Mitsubishi Denki Kabushiki Kaisha

Hidekazu Tani

Tomohiko Kasai

Takashi Nakamura

Shigeo Takata

Noriaki Hayashida

Junichi Kameyama

Yoshihiro Sumida

Hitoshi Iijima

Moriya Miyamoto

Osamu Morimoto

Daisuke Shimamoto

Masahiro Tsuda

Makoto Saitou

Munehiro Yamanaka

Fujio Hitomi

Shuji Oura

Takashi Ikeda

Hirofumi Koge

Fumio Matsuoka

Hiroaki Hama

Mitsunori Kurachi

Yoshinobu Igarashi

Takashi Shiga

Toshihiro Kikukawa

Kouji Ishikawa

Shohichiroh Masuda

An air conditioning apparatus has plural indoor units having: plural heat exchangers; and flow controllers respectively corresponding to the heat exchangers. In each of the indoor units, one heat exchanger is used as a condenser, and another heat exchanger is used as an evaporator, thereby causing the indoor unit to perform a temperature and humidity controlling operation. An indoor unit(s) which is not set to perform the temperature and humidity controlling operation may be caused to perform a heating operation or a cooling operation. Capacity controls on the condensers and the evaporators are performed by corresponding flow controllers. Gas refrigerants ejected from plural heat exchangers serving as evaporators are joined together, and then distributed to plural heat exchangers serving as condensers.

Air conditioning apparatus

Air conditioner

A heat source unit and refrigerant used in an existing refrigeration system are replaced with new refrigerant and a new heat source unit which employs the new refrigerant and is equipped with an oil separator and extraneous-matter trapping device. An indoor unit of the existing refrigeration system may be used, in its present form, or replaced with a new indoor unit. Further, connecting pipes used for the existing refrigeration are reused. After replacement of refrigerant, the refrigeration system performs an ordinary operation after having performed a cleaning operation. The extraneous-matter trapping device is provided in a refrigerant pipe close to the heat source unit or in a bypass channel connected to the refrigerant pipe close to the heat source unit. Alternatively, only the heat source unit of the existing refrigeration system is replaced with a new one, and there is employed refrigeration oil which has no mutual solubility with respect to HFC or has very low mutual solubility.

Refrigeration system, and method of updating and operating the same

A refrigerant circulation system of the present invention includes a compressor, a condenser, a evaporator, a throttle device and a control unit. The control unit controls a composition of a refrigerant circulating in the refrigerant circulation system based on a temperature and pressure of the refrigerant of an inlet and outlet portion of the compressor, condenser, evaporator and throttle device. The control unit controls to open and close the throttle device to change the composition of the refrigerant circulating in the refrigerant circulation system.

Refrigerant circulating system

An air conditioning system in which a single heat source unit (A) comprising a compressor (1), a four-way valve (2), a heat source unit side heat exchanger (3) and an accumulator (4) is connected to a plurality of indoor units (B, C, D) through a first and a second connection pipes (6, 7). Each indoor unit (B, C, D) comprises a suction air temperature detecting device (50) for detecting a suction air temperature of the indoor unit, an opening degree setting device for setting a minimum valve opening degree of the first flow rate controller 9 in accordance with the difference between the target temperature and the suction air temperature and a first valve opening degree control device (52) for controlling the valve opening degree of the first flow rate controller 9 at a predetermined rate to the minimum valve opening degree.

Air-conditioning system

A multi-chamber heat-pump type air conditioner in which a plurality of room units (2, 3, 4) are connected to one heat source unit (1), cooling and heating can be effected selectively for each room unit (2, 3, 4), and cooling can be effected by one room unit and heating can be simultaneously effected by another, wherein the high-level pressure or low-level pressure is controlled from rising high as compared to the time of normal operation, and the reliability of the compressor (17) is improved. In which, a third pressure-detector (48) is provided for detecting a rise in pressure between a compressor (17) and a four-way changeover valve (18), and a control circuit (49) is provided for controlling such that, in the event that the pressure within the pipe is below a predetermined pressure, a sixth valve (45) and a seventh valve (46) are closed, while in the event that the pressure within the pipe exceeds the predetermined pressure, the sixth valve (45) and seventh valve (46) are opened.

An air conditioning system in which a single heat source unit (A) comprising a compressor (1), a four-way valve (2), a heat source unit side heat exchanger (3) and an accumulator (4) is connected to a plurality of indoor units (B, C, D) through a first and a second connection pipes (6, 7). Each indoor unit (B, C, D) comprises a suction air temperature detecting device (50) for detecting a suction air temperature of the indoor unit, an opening degree setting device for setting a minimum valve opening degree of the first flow rate controller 9 in accordance with the difference between the target temperature and the suction air temperature and a first valve opening degree control device (52) for controlling the valve opening degree of the first flow rate controller 9 at a predetermined rate to the minimum valve opening degree. A bypass system is further provided to enable an effective defrost operation.

An air conditioning apparatus which includes a single heat source device and plural indoor units including indoor heat exchangers. Some of the indoor units include a fan for introducing outdoor air, while others include a fan for circulating indoor air. In addition, a controller is provided for controlling operation of one or more of the indoor units to carry out heating, cooling or ventilation in response to a determination of the operation of one or more other indoor units.

An air conditioning system in which a single heat source unit (A) comprising a compressor (1), a four-way valve (2), a heat source unit side heat exchanger (3) and an accumulator (4) is connected to a plurality of indoor units (B, C, D) through a first and a second connection pipes (6, 7) Each indoor unit (B, C, D) comprises a suction air temperature detecting device (50) for detecting a suction air temperature of the indoor unit, an opening degree setting device for setting a minimum valve opening degree of the first flow rate controller 9 in accordance with the difference between the target temperature and the suction air temperature and a first valve opening degree control device (52) for controlling the valve opening degree of the first flow rate controller 9 at a predetermined rate to the minimum valve opening degree.

An air conditioning apparatus comprising: a single heat source device including a compressor, a reversing valve, an outdoor heat exchanger and an accumulator; a plurality of indoor units including indoor heat exchangers and first flow controllers; a first main pipe and a second main pipe for connecting between the heat source device and the indoor units; a first branch joint which can selectively connect one end of the indoor heat exchanger of each indor unit to either one of the first main pipe and the second main pipe; a second branch joint which is connected to the other end of the indoor heat exchanger of each indoor unit through the first flow controllers, and which is also connected to the second main pipe through a second flow controller; the first branch joint and the second branch joint being connected together through the second flow controller; the second branch joint being connected to the first main pipe through a fourth flow controller; a junction device which includes the first branch joint, the second flow controller, the fourth flow controller and the second branch joint, and which is interposed between the heat source device and the indoor units; and the first main pipe having a greater diameter than the second main pipe; and a switching valve arrangement which can be arranged between the first main pipe and the second main pipe in the heat source device to switch the first main pipe and the second main pipe to a low pressure side and to a high pressure side, respectively.

An air conditioning system for multiple rooms, comprising:

Air conditioning system

An air conditioning apparatus comprises a single heat source device including a compressor, a reversing valve, an outdoor heat exchanger and an accumulator; a plurality of indoor units including indoor heat exchangers and first flow controllers; a first main pipe and a second main pipe for connecting between the heat source device and the indoor units, the first main pipe having a greater diameter than the second main pipe, a first branch joint which can selectively connect one end of the indoor heat exchanger of each indoor unit to either one of the first main pipe and the second main pipe; a second branch joint which is connected to the other end of the indoor heat exchanger of each indoor unit through the first flow controllers, and which is also connected to the second main pipe through a second flow controller; the first branch joint and the second branch joint being connected together through the second flow controller; a junction device which includes the first branch joint, the second flow controller and the second branch joint, and which is interposed between the heat source device and the indoor units; and a valve which is provided between the first main pipe and the second main pipe in the heat source device, and which can selectively switch the side of the first main pipe to lower pressure and the side of the second main pipe to higher pressure.

An air conditioning apparatus comprises a switching valve for switching the flowing direction of a refrigerant discharged from a compressor to carry out either cooling operation, heating operation or defrosting operation; an outdoor heat exchanger for receiving the refrigerant supplied by the compressor through the switching valve to make the refrigerant heat exchange with air to be heat exchanged; an indoor heat exchanger for making the refrigerant heat exchange with a fluid to be heat exchanged; an oil separator which is arranged in a discharging side refrigerant pipe connecting the switching valve and the discharge port of the compressor to separate the refrigerant and a refrigerating machine oil which are discharged from the compressor; a first and second accumulators which are connected in series in an intake side refrigerant pipe connecting the switching valve and the intake port of the compressor; a first bypass passage for connecting the oil separator and the second accumulator through a solenoid valve; and a second bypass passage for connecting the oil separator and the intake port of the compressor through a metering device. As a result, the refrigeranting machine oil is returned to the compressor through the first bypass passage or the first and second bypass passages to prevent the compressor from failing due to shortage of the refrigeranting machine oil.

A refrigeration cycle apparatus comprises first and second compressors, a four-way valve, an outdoor heat exchanger, first and second expansion means, at least one indoor heat exchanger, an accumulator, a refrigerant circuit connecting these element in order, a reservoir connected to the accumulator through an overflow pipe and a refrigerant supplying pipe with a first solenoid valve and a feeding pipe with a second solenoid valve for connecting the inlet side of the expansion means to the reservoir, wherein the first and second solenoid valves are opened and closed depending on operational conditions in a refrigeration cycle.

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Wakayama, Japan

Hidekazu Tani