JP6564658B2 - Refrigeration equipment - Google Patents

Description

  The present invention relates to a refrigeration apparatus provided with a supercooler, and in particular, in a separate-type refrigeration apparatus in which a compressor apparatus is installed indoors and a condenser apparatus is installed outdoors, a refrigerant pipe downstream of the supercooler is connected to a refrigerant pipe. It relates to those that suppress condensation.

  As a conventional refrigeration apparatus provided with a supercooler, there is one described in JP2013-142487A (Patent Document 1). The thing of this patent document 1 is equipped with the supercooler (supercooling heat exchanger) which condenses the high-temperature / high pressure gas refrigerant discharged from the compressor in a condenser, and further supercools this condensed liquid refrigerant. Yes. This supercooler is used for the purpose of avoiding that the refrigerant is not completely condensed by the condenser and becoming flash gas, or for improving the refrigeration capacity by lowering the temperature of the liquid refrigerant.

  The subcooler includes a liquid refrigerant cooling circuit that supercools the liquid refrigerant in the main refrigerant pipe flowing through the subcooler with a reduced pressure refrigerant extracted from the high-pressure liquid refrigerant flowing through the main refrigerant pipe. Yes. Further, the decompressed refrigerant after supercooling the high-pressure liquid refrigerant flowing through the main refrigerant pipe in the supercooler is configured to be injected into an intermediate pressure portion of the compressor.

JP2013-142487A

  In the above-mentioned Patent Document 1, the temperature of the refrigerant flowing through the refrigerant pipe on the downstream side of the subcooler may be lowered to a dew point temperature or lower by the supercooler, and in this case, condensation occurs in the refrigerant pipe. Conventionally, in order to prevent this dew condensation, a heat insulating material is attached to the refrigerant pipe in the field, but there is a problem that the work load at the time of construction on the site is increased and the cost of using the heat insulating material is high.

  In addition, when replacing existing products that are not equipped with a supercooler (refrigeration equipment) with a product that is equipped with a supercooler, it may be difficult to attach a heat insulating material when using existing refrigerant piping. In this case, there is a problem that the generation of condensation cannot be prevented or the cooling amount in the supercooler must be suppressed so that the condensation does not occur, and the refrigerating capacity cannot be improved.

  On the other hand, there is a case where heat insulation is applied to the local refrigerant pipe where the refrigeration system is installed. In this case, since there is no problem with condensation, it is desirable to improve the refrigeration capacity by reducing the liquid refrigerant temperature as low as possible. However, in the conventional refrigeration apparatus, sufficient consideration is not given to improving the refrigeration capacity by controlling the liquid refrigerant temperature low.

  Further, a condensing device having a compressor having a compressor (for example, a positive displacement compressor) that sucks and compresses the low-pressure gas refrigerant is installed indoors, and has a condenser that condenses the high-pressure gas refrigerant discharged from the compressor. There is also a separate refrigeration system installed outdoors. In this separate-type refrigeration apparatus, the high-pressure gas refrigerant compressed by the compression apparatus installed indoors is sent to the condensation apparatus installed outdoors, and converted into high-pressure liquid refrigerant by the condenser. After transporting again to the apparatus side, this high-pressure liquid refrigerant is sent to the evaporator to cool the object to be cooled.

  Also in this separate type refrigeration apparatus, a supercooler is provided in the compression device, and a supercooler for further supercooling the high-pressure liquid refrigerant from the condenser is provided in the same manner as in Patent Document 1, and this supercooling is provided. The liquid refrigerant supercooled by the evaporator can be transported to the evaporator. Also in the case of this separate type refrigeration apparatus, it is necessary to suppress the occurrence of condensation when a heat insulating material is not used in the refrigerant pipe on the downstream side of the supercooler. The refrigerant piping on the downstream side of the supercooler has an indoor installation portion and an outdoor installation portion, and it is necessary to suppress the occurrence of condensation on any portion of the refrigerant piping.

  The object of the present invention is to suppress the occurrence of condensation even in the case where a heat insulating material is not used in the refrigerant pipe on the downstream side of the supercooler in a separate type refrigeration apparatus provided with an indoor installation compression apparatus and an outdoor installation condensation apparatus. It is to obtain a refrigeration apparatus that can be used.

  In order to achieve the above object, the present invention provides a compression apparatus that is installed indoors and has a compressor that compresses low-pressure gas refrigerant from an evaporator and a supercooler that supercools high-pressure liquid refrigerant from a condenser, A condenser for condensing the high-pressure gas refrigerant from the compressor, a condenser having a blower for blowing air to the condenser, and a main refrigerant pipe connecting the compressor, the condenser and the subcooler. And the compression device subcools the refrigerant in the main refrigerant pipe flowing through the subcooler with the reduced-pressure refrigerant extracted from the high-pressure liquid refrigerant flowing through the main refrigerant pipe and depressurized. A liquid refrigerant cooling circuit for injecting the reduced pressure refrigerant into the intermediate pressure portion of the compressor, a supercooling expansion device for controlling and reducing the flow rate of the refrigerant flowing through the liquid refrigerant cooling circuit, and detecting an indoor temperature With indoor temperature sensor A controller for controlling the expansion device for supercooling, and the condenser includes an outside air temperature sensor for detecting an outside air temperature, and a controller for controlling the blower. The control device is connected to the control device via a transmission line, and the control device of the compression device includes the subcooling expansion device based on the indoor temperature detected by the indoor temperature sensor and the outside air temperature detected by the outside air temperature sensor. It has a dew condensation suppression mode to be controlled.

  According to the present invention, in a separate-type refrigeration apparatus including an indoor-installed compression device and an outdoor-installed condensing device, the occurrence of condensation is suppressed even when a heat insulating material is not used in the refrigerant pipe downstream of the supercooler. The effect which can obtain the freezing apparatus which can be obtained is acquired.

It is a refrigeration cycle system diagram showing Example 1 of the refrigeration apparatus of the present invention. It is a flowchart explaining the control flow of the dew condensation suppression mode in the control apparatus by the side of the compression apparatus shown in FIG.

  Hereinafter, specific examples of the refrigeration apparatus of the present invention will be described with reference to the drawings.

A first embodiment of the refrigeration apparatus of the present invention will be described with reference to FIGS. FIG. 1 is a refrigeration cycle diagram showing a first embodiment of a refrigeration apparatus of the present invention, and FIG. 2 is a flowchart for explaining a control flow in a dew condensation suppression mode in the control apparatus shown in FIG.
First, the configuration of a separate refrigeration apparatus targeted by this embodiment will be described with reference to FIG.

  In FIG. 1, 100 is a compression device that is a part of a heat source device for generating a cold heat source, and 200 is a condensing device that is another part of the heat source device for generating a cold heat source. The condensing device 200 is connected by a gas refrigerant pipe 71 and a liquid refrigerant pipe 72 that are main refrigerant pipes, and constitutes a refrigerator 600 that is a heat source apparatus. Reference numeral 300 denotes a load device connected to the refrigerator 600, and in this embodiment, a case where the load device 300 is a low-pressure device having the evaporator 5 will be described.

  The refrigerator (heat source device) 600 and the load device (low pressure device) 300 are connected by a liquid side refrigerant pipe 400 and a gas side refrigerant pipe 500 which are main refrigerant pipes to constitute a refrigeration apparatus 700. The compression device 100 is installed indoors such as a store, the condensing device 200 is installed outdoors such as a store, and the refrigerator 600 is a separate type.

  Examples of the load device (low-pressure device) 300 include a showcase that is installed in a store such as a refrigerator, a freezer, and a supermarket to cool food or the like, or an indoor unit of an air conditioner. In the present embodiment, the case where the load device 300 is a refrigerator will be described as an example. Note that the present invention can be similarly implemented even when a plurality of load devices (low-pressure devices) 300 are connected to a single refrigerator 600 without being limited to one.

  The refrigerator (heat source device) 600 includes a compressor 1 such as a scroll compressor that sucks and compresses refrigerant, a condenser 2 that condenses and liquefies high-pressure gas refrigerant discharged from the compressor 1, and this condensation The subcooler 3 further cools and supercools the refrigerant condensed in the cooler 2, the main refrigerant pipe 73 connecting these devices, and the like. The gas refrigerant pipe 71, liquid refrigerant pipe 72, liquid side connection pipe 400, and gas side connection pipe 500 described above are also main refrigerant pipes.

  The compressor 100 constituting the refrigerator 600 includes the compressor 1 and the supercooler 3 that compress the low-pressure gas refrigerant from the evaporator, and the condenser 200 includes the condenser 2 and the compressor 2. A blower (not shown) for blowing air to the condenser is included.

  The compressor 100 subcools the refrigerant from the main refrigerant pipe 73 flowing through the subcooler 3 with a reduced-pressure refrigerant extracted from the high-pressure liquid refrigerant flowing through the main refrigerant pipe 73 and depressurized. The liquid refrigerant cooling circuit 74 for injecting the decompressed refrigerant after the supercooling to the intermediate pressure portion of the compressor 1 and the supercooling for controlling the flow rate of the refrigerant flowing through the liquid refrigerant cooling circuit 74 and reducing the pressure. An expansion device 6, an indoor temperature sensor 30 for detecting the indoor temperature, a control device 60 for controlling the expansion device 6 for supercooling, and the like are provided.

  Furthermore, in the present embodiment, a liquid injection circuit 75 for injecting a part of the high-pressure liquid refrigerant flowing through the main refrigerant pipe 73 and reducing the pressure into the intermediate pressure part of the compressor 1, and the liquid A flow rate adjusting device 7 for controlling the flow rate through the injection circuit 75 is also provided. The compressor 100 also includes a liquid refrigerant temperature sensor 10 that detects the temperature of the liquid refrigerant on the downstream side of the subcooler 3 and an indoor temperature sensor 30 that detects the temperature of the room where the compressor 100 is installed. Is provided.

  The condensing device 200 includes a liquid refrigerant temperature sensor 20 that detects a liquid refrigerant temperature on the downstream side of the condenser 2 and an outdoor temperature sensor 40 that detects an outdoor temperature where the condensing device 200 is installed, that is, an outside air temperature. And a control device 70 for controlling a blower (not shown) for blowing air to the condenser 2. The detection values of the temperature sensors 20 and 40 are input to the control device 70 on the condenser side, and the control device 70 responds to the detection values of the liquid refrigerant temperature sensor 20 and the outside air temperature sensor 40, etc. The number of rotations of a blower provided in the condensing device 200 is controlled.

  The load device (low pressure device) 300 includes an expansion valve 4 that is a decompression unit that decompresses the liquid refrigerant supercooled by the supercooler 3, and the evaporator 5 that evaporates the refrigerant decompressed by the expansion valve 4. The gas refrigerant evaporated in the evaporator 5 flows again to the refrigerator 600 side and is sucked into the compressor 1 of the compressor 100 and compressed.

As the compressor 1, a scroll compressor is used in this embodiment, but various other types of compressors such as a screw compressor may be used.
Further, the liquid refrigerant cooling circuit 74 provided in the compression device 100 includes the subcooling expansion device 6 in a branch pipe 74 a branched from the main refrigerant pipe 73 after passing through the condenser 2 of the condenser 200. Is provided. The subcooling expansion device 6 is composed of an expansion valve capable of opening control, such as an electronic expansion valve, and is controlled by the control device 60 provided in the compression device 100.

  In this embodiment, a plate heat exchanger is used as the supercooling heat exchanger constituting the supercooler 3. The subcooling heat exchanger is not limited to a plate heat exchanger, and various types of heat exchangers such as a double tube heat exchanger can be used.

  In the liquid injection circuit 75, the flow rate adjusting device 7 is provided in a branch pipe 75a branched from the main refrigerant pipe 73 after passing through the condenser 2. The liquid injection circuit 75 extracts a part of the high-pressure liquid refrigerant flowing through the main refrigerant pipe 73 to reduce the pressure, and injects the reduced-pressure refrigerant into the intermediate pressure portion of the compressor 1 to cool the compressor 1. is there. In the present embodiment, the flow rate adjusting device 7 is also composed of an expansion valve capable of opening control such as an electronic expansion valve, and is controlled by the control device 60 on the compression device 100 side.

  The flow rate adjusting valve 7 provided in the liquid injection circuit 75 is based on the temperature of the compressor 1, the discharge gas temperature discharged from the compressor 1, the degree of superheat of the discharge gas, or the like. 60. That is, a detected value from a compressor temperature sensor (not shown) for detecting the temperature of the compressor 1 or a discharge gas temperature sensor (not shown) for detecting the temperature of the discharge gas discharged from the compressor 1. Based on the above, the control device 60 controls the flow rate adjusting device 7.

  The downstream side of the liquid refrigerant cooling circuit 74 and the downstream side of the liquid injection circuit 75 in the compressor 100 are joined together, and are connected to the intermediate pressure portion of the compressor 1 via the joined joining pipe 76. It is configured. In addition, the said intermediate pressure part is a part in which the refrigerant | coolant in a compression process exists, a refrigerant | coolant is injected through the said merge pipe 76 to the part, and the compressor 1 is cooled. Further, the flow rate adjusting device 7 is preferably composed of an electronic expansion valve whose opening degree can be continuously adjusted, but instead of the electronic expansion valve, a plurality of parallel flow paths are provided with a flow area of A combination of a fixed flow rate regulator such as a different capillary tube and an on-off valve may be used, and the flow rate may be adjusted stepwise by switching the flow path by opening and closing the on-off valve.

Next, the basic operation of the separate refrigeration apparatus configured as described above will be described.
The gas refrigerant from the evaporator 5 of the load device 300 passes through the gas side refrigerant pipe 500 and is sucked into the compressor 1 of the compressor 100 installed indoors, and the refrigerant is compressed by the compressor 1. It becomes a high-temperature and high-pressure gas refrigerant, and this gas refrigerant flows into the condenser 2 of the condensing device 200 installed outdoors and is condensed by exchanging heat with the outside air (outdoor air). Become.

  The refrigerant condensed in the condenser 2 flows into the compression device 100 again, and becomes a liquid refrigerant subcooled in the supercooler 3. The supercooled liquid refrigerant flows into the load device 300 again through the liquid side refrigerant pipe 400 and is decompressed by the expansion valve 4 to become a gas-liquid two-phase flow refrigerant. This gas-liquid two-phase flow refrigerant flows into the evaporator 5 and exchanges heat with the secondary refrigerant (for example, air in the refrigerator), takes heat from the secondary refrigerant and cools the secondary refrigerant. Evaporates into a gas refrigerant. This gas refrigerant passes through the gas-side refrigerant pipe 500 again and is again sucked into the compressor 1 of the compressor 100 to constitute a refrigeration cycle. In the evaporator 5, the secondary refrigerant cooled by the refrigerant is supplied into the refrigerator to cool food in the refrigerator.

Here, the prevention of dew condensation in the separate refrigeration apparatus divided into the compression apparatus 100 and the condensation apparatus 200 as described above will be described.
In order to prevent condensation on the downstream side of the supercooler, the indoor temperature sensor 30 provided in the compression device 100 installed indoors can be used to prevent condensation in the compression device 100. That is, the control on the compression device 100 side is performed so that the temperature of the indoor refrigerant pipe 73a on the downstream side of the supercooler 3 becomes a temperature at which dew condensation can be suppressed based on the indoor temperature detected by the indoor temperature sensor 30. A dew condensation suppression mode for controlling the supercooling expansion device 6 may be performed by the device 60.

  For example, a value obtained by giving a predetermined arbitrary difference (differential) to the detected indoor temperature is set as the target temperature of the indoor refrigerant pipe 73a on the downstream side of the subcooler 3, and control is performed so as to approach this target temperature. By performing the dew condensation suppression mode, it is possible to suppress dew condensation in the indoor refrigerant pipe 73a on the downstream side of the subcooler 3. In addition, by setting the target temperature as low as possible (a temperature higher than the dew point temperature and as close to the dew point temperature as possible) within a range where condensation can be suppressed, the refrigeration capacity can be improved.

  However, although it is possible to prevent dew condensation on the indoor refrigerant pipe 73a downstream of the supercooler, it is not possible to prevent dew condensation on the outdoor refrigerant pipe 400 connecting the compression device 100 and the load device 300. That is, the outdoor temperature may be higher than the indoor temperature, such as in summer, and when the target temperature of the refrigerant pipe downstream of the supercooler 3 is determined based on the indoor temperature having a low temperature, the outdoor temperature The temperature of the liquid-side refrigerant pipe 400 is likely to be lower than the outside air temperature, and it is difficult to sufficiently suppress condensation.

  In the separate refrigeration apparatus, an outside air temperature sensor 40 is provided in the condensing device 200, and the outside air temperature sensor 40 is connected to the control device 70 on the condensing device side. However, since the control device 60 on the compression device side and the control device 70 on the condensation device side independently control each other, when the dew condensation suppression mode is performed, the indoors connected to the control device 60 on the compression device side It is necessary to perform control using only the temperature sensor 30, and the outside air temperature sensor 40 cannot be used.

  When the controller 60 on the compressor side performs the dew condensation suppression mode, the indoor temperature sensor 30 measures the indoor temperature, and therefore performs control performed by measuring outdoor outdoor temperature, for example, cold district control. Difficult to do. That is, since the outside air temperature cannot be measured, the detected value of the indoor temperature sensor 30 can only be used, and it becomes difficult to carry out an accurate cold district control operation mode.

  Conversely, it is also conceivable that the indoor temperature sensor 30 is extended to the outdoors to measure the outside air temperature. In this case, although cold district control becomes possible, since indoor temperature cannot be measured, dew condensation suppression mode will be implemented based on measurable outdoor temperature. For this reason, when the indoor temperature becomes high, the dew condensation suppression mode cannot be performed accurately. That is, in the winter season when the outside air temperature is low and the indoor temperature is high, the target temperature is set based on the low outside air temperature, so that the indoor refrigerant pipe 73a on the downstream side of the supercooler 3 may be condensed. Becomes high, and it becomes difficult to suppress condensation.

  As described above, depending on the installation location of the indoor temperature sensor 30, the season in which the control is performed, the dew condensation suppression mode cannot be performed accurately, or control using the outside air temperature, such as cold district control, cannot be performed. There is.

  The cold district control mentioned above is demonstrated. In a region where the outside air temperature is, for example, 0 ° C. or lower, the gas side refrigerant pipe 500 connecting the evaporator 5 and the compressor 1 is long, particularly in a refrigeration apparatus that is long outdoors. Since it is cooled by the outside air, even if the load of the load device 300 rises (internal temperature rise), the pressure decreases by passing through the gas-side refrigerant pipe 500, and the compressor 1 reaches the pressure required for startup. If it does not rise, the refrigeration apparatus will fail to start. In order to avoid this state, when the outside air temperature falls below a predetermined temperature, the starting pressure of the compressor is temporarily lowered below the preset starting pressure to start the refrigeration system. Control that prevents defects is cold district control.

  Therefore, in this embodiment, not only the condensation of the indoor refrigerant pipe 73a downstream of the supercooler but also the condensation of the outdoor liquid side refrigerant pipe 400 connecting the compression device 100 and the load device 300 can be prevented. In addition, the control device 60 of the compression device 100 has a configuration described below in order to enable cold region control in which control is performed using the outside air temperature.

  The compressor 100 is provided with a liquid refrigerant temperature sensor 10 for detecting the temperature of the liquid refrigerant discharged from the supercooler 3 and an indoor temperature sensor 30 for detecting the indoor temperature. , 30 are input to the control device 60. The control device 60 controls the opening degree of the supercooling expansion device 6 of the liquid refrigerant cooling circuit 74 in accordance with detection values from the liquid refrigerant temperature sensor 10 and the outdoor temperature sensor 30. Yes.

  The control device 60 also controls the flow rate adjusting device 7 provided in the liquid injection circuit 75 using the detection values from the liquid refrigerant temperature sensor 10 and the indoor temperature sensor 30.

  In the present embodiment, the control device 60 provided in the compression device 100 and the control device 70 provided in the condensation device 200 are connected by a transmission line 50. By connecting this transmission line 50, it is possible to monitor the operation information and each sensor information in the compression device 100 with the control device 70 provided in the condensation device 200, and conversely with the condensation device 200. It is possible to monitor the operation information and each sensor information by the control device 60 provided in the compression device 100. In addition, the condensing device 200 can be controlled by the control device 60 on the compression device 100 side, and the compression device 100 can be controlled by the control device 70 on the condensing device 200 side.

  As described above, the refrigeration apparatus according to the present embodiment includes the control of the dew condensation suppression mode that suppresses the condensation of the indoor refrigerant pipe 73a and the liquid side refrigerant pipe 400 on the downstream side of the supercooler 3. In this dew condensation suppression mode, operation is performed by determining the target temperature of the liquid refrigerant so that the refrigerant piping downstream of the supercooler does not dew. The target temperature is a value obtained by giving a predetermined arbitrary difference (differential) to the temperature detected by the indoor temperature sensor 30 or the outside air temperature sensor 40. The control device 60 calculates the target temperature and controls the supercooling expansion device 6 based on the target temperature so that the liquid refrigerant temperature downstream of the supercooler 3 approaches the target temperature. To suppress condensation in the refrigerant piping.

  As described above, in this embodiment, the control device 60 on the compression device side and the control device 70 on the condensation device side are connected by the transmission line 50, and the indoor temperature sensor 30 connected to the control device 60 is used for the indoor temperature. Measure. The outdoor temperature sensor 40 connected to the control device 70 measures the outdoor outdoor temperature.

  As described above, since the control device 60 and the control device 70 are connected to each other via the transmission line 50, the operation information and each sensor information in the compression device 100 and the operation in the condensing device 200, respectively. Information and sensor information can be obtained. Therefore, the control device 60 (or the control device 70) can use not only the indoor temperature sensor 30 but also the temperature measured by the outside air temperature sensor 40 when controlling the dew condensation suppression mode. . Therefore, the higher temperature of the temperatures measured by the indoor temperature sensor 30 and the outside air temperature sensor 40 is used to determine the target temperature of the liquid refrigerant on the downstream side of the subcooler 3, and in the dew condensation suppression mode. It becomes possible to carry out driving.

  Accordingly, when operating in the dew condensation suppression mode, when the outside air temperature becomes higher than the indoor temperature as in summer, the control device 60 on the compression device 100 side uses the temperature detected by the outside air temperature sensor 40. By setting the target temperature, it is possible to surely suppress the condensation of not only the indoor refrigerant pipe 73a on the downstream side of the supercooler 3 but also the liquid side refrigerant pipe 400 in a higher temperature atmosphere.

  Even in the summer, when the indoor temperature is higher and the humidity is higher than the outdoor, the control device 60 on the compression device 100 side uses the temperature detected by the indoor temperature sensor 30 and uses it. By setting the target temperature based on this, it is possible to reliably suppress dew condensation not only in the liquid refrigerant pipe 400 but also in the indoor refrigerant pipe 73a on the downstream side of the supercooler 3.

  In winter when the outside air temperature is lower than the indoor temperature, the temperature detected by the indoor temperature sensor 30 is used to set the target temperature, so that not only the liquid side refrigerant pipe 400 but also the supercooling. Condensation of the indoor refrigerant pipe 73a on the downstream side of the vessel 3 can also be reliably suppressed.

  Even in the winter, when the indoor temperature is lower than outdoors, the temperature detected by the outside air temperature sensor 40 may be used as the target temperature.

  As described above, in the present embodiment, since the control device 60 and the control device 70 are connected to each other by the transmission line 50, the control device 60 is the only indoor temperature sensor 30 provided in the compression device 100. In addition, the detected temperature information detected by the outside temperature sensor 40 provided in the condenser 200 can be used. Accordingly, the target temperature of the liquid refrigerant on the downstream side of the subcooler 3 is always determined using the higher one of the temperatures measured by the indoor temperature sensor 30 and the outside air temperature sensor 40 in a seasonal manner. Regardless of this, an effect can be obtained in which the condensation of not only the indoor refrigerant pipe 73a downstream of the supercooler 3 but also the liquid refrigerant pipe 400 provided outdoors is reliably suppressed. Further, even when the compression device 100 includes only the indoor temperature sensor 30, the control device 60 of the compression device 100 can perform control using the outside air temperature detected by the outside air temperature sensor 40. . Thereby, it is possible to obtain a refrigeration apparatus capable of performing the cold region control while performing the dew condensation suppression mode.

  Next, specific control of the dew condensation suppression mode in the first embodiment of the present invention will be described with reference to FIG. FIG. 2 is a flowchart for explaining a control flow in a dew condensation suppression mode in the control device on the compressor side shown in FIG. 2 will be described with reference to FIG. 1 as well.

  First, in step S1, the indoor temperature is detected by the indoor temperature sensor 30 connected to the control device 60 on the compression device 100 side. Further, the outside air temperature is detected by the outside air temperature sensor 40 connected to the control device 70 on the condenser 200 side.

  Next, the process proceeds to step S2, and it is determined whether or not “indoor temperature sensor 30 ≧ outside temperature sensor 40”. In this determination, when the values of the indoor temperature sensor 30 and the outside air temperature sensor 40 are the same, for example, the temperature detected by the outside air temperature sensor 30 on the compression device 100 side closer to the load device (low pressure device) 300 is adopted. Keep it.

  In step S2, if the temperature detected by the indoor temperature sensor 30 is higher, or if the values of the indoor temperature sensor 30 and the outside air temperature sensor 40 are the same, the detection value of the indoor temperature sensor 30 is used in step S3. Decide what to do. If the temperature detected by the outside air temperature sensor 40 is higher in step S2, it is determined in step S4 that the value detected by the outside air temperature sensor 40 is used. When using the detected value of the outside air temperature sensor 40, the control device 60 sends the detected value of the outside air temperature sensor 40 provided on the condenser device 200 side to the control device 70 via the transmission line 50 described above. To get through.

  Then, it moves to step S5 and starts control in the dew condensation suppression mode. In this dew condensation suppression mode, as described above, for example, when the detected value of the indoor temperature sensor 30 is used, the target temperature of the liquid refrigerant downstream of the supercooler is determined based on the detected value. The supercooling expansion device is controlled based on the target temperature.

  For example, the target temperature is a value obtained by adding a predetermined difference (differential) to the detection value of the temperature sensor determined to be used in steps S3 and S4, and the supercooling expansion is performed based on the target temperature. The apparatus 6 is controlled.

  Specifically, the control device 60 controls the opening degree of the supercooling expansion device 6 so that the temperature of the liquid refrigerant detected by the liquid refrigerant temperature sensor 10 approaches the target temperature. Here, immediately after the start of the control in the dew condensation suppression mode, the control device 60 fully closes the supercooling expansion device 6, and then the temperature of the liquid refrigerant detected by the liquid refrigerant temperature sensor 10 is the target temperature. It is preferable to control the opening degree of the supercooling expansion device 6 so as to approach the temperature.

  The arbitrary difference for determining the target temperature is equal to or lower than the detected temperature used for determining the target temperature, even if the operating state in the refrigeration apparatus varies, the liquid refrigerant temperature on the downstream side of the subcooler 3 It is good to decide on a size that can suppress this. Alternatively, the arbitrary difference may be determined so that the target temperature is lower than the detected temperature used to determine the target temperature and higher than the dew point temperature.

  The temperatures detected by the indoor temperature sensor 30 and the outside air temperature sensor 40 are used for the control in the dew condensation suppression mode shown in FIG. 2, but are used for various controls such as a cold region control other than the dew condensation suppression mode. It is also possible to use it. Further, when one of the indoor temperature sensor 30 and the outside air temperature sensor 40 is abnormal, only the temperature sensor that is operating normally is used to control the dew condensation suppression mode or the like. You may do it.

As described above, in the dew condensation suppression mode of this embodiment, the control device 60 of the compression device 100 and the control device 70 of the condensing device 200 are connected by the transmission line 50, and the information of the indoor temperature sensor 30 and the outside air temperature sensor are connected. Forty information can be shared by the control devices 100 and 200, so that the target temperature can always be set based on the higher temperature without worrying about the atmospheric temperature that changes according to the season. It becomes. Therefore, the effect of suppressing the occurrence of condensation can be obtained for the refrigerant pipe on the downstream side of the subcooler 3, that is, the indoor refrigerant pipe 73a and the liquid refrigerant pipe 400 installed outdoors.
Further, since the control device 60 can also share the information of the outside air temperature sensor 40, it is possible to perform cold district control using the outside air temperature while performing the condensation suppression mode.

  In the above description, the control device 60 of the compression device has been described as performing the control of the dew condensation suppression mode, the cold region control, and the like, but in the present embodiment, as described above, the control device 60. And 70 are connected by a transmission line, the control can be performed by the control device 70 of the condenser.

  The present invention is not limited to the above-described embodiments, and includes various modifications. The above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

1: compressor, 2: condenser, 3: supercooler, 4: expansion valve, 5: evaporator,
6: Supercooling expansion device, 7: Flow rate adjusting device, 10: Liquid refrigerant temperature sensor,
20: Liquid refrigerant temperature sensor, 30: Indoor temperature sensor, 40: Outside air temperature sensor,
50: Transmission line, 60: Control device on the compression device side, 70: Control device on the condensation device side,
71: Gas refrigerant piping, 72: Liquid refrigerant piping,
73: main refrigerant piping, 73a: indoor refrigerant piping downstream of the supercooler,
74: main refrigerant cooling circuit, 74a: branch piping,
75: Liquid injection circuit, 75a: Branch piping, 76: Junction piping,
100: compression device, 200: condensing device, 300: load device (low pressure equipment),
400: liquid side refrigerant piping, 500: gas side refrigerant piping, 600: refrigerator (heat source device),
700: Refrigeration apparatus.

Claims (4)

A compressor installed indoors and having a compressor for compressing low-pressure gas refrigerant from the evaporator and a supercooler for supercooling high-pressure liquid refrigerant from the condenser;
A condenser installed outdoors and having a condenser for condensing the high-pressure gas refrigerant from the compressor and a blower for blowing air to the condenser; and
A depressurizing means for depressurizing the liquid refrigerant supercooled by the supercooler; and a load device having an evaporator for evaporating the refrigerant depressurized by the depressurizing means;
A main refrigerant pipe connecting the compressor, the condenser, the supercooler and the evaporator ;
The liquid side refrigerant pipe, which is the main refrigerant pipe connected to the load device downstream of the supercooler, has an outdoor installation part,
The compression device subcools the refrigerant in the main refrigerant pipe flowing through the subcooler with the reduced-pressure refrigerant extracted from the high-pressure liquid refrigerant flowing through the main refrigerant pipe and depressurized. Liquid refrigerant cooling circuit for injecting decompressed refrigerant into the intermediate pressure part of the compressor, supercooling expansion device for controlling and reducing the flow rate of the refrigerant flowing through the liquid refrigerant cooling circuit, and indoor temperature for detecting indoor temperature A sensor and a control device for controlling the supercooling expansion device;
The condensing device includes an outside air temperature sensor that detects an outside air temperature, and a control device that controls the blower.
The control device of the compression device and the control device of the condensing device are connected by a transmission line,
The control device of the compression device includes a dew condensation suppression mode for controlling the expansion device for supercooling based on the indoor temperature detected by the indoor temperature sensor and the outside air temperature detected by the outside air temperature sensor ,
The control device of the compression device determines a target temperature of the liquid refrigerant on the downstream side of the subcooler using the higher temperature of the temperatures measured by the indoor temperature sensor and the outside air temperature sensor,
A liquid refrigerant temperature sensor for detecting the liquid refrigerant temperature downstream of the subcooler is provided, and the controller is configured to control the supercooling so that the temperature of the liquid refrigerant detected by the liquid refrigerant temperature sensor approaches the target temperature. Control the expansion device for
The refrigeration apparatus , wherein the target temperature is a value obtained by adding an arbitrary difference to a detection value of the indoor temperature sensor or the outside air temperature sensor determined to be used for determining the target temperature . 2. The refrigeration apparatus according to claim 1 , wherein the control device fully closes the supercooling expansion device immediately after the start of the control in the dew condensation suppression mode, and thereafter the temperature of the liquid refrigerant detected by the liquid refrigerant temperature sensor. However, the expansion device for supercooling is controlled so that it may approach the target temperature.   2. The refrigeration apparatus according to claim 1, wherein the control device of the compression device uses the outside air temperature detected by the outside air temperature sensor on the condensing device side and compresses when the outside air temperature falls below a predetermined temperature. A refrigeration apparatus comprising a cold region control operation mode in which the start pressure of the machine is temporarily lowered.   2. The refrigeration apparatus according to claim 1, wherein a liquid injection circuit that injects a part of the high-pressure liquid refrigerant flowing through the main refrigerant pipe and decompresses the refrigerant into an intermediate pressure portion of the compressor, and the liquid injection circuit The flow rate adjusting device provided in the liquid injection circuit further includes a temperature of the compressor, a temperature of the discharge gas discharged from the compressor, or a flow rate of the discharge gas. A refrigeration apparatus controlled based on at least one of superheat degrees.

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