JP2015049024A - Refrigeration device and refrigerant amount adjustment method of refrigeration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration device capable of smoothing a refrigerant amount adjustment work in installing a refrigerator and a cooling apparatus.SOLUTION: A refrigeration device R is composed of a refrigerator 3 having a compressor 11 and a gas cooler 46, and a showcase 5 having a main expansion valve 62 and an evaporator 63, and the refrigerator and the showcase are connected by a high-pressure pipe 7 and a low-pressure pipe 9 to constitute a refrigerant circuit 1. A refrigerant compressed by the compressor and passing through the gas cooler is sent to the main expansion valve by the high-pressure pipe, the refrigerant discharged from the evaporator is returned to the compressor by the low-pressure pipe, and the high pressure-side has a supercritical pressure. Control means is disposed to control the compressor and the main expansion valve, and the control means has a function for determining a refrigerant amount in the refrigerant circuit.

Description

  The present invention relates to a refrigerating apparatus in which a refrigerator and a cooling device are connected by a high-pressure pipe and a low-pressure pipe, and a high-pressure side becomes a supercritical pressure, and a refrigerant amount adjusting method thereof.

  Conventionally, a plurality of showcases (cooling devices) are installed in a store such as a supermarket, and the products are displayed and sold while being cooled. These showcases are connected to the refrigerator installed outside the store in parallel by refrigerant piping to form a refrigerant circuit of the refrigeration apparatus, and the refrigerant is supplied to an evaporator provided in each showcase. (For example, see Patent Document 1).

  Further, in recent years, in this type of refrigeration apparatus, it has become impossible to use chlorofluorocarbon-based refrigerants due to natural environmental problems. For this reason, the thing using the carbon dioxide which is a natural refrigerant | coolant is developed as a substitute of a fluorocarbon refrigerant | coolant. It is known that this carbon dioxide refrigerant is a refrigerant having a strong difference between high and low pressures, and has a low temperature with respect to the critical pressure, and the high pressure side of the refrigerant circuit is brought into a supercritical state by compression (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 11-63770 Japanese Patent Publication No. 7-18602

  In the refrigeration apparatus for a showcase as described above, connection work for high-pressure piping and low-pressure piping for connecting the showcase and the refrigerator is performed at the installation site (store). The refrigerant circuit is filled with a predetermined amount of refrigerant from the low-pressure service port provided on the low-pressure side of the refrigerator. In this case, the refrigerant filling amount differs depending on the length of the high-pressure pipe or low-pressure pipe in the store. Therefore, the method of calculating the volume in advance and filling the minimum amount has been adopted.

  However, when the operation of the refrigerator is actually started, if the amount of refrigerant charged is excessive, the high pressure becomes abnormally high and stops due to a predetermined protection operation. This is particularly noticeable when a carbon dioxide refrigerant is used. Further, when the amount of refrigerant filled is small, the required cooling capacity cannot be obtained by the evaporator. For this reason, in the past, the operator adjusted the amount of refrigerant to an appropriate level by replenishing the refrigerant or removing it several times while observing the high pressure and cooling conditions after starting operation. Workability was extremely complicated.

  The present invention has been made in order to solve the conventional technical problems, and a refrigeration apparatus capable of facilitating refrigerant amount adjustment work during installation of a refrigerator and a cooling device, and refrigerant amount adjustment thereof A method is provided.

  The refrigeration apparatus according to the first aspect of the present invention includes a refrigerator having a compression means and a radiator, and a cooling device having an expansion valve and an evaporator, and the refrigerator and the cooling device are connected by a high-pressure pipe and a low-pressure pipe. Thus, a refrigerant circuit is formed, and the refrigerant compressed by the compression means and passed through the radiator is sent to the expansion valve by the high-pressure pipe, and the refrigerant discharged from the evaporator is returned to the compression means by the low-pressure pipe, and the high-pressure side exceeds It is a critical pressure and includes control means for controlling the compression means and the expansion valve, and this control means has a function of determining the amount of refrigerant in the refrigerant circuit.

  According to a second aspect of the present invention, there is provided a refrigeration apparatus comprising high pressure detecting means for detecting the high pressure of the refrigerant circuit and outside air temperature detecting means for detecting the outside air temperature in the above invention, wherein the control means is a high pressure pressure at an appropriate refrigerant amount. Appropriate high pressure-outside air temperature data relating to the relationship between the temperature and the outside air temperature, and the appropriate high pressure-outside air temperature data, the high pressure detected by the high pressure detecting means, and the outside temperature detected by the outside temperature detecting means. On the basis of the above, when the high pressure detected by the high pressure detecting means is higher than the appropriate high pressure at the outside air temperature, the refrigerant amount in the refrigerant circuit is determined to be excessive and output.

  In the refrigeration apparatus of the invention of claim 3, in each of the above inventions, the control means has appropriate valve opening degree data relating to the opening degree of the expansion valve in the normal cooling state of the cooling device in the appropriate refrigerant amount. Based on the appropriate valve opening data, the valve opening of the expansion valve, and the cooling state of the cooling device, the valve opening of the expansion valve when the cooling device is normally cooled is larger than the appropriate valve opening data. In this case, it is determined that the amount of refrigerant in the refrigerant circuit is insufficient, and output.

  The refrigeration apparatus of the invention of claim 4 is characterized in that carbon dioxide is used as a refrigerant in each of the above inventions.

  The refrigerant amount adjusting method of the invention of claim 5 comprises a refrigerator having a compression means and a radiator, and a cooling device having an expansion valve and an evaporator. The refrigerator and the cooling device are connected to a high pressure pipe and a low pressure pipe. The refrigerant circuit is configured by connecting with the refrigerant, compressed by the compression means, and the refrigerant passed through the radiator is sent to the expansion valve by the high-pressure pipe, and the refrigerant discharged from the evaporator is returned to the compression means by the low-pressure pipe, In a refrigeration system in which the high pressure side is at a supercritical pressure, appropriate high pressure-outside air temperature data regarding the relationship between the high pressure in the refrigerant circuit and the outside air temperature at the appropriate amount of refrigerant is created, and when installing the refrigeration system, the high pressure and outside air The temperature is detected, the appropriate high pressure at the outside air temperature is extracted from the appropriate high pressure-outside air temperature data, and if the detected high pressure is higher than the appropriate high pressure, the refrigerant is extracted from the refrigerant circuit. To.

  In addition to the above-described invention, the refrigerant amount adjusting method of the refrigeration apparatus according to the sixth aspect of the invention creates appropriate valve opening degree data relating to the opening degree of the expansion valve in the normal cooling state of the cooling device for the appropriate refrigerant amount. The valve opening degree of the expansion valve is confirmed in a state in which the cooling device is normally cooled, and when the valve opening degree is larger than the appropriate valve opening degree data, the refrigerant is replenished in the refrigerant circuit.

  According to the present invention, the refrigerant circuit includes a refrigerator having a compression means and a radiator, and a cooling device having an expansion valve and an evaporator, and the refrigerator and the cooling device are connected by a high-pressure pipe and a low-pressure pipe. The refrigerant that has been compressed by the compression means and passed through the radiator is sent to the expansion valve by the high-pressure pipe, the refrigerant that has exited the evaporator is returned to the compression means by the low-pressure pipe, and the high-pressure side becomes the supercritical pressure. The refrigeration apparatus includes control means for controlling the compression means and the expansion valve, and this control means has a function of determining the amount of refrigerant in the refrigerant circuit. For example, as in the second aspect of the invention, the apparatus further comprises high pressure detecting means for detecting the high pressure of the refrigerant circuit and outside air temperature detecting means for detecting the outside air temperature, and the control means includes the high pressure and the outside air temperature at the appropriate refrigerant amount. Based on the proper high pressure-outside temperature data, the high pressure detected by the high pressure detecting means and the outside temperature detected by the outside temperature detecting means, When the high pressure detected by the high pressure detecting means is higher than the appropriate high pressure at the outside air temperature, the refrigerant amount in the refrigerant circuit is determined to be excessive and output, so the refrigerant amount in the refrigerant circuit is excessive. Can be accurately and quickly grasped and removed from the refrigerant circuit.

  Further, as in the third aspect of the invention, the control means has appropriate valve opening degree data relating to the opening degree of the expansion valve in the normal cooling state of the cooling device at the appropriate refrigerant amount. And when the opening degree of the expansion valve in the state where the cooling device is normally cooled is larger than the appropriate valve opening degree data based on the opening degree of the expansion valve and the cooling state of the cooling equipment, If the refrigerant amount is determined to be insufficient and output, the fact that the refrigerant amount in the refrigerant circuit is insufficient can be grasped accurately and quickly, and the refrigerant circuit can be replenished. This makes it possible to remarkably improve the workability at the time of installing the refrigeration apparatus, which becomes extremely remarkable when carbon dioxide is used as a refrigerant as in the invention of claim 4.

  According to the refrigerant quantity adjusting method of the invention of claim 5, the refrigerant unit includes a refrigerator having a compression means and a radiator, and a cooling device having an expansion valve and an evaporator. The refrigerator and the cooling device are connected to a high-pressure pipe and The refrigerant circuit is configured by connecting with low-pressure piping, compressed by the compression means, the refrigerant passing through the radiator is sent to the expansion valve with high-pressure piping, and the refrigerant discharged from the evaporator is returned to the compression means with low-pressure piping. In addition, in a refrigeration system in which the high pressure side is at a supercritical pressure, appropriate high pressure-outside air temperature data regarding the relationship between the high pressure of the refrigerant circuit and the outside air temperature at an appropriate amount of refrigerant is created, and when installing the refrigeration system, the high pressure The outside air temperature is detected, the appropriate high pressure at the outside air temperature is extracted from the appropriate high pressure-outside air temperature data, and if the detected high pressure is higher than the appropriate high pressure, the refrigerant is extracted from the refrigerant circuit. Since the operator grasps accurately and quickly the refrigerant quantity in the refrigerant circuit is excessive, it is possible to perform the task of disconnecting from the refrigerant circuit.

  Further, as in the sixth aspect of the invention, appropriate valve opening degree data relating to the opening degree of the expansion valve in the normal cooling state of the cooling device at an appropriate amount of refrigerant is prepared, and the cooling device is normally cooled. If the valve opening degree of the expansion valve is checked and the valve opening degree is larger than the appropriate valve opening degree data, if the refrigerant is replenished in the refrigerant circuit, the operator has insufficient refrigerant amount in the refrigerant circuit. It is possible to accurately and quickly grasp the situation and replenish the refrigerant circuit, and the workability when installing the refrigeration apparatus can be remarkably improved.

It is a figure which shows the refrigerating cycle of the freezing apparatus of one Example to which this invention is applied. It is a figure which shows the structure of the centralized control system of the freezing apparatus of FIG. It is a functional block diagram of the centralized controller which comprises the centralized control system of FIG. It is a functional block diagram of the master controller which comprises the centralized control system of FIG. It is a functional block diagram of the terminal controller which comprises the centralized control system of FIG. It is a flowchart explaining operation | movement of the centralized control system of FIG. It is a figure which shows the appropriate high pressure-air temperature data which the master controller of the centralized control system of FIG. 2 has.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a refrigeration cycle of a refrigeration apparatus R according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating a configuration of a central control system (central control apparatus) of the refrigeration apparatus R. The refrigeration apparatus R in the present embodiment is employed in a store such as a supermarket, and includes a refrigerator 3 installed outside the store and a showcase 5 installed in the store as an example of a cooling device. The refrigerator 3 and each showcase 5 are connected by a high-pressure pipe 7 (liquid pipe) and a low-pressure pipe 9 at the installation site to constitute a predetermined refrigerant circuit 1 of the refrigeration cycle (FIG. 1). (Only one showcase 5 is shown).

  In this case, the refrigerator 3 is provided with a refrigerant outlet 3A and a refrigerant inlet 3B, and each showcase 5 is provided with a refrigerant inlet 5A and a refrigerant outlet 5B. One end of the high-pressure pipe 7 is connected to the refrigerant outlet 3A of the refrigerator 3, and the refrigerant inlet 5A of each showcase 5 is connected to the other end. Further, one end of the low pressure pipe 9 is connected to the refrigerant inlet 3B of the refrigerator 3, and the refrigerant outlet 5B of each showcase 5 is connected to the other end (each showcase 5 is connected to the high pressure pipe 7 and the low pressure pipe). 9 in parallel).

  In this refrigeration cycle, carbon dioxide whose refrigerant pressure (high pressure) on the high pressure side is equal to or higher than its critical pressure (supercritical) is used as the refrigerant. This carbon dioxide refrigerant is a natural refrigerant that is friendly to the global environment and takes into consideration flammability and toxicity. As the lubricating oil, existing oils such as mineral oil (mineral oil), alkylbenzene oil, ether oil, ester oil, and PAG (polyalkyl glycol) are used.

  The refrigerator 3 of an Example is provided with the two compressors 11 as a compression means arrange | positioned in parallel. In this embodiment, the compressor 11 is an internal intermediate pressure type multi-stage compression rotary compressor, and is driven by the hermetic container 12, an electric element (not shown) disposed and housed in the hermetic container 12, and this electric element. The rotary compression mechanism portion is composed of a first rotary compression element (low-stage side first compression element) 18 and a second rotary compression element (high-stage side second compression element) 20. Yes.

  The first rotary compression element 18 compresses the low-pressure refrigerant sucked into the compressor 11 from the low-pressure side of the refrigerant circuit 1 via the low-pressure pipe 9 and the refrigerant introduction port 3B, raises the pressure to an intermediate pressure, and discharges it. The rotary compression element 20 further sucks in the intermediate pressure refrigerant compressed and discharged by the first rotary compression element 18, compresses it to a high pressure, and discharges it to the high pressure side of the refrigerant circuit 1. The compressor 11 is a variable frequency compressor, and the rotation speed of the first rotary compression element 18 and the second rotary compression element 20 can be controlled by changing the operating frequency of the electric element. Yes.

  On the side surface of the hermetic container 12 of the compressor 11, a low-stage suction port 22 and a low-stage discharge port 24 that communicate with the first rotary compression element 18, and a high-stage side that communicates with the second rotary compression element 20. A suction port 26 and a high-stage discharge port 28 are formed. Refrigerant introduction pipes 30 are respectively connected to the low-stage suction ports 22 of the respective compressors 11, merged with the respective refrigerant introduction pipes 31 on the upstream side, and then connected to the low-pressure pipe 9 at the refrigerant introduction port 3 </ b> B. .

  Low-pressure (LP: about 2.6 MPa in a normal operation state) refrigerant gas sucked into the low-pressure portion of the first rotary compression element 18 by the low-stage suction port 22 is intermediate pressure by the first rotary compression element 18. The pressure is increased to (MP: about 5.5 MPa in a normal operation state) and discharged into the sealed container 12. Thereby, the inside of the airtight container 12 becomes an intermediate pressure (MP).

  Then, intermediate pressure discharge pipes 36 are connected to the low-stage discharge ports 24 of the compressors 11 from which the refrigerant gas of intermediate pressure in the hermetic container 12 is discharged. 38 is connected to one end of 38. The intercooler 38 cools the intermediate pressure refrigerant discharged from the first rotary compression element 18 by air, and an intermediate pressure suction pipe 40 is connected to the other end of the intercooler 38. The suction pipe 40 is branched into two and then connected to the high-stage suction port 26 of each compressor 11.

  The medium pressure (MP) refrigerant gas sucked into the intermediate pressure portion of the second rotary compression element 20 by the high-stage suction port 26 is compressed in the second stage by the second rotary compression element 20. It becomes a refrigerant gas of high temperature and pressure (HP: supercritical pressure of about 9 MPa in a normal operation state). The high-stage discharge port 28 provided on the high-pressure chamber side of the second rotary compression element 20 of each compressor 11 is connected to a high-pressure discharge pipe 42, and merges at each downstream side, and an oil separator 44, a gas cooler 46 as a radiator, and an intermediate heat exchanger 80 constituting a split cycle, and is connected to the high-pressure pipe 7 at the refrigerant outlet 3A.

  The gas cooler 46 cools the high-pressure discharged refrigerant discharged from the compressor 11, and a gas cooler blower 47 for air-cooling the gas cooler 46 is disposed in the vicinity of the gas cooler 46. In the present embodiment, the gas cooler 46 is juxtaposed with the intercooler 38 and the oil cooler 74 described above, and these are arranged in the same air passage 45. The air passage 45 is provided with an outside air temperature sensor (outside air temperature detecting means) 56 for detecting the outside air temperature where the refrigerator 3 is disposed. In addition, the high-stage discharge ports 28 and 28 have a discharge pressure sensor 48 that detects the discharge pressure (high-pressure side pressure HP) of the refrigerant discharged from the second rotary compression element 20, and a discharge that detects the discharge refrigerant temperature. A temperature sensor (not shown) or the like is provided.

  On the other hand, each showcase 5 is installed in the store and connected to the high-pressure pipe 7 and the low-pressure pipe 9 in parallel. An electromagnetic valve 60 is attached in front of the refrigerant introduction port 5A of each showcase 5 (on the upstream side of the refrigerant), and the high-pressure pipe 7 is connected to the refrigerant introduction port 5A via the electromagnetic valve 60. This solenoid valve 60 is a valve device that opens a flow path when energized and seals the flow path when not energized, and has a large diameter of 4 mm to 10 mm, and in the embodiment has a diameter of 7.8 mm. Is used.

  A refrigerant inlet 5A, a main expansion valve 62 (main throttle means) as a throttle means, and an evaporator 63 are sequentially connected to the downstream side of the solenoid valve 60, and the outlet side of the evaporator 63 is a refrigerant outlet. Connected to 5B. Each evaporator 63 is provided with an unillustrated cool air circulation blower that blows air to the evaporator 63. The low-pressure pipe 9 connected to the refrigerant outlet 5B is connected to the low-stage suction port 22 communicating with the first rotary compression element 18 of each compressor 11 via the refrigerant introduction pipes 31 and 30 as described above. Connected. Thereby, the refrigerant circuit 1 of the refrigeration apparatus R in the present embodiment is configured. Incidentally, 130 is a safety valve connected to the low pressure pipe 9, 131 is an on-off valve (valve device) connected to the inlet side of the safety valve 130, 132 is a capillary tube (pressure reducing means) 132, and the low pressure increases to the set value. When it does, it opens and leaks the refrigerant.

  1, 58 is a high-pressure sensor (high-pressure detector), 49 is an intermediate pressure sensor, and 32 is a low-pressure sensor (low-pressure detector). Terminal control means). The discharge temperature sensor (not shown) is provided at the high-stage discharge port 28 of each compressor 11 and detects the discharge temperature of the refrigerant discharged from the second rotary compression element 20. The high-pressure sensor 58 is connected to a high-pressure side of the refrigerant circuit 1, in the embodiment, a shunt 82 described later, and detects the high-pressure side pressure HP of the refrigerant that has passed through the intermediate heat exchanger 80. The low-pressure sensor 32 is provided on the refrigerant introduction pipe 31 connected to the low-stage suction port 22 of the compressor 11 on the low-pressure side of the refrigerant circuit 1, in the embodiment, on the downstream side of each evaporator 63. The refrigerant suction pressure (low pressure LP) toward the inlet pipe 30 is detected. The intermediate pressure sensor 49 detects a pressure (intermediate pressure MP) of an intermediate pressure portion of the refrigerant circuit 1, that is, a third communication circuit 103 on the downstream side of an electromagnetic valve 104 described later in the embodiment.

(A) Centralized control system Next, the refrigeration apparatus R of the embodiment can be remotely managed by a centralized control system (the centralized control apparatus of the present invention). That is, both P1 and P2 in FIG. 2 indicate stores such as supermarkets. The centralized control system according to the embodiment includes a master controller MC as a high-order control means and a terminal controller SC as a terminal control means, each of which is installed in each store P1 and P2, and shows of the stores P1 and P2. In order to remotely manage the case 5 and the refrigerator 3, for example, it is constructed from a centralized controller RC as a centralized control means composed of a server installed in the maintenance management company P3.

  As shown in FIG. 3, the centralized controller RC includes a microcomputer 207, a hard disk 208 as a storage device connected to the microcomputer 207, a ROM 209, a RAM 211, an interface 212, an output control unit 214, an input control unit 216, and the like. It functions as a server. The interface 212 is capable of writing data to an external storage medium such as the SD card 210 and reading data from the external storage medium.

  In addition to the control program for the centralized controller RC itself, the hard disk 208 includes various data including data relating to operating conditions sent from the master controller MC of each store P1, P2, and data relating to operating conditions of the showcases 5 and the refrigerator 3. Data and data on the location of the stores P1 and P2 are stored, and a communication protocol and the like are also stored.

  A printer 218 as an output means and a display 219 as a display means are connected to the output control means 214, and a keyboard 221 and a mouse 222 as input means are connected to the input control means 216. Furthermore, a terminal adapter 223 is connected to the microcomputer 207, and exchanges data with the master controller MC of each store P1 and P2 via a communication line L1 such as the Internet.

  Next, the master controller MC is provided in the management room of each store P1, P2, etc., as shown in FIG. 4, a microcomputer 324 as a control means, and a ROM 326, a RAM 327, which are storage devices connected to the microcomputer 324, It comprises an EEPROM 340, an interface 325, a transmission / reception means 329, an output control means 331, an input control means 332, and the like. The transmission / reception means 329 is constituted by a serial interface, and is connected to a terminal controller SC, which will be described later, via a communication line L2.

  The ROM 326 is electrically rewritable and includes a flash memory or the like that retains data even when the power is turned off. The ROM 326 includes a communication protocol, a control program for the master controller MC itself, and the like. The RAM 327 stores various data sent from the terminal controller SC, various data sent to the terminal controller SC, and control data of the master controller MC itself (display data of the liquid crystal display unit 334, etc.). Further, the EEPROM 340 stores data relating to various settings and installation states of the showcase 5 and the refrigerator 3 and is retained even when the power is turned off. Further, the interface 325 enables writing of data to an external storage medium such as the SD card 210 and reading of data from the external storage medium, like the interface 212 provided in the centralized controller RC. is there.

  Here, in the ROM 326, appropriate high pressure-outside temperature data and appropriate valve opening data are written. This appropriate high pressure-air temperature data indicates the relationship between the outside temperature and the high pressure when the refrigerant circuit 1 is filled with an appropriate amount of carbon dioxide refrigerant (appropriate refrigerant amount). As indicated by a straight line indicated by HPX, the higher the outside air temperature, the higher the appropriate high pressure HPX. The appropriate valve opening data is a state in which the interior of the showcase 5 is normally cooled (normal cooling) when the refrigerant circuit 1 is filled with an appropriate amount of refrigerant (appropriate refrigerant amount). The value of the valve opening degree of the main expansion valve 62 in the state). Operations and operations using these will be described later.

  For example, a liquid crystal display unit 334 as a display unit capable of displaying a plurality of columns and lines of characters and graphics and a buzzer 336 as an alarm unit are connected to the output control unit 331, and the input control unit 332 has an input unit. A key switch (function key or the like) 337, a dip switch 338, and a slide switch 339 are connected. The key switch 337 is a switch for performing various settings and display commands, and the dip switch 338 is a switch for setting the connection state of the terminal controller SC. The slide switch 339 is a switch for performing settings related to lighting control of the showcase 5 and night stop.

  Further, a terminal adapter 224 is connected to the microcomputer 324, and it is also possible to exchange data by communication with the centralized controller RC using the communication line L1. Further, the master controller MC is provided with a backup power source 328. The backup power source 328 is always charged, and when a power failure occurs, power is supplied from the backup power source 328 to the microcomputer 324 for a predetermined period.

  Next, the terminal controller SC is provided in each of the showcase 5 and the refrigerator 3 shown in FIG. 1. As shown in FIG. 5, the microcomputer 454 and ROM 456, RAM 457, which are storage devices connected to the microcomputer 454, It comprises an EEPROM 450, an interface 453, a transmission / reception means 458, an output control means 459, and an input control means 461.

  The transmission / reception means 458 is configured by a serial interface, and is connected to the master controller MC via the communication line L2. Further, the interface 453 enables writing of data to an external storage medium such as the SD card 210 and reading of data from the external storage medium, like the interface 212 provided in the centralized controller RC. .

  The ROM 456 stores a communication protocol and a control program for the terminal controller SC itself, and the RAM 457 stores data related to various operating conditions of the showcase 5 and the refrigerator 3 sent from the master controller MC. The EEPROM 450 stores setting data for various operating conditions of the showcase 5 and the refrigerator 3 set by the terminal controller SC, and is retained even when the power is turned off. The output control means 459 is connected with a display means 462 for displaying an alarm, a buzzer 413 as an alarm means, and an actuator 463.

  In the case of the showcase 5, the actuator 463 is a main expansion valve 62, a solenoid valve 60, a defrosting heater, lighting, or the like. In the case of the refrigerator 3, the compressor 11, a gas cooler blower 47, an auxiliary expansion valve described later. (Auxiliary throttle means) 83, each valve (electric expansion valve or electromagnetic valve), etc. are meant. The input control means 461 is connected to a setting switch 464 and a sensor (represented by 466) that detects the internal temperature of the showcase 5 and the temperature and pressure of each part of the refrigerator 3. The temperature and pressure data detected by these sensors 466 are also written in the SD card 210 mounted by the RAM 457 and the interface 453. The setting switch 464 is for setting a channel number from 1 to 50 allocated for the control of the terminal controller SC. The microcomputer 454 has a sensor ID as individual identification information set for each showcase 5 and refrigerator 3.

  When the showcase 5 or the refrigerator 3 is installed, each of the terminal controllers SC is set with one of 1 to 50 by the setting switch 464, and A to C in the master controller MC to which the terminal controller SC is connected. By setting one of the above, the channel number (for example, A01) of each terminal controller SC is assigned and set.

  With the above configuration, in the master controller MC, the key switch 337, the dip switch 338, and the slide switch 339 are used to set the internal temperature, various alarms, and defrosting for each channel number (for example, A01) assigned to each terminal controller SC. Various set values, management temperatures, etc., and operating conditions such as a cooling storage (showcase SC) can be set.

  Data relating to the operating conditions of the showcase 5 and the refrigerator 3 set by the master controller MC is stored in the RAM 327 and the EEPROM 340 by the microcomputer 324 and transmitted from the transmission / reception means 329 to each terminal controller SC. In addition, the data is written in the SD card 210 attached to the interface 325.

  These data are distinguished and transmitted and written for each channel number. In response to a request from the centralized controller RC, the microcomputer 324 of the master controller MC transmits data set by the key switch 337 and the like to the centralized controller RC through the terminal adapter 224. Further, when the program data is transmitted from the centralized controller RC, the master controller MC receives the program data via the terminal adapter 224, and receives the data in the ROM 326 and the data in the SD card 210 attached to the interface 325. Rewrite the data.

  On the other hand, in the terminal controller SC, when the transmission / reception means 458 receives data relating to the operation condition for its own channel number (01 to 50), the microcomputer 454 stores the data in the RAM 457. Similarly, the microcomputer 454 stores data related to the operating conditions in the SD card 210 attached to the interface 453.

  The microcomputer 454 of the terminal controller SC provided in the showcase 5 is a set superheat degree (the superheat degree of the refrigerant in the evaporator 63) among the data related to the internal temperature of the showcase 5 from the sensor 466 and the data related to the operating conditions. And the main expansion valve 62 as the actuator 463 is controlled. The microcomputer 454 of the terminal controller SC provided in the refrigerator 3 compares the data relating to the temperature and pressure of each part of the refrigerator 3 from the sensor 466 with the set value in the data relating to the operating conditions, and serves as the actuator 463. The compressor 11, the gas cooler blower 47, the auxiliary expansion valve 83, each electric expansion valve, and the electromagnetic valve are controlled (details will be described later).

  Such data regarding the operating state of each showcase 5 and refrigerator 3 is sequentially stored in the RAM 457 and updated by the microcomputer 454. Similarly, data related to the operation state is stored and updated in the SD card 210 that is sequentially attached to the interface 453 by the microcomputer 454.

  The microcomputer 324 of the master controller MC polls each terminal controller SC once per minute, for example. When the microcomputer 454 of each terminal controller SC is polled by the master controller MC, the transmission / reception means 458 sends the data relating to the operation state of itself (showcase 5, refrigerator 3) stored in the RAM 457 together with its own channel number. Transmit to the master controller MC. The terminal controller SC automatically transmits data to the master controller MC when the alarm described above occurs in the showcase 5 or the refrigerator 3.

  The master controller MC receives and collects data relating to the operation state by the transmission / reception means 329, and data relating to the operation state for, for example, a maximum of 150 units is installed in the RAM 327 and the interface 325 for each terminal controller SC, that is, for each channel. Stored in the existing SD card 210. Similarly, the data related to the operation state in the RAM 327 and the SD card 210 is updated by transmitting the data related to the operation state from the terminal controller SC by the next polling.

  The master controller MC collects data related to the operation state of each showcase 5 and the refrigerator 3 from each terminal controller SC in such a procedure. Based on the operation of the key switch 337, the microcomputer 324 reads, for example, the internal temperature and the internal set temperature stored in the EEPROM 340 from the data collected in the RAM 327, and displays them on the liquid crystal display unit 334 together with each channel number. In addition, by operating the key switch 337, the transition of the internal temperature of the specific showcase 5 is displayed on the liquid crystal display unit 334 as a graph.

  Then, in response to a request from the centralized controller RC, the collected data regarding the operation state in the RAM 327 is transmitted to the centralized controller RC via the terminal adapter 224. The master controller MC automatically transmits data to the centralized controller RC when an alarm (abnormality) occurs. In the data relating to the operating state, in the embodiment, at least the low pressure of the refrigerator 3 detected by the low pressure sensor 32, the valve opening degree of the main expansion valve 62 of the showcase 5, the power consumption of the refrigerator R (the refrigerator) Detected by an electric energy detection means (not shown) such as a watt hour meter provided at 3 etc.), the operation state of the compressor 11 of the refrigerator 3 (operation frequency and ON (start) / OFF (stop) state) , Data relating to the outside air temperature detected by the outside air temperature sensor 56, the high pressure detected by the high pressure sensor 58, the internal temperature of the showcase 5, and the like are included.

  When the microcomputer 207 of the centralized controller RC of the maintenance management company P3 receives the data regarding the operation state from the master controller MC of each store P1 or P2 via the terminal adapter 223, it is attached to the hard disk 208 and the interface 212. Save in the SD card 210. Then, the microcomputer 207 analyzes data transmitted from the master controller MC by a predetermined keyboard operation and obtains statistics or the like (the number of failures and the distribution of failure contents).

  Further, the microcomputer 207 of the centralized controller RC can input data related to the operating conditions of the showcase 5 and the refrigerator 3 (specified by the channel number) of each store P1, P2 by operating the keyboard 221 and the mouse 22. ing. The input data is stored in the hard disk 208 or the like. Then, the data related to the input operating conditions is transmitted from the centralized controller RC to the master controller MC via the terminal adapter 223, the communication line L1, and the terminal adapter 224.

  The data relating to the operating condition includes a low-pressure control value, a control method of the compressor 11 (an increasing speed of the operating frequency) and the like which will be described later. The master controller MC that has received the data relating to the operating conditions stores it in the RAM 327 and transmits it to each terminal controller SC together with the channel number. Thereby, the centralized controller RC is configured to remotely control the showcase 5 and the refrigerator 3 of each store P1, P2 and to monitor and analyze the operation state.

(B) Basic control by terminal controller SC The terminal controller SC of each showcase 5 opens the electromagnetic valve 60 while the power is turned on during normal operation, and throttles the evaporator 63 with the main expansion valve 62. The supplied refrigerant is supplied and evaporated. In this case, the supercritical carbon dioxide refrigerant that has passed through the gas cooler 46 passes through the electromagnetic valve 60 through the high-pressure pipe 7 and reaches the main expansion valve 62. In the process of being throttled by the main expansion valve 62, the refrigerant is liquefied and flows into the evaporator 63. The liquid refrigerant that has flowed into the evaporator 63 evaporates, thereby exerting a cooling action. The cool air in the cabinet of the showcase 5 cooled by the evaporator 63 is circulated in the cabinet by the above-mentioned cool air circulation blower, and thereby the interior of each showcase 5 is cooled.

  In this case, the terminal controller SC of the showcase 5 controls the main expansion valve 62 as the actuator 463 on the basis of the received data regarding the operating condition addressed to itself, and sets the superheat degree of the refrigerant in the evaporator 63 as described above. To control. That is, when the degree of superheat of the refrigerant exiting the evaporator 63 is higher than the set degree of superheat, the valve opening is enlarged, and when it is low, it is reduced. Then, as the inside of the showcase 5 cools, the evaporation of the refrigerant in the evaporator 63 becomes slow, so the valve opening of the main expansion valve 62 is reduced and converges to the minimum valve opening. Since the cooling capacity is obtained by evaporating the refrigerant in the evaporator 63, the internal temperature is also controlled to the internal set temperature by controlling the superheat degree to the set superheat degree.

  The terminal controller SC of the refrigerator 3 operates the compressor 11 as the actuator 463 and the gas cooler blower 47 based on the received data relating to the operating condition and the opening / opening of each valve (electric expansion valve, electromagnetic valve). Control of opening and closing is performed, and recovery of refrigerant to a refrigerant amount adjustment tank 100 and an additional refrigerant amount adjustment tank 116, which will be described later, and control of discharge of refrigerant to the refrigerant circuit 1 are performed.

  In this case, the terminal controller SC of the refrigerator 3 uses the low-pressure control value composed of the ON value, OFF value, and differential value in the data relating to the operating conditions, and the low-pressure side pressure LP of the refrigerant circuit 1 detected by the low-pressure sensor 32. Is used to control the operating frequency of the compressors 11 and 11. In this case, the differential value is the difference between the low pressure cut value lower than the OFF value and the OFF value, and the relationship between the values is ON value> OFF value> low pressure cut value. When the cooling capacity is insufficient in each showcase 5, the valve opening degree of the main expansion valve 62 is expanded, so that the low pressure side pressure LP increases. The terminal controller SC of the refrigerator 3 increases the operating frequency of the compressor 11 at the predetermined increase speed described above when the low pressure LP detected by the low pressure sensor 32 becomes higher than the ON value. Thereby, the cooling capacity in the evaporator 63 of each showcase 5 is ensured.

  On the contrary, if the cooling capacity becomes excessive in the showcase 5, the main expansion valve 62 reduces the valve opening, so that the low pressure side pressure LP also decreases. The terminal controller SC of the refrigerator 3 reduces the operating frequency of the compressor 11 at a predetermined decrease rate when the low pressure side pressure LP becomes lower than the OFF value. The variable range of the operating frequency of the compressor 11 is, for example, 30 Hz to 60 Hz. This reduces excessive cooling capacity. In addition, when the low pressure side pressure LP is in the range of the OFF value or more and the ON value or less, the operation frequency of the compressor 11 is maintained as it is. Further, even if the operating frequency of the compressor 11 is lowered, the low-pressure side pressure LP is still lowered, and when it is lowered to the low-pressure cut value, the terminal controller SC stops the compressors 11 and 11 and again rises to the ON value. At the time, control for restarting the compressors 11 and 11 is executed.

(C) Refrigerant charging operation during installation Next, operations and operations during refrigerant charging when the refrigerator 3 and the showcase 5 of the refrigeration apparatus R are installed in the stores P1 and P2 will be described with reference to FIGS. To do.

(C-1) Refrigerant amount determination function of master controller MC After connecting the refrigerator 3 and the showcase 5 with the high-pressure pipe 7 and the low-pressure pipe 9 as described above, before connecting the additional refrigerant amount adjusting device 111 described later. In addition, carbon dioxide refrigerant is sealed in the refrigerant circuit 1 from the low-pressure service port. In this case, the amount of refrigerant to be sealed is calculated by calculating the volume in the refrigerant circuit 1 based on the lengths of the high-pressure pipes 7 and 9 of the stores P1 and P2, and the number of showcases 5 connected to the refrigerator 3. Use the minimum amount necessary for the volume. At this time, the amount of refrigerant enclosed in the refrigerant circuit 1 becomes the initial refrigerant (step S1 in the flowchart of FIG. 6 described later).

  In this way, first, after the calculated amount of refrigerant (initial refrigerant) is sealed in the refrigerant circuit 1, the operator transmits data related to the starting operating conditions from the master controller MC to each terminal controller SC, and the compressor of the refrigerator 3. 11 is started to start the operation of the refrigeration apparatus R. FIG. 6 is a flowchart of refrigerant amount determination executed by the master controller MC at the start of the operation. After the above-described initial refrigerant is sealed (step S1), the microcomputer 324 of the master controller MC freezes until the inside of the showcase 5 is normally cooled (cooled to a predetermined range above and below the set temperature in the cabinet). The apparatus R is operated. Next, the outside temperature detected by the outside temperature sensor 56 sent from the terminal controller 5 of the refrigerator 3 in step S2 is taken in, and the above-described appropriate high pressure-outside temperature data (FIG. 7) stored in the ROM 326 is obtained. The appropriate high pressure HPX corresponding to the outside temperature at that time detected by the outside temperature sensor 56 is calculated (extracted).

  Next, the microcomputer 324 of the master controller MC takes in the high pressure HP of the refrigerant circuit 1 detected by the high pressure sensor 58 sent from the terminal controller 5 of the refrigerator 3 in step S3, and the high pressure sensor 58 detects it. The current high pressure HP and the appropriate high pressure HPX are compared to determine whether the high pressure HP is higher than the proper high pressure HPX. If HP> HPX, it is determined that the amount of refrigerant in the refrigerant circuit 1 is excessive because the high pressure HP is too high. In step S5, the display (output of refrigerant amount: excessive) is displayed on the liquid crystal display unit 334 (output). )I do.

  If HP ≦ HPX in step S3, the microcomputer 324 of the master controller MC determines that the high pressure HP is appropriate. Next, in step S4, the main expansion valve 62 sent from the terminal controller 5 of the showcase 5 is determined. The current valve opening is taken in and the appropriate valve opening data stored in the ROM 326 is read. If the current valve opening is larger than the value of the appropriate valve opening data, it is determined that the amount of refrigerant in the refrigerant circuit 1 is small (insufficient), and “liquid amount: insufficient” is displayed on the liquid crystal display unit 334 in step S6. "Is displayed (output).

  Thereafter, unless the excess and / or deficiency of the refrigerant is resolved, the microcomputer 324 returns from step S4 (or step S3) to step S1 and repeats the determination of the refrigerant amount. If it is not excessive in step S3 and not insufficient in step S4, the microcomputer 324 determines that the amount of refrigerant in the refrigerant circuit 1 is appropriate in step S4 and turns off the display.

(C-2) Refrigerant Adjustment Work On the other hand, after the operator starts the operation of the refrigeration apparatus R and the inside of the showcase 5 is normally cooled, the liquid crystal display unit 334 of the master controller MC displays “refrigerant amount: excessive”. "Is displayed (step S5 in the flowchart of FIG. 6), the refrigerant in the refrigerant circuit 1 is extracted from the high-pressure service port 112. On the contrary, when “refrigerant amount: insufficient” is displayed on the liquid crystal display unit 334 (step S6 in the flowchart of FIG. 6), a predetermined amount of refrigerant is replenished (added) into the refrigerant circuit 1 from the low pressure service port 114. I will do it. In either case, the work of removing or replenishing the work when the display disappears is completed.

  As described above, the master controller MC has a function of determining the refrigerant amount in the refrigerant circuit 1 and has appropriate high pressure-outside air temperature data regarding the relationship between the high pressure and the outside air temperature in the appropriate refrigerant amount. The high pressure detected by the high pressure sensor 58 from the appropriate high pressure at the outside air temperature based on the appropriate high pressure-outside air temperature data, the high pressure detected by the high pressure sensor 58, and the outside air temperature detected by the outside temperature sensor 56. When the pressure is high, it is determined that the amount of refrigerant in the refrigerant circuit 1 is excessive and output, so that it is accurately and quickly grasped that the amount of refrigerant in the refrigerant circuit 1 is excessive and is extracted from the refrigerant circuit 1. Is possible.

  In addition, the master controller MC has appropriate valve opening data regarding the valve opening of the main expansion valve 62 in the normal cooling state in the storage of the showcase 5 at the appropriate refrigerant amount. Based on the valve opening degree of the main expansion valve 62 and the cooling state of the showcase 5, the valve opening degree of the main expansion valve 62 in the state where the showcase 5 is normally cooled is based on the appropriate valve opening degree data. If the refrigerant amount is large, it is determined that the refrigerant amount in the refrigerant circuit 1 is insufficient and is output. Therefore, it is accurately and quickly grasped that the refrigerant amount in the refrigerant circuit 1 is insufficient, and the refrigerant circuit 1 is replenished. Is possible. Thus, it is possible to remarkably improve the workability when installing the refrigeration apparatus R in the stores P1 and P2.

(D) Split Cycle Next, returning to FIG. 1, the split cycle of the refrigeration apparatus R of the embodiment will be described. The refrigeration apparatus R in the embodiment includes the first rotary compression element 18 (low stage side) of each compressor 11, an intercooler 38, a merger 81 as a merger that merges two fluid flows, and each compressor. 11 second rotary compression element 20 (higher stage side), oil separator 44, gas cooler 46, flow divider 82, auxiliary expansion valve 83, intermediate heat exchanger 80, electromagnetic valve 60, main expansion valve (main throttle means) 62 and the evaporator 63 constitute a refrigeration cycle.

  The flow divider 82 is a flow dividing device that divides the refrigerant from the gas cooler 46 into two flows. That is, the flow divider 82 of the present embodiment diverts the refrigerant that has exited the gas cooler 46 into the first refrigerant flow and the second refrigerant flow, the first refrigerant flow through the auxiliary circuit, and the second refrigerant flow. In the main circuit.

  The main circuit in FIG. 1 is the first rotary compression element 18 of the compressor 11, the intercooler 38, the merger 81, the second rotary compression element 20, the gas cooler 46, the flow divider 82, and the intermediate heat exchanger 80. 2 is an annular refrigerant circuit comprising a flow path 80B, an electromagnetic valve 60, a main expansion valve 62, and an evaporator 63. The auxiliary circuit is a first circuit of the auxiliary expansion valve 83 and the intermediate heat exchanger 80 from the flow divider 82. A circuit that reaches the merger 81 sequentially through the flow path 80A is shown. The second communication circuit 105 on the downstream side of the solenoid valve 106 and the capillary tube 107, which will be described later, merges with the first flow path 80A inlet on the downstream side of the auxiliary expansion valve 83.

  The auxiliary expansion valve 83 diverts the first refrigerant flow divided by the flow divider 82 and flowing through the auxiliary circuit. The intermediate heat exchanger 80 is a refrigerant (hereinafter referred to as a refrigerant discharged from a lower part of a refrigerant amount adjustment tank 100 described later) via the first refrigerant flow of the auxiliary circuit decompressed by the auxiliary expansion valve 83 and the second communication circuit 105. These are collectively referred to as a first refrigerant flow) and a heat exchanger that performs heat exchange between the second refrigerant flow divided by the flow divider 82. In the intermediate heat exchanger 80, a second flow path 80B through which the second refrigerant flow flows and a first flow path 80A through which the first refrigerant flow flows are provided in a heat exchangeable relationship. Since the second refrigerant flow is cooled by the first refrigerant flow flowing through the first flow path 80A by passing through the second flow path 80B of the intermediate heat exchanger 80, the ratio in the evaporator 63 Enthalpy is reduced.

  That is, in the refrigeration apparatus R in the embodiment having a split cycle, the refrigerant after radiating heat by the gas cooler 46 is divided, and the second refrigerant flow is cooled by the first refrigerant flow decompressed and expanded by the auxiliary expansion valve 83. The specific enthalpy at the inlet of the evaporator 63 can be reduced. As a result, the refrigeration effect can be increased and the performance can be effectively improved as compared with the conventional apparatus. Further, since the divided first refrigerant flow is returned to the second rotary compression element 20 (intermediate pressure portion) from the high-stage suction port 26 of the compressor 11, the first refrigerant flow from the low-stage suction port 22 of the compressor 11 is returned. The amount of the second refrigerant flow sucked into the first rotary compression element 18 (low pressure part) decreases, and the compression work in the first rotary compression element 18 (low stage part) for compression from low pressure to intermediate pressure Decrease. As a result, the compression power in the compressor 11 is reduced and the coefficient of performance is improved.

(E) Oil Separator An oil separator 44 is interposed in the high-pressure discharge pipe 42 that connects the high-stage discharge port 28 of the compressor 11 and the gas cooler 46 described above. The oil separator 44 separates and captures the oil contained in the high-pressure discharged refrigerant discharged from the compressor 11 from the refrigerant. The oil separator 44 returns the captured oil to the compressor 11. An oil return circuit 73 is connected. The oil return circuit 73 is provided with an oil tank 79 and an oil cooler 74 for cooling the captured oil. The oil return circuit 73 is branched into two systems on the downstream side of the oil cooler 74, and the flow rate is adjusted respectively. It is connected to the hermetic container 12 of the compressor 11 via a valve (electric valve) 76. Since the inside of the sealed container 12 of the compressor 11 is maintained at an intermediate pressure as described above, the trapped oil is caused by the differential pressure between the high pressure in the oil separator 44 and the intermediate pressure in the sealed container 12. 12 is returned. The hermetic container 12 of the compressor 11 is provided with an oil level float switch 77 that detects the level of oil held in the hermetic container 12.

  The oil cooler 74 is installed in the same air path 45 as the gas cooler 46 and is air-cooled by the gas cooler blower 47. Then, after passing through the oil cooler 74, it is separated into two systems and returns to the compressor 11 through the flow rate adjusting valve 76. As a result, the oil heated to a high temperature together with the high-temperature refrigerant is cooled by the oil cooler 74 and returned to the compressor 11, so that an increase in the temperature of the compressor 11 can be suppressed.

(F) Bypass piping Further, the refrigerator 3 has an intermediate pressure portion of the refrigerant circuit 1 on the outlet side of the intercooler 38, in the embodiment, an intermediate pressure suction pipe 40 on the outlet side of the intercooler 38, and the low pressure side of the refrigerant circuit 1. In the embodiment, a bypass pipe 84 communicating with the refrigerant introduction pipe 31 is provided. The bypass pipe 84 is provided with an electromagnetic valve 85 that opens the flow path when energized and seals the flow path when not energized.

  The electromagnetic valve 85 of the bypass pipe 84 is opened until the compressor 11 rises to a predetermined operating frequency from the startup when the compressor 11 is restarted after being stopped. When the solenoid valve 85 is opened, the first rotary compression element 18 raises the intermediate pressure, and the refrigerant discharged from the low-stage discharge port 24 to the intermediate pressure discharge pipe 36 passes through the intercooler 38 and bypass pipe 84. Then, the refrigerant flows into the refrigerant introduction pipe 31 on the low pressure side of the refrigerant circuit 1.

  As a result, the intermediate pressure portion and the low pressure side of the refrigerant circuit 1 are equalized, so that the pressure of the intermediate pressure portion and the pressure on the high pressure side approach each other while torque shortage occurs when the compressor 11 is started. This makes it possible to avoid a starting failure due to such a situation. In addition, after the operating frequency of the compressor 11 rises to a predetermined value, the solenoid valve 85 is not energized (closed).

(G) Refrigerant amount adjustment tank Next, adjustment of the circulating refrigerant amount of the refrigerant circuit 1 of the refrigeration apparatus R in the embodiment will be described. A refrigerant amount adjustment tank 100 is connected via a first communication circuit 101 to the high pressure side that is the supercritical pressure of the refrigerant circuit 1, in this embodiment, to the downstream side of the intermediate heat exchanger 80 of the refrigerator 3. . The refrigerant amount adjustment tank 100 is built in the refrigerator 3 together with the compressor 11 and the gas cooler 46, and has a predetermined volume. A first communication circuit 101 is connected to the upper part of the tank 100. Yes. The first communication circuit 101 is provided with an electric expansion valve 102 as a first valve device having a throttling function.

  The refrigerant amount adjustment tank 100 is connected to the third communication circuit 103 that communicates the upper part of the tank 100 with the intermediate pressure portion of the refrigerant circuit 1. In the present embodiment, the other end of the third communication circuit 103 is connected to the intermediate pressure suction pipe 40 on the outlet side of the intercooler 38 of the refrigerant circuit 1 as the intermediate pressure portion. The third communication circuit 103 is provided with an electromagnetic valve 104 as a third valve device.

  The refrigerant amount adjusting tank 100 is connected to the second communication circuit 105 that communicates the lower part of the tank 100 and the intermediate pressure part of the refrigerant circuit 1. In the present embodiment, the other end of the second communication circuit 105 communicates with the inlet of the first flow path 80A of the intermediate heat exchanger 80 that communicates with the intermediate pressure suction pipe 40 as an example of the intermediate pressure section. The second communication circuit 105 is provided with the electromagnetic valve 106 and the capillary tube 107 as a second valve device.

(G-1) Additional refrigerant amount adjusting tank Further, the additional refrigerant amount adjusting device 111 is connected to the refrigeration apparatus R of the embodiment. This additional refrigerant amount adjusting device 111 is an option for the refrigerator 3 in order to add an additional refrigerant amount adjusting tank 116 (also a refrigerant amount adjusting tank) to the refrigerant amount adjusting tank 100 according to the scale of the refrigeration apparatus R. It is attached to the outside of the refrigerator 3 (addition) and is detachably connected to the refrigerant circuit 1. In this case, the additional refrigerant amount adjusting device 111 includes an additional refrigerant amount adjusting tank 116 having a predetermined capacity inside an exterior case (not shown), and a first valve having a throttling function above the additional refrigerant amount adjusting tank 116. A first service port (service valve) 118 that communicates via an electric expansion valve 117 serving as a device, and a third service port that communicates via an electromagnetic valve 119 serving as a third valve device to the upper portion of the additional refrigerant amount adjustment tank 116. A service port (service valve) 121, a solenoid valve 122 as a second valve device, and a second service port (service valve) 124 communicating with a solenoid tube 122 as a second valve device via a capillary tube (not shown). The service ports 118, 121, and 124 are exposed to the outside from the additional refrigerant amount adjusting device 111.

  On the other hand, a high-pressure service port (service valve) 112 is connected in communication with the high-pressure side, which is the supercritical pressure of the refrigerant circuit 1, in the present embodiment, on the downstream side of the intermediate heat exchanger 80 of the refrigerator 3. An intermediate pressure service port (service valve) 113 is preliminarily attached to the third communication circuit 103 communicated with the intermediate pressure suction pipe 40 serving as an intermediate pressure region. A low-pressure service port (service valve) 114 is preliminarily attached to the refrigerant introduction pipe 31 on the low-pressure side of the refrigerant circuit 1, and these service ports 112 to 114 are also exposed to the outside from the refrigerator 3. ing.

  When the additional refrigerant amount adjusting device 111 is connected to the refrigerant circuit 1, the first service port 118 is provided by the first additional communication pipe 126 that constitutes the first additional communication circuit (first communication circuit). Is connected to the high-pressure service port 112 in a detachable manner, and the third service port 121 is connected to the intermediate pressure service port by the third additional communication pipe 127 constituting the third additional communication circuit (third communication circuit). The second service port 124 is detachably connected to the low-pressure service port 114 by the second additional communication pipe 128 constituting the second additional communication circuit (second communication circuit). Connect and communicate.

  As a result, the upper part of the additional refrigerant amount adjustment tank 116 is communicated with the high pressure side of the refrigerant circuit 1 via the first additional communication pipe 126, and the electric expansion valve 117 is provided in the first additional communication circuit. The upper part of the additional refrigerant amount adjusting tank 116 is also communicated with the intermediate pressure portion of the refrigerant circuit 1 via the third additional communication pipe 127, and the electromagnetic valve 119 is provided in the third additional communication circuit. . Further, the lower part of the additional refrigerant amount adjustment tank 116 is communicated with the low pressure side of the refrigerant circuit 1 via the second additional communication pipe 128, and the electromagnetic valve 122 is provided in the second additional communication circuit.

(G-2) Refrigerant recovery / refrigerant release control Hereinafter, recovery of the refrigerant from the refrigerant circuit 1 to the refrigerant quantity adjustment tank 100 and the additional refrigerant quantity adjustment tank 116 by the terminal controller SC of the refrigerator 3 and from them to the refrigerant circuit 1 Control of refrigerant discharge will be described. The terminal controller SC of the refrigerator 3 executes a high-pressure shut-off operation for stopping the operation of the compressor 11 when the high-pressure side pressure HP detected by the high-pressure sensor 58 exceeds a predetermined high-pressure protection value (for example, 12 MPa). It shall be. Based on this premise, the following control regarding refrigerant recovery and release will be described.

  The terminal controller SC of the refrigerator 3 determines the target high pressure THP based on the outside temperature detected by the outside temperature sensor 56. In this case, the lower the outside air temperature, the lower the target high pressure THP for the high pressure side pressure. Next, based on the target high pressure THP and the high pressure side pressure HP of the refrigerant circuit 1 detected by the high pressure sensor 58, the electric expansion valve (first valve device) 102 and the electric expansion valve (first extension valve device) 117, the solenoid valve (second valve device) 106 and the solenoid valve (second extension valve device) 122, the solenoid valve (third valve device) 104, and the solenoid valve (third extension valve device) 119 are controlled. As a result, while collecting the refrigerant in the refrigerant quantity adjustment tank 100 and the additional refrigerant quantity adjustment tank 116, the refrigerant is discharged from them, and the degree of refrigerant collection and refrigerant release is adjusted, so that the inside of the refrigerant circuit 1 Control the amount of circulating refrigerant.

  Next, specific refrigerant recovery and refrigerant discharge control by the terminal controller SC of the refrigerator 3 will be described. In the following description, only the refrigerant recovery and discharge control (control of the electric expansion valve 102 and the electromagnetic valves 106 and 104) of the refrigerant amount adjustment tank 100 will be described, but the electric expansion valve 102 is also applied to the additional refrigerant amount adjustment tank 116. The explanation will be omitted on the assumption that the electric expansion valve 117 and the electromagnetic valves 122 and 119 respectively corresponding to the electromagnetic valves 106 and 104 are controlled similarly to the case of the refrigerant amount adjusting tank 100. However, the additional refrigerant amount adjustment tank 116 is connected to the low pressure side of the refrigerant circuit 1 by the electromagnetic valve 122 and is different from the refrigerant amount adjustment tank 100 in that the refrigerant is discharged.

  Now, assuming that the high-pressure side pressure HP of the refrigerant circuit 1 detected by the high-pressure sensor 58 is in the vicinity of the target high-pressure THP, the terminal controller SC determines the electric expansion valve 102 (in the case of the additional refrigerant amount adjustment tank 116, the electric expansion valve 117). Then, the valve opening of the valve is fully closed, the electromagnetic valve 106 (in the case of the additional refrigerant amount adjustment tank 116, the electromagnetic valve 119, the same applies hereinafter), and the electromagnetic valve 104 (in the additional refrigerant amount adjustment tank 116) is opened. In this case, the electromagnetic valve 122. The same applies hereinafter). In this state, the refrigerant amount adjustment tank 100 (and the additional refrigerant amount adjustment tank 116; the same applies hereinafter) is not communicated with the high pressure side, the upper part is not communicated with the intermediate pressure region, and only the lower part is in the intermediate pressure region (additional refrigerant amount). In the case of the adjustment tank 116, it communicates with the low pressure side). Accordingly, all the refrigerant in the refrigerant amount adjustment tank 100 is discharged to the intermediate pressure region of the refrigerant circuit 1 (low pressure side in the case of the additional refrigerant amount adjustment tank 116; the same applies hereinafter), and the refrigerant amount adjustment tank 100 becomes empty. Therefore, so-called liquid sealing is prevented.

  The terminal controller SC takes in the high pressure side pressure HP detected by the high pressure sensor 58 at every predetermined sampling timing T1 (for example, 200 ms) and compares it with the target high pressure THP. When the high-pressure side pressure HP increases and becomes higher than, for example, the target high-pressure THP + 1.0 (MPa) (target high-pressure THP + 1.0 <high-pressure side pressure HP), the terminal controller SC closes the electromagnetic valve 106 and the electric expansion valve 102 The valve opening is set to a state where the valve is opened from a fully closed state (zero step) to a predetermined step S (for example, 100 steps). Further, the electromagnetic valve 104 is opened.

  As a result, the high-temperature and high-pressure refrigerant discharged from the high-stage discharge port 28 of the compressor 11 passes through the oil separator 44 and is cooled by the gas cooler 46 and the intermediate heat exchanger 80, and then a part thereof is opened. Flows into the refrigerant amount adjustment tank 100 via the first communication circuit 101 (the first additional communication pipe 126 in the case of the additional refrigerant amount adjustment tank 116; the same applies hereinafter). .

  Further, when the high-pressure side pressure HP further increases, for example, becomes higher than the target high-pressure THP + 1.3 (MPa) (target high-pressure THP + 1.3 <high-pressure side pressure HP), the terminal controller SC closes the electromagnetic valve 106 and the electric expansion valve 102 The valve opening is further expanded by a predetermined step S, and the valve opening is expanded from the fully closed state to the step 2S (200 steps) opened. Further, the electromagnetic valve 104 remains open. As a result, the recovery rate of the refrigerant flowing from the first communication circuit 101 into the refrigerant amount adjustment tank 100 via the electric expansion valve 102 is increased.

  Further, when the high-pressure side pressure HP further increases, for example, becomes higher than the target high-pressure THP + 1.6 (MPa) (target high-pressure THP + 1.6 <high-pressure side pressure HP), the terminal controller SC closes the electromagnetic valve 106 and the electric expansion valve 102 The valve opening is further expanded from step 2S (200 steps) by a predetermined step S, and expanded from the fully closed state to the state opened by step 3S (300 steps). Further, the electromagnetic valve 104 remains open. As a result, the recovery rate of the refrigerant flowing into the refrigerant amount adjustment tank 100 from the first communication circuit 101 via the electric expansion valve 102 further increases.

  The third communication circuit 103 (in the case of the additional refrigerant amount adjustment tank 116) that connects the upper part of the refrigerant amount adjustment tank 100 and the intermediate pressure region of the refrigerant circuit 1 by opening the electromagnetic valve 104 so far. The pressure in the refrigerant quantity adjusting tank 100 can be released to the outside of the tank via the third additional communication pipe 127 (hereinafter the same). Therefore, even when the supercritical cycle operation in which the refrigerant in the refrigerant circuit 1 is not liquefied, such as when the outside air temperature becomes high, the pressure in the refrigerant amount adjustment tank 100 decreases and the refrigerant amount adjustment tank The refrigerant flowing into 100 is liquefied and accumulated in the refrigerant quantity adjustment tank 100. That is, when the pressure in the refrigerant quantity adjustment tank 100 drops below the supercritical pressure, the refrigerant changes from the gas region to the saturation region, and the liquid level can be secured.

  Thereby, the refrigerant | coolant in the refrigerant circuit 1 can be collect | recovered to the refrigerant | coolant amount adjustment tank 100 (and expansion refrigerant | coolant amount adjustment tank 116) rapidly and efficiently. Accordingly, it is possible to eliminate the disadvantage that the refrigerant circuit 1 has an excessively high pressure on the high pressure side, resulting in an abnormally high pressure, and it is possible to prevent the compressor 11 from being overloaded due to the high pressure abnormality.

  Thus, the terminal controller SC increases the opening degree of the electric expansion valve 102 as the high-pressure side pressure HP increases, and increases the refrigerant recovery rate to the refrigerant amount adjustment tank 100.

  Next, by collecting the refrigerant in the refrigerant amount adjustment tank 100 in this way, the high-pressure side pressure HP detected by the high-pressure sensor 58 decreases, and the high-pressure side pressure HP is, for example, the target high pressure THP + 0.6 (MPa) or less. When the terminal controller SC decreases, the terminal controller SC reduces the valve opening of the electric expansion valve 102 to step S / 2 (a state in which 50 steps are opened from the fully closed state. The refrigerant recovery speed is the lowest), and the solenoid valve 104 is close up. Further, the electromagnetic valve 106 is opened after a predetermined time t1 (for example, 10 s) and then closed. Thus, a predetermined amount of refrigerant is released from the refrigerant amount adjustment tank 100 to the intermediate pressure region of the refrigerant circuit 1 via the electromagnetic valve 104 while collecting the refrigerant in the refrigerant amount adjustment tank 100 via the electric expansion valve 102. Is done.

  When the refrigerant is discharged, the high pressure side pressure HP continues to decrease, for example, when the target high pressure THP + 1.2 (MPa) or lower (high pressure side pressure HP ≦ target high pressure + 1.2), the terminal controller SC similarly performs the electric expansion. The valve opening degree of the valve 102 is reduced to step S / 2, and the electromagnetic valve 104 is also kept closed. Further, the electromagnetic valve 106 is opened again for a predetermined time t1, and then closed. As a result, while the refrigerant is collected in the refrigerant quantity adjustment tank 100 via the electric expansion valve 102, a predetermined amount of refrigerant further enters the intermediate pressure region of the refrigerant circuit 1 from the refrigerant quantity adjustment tank 100 via the electromagnetic valve 104. Released.

  In addition, when the refrigerant is released, the high pressure side pressure HP continues to decrease, for example, when the target high pressure THP + 0.9 (MPa) or lower (high pressure side pressure HP ≦ target high pressure + 0.9), the terminal controller SC is electrically expanded. The valve opening degree of the valve 102 is reduced to step S / 2, and the electromagnetic valve 104 is also kept closed. Further, the electromagnetic valve 106 is opened again for a predetermined time t1, and then closed. As a result, while the refrigerant is collected in the refrigerant quantity adjustment tank 100 via the electric expansion valve 102, a predetermined amount of refrigerant further enters the intermediate pressure region of the refrigerant circuit 1 from the refrigerant quantity adjustment tank 100 via the electromagnetic valve 104. Released.

  When the refrigerant is discharged, the high pressure side pressure HP continues to decrease. For example, when the pressure falls below the target high pressure THP (high pressure side pressure ≦ target high pressure), the terminal controller SC fully closes the electric expansion valve 102, 104 is also closed. Further, the electromagnetic valve 106 is opened.

  Thus, the terminal controller SC gradually releases the refrigerant from the refrigerant amount adjustment tank 100 as the high pressure side pressure HP decreases, that is, by gradually opening the electromagnetic valve 106 for a predetermined time t1 at every sampling timing T2. Release to the low pressure side.

  By connecting the refrigerant amount adjustment tank 100 and the additional refrigerant amount adjustment tank 116 to the refrigerant circuit 1 in this way, surplus refrigerant in the refrigerant circuit 1 is supplied from the high-pressure side to the refrigerant amount adjustment tank 100 and the additional refrigerant amount. The refrigerant is recovered in the adjustment tank 116, and the refrigerant is discharged from the refrigerant amount adjustment tank 100 to the intermediate pressure region of the refrigerant circuit 1 and from the additional refrigerant amount adjustment tank 116 to the low pressure side, so that the circulating refrigerant amount in the refrigerant circuit 1 is appropriately adjusted. Can be maintained. Thereby, the disadvantage that the high pressure side in the refrigerant circuit 1 becomes abnormally high can be solved, and the overload operation of the compressor 11 due to the high pressure abnormality can be prevented.

  In particular, the terminal controller SC of the refrigerator 3 discharges the refrigerant to the refrigerant amount adjustment tank 100 and the additional refrigerant amount adjustment tank 116 while collecting the refrigerant, and adjusts the degree of collection and discharge based on the target high pressure THP, thereby adjusting the circulation refrigerant amount. Therefore, it is possible to prevent sudden fluctuations in the circulating refrigerant amount accompanying the recovery of the refrigerant to the refrigerant amount adjustment tank 100 and the additional refrigerant amount adjustment tank 116 and the release of the refrigerant therefrom.

  The terminal controller SC of the refrigerator 3 changes the refrigerant recovery rate to the refrigerant amount adjustment tank 100 and the additional refrigerant amount adjustment tank 116 as the high pressure side pressure HP of the refrigerant circuit 1 increases, and the high pressure side pressure HP is changed. Since the refrigerant recovery rate is increased as the temperature rises, excessive refrigerant recovery can be prevented in advance, and the circulation accompanying the recovery of the refrigerant to the refrigerant amount adjustment tank 100 and the additional refrigerant amount adjustment tank 116 is achieved. It is possible to effectively prevent sudden fluctuations in the refrigerant amount.

  Further, while collecting the refrigerant in the refrigerant amount adjustment tank 100 and the additional refrigerant amount adjustment tank 116, the refrigerant is discharged from the refrigerant amount adjustment tank 100 and the additional refrigerant amount adjustment tank 116 based on the high pressure side pressure HP of the refrigerant circuit 1. Then, as the high pressure side pressure HP of the refrigerant circuit 1 decreases, the refrigerant is gradually released from the refrigerant amount adjustment tank 100 and the additional refrigerant amount adjustment tank 116, and thus from the refrigerant amount adjustment tank 100 and the additional refrigerant amount adjustment tank 116. This makes it possible to effectively prevent a sudden change in the amount of circulating refrigerant accompanying the release of the refrigerant.

  Accordingly, it is possible to appropriately maintain and manage the circulating refrigerant amount in the refrigerant circuit 1 of the refrigeration apparatus R in which the high pressure side becomes the critical pressure, and to realize stable cooling performance.

  In the embodiment, it is described that the operator adjusts the refrigerant amount according to the display output of the master controller MC when installing the refrigeration apparatus R. However, the present invention is not limited to this, and an electromagnetic valve or the like is provided in the high-pressure service port or the low-pressure service port. A refrigerant tank is further attached to the solenoid valve of the low-pressure service port, and the master controller MC sends an instruction to the terminal controller SC of the refrigerator 3 to open and close these solenoid valves. The operation may be automated so that a predetermined amount of refrigerant is removed and a predetermined amount is replenished from the refrigerant tank into the refrigerant circuit 1 when it is determined that the refrigerant is insufficient.

  In the embodiment, a showcase installed in a store is taken as an example of a cooling device, but the present invention is also effective for a cooling coil to which a refrigerant is supplied from a refrigerator. Furthermore, the concept of the store in the present invention is not limited to a supermarket or a convenience store, but includes facilities such as production factories and offices. Furthermore, each numerical value illustrated in the embodiment is not limited thereto, and may be appropriately set according to the refrigeration apparatus R.

MC master controller R refrigeration equipment RC centralized controller SC terminal controller 1 refrigerant circuit 3 refrigerator 5 showcase 7 high pressure piping 9 low pressure piping 11 compressor 32 low pressure sensor 56 outside air temperature sensor 58 high pressure sensor 60 solenoid valve 62 main expansion valve 85 Solenoid valve 100 Refrigerant amount adjusting tank 111 Additional refrigerant amount adjusting device 112 High-pressure service port 114 Low-pressure service port 116 Additional refrigerant amount adjusting tank

Claims (6)

The compressor comprises a refrigerator having a compression means and a radiator, and a cooling device having an expansion valve and an evaporator. The refrigerator and the cooling device are connected by a high-pressure pipe and a low-pressure pipe to form a refrigerant circuit, and the compression The refrigerant that has been compressed by the means and passed through the radiator is sent to the expansion valve by the high-pressure pipe, the refrigerant that has exited the evaporator is returned to the compression means by the low-pressure pipe, and the high-pressure side is supercritical pressure. In the refrigeration apparatus
A refrigeration apparatus comprising control means for controlling the compression means and the expansion valve, the control means having a function of determining the amount of refrigerant in the refrigerant circuit. High pressure detection means for detecting high pressure of the refrigerant circuit;
An outside air temperature detecting means for detecting the outside air temperature,
The control means has appropriate high pressure-outside temperature data relating to the relationship between the high pressure and the outside air temperature in an appropriate amount of refrigerant,
Based on the appropriate high pressure-outside temperature data, the high pressure detected by the high pressure detection means, and the outside temperature detected by the outside temperature detection means, the high pressure detection means detects the appropriate high pressure at the outside temperature. 2. The refrigeration apparatus according to claim 1, wherein when the high pressure is high, the refrigerant amount in the refrigerant circuit is determined to be excessive and output. The control means has appropriate valve opening degree data relating to the opening degree of the expansion valve in a normal cooling state of the cooling device in an appropriate refrigerant amount,
Based on the appropriate valve opening data, the valve opening of the expansion valve, and the cooling state of the cooling device, the valve opening of the expansion valve when the cooling device is normally cooled is 3. The refrigeration apparatus according to claim 1, wherein when it is larger than the valve opening degree data, it is determined that the amount of refrigerant in the refrigerant circuit is insufficient and is output.   The refrigeration apparatus according to any one of claims 1 to 3, wherein carbon dioxide is used as the refrigerant. A refrigerator having a compression means and a radiator, and a cooling device having an expansion valve and an evaporator, and connecting the refrigerator and the cooling device with a high-pressure pipe and a low-pressure pipe to constitute a refrigerant circuit, The refrigerant compressed by the compression means and passed through the radiator is sent to the expansion valve by the high-pressure pipe, and the refrigerant discharged from the evaporator is returned to the compression means by the low-pressure pipe, and the high-pressure side is supercritical pressure. A refrigerant amount adjustment method for a refrigeration apparatus,
Create appropriate high pressure-outside air temperature data regarding the relationship between the high pressure of the refrigerant circuit and the outside air temperature at an appropriate amount of refrigerant,
The high-pressure pressure and the outside air temperature are detected, the appropriate high-pressure pressure at the outside-air temperature is extracted from the proper high-pressure pressure-outside air temperature data, and when the detected high-pressure pressure is higher than the appropriate high-pressure pressure, A refrigerant amount adjusting method for a refrigeration apparatus, characterized in that Create appropriate valve opening data regarding the valve opening of the expansion valve in the normal cooling state of the cooling device in an appropriate amount of refrigerant,
The valve opening of the expansion valve is confirmed in a state where the cooling device is normally cooled, and when the valve opening is larger than the appropriate valve opening data, the refrigerant is replenished in the refrigerant circuit. The refrigerant quantity adjustment method of the refrigeration apparatus according to claim 5.

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