Method for Charging Refrigerant into Heat Transferring Apparatus and Refrigerant-Charging Control Apparatus for Heat Transferring Apparatus

Abstract

A method for charging a refrigerant into a heat transferring apparatus (110) includes a pre-charging step (step 902) of charging an inert gas into a refrigerant flow path (10) of the heat transferring apparatus (110) to bring a pressure in the refrigerant flow path (10) of the heat transferring apparatus (110) to a predetermined pressure; and a main charging step (step 902) of charging the refrigerant into the refrigerant flow path (10) of the heat transferring apparatus (110) to a predetermined amount required for the heat transferring apparatus (110) to operate after the pre-charging step (step 904).

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for charging a refrigerant into a heat transferring apparatus and a refrigerant-charging control apparatus for a heat transferring apparatus.BACKGROUND ART

[0002] Apparatuses controlling closed loops working on a thermodynamic cycle are known in the art. Such an apparatus is disclosed in Japanese Patent Publication No. JP 6660095, for example.

[0003] The above Japanese Patent Publication No. JP 6660095 discloses an apparatus controlling a closed loop, which exchanges heat to / from an external heat source by using compression and expansion of a working fluid as a thermal medium, through a Rankine cycle as the thermodynamic cycle. A pump circulating and compressing the working fluid and a tank storing the working fluid in a liquid state, which flows into the pump, are arranged in the closed loop. A pressure source, which is a pressurized gas, is connected to the tank through a pressure control valve. The apparatus disclosed in the above Japanese Patent Publication No. JP 6660095 pressurizes the tank by flowing the gas from a pressure source separately from the working fluid by controlling operation of the pressure control valve during operation of the closed loop to prevent occurrence of cavitation in which the gas is produced in the pump.PRIOR ARTPatent DocumentPatent Document 1: Japanese Patent Publication No. JP 6660095SUMMARY OF THE INVENTIONProblems to be Solved by the Invention

[0005] Here, in the apparatus disclosed in the above Japanese Patent Publication No. JP 6660095, the refrigerant is pressurized by flowing the gas (inert gas) from the pressure source separately from the refrigerant into a flow path of the closed loop (refrigerant flow path) into which the working fluid (refrigerant) is charged. In such a case, in addition to dissolution of the inert gas into the refrigerant in the liquid phase state, variation of an amount of the inert gas dissolving into the refrigerant, depending on temperature and pressure of the refrigerant, makes it difficult to grasp an inflow amount (charging amount) of the inert gas in the refrigerant flow path. Since the temperature at which the refrigerant evaporates and condenses varies depending on the charging amount of the inert gas filled, it is desirable to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a heat transferring apparatus using the thermodynamic cycle.Means for Solving the Problems

[0006] The present invention is intended to solve the above problem, and one object of the present invention is to provide a method for charging a refrigerant into a heat transferring apparatus and a refrigerant-charging control apparatus for a heat transferring apparatus capable of easily grasping a charging amount of an inert gas charged separately from a refrigerant in the heat transferring apparatus using a thermodynamic cycle.

[0007] A method for charging a refrigerant into a heat transferring apparatus according to a first aspect of the present invention includes a pre-charging step of charging an inert gas into a refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure; and a main charging step of charging the refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate after the pre-charging step. Here, the “heat transferring apparatus” stated in this specification refers to a concept that includes a cooling apparatus cooling an object and a heating apparatus heating an object.

[0008] A refrigerant-charging control apparatus for a heat transferring apparatus according to a second aspect of the present invention includes a controller performing control to acquire a pressure in a refrigerant flow path of the heat transferring apparatus detected by a pressure detector, wherein if conducting pre-charging to charge an inert gas into the refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure before conducting main charging to charge a refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate, the controller performs control to determine whether the charging of the inert gas is completed based on the pressure in the refrigerant flow path of the heat transferring apparatus detected by the pressure detector.Effect of the Invention

[0009] In the method for charging a refrigerant into a heat transferring apparatus according to the first aspect of the present invention, after the pre-charging is conducted to charge an inert gas into the refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure, the main charging is conducted to charge a refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate. In the refrigerant-charging control apparatus for a heat transferring apparatus according to the second aspect of the present invention, before the main charging, an inert gas is charged into a refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure. Accordingly, it is possible to prevent difficulty of grasping a charging amount of the inert gas caused by dissolution of the inert gas into the refrigerant dissimilar to a case in which the inert gas is charged into the refrigerant flow path after the refrigerant is charged. Consequently, it is possible to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a heat transferring apparatus using a thermodynamic cycle. Also, in the present invention, since the inert gas is charged before the main charging in which the refrigerant is charged into the refrigerant flow path, a pressure of the inert gas required to charge the refrigerant into the refrigerant flow path can be smaller as compared with the case in which the inert gas is charged after the refrigerant is charged. Accordingly, since a relatively high-pressure inert gas source is not necessarily provided, it is possible to easily charge the inert gas into the refrigerant flow path.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a schematic diagram showing a cooling apparatus using an inert gas together with a carbon dioxide refrigerant.

[0011] FIG. 2 is a flowchart illustrating processing using a method for charging the refrigerant into the cooling apparatus according to the first embodiment.

[0012] FIG. 3 is a schematic diagram showing a configuration of a refrigerant-charging control apparatus and a cooling apparatus according to a second embodiment.

[0013] FIG. 4 is a flowchart illustrating processing using a method for charging the refrigerant into the cooling apparatus according to the second embodiment.

[0014] FIG. 5 is a schematic diagram showing a configuration of a refrigerant-charging control apparatus and a cooling apparatus according to a third embodiment.

[0015] FIG. 6 is a flowchart illustrating processing using a method for charging the refrigerant into the cooling apparatus according to a fourth embodiment.MODES FOR CARRYING OUT THE INVENTION

[0016] The following description will describe embodiments embodying the present invention with reference to the drawings.First Embodiment

[0017] A method for charging a refrigerant (carbon dioxide refrigerant) into a cooling apparatus 110 (heat transferring apparatus), which is to be operated by an operator, according to a first embodiment is first described with reference to FIGS. 1 and 2.(Configuration of Cooling Apparatus)

[0018] The cooling apparatus 110 (see FIG. 1) is a cooling apparatus that uses carbon dioxide as the refrigerant. The cooling apparatus 110 is an apparatus that uses carbon dioxide in a gas-liquid two-phase state in which gas and liquid are mixed. The cooling apparatus 110 includes a condenser 1, a tank 2, a pump 3, an evaporator 4, and an apparatus controller 5. The cooling apparatus 110 prevents occurrence of cavitation in the pump 3 by pressurizing the refrigerant, which is carbon dioxide, by using an inert gas. Cavitation refers to a phenomenon in which a gas is produced in the pump 3 arranged on a refrigerant flow path 10 of the cooling apparatus 110 during operation of the cooling apparatus 110. Cavitation occurs due to the production of the gas if a pressure of the refrigerant in a liquid phase state flowing into the pump 3 becomes smaller than a saturation vapor pressure in the pump 3. The inert gas is charged to a setting amount of the inert gas, which is previously set, to bring the pressure of the refrigerant flowing into the pump 3 arranged on the refrigerant flow path 10 of the cooling apparatus 110 to a pressure not smaller than the saturation vapor pressure of the refrigerant during operation of the cooling apparatus 110. Here, the cooling apparatus 110 is an example of a “heat transferring apparatus” in the claims.

[0019] The refrigerant flow path 10 is formed of the condenser 1, the tank 2, pump 3, the evaporator 4, and pipes, which are connected to the condenser 1, the tank 2, the pump 3 and the evaporator 4, in the cooling apparatus 110.

[0020] The condenser 1 condenses the refrigerant (carbon dioxide). The condenser 1 is configured to cool and condense the refrigerant by using a chiller. The refrigerant flowing out of the condenser 1 is transferred to the tank 2. The tank 2 is a container storing the refrigerant. The refrigerant condensed by the condenser 1 flows into the tank 2. The tank 2 stores the refrigerant in a liquid phase or a gas-liquid two-phase. The refrigerant stored in the tank 2 is transferred to the pump 3. Also, the inert gas is stored in the tank 2 together with the refrigerant.

[0021] The pump 3 transfers the refrigerant (carbon dioxide) stored in the tank 2 to the evaporator 4. The operation of the pump 3 is controlled by the apparatus controller 5. The evaporator 4 cools an object to be cooled (not shown) by evaporating the refrigerant discharged from the pump 3. Subsequently, the refrigerant flowing out of the evaporator 4 is returned to the condenser 1 and is then condensed in the condenser 1.

[0022] The apparatus controller 5 is configured to entirely control the cooling apparatus 110. The apparatus controller 5 includes a processor such as a CPU (Central Processing Unit), a memory, and the like. The apparatus controller 5 is configured to entirely control the cooling apparatus 110 by using control software (program) recorded (stored) in the internal or external memory (storage device).

[0023] The cooling apparatus 110 includes temperature sensors 61 and 62 detecting temperatures of the refrigerant in the refrigerant flow path. Also, the cooling apparatus 110 includes pressure sensors 63 and 64 detecting pressures of the refrigerant in the refrigerant flow path. The pressure sensors 63 and 64 are examples of a “pressure detector” in the claims.

[0024] The temperature sensor 61 is arranged between the tank 2 and the pump 3, and detects the temperature of the refrigerant flowing out of the tank 2. The temperature sensor 62 is arranged between the evaporator 4 and the condenser 1, and detects the temperature of the refrigerant flowing out of the evaporator 4.

[0025] The pressure sensor 63 is arranged between the tank 2 and the pump 3, and detects the pressure of the refrigerant flowing between the tank 2 and the pump 3. The pressure sensor 64 is arranged between the evaporator 4 and the condenser 1, and detects the pressure of the refrigerant flowing between the evaporator 4 and the condenser 1.

[0026] Also, the apparatus controller 5 is connected to the pump 3 for communication. Also, the apparatus controller 5 is connected to the temperature sensors 61 and 62 for communication. Also, the apparatus controller 5 is connected to the pressure sensors 63 and 64 for communication.

[0027] The apparatus controller 5 is configured to control the cooling apparatus 110 by acquiring detection signals from the temperature sensor 61, the temperature sensor 62, the pressure sensor 63, and the pressure sensor 64.

[0028] Also, a cylinder 121, a cylinder 122, and a vacuum pump 123 are connected to the refrigerant flow path 10 of the cooling apparatus 110 through a manifold 7.

[0029] The cylinder 121 is filled with carbon dioxide (refrigerant). A flow control valve 81 is provided between the cylinder 121 and the manifold 7. The flow control valve 81 adjusts a flow rate of carbon dioxide flowing out of the cylinder 121 by adjusting its opening degree.

[0030] The cylinder 122 is filled with the inert gas. The cylinder 122 is filled with nitrogen, for example. A flow control valve 82 is provided between the cylinder 122 and the manifold 7. The flow control valve 82 adjusts a flow rate of inert gas (nitrogen) flowing out of the cylinder 122 by adjusting its opening degree.

[0031] The vacuum pump 123 is a pump that generates a vacuum in the refrigerant flow paths of the cooling apparatus 110. Note that, in this specification, the “vacuum” does not refer to an absolute vacuum but rather to a state in which a particular space is filled with a gas at a pressure lower than atmospheric pressure.

[0032] The manifold 7 is connected to the refrigerant flow path 10 of the cooling apparatus 110. Specifically, an internal flow path of the manifold 7 is connected to the pipe upstream of the tank 2 (between the tank 2 and the condenser 1). Also, the manifold 7 is connected to the pipes that connect the cylinder 121, the cylinder 122 and the vacuum pump 123 to the manifold. The manifold 7 can switch the pipes to which the refrigerant flow path 10 is connect by adjusting the opening degrees of the valves 7a and 7b to close and open flow paths formed inside the manifold. Accordingly, the manifold 7 can switch between introduction of carbon dioxide (refrigerant) into the refrigerant flow path 10, introduction of the inert gas into the refrigerant flow path 10, and generation of a vacuum in (exhaust from) the refrigerant flow path 10.(Refrigerant-Charging Method According to First Embodiment)

[0033] The following description describes a process flow (steps 901 to 904) of the method for charging a refrigerant into the cooling apparatus 110 according to the first embodiment with reference to FIG. 2.

[0034] In step 901, an operator first generates a vacuum in the refrigerant flow path 10. The operator manipulates the manifold 7 (valves 7a and 7b) and the vacuum pump 123 to generate a vacuum in the pipes between refrigerant flow path 10 to the cylinder 121 and the cylinder 122. After generation of a vacuum in the refrigerant flow path 10 is completed, the operator conducts an operation in step 902.

[0035] In step 902, the operator conducts pre-charging. In step 902, after previously charging the inert gas into the refrigerant flow path 10 of the cooling apparatus 110, the operator charges carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 at a charging rate preventing that dry ice (solid) is produced to bring a pressure in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than the triple point pressure of carbon dioxide. In other words, the inert gas is charged into the refrigerant flow path 10 before carbon dioxide is charged into the refrigerant flow path 10. The inert gas is charged into the refrigerant flow path 10 to prevent occurrence of cavitation in the pump 3, as described above. Here, a charging amount (setting amount) of the inert gas required to prevent cavitation depends on the performance of the pump 3. In other words, the pressure in the refrigerant flow path 10 after charging the inert gas into the refrigerant flow path 10 required to prevent cavitation depends on the performance of the pump 3. The inert gas is charged to the charging amount (setting amount), which is previously set, to bring the pressure in the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined pressure at which no cavitation occurs. In the first embodiment, the pressure in the refrigerant flow path 10 after charging the inert gas is smaller than the triple point pressure of carbon dioxide.

[0036] In the first embodiment, in step 902 (pre-charging), the inert gas is previously charged into the refrigerant flow path 10 in which a vacuum is generated before carbon dioxide is charged into the refrigerant flow path 10. In a case in which the inert gas is previously charged into the refrigerant flow path 10 in which a vacuum is generated, no dry ice is naturally generated. Accordingly, the pressure in the refrigerant flow path 10 can be easily increased to approach the triple point pressure of carbon dioxide by previously charging the inert gas as compared with a case in which the pressure in the refrigerant flow path 10 is gradually increased by gradually charging carbon dioxide into the refrigerant flow path 10 in which a vacuum is generated. Accordingly, the pressure in the refrigerant flow path 10 can be increased to not smaller than the triple point pressure of carbon dioxide without producing dry ice in the refrigerant flow path 10 as compared with a case in which the inert gas is charged after carbon dioxide is charged into the refrigerant flow path 10 in which a vacuum is generated by charging carbon dioxide into the refrigerant flow path 10 after previously charging the inert gas into the refrigerant flow path 10 in which a vacuum is generated.

[0037] In step 902, the operator charges carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 at a charging rate preventing that dry ice is produced to bring the pressure in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than the triple point pressure of carbon dioxide (0.52 MPa-a). In other words, the operator charges carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 whose internal pressure is smaller than the triple point pressure of carbon dioxide (0.52 MPa-a) and which has been charged with the inert gas to bring the internal pressure to not smaller than the triple point pressure of carbon dioxide (0.52 MPa-a). For example, carbon dioxide is charged to bring the pressure in the refrigerant flow path 10 of the cooling apparatus 110 from a state of smaller than the triple point pressure of carbon dioxide (0.52 MPa-a) to a state of 0.7 MPa-a or greater. Here, step 902 is an example of a “pre-charging step” in the claims.

[0038] Here, the charging rate of carbon dioxide in step 902 (pre-charging) is smaller than the charging rate of carbon dioxide in step 904 (main charging), which will be described later. The ratio of the charging rate of carbon dioxide in the pre-charging to the charging rate of carbon dioxide in the main charging depends on an internal volume of the cooling apparatus 110 (refrigerant flow path 10). The operator adjusts the opening degrees of the valve 7a and the flow control valve 81 of the manifold 7 to gradually charge carbon dioxide into the refrigerant flow path 10 to prevent that dry ice is produced in the refrigerant flow path 10.

[0039] In step 903, the operator confirms whether temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within a predetermined temperature range. The operator confirms the temperatures in the refrigerant flow path 10 detected by the temperature sensors 61 and 62. The operator then confirms that no dry ice is produced in the refrigerant flow path 10 based on the temperatures in the refrigerant flow path 10 detected by the temperature sensors 61 and 62. The operator may confirm the temperatures in the refrigerant flow path 10 through a display and a gaging instrument (meter) included in the cooling apparatus 110 (not shown) or confirm the temperatures in the refrigerant flow path 10 by using an apparatus for charging operation, which will be described in a second embodiment later.

[0040] If the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall outside the predetermined temperature range, the operator waits until the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range. Subsequently, if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range, the operator starts the main charging of carbon dioxide (step 904).

[0041] In other words, step 904 is activated based on the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 falling within the predetermined temperature range. Here, step 904 is an example of a “main charging step” in the claims.

[0042] In step 904, the operator conducts the main charging of carbon dioxide. Specifically, the operator charges carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount required for the cooling apparatus 110 to operate with the pressure in the refrigerant flow path 10 of the cooling apparatus 110 having been brought to the triple point pressure of carbon dioxide. Specifically, the operator adjusts the opening degrees of the valve 7a and the flow control valve 81 of the manifold 7 to charge the predetermined amount of carbon dioxide required for the cooling apparatus 110 to operate into the refrigerant flow path 10.Advantages of First Embodiment

[0043] In the first embodiment, the following advantages are obtained.

[0044] In the first embodiment, after the pre-charging is conducted to charge an inert gas into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to bring pressures in the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined pressure, the main charging is conducted to charge a refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount required for the cooling apparatus 110 to operate. Accordingly, it is possible to prevent difficulty of grasping a charging amount of the inert gas caused by dissolution of the inert gas into the refrigerant dissimilar to a case in which the inert gas is charged into the refrigerant flow path after the refrigerant is charged. Consequently, it is possible to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a cooling apparatus 110 using a thermodynamic cycle. Also, in the first embodiment, since the inert gas is charged before the main charging in which the refrigerant is charged into the refrigerant flow path 10, a pressure of the inert gas required to charge the refrigerant can be smaller as compared with the case in which the inert gas is charged after the refrigerant is charged. Accordingly, since a relatively high-pressure inert gas source is not necessarily provided, it is possible to easily charge the inert gas into the refrigerant flow path 10.

[0045] Also, since the charging charging amount of the inert gas into the refrigerant flow path 10 can be grasped by charging the inert gas to a predetermined pressure, it is possible to easily grasp the charging amount of the inert gas as compared with a case in which the charging amount is measured based on a weight of the inert gas. In particular, in a case in which the amount of the inert gas required is small, since it is difficult to measure the charging amount based on its weight in some cases, the charging amount of the inert gas can be more effectively grasped by charging the inert gas to the predetermined pressure.

[0046] Also, in the first embodiment, the inert gas is charged to the predetermined pressure at which no cavitation occurs and no gas is produced in a pump 3 arranged on the refrigerant flow path 10 of the cooling apparatus 110 during operation of the cooling apparatus 110 (heat transferring apparatus) in the pre-charging step (step 902). According to this configuration, since the charging amount of the inert gas can be easily grasped by charging the inert gas in the pre-charging step (step 902) before step 904 as main charging of the refrigerant (carbon dioxide), the charging amount of inert gas, which is charged to prevent occurrence of cavitation, can be effectively and easily grasped by charging the inert gas to the predetermined pressure at which no cavitation occurs in the pre-charging step.

[0047] In the first embodiment, the inert gas is charged to bring the pressure in the refrigerant flow path 10 of the cooling apparatus 110 to the predetermined pressure so as to bring the pressure of the refrigerant, which flows into the pump 3 arranged on the refrigerant flow path 10 of the cooling apparatus 110, to not smaller than a saturation vapor pressure of the refrigerant during operation of the cooling apparatus 110 (heat transferring apparatus) in the pre-charging step (step 902). According to this configuration, since the inert gas is charged in the pre-charging step (step 902), it is possible to more effectively and easily grasp that the inert gas is charged to the charging amount (setting amount), which is set to bring the pressure of the refrigerant flowing into the pump 3 during operation of the cooling apparatus 110 to not smaller than the saturation vapor pressure of the refrigerant.

[0048] Also, in the first embodiment, nitrogen as the inert gas is charged to bring the pressure in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to the predetermined pressure in the pre-charging step (step 902). According to this configuration, occurrence of cavitation caused by the inert gas can be stably prevented by charging nitrogen, which is a relatively stable substance, as the inert gas. Accordingly, the cooling apparatus 110 can be more stably operated by charging nitrogen as the inert gas in the pre-charging step (step 902), and the charging amount of inert gas required for the cooling apparatus 110 to more stably operate can be more effectively and easily grasped.

[0049] Also, in the first embodiment, the pre-charging is conducted by previously charging the inert gas into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) and then charging carbon dioxide (refrigerant) into the refrigerant flow path 10 of the cooling apparatus 110, in which a vacuum is generated, at a charging rate preventing that dry ice (solid) is produced to bring a pressure in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than the triple point pressure of carbon dioxide. Accordingly, the main charging can be conducted to charge carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount of carbon dioxide required for the cooling apparatus 110 to operate with the pressure in the refrigerant flow path 10 having been brought to the triple point pressure of carbon dioxide. Consequently, since carbon dioxide can be charged into the refrigerant flow path 10 in a pressure state in which no dry ice is generated during the main charging of carbon dioxide, it is possible to prevent occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide. For these reasons, since an additional device heating or cooling carbon dioxide is not required dissimilar to a case in which carbon dioxide is heated or cooled when charging carbon dioxide, it is possible to prevent a complicated apparatus configuration of the apparatus charging carbon dioxide refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 while preventing occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide.

[0050] In addition, following additional advantages can be acquired by conducting steps discussed below in the method for charging a refrigerant into the cooling apparatus 110 (heat transferring apparatus) according to the first embodiment.

[0051] In the first embodiment, the main charging step (step 904) is activated based on the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) falling within the predetermined temperature range. Accordingly, it is possible to activate the main charging of carbon dioxide after confirming that no temperature drop due to generation of dry ice has occurred in the refrigerant flow path 10. Consequently, it is possible to prevent clogging of the refrigerant flow path 10 caused by generation of dry ice during the main charging of carbon dioxide.

[0052] Also, in the first embodiment, the charging rate of carbon dioxide in the pre-charging step (step 902) is smaller than the charging rate of carbon dioxide in the main charging step (step 904). Accordingly, it is possible to prevent a sharp drop in temperature of carbon dioxide caused by adiabatic expansion as compared with a case in which the charging rate of carbon dioxide in the pre-charging step is substantially equal to the charging rate of carbon dioxide in the main charging step. Consequently, it is possible to prevent carbon dioxide from becoming dry ice in the refrigerant flow path 10 due to the sharp drop in temperature caused by adiabatic expansion. In addition, since the charging rate of carbon dioxide in the main charging step is greater than the charging rate of carbon dioxide in the pre-charging step, it is possible to reduce the time required for the main charging of carbon dioxide. Consequently, it is possible to reduce the time required to charge carbon dioxide to a predetermined amount required for the cooling apparatus 110 (heat transferring apparatus) to operate.Second Embodiment

[0053] The following description describes a method for charging a refrigerant into a cooling apparatus 110 according to a second embodiment in which the refrigerant-charging control apparatus 100 provides indication to urge an operator to conduct an operation in the method for charging the refrigerant into the cooling apparatus 110 with reference to FIGS. 3 and 4.

[0054] The refrigerant-charging control apparatus 100 includes a controller 101 and a display 102. The refrigerant-charging control apparatus 100 is an example of a “refrigerant-charging control apparatus for a heat transferring apparatus” in the claims. The display 102 is an example of a “notifier” in the claims.

[0055] The controller 101 is configured to entirely control the refrigerant-charging control apparatus 100. The controller 101 includes a processor such as a CPU, a memory, and the like. The controller 101 is configured to control charging of carbon dioxide refrigerant into the cooling apparatus 110 by using control software (program) recorded (stored) in the internal or external memory (storage device).

[0056] The controller 101 performs control to acquire temperatures of the refrigerant flowing through the refrigerant flow path 10 of the cooling apparatus 110 detected by temperature sensors 61 and 62. The controller 101 performs control to acquire pressures of the refrigerant flowing through the refrigerant flow path 10 of the cooling apparatus 110 detected by pressure sensors 63 and 64. In other words, the controller 101 controls the acquisition of the pressures in the refrigerant flow path 10 of the cooling apparatus 110 detected by the pressure sensors 63 and 64.

[0057] The display 102 provides indication (notification) of the pressures of the refrigerant flowing through the refrigerant flow path 10 of the cooling apparatus 110 acquired by the controller 101. Also, the display 102 provides indication (notification) of the temperatures of the refrigerant flowing through the refrigerant flow path 10 of the cooling apparatus 110 acquired by the controller 101. In other words, the display 102 provides indication (notification) of information about the charging of the refrigerant (carbon dioxide) in the refrigerant flow path 10 of the cooling apparatus 110. The display 102 includes a liquid crystal display or an organic EL display. The display 102 may also include a gaging instrument (meter).

[0058] The controller 101 performs control to determine whether pre-charging is completed to charge the inert gas and carbon dioxide (refrigerant) into the refrigerant flow path 10 of the cooling apparatus 110, in which a vacuum is generated, to bring a pressure in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than the triple point pressure of carbon dioxide. In the second embodiment, when conducting the pre-charging, the controller 101 controls the determination whether the pre-charging is completed based on the pressures of the refrigerant flowing through the refrigerant flow path 10 of the cooling apparatus 110 (pressures in the refrigerant flow path 10) detected by the pressure sensors 63 and 64.

[0059] Specifically, when conducting the pre-charging, in which an inert gas is charged to a predetermined pressure before main charging, the controller 101 performs control to determine whether the charging of the inert gas is completed based on the pressures in the refrigerant flow path 10 of the cooling apparatus 110 detected by the pressure sensors 63 and 64. For example, the controller 101 previously stores a value of the predetermined pressure in the pre-charging of inert gas corresponding to the charging amount that prevents occurrence of cavitation. During the charging of the inert gas in the pre-charging, it is determined whether the charging of the inert gas is completed based on whether the pressures in the refrigerant flow path 10 detected by the pressure sensors 63 and 64 are increased to the predetermined pressure, which is previously set. Subsequently, the controller 101 similarly determines whether the charging of the refrigerant in the pre-charging is completed based on whether the pressures in the refrigerant flow path 10 (pressures of the refrigerant flowing through the refrigerant flow path 10) detected by the pressure sensors 63 and 64 are increased to not smaller than a value of the triple point pressure of the refrigerant, which is previously set.

[0060] Also, after pre-charging, the controller 101 determines whether the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within a predetermined temperature range. Specifically, the controller 101 determines whether the temperatures in the refrigerant flow path 10 detected by the temperature sensors 61 and 62 fall within the predetermined temperature range. For example, the controller 101 determines whether a difference between the temperatures in the refrigerant flow path 10 detected by the temperature sensors 61 and 62 is smaller than a few ° C. Also, the controller 101 may determine whether all of the temperatures in the refrigerant flow path 10 detected by the temperature sensors 61 and 62 fall within the predetermined temperature range.

[0061] If determining that the pre-charging has been completed, the controller 101 performs control relating to the main charging of the refrigerant flow path 10 of the cooling apparatus 110 with carbon dioxide up to a predetermined amount required for the cooling apparatus 110 to operate while the pressure in the refrigerant flow path 10 of the cooling apparatus 110 is not smaller than the triple point pressure of carbon dioxide.

[0062] In the second embodiment, the controller 101 provides indication (notification) of information indicating that the charging of the inert gas is completed through the display 102 if determining that the charging of the inert gas is completed in the pre-charging. For example, the controller 101 performs control to indicate a sentence (text) such as “Inert gas charging is completed” through the display 102. Also, the controller 101 provides indication (notification) of the pressures in the refrigerant flow path 10 of the cooling apparatus 110 acquired by the pressure sensors 63 and 64 as information indicating that the inert gas charging is completed through the display 102. Also, the controller 101 provides indication (notification) of a sentence (text) urging the operator to charge carbon dioxide (refrigerant) following the completion of the charging of the inert gas in the pre-charging process together with the information indicating that the inert gas charging is completed through the display 102.

[0063] In the second embodiment, the controller 101 performs control to provide indication (notification) urging the operator to conduct the main charging through the display 102 as control relating to the main charging if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range after the pre-charging. For example, the controller 101 performs control to indicate a sentence (text) such as “Please start main charging” through the display 102. Accordingly, the refrigerant-charging control apparatus 100 (display 102) urges the operator to start the main charging.

[0064] In the second embodiment, the manifold 7 (valve 7a) and the flow control valve 81 are manipulated by the operator in response to the indication on the display 102 so that the main charging of carbon dioxide (refrigerant) into the refrigerant flow path 10 is conducted.(Refrigerant-Charging Method According to Second Embodiment)

[0065] The following description describes a process flow of the method for charging a refrigerant into the cooling apparatus 110 (heat transferring apparatus) according to the second embodiment with reference to FIG. 4. In the method for charging the refrigerant into the cooling apparatus 110 according to the second embodiment, steps 931 to 934 are conducted in the pre-charging step of step 902 in FIG. 2. The processes in steps 901, 903 and 904 are the same as in the first embodiment)

[0066] In step 931, in the pre-charging, the inert gas is charged. Subsequently, in step 932, based on the pressures in the refrigerant flow path 10 detected by the pressure sensors 63 and 64, it is determined whether the inert gas is charged to the predetermined pressure at which no cavitation occurs. If it is determined that the inert gas is charged to the predetermined pressure, information indicating that the inert gas charging is completed is indicated on the display 102, and the procedure goes to step 933. If it is not determined that the inert gas is charged to the predetermined pressure, the procedure waits until the inert gas is charged to the predetermined pressure.

[0067] Subsequently, in step 933, the refrigerant (carbon dioxide) is charged in the pre-charging. Subsequently, in step 934, based on the pressures in the refrigerant flow path 10 detected by the pressure sensors 63 and 64, it is determined whether the refrigerant is charged to a pressure not smaller than the triple point pressure. For example, it is determined whether the refrigerant is charged to not smaller than the triple point pressure or not smaller than 0.7 MPa-a. If it is determined that the refrigerant (carbon dioxide) in the pre-charging is charged to not smaller than the triple point pressure, the procedure goes to step 903. If it is not determined that the refrigerant (carbon dioxide) is charged to not smaller than the triple point pressure, the procedure waits.

[0068] Also, in the process flow of the method for charging the refrigerant into the cooling apparatus 110 according to the second embodiment, in step 903, the temperatures in the refrigerant flow path 10 are confirmed by the operator after the indication (notification) is provided by the display 102. The other process flow is the same as that in the first embodiment.Advantages of Second Embodiment

[0069] In the second embodiment, the following advantages are obtained.

[0070] In the second embodiment, before conducting the main charging, the controller 101 charges an inert gas into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to bring pressures in the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined pressure. Accordingly, similar to the first embodiment, it is possible to prevent difficulty of grasping a charging amount of the inert gas caused by dissolution of the inert gas into the refrigerant dissimilar to a case in which the inert gas is charged into the refrigerant flow path after the refrigerant is charged. Consequently, it is possible to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a cooling apparatus 110 using a thermodynamic cycle. Also, in the second embodiment, similar to the first embodiment, since a relatively high-pressure inert gas source is not necessarily provided, it is possible to easily charge the inert gas into the refrigerant flow path.

[0071] Also, in the second embodiment, since, when conducting the pre-charging before main charging, the controller 101 performs control to determine whether the charging of the inert gas is completed based on the pressures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) detected by the pressure sensors 63 and 64, it is possible to more accurately charge the inert gas as compared with a case in which a person determines whether the charging of the inert gas is completed or not by visually checking a gaging instrument (meter) or the like.

[0072] In the second embodiment, after the pressures in the refrigerant flow path 10 are brought to not smaller than the triple point pressure of carbon dioxide in the pre-charging, the controller 101 can conduct control relating to the main charging to charge carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to the predetermined amount of carbon dioxide required for the cooling apparatus 110 to operate. Accordingly, since carbon dioxide can be charged into the refrigerant flow path 10 in a pressure state in which no dry ice is generated during the main charging of carbon dioxide, it is possible to prevent occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide. Consequently, since an additional device heating or cooling carbon dioxide is not required dissimilar to a case in which carbon dioxide is heated or cooled when charging carbon dioxide, it is possible to prevent a complicated apparatus configuration of the apparatus charging carbon dioxide refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 while preventing occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide. In addition, the operator can easily determine whether the pressures in the refrigerant flow path 10 are not smaller than the triple point pressure of carbon dioxide based on the indication of the display 102 (notifier), which provides indication (notification) of the pressures of the refrigerant flowing through the refrigerant flow path 10.

[0073] In addition, following additional advantages can be obtained by the refrigerant-charging control apparatus 100 according to the aforementioned second embodiment added with configurations discussed below.

[0074] In the second embodiment, the refrigerant-charging control apparatus 100 includes a display 102 (notifier) providing notification of information about charging carbon dioxide (refrigerant) into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus). The controller 101 provides notification of information indicating that the charging of the inert gas is completed through the display 102 if determining that the charging of the inert gas is completed. According to this configuration, the operator can easily recognize that the inert gas charging is completed by recognizing the information indicating that the inert gas charging is completed notified by the display 102.

[0075] Also, in the second embodiment, the controller 101 performs control to provide notification of the pressures acquired in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) as the information indicating that the inert gas charging is completed through the display 102 (notifier). According to this configuration, the operator can easily recognize specific values indicating magnitudes of the pressures in the refrigerant flow path 10 by recognizing the information indicating that the inert gas charging is completed notified by the display 102. Consequently, the operator can easily recognize that the inert gas is charged to the predetermined pressure.

[0076] In the second embodiment, after pre-charging, the controller 101 determines whether the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) fall within a predetermined temperature range. Also, the controller performs control to provide indication (notification) urging the operator to conduct the main charging as control relating to the main charging through the display 102 (notifier) if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range after the pre-charging. Accordingly, the operator can easily confirm that no temperature drop due to generation of dry ice has occurred in the refrigerant flow path 10 by visually checking (confirming) the indication on the display 102. Accordingly, after confirming that no temperature drop due to generation of dry ice has occurred in the refrigerant flow path 10 based on the indication on the display 102, the operator can start the main charging of carbon dioxide. As a result, the refrigerant flow path 10 can be more effectively prevented from becoming blocked due to the generation of dry ice during the main charging of carbon dioxide.

[0077] The other advantages of the second embodiment are similar to the first embodiment.Third Embodiment

[0078] The following description describes a method for charging a refrigerant into the cooling apparatus 110 according to a third embodiment. In the third embodiment, a refrigerant-charging control apparatus 200 (see FIG. 5) automatically conduct pre-charging of an inert gas and carbon dioxide, and main charging of carbon dioxide into the cooling apparatus 110. The refrigerant-charging control apparatus 200 is an example of the “refrigerant-charging control apparatus for a heat transferring apparatus” in the claims.

[0079] A controller 101 of the refrigerant-charging control apparatus 200 is configured to control the manifold 7 (valves 7a and 7b), the flow control valve 81, the flow control valve 82, and the vacuum pump 123. Accordingly, the operation that is conducted by manipulation of the operator in the aforementioned first and second embodiments is automatically conducted by control performed by the controller 101 of the refrigerant-charging control apparatus 200.

[0080] In the third embodiment, for example, the controller 101 generates a vacuum in the refrigerant flow path 10 by controlling operations of the vacuum pump 123 and the manifold 7. Subsequently, the controller 101 starts the pre-charging by controlling operations of the manifold 7 and the flow control valve 82 to start the charging of the inert gas. The controller 101 performs control to stop the charging of the inert gas by controlling operations of the manifold 7 and the flow control valve 82 if determining that the charging of the inert gas is completed in the pre-charging. Subsequently, the controller 101 charges the refrigerant in the pre-charging until the pre-charging is completed by controlling operations of the manifold 7 and the flow control valve 81.

[0081] In the third embodiment, the controller 101 performs control of the charging of carbon dioxide as control relating to the main charging if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range. Specifically, the controller 101 controls the manifold 7 (valve 7a) and the flow control valve 81 to allow carbon dioxide charged in the cylinder 121 to flow into refrigerant flow path 10 if the temperatures in refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range after the pre-charging.

[0082] Here, other configurations of the third embodiment are the same as the aforementioned second embodiment. Also, the process flow of the method for charging the refrigerant into the cooling apparatus 110 according to the third embodiment is similar to the process flow in the first embodiment, except that steps are automatically conducted by the refrigerant-charging control apparatus 200 instead of the operator.Advantages of Third Embodiment

[0083] In the third embodiment, the following advantages are obtained.

[0084] In the third embodiment, the controller 101 performs control to stop the charging of the inert gas if determining that the charging of the inert gas is completed. According to this configuration, also in a case in which the inert gas is automatically charged by control performed by the controller 101, the charging amount of the inert gas can be easily and accurately grasped by charging the inert gas in the pre-charging step before charging the refrigerant. For this reason, the inert gas can be more easily and more accurately charged by the controller 101.

[0085] Also, in the third embodiment, similar to the second embodiment, it is possible to prevent a complicated apparatus configuration of the apparatus charging carbon dioxide refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) while preventing occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide.

[0086] In addition, following additional advantages can be obtained by the refrigerant-charging control apparatus 200 according to the aforementioned third embodiment added with configurations discussed below.

[0087] Also, in the third embodiment, after pre-charging, the controller 101 determines whether the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) fall within a predetermined temperature range. Subsequently, control of the charging of carbon dioxide is performed as control relating to the main charging if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range. Accordingly, after confirming that no temperature drop due to generation of dry ice has occurred in the refrigerant flow path 10, the controller 101 performs control of the charging of carbon dioxide (main charging). As a result, the refrigerant flow path 10 can be more effectively prevented from becoming blocked due to the generation of dry ice during the main charging of carbon dioxide. In addition, since the control of the charging of carbon dioxide (main charging) is automatically performed by the controller 101, it is possible to quickly start the control of the charging of carbon dioxide (main charging) as compared with a case in which the operator starts the main charging of carbon dioxide after confirming that no temperature drop due to generation of dry ice has occurred in the refrigerant flow path 10.

[0088] The other advantages of the third embodiment are similar to the first embodiment.Fourth Embodiment

[0089] The following description describes a method for charging a carbon dioxide refrigerant into the cooling apparatus 110 according to a fourth embodiment.

[0090] The method for charging a carbon dioxide refrigerant into the cooling apparatus 110 according to the fourth embodiment is a method to be used in a case in which a pressure in the refrigerant flow path 10 can be increased to not smaller than the triple point pressure of carbon dioxide during charging of an amount of an inert gas required to prevent occurrence of cavitation in the pump 3. In the method for charging carbon dioxide refrigerant into the cooling apparatus 110 according to the fourth embodiment, only the inert gas is charged in the pre-charging dissimilar to the first embodiment in which the inert gas and carbon dioxide are charged in the pre-charging.(Carbon Dioxide Refrigerant-Charging Method According to Fourth Embodiment)

[0091] The following description describes a process flow (steps 911 to 913) of the method for charging a carbon dioxide refrigerant into the cooling apparatus 110 according to the fourth embodiment with reference to FIG. 6.

[0092] In step 911, an operator first generates a vacuum in the refrigerant flow path 10. After the generation of a vacuum in the refrigerant flow path 10 is completed, the operator conducts an operation in step 912. Here, step 911 is a similar process to step 901 in the first embodiment.

[0093] In step 912, the operator conducts the pre-charging to previously charge the inert gas. In step 912, the operator charges the inert gas into the refrigerant flow path 10 of the cooling apparatus 110 in which a vacuum is generated to bring the pressures in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than the triple point pressure of carbon dioxide (0.52 MPa-a). For example, the operator charges the inert gas into the refrigerant flow path 10 to bring the pressures in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than 0.7 MPa-a. In other words, in the fourth embodiment, the predetermined pressure at which no cavitation occurs and to which the inert gas is charged in the pre-charging is greater than the triple point pressure of the refrigerant. In other words, when the inert gas is charged to the predetermined pressure at which no cavitation occurs, the pressure in the refrigerant flow path 10 of the cooling apparatus 110 becomes not smaller than the triple point pressure of carbon dioxide (0.52 MPa-a). Here, step 912 is an example of a “pre-charging step” in the claims.

[0094] In step 913, the operator performs the main charging of carbon dioxide. Specifically, the operator charges carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount required for the cooling apparatus 110 to operate with the pressure in the refrigerant flow path 10 of the cooling apparatus 110 having been brought to the triple point pressure of carbon dioxide. In the fourth embodiment, since only the inert gas (nitrogen) is charged in the pre-charging, no dry ice is generated during the pre-charging. For this reason, after the pre-charging is completed, the main charging can be conducted without confirming the temperatures in the refrigerant flow path 10. Here, the temperatures in the refrigerant flow path 10 may be confirmed similar to the first embodiment after the pre-charging (step 912) is completed considering the temperature drop in the refrigerant flow path 10 caused by adiabatic expansion of the inert gas. Step 913 is an example of the “main charging step” of the claim.Advantages of Fourth Embodiment

[0095] In the fourth embodiment, the following advantages are obtained.

[0096] In the fourth embodiment, the pre-charging is conducted to charge the inert gas into the refrigerant flow path 10 of the cooling apparatus 110 in which a vacuum is generated to bring the pressures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to not smaller than the triple point pressure of carbon dioxide. Accordingly, the main charging can be conducted to charge carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount of carbon dioxide required for the cooling apparatus 110 to operate with the pressure in the refrigerant flow path 10 having been brought to the triple point pressure of carbon dioxide. Consequently, since carbon dioxide can be charged into the refrigerant flow path 10 in a pressure state in which no dry ice is generated during the main charging of carbon dioxide, it is possible to prevent occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide. Accordingly, it is possible to prevent a complicated apparatus configuration of the apparatus charging carbon dioxide refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 while preventing occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide.Modified Embodiments

[0097] Note that the embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is not shown by the above description of the embodiments but by the scope of claims for patent, and all modifications (modified embodiments) within the meaning and scope equivalent to the scope of claims for patent are further included.

[0098] For example, while the example in which the controller 101 of the refrigerant-charging control apparatus 100 performs control to acquire the pressures of the refrigerant flowing through the refrigerant flow path 10 detected by the pressure sensors 63 and 64 (pressure detector) included in the cooling apparatus 110 (heat transferring apparatus) has been shown in the aforementioned second embodiment, the present invention is not limited to this. In the present invention, the refrigerant-charging control apparatus may include a pressure detector, and the controller of the refrigerant-charging control apparatus may control the acquisition of the pressure of the refrigerant flowing through the refrigerant flow path detected by the pressure detector of the refrigerant-charging control apparatus. Also, the controller of the refrigerant-charging control apparatus may perform control relating to the charging of carbon dioxide refrigerant based on a detection result of the pressure detector included in the refrigerant-charging control apparatus.

[0099] For example, while the example in which the controller 101 of the refrigerant-charging control apparatus 100 performs control to acquire the temperatures of the refrigerant flowing through the refrigerant flow path 10 detected by the temperature sensors 61 and 62 included in the cooling apparatus 110 (heat transferring apparatus) has been shown in the aforementioned second embodiment, the present invention is not limited to this. In the present invention, the refrigerant-charging control apparatus may include a temperature sensor, and the controller of the refrigerant-charging control apparatus may control the acquisition of the temperature of the refrigerant flowing through the refrigerant flow path detected by the temperature sensor of the refrigerant-charging control apparatus. Also, the controller of the refrigerant-charging control apparatus may perform control relating to the charging of carbon dioxide refrigerant based on a detection result of the temperature sensor included in the refrigerant-charging control apparatus.

[0100] While the example in which control is performed to provide indication (notification) to urge the operator to conduct the main charging through the display 102 (notifier) has been shown in the aforementioned second embodiment, the present invention is not limited to this. In the present invention, the notifier may produce a sound to urge the operator to conduct the main charging. Here, in a case in which the notifier is a display that provides notification through visual information, the display may be a liquid crystal display, an organic EL display, a backlit indicator instead of a gaging instrument (meter), or a display using micro LEDs. The notifier may be configured to provide both audible information using voice and visual information using the display or the like.

[0101] While the example in which the charging operation of the carbon dioxide refrigerant is conducted by the operator without using the refrigerant-charging control apparatus 100 or 200 has been shown in the aforementioned fourth embodiment. In the present invention, also in the method for charging a carbon dioxide refrigerant in which the pre-charging is conducted to charge the inert gas into the refrigerant flow path of the heat transferring apparatus in which a vacuum is generated to bring the pressures in the refrigerant flow path of the heat transferring apparatus to not smaller than the triple point pressure of carbon dioxide, the refrigerant-charging control apparatus 100 may perform control to provide indication (notification) urging the operator to conduct the main charging through the display 102 (notifier) similar to the second embodiment. Here, in a case in which, after the pre-charging is completed, the main charging is conducted without confirming the temperatures in the refrigerant flow path as described in the fourth embodiment, the controller of the refrigerant-charging control apparatus performs control to provide information through the notifier based on the pressures in the refrigerant flow path of the cooling apparatus (heat transferring apparatus) becoming not smaller than the triple point pressure of carbon dioxide. Also, the entire or a part of operation in the method for charging a carbon dioxide refrigerant in which the pre-charging is conducted to charge the inert gas into the refrigerant flow path of the heat transferring apparatus in which a vacuum is generated to bring the pressures in the refrigerant flow path of the heat transferring apparatus to not smaller than the triple point pressure of carbon dioxide may be automatically conducted by the refrigerant-charging control apparatus 200 similar to the third embodiment.

[0102] While the example in which the controller 101 of the refrigerant-charging control apparatus 200 performs control of the charging of carbon dioxide as control relating to the main charging if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) fall within the predetermined temperature range has been shown in the aforementioned third embodiment, the present invention is not limited to this. In the present invention, the refrigerant-charging control apparatus may include a manipulation receiver such as a touch panel, a keyboard or a computer mouse, and the apparatus controller of the refrigerant-charging control apparatus may control the charging of carbon dioxide (main charging) based on input manipulation of the operator input to the manipulation receiver. Also, the controller of the refrigerant-charging control apparatus may conduct generation of a vacuum in a cooling flow path or pre-charging based on the input manipulation of the operator input to the manipulation receiver.

[0103] While the example in which the refrigerant-charging control apparatus 100 and the refrigerant-charging control apparatus 200 are provided separately from the apparatus controller 5 has been shown in the aforementioned second and third embodiments, the present invention is not limited to this. In the present invention, the control performed by the refrigerant-charging control apparatus 100 and the refrigerant-charging control apparatus 200 may be performed by the apparatus controller 5.

[0104] While the example in which the internal flow path of the manifold 7 is connected to the pipe upstream of the tank 2 (between the tank 2 and the condenser 1) has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, the internal flow path of the manifold 7 may be connected to a pipe in the refrigerant flow path 10 other than the pipe upstream of the tank 2 (between the tank 2 and the condenser 1).

[0105] Also, while the example in which the method for charging a carbon dioxide refrigerant according to the present invention has been described with reference to a flow-driven type flowchart in which processes are sequentially performed along a processing flow for sake of illustration in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, the operations (operation processes) of the method for charging a carbon dioxide refrigerant may be performed by event-driven (event-driven) processing that executes the processes on an event-by-event basis. In this case, the operations (operation processes) of the method for charging a carbon dioxide refrigerant may be executed fully in the event-driven type processing or in combination of the event-driven type processing and flow-driven-step type processing.

[0106] While the example in which carbon dioxide is charged as a refrigerant after nitrogen is charged as an inert gas into the refrigerant flow path 10 in which a vacuum is generated has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, the refrigerant is not limited to carbon dioxide but a fluorocarbon may be used as the refrigerants or a natural refrigerant such as ammonia or water may be used as the refrigerant. Also, the inert gas is not limited to nitrogen but the inert gas may be a rare gas, a fluorocarbon or carbon dioxide. Also, the atmosphere may be used as an inert gas. Also, no vacuum may be generated before the pre-charging. In other words, the inert gas may be charged into the refrigerant flow path at atmospheric pressure to the predetermined pressure. Also, in a case in which a refrigerant other than carbon dioxide is used, if no solid is produced when charging the refrigerant, the pre-charging may be completed and the main charging may be conducted irrespective of whether the pressure becomes not smaller than the triple point pressure or not. In other words, even if the predetermined pressure to which the inert gas is charged in the pre-charging is smaller than the triple point pressure of the refrigerant, the charging of the refrigerant in the main charging may be activated when the charging of the inert gas is completed. In other words, steps 933 and 934 in FIG. 4 may be omitted. In this case, the temperatures in the refrigerant flow path may not be measured. In other words, step 903 in FIG. 4 may be omitted.

[0107] While the example in which the inert gas is charged into the refrigerant flow path 10 to bring the pressure of the refrigerant, which flows into the pump 3, to the predetermined pressure at which no cavitation occurs so as to bring the pressure to not smaller than a saturation vapor pressure of the refrigerant during operation of the cooling apparatus 110 (heat transferring apparatus) in the pre-charging has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, the predetermined pressure as the charging amount of the inert gas in the pre-charging may be set to bring the pressure of the refrigerant flowing into the pump 3 to not smaller than a saturation vapor pressure with the refrigerant being mixed with the inert gas during operation of the heat transferring apparatus.

[0108] While the example in which the inert gas and carbon dioxide (refrigerant) are charged into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. The inert gas and the refrigerant may be charged into a refrigerant flow path in a heating apparatus as the heat transferring apparatus.

[0109] While the example in which the pre-charging step (step 902), which includes charging of the inert gas, and the main charging step (step 904) in which charging of the refrigerant (carbon dioxide) is conducted are provided has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, a step of charging a refrigeration oil into the refrigerant flow path of the heat transferring apparatus may be further provided. The step of charging the refrigerator oil may be conducted before the pre-charging step, after the pre-charging step, or after charging the inert gas during the pre-charging step. Also, the step of charging the refrigerator oil may be conducted after the main charging step.

[0110] While the example in which the cooling apparatus 110 (heat transferring apparatus) includes the tank 2 storing the refrigerant has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, the heat transferring apparatus may be configured to include an accumulator instead of the tank.MODES

[0111] It is understood by those skilled in the art that the exemplary embodiments described above are specific examples of the following aspects.Mode Item 1

[0112] A method for charging a refrigerant into a heat transferring apparatus includes a pre-charging step of charging an inert gas into a refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure; and a main charging step of charging the refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate after the pre-charging step.Mode Item 2

[0113] In the method for charging a refrigerant into a heat transferring apparatus according to mode item 1, the inert gas is charged to the predetermined pressure at which no cavitation occurs and no gas is produced in a pump arranged on the refrigerant flow path of the heat transferring apparatus during operation of the heat transferring apparatus in the pre-charging step.Mode Item 3

[0114] In the method for charging a refrigerant into a heat transferring apparatus according to mode item 1 or 2, the inert gas is charged to bring the pressure in the refrigerant flow path of the heat transferring apparatus to the predetermined pressure so as to bring the pressure of the refrigerant to not smaller than a saturation vapor pressure of the refrigerant before the refrigerant flows into the pump arranged on the refrigerant flow path of the heat transferring apparatus during operation of the heat transferring apparatus in the pre-charging step.Mode Item 4

[0115] In the method for charging a refrigerant into a heat transferring apparatus according to any of mode items 1 to 3, nitrogen as the inert gas is charged to bring the pressure in the refrigerant flow path of the heat transferring apparatus to the predetermined pressure in the pre-charging step.Mode Item 5

[0116] In the method for charging a refrigerant into a heat transferring apparatus according to any of mode items 1 to 4, the refrigerant is charged into the refrigerant flow path of the heat transferring apparatus at a charging rate preventing that a solid of the refrigerant is produced to bring the pressure in the refrigerant flow path of the heat transferring apparatus to not smaller than a triple point pressure of the refrigerant after the inert gas is previously charged into the refrigerant flow path of the heat transferring apparatus to bring the pressure in the refrigerant flow path of the heat transferring apparatus to the predetermined pressure in the pre-charging step.Mode Item 6

[0117] A refrigerant-charging control apparatus for a heat transferring apparatus includes a controller performing control to acquire a pressure in a refrigerant flow path of the heat transferring apparatus detected by a pressure detector, wherein if conducting pre-charging to charge an inert gas into the refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure before conducting main charging to charge a refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate, the controller performs control to determine whether the charging of the inert gas is completed based on the pressure in the refrigerant flow path of the heat transferring apparatus detected by the pressure detector.Mode Item 7

[0118] In the refrigerant-charging control apparatus for a heat transferring apparatus according to mode item 6, the controller performs control to stop the charging of the inert gas if determining that the charging of the inert gas is completed.Mode Item 8

[0119] In the refrigerant-charging control apparatus for a heat transferring apparatus according to mode item 6 or 7, a notifier providing notification of information about the charging of the refrigerant into the refrigerant flow path of the heat transferring apparatus is further provided; and the controller provides notification of information indicating that the charging of the inert gas is completed through the notifier if determining that the charging of the inert gas is completed.Mode Item 9

[0120] In the refrigerant-charging control apparatus for a heat transferring apparatus according to mode item 8, the controller performs control to provide notification of the pressure acquired in the refrigerant flow path of the heat transferring apparatus as the information indicating that charging of the inert gas is completed through the notifier.Mode Item 10

[0121] In the refrigerant-charging control apparatus for a heat transferring apparatus according to any of mode items 6 to 9, the controller performs control relating to the main charging to charge the refrigerant into the refrigerant flow path of the heat transferring apparatus to the predetermined amount required for the heat transferring apparatus to operate if determining that the pre-charging is completed based on the pressure in the refrigerant flow path of the heat transferring apparatus detected by the pressure detector.DESCRIPTION OF REFERENCE NUMERALS10; refrigerant flow path

[0123] 63, 64; pressure sensor (pressure detector)

[0124] 100, 200; refrigerant-charging control apparatus

[0125] 101; controller

[0126] 102; display (notifier)

[0127] 110; cooling apparatus (heat transferring apparatus)

Examples

first embodiment

Advantages of First Embodiment

[0043]In the first embodiment, the following advantages are obtained.

[0044]In the first embodiment, after the pre-charging is conducted to charge an inert gas into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to bring pressures in the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined pressure, the main charging is conducted to charge a refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount required for the cooling apparatus 110 to operate. Accordingly, it is possible to prevent difficulty of grasping a charging amount of the inert gas caused by dissolution of the inert gas into the refrigerant dissimilar to a case in which the inert gas is charged into the refrigerant flow path after the refrigerant is charged. Consequently, it is possible to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a cooling...

second embodiment

Advantages of Second Embodiment

[0069]In the second embodiment, the following advantages are obtained.

[0070]In the second embodiment, before conducting the main charging, the controller 101 charges an inert gas into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to bring pressures in the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined pressure. Accordingly, similar to the first embodiment, it is possible to prevent difficulty of grasping a charging amount of the inert gas caused by dissolution of the inert gas into the refrigerant dissimilar to a case in which the inert gas is charged into the refrigerant flow path after the refrigerant is charged. Consequently, it is possible to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a cooling apparatus 110 using a thermodynamic cycle. Also, in the second embodiment, similar to the first embodiment, since a relatively high-pressure...

third embodiment

Advantages of Third Embodiment

[0083]In the third embodiment, the following advantages are obtained.

[0084]In the third embodiment, the controller 101 performs control to stop the charging of the inert gas if determining that the charging of the inert gas is completed. According to this configuration, also in a case in which the inert gas is automatically charged by control performed by the controller 101, the charging amount of the inert gas can be easily and accurately grasped by charging the inert gas in the pre-charging step before charging the refrigerant. For this reason, the inert gas can be more easily and more accurately charged by the controller 101.

[0085]Also, in the third embodiment, similar to the second embodiment, it is possible to prevent a complicated apparatus configuration of the apparatus charging carbon dioxide refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) while preventing occurrence of clogging of the ref...

TECHNICAL FIELD

[0001] The present invention relates to a method for charging a refrigerant into a heat transferring apparatus and a refrigerant-charging control apparatus for a heat transferring apparatus.BACKGROUND ART

[0002] Apparatuses controlling closed loops working on a thermodynamic cycle are known in the art. Such an apparatus is disclosed in Japanese Patent Publication No. JP 6660095, for example.

[0003] The above Japanese Patent Publication No. JP 6660095 discloses an apparatus controlling a closed loop, which exchanges heat to / from an external heat source by using compression and expansion of a working fluid as a thermal medium, through a Rankine cycle as the thermodynamic cycle. A pump circulating and compressing the working fluid and a tank storing the working fluid in a liquid state, which flows into the pump, are arranged in the closed loop. A pressure source, which is a pressurized gas, is connected to the tank through a pressure control valve. The apparatus disclosed in the above Japanese Patent Publication No. JP 6660095 pressurizes the tank by flowing the gas from a pressure source separately from the working fluid by controlling operation of the pressure control valve during operation of the closed loop to prevent occurrence of cavitation in which the gas is produced in the pump.PRIOR ARTPatent DocumentPatent Document 1: Japanese Patent Publication No. JP 6660095SUMMARY OF THE INVENTIONProblems to be Solved by the Invention

[0005] Here, in the apparatus disclosed in the above Japanese Patent Publication No. JP 6660095, the refrigerant is pressurized by flowing the gas (inert gas) from the pressure source separately from the refrigerant into a flow path of the closed loop (refrigerant flow path) into which the working fluid (refrigerant) is charged. In such a case, in addition to dissolution of the inert gas into the refrigerant in the liquid phase state, variation of an amount of the inert gas dissolving into the refrigerant, depending on temperature and pressure of the refrigerant, makes it difficult to grasp an inflow amount (charging amount) of the inert gas in the refrigerant flow path. Since the temperature at which the refrigerant evaporates and condenses varies depending on the charging amount of the inert gas filled, it is desirable to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a heat transferring apparatus using the thermodynamic cycle.Means for Solving the Problems

[0006] The present invention is intended to solve the above problem, and one object of the present invention is to provide a method for charging a refrigerant into a heat transferring apparatus and a refrigerant-charging control apparatus for a heat transferring apparatus capable of easily grasping a charging amount of an inert gas charged separately from a refrigerant in the heat transferring apparatus using a thermodynamic cycle.

[0007] A method for charging a refrigerant into a heat transferring apparatus according to a first aspect of the present invention includes a pre-charging step of charging an inert gas into a refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure; and a main charging step of charging the refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate after the pre-charging step. Here, the “heat transferring apparatus” stated in this specification refers to a concept that includes a cooling apparatus cooling an object and a heating apparatus heating an object.

[0008] A refrigerant-charging control apparatus for a heat transferring apparatus according to a second aspect of the present invention includes a controller performing control to acquire a pressure in a refrigerant flow path of the heat transferring apparatus detected by a pressure detector, wherein if conducting pre-charging to charge an inert gas into the refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure before conducting main charging to charge a refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate, the controller performs control to determine whether the charging of the inert gas is completed based on the pressure in the refrigerant flow path of the heat transferring apparatus detected by the pressure detector.Effect of the Invention

[0009] In the method for charging a refrigerant into a heat transferring apparatus according to the first aspect of the present invention, after the pre-charging is conducted to charge an inert gas into the refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure, the main charging is conducted to charge a refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate. In the refrigerant-charging control apparatus for a heat transferring apparatus according to the second aspect of the present invention, before the main charging, an inert gas is charged into a refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure. Accordingly, it is possible to prevent difficulty of grasping a charging amount of the inert gas caused by dissolution of the inert gas into the refrigerant dissimilar to a case in which the inert gas is charged into the refrigerant flow path after the refrigerant is charged. Consequently, it is possible to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a heat transferring apparatus using a thermodynamic cycle. Also, in the present invention, since the inert gas is charged before the main charging in which the refrigerant is charged into the refrigerant flow path, a pressure of the inert gas required to charge the refrigerant into the refrigerant flow path can be smaller as compared with the case in which the inert gas is charged after the refrigerant is charged. Accordingly, since a relatively high-pressure inert gas source is not necessarily provided, it is possible to easily charge the inert gas into the refrigerant flow path.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a schematic diagram showing a cooling apparatus using an inert gas together with a carbon dioxide refrigerant.

[0011] FIG. 2 is a flowchart illustrating processing using a method for charging the refrigerant into the cooling apparatus according to the first embodiment.

[0012] FIG. 3 is a schematic diagram showing a configuration of a refrigerant-charging control apparatus and a cooling apparatus according to a second embodiment.

[0013] FIG. 4 is a flowchart illustrating processing using a method for charging the refrigerant into the cooling apparatus according to the second embodiment.

[0014] FIG. 5 is a schematic diagram showing a configuration of a refrigerant-charging control apparatus and a cooling apparatus according to a third embodiment.

[0015] FIG. 6 is a flowchart illustrating processing using a method for charging the refrigerant into the cooling apparatus according to a fourth embodiment.MODES FOR CARRYING OUT THE INVENTION

[0016] The following description will describe embodiments embodying the present invention with reference to the drawings.First Embodiment

[0017] A method for charging a refrigerant (carbon dioxide refrigerant) into a cooling apparatus 110 (heat transferring apparatus), which is to be operated by an operator, according to a first embodiment is first described with reference to FIGS. 1 and 2.(Configuration of Cooling Apparatus)

[0018] The cooling apparatus 110 (see FIG. 1) is a cooling apparatus that uses carbon dioxide as the refrigerant. The cooling apparatus 110 is an apparatus that uses carbon dioxide in a gas-liquid two-phase state in which gas and liquid are mixed. The cooling apparatus 110 includes a condenser 1, a tank 2, a pump 3, an evaporator 4, and an apparatus controller 5. The cooling apparatus 110 prevents occurrence of cavitation in the pump 3 by pressurizing the refrigerant, which is carbon dioxide, by using an inert gas. Cavitation refers to a phenomenon in which a gas is produced in the pump 3 arranged on a refrigerant flow path 10 of the cooling apparatus 110 during operation of the cooling apparatus 110. Cavitation occurs due to the production of the gas if a pressure of the refrigerant in a liquid phase state flowing into the pump 3 becomes smaller than a saturation vapor pressure in the pump 3. The inert gas is charged to a setting amount of the inert gas, which is previously set, to bring the pressure of the refrigerant flowing into the pump 3 arranged on the refrigerant flow path 10 of the cooling apparatus 110 to a pressure not smaller than the saturation vapor pressure of the refrigerant during operation of the cooling apparatus 110. Here, the cooling apparatus 110 is an example of a “heat transferring apparatus” in the claims.

[0019] The refrigerant flow path 10 is formed of the condenser 1, the tank 2, pump 3, the evaporator 4, and pipes, which are connected to the condenser 1, the tank 2, the pump 3 and the evaporator 4, in the cooling apparatus 110.

[0020] The condenser 1 condenses the refrigerant (carbon dioxide). The condenser 1 is configured to cool and condense the refrigerant by using a chiller. The refrigerant flowing out of the condenser 1 is transferred to the tank 2. The tank 2 is a container storing the refrigerant. The refrigerant condensed by the condenser 1 flows into the tank 2. The tank 2 stores the refrigerant in a liquid phase or a gas-liquid two-phase. The refrigerant stored in the tank 2 is transferred to the pump 3. Also, the inert gas is stored in the tank 2 together with the refrigerant.

[0021] The pump 3 transfers the refrigerant (carbon dioxide) stored in the tank 2 to the evaporator 4. The operation of the pump 3 is controlled by the apparatus controller 5. The evaporator 4 cools an object to be cooled (not shown) by evaporating the refrigerant discharged from the pump 3. Subsequently, the refrigerant flowing out of the evaporator 4 is returned to the condenser 1 and is then condensed in the condenser 1.

[0022] The apparatus controller 5 is configured to entirely control the cooling apparatus 110. The apparatus controller 5 includes a processor such as a CPU (Central Processing Unit), a memory, and the like. The apparatus controller 5 is configured to entirely control the cooling apparatus 110 by using control software (program) recorded (stored) in the internal or external memory (storage device).

[0023] The cooling apparatus 110 includes temperature sensors 61 and 62 detecting temperatures of the refrigerant in the refrigerant flow path. Also, the cooling apparatus 110 includes pressure sensors 63 and 64 detecting pressures of the refrigerant in the refrigerant flow path. The pressure sensors 63 and 64 are examples of a “pressure detector” in the claims.

[0024] The temperature sensor 61 is arranged between the tank 2 and the pump 3, and detects the temperature of the refrigerant flowing out of the tank 2. The temperature sensor 62 is arranged between the evaporator 4 and the condenser 1, and detects the temperature of the refrigerant flowing out of the evaporator 4.

[0025] The pressure sensor 63 is arranged between the tank 2 and the pump 3, and detects the pressure of the refrigerant flowing between the tank 2 and the pump 3. The pressure sensor 64 is arranged between the evaporator 4 and the condenser 1, and detects the pressure of the refrigerant flowing between the evaporator 4 and the condenser 1.

[0026] Also, the apparatus controller 5 is connected to the pump 3 for communication. Also, the apparatus controller 5 is connected to the temperature sensors 61 and 62 for communication. Also, the apparatus controller 5 is connected to the pressure sensors 63 and 64 for communication.

[0027] The apparatus controller 5 is configured to control the cooling apparatus 110 by acquiring detection signals from the temperature sensor 61, the temperature sensor 62, the pressure sensor 63, and the pressure sensor 64.

[0028] Also, a cylinder 121, a cylinder 122, and a vacuum pump 123 are connected to the refrigerant flow path 10 of the cooling apparatus 110 through a manifold 7.

[0029] The cylinder 121 is filled with carbon dioxide (refrigerant). A flow control valve 81 is provided between the cylinder 121 and the manifold 7. The flow control valve 81 adjusts a flow rate of carbon dioxide flowing out of the cylinder 121 by adjusting its opening degree.

[0030] The cylinder 122 is filled with the inert gas. The cylinder 122 is filled with nitrogen, for example. A flow control valve 82 is provided between the cylinder 122 and the manifold 7. The flow control valve 82 adjusts a flow rate of inert gas (nitrogen) flowing out of the cylinder 122 by adjusting its opening degree.

[0031] The vacuum pump 123 is a pump that generates a vacuum in the refrigerant flow paths of the cooling apparatus 110. Note that, in this specification, the “vacuum” does not refer to an absolute vacuum but rather to a state in which a particular space is filled with a gas at a pressure lower than atmospheric pressure.

[0032] The manifold 7 is connected to the refrigerant flow path 10 of the cooling apparatus 110. Specifically, an internal flow path of the manifold 7 is connected to the pipe upstream of the tank 2 (between the tank 2 and the condenser 1). Also, the manifold 7 is connected to the pipes that connect the cylinder 121, the cylinder 122 and the vacuum pump 123 to the manifold. The manifold 7 can switch the pipes to which the refrigerant flow path 10 is connect by adjusting the opening degrees of the valves 7a and 7b to close and open flow paths formed inside the manifold. Accordingly, the manifold 7 can switch between introduction of carbon dioxide (refrigerant) into the refrigerant flow path 10, introduction of the inert gas into the refrigerant flow path 10, and generation of a vacuum in (exhaust from) the refrigerant flow path 10.(Refrigerant-Charging Method According to First Embodiment)

[0033] The following description describes a process flow (steps 901 to 904) of the method for charging a refrigerant into the cooling apparatus 110 according to the first embodiment with reference to FIG. 2.

[0034] In step 901, an operator first generates a vacuum in the refrigerant flow path 10. The operator manipulates the manifold 7 (valves 7a and 7b) and the vacuum pump 123 to generate a vacuum in the pipes between refrigerant flow path 10 to the cylinder 121 and the cylinder 122. After generation of a vacuum in the refrigerant flow path 10 is completed, the operator conducts an operation in step 902.

[0035] In step 902, the operator conducts pre-charging. In step 902, after previously charging the inert gas into the refrigerant flow path 10 of the cooling apparatus 110, the operator charges carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 at a charging rate preventing that dry ice (solid) is produced to bring a pressure in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than the triple point pressure of carbon dioxide. In other words, the inert gas is charged into the refrigerant flow path 10 before carbon dioxide is charged into the refrigerant flow path 10. The inert gas is charged into the refrigerant flow path 10 to prevent occurrence of cavitation in the pump 3, as described above. Here, a charging amount (setting amount) of the inert gas required to prevent cavitation depends on the performance of the pump 3. In other words, the pressure in the refrigerant flow path 10 after charging the inert gas into the refrigerant flow path 10 required to prevent cavitation depends on the performance of the pump 3. The inert gas is charged to the charging amount (setting amount), which is previously set, to bring the pressure in the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined pressure at which no cavitation occurs. In the first embodiment, the pressure in the refrigerant flow path 10 after charging the inert gas is smaller than the triple point pressure of carbon dioxide.

[0036] In the first embodiment, in step 902 (pre-charging), the inert gas is previously charged into the refrigerant flow path 10 in which a vacuum is generated before carbon dioxide is charged into the refrigerant flow path 10. In a case in which the inert gas is previously charged into the refrigerant flow path 10 in which a vacuum is generated, no dry ice is naturally generated. Accordingly, the pressure in the refrigerant flow path 10 can be easily increased to approach the triple point pressure of carbon dioxide by previously charging the inert gas as compared with a case in which the pressure in the refrigerant flow path 10 is gradually increased by gradually charging carbon dioxide into the refrigerant flow path 10 in which a vacuum is generated. Accordingly, the pressure in the refrigerant flow path 10 can be increased to not smaller than the triple point pressure of carbon dioxide without producing dry ice in the refrigerant flow path 10 as compared with a case in which the inert gas is charged after carbon dioxide is charged into the refrigerant flow path 10 in which a vacuum is generated by charging carbon dioxide into the refrigerant flow path 10 after previously charging the inert gas into the refrigerant flow path 10 in which a vacuum is generated.

[0037] In step 902, the operator charges carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 at a charging rate preventing that dry ice is produced to bring the pressure in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than the triple point pressure of carbon dioxide (0.52 MPa-a). In other words, the operator charges carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 whose internal pressure is smaller than the triple point pressure of carbon dioxide (0.52 MPa-a) and which has been charged with the inert gas to bring the internal pressure to not smaller than the triple point pressure of carbon dioxide (0.52 MPa-a). For example, carbon dioxide is charged to bring the pressure in the refrigerant flow path 10 of the cooling apparatus 110 from a state of smaller than the triple point pressure of carbon dioxide (0.52 MPa-a) to a state of 0.7 MPa-a or greater. Here, step 902 is an example of a “pre-charging step” in the claims.

[0038] Here, the charging rate of carbon dioxide in step 902 (pre-charging) is smaller than the charging rate of carbon dioxide in step 904 (main charging), which will be described later. The ratio of the charging rate of carbon dioxide in the pre-charging to the charging rate of carbon dioxide in the main charging depends on an internal volume of the cooling apparatus 110 (refrigerant flow path 10). The operator adjusts the opening degrees of the valve 7a and the flow control valve 81 of the manifold 7 to gradually charge carbon dioxide into the refrigerant flow path 10 to prevent that dry ice is produced in the refrigerant flow path 10.

[0039] In step 903, the operator confirms whether temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within a predetermined temperature range. The operator confirms the temperatures in the refrigerant flow path 10 detected by the temperature sensors 61 and 62. The operator then confirms that no dry ice is produced in the refrigerant flow path 10 based on the temperatures in the refrigerant flow path 10 detected by the temperature sensors 61 and 62. The operator may confirm the temperatures in the refrigerant flow path 10 through a display and a gaging instrument (meter) included in the cooling apparatus 110 (not shown) or confirm the temperatures in the refrigerant flow path 10 by using an apparatus for charging operation, which will be described in a second embodiment later.

[0040] If the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall outside the predetermined temperature range, the operator waits until the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range. Subsequently, if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range, the operator starts the main charging of carbon dioxide (step 904).

[0041] In other words, step 904 is activated based on the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 falling within the predetermined temperature range. Here, step 904 is an example of a “main charging step” in the claims.

[0042] In step 904, the operator conducts the main charging of carbon dioxide. Specifically, the operator charges carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount required for the cooling apparatus 110 to operate with the pressure in the refrigerant flow path 10 of the cooling apparatus 110 having been brought to the triple point pressure of carbon dioxide. Specifically, the operator adjusts the opening degrees of the valve 7a and the flow control valve 81 of the manifold 7 to charge the predetermined amount of carbon dioxide required for the cooling apparatus 110 to operate into the refrigerant flow path 10.Advantages of First Embodiment

[0043] In the first embodiment, the following advantages are obtained.

[0044] In the first embodiment, after the pre-charging is conducted to charge an inert gas into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to bring pressures in the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined pressure, the main charging is conducted to charge a refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount required for the cooling apparatus 110 to operate. Accordingly, it is possible to prevent difficulty of grasping a charging amount of the inert gas caused by dissolution of the inert gas into the refrigerant dissimilar to a case in which the inert gas is charged into the refrigerant flow path after the refrigerant is charged. Consequently, it is possible to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a cooling apparatus 110 using a thermodynamic cycle. Also, in the first embodiment, since the inert gas is charged before the main charging in which the refrigerant is charged into the refrigerant flow path 10, a pressure of the inert gas required to charge the refrigerant can be smaller as compared with the case in which the inert gas is charged after the refrigerant is charged. Accordingly, since a relatively high-pressure inert gas source is not necessarily provided, it is possible to easily charge the inert gas into the refrigerant flow path 10.

[0045] Also, since the charging charging amount of the inert gas into the refrigerant flow path 10 can be grasped by charging the inert gas to a predetermined pressure, it is possible to easily grasp the charging amount of the inert gas as compared with a case in which the charging amount is measured based on a weight of the inert gas. In particular, in a case in which the amount of the inert gas required is small, since it is difficult to measure the charging amount based on its weight in some cases, the charging amount of the inert gas can be more effectively grasped by charging the inert gas to the predetermined pressure.

[0046] Also, in the first embodiment, the inert gas is charged to the predetermined pressure at which no cavitation occurs and no gas is produced in a pump 3 arranged on the refrigerant flow path 10 of the cooling apparatus 110 during operation of the cooling apparatus 110 (heat transferring apparatus) in the pre-charging step (step 902). According to this configuration, since the charging amount of the inert gas can be easily grasped by charging the inert gas in the pre-charging step (step 902) before step 904 as main charging of the refrigerant (carbon dioxide), the charging amount of inert gas, which is charged to prevent occurrence of cavitation, can be effectively and easily grasped by charging the inert gas to the predetermined pressure at which no cavitation occurs in the pre-charging step.

[0047] In the first embodiment, the inert gas is charged to bring the pressure in the refrigerant flow path 10 of the cooling apparatus 110 to the predetermined pressure so as to bring the pressure of the refrigerant, which flows into the pump 3 arranged on the refrigerant flow path 10 of the cooling apparatus 110, to not smaller than a saturation vapor pressure of the refrigerant during operation of the cooling apparatus 110 (heat transferring apparatus) in the pre-charging step (step 902). According to this configuration, since the inert gas is charged in the pre-charging step (step 902), it is possible to more effectively and easily grasp that the inert gas is charged to the charging amount (setting amount), which is set to bring the pressure of the refrigerant flowing into the pump 3 during operation of the cooling apparatus 110 to not smaller than the saturation vapor pressure of the refrigerant.

[0048] Also, in the first embodiment, nitrogen as the inert gas is charged to bring the pressure in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to the predetermined pressure in the pre-charging step (step 902). According to this configuration, occurrence of cavitation caused by the inert gas can be stably prevented by charging nitrogen, which is a relatively stable substance, as the inert gas. Accordingly, the cooling apparatus 110 can be more stably operated by charging nitrogen as the inert gas in the pre-charging step (step 902), and the charging amount of inert gas required for the cooling apparatus 110 to more stably operate can be more effectively and easily grasped.

[0049] Also, in the first embodiment, the pre-charging is conducted by previously charging the inert gas into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) and then charging carbon dioxide (refrigerant) into the refrigerant flow path 10 of the cooling apparatus 110, in which a vacuum is generated, at a charging rate preventing that dry ice (solid) is produced to bring a pressure in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than the triple point pressure of carbon dioxide. Accordingly, the main charging can be conducted to charge carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount of carbon dioxide required for the cooling apparatus 110 to operate with the pressure in the refrigerant flow path 10 having been brought to the triple point pressure of carbon dioxide. Consequently, since carbon dioxide can be charged into the refrigerant flow path 10 in a pressure state in which no dry ice is generated during the main charging of carbon dioxide, it is possible to prevent occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide. For these reasons, since an additional device heating or cooling carbon dioxide is not required dissimilar to a case in which carbon dioxide is heated or cooled when charging carbon dioxide, it is possible to prevent a complicated apparatus configuration of the apparatus charging carbon dioxide refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 while preventing occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide.

[0050] In addition, following additional advantages can be acquired by conducting steps discussed below in the method for charging a refrigerant into the cooling apparatus 110 (heat transferring apparatus) according to the first embodiment.

[0051] In the first embodiment, the main charging step (step 904) is activated based on the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) falling within the predetermined temperature range. Accordingly, it is possible to activate the main charging of carbon dioxide after confirming that no temperature drop due to generation of dry ice has occurred in the refrigerant flow path 10. Consequently, it is possible to prevent clogging of the refrigerant flow path 10 caused by generation of dry ice during the main charging of carbon dioxide.

[0052] Also, in the first embodiment, the charging rate of carbon dioxide in the pre-charging step (step 902) is smaller than the charging rate of carbon dioxide in the main charging step (step 904). Accordingly, it is possible to prevent a sharp drop in temperature of carbon dioxide caused by adiabatic expansion as compared with a case in which the charging rate of carbon dioxide in the pre-charging step is substantially equal to the charging rate of carbon dioxide in the main charging step. Consequently, it is possible to prevent carbon dioxide from becoming dry ice in the refrigerant flow path 10 due to the sharp drop in temperature caused by adiabatic expansion. In addition, since the charging rate of carbon dioxide in the main charging step is greater than the charging rate of carbon dioxide in the pre-charging step, it is possible to reduce the time required for the main charging of carbon dioxide. Consequently, it is possible to reduce the time required to charge carbon dioxide to a predetermined amount required for the cooling apparatus 110 (heat transferring apparatus) to operate.Second Embodiment

[0053] The following description describes a method for charging a refrigerant into a cooling apparatus 110 according to a second embodiment in which the refrigerant-charging control apparatus 100 provides indication to urge an operator to conduct an operation in the method for charging the refrigerant into the cooling apparatus 110 with reference to FIGS. 3 and 4.

[0054] The refrigerant-charging control apparatus 100 includes a controller 101 and a display 102. The refrigerant-charging control apparatus 100 is an example of a “refrigerant-charging control apparatus for a heat transferring apparatus” in the claims. The display 102 is an example of a “notifier” in the claims.

[0055] The controller 101 is configured to entirely control the refrigerant-charging control apparatus 100. The controller 101 includes a processor such as a CPU, a memory, and the like. The controller 101 is configured to control charging of carbon dioxide refrigerant into the cooling apparatus 110 by using control software (program) recorded (stored) in the internal or external memory (storage device).

[0056] The controller 101 performs control to acquire temperatures of the refrigerant flowing through the refrigerant flow path 10 of the cooling apparatus 110 detected by temperature sensors 61 and 62. The controller 101 performs control to acquire pressures of the refrigerant flowing through the refrigerant flow path 10 of the cooling apparatus 110 detected by pressure sensors 63 and 64. In other words, the controller 101 controls the acquisition of the pressures in the refrigerant flow path 10 of the cooling apparatus 110 detected by the pressure sensors 63 and 64.

[0057] The display 102 provides indication (notification) of the pressures of the refrigerant flowing through the refrigerant flow path 10 of the cooling apparatus 110 acquired by the controller 101. Also, the display 102 provides indication (notification) of the temperatures of the refrigerant flowing through the refrigerant flow path 10 of the cooling apparatus 110 acquired by the controller 101. In other words, the display 102 provides indication (notification) of information about the charging of the refrigerant (carbon dioxide) in the refrigerant flow path 10 of the cooling apparatus 110. The display 102 includes a liquid crystal display or an organic EL display. The display 102 may also include a gaging instrument (meter).

[0058] The controller 101 performs control to determine whether pre-charging is completed to charge the inert gas and carbon dioxide (refrigerant) into the refrigerant flow path 10 of the cooling apparatus 110, in which a vacuum is generated, to bring a pressure in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than the triple point pressure of carbon dioxide. In the second embodiment, when conducting the pre-charging, the controller 101 controls the determination whether the pre-charging is completed based on the pressures of the refrigerant flowing through the refrigerant flow path 10 of the cooling apparatus 110 (pressures in the refrigerant flow path 10) detected by the pressure sensors 63 and 64.

[0059] Specifically, when conducting the pre-charging, in which an inert gas is charged to a predetermined pressure before main charging, the controller 101 performs control to determine whether the charging of the inert gas is completed based on the pressures in the refrigerant flow path 10 of the cooling apparatus 110 detected by the pressure sensors 63 and 64. For example, the controller 101 previously stores a value of the predetermined pressure in the pre-charging of inert gas corresponding to the charging amount that prevents occurrence of cavitation. During the charging of the inert gas in the pre-charging, it is determined whether the charging of the inert gas is completed based on whether the pressures in the refrigerant flow path 10 detected by the pressure sensors 63 and 64 are increased to the predetermined pressure, which is previously set. Subsequently, the controller 101 similarly determines whether the charging of the refrigerant in the pre-charging is completed based on whether the pressures in the refrigerant flow path 10 (pressures of the refrigerant flowing through the refrigerant flow path 10) detected by the pressure sensors 63 and 64 are increased to not smaller than a value of the triple point pressure of the refrigerant, which is previously set.

[0060] Also, after pre-charging, the controller 101 determines whether the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within a predetermined temperature range. Specifically, the controller 101 determines whether the temperatures in the refrigerant flow path 10 detected by the temperature sensors 61 and 62 fall within the predetermined temperature range. For example, the controller 101 determines whether a difference between the temperatures in the refrigerant flow path 10 detected by the temperature sensors 61 and 62 is smaller than a few ° C. Also, the controller 101 may determine whether all of the temperatures in the refrigerant flow path 10 detected by the temperature sensors 61 and 62 fall within the predetermined temperature range.

[0061] If determining that the pre-charging has been completed, the controller 101 performs control relating to the main charging of the refrigerant flow path 10 of the cooling apparatus 110 with carbon dioxide up to a predetermined amount required for the cooling apparatus 110 to operate while the pressure in the refrigerant flow path 10 of the cooling apparatus 110 is not smaller than the triple point pressure of carbon dioxide.

[0062] In the second embodiment, the controller 101 provides indication (notification) of information indicating that the charging of the inert gas is completed through the display 102 if determining that the charging of the inert gas is completed in the pre-charging. For example, the controller 101 performs control to indicate a sentence (text) such as “Inert gas charging is completed” through the display 102. Also, the controller 101 provides indication (notification) of the pressures in the refrigerant flow path 10 of the cooling apparatus 110 acquired by the pressure sensors 63 and 64 as information indicating that the inert gas charging is completed through the display 102. Also, the controller 101 provides indication (notification) of a sentence (text) urging the operator to charge carbon dioxide (refrigerant) following the completion of the charging of the inert gas in the pre-charging process together with the information indicating that the inert gas charging is completed through the display 102.

[0063] In the second embodiment, the controller 101 performs control to provide indication (notification) urging the operator to conduct the main charging through the display 102 as control relating to the main charging if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range after the pre-charging. For example, the controller 101 performs control to indicate a sentence (text) such as “Please start main charging” through the display 102. Accordingly, the refrigerant-charging control apparatus 100 (display 102) urges the operator to start the main charging.

[0064] In the second embodiment, the manifold 7 (valve 7a) and the flow control valve 81 are manipulated by the operator in response to the indication on the display 102 so that the main charging of carbon dioxide (refrigerant) into the refrigerant flow path 10 is conducted.(Refrigerant-Charging Method According to Second Embodiment)

[0065] The following description describes a process flow of the method for charging a refrigerant into the cooling apparatus 110 (heat transferring apparatus) according to the second embodiment with reference to FIG. 4. In the method for charging the refrigerant into the cooling apparatus 110 according to the second embodiment, steps 931 to 934 are conducted in the pre-charging step of step 902 in FIG. 2. The processes in steps 901, 903 and 904 are the same as in the first embodiment)

[0066] In step 931, in the pre-charging, the inert gas is charged. Subsequently, in step 932, based on the pressures in the refrigerant flow path 10 detected by the pressure sensors 63 and 64, it is determined whether the inert gas is charged to the predetermined pressure at which no cavitation occurs. If it is determined that the inert gas is charged to the predetermined pressure, information indicating that the inert gas charging is completed is indicated on the display 102, and the procedure goes to step 933. If it is not determined that the inert gas is charged to the predetermined pressure, the procedure waits until the inert gas is charged to the predetermined pressure.

[0067] Subsequently, in step 933, the refrigerant (carbon dioxide) is charged in the pre-charging. Subsequently, in step 934, based on the pressures in the refrigerant flow path 10 detected by the pressure sensors 63 and 64, it is determined whether the refrigerant is charged to a pressure not smaller than the triple point pressure. For example, it is determined whether the refrigerant is charged to not smaller than the triple point pressure or not smaller than 0.7 MPa-a. If it is determined that the refrigerant (carbon dioxide) in the pre-charging is charged to not smaller than the triple point pressure, the procedure goes to step 903. If it is not determined that the refrigerant (carbon dioxide) is charged to not smaller than the triple point pressure, the procedure waits.

[0068] Also, in the process flow of the method for charging the refrigerant into the cooling apparatus 110 according to the second embodiment, in step 903, the temperatures in the refrigerant flow path 10 are confirmed by the operator after the indication (notification) is provided by the display 102. The other process flow is the same as that in the first embodiment.Advantages of Second Embodiment

[0069] In the second embodiment, the following advantages are obtained.

[0070] In the second embodiment, before conducting the main charging, the controller 101 charges an inert gas into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to bring pressures in the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined pressure. Accordingly, similar to the first embodiment, it is possible to prevent difficulty of grasping a charging amount of the inert gas caused by dissolution of the inert gas into the refrigerant dissimilar to a case in which the inert gas is charged into the refrigerant flow path after the refrigerant is charged. Consequently, it is possible to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a cooling apparatus 110 using a thermodynamic cycle. Also, in the second embodiment, similar to the first embodiment, since a relatively high-pressure inert gas source is not necessarily provided, it is possible to easily charge the inert gas into the refrigerant flow path.

[0071] Also, in the second embodiment, since, when conducting the pre-charging before main charging, the controller 101 performs control to determine whether the charging of the inert gas is completed based on the pressures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) detected by the pressure sensors 63 and 64, it is possible to more accurately charge the inert gas as compared with a case in which a person determines whether the charging of the inert gas is completed or not by visually checking a gaging instrument (meter) or the like.

[0072] In the second embodiment, after the pressures in the refrigerant flow path 10 are brought to not smaller than the triple point pressure of carbon dioxide in the pre-charging, the controller 101 can conduct control relating to the main charging to charge carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to the predetermined amount of carbon dioxide required for the cooling apparatus 110 to operate. Accordingly, since carbon dioxide can be charged into the refrigerant flow path 10 in a pressure state in which no dry ice is generated during the main charging of carbon dioxide, it is possible to prevent occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide. Consequently, since an additional device heating or cooling carbon dioxide is not required dissimilar to a case in which carbon dioxide is heated or cooled when charging carbon dioxide, it is possible to prevent a complicated apparatus configuration of the apparatus charging carbon dioxide refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 while preventing occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide. In addition, the operator can easily determine whether the pressures in the refrigerant flow path 10 are not smaller than the triple point pressure of carbon dioxide based on the indication of the display 102 (notifier), which provides indication (notification) of the pressures of the refrigerant flowing through the refrigerant flow path 10.

[0073] In addition, following additional advantages can be obtained by the refrigerant-charging control apparatus 100 according to the aforementioned second embodiment added with configurations discussed below.

[0074] In the second embodiment, the refrigerant-charging control apparatus 100 includes a display 102 (notifier) providing notification of information about charging carbon dioxide (refrigerant) into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus). The controller 101 provides notification of information indicating that the charging of the inert gas is completed through the display 102 if determining that the charging of the inert gas is completed. According to this configuration, the operator can easily recognize that the inert gas charging is completed by recognizing the information indicating that the inert gas charging is completed notified by the display 102.

[0075] Also, in the second embodiment, the controller 101 performs control to provide notification of the pressures acquired in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) as the information indicating that the inert gas charging is completed through the display 102 (notifier). According to this configuration, the operator can easily recognize specific values indicating magnitudes of the pressures in the refrigerant flow path 10 by recognizing the information indicating that the inert gas charging is completed notified by the display 102. Consequently, the operator can easily recognize that the inert gas is charged to the predetermined pressure.

[0076] In the second embodiment, after pre-charging, the controller 101 determines whether the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) fall within a predetermined temperature range. Also, the controller performs control to provide indication (notification) urging the operator to conduct the main charging as control relating to the main charging through the display 102 (notifier) if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range after the pre-charging. Accordingly, the operator can easily confirm that no temperature drop due to generation of dry ice has occurred in the refrigerant flow path 10 by visually checking (confirming) the indication on the display 102. Accordingly, after confirming that no temperature drop due to generation of dry ice has occurred in the refrigerant flow path 10 based on the indication on the display 102, the operator can start the main charging of carbon dioxide. As a result, the refrigerant flow path 10 can be more effectively prevented from becoming blocked due to the generation of dry ice during the main charging of carbon dioxide.

[0077] The other advantages of the second embodiment are similar to the first embodiment.Third Embodiment

[0078] The following description describes a method for charging a refrigerant into the cooling apparatus 110 according to a third embodiment. In the third embodiment, a refrigerant-charging control apparatus 200 (see FIG. 5) automatically conduct pre-charging of an inert gas and carbon dioxide, and main charging of carbon dioxide into the cooling apparatus 110. The refrigerant-charging control apparatus 200 is an example of the “refrigerant-charging control apparatus for a heat transferring apparatus” in the claims.

[0079] A controller 101 of the refrigerant-charging control apparatus 200 is configured to control the manifold 7 (valves 7a and 7b), the flow control valve 81, the flow control valve 82, and the vacuum pump 123. Accordingly, the operation that is conducted by manipulation of the operator in the aforementioned first and second embodiments is automatically conducted by control performed by the controller 101 of the refrigerant-charging control apparatus 200.

[0080] In the third embodiment, for example, the controller 101 generates a vacuum in the refrigerant flow path 10 by controlling operations of the vacuum pump 123 and the manifold 7. Subsequently, the controller 101 starts the pre-charging by controlling operations of the manifold 7 and the flow control valve 82 to start the charging of the inert gas. The controller 101 performs control to stop the charging of the inert gas by controlling operations of the manifold 7 and the flow control valve 82 if determining that the charging of the inert gas is completed in the pre-charging. Subsequently, the controller 101 charges the refrigerant in the pre-charging until the pre-charging is completed by controlling operations of the manifold 7 and the flow control valve 81.

[0081] In the third embodiment, the controller 101 performs control of the charging of carbon dioxide as control relating to the main charging if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range. Specifically, the controller 101 controls the manifold 7 (valve 7a) and the flow control valve 81 to allow carbon dioxide charged in the cylinder 121 to flow into refrigerant flow path 10 if the temperatures in refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range after the pre-charging.

[0082] Here, other configurations of the third embodiment are the same as the aforementioned second embodiment. Also, the process flow of the method for charging the refrigerant into the cooling apparatus 110 according to the third embodiment is similar to the process flow in the first embodiment, except that steps are automatically conducted by the refrigerant-charging control apparatus 200 instead of the operator.Advantages of Third Embodiment

[0083] In the third embodiment, the following advantages are obtained.

[0084] In the third embodiment, the controller 101 performs control to stop the charging of the inert gas if determining that the charging of the inert gas is completed. According to this configuration, also in a case in which the inert gas is automatically charged by control performed by the controller 101, the charging amount of the inert gas can be easily and accurately grasped by charging the inert gas in the pre-charging step before charging the refrigerant. For this reason, the inert gas can be more easily and more accurately charged by the controller 101.

[0085] Also, in the third embodiment, similar to the second embodiment, it is possible to prevent a complicated apparatus configuration of the apparatus charging carbon dioxide refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) while preventing occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide.

[0086] In addition, following additional advantages can be obtained by the refrigerant-charging control apparatus 200 according to the aforementioned third embodiment added with configurations discussed below.

[0087] Also, in the third embodiment, after pre-charging, the controller 101 determines whether the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) fall within a predetermined temperature range. Subsequently, control of the charging of carbon dioxide is performed as control relating to the main charging if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 fall within the predetermined temperature range. Accordingly, after confirming that no temperature drop due to generation of dry ice has occurred in the refrigerant flow path 10, the controller 101 performs control of the charging of carbon dioxide (main charging). As a result, the refrigerant flow path 10 can be more effectively prevented from becoming blocked due to the generation of dry ice during the main charging of carbon dioxide. In addition, since the control of the charging of carbon dioxide (main charging) is automatically performed by the controller 101, it is possible to quickly start the control of the charging of carbon dioxide (main charging) as compared with a case in which the operator starts the main charging of carbon dioxide after confirming that no temperature drop due to generation of dry ice has occurred in the refrigerant flow path 10.

[0088] The other advantages of the third embodiment are similar to the first embodiment.Fourth Embodiment

[0089] The following description describes a method for charging a carbon dioxide refrigerant into the cooling apparatus 110 according to a fourth embodiment.

[0090] The method for charging a carbon dioxide refrigerant into the cooling apparatus 110 according to the fourth embodiment is a method to be used in a case in which a pressure in the refrigerant flow path 10 can be increased to not smaller than the triple point pressure of carbon dioxide during charging of an amount of an inert gas required to prevent occurrence of cavitation in the pump 3. In the method for charging carbon dioxide refrigerant into the cooling apparatus 110 according to the fourth embodiment, only the inert gas is charged in the pre-charging dissimilar to the first embodiment in which the inert gas and carbon dioxide are charged in the pre-charging.(Carbon Dioxide Refrigerant-Charging Method According to Fourth Embodiment)

[0091] The following description describes a process flow (steps 911 to 913) of the method for charging a carbon dioxide refrigerant into the cooling apparatus 110 according to the fourth embodiment with reference to FIG. 6.

[0092] In step 911, an operator first generates a vacuum in the refrigerant flow path 10. After the generation of a vacuum in the refrigerant flow path 10 is completed, the operator conducts an operation in step 912. Here, step 911 is a similar process to step 901 in the first embodiment.

[0093] In step 912, the operator conducts the pre-charging to previously charge the inert gas. In step 912, the operator charges the inert gas into the refrigerant flow path 10 of the cooling apparatus 110 in which a vacuum is generated to bring the pressures in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than the triple point pressure of carbon dioxide (0.52 MPa-a). For example, the operator charges the inert gas into the refrigerant flow path 10 to bring the pressures in the refrigerant flow path 10 of the cooling apparatus 110 to not smaller than 0.7 MPa-a. In other words, in the fourth embodiment, the predetermined pressure at which no cavitation occurs and to which the inert gas is charged in the pre-charging is greater than the triple point pressure of the refrigerant. In other words, when the inert gas is charged to the predetermined pressure at which no cavitation occurs, the pressure in the refrigerant flow path 10 of the cooling apparatus 110 becomes not smaller than the triple point pressure of carbon dioxide (0.52 MPa-a). Here, step 912 is an example of a “pre-charging step” in the claims.

[0094] In step 913, the operator performs the main charging of carbon dioxide. Specifically, the operator charges carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount required for the cooling apparatus 110 to operate with the pressure in the refrigerant flow path 10 of the cooling apparatus 110 having been brought to the triple point pressure of carbon dioxide. In the fourth embodiment, since only the inert gas (nitrogen) is charged in the pre-charging, no dry ice is generated during the pre-charging. For this reason, after the pre-charging is completed, the main charging can be conducted without confirming the temperatures in the refrigerant flow path 10. Here, the temperatures in the refrigerant flow path 10 may be confirmed similar to the first embodiment after the pre-charging (step 912) is completed considering the temperature drop in the refrigerant flow path 10 caused by adiabatic expansion of the inert gas. Step 913 is an example of the “main charging step” of the claim.Advantages of Fourth Embodiment

[0095] In the fourth embodiment, the following advantages are obtained.

[0096] In the fourth embodiment, the pre-charging is conducted to charge the inert gas into the refrigerant flow path 10 of the cooling apparatus 110 in which a vacuum is generated to bring the pressures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to not smaller than the triple point pressure of carbon dioxide. Accordingly, the main charging can be conducted to charge carbon dioxide into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount of carbon dioxide required for the cooling apparatus 110 to operate with the pressure in the refrigerant flow path 10 having been brought to the triple point pressure of carbon dioxide. Consequently, since carbon dioxide can be charged into the refrigerant flow path 10 in a pressure state in which no dry ice is generated during the main charging of carbon dioxide, it is possible to prevent occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide. Accordingly, it is possible to prevent a complicated apparatus configuration of the apparatus charging carbon dioxide refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 while preventing occurrence of clogging of the refrigerant flow path 10 caused by generation of dry ice without heating or cooling carbon dioxide.Modified Embodiments

[0097] Note that the embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is not shown by the above description of the embodiments but by the scope of claims for patent, and all modifications (modified embodiments) within the meaning and scope equivalent to the scope of claims for patent are further included.

[0098] For example, while the example in which the controller 101 of the refrigerant-charging control apparatus 100 performs control to acquire the pressures of the refrigerant flowing through the refrigerant flow path 10 detected by the pressure sensors 63 and 64 (pressure detector) included in the cooling apparatus 110 (heat transferring apparatus) has been shown in the aforementioned second embodiment, the present invention is not limited to this. In the present invention, the refrigerant-charging control apparatus may include a pressure detector, and the controller of the refrigerant-charging control apparatus may control the acquisition of the pressure of the refrigerant flowing through the refrigerant flow path detected by the pressure detector of the refrigerant-charging control apparatus. Also, the controller of the refrigerant-charging control apparatus may perform control relating to the charging of carbon dioxide refrigerant based on a detection result of the pressure detector included in the refrigerant-charging control apparatus.

[0099] For example, while the example in which the controller 101 of the refrigerant-charging control apparatus 100 performs control to acquire the temperatures of the refrigerant flowing through the refrigerant flow path 10 detected by the temperature sensors 61 and 62 included in the cooling apparatus 110 (heat transferring apparatus) has been shown in the aforementioned second embodiment, the present invention is not limited to this. In the present invention, the refrigerant-charging control apparatus may include a temperature sensor, and the controller of the refrigerant-charging control apparatus may control the acquisition of the temperature of the refrigerant flowing through the refrigerant flow path detected by the temperature sensor of the refrigerant-charging control apparatus. Also, the controller of the refrigerant-charging control apparatus may perform control relating to the charging of carbon dioxide refrigerant based on a detection result of the temperature sensor included in the refrigerant-charging control apparatus.

[0100] While the example in which control is performed to provide indication (notification) to urge the operator to conduct the main charging through the display 102 (notifier) has been shown in the aforementioned second embodiment, the present invention is not limited to this. In the present invention, the notifier may produce a sound to urge the operator to conduct the main charging. Here, in a case in which the notifier is a display that provides notification through visual information, the display may be a liquid crystal display, an organic EL display, a backlit indicator instead of a gaging instrument (meter), or a display using micro LEDs. The notifier may be configured to provide both audible information using voice and visual information using the display or the like.

[0101] While the example in which the charging operation of the carbon dioxide refrigerant is conducted by the operator without using the refrigerant-charging control apparatus 100 or 200 has been shown in the aforementioned fourth embodiment. In the present invention, also in the method for charging a carbon dioxide refrigerant in which the pre-charging is conducted to charge the inert gas into the refrigerant flow path of the heat transferring apparatus in which a vacuum is generated to bring the pressures in the refrigerant flow path of the heat transferring apparatus to not smaller than the triple point pressure of carbon dioxide, the refrigerant-charging control apparatus 100 may perform control to provide indication (notification) urging the operator to conduct the main charging through the display 102 (notifier) similar to the second embodiment. Here, in a case in which, after the pre-charging is completed, the main charging is conducted without confirming the temperatures in the refrigerant flow path as described in the fourth embodiment, the controller of the refrigerant-charging control apparatus performs control to provide information through the notifier based on the pressures in the refrigerant flow path of the cooling apparatus (heat transferring apparatus) becoming not smaller than the triple point pressure of carbon dioxide. Also, the entire or a part of operation in the method for charging a carbon dioxide refrigerant in which the pre-charging is conducted to charge the inert gas into the refrigerant flow path of the heat transferring apparatus in which a vacuum is generated to bring the pressures in the refrigerant flow path of the heat transferring apparatus to not smaller than the triple point pressure of carbon dioxide may be automatically conducted by the refrigerant-charging control apparatus 200 similar to the third embodiment.

[0102] While the example in which the controller 101 of the refrigerant-charging control apparatus 200 performs control of the charging of carbon dioxide as control relating to the main charging if the temperatures in the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) fall within the predetermined temperature range has been shown in the aforementioned third embodiment, the present invention is not limited to this. In the present invention, the refrigerant-charging control apparatus may include a manipulation receiver such as a touch panel, a keyboard or a computer mouse, and the apparatus controller of the refrigerant-charging control apparatus may control the charging of carbon dioxide (main charging) based on input manipulation of the operator input to the manipulation receiver. Also, the controller of the refrigerant-charging control apparatus may conduct generation of a vacuum in a cooling flow path or pre-charging based on the input manipulation of the operator input to the manipulation receiver.

[0103] While the example in which the refrigerant-charging control apparatus 100 and the refrigerant-charging control apparatus 200 are provided separately from the apparatus controller 5 has been shown in the aforementioned second and third embodiments, the present invention is not limited to this. In the present invention, the control performed by the refrigerant-charging control apparatus 100 and the refrigerant-charging control apparatus 200 may be performed by the apparatus controller 5.

[0104] While the example in which the internal flow path of the manifold 7 is connected to the pipe upstream of the tank 2 (between the tank 2 and the condenser 1) has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, the internal flow path of the manifold 7 may be connected to a pipe in the refrigerant flow path 10 other than the pipe upstream of the tank 2 (between the tank 2 and the condenser 1).

[0105] Also, while the example in which the method for charging a carbon dioxide refrigerant according to the present invention has been described with reference to a flow-driven type flowchart in which processes are sequentially performed along a processing flow for sake of illustration in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, the operations (operation processes) of the method for charging a carbon dioxide refrigerant may be performed by event-driven (event-driven) processing that executes the processes on an event-by-event basis. In this case, the operations (operation processes) of the method for charging a carbon dioxide refrigerant may be executed fully in the event-driven type processing or in combination of the event-driven type processing and flow-driven-step type processing.

[0106] While the example in which carbon dioxide is charged as a refrigerant after nitrogen is charged as an inert gas into the refrigerant flow path 10 in which a vacuum is generated has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, the refrigerant is not limited to carbon dioxide but a fluorocarbon may be used as the refrigerants or a natural refrigerant such as ammonia or water may be used as the refrigerant. Also, the inert gas is not limited to nitrogen but the inert gas may be a rare gas, a fluorocarbon or carbon dioxide. Also, the atmosphere may be used as an inert gas. Also, no vacuum may be generated before the pre-charging. In other words, the inert gas may be charged into the refrigerant flow path at atmospheric pressure to the predetermined pressure. Also, in a case in which a refrigerant other than carbon dioxide is used, if no solid is produced when charging the refrigerant, the pre-charging may be completed and the main charging may be conducted irrespective of whether the pressure becomes not smaller than the triple point pressure or not. In other words, even if the predetermined pressure to which the inert gas is charged in the pre-charging is smaller than the triple point pressure of the refrigerant, the charging of the refrigerant in the main charging may be activated when the charging of the inert gas is completed. In other words, steps 933 and 934 in FIG. 4 may be omitted. In this case, the temperatures in the refrigerant flow path may not be measured. In other words, step 903 in FIG. 4 may be omitted.

[0107] While the example in which the inert gas is charged into the refrigerant flow path 10 to bring the pressure of the refrigerant, which flows into the pump 3, to the predetermined pressure at which no cavitation occurs so as to bring the pressure to not smaller than a saturation vapor pressure of the refrigerant during operation of the cooling apparatus 110 (heat transferring apparatus) in the pre-charging has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, the predetermined pressure as the charging amount of the inert gas in the pre-charging may be set to bring the pressure of the refrigerant flowing into the pump 3 to not smaller than a saturation vapor pressure with the refrigerant being mixed with the inert gas during operation of the heat transferring apparatus.

[0108] While the example in which the inert gas and carbon dioxide (refrigerant) are charged into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. The inert gas and the refrigerant may be charged into a refrigerant flow path in a heating apparatus as the heat transferring apparatus.

[0109] While the example in which the pre-charging step (step 902), which includes charging of the inert gas, and the main charging step (step 904) in which charging of the refrigerant (carbon dioxide) is conducted are provided has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, a step of charging a refrigeration oil into the refrigerant flow path of the heat transferring apparatus may be further provided. The step of charging the refrigerator oil may be conducted before the pre-charging step, after the pre-charging step, or after charging the inert gas during the pre-charging step. Also, the step of charging the refrigerator oil may be conducted after the main charging step.

[0110] While the example in which the cooling apparatus 110 (heat transferring apparatus) includes the tank 2 storing the refrigerant has been shown in the aforementioned first to fourth embodiments, the present invention is not limited to this. In the present invention, the heat transferring apparatus may be configured to include an accumulator instead of the tank.MODES

[0111] It is understood by those skilled in the art that the exemplary embodiments described above are specific examples of the following aspects.Mode Item 1

[0112] A method for charging a refrigerant into a heat transferring apparatus includes a pre-charging step of charging an inert gas into a refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure; and a main charging step of charging the refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate after the pre-charging step.Mode Item 2

[0113] In the method for charging a refrigerant into a heat transferring apparatus according to mode item 1, the inert gas is charged to the predetermined pressure at which no cavitation occurs and no gas is produced in a pump arranged on the refrigerant flow path of the heat transferring apparatus during operation of the heat transferring apparatus in the pre-charging step.Mode Item 3

[0114] In the method for charging a refrigerant into a heat transferring apparatus according to mode item 1 or 2, the inert gas is charged to bring the pressure in the refrigerant flow path of the heat transferring apparatus to the predetermined pressure so as to bring the pressure of the refrigerant to not smaller than a saturation vapor pressure of the refrigerant before the refrigerant flows into the pump arranged on the refrigerant flow path of the heat transferring apparatus during operation of the heat transferring apparatus in the pre-charging step.Mode Item 4

[0115] In the method for charging a refrigerant into a heat transferring apparatus according to any of mode items 1 to 3, nitrogen as the inert gas is charged to bring the pressure in the refrigerant flow path of the heat transferring apparatus to the predetermined pressure in the pre-charging step.Mode Item 5

[0116] In the method for charging a refrigerant into a heat transferring apparatus according to any of mode items 1 to 4, the refrigerant is charged into the refrigerant flow path of the heat transferring apparatus at a charging rate preventing that a solid of the refrigerant is produced to bring the pressure in the refrigerant flow path of the heat transferring apparatus to not smaller than a triple point pressure of the refrigerant after the inert gas is previously charged into the refrigerant flow path of the heat transferring apparatus to bring the pressure in the refrigerant flow path of the heat transferring apparatus to the predetermined pressure in the pre-charging step.Mode Item 6

[0117] A refrigerant-charging control apparatus for a heat transferring apparatus includes a controller performing control to acquire a pressure in a refrigerant flow path of the heat transferring apparatus detected by a pressure detector, wherein if conducting pre-charging to charge an inert gas into the refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure before conducting main charging to charge a refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate, the controller performs control to determine whether the charging of the inert gas is completed based on the pressure in the refrigerant flow path of the heat transferring apparatus detected by the pressure detector.Mode Item 7

[0118] In the refrigerant-charging control apparatus for a heat transferring apparatus according to mode item 6, the controller performs control to stop the charging of the inert gas if determining that the charging of the inert gas is completed.Mode Item 8

[0119] In the refrigerant-charging control apparatus for a heat transferring apparatus according to mode item 6 or 7, a notifier providing notification of information about the charging of the refrigerant into the refrigerant flow path of the heat transferring apparatus is further provided; and the controller provides notification of information indicating that the charging of the inert gas is completed through the notifier if determining that the charging of the inert gas is completed.Mode Item 9

[0120] In the refrigerant-charging control apparatus for a heat transferring apparatus according to mode item 8, the controller performs control to provide notification of the pressure acquired in the refrigerant flow path of the heat transferring apparatus as the information indicating that charging of the inert gas is completed through the notifier.Mode Item 10

[0121] In the refrigerant-charging control apparatus for a heat transferring apparatus according to any of mode items 6 to 9, the controller performs control relating to the main charging to charge the refrigerant into the refrigerant flow path of the heat transferring apparatus to the predetermined amount required for the heat transferring apparatus to operate if determining that the pre-charging is completed based on the pressure in the refrigerant flow path of the heat transferring apparatus detected by the pressure detector.DESCRIPTION OF REFERENCE NUMERALS10; refrigerant flow path

[0123] 63, 64; pressure sensor (pressure detector)

[0124] 100, 200; refrigerant-charging control apparatus

[0125] 101; controller

[0126] 102; display (notifier)

[0127] 110; cooling apparatus (heat transferring apparatus)

Examples

first embodiment

Advantages of First Embodiment

[0043]In the first embodiment, the following advantages are obtained.

[0044]In the first embodiment, after the pre-charging is conducted to charge an inert gas into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to bring pressures in the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined pressure, the main charging is conducted to charge a refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined amount required for the cooling apparatus 110 to operate. Accordingly, it is possible to prevent difficulty of grasping a charging amount of the inert gas caused by dissolution of the inert gas into the refrigerant dissimilar to a case in which the inert gas is charged into the refrigerant flow path after the refrigerant is charged. Consequently, it is possible to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a cooling...

second embodiment

Advantages of Second Embodiment

[0069]In the second embodiment, the following advantages are obtained.

[0070]In the second embodiment, before conducting the main charging, the controller 101 charges an inert gas into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) to bring pressures in the refrigerant flow path 10 of the cooling apparatus 110 to a predetermined pressure. Accordingly, similar to the first embodiment, it is possible to prevent difficulty of grasping a charging amount of the inert gas caused by dissolution of the inert gas into the refrigerant dissimilar to a case in which the inert gas is charged into the refrigerant flow path after the refrigerant is charged. Consequently, it is possible to easily grasp the charging amount of the inert gas charged separately from the refrigerant in a cooling apparatus 110 using a thermodynamic cycle. Also, in the second embodiment, similar to the first embodiment, since a relatively high-pressure...

third embodiment

Advantages of Third Embodiment

[0083]In the third embodiment, the following advantages are obtained.

[0084]In the third embodiment, the controller 101 performs control to stop the charging of the inert gas if determining that the charging of the inert gas is completed. According to this configuration, also in a case in which the inert gas is automatically charged by control performed by the controller 101, the charging amount of the inert gas can be easily and accurately grasped by charging the inert gas in the pre-charging step before charging the refrigerant. For this reason, the inert gas can be more easily and more accurately charged by the controller 101.

[0085]Also, in the third embodiment, similar to the second embodiment, it is possible to prevent a complicated apparatus configuration of the apparatus charging carbon dioxide refrigerant into the refrigerant flow path 10 of the cooling apparatus 110 (heat transferring apparatus) while preventing occurrence of clogging of the ref...

Claims

1. A method for charging a refrigerant into a heat transferring apparatus, the method comprising:a pre-charging step of charging an inert gas into a refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure; anda main charging step of charging the refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate after the pre-charging step.

2. The method for charging a refrigerant into a heat transferring apparatus according to claim 1, wherein the inert gas is charged to the predetermined pressure at which no cavitation occurs and no gas is produced in a pump arranged on the refrigerant flow path of the heat transferring apparatus during operation of the heat transferring apparatus in the pre-charging step.

3. The method for charging a refrigerant into a heat transferring apparatus according to claim 1, wherein the inert gas is charged to bring the pressure in the refrigerant flow path of the heat transferring apparatus to the predetermined pressure so as to bring the pressure of the refrigerant to not smaller than a saturation vapor pressure of the refrigerant before the refrigerant flows into the pump arranged on the refrigerant flow path of the heat transferring apparatus during operation of the heat transferring apparatus in the pre-charging step.

4. The method for charging a refrigerant into a heat transferring apparatus according to claim 1, wherein nitrogen as the inert gas is charged to bring the pressure in the refrigerant flow path of the heat transferring apparatus to the predetermined pressure in the pre-charging step.

5. The method for charging a refrigerant into a heat transferring apparatus according to claim 1, wherein the refrigerant is charged into the refrigerant flow path of the heat transferring apparatus at a charging rate preventing that a solid of the refrigerant is produced to bring the pressure in the refrigerant flow path of the heat transferring apparatus to not smaller than a triple point pressure of the refrigerant after the inert gas is previously charged into the refrigerant flow path of the heat transferring apparatus to bring the pressure in the refrigerant flow path of the heat transferring apparatus to the predetermined pressure in the pre-charging step.

6. A refrigerant-charging control apparatus for a heat transferring apparatus comprisinga controller performing control to acquire a pressure in a refrigerant flow path of the heat transferring apparatus detected by a pressure detector, whereinif conducting pre-charging to charge an inert gas into the refrigerant flow path of the heat transferring apparatus to bring a pressure in the refrigerant flow path of the heat transferring apparatus to a predetermined pressure before conducting main charging to charge a refrigerant into the refrigerant flow path of the heat transferring apparatus to a predetermined amount required for the heat transferring apparatus to operate, the controller performs control to determine whether the charging of the inert gas is completed based on the pressure in the refrigerant flow path of the heat transferring apparatus detected by the pressure detector.

7. The refrigerant-charging control apparatus for a heat transferring apparatus according to claim 6, wherein the controller performs control to stop the charging of the inert gas if determining that the charging of the inert gas is completed.

8. The refrigerant-charging control apparatus for a heat transferring apparatus according to claim 6 further comprising a notifier providing notification of information about the charging of the refrigerant into the refrigerant flow path of the heat transferring apparatus, whereinthe controller provides notification of information indicating that the charging of the inert gas is completed through the notifier if determining that the charging of the inert gas is completed.

9. The refrigerant-charging control apparatus for a heat transferring apparatus according to claim 8, wherein the controller performs control to provide notification of the pressure acquired in the refrigerant flow path of the heat transferring apparatus as the information indicating that charging of the inert gas is completed through the notifier.

10. The refrigerant-charging control apparatus for a heat transferring apparatus according to claim 6, wherein the controller performs control relating to the main charging to charge the refrigerant into the refrigerant flow path of the heat transferring apparatus to the predetermined amount required for the heat transferring apparatus to operate if determining that the pre-charging is completed based on the pressure in the refrigerant flow path of the heat transferring apparatus detected by the pressure detector.

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