JP5769502B2 - Refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus used in a supermarket, a convenience store, a refrigerator, a freezer, or the like, and particularly relates to improving the reliability of a compressor.

  In conventional refrigeration cycle equipment, as a means to protect the compressor, it is determined whether it is in the cooling mode or other mode, and the motor temperature protection range of the compressor is expanded depending on whether the intake temperature is higher than a predetermined temperature. Alternatively, by providing a means for controlling to reduce and counting whether the actual state is in the motor protection area, the motor is stopped when the count number exceeds a predetermined number (for example, patents) Reference 1).

Japanese Patent Laying-Open No. 2009-299945 (page 14, FIG. 6)

  In the conventional refrigeration cycle apparatus, the motor is stopped and the compressor is protected by using means for changing the operating range of the motor according to the temperature of the suction pipe. However, since the refrigeration cycle is stopped, the cooling operation cannot be continued.

  In particular, a refrigeration cycle apparatus used in a supermarket, convenience store, refrigerator, or freezer performs product temperature management. The refrigeration cycle apparatus in this case is a refrigerator, and the object of cooling is a product (thing). On the other hand, air conditioners are intended for people. Unlike the air conditioner, the refrigerator is required to continue cooling operation for 24 hours 365 days. Therefore, if the refrigeration cycle continues to be stopped to protect the motor of the compressor, there is a problem that the quality of the product is deteriorated.

The present invention has been made to solve the above problems, and a first object is to provide a high-quality refrigeration cycle apparatus that protects the motor of the compressor.
And the 2nd objective is to provide the refrigerating-cycle apparatus which can suppress the quality fall of the goods by the stop of a refrigerating cycle.

The refrigeration cycle apparatus according to the present invention includes an inverter compressor, a condenser, an expansion device, and an evaporator, which are sequentially connected by a refrigerant pipe, and a control that controls driving of the inverter compressor. A low pressure detecting means for detecting a suction pressure that is a pressure of a refrigerant on the suction side of the inverter compressor, and a high pressure detecting means for detecting a discharge pressure that is a pressure of a refrigerant on the discharge side of the inverter compressor. And the control unit converts the suction pressure detected by the low pressure detection means into an evaporation temperature in the evaporator, and converts the discharge pressure detected by the high pressure detection means into a condensation temperature in the condenser. The operating frequency of the inverter compressor is equal to or higher than a predetermined high frequency, and the motor temperature of the inverter compressor is a predetermined motor. When there is the converted condensation temperature and the evaporation temperature in a region that is higher than the upper temperature limit value, the operating frequency of the inverter compressor is lowered, and the operating frequency of the inverter compressor is a predetermined low frequency. And when the converted compressor temperature and the evaporation temperature are in a region where the motor temperature of the inverter compressor is higher than a predetermined motor temperature upper limit value, the operation of the inverter compressor is performed. The frequency is increased .

  According to the present invention, the motor temperature of the inverter compressor is estimated using the refrigerator oil temperature detected by the refrigerator oil temperature detecting means, and the motor drive is controlled based on the estimated temperature. Therefore, it is possible to provide a high-quality refrigeration cycle apparatus.

1 is a configuration diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention. It is the figure which showed the relationship between the evaporation temperature of the evaporator 22 in the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention, and the motor temperature of the inverter compressor 11. FIG. It is the figure which showed the relationship between the suction temperature of the inverter compressor 11, and the motor temperature in the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a block diagram of the refrigeration cycle apparatus which concerns on Embodiment 2 of this invention. It is a block diagram of the refrigerating-cycle apparatus which concerns on Embodiment 3 of this invention. It is the figure which showed the relationship between the operating frequency of the inverter compressor 11 in the refrigerating-cycle apparatus which concerns on Embodiment 4 of this invention, and the electric current (compressor electric current) which flows into the inverter compressor 11. FIG. It is a block diagram of the refrigeration cycle apparatus which concerns on Embodiment 5 of this invention. It is the figure which showed the relationship between the evaporation temperature of the evaporator 22, and the condensation temperature of the condenser 12 in the refrigerating-cycle apparatus which concerns on Embodiment 5 of this invention.

Embodiment 1 FIG.
(Configuration of refrigeration cycle equipment)
FIG. 1 is a configuration diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention.
As shown in FIG. 1, the refrigeration cycle apparatus according to the present embodiment includes a condensing unit 10 that is a heat source side unit and two indoor units 20 that are use side units.

  The condensing unit 10 includes two inverter compressors 11, a condenser 12, a liquid reservoir 13, and a controller 15. The two indoor units 20 each include an expansion valve 21 and an evaporator 22.

  Further, the condensing unit 10 is further installed under the shell of the inverter compressor 11, an under-shell thermistor 14 that detects the temperature of the refrigerating machine oil, and a suction circuit that detects the temperature of the refrigerant on the suction side of the inverter compressor 11. A Mr. 16 and a low-pressure sensor 17 for detecting the pressure of the refrigerant on the suction side are provided.

The inverter compressor 11 compresses and discharges a low-temperature and low-pressure gas refrigerant. Further, in the present embodiment, two inverter compressors 11 are provided, and these are connected in parallel. Further, as described above, the inverter compressor 11 includes the lower shell thermistor 14 that detects the temperature of the refrigerating machine oil, and the lower shell thermistor 14 transmits the detected temperature information to the controller 15. .
The under-thermistor thermistor 14 corresponds to the “refrigerator oil temperature detecting means” of the present invention.

  The condenser 12 includes a condenser fan 12a, and heat exchange is performed between the air (outside air or the like) sent by the condenser fan 12a and the refrigerant discharged from the inverter compressor 11 to condense the refrigerant. .

  The liquid reservoir 13 temporarily stores the liquid refrigerant condensed by the condenser 12.

The expansion valve 21 expands and depressurizes the liquid refrigerant that has flowed into the indoor unit 20 from the condensing unit 10 to form a gas-liquid two-phase refrigerant. Moreover, the opening degree of the expansion valve 21 is adjusted, for example, at the site where the refrigeration cycle apparatus is installed.
The expansion valve 21 corresponds to the “expansion device” of the present invention.

  The evaporator 22 includes an evaporator fan 22a, and heats the air (internal air or indoor air, etc.) sent by the evaporator fan 22a and the gas-liquid two-phase refrigerant flowing out of the expansion valve 21. This gas-liquid two-phase refrigerant is evaporated.

As described above, the suction thermistor 16 detects the temperature of the refrigerant on the suction side of the inverter compressor 11, and transmits the detected temperature information to the controller 15. Further, as described above, the low pressure sensor 17 detects the pressure of the refrigerant on the suction side of the inverter compressor 11, and transmits the detected pressure information to the controller 15.
The suction thermistor 16 and the low pressure sensor 17 correspond to the “suction temperature detection means” and the “low pressure detection means” of the present invention, respectively.

  The controller 15 controls the inverter operation of the inverter compressor 11 of the condensing unit 10 and receives each detection information from the lower shell thermistor 14, the suction thermistor 16, and the low pressure sensor 17 as described above. .

  Of the above devices, the inverter compressor 11, the condenser 12, the liquid reservoir 13, the expansion valve 21, the evaporator 22, and the inverter compressor 11 are again connected in a ring shape by refrigerant piping. A refrigeration cycle is configured.

  For example, when the configuration shown in FIG. 1 is applied in a supermarket, the condensing unit 10 is installed outside the store. Moreover, the refrigerant | coolant piping which connects the condensing unit 10 and the indoor unit 20 is arrange | positioned in the ceiling back or the lower surface in a shop. The indoor unit 20 is used for the purpose of cooling the inside of the showcase, and is used for refrigeration for keeping goods such as vegetables cold, or for freezing for preserving ice cream and frozen foods. In addition, the refrigerant pipe connecting the condensing unit 10 and the indoor unit 20 becomes complicated in a large store and may be as long as about 100 [m]. For this reason, since the suction temperature of the refrigerant flowing into the condensing unit 10 is determined by the opening setting of the expansion valve 21 and the length of the refrigerant pipe, the controller 15 detects the refrigerant detected by the suction thermistor 16. The inverter operation of the inverter compressor 11 is controlled based on the suction temperature of the inverter.

(Basic operation of refrigeration cycle equipment)
Next, the basic operation of the refrigeration cycle apparatus according to the present embodiment (particularly, the operation of the refrigerant flowing through the refrigeration cycle) will be described with reference to FIG.

  The high-temperature and high-pressure refrigerant compressed and discharged by the two inverter compressors 11 merges and flows into the condenser 12. In the condenser 12, the high-temperature and high-pressure refrigerant dissipates heat and condenses with respect to the air (outside air or the like) sent by the condenser fan 12 a and flows out from the condenser 12 as a liquid refrigerant. The liquid refrigerant flowing out of the condenser 12 flows out of the condensing unit 10 from the condensing unit liquid refrigerant outlet 30 via the liquid reservoir 13.

  The liquid refrigerant that has flowed out of the condensing unit 10 branches and flows into the indoor unit 20 from the indoor unit liquid refrigerant inlet 40. The liquid refrigerant that has flowed into the indoor unit 20 is expanded and depressurized by the expansion valve 21, becomes a low-temperature low-pressure gas-liquid two-phase refrigerant, and flows into the evaporator 22. The gas-liquid two-phase refrigerant that has flowed into the evaporator 22 is sucked from the air (in-house air or indoor air, etc.) sent by the evaporator fan 22a, evaporates, and becomes a low-temperature and low-pressure gas refrigerant. It flows out from the gas refrigerant outlet 41 to the outside of the indoor unit 20.

  The gas refrigerant that has flowed out of the two indoor units 20 merges and flows into the condensing unit 10 from the condensing unit gas refrigerant inlet 31. The gas refrigerant that has flowed into the condensing unit 10 branches, is sucked into the two inverter compressors 11, and is compressed again. The above operation is repeated.

  Moreover, as a refrigerant | coolant which flows through a refrigerating cycle as mentioned above, a HFC type refrigerant | coolant (R404A or R410A etc.) or a natural refrigerant | coolant (carbon dioxide etc.) is used, for example.

FIG. 2 is a diagram showing the relationship between the evaporation temperature of the evaporator 22 and the motor temperature of the inverter compressor 11 in the refrigeration cycle apparatus according to Embodiment 1 of the present invention, and FIG. 3 shows the refrigeration cycle apparatus. It is the figure which showed the relationship between the suction | inhalation temperature of the inverter compressor 11, and motor temperature.
FIG. 2 shows the relationship between the evaporation temperature and the motor temperature when the degree of superheat of the evaporator 22 is constant. The motor temperature of the inverter compressor 11 increases as the evaporation temperature of the evaporator 22 decreases. This is because the motor in the inverter compressor 11 is cooled by the low-temperature and low-pressure gas refrigerant, so that the amount of refrigerant that cools the motor decreases in a state where the evaporation temperature is low and the density of the gas refrigerant is low. . During operation of the refrigeration cycle device, if the motor of the inverter compressor 11 is used in a high temperature state (for example, 120 ° C. or higher), the motor deteriorates significantly. Therefore, the motor is referred to as a predetermined temperature (hereinafter referred to as “motor temperature upper limit value”). In the case of this example, it is necessary to drive in a state of less than 120 ° C.

Therefore, in the refrigeration cycle apparatus according to the present embodiment, in order to estimate whether or not the motor temperature is lower than the motor temperature upper limit value in order for the motor of the inverter compressor 11 to normally operate, The under-shell temperature detected by 14 is used. Specifically, assuming that the temperature below the shell corresponding to the motor temperature upper limit value is the “shell lower temperature upper limit value” (for example, 85 ° C. in the case of the motor temperature of 120 ° C. described above), the controller 15 When the under-shell temperature detected by the Mr. 14 is less than the under-shell temperature upper limit value, the inverter compressor 11 is driven assuming that the motor temperature is less than the upper motor temperature value. Also, in refrigeration oil, deterioration due to use at high temperatures is remarkable, and since the temperature of refrigeration oil is generally several tens of degrees higher than the temperature of low-temperature and low-pressure gas refrigerant, the motor temperature of inverter compressor 11 is the temperature of refrigeration oil. Therefore, it is necessary to set the above shell lower temperature upper limit value to a temperature at which the inverter compressor 11 can be protected and to a limit that can suppress the deterioration of the refrigerating machine oil. The “unoperational range” in FIG. 2 indicates a region where the motor cannot be driven at a temperature higher than the motor temperature upper limit (120 ° C. in the above example) that is a temperature at which the motor is deteriorated. As the shell lower temperature corresponding to the motor temperature upper limit, the “shell lower temperature upper limit” is shown at the same height position in the graph.
The “under-shell temperature upper limit value” corresponds to the “refrigerator oil temperature upper limit value” of the present invention.

  FIG. 3 shows the relationship between the intake temperature of the inverter compressor 11 and the motor temperature when the evaporation temperature of the evaporator 22 is constant, and the motor temperature of the inverter compressor 11 increases as the intake temperature increases. . This is because the motor in the inverter compressor 11 is cooled by the low-temperature and low-pressure gas refrigerant, so that the motor cannot be sufficiently cooled when the temperature of the gas refrigerant is high, that is, when the intake temperature is high. The “non-operable range” in FIG. 3 indicates a region where the motor cannot be driven at a temperature higher than the motor temperature upper limit (120 ° C. in the above example) that is a temperature at which the motor deteriorates. Similarly, for convenience, the “under-shell temperature upper limit value” is shown at the same height position in the graph as the under-shell temperature corresponding to the motor temperature upper limit value.

  Further, since the refrigeration cycle apparatus according to the present embodiment includes the suction thermistor 16, the suction temperature of the inverter compressor 11 can be detected. As a result, the controller 15 uses the suction temperature detected by the suction thermistor 16 as well as the shell temperature detected by the shell thermistor 14 to accurately set the non-operable range shown in FIG. Can be determined. Specifically, the controller 15 determines that the inhalation temperature detected by the inhalation thermistor 16 is a predetermined temperature (hereinafter referred to as “inhalation temperature upper limit”, for example, 20 ° C.) or higher, or the under-shell thermistor 14. If the detected under-shell temperature is equal to or higher than the under-shell temperature upper limit value, it is determined that the operation is in the non-operational range shown in FIG. 3, the drive of the inverter compressor 11 is stopped, and the refrigeration cycle operation is temporarily performed. Stop. When the suction temperature detected by the suction thermistor 16 is less than the suction temperature upper limit and the shell lower temperature detected by the shell lower thermistor 14 is less than the shell lower temperature upper limit. Then, the drive of the inverter compressor 11 is resumed, and the refrigeration cycle operation is resumed.

  The drive restart condition of the inverter compressor 11 is a case where the suction temperature is less than the suction temperature upper limit value and the shell lower temperature is less than the shell lower temperature upper limit value, but is not limited thereto. That is, when the temperature is less than the suction temperature resumption temperature (for example, 15 ° C.) lower than the suction temperature upper limit by a predetermined value and not lower than the shell lower temperature upper limit, The driving of the inverter compressor 11 may be resumed when the temperature becomes lower than the “under-shell temperature resumption temperature” (for example, 75 ° C.) lower by a predetermined value than the temperature upper limit value.

  Further, the drive stop condition of the inverter compressor 11 is a case where the suction temperature is equal to or higher than the suction temperature upper limit value or the shell lower temperature is equal to or higher than the shell lower temperature upper limit value, but is not limited thereto. That is, the controller 15 may stop the drive of the inverter compressor 11 when the suction temperature is equal to or higher than the suction temperature upper limit value and the shell lower temperature is equal to or higher than the shell lower temperature upper limit value.

  In addition, as a driving resumption condition of the inverter compressor 11, the suction temperature is less than the suction temperature upper limit (or suction temperature restart temperature), and the shell lower temperature is less than the shell lower temperature upper limit (or shell lower temperature restart temperature). However, the present invention is not limited to this. That is, when the intake temperature is less than the intake temperature upper limit (or the intake temperature restart temperature) or the shell lower temperature is less than the shell lower temperature upper limit (or the shell lower temperature restart temperature), The drive of the inverter compressor 11 may be resumed.

Further, as described above, the controller 15 determines whether or not the motor temperature is abnormal based on the temperature information detected by the suction thermistor 16 and the under-shell thermistor 14. It is not limited. That is, the controller 15 may use the refrigerant pressure on the suction side of the inverter compressor 11 detected by the low pressure sensor 17. Specifically, the controller 15 can convert the refrigerant pressure detected by the low pressure sensor 17 into the evaporation temperature of the evaporator 22, and the converted evaporation temperature and the shell thermistor 14 detect. By using the temperature below the shell, the operation impossible range shown in FIG. 2 can be accurately determined.
In this case, the refrigeration cycle apparatus cannot operate as shown in FIGS. 2 and 3 by using the refrigerant pressure by the low pressure sensor 17 in addition to the temperature information detected by the lower shell thermistor 14 and the suction thermistor 16. The range may be determined, or the low-pressure sensor 17 may be used in place of the suction thermistor 16 to determine the non-operable range shown in FIG. Further, the determination method of the non-operational range when using the low-pressure sensor 17 in this way may be based on the determination method using the suction thermistor 16 described above.

(Effect of Embodiment 1)
When the motor temperature of the inverter compressor 11 is estimated using the under-shell temperature detected by the under-shell thermistor 14 as in the above configuration and operation, and the under-shell temperature exceeds a predetermined upper limit value. In addition, since the motor drive is stopped, the deterioration of the motor and the refrigerating machine oil can be suppressed, and a high-quality refrigeration cycle apparatus can be provided.

  Further, not only the temperature under the shell but also the suction temperature detected by the suction thermistor 16 or the evaporation pressure converted from the refrigerant pressure detected by the low-pressure sensor 17 is an area where the motor is deteriorated. The range (see FIG. 2 and FIG. 3) can be accurately estimated, and further, the deterioration of the motor and the deterioration of the refrigerating machine oil can be suppressed.

  Furthermore, when it is determined that the motor is out of the unoperable range, the motor drive of the inverter compressor 11 is promptly restarted, so that the quality deterioration of the product can be suppressed.

  In addition, as shown in FIG. 1, the inverter compressor 11 and the indoor unit 20 in the refrigeration cycle apparatus are each configured to be connected in parallel with each other, but the invention is not limited to this, 3 or more.

Embodiment 2. FIG.
The refrigeration cycle apparatus according to the present embodiment will be described focusing on differences from the configuration and operation of the refrigeration cycle apparatus according to Embodiment 1.

(Configuration of refrigeration cycle equipment)
FIG. 4 is a configuration diagram of a refrigeration cycle apparatus according to Embodiment 2 of the present invention.
As shown in FIG. 4, the condensing unit 10 of the refrigeration cycle apparatus according to the present embodiment includes a display unit 18 a and an output unit 18 b on its outer shell. About another structure, it is the same as that of the refrigerating-cycle apparatus which concerns on Embodiment 1 shown by FIG.

  The display unit 18a is electrically connected to the controller 15 and displays the operation state of the refrigeration cycle apparatus to the outside. For example, as described in the first embodiment, when the drive stop condition of the inverter compressor 11 is satisfied and the controller 15 stops the inverter compressor 11 and stops the refrigeration cycle operation, the refrigeration cycle apparatus is The fact that it is abnormal is displayed outside.

The output unit 18b is electrically connected to the controller 15. For example, as described in the first embodiment, the output unit 18b satisfies the drive stop condition of the inverter compressor 11, and the controller 15 turns the inverter compressor 11 on. When the operation is stopped and the refrigeration cycle operation is stopped, an electrical output (for example, voltage output) is output to the outside. Thereby, for example, when the output unit 18b is connected to a notification means such as an alarm device, the alarm device or the like can notify the abnormality of the refrigeration cycle apparatus to the outside.
As shown in FIG. 4, the output unit 18 b is installed outside the condensing unit 10. However, the present invention is not limited to this, and the output unit 18 b itself is installed inside the condensing unit 10. It is good also as what is installed in. In this case, for example, the alarm device or the like may be connected to the outline of the condensing unit 10 so that the alarm sound generated by the alarm device or the like connected to the output unit 18b can be heard outside.

  The operation of the refrigeration cycle apparatus according to the present embodiment is the same as the operation of the refrigeration cycle apparatus according to Embodiment 1.

(Effect of Embodiment 2)
As described above, when the drive stop condition is satisfied for the inverter compressor 11 and the refrigeration cycle operation is stopped, a display by the display unit 18a or a warning sound such as an alarm connected to the output unit 18b Thus, the abnormal state of the refrigeration cycle apparatus can be immediately known. Thereby, since the operator etc. can know immediately the abnormal state in a refrigerating cycle device, he can cope with it quickly. In addition, as a result of prompt countermeasures for abnormalities, the number of occurrences of abnormalities in the refrigeration cycle apparatus is suppressed, and the frequency of stop and restart operations of the refrigeration cycle operation can be reduced. It is possible to further suppress the quality deterioration of the product due to.

  As shown in FIG. 4, the condensing unit 10 is configured to include both the display unit 18 a and the output unit 18 b, but is not limited thereto, and may be configured to include either one. Even in this case, the above effect can be obtained.

  In the above description, the output unit 18b and the notification unit such as an alarm device are described as separate units. However, the present invention is not limited to this, and the notification unit may be configured integrally. Needless to say.

  In addition, the configuration in which the notification unit such as an alarm device is connected to the output unit 18b has been described, but the present invention is not limited to this, and for example, a remote place connected to a computer such as a personal computer via a network. It is good also as a structure which transmits abnormality of a refrigerating-cycle apparatus to the monitoring apparatus etc. which exist in this. Alternatively, the output unit 18b may function as a wireless LAN (Local Area Network) terminal and transmit an abnormality of the refrigeration cycle apparatus to a monitoring device or the like via the wireless LAN.

Embodiment 3 FIG.
The refrigeration cycle apparatus according to the present embodiment will be described focusing on differences from the configuration and operation of the refrigeration cycle apparatus according to Embodiment 1.

(Configuration of refrigeration cycle equipment)
FIG. 5 is a configuration diagram of a refrigeration cycle apparatus according to Embodiment 3 of the present invention.
As shown in FIG. 5, in the refrigeration cycle apparatus according to the present embodiment, the expansion valve 21 of the indoor unit 20 is an electronic expansion valve, and the expansion valve 21 serving as the electronic expansion valve is electrically connected to the controller 15. And the opening degree is controlled by the controller 15. Other configurations are the same as those of the refrigeration cycle apparatus according to Embodiment 1 shown in FIG.

(Operation of refrigeration cycle equipment)
The operation of the refrigerant in the refrigeration cycle apparatus according to the present embodiment is the same as that of the refrigeration cycle apparatus according to the first embodiment.

  The refrigeration cycle apparatus according to Embodiment 1 is configured to stop the refrigeration cycle operation when the drive stop condition of the inverter compressor 11 is satisfied. On the other hand, in the refrigeration cycle apparatus according to the present embodiment, when the controller 15 detects that the drive stop condition of the inverter compressor 11 is satisfied, the controller 15 stops driving the inverter compressor 11 and performs the refrigeration cycle operation. Instead of stopping, control is performed in the direction of increasing the opening of the expansion valve 21. Thus, when the opening degree of the expansion valve 21 is increased, the pressure reduction width by the expansion valve 21 is reduced in FIG. 2, the evaporation temperature is increased, and the operation is not allowed. Therefore, when the drive stop condition of the inverter compressor 11 is satisfied, the controller 15 can escape from the operation disabled range by controlling the opening degree of the expansion valve 21 and stops the refrigeration cycle operation. There is no need.

(Effect of Embodiment 3)
Even if the drive stop condition of the inverter compressor 11 is satisfied by the controller 15 performing the opening degree control of the expansion valve 21, which is an electronic expansion valve, as described above, the operation is impossible. Since it can remove | deviate from the range, a quality refrigeration cycle apparatus can be provided.

  Further, the controller 15 performs the opening degree control of the expansion valve 21 which is an electronic expansion valve, so that it is not necessary to stop the refrigeration cycle operation even when the drive stop condition of the inverter compressor 11 is satisfied. Since it can be continued, the quality deterioration of goods can be suppressed.

  The configuration shown in FIG. 5 is applied to the refrigeration cycle apparatus according to the first embodiment shown in FIG. 1, but is not limited to this, and the configuration shown in FIG. It is good also as what is applied to the refrigerating cycle device concerning form 2.

Embodiment 4 FIG.
The refrigeration cycle apparatus according to the present embodiment will be described focusing on differences from the configuration and operation of the refrigeration cycle apparatus according to Embodiment 3.

(Configuration of refrigeration cycle equipment)
In the refrigeration cycle apparatus according to the present embodiment, the condensing unit 10 is provided with current detection means (not shown) that detects the current flowing through the inverter compressor 11. This current detection means is electrically connected to the controller 15 and transmits the detected current information to the controller 15. Other configurations are the same as those of the refrigeration cycle apparatus according to Embodiment 3 shown in FIG.

(Operation of refrigeration cycle equipment)
FIG. 6 is a diagram showing the relationship between the operating frequency of the inverter compressor 11 and the current (compressor current) flowing through the inverter compressor 11 in the refrigeration cycle apparatus according to Embodiment 4 of the present invention.
When the operating frequency of the inverter compressor 11 is high and low, there is a characteristic that the compressor current becomes high, and as shown in FIG. 6, a downward convex graph is obtained. When the compressor current increases, the motor temperature of the inverter compressor 11 is insufficiently cooled by the low-temperature and low-pressure gas refrigerant, becomes higher than the motor temperature upper limit (for example, 120 ° C.), and becomes inoperable range. As shown in FIG. 6, there are regions that are not operable, that is, regions that are equal to or higher than the motor temperature upper limit value on the smaller and larger operating frequencies.

  Therefore, in the refrigeration cycle apparatus according to the present embodiment, in order to estimate whether the motor temperature is lower than the motor temperature upper limit value in order to drive the motor of the inverter compressor 11 normally, the above-described current detection is performed. The compressor current detected by the means is used. Specifically, the controller 15 is configured such that the operating frequency of the motor of the inverter compressor 11 is equal to or higher than a predetermined frequency (hereinafter referred to as “frequency upper limit value”), and the compressor current detected by the current detection unit is predetermined. If the current value is equal to or greater than the current value (hereinafter referred to as “first current upper limit value”), it is determined that the operation frequency range shown in FIG. Further, the controller 15 is configured such that the motor operating frequency of the inverter compressor 11 is equal to or lower than a predetermined frequency (hereinafter referred to as “frequency lower limit value”), and the compressor current detected by the current detecting means is a predetermined current value ( If it is equal to or greater than “second current upper limit value” below, it is determined that the operation frequency range shown in FIG. When the controller 15 determines that the vehicle is in the non-operable range state as described above, the controller 15 performs control so that the operation frequency is in an intermediate region that does not belong to both non-operable ranges in FIG. It is possible to escape from the non-operable region indicated by, and there is no need to stop the refrigeration cycle operation.

  The controller 15 is shown in FIGS. 2 and 3 in the same manner as in the first embodiment, based on detection information detected by the detection means of the lower shell thermistor 14, the suction thermistor 16, and the low pressure sensor 17. In the present embodiment, the control for increasing the opening degree of the expansion valve 21 that is an electronic expansion valve is performed when it is determined whether or not it is in the operation disabled range. It is good also as what is implemented together. As a result, it is possible to escape from the non-operable range shown in FIG. 2 and FIG. 3, and there is no need to stop the refrigeration cycle operation.

(Effect of Embodiment 4)
As with the configuration and operation described above, the controller 15 has the effects of the third embodiment, and the controller 15 uses the current flowing through the inverter compressor 11 detected by the current detection means, so that the operation is not possible. By controlling the operation frequency, it is possible to get out of the unoperational range, so that it is possible to provide a refrigeration cycle apparatus with higher quality than that of the third embodiment.

  Moreover, since the controller 15 can be removed from the non-operable range by controlling the operation frequency, the refrigeration cycle operation can be continued without being stopped, thereby suppressing the quality deterioration of the product. it can.

  In addition, although the structure and operation | movement of the refrigerating-cycle apparatus concerning this Embodiment shall be applied with respect to the refrigerating-cycle apparatus which concerns on Embodiment 3 shown by FIG. 5, it is not limited to this, The present invention may be applied to the refrigeration cycle apparatus according to Embodiment 1 or Embodiment 2.

Embodiment 5 FIG.
The refrigeration cycle apparatus according to the present embodiment will be described focusing on differences from the configuration and operation of the refrigeration cycle apparatus according to the fourth embodiment.

(Configuration of refrigeration cycle equipment)
FIG. 7 is a configuration diagram of a refrigeration cycle apparatus according to Embodiment 5 of the present invention.
As shown in FIG. 7, the condensing unit 10 in the refrigeration cycle apparatus according to the present embodiment includes a high-pressure sensor 19 that detects the discharge pressure of the inverter compressor 11. The high pressure sensor 19 transmits the detected pressure information to the controller 15. Other configurations are the same as those of the refrigeration cycle apparatus according to Embodiment 3 shown in FIG.

As shown in FIG. 7, the discharge sides of the two inverter compressors 11 are assumed to be installed in the joined refrigerant pipes. However, the present invention is not limited to this, and each of the two inverter compressors 11 It is good also as what is installed in the refrigerant | coolant piping of the discharge side.
The high pressure sensor 19 corresponds to the “high pressure detection means” of the present invention.

(Operation of refrigeration cycle equipment)
FIG. 8 is a diagram showing the relationship between the evaporation temperature of the evaporator 22 and the condensation temperature of the condenser 12 in the refrigeration cycle apparatus according to Embodiment 5 of the present invention.
The graph (hereinafter referred to as “correlation graph”) showing the relationship between the evaporation temperature and the condensation temperature shown in FIG. 8 is the case where the motor temperature of the inverter compressor 11 is the motor temperature upper limit (for example, 120 ° C.). The relationship between the evaporation temperature of the evaporator 22 and the condensation temperature of the condenser 12 is shown. However, the position and shape of this correlation graph differ depending on the operating frequency of the inverter compressor 11 (for example, the range of 30 [Hz] to 100 [Hz]). For example, the correlation graph shown in FIG. The operation frequency of the inverter compressor 11 is that at a low frequency, and the correlation graph shown in FIG. 8B is that in which the operation frequency is an intermediate frequency (for example, around 50 [Hz]), and FIG. The correlation graph shown in (c) is for the operating frequency at a high frequency (for example, 100 [Hz]). As a general property of these correlation graphs, when the evaporation pressure of the evaporator 22 is low (that is, the evaporation temperature is low) and the circulation amount of the refrigerant is reduced, the cooling of the inverter compressor 11 by the low-temperature and low-pressure gas refrigerant is insufficient. It becomes. Therefore, the motor temperature becomes the motor temperature upper limit value at the part where the condensation temperature of the condenser 12 is low, and if the temperature becomes equal to or higher than the condensation temperature, the operation becomes impossible. Further, when the evaporation pressure of the evaporator 22 is high (that is, the evaporation temperature is high) and the circulation amount of the refrigerant is increased, the cooling action of the inverter compressor 11 by the low-temperature and low-pressure gas refrigerant becomes strong. Therefore, the motor temperature becomes the motor temperature upper limit value at a portion where the condensation temperature of the condenser 12 is high, and if the temperature is equal to or higher than the condensation temperature, the operation is impossible. Therefore, as shown in FIG. 8A to FIG. 8C, the correlation graph between the evaporation temperature and the condensation temperature, which is the motor temperature upper limit value, increases to the right. Moreover, in the area | region of the combination of the evaporation temperature and condensation temperature which belong to the area | region of the upper side of the correlation graph shown by Fig.8 (a)-FIG.8 (c), it becomes a driving | operation impossible range. Further, as shown in FIGS. 8A and 8B, when the operating frequency of the inverter compressor 11 is switched from the low frequency to the intermediate frequency, the position of the correlation graph shifts upward. Further, as shown in FIGS. 8B and 8C, when the operation frequency is switched from the intermediate frequency to the high frequency, the position of the correlation graph transitions downward.

  Therefore, in the refrigeration cycle apparatus according to the present embodiment, in order to estimate whether the motor temperature is less than the motor temperature upper limit value in order for the motor of the inverter compressor 11 to normally operate, the high pressure sensor 19 The detected discharge pressure of the inverter compressor 11, the suction pressure of the inverter compressor 11 detected by the low pressure sensor 17, and the operating frequency of the inverter compressor 11 are used. By using the discharge pressure detected by the high pressure sensor 19, the inverter operation can be controlled more precisely. Specifically, the controller 15 first converts the discharge pressure detected by the high pressure sensor 19 into a condensation temperature, and converts the suction pressure detected by the low pressure sensor 17 into an evaporation temperature.

  And the controller 15 is a correlation graph (for example, figure) in which the operating frequency of the motor of the inverter compressor 11 is equal to or higher than a predetermined frequency (high frequency region), and the converted condensation temperature and evaporation temperature are in the high frequency region. (Correlation graph shown in 8 (c)) If the region is in the above region, it is determined that the vehicle is in an operation impossible range. In this case, the controller 15 reduces the operation frequency of the motor of the inverter compressor 11 in the direction of the intermediate frequency, and controls the condensing temperature and the evaporation temperature so as to be in a region below the correlation graph. It is possible to escape from the impossible region, and it is not necessary to stop the refrigeration cycle operation.

  Further, the controller 15 is a correlation graph in which the operating frequency of the motor of the inverter compressor 11 is equal to or lower than a predetermined frequency (low frequency region), and the converted condensation temperature and evaporation temperature are in a low frequency region. When it exists in the above area | region (correlation graph shown by Fig.8 (a)), it determines that it exists in the state of a driving impossible range. In this case, the controller 15 increases the operating frequency of the motor of the inverter compressor 11 in the direction of the intermediate frequency, and controls the condensing temperature and the evaporating temperature so as to be in a region below the correlation graph. It is possible to escape from the impossible region, and it is not necessary to stop the refrigeration cycle operation.

  The controller 15 is based on the detection information detected by the detection means of the lower shell thermistor 14, the suction thermistor 16 and the low pressure sensor 17, as in the first embodiment, as shown in FIGS. In this embodiment, it is determined whether or not it is in the non-operational range indicated by 6 and when it is determined that it is in the non-operational range, the control for increasing the opening degree of the expansion valve 21 that is an electronic expansion valve is performed. It is good also as what is implemented together with control in a form. As a result, it is possible to escape from the non-operable range shown in FIG. 2 and FIG. 3, and there is no need to stop the refrigeration cycle operation.

(Effect of Embodiment 5)
As in the configuration and operation described above, the controller 15 estimates the motor temperature upper limit value from the detection information by the high-pressure sensor 19 and the low-pressure sensor 17 and the operation frequency, and determines whether or not it is within the operation disabled range. Therefore, it is possible to control the operation frequency to be out of the unoperable range, so that it is possible to provide a high quality refrigeration cycle apparatus.

  In addition, since the controller 15 can move out of the non-operable range by controlling the operation frequency, it is possible to continue without having to stop the refrigeration cycle operation, thereby suppressing product quality deterioration. Can do.

  In addition, although the structure and operation | movement of the refrigerating-cycle apparatus concerning this Embodiment shall be applied with respect to the refrigerating-cycle apparatus which concerns on Embodiment 4, it is not limited to this, Embodiment 1 The present invention may be applied to the refrigeration cycle apparatus according to Embodiment 3.

  10 Condensing Unit, 11 Inverter Compressor, 12 Condenser, 12a Condenser Fan, 13 Liquid Reservoir, 14 Shell Thermistor, 15 Controller, 16 Suction Thermistor, 17 Low Pressure Sensor, 18a Display Unit, 18b Output Unit, DESCRIPTION OF SYMBOLS 19 High pressure sensor, 20 Indoor unit, 21 Expansion valve, 22 Evaporator, 22a Evaporator fan, 30 Condensing unit liquid refrigerant outlet part, 31 Condensing unit gas refrigerant inlet part, 40 Indoor unit liquid refrigerant inlet part, 41 Indoor unit Gas refrigerant outlet.

Claims (13)

A refrigeration cycle comprising an inverter compressor, a condenser, an expansion device, and an evaporator connected in order by refrigerant piping;
A control unit for controlling the drive of the inverter compressor;
Low pressure detecting means for detecting a suction pressure which is a pressure of a refrigerant on a suction side of the inverter compressor;
High pressure detecting means for detecting a discharge pressure which is a pressure of a refrigerant on a discharge side of the inverter compressor;
With
The controller is
Converted from the suction pressure detected by the low pressure detection means to the evaporation temperature in the evaporator,
Converted from the discharge pressure detected by the high pressure detection means to the condensation temperature in the condenser,
The converted condensation temperature and the evaporation are converted into a region where the operation frequency of the inverter compressor is equal to or higher than a predetermined high frequency and the motor temperature of the inverter compressor is higher than a predetermined motor temperature upper limit value. If there is temperature, reduce the operating frequency of the inverter compressor,
The converted condensation temperature and the evaporation are converted into a region where the operation frequency of the inverter compressor is equal to or lower than a predetermined low frequency and the motor temperature of the inverter compressor is higher than a predetermined motor temperature upper limit value. The refrigeration cycle apparatus characterized by increasing the operating frequency of the inverter compressor when there is temperature . A refrigerating machine oil temperature detecting means installed in the inverter compressor for detecting a refrigerating machine oil temperature;
A suction temperature detecting means for detecting a suction temperature which is a temperature of a refrigerant on a suction side of the inverter compressor;
With
The controller is
When the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detection means is equal to or higher than a predetermined refrigerating machine oil temperature upper limit value, and / or the intake temperature detected by the intake temperature detection means is a predetermined intake temperature upper limit. When the drive stop condition, which is a case where the value is greater than or equal to the value, is satisfied, the drive of the inverter compressor is stopped,
Thereafter, when the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detecting means becomes less than the refrigerating machine oil temperature upper limit value, and the intake temperature detected by the intake temperature detecting means is less than the intake temperature upper limit value. The refrigeration cycle apparatus according to claim 1, wherein when the drive resuming condition, which is a case of satisfying, is satisfied, the drive of the inverter compressor is resumed. A refrigerating machine oil temperature detecting means installed in the inverter compressor for detecting a refrigerating machine oil temperature;
A suction temperature detecting means for detecting a suction temperature which is a temperature of a refrigerant on a suction side of the inverter compressor;
With
The controller is
When the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detection means is equal to or higher than a predetermined refrigerating machine oil temperature upper limit value, and / or the intake temperature detected by the intake temperature detection means is a predetermined intake temperature upper limit. When the drive stop condition, which is a case where the value is greater than or equal to the value, is satisfied, the drive of the inverter compressor is stopped,
Thereafter, when the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detection means becomes lower than the refrigerating machine oil restart temperature lower than the refrigerating machine oil temperature upper limit value by a predetermined value, and is detected by the intake temperature detection means The drive of the inverter compressor is resumed when a drive resumption condition that is a case where the suction temperature becomes lower than a resumption temperature of a suction temperature that is lower than the suction temperature upper limit by a predetermined value is satisfied. The refrigeration cycle apparatus according to 1. A refrigerating machine oil temperature detecting means installed in the inverter compressor for detecting a refrigerating machine oil temperature;
A suction temperature detecting means for detecting a suction temperature which is a temperature of a refrigerant on a suction side of the inverter compressor;
With
The controller is
When the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detecting means becomes equal to or higher than a predetermined refrigerating machine oil temperature upper limit value, the intake temperature detected by the intake temperature detecting means becomes equal to or higher than a predetermined intake temperature upper limit value. Or / and when the converted evaporation temperature satisfies a drive stop condition, which is a case where the converted evaporation temperature is equal to or lower than a predetermined evaporation temperature lower limit value, the drive of the inverter compressor is stopped,
Thereafter, when the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detection means becomes less than the refrigerating machine oil temperature upper limit value, the intake temperature detected by the intake temperature detection means becomes less than the intake temperature upper limit value. If and when the evaporation temperature in terms satisfies a a a driving restart condition when it becomes greater than the evaporation temperature lower limit value, according to claim 1, wherein the to restart the actuation of said inverter compressor Refrigeration cycle equipment. A refrigerating machine oil temperature detecting means installed in the inverter compressor for detecting a refrigerating machine oil temperature;
A suction temperature detecting means for detecting a suction temperature which is a temperature of a refrigerant on a suction side of the inverter compressor;
With
The controller is
When the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detecting means becomes equal to or higher than a predetermined refrigerating machine oil temperature upper limit value, the intake temperature detected by the intake temperature detecting means becomes equal to or higher than a predetermined intake temperature upper limit value. Or / and when the converted evaporation temperature satisfies a drive stop condition, which is a case where the converted evaporation temperature is equal to or lower than a predetermined evaporation temperature lower limit value, the drive of the inverter compressor is stopped,
Thereafter, when the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detection means becomes lower than the refrigerating machine oil restart temperature lower than the refrigerating machine oil temperature upper limit value by a predetermined value, the intake temperature detected by the intake temperature detection means Is lower than the resumption temperature of the intake temperature lower than the upper limit value of the intake temperature by a predetermined value, and when the converted evaporation temperature is higher than the resumption temperature of the evaporation temperature higher than the lower limit value of the evaporation temperature by a predetermined value. if it meets the driving restart condition, the refrigeration cycle apparatus according to claim 1, wherein the to restart the actuation of said inverter compressor. A refrigerating machine oil temperature detecting means installed in the inverter compressor for detecting a refrigerating machine oil temperature;
A suction temperature detecting means for detecting a suction temperature which is a temperature of a refrigerant on a suction side of the inverter compressor;
With
The controller is
When the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detecting means is equal to or higher than a predetermined refrigerating machine oil temperature upper limit value, and / or when the converted evaporating temperature is lower than a predetermined evaporating temperature lower limit value. When a certain drive stop condition is satisfied, the drive of the inverter compressor is stopped,
Thereafter, when the refrigerator oil temperature detected by the refrigerator oil temperature detection means becomes less than the refrigerator oil temperature upper limit value, and when the converted evaporation temperature becomes larger than the evaporation temperature lower limit value. if it meets the restart condition, the refrigeration cycle apparatus according to claim 1, wherein the to restart the actuation of said inverter compressor. A refrigerating machine oil temperature detecting means installed in the inverter compressor for detecting a refrigerating machine oil temperature;
A suction temperature detecting means for detecting a suction temperature which is a temperature of a refrigerant on a suction side of the inverter compressor;
With
The controller is
When the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detecting means is equal to or higher than a predetermined refrigerating machine oil temperature upper limit value, and / or when the converted evaporating temperature is lower than a predetermined evaporating temperature lower limit value. When a certain drive stop condition is satisfied, the drive of the inverter compressor is stopped,
Thereafter, when the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detecting means becomes lower than the refrigerating machine oil restart temperature lower than the refrigerating machine oil temperature upper limit value by a predetermined value, and the converted evaporating temperature is lower than the evaporating temperature lower limit. if it meets the driving restart condition is an occurrence of greater than high evaporation temperature restarted temperature by a predetermined value than the value, the refrigeration cycle apparatus according to claim 1, wherein the to restart the actuation of said inverter compressor. A refrigerating machine oil temperature detecting means installed in the inverter compressor for detecting a refrigerating machine oil temperature;
A suction temperature detecting means for detecting a suction temperature which is a temperature of a refrigerant on a suction side of the inverter compressor;
With
The expansion device is an electronic device that is connected to the control unit and whose opening degree is controlled by a command from the control unit,
The controller is
When the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detection means is equal to or higher than a predetermined refrigerating machine oil temperature upper limit value, and / or the intake temperature detected by the intake temperature detection means is a predetermined intake temperature upper limit. If a value or more, the refrigeration cycle apparatus according to claim 1, wherein the pre-Symbol Ru size camphor opening of the expansion device. A refrigerating machine oil temperature detecting means installed in the inverter compressor for detecting a refrigerating machine oil temperature;
A suction temperature detecting means for detecting a suction temperature which is a temperature of a refrigerant on a suction side of the inverter compressor;
With
The expansion device is an electronic device that is connected to the control unit and whose opening degree is controlled by a command from the control unit,
The controller is
When the refrigerating machine oil temperature detected by the refrigerating machine oil temperature detecting means becomes equal to or higher than a predetermined refrigerating machine oil temperature upper limit value, the intake temperature detected by the intake temperature detecting means becomes equal to or higher than a predetermined intake temperature upper limit value. and when, or / and, when the evaporating temperature in terms becomes equal to or lower than a predetermined evaporation temperature lower limit value, the refrigeration cycle apparatus according to claim 1, wherein the pre-Symbol Ru size camphor opening of the expansion device. Current detection means for detecting the compressor current flowing in the inverter compressor,
The controller is
When the operating frequency of the inverter compressor is equal to or higher than a predetermined frequency upper limit value, and when the compressor current detected by the current detection means is equal to or higher than a predetermined first current upper limit value, the inverter compression Reduce the operating frequency of the machine,
When OPERATION frequency of the inverter compressor is equal to or less than a predetermined frequency lower limit, and, when the compressor current detected by said current detecting means becomes a second current limit value or more predetermined, the inverter The refrigeration cycle apparatus according to any one of claims 1 to 9 , wherein the operating frequency of the compressor is increased. Comprising a display unit that is communicable with the control unit and displays an operating state of the refrigeration cycle apparatus;
The refrigeration cycle apparatus according to any one of claims 2 to 7 , wherein when the drive stop condition is satisfied, the control unit causes the display unit to display the fact to the outside. An output unit connected to the control unit;
The refrigeration cycle apparatus according to any one of claims 2 to 7 , wherein when the driving stop condition is satisfied, the control unit causes the output unit to output a voltage to the outside. An indoor unit including the expansion device and the evaporator;
A condensing unit comprising the inverter compressor, the condenser and the control unit;
The refrigeration cycle apparatus according to any one of claims 1 to 12 , wherein the refrigeration cycle apparatus is provided.

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