Filling unit and refrigerant filling method

Abstract

To prevent moisture contained in carbon dioxide from entering a refrigerant circuit.SOLUTION: The present invention is applied to a filling unit (50) for filling carbon dioxide sealed in a container (70) into a refrigerant circuit (R) of a refrigeration cycle device. The filling unit (50) includes a flow path (51) having a first connection port (52a) for connection to the vessel (70) and a second connection port (52b) for connection to the refrigerant circuit (R), and an adsorption part (53) disposed in the flow path (51) and configured to adsorb moisture in carbon dioxide.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a filling kit and a refrigerant filling method. [Background technology]

[0002] In a refrigeration system, after connecting the indoor unit and the outdoor unit with a connecting pipe, carbon dioxide may be charged on-site. Patent Document 1 discloses a refrigerant charging method for charging the refrigerant circuit of a refrigeration system with carbon dioxide charged in a cylinder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2008 / 010519 Summary of the Invention [Problem to be solved by the invention]

[0004] The refrigerant charging method of Patent Document 1 does not take into account the amount of moisture contained in the carbon dioxide in the cylinder.

[0005] The present disclosure provides a filling unit that can remove moisture contained in carbon dioxide. [Means for solving the problem]

[0006] The first aspect is applied to a filling unit (50) for filling a refrigerant circuit (R) of a refrigeration cycle apparatus (10) with carbon dioxide sealed in a container (70). The filling unit (50) includes a flow path (51) having a first connection port (52a) for connection to the container (70) and a second connection port (52b) for connection to the refrigerant circuit (R), and an adsorption part (53) disposed in the flow path (51) for adsorbing moisture in the carbon dioxide.

[0007] In the first aspect, an adsorption section (53) is disposed in a flow path (51) having a first connection port (52a) and a second connection port (52b). With the first connection port (52a) connected to the container (70) and the second connection port (52b) connected to the refrigerant circuit (R), carbon dioxide is charged into the refrigerant circuit (R) from the container (70). This allows the refrigerant circuit (R) to be charged with carbon dioxide through the adsorption section (53). The adsorption section (53) adsorbs moisture in the carbon dioxide. As a result, the moisture in the carbon dioxide can be prevented from entering the refrigerant circuit (R).

[0008] In the second aspect, in the first aspect, when the temperature of the atmosphere surrounding the adsorption section (53) is 30°C and carbon dioxide having a mass M passes through the adsorption section (53), the adsorption section (53) adsorbs a moisture amount of M×0.007% or more.

[0009] In the second embodiment, the adsorption section (53) adsorbs a moisture amount of M×0.007% or more when carbon dioxide having a mass M passes through the adsorption section (53). As a result, even if the purity grade of the carbon dioxide in the container (70) is low, the container (70) can be filled with the carbon dioxide required by the refrigeration cycle apparatus (10).

[0010] In a third embodiment, in the first or second embodiment, the adsorption section (53) contains a molecular sieve (registered trademark).

[0011] In a third embodiment, the adsorption section (53) includes a molecular sieve (registered trademark). A molecular sieve (registered trademark) has a high moisture adsorption performance and therefore adsorbs more moisture in carbon dioxide.

[0012] In a fourth aspect, in the first to third aspects, a filter (54) is further provided in the flow path (51).

[0013] In the fourth aspect, the filter (54) can prevent foreign matter contained in carbon dioxide from entering the refrigerant circuit (R).

[0014] In a fifth aspect, in the fourth aspect, the filter (54) is arranged in the first flow path (51a) from the first connection port (52a) in the flow path to the adsorption part (53).

[0015] In the fifth aspect, the filter (54) is disposed in the first flow path (51a), thereby preventing foreign matter from adhering to the adsorption portion (53).

[0016] In a sixth aspect, in the first to fifth aspects, a first opening / closing unit (55a) is provided which is arranged in a first flow path (51a) from the first connection port (52a) in the flow path (51) to the adsorption unit (53) and opens and closes the first flow path (51a), and a second opening / closing unit (55b) is arranged in the flow path (51) from the adsorption unit (53) to the second flow path (51b) and opens and closes the second flow path (51b).

[0017] In the sixth aspect, when carbon dioxide is filled, the first opening / closing part (55a) and the second opening / closing part (55b) are opened to allow the carbon dioxide to flow through the flow path, thereby filling the refrigerant circuit (R) with carbon dioxide.

[0018] When carbon dioxide is not being filled, the first opening / closing part (55a) and the second opening / closing part (55b) can prevent air from outside the filling unit (50) from flowing into the flow path (51). This allows the first opening / closing part (55a) and the second opening / closing part (55b) to prevent moisture in the air from being adsorbed by the adsorption part (53).

[0019] A seventh aspect is the sixth aspect, wherein the first opening / closing part (55a) and the second opening / closing part (55b) are opening / closing valves (55a, 55b).

[0020] In the seventh aspect, the first flow path (51a) and the second flow path (51b) are closed by closing the on-off valves (55a, 55b), and the first flow path (51a) and the second flow path (51b) are opened by opening the on-off valves (55a, 55b).

[0021] The eighth aspect is applied to a refrigerant charging method for charging carbon dioxide in a container (70) into a refrigerant circuit (R) of a refrigeration cycle apparatus (10). The refrigerant charging method includes adsorbing moisture from the carbon dioxide from the container (70) by an adsorption section (53), and charging the carbon dioxide from which the moisture has been adsorbed into the refrigerant circuit (R).

[0022] In the eighth aspect, the carbon dioxide after moisture has been adsorbed is filled into the refrigerant circuit (R), which makes it possible to prevent moisture from entering the refrigerant circuit (R).

[0023] In the ninth embodiment, in the eighth embodiment, the moisture in the carbon dioxide from the container (70) is adsorbed by the adsorption section (53) to a concentration of 50 ppm or less.

[0024] In the ninth aspect, the adsorption section (53) adsorbs moisture in the carbon dioxide so that the moisture content is 50 ppm or less. This allows the refrigerant circuit (R) to be filled with carbon dioxide of a quality equivalent to Class 3 specified in JIS K 1106. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a piping diagram of a refrigerant circuit of an air conditioner. [Figure 2] FIG. 2 is a diagram showing a schematic configuration of the filling unit. [Figure 3] FIG. 3 is a block diagram showing the relationship between the control unit of the air conditioner and various devices. [Figure 4] FIG. 4 is a piping diagram of the refrigerant circuit in a state where the charging unit is connected in the first charging step. [Figure 5] FIG. 5 is a piping diagram of the refrigerant circuit in a state where the charging unit is connected in the second charging step. [Figure 6] FIG. 6 is a piping diagram of a refrigerant circuit of an air conditioner according to a modified example. [Figure 7] FIG. 7 is a table showing the quality of carbon dioxide as specified in JIS K 1106. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible within the scope of the technical concept of the present disclosure. Since the drawings are intended to conceptually explain the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary to facilitate understanding.

[0027] The present disclosure relates to a method for charging a refrigerant into an air conditioner (10) that uses carbon dioxide as a refrigerant.

[0028] (1) Air conditioning system configuration The air conditioner (10) of this embodiment adjusts the air temperature of an indoor space, which is a target space. The air conditioner (10) performs cooling operation and heating operation. As shown in FIG. 1 , the air conditioner (10) has an outdoor unit (20), an indoor unit (40), a liquid connection pipe (22b), and a gas connection pipe (22a). The outdoor unit (20) is installed outdoors, and the indoor unit (40) is installed indoors. In the air conditioner (10), the outdoor unit (20) and the indoor unit (40) are connected to each other via the liquid connection pipe (22b) and the gas connection pipe (22a), thereby forming a refrigerant circuit (R). In the refrigerant circuit (R), a refrigeration cycle is performed by circulating refrigerant. The air conditioner (10) is a separate type in which the outdoor unit (20) and the indoor unit (40) are connected by two connection pipes (22). The air conditioner (10) is an example of a refrigeration cycle apparatus (10).

[0029] (1-1) Refrigerant circuit The refrigerant circuit (R) is filled with a single refrigerant made of carbon dioxide or a mixed refrigerant containing carbon dioxide. Carbon dioxide has an ozone depletion potential of zero, a low global warming potential, and is an environmentally friendly refrigerant. The refrigerant circuit (R) operates in a vapor compression refrigeration cycle. During heating operation, which will be described later, the refrigerant circuit (R) operates in a supercritical cycle, in which the pressure of the refrigerant compressed by the compressor (24) exceeds the critical pressure.

[0030] The refrigerant circuit (R) includes an outdoor circuit (21) provided in the outdoor unit (20) and an indoor circuit (41) provided in the indoor unit (40). A gas-side shut-off valve (27) is connected to a gas-side end of the outdoor circuit (21), and a liquid-side shut-off valve (28) is connected to a liquid-side end of the outdoor circuit (21). The gas end of the outdoor circuit (21) is connected to a gas-side end of the indoor circuit (41) via the gas-side shut-off valve (27) and a gas connection pipe (22a). The liquid end of the outdoor circuit (21) is connected to a liquid-side end of the indoor circuit (41) via the liquid-side shut-off valve (28) and a liquid connection pipe (22b).

[0031] The outdoor circuit (21) includes a compressor (24), an outdoor heat exchanger (23), a gas-liquid separator (25), a receiver (26), and a four-way selector valve (30).

[0032] The compressor (24) is disposed on the gas side of the outdoor circuit (21). The compressor (24) compresses the drawn refrigerant and discharges the compressed refrigerant. The compressor (24) is a rotary compressor such as a scroll type, a swing piston type, a rolling piston type, or a screw type. The operating frequency (number of revolutions) of the compressor (24) is adjusted by an inverter device. A discharge pipe (24a) is connected to the discharge side of the compressor (24). A suction pipe (24b) is connected to the suction side of the compressor (24).

[0033] The outdoor heat exchanger (23) is disposed in the outdoor circuit (21). The outdoor heat exchanger (23) exchanges heat between outdoor air and carbon dioxide flowing through the refrigerant circuit (R). The gas-liquid separator (25) is disposed on the gas side of the outdoor circuit (21) and is connected to the suction pipe (24b). The gas-liquid separator (25) is a sealed container that stores refrigerant. The gas-liquid separator (25) separates the refrigerant into gas refrigerant and liquid refrigerant. A gas layer and a liquid layer are formed inside the gas-liquid separator (25). The gas layer is formed on the top side of the gas-liquid separator (25). The liquid layer is formed on the bottom side of the gas-liquid separator (25).

[0034] The receiver (26) is disposed on the liquid side of the outdoor circuit (21). The receiver (26) is a sealed container that stores the refrigerant.

[0035] The four-way selector valve (30) is connected to the discharge side of the compressor (24). The four-way selector valve (30) changes the flow path of the refrigerant circuit (R) so as to switch between a first refrigeration cycle, which is a cooling cycle, and a second refrigeration cycle, which is a heating cycle. The four-way selector valve (30) switches between a first state indicated by a solid line in FIG. 1 and a second state indicated by a dashed line in FIG. 1. In the first state, the four-way selector valve (30) connects the suction side of the compressor (24) to the gas side of the indoor heat exchanger (42) and also connects the discharge side of the compressor (24) to the gas side of the indoor heat exchanger (42). In the second state, the four-way selector valve (30) connects the suction side of the compressor (24) to the gas side of the indoor heat exchanger (42) and also connects the discharge side of the compressor (24) to the gas side of the indoor heat exchanger (42).

[0036] The indoor circuit (41) includes an expansion valve (43) and an indoor heat exchanger (42).

[0037] The expansion valve (43) reduces the pressure of the refrigerant and is connected in the refrigerant circuit (R) between the indoor heat exchanger (42) and the outdoor heat exchanger (23).

[0038] The indoor heat exchanger (42) is a fin-and-tube air heat exchanger. The indoor heat exchanger (42) is an example of a utilization-side heat exchanger. An indoor fan (44) provided in the indoor unit (40) is arranged near the indoor heat exchanger (42). The indoor heat exchanger (42) exchanges heat between carbon dioxide flowing therethrough and outdoor air blown by the indoor fan (44). The indoor fan (44) supplies the air cooled or heated by the indoor heat exchanger (42) to the indoor space.

[0039] (1-2) Remote controller The air conditioner (10) has a remote controller (90). A user can select cooling operation or heating operation by operating the remote controller (90).

[0040] (1-3) Control unit As shown in Fig. 3, the air conditioner (10) has a control unit (C). The control unit (C) has an outdoor control unit (C1) and an indoor control unit (C2). The outdoor control unit (C1) and the indoor control unit (C2) are configured to be able to communicate with each other via wire or wirelessly.

[0041] The outdoor control unit (C1) and the indoor control unit (C2) each include an MCU (Micro Controller Unit), an electric circuit, an electronic circuit, and a memory unit. The MCU includes a CPU (Central Processing Unit), a memory, and a communication interface. The memory stores various programs to be executed by the CPU.

[0042] The outdoor control unit (C1) is provided in the outdoor unit (20). The outdoor control unit (C1) controls switching between operation and stop of the compressor (24), the rotation speed of the compressor (24), switching between operation and stop of the outdoor fan (29), the rotation speed of the outdoor fan (29), the opening degree of the expansion valve (43), and switching between opening and closing of the liquid side shut-off valve (28) and the gas side shut-off valve (27).

[0043] The indoor control unit (C2) is provided in the indoor unit (40). The indoor control unit (C2) switches the indoor fan (44) on and off and controls the rotation speed of the indoor fan (44). The indoor control unit (C2) receives a detection signal from the indoor temperature sensor (80).

[0044] (2) Operation of the air conditioner (2-1) Cooling operation In the cooling operation, the control unit (C) sets the four-way selector valve (30) to the first state, operates the compressor (24), the outdoor fan (29), and the indoor fan (44), and adjusts the opening of the expansion valve (43). In Fig. 1, the flow of carbon dioxide in the cooling operation is indicated by solid arrows.

[0045] The refrigerant circuit (R) performs a refrigeration cycle in which the outdoor heat exchanger (23) functions as a radiator and the refrigerant evaporates in the indoor heat exchanger (42).

[0046] Specifically, the carbon dioxide is compressed by the compressor (24) and then dissipates heat in the outdoor heat exchanger (23). The carbon dioxide that has dissipated heat in the outdoor heat exchanger (23) is reduced in pressure by the expansion valve (43) and then flows through the indoor heat exchanger (42). In the indoor heat exchanger (42), the carbon dioxide absorbs heat from the indoor air and evaporates. The evaporated carbon dioxide is compressed again by the compressor (24).

[0047] (2-2) Heating operation In the heating operation, the control unit (C) sets the four-way selector valve (30) to the second state, operates the compressor (24), the outdoor fan (29), and the indoor fan (44), and adjusts the opening of the expansion valve (43). In Fig. 1, the flow of carbon dioxide in the heating operation is indicated by dashed arrows.

[0048] In the refrigerant circuit (R), a refrigeration cycle is performed in which the indoor heat exchanger (42) functions as a radiator and the outdoor heat exchanger (23) functions as an evaporator.

[0049] Specifically, the carbon dioxide is compressed by the compressor (24) and then dissipates heat in the indoor heat exchanger (42). As a result, the indoor air is heated. The carbon dioxide that dissipates heat in the indoor heat exchanger (42) is reduced in pressure by the expansion valve (43) and then evaporated in the outdoor heat exchanger (23). The evaporated carbon dioxide is compressed again by the compressor (24).

[0050] (3) Configuration of the filling unit (3-1) Basic configuration of the filling unit The charging unit (50) is used to charge the refrigerant circuit (R) with carbon dioxide sealed in a cylinder (70). The charging unit (50) has a function of adsorbing moisture in the carbon dioxide. The cylinder (70) is an example of a container. The cylinder (70) is filled with two types of carbon dioxide with the quality specified in JIS K 1106. The cylinder (70) is filled with 20 kg of carbon dioxide. A hose (72) is connected to the cylinder (70). A pressure reducing valve (71) is provided to the hose (72). The pressure reducing valve (71) reduces the pressure of the carbon dioxide flowing through the hose (72).

[0051] 2, the filling unit (50) includes a flow path (51), an adsorption section (53), a filter (54), a first on-off valve (55a), and a second on-off valve (55b). The adsorption section (53), the filter (54), the first on-off valve (55a), and the second on-off valve (55b) are disposed in the flow path (51).

[0052] The flow path (51) is a flow path for flowing carbon dioxide from the container (70) to the refrigerant circuit (R). The flow path (51) may be formed, for example, inside a housing, or inside a pipe or a tube. The flow path (51) has a first connection port (52a) at one end and a second connection port (52b) at the other end. The first connection port (52a) is a connection port for connecting to the container (70). The first connection port (52a) is connected to a hose (72) provided in the container (70). The first connection port (52a) may be connected to a pressure reducing valve (71) or may be directly connected to the container (70). The flow path (51) includes a first flow path (51a) from the first connection port (52a) to the adsorption section (53) and a second flow path (51b) from the adsorption section (53) to the second connection port (52b).

[0053] The second connection port (52b) is a connection port for connection to the refrigerant circuit (R). The second connection port (52b) is connected to a charge port of the liquid side stop valve (28). The second connection port (52b) may be connected to a pipe connected to the charge port.

[0054] The first on-off valve (55a) is disposed in the first flow path (51a). The first on-off valve (55a) is switched between an open state and a closed state of the first flow path (51a). The second on-off valve (55b) is disposed in the second flow path (51b). The second on-off valve (55b) is switched between an open state and a closed state of the second flow path (51b).

[0055] The filter (54) is disposed in the first flow path (51a) between the first on-off valve (55a) and the adsorption part (53). The filter (54) physically captures objects when carbon dioxide is filled. The objects include dust in the container (70) that enters the flow path (51) and dust in the hose (72) attached to the container (70).

[0056] (3-2) Details of the suction part The adsorption section (53) adsorbs moisture in the carbon dioxide passing through the adsorption section (53). Specifically, the adsorption section (53) adsorbs moisture in an amount equal to or greater than 0.007% of the mass of the carbon dioxide passing through the adsorption section (53) when the ambient temperature is 30° C. The amount of moisture adsorbed is expressed by the following equation, where M is the mass of carbon dioxide passing through the adsorption section (53) and W is the amount of moisture adsorbed by the adsorption section (53):

[0057] W=M×0.007% Formula (1) The adsorption section (53) adsorbs 1.4 g or more of moisture when 20 kg of carbon dioxide is passed through the adsorption section (53). In other words, the adsorption section (53) reduces the moisture concentration in the carbon dioxide by 70 ppm or more.

[0058] The adsorption section (53) is an adsorbent material containing molecular sieve (registered trademark). Molecular sieve (registered trademark) types include 3A, 4A, 5A, and 13X. The numbers in the molecular sieve (registered trademark) indicate the pore size (Å). In this embodiment, it is preferable to use 3A molecular sieve (registered trademark), which has the property of being less likely to adsorb carbon dioxide. Molecular sieve (registered trademark) types such as 4A, 5A, and 13X may also be used.

[0059] (4) Filling method A method for filling the refrigerant circuit (R) of the air conditioner (10) with carbon dioxide in a cylinder (70) will be described. The filling method of this embodiment is a method for filling the refrigerant circuit (R) with carbon dioxide after moisture has been adsorbed by the adsorption section (53). An operator performs a depressurization step for reducing the pressure inside the refrigerant circuit (R), and a first filling step and a second filling step for filling the refrigerant circuit (R) with carbon dioxide.

[0060] (4-1) Decompression process The depressurization process is a process of discharging air from the refrigerant circuit (R) to the outside. In the depressurization process, the operator connects a pump (not shown) or the like to the charge port of the liquid-side shut-off valve (28). Next, the operator operates the pump with the liquid-side shut-off valve (28) open to discharge air from the refrigerant circuit (R) to the outside. The operator may also perform the depressurization process by connecting the pump to the gas-side shut-off valve (27).

[0061] (4-2) First filling process The first filling step is a step of filling the refrigerant circuit (R) with carbon dioxide by utilizing the pressure inside the container (70). The first filling step is performed in a state in which the filling unit (50) is connected to the container (70) and the refrigerant circuit (R) as shown in FIG. 4. Specifically, the first connection port (52a) of the filling unit (50) is connected to the hose (72), and the second connection port (52b) is connected to a charge port of the liquid-side shut-off valve (28) of the refrigerant circuit (R). The method of connecting the second connection port (52b) is one example, and it may be connected to the interconnecting pipe (22) of the refrigerant circuit (R) or to a charge port of the gas-side shut-off valve (27).

[0062] First, the worker switches the first on-off valve (55a) and the second on-off valve (55b) to an open state. Next, the worker opens the liquid-side shut-off valve (28) and then opens the pressure reducing valve (71) of the container (70). By opening the pressure reducing valve (71), carbon dioxide is discharged from the container (70) to the filling unit (50). The pressure of the carbon dioxide discharged from the container (70) is preferably 6 MPa to 13 MPa. The worker adjusts the opening of the pressure reducing valve (71) so that the pressure is within the above pressure range.

[0063] The carbon dioxide that has flowed into the filling unit (50) passes through the filter (54), the adsorption section (53), and then the flow path (51) of the filling unit (50) and flows into the refrigerant circuit (R). As the carbon dioxide passes through the filter (54), foreign matter contained in the container (70) and the hose (72) is captured. As the carbon dioxide passes through the adsorption section (53), moisture is adsorbed into the carbon dioxide, and the moisture concentration in the carbon dioxide becomes 50 ppm or less. Then, the carbon dioxide, whose moisture content has been reduced by the adsorption section (53), flows into the refrigerant circuit (R).

[0064] When the operator determines that the required amount of carbon dioxide has been charged, he closes the liquid-side shut-off valve (28). By closing the liquid-side shut-off valve (28), the operator ends the first charging step. The amount of carbon dioxide charged is determined, for example, by checking the weight of the container (70). The operator determines that the amount of carbon dioxide equivalent to the weight lost from the container (70) has been charged into the refrigerant circuit (R).

[0065] If the operator determines that the required amount of carbon dioxide is insufficient, he or she closes the liquid-side shut-off valve (28), ends the first filling step, and starts the second filling step.

[0066] (4-3) Second filling process The second charging step is a step of charging the refrigerant circuit (R) with carbon dioxide by utilizing the pressure of the compressor (24). The second charging step is performed in a state in which the second connection port (52b) of the charging unit (50) is connected to the charge port of the gas side stop valve (27) as shown in FIG.

[0067] Specifically, the worker connects the second connection port (52b) to the charge port of the gas-side shut-off valve (27) with the liquid-side shut-off valve (28) closed. The worker then operates the compressor (24) with the four-way selector valve (30) in the first position and the expansion valve (43) closed. In the refrigerant circuit (R), the expansion valve (43) is closed, so that the compressor (24) transports carbon dioxide from the container (70) to the outdoor heat exchanger (23). This is called a pump-down operation. The worker terminates the second filling step when the required amount of carbon dioxide has been filled into the refrigerant circuit (R). The second filling step may be performed with the four-way selector valve (30) in the second position and with the second connection port (52b) connected to the charge port of the liquid-side shut-off valve (28). The second filling step may be performed after the depressurization step, or the first filling step may be omitted.

[0068] (5) Effects of the embodiment (5-1) The filling unit (50) is used when filling the refrigerant circuit (R) of the refrigeration cycle apparatus (10) with carbon dioxide sealed in a container (70). The filling unit (50) includes a flow path (51) having a first connection port (52a) for connection to the container (70) and a second connection port (52b) for connection to the refrigerant circuit (R), and an adsorption section (53) disposed in the flow path (51) for adsorbing moisture in the carbon dioxide.

[0069] An adsorption section (53) is disposed in a flow path (51) having a first connection port (52a) and a second connection port (52b). Carbon dioxide is charged with the refrigerant circuit (R) with the first connection port (52a) connected to the container (70) and the second connection port (52b) connected to the refrigerant circuit (R). This allows the refrigerant circuit (R) to be charged with carbon dioxide through the adsorption section (53). The adsorption section (53) adsorbs moisture in the carbon dioxide. If moisture in the refrigerant circuit (R) exceeds a permissible amount, the moisture turns to ice when passing through the expansion valve. Ice precipitated inside the expansion valve may clog the flow path. By charging the refrigerant circuit (R) with carbon dioxide after the adsorption section (53) adsorbs the moisture, the refrigerant circuit (R) can be prevented from accumulating ice.

[0070] When water enters the refrigerant circuit (R), copper ions are eluted from the copper piping. As a result, copper precipitates in the copper refrigerant circuit (R) and covers the surface of the steel material. For example, if copper covers the steel material of the compressor (24), the compressor (24) may malfunction. The adsorption section (53) adsorbs the moisture in the carbon dioxide, thereby suppressing the elution of copper ions from the copper piping.

[0071] (5-2) When the temperature of the atmosphere around the adsorption section (53) is 30° C. and carbon dioxide having a mass M passes through the adsorption section (53), the adsorption section (53) adsorbs a moisture amount of M×0.007% or more.

[0072] When carbon dioxide having a mass M passes through the adsorption section (53), it adsorbs a moisture content of M × 0.007% or more. As a result, even if the carbon dioxide in the container (70) has a low purity grade, it can be filled with the carbon dioxide required by the refrigeration cycle device (10). The low-grade carbon dioxide referred to here is carbon dioxide of type 2 quality as specified in JIS K 1106, as shown in FIG. 7. The moisture concentration in the carbon dioxide of type 2 is 120 ppm or less. When the adsorption section (53) adsorbs a moisture content of M × 0.007% or more, the moisture concentration in the carbon dioxide decreases by 70 ppm or more. Therefore, when the type 2 carbon dioxide passes through the adsorption section (53), the moisture concentration in the carbon dioxide decreases from 120 ppm to 50 ppm. When the moisture concentration in the carbon dioxide is 50 ppm, it is equivalent to type 3 quality as specified in JIS K 1106. Therefore, the adsorption section (53) can convert type 2 carbon dioxide into carbon dioxide equivalent to type 3.

[0073] Furthermore, the two types of carbon dioxide are less pure than the three types of carbon dioxide, and therefore can be obtained at a lower cost.

[0074] (5-3) The adsorption section (53) contains a molecular sieve (registered trademark).

[0075] The adsorption section (53) contains a molecular sieve (registered trademark), which adsorbs moisture in the carbon dioxide.

[0076] (5-4) The filter (54) is arranged in the first flow path (51a) from the first connection port (52a) in the flow path to the adsorption part (53).

[0077] The filter (54) is disposed in the first flow path (51a), thereby preventing foreign matter from entering the adsorption part (53).

[0078] (5-5) The filling unit (50) includes a first opening / closing part (55a) disposed in a first flow path (51a) from the first connection port (52a) in the flow path (51) to the adsorption part (53) and configured to open and close the first flow path (51a), and a second opening / closing part (55b) disposed in the flow path (51) from the adsorption part (53) to the second flow path (51b) and configured to open and close the second flow path (51b).

[0079] When carbon dioxide is to be filled, the first opening / closing part (55a) and the second opening / closing part (55b) are opened to allow the carbon dioxide to flow through the flow path (51), thereby filling the refrigerant circuit (R) with carbon dioxide.

[0080] When carbon dioxide is not being filled, the first opening / closing part (55a) and the second opening / closing part (55b) can prevent air from outside the filling unit (50) from flowing into the flow path (51). This can prevent the adsorption part (53) from adsorbing moisture. This can prevent a decrease in the adsorption capacity of the adsorbent.

[0081] (5-6) The first opening / closing part (55a) and the second opening / closing part (55b) are opening / closing valves (55a, 55b).

[0082] The first flow path (51a) and the second flow path (51b) are closed by closing the on-off valves (55a, 55b), whereas the first flow path (51a) and the second flow path (51b) are opened by opening the on-off valves (55a, 55b).

[0083] (5-7) This is a refrigerant charging method for charging carbon dioxide in a container (70) into a refrigerant circuit (R) of a refrigeration cycle apparatus (10). In the refrigerant charging method, moisture in the carbon dioxide from the container (70) is adsorbed by an adsorption section (53), and the carbon dioxide after the moisture has been adsorbed is charged into the refrigerant circuit (R).

[0084] The carbon dioxide after moisture has been adsorbed is filled into the refrigerant circuit (R), which makes it possible to prevent moisture from entering the refrigerant circuit (R).

[0085] (5-8) The moisture in the carbon dioxide from the container (70) is adsorbed by the adsorption section (53) to a concentration of 50 ppm or less.

[0086] The adsorption section (53) adsorbs moisture so that the moisture content in the carbon dioxide is 50 ppm or less, thereby allowing the refrigerant circuit (R) to be filled with carbon dioxide of a quality equivalent to Class 3 specified in JIS K 1106.

[0087] (6) Variations A modification of the filling unit (50) of the above embodiment will be described below, which has a configuration that is fundamentally different from the above embodiment.

[0088] (6-1) Variation 1 The charging unit (50) of the first modification is provided in the refrigeration cycle apparatus (10). The charging unit (50) is accommodated in the outdoor unit (20).

[0089] 6, the filling unit (50) is provided in the outdoor unit (20). The second flow path (51b) includes a second connection port (52b) connected to the charge port of the liquid-side shut-off valve (28) and a third connection port (52c) connected to the charge port of the gas-side shut-off valve (27).

[0090] In the first modification, the worker performs the first filling step and the second filling step with the first connection port (52a) connected to the container (70). The first filling step is performed with the gas-side shut-off valve (27) closed and the liquid-side shut-off valve (28) open, or with the gas-side shut-off valve (27) open and the liquid-side shut-off valve (28) closed.

[0091] The second filling step is performed with the four-way switching valve (30) in the first position, the gas-side shut-off valve (27) open, and the liquid-side shut-off valve (28) closed. The second filling step may be performed with the four-way switching valve (30) in the second position, the gas-side shut-off valve (27) open, and the liquid-side shut-off valve (28) open.

[0092] (6-2) Variation 2 In the second modification, the cylinder (70) is filled with carbon dioxide of a quality specified in ISO 5923. The quality specified in ISO 5923 is a carbon dioxide with a moisture concentration of 150 ppm. The cylinder (70) is filled with 20 kg of carbon dioxide. The adsorption section (53) adsorbs a moisture amount of 0.010% or more of the mass of carbon dioxide passing through the adsorption section (53) when the ambient temperature is 30°C. The amount of moisture adsorbed is expressed by the following equation, where M is the mass of carbon dioxide passing through the adsorption section (53) and W is the amount of moisture adsorbed by the adsorption section (53):

[0093] W=M×0.010% Formula (2) According to the above formula (2), the adsorption unit (53) adsorbs moisture up to a quality specified in ISO 5923 equivalent to Class 3 in JIS K 1106. When 20 kg of carbon dioxide is passed through the adsorption unit (53), the adsorption unit (53) adsorbs 2 g or more of moisture. In other words, the adsorption unit (53) reduces the moisture concentration in the carbon dioxide passing through the adsorption unit by 100 ppm or more. Because the moisture concentration in carbon dioxide, which is the quality specified in ISO 5923, is 150 ppm, the adsorption unit (53) adsorbs moisture down to a moisture concentration of 50 ppm, which is equivalent to Class 3.

[0094] (6-3) Variation 3 In the third modification, the cylinder (70) is filled with carbon dioxide of type 1 quality specified in JIS K 1106. The cylinder (70) is filled with 20 kg of carbon dioxide. The adsorption section (53) adsorbs a moisture amount equal to or greater than 0.115% of the mass of carbon dioxide passing through the adsorption section (53) when the ambient temperature is 30°C. The amount of moisture adsorbed is expressed by the following equation, where M is the mass of carbon dioxide passing through the adsorption section (53) and W is the amount of moisture adsorbed by the adsorption section (53):

[0095] W=M×0.115% Equation (3) According to the above formula (3), the adsorption unit (53) adsorbs moisture up to the equivalent of type 3 carbon dioxide, as specified in JIS K 1106. When 20 kg of carbon dioxide is passed through the adsorption unit (53), the adsorption unit (53) adsorbs 23 g or more of moisture. In other words, the adsorption unit (53) reduces the moisture concentration in the carbon dioxide passing through the adsorption unit by 1150 ppm or more. Since the moisture concentration in carbon dioxide, which is the quality specified in ISO 5923, is 1200 ppm, the adsorption unit (53) adsorbs moisture down to 50 ppm, which is equivalent to type 3.

[0096] (7) Other embodiments The adsorption section (53) may use silica gel or activated alumina instead of Molecular Sieve (registered trademark).

[0097] The first opening / closing part (55a) may be a detachable lid that closes the first connection port (52a).

[0098] The second opening / closing part (55b) may be a detachable lid that closes the second connection port (52b).

[0099] The expansion valve may be provided in the indoor circuit (41) on the liquid side of the outdoor unit (20), or may be provided in both the indoor unit (40) and the outdoor unit (20).

[0100] The filter (54) may be provided in the second flow path (51b). The filter (54) can prevent foreign matter from entering the refrigerant circuit (R).

[0101] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and details are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate as long as the functionality of the subject matter of the present disclosure is not impaired.

[0102] The terms "first," "second," "third," etc. mentioned above are used to distinguish the terms to which these terms are attached, and do not limit the number or order of the terms. [Industrial Applicability]

[0103] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for a charging unit and a refrigerant charging method. [Explanation of symbols]

[0104] 10 Air conditioning equipment (refrigeration cycle equipment) 50 filling units 51 Flow path 51a First flow path 51b Second flow path 52a First connection port 52b Second connection port 53 Adsorption part 54 filters 55a First opening / closing section (first opening / closing valve) 55a, 55b On-off valve 55b Second opening / closing section (second opening / closing valve) 70 Cylinder (Container) R Refrigerant circuit

Claims

1. A filling unit for filling a refrigerant circuit (R) of a refrigeration cycle apparatus (10) with carbon dioxide sealed in a container (70), a flow path (51) having a first connection port (52a) for connection to the container (70) and a second connection port (52b) for connection to the refrigerant circuit (R); an adsorption section (53) disposed in the flow path (51) and configured to adsorb moisture in the carbon dioxide; Filling unit.

2. When the temperature of the atmosphere around the adsorption section (53) is 30° C. and carbon dioxide having a mass M passes through the adsorption section (53), the adsorption section (53) adsorbs a moisture amount of M×0.007% or more.

2. The filling unit of claim 1.

3. The adsorption section (53) contains a molecular sieve (registered trademark).

3. A filling unit according to claim 1 or 2.

4. The device further includes a filter (54) disposed in the flow path (51).

3. A filling unit according to claim 1 or 2.

5. The filter (54) is disposed in a first flow path (51a) of the flow path (51) from the first connection port (52a) to the adsorption part (53).

5. A filling unit according to claim 4.

6. a first opening / closing unit (55a) arranged in a first flow path (51a) of the flow path (51) from the first connection port (52a) to the adsorption unit (53), and configured to open and close the first flow path (51a); a second opening / closing section (55b) disposed in the flow path (51) from the adsorption section (53) to the second flow path (51b) for opening and closing the second flow path (51b); 3. A filling unit according to claim 1 or 2.

7. The first opening / closing part (55a) and the second opening / closing part (55b) are opening / closing valves.

7. A filling unit according to claim 6.

8. A refrigerant charging method for charging carbon dioxide in a container (70) into a refrigerant circuit (R) of a refrigeration cycle apparatus (10), comprising: Moisture in the carbon dioxide from the container (70) is adsorbed by the adsorption section (53), The carbon dioxide after the moisture has been adsorbed is charged into the refrigerant circuit (R). Refrigerant charging method.

9. The moisture in the carbon dioxide from the container (70) is adsorbed by the adsorption section (53) to a level of 50 ppm or less. The refrigerant charging method according to claim 8.

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