Mitsubishi Electric Corporation

Takayoshi Honda

Osamu Morimoto

Daisuke Shimamoto

Koji Nishioka

Koji Azuma

Yuji Motomura

Tatsuo Ono

Tomokazu Kawagoe

An air-conditioning apparatus includes a refrigeration cycle that includes an intermediate heat exchanger configured to exchange heat between a heat source side refrigerant and a heat medium different from the heat source side refrigerant. The apparatus further includes a heat medium circuit that includes at least one pump configured to circulate the heat medium in the intermediate heat exchanger. A controller in the apparatus further activates the pump to circulate the heat medium through the heat medium circuit when, during suspension of an air conditioning operation, the detected temperature of outdoor air is at or below a first predetermined temperature and a first predetermined period of time has elapsed since the pump was stopped.

Air-conditioning apparatus with temperature controlled pump operation

Upon switching of an air-conditioning apparatus from an operation mode in which all of indoor units each including a use side heat exchanger are in non-operation to another operation mode in which at least one of the indoor units starts a cooling operation mode or a heating operation mode, a heat medium conveyed to the use side heat exchanger included in the indoor unit which has received a start instruction is cooled or heated to a predetermined temperature by a heat source side refrigerant, and after that, an air-sending device included in the indoor unit which starts the cooling operation mode or the heating operation mode is actuated.

Air-conditioning apparatus

An air conditioning apparatus includes a refrigerant circuit in which a compressor for compressing heat source-side refrigerant, a first refrigerant channel switching device, a heat source side heat exchanger, an expansion device, and intermediate heat exchangers for performing heat exchange between the heat source-side refrigerant and a heat medium different from the heat source-side refrigerant are connected by pipes. Also, the air conditioning apparatus includes a heat medium circuit in which pumps for circulating the heat medium to be used for the heat exchange performed by the intermediate heat exchangers, a use-side heat exchanger, and channel switching devices for switching passages of the heat medium heated or cooled to the use-side heat exchanger are connected by pipes. The heat medium circuit includes a strainer configured to capture foreign matter contained in the heat medium; and a heat medium relay unit control device configured to perform an operation that causes the strainer to capture foreign matter contained in the heat medium circuit during construction of the heat medium circuit.

When starting a cooling operation mode from a non-operating mode, the blower device of the indoor unit from which the start command is originated is operated. When starting a heating operation mode from a non-operating mode, the blower device of the indoor unit from which the start command is originated is operated after the heat medium temperature becomes equal to or greater than a preconfigured temperature.

An air-conditioning apparatus includes actuation control means including an actuation unit that sequentially opens heat medium flow switching devices or heat medium flow control devices on a one-by-one basis. The actuation control means performs control in such a manner that start time of driving of pumps is later than start of actuation of the heat medium flow switching devices and the heat medium flow control devices.

An air-conditioning apparatus includes a refrigeration cycle that includes one or more intermediate heat exchangers, exchanging heat between a heat source side refrigerant and a heat medium different from the heat source side refrigerant, a heat medium circuit that includes at least one pump configured to circulate the heat medium for heat exchange by the intermediate heat exchanger, a use side heat exchanger configured to exchange heat between the heat medium and air in an air-conditioning target space, and flow switching valves configured to switch between passing the heated heat medium through the use side heat exchanger and passing the cooled heat medium through the use side heat exchanger and in which the pump, the use side heat exchanger, and the flow switching valves are connected by pipes, and a controller configured to calculate an actual temperature efficiency ratio based on a temperature at a heat medium inlet of the heat exchanger in the heat medium circuit and determine whether a flow rate of the heat medium in the heat medium circuit is abnormal based on the actual temperature efficiency ratio and a set reference temperature efficiency ratio.

An air-conditioning apparatus is provided to which, even when a heat medium leaks from a heat medium circuit for some reason and air enters the heat medium circuit, the heat medium circuit can be automatically refilled with the heat medium before a pump is heated and damaged. When it is determined that a rotational speed of a pump is higher than an upper rotational speed limit, the controller determines that the heat medium is leaking from the heat medium circuit and performs a heat-medium-introducing and air-purging control process.

A refrigerant circuit is configured by connecting, by pipes, a compressor that compresses a heat-source-side refrigerant, a first refrigerant flow switching device, a heat-source-side heat exchanger, an expansion device, and one or more intermediate heat exchangers that exchange heat between a heat-source-side refrigerant and a heat medium that is different from the heat-source-side refrigerant. A controller performs control of pumps to drive the pumps at a specific pump capacity or higher to circulate the heat medium at a time when a heat recovery defrosting operation for causing the heat-source-side refrigerant that has been heated by the heat medium in the intermediate heat exchangers to flow into the heat-source-side heat exchanger for defrosting purposes.

In an air-conditioning apparatus including a plurality of indoor units connected to a heat medium converter and a plurality of remote controllers respectively provided for the indoor units, the remote controllers each include a temperature sensor that detect a temperature of a corresponding space to be air-conditioned, and are each configured to communicate with a heat medium converter controller of the heat medium converter and an indoor unit controller of the corresponding indoor unit, transmit an instruction to start and stop an operation and data related to rotation speed of an indoor air-sending device to the corresponding indoor unit controller, and transmit the instruction to start and stop the operation, and a target temperature and a temperature detected by the temperature sensor or a difference therebetween, to the heat medium converter controller.

An air-conditioning apparatus includes a temperature sensor for detecting a temperature of the heat medium sent from each of the intermediate heat exchangers to each of the use-side heat exchangers, and a temperature of the heat medium that has exited each of the use-side heat exchangers, an opening degree controller for regulating a flow rate of the heat medium through each of the heat medium flow control devices, and a computing unit for computing a usage capacity of each of the indoor units from a rotation speed of the pump, an opening degree of each of the heat medium flow control devices, temperatures detected by the temperature sensors, and power consumption of each of the indoor units, and proportionally dividing the power consumption for a common portion among each of the indoor units based on the computed usage capacity and the power consumption of the common portion.

A valve body in each of heat medium flow switching devices has an open portion. When the length from a connection between a first passage pipe and a third passage pipe to a connection between a second passage pipe and the third passage pipe is defined as a casing passage width, a valve body passage width of the open portion in a direction substantially perpendicular to the axis of the valve body is smaller than the casing passage width.

Flow switching device and air-conditioning apparatus including the same

An air-conditioning apparatus includes a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, an expansion device, and a refrigerant flow path in at least one intermediate heat exchanger are connected by a refrigerant pipe, and a heat medium circuit in which a pump, a use-side heat exchanger, and a heat-medium flow path in the at least one intermediate heat exchanger are connected by a heat-medium conveying pipe, the heat medium circuit being configured to cause a heat medium to circulate therethrough. The at least one intermediate heat exchanger comprises a plurality of intermediate heat exchangers. The plurality of intermediate heat exchangers are operative in a heating only operation mode, a cooling only operation mode, and a cooling and heating mixed operation mode in which some of the intermediate heat exchangers serve as the condenser and others of the intermediate heat exchangers serve as the evaporator.

Air-conditioning apparatus and method of designing same

A method for selecting a heat medium in installing an air-conditioning system includes: determining power required for use side heat exchangers corresponding to a plurality of air-conditioned spaces; calculating a total refrigerant amount required when a refrigerant is circulated through all the use side heat exchangers having the determined power; calculating a refrigerant concentration when the total refrigerant amount leaks to each air-conditioned space using the refrigerant, for each air-conditioned space; determining the refrigerant concentration for each air-conditioned space exceeds a predetermined limit concentration; when any air-conditioned space exceeds the limit concentration, selecting, as a nontoxic medium, the circulation heat medium of the use side heat exchanger installed in one of the air-conditioned spaces; and calculating a total refrigerant amount required when the refrigerant is circulated through all other use side heat exchangers.

Method for selecting heat medium of use side heat exchanger in installing air-conditioning system

In an air-conditioning apparatus, when a plurality of pumps are all operating and a heat exchange amount in use-side heat exchangers is equal to or lower than a lower limit of a thermal capacity that can be conveyed in a heat medium circuit B, before at least one of the plurality of pumps is stopped, a refrigerant flow path in the intermediate heat exchanger connected to the pump that is to be stopped is closed. Then, the at least one of the plurality of pumps is stopped, and the thermal capacity required in at least one of the use-side heat exchangers in the rest of the plurality of pumps is conveyed.

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Tokyo, Japan

Takayoshi Honda