Refrigeration equipment

Abstract

To satisfy needs of users when it is detected that a refrigerant leaks from a freezer.SOLUTION: A controller (50) of a freezer (10) selectively performs a first operation and a second operation. The first operation is an operation for performing a leakage notification process when the refrigerant sensor (57) detects refrigerant. The second operation is an operation for performing a leakage notification process when the refrigerant sensor (57) detects refrigerant and a leakage condition is established. The leakage notification process is a process for notifying that a refrigerant leak has been determined from a refrigerant circuit (20). The leakage condition is a condition that indicates that a refrigerant has leaked from the refrigerant circuit (20) based on a state quantity that indicates the state of the refrigerant in the refrigerant circuit (20).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a refrigeration device.

Background Art

[0002] Patent Document 1 discloses a refrigeration device provided with a refrigerant circuit. The refrigerant circuit of the refrigeration device is filled with a flammable refrigerant such as R32 (HFC-32). The refrigeration device includes a sensor that detects leakage of the refrigerant from the refrigerant circuit to the air-conditioned space. When the sensor detects leakage of the refrigerant from the refrigerant circuit to the air-conditioned space, the refrigeration device performs a predetermined operation for safety measures.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The refrigeration device disclosed in Patent Document 1 performs one type of operation as an operation for safety measures. However, when leakage of the refrigerant from the refrigerant circuit to the air-conditioned space is detected, the operations for safety measures desired by the user or administrator of the refrigeration device are not necessarily limited to one. Therefore, the conventional refrigeration device may not be able to fully meet the demands of users and administrators.

[0005] An object of the present disclosure is to satisfy the demands of users and administrators when leakage of the refrigerant from the refrigerant circuit is detected in a refrigeration device that performs a predetermined operation when leakage of the refrigerant from the refrigerant circuit is detected.

Means for Solving the Problems

[0006] A first aspect of the present disclosure is a refrigeration device (10) that controls the temperature of a target space (100) and includes a refrigerant circuit (20) having a compressor (31) to perform a refrigeration cycle, comprising a refrigerant sensor (57) for detecting refrigerant leaked from the refrigerant circuit (20) into the target space (100), and a controller (50) that selectively performs a first operation and a second operation, wherein the first operation is an operation that, when the refrigerant sensor (57) detects refrigerant, determines that it has determined that refrigerant has leaked from the refrigerant circuit (20), and the second operation is an operation that, when the refrigerant sensor (57) detects refrigerant, determines whether a leak condition is met, and if the leak condition is met, performs the leak notification operation, wherein the leak condition is a condition that indicates that refrigerant has leaked from the refrigerant circuit (20) based on a state quantity indicating the state of refrigerant in the refrigerant circuit (20).

[0007] In the first embodiment, the controller (50) of the refrigeration system (10) selectively performs a first operation and a second operation. In the first operation, the controller (50) performs a leak alarm process when the refrigerant sensor (57) detects refrigerant. In the second operation, the controller (50) determines whether the leak condition is met when the refrigerant sensor (57) detects refrigerant, and performs a leak alarm process if the leak condition is met. The refrigerant sensor (57) may mistakenly detect gases other than refrigerant as refrigerant. In the second operation, the controller (50) performs a leak alarm process when the refrigerant sensor (57) detects refrigerant, the leak condition is met, and there is a high probability that refrigerant is actually leaking from the refrigerant circuit (20).

[0008] For example, the controller (50) performs whichever of the two actions, the first action or the second action, is specified by a human, such as an administrator. In the first embodiment, the controller (50) can select which action to perform when the refrigerant sensor (57) detects refrigerant from the first action or the second action. Therefore, compared to the case where the controller (50) can only perform one of the first or second actions, the refrigeration system (10) in this embodiment can perform an action in accordance with the requests of the user or administrator of the refrigeration system (10) when it detects a refrigerant leak from the refrigerant circuit (20).

[0009] A second aspect of this disclosure is that, in the first aspect, the controller (50) stops the compressor (31) when the refrigerant sensor (57) detects refrigerant during the first operation.

[0010] In the second embodiment, the controller (50), in the first operation, performs a leak alarm process and stops the compressor (31) when the refrigerant sensor (57) detects refrigerant.

[0011] A third aspect of the present disclosure is that, in the first or second aspect described above, the controller (50) stops the compressor (31) when the refrigerant sensor (57) detects refrigerant in the second operation, and determines whether the leakage condition is met while the compressor (31) is stopped.

[0012] In the third embodiment, the controller (50) determines whether the leakage condition is met while the compressor (31) is stopped during the second operation.

[0013] A fourth aspect of this disclosure is that, in any one of the first to third aspects described above, the leakage condition is that the pressure of the refrigerant in the refrigerant circuit (20), which is the state quantity, is lower than a predetermined value.

[0014] The controller (50) of the fourth embodiment uses the pressure of the refrigerant in the refrigerant circuit (20) as a state variable, and determines that a leakage condition has been met when the pressure of the refrigerant in the refrigerant circuit (20) is lower than a predetermined value.

[0015] A fifth aspect of this disclosure is that, in any one of the first to fourth aspects described above, the controller (50) selectively performs a third operation and a fourth operation, the third operation being an operation to automatically start the compressor (31) when the leakage condition is not met in the second operation, and the fourth operation being an operation to start the compressor (31) when a start instruction is input when the leakage condition is not met in the second operation.

[0016] In the fifth embodiment, the controller (50) of the refrigeration system (10) selectively performs the third and fourth operations. In this embodiment, the controller (50) performs either the third or fourth operation if the leakage condition is not met in the second operation.

[0017] For example, the controller (50) performs the action designated by a human, such as an administrator, from among the third and fourth actions. In the fifth embodiment, the controller (50) can select the action to perform from the third and fourth actions when the leakage condition is not met in the second action. As a result, the types of actions that the controller (50) can perform when a refrigerant leak from the refrigerant circuit (20) is detected increase, making it possible to meet the demands of users and administrators of the refrigeration system (10).

[0018] A sixth aspect of this disclosure is that, in any one of the first to fifth aspects described above, in the second operation, the controller (50) performs a misjudgment notification process to notify that it has incorrectly determined that refrigerant has leaked from the refrigerant circuit (20) when the leakage condition is not met.

[0019] The controller (50) of the sixth embodiment performs a false judgment notification process when the leakage condition is not met in the second operation. Therefore, it can notify the system when there is a high probability that refrigerant is not actually leaking from the refrigerant circuit (20).

[0020] A seventh aspect of this disclosure is that, in any one of the first to sixth aspects described above, the leakage notification process performed by the controller (50) is a process that causes the display unit (41) to display information indicating that it has determined that refrigerant has leaked from the refrigerant circuit (20).

[0021] In the seventh embodiment, when the controller (50) performs a leak notification process, information indicating that it has determined that refrigerant has leaked from the refrigerant circuit (20) is displayed on the display unit (41). The display unit (41) may be, for example, a display on the remote control of the refrigeration unit (10), or the display of a smartphone owned by the administrator of the refrigeration unit (10).

[0022] In the eighth aspect of the present disclosure, in any one of the first to sixth aspects, the leakage notification process performed by the controller (50) is a process of notifying, by sound or light, that it has been determined that the refrigerant has leaked from the refrigerant circuit (20).

[0023] In the eighth aspect, when the controller (50) performs the leakage notification process, for example, it is notified that it has been determined that the refrigerant has leaked from the refrigerant circuit (20) by generating a warning sound or lighting a warning lamp.

[0024] In the ninth aspect of the present disclosure, in any one of the first to eighth aspects, the controller (50) causes the display unit (41) to display a selection screen for inputting an instruction to select one of the first operation and the second operation, and performs the one selected on the selection screen among the first operation and the second operation.

[0025] In the ninth aspect, the controller (50) causes the display unit (41) to display a selection screen. The controller (50) performs the one selected on the selection screen among the first operation and the second operation. Note that the display unit (41) may be, for example, a display provided on a remote controller of the refrigeration device (10), or a display of a smartphone possessed by an administrator or the like of the refrigeration device (10).

[0026] In the tenth aspect of the present disclosure, in the third aspect, the controller (50) performs a process of causing the display unit (41) to display information indicating that the process related to the refrigerant leakage is being executed during the period when the controller determines whether the leakage condition is satisfied while the compressor (31) is stopped in the second operation.

[0027] In the tenth aspect, while the controller (50) determines whether the leakage condition is satisfied in the second operation, information indicating that the process related to the refrigerant leakage is being executed is displayed on the display unit (41).

[0028] An eleventh aspect of the present disclosure is the fifth aspect described above, in which the controller (50) displays a selection screen on the display unit for inputting an instruction to select one of the third operation and the fourth operation, and performs the one of the third operation and the fourth operation that is selected on the selection screen.

[0029] In the eleventh embodiment, the controller (50) displays a selection screen on the display unit (41). The controller (50) performs the one selected on the selection screen from the third operation and the fourth operation. The display unit (41) may be, for example, a display on the remote control of the refrigeration unit (10), or the display of a smartphone used by the administrator of the refrigeration unit (10). [Brief explanation of the drawing]

[0030] [Figure 1] Figure 1 is a piping diagram showing the configuration of the refrigeration system of Embodiment 1. [Figure 2] Figure 2 is a front view of the remote control provided in the refrigeration device of Embodiment 1. [Figure 3] Figure 3 is a block diagram showing the configuration of the controller included in the refrigeration system of Embodiment 1. [Figure 4] Figure 4 shows the selection screen displayed on the remote control's display. [Figure 5] Figure 5 shows the selection screen displayed on the remote control's display. [Figure 6] Figure 6 shows the selection screen displayed on the remote control's display unit. [Figure 7] Figure 7 is a flowchart showing the first operation performed by the controller of Embodiment 1. [Figure 8] Figure 8 shows the leakage notification screen displayed on the remote control's display unit. [Figure 9] Figure 9 is a flowchart showing the second operation performed by the controller of Embodiment 1. [Figure 10] Figure 10 shows the screen displayed on the remote control's display unit, with text indicating that the leak condition has been met. [Figure 11]Figure 11 shows the false detection notification screen displayed on the remote control's display unit. [Figure 12] Figure 12 is a piping diagram showing the configuration of the refrigeration system of Embodiment 2. [Modes for carrying out the invention]

[0031] Embodiment 1 Embodiment 1 will now be described. The refrigeration device (10) of this embodiment controls the temperature of the target space (100). The target space (100) may be a relatively small space such as a refrigerator or a display case, or it may be a relatively large space such as a refrigerated warehouse or a frozen warehouse.

[0032] - Refrigeration System Configuration - As shown in Figure 1, the refrigeration system (10) of this embodiment comprises one heat source unit (11), three user units (12a, 12b, 12c), a refrigerant sensor (57), a remote controller (hereinafter abbreviated as "remote control (40)"), and a controller (50). The number of user units (12a to 12c) is merely an example. In the refrigeration system (10), the one heat source unit (11) and the three user units (12a to 12c) are connected to each other via a liquid side connecting pipe (23) and a gas side connecting pipe (24) to form a refrigerant circuit (20).

[0033] <Heat source side unit> The heat source unit (11) is a so-called condensing unit and is installed outdoors. The heat source unit (11) is equipped with a heat source circuit (21) and a heat source fan (16). The heat source fan (16) supplies outdoor air to the heat source heat exchanger (32) of the heat source circuit (21), which will be described later.

[0034] <User-side unit> Each of the three user-side units (12a to 12c) is, for example, a unit cooler installed inside the target space (100). In the refrigeration device (10) of this embodiment, the three user-side units (12a to 12c) are installed in a single target space (100).

[0035] Each user-side unit (12a to 12c) is equipped with a user-side circuit (22a, 22b, 22c) and a user-side fan (17a, 17b, 17c). In each user-side unit (12a to 12c), the user-side fan (17a to 17c) supplies internal air from the target space (100) to the user-side heat exchanger (33a to 33c) of the user-side circuit (22a to 22c), which will be described later.

[0036] <Refrigerant Circuit> In the refrigeration system (10) of this embodiment, a refrigerant circuit (20) is formed by one heat source side circuit (21), three utilization side circuits (22a to 22c), a liquid side connecting pipe (23), and a gas side connecting pipe (24). The refrigerant circuit (20) is filled with, for example, R32 (HFC-32) as a refrigerant. R32 is a slightly flammable refrigerant. The refrigerant filled in the refrigerant circuit (20) may be a flammable refrigerant such as propane.

[0037] In the refrigerant circuit (20), the three user-side circuits (22a to 22c) are connected in parallel to each other. Specifically, the liquid side end of the heat source circuit (21) is connected to the liquid side end of each user-side circuit (22a to 22c) via a liquid side connecting pipe (23). The gas side end of the heat source circuit (21) is connected to the gas side end of each user-side circuit (22a to 22c) via a gas side connecting pipe (24).

[0038] The heat source side circuit (21) comprises a compressor (31) and a heat source side heat exchanger (32). In the heat source side circuit (21), the compressor (31) and the heat source side heat exchanger (32) are installed in series, starting from the gas side end and moving towards the liquid side end. The compressor (31) is a fully enclosed compressor equipped with an electric motor (31a). The heat source side heat exchanger (32) is a heat exchanger that exchanges heat between the refrigerant and the outside air.

[0039] A pressure sensor (56) is connected to the heat source circuit (21). The pressure sensor (56) is connected to the suction side of the compressor (31) in the heat source circuit (21). The pressure sensor (56) measures the pressure of the refrigerant in the refrigerant circuit (20).

[0040] The three user-side circuits (22a~22c) have the same configuration. Each user-side circuit (22a~22c) is equipped with a user-side heat exchanger (33a~33c), expansion valves (34a, 34b, 34c), and solenoid valves (35a, 35b, 35c). In each user-side circuit (22a~22c), the solenoid valves (35a~35c), expansion valves (34a~34c), and user-side heat exchanger (33a~33c) are arranged in series, in order from the liquid side end to the gas side end. Each solenoid valve (35a~35c) is an on / off valve. Each expansion valve (34a~34c) is a temperature-activated expansion valve with a temperature-sensing tube. The user-side heat exchanger (33a~33c) is a heat exchanger that exchanges heat between the refrigerant and the air inside the target space (100).

[0041] <Refrigerant sensor> The refrigerant sensor (57) is a sensor that detects gaseous refrigerant in the air. The refrigerant sensor (57) can be a semiconductor-type gas sensor or an NDIR (Non-Dispersive InfraRed) type gas sensor. When the concentration of refrigerant in the air exceeds a predetermined value, the refrigerant sensor (57) outputs a detection signal indicating that refrigerant has been detected.

[0042] In the refrigeration system (10) of this embodiment, the refrigerant sensor (57) is provided in one of the three user-side units (12a to 12c). In the user-side unit (12a), the refrigerant sensor (57) is provided in the passage of the internal air flowing into the user-side unit (12a) and detects the refrigerant contained in the internal air.

[0043] <Remote control> As shown in Figure 2, the remote control (40) comprises a display unit (41), a power button (42), and a number of operation buttons (43). The display unit (41) is a small liquid crystal display located in the center of the remote control (40). The remote control (40) has a display unit (41) for displaying information and is configured to communicate with the controller (50). The remote control (40) is installed in a room where a person is present (for example, the room of the manager of the refrigeration unit (10)).

[0044] <Controller> As shown in Figure 1, the controller (50) comprises a main controller (51) and a sub-controller (52). The main controller (51) and the sub-controller (52) can communicate with each other. The main controller (51) is installed in the heat source side unit (11). The sub-controller (52) is installed in the remote control (40). Note that the installation locations of the main controller (51) and sub-controller (52) shown here are merely examples.

[0045] As shown in Figure 3, the main controller (51) and the sub-controller (52) each include a microcomputer (51a, 52a) mounted on a control board and memory devices (51b, 52b) that store software for operating the microcomputers (51a, 52a). The memory devices (51b, 52b) are semiconductor memories.

[0046] The main controller (51) controls the operation of the refrigeration unit (10). The main controller (51) controls at least the compressor (31) and the heat source side fan (16). For example, the main controller (51) adjusts the rotational speed of the compressor (31) and the heat source side fan (16). The main controller (51) receives the measured value from the pressure sensor (56) and the detection signal from the refrigerant sensor (57) as input.

[0047] The sub-controller (52) performs processing to display various information on the display unit (41). Examples of information that the sub-controller (52) displays on the display unit (41) include information indicating the operating status of the refrigeration system (10), information prompting the manager of the refrigeration system (10) to input operating instructions, and information regarding refrigerant leakage from the refrigerant circuit (20). The sub-controller (52) also performs processing to transmit operating instructions entered by humans such as operators and managers to the main controller (51).

[0048] The controller (50) performs safety actions related to refrigerant leakage from the refrigerant circuit (20). These safety actions will be described later.

[0049] -Cooling operation of the refrigeration system- The refrigeration unit (10) performs a cooling operation. The cooling operation is an operation that adjusts the temperature of the air inside the target space (100).

[0050] When the compressor (31) is activated, the refrigerant circulates in the refrigerant circuit (20). In the refrigerant circuit (20), a refrigeration cycle is performed, with the heat source side heat exchanger (32) functioning as a condenser and each of the user side heat exchangers (33a to 33c) functioning as evaporators.

[0051] The refrigerant discharged from the compressor (31) condenses in the heat source side heat exchanger (32) by releasing heat into the outdoor air. The refrigerant flowing out of the heat source side heat exchanger (32) flows into the liquid side connecting pipe (23) and is distributed to each user side circuit (22a~22c). In each user side circuit (22a~22c), the incoming refrigerant is depressurized as it passes through the expansion valves (34a~34c) before flowing into the user side heat exchangers (33a~33c), where it absorbs heat from the indoor air and evaporates. The refrigerant flowing out of each user side heat exchanger (33a~33c) flows into the gas side connecting pipe (24), merges, and is then drawn into the compressor (31). The compressor (31) compresses the drawn-in refrigerant and discharges it.

[0052] In the heat source unit (11), the heat source fan (16) operates. The heat source unit (11) supplies the drawn-in outdoor air to the heat source heat exchanger (32) and blows the outdoor air that has passed through the heat source heat exchanger (32) out into the outdoor space. In each user-side unit (12a~12c), the user-side fans (17a~17c) operate. Each user-side unit (12a~12c) supplies the drawn-in indoor air to the user-side heat exchanger (33a~33c) and blows the indoor air that has passed through the user-side heat exchanger (33a~33c) out into the target space (100).

[0053] -Safety measures for the controller- As described above, the controller (50) performs safety actions. These safety actions are related to the leakage of refrigerant from the refrigerant circuit (20). In the safety actions, the controller (50) selectively performs the first and second actions described later. In the second action, the controller (50) selectively performs the automatic reset action and the manual reset action described later.

[0054] The sub-controller (52) of the controller (50) performs processing to display the selection screen shown in Figures 4 to 6 on the display unit (41) of the remote control (40). The selection screen is a screen for allowing a person, such as a manager or worker, to input instructions regarding the safety measures operation of the refrigeration system (10).

[0055] As shown in Figure 4, if an administrator or other human selects "Enable" for the "Leakage Alarm Function" on the selection screen, the controller (50) will perform safety measures. On the other hand, if an administrator or other human selects "Disable" for the "Leakage Alarm Function" on the selection screen, the controller (50) will not perform safety measures.

[0056] As shown in Figure 5, if a human, such as an administrator, selects "Yes" for the "Secondary Judgment Processing" on the selection screen, the controller (50) performs the second action. On the other hand, if a human, such as an administrator, selects "No" for the "Secondary Judgment Processing" on the selection screen, the controller (50) performs the first action.

[0057] As shown in Figure 6, if a human, such as an administrator, selects "Operate" for "When miscellaneous gas is detected" on the selection screen, the controller (50) performs an automatic reset operation. On the other hand, if a human, such as an administrator, selects "Stop" for "When miscellaneous gas is detected" on the selection screen, the controller (50) performs a manual reset operation.

[0058] Thus, the selection screen is a screen for allowing a human, such as an administrator or worker, to input instructions to select either the first or second operation, and to select either an automatic return operation or a manual return operation. The controller (50) performs the operation selected by the administrator or other human from the first or second operation. The controller (50) also performs the operation selected by the administrator or other human from the automatic return operation or the manual return operation.

[0059] -Controller's first operation- The first action performed by the controller (50) in the safety action will now be explained. The first action is to perform a leak notification process when the refrigerant sensor (57) detects refrigerant. The leak notification process is a process in which the controller (50) notifies that it has determined that refrigerant has leaked from the refrigerant circuit (20). Here, the first action will be explained with reference to the flowchart in Figure 7.

[0060] <Step ST11> In step ST11, the main controller (51) of the controller (50) monitors for the presence or absence of a detection signal from the refrigerant sensor (57). If no detection signal is received from the refrigerant sensor (57), the main controller (51) continues the process of step ST11. On the other hand, if a detection signal is received from the refrigerant sensor (57), the controller (50) performs the process of step ST12.

[0061] <Step ST12> In step ST12, the main controller (51) of the controller (50) stops the compressor (31). When the compressor (31) stops, the circulation of refrigerant in the refrigerant circuit (20) stops, and as a result, the refrigeration cycle stops. When the process of step ST12 is completed, the controller (50) performs the process of step ST13.

[0062] <Step ST13> In step ST13, the sub-controller (52) of the controller (50) performs a leak notification process. The leak notification process in this embodiment is a process that displays information indicating that the controller (50) has determined that refrigerant has leaked from the refrigerant circuit (20) on the display unit (41) of the remote control (40). In this leak notification process, the sub-controller (52) displays the leak notification screen shown in Figure 8 on the display unit (41) of the remote control (40) as information indicating that the controller (50) has determined that refrigerant has leaked from the refrigerant circuit (20).

[0063] -Controller's second operation- The second action performed by the controller (50) in the safety action operation will now be explained. The second action is to determine whether the leakage condition is met when the refrigerant sensor (57) detects refrigerant, and to perform a leakage notification process if the leakage condition is met. As described above, the leakage notification process is a process that notifies the controller (50) that it has determined that refrigerant has leaked from the refrigerant circuit (20). Here, the second action will be explained with reference to the flowchart in Figure 9.

[0064] <Step ST21> In step ST21, the main controller (51) of the controller (50) monitors for the presence or absence of a detection signal from the refrigerant sensor (57). If no detection signal is received from the refrigerant sensor (57), the main controller (51) continues the process of step ST21. On the other hand, if a detection signal is received from the refrigerant sensor (57), the controller (50) performs the process of step ST22.

[0065] <Step ST22> In step ST22, the main controller (51) of the controller (50) stops the compressor (31). When the compressor (31) stops, the circulation of refrigerant in the refrigerant circuit (20) stops, and as a result, the refrigeration cycle stops. When the process of step ST22 is completed, the controller (50) performs the process of step ST23.

[0066] <Step ST23> In the process of step ST23, the main controller (51) of the controller (50) determines whether the leakage condition is met.

[0067] The leakage condition is a condition indicating that refrigerant has leaked from the refrigerant circuit (20) based on a state quantity indicating the state of the refrigerant in the refrigerant circuit (20). In the leakage condition of the present embodiment, the state quantity indicating the state of the refrigerant in the refrigerant circuit (20) is the pressure of the refrigerant measured by the pressure sensor (56). The leakage condition of the present embodiment is the condition that the measured value P of the pressure sensor (56) is lower than a predetermined reference pressure Ps (P < Ps). The reference pressure Ps is, for example, a pressure slightly higher than the atmospheric pressure. The value of the reference pressure Ps is set to a value lower than the minimum value of "the pressure of the refrigerant in the state where no refrigerant has leaked from the refrigerant circuit (20)".

[0068] Here, the refrigerant sensor (57) may detect a gas other than the refrigerant. Therefore, even when there is no refrigerant in the indoor air in the target space (100), if the gas component that the refrigerant sensor (57) can detect is included in the indoor air, the refrigerant sensor (57) may erroneously output a detection signal. On the other hand, when the measured value P of the pressure sensor (56) is lower than the reference pressure Ps, it can be determined with almost certainty that refrigerant has leaked from the refrigerant circuit (20).

[0069] If the leakage condition is satisfied in the process of step ST23, the refrigerant sensor (57) outputs a detection signal, and the measured value P of the pressure sensor (56) is lower than the reference pressure Ps. Therefore, in this case, the main controller (51) determines that there is a high possibility that refrigerant has actually leaked from the refrigerant circuit (20), and performs the process of step ST24.

[0070] On the other hand, if the leakage condition is not satisfied in the process of step ST23, the refrigerant sensor (57) outputs a detection signal, but the measured value P of the pressure sensor (56) is not less than the reference pressure Ps. Therefore, in this case, the main controller (51) determines that the possibility that refrigerant has actually leaked from the refrigerant circuit (20) is low, and performs the process of step ST25.

[0071] In step ST23, the sub-controller (52) of the controller (50) performs processing to display information on the display unit (41) of the remote control (40) indicating that it is determining whether the leakage condition is met. Specifically, the sub-controller (52) displays the words "Refrigerant Leakage Judgment in Progress" shown in Figure 10 on the display unit (41) of the remote control (40) as information indicating that it is determining whether the leakage condition is met.

[0072] <Step ST24> In step ST24, the sub-controller (52) of the controller (50) performs a leak notification process. The leak notification process in this embodiment is a process that displays information indicating that the controller (50) has determined that refrigerant has leaked from the refrigerant circuit (20) on the display unit (41) of the remote control (40). In this leak notification process, the sub-controller (52) displays the leak notification screen shown in Figure 8 on the display unit (41) of the remote control (40) as information indicating that the controller (50) has determined that refrigerant has leaked from the refrigerant circuit (20).

[0073] <Step ST25> In step ST25, the sub-controller (52) of the controller (50) performs a false detection notification process. The false detection notification process in this embodiment is a process that displays information on the display unit (41) of the remote control (40) indicating that "the refrigerant sensor (57) has incorrectly determined that refrigerant has leaked from the refrigerant circuit (20)." In this false detection notification process, the sub-controller (52) displays the false detection notification screen shown in Figure 11 on the display unit (41) of the remote control (40) as "information indicating that the refrigerant sensor (57) has incorrectly determined that refrigerant has leaked from the refrigerant circuit (20)." More specifically, the information displayed on this false detection notification screen is "information indicating that the controller (50) has determined that the refrigerant sensor (57) has incorrectly detected a gas other than refrigerant as refrigerant."

[0074] By displaying this false detection notification screen on the display unit (41) of the remote control (40), it is possible to notify people such as the manager or operator of the refrigeration system (10) that the compressor (31) has stopped due to the refrigerant sensor (57) mistakenly detecting a refrigerant leak.

[0075] <Step ST26> In the process of step ST26, the main controller (51) of the controller (50) determines whether an automatic return operation or a manual return operation has been selected by a human, such as an administrator.

[0076] The automatic recovery operation is the third operation. Specifically, the automatic recovery operation is "an operation that automatically starts the compressor (31) when the leakage condition is not met in the second operation." If the automatic recovery operation is selected by a human such as an administrator, the main controller (51) performs the process in step ST27.

[0077] The manual reset operation is the fourth operation. Specifically, the manual reset operation is "an operation in which the compressor (31) is started when a start command is input if the leakage condition was not met in the second operation." If the manual reset operation is selected by a person such as an administrator, the main controller (51) performs the process of step ST28.

[0078] <Step ST27> In step ST27, the main controller (51) of the controller (50) starts the compressor (31). When the compressor (31) starts, the refrigerant circulates in the refrigerant circuit (20), and the refrigeration cycle is performed. Therefore, when the main controller (51) performs the process in step ST27, the cooling operation of the refrigeration system (10), which was stopped by the process in step ST22, is restarted, and the air inside each user unit (12a to 12c) is cooled.

[0079] <Step ST28> In step ST28, the main controller (51) of the control unit (50) determines whether or not a start command has been entered by a person such as an administrator. The start command is an instruction to start the compressor (31). The start command is entered by a person such as an administrator by operating the operation button (43) of the remote control (40).

[0080] If a start command is input, the main controller (51) performs the process in step ST27 and starts the compressor (31). On the other hand, if no start command is input, the main controller (51) keeps the compressor (31) in a stopped state.

[0081] -Features of Embodiment 1 (1)- In the refrigeration system (10) of this embodiment, the controller (50) selectively performs a first operation and a second operation. In the first operation, when the refrigerant sensor (57) detects refrigerant, the controller (50) immediately performs leak notification processing. On the other hand, in the second operation, when the refrigerant sensor (57) detects refrigerant, the controller (50) determines whether the leak condition is met, and if the leak condition is met, it performs leak notification processing.

[0082] The refrigerant sensor (57) may mistakenly detect gases other than refrigerant as refrigerant. Therefore, even if the air inside the target space (100) does not contain refrigerant, if the air contains gas components that the refrigerant sensor (57) can detect, the refrigerant sensor (57) may mistakenly output a detection signal. Accordingly, in the second operation, the controller (50) performs a leak notification process if the refrigerant sensor (57) detects refrigerant, the leak condition is met, and there is a high probability that refrigerant is actually leaking from the refrigerant circuit (20).

[0083] In the refrigeration system (10) of this embodiment, the controller (50) performs whichever of the two operations is specified by a person such as an administrator. For example, if the administrator of the refrigeration system (10) wants to take measures such as stopping the refrigeration system (10) if there is even a slight possibility that refrigerant is leaking from the refrigerant circuit (20), the administrator can have the controller (50) perform the first operation. Alternatively, if the administrator of the refrigeration system (10) wants to keep the refrigeration system (10) running until it can be determined with almost certainty that refrigerant is leaking from the refrigerant circuit (20), the administrator can have the controller (50) perform the second operation.

[0084] Thus, in the refrigeration system (10) of this embodiment, a human can select from a first action and a second action for the controller (50) to perform when the refrigerant sensor (57) detects refrigerant. Therefore, compared to the case where the controller (50) can only perform one of the first or second actions, the refrigeration system (10) of this embodiment can perform actions according to the requests of the user or administrator of the refrigeration system (10) when it detects a refrigerant leak from the refrigerant circuit (20).

[0085] -Features of Embodiment 1 (2)- In this embodiment, the controller (50) stops the compressor (31) in the first operation when the refrigerant sensor (57) detects refrigerant. In the second operation, the controller (50) stops the compressor (31) and determines whether the leakage condition is met while the compressor (31) is stopped.

[0086] As described above, the controller (50) of this embodiment always stops the compressor (31) when the refrigerant sensor (57) detects refrigerant. Therefore, the compressor (31) can be stopped even if there is only a slight possibility that refrigerant is leaking from the refrigerant circuit (20), and as a result, the risk caused by refrigerant leakage from the refrigerant circuit (20) can be reduced.

[0087] -Features of Embodiment 1 (3)- The leakage condition for the controller (50) of the present embodiment to determine success or failure in the second operation is the condition that the measured value P of the pressure sensor (56) is lower than a predetermined reference pressure Ps (P < Ps). The value of the reference pressure Ps is set to a value lower than the minimum value of "the pressure of the refrigerant in a state where no refrigerant is leaking from the refrigerant circuit (20)".

[0088] As described above, the refrigerant sensor (57) may detect gases other than the refrigerant. On the other hand, when the measured value P of the pressure sensor (56) is lower than the reference pressure Ps, it can be determined that the refrigerant is almost certainly leaking from the refrigerant circuit (20). The controller (50) of the present embodiment performs a leakage notification process in the second operation when the refrigerant sensor (57) detects the refrigerant and the leakage condition is satisfied. Therefore, in the second operation, the controller (50) of the present embodiment can notify the administrator or the like of the refrigeration device (10) that the controller (50) has determined that the refrigerant is leaking from the refrigerant circuit (20) when it is almost certain that the refrigerant is leaking from the refrigerant circuit (20).

[0089] -Feature (4) of Embodiment 1- In the refrigeration device (10) of the present embodiment, when the leakage condition is not satisfied in the second operation, the controller (50) selectively performs an automatic return operation, which is the third operation, and a manual return operation, which is the fourth operation. In the automatic return operation, when the leakage condition was not satisfied in the second operation, the controller (50) automatically starts the compressor (31). On the other hand, in the manual return operation, when the leakage condition was not satisfied in the second operation, the controller (50) starts the compressor (31) when a start instruction is input by a person such as an administrator.

[0090] In the refrigeration system (10) of this embodiment, the controller (50) performs either an automatic reset operation or a manual reset operation, whichever is specified by a human, such as an administrator. For example, if the administrator of the refrigeration system (10) wants to immediately restart the cooling operation of the refrigeration system (10) if there is almost no possibility of refrigerant leakage from the refrigerant circuit (20), the administrator can have the controller (50) perform an automatic reset operation. Alternatively, if the administrator of the refrigeration system (10) wants to have a human check the status of the refrigeration system before restarting the cooling operation of the refrigeration system (10), even if there is almost no possibility of refrigerant leakage from the refrigerant circuit (20), the administrator can have the controller (50) perform a manual reset operation.

[0091] Thus, in the refrigeration system (10) of this embodiment, a human can select between an automatic reset operation and a manual reset operation when the leakage condition is not met in the second operation. Therefore, compared to the case where the controller (50) can only perform either an automatic reset operation or a manual reset operation, the refrigeration system (10) of this embodiment can perform an operation in accordance with the requests of the user or administrator of the refrigeration system (10) when the leakage condition is not met in the second operation.

[0092] -Features of Embodiment 1 (5)- In the refrigeration system (10) of this embodiment, the controller (50) performs a process to display a leak notification screen (see Figure 8) on the display unit (41) of the remote control (40) as a leak notification process. Therefore, it is possible to reliably inform a person such as the manager of the refrigeration system (10) that there is a possibility of refrigerant leaking from the refrigerant circuit (20).

[0093] -Features of Embodiment 1 (6)- In the second operation of the controller (50), if the refrigerant sensor (57) outputs a detection signal but the leakage condition is not met, it can be determined that the refrigerant sensor (57) has mistakenly detected a gas other than refrigerant as refrigerant, and that there is a high possibility that refrigerant is not actually leaking from the refrigerant circuit (20). Therefore, in this embodiment, the controller (50) performs a misjudgment notification process when the leakage condition is not met in the second operation.

[0094] Therefore, in this embodiment, if the refrigerant sensor (57) mistakenly detects a gas other than refrigerant as refrigerant, and there is a high probability that refrigerant is not actually leaking from the refrigerant circuit (20), this fact can be notified to a person such as the manager of the refrigeration system (10).

[0095] -Features of Embodiment 1 (7)- In the refrigeration system (10) of this embodiment, the controller (50) determines whether the leak condition is met while the compressor (31) is stopped during the second operation. Furthermore, while the controller (50) is determining whether the leak condition is met, it displays information indicating that the leak condition is being determined (specifically, the words "Refrigerant Leak Judgment in Progress" as shown in Figure 10) on the display unit (41) of the remote control (40). This allows the administrator of the refrigeration system (10) to be informed that the refrigeration system (10) is in a state where the compressor (31) has been stopped and the leak condition is being determined.

[0096] -Variation 1 of Embodiment 1- In the refrigeration system (10) of this embodiment, the refrigerant sensor (57) may be installed outside the user-side units (12a to 12c) in the target space (100). The specific gravity of R32 is greater than that of air. Therefore, if the refrigerant filling the refrigerant circuit (20) is R32, the refrigerant sensor (57) may be installed near the floor surface of the target space (100).

[0097] -Modification 2 of Embodiment 1- In the refrigeration system (10) of this embodiment, each of the three user-side units (12a to 12c) may be provided with one refrigerant sensor (57).

[0098] In this modified example, the controller (50) stops the compressor (31) by performing step ST12 when it receives a detection signal from at least one of the refrigerant sensors (57) provided in each user unit (12a to 12c) during the processing of step ST11 of the first operation (see Figure 7). Furthermore, in this modified example, the controller (50) stops the compressor (31) by performing step ST22 when it receives a detection signal from at least one of the refrigerant sensors (57) provided in each user unit (12a to 12c) during the processing of step ST21 of the second operation (see Figure 9).

[0099] In this modified example, the controller (50) adds information to the leak notification screen (see Figure 8) displayed on the display unit (41) of the remote control (40) by the processing of step ST13 or step ST24, to identify the user-side unit (12a~12c) equipped with the refrigerant sensor (57) that output the detection signal. An example of this information is the identification number individually assigned to each user-side unit (12a~12c).

[0100] Embodiment 2 Embodiment 2 will now be described. Here, the differences between the refrigeration device (10) of this embodiment and the refrigeration device (10) of Embodiment 1 will be explained.

[0101] As shown in Figure 12, the refrigeration system (10) of this embodiment comprises one heat source unit (11) and one user unit (12). In the refrigeration system (10) of this embodiment, one heat source unit (11) and one user unit (12) are connected via a liquid side connecting pipe (23) and a gas side connecting pipe (24) to form a refrigerant circuit (20). Furthermore, the refrigeration system (10) of this embodiment, like the refrigeration system (10) of Embodiment 1, comprises one refrigerant sensor (57), one remote control (40), and one controller (50).

[0102] In this embodiment, three refrigeration units (10) are provided for one target space (100). Each of the user-side units (12) of the three refrigeration units (10) is provided for one target space (100).

[0103] In the refrigerant circuit (20) of the refrigeration system (10) of this embodiment, the expansion valve (34) is provided in the heat source side circuit (21). In the heat source side circuit (21), the expansion valve (34) is provided between the liquid side end of the heat source side circuit (21) and the heat source side heat exchanger (32). The expansion valve (34) in this embodiment is a so-called electronic expansion valve. In the refrigeration system (10) of this embodiment, the controller (50) adjusts the opening degree of the expansion valve (34).

[0104] In the refrigeration system (10) of this embodiment, the controller (50) performs the same operation as the controller (50) of Embodiment 1. Specifically, the controller (50) of this embodiment receives the detection signal from the refrigerant sensor (57) and the measured value from the pressure sensor (56), and performs the first operation or the second operation selected by a human, such as an administrator. Furthermore, if the leakage condition is not met in the second operation, the controller (50) of this embodiment performs the automatic reset operation or the manual reset operation selected by a human, such as an administrator.

[0105] Other embodiments The following modifications may be applied to the refrigeration device (10) of the above embodiment. These modifications may be combined or substituted as appropriate, as long as they do not impair the function of the refrigeration device (10).

[0106] -First variation- In the refrigeration system (10) of Embodiments 1 and 2, the leak notification process performed by the controller (50) is not limited to the process of displaying a leak notification screen (see Figure 8) on the display unit (41) of the remote control (40). The leak notification process performed by the controller (50) may also be a process of notifying by sound or light that the controller (50) has determined that refrigerant has leaked from the refrigerant circuit (20).

[0107] An example of leakage notification processing using sound is the process of emitting a warning sound or warning message from a speaker provided on the remote control (40). The controller (50) may also perform leakage notification processing by emitting a warning sound or warning message from a speaker provided outside the refrigeration unit (10) or from the speaker of a smartphone held by the administrator of the refrigeration unit (10).

[0108] An example of a leak detection process using sound is the process of turning on or flashing a warning lamp. The warning lamp may be provided on the remote control (40) of the refrigeration unit (10), or it may be provided on the outside of the refrigeration unit (10).

[0109] -Second variation- In the refrigeration system (10) of Embodiments 1 and 2, the target on which the leakage notification screen (see Figure 8) is displayed by the leakage notification processing performed by the controller (50) is not limited to the display unit (41) of the remote control (40). The controller (50) may also perform the process of displaying the leakage notification screen on a display unit provided outside the refrigeration system (10) as part of the leakage notification processing. An example of a display unit provided outside the refrigeration system (10) is the display of a smartphone held by the administrator of the refrigeration system (10), etc.

[0110] -Third variation- In the refrigeration system (10) of Embodiments 1 and 2, the main controller (51) may be located in a place other than the heat source side unit (11). For example, the main controller (51) may be installed in a control box separate from the heat source side unit (11) and the user side units (12a to 12c).

[0111] -Fourth variation- In the refrigeration apparatus (10) of Embodiments 1 and 2, the controller (50) may be a single unit having the functions of both a main controller (51) and a sub-controller (52). This single unit controller (50) may be provided, for example, in the heat source side unit (11), or it may be installed in a separate control box from the heat source side unit (11) and the user side units (12a to 12c).

[0112] -Fifth variation- The refrigeration devices (10) of Embodiments 1 and 2 may be used as air conditioning devices to conditioned the air in rooms where people are present. In this case, it is desirable that the refrigeration device (10) is switchable between a cooling operation in which the heat source side heat exchanger (32) functions as a condenser and the user side heat exchangers (33a to 33c) function as evaporators, and a heating operation in which the user side heat exchangers (33a to 33c) function as a condenser and the heat source side heat exchanger (32) functions as an evaporator.

[0113] While embodiments and modifications have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, elements of the embodiments, modifications, and other embodiments described above may be combined or substituted as appropriate. In addition, the designations "first," "second," "third," etc. in the specification and claims are used to distinguish the phrases to which these designations are given, and do not limit the number or order of such phrases. [Industrial applicability]

[0114] As explained above, this disclosure is useful for refrigeration equipment. [Explanation of symbols]

[0115] 10 Refrigeration equipment 20 Refrigerant Circuit 31 Compressor 41 Display section 50 Controllers 57 Refrigerant Sensor 100 Target space

Claims

1. A refrigeration device (10) that has a compressor (31) and a refrigerant circuit (20) that performs a refrigeration cycle, and controls the temperature of a target space (100), A refrigerant sensor (57) detects the refrigerant leaking from the refrigerant circuit (20) into the target space (100), The system includes a controller (50) that selectively performs a first operation and a second operation, The first operation described above is a leak notification operation in which, when the refrigerant sensor (57) detects refrigerant, it determines that refrigerant has leaked from the refrigerant circuit (20), and notifies the system. The second operation described above is an operation in which, when the refrigerant sensor (57) detects refrigerant, it determines whether the leakage condition is met, and if the leakage condition is met, it performs the leakage notification process described above. The above leakage conditions are conditions that indicate refrigerant has leaked from the refrigerant circuit (20) based on a state quantity that indicates the state of the refrigerant in the refrigerant circuit (20). The controller (50) displays a selection screen on the display unit (41) for inputting an instruction to select one of the first operation or the second operation, and then performs the operation selected on the selection screen from the first operation or the second operation. Refrigeration equipment.

2. In the first operation described above, the controller (50) stops the compressor (31) when the refrigerant sensor (57) detects refrigerant. The refrigeration apparatus according to claim 1.

3. In the second operation described above, the controller (50) stops the compressor (31) when the refrigerant sensor (57) detects refrigerant, and determines whether the leakage condition is met while the compressor (31) is stopped. The refrigeration apparatus according to claim 1.

4. The above leakage condition is that the pressure of the refrigerant in the refrigerant circuit (20), which is the state quantity mentioned above, is lower than a predetermined value. A refrigeration apparatus according to any one of claims 1 to 3.

5. The above controller (50) selectively performs the third and fourth operations. The third operation described above is an operation to automatically start the compressor (31) when the leakage condition described above is not met in the second operation described above. The fourth operation described above is an operation in which the compressor (31) is started when a start command is input, if the above leakage condition was not met in the second operation described above. A refrigeration apparatus according to any one of claims 1 to 3.

6. In the second operation described above, the controller (50) performs a misjudgment notification process to notify that it has incorrectly determined that refrigerant has leaked from the refrigerant circuit (20) when the above leakage condition is not met. A refrigeration apparatus according to any one of claims 1 to 3.

7. The leakage notification process performed by the controller (50) is a process that displays information on the display unit (41) indicating that it has determined that refrigerant has leaked from the refrigerant circuit (20). A refrigeration apparatus according to any one of claims 1 to 3.

8. The leakage notification process performed by the controller (50) is a process that notifies the controller by sound or light when it determines that refrigerant has leaked from the refrigerant circuit (20). A refrigeration apparatus according to any one of claims 1 to 3.

9. In the second operation, the controller (50) performs a process to display information on the display unit (41) indicating that processing related to refrigerant leakage is being performed while the compressor (31) is stopped and the success or failure of the leakage condition is being determined. The refrigeration apparatus according to claim 3.

10. The controller (50) displays a selection screen on the display unit (41) for inputting an instruction to select one of the third operation or the fourth operation, and then performs the operation selected on the selection screen from the third operation or the fourth operation. The refrigeration apparatus according to claim 5.

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