JPWO2021044507A1 - Refrigeration cycle device - Google Patents

Abstract

The refrigeration cycle device acquires a refrigerant circuit formed by connecting a compressor, a condenser, a decompression device and an evaporator via a refrigerant pipe, and the required frequency of the compressor, and obtains the required frequency of the compressor according to the acquired required frequency. A control device for controlling the command frequency is provided, and the control device determines whether or not the required frequency corresponds to a preset prohibited frequency region, and when it is determined that the required frequency corresponds to the prohibited frequency region. In addition, one of the first frequency smaller than the lower limit value of the prohibited frequency region and the second frequency larger than the upper limit value of the prohibited frequency region was set as the command frequency, and a preset control cycle was started and acquired during the control cycle. Based on the required frequency, the first time with the first frequency as the command frequency and the second time with the second frequency as the command frequency in the control cycle are repeatedly calculated, and after the control cycle starts, the first frequency And when the first time or the second time corresponding to one of the second frequencies elapses, the command frequency is switched from one to the other.

Description

The present invention relates to a refrigeration cycle device including a control device for controlling a command frequency of a compressor.

The refrigeration cycle device controls the command frequency of the compressor according to the air conditioning load. However, when the command frequency of the compressor becomes a value close to an integral multiple of the power supply frequency, or when the command frequency of the compressor matches the resonance frequency of the gas and liquid in the piping of the refrigerant circuit, abnormal vibration due to resonance occurs. May occur and the refrigeration cycle device may become unstable. In the refrigeration cycle apparatus, a technique for controlling the command frequency of the compressor to be outside the preset operation prohibition frequency in order to suppress the occurrence of abnormal vibration due to resonance is disclosed (for example, Patent Document). 1). In Patent Document 1, when the required frequency of the compressor corresponds to the operation prohibited frequency, the frequency is slightly higher than the upper limit of the operation prohibited frequency range and slightly lower than the lower limit, and only for a predetermined time corresponding to each of the two command frequencies. , Alternately controlled to operate the compressor.

Japanese Unexamined Patent Publication No. 7-31193

In Patent Document 1, when the required frequency corresponds to the prohibited frequency, the first operating time in which the compressor is operated at a frequency slightly higher than the upper limit of the prohibited frequency range and the frequency slightly lower than the lower limit of the range are used. The second operating time in which the compressor is operated is uniquely determined. Therefore, in Patent Document 1, the fluctuation of the required frequency cannot be dealt with until the determined first operation time and the second operation time have elapsed. Since the required frequency is determined by the difference between the set temperature and the room temperature, the room temperature does not reach the set temperature during the period when the compressor cannot be operated according to the fluctuation of the required frequency, and the comfort is impaired. On the other hand, when trying to shorten the operation cycle at the two command frequencies in order to shorten the period during which the fluctuation of the required frequency cannot be dealt with, the command frequencies of the compressor are set across the range of the operation prohibited frequencies. Frequent switching between command frequencies makes it impossible to suppress the occurrence of abnormal vibration.

The present invention has been made to solve the above-mentioned problems, and even when the required frequency corresponds to the prohibited frequency region, refrigeration with improved comfort while suppressing the occurrence of abnormal vibration due to resonance. It is intended to provide a cycle device.

The refrigeration cycle device according to the present invention acquires the required frequency of the compressor and the refrigerant circuit formed by connecting the compressor, the condenser, the depressurizing device and the evaporator via the refrigerant pipe, and obtains the required frequency. A control device for controlling the command frequency of the compressor according to the above, and the control device determines whether or not the required frequency corresponds to a preset prohibited frequency region, and the required frequency is determined. When it is determined that the prohibited frequency region is applicable, one of the first frequency smaller than the lower limit value of the prohibited frequency region and the second frequency larger than the upper limit value of the prohibited frequency region is set as the command frequency and is set in advance. The first time in which the first frequency in the control cycle is set as the command frequency and the second frequency are set as the command frequency in the control cycle based on the acquired required frequency during the control cycle. When the first time or the second time corresponding to one of the first frequency and the second frequency elapses after the second time is repeatedly calculated and the control cycle is started. The command frequency is switched from the one to the other.

According to the control device of the refrigeration cycle device of the present invention, during the control cycle, the first time and the second time in the control cycle are repeatedly calculated based on the acquired required frequency, and the calculated first time and the first time are calculated. The command frequency is switched based on 2 hours. As a result, even when the required frequency corresponds to the prohibited frequency region, the fluctuation of the required frequency can be dealt with, so that it is not necessary to shorten the control cycle and the command is given between the two frequencies set above and below the prohibited frequency region. The frequency of switching frequencies is low. Therefore, even when the required frequency corresponds to the prohibited frequency region, it is possible to improve comfort while suppressing the occurrence of abnormal vibration due to resonance.

It is a refrigerant circuit diagram which shows the air conditioner which concerns on embodiment. It is a block diagram which shows the function of the control device of FIG. It is a figure explaining the operation of the compressor when the required frequency drops and reaches within the prohibited frequency region. It is a figure explaining the operation of the compressor when the required frequency rises and reaches within the prohibited frequency region. It is a figure explaining the operation of the compressor when the preceding frequency alternates in a continuous control cycle. It is a flowchart which shows an example of the control performed by the control device of FIG. It is a flowchart branched from the flowchart of FIG. It is explanatory drawing explaining the minimum maintenance time stored in the control apparatus of FIG. It is explanatory drawing explaining the maximum maintenance time stored in the control apparatus of FIG.

Embodiment.
FIG. 1 is a refrigerant circuit diagram showing an air conditioner 100 according to an embodiment. In FIG. 1, the solid line arrow indicates the direction in which the refrigerant flows during the heating operation, and the broken line arrow indicates the direction in which the refrigerant flows during the cooling operation.

As shown in FIG. 1, the air conditioner 100 includes a refrigerant circuit 101 and a control device 20. The refrigerant circuit 101 is configured by connecting a compressor 1, a flow path switching device 5, an outdoor heat exchanger 3, a decompression device 4, and an indoor heat exchanger 2 by a refrigerant pipe 9. The compressor 1 compresses the refrigerant. The frequency of the compressor 1 is variable by an inverter (not shown). The flow path switching device 5 is composed of, for example, a four-way valve, and switches the circulation direction of the refrigerant between the cooling operation and the heating operation. The outdoor heat exchanger 3 is composed of a plurality of fins and a plurality of heat transfer tubes, and operates as a condenser during the cooling operation and as an evaporator during the heating operation. The decompression device 4 is composed of, for example, an expansion valve, and decompresses a high-pressure liquid refrigerant into a low-pressure gas-liquid two-phase refrigerant. The indoor heat exchanger 2 is composed of a plurality of fins and a plurality of heat transfer tubes, and operates as an evaporator during a cooling operation and as a condenser during a heating operation.

That is, in the refrigerant circuit 101 during the cooling operation, the compressor 1, the outdoor heat exchanger 3 operating as a condenser, the decompression device 4, and the indoor heat exchanger 2 operating as an evaporator are annular in the refrigerant pipe 9. Connected to and configured. Further, in the refrigerant circuit 101 during the heating operation, the compressor 1, the indoor heat exchanger 2 operating as a condenser, the decompression device 4, and the outdoor heat exchanger 3 operating as an evaporator are annularly formed by the refrigerant pipe 9. Connected to and configured.

The refrigerant may be any refrigerant as long as it is capable of gas-liquid two-phase within the operating temperature range and operating pressure range, and for example, an HFC-based refrigerant, an HCFC-based refrigerant, or a natural refrigerant is used.

The air conditioner 100 includes an outdoor blower 7 attached to the outdoor heat exchanger 3 and an indoor blower 6 attached to the indoor heat exchanger 2. The outdoor blower 7 is, for example, a propeller fan, and supplies outdoor air to the outdoor heat exchanger 3. The indoor blower 6 is, for example, a cross-flow fan, and supplies indoor air to the indoor heat exchanger 2.

Of the constituent devices of the air conditioner 100, the compressor 1, the outdoor heat exchanger 3, the decompression device 4, the flow path switching device 5, and the outdoor blower 7 are housed in the outdoor unit 11. Of the constituent devices of the air conditioner 100, the indoor heat exchanger 2 and the indoor blower 6 are housed in the indoor unit 10. The indoor unit 10 is installed in a room which is an air-conditioned space.

Further, the air conditioner 100 is provided in the indoor unit 10 and includes a temperature detector 8 for detecting the temperature of the indoor air and a remote controller 12 for inputting a set temperature Tset by the operation of the user. The temperature detector 8 is composed of, for example, a temperature sensor.

The temperature detector 8, the compressor 1, the decompression device 4, the flow path switching device 5, the indoor blower 6, and the outdoor blower 7 are electrically connected to the control device 20 via wiring or the like. The remote controller 12 can communicate with the control device 20. That is, the control device 20 receives the detection value of the temperature detector 8 and the set value of the remote controller 12. Further, the control device 20 has a configuration capable of controlling the compressor 1, the decompression device 4, the flow path switching device 5, the indoor blower 6, and the outdoor blower 7, respectively. The control device 20 is arranged outside the outdoor unit 11 and the indoor unit 10. The control device 20 may be housed in the outdoor unit 11 or may be housed in the indoor unit 10. Alternatively, the control device 20 may be composed of a plurality of control units, and each control unit may be separately housed in the outdoor unit 11 and the indoor unit 10.

Next, the operation of the air conditioner 100 during the cooling operation and the heating operation will be described.

During the cooling operation, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is discharged and flows into the outdoor heat exchanger 3 via the flow path switching device 5. In the outdoor heat exchanger 3 that acts as a condenser during the cooling operation, the outdoor air taken into the outdoor unit 11 by the drive of the outdoor blower 7 passes around the fins of the outdoor heat exchanger 3 and the heat transfer tube to form a refrigerant. The heat is exchanged and blown out of the outdoor unit 11. At this time, the refrigerant is cooled while releasing latent heat of condensation to the outdoor air, and becomes a high-pressure liquid state. The liquid-state refrigerant flowing out of the outdoor heat exchanger 3 passes through the decompression device 4, is depressurized, becomes a low-pressure gas-liquid two-phase state, and flows into the indoor heat exchanger 2. In the indoor heat exchanger 2 that acts as an evaporator during the cooling operation, the indoor air taken into the indoor unit 10 by the indoor blower 6 passes around the fins of the indoor heat exchanger 2 and the heat transfer tube to exchange heat with the refrigerant. However, the indoor air is cooled by being blown into the indoor space. On the other hand, the gas-liquid two-phase state refrigerant that has flowed into the indoor heat exchanger 2 evaporates by absorbing latent heat of vaporization from the indoor air. While the air conditioner 100 is performing the cooling operation, the refrigeration cycle described above is repeated.

During the heating operation, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is discharged and flows into the indoor heat exchanger 2 via the flow path switching device 5. In the indoor heat exchanger 2 that acts as a condenser during the heating operation, the indoor air taken into the indoor unit 10 by the drive of the indoor blower 6 passes around the fins of the indoor heat exchanger 2 and the heat transfer tube to form a refrigerant. It exchanges heat and is blown into the indoor space. As a result, the refrigerant is cooled while releasing latent heat of condensation to the indoor air, and becomes a high-pressure liquid state. The liquid-state refrigerant flowing out of the indoor heat exchanger 2 passes through the decompression device 4, is depressurized, becomes a low-pressure gas-liquid two-phase refrigerant, and flows into the outdoor heat exchanger 3. In the outdoor heat exchanger 3 that acts as an evaporator during the heating operation, the outdoor air taken into the outdoor unit 11 by the drive of the outdoor blower 7 passes around the fins of the outdoor heat exchanger 3 and the heat transfer tube to form a refrigerant. The heat is exchanged and blown out of the outdoor unit 11. On the other hand, the gas-liquid two-phase state refrigerant evaporates by absorbing latent heat of vaporization from the outdoor air. While the air conditioner 100 is performing the heating operation, the refrigeration cycle described above is repeated.

FIG. 2 is a block diagram showing the functions of the control device of FIG. The control device 20 is also referred to as a CPU (Central Processing Unit, central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer or processor) that executes a program stored in dedicated hardware or a memory (not shown). ).

The control device 20 determines the command frequency fz based on the set temperature Tset input via the remote controller 12 and the room temperature Ta detected by the temperature detector 8, and outputs the determined command frequency fz to the compressor 1. do. Further, the control device 20 calculates and outputs a command opening degree to the decompression device 4 according to the operating condition of the refrigeration cycle device. Further, the control device 20 controls the rotation speed of the indoor blower 6, the rotation speed of the outdoor blower 7, and the switching of the flow path switching device 5 according to the operation status of the refrigeration cycle.

FIG. 3 is a diagram illustrating the operation of the compressor when the required frequency is lowered to reach the prohibited frequency region. The control device 20 calculates the required frequency fc so that the room temperature Ta becomes the set temperature Tset in order to adjust the air conditioning capacity according to the air conditioning load, and sets the frequency of the compressor 1 according to the calculated required frequency fc. Control. In FIG. 3, the vertical axis represents the frequency of the compressor 1, and the horizontal axis represents the elapsed time t from the start to the end of the control cycle Tc.

When the required frequency fc of the compressor 1 does not correspond to the prohibited frequency region Rfp, the control device 20 operates the compressor 1 with the required frequency fc as the command frequency fz. On the other hand, when the required frequency fc corresponds to the prohibited frequency region Rfp, the control device 20 operates the compressor 1 with the first frequency f1 or the second frequency f2 set outside the prohibited frequency region Rfp as the command frequency fz. ..

Here, the prohibited frequency region Rfp is a compressor frequency at which pipe vibration and vibration noise due to resonance are likely to occur in the air conditioner 100, and is stored in advance in the control device 20. Hereinafter, a case where the prohibited frequency region Rfp includes a frequency range of 59 hertz to 61 hertz in which vibration is likely to occur in the air conditioner 100 will be described as an example. A plurality of prohibited frequency regions Rfp may be provided, and may be set to a frequency region in which piping vibration or vibration noise is likely to occur depending on the configuration of the air conditioner 100.

Hereinafter, the first frequency f1 is 58 hertz, which is slightly lower than 59 hertz, which is the lower limit value L1 of the prohibited frequency region Rfp, and the second frequency f2 is 61 hertz, which is the upper limit value L2 of the prohibited frequency region Rfp. Described as being slightly higher at 62 hertz. The first frequency f1 may be a frequency smaller than the lower limit value L1 of the prohibited frequency region Rfp, and the second frequency f2 may be a frequency larger than the upper limit value L2 of the prohibited frequency region Rfp. The smaller the deviation from the prohibited frequency regions Rfp of each of the first frequency f1 and the second frequency f2, the smaller the amount of change in the compressor frequency when switching the command frequency fz. Hereinafter, the case corresponding to the prohibited frequency region Rfp means a case where the required frequency fc is larger than the first frequency f1 and smaller than the second frequency f2.

Each function of the control device 20 will be described with reference to FIG. The control device 20 determines parameters required for the storage unit 21, the timekeeping unit 22, the operation control unit 23 that controls each device of the refrigerant circuit 101, and the operation control unit 23 to control the command frequency fz of the compressor 1. It has a plurality of functional parts. The plurality of functional units are a frequency calculation unit 24, a prohibited frequency determination unit 25, a leading frequency determination unit 26, and a time calculation unit 27.

The storage unit 21 is composed of a memory or the like, and various setting values are stored in the storage unit 21. Specifically, the storage unit 21 stores in advance the control values of each device, the set temperature Tset, the control cycle Tc, the first frequency f1 and the second frequency f2 set for the prohibited frequency region Rfp, and the like. ing. Various set values stored in the storage unit 21 are referred to by the operation control unit 23, the frequency calculation unit 24, the prohibited frequency determination unit 25, the preceding frequency determination unit 26, and the time calculation unit 27.

Here, the control cycle Tc is the total of the first time T1 for operating the compressor 1 at the first frequency f1 and the second time T2 for operating the compressor 1 at the second frequency f2, as shown in FIG. It's time. The control cycle Tc is a preset time, for example, 5 minutes. The number of times of switching between the first time T1 and the second time T2 in the control cycle Tc is one or less. The length of the control cycle Tc is not particularly limited to this.

The timekeeping unit 22 is composed of a timer or the like and measures the time. The operation control unit 23 determines the timing for performing various controls with reference to the time measured by the time measuring unit 22.

The frequency calculation unit 24 calculates the required frequency fc based on the set temperature Tset and the room temperature Ta input from the temperature detector 8 according to the command of the operation control unit 23, and outputs the required frequency fc to the prohibited frequency determination unit 25. The frequency calculation unit 24 may be provided in an external device capable of communicating with the control device 20. In this case, the prohibited frequency determination unit 25 of the control device 20 responds to a command from the operation control unit 23 to the outside. It is preferable that the device is configured to acquire the required frequency fc. The required frequency fc is larger when the difference between the room temperature Ta and the set temperature Tset, that is, the air conditioning load is large, and becomes smaller as the air conditioning load is smaller. The frequency calculation unit 24 outputs the calculated requested frequency fc to the prohibited frequency determination unit 25.

When the required frequency fc is input from the frequency calculation unit 24, the prohibited frequency determination unit 25 determines whether or not the required frequency fc corresponds to the prohibited frequency region Rfp, and the required frequency fc does not correspond to the prohibited frequency region Rfp. In this case, the required frequency fc is output to the operation control unit 23. On the other hand, when the required frequency fc corresponds to the prohibited frequency region Rfp, the prohibited frequency determination unit 25 outputs the determination result and the required frequency fc to the effect that the required frequency fc corresponds to the prohibited frequency region Rfp to the preceding frequency determination unit 26. do. When the control cycle Tc is started and the required frequency fc corresponds to the prohibited frequency region Rfp, the determination result and the required frequency fc are output to the operation control unit 23 instead of the preceding frequency determination unit 26. NS.

When the leading frequency determination unit 26 receives a determination result indicating that the required frequency fc corresponds to the prohibited frequency region Rfp from the prohibited frequency determination unit 25, the preceding frequency determination unit 26 has a control cycle Tc of the first frequency f1 and the second frequency f2. The frequency instructed to the compressor 1 is determined in advance.

Specifically, the preceding frequency determination unit 26 first refers to the storage unit 21, and whether the previous command frequency pfz is less than the first frequency f1 or larger than the second frequency f2, the first frequency f1 or the first frequency. It is determined whether or not the frequency is f2. The leading frequency determination unit 26 outputs the first frequency f1 to the operation control unit 23 when it is determined that the previous command frequency pfz is less than the first frequency f1. The preceding frequency determination unit 26 outputs the second frequency f2 to the operation control unit 23 when it is determined that the previous command frequency pfz is larger than the second frequency f2.

The preceding frequency determination unit 26 outputs the previous command frequency pfz to the operation control unit 23 when the prohibited frequency determination unit 25 determines that the previous command frequency pfz is the first frequency f1 or the second frequency f2. .. Here, when the previous command frequency pfz is the first frequency f1 or the second frequency f2, for example, the required frequency fc corresponds to the prohibited frequency region Rfp in the previous control cycle, and the previous command frequency pfz is This is the case where the first frequency is f1 or the second frequency is f2. That is, in the continuous first control cycle and the second control cycle, when it is continuously determined that the required frequency fc corresponds to the prohibited frequency region Rfp, the command frequency pfz at the end of the first control cycle is set. The command frequency fz at the start of the second control cycle. In this way, it is possible to avoid switching the command frequency fz at the boundary of the control cycle Tc when the second control cycle starts, and to suppress the occurrence of abnormal vibration due to resonance.

The preceding frequency determination unit 26 may be configured to alternately alternate the command frequency fz at the start of each control cycle Tc in a plurality of continuous control cycles Tc. Further, the preceding frequency determination unit 26 can be omitted. In this case, of the first frequency f1 and the second frequency f2, the frequency to be the command frequency fz may be set in advance.

The time calculation unit 27 causes the compressor 1 to operate at the second frequency f2 in the control cycle Tc based on the request frequency fc input from the prohibited frequency determination unit 25 by the command of the operation control unit 23. calculate. Specifically, the time calculation unit 27 calculates the second time T2 from the equation (1), where the average value of the command frequency fz of the compressor 1 in the control cycle Tc is the input requested frequency fc. On the other hand, the first time T1 is calculated by subtracting the second time T2 calculated by the equation (1) from the preset control cycle Tc.

[Number 1]
T2 = Tc × (fc-f1) / (f2-f1) ... Equation (1)

When the time calculation unit 27 obtains the second time T2, the time calculation unit 27 refers to the control cycle Tc, the first frequency f1 and the second frequency f2 stored in the storage unit 21.

The time calculation unit 27 outputs the calculated second time T2 to the operation control unit 23. In this way, the second time T2 is calculated based on the acquired required frequency fc for each control cycle Tc, and the first time T1 and the second time T2 in the control cycle Tc are determined.

The operation control unit 23 outputs commands to each of the frequency calculation unit 24, the prohibited frequency determination unit 25, the preceding frequency determination unit 26, and the time calculation unit 27 at preset timings. Further, the operation control unit 23 determines the command frequency fz to be output to the compressor 1 based on the inputs from the frequency calculation unit 24, the prohibited frequency determination unit 25, the preceding frequency determination unit 26, and the time calculation unit 27.

Specifically, the operation control unit 23 outputs the requested frequency fc input from the prohibited frequency determination unit 25 to the compressor 1 as the command frequency fz when the required frequency fc does not correspond to the prohibited frequency region Rfp. Further, the operation control unit 23 uses the first frequency f1 or the second frequency f2 input from the prohibited frequency determination unit 25 or the preceding frequency determination unit 26 as the command frequency fz when the required frequency fc corresponds to the prohibited frequency region Rfp. Output to the compressor 1. The operation control unit 23 starts the timer when the first frequency f1 or the second frequency f2 input from the preceding frequency determination unit 26 is output to the compressor 1 as the command frequency fz. The timer measures the elapsed time t from the start of the control cycle Tc.

The operation control unit 23 controls the timing of switching the command frequency fz within the control cycle Tc according to the command frequency fz preceding in the control cycle Tc. Specifically, when the first time T1 or the second time T2 corresponding to the previously set command frequency fz elapses after the count of the control cycle Tc starts by starting the timer, the command frequency Switch fz. That is, when the first frequency f1 is set to the command frequency fz in advance in the control cycle Tc, the operation control unit 23 elapses the calculated first time T1 after the control cycle Tc starts. When this is done, the command frequency fz is switched from the first frequency f1 to the second frequency f2. On the other hand, when the second frequency f2 is set to the command frequency fz in advance in the control cycle Tc, the operation control unit 23 elapses the calculated second time T2 after the control cycle Tc starts. At that time, the command frequency fz is switched from the second frequency f2 to the first frequency f1. When the control cycle Tc elapses after starting the timer, the operation control unit 23 stops and resets the timer, and outputs a command to each function unit again.

The operation control unit 23 causes the frequency calculation unit 24 to calculate the required frequency fc each time the set time elapses during the control cycle Tc. When the prohibited frequency determination unit 25 determines that the required frequency fc corresponds to the prohibited frequency region Rfp, the operation control unit 23 continues the timer and calculates the first time T1 and the second time T2 in the time calculation unit 27. Output a command. The operation control unit 23 controls the timing of switching the command frequency fz within the control cycle Tc based on the first time T1 and the second time T2 repeatedly input from the time calculation unit 27 during the control cycle Tc. That is, during the control cycle Tc, the first time T1 and the second time T2 are updated every set time, and the command frequency fz is switched at the updated first time T1 or second time T2.

FIG. 3 shows changes in the required frequency fc and changes in the command frequency fz during the control cycle Tc when the second frequency f2 is set to the command frequency fz in advance within the control cycle Tc. FIG. 4 is a diagram illustrating the operation of the compressor when the required frequency rises and reaches the prohibited frequency region. FIG. 4 shows changes in the required frequency fc and changes in the command frequency fz during the control cycle Tc when the first frequency f1 is set to the command frequency fz in advance in the control cycle Tc.

As shown in FIG. 3, when the required frequency fc reaches the prohibited frequency region Rfp from a value larger than the second frequency f2, the second frequency f2 is set as the command frequency fz at the start of the control cycle Tc. NS. On the other hand, as shown in FIG. 4, when the required frequency fc reaches the prohibited frequency region Rfp from a value smaller than the first frequency f1, the first frequency f1 is the command frequency fz at the start of the control cycle Tc. It is said that. With such a configuration, when the required frequency fc changes from outside the prohibited frequency region Rfp to within the prohibited frequency region Rfp, the amount of change in the command frequency fz can be small, and energy saving can be improved.

FIG. 5 is a diagram illustrating the operation of the compressor when the preceding frequencies are alternately switched in a continuous control cycle. FIG. 5 shows an example of changes in the command frequency fz in the continuous first control cycle and the second control cycle when it is determined that the required frequency fc continuously corresponds to the prohibited frequency region Rfp. It is shown. The first time T1 and the second time T2 are different for each control cycle Tc, and are repeatedly calculated and updated even in the same control cycle Tc.

When the preceding frequency in each control cycle Tc is set to a fixed value, the total number of times the command frequency fz is switched in two consecutive control cycles Tc is three times. On the other hand, in the frequency control of FIG. 5, in the first control cycle, the command frequency fz at the start is set to the second frequency f2, and in the second control cycle, the command frequency fz at the start is set to the first frequency f1. The total number of times the command frequency fz is switched in one control cycle Tc is two times. With such a configuration, the frequency at which the frequency of the compressor 1 temporarily becomes the prohibited frequency region Rfp can be reduced, so that the occurrence of abnormal vibration is suppressed and energy saving is improved.

FIG. 6 is a flowchart showing an example of control performed by the control device of FIG. FIG. 7 is a flowchart branched from the flowchart of FIG. The frequency control performed by the control device 20 for the compressor 1 will be described with reference to FIGS. 6 and 7.

The frequency control shown in FIGS. 6 and 7 is repeatedly performed by the control device 20 during the operation of the compressor 1. First, the control device 20 calculates the required frequency fc according to the set temperature Tset input from the remote controller 12 and the room temperature Ta detected by the temperature detector 8 (step S20).

Next, the control device 20 determines whether or not the calculated requested frequency fc corresponds to the preset prohibited frequency region Rfp (step S21). When the required frequency fc does not correspond to the prohibited frequency region Rfp (step S21; NO), the control device 20 outputs the required frequency fc as the command frequency fz (step S22). After step S22, the control device 20 returns to step S20 again and performs a process of calculating the required frequency fc.

On the other hand, when the required frequency fc corresponds to the prohibited frequency region Rfp (step S21; YES), the control device 20 determines whether or not the previous command frequency pfz is less than the first frequency f1 (step S23). .. When the previous command frequency pfz is less than the first frequency f1 (step S23; YES), the control device 20 outputs the first frequency f1 as the command frequency fz (step S24). After that, the control device 20 activates the timer (step S25) and calculates the second time T2 in which the compressor 1 is driven at the second frequency f2 (step S26).

On the other hand, when the previous command frequency pfz is not less than the first frequency f1 (step S23; NO), the control device 20 further determines whether or not the previous command frequency pfz is larger than the second frequency f2 (step S23; NO). Step S35 in FIG. 7). When the previous command frequency pfz is larger than the second frequency f2 (step S35; YES), the control device 20 outputs the second frequency f2 as the command frequency pfz (step S36). After that, the control device 20 starts the timer (step S37) and calculates the second time T2 (step S40). When the previous command frequency pfz is not larger than the second frequency f2 in step S35 (step S35; NO), the control device 20 outputs the previous command frequency pfz as the command frequency fz (step S38). That is, when the previous command frequency pfz is set to the first frequency f1 or the second frequency f2, the previous command frequency pfz is set to the command frequency fz at the start of the current control cycle Tc.

After step S38, the control device 20 determines whether the previous command frequency pfz was the first frequency f1 or the second frequency f2 (step S39). When the previous command frequency pfz is the first frequency f1 in step S39 (step S39; f1), the control device 20 shifts to step S25 of FIG. 6 to start the timer and calculate the second time T2 (step S39; f1). Step S26). On the other hand, in step S39, when the previous command frequency pfz is the second frequency f2 (step S39; f2), the control device 20 shifts to step S37, starts the timer, and calculates the second time T2 (step S39; f2). Step S40).

In step S26, the control device 20 calculates the second time T2 in the control cycle Tc, and then the timer value Tm exceeds the value obtained by subtracting the second time T2 from the control cycle Tc, that is, the first time T1. It is determined whether or not there is (step S27). When the value of the timer exceeds the first time T1, the control device 20 outputs the second frequency f2 as the command frequency fz (step S28). On the other hand, when the value of the timer does not exceed the first time T1 (step S27; NO), the control device 20 outputs the first frequency f1 as the command frequency fz as it is (step S29).

After determining the command frequency fz in steps S28 and S29, the control device 20 again calculates the required frequency fc according to the set temperature Tset input from the remote controller 12 and the room temperature Ta detected by the temperature detector 8. (Step S30). The required frequency fc changes while the command frequency fz is fixed to the second frequency f2, which is a frequency higher than the prohibited frequency region Rfp, and the first frequency f1, which is a frequency lower than the prohibited frequency region Rfp. Therefore, it is possible to deal with fluctuations in the air conditioning load by repeatedly calculating the required frequency fc even during the control cycle Tc.

Next, the control device 20 again determines whether or not the calculated requested frequency fc corresponds to the prohibited frequency region Rfp (step S31). When the required frequency fc does not correspond to the prohibited frequency region Rfp (step S31; NO), the control device 20 outputs the required frequency fc as the command frequency fz (step S51), and then stops the timer to obtain a value. It is reset (step S52), and this control is terminated.

On the other hand, when the required frequency fc corresponds to the prohibited frequency region Rfp in step S31, the control device 20 continues the timer (step S32), and determines whether or not the value Tm of the timer becomes the control cycle Tc or more (step S31). Step S33). In step S33, when the value Tm of the timer becomes equal to or greater than the control cycle Tc (step S33; YES), the control device 20 stops the timer and resets the value (step S34), and ends the control. On the other hand, in step S33, when the timer value Tm is not equal to or more than the control cycle Tc, that is, the timer value Tm is less than the control cycle Tc, the process returns to step S26 and the second time T2 is calculated again.

After starting the timer, the control device 20 calculates the second time T2 in step S40, and then determines whether or not the value Tm of the timer exceeds the second time T2 (step S41). When the value Tm of the timer exceeds the second time T2 (step S41; YES), the control device 20 outputs the first frequency f1 as the command frequency fz (step S42). On the other hand, when the timer value Tm does not exceed the second time T2, that is, when the timer value is the second time T2 or less (step S41; NO), the control device 20 sets the second frequency f2 as the command frequency fz. Output (step S43). After determining the command frequency fz in steps S42 and S43, the control device 20 again calculates the required frequency fc according to the set temperature Tset input from the remote controller 12 and the room temperature Ta detected by the temperature detector 8. (Step S44).

Next, the control device 20 again determines whether or not the requested frequency fc calculated in step S44 corresponds to the prohibited frequency region Rfp (step S45). When the required frequency fc does not correspond to the prohibited frequency region Rfp (step S45; NO), the control device 20 outputs the required frequency fc as the command frequency fz (step S49), and then stops the timer to obtain a value. Reset (step S50) and end this control.

On the other hand, in step S46, when the required frequency fc corresponds to the prohibited frequency region Rfp (step S45; YES), the control device 20 continues the timer (step S46), and the timer value Tm is equal to or larger than the control cycle Tc. It is determined whether or not it has become (step S47). When the value of the timer is equal to or greater than the control cycle Tc, the control device 20 stops the timer, resets the value (step S48), and ends the control. On the other hand, if the timer value Tm is not equal to or greater than the control cycle Tc, that is, if the timer value is less than the control cycle, the process returns to step S40 and the calculation of the second time T2 is repeated.

By setting a threshold value or the like in the first time T1 or the second time T2, it may be configured to suppress the switching of the command frequency fz of the compressor 1 in a short time. Hereinafter, a case where the minimum maintenance time Ttmin and the maximum maintenance time Ttmax are set for the second time T2 will be described as an example. The minimum maintenance time Ttmin and the maximum maintenance time Ttmax are stored in the storage unit 21.

FIG. 8 is an explanatory diagram illustrating the minimum maintenance time stored in the control device of FIG. FIG. 9 is an explanatory diagram illustrating the maximum maintenance time stored in the control device of FIG.

The operation control unit 23 determines whether the second time T2 input from the time calculation unit 27 is the minimum maintenance time Ttmin or less, and when the second time T2 is the minimum maintenance time Ttmin or less (see FIG. 8). The second time T2 is corrected to 0, and the first time T1 is corrected to the control cycle Tc. Further, the operation control unit 23 determines whether the second time T2 input from the time calculation unit 27 is equal to or greater than the maximum maintenance time Ttmax, and when the second time T2 is equal to or greater than the maximum maintenance time Ttmax (see FIG. 9). ), The second time T2 is corrected to the control cycle Tc, and the first time T1 is corrected to 0. On the other hand, when the second time T2 is larger than the minimum maintenance time Ttmin and less than the maximum maintenance time Ttmax, the correction of the second time T2 and the first time T1 is not performed. The operation control unit 23 controls switching of the command frequency fz based on the corrected first time T1 and second time T2.

Here, since the control cycle Tc is a preset time, by setting the minimum maintenance time Ttmin and the maximum maintenance time Ttmax for one of the first time T1 and the second time T2, the other is also the minimum. The same effect as when the maintenance time and the maximum maintenance time are provided can be obtained.

Only the minimum maintenance time Ttmin is stored in the storage unit 21, and the maximum maintenance time Ttmax may be calculated by the equation (2).

[Number 2]
Ttmax = Tc-Ttmin ... (2)

As described above, according to the air conditioner 100 of the embodiment, the first time T1 and the second time T2 in the control cycle Tc are repeatedly calculated based on the acquired required frequency fc during the control cycle Tc. NS. Then, the command frequency fz is switched based on the calculated first time T1 and second time T2. As a result, even when the required frequency fc is within the prohibited frequency region Rfp, the compressor 1 can be operated at a frequency suitable for fluctuations in the required frequency fc within the control cycle Tc, and it is not necessary to shorten the control cycle Tc. Therefore, the frequency of switching the command frequency fz can be reduced. Therefore, even when the required frequency fc corresponds to the prohibited frequency region Rfp, it is possible to improve comfort while suppressing the occurrence of abnormal vibration due to resonance.

Further, the number of times of switching between the first frequency f1 and the second frequency f2 in the control cycle Tc is one or less, and the total time of the first time T1 and the second time T2 is equal to the control cycle Tc. Thereby, the operator can regulate the frequency with which the command frequency fz of the compressor 1 fluctuates across the prohibited frequency region Rfp depending on the length of the control cycle Tc to be set. Further, in the control, the timing of switching the command frequency fz in the control cycle Tc and the end of the control cycle Tc can be controlled based on the start of the control cycle Tc, and the control becomes easy.

Further, the air conditioner 100 repeatedly determines whether or not the acquired required frequency fc corresponds to the prohibited frequency region Rfp, and when the required frequency fc continuously corresponds to the prohibited frequency region Rfp, the previous command frequency. Let pfz be the command frequency fz at the start of the next control cycle Tc. This eliminates the need to switch the command frequency fz at the start of the control cycle Tc, and can reduce the frequency with which the compressor 1 is temporarily operated at a frequency within the prohibited frequency region Rfp. As a result, the occurrence of abnormal vibration due to resonance can be further suppressed, and power consumption due to switching of the command frequency fz can be reduced.

Further, the air conditioner 100 repeatedly determines whether or not the acquired required frequency fc corresponds to the prohibited frequency region Rfp, and when the required frequency fc continuously corresponds to the prohibited frequency region Rfp, each control cycle Tc. The command frequency fz at the start of is alternately exchanged. This eliminates the need to switch the command frequency fz at the start of the control cycle Tc, and the frequency of the compressor 1 is temporarily prohibited frequency region Rfp when the command frequency fz is switched between the first frequency f1 and the second frequency f2. The frequency of being inside can be reduced. As a result, the occurrence of abnormal vibration due to resonance can be further suppressed, and power consumption due to switching of the command frequency fz can be reduced.

Further, the air conditioner 100 corrects the calculated first time T1 and second time T2 by the preset minimum maintenance time Ttmin and maximum maintenance time Ttmax. As a result, it is possible to avoid switching the command frequency fz in a short time, which hardly contributes to the air conditioning capacity, and further suppress the occurrence of abnormal vibration caused by the frequency of the compressor 1 temporarily becoming the prohibited frequency region Rfp. Can be done. Further, since the power consumption due to the switching of the command frequency fz can be reduced, the energy saving property is improved.

Further, in the air conditioner 100, when the required frequency fc changes from outside the prohibited frequency region Rfp to within the prohibited frequency region Rfp, the frequency of the first frequency f1 and the second frequency f2 that is close to the previous command frequency pfz is set. It is output as the command frequency fz. As a result, the amount of change in the command frequency fz when the control cycle Tc starts can be minimized, and energy saving can be improved.

The embodiment of the present invention is not limited to the above embodiment, and various modifications can be made. For example, although the air conditioner 100 has been described as an example of the refrigerating cycle apparatus in the embodiment, the refrigerating cycle apparatus is not limited to this, and may be applied to an apparatus such as a refrigerating apparatus or a refrigerating apparatus. When the refrigerating cycle device is a refrigerating device or a refrigerating device, the flow path switching device 5 may be omitted. Further, although the case where the control cycle Tc is set to 5 minutes has been described, the control cycle Tc can be arbitrarily changed within a range predetermined by the operator or the like.

Further, in the embodiment, the second time T2 is calculated by the equation (1), and the first time T1 is the time obtained by subtracting the second time T2 from the control cycle Tc. May be calculated from the following formula. In this case, the second time T2 is the time obtained by subtracting the first time T1 from the control cycle Tc.

[Number 3]
T1 = Tc × (f2-fc) / (f2-f1) ... (3)

1 Compressor, 2 Indoor heat exchanger, 3 Outdoor heat exchanger, 4 Decompression device, 5 Flow path switching device, 6 Indoor blower, 7 Outdoor blower, 8 Temperature detector, 9 Refrigerator piping, 10 Indoor unit, 11 Outdoor unit , 12 remote control, 20 control device, 21 storage unit, 22 timing unit, 23 operation control unit, 24 frequency calculation unit, 25 prohibited frequency determination unit, 26 leading frequency determination unit, 27 hour calculation unit, 59 frequency range, 100 air harmony. Machine, 101 Refrigerator circuit, L1 lower limit, L2 upper limit, Rfp prohibited frequency range, T1 1st time, T2 2nd time, Ta room temperature, Tc control cycle, Tset set temperature, Ttmax maximum maintenance time, Ttmin minimum maintenance time , F1 1st frequency, f2 2nd frequency, fc required frequency, fz command frequency, pfz command frequency, t elapsed time.

Claims (8)

A refrigerant circuit consisting of a compressor, a condenser, a decompressor, and an evaporator connected via a refrigerant pipe,
A control device that acquires the required frequency of the compressor and controls the command frequency of the compressor according to the acquired required frequency is provided.
The control device is
It is determined whether or not the required frequency corresponds to the preset prohibited frequency region, and the required frequency is determined.
When it is determined that the required frequency corresponds to the prohibited frequency region, one of the first frequency smaller than the lower limit value of the prohibited frequency region and the second frequency larger than the upper limit value of the prohibited frequency region is set as the command frequency. , Start a preset control cycle,
During the control cycle, based on the acquired required frequency, the first time in which the first frequency is the command frequency and the second time in which the second frequency is the command frequency are repeated. Calculate and
When the first time or the second time corresponding to one of the first frequency and the second frequency elapses after the control cycle starts, the command frequency is switched from one to the other. Refrigeration cycle equipment. The number of times the first frequency and the second frequency are switched within the control cycle is one or less.
The refrigeration cycle apparatus according to claim 1, wherein the total time of the first time and the second time is equal to the control cycle. The control device is
It is repeatedly determined whether or not the acquired required frequency corresponds to the prohibited frequency region.
When it is continuously determined that the required frequency corresponds to the prohibited frequency region, the first of the first frequency and the second frequency in the continuous first control cycle and the second control cycle. The refrigeration cycle apparatus according to claim 1 or 2, wherein the command frequency at the end of the control cycle is set to the command frequency at the start of the second control cycle. The control device is
It is repeatedly determined whether or not the acquired required frequency corresponds to the prohibited frequency region.
According to claim 1 or 2, when it is continuously determined that the required frequency corresponds to the prohibited frequency region, the command frequency at the start of each control cycle is alternately replaced in the plurality of continuous control cycles. The refrigeration cycle device described. The control device is
When the calculated second time is equal to or less than the preset minimum maintenance time, the second time in the control cycle is corrected to 0.
The invention according to any one of claims 1 to 4, wherein when the calculated second time is equal to or longer than a preset maximum maintenance time, the second time in the control cycle is corrected to the time of the control cycle. Refrigeration cycle equipment. The control device is
When the calculated first time is equal to or less than the preset minimum maintenance time, the first time in the control cycle is corrected to 0.
The invention according to any one of claims 1 to 4, wherein when the calculated first time is equal to or longer than a preset maximum maintenance time, the first time in the control cycle is corrected to the time of the control cycle. Refrigeration cycle equipment. The control device is
It is repeatedly determined whether or not the acquired required frequency corresponds to the prohibited frequency region.
When it is determined that the required frequency does not correspond to the prohibited frequency region, the compressor is operated at the required frequency.
When it is determined that the required frequency corresponds to the prohibited frequency region, when the previous command frequency is less than the first frequency, the first frequency is set to the command frequency at the start of the control cycle. The refrigeration cycle according to any one of claims 1 to 6, wherein the second frequency is set as the command frequency at the start of the control cycle when the previous command frequency is larger than the second frequency. Device. Equipped with a temperature detector that detects the indoor temperature of the air-conditioned space
The refrigerating cycle device according to any one of claims 1 to 7, wherein the control device acquires the required frequency calculated based on the difference between the room temperature and the set temperature detected by the temperature detector.

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