Cylinder pressure adjustment device

Abstract

A cylinder pressure adjustment device (4) adjusts the pressure inside a refrigerant recovery cylinder (3) when refrigerant from a refrigeration cycle device (100) is recovered to the refrigerant recovery cylinder (3). The cylinder pressure adjustment device (4) comprises a refrigerant path (40) that is connected between the refrigeration cycle device (100) and the refrigerant recovery cylinder (3), an electromagnetic valve (41) that is provided to the refrigerant path (40), a pressure sensor (42) and a temperature sensor (44) that are provided to the portion of the refrigerant path (40) that goes from the electromagnetic valve (41) to the refrigerant recovery cylinder (3), and a control device (43) that controls the electromagnetic valve (41) in accordance with the output of the pressure sensor (42), the temperature sensor (44), and a liquid level sensor (33).

Description

Cylinder pressure regulator

[0001] The present invention relates to a cylinder pressure regulating device.

[0002] As a prior art technique, Japanese Patent Application Laid-Open Publication No. 2020-180746 (Patent Document 1) discloses a refrigerant recovery system that aims to improve refrigerant recovery efficiency. This refrigerant recovery system is configured to charge a refrigerant recovery cylinder with refrigerant from an air conditioner via a recovery device. The cooling device includes a tank that stores water, a water supply pump that pressurizes the water in the tank, a spray nozzle that sprays the pressurized water, and a blower fan. The blower fan blows air containing water sprayed by the spray nozzle toward the refrigerant recovery cylinder. The sent water-containing air cools the refrigerant recovery cylinder.

[0003] Japanese Patent Application Laid-Open No. 2020-180746

[0004] Generally, refrigerant recovery using a recovery device such as that described in JP 2020-180746 A (Patent Document 1) requires a significant amount of time. For example, large refrigeration equipment such as commercial air conditioners requires a large amount of refrigerant, which results in a problem of time-consuming refrigerant recovery. The speed of refrigerant recovery is determined by the volume of the compressor installed in the recovery device. Recovery devices are limited in that the compressor weight cannot be increased due to the burden of portability.

[0005] In contrast, in the recovery target unit, such as an air conditioner, if the compressor is operational, the refrigerant can be recovered more quickly by operating the compressor of the recovery target unit. However, since the recovery target unit cannot grasp the condition of the recovery cylinder, there is a risk that the cylinder may become over-pressurized or the refrigerant may overflow, resulting in an inappropriate condition.

[0006] The present disclosure is intended to solve such problems, and its purpose is to provide a cylinder pressure regulating device that can shorten the time required to recover refrigerant while avoiding an inappropriate state of the cylinder.

[0007] One aspect of the present disclosure relates to a cylinder pressure regulating device for regulating the pressure in a refrigerant recovery cylinder when recovering refrigerant from a refrigeration cycle device in the refrigeration cycle device. The cylinder pressure regulating device includes a refrigerant path connected between the refrigeration cycle device and the refrigerant recovery cylinder, a solenoid valve provided in the refrigerant path, a pressure sensor and a temperature sensor provided in the refrigerant path from the solenoid valve to the refrigerant recovery cylinder, and a control device that controls the solenoid valve in response to outputs of the pressure sensor, the temperature sensor, and a liquid level sensor that monitors the liquid level in the refrigerant recovery cylinder.

[0008] According to the present disclosure, refrigerant can be recovered while monitoring the state of the cylinder, thereby making it possible to reduce the time required to recover refrigerant while avoiding an inappropriate state of the cylinder.

[0009] 1 is a diagram showing the connection relationship of a cylinder pressure regulating device. FIG. 1 is a diagram showing the configuration of a refrigeration cycle apparatus to which a cylinder pressure regulating device is connected in embodiment 1. FIG. 2 is a flowchart for explaining the control of an alarm device and a solenoid valve executed in embodiment 1. FIG. 3 is a diagram showing the configuration of a refrigeration cycle apparatus to which a cylinder pressure regulating device is connected in embodiment 2. FIG. 4 is a flowchart for explaining the control of an alarm device and a solenoid valve executed in embodiment 2. FIG. 4 is a diagram showing the configuration of a refrigeration cycle apparatus to which a cylinder pressure regulating device is connected in embodiment 3. FIG. 5 is a flowchart for explaining the control of an alarm device and a solenoid valve executed in embodiment 3. FIG. 6 is a ph diagram showing the state of a refrigeration cycle apparatus at the beginning of refrigerant recovery. FIG. 7 is a ph diagram showing the state of a refrigeration cycle apparatus at the middle stage of refrigerant recovery. FIG. 8 is a ph diagram showing the state of a refrigeration cycle apparatus at the end of refrigerant recovery. FIG. 9 is a diagram showing the configuration of a refrigeration cycle apparatus to which a cylinder pressure regulating device is connected in embodiment 4. FIG. 10 is a flowchart for explaining the control of an alarm device, a solenoid valve, and a pressure reducing device executed in embodiment 4. FIG. 11 is a diagram showing the configuration of a refrigeration cycle apparatus to which a cylinder pressure regulating device is connected in embodiment 5. FIG. 12 is a flowchart for explaining the control of an alarm device, a solenoid valve, and a pressure reducing device executed in embodiment 5.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Below, embodiments including multiple modifications will be described, but it was originally intended that the configurations described in each embodiment be combined as appropriate. Note that identical or corresponding parts in the drawings will be designated by the same reference numerals, and their description will not be repeated.

[0011] 1 is a diagram showing the connections of a cylinder pressure regulating device 4. The cylinder pressure regulating device 4 is connected between an outdoor unit 2 of a refrigeration cycle device and a refrigerant recovery cylinder 3.

[0012] When a refrigeration cycle device is disposed of, relocated, etc., it is necessary to recover the refrigerant. In the refrigeration cycle device, high-temperature, high-pressure gas refrigerant compressed by compressor 11 is condensed in condenser 12 to become liquid refrigerant, and the liquid refrigerant is reduced in pressure by expansion valve 15 and evaporated in evaporator 16 to become gas refrigerant and returned to the compressor. An operator recovering the refrigerant starts compressor 11 of the refrigeration cycle device, and sends the refrigerant condensed in condenser 12 to refrigerant recovery cylinder 3 via cylinder pressure adjustment device 4.

[0013] During refrigerant recovery, the control device 43 of the cylinder pressure regulating device 4 monitors the pressure, temperature, and liquid level of the refrigerant flowing into the refrigerant recovery cylinder using the pressure sensor 42, temperature sensor 44, and liquid level sensor 33. If the pressure, temperature, or liquid level of the refrigerant recovery cylinder 3 becomes abnormal, the control device 43 of the cylinder pressure regulating device 4 closes the solenoid valve 41 and stops refrigerant recovery.

[0014] FIG. 2 is a diagram showing the configuration of a refrigeration cycle device to which a cylinder pressure regulating device is connected in the first embodiment.

[0015] The device from which the refrigerant is recovered is, for example, a refrigeration cycle device 100 such as an air conditioner. The refrigeration cycle device 100 includes an indoor unit 1, an outdoor unit 2, and extension pipes 14 and 17 connecting these.

[0016] The refrigeration cycle device includes a compressor 11, an outdoor heat exchanger (condenser 12), an expansion valve 15, an indoor heat exchanger (evaporator 16), and service valves 13 and 18. The service valve is also called a valve with a service port, and is provided with a service port for charging refrigerant into a refrigerant circulation path C1.

[0017] 2, the expansion valve 15 and the indoor heat exchanger (evaporator 16) are arranged in the indoor unit 1. The compressor 11, the outdoor heat exchanger (condenser 12), and the service valves 13 and 18 are arranged in the outdoor unit 2.

[0018] The refrigeration cycle apparatus 100 includes a refrigerant circulation path C1. In the refrigerant circulation path C1, the refrigerant discharged from the discharge port of the compressor 11 flows in the order of an outdoor heat exchanger (condenser 12), a service valve 13, an extension pipe 14, an expansion valve 15, an indoor heat exchanger (evaporator 16), an extension pipe 17, and a service valve 18, and then returns to the suction port of the compressor 11.

[0019] The refrigerant recovery cylinder 3 is a container that recovers the refrigerant filled in the refrigeration cycle apparatus 100. The refrigerant recovery cylinder 3 includes a liquid port 32, a gas port 31, and a liquid level sensor 33. The liquid port 32 is an inlet / outlet for liquid refrigerant. The gas port 31 is an inlet / outlet for gas refrigerant. The liquid level sensor 33 detects the liquid level of the liquid refrigerant stored in the refrigerant recovery cylinder 3, and may be, for example, a float switch that indicates when the liquid level has reached a predetermined height. The liquid level sensor 33 may also be another sensor, such as a sensor that can detect the liquid level using ultrasound or the like.

[0020] The cylinder pressure regulating device 4 includes a first connection port P1, a second connection port P2, an electromagnetic valve 41, a pressure sensor 42, a temperature sensor 44, a control device 43, and an alarm device 45.

[0021] The first connection port P1 is configured to be connected to a service valve 13 for recovering refrigerant from the refrigeration cycle apparatus 100, which is a target apparatus for refrigerant recovery, by a charge hose 51. The first connection port P1 may be an end of the charge hose 51 connected to the service valve 13.

[0022] The second connection port P2 is configured to be connected to the liquid port 32 of the refrigerant recovery cylinder 3 by a charge hose 56. The second connection port P2 may be the end of the charge hose 56 that is connected to the liquid port 32.

[0023] The solenoid valve 41 is connected between the first connection port P1 and the second connection port P2. The pressure sensor 42 and the temperature sensor 44 are provided in the refrigerant path between the first connection port P1 and the second connection port P2, at a portion from the solenoid valve 41 to the second connection port P2. The second connection port P2 is connected to the refrigerant recovery cylinder 3.

[0024] The control device 43 includes a CPU and a memory. The control device 43 is configured to control the solenoid valve 41 based on the outputs of the pressure sensor 42, the temperature sensor 44, and the liquid level sensor 33. The CPU is a computing unit that controls the solenoid valve 41 by executing various programs. The CPU has the function of performing various processes by executing the programs, but some or all of these functions may be implemented using dedicated hardware circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0025] The memory provides a storage area for storing program code, various variables, etc. when the CPU executes various programs. Examples of memory include volatile memory such as DRAM (dynamic random access memory) and SRAM (static random access memory), and non-volatile memory such as ROM (read only memory) and flash memory.

[0026] The control device 43 further controls the alarm device 45 based on the outputs of the pressure sensor 42, the temperature sensor 44, and the liquid level sensor 33. The alarm device 45 includes warning lamps 45A to 45C and a recovery completion lamp 45D. The warning lamp 45A alerts the user to an excessive rise in cylinder pressure. The warning lamp 45B alerts the user to an excessive rise in cylinder temperature. The warning lamp 45C alerts the user to an excessive rise in the refrigerant liquid level in the cylinder. The recovery completion lamp 45D alerts the user that the cylinder temperature has exceeded the saturation temperature and that refrigerant recovery has been completed.

[0027] The alarm device 45 may be a display panel, a speaker, a buzzer, or the like for issuing a warning instead of a lamp.

[0028] FIG. 3 is a flowchart for explaining the control of the alarm device and the solenoid valve executed in the first embodiment.

[0029] Before the processing of this flowchart is executed, the operator ensures that the service valves 13, 18 of the refrigeration cycle device 100, the cylinder pressure regulating device 4, and the refrigerant recovery cylinder 3 are connected by charge hoses 51, 52, and 56, and that the solenoid valve 41 is open, and then starts operation of the compressor 11.

[0030] First, in step S1, the control device 43 determines whether the cylinder pressure detected by the pressure sensor 42 is higher than a threshold value Pth. The threshold value Pth is set, for example, based on the withstand pressure of the refrigerant recovery cylinder 3. If the pressure is higher than the threshold value Pth (YES in S1), the control device 43 turns on the warning lamp 45A in step S2 to notify the operator that the pressure has excessively increased, and closes the solenoid valve 41 in step S7 to protect the refrigerant recovery cylinder 3 from further pressure increase.

[0031] If the pressure is equal to or lower than the threshold value Pth (NO in S1), then in step S3, the control device 43 determines whether the refrigerant temperature detected by the temperature sensor 44 is higher than the threshold value Tth. The threshold value Tth is set based on, for example, the saturation temperature corresponding to the withstand pressure, the type of refrigerant being recovered, etc. If the temperature is higher than the threshold value Tth (YES in S3), the control device 43 turns on the warning lamp 45B in step S4 to notify the operator that the temperature has risen excessively, and closes the solenoid valve 41 in step S7 to protect the refrigerant recovery cylinder 3 from high temperatures.

[0032] If the temperature is equal to or lower than the threshold value Tth (NO in S3), then in step S5, the control device 43 determines whether the liquid level of the liquid refrigerant has reached a warning level using the liquid level sensor 33 (e.g., a float switch) provided in the refrigerant recovery cylinder 3. If the liquid level has reached the warning level (YES in S5), the control device 43 turns on the warning lamp 45C in step S6 to notify the operator that the liquid level has reached the warning level, and closes the solenoid valve 41 in step S7 to protect the refrigerant recovery cylinder 3 from overflow of liquid refrigerant.

[0033] In step S5, if the liquid level has not reached the warning level, the control device 43 executes the process from step S1 again. In this case, the recovery of the refrigerant continues.

[0034] When the operator notices that any one of the warning lamps 45A, 45B, and 45C is lit and that an abnormality has occurred in the refrigerant recovery, the operator operates the refrigeration cycle apparatus 100 to stop the compressor 11.

[0035] According to the first embodiment, the compressor 11 of the refrigeration cycle apparatus 100 with a large capacity is used for refrigerant recovery, so the recovery time can be shortened compared to connecting a recovery machine with a smaller capacity compressor. At this time, the cylinder pressure adjusting device 4 monitors the state of the refrigerant recovery cylinder 3, so damage to the refrigerant recovery cylinder can be prevented in advance.

[0036] Embodiment 2. Figure 4 is a diagram showing the configuration of a refrigeration cycle apparatus to which a cylinder pressure regulating device is connected in embodiment 2. The cylinder pressure regulating device 4A shown in Figure 4 further includes a pressure reducing device (60) arranged in series with the solenoid valve 41 in the refrigerant path 40 in addition to the configuration of the cylinder pressure regulating device 4 shown in Figure 2. In embodiment 2, the pressure reducing device includes an expansion valve 60. The control device 43 is configured to control the expansion valve 60 when the solenoid valve 41 is open.

[0037] The other configuration shown in FIG. 4 is similar to the configuration in FIG. 2, and therefore description thereof will not be repeated here.

[0038] Fig. 5 is a flowchart for explaining the control of the alarm device and the solenoid valve executed in the second embodiment. Steps S11 to S16 and S19 in the flowchart of Fig. 5 correspond to steps S1 to S6 and S7 in the flowchart of Fig. 3, respectively, and the processing of these steps is the same, so the description will not be repeated here. Note that the determination value Pth1 in step S11 is the same value as the determination value Pth in step S1.

[0039] In the flowchart of FIG. 5, if the float switch is OFF in step S15 (NO in S15), step S17 is executed.

[0040] In step S17, the control device 43 determines whether the cylinder pressure detected by the pressure sensor 42 is higher than the determination value Pth2. If the pressure is higher than the determination value Pth2 (YES in S17), the control device 43 reduces the opening of the expansion valve 60 to reduce the pressure in step S18, and returns the process to step S11. Note that if the determination value applied in step S11 is Pth1, then Pth2<Pth1. For example, if Pth1=3.0 MPa, Pth2 can be set to 2.9 MPa.

[0041] On the other hand, if the pressure is equal to or less than the determination value Pth2 (NO in S17), the control device 43 returns the process to step S11 without executing the process of step S18.

[0042] 5, when the cylinder pressure, temperature, or liquid level exceeds a threshold indicating an abnormality, the control device 43 closes the solenoid valve 41. Furthermore, during the refrigerant recovery operation, the control device 43 adjusts the expansion valve 60 so that the cylinder pressure does not exceed the second threshold.

[0043] According to the cylinder pressure regulating device of the second embodiment, the refrigerant is recovered while the refrigeration cycle apparatus is operating, as in the first embodiment, so that the refrigerant can be recovered in a shorter time than with a recovery method using a conventional recovery apparatus, and safety can be ensured. Furthermore, according to the cylinder pressure regulating device of the second embodiment, by controlling the cylinder pressure so that it does not exceed a certain value, the closure of the solenoid valve 41 due to an increase in cylinder pressure is suppressed, and recovery by operating the refrigeration cycle apparatus can be continued for a longer period of time than in the first embodiment.

[0044] Embodiment 3. Fig. 6 is a diagram showing the configuration of a refrigeration cycle device connected to a cylinder pressure regulating device in embodiment 3. In embodiment 3, a modified example of the pressure reducing device of the cylinder pressure regulating device in embodiment 2 is shown.

[0045] The cylinder pressure regulating device 4B shown in Fig. 6 includes pressure reducing devices (61, 62) instead of the pressure reducing device (60) in the configuration of the cylinder pressure regulating device 4A shown in Fig. 4. The pressure reducing device includes a capillary tube 62 and an on-off valve 61 connected in parallel to each other. The control device 43 is configured to control the on-off valve 61 when the solenoid valve 41 is open.

[0046] Other configurations shown in FIG. 6 are similar to those in FIGS. 2 and 4, and therefore description thereof will not be repeated here.

[0047] Fig. 7 is a flowchart for illustrating the control of the alarm device and the solenoid valve executed in the third embodiment. In the flowchart of Fig. 7, the process of step S28 is executed instead of step S18 in the flowchart of Fig. 5. In step S28, the control device 43 closes the on-off valve 61. The other processes in the flowchart of Fig. 7 are the same as the processes in the flowchart of Fig. 5, and therefore description thereof will not be repeated.

[0048] 7, when the pressure, temperature, or liquid level exceeds a judgment value indicating an abnormality, the control device 43 closes the solenoid valve 41. Furthermore, when the pressure is equal to or greater than a second judgment value, the control device 43 closes the on-off valve 61.

[0049] According to the cylinder pressure regulating device of the third embodiment, as in the first and second embodiments, the refrigerant is recovered while the refrigeration cycle apparatus is operating, so that the refrigerant can be recovered in a shorter time than with a conventional recovery method using a recovery apparatus, and safety is improved. Furthermore, according to the cylinder pressure regulating device of the third embodiment, the pressure is controlled by the on-off valve 61 and the capillary tube 62 so that the cylinder pressure does not exceed a certain value, thereby preventing the solenoid valve 41 from closing due to an increase in cylinder pressure, and recovery by operating the refrigeration cycle apparatus can be continued for a longer period of time than in the first embodiment.

[0050] Embodiment 4. When the compressor of the refrigeration cycle device is operated to recover refrigerant, the refrigerant flowing into the refrigerant recovery cylinder is in a liquid state at the beginning, a two-phase state at the middle, and a gas state at the end. These state changes are explained using a pH diagram.

[0051] Fig. 8 is a ph diagram showing the state of the refrigeration cycle device at the beginning of refrigerant recovery, Fig. 9 is a ph diagram showing the state of the refrigeration cycle device at the middle stage of refrigerant recovery, and Fig. 10 is a ph diagram showing the state of the refrigeration cycle device at the end of refrigerant recovery.

[0052] In FIG. 8, in the condensation step P2-P3, the refrigerant is supercooled from the gas phase to become completely liquid, so the refrigerant flowing from the outlet of the condenser into the refrigerant recovery cylinder is liquid refrigerant.

[0053] In FIG. 9, in the condensation process of Q2-Q3, when the amount of refrigerant decreases to the point where liquid refrigerant can no longer exist in the heat exchanger, the refrigerant changes only from the gas phase to the two-phase state, and the refrigerant flowing from the outlet of the condenser into the refrigerant recovery cylinder is two-phase refrigerant.

[0054] In FIG. 10, in the condensation process of R2-R3, when the amount of refrigerant decreases to the point where two-phase refrigerant can no longer exist in the heat exchanger, the refrigerant does not change from the gas phase, and the refrigerant that flows from the outlet of the condenser into the refrigerant recovery cylinder is gas refrigerant.

[0055] In the state shown in Figure 10 where gas refrigerant flows into the cylinder, the amount of refrigerant in the cylinder does not increase, and the remaining refrigerant cannot be recovered even if the compressor of the refrigeration cycle device is operated. Therefore, it is necessary to switch to conventional refrigerant recovery using a recovery device used for refrigerant recovery.

[0056] However, because the operator is unaware that gas refrigerant is flowing into the cylinder, he or she does not know when to switch to recovery using the recovery device. This results in wasted time and increases the refrigerant recovery time. Therefore, in the fourth embodiment, the cylinder pressure regulating device notifies the operator of the timing to end recovery while the refrigeration cycle apparatus is running.

[0057] Fig. 11 is a diagram showing the configuration of a refrigeration cycle apparatus connected to a cylinder pressure regulating device according to embodiment 4. The configuration shown in Fig. 11 includes a cylinder pressure regulating device 4C instead of the cylinder pressure regulating device 4 in the configuration shown in Fig. 2, and further includes a refrigerant recovery device 20 connected between the service valve 13 and the first connection port P1 of the cylinder pressure regulating device 4C. The refrigerant inlet of the refrigerant recovery device 20 is connected to the service port of the service valve 13. The refrigerant outlet of the refrigerant recovery device 20 is connected to the first connection port P1 of the cylinder pressure regulating device 4C.

[0058] The configuration of the cylinder pressure regulating device 4C is basically the same as that of the cylinder pressure regulating device 4, although the processing executed by the control device 43 is slightly different. Therefore, the description will not be repeated here.

[0059] The refrigerant recovery device 20 includes a compressor 21 , a heat exchanger 22 , a fan 23 , a pressure sensor 24 , a control device 25 , and a solenoid valve 26 .

[0060] When the solenoid valve 26 is opened, the refrigerant inlet and refrigerant outlet of the refrigerant recovery device 20 are connected to each other. In this case, the compressor 21 of the refrigerant recovery device 20 is stopped, and the refrigeration cycle apparatus 100 is operated to recover the refrigerant.

[0061] As the refrigerant recovery progresses, when the amount of refrigerant that can be recovered by operating the refrigeration cycle apparatus 100 has been recovered, the solenoid valve 26 is closed and the compressor 21 is operated. Note that a refrigerant recovery device that does not include the solenoid valve 26 may be used. For example, the refrigerant may be recovered by operating the refrigeration cycle apparatus 100 without connecting the refrigerant recovery device, and when the amount of refrigerant that can be recovered has been recovered, an operator may connect the refrigerant recovery device.

[0062] The compressor 21 is configured to compress the refrigerant sent from the refrigerant inlet of the refrigerant recovery device 20. The heat exchanger 22 exchanges heat between the compressed refrigerant and air and sends it out toward the refrigerant outlet of the refrigerant recovery device 20. When the refrigerant is recovered by the refrigerant recovery device 20, the solenoid valve 41 of the cylinder pressure regulating device 4C is controlled to an open state.

[0063] Fig. 12 is a flowchart for illustrating the control of the alarm device, the solenoid valve, and the pressure reducing device executed in the fourth embodiment. In steps S31 to S36 of the flowchart in Fig. 12, the same processes as those in steps S11 to S16 of the flowchart in Fig. 5 are executed. Therefore, description of these processes will not be repeated here.

[0064] 12, if the liquid level in the refrigerant recovery cylinder has not reached the determination level and the float switch is OFF (NO in S35), the control device 43 determines in step S37 whether the temperature detected by the temperature sensor 44 is higher than the saturation temperature of the refrigerant. The saturation temperature is obtained from a pre-stored map based on the pressure detected by the pressure sensor 42.

[0065] If the detected temperature is equal to or lower than the saturation temperature (NO in S37), the process from step S31 is executed again. On the other hand, if the detected temperature is higher than the saturation temperature (YES in S37), the control device 43 turns on the recovery completion lamp 45D, which indicates the completion of recovery using the refrigeration cycle apparatus 100. This allows the operator to know that the recovery of the amount of refrigerant that can be recovered by operating the refrigeration cycle apparatus 100 has been completed.

[0066] When the warning lamp or the recovery completion lamp is turned on by the processing of any one of steps S32, S34, S36, and S38, the control device 43 closes the solenoid valve 41 in step S39.

[0067] When the recovery completion lamp 45D lights up, the operator operates the refrigerant recovery device 20. The control device 25 of the refrigerant recovery device 20 then closes the solenoid valve 26 and operates the compressor 21 and the fan 23. The operator also operates the cylinder pressure regulating device 4C to open the solenoid valve 41. As a result, even after the state shown in Figure 10 has been reached and refrigerant recovery by operation of the refrigeration cycle device 100 is no longer possible, the refrigerant remaining in the refrigeration cycle device 100 can still be recovered into the refrigerant recovery cylinder 3.

[0068] According to the cylinder pressure adjusting device 4C of the fourth embodiment, when the recovery of the recoverable amount of refrigerant by operating the refrigeration cycle device is completed, the notification device 45 notifies the operator. This allows the operator to switch to recovery using the refrigerant recovery device at an appropriate time, thereby preventing the recovery time from becoming too long.

[0069] Embodiment 5. Figure 13 is a diagram showing the configuration of a refrigeration cycle apparatus to which a cylinder pressure regulating device is connected in embodiment 5. In embodiment 5, a signal notifying completion of refrigerant recovery is sent from the cylinder pressure regulating device to the refrigeration cycle apparatus 100 and the refrigerant recovery device 20. This enables the refrigeration cycle apparatus 100 and the refrigerant recovery device 20 to recover refrigerant in cooperation with each other. The configuration shown in Figure 13 is the same as the configuration shown in Figure 11, except that a cylinder pressure regulating device 4D is provided instead of the cylinder pressure regulating device 4C.

[0070] The control device 43 of the cylinder pressure adjusting device 4D is configured to be able to communicate with the control device 25 of the refrigerant recovery device 20 and the control device 19 of the refrigeration cycle device 100.

[0071] The cylinder pressure regulating device 4D has a configuration that is basically the same as that of the cylinder pressure regulating device 4C, although the processing executed by the control device 43 is slightly different, and therefore the description will not be repeated here.

[0072] Fig. 14 is a flowchart for illustrating the control executed in the fifth embodiment. First, the processes of steps S31 to S38 are the same as those in Fig. 12, and therefore the description thereof will not be repeated here.

[0073] In step S32, when the warning lamp 45A indicating that the pressure has excessively increased is turned on, the control device 43 transmits a signal notifying that an abnormality has been detected to the control device 19 of the refrigeration cycle apparatus 100. In response to this, the control device 19 stops the compressor 11 in step S41.

[0074] Similarly, in step S34, when the warning lamp 45B indicating that the temperature has risen excessively is turned on, the control device 43 transmits a signal notifying that an abnormality has been detected to the control device 19 of the refrigeration cycle apparatus 100. In response to this, the control device 19 stops the compressor 11 in step S42.

[0075] Similarly, in step S36, when the warning lamp 45C is turned on to indicate that the liquid level in the recovery cylinder 3 has reached the warning level, the control device 43 transmits a signal notifying that an abnormality has been detected to the control device 19 of the refrigeration cycle apparatus 100. In response to this, the control device 19 stops the compressor 11 in step S43.

[0076] After the compressor 11 is stopped in any one of steps S41, S42, and S43, the control device 43 closes the solenoid valve 41 in step S39, and ends the processing of this flowchart.

[0077] On the other hand, if the recovery completion lamp 45D, indicating the completion of recovery using the refrigeration cycle apparatus 100, is lit in step S38, the control device 43 communicates with the control device 19 in step S44 to stop the compressor 11. Subsequently, the control device 43 starts the refrigerant recovery device 20 in step S45. Specifically, the control device 43 sends a start signal to the control device 25 of the refrigerant recovery device 20. The control device 25 then closes the solenoid valve 26 and operates the compressor 21 and the fan 23. Thereafter, the control device 25 compresses and condenses the refrigerant in the refrigeration cycle apparatus 100 while monitoring the pressure with the pressure sensor 24, and sends the condensed liquid refrigerant to the refrigerant recovery cylinder 3 via the cylinder pressure adjustment device 4D.

[0078] 13, the control device 43 is configured to send a notification signal indicating the completion of refrigerant recovery to the refrigeration cycle apparatus 100 and the refrigerant recovery device 20 based on the outputs of the pressure sensor 42 and the temperature sensor 44, as shown in FIG. 14 (S44, S45). In response to this notification signal, the refrigeration cycle apparatus 100 stops the compressor 11, and the refrigerant recovery device 20 starts operation.

[0079] In this way, the notification signal from the cylinder pressure regulator may be used to link the refrigeration cycle apparatus 100 and the refrigerant recovery apparatus 20. In this case, the burden on the operator is further reduced.

[0080] [Summary] The present disclosure will be summarized again with reference to the drawings.

[0081] (Item 1) The present disclosure relates to a cylinder pressure regulating device 4 for regulating the pressure inside a refrigerant recovery cylinder 3 when recovering refrigerant from a refrigeration cycle apparatus 100 into the refrigerant recovery cylinder 3. The cylinder pressure regulating device 4 includes a refrigerant path 40 connected between the refrigeration cycle apparatus 100 and the refrigerant recovery cylinder 3, a solenoid valve 41 provided in the refrigerant path 40, a pressure sensor 42 and a temperature sensor 44 provided in the refrigerant path 40 at a portion from the solenoid valve 41 to the refrigerant recovery cylinder 3, and a control device 43 that controls the solenoid valve 41 in accordance with outputs of the pressure sensor 42, the temperature sensor 44, and a liquid level sensor 33 that monitors the liquid level in the refrigerant recovery cylinder 3.

[0082] (Item 2) In the cylinder pressure regulating device described in item 1, the refrigerant recovery cylinder 3 includes a liquid port 32 serving as an inlet / outlet for liquid refrigerant and a gas port 31 serving as an inlet / outlet for gas refrigerant. The refrigeration cycle apparatus 100 includes a refrigerant circulation path C1 in which a compressor 11, a condenser 12, an expansion device (expansion valve 15), and an evaporator 16 are connected in a circular configuration, a first service valve 13 provided in the refrigerant circulation path C1 between a refrigerant outlet of the condenser 12 and the expansion device (expansion valve 15), and a second service valve 18 provided in the refrigerant circulation path C1 between a refrigerant outlet of the evaporator 16 and a suction port of the compressor 11. A refrigerant path 40 is configured to connect the first service valve 13 and the liquid port 32. The second service valve 18 and the gas port 31 are configured to be connectable by a charge hose 52.

[0083] (Item 3) The cylinder pressure regulating device 4A described in item 1 or 2 further includes a pressure reducing device (60; 61, 62) arranged in series with the solenoid valve 41 in the refrigerant path 40. The control device 43 is configured to control the pressure reducing device (60; 61, 62) when the solenoid valve 41 is open.

[0084] (4) In the cylinder pressure adjusting device 4A described in the 3rd paragraph, the pressure reducing device includes an expansion valve 60 as shown in FIG.

[0085] (Item 5) In the cylinder pressure adjusting device 4B described in item 3, as shown in FIG. 6, the pressure reducing device includes a capillary tube 62 and an on-off valve 61 connected in parallel to each other.

[0086] (Item 6) The cylinder pressure regulating device described in item 1 further includes an alarm device 45 that notifies an operator of the status of refrigerant recovery. As shown in Fig. 12, when the control device 43 detects, based on the outputs of the pressure sensor 42 and the temperature sensor 44, that the recovery of the recoverable amount of refrigerant by operating the refrigeration cycle device has been completed, the control device 43 uses the alarm device 45 to notify the operator (S38) and closes the solenoid valve 41 (S39).

[0087] (Item 7) In the cylinder pressure regulating device described in item 1, as shown in FIG. 14 (S41 to S43), the control device 43 is configured to send a signal to the refrigeration cycle device notifying that refrigerant recovery has been stopped due to an abnormality, based on the outputs of the pressure sensor 42 and the temperature sensor 44.

[0088] (Item 8) In the cylinder pressure regulating device described in item 1, as shown in FIG. 14 (S44), the control device 43 is configured to send a signal to the refrigeration cycle device 100 notifying the completion of refrigerant recovery based on the outputs of the pressure sensor 42 and the temperature sensor 44.

[0089] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims.

[0090] 1 Indoor unit, 2 Outdoor unit, 3 Refrigerant recovery cylinder, 4, 4A, 4B, 4C, 4D Cylinder pressure adjustment device, 11, 21 Compressor, 12 Condenser, 13, 18 Service valve, 14, 17 Extension piping, 15, 60 Expansion valve, 16 Evaporator, 19, 25, 43 Control device, 20 Refrigerant recovery device, 22 Heat exchanger, 23 Fan, 24, 42 Pressure sensor, 26, 41 Solenoid valve, 31 Gas port, 32 Liquid port, 33 Liquid level sensor, 40 Refrigerant path, 44 Temperature sensor, 45 Alarm device, 45A, 45B, 45C Warning lamp, 45D Recovery completion lamp, 51, 52, 56 Charge hose, 61 Opening and closing valve, 62 Capillary tube, 100 Refrigeration cycle device, C1 Refrigerant circulation path, P1 First connection port, P2 Second connection port, P3 Third connection port.

Claims

1. A cylinder pressure adjustment device for adjusting the pressure in a refrigerant recovery cylinder when recovering the refrigerant of a refrigeration cycle device, comprising: a refrigerant path connected between the refrigeration cycle device and the refrigerant recovery cylinder; a solenoid valve provided in the refrigerant path; a pressure sensor and a temperature sensor provided in a portion of the refrigerant path from the solenoid valve to the refrigerant recovery cylinder; and a control device configured to control the solenoid valve according to outputs of the pressure sensor, the temperature sensor, and a liquid level sensor that monitors the liquid level height of the refrigerant recovery cylinder.

2. The refrigerant recovery cylinder includes a liquid port that is an inlet / outlet for liquid refrigerant and a gas port that is an inlet / outlet for gaseous refrigerant. The refrigeration cycle device includes a compressor, a condenser, an expansion device, and an evaporator connected in a loop, and in the loop, a first service valve provided between the refrigerant outlet of the condenser and the expansion device, and a second service valve provided between the refrigerant outlet of the evaporator and the suction port of the compressor. The refrigerant path is configured to connect the first service valve and the liquid port, and the second service valve and the gas port are configured to be connectable by a charge hose. The cylinder pressure adjustment device according to claim 1.

3. The refrigerant path further includes a pressure reducing device arranged in series with the solenoid valve, and the control device is configured to control the pressure reducing device when the solenoid valve is open. The cylinder pressure adjustment device according to claim 1 or 2.

4. The pressure reducing device includes an expansion valve. The cylinder pressure adjustment device according to claim 3.

5. The pressure reducing device includes a capillary tube and an on-off valve connected in parallel with each other. The cylinder pressure adjustment device according to claim 3.

6. The device further includes a notification device for notifying an operator of the refrigerant recovery status. When the control device detects, based on the outputs of the pressure sensor and the temperature sensor, the completion of recovery of an amount of refrigerant that can be recovered by operating the refrigeration cycle device, the control device is configured to notify the operator using the notification device and close the solenoid valve. The cylinder pressure adjustment device according to claim 1.

7. The cylinder pressure regulating device according to claim 1, wherein the control device is configured to send a signal for notifying the stop due to abnormality of refrigerant recovery to the refrigeration cycle device based on the outputs of the pressure sensor and the temperature sensor.

8. The cylinder pressure regulating device according to claim 1, wherein the control device is configured to send a signal for notifying the completion of refrigerant recovery to the refrigeration cycle device based on the outputs of the pressure sensor and the temperature sensor.

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