JP2019184150A - Air conditioner - Google Patents

Abstract

To judge a state of opened or closed state of a shut-off valve in short time when an air-cooling operation is started.SOLUTION: An air conditioner of this invention includes a gas pipe temperature sensor for detecting a temperature of a gas pipe between a gas side closing valve of an outdoor unit and an indoor heat exchanger of an indoor unit. The air conditioner of this invention has a control device for outputting an instruction for starting a cooling inspection operation under "no initial operation" and outputting an instruction to start the cooling inspection operation under "initial operation". In regard to a gas pipe temperature detected by the gas pipe temperature sensor, it is judged by a cooling inspection operation that a gas side closing valve is closed when the gas pipe temperature difference (ΔTg) between the present state and just after starting operation is less than a predetermined value if a first predetermined time (t1) elapses, and it is judged that the gas side closing valve is opened when a gas pipe temperature difference (ΔTg) becomes more than a predetermined value before a first predetermined time (t1) elapses.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to an air conditioner.

  Generally, an outdoor unit is provided with a gas side closing valve and a liquid side closing valve for opening and closing the gas pipe side and the liquid pipe side in the vicinity of the gas side connection end and the liquid side connection end of the refrigerant circuit. . Since these shut-off valves are manual, they must be kept open by the operator at the end of the installation operation. However, forgetting to open can happen due to some mistakes. For this reason, conventionally, after the installation, prior to the start of the cooling operation, an inspection operation for inspecting whether or not these closing valves are forgotten to be opened has been performed. In the conventional inspection operation, the closing valve is closed when the temperature difference between the indoor heat exchanger temperature and the room temperature and the temperature difference between the outdoor heat exchanger temperature and the outside air temperature do not become larger than the predetermined value within a predetermined time from the start of the cooling operation. It was a method to judge. Patent Document 1 is cited as an example of such an inspection method.

  Conventionally, the opening operation of the gas-side closing valve and the liquid-side closing valve has to be performed at the same time as a series of installation operations. Therefore, it is considered that both open / closed states are usually the same. It has been. In addition, when the gas side shut-off valve is closed at the start of the heating operation, immediately after the operation is started, the discharge pressure of the compressor is abnormally increased, the abnormality detection device is activated, and the operation of the compressor is stopped. For this reason, the inspection operation for checking whether or not the closing valve is forgotten to open has been a problem particularly at the start of the cooling operation.

JP 2004-162979 A

  However, in the conventional inspection operation for inspecting forgetting to open the closing valve, since it cannot be determined until the cooling operation is started up, it takes a long time to obtain the result. Therefore, it is necessary to set a guard time in order to eliminate the risk of erroneous detection. Moreover, when the number of connecting pipes and the length of connecting pipes differ greatly depending on installation conditions as in a multi-type air conditioner, there is a problem that it is difficult to set the guard time.

  An object of the present disclosure is to provide an air conditioner that can determine an open / closed state of a closing valve in a short time at the start of cooling operation.

  An air conditioner according to a first aspect includes an outdoor unit including a compressor, an outdoor heat exchanger, a liquid side closing valve that opens and closes a liquid side in a refrigerant circuit, and a gas side closing valve that opens and closes a gas side in the refrigerant circuit; Detecting the temperature of the indoor unit with the indoor heat exchanger connected to the outdoor unit by the liquid side and gas side communication pipes and the gas pipe between the gas side shut-off valve and the indoor heat exchanger When the operation for starting the cooling operation is performed, the command for starting the cooling inspection operation is output if the operation is not performed for the first time, and the operation for starting the normal cooling operation is performed if the operation is performed for the first time. The cooling inspection operation is performed when the gas pipe temperature difference between the current gas pipe temperature detected by the gas pipe temperature sensor and the gas pipe temperature immediately after the start of operation is a first predetermined time. If the gas side is less than the predetermined value after the lapse of time, the gas side closing is performed. It is determined that the valve is closed, and it is determined that the gas side closing valve is open when the gas pipe temperature difference becomes equal to or greater than the predetermined value before the first predetermined time elapses. Yes.

  Here, “cooling inspection operation” means that when the operation for starting the cooling operation is performed, the compressor is operated with the refrigerant circuit in the cooling cycle and the closing valve is opened and closed before the normal cooling operation is started. This refers to driving.

  Also, assuming that the cooling check operation is started with the gas side closing valve opened, the gas pipe between the gas side closing valve and the indoor heat exchanger becomes the suction side of the compressor, and the pressure and temperature of the refrigerant rapidly decrease. To do. Accordingly, the current gas pipe temperature after operation is lower than the gas pipe temperature immediately after the start of operation. Here, the temperature difference between the current gas pipe temperature after the cooling inspection operation and the gas pipe temperature immediately after the start of the cooling inspection operation is referred to as “gas pipe temperature difference”. In addition, the temperature difference that can clearly recognize the gas pipe temperature difference is referred to herein as a “predetermined value” for the gas pipe temperature difference. Then, when the cooling inspection operation is performed with the gas-side shut-off valve opened, the operation time of the cooling inspection operation that is expected to reach the predetermined value of the gas pipe temperature is referred to as a “first predetermined time”. ing.

  According to this air conditioner, when the operation for starting the cooling operation is performed, in the case of “the first operation is performed”, the normal cooling operation is quickly performed. In the case of “no initial operation”, the cooling inspection operation is performed, and the open / close state of the gas-side stop valve can be determined in a short time.

  According to the air conditioner pertaining to the second aspect, when the cooling inspection operation determines that the gas side shutoff valve is closed, the compressor is stopped and the gas side shutoff valve is closed. Configured to display that.

  According to this air conditioner, in the cooling inspection operation, when it is determined that the gas side shut-off valve is closed, the compressor is stopped, so that the compressor can be protected. At this time, since it is displayed that the gas side closing valve is closed, the opening and closing of the liquid side closing valve as well as the gas side closing valve can be confirmed, and these closing valves can be opened.

  According to the air conditioner pertaining to the third aspect, the outdoor unit that detects the outdoor heat exchanger temperature of the electric expansion valve connected to the liquid side communication pipe side with respect to the liquid side closing valve and the outdoor heat exchanger A heat exchanger temperature sensor; and a pipe temperature sensor for detecting a pipe temperature of a pipe connected to the electric expansion valve side with respect to the liquid side shut-off valve. If it is determined that the valve is open, a temperature difference between the outdoor heat exchanger temperature detected by the outdoor heat exchanger temperature sensor and the pipe temperature detected by the pipe temperature sensor is a second predetermined time. When a predetermined value is exceeded before elapses, it is determined that the liquid side closing valve is closed, and the temperature difference is defined as a temperature difference before and after the liquid side closing valve. 2 When the time is less than the predetermined value when a predetermined time has elapsed It is configured to determine that the side stop valve is open.

  Assuming that the cooling check operation is performed with the gas side closing valve open and the liquid side closing valve closed, the refrigerant does not flow to the indoor unit side, so the inlet side of the liquid side closing valve (outdoor heat exchanger Side) refrigerant pressure and temperature rise. On the other hand, the pressure and temperature of the refrigerant on the outlet side (electric expansion valve side) of the liquid side closing valve change in a decreasing direction with a delay. Therefore, this influence appears as a temperature difference between the outdoor heat exchanger temperature detected by the outdoor heat exchanger temperature sensor and the pipe temperature detected by the pipe temperature sensor. In this case, the outdoor heat exchanger temperature and the inlet side temperature of the liquid side closing valve are approximate temperatures having a certain relationship. Therefore, the temperature difference between the outdoor heat exchanger temperature detected by the outdoor heat exchanger temperature sensor and the pipe temperature detected by the pipe temperature sensor is handled as the temperature difference before and after the liquid side shut-off valve. Further, a temperature difference that can clearly recognize the existence of the temperature difference before and after the liquid side closing valve is referred to as a “predetermined value” for the temperature difference before and after the liquid side closing valve. Then, if it is determined that the gas side closing valve is opened and then the liquid side closing valve is closed and the cooling inspection operation is continued, it is predicted that the temperature difference before and after the liquid side closing valve will naturally reach a predetermined value. The operation time of the cooling inspection operation to be performed is referred to as “second predetermined time”.

  According to this air conditioner, in the cooling inspection operation, when it is determined that the gas side closing valve is open, it is determined whether or not the liquid side closing valve is forgotten to be opened. The determination as to whether or not the liquid side closing valve is forgotten to be opened is made when the gas side closing valve is open, and thus is performed in a shorter time than the conventional one.

  According to the air conditioner pertaining to the fourth aspect, when the cooling inspection operation determines that the liquid side closing valve is closed, the compressor is stopped and the liquid side closing valve is closed. Configured to display that.

  According to this air conditioner, in the cooling inspection operation, when it is determined that the liquid side closing valve is closed, the compressor is stopped, so that the compressor can be protected. In addition, when it is determined that the liquid side closing valve is closed, it is displayed that the liquid side closing valve is closed, so it is confirmed that the liquid side closing valve has been left open and the liquid side closing valve is opened. be able to.

According to the air conditioner pertaining to the fifth aspect, the cooling inspection operation is configured to output a normal cooling operation start command when it is determined that the liquid side shut-off valve is open.
According to this air conditioner, even in the case of “no initial cooling operation”, when the gas-side closing valve and the liquid-side closing valve are opened, it is possible to quickly shift to the normal cooling operation. .

The refrigerant circuit figure of the air conditioner which concerns on embodiment. The block diagram of the control apparatus of the same air conditioner, and the peripheral device connected to this control apparatus. The flowchart which shows the control operation | movement until the cooling test driving | operation start at the time of the cooling operation start of the air conditioner. The flowchart which shows the control action of the cooling test | inspection operation at the time of the cooling operation start in the air conditioner. The flowchart which shows the control operation | movement until the heating test | inspection operation start at the time of the heating operation start of the same air conditioner. The flowchart which shows the control action of the heating test | inspection operation at the time of the heating operation start in the same air conditioner.

  Hereinafter, the air conditioner according to the present embodiment will be described. It should be noted that the present disclosure is not limited to the examples described below, is shown by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  As shown in FIG. 1, the air conditioner according to the present embodiment includes three indoor units 20 installed indoors with respect to one outdoor unit 10 installed outdoors. This is a multi-type air conditioner connected in parallel by the connecting pipe L1 and the three connecting pipes L2 on the gas side.

A schematic configuration of the multi-type air conditioner will be described.
The outdoor unit 10 includes a compressor 11 that is variable in rotation speed by an inverter, and a four-way switching valve 12 connected to a discharge pipe and a suction pipe of the compressor 11, and the compressor 11 and the four-way switching valve 12. An accumulator 13 is connected in the middle of the suction pipe connecting the two. The outdoor unit 10 includes an outdoor heat exchanger 14, a liquid side closing valve 15 for opening and closing the liquid side in the refrigerant circuit, and three electric expansion valves connected in parallel with respect to one switching port of the four-way switching valve 12. Sixteen and three liquid side connecting pipe connecting portions 17 are sequentially connected. The outdoor unit 10 has a gas side shut-off valve 18 that opens and closes the gas side in the refrigerant circuit, and three gas side connection pipe connection parts 19 connected in parallel with respect to the other switching port of the four-way switching valve 12. Connected sequentially. The outdoor unit 10 is provided with an outdoor fan 14 a for circulating outside air to the outdoor heat exchanger 14.

On the other hand, each indoor unit 20 is equipped with an indoor heat exchanger 21 and an indoor fan 22 for circulating indoor air to the indoor heat exchanger 21.
In the air conditioner configured as described above, the refrigerant circuit is reversibly switched by switching the four-way switching valve 12, the cooling operation is performed by the cooling cycle, and the heating operation is performed by the heating cycle.

  That is, the air conditioner sets the four-way switching valve 12 to the connection position indicated by the solid line arrow during the cooling operation. The compressor 11, the four-way switching valve 12, the outdoor heat exchanger 14, the liquid side closing valve 15, the electric expansion valve 16, the liquid side communication pipe connection portion 17, the liquid side communication pipe L 1, the indoor heat exchanger 21, A refrigerant circuit that forms a cooling cycle in which the refrigerant is circulated is formed in the order of the gas side communication pipe L2, the gas side communication pipe connection portion 19, the gas side closing valve 18, the four-way switching valve 12, the accumulator 13, and the compressor 11. Further, during the heating operation, the four-way switching valve 12 is set to the connection position indicated by the broken line arrow. The compressor 11, the four-way switching valve 12, the gas-side shutoff valve 18, the gas-side connecting pipe connection portion 19, the gas-side connecting pipe L2, the indoor heat exchanger 21, the liquid-side connecting pipe L1, and the liquid-side connecting pipe A refrigerant circuit that forms a heating cycle in which refrigerant is circulated is formed in the order of the connection portion 17, the electric expansion valve 16, the liquid side closing valve 15, the outdoor heat exchanger 14, the four-way switching valve 12, the accumulator 13, and the compressor 11.

  In this air conditioner, by switching the refrigerant circuit in this way, in the cooling cycle, the outdoor heat exchanger 14 acts as a condenser, and the indoor heat exchanger 21 acts as an evaporator, whereby the indoor fan 22 The indoor air circulated is cooled and dehumidified, and the room is cooled. In the air conditioner, in the heating cycle, the indoor heat exchanger 21 acts as a condenser and the outdoor heat exchanger 14 acts as an evaporator, so that the indoor air circulated by the indoor fan 22 is heated. The room is heated.

  When the air conditioner provided with such a refrigerant circuit is installed, the liquid side communication pipe L1 and the gas are connected to the liquid side communication pipe connection part 17 and the gas side communication pipe connection part 19 of the outdoor unit 10. The indoor unit 20 is connected using the side connection pipe L2. At this time, in the outdoor unit 10, the liquid-side closing valve 15 and the gas-side closing valve 18 are closed, and the refrigerant is prefilled in the refrigerant circuit. Then, after the indoor unit 20 is connected, evacuation is performed in the refrigerant circuit of the indoor unit 20 including the indoor heat exchanger 21, the liquid side communication pipe L1, and the gas side communication pipe L2. When the evacuation is completed, the liquid-side closing valve 15 and the gas-side closing valve 18 of the outdoor unit 10 are opened, so that the refrigerant filled in the outdoor unit 10 causes the indoor heat exchanger 21 of the indoor unit 20 to flow. The refrigerant is discharged into the refrigerant circuit, the liquid side communication pipe L1 and the gas side communication pipe L2. The connection between the outdoor unit 10 and the indoor unit 20 is performed in this way. However, since the liquid-side closing valve 15 and the gas-side closing valve 18 are manually operated, it is possible that the installation operation is ended with these closing valves closed by some mistake.

The air conditioner is provided with various temperature sensors as follows.
That is, the outdoor heat exchanger temperature sensor 31 is provided in the outdoor heat exchanger 14 of the outdoor unit 10. The outdoor heat exchanger temperature sensor 31 is the same as the conventional sensor provided in the outdoor heat exchanger 14 for detecting the condensation temperature during the cooling operation, but the outdoor heat exchange of the liquid side shut-off valve 15 is performed. It is also used as a sensor for detecting the temperature of the pipe 15a on the container 14 side. A pipe temperature sensor 32 for detecting the temperature of the pipe 15b is provided on the pipe 15b connected to the electric expansion valve 16 side of the liquid side closing valve 15. In addition, the branch pipe 15b is branched to form three branch pipes 15c that are connected to the liquid side connecting pipe connecting portion 17, and the electric expansion valve 16 is provided in each branch pipe 15c. Three liquid pipe temperature sensors 33 for detecting the degree of supercooling of the liquid refrigerant at the outlet of the indoor heat exchanger 21 during the heating operation are provided on the liquid side connection pipe connecting portion 17 side.

  Further, on the side of the gas pipe 18 a to which the gas side shut-off valve 18 is connected, the outdoor unit 10 is formed with three branch gas pipes 18 b that are branched from the gas pipe 18 a and communicated with the gas side connecting pipe connection portion 19. A gas pipe temperature sensor 34 is provided for each branch gas pipe 18b.

  The indoor unit 20 is provided with a room temperature sensor 35 for detecting the temperature of the indoor air sent to the indoor heat exchanger 21, and the indoor heat exchanger 21 has a room for detecting the evaporation temperature during the cooling operation. A heat exchanger temperature sensor 36 is provided.

  By providing various temperature sensors as described above, in the cooling operation, the gas pipe temperature sensor 34 connects the gas side shut-off valve 18 and the gas side communication pipe connection portion 19 to the gas pipe 18a and the branch gas pipe 18b. The gas pipe temperature of the gas pipe can be detected.

In this air conditioner, this gas pipe temperature is detected in order to inspect forgetting to open the gas side shut-off valve 18 at the start of the cooling operation.
Further, in the present air conditioner, in the cooling operation, cooling is performed from the temperature difference between the gas pipe temperature detected by the gas pipe temperature sensor 34 and the temperature detected by the indoor heat exchanger temperature sensor 36 (corresponding to the evaporation temperature). The degree of superheat of the refrigerant at the outlet of each indoor heat exchanger 21 during operation is detected, and each electric expansion valve 16 is controlled based on the detected degree of superheat.

  As described above, the gas pipe temperature sensor 34 is used for each branch gas pipe 18b in order to use both a temperature sensor for inspecting forgetting to open the gas side closing valve 18 and a temperature sensor for controlling each electric expansion valve 16. Is provided. In addition, as a temperature sensor for inspecting forgetting to open the gas side closing valve 18, any temperature may be measured as long as the temperature of the gas pipe between the gas side closing valve 18 and the indoor heat exchanger 21 is satisfied. Only one gas pipe 18a may be provided. In this specification, the term “gas pipe temperature” simply refers to the temperature of the gas pipe between the gas side shut-off valve 18 and the indoor heat exchanger 21.

  In the cooling operation and the heating operation of the air conditioner, the outdoor heat exchanger temperature sensor 31 and the pipe temperature sensor 32 detect the temperature difference (ΔTh) before and after the liquid side shut-off valve 15. That is, the temperature of the outdoor heat exchanger 14 and the temperature of the pipe 15a on the outdoor heat exchanger 14 side of the liquid side shut-off valve 15 are approximate temperatures having a certain relationship, and thus are detected by the outdoor heat exchanger temperature sensor 31. The temperature difference between the temperature of the pipe 15b detected by the pipe temperature sensor 32 and the temperature before and after the liquid side shut-off valve 15 (ΔTh).

Here, the relationship between the temperature of the outdoor heat exchanger 14 and the temperature of the pipe 15a on the outdoor heat exchanger 14 side of the liquid side shut-off valve 15 is laid down.
That is, in the normal cooling operation in which the liquid side shut-off valve 15 is open, the outdoor heat exchanger 14 acts as a condenser, and the liquid side shut-off valve 15 on the outdoor heat exchanger 14 side (the inlet side during the cooling operation). ) In the pipe 15a. Therefore, in this case, the temperature of the outdoor heat exchanger 14 becomes the condensation temperature of the refrigerant, and the temperature of the pipe 15a on the outdoor heat exchanger 14 side of the liquid side closing valve 15 becomes the temperature of the liquid refrigerant in the supercooled state. For this reason, a temperature difference corresponding to the degree of supercooling occurs between these two temperatures, but it is an approximate temperature. In this case, the temperature of the pipe 15a and the temperature of the pipe 15b are the same.

  Further, when the gas side shut-off valve 18 is opened and the liquid side shut-off valve 15 is forgotten to be opened during the cooling operation, the outdoor heat exchanger 14 and the pipe 15a are in a state of being pumped down to the outdoor unit 10. Both are filled with liquid refrigerant as the pressure increases. Therefore, the temperature of the outdoor heat exchanger 14 and the temperature of the pipe 15a are substantially the same temperature. The temperature of the pipe 15b decreases because the inside of the pipe 15b is connected to the low pressure side via the electric expansion valve 16.

  In the normal heating operation in which the liquid side shut-off valve 15 is open, the outdoor heat exchanger 14 acts as an evaporator, and the liquid side shut-off valve 15 on the outdoor heat exchanger 14 side (exit in heating operation). The low-pressure refrigerant after passing through the electric expansion valve 16 circulates in the pipe 15a that is the side). Accordingly, both temperatures are substantially the same low-pressure refrigerant temperature. Therefore, in this case, the temperature of the outdoor heat exchanger 14, the temperature of the pipe 15a, and the temperature of the pipe 15b are substantially the same.

  In addition, when the gas-side shut-off valve 18 is opened and the liquid-side shut-off valve 15 is forgotten to be opened during heating operation, the indoor unit 20 is pumped down. The upstream side (the indoor unit 21 side) is closed by the liquid side shut-off valve 15 and is connected to the suction side of the compressor 11. Accordingly, in this case, the refrigerant pressure and the refrigerant temperature of the outdoor heat exchanger 14 and the pipe 15a are decreased as the compressor 11 is operated, and both have the same refrigerant temperature. On the other hand, since the pipe 15b is filled with the liquid refrigerant that has flowed out of the indoor unit 20, the temperature of the pipe 15b approximates the outside air temperature.

  In the present air conditioner, the outdoor heat exchanger temperature sensor 31 and the pipe temperature sensor 32 use the temperature relationship as described above when the cooling operation start operation is performed, and the heating operation start operation. Is used to check whether the liquid side closing valve 15 is forgotten to be opened.

  In the air conditioner, in the heating operation, the degree of supercooling of the liquid refrigerant at the outlet of the indoor heat exchanger 21 is detected by the indoor heat exchanger temperature sensor 36 and the liquid pipe temperature sensor 33, and the detected degree of supercooling is detected. Each electric expansion valve 16 is controlled based on the above.

Next, this air conditioner is equipped with a control device 40 for controlling various operations as shown in FIG.
The control device 40 is actually formed by a control unit mounted on the indoor unit 20 and a control unit mounted on the outdoor unit 10, but functionally operates as an integral unit. Express and describe as an element.

  As shown in FIG. 2, the compressor 11, the four-way switching valve 12, the electric expansion valve 16, the outdoor fan 14 a, and the indoor fan 22 are connected to the control device 40. More specifically, the drive units of these devices are connected to the control device 40. In addition, an outdoor heat exchanger temperature sensor 31, a pipe temperature sensor 32, a liquid pipe temperature sensor 33, a gas pipe temperature sensor 34, a room temperature sensor 35, and an indoor heat exchanger temperature sensor 36 are connected to the control device 40. Further, a remote controller 50 is wirelessly connected to the control device 40.

  The remote controller 50 functions as an operation unit for the air conditioner. The remote controller 50 includes an operation switch for turning on and off the operation of the air conditioner, an operation mode selection unit for selecting an operation mode such as cooling and heating, an air volume setting unit for setting the air volume of the indoor fan 22, a set temperature of indoor air, And a display unit for displaying the open / close state of the gas side shutoff valve 18 and the liquid side shutoff valve 15. The remote controller 50 is configured to be able to transmit and receive wirelessly such as exchanging driving operation information selected or set with the control device 40.

  The control device 40 includes an arithmetic processing device that executes a predetermined control program, and a storage unit that stores information used for the control program and various control processes, and requires a test operation as a functional block. A rejection determination unit 41, an inspection operation control unit 42, a normal operation control unit 43, and an abnormal operation detection unit 44 are provided.

  The inspection operation necessity determination unit 41 determines whether or not the inspection operation for inspecting the open / closed states of the gas-side closing valve 18 and the liquid-side closing valve 15 is necessary when the cooling operation or the heating operation is operated and the operation is started. . The inspection operation necessity determination unit 41 is provided with an initial operation storage unit 41a for storing initial operation information. The initial operation storage unit 41a is configured by, for example, a non-volatile memory, and stores “no initial operation” indicating a state in which neither the cooling operation nor the heating operation is performed when the air conditioner is shipped. When the air conditioner is installed and the cooling operation or the heating operation is performed through the inspection operation, the air conditioner is changed to “with initial operation”, and this is stored.

  The inspection operation control unit 42 controls to perform an inspection operation for inspecting the open / closed states of the gas side closing valve 18 and the liquid side closing valve 15 based on the inspection operation start command in the inspection operation necessity determination unit 41. Since the inspection operation is performed in the case of “no initial operation”, it is set so that the design pressure of the refrigerant circuit is not exceeded in a short time even when the gas side closing valve 18 and the liquid side closing valve 15 are forgotten to be opened. For example, it is conceivable that the compressor 11 is set to be about ½ of the operation frequency during normal operation.

  The normal operation control unit 43 controls the air conditioner so as to perform a normal cooling operation or heating operation that is performed when it is determined that the gas side closing valve 18 and the liquid side closing valve 15 are not forgotten to be opened in the inspection operation. To do. In this normal cooling operation or heating operation, the control device 40 exerts the necessary compression function force based on the difference between the stored indoor target temperature and the room temperature detected by the room temperature sensor 35. Thus, the operation frequency of the compressor 11 is set, and control is performed so as to perform normal cooling or heating operation.

  The abnormal operation detection unit 44 detects abnormal operation of the air conditioner. The abnormal operation detection unit 44 detects an abnormality in the refrigerant circuit based on, for example, compressor output overcurrent detection or compressor rotor position detection failure. In the present embodiment, the abnormal operation detection unit 44 detects the abnormal operation, whereby the compressor 11 can be stopped before the motor coil of the compressor reaches the temperature limit.

  Hereinafter, the inspection operation necessity determination operation by the inspection operation necessity determination unit and the inspection operation operation by the inspection operation control unit 42 following this determination operation in the air conditioner according to the present embodiment will be described with reference to FIGS. This will be explained based on.

First, a case where an operation for starting the cooling operation is performed by the remote controller 50 will be described. In this case, the necessity of the inspection operation is determined based on the flow shown in FIG.
When an operation for starting the cooling operation is performed by the remote controller 50 (step S1), the record in the initial operation storage unit 41a is checked as to whether “no initial operation” is performed (step S2). If the result is YES, that is, if the initial operation (that is, the initial cooling operation or the initial heating operation) has not been performed so far (YES in step S2), the gas side closing valve 18 and the liquid side closing are performed. Since it means that the valve 15 has not been inspected for opening, a cooling inspection operation start command is output (step S3). Further, in the case of NO in step S2, that is, it means that the first operation has been performed, which means that the gas side closing valve 18 and the liquid side closing valve 15 are not forgotten to be opened. Therefore, in this case, a normal cooling operation command is output (step S4). Thus, the inspection operation necessity determination is completed.

  When a cooling inspection operation start command is output in the determination of necessity of the cooling inspection operation, the cooling inspection operation shown in FIG. 4 is performed based on this command. When the cooling inspection operation is started, a display indicating that the cooling inspection operation is being performed is displayed, for example, on the display unit of the remote controller 50 (step S11). In the cooling inspection operation, the refrigerant circuit is brought into a cooling cycle state, and the operation is performed with the operation frequency of the compressor 11 being an operation frequency suitable for the inspection.

  This cooling inspection operation is judged by checking whether the gas pipe temperature difference (ΔTg) between the current gas pipe temperature detected by the gas pipe temperature sensor 34 and the gas pipe temperature immediately after the start of the cooling inspection operation is equal to or greater than a predetermined value. Is done. When the gas side shut-off valve 18 is opened, the refrigerant pressure in the branch gas pipe 18b is rapidly lowered by the operation of the compressor 11, so that the gas pipe temperature difference (ΔTg) becomes a predetermined value or more. However, when the gas side shut-off valve 18 is forgotten to open, the refrigerant pressure in the branch gas pipe 18b does not decrease, so the gas pipe temperature difference (ΔTg) remains below a predetermined value.

  Therefore, when the cooling inspection operation is started, it is displayed that the cooling inspection operation is being performed (step S11). Next, it is determined whether the gas pipe temperature difference (ΔTg) between the current gas pipe temperature detected by the gas pipe temperature sensor 34 and the gas pipe temperature immediately after the start of the cooling test operation is equal to or greater than a predetermined value (step S12). When the gas pipe temperature difference (ΔTg) is less than the predetermined value (when Step S12 is NO), even when the first predetermined time (t1) has elapsed, the gas pipe temperature difference (ΔTg) is less than the predetermined value (Step S13). Is YES), it is determined that the gas side closing valve 18 is closed (step S14). In addition, a display indicating that the gas side closing valve 18 is closed is displayed, for example, on the display unit of the remote controller 50 (step S14). Then, the operation of the compressor 11 is stopped (Step S20), and the display of the cooling inspection operation is stopped (Step S21). Here, the first predetermined time (t1) is a time at which counting is started from the cooling inspection operation start time point.

  On the other hand, when the gas pipe temperature difference (ΔTg) is greater than or equal to a predetermined value (when step S12 is YES), or when the gas pipe temperature difference (ΔTg) becomes greater than or equal to the predetermined value before the fourth predetermined time elapses. (When Step S13 NO → Step S12 is YES), it is determined that the gas side shut-off valve 18 is open (Step S15).

  Subsequently, it is determined whether or not the liquid side shut-off valve 15 has been forgotten to open by looking at the change in temperature difference (ΔTh) before and after the liquid side shut-off valve 15 (step S16). That is, when the liquid side closing valve 15 is opened, it can be said that the state of the refrigerant before and after the liquid side closing valve 15 is the same. In this case, the outdoor heat exchanger temperature and the pipe temperatures of the pipe 15a and the pipe 15b are approximated. Therefore, a large change does not occur in the temperature difference (ΔTh) before and after the liquid side closing valve 15.

  However, when the liquid side shut-off valve 15 is forgotten to open, the refrigerant pressure on the inlet side (outdoor heat exchanger 14 side) of the liquid side shut-off valve 15 rises rapidly, and the refrigerant temperature rises. On the other hand, on the outlet side of the liquid-side closing valve 15 (electric expansion / expansion valve 16 side), the refrigerant pressure decreases and the refrigerant temperature tends to decrease. That is, the outdoor heat exchanger temperature and the piping temperature of the piping 15a are increased, and the piping temperature of the piping 15b is decreased. Therefore, the temperature difference (ΔTh) before and after the liquid side shut-off valve 15 rises exceeding a predetermined value.

  Thus, since the temperature difference (ΔTh) before and after the liquid side closing valve 15 changes, when the temperature difference (ΔTh) before and after the liquid side closing valve 15 is equal to or less than a predetermined value (YES in step S16), a second predetermined value is obtained. If the predetermined value or less is maintained even after the time (t2) has elapsed (YES in step S17), it is determined that the liquid side closing valve 15 is open (step S18). At the same time, the start instruction for the normal cooling operation is output, and the record in the initial operation storage unit 41a is changed to “with initial operation” (step S18), and the display of the cooling inspection operation is stopped (step S21). . Here, in the second predetermined time (t2), it is determined that the gas side shut-off valve 18 is open, and counting is started from the time point.

  On the other hand, when the temperature difference (ΔTh) before and after the liquid side closing valve 15 exceeds a predetermined value (NO in step S16), it is determined that the liquid side closing valve 15 is closed, and the liquid side closing valve 15 is closed. The display is displayed, for example, on the display unit of the remote controller 50 (step S19). Then, the operation of the compressor 11 is stopped (Step S20), and the display of the cooling inspection operation is stopped (Step S21). As described above, the cooling inspection operation is controlled, and it is determined whether the gas side closing valve 18 and the liquid side closing valve 15 are forgotten to be opened.

Next, the case where the operation for starting the heating operation is performed by the remote controller 50 will be described. In this case, the necessity of inspection operation is determined by the operation shown in FIG.
When the operation for starting the heating operation is performed by the remote controller 50 (step S31), the refrigerant circuit is brought into a heating cycle state, and the compressor 11 is started at an operation frequency suitable for the inspection operation, for example. By the way, when the gas side shut-off valve 18 is forgotten to open, since the discharge gas discharged from the compressor 11 has no place to go, the discharge pressure rises abnormally after an extremely short time has elapsed, and the abnormal operation detection unit 44. Is detected and stopped. Therefore, after a short predetermined third predetermined time (t3) has elapsed (step S32), it is determined whether the compressor 11 has been stopped (step S33). The third predetermined time starts counting from the time when the heating operation start operation is performed. When the gas side shut-off valve 18 is forgotten to open, the abnormal operation detection unit 44 is naturally activated. The time is set.

  If the compressor 11 is stopped at this time (YES in step S33), there is a suspicion that the gas side shut-off valve 18 is closed, and an abnormal operation warning is displayed on, for example, the display unit of the remote controller 50 (step). S34). When this display is given, the handling operator checks whether both the gas side closing valve 18 and the liquid side closing valve 15 have been forgotten to be opened.

  If the compressor 11 is not stopped in step S33 (NO in step S33), it is determined that the gas side shut-off valve 18 is open (step S35). In this case, it is subsequently determined whether or not an inspection operation forgetting to open the liquid side closing valve 15 is necessary. Specifically, it is determined whether or not “no initial operation” (step S36). If NO in step S36, it may be determined that there is an initial operation, and therefore it is determined that the liquid side shut-off valve 15 has not been forgotten to be opened. Therefore, in this case, a normal heating operation start command is output (step S37). However, in the case of YES in step S36, since there is no initial operation, it is necessary to check whether the liquid side closing valve 15 is forgotten to open. For this reason, the start command of the inspection operation during heating (the “heating inspection operation” in this specification is abbreviated) is output (step S38). As described above, the operation up to the necessity of the inspection operation when the heating operation start command is output is completed.

  When a heating inspection operation start command is output in the necessity determination of the heating inspection operation, the heating inspection operation shown in FIG. 6 is performed based on this command. When the heating inspection operation is started, a display indicating that the heating inspection operation is being performed is displayed on, for example, the display unit of the remote controller 50 (step S41). In the heating inspection operation, the refrigerant circuit is brought into a heating cycle and the operation frequency of the compressor 11 is set to an operation frequency suitable for inspection.

  As in the case of the cooling inspection operation, the heating inspection operation is the temperature difference between the outdoor heat exchanger temperature detected by the outdoor heat exchanger temperature sensor 31 and the pipe temperature detected by the pipe temperature sensor 32, that is, the liquid side Judgment is made by looking at the change in temperature difference (ΔTh) before and after the closing valve 15. That is, when the liquid side closing valve 15 is opened, the temperature difference (ΔTh) before and after the liquid side closing valve 15 does not substantially change. However, when the liquid side closing valve 15 is forgotten to be opened, the gas side closing valve 18 is opened, so that the pump side is pumped down to the indoor unit 20 side. The refrigerant discharged from the compressor 11 and sent to the indoor heat exchanger 21 is cooled by room air, liquefied, and stored on the indoor unit 20 side. As a result, the refrigerant pressure on the inlet side (electric expansion valve 13 side) during the heating inspection operation of the liquid-side closing valve 15 increases, but the refrigerant temperature is not so different from that before the heating inspection operation starts, that is, close to the outside air temperature. It becomes a state. However, on the outlet side (outdoor heat exchanger 14 side) of the liquid side closing valve 15, the refrigerant is sucked into the compressor 11, and the pressure and temperature of the refrigerant decrease with time. Thereby, the temperature difference (ΔTh) before and after the liquid side closing valve 15 increases beyond a predetermined value.

  Therefore, when the heating inspection operation is started, it is displayed that the heating inspection operation is being performed (step S41). Next, it is determined whether or not the temperature difference (ΔTh) before and after the liquid side closing valve 15 is equal to or less than a predetermined value (step S42). If the temperature difference (ΔTh) before and after the liquid side closing valve 15 is equal to or less than a predetermined value (YES in step S42), the temperature difference (ΔTh) before and after the liquid side closing valve 15 is still present after the fourth predetermined time (t4) has elapsed. ) Is less than or equal to a predetermined value (YES in step S42), it is determined that the liquid side shut-off valve 15 is open (step S46). Then, the start instruction for the normal heating operation is output, and the record in the initial operation storage unit 41a is changed to “with initial operation” (step S46), and the display of the heating inspection operation is stopped (step S47). Here, the fourth predetermined time is a time for which counting is started from the time when the heating inspection operation start command is issued.

  On the other hand, if the temperature difference (ΔTh) before and after the liquid side closing valve 15 exceeds a predetermined value (NO in step S42), or before the fourth predetermined time (t4) elapses, the liquid side closing valve 15 When the temperature difference (ΔTh) before and after exceeds a predetermined value (NO in step S43 → NO in step S42), it is determined that the liquid side closing valve 15 is closed (step S44). In addition, an indication that the liquid side closing valve 15 is closed is displayed, for example, on the display unit of the remote controller 50 (step S44). Then, the operation of the compressor 11 is stopped (step S45), and the display of the heating inspection operation is stopped (step S47). As described above, the heating inspection operation is controlled, and it is determined whether or not the liquid side closing valve 15 is forgotten to be opened.

(Effect of embodiment)
Since the air conditioner according to the present embodiment is configured as described above, the following effects can be achieved.

  (1) According to the present air conditioner, when the operation for starting the cooling operation is performed, in the case of “the first operation is performed”, the normal cooling operation is quickly performed. In the case of “no initial operation”, the cooling inspection operation is performed, and the open / close state of the gas-side shut-off valve 18 is determined in a short time.

  (2) In the conventional inspection method using the guard time, if the guard time is set too long, the compressor 11 may burn out. In this air conditioner, since the determination is made using the detection result of the gas pipe temperature sensor 34, the reaction of forgetting to open the closing valve is accelerated. For this reason, the set time of the guard time is shortened, and the risk of damage to the compressor is also reduced.

  (3) In the cooling inspection operation, when it is determined that the gas side shut-off valve 18 is closed, the compressor 11 is stopped, so that the compressor 11 can be protected. Further, when it is determined that the gas side closing valve 18 is closed, it is displayed that the gas side closing valve 18 is closed, so that the gas side closing valve 18 as well as the liquid side closing valve 15 is also displayed. After confirming the opening and closing, these closing valves can be opened.

  (4) In the cooling inspection operation, when it is determined that the gas side closing valve 18 is open, it is determined whether or not the liquid side closing valve 15 is forgotten to be opened. The determination as to whether or not the liquid side closing valve 15 has been forgotten to be opened is made when the gas side closing valve 18 is open, and thus is performed in a shorter time than the conventional one.

  (5) In the cooling inspection operation, when it is determined that the liquid side closing valve 15 is closed, the compressor 11 is stopped, so that the compressor 11 can be protected. Further, when it is determined that the liquid side closing valve 15 is closed, it is displayed that the liquid side closing valve 15 is closed. Can be released.

  (6) Even in the case of “no initial cooling operation” in the cooling inspection operation, if the gas-side closing valve 18 and the liquid-side closing valve 15 are opened, the normal cooling operation should be immediately performed. Can do.

  (7) This air conditioner is effective when the length of the connecting pipe connecting the outdoor unit 10 and the indoor unit 20 is increased. Therefore, this is particularly effective in a multi-type air conditioner where the length of the connecting pipe is often increased.

  (8) In the present air conditioner, when the operation for starting the heating operation is performed, if no abnormality is determined by the abnormal operation detection unit 44, it is determined that the gas side shut-off valve 18 is open. Whether or not the side closing valve 15 has been forgotten to be opened can be determined in a short time.

(Modification)
The description regarding each of the above embodiments is an example of the form that the air conditioner according to the present disclosure can take, and is not limited to that form. The air conditioner according to the present disclosure may be combined with, for example, the following modifications and at least two modifications not contradicting each other, in addition to the above-described embodiment.

  In the embodiment described above, when the operation for starting the heating operation is performed, the necessity of the heating inspection operation for checking whether the liquid side closing valve 15 is forgotten to be opened after confirming the opening of the gas side closing valve 18 is determined. And, if necessary in this determination, a heating inspection operation is performed. However, as in a conventional air conditioner, it may be an air conditioner that omits the determination of necessity of the inspection operation when the operation for starting the heating operation is performed and the heating inspection operation.

  In the embodiment, in the cooling inspection operation and the heating inspection operation, the operation frequency of the compressor 11 is operated at the special operation frequency for inspection, but it is used for the normal cooling operation and the normal heating operation. It is also possible to perform an inspection operation at an operating frequency.

  In the above embodiment, the second predetermined time when inspecting forgetting to open the liquid side shut-off valve 15 is based on the measurement start after the judgment of opening the gas side shut-off valve 18, but an appropriate timing is measured. Any measure can be used, and the reference for the measurement start can be the time when the cooling operation start operation is performed.

  In the above embodiment, a multi-type air conditioner that connects a plurality of indoor units 20 to a single outdoor unit 10 is not limited to such an air conditioner, but a single outdoor unit. The air conditioner of the type which connects the one indoor unit 20 with respect to 10 may be sufficient.

  In the embodiment described above, the display of the opening / closing inspection result of the liquid side closing valve 15, the display of the opening / closing inspection result of the gas side closing valve 18, the operation display in the case of the inspection operation, etc. are displayed on the display unit of the remote controller 50. However, these display units may be provided in places other than the remote controller 50, for example, the outdoor unit 10 or the indoor unit 20.

  While the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as set forth in the claims. .

L1 Liquid side communication pipe L2 Gas side communication pipe ΔTh Temperature difference ΔTg before and after the liquid side shut-off valve Gas pipe temperature difference (between current gas pipe temperature and gas pipe temperature immediately after start-up) 10 Outdoor unit 11 Compressor 12 4 Path switching valve 13 Accumulator 14 Outdoor heat exchanger 14a Outdoor fan 15 Liquid side shutoff valve 15a (connected to the outdoor heat exchanger side of the liquid side shutoff valve) Pipe 15b (Connected to the electric expansion valve side of the liquid side shutoff valve) Pipe 15c (Branch pipes are connected to electric expansion valves respectively) Branch pipe 16 Electric expansion valve 17 Liquid side communication pipe connection 18 Gas side closing valve 18a (Gas side closing valve is connected) Gas pipe 18b (the gas pipe is branched and communicated with the gas side communication pipe connection part) Branch gas pipe 19 Gas side communication pipe connection part 20 Indoor unit 21 Indoor heat exchanger 22 Indoor fan 31 Outdoor heat exchanger temperature sensor 3 2 Piping temperature sensor 33 Liquid pipe temperature sensor 34 Gas pipe temperature sensor 35 Room temperature sensor 36 Indoor heat exchanger temperature sensor

Claims (5)

An outdoor unit comprising a compressor (11), an outdoor heat exchanger (14), a liquid side closing valve (15) for opening and closing the liquid side in the refrigerant circuit, and a gas side closing valve (18) for opening and closing the gas side in the refrigerant circuit (10) and
An indoor unit (20) having an indoor heat exchanger (21) connected to the outdoor unit (10) by liquid and gas side communication pipes (L1, L2);
A gas pipe temperature sensor (34) for detecting the temperature of the gas pipe between the gas side shut-off valve (18) and the indoor heat exchanger (21);
When the operation for starting the cooling operation is performed, the control device (40) outputs a command for starting the cooling inspection operation if “no initial operation”, and outputs the command for starting the normal cooling operation if “first operation”. )When,
Have
In the cooling inspection operation, a gas pipe temperature difference (ΔTg) between the current gas pipe temperature detected by the gas pipe temperature sensor (34) and the gas pipe temperature immediately after the start of operation has elapsed for a first predetermined time (t1). If it is less than a predetermined value, it is determined that the gas side closing valve (18) is closed, and the gas pipe temperature difference (ΔTg) is greater than or equal to the predetermined value before the first predetermined time (t1) elapses. An air conditioner configured to determine that the gas side shut-off valve (18) is open when The air conditioner according to claim 1,
In the cooling inspection operation, when it is determined that the gas side closing valve (18) is closed, the compressor (11) is stopped and the gas side closing valve (18) is displayed as closed. It is configured as an air conditioner. An air conditioner according to claim 1 or claim 2,
An electric expansion valve (16) connected to the liquid side connecting pipe (L1) side of the liquid side closing valve (15);
An outdoor heat exchanger temperature sensor (31) for detecting an outdoor heat exchanger temperature of the outdoor heat exchanger (14);
A pipe temperature sensor (32) for detecting a pipe temperature of a pipe (15b) connected to the electric expansion valve (16) side with respect to the liquid side closing valve (15),
In addition,
In the cooling inspection operation, when it is determined that the gas side closing valve (18) is open, the outdoor heat exchanger temperature and the pipe temperature sensor detected by the outdoor heat exchanger temperature sensor (31). The temperature difference from the pipe temperature detected by (32) is defined as a temperature difference (ΔTh) before and after the liquid side closing valve (15), and the temperature difference (ΔTh) before and after the liquid side closing valve (15) is a second predetermined value. When a predetermined value is exceeded before the time (t2) elapses, it is determined that the liquid side closing valve (15) is closed, and the temperature difference (ΔTh) before and after the liquid side closing valve (15) is the second value. An air conditioner configured to determine that the liquid side shut-off valve (15) is open when the predetermined time (t2) has elapsed and is less than the predetermined value. The air conditioner according to claim 3,
When the cooling inspection operation determines that the liquid side closing valve (15) is closed, the compressor (11) is stopped and the liquid side closing valve (15) is displayed as closed. It is configured as an air conditioner. The air conditioner according to claim 4,
The air conditioner is configured to output a normal cooling operation start command when it is determined that the liquid side closing valve (15) is open in the cooling inspection operation.