JP6126970B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner.

  In recent years, while crude oil prices and material costs have soared, it is difficult to pass on sales prices of air conditioners, and further cost reduction is urgently needed. On the other hand, energy saving and noise reduction are also important selling points of air conditioners (air conditioners).

  Propeller fans that are widely used in outdoor units of air conditioners are desired to have high efficiency, low noise, and low cost. Propeller fans, which are injection-molded products made of resin material, are widely used because they have a higher degree of freedom in shape than sheet metal and are advantageous for mass production.

  The propeller fan may come into contact with falling objects such as ice blocks or icicles during its rotation. In this case, the blades of the propeller fan made of a resin material are easily damaged. In the case of a relatively large propeller fan that is often used in commercial air conditioners and the like, the outer periphery of the blade rotates at a speed exceeding 100 km / h. Although sufficient consideration has been given to the strength of the propeller fan, propeller fans made of resin material have a limit in preventing damage. The propeller fan rotates in a balanced state under normal conditions. When the blade is damaged, the blade is in a large unbalanced state, and the propeller fan and the support plate for supporting the fan motor are damaged. Depending on the blade breakage, the stress due to the unbalance sometimes reaches several hundred to several thousand times that of the normal state, and there is a limit to increasing the strength of the support plate.

  At this time, if only the propeller fan is damaged, it is only necessary to replace the propeller fan. However, if the support plate is damaged, the dropped propeller fan and the fan motor that drives the propeller fan are replaced with the air conditioner heat exchanger and piping. May be damaged.

  Therefore, in order to detect an abnormality of the propeller fan and take a countermeasure, there is a technique for detecting an abnormality of the blower as disclosed in Patent Document 1. This technology has a detection device that detects at least one of vibration and noise generated from an electric blower, and at least one frequency component of vibration and noise detected by the detection device is specific to a normal electric blower. By comparing with the frequency component, failure detection and failure mode determination of the electric blower are executed.

JP 2010-65594 A

  When the failure diagnosis device of Patent Document 1 is applied to failure diagnosis of an air conditioner (abnormality determination of a blower), a sensor that detects vibration or noise generated from the electric blower and frequency analysis of the detected vibration or noise are performed. Therefore, an arithmetic device for diagnosing a failure and a power supply unit for driving them are required. When a failure diagnosis device having such a configuration is provided in an air conditioner, it causes a significant increase in cost, so it is practically difficult to adopt it as a standard function in a mass-produced air conditioner.

  An object of the present invention is to provide an air conditioner that detects an abnormality of a blower efficiently and inexpensively.

  In order to solve the above problems, an air conditioner that is one embodiment of the present invention includes an indoor unit and an outdoor unit that is connected to the indoor unit through a pipe through which a refrigerant flows. The outdoor unit includes an outdoor heat exchanger, a temperature sensor that detects an outside air temperature, a propeller fan that blows air to the outdoor heat exchanger, a fan motor that drives the propeller fan, and electric power that controls power to the fan motor. A conversion unit, a current detection unit that detects an output current from the power conversion unit to the fan motor, a pulsation component extraction unit that extracts a pulsation component based on the rotation speed of the fan motor from the output current, and the magnitude of the pulsation component A determination unit that calculates a pulsation amount, compares the pulsation amount with a threshold value of the pulsation amount, determines whether or not a propeller fan abnormality has occurred, and determines a threshold value based on the outside air temperature. .

  According to one aspect of the present invention, it is possible to detect an abnormality of a blower efficiently and inexpensively.

It is a front view which shows the structure in the housing | casing of the outdoor unit of the air conditioner of the Example of this invention. It is a right view which shows the structure in the housing of the outdoor unit of the air conditioner of the Example of this invention. The structure of an air blower is shown. The structure of a fan controller is shown. The structure of a pulsation component extraction part is shown. The structure of the outdoor unit of Example 3 is shown. The threshold value correction process of Example 4 is shown. The structure of the air conditioner of Example 5 is shown.

  Hereinafter, an embodiment of an air conditioner of the present invention will be described based on the drawings. In addition, the part which attached | subjected the same code | symbol in each figure has shown the part which is the same or corresponds.

  In the present embodiment, an example will be described in which the present invention is applied to an upper blowing type outdoor unit.

  FIG. 1 is a front view illustrating a configuration of an outdoor unit of an air conditioner according to an embodiment of the present invention, and FIG. 2 illustrates a configuration of the outdoor unit of the air conditioner according to an embodiment of the present invention. It is a right view shown.

  A blower 10 is provided in the upper part of the housing 2 of the outdoor unit 20 of the air conditioner. The blower 10 includes a propeller fan 100, a fan motor 101 that drives the propeller fan 100, a support plate 102 that supports the fan motor 101, and the like. The housing 2 includes a top cover 201 provided around the blower 10, a side cover 202 that covers the side surface of the outdoor unit 20, a bottom plate 203 that forms the bottom surface of the outdoor unit 20, a leg portion 204 that supports the bottom plate 203, and a front surface A front cover 205 provided on the upper side of the side, a service cover 206 that is detachably provided on the lower side of the front side and that enables maintenance of devices installed in the housing 2, a front stay 207 that supports the front side, etc. It consists of An air outlet 200 that opens upward is formed in the upper surface cover 201.

  A heat exchanger (outdoor heat exchanger) 301 in the housing 2 is formed in a substantially U-shape and disposed on the bottom plate 203. Further, the heat exchanger 301 is disposed up to the side cover 202 portions (hereinafter referred to as suction ports 199) on both sides on the rear surface of the housing 2. By rotating the propeller fan 100 of the blower 10, outside air is sucked from the suction port 199 outside the heat exchanger 301, and heat exchange with the refrigerant passing through the inside of the heat exchanger is performed in the heat exchanger 301. The sucked air is configured to be blown upward from the air outlet 200 at the top of the housing 2.

  On the bottom plate 203, refrigeration cycle components such as a compressor 300, an accumulator, and a receiver are installed. A leg portion 204 is fixed to the lower surface of the bottom plate 203, and a fixing anchor hole (not shown) for fixing the housing 2 is formed on the lower surface side of the leg portion 204. It is comprised so that the outdoor unit 20 can be fixed to a local foundation part, a frame, etc. using a hole. Depending on the user, the outdoor unit 20 is often installed on a vibration isolation stand or the like in order to prevent vibration propagation to a building or the like.

  Inside the service cover 206 provided on the front side of the housing 2, an electrical component box 302 for storing electrical components and the like is installed. A main controller 500 that controls the blower 10, the compressor 300, and the like is housed inside the electrical component box 302. The main controller 500 is provided with a microcomputer (microprocessor), and the compressor 300 is based on information from a plurality of temperature sensors and pressure sensors 105 provided in each part, and further an indoor unit (not shown). Control of various components in the outdoor unit 20, such as the air blower 10, a four-way valve, and a solenoid valve (not shown). As the temperature sensor, for example, the outside air temperature sensor 104 is provided in the suction port 199. Inside the electrical component box 302, a fan controller 106 that controls power to the fan motor 101 and a compressor controller 108 that controls power to the compressor 300 are further provided. A commercial power supply 502 is supplied to the main controller 500, the fan controller 106, and the compressor controller 108.

  Next, the detail of the air blower 10 is demonstrated.

  FIG. 3 shows the configuration of the blower 10. The blower 10 includes a propeller fan 100, a fan motor 101, a support plate 102, a fan controller 106, and the like. The fan controller 106 performs control so that the rotational speed of the fan motor 101 matches the rotational speed command in accordance with the rotational speed command from the main controller 500. When the fan controller 106 detects any abnormality such as an overcurrent, the fan controller 106 transmits a signal indicating the abnormality to the main control device 500. In this case, the main controller 500 safely stops the entire system of the refrigeration cycle of the air conditioner, including the compressor 300 and the indoor unit.

  The main controller 500 is connected to controllers such as the fan controller 106 and the compressor controller 108, acquires the state measured by those controllers, and controls those controllers. The compressor controller 108 measures the state of the compressor 300 and sends it to the main control device 500, and controls the compressor 300 in accordance with an instruction from the main control device 500.

  The reason why the fan controller 106 for controlling the blower 10 is modularized independently of the main controller 500 is that the drive control of the fan motor 101 and the abnormality determination process are performed on the product-specific main controller. This is for avoiding the incorporation into 500. This will be specifically described. The control of the refrigeration cycle by the main controller 500 is very complicated, and the specifications are different for various products. If a control program for the blower 10 and an abnormality determination program are incorporated into the control program for the main control device 500, it is necessary to review the control programs for all products when a design change occurs. In order to avoid this, the fan controller 106 is made independent and has a module configuration common to a plurality of products, and the control program of the main control device 500 is configured to describe only the operation when a signal notifying abnormality is received. Adopted.

  Next, the fan controller 106 will be described.

  FIG. 4 shows the configuration of the fan controller 106. The fan controller 106 includes a power conversion unit 15, a current detection unit 4, a phase detection unit 5, a pulsation component extraction unit 6, and an abnormality determination unit 7. The power conversion unit 15 controls the output current to the fan motor 101 in accordance with the rotational speed command from the main control device 500. The power conversion unit 15 is an inverter, for example. The current detection unit 4 detects an output current from the power conversion unit 15 to the fan motor 101. The phase detector 5 detects the phase of the output current. The pulsation component extraction unit 6 extracts the pulsation component (torque pulsation component) of the output current based on the detection values by the current detection unit 4 and the phase detection unit 5. The abnormality determination unit 7 calculates the pulsation amount indicating the magnitude (amplitude) of the pulsation component extracted by the pulsation component extraction unit 6, and compares it with a predetermined threshold value to determine whether the propeller fan 100 is abnormal or normal. Judgment is made. For example, when the pulsation amount exceeds a preset threshold after the operation is started, the abnormality determination unit 7 determines that an abnormality has occurred in the propeller fan 100 and stops the fan motor 3. Thereby, damage to parts other than propeller fan 100 in outdoor unit 20 can be prevented.

  Here, the reason why the pulsation amount is used for the abnormality determination of the propeller fan 100 will be supplemented. As described above, excessive imbalance occurs even if a part of the propeller fan 100 is damaged. However, as long as the blades of the propeller fan 100 are not severely damaged, the air volume itself is not so different from that in the normal state if only part of the propeller fan 100 is damaged. Accordingly, the amount of work (torque) of the fan motor 101 at the time of breakage is almost the same as that at the normal time, and as a result, the magnitude of the output current is hardly different from that at the normal time. Rather, the fluid load change to the blower 10 such as the operating environment and load, the frosted state of the heat exchanger 301, etc. is greater than the load change at the time of breakage. It is impossible to determine whether the load has changed or the load has only changed.

  However, slight fluctuations occur in the generated torque due to fluctuations in the load (load) acting on the bearings in the fan motor 101 due to unbalanced vibrations and fluctuations in the inertial force due to whirling vibrations, resulting in pulsation in the current value. Will occur. Since this pulsation tends to increase as the unbalance amount increases and synchronizes with the rotation period of the propeller fan 100, for example, the pulsation component extraction unit 6 uses a bandpass filter that passes the rotation frequency of the propeller fan 100. If it is high, only the pulsation component due to imbalance can be extracted. In this way, the fan controller 106 can detect an abnormality of the propeller fan 100.

The current detection unit 4 detects a motor current (Iu, Iv, Iw) that is a three-phase output current to the fan motor 101, and performs a first-order lag filter process on the result of conversion in the order of αβ conversion and dq conversion. The q-axis current feedback value Iq that is the input of the pulsation component extraction unit 6 is calculated. αβ conversion and dq conversion can be calculated by the following equations.

  The motor current (Iu, Iv, Iw) can be detected by various methods such as connecting a resistor having a small resistance value to the motor current output section, detecting from the voltage applied to the resistor, and detecting by a current sensor. There is a way. The current detection unit 4 of this embodiment detects the output current of the power conversion unit 15 as a motor current.

  θdc at the time of dq conversion is a d-axis phase and indicates the magnetic pole position of the fan motor 101. The phase detector 5 calculates the mechanical angle phase θr, which is another input of the pulsation component extractor 6, from θdc. Δθdc indicates an angular velocity based on θdc. The phase detector 5 calculates Δθ from Δθdc as in the following equation.

  Δθr = Δθdc / number of pole pairs

  The phase detector 5 calculates Δr by integrating Δθr.

  FIG. 5 shows the configuration of the pulsation component extraction unit 6.

  The pulsation component extraction unit 6 extracts a pulsation component from the q-axis current feedback value Iq and the mechanical angle phase θr. For example, the pulsation component extraction unit 6 calculates sin θr and cos θr by the sin and cos calculation 8 of the mechanical angle phase θr, respectively. Further, the pulsation component extraction unit 6 multiplies the q-axis current feedback value by sin θr and cos θr by a multiplier and performs a first-order lag filter 9 to remove high-frequency components. Here, the set value of the time constant of the first-order lag filter 9 is set by simulation so that the period of the pulsating component can be extracted based on a test by an actual machine. That is, in order to extract the pulsation component, it is necessary to make this time constant larger than the pulsation cycle, so a larger time constant is set for the rotation cycle of propeller fan 100 in which torque pulsation occurs. Further, the pulsation component extraction unit 6 again multiplies the two outputs of the first-order lag filter 9 by sin θr and cos θr, respectively, and adjusts the pulsation component with the adjustment gain K, so that the mechanical angle phase of the output current is increased. Only components that pulsate with a period of θr are extracted. Here, for example, the sampling period Ts is 500 μs, and the filter time constant is 500 ms. Note that the pulsation component extraction unit 6 may be a band-pass filter that allows a frequency component that matches the rotational speed of the fan motor 101 to pass therethrough.

  When the pulsation amount, which is the magnitude of the pulsation component extracted from the pulsation component extraction unit 6, exceeds the preset threshold value, the abnormality determination unit 7 stops the fan motor 3 because it detects an abnormality in the propeller fan 100. In this case, there is a possibility that the propeller fan 100 is erroneously detected as being abnormal with respect to a temporary state in which the waveform of the motor current is disturbed due to an instantaneous power failure. Therefore, in the present embodiment, the threshold is determined from the amplitude of the pulsating component based on the test using the actual machine. For example, the pulsation amount is calculated from the measurement of the maximum value and the minimum value of the current value during normal operation, and is sufficiently larger than the maximum value of the pulsation amount during normal operation and smaller than the maximum value of the pulsation amount when the propeller fan 100 is damaged. By setting the value, it is possible to detect an abnormality of the propeller fan 100 while suppressing erroneous detection.

  However, there may be a case where vibration occurs due to some disturbance and the fan controller 106 erroneously determines that the abnormality is present. For transient vibrations such as earthquakes and gusts, accuracy can be ensured by redundancy such as rediagnosing after a certain period of time. However, for example, in the heating operation during rain / snow in winter, snow and freezing are likely to occur in the vicinity of the propeller fan 100, and they slightly touch the propeller fan 100, so that a larger vibration than in the normal operation occurs. There are things to do. In addition, such an operating environment is also a condition where frost is likely to be generated for the heat exchanger 301. This is a fluid imbalance and causes an increase in torque pulsation of the fan motor 101, and hence an increase in the pulsation component of the current value. There is a case. In such a case, since steady pulsation continues, it is impossible to cope with it as in the case of transient vibration.

  Therefore, the fan controller 106 is further provided with a threshold value changing unit 12 that changes the threshold value of the abnormality determination unit 7 based on the operation information of the outdoor unit 20. The threshold value changing unit 12 according to the present embodiment changes the threshold value for determining abnormality by the abnormality determining unit 7 in a direction in which it is not determined to be abnormal in a state where the outside air temperature is within a predetermined low temperature range. Since the pulsation amount indicates the magnitude of the pulsation component, if the threshold value changing unit 12 changes the threshold value to be high, it is difficult to determine that the pulsation is abnormal. Here, it is desirable to make the upper limit of the temperature range higher than 0 ° C. For example, the upper limit of the temperature range is set to 5 ° C. as the outside air temperature at which icing occurs in the propeller fan 100 in consideration of the decrease in the blowing temperature by the heat exchanger 301 during heating. In order to obtain the outside air temperature, if the detection value of the outside air temperature sensor 104, which is usually used for controlling the refrigeration cycle, is used, it is not necessary to newly provide a temperature sensor, thereby preventing an increase in cost. . Specifically, since the outside air temperature detected by the outside air temperature sensor 104 is acquired by the main controller 500, the fan controller 106 can acquire the outside air temperature via the main controller 500. If the same threshold value is set at all temperatures without using the outside air temperature information, the threshold value must be set large in order to prevent misjudgment under freezing conditions. The sensitivity of abnormal detection of (status) becomes extremely poor. Therefore, by providing the threshold value changing unit 12 that changes the threshold value according to the outside air temperature, it is possible to prevent erroneous determination at the time of freezing without reducing the sensitivity of abnormality detection during normal operation (non-freezing state).

  The fan controller 106 can also set different temperature ranges for heating and cooling as conditions for changing the threshold. For example, during heating, the temperature around the propeller fan 100, that is, the temperature blown out from the heat exchanger 301 is lower than the outside air temperature (suction temperature). It is desirable to set the upper limit of the temperature range to a temperature slightly higher than zero degrees. Conversely, during cooling, the blowout temperature is slightly higher than the outside air temperature, so the lower limit of the temperature range may be set to a temperature slightly lower than zero degrees. By setting in this way, it becomes possible to operate without reducing the sensitivity of abnormality detection in a wide temperature range during normal operation, particularly during cooling operation, while preventing erroneous determination during freezing.

  In addition, the fan controller 106 can change the threshold only in a rainy state where the outside air temperature is near zero degrees. Since snow at the time of snowfall has a low density (specific gravity), the blower 10 is blown off by the blowing air during operation. Further, even if the snow is accumulated, the snow is soft if it is immediately after the snowfall, so that even if the snow comes into contact with the propeller fan 100, no damage occurs. Therefore, the fan controller 106 changes the threshold value only for the winter rain condition, so that the fan controller 106 can be operated without lowering the sensitivity of abnormality detection over a wide temperature range. For example, it is desirable to make the lower limit of the temperature range lower than 0 ° C. as rain conditions. For example, under rain conditions, the lower limit of the temperature range is set to −5 ° C. as the outside air temperature that changes from rain to snow. Furthermore, as a range of the outside air temperature in which the rainfall and the blowing temperature are less than or equal to zero degrees, the condition during heating operation can be set to -5 ° C to 5 ° C, and the condition during cooling operation can be set to -5 ° C to 0 ° C.

  When the refrigerant is slightly flammable or flammable, if the heat exchanger or piping is damaged due to an abnormality in the propeller fan 100 and the refrigerant leaks, there is a possibility of ignition. The refrigerant having slight flammability is, for example, R32. By detecting an abnormality of the propeller fan 100 before the propeller fan 100 falls off, it is possible to prevent ignition.

  The threshold value changing unit 12 of the present embodiment changes the threshold value in a direction in which no abnormality is detected during a heating operation only for a certain period before and after switching to the defrosting mode. If the heating operation is continued, frost is accumulated in the heat exchanger 301, so the main control device 500 performs the defrosting operation at an appropriate timing. However, since the heating operation is interrupted from the user's point of view, it is desirable to minimize the number of defrosting times. Therefore, for example, the defrost state of the heat exchanger 301 is estimated based on the evaporation temperature of the refrigerant, the accumulated operation time from the previous defrost, and the like, and only when the defrost amount is determined to be large The method of entering the mode is taken. That is, immediately before switching to the defrosting mode, there is a situation in which fluid imbalance due to frost formation is likely to occur, and as a result, the pulsation of the output current tends to increase due to the pulsation of torque. In such a situation, although the propeller fan 100 is normal, there is a possibility that it is erroneously determined to be abnormal, so it is desirable to change the threshold for determining abnormality so that it is not detected as abnormal.

  Further, although the heat exchanger 301 is defrosted immediately after defrosting, fluid imbalance is unlikely to occur. However, since the propeller fan 100 is stopped during the defrosting, icing progresses around the propeller fan 100, There are cases where the propeller fan 100 comes into contact with ice blocks. When the defrosting is completed and the operation is resumed in such a state, vibration is generated around the propeller fan 100 due to contact with ice for a while, and pulsation is generated in the output current. Therefore, the threshold value changing unit 12 of the present embodiment has a predetermined first time length before switching to the defrosting mode and a predetermined second time length after switching from the defrosting mode to the normal operation during the heating operation. In the period, the threshold value is changed in a direction in which no abnormality is detected, and erroneous determination is prevented. Thereby, the erroneous detection of the abnormality of the propeller fan 100 can be prevented before and after the defrosting.

  FIG. 6 shows the configuration of the outdoor unit 20 of the third embodiment.

  The outdoor unit 20 of the present embodiment is provided with a raindrop detection sensor 107 in addition to the configuration of the outdoor unit 20 of the first embodiment. As described above, there is a highest risk of damage to the propeller fan 100 during winter rain, but it may not be possible to determine whether it is raining or not only by the outside air temperature. Depending on the region, especially on the Pacific Ocean side, there are few rainy days in winter, so it is desirable to provide the raindrop detection sensor 107 in order to determine the rain conditions more accurately. In recent years, raindrop detection sensors have been widely used for automobile automatic wiper functions and the like, and cost reduction is progressing. This raindrop detection sensor detects the amount of rain from the vibration at the time of raindrop collision or the difference in reflectance at the time of raindrop adhesion.

  In the case where the air conditioner includes a plurality of outdoor units, the module configuration is mainstream in recent up-out type outdoor units, and therefore the raindrop detection sensors 107 do not have to be provided in all the individual outdoor units. A raindrop detection sensor 107 is provided in a specific outdoor unit, and a plurality of outdoor units can share the rain state via a communication line connecting each individual. That is, it is only necessary to provide the raindrop detection sensor 107 only in the main unit outdoor unit among the plurality of outdoor units, and the cost is not increased. By using the raindrop detection sensor 107 in this way, it becomes possible to operate without reducing the abnormality detection sensitivity in a wide temperature range while preventing erroneous determination during freezing.

  The threshold value changing unit 12 of the present embodiment corrects the threshold value of the abnormality determining unit 7 according to the installation state of the product. Although the amount of pulsation used for abnormality detection correlates with the amount of vibration generated, the amount of vibration generated differs even with the same unbalance amount in various product series of air conditioners. Moreover, even if it is the same product, depending on the user, there are various installation forms such as installing the outdoor unit 20 on a vibration isolation frame. That is, when a common threshold is used, depending on the model and installation state, the abnormality detection sensitivity may be reduced when vibration is reduced, and erroneous determination may be caused when vibration is increased. Therefore, the threshold value changing unit 12 according to the present embodiment performs threshold value correction processing for correcting the threshold value for each installation site.

  The threshold value changing unit 12 executes a threshold value correction mode that is an operation mode for correcting the threshold value in advance before entering normal operation, and automatically corrects the threshold value for each individual outdoor unit 20. Since the threshold correction process does not need to be performed many times, for example, the threshold correction process may be incorporated into a test operation mode after product installation, or the threshold correction process may be performed only at the first initial start after the supply power is turned on.

  FIG. 7 shows threshold correction processing according to the fourth embodiment.

  When the operation of the air conditioner is started, the threshold value changing unit 12 determines whether or not the current operation start is the initial start time of the test operation (S110).

  When it is determined that it is the initial start time of the trial operation (S110: yes), the threshold value changing unit 12 executes the threshold value correction mode S120. In the threshold correction mode, the threshold changing unit 12 drives the propeller fan 100 at a predetermined rotation speed (S130), and acquires the pulsation amount from the pulsation component extraction unit 6 (S140). Thereafter, the threshold value changing unit 12 determines a correction value for the threshold value based on the ratio or difference between the preset standard value of the pulsation amount and the acquired pulsation amount (S150), and is set in advance. The threshold value is corrected based on the threshold value and the correction value (S160). Here, the threshold value changing unit 12 may multiply the threshold value by a correction value, or may add a correction value to the threshold value. Thereafter, the threshold value changing unit 12 executes a normal operation mode S170 in which normal operation is performed using the corrected threshold value.

  When it is determined that it is not at the initial start of the trial operation (S110: no), the threshold value changing unit 12 executes a normal operation mode S170 in which normal operation is performed using the threshold value set in the threshold value changing unit 12.

  The above is the threshold correction processing. By adopting such a configuration, it is possible to provide an outdoor unit for an air conditioner that can absorb a wide variety of models and installation forms and can stably detect an abnormality. In this embodiment, the correction value is obtained with one type of rotation speed. However, the threshold value changing unit 12 stores a rotation speed table indicating a plurality of rotation speeds set in advance, and each of the plurality of rotation speeds is stored. A threshold value corresponding to may be obtained. In this case, the threshold value changing unit 12 changes the threshold value according to the rotation speed of the fan motor 101. Thereby, the accuracy of abnormality detection can be improved. In this case, the pulsation component extraction unit 6 may cause the frequency band of the bandpass filter to follow the rotation speed. The threshold value changing unit 12 may store relationship information indicating the relationship between the rotation speed of the fan motor 101 and the threshold value, and may calculate the threshold value from the rotation speed of the fan motor 101 and the relationship information.

  The threshold value changing unit 12 according to this embodiment is configured such that the outdoor unit 20 is connected to a remote monitoring device or a centralized management device (hereinafter referred to as a remote monitoring system 25), and the operation during normal operation stored in the remote monitoring system 25 is performed. Based on the information, the threshold for detecting an abnormality is periodically corrected.

  FIG. 8 shows the configuration of the air conditioner of the fifth embodiment.

  The air conditioner includes a plurality of outdoor units 20, a plurality of indoor units 21, and a remote monitoring system 25. The plurality of outdoor units 20 and the plurality of indoor units 21 are connected by a pipe 22 for flowing a refrigerant, and are connected by a communication line 23 for transmitting information. The remote monitoring system 25 is connected to the plurality of outdoor units 20 via the communication line 24.

  As described above, the pulsation amount varies depending on various models and installation conditions, but there are cases where the pulsation amount varies even with the same model and the same installation conditions. For example, a case where an obstacle (such as a wall) is installed in the vicinity of the suction port 199 of the heat exchanger 301 of the outdoor unit 20 later, or deterioration (corrosion, dust, oil, etc.) of the heat exchanger 301 is observed. This is the case where clogging occurs. Thereby, the load of the propeller fan 100 changes. In order to deal with such a case, operation information including the amount of pulsation during normal operation is accumulated, a threshold is determined based on the accumulated information, and the average pulsation amount in the normal state is It is desirable to determine that an abnormality occurs when it deviates. The accumulated operation information may include the number of rotations or the outside air temperature. However, in order to store data in each outdoor unit 20, an expensive arithmetic device and storage device are required. Therefore, by storing data using the remote monitoring system 25, it is not necessary to provide an expensive device for each outdoor unit 20.

  If the current values of the fan motor 101 and the compressor 300 are accumulated in the remote monitoring system 25 and transmitted to the remote monitoring system 25 in order to use them for abnormality diagnosis and prediction, an enormous communication load is applied. It is not realistic. In this embodiment, the extracted pulsation amount is communicated at regular intervals, so the communication load has little effect. Further, the remote monitoring system 25 can record the time change of the pulsation amount over a long period (several months to several years or more). The threshold value changing unit 12 receives an average pulsation amount in a normal state from the remote monitoring system 25, and changes the threshold value based on the received pulsation amount. Thereby, since the change which progresses very slowly, such as deterioration of the propeller fan 100, the fan motor 101, the heat exchanger 301, etc., can be caught, it can utilize also for a maintenance, preventive maintenance, etc. By adopting such a configuration, it is possible to provide an outdoor unit for an air conditioner that can absorb a wide variety of models and installation forms and can stably detect an abnormality. The remote monitoring system 25 may determine a threshold based on the accumulated information and transmit it to the threshold changing unit 12, or the threshold changing unit 12 receives information based on the accumulated information from the remote monitoring system 25, The threshold may be determined based on the received information.

  Some of the plurality of embodiments described above may be combined.

  Terms used in the air conditioner of one embodiment of the present invention will be described. The detection unit corresponds to the current detection unit 4, the phase detection unit 5, and the like. The determination unit corresponds to the abnormality determination unit 7, the threshold value changing unit 12, and the like. The management device corresponds to the remote monitoring system 25 and the like.

  The present invention is not limited to the above embodiments, and can be modified in various other forms without departing from the spirit of the present invention.

2: Housing 4: Current detection unit 5: Phase detection unit 6: Pulsation component extraction unit 7: Abnormality determination unit 10: Blower 12: Threshold change unit 15: Power conversion unit 20: Outdoor unit 21: Indoor unit 25: Remote Monitoring system 100: Propeller fan 101: Fan motor 104: Temperature sensor 105: Pressure sensor 106: Fan controller 107: Raindrop detection sensor 500: Main controller

Claims (10)

Indoor unit,
An outdoor unit connected to the indoor unit through a pipe for flowing refrigerant;
With
The outdoor unit is
An outdoor heat exchanger,
A temperature sensor for detecting the outside air temperature;
A propeller fan that blows air to the outdoor heat exchanger;
A fan motor for driving the propeller fan;
A power converter for controlling power to the fan motor;
A detection unit for detecting an output current from the power conversion unit to the fan motor;
A pulsation component extraction unit for extracting a pulsation component from the output current;
By calculating a pulsation amount indicating the magnitude of the pulsation component and comparing the pulsation amount with a threshold value of the pulsation amount, it is determined whether or not an abnormality of the propeller fan has occurred, and the outside air temperature is A determination unit that changes the threshold based on;
including,
Air conditioner. The determination unit increases the threshold when the outside air temperature is within a temperature range defined by a lower limit lower than 0 ° C. and an upper limit higher than 0 ° C.,
The air conditioner according to claim 1. During the heating operation, the determination unit increases the threshold value during a predetermined first time length period until the start of the defrosting operation and a predetermined second time length period from the end of the defrosting operation. ,
The air conditioner according to claim 2. The outdoor unit further includes a raindrop detection sensor,
When raindrops are detected by the raindrop detection sensor and the outside air temperature is within the temperature range, the determination unit increases the threshold.
The air conditioner according to claim 2 or 3. The determination unit drives the fan motor at a predetermined rotation number, and determines the threshold based on a comparison between the pulsation amount and a preset standard value of the pulsation amount.
The air conditioner as described in any one of Claims 1-4. The determination unit changes the threshold according to the number of rotations of the fan motor.
The air conditioner according to claim 5. The outdoor unit further includes a main control device that controls a refrigeration cycle in the outdoor unit and the indoor unit,
When determining that the abnormality of the propeller fan has occurred, the determination unit sends information indicating the abnormality to the main control device,
The main control device stops the operation of the refrigeration cycle according to the information indicating the abnormality.
The air conditioner as described in any one of Claims 1-6. The outdoor unit is connected to a management device via a communication line, and transmits an operation status to the management device.
The management device accumulates the operating status,
The determination unit changes the threshold based on the accumulated driving situation.
The air conditioner as described in any one of Claims 1-7. The refrigerant has slight flammability or flammability,
The air conditioner as described in any one of Claims 1-8. During heating operation, the lower limit is −5 ° C., and the upper limit is 5 ° C.
The air conditioner according to claim 2.

Images