JP2002162126A - Air conditioner - Google Patents

Abstract

(57) [Problem] To provide an air conditioner capable of appropriately diverting the existing piping of the original air conditioner without causing a problem of pressure resistance even if the pressure of the refrigerant to be used is high. . A condensing temperature Tc detected by a heat exchanger temperature sensor 35 is set in two steps Tcs1 and Tcs2.
Is provided, and one of these set values is set to the operation switch 11,
The high pressure side pressure Pd is selectively specified in accordance with the operation of 41, and the high pressure side pressure Pd is suppressed based on the specified set value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner in which refrigeration cycle piping is considered.

[0002]

2. Description of the Related Art Generally, an air conditioner comprises an outdoor unit and an indoor unit. The outdoor unit has a compressor, an outdoor heat exchanger, and a decompressor, and the indoor unit has an indoor heat exchanger.The compressor, the outdoor heat exchanger, the decompressor, and the indoor heat exchanger are sequentially arranged. A refrigeration cycle is configured by pipe connection.

[0003] As a refrigerant to be charged into the refrigeration cycle, R
Although there are 22 refrigerants, recently, from the viewpoint of environmental protection, an HFC (fluorocarbon containing hydrogen element) refrigerant having zero ozone destruction coefficient, for example, R407C refrigerant (HFC-32, HFC
Mixed refrigerant of FC-125 and HFC134a) and R410
A refrigerant (HFC-32 50 wt%, HFC-125 5
An air conditioner using 0 wt% mixed refrigerant) has appeared.

When a user replaces an air conditioner using an R22 refrigerant with an air conditioner using an HFC refrigerant, from the viewpoint of effective use of parts, the existing piping of the air conditioner used up to that time, such as an outdoor unit and an indoor unit, is used. It is conceivable to use the so-called transition pipe between them as it is as the transition pipe of the new air conditioner.

[0005]

By the way, among the HFC refrigerants, the R410A refrigerant has a feature that the pressure is about 1.5 times higher than that of the R22 refrigerant.

In the case of a home air conditioner, the diameter of a pipe to be used is small, whereas in the case of a commercial air conditioner, a pipe having a diameter larger than that of a home air conditioner is generally used. is there. The refrigerant pipe is characterized in that, as long as the pipe wall has the same thickness, the larger the pipe diameter, the lower the pressure resistance.

Therefore, if the original air conditioner is for home use, even if the new air conditioner uses the high-pressure R410A refrigerant, there is no problem with the pressure resistance of the crossover piping to be diverted.

[0008] However, if the original air conditioner is for business use and the new air conditioner uses high-pressure R410A refrigerant, there is a possibility that the crossover pipe to be diverted cannot withstand the pressure of the refrigerant. . Especially, the rated cooling capacity is 10kw
In the case of the air conditioners described above, the pressure of the refrigerant may exceed the withstand pressure reference value of the crossing pipe.

The present invention has been made in view of the above circumstances.
An object of the present invention is to provide an air conditioner that can appropriately divert the existing piping of the original air conditioner without causing a problem of pressure resistance even when the pressure of the refrigerant to be used is high. is there.

[0010]

According to a first aspect of the present invention, there is provided an air conditioner comprising: an outdoor unit having a compressor, an outdoor heat exchanger, and a decompressor; an indoor unit having an indoor heat exchanger; Equipment, the outdoor heat exchanger, the decompressor, and the indoor heat exchanger are connected to each other by piping, and a refrigeration cycle for circulating a refrigerant and a plurality of set values for the rise in the temperature or pressure of the refrigerant are selectively designated. Operating means for controlling the temperature and pressure of the refrigerant to be less than a set value specified by the operating means.

An air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect, wherein the refrigerant is limited.
The refrigerant is a high-pressure refrigerant such as an HFC refrigerant.

An air conditioner according to a third aspect of the present invention is the air conditioner according to the first aspect, wherein each set value is limited. Each set value is a second set value to be specified when the existing pipe is unused as the pipe of the refrigeration cycle, and when the existing pipe is used as the pipe of the refrigeration cycle lower than the second set value. Is the first set value to be specified.

An air conditioner according to a fourth aspect of the present invention is the air conditioner according to the first aspect, wherein the operation means is limited. The operating means is provided in at least one of a controller of the outdoor unit, a controller of the indoor unit, and a remote control type operating device attached to the indoor unit.

According to a fifth aspect of the present invention, in the air conditioner of the first aspect, the control means is limited. The control means includes a plurality of high-pressure switches that have different set values and operate when the high-pressure side pressure of the refrigeration cycle becomes equal to or higher than the set value. When the high pressure switch is activated, the temperature or pressure of the refrigerant is suppressed.

According to a sixth aspect of the present invention, in the air conditioner of the fifth aspect, the mounting of each high pressure switch is limited. One of the high-pressure switches is attached to a service port of a packed valve in the outdoor unit.

An air conditioner according to a seventh aspect of the present invention is the air conditioner according to any one of the first to fifth aspects, wherein the control means is limited. The control means suppresses the temperature or pressure of the refrigerant by at least one of control for reducing the capacity of the refrigeration cycle and control for stopping the operation of the compressor.

An air conditioner according to an eighth aspect of the present invention is the air conditioner according to the seventh aspect, wherein the control means is limited. The control means controls the bypass of the refrigerant from the discharge side to the suction side of the compressor, the control to reduce the rotational speed of the compressor, and the rotational speed of the outdoor blower for the outdoor heat exchanger as control to reduce the capacity of the refrigeration cycle. At least one of the control for decreasing and the control for increasing the opening of the expansion valve used as the pressure reducing device is executed.

An air conditioner according to a ninth aspect of the present invention is the air conditioner according to the first aspect, wherein the control means is limited. The control means is a heat exchanger temperature sensor that detects the temperature of the indoor heat exchanger during the heating operation, a high pressure switch that responds to the high pressure of the refrigeration cycle, and a pressure sensor that detects the high pressure of the refrigeration cycle. At least one is used for control.

[0019]

[1] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, the outdoor unit A has packed valves 5 and 6 for connecting a crossing pipe, and the indoor unit B has packed valves 31 and 33 for connecting a crossing pipe. A transfer pipe 21 is connected between the packed valves 5 and 31, and a transfer pipe 22 is connected between the packed valves 6 and 33.
As the connecting pipes 21 and 22, existing pipes of an old air conditioner installed before the air conditioner is installed may be used as they are, or new pipes may be used.

In the outdoor unit A, an outdoor heat exchanger 3 is connected to the refrigerant discharge port of the compressor 1 via a four-way valve 2 via a pipe, and the outdoor heat exchanger 3 is connected to the outdoor heat exchanger 3 via a pressure reducer, for example, an electric expansion valve 4. A packed valve 5 is connected by piping. The refrigerant inlet of the compressor 1 is connected to the packed valve 6 via the four-way valve 2. A bypass pipe 7 is connected from a refrigerant discharge port of the compressor 1 to a refrigerant suction port, and a two-way valve 8 is provided in the bypass pipe 7. An outdoor blower 9 is provided near the outdoor heat exchanger 3.

Reference numeral 10 denotes an outdoor controller, which will be described later.
Controls the air conditioner with 0. An operation switch (operation means) 11 for setting value switching is provided on the outdoor controller 10.
Is provided. Further, the outdoor controller 10 is connected to the four-way valve 2, the electric expansion valve 4, the two-way valve 8, the outdoor blower 9, and the inverter 12. Inverter 12
Rectifies the voltage of the commercial AC power supply 13, converts the rectified voltage into AC having a frequency corresponding to a command from the outdoor controller 10, and outputs the AC. This output is the driving power of the compressor 1.

In the indoor unit B, the packed valve 31,
The indoor heat exchanger 32 is connected between 33 by piping. An indoor blower 34 is provided near the indoor heat exchanger 32, and a heat exchanger temperature sensor 35 is attached to the indoor heat exchanger 32.

An indoor controller 40 is connected to the indoor controller 40 by a signal line 23. This indoor controller 4
At 0, an operation switch (operation means) 41 for setting value switching is provided. Further, the indoor blower 34 and the heat exchanger temperature sensor 35 are connected to the indoor controller 40. Further, a remote control type operation device (hereinafter, referred to as a remote control) 42 for setting various operation conditions such as an operation mode and a set room temperature is provided in the room controller 40.

The heat pump refrigeration cycle is constituted by the pipe connection between the outdoor unit A and the indoor unit B. In this heat pump refrigeration cycle, an HFC (fluorocarbon containing hydrogen element) refrigerant such as R410A refrigerant (HF
C-32 is 50 wt% and HFC-125 is 50 wt% mixed refrigerant).

During the cooling operation and the dry operation, the refrigerant flows in the direction of the solid line in the figure, and the outdoor heat exchanger 3
The indoor heat exchanger 32 functions as an evaporator. During the heating operation, the four-way valve 2 is switched, whereby the refrigerant flows in the direction of the dashed arrow in the drawing, and the indoor heat exchanger 32 functions as a condenser and the outdoor heat exchanger 3 functions as an evaporator.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG.

During the heating operation (YES in step 101),
The temperature of the indoor heat exchanger 32 functioning as a condenser (referred to as condensation temperature Tc) is detected by the heat exchanger temperature sensor 35 (step 102). Then, the release control shown in FIG. 3 is executed based on the detected condensation temperature Tc (step 103). This release control is for preventing an abnormal rise in the high-pressure side pressure Pd, and is performed to prevent the condensation temperature Tc
Rises and enters the region P, the output frequency F of the inverter 12 is reduced (the rotational speed N of the compressor 1 is reduced). After that, when the condensing temperature Tc falls and enters the region Q, the output frequency F remains unchanged. When the condensing temperature Tc falls to the region R, the output frequency F is controlled according to the air conditioning load (normal heating capacity control).

During the cooling operation or the dry operation (NO in step 101), the temperature of the indoor heat exchanger 32 functioning as an evaporator (referred to as evaporation temperature Te) is detected by the heat exchanger temperature sensor 35. (Step 113). Then, based on the detected evaporation temperature Te, the release control shown in FIG. 4 is executed (step 114). This release control is for preventing the freezing of the indoor heat exchanger 32. When the evaporation temperature Te falls and enters the region P, the output frequency F of the inverter 12 is reduced (the rotation speed N of the compressor 1 is reduced). After that, when the evaporating temperature Te rises and enters the region Q, the output frequency F is maintained as it is, and when the condensing temperature Tc rises to the region R, the output frequency F is controlled according to the air conditioning load (normal cooling). / Dry capacity control).

When the high-pressure side pressure Pd increases during the heating operation, the pressure of the refrigerant flowing through the crossover pipes 21 and 22 also increases. The crossover pipes 21 and 22 have a pressure resistance value.
A first set value Tcs1 and a second set value Tcs2 are determined as the condensing temperature Tc corresponding to the refrigerant pressure somewhat lower than the withstand pressure value. First set value Tcs1
Is specified when existing piping is used as piping for the refrigeration cycle. The second set value Tcs2 is designated when the existing piping is not used as the piping of the refrigeration cycle. These set values include Tcs1 <Tcs2
There is a relationship. The set values Tcs1 and Tcs2 are stored in the memory of the outdoor controller 10 or the indoor controller 40, and can be selectively designated by operating one of the operation switches 11 and 41.
An indicator for notifying the designated state, for example, a light emitting diode is provided in the outdoor controller 10 and the indoor controller 40, respectively.

When installing the air conditioner, the connecting pipe 2
If No. 1 and 22 are newly installed, transfer pipe 2
The setting value Tcs2 is designated based on the judgment that the HFC refrigerants 1 and 22 have a sufficient pressure resistance against the high-pressure HFC refrigerant. If the crossover pipes 21 and 22 are existing pipes diverted from the original air conditioner, the set value Tcs1 is designated based on the judgment that the pressure resistance of the crossover pipes 21 and 22 is not so high.

When the set value Tcs2 is designated (YES in step 104), the condensing temperature Tc continues to rise abnormally despite the release control, and as shown in FIG. 5, the condensing temperature Tc is equal to or higher than the set value Tcs2. (YES in step 105), the two-way valve 8 is opened (step 106). This opening allows the compressor 1
A part of the refrigerant discharged from the compressor flows through the bypass pipe 7 to the suction side (low pressure side) of the compressor 1. Then, by the refrigerant bypass, the capacity of the refrigeration cycle is reduced, and as shown in FIG. 6, an increase in the high-pressure side pressure Pd is suppressed.
Due to this suppression, the refrigerant pressure does not exceed the withstand pressure standard value of the transfer pipes 21 and 22, and the transfer pipes 21 and 22
Is prevented beforehand.

Thereafter, the condensing temperature Tc decreases to Tcs2
When entering a holding zone of less than (Tcs2-ΔT) or more,
The open state of the two-way valve 8 is maintained as it is. Condensing temperature T
When c falls to the normal control zone less than (Tcs2-ΔT) (YES in step 107), the two-way valve 8 is closed (step 106).

When the set value Tcs1 is designated (NO in step 104), as shown in FIG. 5, when the condensing temperature Tc enters the protection control zone equal to or higher than the set value Tcs1 (YES in step 109). , The two-way valve 8 is opened (step 110). Due to this opening, a part of the refrigerant discharged from the compressor 1 flows through the bypass pipe 7 to the suction side (low pressure side) of the compressor 1. Then, by the refrigerant bypass, the capacity of the refrigeration cycle is reduced, and as shown in FIG. 6, an increase in the high-pressure side pressure Pd is suppressed. Due to this suppression, even if the high-pressure HFC refrigerant is charged, the refrigerant pressure does not exceed the withstand pressure reference value of the crossover pipes 21 and 22, and the crossover pipes 21 and 22 are prevented from being damaged.

Thereafter, the condensing temperature Tc decreases to Tcs1
When entering the holding zone of less than (Tcs1−ΔT) or more,
The open state of the two-way valve 8 is maintained as it is. Condensing temperature T
When c falls to the normal control zone less than (Tcs1-ΔT) (YES in step 111), the two-way valve 8 is closed (step 112).

As described above, two-stage set values Tcs1 and Tcs2 are provided for the condensing temperature Tc, and one of these set values is selectively designated according to the operation of the operation switch 11 or the operation switch 41. By suppressing the high-pressure side pressure Pd based on the specified set value, even if a high-pressure HFC refrigerant is used, the piping across the existing piping of the original air conditioner can be performed without causing a problem with the pressure resistance. 2
They can be appropriately diverted as 1 and 22. By this diversion, effective use of parts and reduction of cost can be achieved.

In this embodiment, the two-way valve 8 is opened as a means for reducing the capacity of the refrigeration cycle. However, instead of this, as shown in FIG. ), Control to reduce the number of revolutions of the outdoor blower 9, or control to increase the opening of the electric expansion valve 4, may similarly reduce the capacity of the refrigeration cycle. . In this case, the operation of the compressor 1 may be turned off if the high-pressure side pressure Pd cannot be suppressed regardless of the execution of the control.

The operation switches for setting value switching are as follows.
The remote controller 42 is not limited to the outdoor controller 10 and the indoor controller 40.
The outdoor controller 10, the indoor controller 4
0, it may be provided in at least one of the remote controllers 42.

[2] A second embodiment will be described.

As shown in FIG. 8, the bypass pipe 7 and the two-way valve 8 are removed, and the high-pressure side pipe between the refrigerant discharge port of the compressor 1 and the four-way valve 2 responds to the high-pressure side pressure Pd. A first high-voltage switch P1 and a second high-voltage switch P2 are mounted, and these high-voltage switches P1 and P2 are connected to the outdoor controller 10.

The high-pressure switch P1 is turned on (operated) when the high-pressure side pressure Pd exceeds the first set value Pd1, and then turned off (returned) when the high-pressure side pressure Pd falls below (Pd1-ΔP). Therefore, when an existing pipe is used as the pipe of the refrigeration cycle, the pipe is designated. The high-pressure switch P2 is turned on (operated) when the high-pressure side pressure Pd becomes equal to or higher than the second set value Pd2, and then turned off (returned) when the high-pressure side pressure Pd falls below (Pd2-ΔP). Designated when existing piping is not used as piping for the refrigeration cycle. Both setting values have a relationship of Pd1 <Pd2.

The other structure is the same as that of the first embodiment.
The description is omitted.

Next, the operation will be described with reference to the flowchart of FIG.

During the heating operation (YES in step 201),
The condensation temperature Tc is detected by the heat exchanger temperature sensor 35 (Step 202). Then, the detected condensation temperature Tc
, The release control shown in FIG. 3 is executed (step 203). During the cooling operation or the dry operation (NO in step 201), the evaporation temperature Te is detected by the heat exchanger temperature sensor 35 (step 213). Then, based on the detected evaporation temperature Te, the release control shown in FIG. 4 is executed (step 214).

When the high-pressure side pressure Pd increases during the heating operation, the pressure of the refrigerant flowing through the transfer pipes 21 and 22 also increases. The crossover pipes 21 and 22 have a pressure resistance value.
As the high pressure side pressure Pd corresponding to the refrigerant pressure somewhat lower than the pressure resistance value, the first pressure which is the operating point of the high pressure switch P1
, And a second set value Pd2 which is an operating point of the high-voltage switch P2. These high-voltage switches P1 and P2 can be selectively designated by operating one of the operation switches 11 and 41. An indicator for notifying the designated state, for example, a light emitting diode is provided in the outdoor controller 10 and the indoor controller 40, respectively.

When installing the air conditioner, the connecting pipe 2
If No. 1 and 22 are newly installed, transfer pipe 2
The high pressure switch P2 is designated based on the judgment that the high pressure HFC refrigerant has a sufficient pressure resistance with respect to the high pressure HFC refrigerant.
If the crossover pipes 21 and 22 are existing pipes diverted from the original air conditioner, the high pressure switch P1 is designated based on the judgment that the crossover pipes 21 and 22 do not have a high pressure resistance.

If the high-pressure switch P2 is designated (YES in step 204), the high-pressure side pressure Pd continues to rise abnormally despite the release control and the high-pressure switch P2 is turned on (YES in step 205). The operation of the machine 1 is turned off (stopped) (step 206).
When the compressor 1 is turned off, an increase in the high-pressure side pressure Pd is forcibly suppressed. Due to this suppression, the refrigerant pressure is
Therefore, the breakage of the crossover pipes 21 and 22 is prevented beforehand.

Thereafter, the high pressure switch P1 is turned off by the decrease of the high pressure side pressure Pd (YE in step 207).
S), the operation ON (startup) of the compressor 1 is permitted (step 208).

When the high pressure switch P1 is designated (NO in step 204), when the high pressure switch P1 is turned on (YES in step 209), the operation of the compressor 1 is turned off (step 210). When the compressor 1 is turned off, an increase in the high-pressure side pressure Pd is forcibly suppressed. Due to this suppression, even if the high-pressure HFC refrigerant is charged, the refrigerant pressure does not exceed the withstand pressure reference value of the crossover pipes 21 and 22, and the crossover pipes 21 and 22 are prevented from being damaged.

Thereafter, the high-pressure switch P1 is turned off by the decrease of the high-pressure side pressure Pd (YE in step 211).
S), the operation ON of the compressor 1 is permitted (step 21)
2).

As described above, the two high-voltage switches P1 and P2 having different set values are provided, and one of these high-voltage switches is operated by the operation switch 11 or the operation switch 41.
The high pressure side pressure Pd is suppressed based on the ON / OFF of the specified high pressure switch, and the problem of the pressure resistance surface is reduced even if a high pressure HFC refrigerant is used. The existing pipes of the original air conditioner can be appropriately used as the cross pipes 21 and 22 without occurrence. By this diversion, effective use of parts and reduction of cost can be achieved.

As shown in FIG. 10, the present invention can be similarly implemented by mounting either one of the high-pressure switches P1 and P2 to the service port 6a for refilling the refrigerant in the packed valve 6.

In the present embodiment, the release control based on the condensing temperature Tc is performed. However, the refrigerant discharge temperature Td of the compressor 1 is estimated from the condensing temperature Tc, and based on the estimated refrigerant discharge temperature Td. Release control may be performed.

However, it is not always necessary to perform the release control, and the high-pressure side pressure Pd may be suppressed only by operating one of the high-pressure switches P1 and P2.

Regarding the operation switch for setting value switching,
The remote controller 42 is not limited to the outdoor controller 10 and the indoor controller 40.
The outdoor controller 10, the indoor controller 4
0, it may be provided in at least one of the remote controllers 42.

[3] A third embodiment will be described.

As shown in FIG. 11, a pressure sensor P 3 is attached to a high pressure side pipe between the refrigerant discharge port of the compressor 1 and the four-way valve 2, and the pressure sensor P 3 is connected to the outdoor controller 10. . Other configurations are the same as those of the second embodiment.

The operation will be described with reference to the flowchart of FIG.

During the heating operation (YES in step 301),
The condensation temperature Tc is detected by the heat exchanger temperature sensor 35 (Step 302). Then, the detected condensation temperature Tc
, The release control shown in FIG. 3 is executed (step 303). During the cooling operation or the dry operation (NO in step 301), the evaporation temperature Te is detected by the heat exchanger temperature sensor 35 (step 313). Then, based on the detected evaporation temperature Te, the release control shown in FIG. 4 is executed (step 314).

During the heating operation, when the high-pressure side pressure Pd increases, the pressure of the refrigerant flowing through the transfer pipes 21 and 22 also increases. The crossover pipes 21 and 22 have a pressure resistance value.
A first set value Pds1 and a second set value Pds2 are determined as the high pressure side pressure Pd corresponding to the refrigerant pressure somewhat lower than the withstand pressure value. First set value Pds1
Is specified when existing piping is used as piping for the refrigeration cycle. The second set value Pds2 is designated when the existing piping is not used as the piping of the refrigeration cycle. These setting values include Pds1 <Pds2
There is a relationship. In addition, these set values Pds1, Pds2
Are stored in the memory of the outdoor controller 10 or the indoor controller 40, and the operation switch 11 and the operation switch 4
It can be selectively specified by any one of the operations (1). An indicator for notifying the designated state, for example, a light emitting diode is used for the outdoor controller 10 and the indoor controller 40.
Are provided respectively.

At the time of installation of the air conditioner,
If No. 1 and 22 are newly installed, transfer pipe 2
The setting value Pds2 is designated based on the judgment that the pressures 1 and 22 have a sufficient pressure resistance against the high-pressure HFC refrigerant. If the transfer pipes 21 and 22 are existing pipes diverted from the original air conditioner, the set value Pds1 is designated based on the judgment that the pressure resistance of the transfer pipes 21 and 22 is not so high.

If the set value Pds2 has been designated (YES in step 304), the detection pressure (high pressure side pressure) Pd of the pressure sensor P3 continues to abnormally increase despite the release control, and protection is performed at the set value Pds2 or more. When entering the control zone (YES in step 305), the compressor 1 is turned off (step 306). When the compressor 1 is turned off, an increase in the high-pressure side pressure Pd is forcibly suppressed. By this suppression, the refrigerant pressure does not exceed the withstand pressure reference value of the crossover pipes 21 and 22, and the crossover pipes 21 and 22 are prevented from being damaged.

Thereafter, the detected pressure Pd decreases to Pds2
When entering the holding zone of less than (Pds2-ΔP) or more,
The off state of the compressor 1 is maintained as it is. Detection pressure P
When d falls to the normal control zone less than (Pds2−ΔP) (YES in step 307), the compressor 1 is allowed to be turned on (step 308).

If the set value Pds1 is designated (NO in step 304), the detected pressure Pd is set to the set value Pd.
When entering the protection control zone of s1 or more (step 30)
9 (YES), the compressor 1 is turned off (step 31).
0). When the compressor 1 is turned off, an increase in the detected pressure Pd is forcibly suppressed. Due to this suppression, even if high pressure HF
Even if the refrigerant C is charged, the refrigerant pressure is not
Thus, the crossover pipes 21 and 22 are prevented from being damaged.

Thereafter, the condensing temperature Tc decreases and Pds1
If the detected pressure Pd is in the holding zone equal to or higher than (Pds1−ΔP), the off state of the compressor 1 is maintained as it is. Detected pressure Pd is (Pds1-ΔP)
(Step 311)
YES), the compressor 1 is allowed to be turned on (step 3)
12).

As described above, the high-pressure side pressure Pd is
Step setting values Pds1 and Pds2 are provided, and one of these setting values is set to the operation switch 11 or the operation switch 41.
By selectively specifying the pressure in accordance with the operation of the above, and suppressing the high-pressure side pressure Pd based on the specified set value, even if a high-pressure HFC refrigerant is used, the problem of the pressure resistance surface does not occur. Piping 2 over the existing piping of the original air conditioner
They can be appropriately diverted as 1 and 22. By this diversion, effective use of parts and reduction of cost can be achieved.

In this embodiment, the release control based on the condensing temperature Tc is performed. However, the discharge refrigerant temperature Td of the compressor 1 is changed to the condensing temperature Tc or the pressure sensor Pc.
It is also possible to adopt a configuration in which the release pressure is estimated from the detected pressure Pd of No. 3 and the release control is performed based on the estimated discharge refrigerant temperature Td.

However, it is not always necessary to perform the release control, and the high-pressure side pressure Pd may be suppressed only by operating one of the high-pressure switches P1 and P2.

Regarding the operation switch for setting value switching,
The remote controller 42 is not limited to the outdoor controller 10 and the indoor controller 40.
The outdoor controller 10, the indoor controller 4
0, it may be provided in at least one of the remote controllers 42.

[0070]

As described above, according to the present invention, even if the pressure of the refrigerant to be used is high, the existing piping of the original air conditioner can be appropriately diverted without causing the problem of the pressure resistance surface. It can provide an air conditioner that can be used.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a first embodiment.

FIG. 2 is a flowchart for explaining the operation of the first embodiment.

FIG. 3 is a flowchart for explaining release control during a heating operation in each embodiment.

FIG. 4 is a flowchart for explaining release control during a cooling / dry operation in each embodiment.

FIG. 5 is a diagram showing a relationship between a condensing temperature and a control zone in the first embodiment.

FIG. 6 is a diagram showing a relationship between a change in high-pressure side pressure, a change in condensing temperature, and an operation of a two-way valve in the first embodiment.

FIG. 7 is a diagram showing a relationship among a change in a high-pressure side pressure, a change in a condensing temperature, and a change in a rotation speed in a modification of the first embodiment.

FIG. 8 is a diagram showing an overall configuration of a second embodiment.

FIG. 9 is a flowchart for explaining the operation of the second embodiment.

FIG. 10 is a diagram showing a configuration of a modification of the second embodiment.

FIG. 11 is a diagram showing an overall configuration of a third embodiment.

FIG. 12 is a flowchart for explaining the operation of the third embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... 4-way valve, 3 ... Outdoor heat exchanger, 4 ... Electric expansion valve (decompressor), 5,6 ... Packed valve, 7 ... Bypass piping, 8 ... Two-way valve, 9 ... Outdoor blower, 10 outdoor controller, 11 operation switch, 21, 22 crossover piping, 3
1, 33: packed valve, 32: indoor heat exchanger, 35
... heat exchanger temperature sensor, 40 ... indoor controller, 41 ... operation switch, 42 ... remote control

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3L061 BB01 BB04 3L092 AA14 BA05 DA14 EA02 EA03 FA02 FA03 FA04 FA20 FA23 FA26

Claims (9)

[Claims] 1. An outdoor unit having a compressor, an outdoor heat exchanger, and a decompressor, an indoor unit having an indoor heat exchanger, the compressor, the outdoor heat exchanger, the decompressor, and the indoor heat A refrigeration cycle in which an exchanger is connected by piping to circulate the refrigerant; operating means for selectively designating a plurality of set values for the temperature or pressure rise of the refrigerant; and operating means for controlling the temperature or pressure of the refrigerant. An air conditioner comprising: control means for suppressing the value to be less than a set value according to the specification. 2. The air conditioner according to claim 1, wherein the refrigerant is a high-pressure refrigerant such as an HFC refrigerant. 3. The second set value, which is specified when an existing pipe is not used as the pipe of the refrigeration cycle, is set.
And a first set value which is lower than the second set value and is a designated target when an existing pipe is used as the pipe of the refrigeration cycle.
The air conditioner according to 1. 4. The operating unit includes a controller for the outdoor unit,
The air conditioner according to claim 1, wherein the air conditioner is provided in at least one of a controller of the indoor unit and a remote control type operation device attached to the indoor unit. 5. The control means includes a plurality of high-pressure switches having different set values and operating when the high-pressure side pressure of the refrigeration cycle becomes equal to or higher than the set value. Select according to your specifications,
The air conditioner according to claim 1, wherein the temperature or pressure of the refrigerant is suppressed when the selected high-pressure switch is operated. 6. The air conditioner according to claim 5, wherein one of the high-pressure switches is attached to a service port of a packed valve in the outdoor unit. 7. The refrigerant control device according to claim 1, wherein the control means suppresses the temperature or pressure of the refrigerant by at least one of control for reducing the capacity of the refrigeration cycle and control for stopping the operation of the compressor. The air conditioner according to any one of claims 1 to 5. 8. The control means for reducing the capacity of the refrigeration cycle includes a control for bypassing the refrigerant from a discharge side of the compressor to a suction side, a control for reducing the rotation speed of the compressor, and the outdoor heat. The air according to claim 7, wherein at least one of control for reducing the number of revolutions of the outdoor blower for the exchanger and control for increasing the opening of the expansion valve used as the pressure reducer is executed. Harmony machine. 9. The heat exchanger temperature sensor for detecting a temperature of the indoor heat exchanger during a heating operation, a high-pressure switch responsive to a high-pressure side pressure of the refrigeration cycle, and a high-pressure side of the refrigeration cycle. The air conditioner according to claim 1, wherein at least one of the pressure sensors for detecting pressure is used for control.