Daikin Industries, Ltd.

Akitoshi Ueno

Hiroshi Komano

Masaaki Takegami

Yuji Fujimoto

Mikio Kajiwara

Takeo Ueno

Yuusuke Fujimoto

Makoto Ikemiya

Kazuhide Mizutani

Takenori Mezaki

Takuya Horita

Shuichi Taguchi

Daisuke Okamoto

Naoto Tomioka

Yousuke Ohnishi

Yohei Nishide

Masaaki Adachi

Hideaki Kuriyama

Isao Kondo

Kiichirou Satou

Yoshikazu Uehara

Hisaaki Takaoka

Masataka Nakano

Toshiaki Mukaidani

Kouichi Kita

Yasutoshi Mizutani

Yoshihiro Nishioka

Naoto Kimura

Sadanao Kurokawa

Noriyasu Kawakatu

Shougo Mabuchi

Takuya Kitao

Ryuuji Takeuchi

A refrigeration apparatus includes a gas-liquid separator on a downstream side of a radiator, and a refrigerant circuit in which a high pressure of a refrigeration cycle is equal to or higher than a critical pressure. The refrigeration apparatus includes a gas passage that communicates with the gas-liquid separator and at least one of a plurality of heat exchangers provided in the refrigerant circuit, and an opening and closing device that opens and closes the gas passage. There is provided a controller that opens the opening and closing device when a pressure in the gas-liquid separator is equal to or higher than a predetermined value in a state where a compression unit of the refrigerant circuit is stopped to suppress occurrence of pressure abnormality inside the gas-liquid separator in a state where a compressor is stopped.

Heat source unit and refrigeration apparatus

A heat source unit connected to a utilization unit includes a compressor, a first heat exchanger, a first expansion valve, and a receiver. The heat source unit further includes a first cooler and a second cooler. The first cooler cools a primary refrigerant flowing from the receiver toward the utilization unit. The second cooler cools the primary refrigerant flowing from the first heat exchanger functioning as a radiator toward the first expansion valve, using a coolant other than outdoor air.

If a first condition that an intermediate pressure corresponding to a pressure of an intermediate flow path is greater than a predetermined value is satisfied in an operation in which first, second, and third compressors are operated, the control unit executes a first action of increasing the number of revolutions of the third compressor.

A heat source controller performs a first operation when a compression element is in a stopped state and a pressure in a receiver exceeds a predetermined first pressure. The heat source controller allows an inlet of the compression element to communicate with the receiver, and drives the compression element in the first operation.

A flow path switching mechanism () includes first to fourth flow paths () and opening and closing mechanisms (V, V, V, V) that can each open and close a corresponding one of the flow paths (). A first connection point (C) connecting an inflow portion of the first flow path () and an inflow portion of the second flow path () is connected to a discharge portion of a compression unit (). A second connection point (C) connecting an outflow portion of the first flow path () and an inflow portion of the third flow path () is connected to a gas-side end of a heat source heat exchanger (). A third connection point (C) connecting an outflow portion of the second flow path () and an inflow portion of the fourth flow path () is connected to a gas-side end of a second utilization heat exchanger (). A fourth connection point (C) connecting an outflow portion of the third flow path () and an outflow portion of the fourth flow path (), and a gas-side end of a first utilization heat exchanger () are connected to a suction portion of the compression unit ().

Refrigeration device

A multistage compression system uses refrigerant and oil. The multistage compression system includes a low-stage compressor that compresses the refrigerant, a high-stage compressor that further compresses the refrigerant compressed by the low-stage compressor, an oil return pipe that returns the oil discharged by the high-stage compressor to the low-stage compressor, and an oil discharge pipe that discharges the oil in the low-stage compressor. The low-stage compressor includes a compression part that compresses the refrigerant, a motor that drives the compression part, and a container that houses the compression part and the motor. The container forms a high-pressure space storing compressed refrigerant. Inside of the oil return pipe and inside of the oil discharge pipe are connected to the high-pressure space.

Multistage compression system

A multistage compression system uses refrigerant and oil. The multistage compression system includes a low-stage compressor that compresses the refrigerant, a high-stage compressor that further compresses the refrigerant compressed by the low-stage compressor, refrigerant pipes that introduce the refrigerant compressed and discharged by the low-stage compressor into a suction part of the high-stage compressor, an intercooler, and an oil discharge pipe. The intercooler cools the refrigerant discharged by the low-stage compressor before the refrigerant is sucked into the high-stage compressor. The intercooler is disposed between the refrigerant pipes. The oil discharge pipe discharges the oil in the low-stage compressor. The oil discharge pipe connects the low-stage compressor and a portion of the refrigerant pipes. The portion of the refrigerant pipes is on an upstream side of the intercooler.

A container refrigeration device aims to prevent low temperature damage to freight in a container. The container refrigeration device includes: a temperature controlling section () configured to perform, in a switchable manner, first temperature control under which a temperature inside the container (C) is controlled based on a blown air temperature (Tss) and second temperature control under which the temperature inside the container (C) is controlled based on a suction air temperature (Trs) during dehumidification operation; and a control switching section () configured to switch the first temperature control to the second temperature control when the blown air temperature (Tss) is higher than the suction air temperature (Trs) during the dehumidification operation in which part of a refrigerant discharged from a compressor () is allowed to flow into a reheat heat exchanger ().

Refrigeration device for container

According to the present disclosure, in a container refrigeration apparatus configured to cool the inside of a container, the accuracy of determination of occurrence of a lock abnormality and a connection abnormality of a motor is increased, and erroneous detection of the motor abnormalities is reduced or prevented. The container refrigeration apparatus of the present disclosure includes an abnormality determinator configured to compare a value for current flowing through an in-compartment motor with a preset current threshold to determine occurrence of the motor abnormalities of the in-compartment motor, and a threshold changer configured to change the current threshold of the abnormality determinator in accordance with a supply voltage for each supply frequency of a power supply configured to supply power to the in-compartment motor.

Transport refrigeration apparatus

A container refrigeration device aims to improve dehumidification performance of the container refrigeration device. The container refrigeration device is configured to perform, in accordance with a dehumidification load, first dehumidification control under which air having passed through an evaporator is heated by exchanging heat with a refrigerant in a reheat heat exchanger, and blown into an inside of a container, and second dehumidification control under which a pressure of the refrigerant discharged from a compressor and flowing into the reheat heat exchanger is caused to be higher than a pressure of the refrigerant discharged from the compressor under the first dehumidification control, and a flow rate of the refrigerant discharged from the compressor is regulated such that a temperature inside the container is within a predetermined temperature range.

A two-stage cascade refrigerating system including a primary side refrigerant circuit, and at least one secondary side refrigerant circuit. The receiver of the primary refrigerant circuit is arranged such that a first pipe is introduced to the inside of the container such that an open of the first pipe is located at an inside upper portion of the container, and a second pipe is introduced to the inside of a container such that an open end of the second pipe is located at an inside lower portion of the container. The receiver of the secondary side refrigerant circuit(s) is reversible in refrigerant circulation and is arranged such that a first pipe and a second pipe are introduced to the inside of the container such that open ends of both pipes are located at an inside lower position of the container.

Two-refrigerant refrigerating device

A cold-insulation container is disclosed which includes a cold-insulation container main body ( ) which is a heat-insulation structure and a door ( ) for opening and closing an opening portion ( ) of the cold-insulation container main body ( ). Provided in the cold-insulation container main body ( ) are a refrigerating apparatus ( ) and a cold-storage device ( ) which is cooled by the refrigerating apparatus ( ) and stores cold. An external wall of the cold-insulation container main body ( ) and the door are formed from a synthetic resin material.

Cold insulated cabinet

The refrigerating system includes a low stage side refrigerant circuit ( ) formed by connecting a low stage side compressor ( ), a cascade condenser ( ), a low stage side receiver ( ), a low stage side expansion valve ( ) formed of a temperature-sensitive expansion valve and an evaporator ( ) in this order. The system also includes a high stage side refrigerant circuit ( ) formed by connecting a high stage side compressor ( ), a condenser ( ), a high stage side receiver ( ), a high stage side expansion valve ( ) formed of a motor-operated expansion valve and the cascade condenser ( ) in this order. The opening of the high stage side expansion valve ( ) is adjusted so that the pressure sensed by a high-pressure sensor (SPH ) for sensing the high pressure in the low stage side refrigerant circuit ( ) reaches a predetermined target high pressure.

Refrigerator

It includes a heat source side refrigerant circuit ( ) having a plurality of refrigerant heat exchangers ( ), and a plurality of user-side refrigerant circuits ( ). A high pressure gas pipe (LG-H) is connected to the discharge side of outdoor compressors ( ) of the heat source side refrigerant circuit ( ), a low pressure gas pipe (LG-L) to the suction side of the outdoor compressors ( ), and a liquid pipe (LL) to the liquid side of outdoor heat source side heat exchangers ( ). The liquid pipe (LL) is connected to one end side of each refrigerant heat exchanger ( ). The other end side of the respective refrigerant heat exchangers ( ) can be switched by three-way valves ( ) between a state where it is communicated to the high pressure gas pipe (LG-H) and another state where it is communicated to the low pressure gas pipe (LG-L). The liquid pipe (LL) is connected to one end side of a user-side heat exchanger ( ) of the heat source side refrigerant circuit ( ). The other end side of the user-side heat exchanger ( ) can be switched by a three-way valve ( ) between a state where it is communicated to the high pressure gas pipe (LG-H) and another state where it is communicated to the low pressure gas pipe (LG-L).

Refrigeration system

A first refrigeration circuit for a refrigerating apparatus which is formed into a two-stage cascade refrigerating cycle by establishing connection between a high temperature-side refrigerant circuit and a low temperature-side refrigerant circuit through a refrigerant heat exchanger, and a second refrigeration circuit which is formed into a refrigerating cycle different from that of the first refrigeration circuit are provided. A liquid piping line of the high temperature-side refrigerant circuit and a liquid piping line of the second refrigeration circuit are connected together through a first connection piping line and a suction-side gas piping line of the high temperature-side refrigerant circuit and a suction-side gal line of the second refrigeration circuit are connected together through a second connection piping line. Switching members are disposed for selective circulation of a refrigerant of the second refrigeration circuit to the refrigerant heat exchanger of the first refrigeration circuit through each of the connection piping lines, whereby, even when a heat source equipment stops operating in a two-stage cascade refrigerating cycle refrigeration system applied to a showcase or the like, it becomes possible to achieve continuation of refrigeration operation.

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Osaka, Japan

Akitoshi Ueno