JP7224533B2 - Outdoor unit and refrigeration cycle device provided with the same - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to an outdoor unit and a refrigeration cycle device including the same.

International Publication No. 2016/135904 (Patent Document 1) discloses a refrigeration device. The outdoor unit of this refrigeration system includes a compressor, an oil separator, a condenser, a liquid receiver, a subcooling heat exchanger, and an accumulator. The indoor unit includes an expansion valve and an evaporator. In this refrigeration system, the adequacy of the amount of refrigerant charged in the refrigerant circuit is determined based on the temperature efficiency of the subcooling heat exchanger. The temperature efficiency is the degree of subcooling of the refrigerant at the outlet of the subcooling heat exchanger divided by the maximum temperature difference of the subcooling heat exchanger. According to this refrigeration system, it is possible to determine the shortage of refrigerant in the refrigerant circuit (see Patent Document 1).

WO2016/135904

In the refrigeration system described above, it is difficult to accurately determine a decrease in the amount of refrigerant due to a decrease in the degree of supercooling in an operating state in which the degree of supercooling of the refrigerant is small.

A main object of the present disclosure is to provide an outdoor unit and a refrigerating cycle device including the same that can accurately determine the shortage of refrigerant enclosed in the refrigerating cycle device.

An outdoor unit according to the present disclosure is an outdoor unit of a refrigeration cycle device including a refrigerant circuit in which refrigerant circulates. The outdoor unit includes a compressor that compresses the refrigerant and a condenser that condenses the refrigerant discharged from the compressor, a main flow passage that constitutes a part of the refrigerant circuit, and a portion of the refrigerant that flows out from the condenser. and a bypass flow path that guides the section to the intake of the compressor. The bypass flow path includes a detector that detects shortage of refrigerant enclosed in the refrigerant circuit. The detection unit includes a heater that heats the refrigerant flowing through the bypass flow path, a first temperature sensor that detects the temperature of the refrigerant before being heated by the heater, and a first temperature sensor that detects the temperature of the refrigerant heated by the heater. 2 temperature sensors, and a control device that uses the temperatures detected by the first temperature sensor and the second temperature sensor to detect a shortage of the refrigerant sealed in the refrigerant circuit. The main flow path includes a first flow path arranged downstream of the condenser. The bypass flow path further includes a connecting end connected to the first flow path and a raised portion extending upward from the connecting end.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide an outdoor unit and a refrigeration cycle device including the same that can accurately determine the shortage of refrigerant enclosed in the refrigeration cycle device.

1 is a block diagram showing a refrigeration cycle apparatus according to Embodiment 1; FIG. 4 is a cross-sectional view showing a connecting portion between the first flow path and the bypass flow path of the refrigeration cycle apparatus according to Embodiment 1; FIG. 4 is a graph showing the relationship between the flow rate of the refrigerant flowing through the refrigerant circuit and the height of the rising portion of the bypass channel required for gas-liquid separation of the refrigerant. FIG. 4 is a diagram conceptually showing the state of coolant around the heater in a normal state when there is no shortage of coolant; FIG. 5 is a diagram showing an example of change in coolant temperature caused by a heater during normal operation; FIG. 4 is a diagram showing an example of change in coolant temperature caused by a heater when there is a shortage of coolant; 4 is a block diagram showing a modification of the refrigeration cycle apparatus according to Embodiment 1; FIG. FIG. 8 is a cross-sectional view showing a connecting portion between a first flow path and a bypass flow path of the refrigeration cycle apparatus according to Embodiment 2; 4 is a graph showing the relationship between the flow rate of refrigerant flowing through the first flow path of the refrigerant circuit and the height of the rising portion of the bypass flow path required for gas-liquid separation of the refrigerant. FIG. 11 is a cross-sectional view showing a modification of the connecting portion between the first flow path and the bypass flow path of the refrigeration cycle apparatus according to Embodiment 2; FIG. 11 is a block diagram showing a refrigeration cycle apparatus according to Embodiment 3; FIG. 11 is a cross-sectional view showing a connecting portion between a first flow path and a bypass flow path of a refrigeration cycle apparatus according to Embodiment 3; FIG. 11 is a cross-sectional view showing a modification of the connecting portion between the first flow path and the bypass flow path of the refrigeration cycle apparatus according to Embodiment 3; FIG. 10 is a cross-sectional view showing another modification of the connecting portion between the first flow path and the bypass flow path of the refrigeration cycle apparatus according to Embodiment 3;

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings below, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

Embodiment 1.
<Configuration of refrigeration cycle device and outdoor unit>
FIG. 1 is a block diagram showing a refrigeration cycle apparatus using an outdoor unit according to Embodiment 1. FIG. Note that FIG. 1 functionally shows the connection relationship and arrangement configuration of each device in the refrigeration cycle apparatus, and does not necessarily show the arrangement in a physical space. The refrigerating cycle device 1 is, for example, a refrigerator.

As shown in FIG. 1 , the refrigeration cycle device 1 includes an outdoor unit 2 and an indoor unit 3 . The outdoor unit 2 includes a compressor 10, a condenser 20, a fan 22, a liquid reservoir 30, a heat exchanger 40, a fan 42, a sight glass 45, and pipes 80-83,85. Outdoor unit 2 further includes pipe 86 , pipe 87 , detector 70 , pressure sensors 90 and 92 , and controller 100 . Indoor unit 3 includes an expansion valve 50 , an evaporator 60 , a fan 62 , and piping 84 . The indoor unit 3 is connected to the outdoor unit 2 through pipes 83 and 85 .

From a different point of view, the refrigeration cycle device 1 includes a compressor 10, a pipe 80, a condenser 20, a pipe 81A (first pipe portion), a liquid reservoir 30, a pipe 81B (second pipe portion), and a heat exchanger 40. , a pipe 83, an expansion valve 50, a pipe 84, an evaporator 60, and a pipe 85 to provide a refrigerant circuit in which the refrigerant circulates. Refrigerant circulating in the refrigerant circuit includes compressor 10, pipe 80, condenser 20, pipe 81A, reservoir 30, pipe 81B, heat exchanger 40, pipe 83, expansion valve 50, pipe 84, evaporator 60, and Flow through the pipe 85 in this order.

The refrigerant circuit is configured by connecting a first main flow path (main flow path) included in the outdoor unit 2 and a second main flow path included in the indoor unit 3 . The first main flow path includes compressor 10, piping 80, condenser 20, piping 81A, liquid reservoir 30, piping 81B, heat exchanger 40, and a portion of each of piping 83 and piping 85. The second main flow path includes expansion valve 50 , piping 84 , evaporator 60 , and other portions of each of piping 83 and piping 85 .

A pipe 80 connects the outlet of the compressor 10 and the condenser 20 . A pipe 81A connects the condenser 20 and the liquid reservoir 30 . A pipe 81B connects the liquid reservoir 30 and the heat exchanger 40 . A pipe 83 connects the heat exchanger 40 and the expansion valve 50 . A pipe 84 connects the expansion valve 50 and the evaporator 60 . A pipe 85 connects the evaporator 60 and the suction port of the compressor 10 .

The first main flow path includes a first flow path arranged downstream of the condenser 20 and a second flow path arranged upstream of the compressor 10 in the refrigerant circuit. The first flow path is connected between the condenser 20 and the heat exchanger 40, for example, in the first main flow path. The first flow path guides part of the refrigerant that has flowed out of the condenser 20 to the heat exchanger 40 . The first flow path includes piping 81A, liquid reservoir 30, and piping 81B. The second flow path includes piping 85 . The second flow path guides the refrigerant that has flowed out of the evaporator 60 to the suction port of the compressor 10 .

The refrigerating cycle device 1 is branched from the refrigerant circuit, and a bypass flow that returns part of the refrigerant that has flowed out of the condenser 20 to the suction port of the compressor 10 without passing through the heat exchanger 40 and the indoor unit 3. Prepare more roads. The bypass channel includes piping 86 , detector 70 and piping 87 . The refrigerant flowing through the bypass channel flows through the pipe 86 , the detector 70 , and the pipe 87 in order. The pipe 86 of the bypass channel is connected to the first channel pipe 81B of the first main channel. The pipe 87 of the bypass channel is connected to the pipe 85 of the second channel of the first main channel.

FIG. 2 is a cross-sectional view showing a connecting portion between the pipe 81B of the first main channel and the pipe 86 of the bypass channel. As shown in FIG. 2, the pipe 81B has a pipe portion 82 extending in a direction intersecting the vertical direction Z. As shown in FIG. The pipe portion 82 extends in the horizontal direction X, for example.

As shown in FIGS. 1 and 2, the pipe 86 has a connecting end portion 86A connected to the first flow channel of the first main flow channel and a rising portion 86B extending upward from the connecting end portion 86A. and The pipe portion 82 and the connecting end portion 86A and the rising portion 86B of the pipe portion 86 are in a gas-liquid state in which the refrigerant flowing through the pipe portion 82 is a mixture of gas refrigerant (vapor-phase refrigerant) and liquid refrigerant (liquid-phase refrigerant). A gas-liquid separation mechanism is configured to suppress the liquid refrigerant from flowing into the detection unit 70 when the refrigerant is in a phase state, that is, when the refrigerant enclosed in the refrigerant circuit is insufficient. The connection end portion 86A is connected to the tube portion 82 . The extending direction of the rising portion 86B may be inclined with respect to the vertical direction as long as it faces upward. Preferably, the rising portion 86B extends vertically. A pipe 86 connects the pipe 81B and the detector 70 . A pipe 87 connects the detection unit 70 and the pipe 85 .

Preferably, the inner diameter d of the rising portion 86B is larger than the reference inner diameter d0. Here, the reference inner diameter d0 is the inner diameter d when the gas-liquid two-phase refrigerant flows through the pipe portion 82 and the flow velocity of the gas refrigerant flowing into the pipe 86 from the pipe portion 82 becomes zero penetration flow velocity. Zero penetration is a phenomenon in which, when gas-liquid two-phase refrigerant flows upward in a pipe, the liquid refrigerant rises along the pipe wall along with the gas refrigerant. Zero penetration flow velocity is the flow velocity of the refrigerant at which the liquid refrigerant begins to rise up the tube wall with the gas refrigerant. The zero penetration flow velocity can be calculated using a known method from the inner diameter of the pipe, the density of the gas refrigerant, and the density of the liquid refrigerant. By making the inner diameter d of the pipe 86 larger than the reference inner diameter d0, the flow velocity of the gas refrigerant flowing into the pipe 86 becomes lower than the zero penetration flow velocity. Therefore, when the refrigerant flowing through the pipe portion 82 is in a gas-liquid two-phase state in which gas refrigerant and liquid refrigerant are mixed, the liquid refrigerant can be prevented from flowing into the pipe 86 .

Preferably, the height of the rising portion 86B of the pipe 86 with respect to the connection end portion 86A is set when the refrigerant flowing through the pipe portion 82 is in a gas-liquid two-phase state in which gas refrigerant and liquid refrigerant are mixed (encapsulated in the refrigerant circuit). is equal to or higher than the reference height h1 set as follows based on the flow rate of the refrigerant flowing through each of the pipe portion 82 and the pipe 86 when the supplied refrigerant is insufficient.

The flow rate G1 [kg/s] of the refrigerant flowing upstream of the connecting end portion 86A in the pipe portion 82 of the pipe 81B is the flow rate G2 [kg/s] of the refrigerant flowing downstream of the connecting end portion 86A in the pipe portion 82 of the pipe 81B. kg/s] and the flow rate G3 [kg/s] of the refrigerant flowing through the rising portion 86B. Furthermore, according to the law of conservation of energy, the energy of the refrigerant flowing upstream of the connecting end portion 86A in the pipe portion 82 and the energy of the refrigerant flowing downstream of the connecting end portion 86A of the pipe portion 82 flow through the rising portion 86B. equal to the sum of the energy of the refrigerant.

When the pipe portion 82 extends along the horizontal direction X, the kinetic energy K1 [J/s] of the refrigerant flowing in the horizontal direction X upstream of the connection end portion 86A in the pipe portion 82 is The kinetic energy K2 [J/s] of the refrigerant flowing in the horizontal direction X downstream of the end portion 86A, the kinetic energy K3 [J/s] of the refrigerant flowing upward through the rising portion 86B, and the refrigerant flowing upward through the rising portion 86B. It is equal to the sum of the potential energy φ3 of the refrigerant. Each of the kinetic energies K1-K3 is determined by the flow rate G1-G3 of the coolant flowing through each and the flow velocity of the coolant flowing through each. The potential energy φ3 is obtained from the flow rate G3, the gravitational acceleration g [m/s ² ], and the height h [mm] with respect to the connection end 86A. The reference height h1 is the height h when the potential energy φ3 is equal to the value obtained by subtracting the sum of the kinetic energy K2 and the kinetic energy K3 from the kinetic energy K1. With this configuration, when the state of the refrigerant flowing through the tube portion 82 of the pipe 81B is a gas-liquid two-phase state in which gas refrigerant and liquid refrigerant are mixed, the liquid refrigerant flowing into the rising portion 86B reaches the reference height h1. Since it is possible to prevent the liquid refrigerant from reaching a position higher than the above, it is possible to prevent the liquid refrigerant from flowing into the pipe 86 .

As shown in FIG. 1, the pipe 86 has, for example, a portion 86C arranged downstream of the rising portion 86B. A portion 86C arranged downstream of the rising portion 86B in the pipe 86 may extend in any direction.

Compressor 10 compresses the refrigerant sucked from pipe 85 and outputs the compressed refrigerant to pipe 80 . Compressor 10 is configured to adjust the rotation speed according to a control signal from control device 100 . By adjusting the rotation speed of the compressor 10, the circulation amount of the refrigerant is adjusted, and the capacity of the refrigeration cycle device 1 can be adjusted. Various types can be adopted for the compressor 10, for example, a scroll type, a rotary type, a screw type, and the like can be adopted.

The condenser 20 condenses the refrigerant output from the compressor 10 to the pipe 80 and outputs it to the pipe 81A. Condenser 20 is configured such that the high-temperature, high-pressure gas refrigerant output from compressor 10 exchanges heat (radiates heat) with the outside air. This heat exchange causes the refrigerant to condense and change to a liquid phase. The fan 22 supplies outside air to the condenser 20 with which the refrigerant exchanges heat in the condenser 20 . By adjusting the rotational speed of the fan 22, the refrigerant pressure (high-pressure side pressure) on the output side of the compressor 10 can be adjusted.

The liquid reservoir 30 stores the high-pressure liquid refrigerant condensed by the condenser 20 . The heat exchanger 40 is configured such that the liquid refrigerant output from the liquid reservoir 30 to the pipe 81B further exchanges heat (radiates heat) with the outside air. The refrigerant becomes supercooled liquid refrigerant by passing through the heat exchanger 40 . The fan 42 supplies the heat exchanger 40 with outside air with which the refrigerant exchanges heat in the heat exchanger 40 . The sight glass 45 is a window for visually confirming air bubbles (flash gas) in the refrigerant flowing through the pipe 83 .

The expansion valve 50 decompresses the refrigerant output from the heat exchanger 40 to the pipe 83 and outputs the reduced pressure to the pipe 84 . When the opening degree of the expansion valve 50 is changed in the closing direction, the pressure of the refrigerant on the outlet side of the expansion valve 50 decreases and the dryness of the refrigerant increases. When the opening degree of the expansion valve 50 is changed in the opening direction, the refrigerant pressure on the outlet side of the expansion valve 50 increases and the dryness of the refrigerant decreases. A capillary tube may be used instead of the expansion valve 50 .

The evaporator 60 evaporates the refrigerant output from the expansion valve 50 to the pipe 84 and outputs it to the pipe 85 . The evaporator 60 is configured such that the refrigerant decompressed by the expansion valve 50 exchanges heat (absorbs heat) with the air in the indoor unit 3 . The refrigerant passes through the evaporator 60 and evaporates into superheated vapor. Fan 62 supplies outside air to evaporator 60 with which the refrigerant exchanges heat in evaporator 60 . A temperature sensor 201 is arranged around the condenser 20 . A temperature sensor 201 detects the outside air temperature.

As described above, the detection unit 70 is provided between the pipes 86 and 87 . The detection unit 70 includes a capillary tube 71 , a heater 72 , temperature sensors 73 and 74 and a pipe 75 . A capillary tube 71 and a pipe 75 connect between the pipe 86 and the pipe 87 . The upstream end of the capillary tube 71 is connected to the downstream end of the pipe 86 . The upstream end of the capillary tube 71 is connected to, for example, the downstream end of the portion 86C of the pipe 86 (see FIG. 1). A pipe 75 connects between the capillary tube 71 and the pipe 87 .

The capillary tube 71 reduces the pressure of the refrigerant flowing through the bypass circuit. The capillary tube 71 is designed so that when the liquid refrigerant is supplied from the pipe 86, even if the refrigerant passing through the capillary tube 71 is heated by the heater 72, it does not become a single gas phase but a two-phase gas-liquid phase. It is appropriately designed in consideration of the amount of heating. An expansion valve may be used instead of the capillary tube 71 .

A heater 72 and temperature sensors 73 and 74 are provided in a pipe 75 . The heater 72 heats the coolant flowing through the pipe 75 through the capillary tube 71 . The refrigerant is heated by the heater 72 to increase its enthalpy. As described above, the heating amount of the heater 72 is determined according to the specifications of the capillary tube 71 so that the refrigerant passing through the capillary tube 71 is heated by the heater 72 and does not become a single gas phase but a gas-liquid two-phase refrigerant. set. The heater 72 may heat the refrigerant from the outside of the pipe 75, or may be installed inside the pipe 75 in order to more reliably transfer heat from the heater 72 to the refrigerant. When the refrigerating cycle device is ON, the heater 72 may be always ON. Alternatively, the heater 72 may be turned ON only during the refrigerant shortage determination process. Alternatively, the heater 72 may be turned ON only when the compressor 10 is activated. In Embodiment 1, the heater 72 will be described as always being in the ON state when the refrigeration cycle device is ON.

The temperature sensor 73 detects the temperature of the refrigerant before it is heated by the heater 72, that is, the temperature T1 of the refrigerant flowing upstream of the area heated by the heater 72 in the pipe 75, and outputs the detected value to the control device 100. do. On the other hand, the temperature sensor 74 detects the temperature of the refrigerant after the refrigerant is heated by the heater 72, that is, the temperature T2 of the refrigerant flowing downstream of the area heated by the heater 72 in the pipe 75. Output to The temperature sensors 73 and 74 may be installed outside the pipe 75, or may be installed inside the pipe 75 in order to more reliably detect the temperature of the refrigerant. The principle and method of refrigerant shortage determination by the detection unit 70 will be described later in detail.

Pressure sensor 90 detects pressure LP of refrigerant in pipe 85 and outputs the detected value to control device 100 . That is, the pressure sensor 90 detects the refrigerant pressure (low-pressure side pressure) LP on the suction side of the compressor 10 . Pressure sensor 92 detects the pressure HP of the refrigerant in pipe 80 and outputs the detected value to control device 100 . That is, the pressure sensor 92 detects the refrigerant pressure (high-pressure side pressure) HP on the discharge side of the compressor 10 .

The intake temperature sensor 302 is arranged around the intake of the compressor 10 . A suction temperature sensor 302 detects the suction temperature Ts of the refrigerant to the compressor 10 .

The control device 100 includes a CPU (Central Processing Unit) 102, a memory 104 (ROM (Read Only Memory) and RAM (Random Access Memory)), an input/output buffer (not shown) for inputting and outputting various signals, and the like. Consists of The CPU 102 expands a program stored in the ROM into the RAM or the like and executes it. The program stored in the ROM is a program in which processing procedures of the control device 100 are described. The control device 100 controls each device in the outdoor unit 2 according to these programs. This control is not limited to processing by software, and processing by dedicated hardware (electronic circuit) is also possible.

<Description of refrigerant shortage determination>
A method for determining the lack of refrigerant using the detection unit 70 will be described below. Insufficient refrigerant occurs when the initial amount of refrigerant charged into the refrigerant circuit is insufficient, or refrigerant leakage occurs after the start of use.

FIG. 3 is a diagram conceptually showing the state of the coolant around the heater 72 in a normal state when there is no shortage of coolant. Note that, hereinafter, the time when there is no shortage of refrigerant and the amount of refrigerant is within an appropriate range may be simply referred to as "normal time".

Referring to FIG. 1 as well as FIG. 3 , when the amount of refrigerant is proper and normal, the refrigerant flowing out of the condenser 20 is almost in the liquid phase, and the liquid refrigerant is accumulated in the liquid reservoir 30 . As a result, the liquid refrigerant flows through the pipe 86, and the refrigerant that has passed through the capillary tube 71 has a large amount of liquid components. The refrigerant that has passed through the capillary tube 71 is heated by the heater 72 to increase its dryness.

FIG. 4 is a diagram showing an example of changes in coolant temperature caused by the heater 72 during normal operation. In FIG. 4, the horizontal axis indicates the position in the extending direction of the pipe 75, and P1 and P2 indicate the positions where the temperature sensors 73 and 74 are installed, respectively. The vertical axis indicates the coolant temperature at each position of the pipe 75 . Note that FIG. 4 shows a case where the refrigerant is an azeotropic refrigerant (a refrigerant that does not have a temperature gradient, such as R410a).

As shown in FIG. 4, in normal conditions, the refrigerant that has passed through the capillary tube 71 has a large amount of liquid components. is used to change the latent heat of the refrigerant). Therefore, the temperature T2 of the refrigerant after heating the refrigerant by the heater 72 is substantially the same as the temperature T1 of the refrigerant before heating the refrigerant by the heater 72 .

Although not shown, if the refrigerant is a non-azeotropic refrigerant (refrigerant having a temperature gradient, such as R407a, R448a, R449a, R463a, etc.), heating by the heater 72 slightly increases the temperature of the refrigerant. (At most about 10 degrees).

FIG. 5 is a diagram conceptually showing the state of the coolant around the heater 72 when the coolant is insufficient. Referring to FIG. 1 together with FIG. 5, when the refrigerant is insufficient, the refrigerant at the outlet of the condenser 20 is in a two-phase gas-liquid state. A small amount. As a result, the gas-liquid two-phase refrigerant in which the gas refrigerant and the liquid refrigerant are mixed flows through the pipe 86, and the refrigerant that has passed through the capillary tube 71 is in a state in which there are more gas components than in the normal state. Therefore, the coolant that has passed through the capillary tube 71 is heated by the heater 72 to evaporate and its temperature (degree of superheat) rises.

FIG. 6 is a diagram showing an example of changes in coolant temperature caused by the heater 72 when the coolant is insufficient. In FIG. 6, the horizontal axis also indicates the position in the extending direction of the pipe 87, and P1 and P2 indicate the positions where the temperature sensors 73 and 74 are installed, respectively. The vertical axis indicates the coolant temperature at each position of the pipe 75 .

Referring to FIG. 6, when the refrigerant is insufficient, the refrigerant that has passed through capillary tube 71 has a large amount of gas components. Therefore, when the refrigerant is heated by heater 72, the refrigerant evaporates and the temperature of the refrigerant rises. (superheat > 0). Therefore, the temperature T2 of the refrigerant after the heater 72 heats the refrigerant is higher than the temperature T1 of the refrigerant before the heater 72 heats the refrigerant.

When the refrigerant is a non-azeotropic refrigerant, the temperature rise of the refrigerant caused by the heater 72 when the refrigerant is insufficient can be distinguished from the temperature rise of the refrigerant caused by the heater 72 during normal operation (temperature rise based on the temperature gradient of the refrigerant). Also, the heating amount of the heater 72 is appropriately set.

In this manner, the detection unit 70 can determine whether or not there is a shortage of refrigerant in the refrigeration cycle device 1 based on the amount of temperature rise of the refrigerant when the refrigerant is heated by the heater 72 .

<Effect>
The outdoor unit 2 has a bypass channel including the detection unit 70 . Therefore, according to the outdoor unit 2 , shortage of the refrigerant sealed in the refrigerant circuit of the refrigeration cycle device 1 is detected based on the degree of superheat of the refrigerant that has passed through the heater 72 of the detection unit 70 . Specifically, if the degree of superheat of the refrigerant that has passed through the heater 72 is 0, the amount of refrigerant is normal, and if the degree of superheat of the refrigerant that has passed through the heater 72 is (degree of superheat > 0), the refrigerant is insufficient. is determined to occur.

Furthermore, the bypass channel of the outdoor unit 2 further includes a connecting end portion 86A connected to the first channel of the first main channel, and a rising portion 86B extending upward from the connecting end portion 86A. include.

If the bypass flow path of the outdoor unit does not include the connecting end portion 86A and the rising portion 86B, part of the gas-liquid two-phase refrigerant flowing through the pipe portion 82 flows into the detection portion 70 without being separated from the gas and liquid. do. In other words, liquid refrigerant flows into the detection unit 70 . In this case, even if the liquid refrigerant that has flowed into the detection unit 70 is heated by the heater 72, it may not evaporate, and the refrigerant heated by the heater 72 may not be superheated. In this case, the detection unit 70 cannot accurately detect the lack of refrigerant.

On the other hand, in the outdoor unit 2, the connecting end portion 86A and the rising portion 86B suppress the inflow of the liquid refrigerant into the detection portion 70, so that the gas refrigerant or refrigerant with extremely high dryness flows into the pipe 75 of the detection portion 70. do. When such a refrigerant is heated by the heater 72, the refrigerant is surely superheated. As a result, the detection unit 70 of the outdoor unit 2 can accurately detect refrigerant shortage compared to a detection unit of an outdoor unit whose bypass flow path does not include the connection end 86A and the rising portion 86B.

In the outdoor unit 2 , the first flow path includes the liquid reservoir 30 , and the connection end 86A of the pipe 86 is connected to the pipe 81B that guides the liquid refrigerant from the liquid reservoir 30 to the heat exchanger 40 . In this case, the liquid reservoir 30 prevents the refrigeration cycle device 1 from running out of refrigerant.

FIG. 7 is a block diagram showing a modification of the refrigeration cycle device 1 and the outdoor unit 2 shown in FIG. As shown in FIG. 7 , the first flow path of the outdoor unit 2 may not include the liquid reservoir 30 . The refrigeration cycle device 1 includes a compressor 10, a pipe 80, a condenser 20, a pipe 81C, a heat exchanger 40, a pipe 83, an expansion valve 50, a pipe 84, an evaporator 60, and a pipe 85. Have a circuit. Refrigerant circulating in the refrigerant circuit flows through compressor 10, pipe 80, condenser 20, pipe 81C, heat exchanger 40, pipe 83, expansion valve 50, pipe 84, evaporator 60, and pipe 85 in this order. .

A first flow path of the first main flow path includes a pipe 81C. The pipe 81C has a pipe portion 82 extending in a direction intersecting the vertical direction Z. As shown in FIG. The pipe portion 82 extends in the horizontal direction X, for example. A connection end portion 86A of the pipe 86 is connected to the pipe portion 82 of the pipe 81C.

The refrigeration cycle device 1A and the outdoor unit 2A shown in FIG. 7 also have a connection end portion 86A, a rising portion 86B, and a bypass flow path including a detection portion 70, similarly to the refrigeration cycle device 1 and the outdoor unit 2 shown in FIG. , the same effects as those of the refrigeration cycle device 1 and the outdoor unit 2 can be obtained.

Embodiment 2.
FIG. 8 is a cross-sectional view showing a connecting portion between the first flow path and the bypass flow path of the refrigeration cycle apparatus according to Embodiment 2. FIG. The refrigerating cycle apparatus according to Embodiment 2 has basically the same configuration as refrigerating cycle apparatus 1 according to Embodiment 1, but the first flow path includes pipe 88 (third pipe portion) and pipe 89 (third pipe portion). It differs from the refrigeration cycle device 1 in that it has four pipe portions).

The pipe 81B has a portion arranged on the upstream side with respect to the pipes 88 and 89 in the first flow path and a portion arranged on the downstream side with respect to the pipes 88 and 89. .

The pipes 88 and 89 are connected in parallel to the pipe 81B. The pipe 89 is arranged above the pipes 81B and 88 . The pipe 88 is arranged, for example, below the pipe 81B. The upstream ends of the pipes 88 and 89 are connected to the portions of the pipes 81B located upstream with respect to the pipes 88 and 89 in the first flow path. The downstream ends of the pipes 88 and 89 are connected to the portions of the pipes 81B located downstream of the pipes 88 and 89 in the first flow path.

The pipe 88 has, for example, a pipe portion 88A and a pipe portion 88B extending along the vertical direction Z, and a pipe portion 88C extending along the horizontal direction X. As shown in FIG. The pipe portion 88A is arranged upstream of the pipe portions 88B and 88C in the first flow path. The pipe portion 88B is arranged downstream of the pipe portions 88A and 88C in the refrigerant circuit. The pipe portion 88C is arranged downstream of the pipe portion 88A and upstream of the pipe portion 88B.

The upper end of the pipe portion 88A constitutes the end portion of the pipe 88 located on the upstream side. The lower end of the pipe portion 88A is connected to the upstream end portion of the pipe portion 88C. The lower end of the pipe portion 88B is connected to the downstream end portion of the pipe portion 88C. The upper end of the pipe portion 88B constitutes the end portion of the pipe 88 located on the downstream side.

The pipe 89 has, for example, a pipe portion 89A (first portion) and a pipe portion 89B (second portion) extending along the vertical direction Z, and a pipe portion 89C extending along the horizontal direction X. The pipe portion 89A is arranged upstream of the pipe portions 89B and 89C in the first flow path. The pipe portion 89B is arranged downstream of the pipe portions 89A and 89C in the refrigerant circuit. The pipe portion 89C is arranged downstream of the pipe portion 89A and upstream of the pipe portion 89B.

A lower end of the pipe portion 89A constitutes an end portion of the pipe 89 located on the upstream side. The upper end of the pipe portion 89A is connected to the upstream end portion of the pipe portion 89C. The upper end of the pipe portion 89B is connected to the downstream end portion of the pipe portion 89C. A lower end of the pipe portion 89B constitutes an end portion of the pipe 89 located on the downstream side.

The pipe portion 88A and the pipe portion 89A are continuous in the vertical direction Z. As shown in FIG. The pipe portion 88B and the pipe portion 89B are connected in the vertical direction Z. As shown in FIG.

A connection end portion 86A of the pipe 86 is connected to a pipe portion 89C extending along the horizontal direction X in the pipe 89 . A rising portion 86B of the pipe 86 extends upward from the connecting end portion 86A.

In this case, the reference height h1 is the flow rate G4 [kg/s] of the refrigerant flowing upstream of the connecting end portion 86A in the pipe portion 89C of the pipe 89, and Flow rate G5 [kg/s] of refrigerant flowing downstream, flow rate G3 [kg/s] of refrigerant flowing through rising portion 86B, movement of refrigerant flowing in horizontal direction X upstream of connection end portion 86A in tube portion 89C energy K4 [J/s], kinetic energy K5 [J/s] of the refrigerant flowing in the horizontal direction X downstream of the connection end 86A in the pipe portion 89C, kinetic energy K3 [J/s] of the refrigerant flowing upward through the rising portion 86B. J/s] and the potential energy φ3 of the coolant flowing upward through the rising portion 86B.

FIG. 9 shows the relationship between the flow rate of the refrigerant flowing upstream of the connecting end portion 86A in the first flow path and the reference height h1 of the rising portion 86B of the bypass flow path required for gas-liquid separation of the refrigerant. It is a graph which shows an example. The flow rate of the refrigerant flowing upstream of the connecting end portion 86A in the first flow path is the flow rate G1 of the refrigerant flowing upstream of the connecting end portion 86A in the pipe 81B in the first embodiment. is the flow rate G4 of the refrigerant flowing upstream of the connecting end portion 86A in the pipe 89. In the graph shown in FIG. 9, the flow rate G3 of the refrigerant flowing through the rising portion 86B is 0.015 kg/h, the inner diameters of the pipes 81B, 88, 89, and the rising portion 86B are 13 mm, and the density of the refrigerant is 1000 kg/m. ³ was derived. The horizontal axis of FIG. 9 indicates the flow rate (unit: kg/h) of the refrigerant flowing upstream of the connecting end portion 86A in the first flow path, and the vertical axis of FIG. 9 indicates the reference height h1 of the rising portion 86B. .

As shown in FIG. 9, the lower the flow rate of the coolant flowing upstream of the connecting end portion 86A in the first flow path, the lower the reference height h1.

The flow rate G4 of the refrigerant flowing upstream of the connection end 86A in the tube portion 89C of the pipe 89 is less than the flow rate of the refrigerant flowing upstream of the pipe 89 in the first flow path, for example half. When the flow rate of the refrigerant flowing upstream of the pipe 89 in the first flow path is 800 kg/h, the flow rate G4 of the refrigerant flowing upstream of the connecting end portion 86A of the pipe portion 89C is less than 800 kg/h. 400 kg/h. As shown in FIG. 9, the reference height h1 when the flow rate is 800 kg/h is, for example, about 410 mm, whereas the reference height h1 when the flow rate is 400 kg/h is, for example, about 110 mm. becomes.

Therefore, when the flow rates of the refrigerant flowing through the pipes 81B of the gas-liquid separation mechanism shown in FIG. 8 and the gas-liquid separation mechanism shown in FIG. The height h1 is lower than the reference height h1 in the gas-liquid separation mechanism shown in FIG. As a result, in the refrigerating cycle apparatus 1 according to Embodiment 2, the height of the rising portion 86B with respect to the connecting end portion 86A, which is required to satisfy a predetermined standard for detection accuracy of refrigerant shortage, is In the refrigerating cycle device 1 according to Embodiment 1, the height of the rising portion 86B with respect to the connecting end portion 86A is lower than the height required to satisfy the standard for detection accuracy of refrigerant shortage. Therefore, even when the refrigerating cycle device 1 and the outdoor unit 2 according to the second embodiment are downsized compared to the refrigerating cycle device 1 and the outdoor unit 2 according to the first embodiment, shortage of refrigerant can be prevented similarly. It can be detected with high accuracy.

Further, since the pipe 89 is arranged above the pipe 88 , the liquid refrigerant, which has a higher specific gravity than the gas refrigerant, flows easily through the pipe 88 but hardly flows through the pipe 89 . Therefore, the gas-liquid separation mechanism shown in FIG. 8 can perform gas-liquid separation more efficiently than the gas-liquid separation mechanism shown in FIG.

FIG. 10 is a cross-sectional view showing a modification of the refrigeration cycle apparatus and the outdoor unit according to Embodiment 2. FIG. As shown in FIG. 10 , the connecting end 86A of the pipe 86 may continue in the vertical direction Z with the pipe portion 89B (second portion) of the pipe 89 . In the gas-liquid separation mechanism shown in FIG. 10, compared with the gas-liquid separation mechanism shown in FIG. and the gas-liquid separation is more efficient.

Embodiment 3.
FIG. 11 is a block diagram showing a refrigeration cycle apparatus 1B according to Embodiment 3. As shown in FIG. As shown in FIG. 11, the refrigerating cycle device 1B according to Embodiment 3 has basically the same configuration as the refrigerating cycle device 1 according to Embodiment 1, except that the connecting end portion 86A of the pipe 86 is connected to the liquid. It differs from the refrigeration cycle apparatus 1 in that it is connected to the reservoir 30 .

The connecting end portion 86A is configured to guide the refrigerant from the liquid reservoir 30 of the first flow path to the bypass flow path. FIG. 12 is a cross-sectional view showing a connecting portion between the first flow path and the bypass flow path of the refrigeration cycle device 1B. As shown in FIG. 12, the connection end 86A and the rising portion 86B of the pipe 86 are arranged inside the liquid reservoir 30. As shown in FIG. The rising portion 86B is inclined with respect to each of the horizontal direction X and the vertical direction Z, for example. The reference height h1 of the rising portion 86B shown in FIG. 12 is the shortest distance in the vertical direction Z between the connecting end portion 86A and the upper end portion of the rising portion 86B.

As shown in FIG. 12, the pipe 81A has an outlet 81A1 through which the refrigerant flows out and an inclined portion 81A2 extending downward from the outlet 81A1 inside the reservoir 30. As shown in FIG. Inside the liquid reservoir 30, the pipe 81B has an inlet 81B1 into which the refrigerant flows and an inclined portion 81B2 extending upward from the inlet 81B1.

As shown in FIG. 12, the connection end portion 86A is arranged below the outflow port 81A1 of the pipe 81A and above the inflow port 81B1 of the pipe 81B. The connection end portion 86A is arranged, for example, below the upper end portion of the inclined portion 81B2. The upper end portion of the rising portion 86B is arranged, for example, above the upper end portion of the inclined portion 81B2. The connecting end portion 86A is arranged so as to be positioned above the liquid level LS1 of the liquid refrigerant stored in the liquid reservoir 30 when the refrigerant to be detected by the detection portion 70 is insufficient. . The liquid level LS1 is realized in a state in which the liquid level is not disturbed, which will be described later, for example, in a state in which the refrigeration cycle device 1B is stopped.

The outflow port 81A1 of the pipe 81A is arranged so as to overlap the connecting end portion 86A of the pipe 86 when viewed from above. In other words, the connection end portion 86A is arranged directly below the outflow port 81A1. The entire pipe 86 is arranged, for example, below the entire pipe 81A.

In the refrigerating cycle device 1B and the outdoor unit 2B, similarly to the refrigerating cycle device 1 and the outdoor unit 2, the connection end portion 86A and the rising portion 86B suppress the inflow of the liquid refrigerant to the detection portion 70. In the refrigerating cycle device 1B and the outdoor unit 2B, when the liquid level of the liquid refrigerant stored in the liquid reservoir 30 falls below the connection end portion 86A, the gas refrigerant or refrigerant with extremely high dryness reaches the detection portion 70. It flows into pipe 75 . Therefore, the detectors 70 of the refrigerating cycle device 1B and the outdoor unit 2B can detect the refrigerant shortage at the stage when the liquid refrigerant stored in the liquid reservoir 30 starts to decrease.

As shown in FIG. 12, when the outlet 81A1 of the pipe 81A is arranged so as to overlap the connection end 86A of the pipe 86 when viewed from above, the liquid refrigerant stored in the liquid reservoir 30 The surface is easily disturbed immediately below the outflow port 81A1. Therefore, even if there is a shortage of refrigerant to be detected, if a disturbed liquid surface LS2 is formed as shown in FIG. is difficult to detect with high accuracy.

FIG. 13 is a cross-sectional view showing a modification of the connecting portion between the first channel and the bypass channel of the refrigeration cycle device 1B. The outflow port 81A1 of the pipe 81A shown in FIG. 13 is arranged so as not to overlap the connecting end portion 86A of the pipe 86 when viewed from above. The outflow port 81A1 of the pipe 81A is arranged at the center in the horizontal direction X in the liquid reservoir 30, for example. The connecting end portion 86A is arranged on the lateral side of the liquid reservoir 30 in the horizontal direction X, for example. The distance in the horizontal direction X between the connection end 86A and the wall is, for example, the distance in the horizontal direction X between the connection end 86A and the outlet 81A1, and the distance in the horizontal direction X between the connection end 86A and the wall of the liquid reservoir 30. is shorter than the distance in the horizontal direction X between

In this way, even if a disturbed liquid surface LS2 is formed, the liquid surface immediately below the connection end 86A is spaced apart from the liquid surface immediately below the outlet 81A1. It is less disturbed than the liquid surface directly below. Therefore, the liquid refrigerant is less likely to flow into the pipe 86 shown in FIG. 13 than the pipe 86 shown in FIG. 13 even when the liquid surface LS2 is disturbed. As a result, in the refrigerating cycle device 1B and the outdoor unit 2B having the configuration shown in FIG. 13, the detection unit 70 detects the lack of refrigerant with higher accuracy than the refrigerating cycle device 1B and the outdoor unit 2B having the configuration shown in FIG. detectable.

FIG. 14 is a cross-sectional view showing another modification of the connecting portion between the first flow path and the bypass flow path of the refrigeration cycle device 1B. A liquid reservoir 30 shown in FIG. 14 includes a baffle plate 31 . Baffle plate 31 has an upper surface 32 and a lower surface 33 . The baffle plate 31 has at least one through hole 34 extending from the upper surface 32 to the lower surface 33 . A plurality of through holes 34 are formed in the baffle plate 31, for example. The connection end portion 86A is arranged above the upper surface 32 of the baffle plate 31 .

In this way, the liquid level LS3 of the liquid refrigerant stored in the liquid reservoir 30 is less likely to be disturbed by the baffle plate 31. FIG. Therefore, liquid refrigerant is less likely to flow into the pipe 86 shown in FIG. 14 than the pipe 86 shown in FIGS. 12 and 13 . As a result, in the refrigeration cycle device 1B and the outdoor unit 2B having the configuration shown in FIG. can be detected with high accuracy.

In FIG. 14, the outflow port 81A1 of the pipe 81A is arranged so as not to overlap the connecting end portion 86A of the pipe 86 when viewed from above. The distance in the horizontal direction X between the connection end 86A and the outlet 81A1 in the liquid reservoir 30 shown in FIG. may be shorter than the distance in the horizontal direction X between

In Embodiments 1 to 3, the refrigerating cycle devices 1, 1A, 1B and their outdoor units 2, 2A, 2B used for refrigerators have been described as representatives. It is also applicable to harmonizers.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

Reference Signs List 1, 1A, 1B refrigerating cycle device, 2, 2A, 2B outdoor unit, 3 indoor unit, 10 compressor, 20 condenser, 22, 42, 62 fan, 30 liquid reservoir, 31 baffle plate, 32 upper surface, 33 lower surface , 34 through hole, 40 heat exchanger, 45 sight glass, 50 expansion valve, 60 evaporator, 70 detector, 71 capillary tube, 72 heater, 73, 74, 201 temperature sensor, 75, 80, 81A, 81B, 81C , 83, 84, 85, 86, 87, 88, 89 piping, 81A1 outflow port, 81A2, 81B2 inclined portion, 81B1 inflow port, 82, 88A, 88B, 88C, 89A, 89B, 89C pipe portion, 86A connection end portion , 86B riser, 90, 92 pressure sensor, 100 controller, 104 memory.

Claims (10)

An outdoor unit of a refrigeration cycle device comprising a refrigerant circuit in which a refrigerant circulates,
a main flow path including a compressor for compressing the refrigerant and a condenser for condensing the refrigerant discharged from the compressor, and forming part of the refrigerant circuit;
a bypass flow path that guides part of the refrigerant that has flowed out of the condenser to the suction port of the compressor;
The bypass flow path includes a detection unit that detects a shortage of the refrigerant enclosed in the refrigerant circuit,
The detection unit is
a heater that heats the refrigerant flowing through the bypass channel;
a first temperature sensor that detects the temperature of the refrigerant before being heated by the heater;
a second temperature sensor that detects the temperature of the refrigerant heated by the heater;
a control device that detects shortage of the refrigerant sealed in the refrigerant circuit using the temperatures detected by the first temperature sensor and the second temperature sensor,
The main flow path includes a first flow path arranged downstream of the condenser,
The bypass channel further includes a connection end connected to the first channel and a rising portion extending upward from the connection end,
An outdoor unit, wherein the inner diameter is larger than the reference inner diameter when the inner diameter of the rising portion when the flow velocity of the refrigerant flowing into the bypass flow path is zero penetration flow velocity is defined as a reference inner diameter. The first flow path includes a liquid reservoir that stores liquid-phase refrigerant,
2. The outdoor unit according to claim 1, wherein said connection end is connected to said liquid reservoir and is configured to guide said refrigerant from said liquid reservoir to said bypass channel. The first flow path further includes a first pipe portion that guides the refrigerant from the condenser to the liquid reservoir, and a second pipe portion arranged downstream of the liquid reservoir,
3. The liquid reservoir according to claim 2 , wherein the connecting end is arranged below the end of the first tube and above the end of the second tube in the liquid reservoir. Described outdoor unit. 4. The liquid reservoir according to claim 3, wherein the end portion of the first pipe portion is arranged so as not to overlap the end portion of the connection end portion and the end portion of the second pipe portion when viewed from above. Described outdoor unit. the liquid reservoir includes a baffle plate having an upper surface and a lower surface and having a through hole extending from the upper surface to the lower surface;
The outdoor unit according to any one of claims 2 to 4 , wherein the connecting end portion is arranged above the upper surface of the baffle plate . An outdoor unit of a refrigeration cycle device comprising a refrigerant circuit in which a refrigerant circulates,
a main flow path including a compressor for compressing the refrigerant and a condenser for condensing the refrigerant discharged from the compressor, and forming part of the refrigerant circuit;
a bypass flow path that guides part of the refrigerant that has flowed out of the condenser to the suction port of the compressor;
The bypass flow path includes a detection unit that detects a shortage of the refrigerant enclosed in the refrigerant circuit,
The detection unit is
a heater that heats the refrigerant flowing through the bypass channel;
a first temperature sensor that detects the temperature of the refrigerant before being heated by the heater;
a second temperature sensor that detects the temperature of the refrigerant heated by the heater;
a control device that detects shortage of the refrigerant sealed in the refrigerant circuit using the temperatures detected by the first temperature sensor and the second temperature sensor,
The main flow path includes a first flow path arranged downstream of the condenser,
The bypass channel further includes a connection end connected to the first channel and a rising portion extending upward from the connection end,
The first flow path includes a liquid reservoir that stores liquid-phase refrigerant,
The connection end is connected to the liquid reservoir and configured to guide the refrigerant from the liquid reservoir to the bypass channel,
the liquid reservoir includes a baffle plate having an upper surface and a lower surface and having a through hole extending from the upper surface to the lower surface;
The outdoor unit , wherein the connecting end portion is arranged above the upper surface of the baffle plate . The first flow path has a third pipe portion and a fourth pipe portion connected in parallel with the third pipe portion and arranged above the third pipe portion,
The outdoor unit according to claim 1, wherein the connecting end portion is connected to the fourth pipe portion. An outdoor unit of a refrigeration cycle device comprising a refrigerant circuit in which a refrigerant circulates,
a main flow path including a compressor for compressing the refrigerant and a condenser for condensing the refrigerant discharged from the compressor, and forming part of the refrigerant circuit;
a bypass flow path that guides part of the refrigerant that has flowed out of the condenser to the suction port of the compressor;
The bypass flow path includes a detection unit that detects a shortage of the refrigerant enclosed in the refrigerant circuit,
The detection unit is
a heater that heats the refrigerant flowing through the bypass channel;
a first temperature sensor that detects the temperature of the refrigerant before being heated by the heater;
a second temperature sensor that detects the temperature of the refrigerant heated by the heater;
a control device that detects shortage of the refrigerant sealed in the refrigerant circuit using the temperatures detected by the first temperature sensor and the second temperature sensor,
The main flow path includes a first flow path arranged downstream of the condenser,
The bypass channel further includes a connection end connected to the first channel and a rising portion extending upward from the connection end,
The first flow path has a third pipe portion and a fourth pipe portion connected in parallel with the third pipe portion and arranged above the third pipe portion,
The outdoor unit, wherein the connecting end portion is connected to the fourth pipe portion . The fourth pipe portion has a first portion extending in the vertical direction and a second portion disposed downstream of the first portion and extending in the vertical direction,
The outdoor unit according to claim 7 or 8 , wherein said connecting end portion is continuous with said second portion in said vertical direction. The outdoor unit according to any one of claims 1 to 9 ,
A refrigeration cycle apparatus comprising an indoor unit connected to the outdoor unit.

Images