JP6528831B2 - Refrigerant charge determination system - Google Patents

Description

  The present invention relates to a refrigerant charge determination system.

  A refrigerant circulates in a refrigerant circuit mounted on a refrigeration system such as an air conditioner, a freezer, and a water heater. When the refrigerant leaks from the refrigerant circuit, not only the refrigeration system can not exhibit sufficient capacity, but also the leaked refrigerant may affect the environment.

  In order to detect the occurrence of refrigerant leakage, in the air conditioner of Patent Document 1 (Japanese Patent No. 3852472), there is a “refrigerant amount determination operation mode” that determines the suitability of the refrigerant charge amount in the refrigerant circuit. In this mode, the suitability of the refrigerant charge is determined by measuring the degree of subcooling of the refrigerant leaving the radiator. Since the degree of supercooling also fluctuates due to the ambient air temperature of the radiator and heat absorber and other factors, the air conditioner forcibly creates a "stable state" suitable for the determination prior to the determination. Here, the stable state refers to a state in which the condensation pressure, the degree of superheat, the evaporation pressure, and the like in the refrigerant circuit fall within a predetermined range.

  In order to settle the refrigerant circuit of the refrigeration system to such a stable state, it is necessary to wait for a certain period of time while performing special control. In addition, while the refrigerant circuit remains stable, it may be difficult for the refrigeration system to respond quickly to user requests. Therefore, the appropriateness determination of the refrigerant charge amount using the “refrigerant amount determination operation mode” may cause the user to be inconvenient.

  An object of the present invention is to provide a refrigerant charge determination system that can be easily provided with a refrigerant circuit, and can easily determine whether the refrigerant charge is appropriate for detecting whether the refrigerant has leaked therefrom.

  A refrigerant charge determination system according to a first aspect of the present invention includes a refrigerant circuit and a refrigerant storage unit. The refrigerant circuit includes a compressor and an expansion valve, and is configured to circulate a predetermined amount of refrigerant charge that can take the states of liquid refrigerant and gas refrigerant. The refrigerant accommodating portion reduces a circulation amount of the refrigerant circulating in the refrigerant circuit by accommodating a part of the refrigerant in the refrigerant charge amount.

  The refrigerant charge determination system according to a second aspect of the present invention further includes a state quantity acquisition unit and a determination unit in the refrigerant charge determination system according to the first aspect. The state quantity acquisition unit acquires the state quantity of the refrigerant circuit. The determination unit determines the suitability of the refrigerant charge amount based on the response of the state amount to the amount of refrigerant stored in the refrigerant storage unit.

  According to this configuration, since the state quantity related to the behavior of the refrigerant circuit when changing the circulation amount of the refrigerant is acquired, more information can be used for the appropriateness determination of the refrigerant filling amount. Therefore, it is possible to easily determine whether the refrigerant charge amount is appropriate.

  The refrigerant | coolant filling amount determination system which concerns on the 3rd viewpoint of this invention is a refrigerant | coolant filling amount determination system which concerns on a 1st viewpoint or a 2nd viewpoint. WHEREIN: A refrigerant | coolant accommodating part contains the refrigerant | coolant storage container connected to the refrigerant circuit.

  A refrigerant charge determination system according to a fourth aspect of the present invention is the refrigerant charge determination system according to any one of the first aspect to the third aspect, wherein the refrigerant circuit has a radiator of the refrigerant. The state quantity is the degree of subcooling of the refrigerant leaving the radiator.

  The refrigerant charge determination system according to a fifth aspect of the present invention is the refrigerant charge determination system according to any one of the first to third aspects, wherein the state quantity is the opening degree of the expansion valve.

  In the refrigerant charge determination system according to a sixth aspect of the present invention, in the refrigerant charge determination system according to any one of the first to fifth aspects, switching between the first condition and the second condition may be performed. it can. Under the second condition, the refrigerant storage unit stores a larger amount of liquid refrigerant than the first condition by a predetermined storage amount.

  The refrigerant charge determination system according to a seventh aspect of the present invention is the refrigerant charge determination system according to the sixth aspect, wherein the determination unit is a state acquired by the state quantity acquisition unit during transition of the first condition and the second condition. Based on the amount, it is determined whether the refrigerant charge amount is appropriate.

  According to this configuration, the state quantity related to the behavior of the refrigerant circuit during the transition between the first condition and the second condition is acquired, so that more information can be used for the appropriateness determination of the refrigerant charge amount. Therefore, it is possible to easily determine whether the refrigerant charge amount is appropriate.

  The refrigerant charge determination system according to an eighth aspect of the present invention is the refrigerant charge determination system according to the sixth aspect or the seventh aspect, wherein the determination unit determines the state quantity during transition of the first condition and the second condition. When it moves beyond the threshold value, the suitability of the refrigerant charging amount is determined based on the amount of liquid refrigerant contained in the refrigerant containing portion.

  According to this configuration, when the magnitude relation between the state quantity and the threshold value is reversed, the suitability of the refrigerant charging amount is determined based on the amount of liquid refrigerant contained in the refrigerant containing portion. Therefore, the propriety determination can be performed within a relatively short time of the transition period between the two conditions.

  The refrigerant charge determination system according to a ninth aspect of the present invention is the refrigerant charge determination system according to the eighth aspect, wherein the determination unit determines that the amount of liquid refrigerant is smaller than a predetermined liquid refrigerant amount threshold value. Determine that the amount is inappropriate.

  According to this configuration, when the amount of liquid refrigerant stored in the refrigerant storage unit is smaller than the liquid refrigerant amount threshold when there is a change in the state amount, it is determined that the refrigerant filling amount is insufficient. Therefore, the shortage of the refrigerant charge can be determined by the behavior of the state quantity being sufficiently changed by removing a small amount of the refrigerant from the refrigerant circuit.

  A refrigerant charge determination system according to a tenth aspect of the present invention is a refrigerant charge determination system according to any one of the eighth aspect through the ninth aspect, wherein the refrigerant circuit includes a heat source unit having a compressor, and a utilization unit And a communication pipe for moving the refrigerant between the heat source unit and the utilization unit. The communication pipe has a liquid communication pipe that mainly moves the liquid refrigerant, and a gas communication pipe that mainly moves the gas refrigerant. The refrigerant storage unit is connected to the gas communication pipe via the first gas side valve and to the liquid communication pipe via the first liquid side valve.

  According to this configuration, the refrigerant storage unit is connected to the liquid communication pipe and the gas communication pipe. Therefore, the refrigerant accommodating portion can exchange the liquid refrigerant and the gas refrigerant, thereby adjusting the circulation amount of the refrigerant in the refrigerant circuit.

  The refrigerant | coolant filling amount determination system which concerns on the 11th viewpoint of this invention is a refrigerant | coolant filling amount determination system which concerns on a 10th viewpoint. WHEREIN: A refrigerant | coolant accommodating part is further connected to liquid connection piping via 2nd gas side valve.

  According to this configuration, the refrigerant storage unit is connected to the gas communication pipe via the first gas side valve and the second gas side valve arranged in parallel. Therefore, the refrigerant accommodating portion can discharge the gas refrigerant to the gas communication pipe via the other gas side valve while receiving the gas refrigerant from the gas communication pipe via the one gas side valve.

  In the refrigerant charge determination system according to a twelfth aspect of the present invention, in the refrigerant charge determination system according to any one of the eighth aspect to the eleventh aspect, the determination unit transitions from the first condition to the second condition Whether the refrigerant charge amount is appropriate or not is determined based on the state amounts acquired by the state amount acquisition unit both during the transition from the second condition to the first condition.

  According to this configuration, the state quantity is acquired not only during the transition period from the first condition to the second condition, but also during the transition period from the second condition to the first condition. Therefore, more information can be used to determine whether the refrigerant charge amount is appropriate.

  A method according to a thirteenth aspect of the present invention is a method of determining the suitability of the refrigerant charge amount of the refrigerant circuit. The refrigerant circuit includes a compressor, a heat source heat exchanger, a utilization heat exchanger, an expansion valve, a liquid communication pipe, and a gas communication pipe, and is configured to circulate a refrigerant capable of taking a liquid refrigerant and a gas refrigerant state. It is done. The method obtains state quantities during the steps of connecting the refrigerant storage unit to the gas communication pipe and the gas communication pipe, moving the refrigerant between the refrigerant circuit and the refrigerant storage unit, and moving the refrigerant. And determining the suitability of the refrigerant charge amount based on the amount of liquid refrigerant stored in the refrigerant storage unit when the magnitude relation between the state amount and the predetermined threshold value is reversed.

  According to this method, since the state amount is acquired under the condition in which the circulation amount of the refrigerant in the refrigerant circuit is changed, more information can be used for the appropriateness determination of the refrigerant charge amount. Therefore, it is possible to easily determine whether the refrigerant charge amount is appropriate.

  The method according to a fourteenth aspect of the present invention is the method according to the thirteenth aspect, wherein at least one of the heat source heat exchanger and the utilization heat exchanger can operate as a radiator. The state quantity is the degree of subcooling of the refrigerant leaving the radiator.

  According to this method, when the magnitude relation between the degree of subcooling and the degree of subcooling threshold is reversed, the suitability of the refrigerant charging amount is determined based on the amount of liquid refrigerant contained in the refrigerant containing portion. Therefore, the propriety determination can be performed simply.

  The method according to a fifteenth aspect of the present invention is the method according to the thirteenth aspect, wherein the state quantity is the opening degree of the expansion valve.

  According to this method, when the magnitude relation between the opening degree of the expansion valve and the opening degree threshold value is reversed, the suitability of the refrigerant charging amount is determined based on the amount of liquid refrigerant contained in the refrigerant containing portion. Therefore, the propriety determination can be performed simply.

  According to the refrigerant filling amount determination system according to the first aspect to the twelfth aspect of the present invention, the appropriateness determination of the refrigerant filling amount can be easily performed.

  According to the methods pertaining to the thirteenth to fifteenth aspects of the present invention, it is possible to easily determine the appropriateness of the refrigerant charge amount.

It is a block diagram of the refrigerant | coolant filling amount determination system 100 which concerns on 1st Embodiment of this invention. It is a block diagram of processing part 90 of refrigerant charge determination system 100 concerning a 1st embodiment of the present invention. It is a block diagram of the refrigerant | coolant filling amount determination system 100 which concerns on 1st Embodiment of this invention. It is a figure which shows the state of the refrigerant | coolant accommodation unit 70 in normal circulation mode MN. It is a figure which shows the state of the refrigerant | coolant accommodation unit 70 in small amount circulation mode MS. It is a figure which shows the behavior of supercooling degree SC which is a state quantity. It is a figure which shows the behavior of opening degree EVA of the expansion valve which is a state quantity. It is a block diagram of the refrigerant | coolant filling amount determination system 100 which concerns on the modification 1C of 1st Embodiment of this invention. It is a block diagram of the refrigerant | coolant filling amount determination system 100 which concerns on the modification 1E of 1st Embodiment of this invention. It is a block diagram of refrigerant charge determination system 100A concerning a 2nd embodiment of the present invention. It is a block diagram of refrigerant charge determination system 100A concerning modification 2A of a 2nd embodiment of the present invention. It is a block diagram of refrigerant charge determination system 100A concerning modification 2B of a 2nd embodiment of the present invention. It is a block diagram of the refrigerant | coolant filling amount determination system 100B which concerns on 3rd Embodiment of this invention. It is a block diagram of refrigerant charge determination system 100C concerning a 4th embodiment of the present invention. It is a block diagram of refrigerant charge determination system 100D which concerns on 5th Embodiment of this invention.

  Hereinafter, embodiments of an air conditioner according to the present invention will be described using the drawings. In addition, the specific structure of the air conditioning apparatus concerning this invention is not restricted to following embodiment, It can change suitably in the range which does not deviate from the summary of invention.

First Embodiment
(1) Overall Configuration FIG. 1 shows a refrigerant charge determination system 100 according to a first embodiment of the present invention. The refrigerant charge determination system 100 includes the refrigerant circuit 40, and determines whether or not the refrigerant charge V1, which is the amount of refrigerant charged in the refrigerant circuit 40, is appropriate. The refrigerant charge determination system 100 includes a refrigerant circuit 40, a refrigerant storage unit 70, and a processing unit 90.

(2) Detailed configuration (2-1) Refrigerant circuit 40
The refrigerant circuit 40 is for circulating the refrigerant therein to provide the user with heat or cold. The refrigerant circuit 40 is filled with a refrigerant with a refrigerant charge amount V1. In the present embodiment, the refrigerant circuit 40 is configured as an air conditioner, and includes a heat source unit 10, usage units 20a and 20b, and a communication pipe 30.

(2-1-1) Heat source unit 10
The heat source unit 10 is for producing heat or cold, and is often arranged outdoors. The heat source unit 10 includes a compressor 11, a four-way switching valve 12, a heat source heat exchanger 13, a heat source fan 14, a heat source expansion valve 15, a refrigerant holder 16, a liquid side shutoff valve 17, and a gas side shutoff valve 18.

  The compressor 11 compresses the sucked low pressure gas refrigerant and discharges the high pressure gas refrigerant. The four-way switching valve 12 causes the refrigerant circuit 40 to perform either the cold energy utilization operation or the thermal energy utilization operation by switching the pipe connection. The heat source heat exchanger 13 performs heat exchange between the refrigerant and the ambient air. The heat source heat exchanger 13 functions as a radiator of the refrigerant in the cold heat utilization operation, and functions as a heat absorber of the refrigerant in the heat utilization operation. The heat source fan 14 promotes heat exchange between the refrigerant and the ambient air performed by the heat source heat exchanger 13. The heat source expansion valve 15 is for depressurizing the refrigerant as needed. The heat source expansion valve 15 is configured of an electric expansion valve capable of adjusting the opening degree. The refrigerant holder 16 is for separating and holding the liquid component mixed therein from the low pressure gas refrigerant. The refrigerant holder 16 is composed of parts called a so-called accumulator. The refrigerant holder 16 can hold the liquid refrigerant of the holding amount V3. The liquid side shutoff valve 17 is configured to be connected to a liquid communication pipe 31 described later. The gas side shut-off valve 18 is configured to be connected to a gas communication pipe 32 described later. At the time of installation of the heat source unit 10 or the like, the liquid side shutoff valve 17 and the gas side shutoff valve 18 are closed.

(2-1-2) Usage unit 20a, 20b
The utilization units 20a, 20b are for providing the user with the heat or cold generated by the heat source unit 10, and are often arranged indoors. The plurality of usage units 20a and 20b are installed, for example, in another room of the same building. Although the number of utilization units is two in the present embodiment, the number of utilization units may be other than that, that is, one or three or more. Since both usage units 20a and 20b have similar internal structures, only the usage unit 20a will be described below.

  The usage unit 20 a includes a usage expansion valve 21, a usage heat exchanger 22, and a usage fan 23. The utilization expansion valve 21 is for depressurizing the refrigerant as needed. The utilization expansion valve 21 is composed of an electric expansion valve capable of adjusting the opening degree. The utilization heat exchanger 22 performs heat exchange between the refrigerant and the ambient air. The utilization heat exchanger 22 functions as a heat sink of the refrigerant in the cold utilization operation, and functions as a radiator of the refrigerant in the thermal utilization operation. The utilization fan 23 promotes heat exchange between the refrigerant and the ambient air performed by the utilization heat exchanger 22. The utilization fan 23 also sends the air after the heat exchange to the vicinity of the user.

(2-1-3) Connection piping 30
The connection pipe 30 connects the heat source unit 10 and the usage units 20a and 20b. The communication pipe 30 has a liquid communication pipe 31 and a gas communication pipe 32. The liquid communication pipe 31 is a pipe that mainly moves a high pressure liquid refrigerant or a low pressure gas-liquid two-phase refrigerant. The liquid communication pipe 31 connects the liquid-side shutoff valve 17 of the heat source unit 10 and the utilization expansion valve 21 of the utilization units 20a and 20b. The gas communication pipe 32 is a pipe for moving a high pressure gas refrigerant or a low pressure gas refrigerant. The gas communication pipe 32 connects the gas-side shutoff valve 18 of the heat source unit 10 and the use heat exchanger 22 of the use units 20 a and 20 b.

(2-2) The refrigerant accommodating unit 70
The refrigerant accommodating unit 70 is for adjusting a circulation amount of the refrigerant circulating in the refrigerant circuit 40 by accommodating a part of the refrigerant of the refrigerant charge amount V <b> 1 in the refrigerant circuit 40. The refrigerant accommodating unit 70 is attachable to and detachable from the refrigerant circuit 40.

  The refrigerant storage unit 70 includes a refrigerant storage container 75, a first gas side pipe 71, a first gas side valve A, a first liquid side pipe 72, and a first liquid side valve B. The refrigerant container 75 is a tank-like container having a predetermined volume, and accommodates at least one of a gas refrigerant and a liquid refrigerant. In FIG. 1, the refrigerant container 75 contains the liquid refrigerant of the amount V. The first gas side pipe 71 connects the refrigerant container 75 and the gas communication pipe 32. The first liquid side pipe 72 connects the refrigerant container 75 and the liquid communication pipe 31. The first gas side valve A opens and closes the flow path of the first gas side pipe 71. The first liquid side valve B opens and closes the flow path of the first liquid side pipe 72.

(2-3) processing unit 90
The processing unit 90 supervises the processing of the entire refrigerant charge determination system 100. As shown in FIG. 2, the processing unit 90 includes a refrigerant circuit processing unit 50 that performs processing related to the refrigerant circuit 40, a refrigerant accommodation unit processing unit 80 that performs processing related to the refrigerant accommodation unit 70, and a communication line X1 that connects them. Have. The refrigerant circuit processing unit 50 and the refrigerant accommodation unit processing unit 80 can communicate via the communication line X1.

(2-3-1) Refrigerant circuit processing unit 50
The refrigerant circuit processing unit 50 includes a refrigerant circuit control unit 51 and a state quantity acquisition unit 52. The refrigerant circuit control unit 51 drives various mechanisms of the refrigerant circuit 40, that is, the compressor 11, the four-way switching valve 12, the heat source fan 14, the heat source expansion valve 15, the utilization expansion valve 21, and the utilization fan 23. Furthermore, the refrigerant circuit control unit 51 acquires measured values of various sensors provided in the refrigerant circuit 40 such as a temperature sensor or a pressure sensor. Furthermore, the refrigerant circuit control unit 51 acquires an instruction related to the operation input by the user via the operation panel (not shown) installed in the usage units 20a, 20b and the like.

  The state quantity acquisition unit 52 acquires a value called a state quantity from various information handled by the refrigerant circuit control unit 51. The "state amount" is a value used in the determination of the appropriateness of the refrigerant charge amount V1. The state quantity may be derived from measurement values of various sensors provided in the refrigerant circuit 40. Alternatively, the state quantities may be derived from control parameters for driving various mechanisms.

  As shown in FIG. 1, the refrigerant circuit processing unit 50 physically includes the heat source unit control circuit 19 disposed in the heat source unit 10, the utilization unit control circuit 29 disposed in the utilization units 20a and 20b, and the like. Are formed by a communication line X2 connecting the two.

(2-3-2) Refrigerant storage unit processing unit 80
Returning to FIG. 2, the refrigerant storage unit processing unit 80 includes a refrigerant storage unit control unit 81 and a determination unit 82. The refrigerant accommodation unit control unit 81 drives the first gas side valve A and the first liquid side valve B. The determination unit 82 determines the suitability of the refrigerant charge amount V1.

  The refrigerant accommodating unit control section 81 opens and closes the first gas side valve A and the first liquid side valve B, whereby the refrigerant accommodating container 75 can be used as the liquid refrigerant and the gas refrigerant between the liquid communication pipe 31 and the gas communication pipe 32. To receive the gas refrigerant and the liquid refrigerant at the intended ratio. When the volume of the liquid refrigerant contained in the refrigerant container 75 is larger and the volume of the gas refrigerant is smaller, it means that the refrigerant container 75 contains a larger weight of the refrigerant. At this time, the circulation amount of the refrigerant in the refrigerant circuit 40 is further reduced.

  As shown in FIG. 1, the refrigerant storage unit processing unit 80 is physically formed by a refrigerant storage unit control circuit 79 disposed in the refrigerant storage unit 70.

(3) Normal operation (3-1) Common matters The refrigerant charge determination system 100 executes either the cold energy utilization operation or the thermal energy utilization operation by the refrigerant circuit 40. In these operations, the refrigerant circuit control unit 51 controls the compressor 11 and the four paths based on the instruction regarding the operation input by the user and the acquired values of the various sensors provided in the heat source unit 10 and the usage units 20a and 20b. The switching valve 12, the heat source fan 14, the heat source expansion valve 15, the utilization expansion valve 21, and the utilization fan 23 are driven.

(3-2) Cold Utilization Operation The cold utilization operation is an operation for providing cold energy to the user, and corresponds to a cooling operation in the air conditioner.

  The four-way switching valve 12 of the heat source unit 10 makes the connection shown in FIG. The compressor 11 discharges the high pressure gas refrigerant in the direction of the arrow. The high-pressure gas refrigerant then passes through the four-way switching valve 12 to reach the heat source heat exchanger 13, where it is condensed by radiating heat to the ambient air and becomes a high-pressure liquid refrigerant. The high pressure liquid refrigerant passes through the fully opened heat source expansion valve 15 and the opened liquid side closing valve 17 in this order, and exits the heat source unit 10. Thereafter, the high pressure liquid refrigerant moves in the liquid communication pipe 31 and enters the usage units 20a and 20b. The high pressure liquid refrigerant is decompressed by the utilization expansion valve 21 to be a low pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant reaches the utilization heat exchanger 22, where it is vaporized to form a low-pressure gas refrigerant to provide cold heat to the user. The low pressure gas refrigerant then exits the utilization units 20a, 20b. The low pressure gas refrigerant travels in the gas communication pipe 32 and returns to the heat source unit 10. The low-pressure gas refrigerant passes through the opened gas shut-off valve and the four-way switching valve 12 in order, and then reaches the refrigerant holder 16. The refrigerant holder 16 separates and holds the low pressure liquid refrigerant mixed in the low pressure gas refrigerant. The low-pressure gas refrigerant leaving the refrigerant holder 16 is drawn into the compressor 11.

(3-3) Thermal Utilization Operation The thermal utilization operation is an operation for providing a user with thermal energy, and corresponds to a heating operation in an air conditioner.

  The four-way switching valve 12 of the heat source unit 10 makes the connection shown in FIG. The compressor 11 discharges the high pressure gas refrigerant in the direction of the arrow. The high pressure gas refrigerant then passes through the four-way switching valve 12 and the open gas side shut-off valve 18 in order, and exits the heat source unit 10. Thereafter, the high pressure gas refrigerant moves in the gas connection pipe 32 and enters the utilization units 20a and 20b. The high-pressure gas refrigerant reaches the utilization heat exchanger 22, where it condenses into a high-pressure liquid refrigerant and radiates heat to the ambient air to provide the user with heat. The high pressure liquid refrigerant is reduced in pressure by the utilization expansion valve 21 to be a low pressure gas-liquid two-phase refrigerant, and exits the use units 20a and 20b. The low pressure gas-liquid two-phase refrigerant moves in the liquid communication pipe 31 and returns to the heat source unit 10. The low-pressure gas-liquid two-phase refrigerant passes through the opened liquid side shut-off valve 17 and the fully open or partially open heat source expansion valve 15 in this order to reach the heat source heat exchanger 13. The low-pressure gas-liquid two-phase refrigerant evaporates there by absorbing heat from ambient temperature and becomes a low-pressure gas refrigerant. After passing through the four-way switching valve 12, the low-pressure gas refrigerant reaches the refrigerant holder 16. The refrigerant holder 16 separates and holds the low pressure liquid refrigerant mixed in the low pressure gas refrigerant. The low-pressure gas refrigerant leaving the refrigerant holder 16 is drawn into the compressor 11.

(4) Circulation mode The refrigerant charge determination system 100 determines whether the refrigerant charge V1 is appropriate. When performing this suitability determination, the refrigerant charge determination system 100 switches between two circulation modes, the normal circulation mode MN and the small amount circulation mode MS. The circulation mode defines conditions that affect the behavior of the refrigerant.

(4-1) Normal circulation mode MN
The normal circulation mode MN is an operation mode used when the refrigerant circuit 40 performs a normal operation. The circulation amount of the refrigerant circulating to the refrigerant circuit 40 in the normal circulation mode MN is an amount sufficient to execute the cold energy utilization operation or the thermal energy utilization operation. When the normal circulation mode MN is realized, as shown in FIG. 4A, the refrigerant accommodating container 75 of the refrigerant accommodating unit 70 accommodates a small amount of liquid refrigerant indicated by L1. L1 may be substantially zero.

(4-2) Small volume circulation mode MS
The small amount circulation mode MS is an operation mode used when performing the propriety determination. The circulation amount of the refrigerant circulating to the refrigerant circuit 40 in the small amount circulation mode MS is insufficient to execute a stable cold heat utilization operation or a thermal heat utilization operation. That is, the small amount circulation mode MS intentionally causes a refrigerant shortage state in the refrigerant circuit 40. When the small amount circulation mode MS is realized, as shown in FIG. 4B, the refrigerant storage container 75 of the refrigerant storage unit 70 stores a large amount of liquid refrigerant indicated by L2.

  The amount L2 of liquid refrigerant that the refrigerant accommodating unit 70 accommodates in the small amount circulation mode MS is larger by the accommodation amount V2 than the amount L1 of liquid refrigerant that the refrigerant accommodating unit 70 accommodates in the normal circulation mode MN. The storage volume V2 may be substantially the same as the volume of the refrigerant container 75.

  The holding amount V3 of the refrigerant holder 16 is designed to be smaller than the storage amount V2 of the refrigerant storage container 75. This is to maintain the refrigerant shortage even if the refrigerant holder 16 is present.

  The small amount circulation mode MS may be incorporated into the normal operation in which the refrigerant circuit 40 performs air conditioning or the like. For example, the small amount circulation mode MS may be realized when the refrigerant circuit 40 is started. Alternatively, in the normal operation of the refrigerant circuit, the small amount circulation mode MS may be realized at regular intervals.

(4-3) Switching from Normal Circulation Mode MN to Small Amount Circulation Mode MS When switching from the normal circulation mode MN to the small amount circulation mode MS, the refrigerant accommodating unit control unit 81 introduces high-pressure liquid refrigerant into the refrigerant container 75. To open the first liquid side valve B. In addition, the refrigerant storage unit control unit 81 opens the first gas side valve A in order to release the gas refrigerant in the refrigerant storage container 75. After the liquid refrigerant having the storage amount V2 is stored in the refrigerant storage container 75, the refrigerant storage unit control unit 81 closes the first gas side valve A and the first liquid side valve B.

  In order to detect that the liquid refrigerant having the storage amount V2 is stored in the refrigerant storage container 75, the refrigerant storage container 75 may be provided with a sensor such as a liquid level detection sensor.

  Alternatively, various sensors provided in the heat source unit 10 may be used to detect such accommodation completion. That is, when the storage is completed, the probability of the liquid refrigerant flowing out from the first gas side pipe 71 to the gas communication pipe 32 is increased. As a result, the temperature, pressure, dryness, etc. of the refrigerant drawn into the heat source unit 10 from the gas side shut-off valve 18 change. The change may be interpreted by the refrigerant circuit control unit 51 as an indication of the completion of the accommodation, and the event may be notified to the refrigerant accommodation unit control unit 81 via the communication line X1.

(4-4) Switching from the small amount circulation mode MS to the normal circulation mode MN When switching from the small amount circulation mode MS to the normal circulation mode MN, the refrigerant accommodating unit control unit 81 discharges the high pressure liquid refrigerant from the refrigerant container 75 To open the first gas side valve A. At this time, the first liquid side valve B is closed. When the liquid refrigerant having the storage volume V2 is discharged, the refrigerant storage unit control unit 81 closes the first gas side valve A and the first liquid side valve B.

  In order to detect that the liquid refrigerant having the storage amount V2 has been discharged from the refrigerant storage container 75, a sensor such as a liquid level detection sensor may be provided in the refrigerant storage container 75.

  Alternatively, various sensors provided in the heat source unit 10 may be used to detect such discharge completion. That is, when the release is completed, the probability of the further release of the liquid refrigerant from the first gas side pipe 71 to the gas communication pipe 32 decreases. As a result, the temperature, pressure, dryness, etc. of the refrigerant drawn into the heat source unit 10 from the gas side shut-off valve 18 change. The change may be interpreted by the refrigerant circuit control unit 51 as an indication of the completion of discharge, and the event may be notified to the refrigerant accommodation unit control unit 81 via the communication line X1.

(5) Adequacy Determination Operation FIG. 5 shows the suitability determination of the refrigerant charge amount V1. The refrigerant circuit 40 when performing this suitability determination is performing a cold heat utilization operation.

  The upper graph in FIG. 5 shows the transition of the liquid refrigerant amount V stored in the refrigerant storage container 75 of the refrigerant storage unit 70. The period in which the liquid refrigerant amount V is small corresponds to the normal circulation mode MN. The period in which the liquid refrigerant amount V is large corresponds to the small amount circulation mode MS. The switching from the normal circulation mode MN to the small circulation mode MS is performed in the first transition period T1. The switching from the small amount circulation mode MS to the normal circulation mode MN is performed in the second transition period T2. These switching is performed by the refrigerant accommodation unit control unit 81 independently of the control of the refrigerant circuit 40 by the refrigerant circuit control unit 51.

  The lower graph in FIG. 5 is the transition of the state quantity. The state quantity in the present embodiment is the degree of subcooling SC of the refrigerant that exits the heat source heat exchanger 13 that functions as a radiator. As a result of the drive of various mechanisms by the refrigerant circuit control unit 51, the degree of subcooling SC fluctuates. Then, the degree of subcooling SC is calculated by the state quantity acquisition unit 52 based on the measurement values of various sensors.

  In the appropriateness determination of the refrigerant charge amount V1, the refrigerant accommodation unit control unit 81 executes switching from the normal circulation mode MN to the small amount circulation mode MS. In the first transition period T1 in which this switching is performed, the circulating amount of the refrigerant in the refrigerant circuit 40 decreases, and eventually the refrigerant shortage state is reached. The pressure and temperature in each part of the refrigerant circuit 40 also change with the change in the amount of circulation. The refrigerant circuit control unit 51, which operates independently of the refrigerant accommodation unit control unit 81, drives various mechanisms of the refrigerant circuit 40 so as to optimize the cold heat utilization operation being performed, and as a result, the degree of subcooling SC Changes.

  In the lower graph of FIG. 5, the solid line indicates the case where the refrigerant charge amount V1 is appropriate, and the broken line indicates the case where the refrigerant charge amount V1 is insufficient to an inappropriate degree. In both cases, the behavior of the degree of subcooling SC in the first transition period T1 is different. That is, when the refrigerant charge amount V1 is appropriate, the degree of subcooling SC does not fall below a predetermined degree of subcooling threshold SCth indicated by an alternate long and short dash line. On the other hand, when the refrigerant charge amount V1 is insufficient, the degree of subcooling SC is lower than the degree of subcooling SCth. This is because the degree of subcooling SC is lowered regardless of the contents of the control performed by the refrigerant circuit control unit 51 due to the refrigerant shortage state.

  The determination unit 82 of the refrigerant accommodating unit processing unit 80 receives the value of the degree of subcooling SC acquired in the first transition period T1 from the state quantity acquisition unit 52, and compares it with the degree of subcooling SCth. Next, the determination unit 82 acquires the liquid refrigerant amount Vx stored in the refrigerant storage container 75 when the magnitude relationship between the degree of subcooling SC and the degree of subcooling threshold SCth is reversed.

The liquid refrigerant amount Vx may be acquired by the refrigerant containing unit control unit 81 using a liquid level sensor provided in the refrigerant containing container 75. Alternatively, for example, the refrigerant accommodation unit control unit 81 may acquire the following amount shown also in FIG. 5 and convert it into the liquid refrigerant amount Vx.
-The time Px from the start of mode switching to the reversal point of the subcooling degree threshold SCth at the subcooling degree SC
-The ratio Px / P of the relevant time Px to the temporal length P of the first transition period T1
These quantities are not the liquid refrigerant quantity Vx itself, but are alternative numerical values related to the liquid refrigerant quantity Vx. As these are time-related quantities, they are easy to measure.

  The determination unit 82 determines the suitability of the refrigerant charge amount V1 based on the liquid refrigerant amount Vx when the magnitude relationship between the degree of subcooling SC and the degree of subcooling threshold SCth is reversed. For example, the liquid refrigerant amount Vx is compared with a predetermined liquid refrigerant amount threshold Vth (not shown). When the liquid refrigerant amount Vx is larger than the liquid refrigerant amount threshold Vth, the determination unit 82 determines that the refrigerant charge amount V1 is appropriate. When the liquid refrigerant amount Vx is smaller than the liquid refrigerant amount threshold value Vth, the determination unit 82 determines that the refrigerant charge amount V1 is insufficient and is inappropriate. The series of processes of the determination unit 82 are also executed independently of the control of the refrigerant circuit 40 by the refrigerant circuit control unit 51.

  Furthermore, the determination unit 82 stores the liquid refrigerant amount Vx, and holds it even after the determination of appropriateness is completed. The data of the liquid refrigerant amount Vx stored in the determination unit 82 is referred to in order to improve the accuracy of the determination in the subsequent suitability determination.

(6) Characteristics (6-1)
Since the state quantity related to the behavior of the refrigerant circuit during the transition between the normal circulation mode MN and the small circulation mode MS is acquired, more information can be used for the suitability determination of the refrigerant charge amount V1. Therefore, the appropriateness determination of the refrigerant charge amount V1 can be easily performed.

(6-2)
When the magnitude relationship between the degree of subcooling SC and the degree of subcooling threshold SCth is reversed, it is determined whether the refrigerant charge amount V1 is appropriate based on the liquid refrigerant amount Vx contained in the refrigerant accommodation unit 70. Therefore, the propriety determination can be performed within a relatively short time of the first transition period T1.

(6-3)
When the liquid refrigerant amount Vx is smaller than the liquid refrigerant amount threshold Vth, it is determined that the refrigerant charge amount V1 is insufficient. Therefore, the shortage of the refrigerant charge amount V1 can be determined by the phenomenon that the behavior of the degree of supercooling SC is sufficiently changed by removing only a small amount of refrigerant from the refrigerant circuit 40.

(6-4)
The refrigerant accommodating unit 70 is connected to the liquid communication pipe 31 and the gas communication pipe 32. Therefore, the refrigerant accommodating unit 70 can exchange the liquid refrigerant and the gas refrigerant, whereby the circulation amount of the refrigerant in the refrigerant circuit 40 can be adjusted.

(7) Modified Example A modified example of the present embodiment is shown below. A plurality of modifications may be combined appropriately as long as no contradiction arises.

(7-1) Modified Example 1A: Acquisition Timing of State Amount In the above-described refrigerant filling amount determination system 100, the acquisition of the subcooling degree SC, which is the state amount, is the normal circulation mode as already described with reference to FIG. It is performed only in the first transition period T1 in which the switching from the MN to the small amount circulation mode MS is performed. Alternatively, the acquisition of the subcooling degree SC may be performed in the second transition period T2 in which the small circulation mode MS is switched to the normal circulation mode MN.

  Furthermore, acquisition of the degree of subcooling SC includes one switching from the normal circulation mode MN to the small circulation mode MS, and one switching from the small circulation mode MS to the normal circulation mode MN. It may be performed in one "round trip", that is, in the middle of the first transition period T and in the middle of the second transition period T2.

  Furthermore, acquisition of the degree of subcooling SC may be performed over a plurality of such "round trip" of mode switching, that is, over a plurality of first transition periods T1 and a plurality of second transition periods T2.

  According to this configuration, more data can be acquired regarding mode switching. Therefore, it is possible to improve the determination accuracy in the appropriateness determination of the refrigerant charge amount V1 to be executed in the future.

  Alternatively, the acquisition of the subcooling degree SC, which is the state quantity, may be performed during the small amount circulation mode MS instead of the first transition period T1 or the second transition period T2. Any method may be employed as a method for determining the suitability of the refrigerant charge amount V1 from the degree of subcooling SC to be acquired.

(7-2) Modified Example 1B: State Amount In the above-described refrigerant charge amount determination system 100, the degree of supercooling SC is used as the amount of state used for the appropriateness determination. Instead of this, as shown in FIG. 6, the opening degree EVA of the utilization expansion valve 21 may be used as the state quantity.

  FIG. 6 shows the appropriateness determination of the refrigerant charge amount V1. The refrigerant circuit 40 when performing this suitability determination is performing a cold heat utilization operation. The upper graph in FIG. 6 shows the transition of the liquid refrigerant amount V stored in the refrigerant storage container 75 of the refrigerant storage unit 70, as in the upper graph in FIG.

  The lower graph in FIG. 6 is the transition of the state quantity. The state quantity in this modification is a transition of the opening degree EVA of the utilization expansion valve 21 provided immediately before the utilization heat exchanger 22 functioning as a heat absorber. The opening degree EVA is controlled by the refrigerant circuit control unit 51 based on measured values of various sensors of the heat source unit 10 and the usage units 20a and 20b and an instruction regarding operation acquired from the user. In the refrigerant circuit processing unit 50, the state quantity acquisition unit 52 can acquire the opening degree EVA, which is a state quantity, from the refrigerant circuit control unit 51.

  In the appropriateness determination of the refrigerant charge amount V1, the refrigerant accommodation unit control unit 81 executes switching from the normal circulation mode MN to the small amount circulation mode MS. In the first transition period T1 in which this switching is performed, the circulating amount of the refrigerant in the refrigerant circuit 40 decreases, and eventually the refrigerant shortage state is reached. The pressure and temperature in each part of the refrigerant circuit 40 also change with the change in the amount of circulation. The refrigerant circuit control unit 51, which operates independently of the refrigerant accommodation unit control unit 81, drives various mechanisms of the refrigerant circuit 40 so as to optimize the cold energy utilization operation being performed, and as a result, the opening degree EVA changes Do.

  In the lower graph of FIG. 6, the solid line indicates the case where the refrigerant charge amount V1 is appropriate, and the broken line indicates the case where the refrigerant charge amount V1 is insufficient to an inappropriate extent. In these two cases, the behavior of the opening EVA in the first transition period T1 is different. That is, when the refrigerant charge amount V1 is appropriate, the opening degree EVA does not exceed the predetermined opening degree threshold EVAth indicated by the one-dot chain line. On the other hand, when the refrigerant charge amount V1 is insufficient, the opening degree EVA exceeds the opening degree threshold EVAth. This is because the refrigerant circuit control unit 51 tries to make the opening degree EVA of the utilization expansion valve 21 larger in order to eliminate the decrease in the cooling efficiency due to the refrigerant shortage state.

  The determination unit 82 of the refrigerant accommodating unit processing unit 80 receives the value of the opening degree EVA acquired in the first transition period T1 from the state quantity acquisition unit 52, and compares it with the opening degree threshold EVAth. Next, when the magnitude relation between the opening degree EVA and the opening degree threshold value EVAth is reversed, the determination unit 82 acquires the liquid refrigerant amount Vx in which the refrigerant container 75 is accommodated.

  The determination unit 82 determines the suitability of the refrigerant charge amount V1 based on the liquid refrigerant amount Vx when the magnitude relationship between the opening degree EVA and the opening degree threshold value EVAth is reversed. For example, the liquid refrigerant amount Vx is compared with a predetermined liquid refrigerant amount threshold Vth (not shown). When the liquid refrigerant amount Vx is larger than the liquid refrigerant amount threshold Vth, the determination unit 82 determines that the refrigerant charge amount V1 is appropriate. When the liquid refrigerant amount Vx is smaller than the liquid refrigerant amount threshold value Vth, the determination unit 82 determines that the refrigerant charge amount V1 is insufficient and is inappropriate. The series of processes of the determination unit 82 are also executed independently of the control of the refrigerant circuit 40 by the refrigerant circuit control unit 51.

  Furthermore, the determination unit 82 stores the liquid refrigerant amount Vx, and holds it even after the determination of appropriateness is completed. The data of the liquid refrigerant amount Vx stored in the determination unit 82 is referred to in order to improve the accuracy of the determination in the subsequent suitability determination.

  According to this configuration, the acquired state quantity is the opening degree EVA of the utilization expansion valve 21. The opening degree EVA is determined by the refrigerant circuit control unit 51, and the state quantity acquisition unit 52 can easily acquire it. Therefore, the appropriateness determination of the refrigerant charge amount V1 can be performed more easily.

(7-3) Modified Example 1C: Form of Refrigerant Containing Container 75 In the above-described refrigerant filling amount determination system 100, the refrigerant containing container 75 has a tank shape. Instead of this, as shown in FIG. 7, the refrigerant storage container 75 may be configured using a pipe that is long enough to have a sufficient volume.

  According to this configuration, the refrigerant storage container 75 can be configured by normal piping and does not require special components. Accordingly, the cost reduction of the refrigerant charge determination system 100 can be achieved.

(7-4) Modification 1D: First gas side valve A
In the refrigerant charge determination system 100 described above, the first gas side valve A can open and close the flow path of the first gas side pipe 71. Instead of this, as the first gas side valve A, not only mere opening and closing of the first gas side pipe 71 can be used, but also one that can change the flow passage area of the first gas side pipe 71 may be adopted. For example, the first gas side valve A can be configured by an electric valve capable of adjusting the opening degree.

  According to this configuration, when releasing the high pressure liquid refrigerant from the refrigerant storage container 75 for switching from the small amount circulation mode MS to the normal circulation mode MN, the refrigerant storage unit control unit 81 sets the first liquid side valve B While closing, the first gas side valve A can be opened with a small opening. Thereby, the high pressure liquid refrigerant stored in the refrigerant storage container 75 is gradually ejected to the gas communication pipe 32. Therefore, since a large amount of liquid refrigerant does not rapidly flow into the compressor 11, damage to the compressor 11 can be suppressed.

(7-5) Modification 1E: Number of Refrigerant Accommodating Units 70, Volume of Refrigerant Accommodating Container 75 In the above-described refrigerant filling amount determination system 100, the number of refrigerant accommodating units 70 is one. Instead of this, as shown in FIG. 8, the number of refrigerant accommodating units 70 may be two or three or more. Furthermore, the capacities of the refrigerant storage containers 75 possessed by the respective refrigerant storage units 70 may be made different, whereby the capacity V2 may be made different.

  According to this configuration, it is possible to realize a plurality of small amount circulation modes MS corresponding to various degrees of refrigerant shortage. Therefore, more data can be acquired for the state quantity at the time of mode switching, and the determination accuracy can be further improved.

(7-6) Modification 1F: Refrigerant holder 16
In the above-mentioned refrigerant | coolant filling amount determination system 100, the refrigerant | coolant holder 16 is comprised from components called what is called an accumulator. Alternatively, the refrigerant holder 16 may be composed of other components such as a high pressure receiver and a low pressure receiver.

  According to this configuration, the refrigerant circuit 40 including the high-pressure receiver, the low-pressure receiver, and other components can determine whether the refrigerant charge amount V1 is appropriate.

(7-7) Modified Example 1G: Type of Operation In the above-described refrigerant filling amount determination system 100, the refrigerant circuit 40 performs the cold heat utilization operation in the appropriateness determination of the refrigerant filling amount V1. Instead of this, the refrigerant circuit 40 may execute the heat utilization operation in the appropriateness determination of the refrigerant charge amount V1.

  According to this configuration, for example, the suitability of the refrigerant charge amount V1 can be determined also during execution of the thermal utilization operation such as in winter.

(7-8) Modified Example 1H: Type of Refrigerant Circuit 40 In the above-described refrigerant charge determination system 100, the refrigerant circuit 40 is configured as an air conditioner. Instead of this, the refrigerant circuit 40 may be configured as a device other than the air conditioner, such as a freezer or a water heater.

  According to this configuration, the suitability determination of the refrigerant charge amount V1 can be performed for the refrigerant circuits 40 other than the air conditioner.

(7-9) Modification 1 I: Completion of Storage and Release of Refrigerant In the above-described refrigerant charge determination system 100, switching between the normal circulation mode MN and the small circulation mode MS in two modes is performed using a sensor such as a liquid level detection sensor The measurement result or the monitoring result of the refrigerant circuit 40 by the refrigerant circuit control unit 51 is used. Instead of this, time measurement results by a timer may be used. That is, the storage or discharge is considered to be completed after a predetermined time has elapsed from the start of storage or discharge of the refrigerant.

  According to this configuration, detection of completion is easy.

Second Embodiment
(1) Configuration FIG. 9 shows a refrigerant charge determination system 100A according to a second embodiment of the present invention. The refrigerant charge determination system 100A is the first in that the refrigerant storage container 75 of the refrigerant storage unit 70 is connected to the gas communication pipe 32 not only by the first gas side pipe 71 but also by the second gas side pipe 73. It differs from the embodiment. The second gas side pipe 73 is provided with a second gas side valve C. The second gas side valve C opens and closes the flow path of the second gas side pipe 73.

(2) Characteristics According to this configuration, in the normal operation, both the first gas side valve A and the second gas side valve C can be opened, and the first liquid side valve B can be closed. The low-pressure gas refrigerant moving in the gas communication pipe 32 enters the refrigerant storage container 75 from the first gas side pipe 71, and exits the refrigerant storage container 75 again from the second gas side pipe 73. Therefore, it is easy to fill the refrigerant container 75 with the low pressure gas refrigerant, and the liquid refrigerant can be prevented from remaining in the refrigerant container 75.

(3) Modifications (3-1) Modification 2A: Form of Refrigerant Containing Container 75 In the above-described refrigerant filling amount determination system 100A, the refrigerant containing container 75 has a tank shape. Instead of this, as shown in FIG. 10, the refrigerant storage container 75 may be configured using a pipe that is long enough to have a sufficient volume.

  According to this configuration, the refrigerant storage container 75 can be configured by normal piping and does not require special components. Accordingly, the cost reduction of the refrigerant charge determination system 100 can be achieved.

(3-2) Modification 2B: Number of Refrigerant Accommodating Units 70, Volume of Refrigerant Accommodating Container 75 In the above-described refrigerant charge determination system 100A, the number of refrigerant accommodating units 70 is one. Instead of this, as shown in FIG. 11, the number of refrigerant accommodating units 70 may be two or three or more. Furthermore, the capacities of the refrigerant storage containers 75 possessed by the respective refrigerant storage units 70 may be made different, whereby the capacity V2 may be made different.

  According to this configuration, it is possible to realize a plurality of small amount circulation modes MS corresponding to various degrees of refrigerant shortage. Therefore, more data can be acquired for the state quantity at the time of mode switching, and the determination accuracy can be further improved.

(3-3) Modification 2C: Second gas side valve C
In the above-described refrigerant charge determination system 100A, the second gas side valve C can open and close the flow path of the second gas side pipe 73. Instead of this, as the second gas side valve C, not only mere opening and closing of the second gas side pipe 73 can be used, but also one that can change the flow passage area of the second gas side pipe 73 may be adopted. For example, the second gas side valve C can be configured by an electric valve capable of adjusting the opening degree.

  According to this configuration, when releasing the high pressure liquid refrigerant from the refrigerant storage container 75 for switching from the small amount circulation mode MS to the normal circulation mode MN, the refrigerant storage unit control unit 81 sets the first liquid side valve B While closing, the second gas side valve C can be opened with a small opening. Thereby, the high pressure liquid refrigerant stored in the refrigerant storage container 75 is gradually ejected to the gas communication pipe 32. Therefore, since a large amount of liquid refrigerant does not rapidly flow into the compressor 11, damage to the compressor 11 can be suppressed.

(3-4) Others Each modification according to the first embodiment may be applied to the second embodiment.

Third Embodiment
(1) Configuration FIG. 12 shows a refrigerant charge determination system 100B according to a third embodiment of the present invention. The refrigerant charge determination system 100B is different from the first embodiment in the structure of the refrigerant storage unit 70 and the connection with the communication pipe 30.

  The refrigerant storage container 75 of the refrigerant storage unit 70 is different from the first embodiment in that the refrigerant storage container 75 is connected to the liquid communication pipe 31 not only by the first liquid side pipe 72 but also by the second liquid side pipe 74. The second liquid side pipe 74 is provided with a second liquid side valve D. The second liquid side valve D opens and closes the flow path of the second liquid side pipe 74.

  Further, a liquid communication pipe closing valve E is provided between a connection portion with the first liquid side pipe 72 and a connection portion with the second liquid side pipe 74 in the liquid communication pipe 31.

  When switching from the normal circulation mode MN to the small amount circulation mode MS, the refrigerant storage unit control unit 81 sets the first liquid side valve B and the second liquid side valve D in order to introduce the high pressure liquid refrigerant into the refrigerant storage container 75. While opening, close the fluid communication piping closing valve E. The high pressure liquid refrigerant moving in the liquid communication pipe 31 flows through a path connecting the first liquid side pipe 72, the refrigerant container 75, and the second liquid side pipe 74. In the process, the refrigerant container 75 is filled with the high pressure liquid refrigerant. Ru.

(2) Features According to this configuration, it is easy to guide the high pressure liquid refrigerant to the refrigerant storage container 75. Therefore, the switching from the normal circulation mode MN to the small volume circulation mode MS is performed quickly.

(3) Modifications Each modification according to the first embodiment or the second embodiment may be applied to the third embodiment.

Fourth Embodiment
FIG. 13 shows a refrigerant charge determination system 100C according to a fourth embodiment of the present invention. In the first to third embodiments, the refrigerant accommodation unit 70 is provided independently of the refrigerant circuit 40. Instead of this, in the fourth embodiment, the components of the refrigerant circuit 40 bear the function of the refrigerant accommodating unit 70. For example, the function of the refrigerant accommodating unit 70 is at least one selected from the heat exchangers 13 and 22, the accumulator 16, and a receiver not shown. The amount of liquid refrigerant stored in these components can be varied by controlling the compressor 11 or the expansion valve 22 and other components.

  According to this configuration, the suitability of the refrigerant charge amount V1 is determined by using only the components of the refrigerant circuit 40. Therefore, the cost of the refrigerant charge determination system 100C can be reduced.

Fifth Embodiment
(1) Configuration FIG. 14 shows a refrigerant charge determination system 100D according to a fifth embodiment of the present invention. The refrigerant charge determination system 100D includes a first lower system 100X, a second lower system 100Y, a third lower system 100Z, a first central controller 200X, a second central controller 200Y, and a management center 300. There is.

  The first lower system 100X, the second lower system 100Y, and the third lower system 100Z are all installed in, for example, a single building, and the first to fourth embodiments or their modifications are provided. It is comprised by the refrigerant | coolant filling amount determination system which concerns on either. The first subordinate system 100X has one heat source unit 10X, three utilization units 20Xa to 20Xc, and one refrigerant accommodation unit 70X. The second lower system 100Y includes one heat source unit 10Y, four utilization units 20Ya to 20Yd, and one refrigerant accommodation unit 70Y. The third lower system 100Z includes one heat source unit 10Z, four utilization units 20Za to 20Zd, and one refrigerant accommodation unit 70Z.

  The first central controller 200X and the second central controller 200Y integrally control lower systems disposed in predetermined areas. The first centralized controller 200X controls the first lower system 100X and the second lower system 100Y. The second centralized controller 200Y controls the third lower system 100Z.

  The management center 300 manages a large number of lower systems. The management center 300 communicates with the first centralized controller 200X and the second centralized controller 200Y through a public or dedicated network N.

  The determination unit 82 of the processing unit 90 for the first lower system 100X, the second lower system 100Y, and the third lower system 100Z is the first centralized controller 200X, the second centralized controller 200Y, or the management center 300. Provided in The determination unit 82 is based on the liquid refrigerant amount Vx when the magnitude relation between the state amount and the threshold of the state amount is reversed for all of the first lower system 100X, the second lower system 100Y, and the third lower system 100Z. Then, it is determined whether the refrigerant charge amount V1 is appropriate.

  Furthermore, the determination unit 82 accumulates data of the liquid refrigerant amount Vx collected from all of the first lower system 100X, the second lower system 100Y, and the third lower system 100Z. The data of the liquid refrigerant amount Vx stored in the determination unit 82 is referred to in order to improve the accuracy of the determination in the subsequent suitability determination. At this time, data transmitted from another lower system (for example, second lower system 100Y or third lower system 100Z) for the lower system (for example, first lower system 100X) that is the target of the propriety determination. Can be used.

(2) Features According to this configuration, the determination unit 82 can collect, from a plurality of lower systems, a vast amount of data that can be used for determining the propriety. Therefore, the accuracy of the propriety judgment of each lower system can be further improved.

(3) Modifications Each modification according to the first to fourth embodiments may be applied to the fifth embodiment.

DESCRIPTION OF SYMBOLS 10 heat source unit 11 compressor 19 heat source unit control circuit 20a, 20b utilization unit 21 expansion valve (use expansion valve)
22 Use heat exchanger 29 Use unit control circuit 30 Refrigerant connection piping 31 Liquid connection piping 32 Gas connection piping 40 Refrigerant circuit 50 Refrigerant circuit processing unit 51 Refrigerant circuit control unit 52 Condition quantity acquisition unit 70 Refrigerant accommodation unit 75 Refrigerant accommodation container 79 Refrigerant Containment unit control circuit 80 Containment unit processing unit 81 Containment unit control unit 82 Judgment unit 90 Treatment unit 100 Refrigerant filling amount judgment system A 1st gas side valve B 1st liquid side valve C 2nd gas side valve D 2nd liquid side valve E Liquid connection piping closing valve V1 Refrigerant charge V2 Capacity V3 Hold

Patent No. 3852472

Claims (14)

A refrigerant circuit (40) having a compressor (11) and an expansion valve (21) and configured to circulate a predetermined refrigerant charge (V1) capable of taking a state of liquid refrigerant and gas refrigerant;
A refrigerant accommodating portion (70) for reducing a circulation amount of the refrigerant circulating in the refrigerant circuit by accommodating a part of the refrigerant in the refrigerant charge amount;
A refrigerant circuit control unit (51) for controlling the refrigerant circuit;
A refrigerant storage unit control unit (81) that controls the refrigerant storage unit independently of the control of the refrigerant circuit by the refrigerant circuit control unit;
A state quantity acquisition unit (52) for acquiring a state quantity of the refrigerant circuit when the expansion valve is open;
A determination unit (82) that determines the appropriateness of the refrigerant charge amount based on the response of the state amount to the amount of the refrigerant stored in the refrigerant storage unit;
Equipped with
Refrigerant charge determination system (100). The refrigerant storage unit includes a refrigerant storage container (75) connected to the refrigerant circuit.
The refrigerant charge determination system according to claim 1. The refrigerant circuit includes a radiator of the refrigerant,
The state quantity is a degree of subcooling (SC) of the refrigerant exiting the radiator.
The refrigerant | coolant filling amount determination system of Claim 1 or Claim 2. The state quantity is an opening degree (EVA) of the expansion valve.
The refrigerant | coolant filling amount determination system of Claim 1 or Claim 2. First condition (MN),
A second condition (MS) in which the refrigerant storage unit stores the liquid refrigerant by a predetermined storage amount (V2) more than the first condition (MN);
Can be switched,
The refrigerant charge determination system according to any one of claims 1 to 4. The determination unit determines the suitability of the refrigerant charge amount (V1) based on the state amount acquired by the state amount acquisition unit during transition of the first condition (MN) and the second condition (MS). Do,
The refrigerant charge determination system according to claim 5. The determination unit is
The liquid refrigerant stored in the refrigerant storage unit when the state quantity moves beyond a predetermined threshold (SCth, EVAth) during transition of the first condition (MN) and the second condition (MS) Determining the suitability of the refrigerant charge amount (V1) based on the amount (Vx) of
The refrigerant | coolant filling amount determination system of Claim 5 or Claim 6.   The determination unit determines that the refrigerant charge amount (V1) is inappropriate when the amount (Vx) of the liquid refrigerant is smaller than a predetermined liquid refrigerant amount threshold (Vth). The refrigerant | coolant filling amount determination system of description. The refrigerant circuit is
A heat source unit (10) having the compressor;
Use units (20a, 20b),
A communication pipe (30) for moving the refrigerant between the heat source unit and the utilization unit;
And further
The connection pipe is
A liquid communication pipe (31) for mainly moving the liquid refrigerant;
A gas communication pipe (32) for mainly moving the gas refrigerant;
Have
The refrigerant storage unit is connected to the gas communication pipe via a first gas side valve (A) and to the liquid communication pipe via a first liquid side valve (B).
The refrigerant charge determination system according to any one of claims 7 or 8. The refrigerant storage unit is further connected to the gas communication pipe via a second gas side valve (C).
The refrigerant | coolant filling amount determination system of Claim 9. The determination unit is
During the transition from the first condition (MN) to the second condition (MS), and
During transition from the second condition (MS) to the first condition (MN),
The propriety of the refrigerant charge amount (V1) is determined based on the state amount acquired by the state amount acquisition unit in both of
The refrigerant charge determination system according to any one of claims 7 to 10. A refrigerant (11), a heat source heat exchanger (13), a utilization heat exchanger (22), an expansion valve (21), a liquid communication pipe (31), and a gas communication pipe (32); A method of determining the propriety of the refrigerant charge (V1) of the refrigerant circuit (40) configured to circulate a refrigerant capable of taking the state of the gas refrigerant,
Connecting a refrigerant storage unit (70) to the gas communication pipe and the gas communication pipe;
Moving the refrigerant between the refrigerant circuit and the refrigerant storage unit;
Acquiring a state quantity during the step of moving the refrigerant;
Determining the suitability of the refrigerant charge amount (V1) based on the amount (Vx) of the liquid refrigerant contained in the refrigerant containing portion when the magnitude relation between the state amount and the predetermined threshold value is reversed , only including,
The method, wherein the state quantity is at least one of a degree of subcooling (SC) of the refrigerant exiting the radiator and an opening degree (EVA) of the expansion valve . At least one of the heat source heat exchanger and the utilization heat exchanger can operate as a radiator;
The state quantity is a degree of subcooling (SC) of the refrigerant exiting the radiator.
A method according to claim 12. The state quantity is an opening degree (EVA) of the expansion valve.
A method according to claim 12.

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