JP2006170528A - Air conditioner - Google Patents

Abstract

[PROBLEMS] To reduce the pressure of the equipment due to frequent start and stop of the equipment at a low outside air temperature where the suction pressure frequently decreases due to frost formation on the outdoor heat exchanger, even though heating capacity is required. Provided is an air conditioner that solves the problem to be solved.
In a heating operation, when the suction pressure detected by the suction pressure detection means is equal to or lower than a predetermined set value determined for each outside air temperature, the suction frequency is reduced by reducing the operating frequency of the compressor. Not only can the pressure drop be suppressed and the progress of frost formation on the outdoor heat exchanger 2 can be delayed, but also the operation according to the required capacity on the indoor side can be performed.
[Selection] Figure 5

Description

  The present invention relates to an air conditioner.

In the heating operation under a low outside air temperature, when the frosting of the outdoor heat exchanger progresses and the suction pressure decreases, the operation control method in the conventional air conditioner is as shown in the flowchart of FIG. There is one that stops the compressor by operation or abnormally stops the device (for example, see Patent Document 1).
JP-A-8-254362

  However, in the case of such an operation control method, the frequency of starting and stopping of the equipment is low under a low outside air temperature where the suction pressure frequently decreases due to frost formation on the outdoor heat exchanger, even though heating capacity is necessary. In some cases, the capacity to heat up the room was insufficient.

  The present invention solves the above-mentioned conventional problems, and has the ability to warm the room by lowering the frequency without stopping the compressor even when the suction pressure is lowered in the heating operation under a low outside air temperature. An object of the present invention is to provide an air conditioner equipped with an operation control method that does not run short.

  In order to solve the above-mentioned problems, the present invention reduces the frequency of the compressor when the suction pressure is equal to or lower than a predetermined set value determined for each outside air temperature.

  According to the operation control method of the present invention, in the heating operation under the low outside air temperature, even when the suction pressure is reduced, the frequency is reduced without stopping the compressor, so that the ability to warm the room is not insufficient. The progress of frost formation on the outdoor heat exchanger can be delayed.

  According to a first aspect of the present invention, during the heating operation, if the suction pressure detected by the suction pressure detection means is equal to or lower than a predetermined set value determined for each outside air temperature, the suction pressure is reduced by reducing the operating frequency of the compressor. Can be suppressed, the progress of frost formation on the outdoor heat exchanger can be delayed, and the indoor heating capacity can be maintained without deteriorating.

  In particular, in the air conditioner according to the first aspect of the present invention, the second aspect of the invention relates to the reduction of the suction pressure by changing the amount of decrease in the compressor operating frequency in accordance with the temperature difference between the indoor unit suction temperature and the remote controller set temperature. Not only can the decrease be suppressed and the progress of frost formation on the outdoor heat exchanger can be delayed, but also the operation according to the required capacity in the room can be performed and the comfort can be improved.

  According to a third aspect of the invention, in particular, in the air conditioner according to the first aspect of the invention, the outdoor heat exchanger temperature detected by the outdoor heat exchanger temperature detecting means during heating operation is a predetermined set value determined for each outdoor temperature. If it is below, by reducing the operating frequency of the compressor, the reduction of the suction pressure can be suppressed, the progress of frost formation on the outdoor heat exchanger can be delayed, and the indoor heating capacity can be maintained without decreasing. it can.

According to a fourth aspect of the invention, in particular, in the air conditioner according to the third aspect of the invention, the amount of suction pressure is reduced by changing the amount of decrease in the compressor operating frequency in accordance with the difference between the indoor unit suction temperature and the remote controller set temperature. Not only can the decrease be suppressed and the progress of frost formation on the outdoor heat exchanger can be delayed, but also the operation according to the required capacity in the room can be performed and the comfort can be improved.

  The fifth aspect of the present invention is the air conditioning apparatus according to any one of the first to fourth aspects of the present invention, by limiting the number of operations in the operation of lowering the compressor frequency, thereby suppressing the frequency from being lowered too much, and the required capacity in the room. On the other hand, it is possible to prevent the heating capacity of the equipment from being largely insufficient.

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

(Embodiment 1)
FIG. 1 is a refrigeration cycle diagram showing an embodiment of the present invention.

  In the figure, the refrigeration cycle includes a variable capacity compressor 1, an outdoor heat exchanger 2, an outdoor blower 3, an electric expansion valve 4 that can be depressurized, a four-way valve 5 that switches between a cooling operation and a heating operation, and an outdoor heat exchanger temperature. An outdoor unit comprising a detection unit 6, a suction pressure detection unit 7, an outside air temperature detection unit 8, and an outdoor unit control device 9, an indoor heat exchanger 10, an indoor blower 11, an electric expansion valve 12 that can be decompressed, an indoor unit It is comprised with the indoor unit which consists of the suction air temperature detection means 13 and the indoor unit control apparatus 14.

  FIG. 2 is a suction pressure set value table for explaining the operation control method of the present invention, in which a predetermined suction pressure set value is assigned for each outside air temperature.

  FIG. 3 is an operation flowchart for explaining the operation control method of the present invention.

During the heating operation, the suction pressure detection means 7 detects the suction pressure Ps, and the outside air temperature detection means 8 detects the outside air temperature To.
Next, referring to FIG. 2, the suction pressure set values Ps_1 to Ps_6 corresponding to the outside air temperature are obtained and compared with the actual suction pressure Ps.

If the suction pressure Ps is equal to or lower than the suction pressure set value, the current frequency is multiplied by a predetermined frequency reduction coefficient Kf to reduce the frequency.
By these operations, it is possible to suppress a decrease in the suction pressure, delay the progress of frost formation on the outdoor heat exchanger, and maintain the indoor heating capacity without deteriorating.

(Embodiment 2)
FIG. 4 is a frequency reduction coefficient table for explaining the operation control method of the present invention, in which a predetermined frequency reduction coefficient is assigned for each temperature difference between the remote controller set temperature and the indoor intake air temperature.

  FIG. 5 is an operation flowchart for explaining the operation control method of the present invention.

  As in the first embodiment, during the heating operation, the suction pressure detection means 7 detects the suction pressure Ps, and the outside air temperature detection means 8 detects the outside air temperature To.

  Further, the intake air temperature Ti is detected by the indoor intake air temperature detection means, the temperature difference ΔD between the remote control set temperature and Ti is calculated, and the frequency reduction coefficient Kf is obtained from FIG.

If the suction pressure Ps is equal to or lower than the suction pressure set value, the current frequency is multiplied by Kf to lower the frequency.

  By these operations, it is possible not only to suppress the reduction of the suction pressure and delay the progress of frost formation on the outdoor heat exchanger, but also to operate according to the required capacity in the room and improve the comfort.

(Embodiment 3)
FIG. 6 is an outdoor unit heat exchanger temperature setting value table for explaining the operation control method of the present invention, in which predetermined outdoor unit heat exchanger temperature setting values are assigned for each outdoor temperature.

  FIG. 7 is an operation flowchart for explaining the operation control method of the present invention.

  During the heating operation, the outdoor unit heat exchanger temperature detecting means 6 detects the outdoor unit heat exchanger temperature Te, and the outside air temperature detecting means 8 detects the outside air temperature To.

  Next, the outdoor unit heat exchanger temperature set values Te_1 to Ps_6 corresponding to the outside air temperature are obtained from FIG. 7 and compared with the actual outdoor unit heat exchanger temperature Te.

  If the outdoor unit heat exchanger temperature Te is equal to or lower than the outdoor unit heat exchanger temperature set value, the current frequency is multiplied by a predetermined frequency decrease coefficient Kf to decrease the frequency.

  By these operations, it is possible to suppress a decrease in the suction pressure, delay the progress of frost formation on the outdoor heat exchanger, and maintain the indoor heating capacity without deteriorating.

(Embodiment 4)
FIG. 8 is an operation flowchart for explaining the operation control method of the present invention.

  As in the third embodiment, during the heating operation, the outdoor unit heat exchanger temperature detection means 6 detects the outdoor unit heat exchanger temperature Te, and the outside air temperature detection means 8 detects the outside air temperature To.

  Further, the intake air temperature Ti is detected by the indoor intake air temperature detection means, the temperature difference ΔD between the remote control set temperature and Ti is calculated, and the frequency reduction coefficient Kf is obtained from FIG.

  If the outdoor unit heat exchanger temperature Te is equal to or lower than the outdoor unit heat exchanger temperature set value, the current frequency is multiplied by Kf to decrease the frequency.

  By these operations, it is possible not only to suppress the reduction of the suction pressure and delay the progress of frost formation on the outdoor heat exchanger, but also to operate according to the required capacity in the room and improve the comfort.

(Embodiment 5)
FIG. 9 is an operation flowchart for explaining the operation control method of the present invention.

  During the heating operation, the suction pressure detection means 7 detects the suction pressure Ps, and the outside air temperature detection means 8 detects the outside air temperature To.

  Next, referring to FIG. 2, the suction pressure set values Ps_1 to Ps_6 corresponding to the outside air temperature are obtained and compared with the actual suction pressure Ps. If the suction pressure Ps is equal to or lower than the suction pressure set value, the current frequency is multiplied by a predetermined frequency reduction coefficient Kf to reduce the frequency. The frequency reduction operation is performed a maximum of three times, and when it is exceeded, the current frequency is maintained.

In addition, this description is based on the first embodiment in which the number of times is limited. Similarly, the number of times in the second to fourth embodiments may be limited.

  By these operations, it is possible to suppress the frequency from being lowered excessively and to prevent the heating capacity of the device from being largely insufficient with respect to the required capacity in the room.

  The operation control method of the present invention is not limited to an air conditioner composed of a pair of indoor units and outdoor units, and can also be applied to a multi-room air conditioner.

Refrigeration cycle diagram showing an embodiment of the present invention Suction pressure setting diagram showing Embodiments 1 and 5 of the present invention Operation flowchart showing Embodiment 1 of the present invention Frequency reduction coefficient diagram showing Embodiments 2 and 4 of the present invention Operation flowchart showing Embodiment 2 of the present invention Outdoor unit heat exchanger temperature setting diagram showing Embodiment 3 of the present invention Operation flowchart showing Embodiment 3 of the present invention Operation flowchart showing Embodiment 4 of the present invention Operation flowchart showing Embodiment 5 of the present invention Conventional flowchart

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capacitance variable compressor 2 Outdoor heat exchanger 3 Outdoor fan 4 Outdoor unit motor-driven expansion valve 5 Four-way valve 6 Outdoor heat exchanger temperature detection means 7 Suction pressure detection means 8 Outside air temperature detection means 9 Outdoor unit control device 10 Room Inner heat exchanger 11 Indoor fan 12 Indoor unit electric expansion valve 13 Indoor unit intake air temperature detection means 14 Indoor unit controller

Claims (5)

Variable capacity compressor, outdoor heat exchanger, outdoor fan, electric expansion valve, four-way valve, outdoor heat exchanger temperature detection means, suction pressure detection means, outside air temperature detection means, outdoor unit equipped with outdoor unit control device And an indoor unit provided with an indoor side heat exchanger, an indoor blower, an electric expansion valve, an indoor unit intake air temperature detection means, and an indoor unit control device, and inhalation during heating operation An air conditioner that reduces the operating frequency of the compressor when the suction pressure detected by the pressure detection means is equal to or lower than a predetermined set value determined for each outside air temperature. The air conditioner according to claim 1, wherein the amount of decrease in the compressor operating frequency is changed in accordance with the difference between the indoor unit suction temperature and the remote controller set temperature. During heating operation, if the outdoor heat exchanger temperature detected by the outdoor heat exchanger temperature detecting means is not more than a predetermined set value determined for each outside air temperature, the operating frequency of the compressor is lowered. The air conditioning apparatus according to claim 1. The air conditioner according to claim 3, wherein the amount of decrease in the compressor operating frequency is changed in accordance with a difference between the indoor unit suction temperature and the remote controller set temperature. The air conditioner according to any one of claims 1 to 4, wherein a frequency limit is provided for the operation of lowering the compressor frequency.

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