-pipe heat exchanger having the inner pipe and the outer pipe, the outer pipe is dented from its outside toward its inside, thereby forming a plurality of projections which are dented toward the inner pipe. Examples of shapes of the projection are substantially conical shape, substantially truncated shape, substantially spherical surface shape, substantially cylindrical shape, substantially elliptic cylindrical shape and the like. The projections are disposed helically or in a staggered configuration such as to surround the inner pipe. With this structure, only by subjecting the outer pipe to simple working such as press working, it is possible to increase the turbulent flow of fluid flowing between the inner pipe and the outer pipe, and to facilitate heat transfer from fluid flowing in the inner pipe to fluid flowing between the inner pipe and the outer pipe.

Double-pipe heat exchanger

It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range. A refrigeration cycle apparatus uses carbon dioxide as refrigerant and has a compressor, an outdoor heat exchanger, an expander and an indoor heat exchanger. An injection circuit for introducing high pressure refrigerant is provided in a halfway of an expansion process of said expander.

It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range by using an expander which is operated in accordance with a flowing direction of refrigerant. A determining method of a high pressure of a refrigeration cycle apparatus in which a refrigeration cycle uses carbon dioxide as refrigerant and has a compressor, an outdoor heat exchanger, an expander and an indoor heat exchanger, and the refrigeration cycle including a bypass circuit provided in parallel to said expander, and a control valve which adjusts a flow rate of refrigerant flowing through said bypass circuit, said compressor being driven by power recover by said expander, wherein if an optimal high pressure of a first refrigeration cycle flowing through said expander and a second refrigeration cycle flowing through said bypass circuit is defined as Ph, and a bypass amount ratio flowing through said bypass circuit in said Ph is defined as Rb, and a maximum refrigeration cycle efficiency of said first refrigeration cycle in said Ph is defined as COPe, and a maximum refrigeration cycle efficiency of said second refrigeration cycle in said Ph is defined as COPb, the optimal high pressure Ph which maximizes (1&#x2212;Rb)&#xd7;COPe+Rb&#xd7;COPb is determined.

Determining method of high pressure of refrigeration cycle apparatus

A temperature control device of a heating apparatus comprising: an input unit for receiving input of a set temperature; a heating/cooling unit for raising/dropping temperature of a medium, from which a person receives heat; a set temperature reaching unit for controlling the heating/cooling unit so that temperature of the medium is raised to the set temperature and maintained afterwards; a time judgement unit for judging whether a given time has passed after the temperature of the medium is raised to the set temperature; and an imperceptible temperature change unit for controlling the heating/cooling unit, if the time judgement unit judges that the given time has passed, so that the temperature of the medium drops/rises by an amount within a given range by which human beings cannot perceive changes in temperature at a temperature change rate by which human beings cannot perceive changes in temperature. According to the temperature control device, after a person sets a room temperature, it drops/rises by an amount which cannot be perceived by the person during heating/cooling.

Temperature control device of a heating or cooling apparatus for saving

An air conditioner includes a comprising temperature regulator for regulating air temperature in a room, a circulating mechanism for circulating the temperature regulated air, a first room temperature detector for detecting room temperature in a set location in the room, a second room temperature detector for detecting room temperature in a location lower than the first room temperature detector, and a controllor for controlling the temperature regulator in accordance with outputs from the first and second room temperature detectors so as to efficiently equalize indoor temperatures and reduce energy consumption.

Growing community of inventors

Shiga, Japan

Yuji Inoue