Refrigeration cycle device

Abstract

A refrigeration cycle device has a refrigerant circuit, a compressor, a condenser, an evaporator, a branch circuit, an expansion valve, an adjusting valve, a first temperature detecting section, a first pressure detecting section, a second temperature detecting section, a second pressure detecting section, and a control section. The control section performs excess / deficiency determination of an enclosed amount of refrigerant enclosed in the refrigerant circuit based on a relationship between a discharge refrigerant temperature from the compressor detected by the first temperature detecting section, a discharge refrigerant pressure from the compressor detected by the first pressure detecting section, a suction refrigerant temperature to the compressor detected by the second temperature detecting section, a suction refrigerant pressure to the compressor detected by the second pressure detecting section, and an opening degree of the adjusting valve.

Description

Technical Field

[0001] Embodiments of the present invention relate to a refrigeration cycle device. Background Technology

[0002] A refrigeration cycle system consists of a refrigerant circuit with a compressor, condenser, expansion valve, and evaporator as its main components. A specified amount of refrigerant is sealed into the refrigerant circuit. For example, when cooling or heating a space using a refrigeration cycle system, the refrigerant circulates in the refrigerant circuit, exchanging heat with the outside and inside air. If the refrigeration cycle system is not operating with an appropriate amount of refrigerant, the air conditioning capacity cannot be fully utilized, potentially reducing energy efficiency and reliability. Therefore, to improve the energy efficiency and reliability of the refrigeration cycle system, it is necessary to operate it with an appropriate amount of refrigerant.

[0003] One method for determining whether the amount of refrigerant injected into the refrigerant circuit (refrigerant charge) is appropriate is to install sound wave transmitting and receiving elements in the liquid line of the refrigerant circuit to monitor the refrigerant flow state, and then determine whether the refrigerant charge is appropriate based on the monitoring results. However, adding components such as sound wave elements for this monitoring can easily lead to increased costs.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Patent No. 3531440 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The present invention was made in view of the above circumstances, and its object is to provide a refrigeration cycle device that can minimize the increase in cost caused by the addition of components and determine whether the amount of refrigerant injected into the refrigerant circuit (refrigeration charge) is appropriate.

[0009] Methods for solving problems

[0010] According to an embodiment, a refrigeration cycle device includes a refrigerant circuit, a compressor, a condenser, an evaporator, a branch circuit, an expansion valve, a regulating valve, a first temperature detection unit, a first pressure detection unit, a second temperature detection unit, a second pressure detection unit, and a control unit. The refrigerant circuit includes a main flow path for refrigerant circulation. The compressor draws in refrigerant from the main flow path, compresses it, and discharges the refrigerant into the main flow path. The condenser condenses the refrigerant. The evaporator evaporates the refrigerant. The branch circuit is included in the refrigerant circuit, causing a portion of the refrigerant flowing from the condenser to the evaporator to be diverted from the main flow path downstream of the condenser, and the diverted refrigerant is injected into the compressor. The expansion valve depressurizes at least a portion of the refrigerant flowing from the condenser to the evaporator downstream of the branch circuit. The regulating valve regulates the flow rate of the refrigerant flowing in the branch circuit. The first temperature detection unit detects the discharge temperature of the refrigerant discharged from the compressor upstream of the condenser in the main flow path. The first pressure detection unit detects the discharge pressure of the refrigerant discharged from the compressor upstream of the condenser in the main flow path. The second temperature detection unit detects the suction temperature of the refrigerant drawn into the compressor downstream of the evaporator in the main flow path. The second pressure detection unit detects the suction pressure of the refrigerant drawn into the compressor downstream of the evaporator in the main flow path. The control unit determines the excess or deficiency of the refrigerant supplied to the refrigerant circuit based on the relationship between the discharge temperature detected by the first temperature detection unit, the discharge pressure detected by the first pressure detection unit, the suction temperature detected by the second temperature detection unit, the suction pressure detected by the second pressure detection unit, and the opening degree of the adjusting valve. Attached Figure Description

[0011] Figure 1 This is a diagram schematically illustrating the configuration of a refrigeration cycle apparatus according to an embodiment, including a refrigeration cycle.

[0012] Figure 2 This is a control flowchart for determining whether the amount of refrigerant in the refrigeration cycle device of the embodiment is appropriate.

[0013] Figure 3 This is a Ph graph (pressure-enthalpy graph) of the refrigeration cycle device in the embodiment. Detailed Implementation

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0015] Figure 1This is a schematic circuit diagram illustrating the refrigeration cycle of the refrigeration cycle device 1 according to this embodiment. The refrigeration cycle device 1 can operate in cooling mode, heating mode, or both modes, and can be used as an air conditioner, a water-cooled heat source unit, an air-cooled heat pump unit, a condensing unit, etc.

[0016] like Figure 1 As shown, the refrigeration cycle unit 1 includes, as its main components, a compressor 11, a first temperature detection unit 12, a first pressure detection unit 13, a condenser 14, a refrigerant storage device 15, an expansion valve 16, an evaporator 17, a second pressure detection unit 18, and a second temperature detection unit 19. These components are connected via a refrigerant circuit 20, forming the refrigeration cycle unit 10. The refrigerant circuit 20 includes a main refrigerant circulation path 21 and branch paths 22 branching off from the main refrigerant circulation path 21.

[0017] The compressor 11 includes, for example, a compressor body 1a and a receiver 1b. The compressor body 1a, as a main component, includes a sealed container, a rotary compression mechanism, an electric mechanism, etc., and compresses the gaseous refrigerant supplied from the receiver 1b to discharge the high-temperature, high-pressure gaseous refrigerant into the main flow path 21. The receiver 1b performs gas-liquid separation on the refrigerant supplied via the main flow path 21 and supplies the gaseous refrigerant to the compressor body 1a.

[0018] The first temperature detection unit 12 detects the discharge temperature (hereinafter referred to as the discharge refrigerant temperature) of the refrigerant discharged from the compressor 11 upstream of the condenser 14 in the main flow path 21. The first temperature detection unit 12 is, for example, located near the refrigerant outlet (not shown) of the compressor body 1a, and detects the temperature of the gaseous refrigerant as the discharge refrigerant temperature. The first temperature detection unit 12 is, for example, a temperature sensor (thermostat) with a temperature sensing element disposed in the piping of the main flow path 21 to detect the discharge refrigerant temperature. The first temperature detection unit 12 is operated and controlled by the control unit 40 (described later), which transmits the detected discharge refrigerant temperature value to the control unit 40 via wired or wireless means.

[0019] The first pressure detection unit 13 detects the discharge pressure (hereinafter referred to as discharge refrigerant pressure) of the refrigerant discharged from the compressor 11 upstream of the condenser 14 in the main flow path 21. The first pressure detection unit 13 is, for example, located near the refrigerant discharge port (not shown) of the compressor body 1a, and detects the pressure of the gaseous refrigerant as the discharge refrigerant pressure. Figure 1In the example shown, the first pressure detection unit 13 is located downstream of the first temperature detection unit 12. However, the first pressure detection unit 13 can also be located upstream of the first temperature detection unit 12. The first pressure detection unit 13 is, for example, a pressure sensor or the like, in which a pressure-sensing element is disposed within the piping of the main flow path 21 to detect the pressure of the discharged refrigerant. The first pressure detection unit 13 is controlled by the control unit 40 (described later) to transmit the detected value of the discharged refrigerant pressure to the control unit 40 via wired or wireless means.

[0020] The condenser 14 is located downstream of the compressor body 1a in the main flow path 21. It condenses the high-temperature and high-pressure gaseous refrigerant discharged from the compressor body 1a by exchanging heat with air and the like, thus changing it into a high-pressure liquid refrigerant.

[0021] The refrigerant storage device 15 stores excess refrigerant (hereinafter referred to as surplus refrigerant) exceeding the appropriate amount supplied to the refrigerant circuit 20 (mainstream path 21 and branch paths 22). The refrigerant storage device 15 is, for example, a receiver or liquid receiver. Figure 1 In the example shown, the refrigerant storage device 15 is located downstream of the condenser 14 in the main flow path 21, storing the remaining high-pressure liquid refrigerant after condensation by the condenser 14. Furthermore, the location of the refrigerant storage device 15 is not limited to... Figure 1 The example shown.

[0022] Expansion valve 16 depressurizes the high-pressure liquid refrigerant condensed by condenser 14, transforming it into a low-pressure gas-liquid two-phase refrigerant. Figure 1 In the example shown, the expansion valve 16 is positioned downstream of the refrigerant storage device 15 in the main flow path 21 and the branch flow path 22. It depressurizes the high-pressure liquid refrigerant flowing from the refrigerant storage device 15 after condensation by the condenser 14, transforming it into a low-pressure gas-liquid two-phase refrigerant. At this time, the expansion valve 16, depending on the opening degree of the adjusting valve 23, allows a portion or all of the high-pressure liquid refrigerant flowing from the refrigerant storage device 15 after condensation by the condenser 14 to pass through. That is, the expansion valve 16 depressurizes at least a portion of the refrigerant flowing from the condenser 14 to the evaporator 17 downstream of the branch flow path 22. The expansion valve 16 is operated and controlled by the control unit 40 (described later), which assigns the opening value to the control unit 40 via wired or wireless means.

[0023] Evaporator 17 is located downstream of expansion valve 16 in main path 21. Through heat exchange with air, etc., the gas-liquid two-phase refrigerant passing through expansion valve 16 evaporates and changes into low-temperature, low-pressure gas-phase refrigerant.

[0024] The second pressure detection unit 18 detects the suction pressure (hereinafter referred to as suction refrigerant pressure) of the refrigerant drawn into the compressor 11 downstream of the evaporator 17 in the main flow path 21. The second pressure detection unit 18 is, for example, located near the refrigerant inlet (not shown) of the receiver 1b, and detects the pressure of the gas-liquid two-phase refrigerant as the suction refrigerant pressure. The second pressure detection unit 18 is, for example, a pressure sensor or pressure sensor with a pressure-sensitive element disposed in the piping of the main flow path 21 that detects the suction refrigerant pressure. The second pressure detection unit 18 is operated by the control unit 40 (described later), and the detected discharge refrigerant pressure value is transmitted to the control unit 40 via wired or wireless means.

[0025] The second temperature detection unit 19 detects the suction temperature (hereinafter referred to as suction refrigerant temperature) of the refrigerant drawn into the compressor 11 downstream of the evaporator 17 in the main flow path 21. The second temperature detection unit 19 is, for example, located near the refrigerant inlet (not shown) of the receiver 1b, and detects the temperature of the gas-liquid two-phase refrigerant as the suction refrigerant temperature. Figure 1 In the example shown, the second temperature detection unit 19 is located downstream of the second pressure detection unit 18. However, the second temperature detection unit 19 can also be located upstream of the second pressure detection unit 18. The second temperature detection unit 19 is, for example, a temperature sensor (thermistor) whose temperature-sensing element is disposed in the piping of the main flow path 21 to detect the temperature of the intake refrigerant. The second temperature detection unit 19 is controlled by the control unit 40 (described later) to transmit the detected intake refrigerant temperature value to the control unit 40 via wired or wireless means.

[0026] like Figure 1 As shown, the main flow path 21 branches off between the condenser 14 and the expansion valve 16, specifically between the refrigerant storage device 15 and the expansion valve 16, via a branch path 22, which bypasses the compressor body 1a of the compressor 11. The branch path 22 is a bypass path for the main flow path 21. The branch path 22 diverts a portion of the refrigerant flowing from the condenser 14 to the evaporator 17 from the main flow path 21. Figure 1 In the example shown, branch 22, downstream of refrigerant storage device 15 and upstream of expansion valve 16, diverts a portion of the high-pressure liquid refrigerant condensed by condenser 14 and flowing out of refrigerant storage device 15.

[0027] A regulating valve 23 is provided in branch line 22. The regulating valve 23 depressurizes the high-pressure liquid refrigerant flowing in branch line 22, changing it into a low-pressure gas-liquid two-phase refrigerant. Furthermore, the regulating valve 23 adjusts the flow rate of the refrigerant flowing in branch line 22 according to its opening degree. The regulating valve 23 is operated and controlled by the control unit 40 (described later), which transmits the opening value to the control unit 40 via wired or wireless means. The regulating valve 23 is adjusted to an appropriate opening degree (hereinafter referred to as appropriate opening degree) based, for example, on the discharge refrigerant temperature.

[0028] In this embodiment, as an example, the appropriate opening degree is defined as the value of the opening degree of the regulating valve 23 preset under specified conditions. These specified conditions (hereinafter referred to as the prerequisite conditions) are that the discharge refrigerant temperature, discharge refrigerant pressure, intake refrigerant temperature, and intake refrigerant pressure are all appropriate values, and the amount of refrigerant injected into the refrigerant circuit 20 is appropriate (the optimal amount described later) while operating the refrigeration cycle device 1. By adjusting the opening degree of the regulating valve 23 to the appropriate opening degree, the flow rate of the refrigerant in the branch circuit 22 (hereinafter referred to as the injection flow rate) is adjusted to an appropriate amount. That is, the appropriate opening degree is preset so that the injection flow rate becomes appropriate under these specified conditions. The value of the appropriate opening degree is tabulated, for example, in association with the optimal amount of refrigerant described later, and stored in the storage device of the control unit 40, and is appropriately read into the memory as a parameter during the operation of the refrigeration cycle device 1. As a result, the opening of the regulating valve 23 is adjusted to be an appropriate opening, and the injection flow rate is adjusted to an appropriate amount.

[0029] Branch line 22 injects low-pressure gas-liquid two-phase refrigerant, which has passed through regulating valve 23, into compressor body 1a. That is, branch line 22 is a so-called injection flow path. By injecting gas-liquid two-phase refrigerant into compressor body 1a, compressor body 1a is cooled, and the temperature of the refrigerant discharged from compressor body 1a (more precisely, the discharge refrigerant temperature) decreases.

[0030] In addition to these components, the refrigeration cycle device 1 also includes a notification unit 30 and a control unit 40.

[0031] The notification unit 30, controlled by the control unit 40, notifies that the amount of refrigerant supplied to the refrigeration cycle unit 1 (hereinafter referred to as the refrigerant charge) is not appropriate. The refrigerant charge is the amount of refrigerant supplied to the refrigerant circuit 20; specifically, it is the current amount of refrigerant supplied to the piping constituting the refrigerant circuit 20 (mainstream path 21 and branch path 22). The appropriate amount of refrigerant is the appropriate refrigerant charge that should be supplied to the refrigerant circuit 20, and is preset, for example, the amount supplied to achieve the desired air conditioning performance for the refrigeration cycle unit 1, under assumed conditions such as the piping lengths of the mainstream path 21 and branch path 22.

[0032] Furthermore, the assumed main pipe length 21 and branch pipe length 22 vary depending on environmental conditions such as the environment in which the refrigeration cycle unit 1 is installed. Therefore, the appropriate amount of refrigerant can be set to multiple values, for example, at the factory, based on these conditions. In this case, the most appropriate value is selected from the multiple preset appropriate amounts based on the pipe length after the refrigeration cycle unit 1 is installed, i.e., the actual installed pipe length. This selection can be performed manually or automatically by the control unit 40. The selected appropriate amount (hereinafter referred to as the optimal amount) is stored, for example, in a storage device of the control unit 40 described later, and is appropriately read into the memory as a parameter.

[0033] For example, if the refrigerant charge is insufficient, the notification unit 30 will issue a notification indicating that the refrigerant charge is inadequate relative to the optimal amount. In this case, refrigerant may leak from the main pipe 21 and branch pipe 22. Therefore, the notification unit 30 will notify the user or operator (hereinafter referred to as "users") of this abnormal condition, indicating that the refrigeration cycle unit 1 is not operating properly and is in an abnormal state that prevents the desired air conditioning from being performed. As a result, users and operators (hereinafter referred to as "users") are thoroughly informed and reminded, for example, that a temporary shutdown of the refrigeration cycle unit 1 is required for maintenance work.

[0034] Furthermore, if the refrigerant charge exceeds the optimal amount, the notification unit 30 can also issue a notification indicating that the refrigerant charge is excessive relative to the optimal amount. In this case, the remaining refrigerant can be stored in the refrigerant storage device 15, so it will not immediately hinder the proper operation of the refrigeration cycle device 1. However, by notifying the user that the refrigerant charge is excessive relative to the optimal amount, it can prompt the user to pay attention. In addition, if the refrigerant charge is at the optimal amount, and the refrigerant charge is in a normal state without excess or deficiency, the notification unit 30 can also notify that the refrigeration cycle device 1 can continue to operate properly.

[0035] The notification unit 30 can be equipped with indicator lights, monitors, panels, speakers, or combinations thereof. For example, when the refrigerant charge is insufficient relative to the optimal level, the notification unit 30 can thoroughly inform users, operators, etc. (hereinafter referred to as users, etc.) of the refrigerant leak by illuminating (flashing) a red indicator light, sounding a warning audible tone, playing or displaying a warning message, or illuminating a laser beam. On the other hand, when the refrigerant charge is excessive relative to the optimal level, the notification unit 30 can provide only minimal notification, such as illuminating a yellow or blue indicator light or displaying a confirmation message. Furthermore, when the refrigerant charge is above the optimal level, or when the refrigerant charge is at the optimal level, the notification unit 30 may not provide any notification.

[0036] The location of the notification unit 30 can be anywhere as long as it can adequately and thoroughly inform and remind users. For example, the notification unit 30 can be equipped in the central management room of the refrigeration cycle unit 1, or as an operating remote control.

[0037] The control unit 40 controls the operation of the refrigeration cycle unit 1. In this embodiment, the control unit 40 controls the operation of the compressor 11, the first temperature detection unit 12, the first pressure detection unit 13, the refrigerant storage device 15, the expansion valve 16, the second pressure detection unit 18, the second temperature detection unit 19, the regulating valve 23, and the notification unit 30 in the refrigeration cycle unit 10. For example, the control unit 40 controls the start and stop of the compressor 11, its speed, frequency, etc., and adjusts the opening of the expansion valve 16 and the regulating valve 23 accordingly. In addition, during the operation control of the refrigeration cycle unit 1, the control unit 40 determines the excess or deficiency of the refrigerant in the refrigerant circuit 20, i.e., whether the refrigerant dosage is appropriate, based on the relationship between the discharge refrigerant temperature, the discharge refrigerant pressure, the intake refrigerant temperature, the intake refrigerant pressure, and the opening of the regulating valve 23, as described later.

[0038] The control unit 40 includes a CPU, memory, storage device (non-volatile memory), input / output circuits, timers, etc., and performs prescribed arithmetic operations. For example, the control unit 40 reads various data through the input / output circuits, uses a program read from the storage device into the memory, and performs arithmetic operations on the CPU. Based on the processing results, it controls the operation of the compressor 11, the first temperature detection unit 12, the first pressure detection unit 13, the refrigerant storage device 15, the expansion valve 16, the second pressure detection unit 18, the second temperature detection unit 19, the regulating valve 23, and the notification unit 30. At this time, the control unit 40 transmits and receives control signals and data signals with them via wired or wireless means. That is, the control unit 40 is electrically connected to each of the components that are controlled via wired or wireless means.

[0039] In the refrigeration cycle device 1 with the above-described configuration, the operation control of the refrigeration cycle device 1 performed by the control unit 40, specifically the control for determining the excess or deficiency of refrigerant charge in the refrigerant circuit 20 during the operation control of the refrigeration cycle device 1 (hereinafter referred to as the refrigerant charge adequacy determination process), will be described according to the control flow of the control unit 40. Figure 2 The control flow of the control unit 40 indicates the process of determining whether the cooling dosage is appropriate.

[0040] When determining whether the refrigerant dosage is appropriate, the refrigeration cycle unit 1 starts operating (S101). Specifically, the control unit 40 starts the compressor 11 and opens the expansion valve 16 to circulate the refrigerant in the main flow path 21. At this time, the control unit 40 adjusts the regulating valve 23 to an appropriate opening degree as the aforementioned prerequisite is met, adjusting the refrigerant flow rate (injection flow rate) in the branch path 22 to an appropriate amount. That is, at the start of operation, the refrigeration cycle unit 1 is operated with the regulating valve 23 adjusted to an appropriate opening degree to make the injection flow rate appropriate. In this state, triggered by the operation of the refrigeration cycle unit 1, the control unit 40 can perform the refrigerant dosage appropriateness determination process.

[0041] Thus, while the refrigeration cycle device 1 is operating, the control unit 40 acquires various values ​​(operational data) indicating the operating status of the refrigeration cycle device 1 (S102). This operational data includes the discharge refrigerant temperature, discharge refrigerant pressure, intake refrigerant temperature, intake refrigerant pressure, and the opening degree of the adjusting valve 23. Therefore, the control unit 40 acquires this operational data from the first temperature detection unit 12, the first pressure detection unit 13, the second temperature detection unit 19, the second pressure detection unit 18, and the adjusting valve 23, respectively.

[0042] Next, the control unit 40 determines whether the amount of refrigerant in the refrigerant circuit 20 is appropriate based on the acquired operating data (S103). That is, the control unit 40 determines whether the amount of refrigerant is appropriate based on the relationship between the discharge refrigerant temperature, discharge refrigerant pressure, suction refrigerant temperature, suction refrigerant pressure, and the opening degree of the adjusting valve 23. For example, if the discharge refrigerant temperature, discharge refrigerant pressure, suction refrigerant temperature, and suction refrigerant pressure are all predetermined values ​​(appropriate values ​​under the premise), the control unit 40 determines whether the amount of refrigerant is appropriate based on the relationship between the opening degree of the adjusting valve 23 and the appropriate opening degree. In this embodiment, the refrigeration cycle device 1 is, for example, pre-set at the factory to operate with multiple appropriate amounts of refrigerant, including the values ​​of discharge refrigerant temperature, discharge refrigerant pressure, suction refrigerant temperature, suction refrigerant pressure, and the appropriate opening degree of the adjusting valve 23. These values ​​are tabulated, for example, associated with multiple appropriate amounts of refrigerant, and stored in the storage device of the control unit 40. Alternatively, the value could be presented as a numerical range and stored in the storage device of the control unit 40.

[0043] Furthermore, even after the control unit 40 maintains the appropriate opening value of the adjusting valve 23 in the storage device, it can be changed according to the actual conditions after the refrigeration cycle device 1 starts operating, such as changes in the refrigerant charge (the current amount of refrigerant sealed in). As described above, the appropriate amount of refrigerant may change from a preset initial value depending on conditions such as the environment in which the refrigeration cycle device 1 is installed, such as the actual piping lengths of the main pipeline 21 and branch pipeline 22. That is, the control unit 40 maintains the appropriate amount of refrigerant in a manner that allows for changes from the initial value.

[0044] Therefore, the optimal amount of refrigerant (a value selected from multiple optimal amounts) may change from the initial value of the optimal amount and be set to the value calculated during the installation of the refrigeration cycle unit 1, and maintained in the storage device of the control unit 40. By assuming such a situation and being able to change the value of the appropriate opening of the adjusting valve 23, the accuracy of determining whether the refrigerant amount is appropriate can be improved. That is, when the optimal amount of refrigerant changes from the initial value, the control unit 40 can change and correct the value of the appropriate opening of the adjusting valve 23, and maintain the corrected value. For example, in building multi-air conditioning systems, the amount of additional refrigerant to be added is calculated based on the length of the connecting piping, and even in cases where refrigerant is added on-site during installation, or where the appropriate amount of refrigerant is added to the refrigerant circuit after installation, such as with a refrigeration unit, it can be appropriately handled.

[0045] When determining whether the refrigerant charge is appropriate, the control unit 40 compares the obtained opening value of the adjusting valve 23, i.e., the current value of the opening of the adjusting valve 23, with the appropriate opening value. The appropriate opening value is read from the control unit 40's storage device into its memory, for example. For instance, if the opening value of the adjusting valve 23 exceeds the appropriate opening value, the control unit 40 determines that the refrigerant charge is inappropriate; specifically, it determines that the refrigerant charge does not meet the optimal amount (the refrigerant charge is insufficient relative to the optimal amount, or more precisely, the appropriate amount). Conversely, if the opening value of the adjusting valve 23 is less than the appropriate opening value, the control unit 40 determines that the refrigerant charge is inappropriate; specifically, it determines that the refrigerant charge exceeds the optimal amount (the refrigerant charge is excessive relative to the optimal amount, or more precisely, the appropriate amount). Furthermore, if the refrigerant charge is the optimal amount, or more precisely, the appropriate amount, the control unit 40 determines that the refrigerant charge is neither excessive nor insufficient, and is appropriate.

[0046] The reasons for making this judgment are as follows. Figure 3 This is a pressure-enthalpy diagram (PH diagram) showing the refrigeration cycle device 1 of this embodiment. Figure 3 In this context, M represents the amount of refrigerant flowing in evaporator 17. Additionally, m is the injection flow rate; subscript 1 (m1) indicates the injection flow rate (m1) when the refrigerant is at its optimal level, and subscript 2 indicates the injection flow rate (m2) when the refrigerant is insufficient relative to the optimal level. Similarly, in... Figure 3 In this diagram, SC1 represents the subcooling at the outlet of condenser 14 when the refrigerant charge is optimal. SC2 represents the subcooling at the outlet of condenser 14 when the refrigerant charge is insufficient relative to the optimal charge. h1, h2, h3, and h4 represent the enthalpy at each state point. Tsuc represents the intake refrigerant temperature, and Td represents the discharge refrigerant temperature.

[0047] When the refrigerant charge is optimal, in other words, when the subcooling at the outlet of condenser 14 is SC1, the injection flow rate (m1) is calculated using the formula m1 = M(h4 - h3) / (h3 - h1). Conversely, when the refrigerant charge is insufficient relative to the optimal charge, in other words, when the subcooling at the outlet of condenser 14 is SC2, the injection flow rate (m2) is calculated using the formula m2 = M(h4 - h3) / (h3 - h2). Figure 3 As shown, SC2 is smaller than SC1, therefore (h3-h1) > (h3-h2). Thus, when the refrigerant charge is insufficient relative to the optimum, the injection flow rate (m2) is greater than the injection flow rate (m1) when the refrigerant charge is optimal. Consequently, when the refrigerant charge is insufficient relative to the optimum, the opening degree of the regulating valve 23 in the injection flow path 22 is greater than the opening degree (appropriate opening degree) of the regulating valve 23 when the refrigerant charge is optimal.

[0048] Therefore, if the opening value of the adjusting valve 23 is not an appropriate opening, it can be determined that the refrigerant charge is not optimal. For example, if the opening value of the adjusting valve 23 exceeds the appropriate opening value, it can be determined that the refrigerant charge does not meet the optimal requirement (the refrigerant charge is insufficient relative to the optimal amount). Furthermore, if the opening value of the adjusting valve 23 is less than the appropriate opening value, it can be determined that the refrigerant charge exceeds the optimal amount (the refrigerant charge is excessive relative to the optimal amount). And, if the opening value of the adjusting valve 23 is an appropriate opening, it can be determined that the refrigerant charge is optimal, meaning that the refrigerant charge is neither excessive nor insufficient, and is appropriate.

[0049] If the determination result in S103 is that the cooling dose is not optimal (yes in S104 or S106), the control unit 40 activates the notification unit 30 to notify that the cooling dose is not optimal, as described below.

[0050] If it is determined that the refrigerant charge is insufficient relative to the optimal amount (S104 indicates yes), the control unit 40 instructs the notification unit 30 to notify the refrigeration cycle unit 1 that it is not operating properly and is in an abnormal state where desired air conditioning cannot be performed (S105). For example, the control unit 40 activates the notification unit 30 by illuminating (flashing) a red indicator light, sounding a warning audible beep, playing or displaying a warning message, or illuminating with a laser. This allows for thorough notification and alerting of users regarding refrigerant leakage.

[0051] Furthermore, if it is determined that the refrigerant charge exceeds the optimal amount, i.e., the refrigerant charge is excessive relative to the optimal amount (not in S104 and yes in S106), the control unit 40 stores the remaining refrigerant in the refrigerant storage device 15 (S107). That is, the control unit 40 activates the refrigerant storage device 15 to begin storing the remaining refrigerant. Thus, the remaining refrigerant is stored in the refrigerant storage device 15, and the refrigerant charge is adjusted to the optimal amount. Therefore, the refrigeration cycle device 1 can continue to operate appropriately, achieving the desired air conditioning.

[0052] Furthermore, the control unit 40 activates the notification unit 30 to alert the user (S108). For example, the control unit 40 activates the notification unit 30 by illuminating a yellow indicator light or displaying a confirmation message. In this way, only the minimum notification is required. However, in this case, the control unit 40 may also choose not to activate the notification unit 30 and not issue any notification. Even without any notification, since the remaining refrigerant is stored in the refrigerant storage device 15 (S107), it is possible to avoid immediately hindering the proper operation of the refrigeration cycle device 1.

[0053] If the notification unit 30 issues the desired notification (S105 or S108), the control unit 40 determines the operation stop condition of the refrigeration cycle device 1 (S109). Alternatively, if it is determined in S103 that the refrigerant charge is optimal (but not in S104 and not in S106), the control unit 40 determines the operation stop condition of the refrigeration cycle device 1 (S109). Furthermore, in this case, the control unit 40 may, for example, notify the notification unit 30 that the refrigerant charge is optimal before determining the operation stop condition. The operation stop condition is the determination condition for whether to stop the operation of the refrigeration cycle device 1, for example, based on whether the control unit 40 receives a signal indicating that the operation of the refrigeration cycle device 1 has stopped. The signal indicating operation stop is sent, for example, by selecting operation stop from the central management room of the refrigeration cycle device 1, a remote control, or the like.

[0054] If the operation stop condition is not met, the control unit 40 obtains the operation data of the refrigeration cycle device 1 (S102), and determines again whether the refrigerant charge in the refrigerant circuit 20 is appropriate based on the obtained operation data (S103). Then, the subsequent processing is selectively repeated according to the determination result (S104 to S108).

[0055] In contrast, when the operation stop condition is met, the control unit 40 stops the operation of the refrigeration cycle device 1 (S110).

[0056] That is, during the operation of the refrigeration cycle device 1, a series of processes for determining whether the refrigerant dosage is appropriate are repeatedly performed. Then, when the refrigeration cycle device 1 stops operating, the series of processes for determining whether the refrigerant dosage is appropriate also ends.

[0057] Thus, according to this embodiment, the first temperature detection unit 12, the first pressure detection unit 13, the second temperature detection unit 19, the second pressure detection unit 18, and the adjusting valve 23 can be used to determine whether the amount of refrigerant injected into the refrigerant circuit 20 (refrigeration charge) is appropriate. These components can be the same as those conventionally present in the refrigeration cycle device 1. Therefore, it is not necessary to add dedicated components for determining whether the refrigerant charge is appropriate, such as sound wave transmitting and receiving components. That is, the cost increase caused by adding components can be minimized while determining whether the amount of refrigerant injected into the refrigerant circuit 20 (refrigeration charge) is appropriate. As a result, excess or deficiency of refrigerant charge in the refrigerant circuit 20 can be suppressed. Therefore, the refrigeration cycle device 1 can operate properly and achieve the desired air conditioning performance, and the energy efficiency and reliability of the refrigeration cycle device 1 can be improved.

[0058] Furthermore, by providing expected notifications when the refrigerant charge in the refrigerant circuit 20 is excessive or insufficient, users can be fully informed and reminded regarding the appropriateness of the refrigerant charge. For example, if the refrigerant charge is insufficient relative to the optimal amount, the refrigeration cycle unit 1 can be temporarily stopped for inspection. This allows for immediate repair or replacement of the main flow path 21 and branch flow paths (injection flow paths) 22, or refrigerant replenishment, enabling the refrigeration cycle unit 1 to quickly return to proper operation. Additionally, by providing expected notifications when the refrigerant charge is excessive relative to the optimal amount, or when the refrigerant charge is at the optimal amount, it is possible to prevent, for example, abnormal conditions where the refrigeration cycle unit 1 is not operating properly and thus cannot achieve the desired air conditioning.

[0059] Furthermore, by adjusting the value of the appropriate opening of the regulating valve 23 according to the operating status of the installed refrigeration cycle device 1, the excess or deficiency of refrigerant in the refrigerant circuit 20 can be more appropriately suppressed, thereby further preventing the reduction of the energy efficiency and reliability of the refrigeration cycle device 1.

[0060] Furthermore, in the above embodiment, the refrigeration cycle device 1 includes a first pressure detection unit 13 for detecting the discharge refrigerant pressure and a second pressure detection unit 18 for detecting the intake refrigerant pressure. However, instead of these pressure detection units 13 and 18, the discharge refrigerant pressure and intake refrigerant pressure can be calculated based on methods such as converting the saturated vapor pressure from the refrigerant's condensation temperature or evaporation temperature, or by converting based on the relationship between the outside air temperature and the condenser fan speed, and the evaporator fan speed and the outside air temperature. In this case, the pressure detection units 13 and 18 can be omitted, further suppressing the cost increase caused by the addition of components.

[0061] The embodiments of the present invention have been described above, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents.

[0062] Explanation of reference numerals in the attached figures

[0063] 1…Refrigeration cycle unit, 1a…Compressor body, 1b…Receiver, 10…Refrigeration cycle section, 11…Compressor, 12…First temperature detection section, 13…First pressure detection section, 14…Condenser, 15…Refrigerant storage device, 16…Expansion valve, 17…Evaporator, 18…Second pressure detection section, 19…Second temperature detection section, 20…Refrigerant circuit, 21…Main flow path, 22…Branch path (injection flow path), 23…Adjusting valve, 30…Notification section, 40…Control section.

Claims

1. A refrigeration cycle device, characterized in that, have: The refrigerant circuit includes the main path for refrigerant circulation; The compressor draws in the refrigerant from the main flow path, compresses it, and discharges the refrigerant into the main flow path. A condenser is used to condense the refrigerant. An evaporator is used to evaporate the refrigerant; A branch path, included in the refrigerant circuit, causes a portion of the refrigerant flowing from the condenser to the evaporator to be diverted from the main flow path downstream of the condenser, and the diverted refrigerant is injected into the compressor. An expansion valve that reduces the pressure of at least a portion of the refrigerant flowing from the condenser to the evaporator downstream of the branch line; Adjusting valve to adjust the flow rate of the refrigerant flowing in the branch circuit; The first temperature detection unit detects the discharge temperature of the refrigerant discharged from the compressor upstream of the condenser in the main flow path; The first pressure detection unit detects the discharge pressure of the refrigerant discharged from the compressor upstream of the condenser in the main flow path; The second temperature detection unit detects the intake temperature of the refrigerant drawn into the compressor downstream of the evaporator in the main flow path; The second pressure detection unit detects the suction pressure of the refrigerant drawn into the compressor downstream of the evaporator in the main flow path; as well as The control unit determines whether the amount of refrigerant sealed into the refrigerant circuit is excessive or insufficient based on the relationship between the discharge temperature detected by the first temperature detection unit, the discharge pressure detected by the first pressure detection unit, the suction temperature detected by the second temperature detection unit, the suction pressure detected by the second pressure detection unit, and the opening degree of the adjusting valve.

2. The refrigeration cycle device according to claim 1, characterized in that, The control unit The opening value of the adjusting valve, which is preset to an appropriate value under the conditions that the discharge temperature, discharge pressure, suction temperature, and suction pressure are all appropriate values ​​and the amount of refrigerant sealed in the refrigerant circuit is appropriate, is maintained at an appropriate opening value. If the current value of the opening of the regulating valve exceeds the appropriate opening value when determining the excess or deficiency of the refrigerant filling amount, it is determined that the refrigerant filling amount is insufficient relative to the appropriate amount; if the current value of the opening is less than the appropriate opening value, it is determined that the refrigerant filling amount is excessive relative to the appropriate amount; if the current value of the opening is the appropriate opening value, it is determined that the refrigerant filling amount is the appropriate amount.

3. The refrigeration cycle device according to claim 2, characterized in that, The control unit maintains the appropriate opening value of the regulating valve in a variable manner.

4. The refrigeration cycle device according to claim 3, characterized in that, The control unit maintains the appropriate amount of refrigerant inlet in a manner that allows changes from a preset initial value. If the appropriate amount changes from the initial value, the control unit changes and corrects the value of the appropriate opening of the regulating valve and maintains the corrected value.

5. The refrigeration cycle apparatus according to any one of claims 2 to 4, characterized in that, The refrigeration cycle device also includes a notification unit that notifies the user that the amount of refrigerant being introduced is not the appropriate amount. If the control unit determines that the amount of refrigerant being filled is not the appropriate amount, it activates the notification unit to notify that the amount of refrigerant being filled is not the appropriate amount.

6. The refrigeration cycle device according to claim 5, characterized in that, The refrigeration cycle device also includes a refrigerant storage device that stores excess refrigerant beyond the appropriate amount when the amount of refrigerant supplied exceeds the appropriate amount. If the control unit determines that the amount of refrigerant being filled is insufficient relative to the appropriate amount, the notification unit will notify the control unit of the determination result. If the control unit determines that the amount of refrigerant being filled is excessive relative to the appropriate amount, the control unit will store the remaining refrigerant in the refrigerant storage device.

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