Refrigeration cycle device

Abstract

To provide a refrigeration cycle device capable of suppressing excessive rise in internal temperature of a compressor when the compressor starts.SOLUTION: A refrigeration cycle device includes: a first by-pass refrigerant circuit communicating main refrigerant circuits on a downstream side and an upstream side of a compressor; a first by-pass valve installed on the first by-pass refrigerant circuit and opening / closing the first by-pass refrigerant circuit; a water temperature sensor detecting a temperature of water flowing into a user-side heat exchanger through a water pipe; and a controller making the first by-pass refrigerant circuit open by the first by-pass valve when recognizing an operation state of the compressor on the basis of the temperature detected by the water temperature sensor when the compressor starts and recognizing that the compressor is in a prescribed refrigerant discharge shortage state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a configuration for a water heater that heats water in a hot water tank using a refrigeration cycle, in which an overshoot of the compressor's discharge pressure is suppressed by providing a dead time period during which the opening of the pressure reducing device is kept constant when the compressor is started. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-346449 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a refrigeration cycle device that can suppress an excessive rise in the internal temperature of a compressor when the compressor is started. [Means for solving the problem]

[0005] a first bypass refrigerant circuit connecting the main refrigerant circuit downstream and upstream of the compressor; a first bypass valve provided in the first bypass refrigerant circuit for opening and closing the first bypass refrigerant circuit; a water temperature sensor for detecting the temperature of water flowing from the water piping into the user-side heat exchanger; and a controller for recognizing the operating state of the compressor based on the temperature detected by the water temperature sensor when the compressor is started, and for opening the first bypass refrigerant circuit by using the first bypass valve when the compressor is recognized to be in a predetermined refrigerant discharge shortage state. [Effects of the Invention]

[0006] The refrigeration cycle device of the present disclosure can suppress an excessive rise in the internal temperature of the compressor when the compressor is started. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing the configuration of a refrigeration cycle device according to an embodiment of the present invention; [Figure 2] Control block diagram of a refrigeration cycle device according to an embodiment [Figure 3] Flowchart of response processing at the time of compressor startup in the embodiment [Figure 4] 1 is a configuration diagram of a refrigeration cycle device according to another first embodiment. [Figure 5] 10 is a configuration diagram of a refrigeration cycle device according to another second embodiment. [Figure 6] 10 is a configuration diagram of a refrigeration cycle device according to another third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (Findings that formed the basis of this disclosure) At the time the inventors arrived at the idea of ​​this disclosure, there was a technology in a heat pump water heater using a refrigeration cycle device that set a dead time period during which the opening of the pressure reducing device (expansion valve) was kept constant when the compressor was started. This technology improved the efficiency of operation during start-up by waiting for a delay in the temperature increase relative to the pressure in the transient state during compressor start-up, thereby realizing a heat pump water heater with high durability.

[0009] However, with the above technology, the opening of the expansion valve is limited when the compressor is started, which results in a disadvantage that the amount of refrigerant drawn into the compressor is insufficient, resulting in an insufficient amount of refrigerant circulating. Furthermore, depending on the temperature of the water flowing into the user-side heat exchanger that heats the water, the pressure of the refrigerant discharged from the compressor may be lower than the pressure of the refrigerant in the user-side heat exchanger, causing the refrigerant to stagnate, resulting in an excessive rise in the internal temperature of the compressor and leading to compressor failure. The inventors discovered a problem of how to avoid these disadvantages, and the subject matter of the present disclosure was formed in order to solve this problem. Therefore, the present disclosure provides a refrigeration cycle device that can suppress an excessive rise in the internal temperature of a compressor when the compressor is started.

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0011] (Embodiment) Hereinafter, an embodiment will be described with reference to FIGS. [1. Configuration] 1 is a configuration diagram of a refrigeration cycle device 1 according to this embodiment. The refrigeration cycle device 1 is a vapor compression type refrigeration cycle device, and includes a main refrigerant circuit 10, bypass refrigerant circuits 20 and 30, and a controller 50. The refrigeration cycle device 1 is installed outdoors, and is connected to a heating terminal (not shown) by a user-side heat medium circuit 100 to form a hot water heating system.

[0012] The main refrigerant circuit 10 is configured by connecting in order a compressor 11 that compresses the refrigerant, a user-side heat exchanger 12 that functions as a radiator, an economizer 13, a main expansion valve 14, and a heat-source-side heat exchanger 15 that functions as an evaporator via refrigerant piping 16. The main expansion valve 14 is an opening adjustment valve whose opening can be changed by a stepping motor or the like. In this embodiment, a four-way valve 17 is provided in the refrigerant piping 16 between the compressor 11 and the user-side heat exchanger 12. The four-way valve 17 switches the flow direction of the refrigerant discharged from the compressor 11.

[0013] That is, the four-way valve 17 switches between a first direction state in which the refrigerant discharged from the compressor 11 flows in the following direction: compressor 11 → four-way valve 17 → user-side heat exchanger 12 → economizer 13 → main expansion valve 14 → heat-source-side heat exchanger 15 → four-way valve 17 → compressor 11, as shown by the dashed arrows in FIG. 1 , and a second direction state in which the refrigerant flows in the opposite direction to the first direction state: compressor 11 → four-way valve 17 → heat-source-side heat exchanger 15 → main expansion valve 14 → economizer 13 → user-side heat exchanger 12 → four-way valve 17 → compressor 11. In the second direction state, the heat-source-side heat exchanger 15 functions as a radiator, and the user-side heat exchanger 12 functions as an evaporator. In this embodiment, a case will be described in which the refrigeration cycle apparatus 1 is operated in the first direction state and the user-side heat exchanger 12 functions as a radiator.

[0014] The bypass refrigerant circuit 20 branches off from the main refrigerant circuit 10 between the user-side heat exchanger 12 and the main expansion valve 14, and is connected to an injection port 11a provided in a compression chamber of the compressor 11. The compressor 11 is a scroll-type compressor. A bypass expansion valve 21 and an economizer 13 are connected to the bypass refrigerant circuit 20, in this order from the upstream side. The bypass expansion valve 21 is an opening / closing valve that can be switched between an open state and a closed state, or an opening degree changing valve that can adjust the opening degree.

[0015] A portion of the high-pressure refrigerant that has passed through the user-side heat exchanger 12 flows into the bypass refrigerant circuit 20 and is reduced in pressure by the bypass expansion valve 21 to become intermediate-pressure refrigerant. The intermediate-pressure refrigerant exchanges heat with the high-pressure refrigerant flowing through the main refrigerant circuit 10 in the economizer 13, and is then injected into the compressor 11. The refrigerant injected into the compressor 11 merges with the refrigerant being compressed in the compression chamber of the compressor 11. The compressor 11 merges the injected refrigerant with the refrigerant being compressed, and recompresses it.

[0016] The bypass refrigerant circuit 30 connects the discharge side of the compressor 11 with the suction side of the main refrigerant circuit 10, and is provided with a bypass two-way valve 31. The bypass two-way valve 31 is an on-off valve that can be switched between an open state and a closed state. Here, the bypass refrigerant circuit 20 and the bypass refrigerant circuit 30 correspond to the first bypass refrigerant circuit of the present disclosure that connects the upstream side of the compressor 11 with the downstream side of the main refrigerant circuit 10. Furthermore, the bypass expansion valve 21 and the bypass two-way valve 31 correspond to the first bypass valve of the present disclosure that opens and closes the first bypass refrigerant circuit.

[0017] The use-side heat medium circuit 100 is configured by connecting a use-side heat exchanger 12, a transfer pump 102, and a heating terminal (not shown) via heat medium piping 101. Water or antifreeze can be used as the heat medium flowing through the use-side heat medium circuit 100. In this embodiment, water is used as the heat medium, and the heat medium piping corresponds to the water piping in this disclosure. The use-side heat exchanger 12 heats the water flowing through the heat medium piping 101 by exchanging heat between the water flowing through the heat medium piping 101 and the refrigerant discharged from the compressor 11 to the main refrigerant circuit 10. The water heated by the use-side heat exchanger 12 is used for heating using heat radiation from the heating terminal, and the water that has been cooled by heat radiation from the heating terminal is heated again by the use-side heat exchanger 12.

[0018] When the refrigeration cycle device 1 constitutes a hot water supply system of a storage type, the heat medium piping 101 is connected to the top and bottom of the hot water storage tank, and the water stored in the hot water storage tank is heated by the user-side heat exchanger 12 and supplied from the top of the hot water storage tank into the hot water storage tank through the heat medium piping 101, and low-temperature water is supplied from the bottom of the hot water storage tank to the heat medium piping 101 and heated by the user-side heat exchanger 12.

[0019] A discharge pressure sensor 40 is provided in the main refrigerant pipe 16 on the discharge side of the compressor 11 to detect the pressure of the refrigerant discharged from the compressor 11. A water temperature sensor 42 is provided in the heat medium pipe 101 on the inlet side of the use-side heat exchanger 12 to detect the temperature of water flowing into the use-side heat exchanger 12. An outside air temperature sensor 41 is provided near the heat-source-side heat exchanger 15 to detect the outside air temperature.

[0020] Fig. 2 is a control block diagram of the refrigeration cycle apparatus 1. Referring to Fig. 2, a controller 50 is connected to a discharge pressure sensor 40, an outside air temperature sensor 41, and a water temperature sensor 42, and detection signals from these sensors are input to the controller 50. The controller 50 is also connected to the compressor 11, the main expansion valve 14, the four-way valve 17, the heat source fan 18, the bypass expansion valve 21, the bypass two-way valve 31, and the transfer pump 102, and the operation of these controlled objects is controlled by control signals output from the controller 50.

[0021] A remote control 60 is connected to the controller 50 to perform operations such as starting and stopping the operation of the refrigeration cycle apparatus 1. The remote control 60 has a switch and a display unit, and an operation signal of the switch is input to the controller 50, and the operating state of the refrigeration cycle apparatus 1 is displayed on the display unit of the remote control 60 in accordance with a display signal output from the controller 50.

[0022] The controller 50 includes a processor 51, a memory 52, etc., and the memory 52 stores a program 53 for controlling the refrigeration cycle apparatus 1 and control data 54 for determining control conditions, etc., of the refrigeration cycle apparatus 1. The processor 51 controls the operation of the refrigeration cycle apparatus 1 by reading and executing the program 53.

[0023] [2. Response process when compressor starts] The process executed by the controller 50 when starting the compressor 11 will be described with reference to the flowchart shown in Fig. 3. For example, in response to an operation to start heating operation using the remote control 60, the controller 50 executes the process according to the flowchart shown in Fig. 3 when starting circulation of water in the use-side heat medium circuit 100 by the transfer pump 102 and circulation of refrigerant in the main refrigerant circuit 10 by the compressor 11.

[0024] 3, when the compressor 11 is started, the controller 50 proceeds to step S2. In step S2, the controller 50 recognizes the temperature of the water flowing into the use-side heat exchanger 12 based on the detection signal of the water temperature sensor 42. In the following step S3, the controller 50 recognizes the outside air temperature based on the detection signal of the outside air temperature sensor 41. In the next step S4, the controller 50 determines whether the temperature of the water flowing into the use-side heat exchanger 12 is higher than the outside air temperature by Tth (corresponding to the first predetermined temperature in the present disclosure) or more. A state in which the temperature of the water flowing into the use-side heat exchanger 12 is higher than the outside air temperature by Tth or more corresponds to a refrigerant discharge insufficient state in the present disclosure.

[0025] If the water temperature is higher than the outside air temperature by Tth or more (water temperature−outside air temperature≧Tth), the controller 50 proceeds to step S5, and if the water temperature is less than the outside air temperature+Tth, the controller 50 proceeds to step S20. In step S20, the controller 50 executes normal heating operation control, controlling the rotation speed of the compressor 11, the aperture of the main expansion valve 14, opening / closing of the bypass expansion valve 21, etc., so that the temperature of the water flowing out of the use-side heat exchanger 12 becomes a predetermined target temperature.

[0026] Steps S5 to S9 are processes for suppressing an excessive rise in the internal temperature of compressor 11. Controller 50 opens bypass expansion valve 21 in step S5 and opens bypass two-way valve 31 in step S6. This increases the amount of refrigerant drawn into compressor 11 and the amount of refrigerant discharged from compressor 11, resulting in a decrease in the amount of refrigerant remaining in compressor 11, and suppresses an excessive rise in the internal temperature of compressor 11.

[0027] In the next step S7, the controller 50 recognizes the temperature of the water flowing into the utilization-side heat exchanger 12 based on the temperature detected by the water temperature sensor 42, and in step S8 recognizes the outside air temperature based on the detection signal of the outside air temperature sensor 41. In the next step S9, the controller 50 determines whether the state in which the water temperature is higher than the outside air temperature by Tth or more continues.

[0028] If the water temperature is equal to or higher than the outside air temperature by Tth, the controller 50 proceeds to step S7, in which case the bypass expansion valve 21 and the bypass two-way valve 31 are maintained open. On the other hand, if the water temperature is lower than the outside air temperature + Tth, the controller 50 proceeds to step S10. In step S10, the controller 50 closes the bypass two-way valve 31, and then in step S11, the controller 50 transitions to normal heating operation control.

[0029] It is assumed that the processing of steps S5 and S6 keeps the bypass expansion valve 21 and the bypass two-way valve 31 open, gradually increasing the flow rate of the refrigerant in the main refrigerant circuit 10 and preventing an excessive rise in the internal temperature of the compressor 11. Therefore, when a predetermined time has elapsed since the compressor 11 was started in step S1, even if the condition of step S9 is met, the processing may be forced to proceed to step S10 and transition to normal heating operation control in step S11.

[0030] [3. Effects, etc.] As described above, in this embodiment, the refrigeration cycle apparatus 1 has the compressor 11, the user-side heat exchanger 12, the economizer 13, the main expansion valve 14, and the heat-source-side heat exchanger 15 connected in this order, and has the main refrigerant circuit 10 through which a refrigerant circulates. The user-side heat exchanger 12 is connected to the heat medium piping 101 and performs heat exchange between water circulating in the heat medium piping 101 and the refrigerant circulating in the main refrigerant circuit 10. The refrigeration cycle apparatus 1 is also equipped with bypass refrigerant circuits 20, 30 that connect the downstream side and upstream side of the compressor 11 to the main refrigerant circuit 10. The bypass expansion valve 21 is provided in the bypass refrigerant circuit 20 and opens and closes the bypass refrigerant circuit 20. The bypass two-way valve 31 is provided in the bypass refrigerant circuit 30 and opens and closes the bypass refrigerant circuit 30. The water temperature sensor 42 detects the temperature of the water flowing from the heat medium piping 101 into the user-side heat exchanger 12. The outside air temperature sensor 41 and the controller 50. When the controller 50 recognizes that the temperature detected by the water temperature sensor 42 is lower than the outside air temperature by Tth or more, indicating a refrigerant discharge shortage state, at the time of starting the compressor 11, the controller 50 opens the bypass expansion valve 21 and the bypass two-way valve 31. In the refrigeration cycle apparatus 1, if it is recognized that the compressor 11 is in a state of insufficient refrigerant discharge when the compressor 11 is started, the bypass expansion valve 21 and the bypass two-way valve 31 are opened to increase the amount of refrigerant drawn into the compressor 11 and promote refrigerant circulation. This makes it possible to prevent the internal temperature of the compressor 11 from excessively rising due to refrigerant stagnation in the compressor 11.

[0031] (Other embodiments) As described above, the above embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made.

[0032] In the above embodiment, in step S4 of FIG. 3 , the controller 50 recognizes a state in which the temperature of the water flowing into the use-side heat exchanger 12 is lower than the outside air temperature by at least a first predetermined temperature (Tth) as a refrigerant discharge shortage state of the present disclosure. In another embodiment, a state in which the temperature of the water flowing into the use-side heat exchanger 12 is lower than the saturation temperature of the refrigerant corresponding to the pressure detected by the discharge pressure sensor 40 by at least a second predetermined temperature may be recognized as a refrigerant discharge shortage state of the present disclosure. For example, the second predetermined temperature may be set to 0°C, and the corresponding process from step S5 onward in FIG. 3 may be executed when the saturation temperature of the refrigerant discharge pressure from the compressor 11 is equal to or lower than the water temperature. In this case, the controller 50 calculates the saturation temperature of the refrigerant corresponding to the pressure detected by the discharge pressure sensor 40 using a conversion table or conversion formula for refrigerant pressure and saturation temperature included in the control data stored in the memory 52. ​​Alternatively, a refrigerant discharge shortage state may be recognized based on other conditions related to the temperature of the water flowing into the use-side heat exchanger 12.

[0033] 3, the controller 50 may open the bypass expansion valve 21 and the bypass two-way valve 31 in steps S5 and S6, and may also open the main expansion valve 14 to a predetermined opening degree or more (for example, fully open). This allows the amount of refrigerant drawn into the compressor 11 to be further increased.

[0034] In the above embodiment, the first bypass refrigerant circuit and first bypass valve of the present disclosure are configured to include the bypass refrigerant circuit 26 and the bypass two-way valve 27, and the bypass refrigerant circuit 30 and the bypass two-way valve 31. However, the first bypass refrigerant circuit and first bypass valve of the present disclosure may be configured to include only the bypass refrigerant circuit 26 and the bypass two-way valve 27, or only the bypass refrigerant circuit 30 and the bypass two-way valve 31.

[0035] 1, a configuration may be adopted in which a bypass refrigerant circuit 22 (corresponding to the second bypass refrigerant circuit in the present disclosure) that connects the upstream side and downstream side of the bypass expansion valve 21 of the bypass refrigerant circuit 20, and a bypass two-way valve 23 (corresponding to the second bypass valve in the present disclosure) that is provided in the bypass refrigerant circuit 22 and opens and closes the bypass refrigerant circuit 22, as shown in Fig. 4. In this case, in step S5 of the flowchart in Fig. 3, the controller 50 opens the bypass expansion valve 21 and also the bypass two-way valve 23. This allows the amount of refrigerant drawn from the bypass refrigerant circuit 20 into the injection port 11a of the compressor 11 to be further increased.

[0036] Similarly, the bypass refrigerant circuit 30 may also be configured to include a bypass refrigerant circuit 33 (corresponding to the second bypass refrigerant circuit in the present disclosure) that connects the upstream side and downstream side of the bypass two-way valve 31, and a bypass two-way valve 32 (corresponding to the second bypass valve in the present disclosure) that is provided in the bypass refrigerant circuit 33 and opens and closes the bypass refrigerant circuit 33. In this case, in step S6 of the flowchart in Fig. 3, the controller 50 opens the bypass two-way valve 31 and also opens the added bypass two-way valve 32. This allows the amount of refrigerant drawn from the bypass refrigerant circuit 30 to be further increased.

[0037] 1, a configuration may be adopted in which a bypass refrigerant circuit 24 connects the upstream side of the main expansion valve 14 with the downstream side of the main refrigerant circuit 10, and a bypass two-way valve 25 is provided in the bypass refrigerant circuit 24 to open and close the bypass refrigerant circuit 24, as shown in Fig. 5. In this case, in steps S5 and S6 of the flowchart in Fig. 3, the controller 50 opens the bypass expansion valve 21 and the bypass two-way valve 31, opens the main expansion valve 14 to a predetermined opening degree or more, and also opens the bypass two-way valve 25. This allows the amount of refrigerant flowing from the refrigerant pipe 16 into the compressor 11 to be further increased.

[0038] 6, the economizer 13 may be omitted from the configuration shown in FIG. 1, and a bypass refrigerant circuit 26 (corresponding to the first bypass circuit in the present disclosure) branching off from the main refrigerant circuit 10 between the user-side heat exchanger 12 and the main expansion valve 14 and communicating with the main refrigerant circuit 10 upstream of the compressor 11, and a bypass two-way valve 27 (corresponding to the first bypass valve in the present disclosure) provided in the bypass refrigerant circuit 26 for opening and closing the bypass refrigerant circuit 26 may be provided. In this case, in step S5 of the flowchart in FIG. 3, the controller 50 opens the bypass two-way valve 27 instead of the bypass expansion valve 21.

[0039] The controller in the present disclosure may be any device capable of controlling the device in the present disclosure. When describing the subject matter of the invention, the device controlling the device in the present disclosure may be referred to as a control means, a controller, or similar terms in addition to a controller. The controller can be implemented in various ways. For example, a processor may be used as the controller. Using a processor as the controller enables various processes to be performed by loading a program from a storage medium storing the program into the processor and executing the program. This allows the process content to be changed by modifying the program stored in the storage medium, thereby increasing the flexibility of changing the control content. Examples of processors include a central processing unit (CPU) and a microprocessing unit (MPU). Examples of storage media include a hard disk, flash memory, and optical disk. Furthermore, the controller may be implemented using wired logic, which does not allow rewriting of programs. Using wired logic as the controller is effective in improving processing speed. Examples of wired logic include an application-specific integrated circuit (ASIC). Furthermore, the controller may be implemented by combining a processor and wired logic. By combining a processor and wired logic to implement a controller, it is possible to increase the flexibility of software design while improving processing speed. Furthermore, the controller and a circuit having a function other than the controller may be implemented using a single semiconductor element. An example of a circuit having a different function is an A / D / D / A conversion circuit. Furthermore, the controller may be implemented using a single semiconductor element or multiple semiconductor elements. When using multiple semiconductor elements, each control function described in the claims may be implemented using different semiconductor elements. Furthermore, the controller may be implemented using a configuration including semiconductor elements and passive components such as resistors or capacitors.

[0040] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0041] (Addition) The above description of the embodiments discloses the following techniques.

[0042] (Technology 1) A refrigeration cycle apparatus having a main refrigerant circuit in which a refrigerant circulates, in which a compressor, a user-side heat exchanger, an expansion valve, and a heat-source-side heat exchanger are connected in that order, wherein the user-side heat exchanger is connected to a water piping and performs heat exchange between water circulating in the water piping and refrigerant circulating in the main refrigerant circuit, the refrigeration cycle apparatus comprising: a first bypass refrigerant circuit connecting the main refrigerant circuit downstream and upstream of the compressor; a first bypass valve provided in the first bypass refrigerant circuit and opening and closing the first bypass refrigerant circuit; a water temperature sensor that detects the temperature of water flowing from the water piping into the user-side heat exchanger; and a controller that, when the compressor is started, recognizes the operating state of the compressor based on the temperature detected by the water temperature sensor, and opens the first bypass refrigerant circuit using the first bypass valve when it recognizes that the compressor is in a predetermined refrigerant discharge shortage state. This configuration can prevent the internal temperature of the compressor from rising excessively when the compressor is started.

[0043] (Technology 2) The refrigeration cycle apparatus according to Technology 1, further comprising an economizer connected to the main refrigerant circuit between the user-side heat exchanger and the expansion valve, the compressor having an injection port communicating with a compression chamber, and the first bypass refrigerant circuit being a refrigerant circuit branching off from the main refrigerant circuit between the user-side heat exchanger and the economizer and communicating with the injection port via the economizer. With this configuration, when the compressor is started, the first bypass refrigerant circuit is opened and the high-pressure refrigerant that has been affected by the water heat exchanger is drawn into the injection port of the compressor, thereby increasing the amount of refrigerant circulating and suppressing the temperature rise of the compressor's mechanical parts.

[0044] (Technology 3) The refrigeration cycle device according to Technology 1 or Technology 2, wherein the main refrigerant circuit is installed outdoors and includes an outdoor air temperature sensor that detects the outdoor air temperature, and the controller recognizes a state in which the detected temperature of the water temperature sensor is higher than the detected temperature of the outdoor air temperature sensor by at least a first predetermined temperature as the refrigerant discharge insufficient state. With this configuration, a situation in which the detected temperature of the water temperature sensor is higher than the detected temperature of the outside air temperature sensor by at least a first predetermined temperature is determined to be a state in which the refrigerant discharge from the compressor is insufficient, thereby preventing the internal temperature of the compressor from rising excessively.

[0045] (Technology 4) The refrigeration cycle device according to Technology 1 or Technology 2, further comprising a discharge pressure sensor for detecting the pressure of the refrigerant discharged from the compressor, wherein the controller recognizes a state in which the temperature detected by the water temperature sensor is lower by at least a second predetermined temperature than the saturation temperature of the refrigerant corresponding to the detected pressure of the discharge pressure sensor as the refrigerant discharge insufficient state. With this configuration, a state in which the detected temperature of the water temperature sensor is lower by a second predetermined temperature or more than the saturation temperature of the refrigerant corresponding to the detected pressure of the discharge pressure sensor is judged to be a state in which the refrigerant discharge from the compressor is insufficient, and the internal temperature of the compressor can be prevented from rising excessively.

[0046] (Technology 5) A refrigeration cycle apparatus according to any one of Technologies 1 to 4, further comprising: a second bypass refrigerant circuit connecting the first bypass refrigerant circuit on the upstream side with the first bypass refrigerant circuit on the downstream side of the first bypass valve; and a second bypass valve provided in the second bypass refrigerant circuit for opening and closing the second bypass refrigerant circuit, wherein when the controller recognizes that the compressor is in the refrigerant discharge shortage state at the time of startup of the compressor, the controller opens the first bypass refrigerant circuit with the first bypass valve and opens the second bypass refrigerant circuit with the second bypass valve. With this configuration, when the compressor is started, the second bypass refrigerant circuit is opened by the second bypass valve, thereby increasing the amount of refrigerant drawn into the compressor and suppressing an increase in the internal temperature of the compressor.

[0047] (Technology 6) A refrigeration cycle device according to any one of technologies 1 to 5, wherein the expansion valve has an opening degree changing function, and when the controller recognizes that the compressor is in a state of insufficient refrigerant discharge at the time of startup of the compressor, the controller opens the first bypass refrigerant circuit using the first bypass valve and sets the opening degree of the expansion valve to a predetermined opening degree or more. With this configuration, when the compressor is started, the opening of the expansion valve is set to a predetermined opening or more, thereby increasing the amount of refrigerant drawn into the compressor and suppressing an increase in the internal temperature of the compressor. [Industrial Applicability]

[0048] The present disclosure is applicable to applications in which an excessive rise in the internal temperature of a compressor is suppressed when the compressor is started. [Explanation of symbols]

[0049] 1 Refrigeration cycle device 10 Main refrigerant circuit 11 Compressor 12 User side heat exchanger 13 Economizer 14 Main expansion valve 15 Heat source side heat exchanger 16 Refrigerant piping 17 Four-way valve 20 Bypass refrigerant circuit 21 Bypass expansion valve 30 Bypass refrigerant circuit 31 Bypass two-way valve 40 Discharge pressure sensor 41 Outside air temperature sensor 42 Water temperature sensor 50 Controllers 60 Remote Control 100 User-side heat carrier circuit 101 Heat carrier circuit 102 Transfer pump

Claims

1. A refrigeration cycle device having a main refrigerant circuit in which a compressor, a user-side heat exchanger, an expansion valve, and a heat source-side heat exchanger are connected in sequence, and in which a refrigerant circulates, the user-side heat exchanger is connected to a water pipe and performs heat exchange between water flowing through the water pipe and a refrigerant flowing through the main refrigerant circuit; a first bypass refrigerant circuit connecting the main refrigerant circuit on the downstream side and the upstream side of the compressor; a first bypass valve provided in the first bypass refrigerant circuit for opening and closing the first bypass refrigerant circuit; a water temperature sensor that detects the temperature of water flowing from the water pipe into the utilization-side heat exchanger; a controller that, upon start-up of the compressor, recognizes an operating state of the compressor based on the temperature detected by the water temperature sensor, and, when it recognizes that the compressor is in a predetermined refrigerant discharge shortage state, opens the first bypass refrigerant circuit by the first bypass valve; A refrigeration cycle device comprising:

2. an economizer connected to the main refrigerant circuit between the user-side heat exchanger and the expansion valve; the compressor has an injection port communicating with a compression chamber, The first bypass refrigerant circuit is a refrigerant circuit that branches off from the main refrigerant circuit between the user-side heat exchanger and the economizer, and communicates with the injection port via the economizer. The refrigeration cycle device according to claim 1.

3. The main refrigerant circuit is installed outdoors, An outside air temperature sensor is provided to detect the outside air temperature, The controller recognizes a state in which the temperature detected by the water temperature sensor is higher than the temperature detected by the outside air temperature sensor by at least a first predetermined temperature as the refrigerant discharge insufficient state. The refrigeration cycle device according to claim 1 or 2.

4. a discharge pressure sensor for detecting the pressure of the refrigerant discharged from the compressor; The controller recognizes a state in which the temperature detected by the water temperature sensor is lower by a second predetermined temperature or more than the saturation temperature of the refrigerant corresponding to the detected pressure of the discharge pressure sensor as the refrigerant discharge insufficient state. The refrigeration cycle device according to claim 1 or 2.

5. a second bypass refrigerant circuit connecting the first bypass refrigerant circuit on the upstream side and the first bypass valve on the downstream side; a second bypass valve provided in the second bypass refrigerant circuit to open and close the second bypass refrigerant circuit, When the controller recognizes that the compressor is in the refrigerant discharge shortage state at the time of startup of the compressor, the controller opens the first bypass refrigerant circuit by the first bypass valve and opens the second bypass refrigerant circuit by the second bypass valve. The refrigeration cycle device according to claim 1 or 2.

6. The expansion valve has an opening degree changing function, When the controller recognizes that the compressor is in the refrigerant discharge shortage state at the time of startup of the compressor, the controller opens the first bypass refrigerant circuit by the first bypass valve and sets the opening degree of the expansion valve to a predetermined opening degree or more. The refrigeration cycle device according to claim 1 or 2.

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