JP4468222B2 - Refrigeration apparatus and air conditioner equipped with the same - Google Patents

Description

  The present invention relates to a refrigeration apparatus including an indoor unit and an outdoor unit, and an air conditioner including the refrigeration apparatus.

  Conventionally, a compressor, a condenser, a first pressure reducing device, and an evaporator are sequentially connected by a refrigerant pipe that circulates using a non-azeotropic refrigerant as a refrigerant, and the first through an outlet of the compressor. A bypass pipe connecting and connecting a high pressure side up to the first pressure reducing device and a low pressure side from the first pressure reducing device to the compressor inlet via a second pressure reducing device; and the second pressure reducing device from the high pressure side of the bypass pipe Cooling means for cooling the non-azeotropic mixed refrigerant flowing into the refrigerant, a temperature detector and a pressure detector for detecting the temperature of the low-pressure refrigerant and the pressure of the low-pressure refrigerant at the outlet of the second decompression device, and the temperature There is a refrigerating and air-conditioning apparatus using a non-azeotropic refrigerant mixture that includes a detector and a composition calculator that calculates a refrigerant composition circulating inside the refrigeration cycle from a signal detected by the pressure detector (example) If, Patent Document 1).

  In this refrigeration air conditioner, signals from the temperature detector and the pressure detector are calculated by a composition calculator, and the refrigerant composition of the refrigerant circulating in the refrigeration cycle is detected based on the calculation result. In other words, when the refrigerant composition changes due to changes in the operating conditions and load conditions of the refrigeration air conditioner, or when the refrigerant composition changes due to refrigerant leakage while the refrigeration air conditioner is in use, or when the refrigerant composition changes due to malfunction during refrigerant charging. Even in this case, a non-azeotropic refrigerant mixture is used as the refrigerant so that the refrigerant composition of the refrigerant circulating in the refrigeration cycle can be accurately detected.

JP-A-8-75280 (6th page, FIG. 1 and FIG. 8)

  The above-described refrigeration and air-conditioning apparatus can exhibit its function and performance only when a non-azeotropic refrigerant mixture is enclosed. That is, the refrigerant composition of the non-azeotropic refrigerant mixture is calculated based on temperature and pressure, and the change in the refrigerant composition of the non-azeotropic refrigerant mixture is detected from the calculation result. However, the refrigerant enclosed in the refrigeration air conditioner is not limited to the non-azeotropic refrigerant mixture. For example, a refrigerant such as a single refrigerant or a pseudo-azeotropic refrigerant may be used for the refrigeration air conditioner.

  Therefore, when a refrigerant such as a single refrigerant or a pseudo-azeotropic refrigerant is used in the refrigeration air conditioner, there is a problem that the function and performance cannot be exhibited. There is also a problem that the type of refrigerant other than the non-azeotropic refrigerant mixture cannot be determined. Furthermore, since the operation | movement corresponding to refrigerant | coolants other than a non-azeotropic refrigerant mixture cannot be performed, there also existed a problem of causing failure of a refrigerating air-conditioning apparatus and a loss of energy.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a refrigeration apparatus that can determine the refrigerant used in the refrigeration apparatus and realize the operation corresponding to the refrigerant. . In addition to the determination of the refrigerant, whether there is an abnormality such as an abnormality that the refrigerant to be sealed is not sealed (refrigerant misfilling abnormality) or an abnormality that foreign matter is mixed in the refrigerant (foreign matter mixing abnormality) is determined. It is another object of the present invention to provide a refrigeration apparatus that enables this.

The refrigeration apparatus according to the present invention includes a compressor, a switching valve, a heat source side heat exchanger, a cooled side of a double pipe heat exchanger, a first flow rate adjusting means, a use side heat exchanger, the switching valve, and an accumulator . The refrigerant pipe has a refrigeration cycle sequentially connected by a refrigerant pipe, and the refrigerant pipe is branched between the double pipe heat exchanger and the first flow rate adjusting means, so that the second flow rate adjusting means and the double pipe heat exchanger are branched. A refrigeration apparatus connected to the suction side of the compressor via a cooling side of the first pressure detecting means for detecting the pressure of the refrigerant discharged from the compressor, and detecting the temperature of the condensed refrigerant And a control means for determining at least one of the type and quality of the refrigerant circulating in the refrigeration cycle based on detection information from the first pressure detection means and the condensation temperature detection means. , wherein, prior to shipment The cooling operation is performed by controlling the opening degree of the second flow rate adjusting means so that the refrigerant temperature detected by the condensation temperature detecting means becomes the saturation temperature, and the first pressure detecting means after a predetermined time has passed and Cooling operation is performed by controlling the opening degree of the second flow rate adjusting means so that α1 calculated from the detection information from the condensing temperature detecting means and the temperature of the refrigerant detected by the condensing temperature detecting means after shipment becomes the saturation temperature. At least one of the type and the quality of the refrigerant circulating in the refrigeration cycle by comparing with α3 calculated from the detection information from the first pressure detection means and the condensation temperature detection means after execution of a predetermined time It is characterized by distinguishing .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
FIG. 1 is a refrigerant circuit diagram showing a refrigeration apparatus 50 according to Embodiment 1 of the present invention. The refrigeration apparatus 50 includes a compressor 11, a four-way valve 12 that is a switching valve, a heat source side heat exchanger 13, a double pipe heat exchanger 14, a first flow rate adjusting means 21, and a use side heat exchanger 15. And the accumulator 16 are sequentially connected in series by the refrigerant pipe 10.

  The double pipe heat exchanger 14 is composed of a cooled side pipe 14a and a cooling side pipe 14b. The first flow rate adjusting means 21 is configured by connecting a throttle device 21a and a throttle device 21b in parallel. Moreover, the use side heat exchanger 15 is configured by connecting a first heat exchanger 15a and a second heat exchanger 15b in parallel.

  The refrigerant pipe 10 branches between the cooled side pipe 14a of the double pipe heat exchanger 14 and the first flow rate adjusting means 21, and is connected to the inlet side of the cooling side pipe 14b. Between the branched refrigerant pipe 10 and the inlet side of the cooling side pipe 14b, a throttle device 22 as a second flow rate adjusting means is provided. Moreover, the refrigerant | coolant piping 10 branches between the four-way valve 12 and the accumulator 16, and is connected to the exit side of the cooling side piping 14b.

  The first pressure sensor 31 serving as the first pressure detection means is provided on the refrigerant discharge side of the compressor 11. The second pressure sensor 32 as the second pressure detecting means is provided between the four-way valve 12 and the accumulator 16. The first temperature sensor 41 is provided between the heat source side heat exchanger 13 and the double pipe heat exchanger 14. The refrigerating apparatus 50 is provided with a control device 17 that is a control unit that controls the entire refrigerating device 50 based on detection information of each sensor, and a storage device 18 that is a storage unit that stores various types of information. .

  The refrigeration apparatus 50 is used in an air conditioner including a plurality of outdoor units (heat source side heat exchangers) and a plurality of indoor units (use side heat exchangers) connected to these outdoor units by a refrigerant pipe 10. The cooling operation and the heating operation are performed. In this way, the refrigeration apparatus 50 constitutes a refrigeration cycle in which the refrigerant circulates in the refrigerant pipe 10, and realizes a cooling operation and a heating operation by the characteristics of the refrigerant.

  The compressor 11 compresses a refrigerant into a high-temperature and high-pressure refrigerant. The four-way valve 12 switches the refrigerant flow between the cooling operation and the heating operation. The heat source side heat exchanger 13 condensates and evaporates the refrigerant by heat exchange between the refrigerant and air. The double pipe heat exchanger 14 further cools the refrigerant condensed and liquefied by the heat source side heat exchanger 13 during the cooling operation.

  The throttling device 21a and the throttling device 21b of the first flow rate adjusting means 21 are generally called a pressure reducing valve or an expansion valve, and depressurize the refrigerant. The use side heat exchanger 15 converts the refrigerant into evaporated gas and condensates by heat exchange between the refrigerant and air. The refrigerant pipe 10 conducts a refrigerant that is compressed into a gas or decompressed into a liquid. The accumulator 16 stores excess refrigerant.

  The control device 17 determines the type of refrigerant based on detection information transmitted from various sensors such as the first pressure sensor 31, the second pressure sensor 32, and the first temperature sensor 41, and the second flow rate adjusting unit 21 The flow rate of the refrigerant is adjusted by controlling the expansion device 22 or the like, and may be configured by a microcomputer or the like. The storage device 18 stores detection information detected by each sensor in order to determine the refrigerant, and may be configured by a nonvolatile memory, an HDD (hard disk device), or the like.

  The expansion device 22 serving as the second flow rate adjusting means is controlled to be opened during the refrigerant operation, and causes the refrigerant to flow through the cooling side pipe 14b of the double pipe heat exchanger 14, and may be constituted by an on-off valve or the like. The expansion device 22 is controlled to be closed during heating operation. The first pressure sensor 31 detects the pressure (high pressure) of the refrigerant discharged from the compressor 11.

  The second pressure sensor 32 detects the pressure (low pressure) of the refrigerant sucked into the compressor 11. The first temperature sensor 41 functions as a condensation temperature detection means and an evaporation temperature detection means, and detects the temperature of the refrigerant circulating in the refrigeration cycle. Note that the first temperature sensor 41 may be a thermistor or the like.

  Examples of the refrigerant sealed in the refrigerant pipe 10 include non-azeotropic mixed refrigerant, pseudo-azeotropic mixed refrigerant, and single refrigerant. Non-azeotropic refrigerant mixture includes R407C (R32 / R125 / R134a) which is an HFC (hydrofluorocarbon) refrigerant. Since this non-azeotropic refrigerant mixture is a mixture of refrigerants having different boiling points, it has a characteristic that the composition ratio of the liquid-phase refrigerant and the gas-phase refrigerant is different. The pseudo azeotropic refrigerant mixture includes R410A (R32 / R125) and R404A (R125 / R143a / R134a) which are HFC refrigerants. This pseudo azeotrope refrigerant has the same characteristic as that of the non-azeotrope refrigerant and has an operating pressure of about 1.6 times that of R22.

  The single refrigerant includes R22, which is an HCFC (hydrochlorofluorocarbon) refrigerant, R134a, which is an HFC refrigerant, and the like. Since this single refrigerant is not a mixture, it has the property of being easy to handle. In addition, HC (hydrocarbon-based) refrigerants such as propane, isobutane, and ammonia can be used. R22 represents chlorodifluoromethane, R32 represents difluoromethane, R125 represents pentafluoroethane, R134a represents 1,1,1,2-tetrafluoroethane, and R143a represents 1,1,1-trifluoroethane.

FIG. 2 is a refrigerant circuit diagram illustrating the flow of the refrigerant during the cooling operation.
First, the refrigerant heated to high temperature and high pressure by the compressor 11 is discharged from the compressor 11 (arrow A) and flows into the heat source side heat exchanger 13 via the four-way valve 12 (arrow B). The refrigerant that has flowed into the heat source side heat exchanger 13 exchanges heat with air to be condensed and liquefied. That is, the refrigerant dissipates heat and changes to a liquid having substantially the same temperature as the outside air. Then, it flows into the to-be-cooled side pipe 14a of the double pipe heat exchanger 14 (arrow C), and is further cooled.

  The cooled refrigerant flows into the first flow rate adjusting means 21 and the cooling side pipe 14b (arrow D and arrow J). That is, the expansion device 22 during the cooling operation is controlled to open, and a part of the refrigerant flows into the cooling side pipe 14b. The refrigerant flowing into the first flow rate adjusting means 21 is depressurized by the expansion device 21a and the expansion device 21b, and changes to a low-temperature / low-pressure condensed two-phase refrigerant. The refrigerant exchanges heat with air in the first heat exchanger 15a and the second heat exchanger 15b of the use side heat exchanger 15 to be evaporated and gasified (arrow E). That is, it absorbs heat from the air (cools the air) and changes to a gas.

  Thereafter, the refrigerant exits from the use side heat exchanger 15 (arrow F), passes through the four-way valve 12 (arrow G), and flows into the accumulator 16 (arrow H, arrow I). Then, excessive refrigerant is stored in the accumulator 16 and is sucked into the compressor 11. On the other hand, the refrigerant (arrow J) flowing into the cooling side pipe 14b is first decompressed by the expansion device 22 and then flows into the cooling side pipe 14b. And it heat-exchanges with the refrigerant | coolant which flows through the to-be-cooled side piping 14a within the double pipe heat exchanger 14, and it evaporates.

  That is, the refrigerant that flows through the cooled side pipe 14a absorbs heat (cools the refrigerant) and changes to a gas. As a result, the refrigerant flowing through the cooled side piping 14a is further cooled. Thereafter, the refrigerant returns to the refrigeration cycle (arrow K) and flows into the accumulator 16 (arrow I). Then, excessive refrigerant is stored in the accumulator 16 and is sucked into the compressor 11. As described above, the cooling operation is performed by circulating the refrigerant in the refrigeration cycle.

FIG. 3 is a refrigerant circuit diagram showing a refrigerant flow during heating operation.
The heating operation is performed by switching the refrigerant flow with the four-way valve 12 and circulating the refrigerant in the refrigeration cycle, contrary to the cooling operation. First, the refrigerant heated to high temperature and high pressure by the compressor 11 is discharged from the compressor 11 (arrow a) and flows into the use side heat exchanger 15 via the four-way valve 12 (arrow b). The refrigerant that has flowed into the use-side heat exchanger 15 exchanges heat with air to be condensed and liquefied (arrow c). That is, the refrigerant dissipates heat (warms up the air) and changes to a liquid.

  The liquefied refrigerant flows into the first flow rate adjusting means 21, is decompressed by the expansion device 21a and the expansion device 21b, and changes to a low-temperature / low-pressure condensed two-phase refrigerant. The refrigerant exits the first flow rate adjusting means 21 (arrow d) and flows into the heat source side heat exchanger 13 via the double pipe heat exchanger 14 (arrow e). The refrigerant exchanges heat with air in the heat source side heat exchanger 13 to evaporate. That is, it absorbs heat from air and changes to gas.

  Note that the expansion device 22 in the heating operation is controlled to be closed, and the refrigerant does not flow into the cooling side pipe 14b. The refrigerant (arrow f) exiting from the heat source side heat exchanger 13 passes through the four-way valve 12 (arrow g) and flows into the accumulator 16 (arrow h and arrow i). Excess refrigerant is stored in the accumulator 16 and sucked into the compressor 11. In this way, the heating operation is performed by circulating the refrigerant in the refrigeration cycle, contrary to the cooling operation.

Next, the flow of abnormality detection processing in the refrigeration apparatus 50 will be described.
FIG. 4 is a flowchart showing an example of an operation flow for recording the operation state of the refrigeration apparatus 50 before shipment. The refrigeration apparatus 50 that has been manufactured is evacuated, and then a test operation is performed with the refrigerant to be sealed enclosed. And the value (normal operation state value) which shows the operation state at that time is memorize | stored, and it is set as the reference value at the time of trial operation (cooling and heating) again after shipment. The test run before shipment is referred to as a pre-test run.

  That is, by detecting a normal operation state value obtained in the pre-trial operation and a value (actually measured value) indicating an operation state obtained in the trial operation after shipment, an abnormality occurring in the refrigeration cycle of the refrigeration apparatus 50 is detected. Is possible. For example, abnormalities that occur in the refrigeration cycle include abnormalities that the refrigerant to be sealed is not sealed (refrigerant misfilling abnormality), abnormalities that foreign matter is mixed in the refrigerant (foreign matter contamination abnormality), and the like. There is.

  In addition, the refrigerant | coolant enclosed has types, such as a non-azeotrope mixed refrigerant | coolant, a pseudo azeotrope mixed refrigerant | coolant, a single refrigerant | coolant, etc. as mentioned above, and each has a characteristic property. The refrigerant can be discriminated based on the characteristic properties of the refrigerant. That is, the normal operation state value and refrigerant characteristics (saturation temperature with respect to pressure, etc.) obtained in the pre-trial operation are stored, and those values are compared with the actual measurement values to determine the type of the enclosed refrigerant. It is possible to do.

  In the pre-test operation, first, the cooling operation of the refrigeration apparatus 50 is executed. At this time, the expansion device 22 as the second flow rate adjusting means is fixed at a predetermined opening, and the cooling operation is started (step S101). The predetermined opening of the expansion device 2 is adjusted so that the temperature of the refrigerant detected by the first temperature sensor 41 (condensation temperature detection means) becomes the saturation temperature. During the cooling operation, the refrigerant is circulated in the refrigeration cycle as shown in FIG.

  The cooling operation is continued until the refrigeration apparatus 50 is stabilized (for example, 10 minutes) (step S102). This may be a time until the refrigerant circulates for lubrication. When the predetermined time has elapsed and the refrigeration apparatus 50 is stabilized (step S102; YES), the control device 17 determines the first temperature sensor 41 from the saturation temperature of the refrigerant calculated from the detection information (pressure information) of the first pressure sensor 31. The actual detection information (temperature information) is subtracted and the difference (α1) is calculated (step S103).

  This α1 serves as a reference for an error in information detected by the first pressure sensor 31 and the first temperature sensor 41 in the early stage of the cooling operation. That is, it is possible to diagnose an error in the initial stage of the cooling operation by comparing various information of the refrigerant actually detected by the first pressure sensor 31 and the first temperature sensor 41 with α1 when the cooling trial operation is performed after shipment. it can. Α1 is stored in the storage device 18 (step S104). Further, when α1 is stored in the storage device 18, it may be stored automatically or may be stored manually.

  Next, the heating operation of the refrigeration apparatus 50 is executed in the pre-trial operation. At this time, the expansion device 22 as the second flow rate adjusting means is closed and the heating operation is started (step S105). Similarly to the cooling operation, the heating operation is continued until the refrigeration apparatus 50 is stabilized (for example, 10 minutes) (step S106).

  When the predetermined time has elapsed and the refrigeration apparatus 50 is stabilized (step S106; YES), the control device 17 determines the first temperature sensor 41 (evaporation temperature detection) from the refrigerant saturation temperature calculated from the pressure information of the second pressure sensor 32. The temperature information of (means) is subtracted and the difference (α2) is calculated (step S107). This α2 is a reference for an error in information detected by the first pressure sensor 31 and the first temperature sensor 41 in the early stage of the heating operation. That is, it is possible to diagnose an error in the early stage of the heating operation by comparing various information of the refrigerant actually detected by the first pressure sensor 31 and the first temperature sensor 41 with α1 when the heating trial operation is performed after shipment. it can. Α2 is also stored in the storage device 18 in the same manner as α1 (step S108).

  This completes the pre-trial operation. Thereafter, the refrigeration apparatus 50 is shipped and a refrigerant discrimination test operation is performed at the site where the refrigeration apparatus 50 is installed. In general, piping work, refrigerant charging, and additional refrigerant charging are often performed at the time of installation when the refrigeration apparatus 50 is installed locally after shipment. That is, at the time of construction of the refrigeration apparatus 50, there is a high possibility that a refrigerant different from the refrigerant to be originally enclosed is filled, or that foreign matter such as moisture and air is mixed because the refrigerant pipe is not sufficiently evacuated. .

  FIG. 5 is a flowchart showing the flow of abnormality determination processing during cooling operation. When the construction is completed on site, the cooling trial operation of the refrigeration apparatus 50 is started. In this cooling trial operation, it is desirable to operate with all the indoor units constituting the air conditioner in which the refrigeration apparatus 50 is used.

  In the refrigeration apparatus 50, the expansion device 22 is fixed at a predetermined opening, and the cooling trial operation is started (step S201). The predetermined opening degree of the expansion device 22 is adjusted similarly to the pre-trial operation. The cooling trial operation is continued until the refrigeration apparatus 50 is stabilized (for example, 10 minutes) (step S202). This may be a time until the refrigerant circulates for lubrication. The reason is the same as in the pre-trial operation.

  When the predetermined time has elapsed and the refrigeration apparatus 50 is stabilized (step S202; YES), the control device 17 obtains the temperature information of the first temperature sensor 41 from the saturation temperature of the refrigerant calculated from the pressure information of the first pressure sensor 31. Then, the difference (α3) is calculated (step S203). Then, the control device 17 compares α3 with α1 stored in the storage device 18 to determine whether there is an abnormality (step S204).

  The control device 17 calculates the absolute value (ABS (α3-α1)) of the difference between α3 and α1, and diagnoses whether this calculated value is within an allowable range indicating the set normal state. If this calculated value is within the allowable range, it is determined that there is no abnormality, and if it is not within the allowable range, it is determined that there is an abnormality. For example, if 3 is set as the value indicating the allowable range, the control device 17 is not within the allowable range if the absolute value of the difference between α3 and α1 is 3 or more. If there is no abnormality. As described above, the abnormality includes a refrigerant misencapsulation abnormality and a foreign matter mixing abnormality.

  It is desirable to set the allowable range indicating the normal state in detail so that the type of abnormality can be specifically determined. That is, the target to be compared with α3 is not limited to α1, and other reference values may be compared. For example, if various abnormalities (refrigerant misfilling abnormality or foreign matter mixing abnormality) are reproduced in the pre-test operation and multiple characteristic and specific values obtained from the various abnormalities are calculated, the abnormality can be identified more accurately. It becomes possible to judge. In the case of a refrigerant misencapsulation abnormality, the type of refrigerant can be determined from the characteristics of the encapsulated refrigerant.

  When determining that there is an abnormality (step S204; YES), the control device 17 issues an abnormality to notify the user, a worker, or the like of the abnormality (step S205). If the control device 17 determines that there is no abnormality (step S204; NO), it does not issue an abnormality (step S206). Then, the cooling trial operation is terminated. If there is no abnormality, the cooling trial operation may be continued as it is.

  Further, the abnormal alarm may be issued by a buzzer, a voice, or the like, or may be displayed on an operation display unit such as a remote controller (not shown). Furthermore, if a plurality of types of abnormality is prepared, the abnormality type corresponding to the type can be easily identified. In addition, when the control device 17 determines that there is an abnormality, the refrigeration device 50 may be forcibly stopped or may not be stopped. Here, the cooling trial operation after the construction of the refrigeration apparatus 50 has been described as an example. However, the present invention is not limited to this, and abnormality determination can be similarly performed during the normal cooling operation.

  FIG. 6 is a flowchart showing a flow of abnormality determination processing during heating operation. When the construction is completed on site, the heating trial operation of the refrigeration apparatus 50 is started. In this heating trial operation, it is desirable to operate with all the indoor units constituting the air conditioner in which the refrigeration apparatus 50 is used.

  In the refrigeration apparatus 50, the expansion device 22 is closed and the heating trial operation is started (step S301). The heating trial operation is continued until the refrigeration apparatus 50 is stabilized (for example, 10 minutes) (step S302). This may be a time until the refrigerant circulates for lubrication. The reason is the same as in the pre-test operation and the cooling test operation.

  When the predetermined time has elapsed and the refrigeration apparatus 50 is stabilized (step S302; YES), the control device 17 obtains the temperature information of the first temperature sensor 41 from the saturation temperature of the refrigerant calculated from the pressure information of the first pressure sensor 31. The difference (α4) is calculated by subtracting (step S303). Then, the control device 17 compares α4 with α2 stored in the storage device 18 to determine whether there is an abnormality (step S304).

  The control device 17 calculates the absolute value (ABS (α4-α2)) of the difference between α4 and α2, and diagnoses whether this calculated value is within an allowable range indicating a set normal state. If this calculated value is within the allowable range, it is determined that there is no abnormality, and if it is not within the allowable range, it is determined that there is an abnormality. The allowable range may be set in the same manner as in the cooling trial operation. If there is an abnormality having a characteristic different from the cooling trial operation, the characteristic value may be calculated and stored in the pre-trial operation.

  When determining that there is an abnormality (step S304; YES), the control device 17 issues an abnormality to notify the user, a worker, or the like of the abnormality (step S305). If the controller 17 determines that there is no abnormality (step S304; NO), it does not issue an abnormality (step S306). Then, the heating trial operation is terminated. If there is no abnormality, the heating trial operation may be continued as it is.

  Further, the abnormal alarm may be issued by a buzzer, a voice, or the like, or may be displayed on an operation display unit such as a remote controller (not shown). Furthermore, if a plurality of types of abnormality is prepared, the abnormality type corresponding to the type can be easily identified. In addition, when the control device 17 determines that there is an abnormality, the refrigeration device 50 may be forcibly stopped or may not be stopped. Here, the heating trial operation after the construction of the refrigeration apparatus 50 has been described as an example. However, the present invention is not limited to this, and abnormality determination can be similarly performed during the normal heating operation.

  In the cooling operation and the heating operation, surplus refrigerant generated due to the operation condition and load condition is stored in the accumulator 16. The refrigerant stored in the accumulator 16 is divided and stored for each component constituting the refrigerant. For this reason, when the refrigerant is stored in the accumulator 16, the composition of the refrigerant circulating in the refrigeration cycle changes.

  Therefore, for such an operation involving a change in the composition of the refrigerant, for example, both the case where only one of the expansion device 21a or the expansion device 21b of the first flow rate adjusting means 21 is opened during the heating operation and both. When the difference between the saturation temperature of the refrigerant calculated from the pressure detected by the second pressure sensor 32 and the temperature detected by the first temperature sensor 41 changes greatly in the case of being open, the non-azeotropic refrigerant mixture is added to the refrigerant. It can be determined that it is in use.

  Further, even if the temperature detected by the first temperature sensor 41 greatly fluctuates with respect to the predetermined pressure detected by the second pressure sensor 32, it is determined that a non-azeotropic refrigerant mixture is used as the refrigerant. be able to. That is, it is determined that the refrigerant is a non-azeotropic refrigerant mixture, assuming that the saturation temperature with respect to a predetermined pressure has changed with respect to the change of surplus refrigerant and the way of stagnation of refrigerant in the use-side heat exchanger 15, It can be distinguished from a pseudo-azeotropic refrigerant mixture. The stagnation of the refrigerant is a phenomenon in which the refrigerant stays in the equipment.

[Embodiment 2]
FIG. 7 is a refrigerant circuit diagram showing a refrigeration apparatus 50a according to Embodiment 2 of the present invention. The parts common to those in FIG.
The second temperature sensor 42 is provided between the refrigerant outlet side of the expansion device 22 and the refrigerant inlet side of the cooling side pipe 14b. The third temperature sensor 43 is provided between the first flow rate adjusting means 21 and the use side heat exchanger 15. The fourth temperature sensor 44 is provided in the use side heat exchanger 15. The fifth temperature sensor 45 is provided in the heat source side heat exchanger 13.

  These temperature sensors detect the temperature of the refrigerant at the provided location. The detected temperatures detected by these temperature sensors are transmitted to the control device 17. In the first embodiment, the case where the reference values (α1, α2) for abnormality determination are calculated based on the detection information of the first pressure sensor 31, the second pressure sensor 32, and the first temperature sensor 41 has been described as an example. In the second embodiment, based on detection information of the first pressure sensor 31 and the second pressure sensor 32, and the second temperature sensor 42, the third temperature sensor 43, the fourth temperature sensor 44, and the fifth temperature sensor 45. A case where the reference value for abnormality determination is calculated will be described as an example.

  The fifth temperature sensor 45 is provided in the heat transfer tube of the heat source side heat exchanger 13 and detects the temperature of the condensed and liquefied refrigerant (condensed two-phase refrigerant) during the cooling operation. Therefore, in the cooling operation, a value obtained by subtracting the condensation saturation temperature of the refrigerant detected by the fifth temperature sensor 45 from the saturation temperature calculated from the refrigerant pressure detected by the first pressure sensor 31 may be used as the reference value for the abnormality determination. Further, during the cooling operation, a value obtained by subtracting the refrigerant temperature of the refrigerant detected by the second temperature sensor 42 from the saturation temperature calculated from the refrigerant pressure detected by the second pressure sensor 32 may be used as the reference value for the abnormality determination. Further, during cooling operation, a value obtained by subtracting the refrigerant temperature of the refrigerant detected by the third temperature sensor 43 from the saturation temperature calculated from the refrigerant pressure detected by the second pressure sensor 32 may be used as a reference value for abnormality determination.

  The 4th temperature sensor 44 is provided in the heat exchanger tube of the use side heat exchanger 15, and detects the temperature of the condensed two-phase refrigerant at the time of heating operation. Therefore, in the heating operation, a value obtained by subtracting the condensation saturation temperature of the refrigerant detected by the fourth temperature sensor 44 from the saturation temperature calculated from the refrigerant pressure detected by the first pressure sensor 31 may be used as the reference value for the abnormality determination.

  As described above, the abnormality determination is performed based on the detection information of the first pressure sensor 31 and the second pressure sensor 32, the second temperature sensor 42, the third temperature sensor 43, the fourth temperature sensor 44, and the fifth temperature sensor 45. Since the reference value can be used, the abnormality determination can be performed more reliably. If the calculated reference value is used in combination, the certainty of abnormality determination is further increased. Further, α1 and α2 calculated in the first embodiment may be used together. The reference value calculated here may be stored in the storage device 18.

  In the first embodiment, the case where the forced stop or the operation is continued after performing the abnormality determination has been described as an example, but the operation corresponding to the determined refrigerant may be executed. This is because the refrigeration apparatus 50 can be operated without degrading performance if it can be operated to exert its refrigerant ability even if it is misencapsulated. Further, if the refrigerant to be sealed must be sealed, the refrigeration apparatus 50 will not be operated during that time, and it will be time consuming for users, workers, and the like.

  In order to prevent such a situation, the characteristics of each refrigerant may be stored in advance in the storage device 18 so that the optimum operation according to the type of refrigerant is possible. That is, after determining the type of refrigerant and specifying the type of refrigerant, the control device 17 determines the throttle device 21a or the like so that the optimum operation corresponding to the refrigerant can be realized from the characteristics stored in the storage device 18. The diaphragm device 21b and the diaphragm device 22 may be controlled.

It is a refrigerant circuit figure which shows the freezing apparatus which concerns on Embodiment 1 of this invention. It is a refrigerant circuit figure which shows the flow of the refrigerant | coolant at the time of air_conditionaing | cooling operation. It is a refrigerant circuit figure which shows the flow of the refrigerant | coolant at the time of heating operation. It is a flowchart which shows the flow of the pre trial operation of a freezing apparatus. It is a flowchart which shows the flow of the cooling trial operation of a freezing apparatus. It is a flowchart which shows the flow of the heating trial operation of a freezing apparatus. It is a refrigerant circuit figure which shows the freezing apparatus which concerns on Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Refrigerant piping, 11 Compressor, 12 Four way valve, 13 Heat source side heat exchanger, 14 Double pipe heat exchanger, 15 Use side heat exchanger, 15a 1st heat exchanger, 15b 2nd heat exchanger, 16 Accumulator , 17 Control device, 18 Storage device, 21 First flow rate adjusting means, 21a Throttle device, 21b Throttle device, 22 Throttle device, 31 First pressure sensor, 32 Second pressure sensor, 41 First temperature sensor, 42 Second temperature Sensor, 43 3rd temperature sensor, 44 4th temperature sensor, 45 5th temperature sensor, 50 freezing apparatus, 50a freezing apparatus.

Claims (9)

A refrigeration cycle in which a compressor, a switching valve, a heat source side heat exchanger, a cooled side of a double pipe heat exchanger, a first flow rate adjusting means, a use side heat exchanger, the switching valve, and an accumulator are connected sequentially by a refrigerant pipe. The refrigerant pipe is branched between the double pipe heat exchanger and the first flow rate adjusting means, and the compression is performed via the second flow rate adjusting means and the cooling side of the double pipe heat exchanger. A refrigeration system connected to the suction side of the machine,
First pressure detection means for detecting the pressure of the refrigerant discharged from the compressor;
Condensation temperature detection means for detecting the temperature of the condensed refrigerant;
Control means for discriminating at least one of the type and quality of the refrigerant circulating in the refrigeration cycle based on detection information from the first pressure detection means and the condensation temperature detection means,
The control means includes
Before the shipment, the opening of the second flow rate adjusting unit is controlled so that the refrigerant temperature detected by the condensing temperature detecting unit becomes a saturation temperature, and the cooling operation is executed. Calculated from the detection information from the means and the condensation temperature detection means,
The first pressure detecting means after a predetermined time has elapsed by controlling the opening of the second flow rate adjusting means so that the refrigerant temperature detected by the condensing temperature detecting means becomes a saturation temperature after shipment. And at least one of the type and quality of the refrigerant circulating in the refrigeration cycle by comparing α3 calculated from the detection information from the condensation temperature detection means . The control means includes
A value obtained by subtracting the refrigerant temperature detected by the condensing temperature detection means from the saturation temperature of the refrigerant calculated from the pressure of the refrigerant detected by the first pressure detection means during operation performed with the refrigerant to be enclosed. The refrigeration apparatus according to claim 1, wherein the reference value is used for determining at least one of the type and quality of the refrigerant. The control means includes
A value obtained by subtracting the refrigerant temperature detected by the condensing temperature detection means from the saturation temperature of the refrigerant calculated from the refrigerant pressure detected by the first pressure detection means at the time of operation performed after completion of the construction, and the reference value The refrigeration apparatus according to claim 1, wherein at least one of the type and quality of the refrigerant is determined. The control means includes
A value obtained by subtracting the refrigerant temperature detected by the condensing temperature detection means from the saturation temperature of the refrigerant calculated from the refrigerant pressure detected by the first pressure detection means at the time of operation performed after completion of the construction, and the reference value When it is not within a predetermined range indicating the normal state of the refrigeration cycle, it is determined that an abnormality has occurred in the refrigeration cycle. Refrigeration equipment. The control means includes
Based on the change in the saturation temperature of the refrigerant calculated from the refrigerant pressure detected by the first pressure detection means or the second pressure detection means, whether the refrigerant is a non-azeotropic refrigerant mixture, a pseudo-azeotropic refrigerant mixture, or a single refrigerant the refrigerating device according to claim 1, characterized in that to determine. Alarm means for informing the state of the refrigeration apparatus,
The control means includes
6. The refrigeration apparatus according to claim 1 , wherein when at least one of the type and quality of the refrigerant is determined, the determination result is displayed on the alarm means . The control means includes
When it is determined that an abnormality has occurred in the refrigeration cycle,
The refrigeration apparatus according to claim 6, wherein the occurrence of the abnormality is reported to the alarm means . Forcibly stopping means for forcibly stopping the refrigeration apparatus;
The control means includes
The refrigeration apparatus according to any one of claims 1 to 7 , wherein when it is determined that an abnormality has occurred in the refrigeration cycle, the refrigeration apparatus is forcibly stopped by controlling the forced stop means . An air conditioner comprising the refrigeration apparatus according to any one of claims 1 to 8 .

Images