JP2009041845A - Operation control method of multi-room type air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an operation control method of a multi-type air conditioner capable of securing low pressure of a compressor and performing suitable operation without undermining reliability. <P>SOLUTION: In the operation control method of the multi-type air conditioner comprising an outdoor machine 17 provided with the compressor 1, an outdoor blower 6, an outdoor heat exchanger 5, and a main expansion valve 8, a plurality of indoor machines 18 connected to the outdoor machine 17 and respectively having indoor heat exchangers 9, and a bypass circuit 3 for connecting a discharge pipe 1a and a suction pipe 1b of the compressor 1 via an expansion valve 15, when compressor operation frequency is the lowest frequency or more in cooling or heating operation, if low pressure is below a first set value, an opening of the expansion valve 15 is made to be a first set opening. If the low pressure is below a second set value, the opening of the expansion valve 15 is made to be a second set opening. While reduction of the low pressure of the compressor 1 is prevented, suitable cooling/heating operation can be performed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an operation control method for a multi-room air conditioner.

  Conventionally, the operation control method of this type of multi-room air conditioner will be described with reference to FIGS. FIG. 17 is a refrigeration cycle diagram of a multi-room air conditioner adopting a conventional multi-room air conditioner operation control method, FIG. 18 is a flowchart showing a control method of the multi-room air conditioner, FIG. FIG. 20 is a time chart showing a control method of the multi-room air conditioner, and FIG. 20 is a block diagram showing a control method of the multi-room air conditioner.

  17-20, the conventional multi-room air conditioner is composed of one outdoor unit 17 and a plurality of indoor units 18 connected to the outdoor unit 17, and the outdoor unit 17 is a variable capacity type. Each indoor unit includes a compressor 1, a four-way valve 2, a gas bypass circuit 3, an outdoor heat exchanger 5, an outdoor blower 6, an outdoor air temperature sensor 7, and a main expansion valve 8 that is a pressure reducing device. 18 is an indoor heat exchanger 9, an indoor blower 10, an indoor pipe temperature sensor 11 that detects the temperature of a refrigerant pipe (not shown) of the indoor heat exchanger 9, and an indoor suction that detects the temperature of indoor air. And a temperature sensor 12.

The gas bypass circuit 3 bypasses the discharge pipe 1 a and the suction pipe 1 b of the compressor 1 via the capillary tube 13 and the electromagnetic two-way valve 4. Here, when the compressor operating frequency is not less than the lowest frequency during cooling or heating operation, when the low pressure sensor (not shown) detects negative pressure, the electromagnetic two-way valve 4 is turned on and opened, and the discharged high temperature and pressure are discharged. Since the refrigerant flows to the suction pipe 1b, the compressor 1 can be prevented from becoming negative pressure (see, for example, Patent Document 1).
JP-A-8-28982

  However, in the above-described conventional multi-chamber air conditioner operation control method, although the discharge pipe 1a and the suction pipe 1b are connected via the electromagnetic two-way valve 4 and the capillary tube 13, high-temperature and high-pressure refrigerant is discharged. However, there is a problem that the loss of capacity is large and the reliability of the compressor 1 is ensured, but the cooling or heating capacity is insufficient, which causes discomfort to the user.

  The present invention solves the above-mentioned conventional problems, and can adjust the opening degree of the expansion valve according to the degree of low pressure to ensure a low pressure without lowering the capacity, thereby impairing the reliability of the compressor. It is an object of the present invention to provide an operation control method for a multi-room air conditioner that can be appropriately operated.

  In order to solve the above-described conventional problems, an operation control method for a multi-room air conditioner according to the present invention includes an outdoor unit provided with a compressor, an outdoor fan, an outdoor heat exchanger, and a pressure reducing device, and the outdoor unit. In the operation method of the multi-room air conditioner comprising a plurality of indoor units connected to each other and each having an indoor heat exchanger, and a bypass circuit connecting the discharge pipe and the suction pipe of the compressor via an expansion valve, When the compressor operating frequency is equal to or higher than the lowest frequency during cooling or heating operation, when the low pressure falls below the first set value, the opening of the expansion valve is set to the first set opening, and the low pressure is set to the second setting. If the value falls below the value, the opening of the expansion valve is set to the second set opening, and it is possible to prevent a decrease in the low pressure of the compressor and at the same time to perform an appropriate cooling / heating operation.

  The operation control method for a multi-room air conditioner according to the present invention includes a compressor, an outdoor fan, an outdoor heat exchanger, an outdoor unit provided with a pressure reducing device, and an outdoor unit connected to the outdoor unit, In a method for operating a multi-room air conditioner comprising a plurality of indoor units having a cooler, and a bypass circuit for connecting a discharge pipe and a suction pipe of the compressor via an expansion valve, the compressor is operated during cooling or heating operation. When the operating frequency is equal to or higher than the set frequency, when the intake temperature falls below the first set value, the opening of the expansion valve is set to the first set opening, and when the intake temperature falls below the second set value, The opening degree of the expansion valve is set to the second set opening degree, and an appropriate air conditioning operation can be performed at the same time as preventing a decrease in the low pressure of the compressor.

  The operation control method for a multi-room air conditioner according to the present invention includes a compressor, an outdoor fan, an outdoor heat exchanger, an outdoor unit provided with a pressure reducing device, and an outdoor unit connected to the outdoor unit, In a multi-room air conditioner operation method comprising a plurality of indoor units having a cooler and a bypass circuit that connects a discharge pipe and a suction pipe of the compressor via an expansion valve, the compressor operating frequency during cooling operation When the minimum temperature of the indoor heat exchanger is lower than the first set value among the plurality of indoor units when the frequency is equal to or higher than the set frequency, the opening of the expansion valve is set as the first set opening, When the lowest temperature of the indoor heat exchanger falls below the second set value, the second set opening degree is set, and a proper cooling and heating operation can be performed while preventing a decrease in the low pressure of the compressor. .

  The operation control method for a multi-room air conditioner according to the present invention includes a compressor, an outdoor fan, an outdoor heat exchanger, an outdoor unit provided with a pressure reducing device, and an outdoor unit connected to the outdoor unit, In a method for operating a multi-room air conditioner comprising a plurality of indoor units having a cooler, and a bypass circuit for connecting a discharge pipe and a suction pipe of the compressor via an expansion valve, the compressor is operated during cooling or heating operation. When the operating frequency is equal to or higher than the set frequency, the outdoor suction temperature is lower than the set value, and when the number of operating indoor units is equal to or less than the first set number, the opening of the expansion valve is set to the first setting. When the number of operating indoor units is less than or equal to the second set number, the opening of the expansion valve is set to the second set opening, and at the same time preventing a decrease in the low pressure of the compressor, Proper air conditioning operation can be performed.

  The operation control method for a multi-room air conditioner according to the present invention includes a compressor, an outdoor fan, an outdoor heat exchanger, an outdoor unit provided with a pressure reducing device, and an outdoor unit connected to the outdoor unit, In a method for operating a multi-room air conditioner comprising a plurality of indoor units having a cooler, and a bypass circuit for connecting a discharge pipe and a suction pipe of the compressor via an expansion valve, the compressor is operated during cooling or heating operation. When the operating frequency is equal to or higher than the set frequency, when the outdoor suction temperature is lower than the set value, and the operating horsepower number of the indoor unit falls below the first set value, the opening of the expansion valve is set to the first setting When the operating horsepower number of the indoor unit is less than a second set value, the opening of the expansion valve is set to a second set opening, and at the same time preventing a decrease in the low pressure of the compressor, Proper air conditioning operation can be performed.

  The operation control method for a multi-room air conditioner according to the present invention can eliminate a decrease in compressor low pressure during cooling or heating operation, and can prevent a decrease in cooling / heating capacity.

The first invention includes a compressor, an outdoor fan, an outdoor heat exchanger, an outdoor unit provided with a pressure reducing device, a plurality of indoor units connected to the outdoor unit, each having an indoor heat exchanger, and the compression In the operation method of the multi-chamber air conditioner having a bypass circuit connecting the discharge pipe and the suction pipe of the compressor through an expansion valve, when the compressor operating frequency is the minimum frequency or higher during cooling or heating operation, the low pressure is When the opening is lower than the first set value, the opening of the expansion valve is the first set opening, and when the low pressure is lower than the second setting, the opening of the expansion valve is the second set opening. Thus, it is possible to prevent a decrease in the low pressure of the compressor and at the same time perform proper air conditioning operation.

  A second invention includes a compressor, an outdoor fan, an outdoor heat exchanger, an outdoor unit provided with a pressure reducing device, a plurality of indoor units connected to the outdoor unit, each having an indoor heat exchanger, and the compression In the operation method of a multi-chamber air conditioner equipped with a bypass circuit that connects the discharge pipe and suction pipe of the compressor through an expansion valve, when the compressor operating frequency is higher than the set frequency during cooling or heating operation, the suction temperature Falls below the first set value, the opening of the expansion valve is set to the first set opening, and when the intake temperature falls below the second set value, the opening of the expansion valve is opened to the second set opening. Therefore, it is possible to prevent a decrease in the low pressure of the compressor and at the same time perform an appropriate air conditioning operation.

  According to a third aspect of the present invention, there is provided an outdoor unit provided with a compressor, an outdoor fan, an outdoor heat exchanger, a decompression device, a plurality of indoor units connected to the outdoor unit, each having an indoor heat exchanger, and the compression In the operation method of the multi-chamber air conditioner having a bypass circuit that connects the discharge pipe and the suction pipe of the compressor via an expansion valve, when the compressor operating frequency is equal to or higher than the set frequency during cooling operation, the plurality of indoor When the lowest temperature of the indoor heat exchanger falls below the first set value in the machine, the opening of the expansion valve is set to the first set opening, and the lowest temperature of the indoor heat exchanger is If it falls below the set value of 2, the second set opening is set, and a low pressure reduction of the compressor can be prevented, and at the same time, an appropriate cooling / heating operation can be performed.

  A fourth invention includes an outdoor unit provided with a compressor, an outdoor fan, an outdoor heat exchanger, a decompression device, a plurality of indoor units connected to the outdoor unit, each having an indoor heat exchanger, and the compression In the operation method of a multi-room air conditioner equipped with a bypass circuit that connects the discharge pipe and suction pipe of the compressor via an expansion valve, when the compressor operating frequency is higher than the set frequency during cooling or heating operation, outdoor suction When the temperature is lower than a set value and the number of operating indoor units is equal to or less than the first set number, the opening of the expansion valve is set as the first set opening, and the number of operated indoor units is When the number is less than or equal to the second set number, the opening degree of the expansion valve is set to the second set opening degree, and an appropriate cooling and heating operation can be performed while preventing a decrease in the low pressure of the compressor.

  According to a fifth aspect of the present invention, there is provided an outdoor unit provided with a compressor, an outdoor fan, an outdoor heat exchanger, a decompression device, a plurality of indoor units connected to the outdoor unit, each having an indoor heat exchanger, and the compression In the operation method of a multi-room air conditioner equipped with a bypass circuit that connects the discharge pipe and suction pipe of the compressor via an expansion valve, when the compressor operating frequency is higher than the set frequency during cooling or heating operation, outdoor suction When the temperature is lower than a set value and the operating horsepower number of the indoor unit falls below a first set value, the opening degree of the expansion valve is set to the first set opening degree, and the operating horsepower number of the indoor unit is set. When the value falls below the second set value, the opening of the expansion valve is set to the second set opening, so that the lowering of the low pressure of the compressor can be prevented, and at the same time, an appropriate cooling / heating operation can be performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a refrigeration cycle diagram of a multi-room air conditioner adopting the operation control method of the multi-room air conditioner according to the first embodiment of the present invention, and FIG. 2 is a diagram of the multi-room air conditioner. FIG. 3 is a block diagram showing the operation control method, FIG. 3 is a flowchart showing the operation control method of the multi-room air conditioner, and FIG. 4 is a time chart showing the operation control method of the multi-room air conditioner. In addition, about the same part as the refrigerating cycle of the said conventional multi-chamber type air conditioner, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

In the present embodiment, as shown in FIG. 1, the gas bypass circuit 3 connects the discharge pipe 1a of the compressor 1 and the accumulator 14 on the suction pipe 1b side via an expansion valve 15 and a capillary tube 13, The apparatus includes a low-pressure detector 20 that detects a low-pressure, and other configurations are the same as those of the conventional multi-chamber air conditioner refrigeration cycle.

  Next, the operation control method for the multi-chamber air conditioner in the present embodiment, in particular, the operation for controlling the expansion valve 15 in the gas bypass circuit 3 will be described with reference to FIGS.

  During cooling or heating operation, the compressor is operating at a set frequency or lower. At this time, the expansion valve 15 in the gas bypass circuit 3 is fully closed. Next, when the operating frequency of the compressor 1 is increased and the pressure detected by the low pressure detector 20 is lower than the set value PL1 at a set value Hz1 or more, the opening of the expansion valve 15 is opened to Ps1. Further, when the low pressure sensor falls below the set value PL2, the opening of the expansion valve 15 is opened to Ps2. Thereby, an appropriate expansion valve opening degree is set according to a low pressure state, and a high-temperature and high-pressure refrigerant is allowed to flow into the suction pipe 1b, whereby the low pressure can be increased and an appropriate cooling / heating operation can be performed.

(Embodiment 2)
FIG. 5 is a block diagram showing an operation control method for a multi-room air conditioner according to the second embodiment of the present invention, FIG. 6 is a flowchart showing an operation control method for the multi-room air conditioner, and FIG. These are time charts which show the operation control method of the multi-room air conditioner. In addition, about the same part as the said conventional multi-chamber type air conditioner and the refrigerating cycle in 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The operation control method of the multi-room air conditioner in the present embodiment is as follows.

  5-7, the compressor operating frequency is operating below the set frequency during cooling or heating operation. At this time, the expansion valve 15 in the gas bypass circuit 3 is fully closed. Next, when the operating frequency set value Hz1 or more of the compressor 1 is higher and the intake temperature detected by the intake temperature detecting device 21 is lower than the set value Ts1, the opening degree of the expansion valve 15 is opened to Ps1. Further, when the suction temperature falls below the set value Ts2, the opening of the expansion valve 15 is opened to Ps2. In this way, by flowing the high-temperature and high-pressure refrigerant to the suction pipe 1b, the low-pressure can be increased and an appropriate cooling / heating operation can be performed.

(Embodiment 3)
FIG. 8 is a block diagram showing an operation control method for a multi-room air conditioner according to the third embodiment of the present invention, FIG. 9 is a flowchart showing an operation control method for the multi-room air conditioner, and FIG. These are time charts which show the operation control method of the multi-room air conditioner. In addition, about the same part as the conventional multi-chamber air conditioner and the refrigerating cycle in the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The operation control method of the multi-room air conditioner in the present embodiment is as follows.

  8-10, at the time of air_conditionaing | cooling operation, it is driving | operating with the compressor operating frequency below a setting frequency. At this time, the expansion valve 15 in the gas bypass circuit 3 is fully closed. Next, when the operating frequency of the compressor 1 is equal to or higher than the set value Hz1 and the lowest temperature among the temperatures of the indoor heat exchanger 9 detected by the indoor pipe temperature sensor 11 falls below the set value Te1, the expansion valve Open 15 to Ps1. Further, when the lowest temperature of the indoor heat exchanger 9 falls below the set value Te2, the opening of the expansion valve 15 is opened to Ps2. In this way, by flowing the high-temperature and high-pressure refrigerant to the suction pipe 1b, the low-pressure can be increased and an appropriate cooling operation can be performed.

(Embodiment 4)
FIG. 11 is a block diagram showing an operation control method for a multi-room air conditioner according to the fourth embodiment of the present invention, FIG. 12 is a flowchart showing an operation control method for the multi-room air conditioner, and FIG. These are time charts which show the operation control method of the multi-room air conditioner. In addition, about the same part as the conventional multi-chamber air conditioner and the refrigerating cycle in the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The operation control method of the multi-room air conditioner in the present embodiment is as follows.

  11-13, at the time of air_conditioning | cooling or heating operation, it is drive | operating with the compressor operating frequency below a setting frequency. At this time, the expansion valve 15 in the gas bypass circuit 3 is fully closed. Next, when the operating frequency of the compressor 1 is equal to or higher than the set value Hz1 and the outdoor suction temperature detected by the outdoor suction temperature detecting device 23 is lower than the set value To1, the number of the indoor units 18 operated is set to the first setting. When the number is N1 or less, the opening of the expansion valve 15 is opened to Ps1. Further, when the number of operating indoor units 18 falls below the second set number N2, the opening degree of the expansion valve 15 is opened to Ps2. Thus, by flowing the high-temperature and high-pressure refrigerant to the suction pipe 1b, the low-pressure can be increased and an appropriate cooling / heating operation can be performed.

(Embodiment 5)
FIG. 14 is a block diagram showing an operation control method for a multi-room air conditioner according to the fifth embodiment of the present invention, FIG. 15 is a flowchart showing an operation control method for the multi-room air conditioner, and FIG. These are time charts which show the operation control method of the multi-room air conditioner. In addition, about the same part as the conventional multi-chamber air conditioner and the refrigerating cycle in the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The operation control method of the multi-room air conditioner in the present embodiment is as follows.

  14 to 16, the compressor is operating at a compressor operating frequency or lower during cooling or heating operation. At this time, the expansion valve 15 in the gas bypass circuit 3 is fully closed. Next, when the operating frequency of the compressor 1 is equal to or higher than the set value Hz1 and the outdoor suction temperature is lower than the set value To1, the opening degree of the expansion valve 15 is set to Ps1 when the operating horsepower number of the indoor unit 18 is equal to or lower than the set value HP2. Open until. Further, when the operating horsepower number of the indoor unit 18 falls below the set value HP1, the opening degree of the expansion valve is opened to Ps2. In this way, by flowing the high-temperature and high-pressure refrigerant to the suction pipe 1b, it is possible to raise the low pressure and perform proper air conditioning operation.

  As described above, the operation control method for a multi-room air conditioner according to the present invention can ensure a low pressure of the compressor without lowering the cooling or heating capacity. Air-conditioning operation can be performed.

Refrigeration cycle diagram of a multi-room air conditioner employing the operation control method for the multi-room air conditioner according to Embodiment 1 of the present invention. Block diagram showing the operation control method of the multi-room air conditioner Flowchart showing the operation control method of the multi-room air conditioner Time chart showing the operation control method of the multi-room air conditioner The block diagram which shows the operation control method of the multi-room air conditioner in Embodiment 2 of this invention. Flowchart showing the operation control method of the multi-room air conditioner Time chart showing the operation control method of the multi-room air conditioner The block diagram which shows the operation control method of the multi-room air conditioner in Embodiment 3 of this invention. Flowchart showing the operation control method of the multi-room air conditioner Time chart showing the operation control method of the multi-room air conditioner The block diagram which shows the operation control method of the multi-room air conditioner in Embodiment 4 of this invention Flowchart showing the operation control method of the multi-room air conditioner Time chart showing the operation control method of the multi-room air conditioner The block diagram which shows the operation control method of the multi-room air conditioner in Embodiment 5 of this invention. Flowchart showing the operation control method of the multi-room air conditioner Time chart showing the operation control method of the multi-room air conditioner Refrigeration cycle diagram of a multi-room air conditioner that employs a conventional multi-room air conditioner operation control method Flowchart showing the operation control method of the multi-room air conditioner Time chart showing the operation control method of the multi-room air conditioner Block diagram showing the operation control method of the multi-room air conditioner

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 1a Discharge pipe 1b Suction pipe 2 4-way valve 3 Gas bypass circuit 5 Outdoor heat exchanger 6 Outdoor blower 8 Outdoor main expansion valve (pressure reduction device)
DESCRIPTION OF SYMBOLS 9 Indoor heat exchanger 10 Indoor fan 11 Indoor piping temperature sensor 12 Indoor suction temperature sensor 15 Expansion valve 17 Outdoor unit 18 Indoor unit

Claims (5)

An outdoor unit provided with a compressor, an outdoor fan, an outdoor heat exchanger, a decompression device, a plurality of indoor units connected to the outdoor unit and each having an indoor heat exchanger, a discharge pipe and a suction port of the compressor In the operation method of a multi-chamber air conditioner having a bypass circuit that connects a pipe via an expansion valve, when the compressor operating frequency is equal to or higher than the lowest frequency during cooling or heating operation, the low pressure is set to the first set value. If lower, the opening of the expansion valve is the first set opening, and if the low pressure is lower than the second set value, the opening of the expansion valve is the second set opening. Operation control method for multi-room air conditioner. An outdoor unit provided with a compressor, an outdoor fan, an outdoor heat exchanger, a decompression device, a plurality of indoor units connected to the outdoor unit and each having an indoor heat exchanger, a discharge pipe and a suction port of the compressor In the operation method of a multi-chamber air conditioner having a bypass circuit that connects a pipe through an expansion valve, when the compressor operating frequency is equal to or higher than the set frequency during cooling or heating operation, the suction temperature is the first set value. The opening of the expansion valve is set to a first set opening, and the opening of the expansion valve is set to a second set opening when the intake temperature falls below a second set value. An operation control method for a multi-room air conditioner. An outdoor unit provided with a compressor, an outdoor fan, an outdoor heat exchanger, a decompression device, a plurality of indoor units connected to the outdoor unit and each having an indoor heat exchanger, a discharge pipe and a suction port of the compressor In the operation method of the multi-chamber air conditioner having a bypass circuit that connects a pipe via an expansion valve, when the compressor operating frequency is equal to or higher than a set frequency during cooling operation, among the plurality of indoor units, When the lowest temperature of the indoor heat exchanger falls below the first set value, the opening of the expansion valve is set to the first set opening, and the lowest temperature of the indoor heat exchanger falls below the second set value. And the operation control method of the multi-room air conditioner characterized by setting it as the 2nd setting opening degree. An outdoor unit provided with a compressor, an outdoor fan, an outdoor heat exchanger, a decompression device, a plurality of indoor units connected to the outdoor unit and each having an indoor heat exchanger, a discharge pipe and a suction port of the compressor In the operation method of a multi-room air conditioner having a bypass circuit that connects a pipe through an expansion valve, when the compressor operating frequency is equal to or higher than the set frequency during cooling or heating operation, the outdoor suction temperature is lower than the set value. If the number of the indoor units operated is equal to or less than the first set number, the opening degree of the expansion valve is set to the first set opening degree, and the number of operated indoor units is equal to or less than the second set number. In this case, the operation control method for a multi-room air conditioner is characterized in that the opening of the expansion valve is set to a second set opening. An outdoor unit provided with a compressor, an outdoor fan, an outdoor heat exchanger, a decompression device, a plurality of indoor units connected to the outdoor unit and each having an indoor heat exchanger, a discharge pipe and a suction port of the compressor In the operation method of a multi-room air conditioner having a bypass circuit that connects a pipe through an expansion valve, when the compressor operating frequency is equal to or higher than the set frequency during cooling or heating operation, the outdoor suction temperature is lower than the set value. If the operating horsepower number of the indoor unit is lower than the first set value, the opening degree of the expansion valve is set to the first set opening degree, and the operating horsepower number of the indoor unit is the second set value. The operation control method for a multi-chamber air conditioner is characterized in that the opening of the expansion valve is set to a second set opening when the pressure is less than.

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