JP2008014606A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To protect a compressor by judging that a refrigerant does not flow because of mixing of foreign matter in a refrigerating cycle, in operating an air conditioner. <P>SOLUTION: A compressor operational frequency is gradually increased to a prescribed frequency when temperature difference between a room temperature and an indoor heat exchanger is less than a prescribed temperature after the lapse of a prescribed time from the start of the operation, a state free from blockage is judged and a normal operation is recovered when the temperature difference between the room temperature and the indoor heat exchanger becomes more than the prescribed temperature during increasing the frequency or at a prescribed frequency, and failure such as the blockage is judged, and the compressor is stopped, when the temperature difference between the room temperature and the indoor heat exchange is less than the prescribed value, even when the compressor operational frequency reaches the prescribed frequency. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an air conditioner, and relates to an air conditioner that protects a compressor.

  Conventionally, this type of air conditioner control method is based on a constant value of the compressor surface temperature or operating current in order to protect the compressor by assuming a malfunction such as when a foreign object is clogged in the refrigeration cycle. To stop the operation of the compressor when the temperature exceeds the limit, or to detect the temperature difference between the room temperature and the indoor heat exchanger for cost reduction, stop the compressor if the temperature difference is within the specified temperature (See, for example, Patent Document 1).

FIG. 3 is a flowchart showing a conventional compressor protection control method described in Patent Document 1. As shown in FIG. 3, it is determined whether the air conditioner is started to be cooled or heated and whether or not the compressor has been operated for 30 minutes or more (step ST31). In the following (step ST32), when the temperature difference between the room temperature and the indoor heat exchange temperature is within 2 ° C. (step ST33), or the temperature difference between the outside air temperature and the outdoor heat exchange temperature is within 2 ° C. (step ST34), freezing The refrigerant is not flowing in the cycle, that is, the gas is completely exhausted from the refrigeration cycle, the electronic expansion valve is locked closed, or the valve is fully closed due to foreign matter entering the valve Alternatively, it can be determined that there is a problem such as forgetting to open the two- or three-way valve, and the compressor can be stopped (step ST41) to protect it.
JP 2003-90582 A

  However, in the above conventional technique, when the user sets the remote control temperature at a temperature close to room temperature, the frequency difference is low even if the operation is performed for a certain period of time. Even when the compressor is sunk and the temperature is sufficiently lowered due to a long pipe, it is difficult to cause a temperature difference, and if both are abnormal, there is a risk of erroneous detection. This invention solves the said conventional subject, and when a valve obstruction is doubtful, it aims at providing the air conditioner which can judge whether it is obstruct | occluded without misdetection, without impairing living environment performance. To do.

In order to solve the above-mentioned conventional problems, the air conditioner of the present invention sets the compressor operating frequency when the temperature difference between the room temperature and the indoor heat exchanger is less than the predetermined temperature after the elapse of a predetermined time from the start of operation. When the temperature difference between room temperature and the indoor heat exchanger exceeds the specified temperature during the increase or at the specified frequency, it is determined that the blockage is not blocked and the normal operation is resumed. Even when the frequency is reached, when the temperature difference between the room temperature and the indoor heat exchanger is less than a predetermined value, it is determined that there is a problem such as blockage and the compressor is stopped.
As a result, the operating frequency can be increased to a value at which it can be determined whether or not it is blocked, and it can be determined whether or not it is blocked without erroneous detection. In addition, the operating frequency is gradually changed, and it is determined that the blockage is not blocked at the stage when the temperature difference is reached, and the normal operation is restored. Therefore, the blockage can be determined without deteriorating the living environment comfort.

  When the valve blockage is doubtful, it can be determined whether the blockage occurs without erroneous detection without impairing the living environment performance.

  In the first aspect of the invention, when the temperature difference between the room temperature and the indoor heat exchanger is less than a predetermined temperature after the lapse of a predetermined time from the start of operation, the compressor operating frequency is gradually increased to a predetermined frequency, and during the increase or predetermined If the temperature difference between the room temperature and the indoor heat exchanger exceeds the specified temperature at the frequency, it is determined that the blockage is not blocked and the normal operation is resumed. When the temperature difference of the exchanger is less than a predetermined value, it is determined that there is a problem such as blockage and the compressor is stopped. Therefore, it is possible to determine whether the blockage is made without erroneous detection without impairing the living environment performance.

  In the second invention, particularly in the air conditioner of the first invention, when the compressor operating frequency is equal to or higher than a predetermined frequency, if the temperature difference between the room temperature and the indoor heat exchanger is less than a predetermined value, the indoor fan speed is reduced to a predetermined value or less. If the temperature difference between the room temperature and the indoor heat exchanger exceeds the specified temperature after regulating the indoor fan speed, it is determined that the blockage is not blocked and normal operation is resumed. When the temperature difference between the indoor heat exchanger and the indoor heat exchanger is less than a predetermined value, it is determined that there is a problem such as blockage, and the compressor is stopped. Therefore, it can be more reliably determined whether the blockage is detected without erroneous detection.

  In the third invention, particularly in the first or second air conditioner, when the compressor is determined to be blocked and the compressor is stopped, the control is performed again and the detection is further prevented by performing the control a plurality of times. Can do.

  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 shows a configuration diagram of a refrigeration cycle of an air conditioner according to an embodiment of the present invention. In FIG. 1, 1 is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger, 4 is an outdoor electronic expansion valve, 5 is an outdoor heat exchanger, and forms the refrigerating cycle. Moreover, the indoor heat exchanger 3 switches or adjusts the outdoor electronic expansion valve 4 and the indoor electronic valve 8 at the time of reheat dehumidification, and the refrigerant passes through the capillary tube 9 so that the indoor unit condensation heat exchanger 6 and the indoor unit evaporating heat. It is divided into the exchanger 7 and reheat dehumidification becomes possible. Reference numeral 10 denotes an indoor unit condensation heat exchanger sensor that detects the temperature of the indoor unit condensation heat exchanger 6, 11 denotes an indoor unit evaporation heat exchanger temperature sensor that detects the temperature of the indoor unit evaporation heat exchanger 7, and 12 denotes It is a room temperature sensor that detects the temperature in the room.

  The operation and action of the air conditioner control method configured as described above will be described below.

FIG. 2 is a flowchart in the embodiment of the present invention. First, at ST0, the compressor 1 starts operation and proceeds to ST1. At ST1, it is determined whether or not the compressor operation has started for 30 minutes or more and is not blocked, and whether or not it is 30 minutes or more. If so, the process proceeds to ST2. Otherwise, return to ST1. In ST2, it is determined whether or not the difference between the room temperature and the indoor heat exchanger temperature is within 2 ° C. If so, the process proceeds to ST3, and if not, it is determined not to be blocked and the process returns to ST1. In ST3, it is determined whether or not the operation frequency is 30 Hz or more. If so, the process proceeds to ST5, and if not, the process proceeds to ST4. In ST4, the operating frequency is increased by 1 Hz every 30 seconds to 30 Hz, and the process returns to ST2. In ST5, it is determined whether or not the difference between the room temperature and the indoor heat exchanger temperature is within 2 ° C. If so, the process proceeds to ST6, otherwise it is determined that the blockage is not blocked, and the process returns to ST1. In ST6, the indoor fan speed is restricted to 500 rpm or less, and the process proceeds to ST7. In ST7, it is determined whether or not the difference between the room temperature and the indoor heat exchanger temperature is within 2 ° C. If so, the process proceeds to ST8, otherwise it is determined that the blockage is not blocked and the process returns to ST1. In ST8, the compressor is stopped and the process proceeds to ST9. In ST9, a timer is set, and the process proceeds to ST10. In ST10, it is determined whether or not 3 minutes have elapsed since the timer was set. If so, the process proceeds to ST11, and if not, the process returns to ST10. Operation is resumed in ST11 and proceeds to ST12. In ST12, the counter is set, and the process proceeds to ST13. In ST13, it is determined whether the compressor stop process has been repeated three times. If so, the process proceeds to ST14, and if not, the process returns to ST1.

  As described above, in the present embodiment, after a predetermined time has elapsed from the start of operation, when the temperature difference between the room temperature and the indoor heat exchanger is less than the predetermined temperature, the compressor operating frequency is gradually increased to the predetermined frequency. When the temperature difference between the room temperature and the indoor heat exchanger exceeds the predetermined temperature during the rise or at a predetermined frequency, it is determined that the blockage is not blocked and the normal operation is resumed, and the compressor operating frequency reaches the predetermined frequency. However, if the temperature difference between the room temperature and the indoor heat exchanger is less than the specified value, it is judged that there is a problem such as blockage and the compressor is stopped. Can do.

In the present embodiment, when the compressor operating frequency is equal to or higher than a predetermined frequency, if the temperature difference between the room temperature and the indoor heat exchanger is less than a predetermined value, the indoor fan speed is regulated to be equal to or lower than a predetermined value. If the temperature difference between the room temperature and the indoor heat exchanger exceeds the specified temperature after regulating the indoor fan speed, it is determined that the blockage is not blocked and normal operation is resumed. After regulating the indoor fan speed, the room temperature and the temperature of the indoor heat exchanger When the difference is less than a predetermined value, it is determined that there is a problem such as blockage and the compressor is stopped. Therefore, it can be more reliably determined whether the blockage is detected without erroneous detection.
Further, in the present embodiment, when it is determined that the compressor is blocked and the compressor is stopped, the control is performed again, and the detection can be further prevented by performing the control a plurality of times.

  As described above, the air conditioner according to the present invention can be applied to various air conditioners because it is possible to determine whether the valve is blocked without erroneous detection without impairing living environment performance when valve blockage is suspected.

The block diagram which shows the refrigerating cycle of the air conditioner by this invention The flowchart of the control method of the air conditioner by this invention The flowchart of the control method of the air conditioner by a prior art example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Outdoor electronic expansion valve 5 Outdoor heat exchanger 6 Indoor unit condensation heat exchanger 7 Indoor unit evaporative heat exchanger 8 Indoor electronic valve 9 Capillary tube 10 Indoor unit condensation heat exchanger sensor 11 Indoor unit evaporative heat exchanger sensor 12 Room temperature sensor

Claims (3)

Compressor, indoor heat exchanger, outdoor heat exchanger, no overload relay fixed directly to the compressor as a means for detecting malfunctions such as blockage of a refrigeration cycle having a throttle device, a compressor instead In an air conditioner having a discharge temperature sensor for detecting the temperature of the discharge temperature gas, and further having room temperature detection means and the indoor heat exchanger temperature detection means, after a predetermined time has elapsed since the start of operation, room temperature and room heat exchange When the temperature difference between the chambers is less than the predetermined temperature, the compressor operating frequency is gradually increased to the predetermined frequency, and when the temperature difference between the room temperature and the indoor heat exchanger becomes higher than the predetermined temperature during the increase or at the predetermined frequency, Even if the compressor operation frequency reaches the predetermined frequency and the compressor operating frequency reaches the predetermined frequency, if the temperature difference between the room temperature and the indoor heat exchanger is less than the predetermined value, there is a problem such as blockage. An air conditioner characterized by comprising stop judgment and compressor. When the compressor operating frequency is equal to or higher than the predetermined frequency, if the temperature difference between the room temperature and the indoor heat exchanger is less than the predetermined value, the indoor fan speed is regulated to be below the predetermined value. If the temperature difference of the heat exchanger exceeds the specified temperature, it is determined that the blockage is not blocked and the normal operation is resumed. The air conditioner according to claim 1, wherein the compressor is stopped after determining that there is a problem. 3. The air conditioner according to claim 1, wherein when the compressor is determined to be blocked and the compressor is stopped, the control is performed again and performed a plurality of times.

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