Hitachi, Ltd.

Kyuhei Ishibane

Kensaku Oguni

Kazumoto Urata

Hiromu Yasuda

Shigeaki Kuroda

Takao Senshu

Hiroaki Matsushima

Kazuhiro Endoh

Masayuki Nonaka

Akira Atsumi

Takeshi Endoh

Kazutaka Suefuji

Toshio Hatada

Masakatsu Hayashi

Tetsuya Arata

Hirokiyo Terada

Hideyuki Kimura

Hiroshi Kogure

Naoto Katsumata

Taketoshi Mochizuki

Takashi Sano

Hironori Etou

A refrigeration cycle comprises a compressor, an indoor heat exchange, an outdoor heat exchanger, a liquid receiver; and a pressure reducer connected in series to form a closed loop. The liquid receiver and the pressure reducer connected in series are connected between the indoor heat exchanger and said outdoor heat exchanger. A non-azeotropic mixture refrigerant comprising at least two kinds of refrigerant of different boiling temperatures mixed together is charged in and circulated through the refrigeration cycle. The mixing ratio of the azeotropic mixture refrigerant circulated thorough the refrigeration cycle is controlled substantially constant.

Refrigeration cycle and method of controlling the same

A refrigeration cycle comprises a compressor, an indoor heat exchanger, an outdoor heat exchanger, a liquid receiver; and a pressure reducer connected in series to form a closed loop. The liquid receiver and the pressure reducer connected in series are connected between the indoor heat exchanger and said outdoor heat exchanger. A non-azeotropic mixture refrigerant comprising at least two kinds of refrigerant of different boiling temperatures mixed together is charged in and circulated through the refrigeration cycle. The mixing ratio of the azeotropic mixture refrigerant circulated thorough the refrigeration cycle is controlled substantially constant.

A mixed-refrigerant comprising two or more types of refrigerants having different boiling points is enclosed in a refrigerating cycle and a capacitance sensor is used as a device for detecting a composition of the mixed-refrigerant. The electrostatic capacitance sensor is disposed in an evaporation portion of the refrigerating cycle. The refrigerating cycle has a refrigerant composition calculating device for calculating a composition of the refrigerant in the refrigerating cycle in accordance with an output signal from the capacitance sensor and an adequate composition judging device for judging whether or not the composition of the mixed-refrigerant circulating in the refrigerating cycle is in an adequate state in accordance with an output signal from the refrigerant composition calculating device.

Apparatus for detecting composition of refrigerant and method therefor

A refrigerant flow control system associated with a refrigerant circulating circuit having a compressor, a condenser, an expansion valve and an evaporator, includes a branch pipe extending from a discharge pipe of the compressor and having on sealed free end. A first temperature sensor is disposed on the branch pipe near the sealed free end for detecting a condensation temperature of a refrigerant which is condensed in the branch pipe. A second temperature sensor is disposed on the discharge pipe of the compressor for detecting a temperature of the gaseous refrigerant discharged from the compressor. The signals representative of the condensation temperature and the temperature of the discharge gaseous refrigerant are inputted to a control device. The control device calculates a difference between the two detected temperatures, and a degree of superheat of the discharged gaseous refrigerant and transfers to the expansion valve a command signal representative of the calculation results, thereby controlling an opening of the expansion valve.

Refrigerant flow control system for use with refrigerator

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

An expansion valve has a refrigerant inlet passage, a refrigerant outlet passage, a valve chest to which both the passages open, a diaphragm chamber communicating with a heat-sensitive bulb through a tube of small diameter, and a valve body actuated in response to the operation of a diaphragm, the valve body being disposed facing a valve seat in the valve chest to regulate a passage defined between the valve seat and the valve body, to thereby control the flow rate of a refrigerant. The valve seat is adapted to be axially movable along the inner wall of the valve chest. In addition, means are provided for moving the valve seat in accordance with a change in pressure in the refrigerant circuit.

Expansion valve

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Shimizu, Japan

Kyuhei Ishibane