JP5071063B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner, and more particularly to an air conditioner having a function of performing a drying operation of an indoor heat exchanger built in an indoor unit and suppressing the growth of mold and bacteria.

In this type of conventional air conditioner, in order to suppress the growth of mold and bacteria in the indoor heat exchanger in the indoor unit and the vicinity thereof, after the cooling operation or dehumidifying operation, the air blowing operation is performed according to the operation time. An air conditioner has been proposed in which drying operation is combined with dehumidifying operation and heating operation to shorten drying time, save energy by improving efficiency, and improve comfort (for example, see Patent Document 1). ).
JP 2001-41542 A

  However, in the configuration of the conventional air conditioner, in order to dry the condenser part of the indoor heat exchanger during the dehumidifying operation, the indoor condenser temperature must be kept at a high temperature (for example, 35 ° C. or higher). To that end, it is necessary to adjust the condensation capacity of the outdoor heat exchanger by changing or stopping the rotational speed of the outdoor blower, but when the outdoor blower is stopped, the drive efficiency of the compressor or indoor blower When the temperature is low, there is a problem that the temperature of the control device built in the outdoor unit rises.

  This invention solves the said conventional subject, and it aims at providing the air conditioner which can dry an indoor heat exchanger, suppressing the temperature rise of a control apparatus.

In order to solve the above-described conventional problems, an air conditioner of the present invention includes an outdoor unit and an indoor unit connected to the outdoor unit, and includes a compressor, a four-way valve, and outdoor heat provided in the outdoor unit. A refrigeration cycle is configured by sequentially connecting an exchanger, an expansion valve, and an indoor heat exchanger provided in the indoor unit, a dehumidifying valve is provided in the middle of the piping of the indoor heat exchanger, and the dehumidifying valve serves as an expansion mechanism comprising a operating dehumidification function, the drying operation of the indoor heat exchanger is an air conditioner that performs a combination of a heating operation and dehumidifying operation and air blowing operation, the at dehumidifying operation of the indoor heat exchanger, the indoor heat Condenser temperature detection means for outputting the temperature of the exchanger as the condenser temperature is provided, the output value of the condenser temperature detection means is compared with the target condenser temperature value, and the output value is the target condenser temperature value. Provided in the outdoor unit to be Is for controlling the rotational speed of the outer blower, when the output value is larger than the target condenser temperature value, the outdoor blower so as to be stopped
If the stop state continues for a predetermined stop limit time, the outdoor blower forcibly starts operation, even if the output value becomes larger than the target condenser temperature value during this period, The predetermined stop prohibition time is for prohibiting the stop of the outdoor fan and maintaining the operation. Even when the drive efficiency of the compressor or the indoor fan is low, the temperature of the control device is maintained while keeping the indoor condensing temperature at a high temperature. The rise can be suppressed.

  The air conditioner of the present invention can suppress the temperature rise of the control device while keeping the indoor condenser temperature at a high temperature even when the drive efficiency of the compressor and the indoor blower is low.

1st invention is comprised from the outdoor unit and the indoor unit connected to the said outdoor unit, The compressor provided in the said outdoor unit, a four-way valve, an outdoor heat exchanger, an expansion valve, and provided in the said indoor unit The indoor heat exchangers are sequentially connected to form a refrigeration cycle, a dehumidifying valve is provided in the middle of the indoor heat exchanger, and the dehumidifying valve is operated as an expansion mechanism. drying operation of the vessel is an air conditioner that performs a combination of a heating operation and dehumidifying operation and air blowing operation, and outputs the at dehumidifying operation of the indoor heat exchanger, the temperature of the indoor heat exchanger as a condenser temperature condensation An outdoor air blower provided in the outdoor unit so as to compare the output value of the condenser temperature detecting means with the target condenser temperature value and to make the output value equal to the target condenser temperature value. To control the rotation speed of When the output value becomes larger than the target condenser temperature value, the outdoor blower is assigned to be in a stopped state, and when the stopped state continues for a predetermined stop limit time, the outdoor blower is forced In the meantime, even when the output value becomes larger than the target condenser temperature value during this period, the predetermined stop prohibition time is to prohibit the outdoor fan from stopping and maintain the operation . Even when the drive efficiency of the compressor or the indoor blower is low, the temperature increase of the control device can be suppressed while keeping the indoor condensation temperature at a high temperature.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
Hereinafter, the air conditioner in the 1st Embodiment of this invention is demonstrated using FIGS.

  FIG. 1 shows the refrigeration cycle of the air conditioner in the present embodiment. The compressor 6, the four-way valve 8, the outdoor heat exchanger 10, the expansion valve 12, and the indoor unit 4 provided in the outdoor unit 2 are shown. The provided indoor heat exchanger 14 is sequentially connected by a refrigerant pipe 7 to constitute a heat pump refrigeration cycle, and a dehumidifying valve 13 is provided in the middle of the indoor heat exchanger 14 pipe.

  The indoor blower 16 blows indoor air to the indoor heat exchanger 14, the outdoor blower 18 blows outdoor air to the outdoor heat exchanger 10, the room temperature sensor 20 detects the room temperature, and the indoor heat exchanger. The pipe temperature sensor 22 detects the indoor condenser temperature during the dehumidifying operation of the indoor heat exchanger 14, and the control device 24 controls the refrigeration cycle.

  Here, the drying operation is performed by removing moisture from the indoor heat exchanger 14 in which condensation or the like has been generated by the cooling operation or the dehumidifying operation of the air conditioner and drying the air, and increasing the temperature to suppress the activity of mold. This is a combination of operation, dehumidification operation, and heating operation.

  FIG. 2 shows a timing chart when the drying operation of the indoor heat exchanger is performed.

  As shown in FIG. 2, when the drying operation of the indoor heat exchanger 14 is performed, the compressor 6 and the outdoor blower 18 are stopped and the cooling or dehumidifying operation is stopped at time t1. In addition, the indoor blower 16 whose rotation speed has been determined according to the operation mode up to time t1 and the set air volume of the remote controller (not shown) is set to the first speed (for example, about 900 rpm), and the first time Blowing operation is performed. At this time, the opening degree of the expansion valve 12 is controlled so as to reach a target discharge temperature determined in accordance with the compressor frequency during the cooling or dehumidifying operation (discharge temperature control), and the four-way valve 8 is OFF. The refrigeration cycle during cooling operation is maintained.

  Returning to the timing chart of FIG. 2, the drying operation of the indoor heat exchanger 14 will be further described. From time t1 to time t2 (for example, about 3 minutes), the air blowing operation is performed, and at time t2, the compressor 6 is While the operation is resumed at the first operating frequency (for example, about 16 Hz) with the frequency suppressed, the outdoor blower 18 is controlled in rotation speed so that the indoor condenser temperature becomes the target condenser temperature Ta (for example, 39 ° C.). Is performed (condenser temperature control) and dehumidifying operation is performed.

  During the dehumidifying operation, the expansion valve 12 is set to the maximum pulse (for example, about 480 pulses) and is fully opened, and the dehumidifying valve 13 operates as an expansion mechanism. The indoor blower 16 operates at a second speed (for example, about 500 rpm) lower than the first speed.

  After completion of the dehumidifying operation for a predetermined time (for example, about 55 minutes), at time t3, the second blowing operation is started, the compressor 6 and the outdoor blower 18 are stopped, and the indoor blower 16 is moved from the second speed to the second speed. The speed is changed to 1. In addition, the pulse number of the expansion valve 12 is maintained continuously from the maximum pulse.

  At a time t4 after a lapse of a predetermined time (for example, about 3 minutes) from the time t3, the four-way valve 8 is switched to enter the heating operation, the indoor heat exchanger 14 is dried, and the moisture generated during the cooling or dehumidifying operation is removed. Remove with dust. During the heating operation, the compressor 6 is maintained at a second operation frequency (for example, about 30 Hz) higher than the first operation frequency, and the outdoor blower 18 is operated at the same speed as in the dehumidifying operation. Further, the expansion valve 12 is set to a predetermined pulse (for example, about 400 pulses) smaller than the maximum pulse, and the indoor blower 16 is set to the second speed again.

  After completion of the heating operation for a predetermined time (for example, about 30 minutes), at time t5, the four-way valve 8 is turned off to return to the refrigeration cycle during the cooling operation, the compressor 6 and the outdoor blower 18 are stopped, and the indoor blower 16 Is changed from the second speed to the first speed, and the third blowing operation is performed. At this time, the number of pulses of the expansion valve 12 is reset to the maximum pulse from the predetermined pulse.

  After performing the third blowing operation for a predetermined time (for example, about 3 minutes), the state returns to the state before the drying operation of the indoor heat exchanger 14 (cooling or dehumidifying operation) (FIG. 3 shows a case of stopping. ing).

  Here, during the drying operation of the indoor heat exchanger 14, a total of three air blowing operations are performed before and after the dehumidifying operation and the heating operation. This is a large pressure difference between the suction pressure and the discharge pressure of the compressor 6. This is to make the suction pressure and the discharge pressure uniform (startup protection of the compressor 6).

  FIG. 3 shows an example of a block diagram of the control device 24, and controls the outdoor blower 18 during the dehumidifying operation during the drying operation.

  In the block diagram of FIG. 3, the outdoor blower control means 32 rotates the outdoor blower 18 so that the output value Tt of the condenser temperature detection means 30 to which the output of the pipe temperature sensor 22 is inputted becomes a predetermined target condenser temperature Ta. Control the number. Reference numeral 25 denotes a time measuring means for measuring the time during which the operation of the outdoor fan 18 is stopped (stop time).

  FIG. 4 shows a control flowchart of the outdoor blower 18 during the dehumidifying operation during the drying operation. Table 1 shows an allocation table of the rotational speed tap and the rotational speed of the outdoor blower 18.

  In the flowchart of FIG. 4, when the dehumidifying operation at the time of the drying operation is started, the outdoor blower 18 is operated with a predetermined rotational speed tap (for example, tap 4) (step S1).

  Every predetermined time (for example, about 1 minute), the output value Tt of the condenser temperature detecting means 30 to which the output of the pipe temperature sensor 22 is inputted is compared with the target condenser temperature Ta (step S3), and Ta + ΔT <Tt If so, the rotational speed tap is increased (step S4), and if Ta−ΔT> Tt (step S5), if the rotational speed tap is not tap 0, the rotational speed tap is lowered by 1 tap (step S6).

  In the case of Ta + ΔT ≧ Tt ≧ Ta−ΔT, the current rotational speed tap is maintained. Here, ΔT is ΔT ≧ 0, for example, 1 ° C. When the rotation speed tap is tap 0, tap 0 is maintained even when Ta + ΔT <Tt. When tap 0 exceeds stop limit time T1 (for example, about 10 minutes) (step S10), outdoor fan 18 restarts operation with tap 1 (step S11), and after restart, stop prohibition time T2 (for example, about 2 minutes) prohibits the tap 0 and keeps the tap 1 even when Ta + ΔT <Tt during operation with the tap 1 (step S14). Here, the temperature of the control device 24 that has risen while the outdoor blower 18 is stopped is cooled during the stop inhibition time T2.

  As described above, according to the present embodiment, during the dehumidifying operation in the drying operation of the indoor heat exchanger 14, the stop time of the outdoor blower 18 and the stop prohibition time are provided, and the stop state of the outdoor blower 18 is the stop state. When the time limit is reached, the operation of the outdoor blower 18 is resumed, and the stop of the outdoor blower 18 is prohibited until the stop prohibition time has elapsed. While the indoor condensing temperature is kept high, an increase in the temperature of the control device 24 can be suppressed.

  The air conditioner according to the present invention provides an outdoor fan stop limit time and a stop prohibition time during a dehumidifying operation in the drying operation of the indoor heat exchanger, and when the outdoor fan stop state reaches the stop limit time, the outdoor fan Controls while maintaining the inlet temperature of the indoor heat exchanger at a high temperature even when the drive efficiency of the compressor or indoor fan is low by prohibiting the outdoor fan from stopping until the stop prohibition time has elapsed. Since the temperature rise of the apparatus can be suppressed, it is useful not only as a home air conditioner but also as a commercial air conditioner.

Schematic which shows the refrigerating cycle of the air conditioner in Embodiment 1 of this invention. Timing chart for the drying operation of the indoor heat exchanger of the air conditioner Block diagram of the control device for the air conditioner Flow chart of control of outdoor fan during dehumidifying operation during drying operation of the air conditioner

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Outdoor unit 4 Indoor unit 6 Compressor 8 Four-way valve 10 Outdoor heat exchanger 12 Expansion valve 13 Dehumidification valve 14 Indoor heat exchanger 16 Indoor blower 18 Outdoor blower 20 Room temperature sensor 22 Piping temperature sensor 24 Control apparatus 30 Condensing temperature detection means

Claims (1)

An outdoor unit, an indoor unit connected to the outdoor unit, a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve provided in the outdoor unit, and an indoor heat exchanger provided in the indoor unit Are connected in sequence to form a refrigeration cycle, a dehumidifying valve is provided in the middle of the piping of the indoor heat exchanger, and the dehumidifying valve is operated as an expansion mechanism, and the drying operation of the indoor heat exchanger is blown an air conditioner for performing a combination of the heating operation and the operation and the dehumidifying operation, the at dehumidifying operation of the indoor heat exchanger, equipped with a condenser temperature detecting means for outputting a temperature of the indoor heat exchanger as a condenser temperature The output value of the condenser temperature detecting means is compared with the target condenser temperature value, and the rotational speed of the outdoor fan provided in the outdoor unit is controlled so that the output value becomes the target condenser temperature value. The output value is When the outdoor condenser becomes larger than the target condenser temperature value, the outdoor fan is assigned to be in a stopped state, and when the stopped state continues for a predetermined stop limit time, the outdoor fan is forcibly started. In the meantime, even when the output value becomes larger than the target condenser temperature value during this period, the predetermined stop prohibition time prohibits the stop of the outdoor fan and maintains the operation. .

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