JPH0752046B2 - Operation control device for air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Use) The present invention comprises a plurality of heat exchangers on the use side, and each heat exchanger on the use side is individually switched and connected to a high pressure gas line and a low pressure gas line. The present invention relates to the operation control device of the air conditioner described above, and particularly to a measure for preventing switching noise during connection switching.

(Prior Art) Conventionally, in an air conditioner in which a plurality of indoor units are connected in parallel to an outdoor unit, as disclosed in, for example, Japanese Patent Laid-Open No. 61-110859, a high pressure gas line, a low pressure gas line, and The liquid line is extended from the outdoor side to the indoor side, and the heat source side heat exchanger and the gas pipe side of each usage side heat exchanger are switched to selectively communicate with the high pressure gas line and the low pressure gas line, respectively. When the air conditioner is in operation, a connection switching mechanism is provided to switch the connection with the gas line of each heat exchanger between the high pressure gas line and the low pressure gas line according to operating conditions. In this case, the cooling operation and the heating operation are individually performed according to the indoor demand, and on the heat source side, the heat source side heat exchanger is switched to the evaporator or the condenser according to the change of the indoor demand, so that the air conditioning is comfortable. Which the attempt is made and the improvement of the operation efficiency is a known technique.

(Problems to be Solved by the Invention) When switching the refrigerant cycle, the compressor may be switched during operation (for example, during reverse cycle defrosting), or the cycle may be switched at the same time when the compressor is stopped. Many, but in each case,
Usually, since the refrigerant state changes abruptly, the change in speed of the refrigerant flowing through the connection switching mechanism becomes extremely large, and a loud switching noise is generated. Normally, since the cycle switching mechanism such as the four-way switching valve is installed outdoors, even if the switching noise as described above becomes a little loud, the feeling of air conditioning is hardly affected.

However, when the connection switching mechanism is provided individually for each of the use side heat exchangers to switch the refrigerant cycle as in the conventional one, the connection switching mechanism is arranged in each room, and thus the switching noise as described above is generated. The user may feel uncomfortable and the comfort of air conditioning may be impaired.

The present invention has been made in view of the above problems, and an object thereof is to provide a means for effectively reducing the switching noise of the connection switching mechanism at the time of cycle switching in each heat exchanger on the use side, thereby providing air conditioning. It is to improve comfort.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the first means for solving the problem is as shown in FIG. 1A (the broken line and the dotted line are not included), and the compressor (1)
And an outdoor unit (A) in which a plurality of heat source side heat exchangers (2a), (2b) and a plurality of heat source side pressure reducing valves (25a), (25b) with adjustable flow rates are connected in parallel. , A plurality of indoor units (B) connected in parallel to the outdoor unit (A) and having a usage-side pressure reducing valve (51) and a usage-side heat source exchanger (5), and the compressor (1) The high pressure gas line (31) extending from the discharge side of the compressor, the low pressure gas line (32) extending from the suction side of the compressor (1), and the gas pipes of the heat source side heat exchangers (2a) and (2b). High-pressure gas line (3
An outdoor connection switching means (21) for selectively switching between the evaporator (1) and the low pressure gas line (32) and individually switching between the evaporator and the condenser.
a) and (21b) and the gas pipes of the respective heat exchangers (5), ... on the utilization side are connected to the high pressure gas line (31) and the low pressure gas line (3).
It is premised on an air conditioner equipped with an indoor connection switching mechanism (35) that selectively communicates with 2) and switches the refrigeration cycle individually.

Then, as an operation control device of the air conditioner, at the time of switching the refrigeration cycle of each of the use side heat exchangers (5), a part of the plurality of heat source side heat exchangers (2a), (2b) is an evaporator. After the other is replaced with a condenser, the outdoor connection switching means (21a), (21b) for switching the cycle of the utilization side heat exchanger (5)
And a switching operation control means (101A) for controlling the indoor connection switching mechanism (35).

A second solution is, as shown in FIG. 1B (not including a dotted line portion), a compressor (1) whose operating capacity is variably adjusted by a capacity adjusting mechanism (11), and a heat source side heat exchanger (2). ) And an outdoor unit (A) having a heat source side pressure reducing valve (25) whose flow rate can be adjusted, and a outdoor side unit (A) connected in parallel to the outdoor side unit (A), and a use side pressure reducing valve (51) and a use side heat source exchanger ( 5) having a plurality of indoor units (B), a high pressure gas line (31) extending from the discharge side of the compressor (1), and a low pressure gas line (32) extending from the suction side of the compressor (1).
And an outdoor connection switching means for selectively connecting the gas pipe of the heat source side heat exchanger (2) to the high pressure gas line (31) and the low pressure gas line (32) to switch between the evaporator and the condenser ( 21) and an indoor connection for selectively switching the refrigeration cycle by selectively connecting the gas pipes of each of the use side heat exchangers (5), ... With the high pressure gas line (31) and the low pressure gas line (32) An air conditioner provided with the switching mechanisms (35), ... Is assumed.

Then, as an operation control device of the air conditioner, after switching the cycle of each of the use side heat exchangers (5), the operating capacity of the compressor (1) is set to the minimum capacity value, and then the use side heat exchanger ( A switching operation control means (101B) for controlling the indoor connection switching mechanism (35) and the capacity adjusting mechanism (11) so as to switch the cycle of 5) is provided.

The third solution means has a compressor (1), a heat source side heat exchanger (2) and a heat source side pressure reducing valve (25) with adjustable flow rate, as shown in FIG. 1B (not including the broken line portion). An outdoor unit (A) and a plurality of indoor units (B), ..., Which are connected in parallel to the outdoor unit (A) and have a use-side pressure reducing valve (51) and a use-side heat source exchanger (5); A high pressure gas line (31) extending from the discharge side of the compressor (1) and a low pressure gas line (32) extending from the suction side of the compressor (1).
And an outdoor connection switching means for selectively connecting the gas pipe of the heat source side heat exchanger (2) to the high pressure gas line (31) and the low pressure gas line (32) to switch between the evaporator and the condenser ( 21) and an indoor connection for selectively switching the refrigeration cycle by selectively connecting the gas pipes of each of the use side heat exchangers (5), ... With the high pressure gas line (31) and the low pressure gas line (32) Switching mechanism (35), ... And the high-pressure gas line (31)
An air conditioner provided with a bypass opening / closing means (45) for connecting and disconnecting the low pressure gas line (32) and the low pressure gas line (32).

Then, as an operation control device of the air conditioner, when the refrigerant is bypassed from the high pressure gas line (31) to the low pressure gas line (32) at the time of switching the cycle of each of the use side heat exchangers (5), the use side A switching operation control means (101C) for controlling the indoor connection switching mechanism (35) and the bypass opening / closing means (45) so as to switch the cycle of the heat exchanger (5) is provided.

As shown in FIG. 1A (not including a dotted line portion), a fourth solution means is the air conditioner of the first solution means,
The operation capacity of the compressor (1) is adjusted by the capacity adjusting mechanism (11), and as an operation control device of the air conditioner,
At the time of switching the cycle of each utilization side heat exchanger (5), a part of the plurality of heat source side heat exchangers (2a) and (2b) is used as an evaporator and the other is used as a condenser, and a compressor (1 ), The operating capacity is minimized, and then the outdoor connection switching means (21a), (21b), the indoor connection switching mechanism (35) and the capacity adjusting mechanism (11) are switched so as to switch the cycle of the use side heat exchanger (5). The switching operation control means (101D) for controlling the above is provided.

The fifth solving means is, as shown in FIG. 1A (not including the broken line portion), in the air conditioner of the first solving means,
By-pass opening / closing means (45) for connecting and disconnecting the high-pressure gas line (31) and the low-pressure gas line (32) is provided, and each usage-side heat exchanger (5) serves as an operation control device of the air conditioner.
Multiple heat source side heat exchangers (2a),
After part of (2b) is used as an evaporator and the other as a condenser, and the refrigerant is bypassed from the high pressure gas line (31) to the low pressure gas line (32), the cycle of the utilization side heat exchanger (5) Outdoor connection switching means (21a), (21
b), indoor connection switching mechanism (35) and bypass opening / closing means (4
The configuration is such that a switching operation control means (101E) for controlling 5) is provided.

A sixth solving means is, as shown in FIG. 1B, a high pressure gas line (31) in the air conditioner of the second solving means.
Bypass opening / closing means (45) for connecting and disconnecting the low pressure gas line (32) with the low pressure gas line (32) is provided, and as an operation control device of the air conditioner, when switching the cycle of each usage side heat exchanger (5),
While making the operating capacity of the compressor (5) the minimum capacity value,
After bypassing the refrigerant from the high pressure gas line (31) to the low pressure gas line (32), the indoor connection switching mechanism (35), the capacity adjusting mechanism (11) and the bypass are switched so as to switch the cycle of the use side heat exchanger (5). A switching operation control means (101G) for controlling the opening / closing means (45) is provided.

As shown in FIG. 1A, the seventh solution means is that in the air conditioner of the fourth solution means, the operating capacity of the compressor (1) is adjusted by the capacity adjusting mechanism (11), Bypass opening / closing means (45) for connecting and disconnecting the gas line (31) and the low-pressure gas line (32) is provided, and as the operation control device of the air conditioner, cycle switching in each heat exchanger (5) on the use side is performed. When multiple heat source side heat exchangers (2
Part of a) and (2b) is used as an evaporator and the other as a condenser, and the operating capacity of the compressor (1) is set to the minimum capacity value, and the high pressure gas line (31) to the low pressure gas line (32) After bypassing the refrigerant to the outdoor side, the outdoor side connection switching means (21a), (21b) so as to switch the cycle of the use side heat exchanger (5),
Switching operation control means (101) for controlling the indoor connection switching mechanism (35), the capacity adjusting mechanism (11) and the bypass opening / closing means (45).
H) is provided.

(Operation) With the above configuration, in the invention of claim (1), the gas pipe of the use side heat exchanger (5) is connected to the high pressure gas line (31) and the low pressure gas line (32) by the indoor connection switching mechanism (35). ) And the refrigerating cycle of the utilization side heat exchanger (5) is switched between the cooling cycle and the heating cycle, the switching operation control means (101A) controls the plurality of heat source sides. After some of the heat exchangers (2a) and (2b) function as evaporators and others function as condensers,
The cycle is switched. Therefore, since the heat source side heat exchangers (2a) and (2b) function as the evaporator and the condenser with respect to the common outdoor air temperature, the high and low differential pressure is inevitably small, and as a result, At the time of cycle switching, the flow velocity of the refrigerant passing through the indoor connection switching mechanism (35) is reduced, and the refrigerant switching noise is reduced.

In the invention of claim (2), when the cycle of the utilization side heat exchanger (5) is switched, the switching operation control means (101B) holds the capacity of the compressor (1) at the minimum capacity value, and then the utilization side. Since the indoor connection switching mechanism (35) and the capacity adjusting mechanism (11) are controlled so as to switch the cycle of the heat exchanger (5), the cycle of the use-side heat exchanger (5) in a state where the circulation amount of the refrigerant is extremely small. Is switched. Therefore, the flow velocity of the refrigerant at the time of cycle switching is weakened, and the switching noise is effectively reduced.

According to the invention of claim (3), when the cycle of the utilization side heat exchanger (5) is switched, the switching operation control means (101C) opens the on-off valve (42a) of the pressure equalizing bypass passage (42) to open the high pressure gas. The indoor connection means (35) and the bypass opening / closing means (45) so that the refrigerant is bypassed from the line (31) to the low pressure gas line (32) and then the cycle of the utilization side heat exchanger (5) is switched.
Is controlled, the cycle is switched while the high-pressure side pressure and the low-pressure side pressure are equalized. Therefore,
The flow velocity of the refrigerant at the time of cycle switching is reduced, and the switching noise of the refrigerant is reduced as much as possible.

According to the invention of claim (4), by the switching operation control means (101D), a part of the plurality of heat source side heat exchangers (2a), (2b) becomes an evaporator and the other becomes a condenser, and the compression is performed. Since the cycle is switched after the capacity of the machine (1) is maintained at the minimum capacity, the switching noise of the refrigerant is reduced by the decrease in the high / low differential pressure and the decrease in the refrigerant circulation amount.

In the invention of claim (5), by the switching operation control means (101E), a part of the plurality of heat source side heat exchangers (2a), (2b) becomes an evaporator and the other becomes a condenser, and the high pressure gas Line (3
Refrigerant is bypassed from 1) to the low pressure gas line (32),
Since the cycle switching is performed after the high and low differential pressure is reliably reduced, the refrigerant switching noise is reduced.

In the invention of claim (6), the switching operation control means (101F) keeps the compressor (1) at the minimum capacity value, and the refrigerant is bypassed from the high pressure gas line (31) to the low pressure gas line (32). After that, since the cycle is switched, the switching noise of the refrigerant is reduced by equalizing the high pressure side pressure and the low pressure side pressure and reducing the refrigerant circulation amount.

According to the invention of claim (7), by the switching operation control means (101G), a part of the plurality of heat source side heat exchangers (2a), (2b) becomes an evaporator and the other becomes a condenser, and the compressor ( 1) is kept at the minimum capacity value, and the refrigerant is bypassed from the high pressure gas line (31) to the low pressure gas line (32), and then the cycle is switched, so that the high and low differential pressure and the refrigerant circulation amount are surely small. Then, the flow velocity of the refrigerant passing through the indoor connection switching mechanism (35) becomes extremely small, and the switching noise is significantly reduced.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing.

As shown in FIG. 2, (X) is composed of a plurality of (three in the drawing) indoor units (B), (B), ... Connected in parallel to one outdoor unit (A). It is a multi-type air conditioner.

The outdoor unit (A) includes a compressor (1) whose capacity is variably adjusted by an inverter (11), two first and second outdoor heat exchangers (2a) which are heat source side heat exchangers, (2b) and a refrigerant circuit (3) is provided on the discharge side of the compressor (1).
The high pressure gas line (31) is connected to the suction side, and the low pressure gas line (32) is connected to the suction side. The outdoor heat exchangers (2a) and (2b) are provided in parallel with the compressor (1), and one end of each of the outdoor heat exchangers (2a) and (2b) is a four-way path. While being switchably connected to the high-pressure gas line (31) and the low-pressure gas line (32) via gas pipes (22a) and (22b) equipped with switching valves (21a) and (21b),
The liquid pipes (33-1) and (33) of the liquid line (33) in the refrigerant circuit (3) are provided at the other ends of the outdoor heat exchangers (2a) and (2b).
-2) is connected. The four-way switching valves (21a) and (21b) are switched to solid lines in the figure when the outdoor heat exchangers (2a) and (2b) function as condensers, and the gas pipes (22a) and (22b). ) Communicates with the high-pressure gas line (31) and, conversely, when each of the outdoor heat exchangers (2a), (2b) functions as an evaporator, the gas pipes (22a), (22b) are switched to the broken lines in the figure. It is designed to communicate with the low pressure gas line (32),
The four-way switching valves (21a), (21b) each have a function as an outdoor connection switching means. One port of the four-way switching valves (21a) and (21b) is connected to a gas pipe between the four-way switching valves (21a) and (21b) and the low pressure gas line (32) via a capillary. Has been done.

Further, the low pressure gas line (32) has a gas pipe (22a),
An accumulator (41) is provided on the downstream side of the connection portion of (22b), and a pressure equalizing bypass passage (42) is connected between the gas lines (31) and (32). The pressure equalizing bypass passage (42) is provided with an on-off valve (42a) and a flow rate adjusting capillary (42b), and one end of the high pressure gas line (3).
The other end is connected to the low pressure gas line (32) on the upstream side of the accumulator (41). That is, by the bypass passage (42) and the equalizing on-off valve (42a),
Refrigerant from high pressure gas line (31) to low pressure gas line (32)
By-pass opening / closing means (45) for bypassing to the.

In addition, each liquid pipe (33-1) in the liquid line (33),
(33-2) is connected to the regever (43) to merge the liquid refrigerant, and the liquid line (33) is connected to the receiver (43). Further, in each of the liquid pipes (33-1) and (33-2), there are two first and second outdoor electric expansion valves (25) which are heat source side pressure reducing valves.
a) and (25b) are provided respectively, and the outdoor electric expansion valves (25a) and (25b) are respectively installed in the outdoor heat exchangers (2a) and (2a).
The liquid refrigerant is decompressed when (2b) functions as an evaporator, and the flow rate of the liquid refrigerant is adjusted when it functions as a condenser.

In addition, (26) is an outdoor fan which is disposed in the vicinity of the outdoor heat exchangers (2a) and (2b).

On the other hand, each of the high pressure gas line (31), the low pressure gas line (32) and the liquid line (33) are arranged so as to extend to the inside of the room and through the flow dividers (31a), (32a) and (33a), respectively. High pressure branch pipe (31b), (31b), ..., low pressure branch pipe (32
b), (32b), ... And liquid branch pipes (33b), (33b), .. These branch pipes (31b), (32b), (33b) are used as indoor units (B), (B). ),…It is connected to the.

Each of the indoor units (B), (B), ... Has the same structure and includes an indoor heat exchanger (5) that is a usage-side heat exchanger and an indoor electric expansion valve (51) that is a usage-side decompression mechanism. It is configured. The indoor electric expansion valve (51) is provided with the liquid branch pipe (33
b), the liquid branch pipe (33b) is connected to one end of the indoor heat exchanger (5), and the other end of the indoor heat exchanger (5) is connected to the high pressure through the gas pipe (5a). It is connected to the branch pipe (31b) and the low pressure branch pipe (32b). A high pressure on-off valve (52) and a low pressure on-off valve (53) are respectively provided at the ends of the high pressure branch pipe (31b) and the low pressure branch pipe (32b),
The indoor heat exchanger (5) controls the opening and closing of the on-off valves (52) and (53) so that the high pressure gas line (31) and the low pressure gas line (32).
When the indoor heat exchanger (5) functions as an evaporator (during cooling), the low-pressure on-off valve (53) functions as a condenser (during heating). The high pressure on-off valve (52) is opened to selectively connect the gas pipe of the indoor heat exchanger (5) to the high pressure gas line (31) and the low pressure gas line (32). The high pressure on-off valve (52) and the low pressure on-off valve (53) form an indoor connection switching mechanism (35).

Then, the compressor (1), the outdoor heat exchanger (2a), (2
b) The indoor heat exchangers (5), (5), ... Are connected by a high pressure gas line (31), a low pressure gas line (32) and a liquid line (33) to form the refrigerant circuit (3). There is.

In addition, (57) is an indoor fan arranged in the vicinity of the indoor heat exchanger (5).

Further, various sensors are provided in the refrigerant circuit (3), (Th1) is a liquid temperature sensor for detecting the temperature of the liquid refrigerant of the indoor unit (B), and (Th2) is a gas refrigerant of the indoor unit (B). A gas temperature sensor that detects the temperature, (Th3) is a room temperature sensor that detects the intake air temperature of the indoor fan (57), and (Th3)
4) is a liquid temperature sensor that detects the temperature of the liquid refrigerant on the outdoor heat exchangers (2a), (2b), and (Th5) is the outdoor heat exchangers (2a), (2
b) Gas temperature sensor to detect the temperature of gas refrigerant, (Th6)
Is an outside air temperature sensor that detects the outside air temperature, (Th7) is a discharge gas temperature sensor that detects the discharge gas refrigerant temperature of the compressor (1), (HPS) is a high pressure that detects the discharge gas refrigerant pressure of the compressor (1) It is a pressure sensor. (LPS) is a low pressure sensor.

Next, the air conditioning operation of this air conditioner (1) will be described.

First, when performing cooling operation of each indoor unit (B), (B), ..., Both four-way switching valves (21a) of the outdoor unit (A),
Switch (21b) to the solid line in Fig. 2 to switch the gas pipes (22a), (22
b) is connected to the high pressure gas line (31), while the indoor units (B), (B), ... Close the high pressure on-off valve (52), open the low pressure on-off valve (53), and open the gas pipe (5a). To the low pressure branch pipe (32b). In this state, the high pressure gas refrigerant discharged from the compressor (1) is transferred to each outdoor heat exchanger (2
a) and (2b) and condensed, and the condensed liquid refrigerant passes through the liquid line (33) to the indoor units (B), (B),
, Then the indoor electric expansion valves (51), (51), ... expand, and then the indoor heat exchangers (5), (5), ... evaporate, flow through the low pressure gas line (32), and are compressed. I will return to the aircraft (1).

On the other hand, when the indoor units (B), (B), ... Are heated, the refrigerant flows in the opposite direction to that during cooling, and the four-way switching valves (21a), (21b) of the outdoor unit (A) are moved to the second position. Switching to the broken line in the figure, in each indoor unit (B), (B), ..., the high pressure on-off valve (52) is opened, the low pressure on-off valve (53) is closed, and the refrigerant heats the indoor heat from the high pressure gas line (31). It is condensed in the vessel (5), flows through the liquid line (33), and is operated by the outdoor electric expansion valve (25a),
It expands at (25b), evaporates at the outdoor heat exchangers (2a) and (2b), and returns to the compressor (1).

Then, during the cooling operation, for example, the on-off valves (52) and (53) in one indoor unit (B) are switched to the heating operation, and conversely, during the heating operation, for example, one indoor room Double on-off valves (52), (53) in unit (B)
Is switched to the cooling operation, and so-called simultaneous cooling and heating operation is performed. At that time, for example, all indoor units (B), (B),
When two of the ... perform heating operation and one performs cooling operation, the liquid refrigerant flowing out from the indoor units (B) and (B) in heating operation merges in the flow divider (33a) of the liquid line (33). After that, it flows into the indoor unit (B) in the cooling operation, evaporates and returns to the compressor (1) through the low pressure gas line (32).

During this simultaneous cooling and heating operation, two outdoor heat exchangers (2
A) and (2b) operate as an evaporator or a condenser according to the indoor load, and one unit is operated and the other one is stopped.

Next, each of the indoor units (B), which is a feature of the present invention,
Regarding the control at the time of switching the heating and cooling operation in ...
A description will be given based on the flowcharts of FIGS. 3 and 4.
FIG. 3 shows the control contents in the indoor unit (B). At the same time when the operation is started in step S ₁ , a pressure equalization request signal is output and each of the indoor branch pipes (31b), (32b)
Of all closed-off valve (52), (53), the pressure equalization in the determination of Step S ₂ is finished, the process proceeds to step S _3, the air-conditioning request to determine whether the heating operation or cooling operation.

If the cooling operation is required in the above determination, in step S ₄ , the high pressure on-off valve (52) is closed and the low pressure on-off valve (53) is opened without requesting the pressure equalization, and the indoor heat exchanger ( 5)
By connecting the gas pipe (5a) of the above to the low pressure gas line (32), the indoor heat exchanger (5) functions as an evaporator,
Cool the room. Then, while performing the cooling operation, the heating demand is made in the determination of step S _5, the process proceeds to step S _6, and outputs a pressure equalization request signal to the outdoor side, the on-off valve (52), When (53) is closed and the pressure equalization is completed in the determination in step S ₇ , the process proceeds to step S ₈ described later.

On the other hand, if the heating operation in the determination of the step S ₃ is required, or when the pressure equalization is completed is determined at the above step S _7, the process proceeds to step S _8, the high pressure off valve (52) The indoor heat exchanger (5) functions as a condenser by opening and closing the low pressure on-off valve (53) and connecting the gas pipe (5a) of the indoor heat exchanger (5) to the high pressure gas line (31). Let
Heating the room. Then, while performing the heating operation, when the cooling requirement is made in the determination of step S _9, the
Outputs a pressure equalization request signal to the outdoor side in step S _10, the on-off valve (52), (53) closed and with the pressure equalization that ends at the determination of step S _11, the step S ₄ After that, the cooling operation is controlled.

On the other hand, FIG. 4 shows the control contents of the operation in the outdoor unit (A). While the normal operation is performed in step R ₁ , the above-mentioned pressure equalization request signal is input from the indoor side in step R _2. When the count of the timer (not shown) starts with a predetermined set time (for example, a value of about 2 minutes) step R _3, in step R _4, and controls the equalizing pressure operation. That is,
Set the operating capacity of the compressor (1) to the minimum value Fmin (for example, a value of about 20% of the rated capacity), the air volume of the indoor fan (26) to the high air volume "H", and the first outdoor heat exchanger (2a). Evaporator and first
Open the outdoor electric expansion valve (25a) halfway to open the second outdoor heat exchanger (2
b) to the condenser, the second outdoor electric expansion valve (25b) is fully opened, and the pressure equalizing on-off valve (42a) of the pressure equalizing bypass passage (42) is opened to allow low pressure gas to flow from the high pressure gas line (31). Bypassing the refrigerant in the line (32) to reduce the high and low differential pressure. During this period, the indoor electric expansion valve (51) is closed, and the indoor fan (57) is operating during the cooling operation and stopped during the heating operation. However, when the entire outdoor unit (A) is turned off, the compressor (1) and the outdoor fan (26) are stopped, and the first and second outdoor electric expansion valves (25
The openings of a) and (25b) are set to maintain the half open and full open states, respectively.

Then, steps up to determination by the timer count of R ₅ has reached the set time, performs control the pressure equalization, when the time is up, at step R _6, after outputting a pressure equalization completion signal to the indoor side, the steps R ₁ Return to normal operation.

In the above embodiment, the pressure equalizing operation is performed only for the set time, but the high and low differential pressure has a predetermined value (for example, about 3 kg / cm ² ).
You may make it perform a pressure equalization operation until it reaches.

In the above flow, steps S ₇ S ₈ and step S
The control from ₁₀ to S _{4 and} the control from step R ₄ constitute the switching operation control means (101G) in the invention of claim (7).

Here, the above embodiment corresponds to the invention of claim (7), but in the control of step R ₄ , the capacity control of the compressor (1), the outdoor heat exchangers (2a), (2b) By selecting a combination of the switching control of the evaporator and the condenser and the opening control of the pressure equalizing on-off valve (42a), the switching operation control means (101A) to (101) in each of the inventions of claims (1) to (6). It is easy to understand that 101F) is composed.

Therefore, in the invention of claim (1), the gas pipe (5a) of the indoor heat exchanger (5) is selected between the high pressure gas line (31) and the low pressure gas line (32) by the indoor connection switching mechanism (35). The cycle of the indoor heat exchanger (5) is switched between the cooling cycle and the heating cycle by switching so as to communicate with each other. Here, in the conventional case, when the cycle of each indoor heat exchanger (5) is individually switched, the switching operation is performed while maintaining the operation of the other indoor units (B) as it is, so that the high and low differential pressure is considerably reduced. Therefore, there is a risk that the switching noise associated with the switching of the flow of the refrigerant becomes loud indoors, and the feeling of air conditioning is impaired.

On the other hand, in the present invention, when the cycle of each indoor heat exchanger (5) is switched, a part of the plurality of outdoor heat exchangers (2a) and (2b) is evaporated by the switching operation control means (101A). After allowing the others to function as condensers, cycle switching is performed. Therefore, each outdoor heat exchanger (2a), (2
Since b) functions in the evaporator and the condenser with respect to the common outdoor air temperature, the high and low differential pressure is inevitably small, and as a result, each of the indoor connection switching mechanisms (35) functions as the indoor connection switching mechanism (35) during cycle switching. The flow velocity of the refrigerant passing through the on-off valves (52) and (53) is reduced, so that the switching noise of the refrigerant can be effectively reduced, so that the feeling of air conditioning can be improved.

According to the invention of claim (2), when the cycle of the indoor heat exchanger (5) is switched, after the capacity of the compressor (1) is kept at the minimum capacity value by the switching operation control means (101B), the indoor heat exchange is performed. Indoor connection switching mechanism (3 to switch the cycle of the device (5)
Since 5) and the capacity adjusting mechanism (11) are controlled, the cycle of the indoor heat exchanger (5) is switched while the circulation amount of the refrigerant is extremely small, the flow of the refrigerant is weakened, and the switching is performed. The sound will be effectively reduced. Therefore, it is possible to improve the feeling of air conditioning.

According to the invention of claim (3), when the cycle of the indoor heat exchanger (5) is switched, the switching operation control means (101C) opens the on-off valve (42a) of the pressure equalizing bypass passage (42) to open the high pressure gas line. Since the indoor connection means (35) and the bypass opening / closing means (45) are controlled so as to switch the cycle of the indoor heat exchanger (5) after bypassing the refrigerant from the (31) to the low pressure gas line (32), the high pressure side The cycle is switched while the pressure and the pressure on the low pressure side are equalized. Therefore, the flow velocity of the refrigerant at the time of cycle switching is reduced, and the switching noise of the refrigerant accompanying the cycle switching is reduced as much as possible. Therefore, it is possible to improve the feeling of air conditioning.

Hereinafter, in the inventions of claims (4) to (7), the effects of the inventions of claims (1), (2), and (3) above can be obtained according to each combination, and the above claims ( 1),
The effect of the invention of (2) or (3) can be obtained more significantly.

(Effect of the invention) As described above, according to the invention of claim (1), the gas pipes of the plurality of heat exchangers on the utilization side are individually switched to the high-pressure gas line and the low-pressure gas line to switch the cycle. In the air conditioner configured as described above, a plurality of heat source side heat exchangers are provided, and each heat source side heat exchanger can be individually switched to an evaporator and a condenser, and the refrigeration cycle of the use side heat exchanger At the time of switching, the heat source side heat exchanger functions as an evaporator and the other functions as a condenser before switching the cycle of the heat exchanger on the use side. It is possible to effectively reduce the switching noise of the refrigerant that accompanies the cycle switching of the container, and thus improve the feeling of air conditioning.

According to the invention of claim (2), the compressor of the air conditioner is of a variable capacity type, and when the cycle of the use side heat exchanger is switched,
After the capacity of the compressor is maintained at the minimum capacity value, the cycle of the heat exchanger on the utilization side is switched, so the refrigerant switching noise can be reduced by reducing the refrigerant circulation amount. Therefore, the feeling of air conditioning can be improved.

According to the invention of claim (3), the refrigerant can be bypassed from the high-pressure gas line to the low-pressure gas line, and the refrigerant can be bypassed from the high-pressure gas line to the low-pressure gas line during cycle switching of the usage-side heat exchanger. Therefore, since the cycle of the heat exchanger on the utilization side is switched, the switching noise of the refrigerant can be reduced as much as possible by reducing the high and low differential pressure.

According to the invention of claim (4), part of the plurality of heat source side heat exchangers is used as an evaporator and the other is used as a condenser, and the capacity of the compressor is minimized, and then the use side heat exchanger is used. Since the cycle is switched, the switching noise of the refrigerant can be more remarkably reduced due to the reduction of the high / low differential pressure and the reduction of the refrigerant circulation amount.

According to the invention of claim (5), a part of the plurality of heat source side heat exchangers is used as an evaporator and the other is used as a condenser, and the refrigerant is bypassed from the high pressure gas line to the low pressure gas line before being used. Since the cycle of the side heat exchanger is switched, the switching noise of the refrigerant can be more remarkably reduced due to the remarkable reduction of the high and low differential pressure.

According to the invention of claim (6), the capacity of the compressor is set to the minimum capacity value, and after the refrigerant is bypassed from the high pressure gas line to the low pressure gas line, the cycle of the utilization side heat exchanger is switched. Therefore, the switching noise of the refrigerant can be more significantly reduced due to the decrease in the high and low differential pressure and the decrease in the refrigerant circulation amount.

According to the invention of claim (7), a part of the plurality of heat source side heat exchangers is used as an evaporator and the other is used as a condenser, the capacity of the compressor is set to a minimum capacity value, and the high pressure gas line lowers the pressure. After bypassing the refrigerant in the gas line, the cycle of the heat exchanger on the use side is switched, so that the switching noise of the refrigerant can be more significantly reduced due to the decrease in the high and low differential pressure and the decrease in the refrigerant circulation amount. it can.

[Brief description of drawings]

FIG. 1A is a block diagram showing the configuration of the invention of claims (1), (4), (5) and (7), and FIG. 1B is the claim (2),
It is a block diagram which shows the structure of invention of (3) and (6). 2 and the following show an embodiment of the present invention, FIG. 2 is a refrigerant piping system diagram showing the configuration of an air conditioner, FIG. 3 is a flow chart diagram showing control contents on the indoor side, and FIG. It is a flowchart figure which shows the content of control. 1 …… Compressor 2 …… Outdoor heat exchanger (heat source side heat exchanger) 5 …… Indoor heat exchanger (use side heat exchanger) 11 …… Inverter (capacity adjusting mechanism) 21 …… Four-way switching valve ( Outdoor connection switching means) 25 …… Outdoor electric expansion valve (heat source side pressure reducing valve) 31 …… High pressure gas line 32 …… Low pressure gas line 35 …… Indoor connection switching mechanism 45 …… Bypass opening / closing means 101 …… Switching operation control means

Claims (7)

[Claims] 1. A plurality of heat source side heat exchangers (2a), (2b) for a compressor (1) and a heat source side pressure reducing valve (25) capable of adjusting a flow rate.
An outdoor unit (A) in which a plurality of pairs of a) and (25b) are connected in parallel, and a parallel connection to the outdoor unit (A), and a use-side pressure reducing valve (51) and a use-side heat source exchange A plurality of indoor units (B) having a container (5), and a high pressure gas line (31) extending from the discharge side of the compressor (1) and a low pressure gas extending from the suction side of the compressor (1). The line (32) and the gas pipes of the heat source side heat exchangers (2a) and (2b) are selectively communicated with the high pressure gas line (31) and the low pressure gas line (32) to individually vaporize. And the condenser, and the outdoor connection switching means (21a), (21b), and the gas pipes of the heat exchangers (5) for use on the side of the high pressure gas line (31) and the low pressure gas line (32). An air conditioner provided with an indoor connection switching mechanism (35), which selectively communicates with the At the time of switching the refrigeration cycle of each of the use side heat exchangers (5),
After a part of the plurality of heat source side heat exchangers (2a) and (2b) is used as an evaporator and the other is used as a condenser, the outdoor connection switching means (for switching the cycle of the use side heat exchanger (5)) twenty one
An operation control device for an air conditioner, comprising a switching operation control means (101A) for controlling a), (21b) and an indoor connection switching mechanism (35). 2. An outdoor unit having a compressor (1) whose operating capacity is variably adjusted by a capacity adjusting mechanism (11), a heat source side heat exchanger (2), and a heat source side pressure reducing valve (25) with adjustable flow rate. (A) and the outdoor unit (A) are connected in parallel, and the use-side pressure reducing valve (51) and the use-side heat source exchanger (5)
, And a plurality of indoor units (B) having a high pressure gas line (31) extending from the discharge side of the compressor (1) and a low pressure gas line (32) extending from the suction side of the compressor (1). And an outdoor connection switching means for selectively connecting the gas pipe of the heat source side heat exchanger (2) to the high pressure gas line (31) and the low pressure gas line (32) to switch between the evaporator and the condenser ( 21) and an indoor connection for selectively switching the refrigeration cycle by selectively connecting the gas pipes of each of the use side heat exchangers (5), ... With the high pressure gas line (31) and the low pressure gas line (32) In an air conditioner provided with a switching mechanism (35), ..., When switching the cycle of each of the utilization side heat exchangers (5), the operating capacity of the compressor (1) is set to a minimum capacity value, The indoor connection switching mechanism (35) for switching the cycle of the side heat exchanger (5) Operation control device for an air-conditioning apparatus characterized by comprising a switching operation control means for controlling the fine volume adjustment mechanism (11) (101B). 3. An outdoor unit (A) having a compressor (1), a heat source side heat exchanger (2) and a heat source side pressure reducing valve (25) capable of adjusting the flow rate, and connected in parallel to the outdoor unit (A). And a plurality of indoor units (B) having a usage-side pressure reducing valve (51) and a usage-side heat source exchanger (5), and a high-pressure gas line (31) extending from the discharge side of the compressor (1). And a low pressure gas line (32) extending from the suction side of the compressor (1) and a gas pipe of the heat source side heat exchanger (2) for the high pressure gas line (31) and the low pressure gas line (32). The outdoor connection switching means (21) for switching between the evaporator and the condenser by making them communicate with each other, and the gas pipes of each of the use side heat exchangers (5), ..., With the high pressure gas line (31) and the low pressure gas line (31). Indoor connection switching mechanism (35), which selectively communicates with 32) and switches the refrigeration cycle individually. In an air conditioner provided with a bypass opening / closing means (45) for connecting and disconnecting the high-pressure gas line (31) and the low-pressure gas line (32), the cycle switching of each of the use side heat exchangers (5) At this time, after the refrigerant is bypassed from the high pressure gas line (31) to the low pressure gas line (32), the indoor connection switching mechanism (35) and the bypass opening / closing means (45) are switched so as to switch the cycle of the use side heat exchanger (5). ) Is provided with a switching operation control means (101C). 4. A plurality of heat source side heat exchangers (2a), (2b) for a compressor (1) whose operating capacity is variably adjusted by a capacity adjusting mechanism (11), and a heat source side decompression with adjustable flow rate. Valve (25
An outdoor unit (A) in which a plurality of pairs of a) and (25b) are connected in parallel, and a parallel connection to the outdoor unit (A), and a use-side pressure reducing valve (51) and a use-side heat source exchange A plurality of indoor units (B) having a container (5), ..., A high pressure gas line (31) extending from the discharge side of the compressor (1) and a low pressure extending from the suction side of the compressor (1). The gas line (32) and the gas pipes of the heat source side heat exchangers (2a) and (2b) are selectively communicated with the high pressure gas line (31) and the low pressure gas line (32) to individually evaporate. The outdoor connection switching means (21a), (21b) for switching between the condenser and the condenser, and the gas pipes of each of the use-side heat exchangers (5), ... For the high-pressure gas line (31) and the low-pressure gas line (32). And an indoor connection switching mechanism (35), which selectively communicates with and to individually switch the refrigeration cycle, At the time of switching the cycle of each of the use side heat exchangers (5), some of the plurality of heat source side heat exchangers (2a), (2b) are used as evaporators and the other are used as condensers. After the operating capacity of the compressor (1) is minimized, the outdoor connection switching means (21a) for switching the cycle of the utilization side heat exchanger (5),
(21b), indoor connection switching mechanism (35) and capacity adjustment mechanism (1
An operation control device for an air conditioner, comprising a switching operation control means (101D) for controlling 1). 5. A plurality of heat source side heat exchangers (2a), (2b) for the compressor (1) and a heat source side pressure reducing valve (25) with adjustable flow rate.
An outdoor unit (A) in which a plurality of pairs of a) and (25b) are connected in parallel, and a parallel connection to the outdoor unit (A), and a use-side pressure reducing valve (51) and a use-side heat source exchange A plurality of indoor units (B) having a container (5), and a high pressure gas line (31) extending from the discharge side of the compressor (1) and a low pressure gas extending from the suction side of the compressor (1). The line (32) and the gas pipes of the heat source side heat exchangers (2a) and (2b) are selectively communicated with the high pressure gas line (31) and the low pressure gas line (32) to individually vaporize. And the condenser, and the outdoor connection switching means (21a), (21b), and the gas pipes of the heat exchangers (5) for use on the side of the high pressure gas line (31) and the low pressure gas line (32). The indoor connection switching mechanism (35), which selectively communicates with each other to individually switch the refrigeration cycle, and the high-pressure gas line. In an air conditioner provided with a bypass opening / closing means (45) for connecting and disconnecting the (31) and the low-pressure gas line (32), the plurality of heat exchangers (5) at the time of switching the cycle Part of the heat source side heat exchangers (2a) and (2b) are used as evaporators and the other as condensers, and the high pressure gas line (31)
After bypassing the refrigerant from the low pressure gas line (32),
Switching operation control means (101E) for controlling the indoor / outdoor connection switching means (21a) and (21b), the indoor connection switching mechanism (35) and the bypass opening / closing means (45) so as to switch the cycle of the heat exchanger on the use side (5). ) Is provided, the operation control device of the air conditioner. 6. An outdoor unit having a compressor (1) whose operating capacity is variably adjusted by a capacity adjusting mechanism (11), a heat source side heat exchanger (2), and a heat source side pressure reducing valve (25) with adjustable flow rate. (A) and the outdoor unit (A) are connected in parallel, and the use-side pressure reducing valve (51) and the use-side heat source exchanger (5)
, And a plurality of indoor units (B) having a high pressure gas line (31) extending from the discharge side of the compressor (1) and a low pressure gas line (32) extending from the suction side of the compressor (1). And an outdoor connection switching means for selectively connecting the gas pipe of the heat source side heat exchanger (2) to the high pressure gas line (31) and the low pressure gas line (32) to switch between the evaporator and the condenser ( 21) and an indoor connection for selectively switching the refrigeration cycle by selectively connecting the gas pipes of each of the use side heat exchangers (5), ... With the high pressure gas line (31) and the low pressure gas line (32) In the air conditioner equipped with a switching mechanism (35), ..., And a bypass bypass opening and closing means (45) for connecting and disconnecting the high pressure gas line (31) and the low pressure gas line (32). When switching the cycle of the compressor (5), the operating capacity of the compressor (5) is minimized. As well as to the amount value,
After bypassing the refrigerant from the high pressure gas line (31) to the low pressure gas line (32), the indoor connection switching mechanism (35), the capacity adjusting mechanism (11) and An operation control device for an air conditioner, comprising a switching operation control means (101G) for controlling a bypass opening / closing means (45). 7. A plurality of heat source side heat exchangers (2a), (2b) for a compressor (1) whose operating capacity is variably adjusted by a capacity adjusting mechanism (11), and a heat source side decompression with adjustable flow rate. Valve (25
An outdoor unit (A) in which a plurality of pairs of a) and (25b) are connected in parallel, and a parallel connection to the outdoor unit (A), and a use-side pressure reducing valve (51) and a use-side heat source exchange A plurality of indoor units (B) having a container (5), and a high pressure gas line (31) extending from the discharge side of the compressor (1) and a low pressure gas extending from the suction side of the compressor (1). The line (32) and the gas pipes of the heat source side heat exchangers (2a) and (2b) are selectively communicated with the high pressure gas line (31) and the low pressure gas line (32) to individually vaporize. And the condenser, and the outdoor connection switching means (21a), (21b), and the gas pipes of the heat exchangers (5) for use on the side of the high pressure gas line (31) and the low pressure gas line (32). The indoor connection switching mechanism (35), which selectively communicates with each other to individually switch the refrigeration cycle, and the high-pressure gas line. An air conditioner provided with a bypass opening / closing means (45) for connecting and disconnecting the (31) and the low-pressure gas line (32), wherein the plurality of the above-mentioned plurality of heat exchangers (5) are used at the time of cycle switching in each of the utilization side heat exchangers (5) Part of the heat source side heat exchangers (2a), (2b) is an evaporator and the other is a condenser, and the operating capacity of the compressor (1) is set to a minimum capacity value, and the high pressure gas line ( After bypassing the refrigerant from 31) to the low-pressure gas line (32), the outdoor connection switching means (21a), (21b), indoor connection switching mechanism (35) so as to switch the cycle of the utilization side heat exchanger (5). An operation control device for an air conditioner, comprising a switching operation control means (101H) for controlling the capacity adjusting mechanism (11) and the bypass opening / closing means (45).