JP2006207932A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately determine a degree of refrigerant deficiency of an air conditioner. <P>SOLUTION: A refrigerant circuit is composed by annularly connecting a constant speed compressor 15, a four-wave valve 16, an outdoor side heat exchanger 17, a pressure reducing expansion valve 18, and an indoor side heat exchanger 19. The degree of refrigerant insufficiency can be determined on the basis of a time ratio of operation and stoppage by providing an indoor blower, operating the indoor blower 20 at a predetermined rotational frequency, and carrying out operation and stoppage control of the constant speed compressor 15 such that a temperature difference between an indoor temperature and a blowout air temperature is between a first predetermined value and a second predetermined value. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an air conditioner that determines a lack of refrigerant.

  Conventionally, this type of air conditioner has input current detection means for detecting the input current to the compressor, and controls the operating frequency of the compressor so that the input current during the cooling operation does not exceed an allowable value. Thus, the compressor is protected from an overload state, and a temperature detecting means is provided in the intermediate portion of the indoor heat exchanger, and the intermediate temperature detected during the cooling operation by the temperature detecting means is a predetermined value or more. When it continues for a predetermined time, it is determined that the refrigerant is insufficient, and the operation of the compressor is stopped (see, for example, Patent Document 1).

  FIG. 4 shows a conventional air conditioner described in Patent Document 1. As shown in FIG.

As shown in FIG. 4, a refrigeration cycle comprising a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a throttle means 4, and an indoor heat exchanger 5, and input current detection means for detecting an input current to the compressor 1. 11.
JP-A-8-261543

  However, in the conventional configuration, since the refrigerant shortage is determined in the normal cooling operation, it is not possible to determine that the refrigerant is insufficient if the refrigerant is not short enough to protect the compressor.

  On the other hand, for air conditioner users, even if the refrigerant is not short enough to protect the compressor, if the refrigerant runs short of the amount that can ensure the design performance, the cooling will be slow. Had the problem of not being able to provide performance.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide an air conditioner that can determine that a refrigerant is insufficient from an amount that can ensure design performance.

  In order to solve the above-mentioned conventional problems, the air conditioner of the present invention has a constant rotational speed of an indoor fan, and the temperature difference between the indoor temperature and the blown air temperature is a first predetermined value and a second predetermined value. Control stop of operation so that there is a gap.

  Thereby, when the time ratio of the operation to the stop is higher than a predetermined value, it can be determined that the refrigerant is insufficient.

  Further, the air conditioner of the present invention controls the operation stop so that the rotational speed of the indoor fan is constant and the temperature difference between the indoor temperature and the indoor heat exchange is between the first predetermined value and the second predetermined value. To do.

  Thereby, when the time ratio of the operation to the stop is higher than a predetermined value, it can be determined that the refrigerant is insufficient.

  The air conditioner of the present invention can accurately determine the degree of refrigerant shortage.

  A first aspect of the invention comprises a compressor, a four-way valve, an outdoor heat exchanger, a decompression expansion valve, and an indoor heat exchanger that are connected in an annular shape to form a refrigerant circuit, including an indoor blower, and the indoor blower The refrigerant runs out by controlling the operation of the compressor so that the temperature difference between the room temperature and the blown air temperature is between the first predetermined value and the second predetermined value. As the operation time ratio with respect to the compressor stop time increases, the degree of refrigerant shortage can be determined by the operation time ratio of the compressor.

  According to a second aspect of the present invention, a compressor, a four-way valve, an outdoor heat exchanger, a decompression expansion valve, and an indoor heat exchanger are annularly connected to form a refrigerant circuit, and an indoor blower is provided. By operating at the rotational speed and controlling the operation of the compressor so that the temperature difference between the indoor temperature and the indoor heat exchanger is between the first predetermined value and the second predetermined value, the refrigerant is insufficient. As the operation time ratio increases, the operation time ratio with respect to the compressor stop time becomes higher. Therefore, the degree of refrigerant shortage can be determined based on the operation time ratio of the compressor.

  In the third aspect of the invention, in particular, since the operation of the first or second aspect of the invention is performed every predetermined time, it is possible to regularly check the degree of shortage of the refrigerant accurately.

  The fourth invention is characterized in that, in particular, the operation of the first or second invention is started by an input from the controller of the air conditioner. The degree can be confirmed when necessary.

  In the fifth aspect of the invention, in particular, in the air conditioners of the first to fourth aspects of the invention, the determination result of the lack of refrigerant is displayed on the display. The degree determination result can be notified.

  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 of an air conditioner according to a first embodiment of the present invention.
The compressor 15 is a constant speed compressor, and when the motor of the compressor is energized, the compressor rotates at a constant speed.

  The refrigerant discharged from the compressor 15 passes through the four-way valve 16, is liquefied and condensed by the outdoor heat exchanger 17 during cooling, is decompressed and expanded by the decompression expansion valve 18, and absorbs heat by the indoor heat exchanger 19. During heating, it is liquefied and condensed by the indoor heat exchanger 19, decompressed and expanded by the decompression expansion valve 18, absorbed by the outdoor heat exchanger 17, and sucked into the compressor 15 through the four-way valve 16.

  20 is an indoor blower, 21 is an indoor temperature sensor that detects the intake air temperature of the indoor unit, 22 is a blowout temperature sensor that detects the blowout air temperature of the indoor unit, and 23 is a control device that controls the operation and stop of the compressor 15. A circuit for counting the operation time and the stop time of the compressor 15 and calculating the ratio of the operation and the stop time is also provided.

  Reference numeral 24 denotes an indoor heat exchange sensor that detects the temperature at the center of the indoor heat exchanger, and reference numeral 25 denotes an air conditioner controller that also has a display function for displaying the refrigerant shortage degree determination result.

  About the air conditioner comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  When the rotational speed of the indoor blower 20 is made constant and the compressor 15 is controlled so that the temperature difference between the indoor temperature and the blown air temperature is between the first predetermined value and the second predetermined value, The air conditioning capacity inside becomes a constant value.

  Therefore, if the refrigerant is insufficient, the circulation rate is reduced, and the compressor operation time is increased in order to achieve the same air conditioning capability.

  The present invention is characterized by using this characteristic to determine the degree of refrigerant shortage.

  FIG. 2 is a flowchart in Embodiment 1 of the present invention, and the temperature difference in the chart is the difference between the room temperature and the blowing temperature. FIG. 3 is a control time chart in the first embodiment.

  When the controller 25 receives an input for starting the refrigerant shortage determination operation or when the control device 23 reaches a predetermined time for starting the refrigerant shortage determination operation (STEP 1), the control device 23 receives the input (STEP 1), and the indoor blower 20 is set at a constant predetermined rotational speed. When the temperature difference between the detected value of the blowout temperature sensor 22 and the detected value of the indoor temperature sensor 21 is smaller than the first predetermined value, the compressor 15 is operated, and when it is larger than the second predetermined value Controls to stop the compressor 15 (STEP 3).

  The operation of STEP 3 is continued until the first predetermined time has elapsed (STEP 4).

  After the first predetermined time has elapsed, when the temperature difference between the detected value of the outlet temperature sensor 22 and the detected value of the indoor temperature sensor 21 is smaller than the first predetermined value, the compressor 15 is operated and the operating time is counted. When it is larger than the predetermined value of 2, the compressor 15 is controlled to stop (STEP 5), and the operation of STEP 5 is continued until the second predetermined time elapses (STEP 6).

  When the second predetermined time has elapsed, the total operation time counted by the compressor 15 is compared with a predetermined value to determine the refrigerant amount (STEP 7).

  If the total operation time of the compressor 15 is less than or equal to a predetermined value, it is determined that there is no refrigerant shortage and the result is displayed on the display of the controller 25 (STEP 8). Is displayed on the display (STEP 9).

  As described above, in the present embodiment, it is possible to accurately determine the degree of refrigerant shortage by determining the refrigerant shortage in the operation time ratio of the compressor 15 when operating with a constant air conditioning capability.

  Further, in the present embodiment, by making the determination with respect to the operation time ratio of the compressor 15 finer, it is possible to determine that there is no refrigerant shortage, the refrigerant is insufficient in the operable range, and the device may be damaged due to the refrigerant shortage, It is also possible to provide information for performing an appropriate measure against the refrigerant shortage.

(Embodiment 2)
The configuration of the air conditioner according to the second embodiment of the present invention is the same as that of the first embodiment, and a description thereof will be omitted.

  The indoor heat exchange temperature is the evaporating temperature during cooling and the condensing temperature during heating. Therefore, if the rotational speed of the indoor fan is made constant and the rotational speed of the compressor is controlled so that the difference between the indoor heat exchange temperature and the indoor temperature becomes constant, the indoor air conditioning capacity becomes a constant value.

  The present invention is characterized by using this characteristic to determine the degree of refrigerant shortage.

  The air conditioner of the second embodiment of the present invention performs operation control with the temperature difference in the flowchart of FIG. 2 as the difference between the room temperature and the indoor heat exchange temperature.

  When the controller 25 receives an input for starting the refrigerant shortage determination operation or when the control device 23 reaches a predetermined time for starting the refrigerant shortage determination operation (STEP 1), the control device 23 receives the input (STEP 1), and the indoor blower 20 is set at a constant predetermined rotational speed. When the temperature difference between the detected value of the indoor heat exchange sensor 24 and the detected value of the indoor temperature sensor 21 is smaller than the first predetermined value, the compressor 15 is operated and is larger than the second predetermined value. If so, the compressor 15 is controlled to stop (STEP 3).

  The operation of STEP 3 is continued until the first predetermined time has elapsed (STEP 4). When the temperature difference between the detected value of the indoor heat exchanger temperature sensor 24 and the detected value of the indoor temperature sensor 21 is smaller than the first predetermined value after the first predetermined time has elapsed, the compressor 15 is operated and the operation time is counted. When it is larger than the second predetermined value, the compressor 15 is controlled to stop (STEP 5). The operation of STEP 5 is continued until the second predetermined time elapses (STEP 6).

  When the second predetermined time has elapsed, the total operation time counted by the compressor 15 is compared with a predetermined value to determine the refrigerant amount (STEP 7).

  If the total operation time of the compressor 15 is less than or equal to a predetermined value, it is determined that there is no refrigerant shortage and the result is displayed on the display of the controller 25 (STEP 8). Is displayed on the display (STEP 9).

  As described above, in the present embodiment, it is possible to accurately determine the degree of refrigerant shortage by determining the refrigerant shortage in the operation time ratio of the compressor 15 when operating with a constant air conditioning capability.

  As described above, since the air conditioner according to the present invention can accurately determine the degree of refrigerant shortage, it can be applied to uses such as refrigerators, vending machines, and ice makers that use compressors.

Configuration diagram of air conditioner according to Embodiment 1 and Embodiment 2 of the present invention Control flowchart in Embodiment 1 and Embodiment 2 of the present invention Control time chart in Embodiment 1 of the present invention Schematic of conventional air conditioner cycle and control device

Explanation of symbols

DESCRIPTION OF SYMBOLS 15 Compressor 16 Four-way valve 17 Outdoor heat exchanger 18 Decompression expansion valve 19 Indoor side heat exchanger 20 Indoor fan 21 Indoor temperature sensor 22 Blowing temperature sensor 24 Indoor heat exchange sensor 25 Controller

Claims (5)

A constant-speed compressor, a four-way valve, an outdoor heat exchanger, a decompression expansion valve, and an indoor heat exchanger are connected in a ring to form a refrigerant circuit, and an indoor blower is provided. The indoor blower is operated at a predetermined number of rotations. The compressor is controlled to stop so that the temperature difference between the room temperature and the blown air temperature is between the first predetermined value and the second predetermined value. An air conditioner characterized by determining the degree of air. A constant-speed compressor, a four-way valve, an outdoor heat exchanger, a decompression expansion valve, and an indoor heat exchanger are connected in a ring to form a refrigerant circuit, and an indoor blower is provided. The indoor blower is operated at a predetermined number of rotations. The compressor is controlled to stop so that the temperature difference between the indoor temperature and the indoor heat exchanger is between the first predetermined value and the second predetermined value, and the refrigerant is determined according to the time ratio between the operation and the stop. An air conditioner characterized by determining the degree of lack. An air conditioner that performs the operation according to claim 1 or 2 every predetermined time. An air conditioner that performs the operation according to claim 1 or 2 by an input from a controller. The air conditioner according to any one of claims 1 to 4, wherein a determination result of refrigerant shortage is displayed on a display.

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