JPH0468872B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an operation control device that controls an inverter of an air conditioner.

(Prior art) Conventionally, as an operation control device for this type of air conditioner, a compressor whose rotation speed can be controlled by frequency conversion is provided, and the operation of the compressor is controlled according to the required frequency based on the air conditioning load. This is already known, for example, in Japanese Utility Model Application Publication No. 59-79777.

As shown in FIG. 4, the operation control device of the above publication includes a compressor 6 whose rotational speed can be controlled by frequency conversion, an indoor heat exchanger A, an outdoor heat exchanger B, and a four-way switching valve. C forms a refrigeration cycle, and detection sensors a and b for detecting the refrigerant temperature are arranged on the refrigerant suction side and the refrigerant discharge side of the compressor 6 in the refrigeration cycle, respectively. b to detect the temperature difference of the refrigerant, that is, the air conditioning load, while the refrigeration cycle is equipped with the detection sensors a,
An electromagnetic expansion valve D is interposed which opens and closes based on the detection result obtained by b.

By doing so, when the air conditioner is operating and the air conditioning load detected by each of the detection sensors a and b is large, the compressor 6 is operated in a high frequency region to increase the rotation speed of the compressor 6. Generally, high capacity operation is performed, and when the air conditioning load is small, the compressor 6 is operated in a low frequency region,
The rotational speed of the compressor 6 is kept low to perform low capacity operation.

By the way, in the above air conditioner operation control device, when the compressor 6 is operated in a low frequency range, abnormal vibrations may occur in the compressor 6, and this can be explained based on FIG. I will explain.

Fig. 3 will be explained in detail later, so the high pressure pressure curve of the compressor 6 is shown with the high pressure HP on the vertical axis and the frequency on the horizontal axis, and the low frequency of 30 to 35. In this region, an abnormal vibration region of the compressor 6 is formed on the upper side of the high pressure curve.

However, in the case where the air conditioner is operated under inverter control, the operating frequency of the compressor 6 is 30 to 30.
35, when the high pressure of the compressor 6 is raised to the upper side of the high pressure curve and the input current of the compressor 6 becomes higher than the reference value, the compression Abnormal vibrations occurred in machine 6.

Therefore, in general, the operating frequency range of the compressor 6 is reduced, that is, the operating frequency of the compressor 6 is set outside the low frequency range of 30 to 35, or the output voltage of the compressor 6 is reduced. This change was made to prevent abnormal vibrations of the compressor 6.

(Problems to be Solved by the Invention) As described above, in order to prevent abnormal vibrations of the compressor 6, the operating frequency range of the compressor 6 may be reduced or the output voltage of the compressor 6 may be changed. In this case, there was a problem that the capacity and efficiency of the compressor 6 inevitably decreased.

The present invention has been made in view of the above-mentioned problems, and its purpose is to: when the control conditions approach the abnormal vibration region when controlling the operation of the compressor;
By temporarily shifting the operating frequency of the compressor to a region outside the abnormal vibration region and operating the compressor at a frequency outside the abnormal vibration region, this compression can be improved without reducing the capacity or efficiency of the compressor. An object of the present invention is to provide an operation control device for an air conditioner that can reliably prevent abnormal vibrations of the machine.

(Means for Solving the Problems) As shown in the embodiment of the drawings, the present invention includes a compressor 6 whose rotation speed can be controlled by frequency conversion, and operates at a required frequency 1 based on the air conditioning load. In the operation control device for an air conditioner, an operation region in which the operating frequency of the compressor 6 is within a low frequency region and the input current of the compressor 6 is higher than a reference value is defined as an abnormal vibration region, and the required frequency 1 is determined as an abnormal vibration region. has entered the low frequency region of the abnormal vibration region, and when the determining means determines that the required frequency 1 has entered the low frequency region, the input current is at a reference value. In the above case, the operation is performed with the operating frequency 2 shifted outside the low frequency region, and when it is determined that the required frequency 1 has entered the low frequency region of the abnormal vibration region, and the input current is The present invention is characterized by comprising an operation control means for operating at the required frequency 1 when the frequency is below a reference value.

(Function) When the compressor 6 is operated under inverter control, the operating frequency of the compressor 6 becomes as shown in FIG.
30 to 35, the compressor 6
is operated in an operating region where the input current is higher than the reference value, the determining means determines that the required frequency 1 has entered the low frequency region of the abnormal vibration region, and at the same time, the operation controlling means The operating frequency 2 of the compressor 6 is shifted outside the low frequency range, and the compressor 6 can be operated at a frequency outside the low frequency range, that is, a frequency range that avoids the abnormal vibration range, without causing abnormal vibration. is carried out.

Further, even when the operating frequency of the compressor 6 is in the same low frequency range as in the case described above, when the input current of the compressor 6 is operated in an operating range lower than the reference value, the determining means Although it is determined that the required frequency f1 has entered the low frequency region of the abnormal vibration region, the operating frequency of the compressor 6 is not shifted by the operation control means and the required frequency f1 is It is operated based on the following.

(Example) The operation control device for an air conditioner according to the present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 is a block diagram showing an operation control device for an air conditioner, in which a setting means 1 for setting the room temperature;
A room temperature detection means 2 for detecting room temperature is connected to the input side of the temperature difference detection means 3, and a frequency calculation means 4 is connected to the output side of the temperature difference detection means 3.
The calculating means 4 calculates the temperature difference between the set room temperature set by the setting means 1 and the detected room temperature detected by the detecting means 2, that is, the air conditioning load. A controller 5 is connected so that a compressor 6 connected to the output side of the inverter controller 5 is operated and controlled by an output signal from the inverter controller 5.

Further, on the output side of the inverter controller 5, it is determined that the required frequency 1 based on the air conditioning load of the compressor 6 has entered the low frequency region (30 to 50 frequency region) of the abnormal vibration region shown in FIG. At the same time, when the determining means 7 determines that the required frequency 1 has entered the low frequency region and the input current to the compressor 6 is equal to or higher than the reference value, the operation is started. When operation is performed with frequency 2 shifted outside the low frequency region, and when the determining means 7 determines that the required frequency 1 has entered the low frequency region, the input current to the compressor 6 is below the reference value, an operation control means 8 that operates based on the required frequency 1 is connected to the output side of the discrimination means 7, and the discrimination means 7 and the calculation control means 8 control the compressor. 6 operation control was performed.

FIG. 3 is an explanatory diagram illustrating that abnormal vibration occurs in the compressor 6 when the compressor 6 is operated in a low frequency region, and the vertical axis shows high pressure
The high-pressure pressure curve of the compressor 6 with HP and frequency on the horizontal axis is shown, and the maximum frequency max in the low frequency region where abnormal vibration occurs in the compressor 6 is 35
In addition, the lowest frequency min is set to 30, which is the same as the lowest operating frequency in the compressor 6, and the abnormal vibration of the compressor 6 is set to the upper side of the high pressure curve in these low frequency regions 30 to 35. forming an area.

As described above, the lowest frequency min in the low frequency range that causes abnormal vibrations in the compressor 6 is set to be the same as the lowest operating frequency in the compressor 6, and the compressor 6 By controlling the operation of the compressor 6, the operation control range of the compressor 6 can be increased. In other words, the operation of the compressor 6 can be efficiently controlled over a wide range.

Next, the operation control mode of the air conditioner will be explained based on the flowchart shown in FIG. 2.

First, at the same time as the operation of the air conditioner is started, the determination means 7 determines that the required frequency 1 corresponding to the air conditioning load of the compressor 6 is in the low frequency range shown in FIG. If yes, that is, if the requested frequency 1 is in the low frequency region,
It is determined whether the input current Iin of the compressor 6 is greater than or equal to a predetermined reference value Ik, and if yes, that is, the control conditions for the compressor 6 are formed on the upper side of the high pressure curve in the figure. When entering the abnormal vibration region, the operating frequency 2 of the compressor 6 is temporarily shifted up by the operation control means 8 to the minimum frequency exceeding the maximum frequency in the low frequency region, that is, the 36th frequency in the figure. The operation of the compressor 6 is controlled.

By doing so, the compressor 6 can be operated in a region away from the low frequency region of the abnormal vibration region without causing abnormal vibrations.

Furthermore, when the required frequency 1 determined by the determining means 7 is outside the low frequency range (30 to 35), and the input current Iin of the compressor 6 is less than or equal to a predetermined reference value Ik. At times, the operation of the compressor 6 is controlled while maintaining the required frequency 1.

In the above embodiment, the low frequency range in which abnormal vibration occurs in the compressor 6 is set to 30 to 35, and when the control condition of the compressor 6 is in the low frequency range, the compressor 6 When the input current Iin becomes larger than the reference value Ik, the operating frequency 2 of the compressor 6 is shifted up to 36 frequencies higher than the low frequency, but the low frequency region is set outside the range. For example, when the compressor 6 is set at an intermediate portion of the operating frequency range, and there is a risk of abnormal vibrations in the compressor 6, the frequency range may be set at an intermediate portion of the operating frequency range. It is also possible to shift the frequency to that frequency.

(Effects of the Invention) As explained above, in the air conditioner operation control device according to the present invention, the operating frequency of the compressor 6 is within the low frequency region, and the input current of the compressor 6 is
determining means 7 for defining an operating region in which Iin is higher than a reference value Ik as an abnormal vibration region, and determining that a required frequency 1 based on the air conditioning load of the compressor 6 has entered a low frequency region of the abnormal vibration region; Discrimination means 7
When it is determined that the required frequency 1 has entered the low frequency region, and the input current
When Iin is greater than or equal to the reference value Ik, operation is performed with the operating frequency 2 shifted outside the low frequency region, and the determining means 7 determines that the required frequency 1 has entered the low frequency region of the abnormal vibration region. when the input current Iin is equal to the reference value Ik
Since the operation control means 8 is provided to operate based on the required frequency 1 in the following cases, abnormal vibrations of the compressor 6 can be suppressed without reducing the capacity or efficiency of the compressor 6 as in the conventional case. It has now been possible to definitely prevent this.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the operation control device for an air conditioner according to the present invention, Fig. 2 is a flowchart showing the operation control mode of the air conditioner, and Fig. 3 is a diagram showing abnormal vibrations occurring in the compressor. FIG. 4 is a diagram illustrating a conventional example. 6...Compressor, 7...Discrimination means, 8...Operation control means, 1...Required frequency, 2...Operating frequency, max...Maximum frequency, min...Minimum frequency, Iin...Input current, Ik ……Reference value.

Claims (1)

[Claims] 1. A compressor 6 whose rotation speed can be controlled by frequency conversion, and a required frequency 1 based on the air conditioning load.
In the operation control device for an air conditioner that operates in a determining means for determining that the required frequency 1 has entered the low frequency region of the abnormal vibration region; and an input signal when the determining means determines that the required frequency 1 has entered the low frequency region. When the current is equal to or higher than the reference value, operation is performed by shifting the operating frequency 2 to outside the low frequency region, and when it is determined that the required frequency 1 has entered the low frequency region of the abnormal vibration region. An operation control device for an air conditioner, comprising operation control means for operating at the required frequency 1 when the input current is below the reference value. 2. The low frequency region of the abnormal vibration region includes the lowest frequency min of the operating frequency region of the compressor 6, and the operation control means sets the operating frequency 2 to the maximum frequency of the low frequency region in the abnormal vibration region.
The air conditioner operation control device according to claim 1, wherein the air conditioner operation control device is configured to shift up to a minimum frequency exceeding max.