Hitachi, Ltd.

Hirokiyo Terada

Kensaku Oguni

Takao Senshu

Minetoshi Izushi

Makoto Nagai

Hiromu Yasuda

Kenji Tokusa

Akira Atsumi

Masamichi Hanada

Hiroshi Takenaka

Kazumoto Urata

Shigeaki Kuroda

Masatoshi Muramatsu

Naoto Katsumata

Shunji Sasaki

Kazuo Yoshioka

Yasuji Sakuma

Kazutaka Suefuji

Takeshi Endo

Toshio Hatada

Masahiro Ito

Susumu Nakayama

Masakatsu Hayashi

Tetsuya Arata

Masaaki Itoh

Hiroshi Kogure

Shinichi Shimode

Sigeaki Kuroda

Takeo Tanaka

Yoshihiko Mochizuki

Kyuhei Ishibane

Minoru Sato

Rumi Minakata

Fumihiko Kitani

Shinya Okabe

Michiko Endo

Hiromi Tsuji

Ryouji Sato

An air conditioner in accordance with the invention comprises a first unit including a compressor and a heat exchanger; a second unit including a heat exchanger; a refrigerant circuit connecting the compressor and the heat exchanger of the first unit, with the heat exchanger of the second unit, through which a refrigerant flows; a refrigerant pressure reduction valve disposed in the refrigerant circuit and provided in the second unit; a control unit provided in the first unit for controlling the refrigerant pressure reduction valve in the second unit.

Air conditioner

A refrigerating system having a refrigerating cycle constructed by connecting an accumulator, a refrigerant compressor, a four-way valve, an outdoor unit heat exchanger, an outdoor unit expander, a receiver, an indoor unit expander and an indoor unit heat exchanger sequentially by pipes. Normally, excessive refrigerant is stored in the receiver and when it becomes necessary to raise a ratio of lower boiling point refrigerants, a flow amount of the refrigerant is decreased by restricting the outdoor unit expander during the cooling operation or by restricting the indoor unit expander during the heating operation to move the excessive refrigerant within the receiver to the accumulator. Thereby, the composition of the refrigerant circulating within the refrigerating system using non-azeotrophic refrigerant mixtures may be changed without using a complicated system structure or control method thereof and the capacity of the refrigerating cycle may be changed.

Refrigerating system and operating method thereof

An air conditioner comprises a first unit including a compressor and a heat exchanger, a second unit including a heat exchanger, a refrigerant circuit connecting the compressor and the heat exchanger of the first unit, with the heat exchanger of the second unit, through which a refrigerant flows, a refrigerant pressure reduction valve disposed in the refrigerant circuit and provided in the second unit, a control unit provided in the first unit for controlling the refrigerant pressure reduction valve in the second unit.

A fin-tube type heat exchanger has parallel heat transfer tubes and a stack of a plurality of plate fins mounted on the tubes. Heat exchange is conducted between a first fluid flowing through the tubes and a second fluid flowing through the stack across each of the fins. Each fin has flat tube-mounting portions spaced in the longitudinal direction of the fin and formed with tube-mounting holes and a louver section disposed between each adjacent pair of tube-mounting portions. The louver section has elongated slats extending longitudinally of the fin and having side edges each spaced from an adjacent side edge of an adjacent slat. The slats are classified into two groups in respect of the cross-sectional shape. The slats of one group have generally flat cross-sections to reduce the resistance of the fin to the flow of the second fluid through the stack and are disposed in planes offset from the plane of the tube-mounting portions. The slats of the other group have V-shaped or inverted V-shaped cross-sections to increase stiffness of the fin in the longitudinal direction thereof.

Fin-tube type heat exchanger

An active noise control system for a three-dimensional space, including noise detecting means, sound generating means, noise control effect detecting means and a control device consisting of a phase of a wave signal fed from the noise detecting means wherein a plurality of noise control effect detecting means and sound generating means are disposed at a distance shorter than a wavelength of the noise to be controlled, and input signals of the respective sound generating means and output signals of the respective noise control effect detecting means are fed through filters, separately, to control the sound for active noise control. In case of an air conditioner, the noise control effect detecting means are disposed at positions where an air stream flowing through the air conditioner is not obstructed thereby.

Active noise control apparatus for three-dimensional space

An air-conditioner system having a compressor, a plurality of heat exchangers for heating or cooling the air in a room, a radiator for transferring heat energy of refrigerant outside of the room, a plurality of orifices, a manifold with a main port and a plurality of sub-ports, flow direction control multi-port valves directing the flow of the refrigerant from the compressor to the main port and not from the main port to the compressor when at least one of the heat-exchangers is heating the room. The refrigerant does not flow from the compressor to the radiator when at least one of the heat exchangers is heating and none of the heat exchangers is cooling. Also, it does not flow from the compressor to the main port but flows instead from the compressor to the radiator and from the main port to the compressor when none of the heat exchangers is heating and at least one of the heat exchangers is cooling. The system also employs a plurality of valve pairs each of which having a first valve and second valve such that the first valve opens (closes) when the second valve closes (opens). The first valves are arranged for providing flow of refrigerant to the inlet of the compressor from the heat exchangers and the second valves provide flow of refrigerant from the outlet port of the compressor to the respective heat exchanger first ports via the sub-ports of the manifold.

Air-conditioner system

An air conditioner mounted on a vertical wall and an method, with the air conditioner including air intake ports and air exhaust ports provided on each side of and air conditioner body which contains heat exchangers, fans and motors. The air is drawn in from the sides of the air conditioner where it is heat-exchanged and then discharged from sides thereof.

Air conditioner and air conditioning method

An air conditioner includes a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger which are connected via pipings to form a heat pump type refrigerant circuit, the four-way valve being switched over to select a heating or cooling mode of operation. This air conditioner is further provided with a first and second branch pipes which extend from an outlet conduit of the compressor, the first branch pipe forming a first bypass pipe connected to an inlet conduit of the compressor. The first and second branch pipes have first and second valves, respectively. The air conditioner is also provided with a microcomputer for selectively opening and closing the second valve in response to the degree of superheating of discharged gaseous refrigerant after the first valve has been opened so that the discharged gaseous refrigerant is supplied to the outdoor heat exchanger to effect a defrosting operation while a heating operation is continued. When the degree of superheating of discharged gaseous refrigerant is low, a part of discharged gas is supplied to the inlet conduit so as to regulate the degree of superheating.

Defrosting of refrigerator system out-door heat exchanger

The present invention is characterized by selecting, during heating, the hot air blowing mode in which a compressor and a blower for an indoor heat exchanger are each controlled as to r.p.m. to control the temperature of outlet air blown from an air conditioner at a higher temperature, and the normal mode in which the room temperature is controlled. Also, as required, an air passage of the outlet is set to be narrow to blow hot air in a confined space, or the air passage of the outlet is set wide to disperse warm air during normal operation.

Control method and apparatus for an air conditioner using a heat pump

A refrigeration system suitable for use in an air conditioner has a main refrigerant circuit including a compressor, a condenser, a first pressure reducer, a gas-liquid separator, a second pressure reducer and an evaporator connected in series to form a closed loop, and a gas injection passage providing a communication between the gaseous phase part of the gas-liquid separator and a compression chamber of the compressor. A stop valve is disposed in the inlet and outlet pipes of the gas-liquid separator, and a bypass passage is provided for connecting directly the outlet pipe of the condenser to the inlet pipe of the evaporator to bypass the gas-liquid separator. The stop valve is adapted to be controlled such that, when the gas injection to the compressor through the gas injection passage is not conducted, the refrigerant flows through the bypass passage bypassing the gas-liquid separator, while the gas-liquid separator functions as a receiver for adjusting the amount of refrigerant circulated in the main refrigerant circuit.

Refrigeration system

A refrigeration apparatus has a refrigerant circuit which is constituted by a compressor, a condenser, a first pressure reducer, a gas-liquid separator, a second pressure reducer and an evaporator connected to one another in series. The refrigeration apparatus also has a gas injection line connected between a gaseous phase portion of the gas-liquid separator and a compression chamber of the compressor. The improvement comprises a liquid refrigerant extracting passage providing a communication between a portion of the gas-liquid separator at a predetermined level and a portion of the low-pressure side of the refrigerant circuit. With this arrangement, it is possible to stabilize the level of the liquid refrigerant in the gas-liquid separator.

Refrigeration apparatus

An air conditioning system including at least one water-cooling type air conditioning unit, a heat pump chilling unit, an ancillary heat exchanger in said water-cooling type air conditioning unit, and a cold and heat accumulating tank divided into two tank sections differing from each other in volume and the temperature of water contained therein. In a cooling mode, cold water of relatively high temperature and cold water of relatively low temperature are accumulated by operating the heat pump chilling unit at night, and when a normal heating operation is performed, the cold water of relatively high temperature is used as cooling water for a condenser of the water-cooling type air conditioning unit and when the water-cooling type air conditioning unit is inoperable as when power failure occurs at peak load, the cold water of relatively low temperature is supplied to the ancillary heat exchanger to carry out cooling. In a heating mode, warm water of relatively high temperature and warm water of relatively low temperature are accumulated by operating the heat pump chilling unit at night, and at startup in a heating operation, the warm water of relatively high temperature is supplied to the ancillary heat exchanger to start the heating operation, and in a normal heating operation, the warm water of relatively low temperature is directly used as a heat source water for a water side heat exchanger of the air conditioning unit or as a heating heat source.

Air conditioning system

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Shizuoka, Japan

Hirokiyo Terada