JP2006226567A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of preventing defrosting when frost is not attached to an outdoor heat exchanger by integrating time only when a period of an overload protection operation in a heater operation exceeds a predetermined value. <P>SOLUTION: In an overload condition in the heater operation of this air conditioner, a defrosting operation is executed by determining a stop time of an outdoor blower 6, and by integrating time only when frost is attached to the outdoor heat exchanger 3, whereby the air conditioner is allowed to always effectively execute the defrosting operation without damaging a compressor 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an air conditioner equipped with defrosting control.

 Conventionally, in the heating operation of an air conditioner, when the indoor heat exchanger temperature rises to a preset overload protection operation start temperature, the operation of the outdoor blower is stopped, and when the indoor heat exchanger temperature falls to the overload protection operation release temperature, the outdoor blower operation is stopped. Some were equipped with an overload protection function to resume the operation.

 For example, in the defrosting control device for an air conditioner according to the invention described in Patent Document 1, the outdoor blower stops during the overload protection operation during heating operation, so that the evaporation pressure is significantly reduced and the temperature becomes below freezing point. Since a large amount of condensed water adhering to the outdoor heat exchanger freezes, the stop time of the outdoor fan during overload protection operation is integrated, and the defrosting operation is performed when the integrated value reaches a predetermined value. Yes.

 With this configuration, since the defrosting operation is performed when the outdoor fan stop time accumulated during the overload protection operation reaches a predetermined value, it could be melted before the ice of the outdoor heat exchanger grows greatly .

 Below, the defrost control apparatus of the conventional air conditioner is demonstrated.

 FIG. 8 shows a conventional air conditioner. 1 is a compressor, 2 is a four-way valve, 3 is an outdoor heat exchanger, 4 is a decompressor using a capillary tube or the like, 5 is an indoor heat exchanger, and 1, 2, 5, 4, Then, the flow returns to the compressor 1 via the four-way valve 2 again.

 6 is an outdoor fan for air-cooling the outdoor heat exchanger 3 and the like, 7 is an indoor fan for sending the air heat-exchanged by the indoor heat exchanger 5 into the room, 8 is a compressor 1, a four-way valve 2, and an outdoor fan 6 In addition to the indoor blower 7, an outdoor unit control unit 9 for controlling the air direction adjusting device and the like (not shown) is also provided.

 The outdoor unit control unit 8 detects the outside air temperature detected by a temperature sensor (not shown), the temperature of the outdoor heat exchanger 3, the high pressure detected by the pressure sensor 10, and a current sensor (not shown). Information on the input current and the like is input via the A / D converter 11, and the indoor unit controller 9 detects the indoor temperature detected by the temperature sensor 12 and the indoor heat exchanger 5 detected by the temperature sensor 13. Information relating to temperature and the like is input via the A / D converter 14.

 In the heating operation, when the temperature of the indoor heat exchanger 5 rises to a preset overload protection operation start temperature, the operation of the outdoor fan 6 is stopped, and the temperature of the indoor heat exchanger 5 reaches the overload protection operation release temperature. By repeating the overload protection operation of restarting the operation of the outdoor blower 6 when it descends, it is designed to prevent the icy expansion of the outdoor heat exchanger 3, but the stop time of the outdoor blower 6 in the overload protection operation is integrated. When the integrated value reaches a predetermined value, the defrosting operation is started.

 If the defrosting operation is performed when the outside air temperature is higher than a certain level, the outdoor heat exchanger 3 is not frosted, so that an excessive pressure exceeding the allowable value may be applied to the inlet side of the compressor 1. .

 Therefore, in the conventional example, in order to eliminate such a problem, the input current during the defrosting operation is detected, and when the value exceeds a predetermined value, the defrosting operation is terminated.

Further, when the defrosting operation is completed, the integrated value of the stop time of the outdoor fan 6 is returned to zero to prepare for the next integration.
JP-A-7-55222

However, in the conventional configuration, since it enters the defrosting operation only by accumulating the time of the overload protection operation, the defrosting operation is performed even when the outdoor heat exchanger 3 is not frozen, There is a possibility that an excessive pressure is temporarily applied to the compressor 1 to shorten the life of the compressor.
The present invention solves the above-mentioned conventional problem, and frost is formed on the outdoor heat exchanger 3 by accumulating only when the overload protection operation time during heating operation exceeds a predetermined time. An object of the present invention is to provide an air conditioner that can prevent defrosting when it is not.

In order to solve the conventional problems, an air conditioner of the present invention includes a constant speed compressor, a four-way valve, an outdoor heat exchanger, a decompressor, and an indoor heat exchanger in a refrigerant circuit. An indoor heat exchange temperature detection means configured to circulate and detect the indoor heat exchanger, an outdoor fan disposed in the outdoor heat exchanger, and the indoor heat exchange temperature detection means are set in advance during heating operation. In an air conditioner comprising an overload protection device that stops the operation of the outdoor fan when the temperature rises to the overload protection operation start temperature and restarts the operation of the outdoor fan when the temperature drops to the overload protection operation release temperature, An outdoor fan stop time calculating means for calculating a stop time of the outdoor blower during an overload protection operation, an outdoor fan stop time calculated by the outdoor fan stop time calculating means, and a preset overload protection operation time. In comparison, an overload protection operation integration means for integrating only when the outdoor fan stop time is longer than the overload protection operation time is provided, and the overload protection operation integration time integrated by the overload protection operation integration means is previously provided. When the set accumulated time is reached, the defrosting operation control device starts the defrosting operation so that the compressor is not always damaged by the useless defrosting operation such as when the outdoor heat exchanger is not frosted. The defrosting operation can be effectively performed.

  The air conditioner of the present invention can always be effectively defrosted without performing a useless defrosting operation such as when the outdoor heat exchanger is not frosted even in an overload condition during heating operation. .

The first invention comprises a constant speed compressor, a four-way valve, an outdoor heat exchanger, a decompressor, and an indoor heat exchanger, and is configured to circulate in a refrigerant circuit, wherein the indoor heat exchanger When the indoor heat exchange temperature detecting means rises to a preset overload protection operation start temperature during heating operation, the indoor heat exchange temperature detecting means for detecting the indoor heat exchange temperature detecting means and an outdoor fan arranged in the outdoor heat exchanger In an air conditioner comprising an overload protection device that stops the operation of the outdoor blower and restarts the operation of the outdoor blower when the temperature drops to the overload protection operation release temperature, the outdoor blower of the outdoor blower is operated during the overload protection operation. The outdoor blower stop time calculation means for calculating the stop time, the outdoor blower stop time calculated by the outdoor blower stop time calculation means and the preset overload protection operation time are compared, and the outdoor blower stop time is more Overload protection operation integration means for integrating only when it is longer than the overload protection operation time is provided, and defrosting is performed when the overload protection operation integration time integrated by the overload protection operation integration means reaches a preset integration time By starting the defrosting operation with the operation control device, air that can be effectively defrosted at all times without damaging the compressor by useless defrosting operation such as when the outdoor heat exchanger is not frosted A harmony machine can be provided.
In the second invention, the overload protection operation integration time of the first invention is reset more particularly when the outdoor fan stop time is shorter than the overload protection operation time, so that the outdoor heat exchanger can be more reliably It is possible to prevent useless defrosting operation such as when frost is not attached.
In the third aspect of the invention, in particular, when the indoor heat exchanger temperature falls to the overload protection operation release temperature after the start of the defrosting operation of the first aspect of the invention reaches the preset integration time. The four-way valve switching sound at the start of the defrosting operation can be reduced and the useless defrosting operation such as when the outdoor heat exchanger is not frosted can be prevented more reliably.
In the fourth aspect of the invention, in particular, when the predetermined time from the start of the heating operation of the first aspect of the invention is not integrated with the overload protection operation time, the outdoor heat exchanger is more reliably and reliably not frosted. Useless defrosting operation can be prevented and the heating operation ratio can be improved.

 In the fifth aspect of the invention, particularly when the outdoor heat exchanger temperature when the temperature drops to the overload protection operation release temperature of the first aspect of the invention and restarts the operation of the outdoor fan is equal to or higher than a predetermined temperature, the outdoor fan stop time is integrated. By not, it is possible to reliably prevent useless defrosting operation such as when the outdoor heat exchanger is not frosted.

The sixth aspect of the invention resets the overload protection operation integration time particularly when the outdoor heat exchanger temperature when the temperature drops to the overload protection operation release temperature and restarts the operation of the outdoor fan is equal to or higher than a predetermined temperature. Thus, it is possible to reliably prevent useless defrosting operation such as when the outdoor heat exchanger is not frosted.
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)
FIG. 1 is an example of an air conditioner defrost control device according to the first embodiment, and FIG. 2 shows a flow during the defrost control operation of the air conditioner according to the first embodiment. In one embodiment of the present invention, the same reference numerals are given to the same components as those described for the conventional example, and the description thereof is omitted.
In FIG. 1, 21 is an indoor heat exchanger temperature detecting means, and 22 is an overload protection device for operating and stopping the outdoor blower 6 depending on the indoor heat exchanger temperature detected by the indoor heat exchanger detecting means 21. , 23 is an outdoor fan stop time calculating means for calculating the time when the outdoor fan 6 is stopped, and 24 is a comparing means for determining whether the outdoor fan is stopped or not based on the length of the outdoor fan stop time calculated by the outdoor fan stop time calculating means, 25 Is an overload protection operation integration means for accumulating the outdoor fan stop time only when it is determined by the comparison means 24 that accumulation is possible, and 26 is when the time accumulated by the overload protection operation integration means 25 exceeds a specified value. It is a defrost operation control apparatus which starts a defrost operation. About the defrost control apparatus of the air conditioner comprised as mentioned above, the operation | movement is demonstrated below.
During the heating operation, the high-pressure gas refrigerant discharged from the constant speed compressor 1 is heat-exchanged by the indoor blower 7 in the indoor heat exchanger 5 to be liquefied, depressurized by the decompressor 4, and then the outdoor blower 6 in the outdoor heat exchanger 3. The heat exchange is performed to convert the gas into low-pressure gas and return to the compressor 1 again. At this time, the outdoor fan 6 is operated and stopped by the load on the indoor side and the outdoor side, and the temperature of the indoor heat exchanger 5 is kept at a predetermined temperature, so that the air conditioning state is always kept comfortable. When the temperature on the indoor side or the outdoor side rises due to load fluctuation, the outdoor blower 6 continues to stop and enters the defrosting operation due to the accumulation of the stop time. This will be described with reference to a flowchart at the time of defrosting operation.

 Heating operation is started in STEP 1 and normal operation is performed in STEP 2.

 In STEP 3, an overload control entry determination is made, and if the indoor heat exchange temperature (Tc) detected by the indoor heat exchange temperature detection means 21 is equal to or higher than a predetermined temperature (Tc 1), the process proceeds to STEP 4, otherwise, the process returns to STEP 2. .

 In STEP4, the outdoor fan 6 is stopped by the overload protection device 22, the overload control timer (Time) is reset in STEP5, and the overload control timer is started in STEP6.

 In STEP7, if the overload control timer (Time) is equal to or longer than the predetermined time (T1) by the overload protection operation integrating means 25, the process proceeds to STEP8; otherwise, the process proceeds to STEP9. In STEP 8, the overload control integration timer 25 adds the overload control timer to the overload control integration timer (T2), and in STEP 11, the overload control integration timer is started.

On the other hand, in STEP 9, when the overload control release determination is performed and the indoor heat exchange temperature (Tc) detected by the indoor heat exchange temperature detection means 21 is less than a predetermined temperature (Tc2), the outdoor fan 6 is operated in STEP 10. After restarting, return to STEP2, otherwise return to STEP7.
In STEP 12, the defrost operation control device 26 performs the defrost determination based on the overload control integration time (T2). If the overload control integration time (T2) is equal to or longer than the predetermined time (JOSO-IN), the process proceeds to STEP13. Otherwise, go to STEP14.

 In STEP 13, the defrosting operation is started, and in STEP 15, the overload control integration time (T2) is reset.

 When the defrosting operation is completed in STEP16, the process returns to STEP2.

 On the other hand, in STEP14, when the overload control release determination is performed and the indoor heat exchanger temperature (Tc) detected by the indoor heat exchanger temperature detecting means 21 is less than a predetermined temperature (Tc2), the outdoor fan 6 is operated in STEP10. After restarting, return to STEP2, otherwise return to STEP12.

By repeating the above cycle, the defrosting operation can always be effectively performed without performing a useless defrosting operation such as when the outdoor heat exchanger 3 is not frosted even in the overload condition during the heating operation. Since it can do, the air conditioner which implement | achieves optimal space on any conditions can be provided.
(Embodiment 2)
FIG. 3 shows a flow at the time of dew operation of the air conditioner in the second embodiment.
The basic operation is the same as that of the first embodiment. However, when the overload control timer (Time) is less than the predetermined time (T1) and the overload control release condition is satisfied, an overload is performed. The control integration time (T2) is reset.

Even if compared with 1st Embodiment by this structure, when the frost does not adhere to the outdoor heat exchanger 3, it is set as the specification which is hard to enter into a defrost operation.
(Embodiment 3)
FIG. 4 shows a flow at the time of dew operation of the air conditioner in the third embodiment.
The basic operation is the same as that of the first embodiment, but the start of the defrosting operation is matched with the timing when the overload control is canceled.
Compared to the first embodiment, this configuration makes it difficult to enter the defrosting operation when the outdoor heat exchanger 3 is not frosted, and the four-way valve 2 is switched when the defrosting operation is entered. The sound reduction effect is aimed at.
(Embodiment 4)
FIG. 5 shows a flow at the time of dew operation of the air conditioner in the fourth embodiment.
The basic operation is the same as that of the first embodiment, but overload protection is not integrated for a predetermined time (Fht) from the start of the heating operation.
Even if compared with 1st Embodiment by this structure, when the frost does not adhere to the outdoor heat exchanger 3, it is set as the specification which is hard to enter into a defrost operation.
(Embodiment 5)
FIG. 6 shows a flow at the time of dew operation of the air conditioner in the fifth embodiment.
The basic operation is the same as that of the first embodiment, but the outdoor heat exchange detected by the outdoor heat exchange temperature detecting means 27 when the overload control timer (Time) is equal to or longer than a predetermined time (T1). The overload control time is integrated only when the temperature (Te) is lower than the predetermined temperature (Te1).
Even if compared with 1st Embodiment by this structure, when the frost does not adhere to the outdoor heat exchanger 3, it is set as the specification which is hard to enter into a defrost operation.
(Embodiment 6)
FIG. 7 shows a flow at the time of dew operation of the air conditioner in the sixth embodiment.
The basic operation is the same as that of the first embodiment, but the outdoor heat exchange temperature (Te) detected by the outdoor heat exchange temperature detection means 27 when the overload control is canceled is a predetermined temperature (Te1). ) In the above case, the overload control integration time (T2) is reset.
Even if compared with 1st Embodiment by this structure, when the frost does not adhere to the outdoor heat exchanger 3, it is set as the specification which is hard to enter into a defrost operation.

As described above, the defrost control device for an air conditioner of the present invention always performs wasteful defrosting operation such as when the outdoor heat exchanger is not frosted even in an overload condition during heating operation. Since it can be effectively defrosted, it can be applied not only to air conditioners but also to refrigeration cycles of refrigerators and dehumidifiers.

The block diagram of the defrost control apparatus of the air conditioner in Embodiment 1 of this invention The flowchart at the time of defrosting control of the air conditioner in Embodiment 1 of this invention The flowchart at the time of defrosting control of the air conditioner in Embodiment 2 of this invention The flowchart at the time of defrosting control of the air conditioner in Embodiment 3 of this invention The flowchart at the time of defrosting control of the air conditioner in Embodiment 4 of this invention The flowchart at the time of defrosting control of the air conditioner in Embodiment 5 of this invention The flowchart at the time of defrosting control of the air conditioner in Embodiment 6 of this invention Configuration diagram of a conventional defrost control device for an air conditioner

Explanation of symbols

1 Compressor (constant speed compressor)
2 Four-way valve 3 Outdoor heat exchanger 4 Pressure reducer 5 Indoor heat exchanger 6 Outdoor fan 7 Indoor fan 8 Outdoor unit controller 9 Indoor unit controller 10 Pressure sensor 11 A / D converter 12 Indoor temperature sensor 13 Indoor heat exchange temperature Sensor 14 A / D converter 21 Indoor heat exchange temperature detection means 22 Overload protection device 23 Outdoor fan stop time calculation means 24 Comparison means 25 Overload protection operation integration means 26 Defrosting operation control device 27 Outdoor heat exchange temperature detection means Tc Indoor heat exchange temperature Tc1 Predetermined indoor heat exchange temperature Tc2 when entering overload control Predetermined indoor heat exchange temperature Time when overload control is released Overload control timer T1 Predetermined time T2 for overload control integration Overload control Integration time JOSO-IN Defrost control entry determination time Te Outdoor heat exchange temperature Te1 Predetermined outdoor heat exchange temperature for overload control integration

Claims (6)

A constant speed compressor, a four-way valve, an outdoor heat exchanger, a decompressor, and an indoor heat exchanger are configured to circulate in the refrigerant circuit, and detect the indoor heat exchanger. The outdoor air blower disposed in the outdoor heat exchanger has a temperature detection means, and when the indoor heat exchanger temperature detection means rises to a preset overload protection operation start temperature during heating operation, the outdoor blower is operated. In an air conditioner comprising an overload protection device that stops and restarts the operation of the outdoor fan when the temperature drops to the overload protection operation release temperature, the outdoor unit calculates the stop time of the outdoor fan during the overload protection operation The blower stop time calculation means and the outdoor blower stop time calculated by the outdoor blower stop time calculation means are compared with a preset overload protection operation time, and the outdoor blower stop time is the overload protection. An overload protection operation integration means for integrating only when the operation time is longer than the operation time is provided, and when the overload protection operation integration time integrated by the overload protection operation integration means reaches a preset integration time, a defrosting operation control device The air conditioner characterized by starting defrost operation by. The air conditioner according to claim 1, wherein when the outdoor fan stop time is shorter than an overload protection operation time, the overload protection operation integration time is reset. The defrosting operation start is made to stand by until the indoor heat exchanger temperature drops to the overload protection operation release temperature after the overload protection operation integration time reaches a preset integration time. Item 2. An air conditioner according to Item 1. The air conditioner according to claim 1, wherein the overload protection operation time is not accumulated for a predetermined time from the start of the heating operation. 2. The air conditioner according to claim 1, wherein the outdoor fan stop time is not integrated when the outdoor heat exchanger temperature when the temperature drops to an overload protection operation release temperature and the operation of the outdoor fan is resumed is equal to or higher than a predetermined temperature. Machine. The overload protection operation integration time is reset when the outdoor heat exchanger temperature when the temperature drops to the overload protection operation release temperature and the operation of the outdoor fan is resumed is equal to or higher than a predetermined temperature. Air conditioner.

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