JPH0311256A - Multi-type air conditioner - Google Patents

Abstract

PURPOSE:To obviate the need for confirmation operation for mispiping and misconnection by carrying out normal operation on the basis of data of storage means storing results of decision by signal processing means which judge to which indoor unit each liquid branch pipe and each gas branch pipe are connected based on the detected signals at the refrigerant operation cycle during the test operation. CONSTITUTION:An operation control means 47 controlling space cooling or space heating operation is installed and further an operation control part 42 at the test operation time and a signal processing means 45 which decides the arbitrary piping connecting condition at the test operation time and installed. Into this means 45 respective detected temp. at temp. sensors 31 of heat exchangers for respective indoor units A-D, room temp. sensors 33, and temp. sensors 32 for respective gas branch pipes are fed and the results of decision by the means 45 are stored in a storage means 46. Data in the means 46 are delivered to the means 47 and on the basis of these data the operation of a compressor 1, switching operation of a four-way transfer valve 4, and opening and closing control of primary and secondary electric motor-driven expansion valves 8, 23 is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multi-type air conditioner configured by connecting a plurality of indoor units to one outdoor unit.

(Prior Art) As a conventional example of the above-mentioned multi-type air conditioner, there can be mentioned, for example, a device described in Japanese Patent Application Laid-open No. 134436/1983. The device connects the discharge piping and suction piping of the compressor built into the outdoor unit to a four-way switching valve.
Furthermore, connect an outdoor heat exchanger and a liquid pipe to one connection port of this four-way switching valve, and a gas pipe to the other connection port, and then connect the tips of the gas pipes to the four gas branch pipes, and The tips of the liquid pipes are branched into four liquid branch pipes, each equipped with an electric expansion valve, and installed in each of the four indoor units between these gas branch pipes and liquid branch pipes. The indoor heat exchangers are connected in parallel to each other by connecting pipes. Furthermore, transmission lines for transmitting various signals are connected between the outdoor unit and each indoor unit.

(Spy N to be solved by the invention) By the way, the connection between the above outdoor unit and each indoor unit is made by laying connection piping at the installation site, but at this time, the above gas branch pipe and liquid If a plurality of piping connection ports on the outdoor unit side, which are formed by pairs with branch pipes, are incorrectly connected to each indoor unit, a problem arises in that a great deal of effort is required to confirm the connection. Since the pipe diameters mentioned above are different between the gas side and the legal example, there is no risk of confusion between them, but since connecting piping with the same pipe diameter is used on the gas side and the source side, the outdoor unit On the other hand, it was not possible to sufficiently confirm which indoor unit the connection piping was coming from.
For this reason, as shown in FIG. 8, for example, a 31Jl connection boat 58 is made up of multiple pairs of gas side ports 52 to 54 of the outdoor units 1 to 51 and respective legal boats 55 to 57.
．． At 59.60, the indoor heat exchangers 64 of the indoor units 61, 62, and 63 located above rooms A, B, and C, respectively.
．． 65 and 66, according to the installation specifications, the indoor heat exchanger 64 of room A is connected to the first connection boat 58, and the indoor heat exchanger of room B is connected to the second connection boat 59, as shown by the broken line in the figure. Although the indoor heat exchanger 66 in room C is connected to the exchanger 65 and the third connection boat 60, for example, as shown by the solid line in the figure, the indoor heat exchanger 64 in room A is connected to the exchanger 65 and the third connection boat 60. is the gas side port 53 of the second connection port 59 and the third
This may result in incorrect piping, such as connecting the connection port 60 to the standard port 57. Similarly, erroneous connections also occur with respect to the transmission line.

In such a state of incorrect piping and incorrect connections, for example, when only the operation switch of the indoor unit 61 in room A is turned ON and a cooling test run is started, the outdoor unit side connects the liquid branch pipe leading to the first connection port 58. Although the operation is performed by opening the installed electric expansion valve, since the refrigerant that has passed through this electric expansion valve is not supplied to the indoor unit 61, cold air cannot be blown out in room A. As a result, it is detected that there is an incorrect piping, and in this case, it is necessary to check the indoor heat exchanger in the other room where the temperature decreases and check the connection state of the legal connection piping. Furthermore, even after correcting this legal connection piping to a normal connection state,
On the outdoor unit side, the opening degree control (superheat degree control) of the electric expansion valve described above is performed based on the temperature of the refrigerant after evaporation detected in the gas branch pipe leading to the first connection port. Since the refrigerant from room A does not flow through the gas branch pipe, the above-mentioned degree of superheat control is not performed normally, which causes, for example, a low pressure abnormality. As a result, it is necessary to further investigate which gas branch pipe is causing the temperature drop and to correct the gas-side connecting pipe. While conducting trial runs of each room in sequence,
The work of checking the correspondence between the operating conditions between the outdoor side and each indoor side takes a considerable amount of time and requires a large number of people.

The present invention has been made in view of the above, and an object thereof is to provide a multi-type air conditioner that eliminates the need to check for incorrect piping and connections as described above.

(Means for Solving the Problems) Therefore, as shown in FIG. 1, the multi-type air conditioner of the present invention includes a compressor 1 and an outdoor The other end of the liquid pipe 11, one end of which is connected to the outdoor heat exchanger 7, is connected to a plurality of liquid branch pipes 1 each having an on-off valve 23 interposed therein.
7-1 to 17-4, and the other end of the gas pipe 6, one end of which is connected to the other of the discharge side or suction side of the compressor 1, is branched into a plurality of gas branch pipes 19-1 to 19-4, respectively. Each of the indoor heat exchangers 22 of the plurality of indoor units A to D is connected between the liquid branch pipes 17-1 to 17-4 and the gas branch pipes 19-1 to 19-4 of the outdoor unit X configured as follows. It is a multi-type air conditioner consisting of the above-mentioned indoor heat exchangers 22 and each during a refrigerant circulation cycle in which the refrigerant discharged from the compressor 1 is circulated to the above-mentioned outdoor heat exchanger 7 and indoor heat exchanger 22. Heat exchanger temperature detection means 31 and gas branch temperature detection means 32 are provided to detect temperature changes in gas branch pipes 19-1 to 19-4, respectively, and any one of the on-off valves 23 is opened. Each of the liquid branch pipes 17-1 to 17-4 and the gas branch pipe 19-
1 to 19-4 are connected to which indoor unit A to D, and a storage means 46 that stores the determination result of the signal processing means 45 during the test run.
An operation control means 47 is provided which normally operates according to the data stored in the storage means 46.

(Function) In the above multi-type air conditioner, each liquid branch pipe 17-
Opening any one of the on-off valves 23 provided in 1 to 17-4 to circulate the refrigerant discharged from the compressor 1 from the outdoor heat exchanger 7 side to the indoor heat exchanger 22, for example. When performing a trial run in the refrigerant circulation cycle during cooling, the indoor heat exchanger 22 connected to the liquid branch pipe in which the opened on-off valve 23 is interposed and the indoor heat exchanger 22 connected to the indoor heat exchanger 22 are The refrigerant circulates through the gas branch pipes in which the refrigerant flows, and therefore the temperature decreases only in the indoor heat exchanger 22 and the gas branch pipes through which the refrigerant flows (temperature rises in the case of a circulation cycle during heating). The indoor heat exchanger 22 and gas branch pipes that cause temperature changes are detected by both the temperature detection means 31 and 32, and based on the detection signals, the signal processing means 45 detects each of the liquid branch pipes 17-1 to 17-4 and the gas branch pipe 1.
It is determined which indoor unit A-D each of 9-1 to 19-4 is connected to, and the determination result is stored in the storage means 46 L2.

On the other hand, during normal operation, the outdoor unit X is controlled by the operation control means 47 based on the data stored in the storage means 46 obtained during the trial operation. Therefore, normal operation can be performed without checking for incorrect piping or incorrect connections.

(Embodiments) Next, specific embodiments of the multi-type air purifier of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a refrigerant circuit diagram of a multi-type air conditioner configured by connecting first to fourth indoor units A to D to one outdoor unit X. A compressor 1 is installed inside the outdoor Uniso +-X, and the discharge piping 2 of this compressor 1
and suction pipe 3 are each connected to a four-way switching valve 4, and a first gas pipe 5 and a second gas pipe 6 are further connected to this four-way switching valve 4. An outdoor heat exchanger 7 is connected to the first gas pipe 5, and a first electric expansion valve 8, a liquid receiver 9, and a liquid closing valve 10 are sequentially provided to the outdoor heat exchanger 7. A tube 11 is further connected. Note that the above compression [1 is
It has an inverter 12 for controlling its rotation speed. Further, an accumulator 13 is provided in the suction pipe 3, a gas shutoff valve 14 is provided in the second gas pipe 6, and an outdoor fan 15 is provided in the outdoor heat exchanger 7.

-F The tip of the liquid pipe 11 branches into first to fourth liquid branch pipes 17-1 to 17-4 connected to the first to fourth measured piping connection boats 16 to 1 to 16-4, respectively. The tip of the second gas pipe 6 is connected to the first to fourth gas side piping connection boats 18-1 to 18-4, respectively.
It is branched into gas branch pipes 19-1 to 19-4.

And between each of the above-mentioned measured piping connection boats 16-1 to 16-4 and the gas side piping connection ports 1s-i to 18-4, machine side connecting piping 20...20 and gas side connecting piping 2 are provided, respectively.
Indoor heat exchangers 22 (only the first indoor unit I-A is shown) installed in the first to fourth indoor units A-D are connected in parallel to each other by 1 . . . 21 . In addition, second electrically operated expansion valves (opening/closing valves) 23, . . . 23 are interposed in each of the liquid branch pipes 17-1 to 17-4. Further, each of the indoor units A to D is composed of the indoor heat exchanger 22 and the indoor fan 24, respectively.

Cooling operation in the air conditioner having the configuration shown in section 2 is performed by placing the four-way switching valve 4 in the switching position shown by the solid line in the figure, and evaporating the refrigerant discharged from the compressor 1 from the outdoor heat exchanger 7, which serves as a condenser. This is done by circulating the heat to each indoor heat exchanger 22, which serves as a heat exchanger. At this time, the first electric expansion valve 8 is fully opened, and each of the second electric expansion valves 23 . . . 23 controls the degree of superheating of the refrigerant. Note that the second electric expansion valve 23 corresponding to the indoor unit in the room where cooling is stopped is fully opened. In order to control the degree of superheating during the cooling operation, a heat exchanger temperature sensor (heat exchanger temperature detection means) 31 consisting of a thermistor or the like detects the temperature of each indoor heat exchanger 22 as the refrigerant evaporation temperature. It is attached to the exchanger 22...22, and the gas branch pipe 19-
A gas branch pipe temperature sensor (gas branch pipe temperature detection means) 32 is attached to each gas branch pipe 19-1 to 19-4, which detects the temperatures 1 to 19-4 as superheating temperatures of the evaporative refrigerant. Further, each of the indoor units I-A to D is further provided with a room temperature sensor 33 that detects the indoor temperature.

On the other hand, in heating operation, the four-way switching valve 4 is switched to the switching position shown by the broken line in the figure, and the refrigerant discharged from the compressor 1 is transferred from the indoor heat exchanger 22, which serves as a condenser, to the outdoor heat exchanger 7, which serves as an evaporator. This is done by circulating the flow to. In this case, the first electric expansion valve 8 controls the degree of superheating of the evaporative refrigerant. In addition, each second electric expansion valve 23...23 controls the amount of refrigerant distributed to each indoor heat exchanger 22, but this is done so that the condensed refrigerant temperature at the outlet of each indoor heat exchanger 22 is the same temperature. This is done by controlling the opening degree of each of the second electric expansion valves 23 . . . 23 . The second electric expansion valve 23 corresponding to the indoor unit in the stop room is opened at a predetermined stop opening (in order to prevent liquid from returning to the pressure N machine 1, a small amount of refrigerant corresponding to natural heat dissipation is allowed to flow). the desired opening). In order to control the degree of superheating during the heating operation, an outdoor heat exchanger temperature sensor 34 for detecting the temperature of the outdoor heat exchanger 7 as a refrigerant evaporation temperature is attached to the outdoor heat exchanger 7, and A suction pipe temperature sensor 35 is attached to the suction pipe 3 for detecting the superheat temperature of the evaporative refrigerant. In addition, a liquid branch pipe temperature sensor 36 is used to detect the condensed refrigerant temperature at the outlet of each indoor heat exchanger 22.
...36 is attached to each liquid branch pipe 17-1 to 17-4.

In the above device, even if the connecting pipes 20.2I connecting the outdoor unit Each connecting pipe 20.21 on the side
An operation control function is provided to perform operation according to the connection order of the controllers, and a control block diagram thereof is shown in FIG. The details of the operation control function will be described in detail with reference to the control flowcharts shown in FIGS. 5 to 7, which will be described later. In FIG. 3, 41 is the outdoor unit
The outdoor control device is provided inside the vehicle, and a microcomputer or the like can be used as the outdoor control device. As shown in FIG. 1, this outdoor control device 41 has an operation switch that is turned on and off by the user on each of the indoor units A to D.
An operation control means 47 for normal operation is provided, which controls the cooling operation or heating operation described above when the N operation is performed.
Furthermore, there are provided a test run operation control section 42 for performing a trial run in an arbitrary pipe connection state, and a signal processing means 45 for determining an arbitrary pipe connection state during the test run. This signal processing means 45 includes each indoor unit A-D.
The heat exchanger temperature sensors 31 respectively arranged in the...
3I and room temperature sensor 33...33, and each gas branch pipe temperature sensor 32...32 are inputted, and the determination result by the signal processing means 45 is stored in the storage means 46. It is made to be done. on the other hand,
During normal steady operation, the data in this storage means 46 is output to the operation control means 47.
Based on this data, compressor 1 is operated and four-way switching valve 4 is operated.
switching, and the first and second electric expansion valves 8.23...23
The opening/closing control is performed.

In FIG. 4 showing a state in which the piping connection process for starting the trial run is completed, the first to fourth piping boats to be measured 16-1 to 16-4 and the gas side piping connection boats H8-1 to
18-4 are the first to fourth groups 48-1 to 48-4, respectively.
Connectors 49-1 to 49-4 are arranged in pairs, and each group 48-1 to 48-4 is provided with connection connectors 49-1 to 49-4 to which the transmission lines 44 of the indoor units A to D are respectively connected.

The communication pipes 20 and 21 and the transmission line 44 are connected to the boats and connectors in any order.

Also, each indoor unit) A-D indoor heat exchanger temperature sensor 3
1...31 are sequentially given numbers DCn (n-1 to 4), and similarly, gas branch pipe temperature sensors 32-=32 are also given Il numbers.
! II next, DGn (n = 1 to 4) is given.

Furthermore, the outdoor control device 41 can be switched freely between a test run mode for checking the connection state of piping and wiring and a normal steady operation mode.Switching control between the two modes will be explained with reference to FIG.

In the fifth circle, first, in step S1, it is determined whether or not the switching operation has been performed to the test run mode, and if it is the test run mode, the process proceeds to step S2, and if it is not the test run mode, the process proceeds to step s3 for normal operation control. . When it is determined that it is the test run mode, the process proceeds from step S2 to step S4, and in step S4, the connection state of the piping and wiring shown in FIG. 4 is stored. Next, in step S5, it is determined whether the storage process has been completed, and if it has been completed, the process proceeds to step S3 of the normal operation control, and if it has not been completed, the process returns to step S2.

During the test run, the test run shaft movement control section 42 first turns off the four-way switching valve 4 and positions it at the switching position for the cooling operation described above.
fully open. Next, the axis movement control unit 42 during the test run selects the second electric expansion valve 23, which is connected to the connection boat 16-1 of the group 48-1 assumed to be for outdoor unit XT: room A, for example. Open the expansion valve 23,
And the other second electric expansion valves 23 are kept fully closed. Thereafter, the compressor 1 starts operating at a predetermined inverter frequency. As a result, operation is started in the cooling cycle in which the refrigerant discharged from the compressor 1 during the test run circulates from the outdoor heat exchanger 7 side to the indoor heat exchanger 22. This second
When the electric expansion valves 23, . will flow.

Then, in step 510 of FIG. 6 showing the details of the piping wiring determination process in step S2, the second electric expansion valves 23... It is determined whether or not opening/closing control is being performed, and if the opening/closing state is determined, the process advances to the next step S11. Note that in step SIO, the operating state of the outdoor unit X that is flowing refrigerant to the liquid branch pipe 17-1 of the group 48-1, which is assumed to be for room A, is described as "rA room operation".

By the way, in the cooling cycle in which the second electric expansion valves 23 are opened and closed, the high temperature and high pressure liquid refrigerant condensed in the outdoor heat exchanger 7 shown in FIG.
When passing through the electric expansion valve 23, the refrigerant becomes a low-temperature, low-pressure liquid refrigerant, flows into the indoor heat exchanger 22 connected to the first liquid branch pipe 17-1 via the legal connection pipe 20, and evaporates. This changes the indoor heat exchanger 22 to a low temperature state. The evaporative refrigerant is then transferred to the indoor heat exchanger 22.
is returned to the compressor 1 via a gas branch pipe connected by a gas side communication pipe 21. At this time, the gas branch pipe through which the evaporative refrigerant passes also changes to a low temperature state. Therefore, the indoor heat exchanger 22 in which indoor unit is connected to the first liquid branch pipe 17-1, and to which gas branch pipe 19-1 to 19-4 this indoor heat exchanger 22 is further connected. During the cooling cycle operation, the temperature detecting means 31 and 32 sequentially detect which of the indoor heat exchangers 22 and the gas branch pipes 19-1 to 19-4 causes a temperature drop. By determining this detection signal by the signal processing means 45, it is possible to determine which indoor units A to D are connected to which boat and connector.

To explain this piping wiring determination process in the connection state shown in FIG. 4, if refrigerant is flowing in the liquid branch pipes 17 to 1 of group 48-1,
The refrigerant flows, for example, to the indoor unit C for room C through the connecting pipe 20 to be measured, which is connected to the group 48-4. The signal is input to the outdoor control device 41 of the outdoor unit X from the connector 49-4. At the same time, indoor unit C
The refrigerant expanded into a gaseous state through the O gas side connecting pipe 21 returns to the outdoor unit X through the gas side pipe connecting bow [8-2] of the group 48-2. At this time, the gas branch pipe temperature sensor 32 numbered DG2 becomes the lowest temperature.

In the first stage of the trial run as described above, step Sl! Then, the number DGn of the lowest temperature sensor 32 among the gas branch pipe temperature sensors 32 . . . 32 is detected. For example, in the connection state shown in FIG. 4, the sensor 32 numbered DG2 has the lowest temperature, and its detection signal is input to the outdoor control device 41. Next, in step S12, the detected number DG
It is determined that the gas side piping connection bore 8-2 corresponding to No. 2 is for indoor unit C. That is, in step 512, it is determined that the refrigerant sent out from the group 48-1, which is assumed to be for the outdoor unit XOA room, returns to the connection boat 18-2 through the indoor unit C. In step S12, "the NO DGn is used for room A"
It states:

Then, in step S13, each of the heat exchanger temperature sensors 3
The number DCn of the lowest temperature sensor 31 among 1...31 is detected. For example, in the connection state shown in FIG. 4, the sensor 31 with number DC3 is detected. In other words, the connection boat 16- of group 48-1, which is assumed to be for room A on the indoor unit X side,
The refrigerant flowing out from 1 flows into the indoor unit C, and the detection signal from the sensor 31 with this number DC3 is inputted to the connection connector 49-4 of the group 48-4 through the transmission line 44. Therefore, in step S14, the outdoor control device 41 detects that the signal from the sensor 31 of the indoor unit C is input to the connector 49-4 with the lowest detected temperature. Note that step 51.4
describes this as ``the indoor unit with that number is for room A''.

As a result of (2), the outdoor control device 41 combines the connection boat 16-1 of the group 48-1, the connection boat 18-2 of the group 4B-2, and the connection connector 49-4 of the group 48-4 into one set. It is possible to check the state in which the indoor unit C is controlled by each of the connection boats 16-1, 18-2 and the connection connector 494.

In step S10 above, connection boat 16-1 of group 48-1
If the outdoor unit X is not operated so as to flow the refrigerant, the process advances from step 510 to step S15. At this time, on the outdoor unit
4 above so that the refrigerant flows only from the connecting boat 16-2.
The second electric expansion valves 23, . . . 23 are controlled to open and close, and the same determination process as steps 511 to S14 in FIG. 6 is performed. Therefore, by sequentially repeating the above determination process for each group 48-2 to 48-4, each of the remaining groups 48-2 to 48-4 is
- To which indoor unit A, B or D does the refrigerant flow from the connecting holes 62 to 16-4 of 2 to 48-4 and to which group 4?
8-L 48-3. Returns from connection boat 18-1 or 18-3.18-4 of 48-4 to outdoor unit
3, and each group 4 of outdoor unit
The determinations from 8-2 to 48-4 are made in the same manner as above. Regarding this, in step S15, each room is judged in the same way as the rA room.''

After performing the above test run, as shown in step S20 in FIG. 7, the data obtained in the determination process for all groups 48-1 to 48-4 is stored in the storage means 46 (FIG. 1). When the mode is switched to the normal steady operation mode, it is determined in step S1 of FIG. 5 that the mode is not the trial operation mode, and step
The process advances from step S3 to step S3, where the operation control means 47 performs normal operation control based on the data stored in the storage means 46. Therefore, without having to perform the troublesome work of checking the connection status of piping and wiring as in the past, the second connection of the outdoor unit
The electric expansion valves 23, . . . 23, etc. are controlled to flow a predetermined refrigerant to each group 48-1 to 48-4, eliminating the need for troublesome piping and wiring connection work.

In addition, although the above description has been given as an example of a multi-type air conditioner that connects four indoor units A to D, the present invention is also applicable to multi-type air conditioners that are configured with other connected numbers. be able to. Further, in the above description, the trial run was performed in the cooling circulation cycle, but depending on the case, it is also possible to detect temperature rise changes in the indoor heat exchanger and gas branch pipes in the heating circulation cycle.

(Effects of the Invention) As described above, in the multi-type air conditioner of the present invention, the indoor heat exchanger and the gas branch pipe that cause temperature changes during trial operation are detected by both the temperature detection means, and a signal is sent based on the detection signal. The processing means can determine which indoor unit each liquid branch pipe and gas branch pipe is connected to, and this determination result can be stored in the storage means.

On the other hand, during normal operation, the operation of the outdoor unit can be controlled by the operation control means based on the data stored in the storage means obtained during the test run, and there is no need to check for incorrect piping or connections. normal operation is also possible.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of the present invention, and FIG. 2 is a refrigerant circuit diagram of a multi-type air conditioner according to an embodiment of the present invention.
Fig. 3 is a block diagram of the operation control during the test run of the air conditioner, Fig. 4 is a structural diagram showing the connection state during the test run, Fig. 5 is a control flowchart of the control device, and Fig. 6 is the piping wiring determination. FIG. 7 is a control flowchart of the process, FIG. 7 is a control flowchart of the storage process, and FIG. 8 is a schematic diagram showing an example of incorrect piping between the outdoor unit and the indoor unit. DESCRIPTION OF SYMBOLS 1...Compressor, 6...Second gas pipe, 7.Outdoor heat exchanger, 11...Liquid pipe, 17-1 to 17-4...Liquid branch pipe, 19-1 to 19-4 ... Gas branch pipe, 22 ... Indoor heat exchanger, 23 ... Second electric expansion valve (on-off valve), 31
...Heat exchanger temperature sensor (heat exchanger temperature detection means),
32... Gas branch pipe temperature sensor (gas branch pipe temperature detection means), 45... Signal processing means, 46... Storage means, 4
7...Operation control means, X...Outdoor unit, A-D
...Indoor unit. Figure 1

Claims (1)

[Claims] 1. A compressor (1) and an outdoor heat exchanger (7) connected to either the discharge side or the suction side of this compressor (1) are installed internally, and one end is connected to the outdoor heat exchanger (7). The other end of the liquid pipe (11) connected to the liquid pipe (11) is connected to a plurality of liquid branch pipes (17-1 to 17-4) each having an on-off valve (23), and also to the discharge side of the compressor (1). Alternatively, the other end of the gas pipe (6), one end of which is connected to the other end of the suction side, is connected to a plurality of gas branch pipes (19-1
- 19-4) between the liquid branch pipes (17-1 to 17-4) and the gas branch pipes (19-1 to 19-4) of the outdoor unit (X), which are configured by branching into A multi-type air conditioner in which indoor heat exchangers (22) of units (A to D) are connected to each other, the compressor (1)
Each indoor heat exchanger (22) and each gas branch pipe (19-1 to 19) during a refrigerant circulation cycle in which refrigerant discharged from the outdoor heat exchanger (7) and the indoor heat exchanger (22) are circulated.
-4) are provided with a heat exchanger temperature detection means (31) and a gas branch pipe temperature detection means (32) for detecting the temperature changes respectively, and one of the above-mentioned on-off valves (23) is opened. Each of the liquid branch pipes (17-1 to 17-4) and the gas branch pipe (19) are
-1 to 19-4) are connected to which indoor unit (A to D) a signal processing means (45) is provided,
A storage means (46) for storing the determination result of the signal processing means (45) during the trial run is provided, and an operation control means (47) is provided for normal operation based on the data of the storage means (46). Multi-type air conditioner.