JP2012063034A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner capable of detecting the presence of characteristic deviation of a pressure detector.SOLUTION: An outdoor unit 11 includes a compressor 1, an outdoor heat exchanger 3, an outdoor blower 4, an outdoor electric expansion valve 5, a four-way valve 6, a discharge pressure detector 2, an intake pressure detector 8, an outside air temperature detector 9, and an outdoor unit control device 10. A multi-room type air conditioner includes the outdoor unit and a plurality of indoor units 16 equipped with an indoor heat exchanger 12, an indoor blower 13, an indoor electric expansion valve 14, and an indoor control device 15. At the start of operation, the value detected with the discharge pressure detector is compared with the value detected with the intake pressure detector. If a differential pressure between the values detected with respective pressure detector is large, abnormal conditions at the pressure detector are indicated on an indicator arranged on the outdoor unit control device.

Description

  The present invention relates to an air conditioner equipped with pressure detection means, and more particularly to control for determining a decrease in detection accuracy of pressure detection means.

  Conventionally, this type of air conditioner employs capacity control means such as low-pressure constant frequency control in cooling operation and high-pressure constant frequency control in heating operation. For example, as shown in the refrigeration cycle diagram in the conventional air conditioner of FIG. 3, the low pressure constant frequency control using the low pressure detection means arranged in the suction pipe in the cooling operation, and the high pressure pressure arranged in the discharge pipe in the heating operation. High pressure constant frequency control using the detection means is performed (see, for example, Patent Document 1).

JP-A-3-241260

  However, in the conventional configuration described above, since the operating frequency of the compressor, which can be said to be an important determinant of the air conditioning capacity in the air conditioner, depends on the detection value of the pressure detection means, the characteristic of the pressure detection means is shifted. There was a problem that the influence of the was large, and comfort was impaired.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide an air conditioner that can detect the presence or absence of a characteristic deviation of a pressure detection means.

  In order to solve the above-described conventional problems, an air conditioner of the present invention includes a compressor, an outdoor heat exchanger, an outdoor fan, an outdoor electric expansion valve, a four-way valve, a discharge pressure detection unit, and a suction pressure. A plurality of indoor units including an outdoor unit including a detection unit, an outdoor air temperature detection unit, and an outdoor unit control device, an indoor heat exchanger, an indoor blower, an indoor electric expansion valve, and an indoor unit control unit In the multi-chamber type air conditioner configured by the above, when the values detected by the discharge pressure detection means and the suction pressure detection means are compared at the start of operation, and the differential pressure between the values detected by the respective pressure detection means is large By displaying the abnormality of the pressure detection means on the display unit arranged on the outdoor unit control device, the normal operation cannot be continued due to the false detection of the pressure detection means. Prevent machine failure It can be.

  The present invention can provide an air-conditioning apparatus that can detect the presence or absence of a characteristic deviation of the pressure detection means.

Refrigeration cycle diagram of the air-conditioning apparatus according to Embodiment 1 of the present invention The flowchart figure of the air conditioning apparatus in Embodiment 2 of this invention. The flowchart figure of the air conditioning apparatus in Embodiment 3 of this invention. The flowchart figure of the air conditioning apparatus in Embodiment 4 of this invention. Refrigeration cycle diagram in a conventional air conditioner

  An air conditioner according to a first aspect of the present invention includes a compressor, an outdoor heat exchanger, an outdoor fan, an outdoor electric expansion valve, a four-way valve, discharge pressure detection means, suction pressure detection means, and outdoor air temperature detection means. And a multi-room type comprising a plurality of indoor units including an outdoor unit including an outdoor unit control device, an indoor heat exchanger, an indoor fan, an indoor electric expansion valve, and an indoor unit control device. In the air conditioner, the values detected by the discharge pressure detection means and the suction pressure detection means at the start of operation are compared, and if the differential pressure detected by each pressure detection means is large, the abnormality of the pressure detection means is detected outdoors. By displaying on the display unit on the machine control device, it is possible to prevent insufficient performance and compressor failure due to non-detection of pressure protection, which are caused by the fact that normal operation cannot be continued due to erroneous detection of the pressure detection means. .

  The air conditioner according to a second aspect of the present invention compares the values detected by the discharge pressure detection means and the suction pressure detection means at the start of operation with a stop time equal to or greater than a certain value, particularly in the first aspect of the invention. When the pressure difference detected by the air pressure is large, the abnormal condition of the pressure detection means is displayed on the indicator provided on the outdoor unit control unit, so that the air conditioner has a long stop time and ensures that the high and low pressures are balanced. When the air conditioner in a startable state is ready for operation, erroneous detection of the high pressure detection means or low pressure detection means can be determined by the stop time of the air conditioner, Compressor failure due to insufficient performance and pressure protection non-detection caused by the inability to continue operation can be prevented.

  In the air conditioner of the third invention, in particular, in the first invention, the values detected by the discharge pressure detecting means and the suction pressure detecting means at the start of operation when the stop time is equal to or greater than a certain value and the outside air temperature change is equal to or less than the certain value. In comparison, when the pressure difference between the values detected by the pressure detection means is large, the abnormality of the pressure detection means is displayed on the indicator arranged on the outdoor unit control device, so that the stop time of the air conditioner is long. In addition, when the air conditioner in a state where the high and low pressures are balanced and can be started up is surely operated when the outside air temperature change is small, erroneous detection of the high pressure detection means or the low pressure detection means is detected. Judgment can be made based on the stop time and the change in outside air temperature, and it is possible to prevent poor performance due to incorrect detection of the pressure detection means and failure of the compressor due to inadequate performance and non-detection of pressure protection. It can be.

  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 a refrigeration cycle diagram of the air conditioner of the present invention. Compressor 1, outdoor heat exchanger 3, outdoor blower 4, outdoor electric expansion valve 5, four-way valve 6, discharge pressure detection means 2, suction pressure detection means 8, and outside air temperature detection means 9, An outdoor unit 11 provided with an outdoor unit control device 10, an indoor heat exchanger 12, an indoor blower 13, an indoor electric expansion valve 14, and a plurality of indoor units 16 provided with an indoor unit control device 15. Has been.

  FIG. 2 is a flowchart of the air conditioner according to the first embodiment. In the present embodiment, when the operation start signal is received (STEP 01) from the indoor unit control device 15, the value Pd (MPa) (STEP 02) detected by the discharge pressure detecting means 2 and the suction pressure detecting means 8 are detected. The value Ps (MPa) (STEP02) is compared (STEP03). If the differential pressure does not exceed the predetermined value ΔP, the operation of the air conditioner is started (STEP04), and the differential pressure exceeds the predetermined value ΔP. In the case of failure, an abnormality display (STEP 05) is performed on a display (for example, 7 segments) arranged on the outdoor unit control device 10.

As a result, the high-pressure detection means or the low-pressure detection means can be erroneously detected before the air conditioner in a state where the high and low pressures are balanced and can be started, and normal operation can be performed by the erroneous detection of the pressure detection means. It is possible to prevent compressor failure due to insufficient performance and non-detection of pressure protection, which are caused by being unable to continue.

(Embodiment 2)
FIG. 3 is a flowchart of the air conditioner according to the second embodiment. In the present embodiment, when the operation is stopped (STEP 31), the stop time is counted (STEP 32), and when the operation start signal is received (STEP 33) from the indoor unit controller 15, the stop time has passed a certain threshold (Time_offA). The stop time determination (STEP 34) is performed. If the stop time has not passed the fixed threshold (Time_offA), the operation of the air conditioner is started (STEP 38).

  In STEP 34, when the stop time has passed a certain threshold (Time_offA), the value Pd (MPa) detected by the discharge pressure detecting means 2 (STEP 35) and the value Ps (MPa) detected by the suction pressure detecting means 8 (STEP 35) is compared (STEP 36).

  As a result, when the differential pressure does not exceed the predetermined value ΔP, the operation of the air conditioner is started (STEP 38), and when the differential pressure exceeds the predetermined value ΔP, the display arranged on the outdoor unit control device 10 An abnormal display (STEP 37) is performed on a device (for example, 7 segments). This makes it possible to prevent false detection of the high-pressure pressure detection means or the low-pressure pressure detection means before the operation of the air conditioner in a state where the air conditioner can be started with a long balance between high and low pressures. It can be determined by the stop time of the machine, and it is possible to prevent a compressor failure due to insufficient performance and pressure protection non-detection, which occur because normal operation cannot be continued due to erroneous detection of the pressure detection means.

(Embodiment 3)
FIG. 4 is a flowchart of the air conditioner of the third embodiment. In the present embodiment, when the operation is stopped (STEP 41), the stop time is counted (STEP 42), and when the operation start signal is received (STEP 43) from the indoor unit controller 15, the outside air temperature detection means 9 detects the outside air temperature. An outside air temperature change determination (STEP 44) is performed as to whether the change in T0 (° C.) has continued within a predetermined value S (K) for a predetermined time N (minutes) or longer.

  As a result, if the change in the outside air temperature T0 (° C.) does not continue within the predetermined value S (K) for the predetermined time N (minutes) or longer, the operation of the air conditioner is started (STEP 49), and the outside air temperature T0 ( When the change in (° C.) continues within the predetermined value S (K) for the predetermined time N (minutes) or longer, the process proceeds to STEP 45.

  Then, in STEP 45, a stop time determination (STEP 45) is performed to determine whether the stop time has passed a certain threshold value (Time_offA). If the stop time has exceeded a certain threshold (Time_offA), the process proceeds to STEP46.

  In STEP 46, the value Pd (MPa) (STEP 46) detected by the discharge pressure detecting means 2 and the value Ps (MPa) (STEP 46) detected by the suction pressure detecting means 8 are compared (STEP 47), and the differential pressure is determined. If the pressure does not exceed the predetermined value ΔP, the operation of the air conditioner is started (STEP 49). If the differential pressure exceeds the predetermined value ΔP, the indicator (for example, 7 segments) arranged on the outdoor unit control device 10 is displayed. Abnormal display (STEP 48) is performed.

As a result, when the air conditioner in a state where the air conditioner in a state where the high and low pressures can be balanced and started can be reliably operated when the stop time of the air conditioner is long and the outside air temperature change is small, Misdetection of low-pressure pressure detection means can be determined by the stop time of the air conditioner and changes in the outside air temperature, resulting in insufficient performance due to incorrect detection of the pressure detection means, non-detection of pressure protection It is possible to prevent a compressor failure due to.

  The air conditioner of the present invention is not limited to a single-system multi-room air conditioner, and can also be applied to an outdoor multi-type air conditioner in which a plurality of systems of outdoor units are connected.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Discharge pressure detection means 3 Outdoor heat exchanger 4 Outdoor blower 5 Outdoor electric expansion valve 6 Four-way valve 8 Suction pressure detection means 9 Outdoor temperature detection means 10 Outdoor unit control apparatus 11 Outdoor unit 12 Indoor heat exchanger 13 Indoor blower 14 indoor electric expansion valve 15 indoor unit control device 16 indoor unit

Claims (3)

A compressor, an outdoor heat exchanger, an outdoor fan, an outdoor electric expansion valve, a four-way valve, a discharge pressure detection means, a suction pressure detection means, an outside air temperature detection means, and an outdoor unit control device are provided. Discharge pressure at the start of operation in a multi-room air conditioner composed of an outdoor unit, an indoor heat exchanger, an indoor blower, an indoor electric expansion valve, and a plurality of indoor units equipped with an indoor unit control device The value detected by the detection means and the suction pressure detection means is compared, and if the differential pressure between the values detected by the respective pressure detection means is large, an abnormality of the pressure detection means is displayed on the indicator arranged on the outdoor unit control device. An air conditioner characterized by displaying. The value detected by the discharge pressure detection means and the suction pressure detection means at the start of operation when the stop time is equal to or greater than a certain value is compared. If the differential pressure detected by each pressure detection means is large, the pressure detection means is abnormal. Is displayed on a display device arranged on the outdoor unit control device. The values detected by the discharge pressure detection means and the suction pressure detection means at the start of operation when the stop time is equal to or greater than a certain value and the outside air temperature change is equal to or less than a certain value are compared. The air conditioner according to claim 1, wherein when it is larger, an abnormality of the pressure detecting means is displayed on a display device arranged on the outdoor unit control device.