JP2016180582A - Refrigerant flow condition detection device of refrigeration cycle and control device of electric compressor for refrigeration cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently cool a power switching element by a suction refrigerant even if a suction amount of the refrigerant is small.SOLUTION: A temperature of a partitioning wall 11c with which a power switching element 9b is kept into contact, is regarded as a temperature threshold value in a normal time of the power switching element 9b corresponding to output power of an invertor circuit 9 and a rotational frequency of an electric motor 5, in a case where the power switching element 9b generating heat according to output power from the invertor circuit 9 to the electric motor 5 is cooled by a refrigerant flowing in a suction chamber 7b of a housing 7 with a flow rate according to a rotational frequency of the electric motor 5, when the refrigerant of a refrigeration cycle 13 is circulated with a normal amount. In a case where a temperature of the partitioning wall 11c detected by a wall temperature sensor 9e as the power switching element 9b is over the temperature threshold value defined by a temperature table corresponding to a detection temperature of a substrate temperature sensor 9f, leakage of the refrigerant of the refrigeration cycle 13 is determined, and an operation of an electric compressor 1 is stopped.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control device for an electric compressor for a refrigeration cycle that compresses a refrigerant, and more particularly to a detection device that detects a state of the flow rate of the refrigerant in the refrigeration cycle.

  The compressor used in the refrigeration cycle sucks low-temperature and low-pressure refrigerant and discharges the refrigerant that has been compressed to high temperature and pressure. Among compressors, there is an electric compressor having an electric motor as a power source of a refrigerant compression mechanism, and the electric compressor is provided with a drive circuit that converts DC power from a power source into AC by an inverter and supplies the AC to the electric motor. .

  The inverter includes power switching elements such as IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal Oxide Semiconductor Field Effect Transistors).

  The power switching element generates heat due to a loss during switching (switching loss). If the temperature of the power switching element rises above the heat resistance temperature due to this heat generation, the power switching element is damaged.

  Therefore, in order to limit or stop the operation of the electric compressor when the temperature of the power switching element exceeds the threshold, the temperature of the power switching element is estimated from the temperature detected by the sensor on the mounting board of the power switching element. Monitoring has been conventionally proposed (for example, Patent Document 1).

  Further, in the electric compressor described above, the power switching element is brought into contact with the partition wall exposed in the space for accommodating the compression mechanism and the electric motor, and the power switching element is cooled by the refrigerant flowing in the space for accommodating the compression mechanism and the electric motor. It is often performed (for example, Patent Document 2).

International Publication No. 2012/042899 JP 2005-54716 A

  Therefore, when monitoring the temperature of the power switching element that is cooled by the refrigerant, the degree of cooling of the power switching element by the refrigerant varies depending on the amount of refrigerant circulating in the refrigeration cycle. It is important to monitor the temperature of the switching element and control the operation of the electric compressor.

  The present invention has been made in view of the above circumstances, and an object of the present invention is for a refrigeration cycle according to the state of the refrigerant flow rate of the refrigeration cycle that affects the degree of cooling of the power switching element of the electric compressor for the refrigeration cycle. Another object of the present invention is to provide a control device that can appropriately control the operation of the electric compressor, and a detection device that can detect the flow rate state of the refrigerant flowing through the refrigeration cycle, which is useful for that purpose.

In order to achieve the above object, a refrigerant flow state detection apparatus for a refrigeration cycle according to a first aspect of the present invention includes:
In an apparatus for detecting a refrigerant flow state in a refrigeration cycle including an electric compressor that drives a refrigerant compression mechanism with an electric motor,
Element temperature detecting means for detecting the temperature of the electronic component of the drive circuit that is in contact with a partition wall that partitions the main body housing in which the compression mechanism and the electric motor are housed from the circuit housing in which the drive circuit of the electric motor is housed. When,
Temperature table storage means for storing a temperature table in which a temperature threshold value of the electronic component corresponding to the output power from the drive circuit to the electric motor and the rotation speed of the electric motor is set;
The state of the refrigerant flow rate in the refrigeration cycle is detected by comparing the temperature threshold on the temperature table corresponding to the output power and the rotation speed of the electric motor with the temperature detected by the element temperature detecting means. Detection means;
Is provided.

In addition, the control device for the electric compressor for the refrigeration cycle according to the second aspect of the present invention,
In an apparatus for controlling the operation of an electric compressor for a refrigeration cycle in which a refrigerant compression mechanism is driven by an electric motor,
A refrigerant flow state detection device for a refrigeration cycle according to the first aspect of the present invention;
Stop control means for stopping the operation of the electric compressor based on the refrigerant flow state in the refrigeration cycle detected by the detection means of the refrigerant flow state detection apparatus of the refrigeration cycle;
Is provided.

Furthermore, the control device for the electric compressor for the refrigeration cycle according to the third aspect of the present invention provides:
In an apparatus for controlling the operation of an electric compressor for a refrigeration cycle in which a refrigerant compression mechanism is driven by an electric motor,
Element temperature detection means for detecting the temperature of the electronic component of the drive circuit of the electric motor;
As a refrigerant flow state in the refrigeration cycle, refrigerant leakage detection means for detecting refrigerant leakage in the refrigeration cycle,
When the temperature detected by the element temperature detecting means is equal to or higher than the upper limit temperature that guarantees normal operation of the electronic component, the operation of the electric compressor is stopped, and the refrigerant leak detecting means is configured to leak refrigerant in the refrigeration cycle. Stop control means for stopping the operation of the electric compressor, even if the detected temperature of the element temperature detection means is less than the upper limit temperature,
Is provided.

  According to the present invention, it is possible to appropriately control the operation of the electric compressor for the refrigeration cycle in accordance with the state of the refrigerant flow rate of the refrigeration cycle that affects the degree of cooling of the power switching element of the electric compressor for the refrigeration cycle. The state of the flow rate of the refrigerant flowing through the refrigeration cycle can be detected.

1 is a partially cutaway front view of an electric compressor according to a first embodiment of the present invention. It is a principal part expanded sectional view which shows the circuit accommodating part of FIG. It is the II arrow directional view of the circuit accommodating part which removed the cap of FIG. (A) is a graph showing the correlation between the output power to the electric motor of the inverter circuit of FIG. 1 and the rotational speed of the electric motor, and (b) is the temperature of the power switching element of the inverter circuit of FIG. 1 and the rotational speed of the electric motor. It is a graph which shows correlation with. It is explanatory drawing which shows the temperature table memorize | stored in the memory of the controller according to the atmospheric temperature zone of the circuit accommodating part of FIG. It is explanatory drawing which shows the temperature table memorize | stored in the memory of the controller according to the atmospheric temperature zone of the circuit accommodating part of FIG. It is explanatory drawing which shows the temperature table memorize | stored in the memory of the controller according to the atmospheric temperature zone of the circuit accommodating part of FIG. It is explanatory drawing which shows the temperature table memorize | stored in the memory of the controller according to the atmospheric temperature zone of the circuit accommodating part of FIG. It is a flowchart which shows the procedure of the detection of the refrigerant | coolant leak of the refrigerating cycle and the operation control of an electric compressor which the controller of FIG. 2 performs using the temperature table memorize | stored in memory. It is a flowchart which shows the procedure of the prediction of the time when the refrigerant | coolant of the refrigerating cycle which the controller of the electric compressor which concerns on 2nd Embodiment of this invention will be in a leak state performed using the temperature table memorize | stored in memory, and the operation control of an electric compressor. . It is a flowchart which shows the detailed procedure regarding prediction of the refrigerant | coolant leakage state arrival time of FIG. It is a graph which shows the time-dependent change of the rotation speed of the electric motor memorize | stored in the non-volatile memory of the electric compressor which concerns on 2nd Embodiment of this invention, and the output electric power with respect to an electric motor from an inverter circuit about a certain time zone of a day. . The ambient temperature of the circuit housing portion stored in the nonvolatile memory of the electric compressor according to the second embodiment of the present invention, the temperature of the power switching element of the inverter circuit, the temperature of the power switching element, and the rotation speed of the electric motor 13 is a graph showing the change over time with the temperature threshold value defined in the temperature table corresponding to the ambient temperature of the circuit housing portion stored in the memory of the controller corresponding to the time zone in the same time zone as the graph of FIG. It is a graph which shows the time change of the temperature margin which is a temperature difference of the temperature of a power switching element shown in the graph of FIG. 13, and a temperature threshold value about the same time slot | zone as the graph of FIG.12 and FIG.13. The distribution of the temperature and temperature threshold of the power switching element shown in the graph of FIG. 13 for the number of days stored in the memory of the controller, the temperature margin shown in the graph of FIG. 14, and the average value of the temperature margin, It is a graph shown according to the rotation speed of an electric motor. It is a graph which shows the transition of the average value of the temperature margin shown in the graph of FIG. 15 about the number of days memorize | stored in the memory of the controller, and the prediction of a future change according to the rotation speed of an electric motor. It is a flowchart which shows the procedure of the operation control of the electric compressor based on the refrigerant | coolant detection of the refrigerant | coolant of the refrigerating cycle which the controller of the electric compressor which concerns on 3rd Embodiment of this invention performs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front sectional view showing an electric compressor according to a first embodiment of the present invention.

  The electric compressor 1 according to the first embodiment shown in FIG. 1 includes a compression mechanism 3 and an electric motor 5, a housing 7 (corresponding to a main body housing in claims) in which these are housed, and a drive circuit for the electric motor 5. It has an inverter case 11 in which an inverter circuit 9 (corresponding to a drive circuit in claims) is accommodated. The refrigerant compressed by the electric compressor 1 is discharged from the electric compressor 1, circulates through the refrigeration cycle 13, and is sucked back to the electric compressor 1.

  The compression mechanism 3 includes a pair of side blocks 3a and 3b, a cylinder block 3c sandwiched between them, and a columnar rotor 3e accommodated in an elliptical cylinder chamber 3d formed inside the cylinder block 3c. doing. A plurality of vanes (not shown) are supported on the peripheral surface of the rotor 3e so as to appear and retract.

  When the rotor 3e is rotated in the cylinder chamber 3d by the electric motor 5, each vane of the rotor 3e appears and disappears following the inner peripheral surface of the cylinder chamber 3d, and the two vanes adjacent to the rotor 3e and the cylinder chamber 3d The volume of the configured space changes. Then, while the space volume increases, low-pressure refrigerant is sucked through a suction port (not shown) formed in the side block 3a, and the sucked refrigerant is compressed as the space volume decreases. The compressed high-pressure refrigerant is discharged from a discharge port (not shown) formed in the side block 3b.

  The housing 7 has a cylindrical shape with one end closed. The housing 7 accommodates the compression mechanism 3, and the accommodated compression mechanism 3 exposes the inside of the housing 7 to the closed discharge chamber 7 a on the closed side where the side block 3 b is exposed and the side block 3 a. It is partitioned off from the suction chamber 7b on the opening side. An electric motor 5 is accommodated in the suction chamber 7 b, and the suction chamber 7 b is sealed by an inverter case 11 attached to the opening 7 c of the housing 7.

  The inverter case 11 is disposed outside the suction chamber 7b (housing 7), which closes the suction chamber 7b by closing the opening 7c of the housing 7 and seals the suction chamber 7b, and accommodates the inverter circuit 9. The circuit accommodating part 11b (equivalent to the circuit housing in a claim) is divided and comprised by the partition wall 11c.

  The circuit housing portion 11b has a bottomed cylindrical shape with the partition wall 11c as the bottom, as shown in the enlarged cross-sectional view of the main part of FIG. A plurality of mounting bosses 11d are erected on the peripheral edge of the partition wall 11c toward the circuit housing portion 11b, and the circuit board 9a of the inverter circuit 9 is screwed to the tip of each mounting boss 11d. The circuit housing portion 11b is sealed by a cap 11g attached to the opening 11f.

  As shown in FIG. 3, which is a view taken along the line I-I of FIG. 2, the circuit board 9 a has power switching elements 9 b such as IGBTs and MOSFETs constituting the inverter circuit 9 and power switching elements 9 b turned on and off. A controller 9c for controlling the operation of the inverter circuit 9 is mounted. The controller 9c is constituted by, for example, a microcomputer incorporating a nonvolatile memory 9d (corresponding to the temperature table storage means in the claims).

  As shown in FIG. 2, the casing of the power switching element 9b is brought into surface contact with a thick contact portion 11e formed on the surface of the partition wall 11c on the circuit accommodating portion 11b side in order to improve heat radiation efficiency. ing.

  As shown in FIG. 3, the circuit board 9a includes a wall temperature sensor 9e that detects the temperature of the partition wall 11c as the temperature of the power switching element 9b in the vicinity of the contact portion 11e (element temperature detection in claims). And a substrate temperature sensor 9f (corresponding to the ambient temperature detection means in the claims) for detecting the temperature of the circuit board 9a as the ambient temperature of the circuit housing portion 11b.

  In the electric compressor 1 of the present embodiment having the above-described configuration, the amount of heat generated by the power switching element 9b increases as the output power from the power switching element 9b of the inverter circuit 9 to the electric motor 5 increases. It becomes high temperature. Along with this, as the output power from the power switching element 9b to the electric motor 5 increases, the rotational speed of the electric motor 5 of the inverter circuit 9 increases as shown in the graph of FIG.

  If the rotation speed of the electric motor 5 increases, the amount of refrigerant circulating in the refrigeration cycle 13 increases. Therefore, if the refrigeration load in the refrigeration cycle 13 is the same as before the increase in the rotation speed of the electric motor 5, the contact portion 11e The cooling efficiency by which the power switching element 9b having the casing in surface contact is cooled by the refrigerant increases, and the amount of heat removed from the power switching element 9b by the refrigerant increases.

  Therefore, between the rotation speed of the electric motor 5 and the temperature of the power switching element 9b (IPM), as shown in the graph of FIG. 4B, the power switching element increases as the rotation speed of the electric motor 5 increases. There is a negative correlation that the temperature of 9b is lowered.

  Therefore, a temperature table in which the temperature of the power switching element 9b corresponding to the output power from the power switching element 9b of the inverter circuit 9 to the electric motor 5 and the rotation speed of the electric motor 5 is stored in the nonvolatile memory 9d of the controller 9c. As shown in the explanatory diagrams of FIG. 5 to FIG. 8, the contents are stored for each atmosphere temperature zone of the circuit housing portion 11b.

  In each temperature table, when the amount of refrigerant in the refrigeration cycle is normal, the number of rotations of the electric motor 5 driven by the electric power switching element 9b that generates heat according to the electric power output to the electric motor 5 is shown. The temperature after being cooled by the refrigerant that has passed through the suction chamber 7b of the housing 7 at a flow rate according to the above is defined as the upper limit value that is allowed as the temperature of the power switching element 9b, that is, the temperature threshold value.

  Therefore, the controller 9c corresponds to the temperature detected by the wall temperature sensor 9e as the temperature of the power switching element 9b and the output power from the power switching element 9b to the electric motor 5 and the rotation speed of the electric motor 5 at that time. When the temperature threshold value on the temperature table is exceeded, it is detected that the refrigerant in the refrigeration cycle 13 has decreased due to leakage.

  The controller 9c sets the temperature threshold value defined in the temperature table of FIG. 5 when the temperature of the circuit board 9a detected by the board temperature sensor 9f as the ambient temperature of the circuit housing portion 11b is −40 to 0 deg. Used to detect refrigerant leakage in the refrigeration cycle 13. Further, the controller 9c uses the temperature threshold defined in the temperature table of FIG. 6 for detecting refrigerant leakage in the refrigeration cycle 13 when the temperature of the circuit board 9a is 0 to 40 deg.

  Similarly, the controller 9c sets the temperature threshold defined in the temperature table of FIG. 7 when the temperature of the circuit board 9a detected by the board temperature sensor 9f as the ambient temperature of the circuit housing portion 11b is 41 to 80 degrees. Used to detect refrigerant leakage in the refrigeration cycle 13. Further, the controller 9c uses the temperature threshold defined in the temperature table of FIG. 8 to detect refrigerant leakage in the refrigeration cycle 13 when the temperature of the circuit board 9a is 81 to 120 deg.

  The contents of the temperature threshold value defined in the temperature table of FIG. 5 to FIG. 8 described above can be obtained by experiments and determined in advance. The temperature threshold value when the rotation speed of the electric motor 5 is zero indicates the temperature threshold value when the electric motor 5 is stopped, that is, before the electric compressor 1 is started.

  Next, the procedure in which the controller 9c detects refrigerant leakage in the refrigeration cycle 13 using the temperature tables of FIGS. 5 to 8 and controls the operation of the electric compressor 1 will be described with reference to the flowchart of FIG. Note that the controller 9c repeatedly executes the procedure of the flowchart of FIG. 9 at regular intervals.

  First, the controller 9c acquires the detected temperatures of the wall temperature sensor 9e and the substrate temperature sensor 9f as the temperatures of the power switching element 9b and the circuit housing portion 11b (step S1), and corresponds to the detected temperature of the substrate temperature sensor 9f. A temperature table is selected from the temperature tables shown in FIGS. 5 to 8 (step S3). Then, the temperature threshold value corresponding to the output power from the power switching element 9b of the inverter circuit 9 to the electric motor 5 and the rotational speed of the electric motor 5 defined in the selected temperature table is specified (step S5). .

  Here, the output power from the power switching element 9b to the electric motor 5 and the rotation speed of the electric motor 5 may be specified from a control command value when the controller 9c turns on and off the power switching element 9b. Further, for example, the output power from the power switching element 9b to the electric motor 5 and the rotation speed of the electric motor 5 may be specified by actual measurement, for example, by actually detecting the rotation speed of the electric motor 5 using a rotation sensor (not shown). Good.

  Then, the controller 9c checks whether or not the detected temperature of the wall temperature sensor 9e acquired in step S1 exceeds the temperature threshold value specified in step S3 (step S7), and if not (step S7) NO), and a series of processes are terminated assuming that no leakage is detected in the refrigerant of the refrigeration cycle 13.

  On the other hand, if the detected temperature of the wall temperature sensor 9e exceeds the temperature threshold value (YES in step S7), the controller 9c determines that the refrigerant in the refrigeration cycle 13 has been leaked, and the controller 9c After stopping the operation (step S9), the series of processes is terminated.

  As is clear from the above description, in the electric compressor 1 of the first embodiment, the controller 9c corresponds to the detection means and the stop control means in the claims.

  As described above, according to the electric compressor 1 of the first embodiment, when the refrigerant in the refrigeration cycle 13 circulates in a normal amount, switching for electric power that generates heat according to the output power from the inverter circuit 9 to the electric motor 5 is performed. When the element 9b is cooled by the refrigerant flowing through the suction chamber 7b of the housing 7 at a flow rate corresponding to the number of revolutions of the electric motor 5, the temperature of the power switching element 9b (the partition wall 11c against which the power switch element 9b is in contact) The temperature threshold value in the normal state of the power switching element 9b corresponding to the output power of the inverter circuit 9 and the rotation speed of the electric motor 5 was used.

  And the temperature threshold value mentioned above was set as a temperature table according to the temperature zone of the circuit board 9a which the board | substrate temperature sensor 9f detects as atmospheric temperature of the circuit accommodating part 11b, and was memorize | stored in the non-volatile memory 9d of the controller 9c.

  Further, the temperature of the partition wall 11c detected by the wall temperature sensor 9e as the temperature of the power switching element 9b is defined by the temperature table corresponding to the detected temperature of the substrate temperature sensor 9f in the temperature tables of FIGS. When the temperature threshold is exceeded, the detected temperature of the wall temperature sensor 9e (the temperature of the power switching element 9b) has not reached the heat-resistant temperature (upper limit temperature) that guarantees the normal operation of the power switching element 9b. Also, the operation of the electric compressor 1 is stopped because the refrigerant in the refrigeration cycle 13 is leaking.

  For this reason, it is possible to detect the refrigerant leakage of the refrigeration cycle 13 that affects the degree to which the power switching element 9b of the electric compressor 1 for the refrigeration cycle 13 is cooled, and using the detection result, the electric compressor The operation of 1 can be appropriately controlled.

  That is, in the electric compressor 1 of the present invention according to the first embodiment described above, the electronic component (the power switching element 9b) of the drive circuit (inverter circuit 9) of the electric motor 5 is connected to the drive circuit ( The main body housing which generates heat with the amount of heat corresponding to the output power of the inverter circuit 9) and is partitioned from the circuit housing (circuit housing portion 11b) by the partition wall 11c with which the electronic component (power switching element 9b) is in contact. The electronic component (power switching element 9b) is cooled by the refrigerant flowing through (housing 7), and the amount of heat corresponding to the flow rate is removed from the electronic component (power switching element 9b).

  Therefore, when the refrigerant circulates through the refrigeration cycle 13 in a normal amount, the electronic components of the drive circuit that generate heat in accordance with the output power from the drive circuit to the electric motor have a flow rate corresponding to the number of revolutions of the electric motor. The temperature when cooled by the refrigerant flowing through the housing is set in the temperature table as a normal temperature threshold of the electronic component corresponding to the output power of the drive circuit and the rotation speed of the electric motor, and stored in the storage means Keep it. This temperature threshold value can be determined in advance by experiments or the like.

  On the other hand, when the amount of refrigerant circulating through the refrigeration cycle 13 is reduced due to leakage, the amount of refrigerant flowing through the main body housing (housing 7) is reduced even if the rotation speed of the electric motor 5 is the same, and the electronic component (electric power) by the refrigerant The cooling efficiency of the switching element 9b) is reduced. Then, the temperature of the electronic component (power switching element 9b) detected by the element temperature detection means (wall temperature sensor 9e) is stored in the storage means (nonvolatile) when the output power to the electric motor 5 and the rotation speed of the electric motor 5 are the same. It exceeds the normal temperature threshold set in the temperature table stored in the memory 9d).

  Therefore, the detection means (controller 9c) detects the temperature of the electronic component (power switching element 9b) detected by the element temperature detection means (wall temperature sensor 9e) and the output power from the drive circuit (inverter circuit 9) to the electric motor 5. And the temperature threshold value on the temperature table corresponding to the rotation speed of the electric motor 5 are compared. When the temperature of the electronic component (power switching element 9b) detected by the element temperature detecting means (wall temperature sensor 9e) is higher than the temperature threshold, the refrigerant in the refrigeration cycle 13 is leaking. Is detected.

  For this reason, it is possible to detect the refrigerant leakage of the refrigeration cycle 13 that affects the degree to which the electronic component (the power switching element 9b) of the electric compressor 1 for the refrigeration cycle 13 is cooled.

  Further, according to the electric compressor 1 of the present invention related to the first embodiment described above, the refrigeration cycle is detected using the detection result of the refrigerant flow state of the refrigeration cycle 13 by the refrigerant flow state detection device of the refrigeration cycle 13. The operation of the electric compressor 1 for 13 can be appropriately controlled.

  In the electric compressor 1 of the first embodiment described above, the temperature is defined by the temperature table corresponding to the temperature of the partition wall 11c detected by the wall temperature sensor 9e as the temperature of the power switching element 9b and the detected temperature of the substrate temperature sensor 9f. The operation of the electric compressor 1 is stopped when it is detected that the refrigerant in the refrigeration cycle 13 is leaked by comparison with the temperature threshold value.

  However, instead of detecting that the refrigerant in the refrigeration cycle 13 is leaking, the time when the refrigerant in the refrigeration cycle 13 is leaked is predicted in advance, and the operation of the electric compressor 1 is stopped when that time arrives. You may make it make it.

  Hereinafter, an electric compressor according to a second embodiment of the present invention configured as described above will be described with reference to FIGS. 10 to 16.

  The electric compressor according to the second embodiment has the same configuration as the electric compressor 1 of the first embodiment shown in FIGS. 1 to 3. However, part of the procedure for controlling the operation of the electric compressor 1 performed by the controller 9c shown in FIG. 2 is different from the procedure performed by the controller 9c of the first embodiment shown in the flowchart of FIG.

  Therefore, a procedure for the controller 9c of the electric compressor 1 according to the second embodiment to predict the time when the refrigerant of the refrigeration cycle 13 enters a leak state using the temperature tables of FIGS. 5 to 8 and to control the operation of the electric compressor 1. Will be described with reference to the flowchart of FIG. In the following description, the description of the same procedure as that of the flowchart of FIG. 9 performed by the controller 9c of the first embodiment will be simplified, and a procedure different from the procedure of the flowchart of FIG. 9 will be described exclusively. Also in the electric compressor 1 according to the second embodiment, the controller 9c repeatedly executes the procedure of the flowchart of FIG. 10 at regular intervals.

  Then, the controller 9c of the electric compressor 1 according to the second embodiment, as shown in FIG. 10, before the step S1 of the flowchart of FIG. 9, has a margin zero where the temperature margin predicted in the past in the procedure described later becomes zero. It is confirmed whether or not the time has come (step S0).

  Here, the temperature margin refers to the detected temperature of the wall temperature sensor 9e acquired by the controller 9c in the past as the temperature of the power switching element 9b in the procedure of step S1, and the controller 9c in the procedures of steps S3 and S5 following that. It is the temperature difference from the specified temperature threshold.

  When the margin zero point predicted in the past has not yet arrived (NO in step S0), the process proceeds to step S1. On the other hand, when the margin zero point has arrived (YES in step S0), it is assumed that the point in the past when the refrigerant in the refrigeration cycle 13 is leaking has actually arrived, and the process proceeds to step S9, where the electric compressor 1 After stopping the operation, a series of processing is terminated.

  Moreover, the controller 9c of the electric compressor 1 according to the second embodiment has detected that the detected temperature of the wall temperature sensor 9e acquired in step S1 exceeds the temperature threshold specified in step S3 in step S7 of the flowchart of FIG. If not (NO), as shown in FIG. 10, the refrigerant leak state arrival time is predicted (step S11).

  In the prediction of the point of time when the refrigerant leakage state arrives in step S11, the controller 9c of the electric compressor 1 according to the second embodiment first sets the values of the parameters related to the electric compressor 1 together with time stamp information, as shown in the flowchart of FIG. It memorize | stores in the non-volatile memory 9d (step S111). This time stamp information can be information indicating an elapsed time from the start of rotation of the electric motor 5, for example. Of course, the current time may be used as time stamp information.

  Here, the parameters to be stored in the nonvolatile memory 9d are the detected temperatures of the wall temperature sensor 9e and the substrate temperature sensor 9f (the temperatures of the power switching element 9b and the circuit housing portion 11b) acquired in step S1 of the flowchart of FIG. The temperature threshold value specified in step S5, the rotational speed of the electric motor 5 used to specify the temperature threshold value, and the output power to the electric motor 5 from the power switching element 9b.

  Therefore, the controller 9c uses the parameters stored in the non-volatile memory 9d in time series, for example, as shown in the graph of FIG. 12, the rotation speed of the electric motor 5 or the like based on the elapsed time from the start of rotation of the electric motor 5. The transition of the output power from the power switching element 9b to the electric motor 5 can be analyzed.

  Similarly, the controller 9c determines the wall temperature sensor 9e and the substrate temperature from the parameters stored in the non-volatile memory 9d in time series, for example, the elapsed time from the start of rotation of the electric motor 5, as shown in the graph of FIG. It is possible to analyze the transition between the detected temperature of the sensor 9f (the temperature of the power switching element 9b and the circuit housing portion 11b) and the temperature threshold value.

  Next, as shown in FIG. 11, the controller 9c has the same time stamp as the detected temperature of the wall temperature sensor 9e (the temperature of the power switching element 9b) and the temperature threshold value stored in the nonvolatile memory 9d in step S111. Along with the information, the temperature difference between the temperature detected by the wall temperature sensor 9e and the temperature threshold, that is, the temperature margin, is stored in the nonvolatile memory 9d (step S112).

  Therefore, the controller 9c can analyze the transition of the temperature margin due to the elapsed time from the start of the rotation of the electric motor 5, as shown in the graph of FIG. 14, from the temperature margin stored in the nonvolatile memory 9d in time series. it can.

  Then, as shown in FIG. 11, the controller 9 c calculates the temperature margin distribution and its average value for each predetermined period (for example, every day) from the parameters stored in the nonvolatile memory 9 d in time series. It is acquired for each rotation number (in this embodiment, in increments of 500 RPM) (step S113).

  Here, as shown in the graph of FIG. 15, the distribution of the temperature margin for each predetermined period according to the number of rotations of the electric motor 5 is the temperature detected by the wall temperature sensor 9e stored in the nonvolatile memory 9d in time series ( It can be obtained from the distribution of the electric power switching element 9b) and the temperature threshold value for each predetermined period for each rotation speed of the electric motor 5.

  Further, the distribution of the detected temperature of the wall temperature sensor 9e (the temperature of the power switching element 9b) and the temperature threshold for each predetermined period for each number of rotations of the electric motor 5 is the number of rotations of the electric motor 5 shown in FIG. And the temperature detected by the wall temperature sensor 9e shown in FIG. 13 (the temperature of the power switching element 9b) and the temperature threshold are related to each other with the same elapsed time from the start of rotation of the electric motor 5, and the number of rotations. It can be obtained by classifying separately.

  Then, as shown in FIG. 11, the controller 9c determines that the temperature margin is zero from the transition of the average value of the temperature margin distribution for each predetermined period acquired for each rotation speed of the electric motor 5 in step S113. Are predicted for each rotation speed of the electric motor 5 (step S114).

  There is no particular limitation on the method of predicting the time point when the margin is zero. For example, for each rotation speed of the electric motor 5, a predetermined period from the past (for example, 500 days. At the maximum, after the time of the oldest parameter stored in the nonvolatile memory 9 d in step S 111) to the present The time point at which the margin becomes zero may be predicted from the transition of the average value of the temperature margin for each period.

  In that case, for example, a decreasing tendency (slope) of the average value of the temperature margin is estimated, and a future time point when the average value of the temperature margin becomes zero as shown by a broken line in the graph of FIG. 16 from the estimated decreasing tendency. Can be predicted for each rotation speed of the electric motor 5.

  Subsequently, as shown in FIG. 11, the controller 9c determines that the shortest time closest to the current time is the non-volatile memory 9d among the time points where the margin is zero predicted for each rotation speed of the electric motor 5 in step S114. It is confirmed whether or not it arrives before the previously predicted margin zero point (margin zero point used for the confirmation in step S0 in FIG. 10) stored in (step S115).

  If the shortest margin zero predicted in step S114 comes before the previously predicted margin zero stored in the nonvolatile memory 9d (YES in step S115), the nonvolatile memory The margin zero time predicted in the past stored in 9d is updated to the time when the shortest margin zero predicted in step S114 is reached (step S116), and the process proceeds to step S117 described later.

  On the other hand, when the shortest margin zero predicted in step S114 does not come before the previously predicted margin zero stored in the nonvolatile memory 9d (NO in step S115), step S116 is skipped and the process proceeds to step S117.

  In step S117, the controller 9c confirms whether the margin zero point stored in the nonvolatile memory 9d satisfies the warning condition. Here, the warning condition can be, for example, that the period from the present to the margin zero point stored in the nonvolatile memory 9d is equal to or less than the warning reference period (for example, 30 days).

  If the margin zero point stored in the nonvolatile memory 9d does not satisfy the warning condition (NO in step S117), the series of processes is terminated. On the other hand, if the margin zero point stored in the non-volatile memory 9d satisfies the warning condition (YES in step S117), the controller 9c executes a warning operation (step S118) and then ends the series of processes. To do.

  Note that the warning operation is, for example, an operation that warns (warns) that the refrigerant in the refrigeration cycle 13 is in a leak state while the refrigerant is near (in a period equal to or shorter than the warning reference period). This warning operation may be performed toward the driver of the vehicle or may be performed toward a mechanic that maintains the vehicle.

  When performing a warning operation for the driver of the vehicle, for example, a command to turn on a dedicated warning symbol in a vehicle combination meter or to turn on or blink a warning symbol used in combination with another warning in a dedicated pattern, The controller 9c may output to the ECU (Electronic Control Unit or Engine Control Unit) of the vehicle.

  Further, when a warning operation is performed toward a mechanic that maintains the vehicle, the controller 9c may output the above-described warning symbol lighting or blinking command to the vehicle ECU. The controller 9c may output a command for setting a possible flag to the ECU.

  As apparent from the above description, in the electric compressor 1 of the second embodiment, the controller 9c corresponds to the warning processing means in the claims, and the nonvolatile memory 9d serves as the temperature margin storage means in the claims. It corresponds.

  According to the electric compressor 1 of the second embodiment configured as described above, the detected temperature of the wall temperature sensor 9e (the temperature of the power switching element 9b) and the temperature threshold stored together with the time stamp information in the nonvolatile memory 9d. The change in temperature difference (temperature margin) from the value is monitored for each rotation speed of the electric motor 5.

  Then, from the transition of the temperature margin (the average value of the distribution) by the number of rotations of the electric motor 5, a margin zero point at which the temperature margin becomes zero is predicted for each number of rotations of the electric motor 5, and when the margin zero point arrives, Assuming that the time when the refrigerant in the refrigeration cycle 13 enters a leakage state, the detected temperature of the wall temperature sensor 9e (the temperature of the power switching element 9b) is the heat resistant temperature (upper limit temperature) that guarantees the normal operation of the power switching element 9b The operation of the electric compressor 1 is stopped even if it has not reached.

  For this reason, similarly to the electric compressor 1 of the first embodiment, the time point when the refrigerant of the refrigeration cycle 13 that affects the degree of cooling of the power switching element 9b of the electric compressor 1 for the refrigeration cycle 13 enters a leakage state is predicted. It is possible to detect, and the operation of the electric compressor 1 can be appropriately controlled using the detection result.

  Note that the transition of the temperature margin (average value of the distribution) used for the prediction at the time of the margin zero does not have to be monitored for each rotation speed of the electric motor 5, for example, the temperature margin (through the total rotation speed of the electric motor 5 ( It is also possible to predict the margin zero point from the transition of the average value of the distribution.

  In the electric compressor 1 of the first and second embodiments described above, the temperature detected outside the circuit board 9a may be used as the ambient temperature of the circuit housing portion 11b, and similarly, the temperature detected outside the partition wall 11c. May be used as the temperature of the power switching element 9b. Or you may obtain | require by estimation the atmospheric temperature of the circuit accommodating part 11b, or the temperature of the switching element 9b for electric power.

  Further, the temperature threshold value may be defined by a single temperature table regardless of the ambient temperature of the circuit housing portion 11b. However, as in the first and second embodiments described above, the temperature threshold of the power switching element 9b is set according to the temperature of the circuit board 9a detected by the board temperature sensor 9f as the ambient temperature of the circuit housing portion 11b. If the temperature table to be defined is set for each of a plurality of temperature zones and used properly, the refrigerant leakage of the refrigeration cycle 13 can be detected more accurately.

  Further, the object to be cooled by the refrigerant circulating in the refrigeration cycle 13 may be an electronic component that generates heat other than the power switching element 9 b of the inverter circuit 9.

  Further, in the first and second embodiments described above, it is detected that the refrigerant in the refrigeration cycle 13 is leaking, or the refrigerant in the refrigeration cycle 13 is in a leak state, which is used as a trigger for stopping the operation of the electric compressor 1. Is a comparison result between the temperature of the partition wall 11c detected by the wall temperature sensor 9e as the temperature of the power switching element 9b and the temperature threshold defined by the temperature table corresponding to the detected temperature of the substrate temperature sensor 9f. It was supposed to be performed using.

  However, it is possible to detect in advance that the refrigerant in the refrigeration cycle 13 is leaking by a method other than the comparison with the temperature threshold value of the partition wall 11c, or predict in advance when the refrigerant in the refrigeration cycle 13 is in a leaking state, Based on these results, the operation of the electric compressor 1 may be stopped.

  Similarly to the electric compressor 1 according to the second embodiment, the electric compressor according to the third embodiment of the present invention configured as described above has the same configuration as the electric compressor 1 according to the first embodiment shown in FIGS. 1 to 3. It can be. However, the procedure for controlling the operation of the electric compressor 1 performed by the controller 9c shown in FIG. 2 is different from the procedure performed by the controller 9c of the first embodiment or the second embodiment shown in the flowcharts of FIGS. Become.

  That is, the controller 9c detects the refrigerant leakage of the refrigeration cycle 13 as in the operation control procedure of the electric compressor performed by the controller of the electric compressor according to the third embodiment of the present invention shown in the flowchart of FIG. Necessary values of each parameter related to the electric compressor 1 are acquired (step S21).

  And the controller 9c confirms whether the refrigerant | coolant leakage of the refrigerating cycle 13 was detected from the analysis result of the value of each acquired parameter, the comparison result with a reference value, etc. (step S23). If refrigerant leakage has not been detected (NO in step S23), the series of processes is terminated.

  On the other hand, when the refrigerant leakage of the refrigeration cycle 13 is detected (YES in step S23), the controller 9c stops the operation of the electric compressor 1 (step S25), and ends the series of processes.

  As is clear from the above description, in the electric compressor 1 of the third embodiment, the controller 9c corresponds to the refrigerant leak detection means and the stop control means in the claims.

  In the electric compressor 1 of the third embodiment configured as described above, when the refrigerant leakage of the refrigeration cycle 13 is detected, the temperature detected by the wall temperature sensor 9e (the temperature of the power switching element 9b) is the same as that of the power switching element 9b. The operation of the electric compressor 1 is stopped even if the heat-resistant temperature (upper limit temperature) that guarantees normal operation has not been reached.

  Therefore, similarly to the electric compressor 1 of the first embodiment or the second embodiment, the detection result of the refrigerant leakage of the refrigeration cycle 13 that affects the degree to which the power switching element 9b of the electric compressor 1 for the refrigeration cycle 13 is cooled. Can be used to appropriately control the operation of the electric compressor 1.

  In the first to third embodiments described above, when refrigerant leakage in the refrigeration cycle 13 is detected, or when it is estimated that the refrigerant in the refrigeration cycle 13 is leaking, the timing has arrived. Sometimes, the operation of the electric compressor 1 is stopped, but when the refrigerant leakage of the refrigeration cycle 13 is detected or when the time when the predicted refrigerant leakage state arrives, the result is the operation of the electric compressor 1. It may be used for purposes other than stopping.

  Furthermore, in the above embodiment, the case where the present invention is applied to the electric compressor 1 having the vane rotary type compression mechanism 3 that rotates the rotor 3e in the cylinder chamber 3d has been described as an example. However, the present invention includes, for example, an electric motor that rotates a compression mechanism and a rotating body of the compression mechanism, such as a scroll compressor that rotates a movable scroll with respect to a fixed scroll, and compresses gas, and an electric motor drive circuit. The present invention can be widely applied to electric compressors accommodated in adjacent spaces partitioned by a partition plate.

  The present invention can be used in an electric compressor in which a refrigerant compression mechanism is driven by an electric motor.

DESCRIPTION OF SYMBOLS 1 Electric compressor 3 Compression mechanism 3a, 3b Side block 3c Cylinder block 3d Cylinder chamber 3e Rotor 5 Electric motor 7 Housing (main body housing)
7a Discharge chamber 7b Suction chamber 7c Opening 9 Inverter circuit (drive circuit)
9a Circuit board 9b Power switching element (electronic component)
9c controller (detection means, stop control means, warning processing means, refrigerant leak detection means)
9d Non-volatile memory (temperature table storage means, temperature margin storage means)
9e Wall temperature sensor (element temperature detection means, temperature sensor)
9f Substrate temperature sensor (atmosphere temperature detection means)
11 Inverter case 11a Lid 11b Circuit housing (circuit housing)
11c Partition wall 11d Mounting boss 11e Contact part 11f Circuit accommodating part opening 11g Cap 13 Refrigeration cycle

Claims (10)

In the apparatus for detecting the flow rate state of the refrigerant in the refrigeration cycle (13) including the electric compressor (1) that drives the refrigerant compression mechanism (3) by the electric motor (5),
A partition wall (11c) that partitions the main body housing (7) in which the compression mechanism (3) and the electric motor (5) are housed from the circuit housing (11b) in which the drive circuit (9) of the electric motor (5) is housed. Element temperature detecting means (9e) for detecting the temperature of the electronic component (9b) of the drive circuit (9) in contact with
A temperature table in which the temperature threshold of the electronic component (9b) corresponding to the output power from the drive circuit (9) to the electric motor (5) and the rotation speed of the electric motor (5) is stored is stored. Temperature table storage means (9d);
By comparing the temperature threshold on the temperature table corresponding to the output power and the rotation speed of the electric motor (5) with the temperature detected by the element temperature detecting means (9e), the refrigeration cycle (13) Detecting means (9c) for detecting the state of the flow rate of the refrigerant in
A refrigerant flow rate state detection device for a refrigeration cycle.   An ambient temperature detecting means (9f) for detecting the ambient temperature of the circuit housing (11b) is further provided, and the temperature threshold value of the temperature table is set corresponding to the ambient temperature of the circuit housing. The detection means (9c) includes the temperature threshold value on the temperature table corresponding to the output power, the rotational speed of the electric motor (5), and the ambient temperature, and the element temperature detection means (9e). The refrigerant flow state detection device for a refrigeration cycle according to claim 1, wherein the state of the refrigerant flow rate in the refrigeration cycle (13) is detected by comparison with a detected temperature by means of the refrigerant.   The refrigerant temperature state detection device for a refrigeration cycle according to claim 1 or 2, wherein the element temperature detection means (9e) includes a temperature sensor (9e) for detecting the temperature of the partition wall (11c).   The refrigerant flow state detection device for a refrigeration cycle according to claim 1, 2 or 3, wherein the electronic component (9b) is a power switching element (9b) constituting an inverter circuit (9).   The detection means (9c) is configured such that the temperature threshold value on the temperature table corresponding to the output power and the rotation speed of the electric motor (5), and the temperature detected by the element temperature detection means (9e). The refrigerant flow state detection device for a refrigeration cycle according to claim 1, 2, 3, or 4, wherein a refrigerant leak in the refrigeration cycle (13) is detected as a state of a refrigerant flow rate in the refrigeration cycle (13) by comparison. The temperature difference between the temperature threshold on the temperature table corresponding to the output power and the rotation speed of the electric motor (5) and the temperature detected by the element temperature detecting means (9e) is stored as a temperature margin. Temperature margin storage means (9d) for further comprising:
The detection means (9c) predicts the temperature margin as a state of the refrigerant flow rate in the refrigeration cycle (13), which is predicted from a change with time in the past temperature margin stored in the temperature margin storage means (9d). Detects when the refrigerant becomes zero and the refrigerant in the refrigeration cycle (13) enters a leakage state.
The refrigerant | coolant flow state detection apparatus of the refrigerating cycle of Claim 1, 2, 3 or 4. The temperature margin storage means (9d) stores the temperature margin according to the number of rotations of the electric motor (5),
The detection means (9c) predicts each of the past temperature margins stored in the temperature margin storage means (9d) according to the number of rotations of the electric motor (5) from a change over time of an average value every predetermined period. Among the time points when the refrigerant in the refrigeration cycle (13) according to the number of rotations of the electric motor (5) is in a leaked state, the time point that comes the earliest is the refrigerant leaked in the refrigeration cycle (13). Predict as
The refrigerant | coolant flow state detection apparatus of the refrigerating cycle of Claim 6.   When the time point at which the refrigerant in the refrigeration cycle (13) enters a leakage state predicted by the detection means (9c) satisfies a predetermined warning condition, the refrigerant leakage state in the refrigeration cycle (13) is notified. The refrigerant | coolant flow state detection apparatus of the refrigerating cycle of Claim 6 or 7 further equipped with the warning process means (9c) which performs the warning process to perform. In an apparatus for controlling the operation of an electric compressor (1) for a refrigeration cycle that drives a refrigerant compression mechanism (3) by an electric motor (5),
Refrigerant flow state detection device for refrigeration cycle according to claim 1, 2, 3, 4, 5, 6, 7 or 8.
Stop control means (9c) for stopping the operation of the electric compressor (1) based on the refrigerant flow state in the refrigeration cycle (13) detected by the detection means (9c) of the refrigerant flow state detection apparatus for the refrigeration cycle. When,
The control apparatus of the electric compressor for refrigeration cycles provided with. In an apparatus for controlling the operation of an electric compressor (1) for a refrigeration cycle that drives a refrigerant compression mechanism (3) by an electric motor (5),
Element temperature detecting means (9e) for detecting the temperature of the electronic component (9b) of the drive circuit (9) of the electric motor (5);
As a refrigerant flow state in the refrigeration cycle (13), refrigerant leakage detection means (9c) for detecting refrigerant leakage in the refrigeration cycle (13);
When the temperature detected by the element temperature detecting means (9e) is equal to or higher than the upper limit temperature that guarantees the normal operation of the electronic component (9b), the operation of the electric compressor (1) is stopped and the refrigerant leak detection is performed. When the means (9c) detects the refrigerant leak in the refrigeration cycle (13), the operation of the electric compressor (1) is performed even if the temperature detected by the element temperature detecting means (9e) is lower than the upper limit temperature. Stop control means (9c) for stopping
The control apparatus of the electric compressor for refrigeration cycles provided with.

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