JP2006118731A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a start control time by controlling the start of a compressor on the basis of an operating state, and to improve comfortable sensation. <P>SOLUTION: This air conditioner comprises the refrigerant compressor, a refrigerant circuit constituted by circularly connecting a four-way valve, an outdoor-side heat exchanger, a pressure reducing expansion valve and an indoor-side heat exchanger, and a control circuit for controlling a rotating speed of the compressor, and a rotational frequency of the compressor is increased when the variation of suction pressure of the air conditioner becomes less than a prescribed value, thus the start of the compressor can be controlled on the basis of a state of the refrigerant circuit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an air conditioner equipped with an operation control device for a refrigerant compressor.

  Conventionally, this type of control device is as shown in FIG. 5 (see, for example, Patent Document 1).

  That is, the refrigerant compressor 1 is a variable frequency compressor, and controls the capacity by changing the rotational frequency of the compressor by changing the power supply frequency. The refrigerant discharged from the refrigerant compressor 1 passes through the four-way valve 2, is liquefied and condensed in the indoor heat exchanger 3, is decompressed and expanded in the decompression expansion valve 4, and is cooled from the substance to be cooled in the outdoor heat exchanger 5. It absorbs heat and is sucked into the refrigerant compressor 1 through the four-way valve 2. Reference numeral 6 denotes a control device that controls the rotational speed of the refrigerant compressor 1, and uses a commercial power source 7 as a primary power source. Reference numeral 8 denotes a speed signal unit, which detects the temperature of the substance to be cooled by the temperature detector 9, detects a difference from the set temperature by the detector 10, and sends a signal to the speed signal unit 8 to send the refrigerant compressor 1. Control the number of revolutions.

  The speed signal unit 8 is provided with a start control circuit 11 and a priority circuit controlled by the start circuit 11 for a predetermined time when the refrigerant compressor 1 is started.

  FIG. 6 shows the rotational speed control at the time of starting the refrigerant compressor 1, where the horizontal axis represents the time from the start and the vertical axis represents the rotational speed of the refrigerant compressor 1.

  While the refrigerant compressor 1 is stopped, a so-called stagnation phenomenon in which the refrigerant melts and accumulates in the lubricating oil frequently occurs. When activated from this state, a large amount of lubricating oil in the refrigerant compressor 1 is discharged to the outside of the refrigerant compressor 1 by the discharged refrigerant.

However, since the first holding frequency f1 shown in FIG. 6 is set to a low frequency, the amount of lubricating oil taken out is small, and the lubricating oil is secured. However, since the speed is low, the amount of lubricating oil supplied to the sliding portion is small, and therefore operating for a long time reduces the reliability. Therefore, after holding for a relatively short predetermined time, the second holding frequency f2 is provided to start the warm-up operation. After the operation at the second holding frequency f2, the operation is performed at the rotation speed corresponding to the load.
JP-A-7-301460

  However, in the conventional configuration, immediately after the start of the compressor, the first holding frequency f1 is held for a certain time (first holding time T1), and then the higher second holding frequency f2 is held for a certain time (second holding time T2). Therefore, even if the outside air temperature, the room temperature, and the refrigerant stagnation level that affect the operation state of the air conditioner are different, constant starting control is always performed.

  Therefore, in order to ensure the reliability of the compressor, it is necessary to set the first holding time T1 and the second holding time T2 according to the most severe operation state, so the start-up control time becomes long and the room temperature reaches the target. Because the time to do becomes late, comfort is impaired.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide an air conditioner that improves the comfort by shortening the startup control time by performing the startup control of the compressor according to the operating state. .

  In order to solve the above-mentioned conventional problems, the air conditioner of the present invention is characterized in that the rotational speed of the compressor is increased when the change in the suction pressure becomes a predetermined value or less.

  Thereby, the starting control of the compressor according to the state of the refrigerant circuit can be performed.

  In addition, the air conditioner of the present invention is characterized in that when the change in the compressor operating current becomes a predetermined value or less, the rotational speed of the compressor is increased.

Thereby, the start-up control of the compressor can be performed according to the state of the refrigerant circuit.
Further, the air conditioner of the present invention is characterized in that the rotation speed of the compressor is increased when the change in the evaporation temperature becomes a predetermined value or less.

  Thereby, the start-up control of the compressor can be performed according to the state of the refrigerant circuit.

  The air conditioner of the present invention can shorten the startup control time and improve the comfort.

  A first invention is a control circuit for controlling the rotational speed of a compressor by connecting a refrigerant compressor, a four-way valve, an outdoor heat exchanger, a decompression expansion valve, and an indoor heat exchanger in an annular shape to form a refrigerant circuit. And controlling the start-up of the compressor according to the state of the refrigerant circuit by increasing the rotational speed of the compressor when the change in the suction pressure of the air conditioner falls below a predetermined value. It is possible to shorten the startup control time and improve the comfort.

  The second aspect of the invention is characterized in that, in particular, the air conditioner of the first aspect of the invention is configured to increase the rotational speed of the compressor when the change in the compressor operating current of the air conditioner becomes a predetermined value or less. By doing so, the start-up control of the compressor according to the state of the refrigerant circuit can be performed, the start-up control time can be shortened, and the comfort can be improved.

  The third aspect of the invention is characterized in that, in particular, the air conditioner of the first aspect of the invention is characterized in that the rotation speed of the compressor is increased when the change in the evaporation temperature of the air conditioner becomes a predetermined value or less. Thus, the start-up control of the compressor according to the state of the refrigerant circuit can be performed, the start-up control time can be shortened, and the comfort can be improved.

  According to a fourth aspect of the invention, in particular, the air conditioner according to any one of the first to third aspects of the invention is characterized in that the initial value of the rotational speed of the compressor at the time of startup is determined by the outer temperature of the compressor Startup can be started at a compressor speed suitable for the state of the compressor at startup, and startup control time can be shortened and comfort can be improved.

  According to a fifth aspect of the invention, in particular, the air conditioner according to any one of the first to third aspects of the invention is characterized in that the initial value of the rotational speed of the compressor at startup is determined by the discharge pipe temperature of the compressor. Thus, the start-up can be started at the compressor speed suitable for the state of the compressor at the start-up, and the start-up control time can be shortened and the comfort can be improved.

  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 control device circuit diagram of an air conditioner according to a first embodiment of the present invention.

  The refrigerant compressor 21 is a variable frequency compressor, and controls the capacity by changing the rotational frequency of the compressor by changing the power frequency. The refrigerant discharged from the refrigerant compressor 21 passes through the four-way valve 22, is liquefied and condensed in the outdoor heat exchanger 23, is decompressed and expanded in the decompression expansion valve 24, and is cooled from the substance to be cooled in the indoor heat exchanger 25. It absorbs heat and is sucked into the refrigerant compressor 21 through the four-way valve 22. 26 is a control device for controlling the rotational speed of the refrigerant compressor 21, 27 is a suction pressure sensor, 28 is an outer temperature sensor of the compressor 21, 29 is a current sensor for detecting the operating current of the compressor, and 30 is an outdoor side. An outdoor heat exchange temperature sensor that detects the evaporation temperature during heating of the heat exchanger 23, 31 is an indoor heat exchange temperature sensor that detects the evaporation temperature during cooling of the indoor heat exchanger 25, and 32 is a discharge that detects the discharge temperature. It is a temperature sensor.

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

  FIG. 2 is an operation flowchart according to the first embodiment of the present invention.

  First, the initial rotational speed of the compressor is determined by the controller 26 based on the temperature detected by the outer temperature sensor 28 (STEP 1), and the operation is started (STEP 2).

  Next, the suction pressure is detected by the suction pressure sensor 27 at predetermined intervals (STEP 3). The difference between the previous detection value and the current detection value is calculated. If it is larger than the predetermined value, the process returns to STEP 3. If it is within the predetermined value, the process proceeds to STEP 5 (STEP 4), and the rotation speed of the compressor is increased by a predetermined value (STEP 5). Then, it drive | operates with the rotation speed according to load.

  By performing start-up control in this way, the initial rotational speed is determined based on the outer temperature of the compressor, and when the temperature of the lubricating oil is low, the initial rotational speed is set to low, and when it is high, operation is started at a higher rotational speed. Thus, the operation can be started at a low rotation speed when the refrigerant stagnation is large and at a higher rotation speed when the refrigerant is low. Furthermore, since the rotation speed of the compressor is further increased after the change in the suction pressure is within a predetermined value, there is no forming due to a rapid decrease in the suction pressure.

  Therefore, unlike the prior art, in order to ensure the reliability of the compressor, it is not always necessary to maintain the rotation speed of the compressor for a certain period of time in any state, and the compressor is started according to the state of the refrigerant circuit. It is possible to provide an air conditioner that can perform control and shortens the start-up control time and improves comfort while ensuring the reliability of the compressor.

(Embodiment 2)
In the present embodiment, the control device circuit diagram of the air conditioner is the same, and the description is omitted.

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

  FIG. 3 is an operation flowchart according to the second embodiment of the present invention.

  First, the initial rotational speed of the compressor is determined by the controller 26 based on the temperature detected by the outer temperature sensor 28 (STEP 1), and the operation is started (STEP 2).

  Next, the compressor operating current is detected by the current sensor 29 at predetermined intervals (STEP 3).

The difference between the previous detection value and the current detection value is calculated. If it is larger than the predetermined value, the process returns to STEP 3, and if it is within the predetermined value, the process proceeds to STEP 5 (STEP 4).
The number of rotations of the compressor is increased by a predetermined value (STEP 5). Then, it drive | operates with the rotation speed according to load.

  The operating current of the compressor varies depending on the operating load of the compressor and the motor winding temperature of the compressor. That is, the current value is low when the winding temperature is low immediately after startup and the differential pressure between discharge and suction pressure is small, and the current value increases when the winding temperature rises and the differential pressure increases.

  Therefore, since the change in the compressor current value is within a predetermined value, the compressor is warmed, the stagnation of the refrigerant is reduced, and the refrigerant circuit is stabilized to increase the rotation of the compressor. Absent.

  Therefore, unlike the prior art, in order to ensure the reliability of the compressor, it is not always necessary to maintain the rotation speed of the compressor for a certain period of time in any state, and the compressor is started according to the state of the refrigerant circuit. It is possible to provide an air conditioner that can perform control and shortens the start-up control time and improves comfort while ensuring the reliability of the compressor.

(Embodiment 3)
In the present embodiment, the control device circuit diagram of the air conditioner is the same, and the description is omitted.

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

  FIG. 4 is an operation flowchart according to the third embodiment of the present invention.

  First, the initial rotational speed of the compressor is determined by the controller 26 based on the temperature detected by the discharge temperature sensor 32 (STEP 1), and the operation is started (STEP 2). Next, at predetermined intervals, the evaporating temperature is detected by the indoor heat exchanger temperature sensor 31 during cooling and by the outdoor heat exchanger temperature sensor 30 during heating (STEP 3).

  The difference between the previous detection value and the current detection value is calculated. If the difference is larger than the predetermined value, the process returns to STEP 3. If it is within the predetermined value, the process proceeds to STEP 5 (STEP 4), and the rotation speed of the compressor is increased by a predetermined value (STEP 5). Then, it drive | operates with the rotation speed according to load.

  By performing the start-up control in this way, the initial rotational speed is determined by the discharge temperature of the compressor, and when the discharge pipe temperature is low and the temperature of the lubricating oil is low, the rotational speed is low, and when it is high, the rotational speed is higher than that. By starting the operation, the operation can be started at a low rotation speed when the refrigerant stagnation is large and at a higher rotation speed when the refrigerant is low.

  Furthermore, since the rotation speed of the compressor is further increased after the change in the evaporation temperature falls within a predetermined value, there is no forming due to a rapid decrease in the suction pressure.

  Therefore, unlike the prior art, in order to ensure the reliability of the compressor, it is not always necessary to maintain the rotation speed of the compressor for a certain period of time in any state, and the compressor is started according to the state of the refrigerant circuit. It is possible to provide an air conditioner that can perform control and shortens the start-up control time and improves comfort while ensuring the reliability of the compressor.

  As described above, the air conditioner according to the present invention can shorten the start-up control time of the compressor and improve the comfort, so that it is possible to control the refrigerator such as a refrigerator that can control the rotation speed of the compressor. It can also be applied to applications.

Air conditioner control device circuit diagram in the first to third embodiments of the present invention Operation flowchart according to the first embodiment of the present invention Operation flowchart according to the second embodiment of the present invention Operation flowchart in Embodiment 3 of the present invention Conventional air conditioner control device circuit diagram Operating characteristic diagram of conventional air conditioner control device

Explanation of symbols

21 Compressor 22 Four-way valve 23 Outdoor heat exchanger 24 Pressure reduction expansion valve 25 Indoor heat exchanger 27 Suction pressure sensor

Claims (5)

A refrigerant 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 a control circuit for controlling the rotation speed of the compressor is provided to start the compressor An air conditioner characterized in that when the change in the suction pressure of the air conditioner becomes a predetermined value or less, the rotation speed of the compressor is increased. A refrigerant 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 a control circuit for controlling the rotation speed of the compressor is provided to start the compressor An air conditioner characterized in that when the change in compressor operating current becomes a predetermined value or less, the rotational speed of the compressor is increased. A refrigerant 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 a control circuit for controlling the rotation speed of the compressor is provided to start the compressor An air conditioner characterized in that when the change in the evaporation temperature becomes a predetermined value or less, the rotational speed of the compressor is increased. The air conditioner according to any one of claims 1 to 3, wherein an initial value of the rotational speed of the compressor at the time of startup is determined by an outer temperature of the compressor. The air conditioner according to any one of claims 1 to 3, wherein an initial value of the rotational speed of the compressor at the time of startup is determined by a discharge pipe temperature of the compressor.

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