JP2007155261A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten dehumidifying time to prevent lowering of room temperature during heating operation in an unmanned state. <P>SOLUTION: A controller 6 executes an unmanned operation mode for performing heating operation for maintaining the room temperature constant in an unmanned state. When frost forms on an outdoor heat exchanger 5 during the heating operation, it performs dehumidifying operation. The controller 6 drives an indoor blower 7 without stopping it. Heat exchange on the indoor side is promoted, and dehumidifying time is shortened. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air conditioner that performs a defrosting operation when an outdoor heat exchanger is frosted during a heating operation.

  In an air conditioner in which a refrigeration cycle is formed, when the outside air temperature is low, the temperature of the outdoor heat exchanger that serves as an evaporator during heating operation decreases, and frost adheres to the surface of the outdoor heat exchanger. The lower the outside temperature, the easier frost accumulates. When the outdoor heat exchanger is frosted, the heating capacity is reduced, so that the defrosting operation is performed. In order to detect frost formation, the temperature of the outdoor heat exchanger is detected. When it is detected that the temperature of the outdoor heat exchanger has become equal to or lower than a predetermined temperature, the defrosting operation is started. In the defrosting operation, the refrigerant flow in the refrigeration cycle is reversed from that in the heating operation, and reverse frosting is performed by flowing a high-temperature and high-pressure gas refrigerant through the outdoor heat exchanger, thereby melting the frost.

When the amount of frost attached is large, the defrosting time becomes long. During the defrosting operation, when the temperature of the indoor heat exchanger decreases and the indoor blower is driven, air blowing with a cool wind feeling is performed. Even though the heating operation is being performed, the cold air blows out, which makes the user uncomfortable. Therefore, as described in Patent Document 1, the indoor blower is stopped during the defrosting operation.
JP 2004-232981 A (paragraph 0039)

  When there is a person in the room, it is preferable to stop the indoor blower during the defrosting operation. However, heating operation may be performed in an unattended state. For example, when a house is left unattended for a long time in a cold area, there is a demand to keep the room temperature constant in order to prevent the house from being damaged by freezing or the like. In the air conditioner, since heating can be performed without using fire, heating operation can be performed with confidence even in an unattended state. In response to such a request, there is an unattended operation mode in which heating operation is performed in an unattended state.

  Even in the unattended operation mode, the defrosting operation is performed when the outdoor heat exchanger is frosted. Due to the defrosting operation, the room temperature is lowered even if the indoor blower is stopped. And if defrost time becomes long, the temperature of an indoor heat exchanger will fall. When the defrosting operation is completed and the heating operation is performed again, the indoor blower is not driven and the warm air is not blown out until the temperature of the indoor heat exchanger rises. Thus, the longer the time during which the blowing is stopped, the lower the temperature of the entire room. For this reason, the room cannot be maintained at a constant temperature, and the function of the unattended operation mode is not sufficiently exhibited.

  In view of the above, an object of the present invention is to provide an air conditioner that can shorten the defrosting time when performing the defrosting operation during the unattended operation mode.

  The present invention is an air conditioner that has an indoor heat exchanger and an outdoor heat exchanger, and blows out the air heat-exchanged by the indoor blower into the room, and is used for heating to keep the room temperature in an unattended room constant And a control device that executes an unattended operation mode, and when the defrosting operation is performed during execution of the unattended operation mode, the control device drives the indoor blower without stopping. In the case of normal heating operation, the indoor blower is stopped when performing the defrosting operation.

  In the unmanned state, the indoor fan can be driven during the dehumidifying operation, and cold air can be blown into the room. At this time, in the indoor heat exchanger, heat exchange is promoted, and a high-temperature refrigerant flows into the outdoor heat exchanger. The frost in the outdoor heat exchanger melts quickly and the defrosting time is shortened. Therefore, the time until the heating operation is restarted is shortened, and the decrease in the room temperature is reduced.

  In addition, a human detection sensor that detects the presence or absence of a person is provided, and the control device executes the unattended operation mode when it is detected that it is in an unattended state during the heating operation. Thus, when the unmanned state is detected, the defrosting time can be shortened by driving the indoor blower during the defrosting operation. On the other hand, when there is a person, the indoor blower is stopped during the defrosting operation, so that the cold air does not blow out and the person is not uncomfortable.

  According to the present invention, since the dehumidifying time can be shortened during execution of the unattended operation mode, the stop time of the heating operation is shortened, and the decrease in the room temperature can be reduced. Therefore, even if the heating operation is performed for a long time, the room temperature hardly changes and the room temperature can be kept constant.

  By setting such an unattended operation mode, it is possible to respond to a request to perform a heating operation in an unattended state in order to prevent the house from being damaged by freezing or the like in a cold region. Further, the present invention can also be applied to a case where an information device such as a computer is installed and kept constant at room temperature so that the device operates stably.

  The air conditioner of this embodiment is shown in FIG. In the air conditioner, the compressor 1, the four-way valve 2, the indoor heat exchanger 3, the expansion valve 4, and the outdoor heat exchanger 5 are connected by piping to form a refrigeration cycle. The air conditioner includes a control device 6. The control device 6 drives and controls the compressor 1, the indoor blower 7, the outdoor blower 8, the expansion valve 4, and the four-way valve 2 according to the heating operation and the cooling operation. During the heating operation, as indicated by the arrows in the figure, the refrigerant flows, and during the cooling operation, the four-way valve 2 is switched and the refrigerant flows in the reverse direction.

  And the temperature detector 9 which detects the temperature of the outdoor heat exchanger 5 is provided. The temperature detector 9 is attached in the vicinity of the inlet side of the outdoor heat exchanger 5 during the heating operation, and detects the temperature of the refrigerant flowing into the outdoor heat exchanger 5 during the heating operation. A room temperature detector for detecting the temperature in the room is also provided.

  The control device 6 controls the heating operation and the cooling operation based on the temperature detected by the room temperature detector. Moreover, the control apparatus 6 judges frost formation of the outdoor heat exchanger 5 based on the temperature detected by the temperature detector 9, and performs a defrosting operation by reverse defrosting when it is judged that frost formation has occurred. When the temperature detector 9 detects that the temperature on the inlet side of the outdoor heat exchanger 5 has become equal to or lower than a predetermined temperature, the control device 6 determines that frost formation has occurred.

  In the present air conditioner, an unattended operation mode in which heating operation is performed in an unattended state is set as one of operation modes. When the unattended operation mode is selected, the control device 6 automatically performs the heating operation so as to reach the set temperature, detects the presence or absence of frost formation in the outdoor heat exchanger 5, and detects frost formation. Perform defrosting operation. During this defrosting operation, the indoor blower 7 is driven. In the operation mode in which the normal heating operation is performed, the indoor blower 7 is stopped during the defrosting operation.

  In the unattended operation mode, when the operation button is operated, the operation starts immediately, and the manual operation that continues operation until the stop button is operated, and the start date and time and stop date are set. It is possible to select an automatic operation that starts and automatically stops when the stop date and time comes.

  As described above, by performing the unattended operation mode, the heating operation is performed in the unattended room, and the room temperature is kept constant. And when performing a defrost operation, the indoor air blower 7 is driven, without stopping. By this ventilation, the indoor heat exchanger 3 exchanges heat between the indoor air and the refrigerant. The refrigerant absorbs heat and is vaporized, returns to the compressor 1, becomes high-temperature and high-pressure refrigerant gas, and is discharged to the outdoor heat exchanger 5. Therefore, since the high-temperature refrigerant flows through the outdoor heat exchanger 5, frost can be melted quickly, and the defrosting time can be shortened.

  If the temperature of the outdoor heat exchanger 5 is detected by the temperature detector 9 and the control device 6 determines that the defrosting is completed, the defrosting operation is terminated and the heating operation is performed. Thus, since the defrosting time is shortened, the stop time of the heating operation is shortened, the decrease in the room temperature is reduced, and the change in the room temperature can be minimized. Moreover, since the room is unattended, even if cold air is blown out, there is no unpleasant feeling.

  Here, in the above, the unattended operation mode is executed by an operation of an input button or a reservation setting. The unattended operation mode may be automatically executed. That is, a human detection sensor such as an infrared sensor that detects the presence or absence of a person is provided in the indoor unit, and the control device 6 determines whether it is an unattended operation mode or a normal operation mode according to the presence or absence of a person during the heating operation.

  As shown in FIG. 2, when it is determined that the vehicle is unattended during the heating operation, the mode is shifted to the unattended operation mode. If it detects that there is a person, the operation mode which performs normal heating operation will be performed. The determination of the presence / absence of a person is repeated until the driving is completed.

  Therefore, in the unmanned state, the indoor blower 7 is driven in the defrosting operation, and the defrosting time is shortened. When there is a person, the indoor blower 7 is stopped in the defrosting operation, the cold air is not blown out, and the person is not uncomfortable.

  In addition, this invention is not limited to the said embodiment, Of course, many corrections and changes can be added to the said embodiment within the scope of the present invention.

Overall configuration diagram of the air conditioner of the present invention Flow chart of heating operation according to the presence or absence of people

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Expansion valve 5 Outdoor heat exchanger 6 Control apparatus 7 Indoor fan 8 Outdoor fan 9 Temperature detector

Claims (3)

An air conditioner that has an indoor heat exchanger and an outdoor heat exchanger, and blows out the air heat-exchanged by the indoor blower into the room, and performs unattended operation for keeping the room temperature in an unattended room constant An air conditioner comprising: a control device that executes a mode, and the control device drives the indoor blower without stopping when performing a defrosting operation during execution of the unattended operation mode. An air conditioner that has an indoor heat exchanger and an outdoor heat exchanger and blows out the air heat-exchanged by the indoor blower into the room, and controls to stop the indoor blower when performing the defrosting operation during the heating operation An unmanned operation mode for performing a heating operation for keeping the room temperature in an unattended room constant is set, and the control device performs the defrosting operation while the unattended operation mode is being performed. An air conditioner characterized by being driven. The air conditioner according to claim 1 or 2, further comprising a human detection sensor for detecting the presence or absence of a person, wherein the control device executes an unattended operation mode when detecting that it is in an unattended state during heating operation. Machine.

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