CN107208952B

CN107208952B - Refrigerating device

Info

Publication number: CN107208952B
Application number: CN201580072716.5A
Authority: CN
Inventors: 森田久登; 齐藤信; 佐多裕士; 池田隆
Original assignee: Mitsubishi Corp
Current assignee: Mitsubishi Corp
Priority date: 2015-02-27
Filing date: 2015-02-27
Publication date: 2019-12-20
Anticipated expiration: 2035-02-27
Also published as: JPWO2016135956A1; WO2016135956A1; JP6289727B2; CN107208952A

Abstract

The refrigeration device of the present invention comprises: a heat source side unit having a compressor, a heat source side heat exchanger, a liquid container, and a supercooling heat exchanger; a usage-side unit having an expansion valve and a usage-side heat exchanger; a refrigerant pipe connecting the heat source side unit and the usage side unit; a control device that determines whether or not an appropriate amount of refrigerant is sealed in a refrigerant circuit formed by a heat source-side unit, a usage-side unit, and refrigerant piping, based on temperature efficiency of a supercooling heat exchanger; and a notification unit that notifies information relating to a refrigerant sealing amount in the refrigerant circuit, wherein the control device, when performing additional sealing in which a refrigerant is additionally sealed and sealed, causes the notification unit to notify a content that urges the sealing of the refrigerant when the temperature efficiency is less than a predetermined determination threshold, and when ending the additional sealing, determines an insufficient sealing amount that is an insufficient amount of the refrigerant with respect to a predetermined reference refrigerant amount, and causes the notification unit to notify the insufficient sealing amount.

Description

Refrigerating device

Technical Field

The present invention relates to a refrigeration apparatus in which a refrigerant circuit in which a refrigerant is sealed is formed.

Background

In the refrigeration apparatus, the occurrence of an excess or deficiency in the amount of refrigerant becomes a cause of a problem such as a reduction in the capacity of the refrigerant apparatus or damage to constituent equipment. In order to prevent such a problem, a refrigeration apparatus having a function of determining excess or deficiency of the amount of refrigerant to be sealed is known.

As a refrigerant sealing method in a conventional refrigeration apparatus, for example, the following methods are proposed: when the temperature efficiency obtained by dividing the degree of supercooling of the refrigerant at the outlet of the supercooling heat exchanger by the maximum temperature difference of the supercooling heat exchanger is equal to or greater than a predetermined determination threshold value, the insufficient sealed amount, which is the amount of refrigerant insufficient to a predetermined reference amount of refrigerant, is calculated based on the density and the internal volume of the refrigerant in each of the condenser, the liquid extension pipe, the gas extension pipe, and the evaporator (see, for example, patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2012 and 132639

Disclosure of Invention

Problems to be solved by the invention

The refrigerant sealing in the refrigeration apparatus is performed in three stages, i.e., initial sealing, additional sealing, and final additional sealing. In a conventional refrigeration apparatus, as in patent document 1, after a certain amount of refrigerant is sealed in initial sealing, additional sealing is performed several times until the temperature efficiency of the supercooling heat exchanger becomes equal to or higher than a predetermined determination threshold, and final additional sealing for compensating for a margin is performed at a stage when the determination threshold is exceeded, thereby sealing an appropriate amount of refrigerant. Here, since it takes about 10 minutes even if one additional sealing is shortest, there is a problem that it takes much time and labor to perform the additional sealing several times until the determination threshold is exceeded in the conventional configuration.

In addition, conventionally, in order to stabilize the value of the temperature efficiency, the compressor is continuously operated for a predetermined time (for example, 30 minutes) after the initial sealing, but when the initial sealing amount is too small, the compressor may be stopped due to the low pressure protection or the discharge temperature abnormality. Therefore, there is a problem that continuous operation of the compressor for a predetermined time is required again. Further, since the conventional refrigeration apparatus is configured to calculate and display the amount of enclosed air at each time of enclosing, there is a problem as follows: the information related to the refrigerant sealing amount cannot be known until the sealing amount is displayed.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a refrigeration apparatus in which a more appropriate amount of refrigerant is sealed in a shorter time without taking much time.

Means for solving the problems

The refrigeration device of the present invention comprises: a heat source side unit having a compressor, a heat source side heat exchanger, a liquid container, and a supercooling heat exchanger; a usage-side unit having an expansion valve and a usage-side heat exchanger; a refrigerant pipe connecting the heat source side unit and the usage side unit; a control device that determines whether or not an appropriate amount of refrigerant is sealed in a refrigerant circuit formed by a heat source-side unit, a usage-side unit, and refrigerant piping, based on temperature efficiency of a supercooling heat exchanger, the temperature efficiency of which is a value obtained by dividing a degree of supercooling of refrigerant at an outlet of the supercooling heat exchanger by a maximum temperature difference of the supercooling heat exchanger; and a notification unit that notifies information relating to a refrigerant sealing amount in the refrigerant circuit, wherein the control device, when performing additional sealing in which a refrigerant is additionally sealed and sealed, causes the notification unit to notify a content that urges the sealing of the refrigerant when the temperature efficiency is less than a predetermined determination threshold, and when ending the additional sealing, determines an insufficient sealing amount that is an insufficient amount of the refrigerant with respect to a predetermined reference refrigerant amount, and causes the notification unit to notify the insufficient sealing amount.

ADVANTAGEOUS EFFECTS OF INVENTION

In the present invention, the control device that determines whether or not the amount of refrigerant sealed in the refrigerant circuit is appropriate reports the content of urging the refrigerant sealing during the additional sealing period, and calculates and reports the insufficient sealing amount when the additional sealing is completed, so that the additional sealing after the initial sealing can be smoothly performed, and the insufficient sealing amount can be accurately calculated, and therefore, a more appropriate amount of refrigerant can be sealed in a shorter time without taking much time.

Drawings

Fig. 1 is a refrigerant circuit diagram of a refrigeration apparatus according to embodiment 1 of the present invention.

Fig. 1A is a refrigerant circuit diagram showing an example in which a compression unit including a compressor and a liquid container is disposed indoors in a refrigeration apparatus according to embodiment 1 of the present invention.

Fig. 1B is a refrigerant circuit diagram showing an example in which a compression unit including a compressor is disposed indoors in the refrigeration apparatus according to embodiment 1 of the present invention.

Fig. 2 is a schematic diagram showing a change in temperature of the refrigerant when an appropriate refrigerant is sealed in embodiment 1 of the present invention.

Fig. 3 is a schematic diagram showing the change in temperature of the refrigerant when the amount of refrigerant is insufficient in embodiment 1 of the present invention.

Fig. 4 is a flowchart showing the refrigerant amount determination operation in embodiment 1.

Fig. 5A is a conceptual diagram illustrating a case where the stability determination condition is satisfied in embodiment 1.

Fig. 5B is a conceptual diagram illustrating a case where the stability determination condition is not satisfied in embodiment 1.

Fig. 6 is a graph showing the relationship between the refrigerant density and the condensation temperature in the heat source side heat exchanger 3 in embodiment 1 of the present invention.

Fig. 7 is a graph showing the relationship between the refrigerant density in the first pipe and the liquid pipe temperature in embodiment 1 of the present invention.

Fig. 8 is a graph showing the relationship between the refrigerant density and the evaporation temperature in the second pipe in embodiment 1 of the present invention.

Fig. 9A is a graph showing a relationship between the average density in the evaporator and the evaporation temperature in embodiment 1 of the present invention.

Fig. 9B is a graph corresponding to fig. 9A and showing a relationship between the average density in the evaporator and the evaporation temperature.

Fig. 10 is a graph showing a relationship between the average density in the liquid container and the condensation temperature in embodiment 1 of the present invention.

Fig. 11 is a schematic diagram showing an example of display on the notification unit according to embodiment 2 of the present invention.

Detailed Description

[ embodiment 1]

Fig. 1 is a refrigerant circuit diagram of a refrigeration apparatus according to embodiment 1 of the present invention. As shown in fig. 1, the refrigeration apparatus according to embodiment 1 includes a heat source side unit 100 disposed outdoors, for example, and a usage side unit 200 disposed indoors, for example. The heat-source-side unit 100 includes a compressor 1, an oil separator 2, a heat-source-side heat exchanger 3, a liquid container 4, a supercooling heat exchanger 5, and an accumulator 8. The use-side unit 200 includes an expansion valve 6 and a use-side heat exchanger 7. The heat source-side unit 100 and the usage-side unit 200 are connected by a first pipe 10, which is a liquid pipe, for example, and a second pipe 11, which is a gas pipe, for example.

The refrigeration apparatus according to embodiment 1 includes a refrigerant circuit in which the refrigerant compressor 1, the oil separator 2, the heat source side heat exchanger 3, the liquid container 4, the supercooling heat exchanger 5, the expansion valve 6, the use side heat exchanger 7, and the accumulator 8 are sequentially circulated. That is, the refrigerant circuit is formed by the heat source-side unit 100, the usage-side unit 200, and the first pipe 10 and the second pipe 11 as refrigerant pipes. In embodiment 1, the heat source side heat exchanger 3 functions as a condenser of the refrigerant compressed by the compressor 1, and the use side heat exchanger 7 functions as an evaporator of the refrigerant sent from the heat source side heat exchanger 3 through the liquid container 4 and the expansion valve 6.

The heat source side unit 100 is provided with a first temperature sensor 15, a second temperature sensor 18, and an outside air temperature sensor 16, and the usage side unit 200 is provided with a third temperature sensor 19. The first temperature sensor 15 is provided at an arbitrary position in a flow path from the outlet side of the heat source-side heat exchanger 3 to the inlet side of the supercooling heat exchanger 5, and detects the temperature of the refrigerant flowing through the flow path. Hereinafter, the temperature detected by the first temperature sensor 15 is referred to as "condenser outlet temperature TH 5". The condenser outlet temperature TH5 may be obtained by detecting the pressure and converting the saturation temperature.

The second temperature sensor 18 is provided at an arbitrary position in a flow path from the outlet side of the supercooling heat exchanger 5 to the inlet side of the expansion valve 6, and detects the temperature of the refrigerant flowing through the flow path. Hereinafter, the detected temperature of the second temperature sensor 18 is referred to as "subcooling heat exchanger outlet temperature TH 8". The outside air temperature sensor 16 detects the temperature of air that exchanges heat with the refrigerant of the heat source side heat exchanger 3. Hereinafter, the temperature detected by the outside air temperature sensor 16 is referred to as "outside air temperature TH 6".

The third temperature sensor 19 is provided at an arbitrary position in a flow path from the outlet side of the expansion valve 6 to the inlet side of the use side heat exchanger 7, and detects the temperature of the refrigerant flowing through the flow path. Hereinafter, the temperature detected by the third temperature sensor 19 is referred to as "evaporation temperature ET". The evaporation temperature ET may be determined by detecting the pressure and converting the saturation temperature.

The heat source side unit 100 includes a control device 20 for determining whether or not the amount of refrigerant sealed in the refrigerant circuit is appropriate, and an informing unit 21 for informing information related to the amount of refrigerant sealed in the refrigerant circuit, the informing unit 21 being composed of, for example, a 7-segment LED. The control device 20 is constituted by, for example, a microcomputer provided on a control board of the refrigeration apparatus. The notification unit 21 according to embodiment 1 is provided in the control device 20, and notifies various determination results or various information described later as information related to the amount of refrigerant sealed in the refrigerant circuit.

In embodiment 1, the controller 20 determines whether or not the refrigerant amount is appropriate, using the temperature efficiency ∈ (hereinafter, also simply referred to as "temperature efficiency ∈") of the supercooling heat exchanger 5 whose variation due to the operating condition is smaller than the degree of supercooling. Temperature information detected by the first temperature sensor 15, the second temperature sensor 18, the outside air temperature sensor 16, and the third temperature sensor 19 is input to the control device 20. The control device 20 calculates the temperature efficiency ∈ using the temperature information.

When performing additional sealing for adding and sealing in the refrigerant, the control device 20 causes the notification unit 21 to notify the content for urging the refrigerant sealing, the content for urging the refrigerant sealing speed to decrease, or the content for urging the refrigerant sealing to be interrupted, based on the magnitude relationship between the temperature efficiency ∈ and the preset determination threshold ∈ line1 and interruption determination threshold ∈ line2, and when the additional sealing is finished, obtains the insufficient sealing amount, which is the amount of shortage of the refrigerant with respect to the preset reference refrigerant amount, and notifies the notification unit 21. More specifically, when the temperature efficiency ∈ is less than the determination threshold ∈ line1 for a predetermined time or longer continuously during the operation of the compressor 1, the control device 20 causes the notification unit 21 to notify the content of urging the refrigerant sealing. Further, when the temperature efficiency ∈ is less than the preset interruption determination threshold ∈ line2 for a predetermined time or longer during the operation of the compressor 1, the control device 20 causes the notification unit 21 to notify the content that urges the refrigerant sealing speed to decrease. When the temperature efficiency e is equal to or greater than the interruption determination threshold value epsilon line2 for a predetermined time period or more, the control device 20 causes the notification unit 21 to notify the content of urging the refrigerant sealing interruption.

The control device 20 calculates an initial sealing amount based on field information input from the outside via a substrate or the like, and causes the notification unit 21 to notify the calculated initial sealing amount. Here, the field information includes information on at least the specifications (for example, internal volumes) of the first pipe 10 and the use side heat exchanger 7, and the target evaporation temperature or the low pressure protection on-state value and the off-state value. More specifically, the field information includes information on the internal volumes of the heat source side heat exchanger 3, the first pipe 10, the second pipe 11, the use side heat exchanger 7, and the liquid container 4.

The control device 20 calculates a shortage of the amount of sealing, which is an insufficient amount of refrigerant with respect to a preset reference refrigerant amount, based on at least the density and the internal volume of the refrigerant in each of the heat source side heat exchanger 3, the first pipe 10, the second pipe 11, the use side heat exchanger 7, and the liquid container 4, and causes the notification unit 21 to notify the calculated shortage of the amount of sealing.

In embodiment 1, the information on the internal volume of the use-side heat exchanger 7 included in the field information is divided into two or more patterns (patterns) in advance based on the information on the temperature zone (for example, the target evaporation temperature or the low pressure protection cutoff value). More specifically, each of the modes includes at least a mode satisfying a refrigeration condition and a mode satisfying a freezing condition, and is configured by three or more modes when at least one of the refrigeration condition and the freezing condition is subdivided, for example. The control device 20 is configured to: when the insufficient sealing amount is determined, the value of each mode is used as the internal volume of the use side heat exchanger 7.

Here, the flow of the refrigerant in the refrigerant circuit of embodiment 1 will be described. The high-temperature high-pressure gas refrigerant discharged from the variable-capacity compressor 1 is separated from the refrigeration machine oil contained therein by the oil separator 2 and then flows into the heat source side heat exchanger 3. The high-temperature and high-pressure gas refrigerant flowing into the heat source side heat exchanger 3 is condensed into a high-pressure liquid refrigerant (liquid or two-phase state) in the heat source side heat exchanger 3, and is stored in the liquid container 4. The high-pressure liquid refrigerant stored in the liquid container 4 is further heat-exchanged in the supercooling heat exchanger 5 to become a supercooled liquid refrigerant. The refrigerant that has become a high-pressure liquid in the supercooling heat exchanger 5 becomes a low-temperature low-pressure two-phase refrigerant in the expansion valve 6 of the usage-side unit 200, and flows into the usage-side heat exchanger 7. Then, the refrigerant turns into a low-temperature and low-pressure gas refrigerant in the use side heat exchanger 7, and returns to the compressor 1 via the accumulator 8.

In fig. 1, the case where one usage-side unit 200 is connected to one heat source-side unit 100 is illustrated, but the present invention is not limited thereto, and any number of usage-side units 200 may be connected to the heat source-side unit 100. The refrigeration device with the structure comprises: a plurality of first pipes 10, one ends of the plurality of first pipes 10 being connected to the supercooling heat exchanger 5 and the other ends thereof being connected to the plurality of expansion valves 6; and at least one second pipe 11, one end of the at least one second pipe 11 being connected to the compressor 1 and the other end being connected to the at least one use side heat exchanger 7. That is, a plurality of use-side units 200 may be provided, and the plurality of use-side units 200 may be configured to include at least a unit cooler and a showcase. In addition, when the insufficient sealing amount is determined, the control device 20 may appropriately use the internal volume of the unit cooler, the internal volume of the showcase, or the internal volume in the case where the unit cooler and the showcase are mixed as the internal volume of the use-side heat exchanger 7.

In the case where a plurality of usage-side units 200 are provided, the control device 20 may use the evaporation temperature band in each of the plurality of usage-side units 200 as the specification information of the usage-side heat exchanger 7 when determining the insufficient sealing amount. In this configuration, the control device 20 may divide the plurality of usage-side units 200 into two or more groups (for example, a group in which the evaporation temperature used as the usage-side unit 200 is a refrigeration zone, a group in which the evaporation temperature is a refrigeration zone, or a group in which the evaporation temperature is a refrigeration zone) using a preset temperature threshold value based on the evaporation temperature zone in each of the plurality of usage-side units 200, and may appropriately use the internal volume of each group as the internal volume of the usage-side heat exchanger 7.

In embodiment 1, the case where the amount of refrigerant sealed in the refrigerant circuit formed by connecting the heat source side unit 100 and the usage side unit 200 is determined has been described, but the present invention is not limited to this. That is, the refrigeration apparatus according to embodiment 1 may be configured to form a refrigerant circuit (refrigeration cycle) by joining refrigerant pipes (liquid pipes, gas pipes) to the use-side unit 200 installed on site, for example, as in a condensation unit (condensation unit).

As shown in fig. 1A or 1B, a part of the heat-source-side unit 100 may be separately disposed in the room. Fig. 1A is a refrigerant circuit diagram showing an example in which a compression unit 300A including a compressor 1 and a liquid container 4 is disposed indoors in the refrigeration apparatus according to embodiment 1. Fig. 1B is a refrigerant circuit diagram showing an example in which a compression unit 300B including the compressor 1 is disposed indoors in the refrigeration apparatus according to embodiment 1. In the example shown in fig. 1A, the heat source-side heat exchanger 3 and the compression unit 300A in the heat source-side unit 100A are connected by an extension pipe 12. The refrigeration apparatus of fig. 1A does not have the supercooling heat exchanger 5, and has the electronic expansion valve 13 and the double-pipe subcooler 14 in the compression unit 300A. In the example shown in fig. 1B, the heat source side unit 100B and the compression unit 300B are connected by the extension pipe 12. That is, as shown in fig. 1A and 1B, the refrigeration apparatus according to embodiment 1 can be realized also in a remote-controlled condensation unit in which compression units 300A and 300B including the compressor 1 are installed indoors and heat-source-side units 100A and 100B including the heat-source-side heat exchanger 3 are installed outdoors.

Further, for example, like a cooling unit, a refrigeration apparatus may be provided in which the compressor 1, the heat source side heat exchanger 3, the supercooling heat exchanger 5, the expansion valve 6, the use side heat exchanger 7, and other accessory devices constituting the refrigerant circuit are provided in one unit and connected by pipes. The configuration of the refrigerant circuit is not limited to the above configurations. For example, a four-way valve or the like for switching the refrigerant flow path may be provided to switch between the cooling operation and the heating operation. Further, at least one of the oil separator 2, the liquid container 4, and the accumulator 8 may not be provided.

Next, the relationship between the refrigerant charge amount and the degree of supercooling will be described. Fig. 2 is a schematic diagram showing a change in temperature of the refrigerant when an appropriate refrigerant is sealed in embodiment 1. Fig. 3 is a schematic diagram showing a change in temperature of the refrigerant when the amount of the refrigerant is insufficient in embodiment 1. In fig. 2 and 3, the vertical axis represents temperature, and the temperature is higher at the upper part. The horizontal axis indicates the refrigerant flow paths of the outlet-side pipes (liquid pipes) of the heat source-side heat exchanger 3, the supercooling heat exchanger 5, and the supercooling heat exchanger 5.

Arrow a in fig. 2 indicates a change in the temperature of the refrigerant in each refrigerant flow path when an appropriate amount of refrigerant is sealed into the refrigeration apparatus. When an appropriate amount of refrigerant is sealed in the refrigeration apparatus, the two-phase refrigerant from the heat source side heat exchanger 3 is separated into gas and liquid in the liquid container 4, and the liquid container 4 is in a saturated liquid state in which the liquid refrigerant is stored. Therefore, the liquid refrigerant from the liquid container 4 flows into the supercooling heat exchanger 5, and the heat exchange by the supercooling heat exchanger 5 contributes to supercooling of the entire liquid refrigerant.

The arrow b in fig. 3 indicates the change in the refrigerant temperature in each refrigerant flow path when the amount of refrigerant is insufficient. When the amount of refrigerant is insufficient, the outlet of the heat source side heat exchanger 3 is in a dry state, and the liquid container 4 does not store the liquid refrigerant, and the two-phase refrigerant flows into the supercooling heat exchanger 5. Therefore, the two-phase refrigerant is condensed, liquefied, and supercooled by the heat exchange performed by the supercooling heat exchanger 5. Therefore, when the refrigerant quantity is insufficient, the degree of supercooling is reduced as compared with the case of the arrow a in fig. 2. The supercooling heat exchanger 5 in fig. 2 and 3 corresponds to the double-pipe subcooler 14 shown in fig. 1A.

(refrigerant sealing amount determination operation)

Here, an operation related to the determination of whether or not the refrigerant amount is appropriate by the control device 20 will be described. The controller 20 in embodiment 1 determines whether or not the amount of refrigerant sealed in the refrigerant circuit is appropriate based on the temperature efficiency ∈ of the supercooling heat exchanger 5. The temperature efficiency ∈ of the supercooling heat exchanger 5 is a value obtained by dividing the degree of supercooling of the refrigerant at the outlet of the supercooling heat exchanger 5 (condenser outlet temperature TH5 — supercooling heat exchanger outlet temperature TH8) by the maximum temperature difference of the supercooling heat exchanger 5 (condenser outlet temperature TH5 — outside air temperature TH6), and is represented by the following equation 1.

[ mathematical formula 1]

The temperature efficiency ∈ of the supercooling heat exchanger 5 indicates the performance of the supercooling heat exchanger 5, and as described above, the variation due to the operating conditions is small compared to the degree of supercooling. Therefore, the accuracy of determining the shortage of the refrigerant amount can be improved without setting the threshold value for each operation condition.

Next, a specific example of the operation for determining whether or not the refrigerant amount is appropriate using the temperature efficiency ∈ of the supercooling heat exchanger 5 will be described based on the sealing step shown in fig. 4. Fig. 4 is a flowchart showing the refrigerant amount determination operation in embodiment 1.

(S101～S102)

For example, when a refrigerant quantity judging operation mode is set by operating a switch or the like on a control board of the refrigeration apparatus, the control device 20 starts a refrigerant quantity judging operation (fig. 4: step S101). Next, the operator at the site inputs the specifications of the first pipe 10, the second pipe 11, and the use side heat exchanger 7, and information (site information) on the target evaporation temperature or the low pressure protection on-value and off-value (fig. 4: step S102). The first pipe 10 and the second pipe 11 are specified based on pipe diameters and pipe lengths. The usage-side heat exchanger 7 is specified assuming three cases of a showcase, a unit cooler, and a mixture of the showcase and the unit cooler as the usage-side unit 200 to be connected. In embodiment 1, the specification of the use-side heat exchanger 7 is classified into, for example, 6 modes according to the target evaporation temperature or the low-pressure protection cutoff value. Therefore, an operator on site determines which freezing condition or which refrigerating condition is satisfied by the use-side unit 200 based on the target evaporation temperature or the low-pressure protection cutoff value, and sets the specification of the use-side heat exchanger 7 to any one of the 6 modes.

(S103)

Next, the control device 20 calculates the initial sealing amount based on the field information input in step S102. More specifically, the controller 20 calculates the initial amount of encapsulation using a functional expression of a preset pipe length in accordance with the specifications of the first pipe 10, the second pipe 11, and the use side heat exchanger 7. The controller 20 also causes the notification unit 21 to notify the calculated initial sealing amount (fig. 4: step S103). In embodiment 1, the notification unit 21 is composed of, for example, 7-segment LEDs, and displays information on the initial sealing amount. In the following, a case where the notification unit 21 is a 7-segment LED will be described, but the notification method is not limited to this.

(S104～S105)

Next, the operation of the compressor 1 is started. That is, the control device 20 operates the compressor 1 at a predetermined operating frequency (fig. 4: step S104). In addition, when the refrigerant amount is determined, the presence or absence of the refrigerant shortage cannot be accurately determined in the detection method for the entire operation range. This is because the outlet of the supercooling heat exchanger 5 may be a two-phase refrigerant in a state where the compressor 1 is operated at a high operating frequency, and in this state, when the operating frequency of the compressor 1 increases or decreases, the pressure loss largely changes, and the refrigerant shortage cannot be accurately determined. Therefore, in embodiment 1, in order to eliminate the influence of the pressure loss, the compressor 1 is operated at a predetermined operating frequency determined based on the above-described situation.

In the description of the operation, a case will be described in which the compressor 1 is assumed to be a constant speed machine and the compressor 1 is operated in a state of being fixed at 50Hz or 60Hz, but the operation is not limited to this, and the compressor 1 may be a speed machine. In embodiment 1, in order to further reduce the influence of the pressure loss, the operation is performed at a predetermined fixed frequency to determine whether or not the refrigerant amount is appropriate, but the present invention is not limited to this determination method, and the compressor 1 may be operated at a frequency within a predetermined range in which the influence of the pressure loss is small.

The controller 20 acquires temperature information necessary for calculating the temperature efficiency ∈ (temperature information necessary for calculating the temperature efficiency ∈) from the first temperature sensor 15, the second temperature sensor 18, the third temperature sensor 19, and the outside air temperature sensor 16 (fig. 4: step S105).

(S106～S113)

The controller 20 calculates the temperature efficiency epsilon based on the temperature information using equation 1, and determines the refrigerant-sealed state using a preset determination threshold epsilon line1 and an interruption determination threshold epsilon line2 based on the value of the calculated temperature efficiency epsilon. Further, between the determination threshold value epsilon line1 and the interruption determination threshold value epsilon line2, there is a relationship of "determination threshold value epsilon line1< interruption determination threshold value epsilon line 2".

More specifically, when the compressor 1 is in operation and the temperature efficiency ∈ is less than the determination threshold ∈ line1 for a predetermined period of time (e.g., 3 minutes) or longer (fig. 4: step S106/no), the control device 20 determines that the amount of refrigerant is small and causes the notification unit 21 to notify the content prompting the refrigerant sealing. The notification is based on the elapse of a predetermined time. The controller 20 prompts the sealing of the refrigerant by displaying the contents of prompting the sealing of the refrigerant on the 7-segment LED as the notification unit 21, for example (fig. 4: step S107). Then, the control device 20 acquires temperature information necessary for calculating the temperature efficiency ∈ (fig. 4: step S105), and determines whether or not the amount of refrigerant is small (fig. 4: step S106). That is, the controller 20 repeats step S105 to step S107 while determining that the amount of refrigerant is small (step S106/no in fig. 4).

On the other hand, when the compressor 1 is in operation and the temperature efficiency ∈ is equal to or greater than the determination threshold ∈ line1 for a predetermined period of time (for example, 3 minutes) in succession (fig. 4: step S106/yes), the controller 20 determines that the amount of refrigerant has reached the reference amount, and proceeds to the determination process using the interruption determination threshold ∈ line2 as the next step.

In the determination process using the interruption determination threshold value epsilon line2 (fig. 4: steps S108 to S113), the control device 20 first reports the content of urging the refrigerant sealing from the reporting section 21. When the refrigerant sealing is started in the previous step, the refrigerant sealing is continued (fig. 4: step S108). Next, the control device 20 determines whether or not the compressor 1 is operating and the temperature efficiency ∈ is less than the interruption determination threshold value ∈ line2 for a predetermined time (for example, 2 minutes) or longer after the start of sealing (fig. 4: step S109).

When the temperature efficiency epsilon is equal to or greater than the interruption determination threshold epsilon line2 for a predetermined time (e.g., 2 minutes) after the start of sealing (fig. 4: step S109/no), the control device 20 determines that the refrigerant is sufficiently sealed, and causes the notification unit 21 to notify the content of urging the interruption of refrigerant sealing in order to interrupt the refrigerant sealing. For example, the controller 20 displays "StoP" on a 7-segment LED as the notification unit 21 (FIG. 4: step S113).

On the other hand, when the temperature efficiency ∈ is smaller than the interruption determination threshold ∈ line2 (fig. 4: step S109/yes), the control device 20 acquires temperature information necessary for calculation of the temperature efficiency ∈ (fig. 4: step S110), and determines whether or not the compressor 1 is operating and the temperature efficiency ∈ is equal to or greater than the interruption determination threshold ∈ line2 for a predetermined time (e.g., 2 minutes) (fig. 4: step S111).

When the temperature efficiency e is equal to or greater than the interruption determination threshold value epsilon line2 for a predetermined period of time (e.g., 2 minutes) continuously or more (fig. 4: step S111/yes), the control device 20 determines that the refrigerant is sufficiently sealed, and notifies the notification unit 21 of a content urging interruption of the refrigerant sealing in order to interrupt the refrigerant sealing (fig. 4: step S113).

On the other hand, when the temperature efficiency e is less than the interruption determination threshold value epsilon line2 for a predetermined time (e.g., 2 minutes) or longer (fig. 4: step S111/no), the control device 20 causes the notification unit 21 to notify that the refrigerant sealing speed is to be reduced, because the refrigerant sealing amount gradually approaches the interruption determination threshold value epsilon line 2. For example, in order to decrease the speed of refrigerant sealing, the controller 20 displays "Slou" on a 7-segment LED as the notification unit 21 (FIG. 4: step S112). Subsequently, the control device 20 acquires temperature information necessary for calculating the temperature efficiency ε (FIG. 4: step S110). That is, the control device 20 repeats steps S110 to S112 until the temperature efficiency ∈ continues for a predetermined time (for example, 2 minutes) or more to be equal to or more than the interruption determination threshold value ∈ line2 (fig. 4: step S111/yes).

Here, the refrigerant sealing speed is normalized as follows.

After the start of step S108, about 3% of the maximum amount of sealed refrigerant is sealed in one minute.

Slou shows that about 1% of the maximum amount of enclosed refrigerant is enclosed in one minute.

As described above, according to the refrigeration apparatus of embodiment 1, since it is not necessary to instruct the additional sealing amount in several times as in the conventional technique, the time (minimum 10 minutes) and labor required for each sealing can be omitted.

[ judgment processing of undetectable Condition ]

At the same time, the control device 20 determines whether or not the current operating state meets the undetectable condition. As the undetectable condition, for example, the following conditions are set in advance, and when any of the following conditions is satisfied, the control device 20 determines that the undetectable condition is satisfied, and sets the temperature efficiency ∈ calculated using equation 1 to an invalid value. This is because, when the following condition is satisfied, the value of the temperature efficiency ∈ becomes unstable or becomes small, and false detection occurs.

The ambient temperature is outside the operating temperature range.

The temperature difference between the condenser outlet temperature TH5 and the outside air temperature TH6 is large.

The temperature efficiency ∈ is negative, or the denominator of the calculation expression (expression 1) of the temperature efficiency ∈ is 0.

The processing for determining the undetectable condition is always performed in the subsequent encapsulation step, and is not limited to this encapsulation step.

The content of urging the refrigerant sealing, which is notified by the control device 20 in step S107, may be different from the content of urging the refrigerant sealing, which is notified by the control device 20 in step S108. For example, in the latter case, information including the content of the transition of the control device 20 to the determination process using the interruption determination threshold value epsilon line2 may be reported.

(S114～S115)

When the reception is a notification to prompt interruption of refrigerant sealing and the refrigerant sealing is interrupted, the controller 20 continuously operates the compressor 1 for a predetermined time. Then, the controller 20 stores the respective temperature efficiencies ε calculated after the start of the continuous operation of the compressor 1 in a buffer provided inside or outside (FIG. 4: step S114).

The controller 20 waits until the continuous operation time of the compressor 1 after the interruption of the refrigerant sealing reaches a stable reference time (for example, 30 minutes) for stabilizing the value of the temperature efficiency ∈ (fig. 4: step S115). That is, after the interruption of the refrigerant sealing, the controller 20 continues the operation of the compressor 1 until the stabilization reference time elapses in order to wait for the stabilization of the value of the temperature efficiency ∈ (fig. 4: step S115). During the continuous operation of the compressor 1, the minimum amount of refrigerant necessary for the refrigerant sealing is already sealed in the refrigerant circuit through the above steps S106 to S113, so that it is possible to prevent the occurrence of abnormal stop of the compressor 1 due to an excessively small sealed amount.

(S116～S117)

The control device 20 determines whether or not the condition for calculating the average temperature efficiency ε A is satisfied. The condition for calculating the average temperature efficiency ε A is as follows: the latest plural (for example, 10) temperature efficiencies epsilon stored in the buffer in the above steps S114 and S115 are effective values rather than ineffective values (fig. 4: step S116) and are within the stability determination condition (fig. 4: step S117).

Here, the stability determination condition will be described. Fig. 5A is a conceptual diagram illustrating a case where the stability determination condition is satisfied in embodiment 1. Fig. 5B is a conceptual diagram illustrating a case where the stability determination condition is not satisfied in embodiment 1. As the stability determination condition, a plurality of (for example, 10) temperature efficiencies ∈ calculated in step S115 and a condition that the operating frequency at each calculation does not greatly fluctuate are set.

In embodiment 1, for example, when the frequency of the compressor 1 satisfies the condition of the following equation 2 and when the temperature efficiency ∈ satisfies the condition of the following equation 3, the control device 20 determines that the stability determination condition is satisfied.

[ mathematical formula 2]

[ mathematical formula 3]

That is, as shown in fig. 5A, when all the variation amounts from the average value of the target data converge to the predetermined value η (open circle flag), it is determined that the stability determination condition is satisfied (fig. 4: step S117/yes). On the other hand, as shown in fig. 5B, when at least one of the amounts of change from the average value of the target data exceeds the predetermined value (η) (black circle mark), it is determined that the settling determination condition is not satisfied (fig. 4: step S117/no). However, when the value of the temperature efficiency ∈ is small, the deviation from the variation width is large, and therefore the possibility of exceeding the predetermined value η becomes high. Therefore, when the temperature efficiency ∈ is smaller than a predetermined value (for example, 0.25), the above-described stability determination condition is disregarded.

As described above, the controller 20 can more accurately determine whether or not the refrigerant amount is appropriate by calculating the average temperature efficiency ∈ a described later in a state where the temperature efficiency ∈ and the operating frequency of the compressor 1 are stable. Further, the control device 20 determines that the determination is impossible when the plurality of latest temperature efficiency data have invalid values or when the stability determination condition is not satisfied, based on the above-described undetectable condition or the like.

(S118～S121)

When determining that the stability determination condition is not satisfied (no in S117 in fig. 4), the control device 20 determines that determination is impossible, and causes the notification unit 21 to alternately notify the content prompting the other method (the content prompting the refrigerant encapsulation by the other method) and the error (the cause of the non-determination). For example, the control device 20 alternately performs a display for urging the refrigerant to be sealed by another method and an error display for indicating the cause of the inconclusive determination on the 7-segment LED as the notification unit 21 (FIG. 4: step S120).

Here, another method of enclosing the refrigerant includes, for example, the following methods: by using an LED lamp provided separately as the notification unit 21, the lamp is turned on if the temperature efficiency ∈ is equal to or higher than the threshold value, and is turned on if the temperature efficiency ∈ is lower than the threshold value, and the lamp is turned off if the operation of the compressor 1 is stopped or the thermistor is in an abnormal state, whereby a required amount of refrigerant can be sealed in. Further, there is also a method of: by attaching a window to the first pipe 10 in advance, the refrigerant is sealed until the flash gas (flash gas) disappears while confirming the window, and about 10% of the refrigerant is additionally sealed as a shortage after the flash gas disappears, thereby securing a necessary amount of the refrigerant. There are also methods such as: by mounting the window in the liquid container 4 in advance, the required amount of refrigerant is secured by sealing the refrigerant up to the set liquid level while confirming the window. As described above, when the determination is not possible at a time, it takes a lot of time and effort for the control device 20 to perform the refrigerant amount determination again. Further, for example, when the determination is impossible due to a change in temperature conditions such as the outside air temperature, there is a high possibility that the determination is impossible even if the trial is performed again. Therefore, when the determination is not possible, the control device 20 notifies the content of urging the refrigerant to be sealed through the notification portion 21 by using, for example, the LED lamp or the window provided in advance as described above. However, when the determination is not possible several times, the control device 20 may notify the content of urging another method.

On the other hand, when it is determined that the stability determination condition is satisfied (fig. 4: step S117/yes), the control device 20 calculates an average value of the plurality of temperature efficiencies ∈ calculated in step S114 as an average temperature efficiency ∈ a (fig. 4: step S118). Then, the control device 20 determines whether or not the average temperature efficiency ε A is smaller than a preset average determination threshold ε lineA (FIG. 4: step S119).

When the average temperature efficiency ε A is smaller than the average determination threshold ε lineA (FIG. 4: step S119/YES), the control device 20 determines that the refrigerant is insufficient, and notifies the content of urging the refrigerant sealing by another method and the cause of the non-determination (FIG. 4: step S120). On the other hand, when the average temperature efficiency ε A is equal to or higher than the average determination threshold ε lineA in step S120 (FIG. 4: step S119/NO), the control device 20 calculates the insufficient amount of refrigerant to be sealed relative to the preset reference amount of refrigerant (FIG. 4: step S121).

When the average determination threshold value epsilon lineA is exceeded, the operator does not need to seal the refrigerant when the refrigerant sealing amount has exceeded the allowable sealing amount. The operator is allowed to confirm that several kg of refrigerant is sealed until the amount of refrigerant sealed exceeds the average determination threshold value epsilon lineA. On the other hand, if the amount of the sealed refrigerant is smaller than the allowable sealed amount, the calculated insufficient sealed amount of the refrigerant is additionally sealed. The following describes details of operations related to the final additional sealing.

(operation for calculating the amount of insufficient sealing)

The control device 20 determines the insufficient sealing amount Δ Mr, which is an amount of shortage of the refrigerant with respect to a preset reference refrigerant amount, based on the density and the internal volume of the refrigerant in each of the heat source side heat exchanger 3, the first pipe 10, the second pipe 11, the use side heat exchanger 7, and the liquid container 4. This prevents the amount of refrigerant sealed from varying due to changes in the outside air conditions caused by seasons or the like, and seals an appropriate amount of refrigerant.

More specifically, the controller 20 calculates the insufficient sealing amount Δ Mr by summing the insufficient sealing amounts of the five elements (the liquid container 4, the heat source side heat exchanger 3, the use side heat exchanger 7, the first pipe 10, and the second pipe 11) having large variations in the amount of refrigerant in the configuration of the refrigeration apparatus by the following equation 4.

[ mathematical formula 4]

ΔMr＝ΔMr_cond+ΔMr_PL+ΔMr_PG+ΔMr_eva+ΔMr_recG… (math type 4)

Here,. DELTA.Mr_condIs the insufficient sealing amount of the heat source side heat exchanger 3.Δ Mr_PLIs the insufficient sealing amount of the first pipe 10. Δ Mr_PGIs the insufficient sealing amount of the second pipe 11. Δ Mr_evaIs the shortage of the usage-side heat exchanger 7.Δ Mr_recGIs the insufficient sealing amount of the liquid container 4. The following describes details of the operation of calculating each of the insufficient sealed amounts.

[ insufficient sealing amount Δ Mr of the heat source side heat exchanger 3_cond]

The control device 20 controls the heat source-side heat exchanger 3 based on a preset refrigerant density ρ_condThe difference (density fluctuation [ Delta ] rho) between the preset reference density and the density (density at the time of sealing) of the refrigerant is obtained from the relationship with the condensation temperature and the condenser outlet temperature TH5_cond) The obtained difference is compared with the internal volume V of the heat source side heat exchanger 3_condThe product is multiplied to determine the insufficient sealing amount DeltaMr of the heat source side heat exchanger 3_cond。

Refrigerant density ρ of the heat source side heat exchanger 3_condThe relationship with the condensing temperature is shown in fig. 6, for example. Fig. 6 is a graph showing the relationship between the refrigerant density and the condensation temperature in the heat source side heat exchanger 3 in embodiment 1. As shown in fig. 6, the refrigerant density of the heat source side heat exchanger 3 changes according to the condensation temperature. The slope of the graph shown in fig. 6 is "1.7", and is a coefficient of the following equation 5. The reference density is, for example, the rootThe setting is made according to a reference condition under which the refrigerant density in the heat source side heat exchanger 3 becomes maximum.

In the example of fig. 6, when the condensation temperature 60 ℃ at which the refrigerant density becomes maximum is set as the reference condition, the density of the heat source-side heat exchanger 3 varies by Δ ρ_condCan be obtained by the following equation 5. That is, the controller 20 calculates the density variation Δ ρ from equation 5_condAnd the internal volume V of the heat source side heat exchanger 3_condThe heat source side heat exchanger 3 is multiplied by the calculated shortage sealing amount Δ Mr_cond(equation 6).

[ math figure 5]

Δρ_cond1.7 × (60-CT) … (math figure 5)

[ mathematical formula 6]

ΔMr_cond＝Δρ_cond×V_cond… (math type 6)

[ insufficient sealing amount Δ Mr of the first pipe 10_PL]

The control device 20 is based on a preset refrigerant density ρ in the first pipe 10_PLThe difference (density fluctuation [ Delta ] rho) between the preset reference density and the density of the refrigerant (density at the time of sealing) is obtained from the relationship with the liquid pipe temperature and the supercooling heat exchanger outlet temperature TH8_PL) The obtained difference is compared with the internal volume V of the first pipe 10_PLMultiplying the calculated value to obtain the insufficient sealing amount Δ Mr in the first pipe 10_PL。

Refrigerant density ρ of the first pipe 10_PLThe relationship with the liquid tube temperature is shown, for example, in fig. 7. Fig. 7 shows the refrigerant density ρ in the first pipe 10 according to embodiment 1_PLGraph of relationship to liquid line temperature. As shown in fig. 7, the refrigerant density of the first pipe 10 changes according to the liquid pipe temperature. The slope of the graph shown in fig. 7 is "-5", which is a coefficient of the following equation 7. The reference density is set, for example, based on a reference condition that the refrigerant density in the first pipe 10 becomes maximum.

In the example of fig. 7, when the liquid pipe temperature 17 ℃ at which the refrigerant density becomes maximum is set as the reference condition, the density of the first pipe 10 fluctuatesΔρ_PLCan be obtained by the following equation 7. That is, the controller 20 calculates the density variation Δ ρ from equation 7_PLAnd the internal volume V of the first pipe 10_PLThe product is multiplied to calculate the insufficient sealing amount Δ Mr of the first pipe 10_PL(equation 8).

[ math figure 7]

Δρ_PL= 5 × (17-TH8) … (math figure 7)

[ mathematical formula 8]

ΔMr_PL＝Δρ_PL×V_PL… (mathematics type 8)

[ insufficient sealing amount Δ Mr of the second pipe 11_PG]

The control device 20 is based on a preset refrigerant density ρ in the second pipe 11_PGThe difference (density fluctuation [ Delta ] rho) between the preset reference density and the density of the refrigerant (density at the time of sealing) is obtained from the relationship with the evaporation temperature ET and the evaporation temperature ET_PG) The obtained difference is compared with the internal volume V of the second pipe 11_PGMultiplying the calculated value to obtain the insufficient sealing amount Δ Mr in the second pipe 11_PG。

Refrigerant density ρ of the second pipe 11_PGThe relationship with the evaporation temperature ET is shown in fig. 8, for example. Fig. 8 is a graph showing the relationship between the refrigerant density and the evaporation temperature in the second pipe in embodiment 1. As shown in fig. 8, the refrigerant density in the second pipe 11 changes according to the evaporation temperature ET, and the range (Δ ET) of the fluctuation in the evaporation temperature ET is 5 ℃. The slope of the graph shown in fig. 8 is "0.8", and is a coefficient of the following equation 9. The reference density is set, for example, based on a condition that the refrigerant density in the second pipe 11 is maximized.

In embodiment 1, assuming that the actually used target evaporation temperature ETm is different from the evaporation temperature ET at the time of refrigerant sealing, the controller 20 calculates the density variation Δ ρ of the second pipe 11 by the following equation 9 in the example of fig. 8_PG. Further, the controller 20 calculates the density fluctuation Δ ρ_PGAnd the internal volume V of the second pipe 11_PGMultiplying the calculated value by the calculated value to calculate the insufficient sealing amount Δ Mr of the second pipe 11_PG(equation 10).

[ mathematical formula 9]

Δρ_PG0.8 × (Δ ET (5) + (ETm-ET)) … (equation 9)

[ mathematical formula 10]

ΔMr_PG＝Δρ_PG×V_PG… (math type 10)

[ insufficient sealing amount Δ Mr of use-side heat exchanger 7_eva]

The control device 20 controls the refrigerant flow rate of the refrigerant in the use side heat exchanger 7 based on the preset refrigerant density ρ_evaThe relationship between the evaporation temperature ET and the inlet temperature of the use side heat exchanger 7, the evaporation temperature ET, and the supercooling heat exchanger outlet temperature TH8, and the difference (density fluctuation Δ ρ) between the preset reference density and the density of the refrigerant (density at the time of sealing) is obtained_eva) The obtained difference is compared with the internal volume V of the use side heat exchanger 7_evaThe product is multiplied to determine the insufficient sealing amount Δ Mr in the use side heat exchanger 7_eva。

Refrigerant density ρ of use-side heat exchanger 7_evaThe relationship with the evaporation temperature ET is shown in fig. 9, for example. Fig. 9A is a graph showing the relationship between the average density in the use side heat exchanger 7 and the evaporation temperature in embodiment 1. Fig. 9B is a schematic diagram corresponding to the graph of fig. 9A and showing a relationship between the average density in the evaporator and the evaporation temperature. In the example of fig. 9A and 9B, the inlet state of the use side heat exchanger 7 is expressed by the condition of (1) the maximum to (4) the minimum. In addition, the refrigerant density ρ of the use-side heat exchanger 7_evaThe range (Δ ET) of the evaporation temperature ET fluctuation is 5 ℃ depending on the evaporation temperature ET and the inlet state (inlet temperature) of the use-side heat exchanger 7. However, in the case where the refrigeration apparatus according to embodiment 1 is not an inverter refrigerator but a constant-speed refrigerator, the low-pressure protection duty is used instead of the target evaporation temperature. The slope of the graph shown in fig. 9A is "3", and is a coefficient of the following equation 11.

In embodiment 1, assuming that the actually used target evaporation temperature ETm is different from the evaporation temperature ET at the time of refrigerant sealing, the controller 20 uses the following mathematical expressionEquation 11 calculates the density variation Δ ρ of the use side heat exchanger 7_eva. That is, the controller 20 calculates the density variation Δ ρ using equation 11_evaAnd the internal volume V of the use side heat exchanger 7_evaThe product is multiplied to calculate the insufficient sealing amount Δ Mr in the use side heat exchanger 7_eva(equation 12).

[ mathematical formula 11]

[ mathematical formula 12]

ΔMr_eva＝Δρ_eva×V_eva… (math type 12)

[ insufficient sealing amount DeltaMr of the liquid container 4_recG]

The control device 20 controls the refrigerant density ρ in the liquid container 4 based on the preset density_recGThe difference (density fluctuation [ Delta ] rho) between the preset reference density and the density (density at the time of sealing) of the refrigerant is obtained from the relationship with the condensation temperature and the condenser outlet temperature TH5_recG) The obtained difference is compared with the internal volume V of the liquid container 4_recGMultiplying the sum to determine the insufficient sealing amount Δ Mr of the liquid container 4_recG。

Refrigerant density ρ of the liquid container 4_recGThe relationship with the condensing temperature is shown in fig. 10, for example. Fig. 10 is a graph showing a relationship between the average density in the liquid container 4 and the condensation temperature in embodiment 1. As shown in fig. 10, the refrigerant density of the liquid container 4 changes according to the condensation temperature. The slope of the graph shown in fig. 10 is "3.3", and is a coefficient of the following equation 13. The reference density is set, for example, based on a reference condition that the refrigerant density in the liquid container 4 becomes maximum.

In the example of fig. 10, when the condensation temperature 60 ℃ at which the refrigerant density becomes maximum is set as the reference condition, the density of the liquid container 4 varies by Δ ρ_recGCan be obtained by the following equation 13. That is, the controller 20 calculates the density variation Δ ρ from the equation 13_recGAnd liquid container4 internal volume V_recGMultiplying the calculated value by the calculated value to calculate the insufficient sealing amount Δ Mr of the liquid container 4_recG(equation 14).

[ mathematical formula 13]

Δρ_recG3.3 × (60-GT) … (math figure 14)

[ mathematical formula 14]

ΔMr_recG＝Δρ_recG×V_recG… (math 14)

Here, although an example in which the insufficient sealed amount is calculated from the elements having a large amount of refrigerant fluctuation is shown, if the insufficient sealed amount is calculated from information on the elements such as the compressor 1, the accumulator 8, and the oil separator 2, or the pipes and the injection circuit connecting the elements, a more accurate amount can be calculated.

As described above, in the refrigeration apparatus according to embodiment 1, the control device 20 that determines whether or not the amount of refrigerant sealed in the refrigerant circuit is appropriate reports the content that urges the refrigerant to be sealed, the content that urges the refrigerant sealing speed to be decreased, or the content that urges the interruption of the refrigerant sealing during the additional sealing period, and calculates and reports the amount of insufficient sealing when the additional sealing is completed.

That is, the refrigeration apparatus according to embodiment 1 is configured such that: at the time of additional sealing after the initial sealing, the control device 20 urges the refrigerant sealing speed to decrease when the refrigerant sealing amount exceeds a certain amount. Therefore, according to the refrigeration apparatus of embodiment 1, since the refrigerant sealing in at different speeds can be continuously performed and the additional sealing can be completed at one time, it is not necessary to perform the additional sealing in several times and with a long time as in the conventional refrigeration apparatus, and the minimum necessary amount of refrigerant can be sealed before the insufficient sealing amount is calculated. Further, according to the refrigeration apparatus of embodiment 1, since the continuous operation of the compressor 1 is required for a predetermined time after the end of additional sealing, it is possible to prevent the occurrence of abnormal stop due to a small amount of refrigerant sealing. That is, in the continuous operation of the compressor 1 after step S114 in fig. 4, since the above-described steps S106 to S113 have already been performed, the minimum amount of refrigerant necessary for the refrigerant sealing is sealed in the refrigerant circuit, and therefore, it is possible to prevent the occurrence of the abnormal stop of the compressor 1 due to the excessively small sealed amount. Further, since the control device 20 calculates the average temperature efficiency ∈ a in a state where the temperature efficiency ∈ and the operating frequency of the compressor 1 are stable, it is possible to more accurately determine whether or not the refrigerant amount is appropriate.

In the conventional configuration, the insufficient amount of enclosure, which is an amount of refrigerant insufficient for a preset reference amount of refrigerant, is determined based on the density and the internal volume of the refrigerant in the heat source side heat exchanger 3, the first pipe 10, the second pipe 11, and the use side heat exchanger 7, in which the amount of refrigerant changes relatively greatly with temperature change. However, when the range of change in the density of the gas refrigerant is also taken into consideration, the amount of refrigerant changes greatly in the element such as the liquid container 4 having a relatively large volume, and it is necessary to take the amount of refrigerant change in the liquid container 4 into consideration as a condition for calculating the amount of refrigerant enclosed. In this regard, the refrigeration apparatus according to embodiment 1 is configured as follows: the expansion calculating means, that is, the control device 20 uses the specification information of the liquid container 4 when calculating the insufficient sealed amount. Therefore, the insufficient amount of refrigerant to be sealed can be calculated more accurately with respect to the desired reference refrigerant amount.

Further, the conventional refrigeration apparatus is configured to: if the conditions (undetectable condition, stability determination condition) set in advance are met, the determination of the refrigerant charge amount is forcibly terminated, and the subsequent determination is not performed. In this regard, according to the refrigeration apparatus of embodiment 1, when it is determined that the stability determination condition or the like is not satisfied, the control device 20 causes the notification unit 21 to alternately notify the contents and the error that urge the other method, so that the refrigerant enclosing operation can be completed. That is, the refrigerant sealing can be completed by one determination, and the determination of the amount of refrigerant sealing does not return to the starting point depending on the temperature condition or the like.

In addition, the refrigeration apparatus of patent document 1 has the following problems: only the display of the sealing amount or the sealing completion display is performed, and information related to the refrigerant sealing amount (information such as which sealing stage is currently performed and how much sealing is performed, and the insufficient sealing amount is displayed) cannot be grasped. In this regard, in the refrigeration apparatus according to embodiment 1, the control device 20 is configured to cause the notification unit 21 to notify the content urging the refrigerant sealing, the content urging the decrease in the refrigerant sealing speed, or the content urging the interruption of the refrigerant sealing, based on the magnitude relationship between the temperature efficiency ∈ and the determination threshold ∈ line1 or the interruption determination threshold ∈ line2, so that it is possible to appropriately grasp the information related to the refrigerant sealing amount, such as the refrigerant sealing amount up to the present time.

In addition, in the conventional configuration, the input of the field information such as the condenser, the evaporator, or the extension pipe length is required at the determination start time, but the following problems are present in the prior art: as the evaporator side information, the load equipment to be handled is selected only from the unit cooler and the showcase, and the case where the unit cooler and the showcase are mixed cannot be handled. In this regard, in the refrigeration apparatus according to embodiment 1, the plurality of use-side units 200 are configured to include at least the unit cooler and the showcase, and the control device 20 is configured to use, as the specification information of the use-side heat exchanger 7, information of the internal volume of the unit cooler, the internal volume of the showcase, or the internal volume in the case where the unit cooler and the showcase are mixed when the insufficient sealing amount is obtained, so that the refrigeration apparatus can also cope with the case where the unit cooler and the showcase are mixed.

[ embodiment 2]

Next, a refrigeration apparatus according to embodiment 2 will be described with reference to fig. 11. Fig. 11 is a schematic diagram showing an example of display on the notification unit 21 in embodiment 2, and specifically shows a 7-segment LED display during the refrigerant charge amount determination period. That is, the refrigeration apparatus according to embodiment 2 has the following features: by using the 7-segment LED as the notification unit 21, it is possible to notify each piece of information of the refrigerant-sealed amount determination period. The same reference numerals are used for the same components as those in embodiment 1, and the description thereof is omitted.

The control device 20 according to embodiment 2 also reports the temperature efficiency ∈ when the notification unit 21 notifies the content of urging the refrigerant sealing. Here, each display illustrated in fig. 11 is a content displayed without performing a specific display such as an initial sealed amount, an insufficient sealed amount, or an error code. As shown in fig. 11, by displaying "the current refrigerant sealing stage", "the low pressure", and "the value of the temperature efficiency ∈" in this order, the current refrigerant sealing state (what kind of refrigerant sealing state is) becomes clear. The controller 20 is configured to display the instantaneous value as a value of the temperature efficiency ∈. Therefore, for example, if the preset interruption determination threshold value epsilon line2 is known in steps S109 to S111 in fig. 4, the operator can determine to what extent the sealing speed is lowered and to what extent the sealing is stopped.

In the above description, the reporting method is described by taking a case where a 7-segment LED is applied as the reporting unit 21 as an example, but the present invention is not limited thereto, and the reporting unit 21 may be a liquid crystal display, for example. The notification unit 21 may perform any display such as a level display using a plurality of LED lamps or the like, or a display in which the emission color of LEDs is changed. The notification method of the notification unit 21 is not limited to display, and specific information may be notified by a buzzer sound, voice, or the like, for example.

In the refrigeration apparatus according to embodiment 2, the control device 20 is also configured to notify the content of urging the refrigerant sealing during the additional sealing period and calculate and notify the insufficient sealing amount when the additional sealing is completed, and therefore, the additional sealing after the initial sealing can be smoothly performed and the insufficient sealing amount can be accurately calculated, and therefore, a more appropriate amount of refrigerant can be sealed in a shorter time without taking much time. In addition, in the refrigeration apparatus according to embodiment 2, by using the notification unit 21 configured by 7-segment LEDs or the like to sequentially notify information such as "the current refrigerant sealing stage", "the low pressure", and "the value of the temperature efficiency ∈", the operator can clearly recognize the progress of the refrigerant sealing operation, the refrigerant sealing state, and the like, and thus, the operability can be improved. That is, according to the refrigeration apparatus of embodiment 2, since the information that can be notified can be made more detailed by the LED display or the like performed at the time of the refrigerant amount determination, the scope of the technique can be expanded, and the work level at the time of refrigerant containment can be easily grasped.

[ embodiment 3]

Next, an enclosing step of the refrigeration apparatus in embodiment 3 will be described with reference to fig. 4. Fig. 4 is a flowchart showing the enclosing step described in embodiment 1. The same reference numerals are used for the same components as those in embodiments 1 and 2, and the description thereof is omitted.

The control device 20 of embodiment 3 is configured to: after the initial sealing, the steps from the start of the operation of the compressor 1 to the completion of the additional sealing (step S105 to step S113 in fig. 4) are performed by another method, and after the continuous operation of the compressor 1 (step S114 in fig. 4), the sealing step is performed in the same manner as in embodiment 1.

Here, as the other method, for example, the same method as the other method of refrigerant sealing described in embodiment 1 can be used. That is, other methods are, for example: a method of confirming an LED lamp separately installed and sealing a refrigerant until the temperature efficiency ∈ becomes a threshold value or more and turning on the LED lamp; a method of sealing the refrigerant until the flash gas disappears while checking a window previously attached to the first pipe 10; or a method of sealing the refrigerant up to a predetermined liquid level while checking a window previously attached to the liquid container 4.

Therefore, the control device 20 according to embodiment 3 executes the notification for performing the refrigerant sealing by the method of the above example and the like without shifting to step S105 when step S104 is completed. When the operator who has finished the additional sealing performs the substrate operation or the like based on the notification and notifies that the content of the additional sealing is finished, the control device 20 proceeds to the sealing step after step S114.

The control device 20 of the refrigeration apparatus according to embodiment 3 is configured as follows: the sealing steps after the start of the operation of the compressor after the initial sealing, that is, the additional sealing steps, are performed by another method, and when the sealing by another method is finished, the insufficient sealing amount is calculated and reported. Therefore, since the refrigerant can be smoothly sealed by disregarding the undetectable condition and the stability determination condition in the additional sealing step, an appropriate amount of refrigerant can be smoothly sealed. That is, according to the refrigeration apparatus of embodiment 3, since the determination as to whether or not the undetectable condition and the stability determination condition are satisfied is not performed at the time of the refrigerant quantity determination, an appropriate amount of refrigerant can be sealed without becoming undetectable.

The above embodiments are preferable specific examples of the refrigeration apparatus, and the technical scope of the present invention is not limited to these embodiments, in particular, as long as the present invention is not limited to the description. For example, although fig. 1 to 3 illustrate a configuration in which the notification unit 21 is provided in the control device 20, the present invention is not limited thereto, and the notification unit 21 may be provided in a configuration different from that of the control device 20. Further, although the control device 20 has been described as an example of alternately notifying the contents of urging another method and an error when it is determined that the stability determination condition is not satisfied (S117/no in fig. 4), the present invention is not limited to this, and for example, the operator may select arbitrary notification information. Further, in fig. 11, an example is shown in which the control device 20 sequentially displays "the current refrigerant sealing stage", "the low pressure", and "the value of the temperature efficiency ∈" as the LED segments serving as the notification unit 21, but the present invention is not limited to this, and for example, the operator may select and switch arbitrary display information.

Description of reference numerals

1 compressor, 2 oil separator, 3 heat source side heat exchanger, 4 liquid container, 5 subcooling heat exchanger, 6 expansion valve, 7 use side heat exchanger, 8 accumulator, 10 first pipe (liquid pipe), 11 second pipe (gas pipe), 12 extension pipe, 13 electronic expansion valve, 14 double pipe subcooler, 15 first temperature sensor, 16 outside air temperature sensor, 18 second temperature sensor, 19 third temperature sensor, 20 control device, 21 notification part, 100A, 100B heat source side unit, 200 use side unit, 300A, 300B compression unit, ET evaporation temperature, ETm target evaporation temperature, TH5 condenser outlet temperature, TH6 outside air temperature, TH8 subcooling heat exchanger outlet temperature, V8 subcooling heat exchanger outlet temperature_PG、V_PL、V_cond、V_eva、V_recGInternal volume, Δ Mr less than the amount of enclosure, Δ ρ_PG、Δρ_PL、Δρ_cond、Δρ_eva、Δρ_recGDensity variation, ε temperature efficiency,. epsilon.A average temperature efficiency,. epsilon.line 1 decision threshold,. epsilon.line 2 interrupt decision threshold,. epsilon.line A average decision threshold,. eta.predetermined value,. rho_PG、ρ_PL、ρ_cond、ρ_eva、ρ_recGThe density of the refrigerant.

Claims

1. A refrigeration device, wherein the refrigeration device has:

a heat source side unit having a compressor, a heat source side heat exchanger, a liquid container, and a supercooling heat exchanger;

a usage-side unit having an expansion valve and a usage-side heat exchanger;

a refrigerant pipe that connects the heat source-side unit and the usage-side unit;

a control device that determines whether or not an amount of refrigerant sealed in a refrigerant circuit formed by the heat source-side unit, the usage-side unit, and the refrigerant piping is appropriate, based on temperature efficiency of the supercooling heat exchanger, which is a value obtained by dividing a degree of supercooling of the refrigerant at an outlet of the supercooling heat exchanger by a maximum temperature difference of the supercooling heat exchanger, which is a difference between a condenser outlet temperature and an outside air temperature; and

a notification unit that notifies information relating to a refrigerant sealing amount in the refrigerant circuit,

the control device makes the notification portion notify the content of urging the refrigerant sealing when the temperature efficiency is less than a preset determination threshold value for a predetermined time or more continuously when additional sealing for additionally sealing the refrigerant is performed during the operation of the compressor,

after the temperature efficiency is continuously above the determination threshold for a predetermined time or more,

the notification unit is configured to notify a content that urges a decrease in the refrigerant sealing speed when the temperature efficiency is less than or equal to an interruption determination threshold that is set larger than the determination threshold for a predetermined period of time, and to notify a content that urges a refrigerant sealing interruption when the temperature efficiency is greater than or equal to the interruption determination threshold for a predetermined period of time,

when the additional sealing is finished, a shortage sealing amount, which is an amount of shortage of the refrigerant with respect to a preset reference refrigerant amount, is obtained and reported by the reporting section.

2. The refrigeration device of claim 1,

the heat source side heat exchanger functions as a condenser for the refrigerant compressed by the compressor,

the usage-side heat exchanger functions as an evaporator of the refrigerant sent from the heat-source-side heat exchanger via the liquid container and the expansion valve.

3. The refrigeration apparatus according to claim 1 or 2,

the refrigerant pipe includes:

a first pipe having one end connected to the supercooling heat exchanger and the other end connected to the expansion valve; and

a second pipe having one end connected to the compressor and the other end connected to the use-side heat exchanger,

the control device obtains the insufficient sealing amount based on at least the density and the internal volume of the refrigerant in each of the heat source side heat exchanger, the first pipe, the second pipe, the use side heat exchanger, and the liquid container.

4. The refrigeration device of claim 3,

the control device calculates an initial sealing amount based on at least the density and the internal volume of the refrigerant in the first pipe and the usage-side heat exchanger, and causes the notification unit to notify the calculated initial sealing amount.

5. The refrigeration device of claim 3,

the utilization-side unit is provided in plurality,

a plurality of the utilization-side units include at least a unit cooler and a showcase,

when the insufficient sealing amount is obtained, the control device uses the internal volume of the unit cooler, the internal volume of the showcase, or the total internal volume of the unit cooler and the showcase in the case where both the unit cooler and the showcase are connected, as the internal volume of the use-side heat exchanger.

6. The refrigeration device of claim 3,

the internal volume of the utilization-side heat exchanger is divided into two or more modes in advance based on information on the evaporation temperature band of the utilization-side heat exchanger,

the control device uses the value of each mode as the internal volume of the use-side heat exchanger when determining the insufficient sealing amount.

7. The refrigeration device according to any one of claims 1, 2 and 4 to 6,

the control device also notifies the temperature efficiency when the notification portion notifies the content of urging the sealing of the refrigerant.