Mitsubishi Electric Corporation

Atsushi Kawashima

Masakazu Sato

Yasuhide Hayamaru

Masakazu Kondo

Yusuke Tashiro

Naoki Nakagawa

Shohei Ishimura

Masanori Sato

Kazunori Hatakeyama

Kazuya Watanabe

Naofumi Takenaka

Yusuke Adachi

Soshi Ikeda

Takuji Morimoto

Keiichiro Shizu

Hideto Nakao

Genta Yoshimura

Akinori Sakabe

Yoshiyuki Tada

Yuta Tokuda

Keisuke Sugiura

Provided is an air-conditioning apparatus having a low-outside-air-temperature cooling operation mode including: a refrigerant circuit; an outdoor fan; an outdoor air temperature sensor; an indoor heat exchanger intermediate temperature sensor; an indoor heat exchanger outlet temperature sensor; and a controller configured to, when a measured value from the outdoor air temperature sensor is equal to or less than a predetermined value, perform the low-outside-air-temperature cooling operation mode, wherein in the low-outside-air-temperature cooling operation mode, the controller is configured to reduce a rotation speed of the outdoor fan, and to, when a difference between a measured value from the indoor heat exchanger outlet temperature sensor and a measured value from the indoor heat exchanger intermediate temperature sensor is equal to or greater than a first threshold, increase an opening degree of the pressure reducing device.

Air-conditioning apparatus

An inference device obtains an inference value of a time taken to melt frost for defrosting temperature information representing a temperature of an outdoor-side heat exchanger included by an outdoor unit of an air-conditioning apparatus or a state of change in the temperature. In the inference device, the time taken to melt frost is a period during which the temperature of the outdoor-side heat exchanger is stable within a first range. The inference device includes a first data acquisition unit that acquires the defrosting temperature information of the air-conditioning apparatus, and an inference unit that obtains, by using a trained model that infers a time taken to melt frost from the defrosting temperature information and in accordance with the defrosting temperature information acquired by the first data acquisition unit, an inference value of the time taken to melt frost for the defrosting temperature information.

Inference device and learning device

An air-conditioning apparatus includes an indoor unit and an outdoor unit including a compressor that compresses a refrigerant and a motor drive system that drives the compressor. The motor drive system includes an inverter that converts a DC voltage into an AC voltage, and an electric motor including three stator windings with both ends open. The electric motor operates based on the AC voltage obtained by the inverter. The motor drive system further includes a connection state switching unit that has a function to change the connection state of the three stator windings included in the electric motor, and sets the connection state to a star connection at the start of operation of the air-conditioning apparatus.

When a controller performs a defrosting operation in which frost on an outdoor heat exchanger is caused to be melted, the controller is configured to perform a first defrosting control in which a switching state of a switching device is set to a first state, after the controller performs the first defrosting control, perform a second defrosting control in which the switching state of the switching device is set to a second state, and after the controller performs the second defrosting control, perform a third defrosting control in which the switching state of the switching device is set to the first state.

A refrigeration cycle apparatus includes: a compressor; an indoor heat exchanger; an outdoor heat exchanger including first and second outdoor heat exchangers; a bypass flow passage causing a discharge side of the compressor to communicate with the first or second outdoor heat exchanger; a flow control valve at the bypass flow passage; and a controller performing a heating operation in which the first and second outdoor heat exchangers operate as an evaporator and the indoor heat exchanger operates as a condenser and a simultaneous heating and defrosting operation in which part of refrigerant the compressor discharges is supplied to one of the first and second outdoor heat exchangers through the bypass flow passage, the other of the outdoor heat exchangers operates as an evaporator, the indoor heat exchanger operates as a condenser, and an upper limit frequency of the compressor changes to a value higher than in the heating operation.

Refrigeration cycle apparatus

An air-conditioning apparatus includes a main circuit in which a compressor, a flow switching device, an indoor heat exchanger, a pressure reducing device, and a plurality of parallel heat exchangers connected in parallel with each other are connected by pipes, a bypass pipe, a flow control device provided to the bypass pipe and configured to adjust a flow rate of refrigerant flowing through the bypass pipe, an evaporating pressure sensor configured to measure an evaporating pressure of the refrigerant, and a controller. The air-conditioning apparatus is configured to operate in a normal heating operation mode and a heating-defrosting operation mode. When an operation associated with the normal heating operation mode is switched to an operation associated with the heating-defrosting operation mode, the controller adjusts an opening degree of the flow control device using the evaporating pressure in the parallel heat exchanger and a driving frequency of the compressor.

An air-conditioning apparatus includes a load-side heat exchanger including a first heat exchanger disposed on a windward of a second heat exchanger in a direction of an air flow generated by an air-sending device. The air flow passing through the first heat exchanger passes through a second heat exchanger. During cooling operation, a bypass valve causes a part of refrigerant flowing through a first refrigerant pipe to flow through a coupling pipe through a bypass pipe. During heating operation, the bypass valve blocks a flow of the refrigerant flowing from the coupling pipe toward the first refrigerant pipe through the bypass pipe, and causes all of the refrigerant flowing through the coupling pipe to flow from the coupling pipe to the first heat exchanger.

In an air-conditioning apparatus, a first flow passage selection device and a second flow passage selection device each are a constant-energized-type three-way valve in which a position of a main valve can be fixed in a de-energized state. When the refrigerant circuit is switched to the cooling circuit by a flow switching device, when at least one of the first flow passage selection device and the second flow passage selection device is in a de-energized state, the first flow passage selection device or the second flow passage selection device in the de-energized state is configured to output refrigerant discharged from the compressor and input therein via the flow switching device and the bypass pipe to a corresponding one of an upper-side outdoor heat exchanger and a lower-side outdoor heat exchanger.

The refrigeration cycle apparatus includes a refrigerant circuit, a controller to control the refrigerant circuit, a bypass flow path, and a flow control valve. The bypass flow path communicates between the discharge side of the compressor and the first outdoor heat exchanger or between the discharge side of the compressor and the second outdoor heat exchanger. The flow control valve is provided to the bypass flow path. The refrigerant circuit is configured to be able to perform a heating defrosting simultaneous operation. The heating defrosting simultaneous operation is an operation of supplying part of the refrigerant discharged from the compressor to one of the first outdoor heat exchanger and the second outdoor heat exchanger via the bypass flow path, causing the other of the first outdoor heat exchanger and the second outdoor heat exchanger to serve as an evaporator, and causing the indoor heat exchanger to serve as a condenser.

A refrigeration cycle apparatus includes: a first four-way valve having first to fourth ports; a second four-way valve and a third four-way valve each having fifth to eighth ports; a compressor; a discharge pipe connecting a discharge port of the compressor and the first port; a suction pipe connecting a suction port of the compressor and the second port; a first high pressure pipe connecting the discharge pipe and the fifth ports; a second high pressure pipe connecting the third port and the first high pressure pipe; a first valve provided at the first high pressure pipe; a second valve provided at the second high pressure pipe; a low pressure pipe connecting the suction pipe and the sixth ports; a first outdoor heat exchanger connected with the seventh port of the second four-way valve; a second outdoor heat exchanger connected with the seventh port of the third four-way valve; and an indoor heat exchanger connected with the fourth port.

Growing community of inventors

Tokyo, Japan

Atsushi Kawashima