Refrigeration cycle device

Abstract

Provided is a refrigeration cycle device having a compressor, a condenser, an expansion valve, and an evaporator, said refrigeration cycle device comprising: a refrigerant circuit which is configured by connecting, via extension piping, an outdoor unit having a compressor and an outdoor heat exchanger that serves as the condenser or evaporator, and an indoor unit having an indoor heat exchanger that serves as the evaporator or condenser; and a control device which controls the compressor and the expansion valve. The control device is provided with a control unit that has a determination unit which determines whether or not the extension piping is differing-diameter piping having an inner diameter smaller than pre-set reference piping, and a correction unit which performs a correction calculation for suppressing pressure loss in the refrigerant circuit, and that performs device control on the basis of the results of the correction calculation when the extension piping is differing-diameter piping.

Description

Refrigeration cycle equipment

[0001] This technology relates to a refrigeration cycle device, and in particular to pressure loss in an extension pipe connecting an outdoor unit and an indoor unit.

[0002] There is a refrigeration cycle device that configures a refrigerant circuit by connecting a compressor, a condenser, an expansion valve, and an evaporator with piping to allow refrigerant to circulate. Refrigeration cycle devices are often installed using a separate system in which the components, which are installed separately in an outdoor unit (heat source unit) and an indoor unit (load unit), are connected with extension piping. Conventionally, copper or stainless steel, etc., has been commonly used as the material for the extension piping.

[0003] JP 2010-261644 A

[0004] However, due to the recent rise in the cost of materials such as copper, there has been a trend toward using aluminum and other materials for extension piping. Aluminum is a metal with lower strength than copper, stainless steel, etc. Furthermore, in order to connect the outdoor unit and the indoor unit using the same terminals as conventional extension piping, while maintaining the same outer diameter as conventional extension piping and ensuring the same pressure resistance, extension piping made from a low-strength metal will be thicker and have a smaller inner diameter than conventional extension piping.

[0005] In extension pipes with a small inner diameter, the flow rate of the refrigerant passing through the pipe increases, resulting in a large pressure loss. Furthermore, as the extension pipe becomes longer, the refrigerant pressure in the pipe drops, reducing the air conditioning capacity to condition the indoor air, which is the load. In particular, a pressure drop can easily cause condensation during cooling operation.

[0006] Therefore, in order to solve the above-mentioned problems, an object is to provide a refrigeration cycle device that can accurately determine that an extension pipe with a small inner diameter has been used and can take appropriate action based on the determination.

[0007] The disclosed refrigeration cycle device is a refrigeration cycle device having a compressor, a condenser, an expansion valve, and an evaporator, and is equipped with a refrigerant circuit formed by connecting an outdoor unit having an outdoor heat exchanger and compressor that serves as a condenser or evaporator, and an indoor unit having an indoor heat exchanger that serves as an evaporator or condenser, with an extension pipe, and a control device that controls the compressor and the expansion valve, and the control device has a determination unit that determines whether the extension pipe is a different diameter pipe with an inner diameter smaller than a predetermined reference pipe, a correction unit that performs correction calculations to suppress pressure loss in the refrigerant circuit, and a control unit that controls equipment based on the results of the correction calculations when the extension pipe is a different diameter pipe.

[0008] In the disclosed refrigeration cycle device, a determination unit in the control unit of the control device determines whether the extension pipe is a different-diameter pipe. If the extension pipe is a different-diameter pipe, a correction unit performs a pressure loss suppression correction process to perform a correction calculation, and the control unit performs equipment control based on the results of the correction calculation. This allows the control device to perform equipment control of the device corresponding to the extension pipe. The control device suppresses and controls pressure loss in the refrigerant circuit, thereby maintaining capacity and preventing condensation and improving quality.

[0009] FIG. 1 is a diagram showing the configuration of a refrigeration cycle apparatus according to embodiment 1. FIG. 2 is a Ph diagram in the refrigeration cycle apparatus. FIG. 3 is a diagram explaining the configuration of a control device 400 in an air conditioning apparatus 1 according to embodiment 1. FIG. 4 is a diagram showing the flow of processing related to different diameter piping according to embodiment 1. FIG. 5 is a diagram explaining the configuration of a control device 400 in an air conditioning apparatus 1 according to embodiment 3. FIG. 6 is a diagram showing the flow of processing related to different diameter piping according to embodiment 3. FIG. 7 is a diagram explaining the configuration of a control device 400 in an air conditioning apparatus 1 according to embodiment 4. FIG. 8 is a diagram showing the flow of processing related to different diameter piping according to embodiment 4.

[0010] Refrigeration cycle devices and the like according to embodiments will be described below with reference to the drawings. In the following drawings, components with the same reference numerals are identical or equivalent and will be common throughout the following embodiments. The dimensional relationships between components in the drawings may differ from those in reality. The configurations of components shown throughout the specification are merely illustrative and are not limited to those described in the specification. In particular, the combinations of components are not limited to those in each embodiment; components described in other embodiments may be applied to other embodiments. Furthermore, the levels of pressure and temperature are not determined in relation to absolute values, but are determined relatively in terms of the state and operation of the device. When multiple similar devices are distinguished by subscripts, the subscripts may be omitted if there is no need to distinguish or identify them.

[0011] Embodiment 1. FIG. 1 is a diagram showing the configuration of a refrigeration cycle apparatus according to Embodiment 1. Here, as an example of a refrigeration cycle apparatus, an air conditioner 1 that conditions the air of a room that is a space to be air-conditioned will be described. As shown in FIG. 1 , the air conditioner 1 of Embodiment 1 has an outdoor unit 200, an indoor unit 100, and two extension pipes 300. The compressor 210, four-way valve 220, outdoor heat exchanger 230, and expansion valve 240 of the outdoor unit 200 are connected to the indoor heat exchanger 110 of the indoor unit 100 via the extension pipes 300, forming a refrigerant circuit that circulates refrigerant to supply heat. The configuration of the refrigerant circuit is not limited to the configuration shown in FIG. 1 . For example, the indoor unit 100 may have the expansion valve 240. Furthermore, while the air conditioner 1 of Embodiment 1 is configured with one outdoor unit 200 and one indoor unit 100 connected by pipes, the number of units that can be connected is not limited.

[0012] Here, the extension pipe 300 in the first embodiment is a pipe made of a metal such as aluminum or an aluminum-containing metal (hereinafter referred to as a low-strength metal), which has lower strength than commonly used pipes such as copper or stainless steel. When a low-strength metal is used as the pipe material, in order to ensure the same pressure resistance as a general pipe, the pipe made of the low-strength metal must be thicker than the general pipe. It is desirable that the extension pipe 300 be configured so that it can be connected to the outdoor unit 200 and the indoor unit 100 in the same way as a general conventional pipe made of a material such as copper (hereinafter referred to as a standard pipe). Therefore, the outer diameter of the extension pipe 300 is set to the same diameter as the standard pipe. Therefore, the extension pipe 300 is a pipe with a smaller inner diameter than the standard pipe (hereinafter referred to as a different-diameter pipe).

[0013] The outdoor unit 200 in the first embodiment has, as components that constitute a refrigerant circuit, a compressor 210, a four-way valve 220, and an outdoor heat exchanger 230. The outdoor unit 200 also has an outdoor blower 250 and a control device 400. The control device 400 will be described later.

[0014] The compressor 210 compresses the drawn refrigerant and discharges it. The compressor 210 is, for example, a scroll compressor, a rotary compressor, or a vane compressor. The compressor 210 can change the amount of circulated refrigerant discharged by the compressor 210 by changing the drive frequency as desired using, for example, an inverter circuit.

[0015] The four-way valve 220 serving as the flow path switching device is, for example, a valve that switches the flow of refrigerant between cooling operation and heating operation. During heating operation, the four-way valve 220 connects the discharge side of the compressor 210 to the indoor heat exchanger 110 and connects the suction side of the compressor 210 to the outdoor heat exchanger 230. During cooling operation, the four-way valve 220 connects the discharge side of the compressor 210 to the outdoor heat exchanger 230 and connects the suction side of the compressor 210 to the indoor heat exchanger 110. While the four-way valve 220 is used here as an example, the flow path switching device is not limited to this. For example, the flow path switching device may be configured by combining multiple two-way valves, etc.

[0016] The outdoor heat exchanger 230 is a heat exchanger that exchanges heat between the refrigerant and outdoor air. The outdoor heat exchanger 230 is, for example, a fin-tube heat exchanger. In the first embodiment, the outdoor heat exchanger 230 functions as an evaporator during heating operation, absorbing heat from the refrigerant to evaporate it, converting it into a gaseous refrigerant (hereinafter referred to as a gas refrigerant) and passing it through the system. In the cooling operation, the outdoor heat exchanger 230 functions as a condenser, condensing the refrigerant to release heat, converting it into a liquid refrigerant (hereinafter referred to as a liquid refrigerant) and passing it through the system. The outdoor heat exchanger 230 in the first embodiment is also equipped with an outdoor two-phase pipe temperature sensor 231 and an outdoor heat exchanger temperature sensor 232. The outdoor two-phase pipe temperature sensor 231 and the outdoor heat exchanger temperature sensor 232 will be described later. When driven, the outdoor blower 250 passes air from outside the outdoor unit 200 through the outdoor heat exchanger 230 to form an air flow that flows out from inside the outdoor unit 200 , thereby promoting heat exchange in the outdoor heat exchanger 230 .

[0017] The expansion valve 240, which functions as a flow control device, a throttle device, or the like, is a valve that reduces the pressure of the refrigerant to expand it. The expansion valve 240 includes, for example, an electronic expansion valve. The expansion valve 240 adjusts its opening based on instructions from the control device 400 (described later) or the like, thereby reducing the pressure and adjusting and controlling the amount of refrigerant passing through.

[0018] The indoor unit 100 conditions the air inside the room. The indoor unit 100 includes an indoor heat exchanger 110 as a component of a refrigerant circuit. The indoor unit 100 also includes an indoor blower 120. The indoor heat exchanger 110 exchanges heat between the refrigerant and the indoor air in the space to be air-conditioned. The indoor heat exchanger 110 is, for example, a fin-tube heat exchanger. For example, during heating operation, the indoor heat exchanger 110 functions as a condenser, condensing the refrigerant and passing the liquid refrigerant. During cooling operation, the indoor heat exchanger 110 functions as an evaporator, evaporating the refrigerant and passing the gas refrigerant. The indoor heat exchanger 110 in the first embodiment is also equipped with an indoor two-phase pipe temperature sensor 111 and an indoor heat exchanger temperature sensor 112. The indoor two-phase pipe temperature sensor 111 and the indoor heat exchanger temperature sensor 112 will be described later. The indoor blower 120 passes air through the indoor heat exchanger 110 to promote heat exchange in the indoor heat exchanger 110, and supplies the air that has passed through the indoor heat exchanger 110 to the room, which is the space to be air-conditioned. Here, the indoor blower 120 basically operates at a rotation speed based on the air volume set by the occupant in the room.

[0019] Here, the remote controller (hereinafter referred to as the remote control) 500 is connected to the indoor unit 100 via wired or wireless communication. The remote control 500 is a device that allows a user to issue operational instructions to control the operation of the air conditioning apparatus 1. Signals related to operational instructions sent from the remote control 500 are sent to a control device 400 included in the outdoor unit 200 via a communication line (not shown) that transmits and receives signals between the indoor unit 100 and the outdoor unit 200, and are processed there.

[0020] Next, the operation of each device in the air conditioner 1 will be described based on the flow of refrigerant. First, the operation of each device in the refrigerant circuit during heating operation will be described based on the flow of refrigerant. Solid arrows in FIG. 1 indicate the flow of refrigerant during heating operation. High-temperature, high-pressure gas refrigerant compressed and discharged by the compressor 210 passes through the four-way valve 220 and flows into the indoor heat exchanger 110. While passing through the indoor heat exchanger 110, the gas refrigerant condenses and liquefies by exchanging heat with, for example, the air in the space to be air-conditioned. The condensed and liquefied refrigerant passes through the expansion valve 240. The refrigerant is decompressed as it passes through the expansion valve 240. The refrigerant, which has been decompressed by the expansion valve 240 and is now in a two-phase gas-liquid state, passes through the outdoor heat exchanger 230. In the outdoor heat exchanger 230, the refrigerant evaporates by exchanging heat with outdoor air sent from the outdoor blower 250. The gasified refrigerant passes through the four-way valve 220 and is drawn back into the compressor 210. In this manner, the refrigerant circulates within the refrigerant circuit of the air conditioner 1, and air conditioning related to heating is performed.

[0021] Next, cooling operation will be described. The dotted arrows in FIG. 1 indicate the flow of refrigerant during cooling operation. The high-temperature, high-pressure gas refrigerant compressed and discharged by the compressor 210 passes through the four-way valve 220 and flows into the outdoor heat exchanger 230. The refrigerant then passes through the outdoor heat exchanger 230, where it condenses and liquefies by exchanging heat with outdoor air supplied by the outdoor blower 250. The liquefied refrigerant then passes through the expansion valve 240. As it passes through the expansion valve 240, the refrigerant is reduced in pressure and enters a two-phase gas-liquid state. The refrigerant, once reduced in pressure by the expansion valve 240 and brought into a two-phase gas-liquid state, passes through the indoor heat exchanger 110. In the indoor heat exchanger 110, the refrigerant evaporates by exchanging heat with, for example, the air in the space to be air-conditioned. The gasified refrigerant then passes through the four-way valve 220 and is drawn back into the compressor 210. In this manner, the refrigerant circulates within the refrigerant circuit of the air conditioner 1, performing air conditioning related to cooling.

[0022] 2 is a Ph diagram of the refrigeration cycle apparatus. As described above, the outdoor two-phase pipe temperature sensor 231 and the outdoor heat exchanger temperature sensor 232 are attached to the outdoor heat exchanger 230. The indoor two-phase pipe temperature sensor 111 and the indoor heat exchanger temperature sensor 112 are attached to the indoor heat exchanger 110. These temperature sensors are detection devices that detect the refrigerant temperature at the attached positions and send signals containing data related to the detected temperatures to the control device 400, which will be described later.

[0023] The outdoor two-phase pipe temperature sensor 231 and the indoor two-phase pipe temperature sensor 111 detect the refrigerant temperature in the heat exchanger as the heat exchanger exit temperature, which is the detection temperature. Although not particularly limited, the outdoor two-phase pipe temperature sensor 231 and the indoor two-phase pipe temperature sensor 111 are installed in positions that allow them to detect the refrigerant temperature at approximately the midpoint of its path through the heat exchanger. In this way, the outdoor two-phase pipe temperature sensor 231 and the indoor two-phase pipe temperature sensor 111 are installed in positions that are intended to detect the temperature of point P2 or point P3 on the p-h diagram (Mollier diagram) of FIG. 2 . Therefore, the heat exchanger exit temperature is the saturation temperature (condensation temperature or evaporation temperature) of the refrigerant in a two-phase gas-liquid state during the condensation or evaporation phase of the refrigeration cycle.

[0024] The outdoor heat exchanger temperature sensor 232 and the indoor heat exchanger temperature sensor 112 are detection devices that detect the temperature of the refrigerant flowing into and out of the heat exchangers as the heat exchanger inlet temperature, which serves as a detection temperature, and send a detection signal to the control device 400. In this example, the outdoor heat exchanger temperature sensor 232 is installed in a position that forms the refrigerant flow path between the expansion valve 240 and the outdoor heat exchanger 230. The indoor heat exchanger temperature sensor 112 is installed in a position that forms the refrigerant flow path between the outdoor heat exchanger 230 and the expansion valve 240 via the extension pipe 300. Therefore, the outdoor heat exchanger temperature sensor 232 and the indoor heat exchanger temperature sensor 112 can detect the temperature at point P2b or point P3a on the p-h diagram in FIG. 2 . If the pressure loss of the refrigerant in the condenser is large, the gradient from point P2a, which is the refrigerant inlet of the condenser, through point P2, to point P2b, which is the refrigerant outlet, becomes large. Here, the air conditioner 1 may be provided with an outdoor heat exchanger temperature sensor 232 and an indoor heat exchanger temperature sensor 112 that detect the temperature at point P2b or point P3a on the ph diagram in Figure 2.

[0025] 3 is a diagram illustrating the configuration of the control device 400 in the air conditioning apparatus 1 according to embodiment 1. The control device 400 is a device that controls each device of the air conditioning apparatus 1. Here, the outdoor unit 200 is described as having the control device 400, but this is not limited to this. Another unit may have the control device 400. Furthermore, the control device 400 may be a device independent of the unit that has the devices that make up the air conditioning apparatus 1.

[0026] The control device 400 includes a control unit 410, a storage unit 420, and a switching unit 430. The control unit 410 includes, for example, a control and arithmetic processing device such as a CPU (Central Processing Unit) or a microcomputer. The control unit 410 processes data in signals sent from various sensors and sends control signals to devices in the refrigerant circuit of the air conditioning apparatus 1 to control the devices. The control unit 410 in the first embodiment includes a determination unit 411, a correction unit 412, and a setting unit 413. The determination unit 411 performs a determination process particularly regarding the extension pipe 300. The correction unit 412 performs a pressure loss suppression correction process to suppress pressure loss when the extension pipe 300 is a different-diameter pipe. Therefore, when the extension pipe 300 is a different-diameter pipe, the control unit 410 sends a device control signal to the air conditioning apparatus 1 and performs control based on the correction content processed by the correction unit 412. The setting unit 413 also performs processes related to various settings. Here, the setting unit 413 performs settings relating to different diameter pipes, in particular, based on the determination of the determination unit 411 .

[0027] The storage unit 420 also includes, for example, a volatile storage device (not shown) such as random access memory (RAM) that can temporarily store data, and a non-volatile auxiliary storage device (not shown) such as flash memory. The storage unit 420 of the first embodiment particularly includes a setting storage unit 421. The setting storage unit 421 stores the settings made by the setting unit 413 as setting data. The storage unit 420 also includes data in the form of a program that describes the processing procedures to be performed by the control arithmetic processing device. The control unit 410 then executes processing based on the program data. However, the present invention is not limited to this, and the control device 400 may also be a device (hardware) dedicated to control.

[0028] The switching unit 430 has a switching device such as a changeover switch that an operator manually switches whether the extension pipe 300 is a different diameter pipe. When the operator performs a switching operation using the changeover device, a signal is switched in the switching unit 430. For example, when the operator positions the changeover switch to the side where the extension pipe 300 is a different diameter pipe, the setting unit 413 of the control unit 410 stores data indicating that the extension pipe 300 is a different diameter pipe in the setting memory unit 421 of the memory unit 420.

[0029] Fig. 4 is a diagram showing a processing flow relating to a different-diameter pipe according to embodiment 1. The processing in Fig. 4 is mainly performed by the control unit 410 of the control device 400. When power is supplied and control is started, the determination unit 411 of the control unit 410 determines whether the extension pipe 300 is a different-diameter pipe based on the setting data stored in the setting storage unit 421 of the storage unit 420 (step S1).

[0030] When the determination unit 411 determines that the extension pipe 300 is a different-diameter pipe, the correction unit 412 of the control unit 410 performs a pressure-loss suppression correction process (step S2). The pressure-loss suppression correction process involves performing a correction calculation on the target drive frequency of the compressor 210 (hereinafter referred to as the target drive frequency), the opening of the expansion valve 240, and the rotation speed of the outdoor blower 250 (step S3). The control unit 410 then performs corrections based on the correction calculation results, continues controlling the equipment (step S4), and ends the process related to the different-diameter pipe.

[0031] On the other hand, if the judgment unit 411 determines that the extension pipe 300 is not a different diameter pipe, the control unit 410 continues to control the equipment using normal control without performing pressure loss suppression correction processing (step S5), and terminates processing related to the different diameter pipe.

[0032] The pressure loss suppression correction process of the correction unit 412 when the air conditioner 1 is operating in cooling mode will be described. The correction unit 412 performs a correction to lower the target drive frequency so that the evaporation temperature in the indoor heat exchanger 110 is equal to or higher than the preset evaporation temperature threshold. Lowering the target drive frequency also lowers the drive frequency of the compressor 210, thereby reducing the flow rate of the refrigerant through the extension pipe 300. This reduces pressure loss in the extension pipe 300. When the correction unit 412 performs this process, limitations are set to ensure air conditioning capacity, such as ensuring that the target drive frequency corrected by the correction unit 412 does not fall below the rated frequency. Furthermore, even if the refrigerant flow rate decreases due to a reduction in the drive frequency of the compressor 210, the correction unit 412 corrects the opening degree of the expansion valve 240 to achieve the set degree of subcooling SC in order to maintain air conditioning capacity. Here, the degree of subcooling SC during cooling mode is the temperature difference between the outdoor two-phase pipe temperature sensor 231 and the outdoor heat exchanger temperature sensor 232. Correction unit 412 corrects the opening degree of expansion valve 240 to prevent the condensing temperature in outdoor heat exchanger 230 from becoming too high. Therefore, correction unit 412 corrects the rotation speed of outdoor blower 250 so that the condensing temperature becomes equal to or lower than the set upper limit condensing temperature. Here, the correction calculation has been described as being performed on the drive frequency of compressor 210, the opening degree of expansion valve 240, and the rotation speed of outdoor blower 250, but the correction calculation may be performed on at least one device.

[0033] The pressure loss suppression correction process of the correction unit 412 when the air conditioner 1 is performing heating operation will be described. The correction unit 412 performs a correction to lower the target drive frequency so that the condensing temperature in the indoor heat exchanger 110 is equal to or lower than the set condensing temperature threshold. When the correction unit 412 performs this process, limitations are set to ensure air conditioning capacity, such as ensuring that the target drive frequency corrected by the correction unit 412 does not fall below the rated frequency. Furthermore, to maintain air conditioning capacity, the correction unit 412 corrects the opening degree of the expansion valve 240 to achieve a set subcooling degree SC. The subcooling degree SC during heating operation is the temperature difference between the indoor two-phase pipe temperature sensor 111 and the indoor heat exchanger temperature sensor 112. While the correction calculation has been described as being performed on the drive frequency of the compressor 210 and the opening degree of the expansion valve 240, the correction calculation may be performed on either one of the devices.

[0034] As described above, according to the air conditioning apparatus 1 of the first embodiment, the determination unit 411 of the control unit 410 in the control device 400 determines whether the extension pipe 300 is a different-diameter pipe. If the extension pipe 300 is a different-diameter pipe, the correction unit 412 of the control unit 410 performs a pressure loss suppression correction process to perform a correction calculation, and the control unit 410 controls the compressor 210 and other devices based on the results of the correction calculation. This allows the control device 400 to control the air conditioning apparatus 1 corresponding to the extension pipe 300. By suppressing and controlling pressure loss within the refrigerant circuit, the control device 400 can maintain air conditioning capacity and prevent condensation, thereby improving quality. Furthermore, the control device 400 can reflect the settings for the extension pipe 300 made by the operator by having the determination unit 411 make a determination based on the settings switched by the switching unit 430.

[0035] Embodiment 2 In the air conditioning apparatus 1 of the above-described embodiment 1, whether or not the extension pipe 300 is a different diameter pipe is set by operating the switching device in the switching unit 430. In the air conditioning apparatus 1 of embodiment 2, an operator performs a setting operation to determine whether or not the extension pipe 300 is a different diameter pipe via the remote control 500. For example, when an operator performs an operation to determine that the extension pipe 300 is a different diameter pipe, the setting unit 413 of the control unit 410 stores data to the effect that the extension pipe 300 is a different diameter pipe in the setting memory unit 421 of the memory unit 420.

[0036] As described above, the air conditioning apparatus 1 in the second embodiment can set whether or not the extension pipe 300 is a different diameter pipe using the remote control 500. Because the setting can be made using the remote control 500 that is provided in advance in the air conditioning apparatus 1, there is no need to provide a switching device for setting different diameter pipes in the switching unit 430, for example.

[0037] Embodiment 3 In the air conditioning apparatus 1 in the above-described embodiment 1, whether or not the extension pipe 300 is a different-diameter pipe is set based on the operation of the switching unit 430. Furthermore, in the air conditioning apparatus 1 in embodiment 2, whether or not the extension pipe 300 is a different-diameter pipe is set based on the operation of the remote control 500. Therefore, setting whether or not the extension pipe 300 is a different-diameter pipe is performed manually. In the air conditioning apparatus 1 in embodiment 3, the control device 400 determines whether or not the extension pipe 300 is a different-diameter pipe based on a comparison with data obtained when operation is performed in a preset initial mode for, for example, a test run.

[0038] FIG. 5 is a diagram illustrating the configuration of the control device 400 in the air conditioning apparatus 1 according to embodiment 3. In FIG. 5, components with the same reference numerals as those in FIG. 3 perform the same operations as those described in embodiment 1. As shown in FIG. 5, in the air conditioning apparatus 1 according to embodiment 3, the storage unit 420 of the control device 400 includes a reference value storage unit 422. The reference value storage unit 422 stores reference operating data when the air conditioning apparatus 1 is operated in the initial mode, ie, when the reference pipe is used as the extension pipe 300. The initial mode is a mode in which the air conditioning apparatus 1 is operated with a preset compressor 210 drive frequency and subcooling degree SC under an environment of a predetermined outdoor air temperature and the suction temperature (indoor temperature) of the air drawn into the indoor unit 100. The initial operating data is, for example, data indicating the relationship between the temperature detected by the indoor two-phase pipe temperature sensor 111 and the opening degree of the expansion valve 240. The temperature detected by the indoor two-phase pipe temperature sensor 111 is the evaporation temperature during cooling operation and the condensation temperature during heating operation. The initial operation data has a plurality of patterns of data according to the combination of the operation forms of the initial modes.

[0039] 6 is a diagram showing the flow of processing related to the reduced diameter pipe according to embodiment 3. When power is supplied, the control unit 410 starts controlling the devices of the air conditioning apparatus 1 and operates in the initial mode (step S11). Then, after a predetermined set time has elapsed (step S12), the control unit 410 acquires the temperature detected by the indoor two-phase pipe temperature sensor 111 (step S13).

[0040] The determination unit 411 of the control unit 410 determines whether the operating state deviates from the temperature detected by the indoor two-phase pipe temperature sensor 111 based on the reference operating data stored in the reference value storage unit 422 (step S14). Specifically, when the pressure loss is large, the evaporation temperature decreases during cooling operation and the condensation temperature increases during heating operation. Therefore, the control unit 410 controls the expansion valve 240 to increase the opening degree to increase the evaporation temperature during cooling operation and the condensation temperature during heating operation. Therefore, if the opening degree of the expansion valve 240 during operation is greater than the opening degree of the expansion valve 240 in the reference operating data relative to the temperature detected by the indoor two-phase pipe temperature sensor 111, the determination unit 411 determines that the extension pipe 300 is a different-diameter pipe.

[0041] When the determination unit 411 determines that the extension pipe 300 is a different-diameter pipe, the correction unit 412 of the control unit 410 performs a pressure-loss suppression correction process (step S15). As described above, the pressure-loss suppression correction process performs a correction calculation on the target drive frequency of the compressor 210, the opening of the expansion valve 240, and the rotation speed of the outdoor blower 250 (step S16). The control unit 410 makes corrections based on the correction calculation results and continues controlling the equipment (step S17), and ends the process related to the different-diameter pipe.

[0042] On the other hand, if the determination unit 411 determines that the extension pipe 300 is not a different diameter pipe, the control unit 410 continues to control the normal equipment without performing the pressure loss suppression correction process (step S18), and ends the process related to the different diameter pipe.

[0043] As described above, according to the air conditioning apparatus 1 of the third embodiment, the memory unit 420 stores reference operating data obtained when the air conditioning apparatus 1 is operated in the initial mode using an extension pipe made of a commonly used reference pipe such as copper or SUS in the reference value memory unit 422. The determination unit 411 then compares the initial operating data obtained when the air conditioning apparatus 1 is operated in the initial mode using the extension pipe 300 with the reference operating data to determine whether the extension pipe 300 is a different-diameter pipe. This makes it possible to automatically determine whether the extension pipe 300 is a different-diameter pipe, thereby preventing setting errors by the operator or user.

[0044] Here, the description has been given assuming that the determination unit 411 makes a determination regarding a different diameter pipe each time control related to the operation of the air conditioning apparatus 1 is performed, but this is not limited to this. The setting unit 413 of the control unit 410 may store data indicating that the extension pipe 300 is a different diameter pipe in the setting storage unit 421 of the storage unit 420, so that from the next operation onwards, the determination unit 411 may make a determination similar to that in embodiment 1.

[0045] Embodiment 4 In the above-described embodiment 3, the control device 400 stores initial operating data in the reference value storage unit 422 of the storage unit 420, and the determination unit 411 determines whether the extension pipe 300 is a different-diameter pipe based on the operating state when the air conditioning apparatus 1 is operating in the initial mode. Here, when operating the air conditioning apparatus 1 in the initial mode, the expected operating state differs depending on operating conditions such as the environment. For this reason, the reference value storage unit 422 needs to store a large amount of data as reference operating data.

[0046] Therefore, in the air conditioner 1 of embodiment 4, when the air conditioner 1 is operated in the initial mode, the compressor 210 is driven at a plurality of different drive frequencies to operate the air conditioner 1 in a plurality of patterns, with regard to the determination made by the determination unit 411. Then, the determination unit 411 determines whether or not the extension pipe 300 is a different diameter pipe based on the rate of change in pressure loss (hereinafter referred to as the pressure loss change rate) predicted from the plurality of operation patterns.

[0047] FIG. 7 is a diagram illustrating the configuration of the control device 400 in an air conditioning apparatus 1 according to embodiment 4. In FIG. 7, components assigned the same reference numerals as those in FIGS. 3 and 5 perform the same operations as those described in embodiments 1 and 2. As shown in FIG. 7, in the air conditioning apparatus 1 according to embodiment 4, the control unit 410 of the control device 400 has a prediction calculation unit 414. The prediction calculation unit 414 calculates a pressure drop change rate A based on temperatures detected by the indoor two-phase pipe temperature sensor 111 and the indoor heat exchanger temperature sensor 112. Furthermore, the reference value storage unit 422 of the storage unit 420 according to embodiment 4 stores, as initial operating data, a reference pressure drop change rate A1 when the air conditioning apparatus 1 is operated in the initial mode using commonly used pipes such as copper or SUS as the extension pipe 300.

[0048] Here, the rate of change in pressure drop in the fourth embodiment will be described. The saturation pressure of the refrigerant at the location where each temperature sensor is installed is calculated from the temperatures detected by the indoor two-phase pipe temperature sensor 111 and the indoor heat exchanger temperature sensor 112. The pressure difference between the saturation pressure of the refrigerant at the location where the indoor heat exchanger temperature sensor 112 is installed and the saturation pressure of the refrigerant at the location where the indoor two-phase pipe temperature sensor 111 is installed is defined as the pressure drop Δp. If the pressure drops Δp when the compressor 210 is driven at two different drive frequencies are defined as a first pressure drop Δp1 and a second pressure drop Δp2, then the rate of change in pressure drop A is A = Δp2 / Δp1.

[0049] FIG. 8 is a diagram showing a process flow for a reduced-diameter pipe according to the fourth embodiment. When power is supplied, the control unit 410 starts controlling the air conditioning apparatus 1 and operates in the initial mode (step S21). At this time, the control unit 410 drives the compressor 210 at the drive frequency F1. When a predetermined first set time has elapsed (step S22), the control unit 410 acquires the temperatures detected by the indoor two-phase pipe temperature sensor 111 and the indoor heat exchanger temperature sensor 112 (step S23). The prediction calculation unit 414 then calculates a first pressure loss Δp1 based on the temperatures detected by the indoor two-phase pipe temperature sensor 111 and the indoor heat exchanger temperature sensor 112 (step S24).

[0050] Next, the control unit 410 changes the drive frequency and drives the compressor 210 at drive frequency F2 (step S25). After a predetermined second set time has elapsed (step S26), the control unit 410 acquires temperatures detected by the indoor two-phase pipe temperature sensor 111 and the indoor heat exchanger temperature sensor 112 (step S27). The prediction calculation unit 414 then calculates a second pressure loss Δp2 based on the temperatures detected by the indoor two-phase pipe temperature sensor 111 and the indoor heat exchanger temperature sensor 112 (step S28). The prediction calculation unit 414 calculates a pressure loss change rate A from the first pressure loss Δp1 and the second pressure loss Δp2 (step S29).

[0051] The determination unit 411 of the control unit 410 determines whether the rate of change in pressure drop A is greater than the reference rate of change in pressure drop A1 based on the initial operating data stored in the reference value storage unit 422 (step S30).

[0052] If the determination unit 411 determines that the rate of change in pressure drop A is greater than the reference rate of change in pressure drop A1, the determination unit 411 determines that the extension pipe 300 is a different-diameter pipe, and the correction unit 412 of the control unit 410 performs a pressure drop suppression correction process (step S31). As described above, the pressure drop suppression correction process performs a correction calculation on the target drive frequency of the compressor 210, the opening of the expansion valve 240, and the rotation speed of the outdoor blower 250 (step S32). The control unit 410 makes corrections based on the correction calculation results, continues controlling the equipment (step S33), and ends the process related to the different-diameter pipe.

[0053] On the other hand, if the pressure loss change rate A is not greater than the reference pressure loss change rate A1, the judgment unit 411 determines that the extension pipe 300 is not a different diameter pipe, and the control unit 410 continues to control the normal equipment without performing pressure loss suppression correction processing (step S34), and terminates processing related to the different diameter pipe.

[0054] As described above, according to the air conditioning apparatus 1 of embodiment 4, the determination unit 411 makes a determination using the pressure loss change rate, which is the rate of change of pressure loss in the refrigerant circuit, as the initial operating data and the reference operating data. Therefore, in addition to the effects described in embodiment 1 and the like, there is no need to store a large amount of data corresponding to the operating conditions for the reference operating data when operation is performed in the initial mode with extension piping using the reference piping, and the data used by the determination unit 411 for determination can be reduced.

[0055] In the first embodiment and the like described above, the air conditioner 1 has been described, but the present invention can also be applied to other refrigeration cycle devices such as a refrigerator, a freezer, or a hot water supply device.

[0056] 1 Air conditioning device, 100 Indoor unit, 110 Indoor heat exchanger, 111 Indoor two-phase pipe temperature sensor, 112 Indoor heat exchanger temperature sensor, 120 Indoor blower, 200 Outdoor unit, 210 Compressor, 220 Four-way valve, 230 Outdoor heat exchanger, 231 Outdoor two-phase pipe temperature sensor, 232 Outdoor heat exchanger temperature sensor, 240 Expansion valve, 250 Outdoor blower, 300 Extension piping, 400 Control device, 410 Control unit, 411 Determination unit, 412 Correction unit, 413 Setting unit, 414 Prediction calculation unit, 420 Memory unit, 421 Setting memory unit, 422 Reference value memory unit, 430 Switching unit, 500 Remote control.

Claims

1. A refrigeration cycle device having a compressor, a condenser, an expansion valve, and an evaporator, a refrigerant circuit configured by connecting an outdoor unit having an outdoor heat exchanger serving as the condenser or the evaporator and the compressor, and an indoor unit having an indoor heat exchanger serving as the evaporator or the condenser, with an extension pipe; a control device for controlling the compressor and the expansion valve; Equipped with The control device includes: A determination unit that determines whether the extension pipe is a different diameter pipe having an inner diameter smaller than that of a reference pipe that is a preset reference; a correction unit that performs a correction calculation to suppress a pressure loss in the refrigerant circuit when the determination unit determines that the extension pipe is the different diameter pipe, A refrigeration cycle apparatus comprising: a control unit that performs, when the extension pipe is the different diameter pipe, correction based on a result of the correction calculation of the correction unit to control equipment.

2. The control device includes a switching unit that switches whether the extension pipe is the different diameter pipe, The refrigeration cycle apparatus according to claim 1 , wherein the control unit includes a setting unit that sets whether the extension pipe is the different diameter pipe or not based on the switching of the switching unit.

3. a remote controller for sending a signal related to an input instruction to the control device; The refrigeration cycle apparatus according to claim 1 , wherein the control unit includes a setting unit that sets whether the extension pipe is the different diameter pipe or not based on a signal sent from the remote controller.

4. the control device includes a storage unit that stores reference operation data indicating an operating state of the refrigerant circuit when the outdoor unit and the indoor unit are operated using the reference piping in an initial mode based on environment and equipment control preset in the reference piping, 2. The refrigeration cycle apparatus according to claim 1, wherein the determination unit determines whether the extension pipe is the different diameter pipe based on a comparison between initial operation data indicating an operating state when operating in the initial mode and the reference operation data.

5. An indoor two-phase pipe temperature sensor is provided to detect the evaporation temperature or condensation temperature of the refrigerant in the indoor heat exchanger, The refrigeration cycle apparatus of claim 4, wherein the determination unit compares the initial operating data indicating the opening degree of the expansion valve at the detected temperature of the indoor side two-phase pipe temperature sensor with the reference operating data indicating the opening degree of the expansion valve at a temperature corresponding to the detected temperature, and if it determines that the initial operating data is greater than the reference operating data, it determines that the extension pipe is the different diameter pipe.

6. 5. The refrigeration cycle apparatus according to claim 4, wherein the reference operating data and the initial operating data are a rate of change in pressure drop due to the pressure loss in the extension pipe when the compressor is driven at different driving frequencies and operated in a plurality of the initial modes.

7. an indoor two-phase pipe temperature sensor that detects the evaporation temperature or condensation temperature of the refrigerant in the indoor heat exchanger; an indoor heat exchanger temperature sensor for detecting a temperature of the refrigerant flowing out from the indoor heat exchanger; The control unit calculates a pressure difference of saturation pressures calculated from the detected temperatures of the indoor side two-phase pipe temperature sensor and the indoor side heat exchanger temperature sensor, and has a prediction calculation unit that calculates the pressure loss change rate due to the pressure loss in the extension piping from the pressure difference obtained when operating in a plurality of the initial modes.

8. an outdoor fan that passes air through the outdoor heat exchanger; The refrigeration cycle apparatus according to any one of claims 1 to 7, wherein the correction unit performs the correction calculation for at least one of a drive frequency of the compressor, an opening degree of the expansion valve, and a rotation speed of the outdoor blower.

9. The refrigeration cycle apparatus according to any one of claims 1 to 7, wherein the different diameter pipe is made of aluminum or a metal containing aluminum, which has a lower strength than the standard pipe.