Airtightness test device and airtightness test method

Abstract

This airtightness testing device comprises a differential pressure gauge and temperature measurement device. The differential pressure gauge measures the differential pressure between the pressure of fluid in refrigerant piping inside an air conditioner and the pressure of fluid in an airtight reference container. The temperature measurement device is connected to the refrigerant piping and measures the temperature of the fluid in the refrigerant piping. The temperature measurement device comprises a temperature measurement container and temperature acquisition unit. The temperature measurement container is in communication with the refrigerant piping and is capable of sealing fluid therein. The temperature acquisition unit is disposed inside the temperature measurement container and measures the temperature of the fluid. The temperature measurement container satisfies at least one condition from among the condition that the thermal diffusivity of the temperature measurement container be greater than or equal to the thermal diffusivity of the refrigerant piping and the condition that the thermal conductivity of the temperature measurement container be greater than or equal to the thermal conductivity of the refrigerant piping.

Description

[Technical field]

[0001] The present disclosure relates to an airtightness testing device and an airtightness testing method for checking the airtightness of an air conditioner. [Background technology]

[0002] A refrigerant is charged into an air conditioner when it is installed or repaired. In order to prevent leakage of the refrigerant from the refrigerant piping of the air conditioner, a nitrogen pressurized leak test is performed before charging the refrigerant into the air conditioner. In the nitrogen pressurized leak test, nitrogen is charged into the refrigerant piping, pressurized, and after a predetermined time has passed, the airtightness is judged based on the presence or absence of a pressure drop in the refrigerant piping.

[0003] In nitrogen pressure leak testing, a pressure gauge is sometimes used to check airtightness. However, since the measurement range of the pressure gauge depends on the value of the pressurized pressure, the measurement range becomes large and the response to pressure changes may become poor. Therefore, after nitrogen is sealed in the refrigerant pipe and pressurized, it may take a long time before the airtightness of the refrigerant pipe can be evaluated.

[0004] In addition to the method using a pressure gauge, the nitrogen pressurization leak test also includes the differential pressure gauge method, which uses a differential pressure gauge. In the differential pressure gauge method, the airtightness of the test object is confirmed based on the pressure difference between the pressure of the nitrogen sealed in the test object, such as an air conditioner, and the pressure of the nitrogen sealed in a reference container for comparison. Since the measurement range of a differential pressure gauge does not depend on the value of the pressurized pressure, the measurement range can be narrowed. Therefore, the differential pressure gauge method can improve responsiveness to pressure changes.

[0005] On the other hand, because the differential pressure gauge has high sensitivity, it may be affected by pressure changes caused by temperature changes in the outside air. To eliminate the effects of such temperature changes, the differential pressure gauge method requires that the temperature of the nitrogen be measured during the differential pressure measurement and the pressure value be corrected based on the measured temperature.

[0006] Conventionally, in order to measure the temperature of a fluid such as nitrogen filled in the refrigerant pipe, a method is known in which a temperature measuring device is attached to the surface of the refrigerant pipe and the temperature of the fluid in the refrigerant pipe is estimated based on the surface temperature of the refrigerant pipe. However, with this method, the change in temperature of the fluid in the refrigerant pipe may be delayed by the time required for heat conduction relative to the change in the outside air temperature. Therefore, there is a possibility that an error occurs between the temperature measured by the temperature measuring device and the temperature of the fluid in the refrigerant pipe. As a configuration for reducing such an error, Patent Document 1 discloses a configuration in which a temperature detector exposed in the refrigerant pipe directly measures the temperature of the fluid in the refrigerant pipe. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 63-170121 Summary of the Invention [Problem to be solved by the invention]

[0008] Here, since the outdoor unit of the air conditioner is exposed to the outside air while the indoor unit is not, a temperature difference may occur between the fluid in the outdoor unit and the fluid in the indoor unit. The outdoor unit may include a heat exchanger with a large surface area, and since the temperature change of the outside air is considered to be larger than the temperature change of the room, the temperature of the fluid in the outdoor unit is considered to be a representative temperature that determines the magnitude of the pressure of the fluid in the air conditioner. Therefore, in order to highly accurately correct the value of the pressure of the fluid based on the temperature measured by the temperature measuring device, it is desirable for the temperature measuring device to measure the temperature of the fluid in the refrigerant piping on the outdoor unit side.

[0009] In addition, if the temperature diffusion in the air conditioner is due to the movement of fluid molecules, it is considered that the temperature measured by the temperature measuring device also depends on the temperature of the temperature measuring device itself. Therefore, in correcting the value of the pressure of the fluid, the temperature measuring device needs to measure the temperature of the fluid affected by the temperature of the surrounding air after the temperature measuring device itself exchanges heat with the surrounding air. For example, when the temperature measuring device measures the temperature of the fluid in the refrigerant piping on the outdoor unit side, the temperature measuring device needs to measure the temperature of the fluid affected by the temperature of the outside air after the temperature measuring device itself exchanges heat with the outside air. However, Patent Document 1 does not show a configuration in which the temperature measuring device itself exchanges heat with the surrounding air, and therefore the accuracy of the temperature measurement of the fluid may decrease. Therefore, in the past, the value of the pressure of the fluid corrected based on the temperature of the fluid had an error from the actual pressure value, which could result in a decrease in the accuracy of the airtightness test.

[0010] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide an airtightness testing device and an airtightness testing method that improve the accuracy of airtightness testing of refrigerant piping. [Means for solving the problem]

[0011] The airtightness testing apparatus of the present disclosure is an airtightness testing apparatus for testing the airtightness of refrigerant piping in an air conditioner, and comprises a differential pressure gauge that measures a differential pressure, which is the difference between the pressures of the fluid filled in the refrigerant piping and an airtight reference container, and a temperature measuring device connected to the refrigerant piping and measuring the temperature of the fluid in the refrigerant piping, wherein the temperature measuring device has a temperature measuring container that is connected to the refrigerant piping and is capable of sealing the fluid therein, and a temperature acquisition unit that is installed in the temperature measuring container and measures the temperature of the fluid, and the temperature measuring container satisfies either or both of the following conditions: the thermal diffusivity is greater than or equal to the thermal diffusivity of the refrigerant piping, and the thermal conductivity is greater than or equal to the thermal conductivity of the refrigerant piping.

[0012] The airtightness testing method disclosed herein is an airtightness testing method performed by an airtightness testing apparatus for testing the airtightness of refrigerant piping in an air conditioner, the airtightness testing apparatus comprising a temperature measuring device connected to the refrigerant piping, the temperature measuring device having a temperature measuring container that communicates with the refrigerant piping and can seal a fluid inside, and a temperature acquisition unit that is installed in the temperature measuring container and measures the temperature of the fluid, the temperature measuring container satisfying either or both of the following conditions: a thermal diffusivity is equal to or greater than the thermal diffusivity of the refrigerant piping, and a thermal conductivity is equal to or greater than the thermal conductivity of the refrigerant piping, the airtightness testing method is performed by installing the temperature measuring device in an outdoor unit of the air conditioner, and includes a step of measuring a differential pressure which is the difference between the pressures of the fluid filled in the refrigerant piping and an airtight reference container, and a step of measuring the temperature of the fluid in the refrigerant piping. Effect of the Invention

[0013] According to the airtightness test device and airtightness test method of the present disclosure, the temperature measurement container of the temperature measurement device satisfies one or both of the conditions that the thermal diffusivity is equal to or greater than the thermal diffusivity of the refrigerant pipe and the thermal conductivity is equal to or greater than the thermal conductivity of the refrigerant pipe. As a result, the temperature of the fluid in the temperature measurement container and the temperature of the fluid in the refrigerant pipe are close to each other. Therefore, the temperature measurement device can measure the temperature of the fluid in the refrigerant pipe with high accuracy by the temperature acquisition unit measuring the temperature of the fluid in the temperature measurement container. Therefore, according to the airtightness test device, the value of the pressure of the fluid can be accurately corrected based on the temperature obtained with high accuracy. Therefore, the accuracy of the airtightness test based on the pressure difference between the pressure of the fluid in the refrigerant pipe and the pressure of the fluid in the reference container is improved. [Brief description of the drawings]

[0014] [Figure 1] 1 is a block diagram showing a configuration example of an airtightness testing device according to a first embodiment. [Diagram 2] 1 is a schematic diagram showing a configuration example of a temperature measuring device according to a first embodiment. FIG. [Diagram 3] FIG. 2 is a schematic diagram showing an example of installation of an airtightness test device according to the first embodiment. [Figure 4] 5 is a flowchart illustrating a process flow in a first half of an airtight test according to the first embodiment. [Diagram 5] 10 is a flowchart illustrating a process flow in a latter half of an airtight test according to the first embodiment. [Figure 6] FIG. 11 is a schematic diagram showing an example of installation of an airtightness testing device according to the second embodiment. [Figure 7] FIG. 11 is a block diagram showing a configuration example of an airtightness testing device 200 according to a third embodiment. [Figure 8] FIG. 11 is a schematic diagram showing an example of installation of an airtightness testing device according to embodiment 3. [Figure 9] 13 is a flowchart illustrating a process flow of an airtight test according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an airtightness testing device according to an embodiment will be described in detail with reference to the drawings. Note that the size relationships of the components in the drawings may differ from the actual size relationships.

[0016] Embodiment 1 Fig. 1 is a block diagram showing a configuration example of an airtightness testing device according to embodiment 1. The airtightness testing device 100 is a device for testing the airtightness of refrigerant piping in an air conditioner, and includes a reference container 1, a differential pressure gauge 2, a temperature measuring device 3, an information collecting device 4, and a processing device 5. Note that in Fig. 1, the reference container 1, the differential pressure gauge 2, etc. are shown within a dashed line frame to facilitate understanding of the components included in the airtightness testing device 100, but these components are not necessarily arranged together in a single housing, etc.

[0017] The reference container 1 is an airtight container that does not leak a fluid such as nitrogen gas to the outside when the fluid is sealed inside. The reference container 1 in the first embodiment is assumed to have thermal insulation properties. In an airtight test using the airtightness test device 100, the airtightness of the refrigerant piping is confirmed based on the pressure of the fluid sealed in the refrigerant piping, which is based on the pressure of the fluid sealed inside the reference container 1.

[0018] The differential pressure gauge 2 is connected to each of the refrigerant piping and the reference container 1, and measures the differential pressure between the pressure of the fluid in the refrigerant piping and the pressure of the fluid in the reference container 1. In the following, the term "pressure" includes the value of pressure, and the term "differential pressure" includes the value of differential pressure. The temperature measuring device 3 measures the temperature of the fluid in the refrigerant piping.

[0019] The information collecting device 4 is, for example, a data logger, and collects the measurement results from the differential pressure gauge 2 and the temperature measuring device 3. The processing device 5 performs processing based on the data collected by the information collecting device 4.

[0020] Fig. 2 is a schematic diagram showing a configuration example of the temperature measuring device in the first embodiment. Fig. 3 is a schematic diagram showing an installation example of the airtightness test device according to the first embodiment. The temperature measuring device 3 has a temperature measuring container 30 and a temperature acquisition unit 31. The temperature measuring container 30 is a container capable of sealing a fluid therein, and forms the outer shell of the temperature measuring device 3. The temperature measuring container 30 is made of, for example, metal.

[0021] The temperature measurement container 30 is connected to the refrigerant piping 70 in the outdoor unit 7 by the inspection pipe 6, and the space inside the temperature measurement container 30 communicates with the space inside the refrigerant piping 70 via the inspection pipe 6. Therefore, when a fluid is sealed inside the refrigerant piping 70 or the temperature measurement container 30, the fluid can flow between the temperature measurement container 30 and the refrigerant piping 70.

[0022] The temperature measurement container 30 in the first embodiment satisfies either or both of the following conditions: the thermal diffusivity is equal to or greater than the thermal diffusivity of the refrigerant piping 70, and the thermal conductivity is equal to or greater than the thermal conductivity of the refrigerant piping 70. The material of the temperature measurement container 30 may be the same as the material of the refrigerant piping 70. For example, the material of the temperature measurement container 30 may be copper, which is widely used as the material of the refrigerant piping 70. The temperature measurement container 30 may be obtained by processing the refrigerant piping 70.

[0023] The heat capacity increases as the internal volume increases. In order to shorten the time it takes for heat from the outside to be transferred to the fluid in the temperature measurement container 30, it is desirable for the internal volume of the temperature measurement container 30 to be small. In the first embodiment, the internal volume of the temperature measurement container 30 is set to, for example, 50 cm 3 ] below.

[0024] The temperature measurement container 30 is provided with a piping side connection port 32 for connecting to the refrigerant piping 70. The piping side connection port 32 is formed, for example, by a flare-type female joint. An inspection pipe 6 is connected to the piping side connection port 32, and the temperature measurement container 30 is connected to the refrigerant piping 70 or a manifold bundling the refrigerant piping 70 via the inspection pipe 6 connected to the piping side connection port 32. This allows the space inside the temperature measurement container 30 to communicate with the space inside the refrigerant piping 70. In the first embodiment, a branching tool 8 such as a tee is provided to the piping side connection port 32, and the inspection pipe 6 is connected to the piping side connection port 32 via the branching tool 8.

[0025] The temperature measurement container 30 is provided with a fluid transfer connection port 33 for connecting to a fluid supply device 9. The fluid supply device 9 is, for example, a nitrogen cylinder, and is a device for supplying fluid into the refrigerant pipe 70 and the reference container 1. The fluid supply device 9 in the first embodiment is provided with a supply side valve (not shown), and when the supply side valve is opened, the fluid flows out of the fluid supply device 9 to the outside.

[0026] The fluid transfer connection port 33 is formed by, for example, a flare-type male joint. An inspection pipe 6 is connected to the fluid transfer connection port 33, and the temperature measurement container 30 is connected to the fluid supply device 9 via the inspection pipe 6 connected to the fluid transfer connection port 33. The refrigerant pipe 70 is connected to the fluid supply device 9 via the temperature measurement container 30.

[0027] A first valve 34 is installed at the fluid transfer connection port 33. In an open state, the first valve 34 allows the fluid flowing out from the fluid supply device 9 to flow into the temperature measurement container 30. This allows the temperature measurement container 30 and the refrigerant piping 70 to be filled with the fluid from the fluid supply device 9. In a closed state, the first valve 34 blocks the fluid flowing out from the fluid supply device 9 from flowing into the temperature measurement container 30. This prevents the fluid from the fluid supply device 9 from flowing into the temperature measurement container 30 and the refrigerant piping 70. The first valve 34 is preferably a valve having a stop valve, such as a packless valve.

[0028] The temperature measurement container 30 has pressure resistance capable of withstanding a pressure equal to or greater than a first pressure corresponding to a predetermined set filling amount when the refrigerant piping 70 is filled with the fluid. The set filling amount is the total amount of fluid filled into the refrigerant piping 70 in an airtightness test for checking the airtightness of the refrigerant piping 70. The set filling amount is determined in advance as an amount that ensures the pressure resistance of the refrigerant piping 70 for a time required to check the airtightness of the refrigerant piping 70 and reduces the amount of fluid used. The first pressure corresponding to the set filling amount is, for example, 2 [MPa].

[0029] The temperature measurement container 30 is provided with an exterior opening 35 that connects the space inside the temperature measurement container 30 with the exterior space, and the exterior opening 35 is provided with a sealant 36 that closes the exterior opening 35. The sealant 36 is capable of withstanding the filling of the temperature measurement container 30 with a high-pressure fluid equal to or higher than a first pressure. As the sealant 36, for example, a compression fitting is desirable.

[0030] The temperature acquiring unit 31 is disposed in the temperature measurement container 30 and measures the temperature of the fluid in the temperature measurement container 30. The temperature acquiring unit 31 in the first embodiment is provided in the sealing material 36. The temperature acquiring unit 31 is capable of withstanding the fact that the temperature measurement container 30 is filled with a high-pressure fluid of a first pressure or higher. As the temperature acquiring unit 31, a sheath-type thermocouple that is highly responsive and can withstand a high-pressure state for a long period of time is desirable.

[0031] A plurality of fins 37 are arranged inside the temperature measurement container 30. The plurality of fins 37 are made of, for example, aluminum. It is preferable that the plurality of fins 37 are arranged evenly spread out inside the temperature measurement container 30. The plurality of fins 37 can increase the surface area inside the temperature measurement container 30. This allows the temperature acquisition unit 31 to detect temperature changes of the fluid inside the temperature measurement container 30 with high sensitivity.

[0032] The temperature measuring device 3 is provided with a first mounting fixture 38. The first mounting fixture 38 is, for example, a mounting hook. The material of the first mounting fixture 38 is not limited, but it is desirable for it to be made of a durable material such as steel.

[0033] The temperature measuring device 3 is installed by the first mounting fixture 38 in the same environment as the installation environment of the outdoor unit 7. For example, the temperature measuring device 3 is installed by the first mounting fixture 38 at a position where the distance between the temperature measuring device 3 and the refrigerant piping 70 in the outdoor unit 7 is within a predetermined first distance. The first distance is, for example, 10 cm or more and 50 cm or less. In FIG. 3, the temperature measuring device 3 is shown outside the outdoor unit 7 to avoid cluttering the drawing, but in the first embodiment, the temperature measuring device 3 is installed inside the outdoor unit 7.

[0034] By installing the temperature measuring device 3 at a position close to the refrigerant piping 70 in the outdoor unit 7 and setting the thermal diffusivity of the temperature measuring container 30 to be equal to or higher than the thermal diffusivity of the refrigerant piping 70, the temperature of the fluid in the temperature measuring container 30 and the temperature of the fluid in the refrigerant piping 70 in the outdoor unit 7 can be made close to each other. Also, by installing the temperature measuring device 3 at a position close to the refrigerant piping 70 in the outdoor unit 7 and setting the thermal conductivity of the temperature measuring container 30 equal to the thermal conductivity of the refrigerant piping 70, the temperature of the fluid in the temperature measuring container 30 and the temperature of the fluid in the refrigerant piping 70 in the outdoor unit 7 can be made close to each other. Therefore, by the temperature acquiring unit 31 measuring the temperature of the fluid in the temperature measuring container 30, the temperature measuring device 3 can measure the temperature of the fluid in the refrigerant piping 70 with high accuracy.

[0035] The temperature acquiring unit 31 is connected to the information collecting device 4 via the first signal line 14, and transmits the measured temperature to the information collecting device 4. Note that the temperature acquiring unit 31 may perform wireless communication with the information collecting device 4 instead of wired communication via the first signal line 14, and may transmit the measured temperature to the information collecting device 4 via wireless communication.

[0036] The differential pressure gauge 2 is connected to two joints in the refrigerant piping 70 via the inspection pipe 6 and the guide device 10. In the first embodiment, one of the two joints is provided on the discharge side of a compressor (not shown) in the outdoor unit 7, and the other is provided on the suction side of the compressor. In the following, the joint provided on the discharge side of the compressor may be referred to as a high-pressure joint 71. In the following, the joint provided on the suction side of the compressor may be referred to as a low-pressure joint 72. The inspection pipe 6 connecting the differential pressure gauge 2 to the two joints is branched into two on the side connected to the two joints. The fluid in each of the high-pressure joint 71 and the low-pressure joint 72 flows to the differential pressure gauge 2 through the inspection pipe 6. At this time, the fluid from each of the high-pressure joint 71 and the low-pressure joint 72 merges in the inspection pipe 6, which is a single pipe on the side of the differential pressure gauge 2, and flows to the differential pressure gauge 2.

[0037] The differential pressure gauge 2 is connected to the reference container 1 via an inspection tube 6 and a guiding device 10. This allows the fluid in the reference container 1 to flow to the differential pressure gauge 2.

[0038] The guiding device 10 includes a branch pipe 11, a second valve 12, and a third valve 13. The branch pipe 11 connects the following two inspection pipes 6. One of the two inspection pipes 6 is an inspection pipe 6 that connects the differential pressure gauge 2 to each of the high pressure joint 71 and the low pressure joint 72. The other is an inspection pipe 6 that connects the differential pressure gauge 2 to the reference container 1. In FIG. 3, the branch pipe 11 is indicated by a dashed line to distinguish it from the inspection pipe 6.

[0039] The second valve 12 is provided on the inspection pipe 6 connecting the differential pressure gauge 2 to each of the high pressure joint 71 and the low pressure joint 72, and on the branch pipe 11. In the open state, the second valve 12 allows the fluid from the refrigerant pipe 70 at the high pressure joint 71 and the low pressure joint 72 to flow to the branch pipe 11. In the first embodiment, in the open state, the second valve 12 allows the fluid from the refrigerant pipe 70 at the high pressure joint 71 and the low pressure joint 72 to flow to the differential pressure gauge 2. However, in the open state, the second valve 12 may block the flow of the fluid from the refrigerant pipe 70 at the high pressure joint 71 and the low pressure joint 72 to the differential pressure gauge 2. In the closed state, the second valve 12 blocks the flow of the fluid from the refrigerant pipe 70 at the high pressure joint 71 and the low pressure joint 72 to the branch pipe 11. In addition, in the closed state, the second valve 12 allows the fluid from the inside of the refrigerant pipe 70 at the high pressure joint 71 and the low pressure joint 72 to flow to the differential pressure gauge 2.

[0040] The third valve 13 is provided in the inspection pipe 6 connecting the differential pressure gauge 2 and the reference container 1, and in the branch pipe 11. In the open state, the third valve 13 allows the fluid from inside the reference container 1 to flow to the branch pipe 11. In the first embodiment, in the open state, the third valve 13 allows the fluid from inside the reference container 1 to flow to the differential pressure gauge 2. However, in the open state, the third valve 13 may block the flow of the fluid from inside the reference container 1 to the differential pressure gauge 2. In the closed state, the third valve 13 blocks the flow of the fluid from inside the reference container 1 to the branch pipe 11. In addition, in the closed state, the third valve 13 allows the fluid from inside the reference container 1 to flow to the differential pressure gauge 2.

[0041] When the second valve 12 and the third valve 13 are in an open state, the inside of the refrigerant pipe 70 and the inside of the reference container 1 are communicated with each other, and fluid flows between the refrigerant pipe 70 and the reference container 1. When the second valve 12 and the third valve 13 are in a closed state, fluid does not flow between the refrigerant pipe 70 and the reference container 1.

[0042] In the first embodiment, the differential pressure gauge 2 is connected to the high pressure joint 71 and the low pressure joint 72 via the branching tool 8 provided at the piping side connection port 32 of the temperature measurement container 30. This connects the temperature measurement container 30, the refrigerant piping 70, and the differential pressure gauge 2. The second valve 12 in the guiding device 10 is located between the differential pressure gauge 2 and the branching tool 8.

[0043] When the first valve 34, the second valve 12, and the third valve 13 are in an open state, the fluid flowing out from the fluid supply device 9 flows into the temperature measurement container 30, the refrigerant piping 70, and the reference container 1. As a result, the temperature measurement container 30, the refrigerant piping 70, and the reference container 1 are filled with the fluid.

[0044] The differential pressure gauge 2 measures the differential pressure between the pressure of the fluid in the refrigerant pipe 70 and the pressure of the fluid in the reference container 1 after the temperature measurement container 30, the refrigerant pipe 70, and the reference container 1 are filled with fluid and the pressures are equalized. The differential pressure gauge 2 is connected to the information collecting device 4 by a second signal line 15, and transmits the measured differential pressure to the information collecting device 4. Note that the differential pressure gauge 2 may perform wireless communication with the information collecting device 4 instead of wired communication via the second signal line 15, and may transmit the measured differential pressure to the information collecting device 4 by wireless communication.

[0045] The information collecting device 4 stores the measurement results received from each of the temperature measuring device 3 and the differential pressure gauge 2. The information collecting device 4 communicates with the processing device 5 via a third signal line 16. Note that the information collecting device 4 may perform wireless communication with the processing device 5 instead of wired communication via the third signal line 16.

[0046] The processing device 5 receives the information stored in the information collecting device 4 and performs processing using the received information. The processing device 5 and the information collecting device 4 may be integrated together.

[0047] The processing device 5 judges whether or not there is leakage of the fluid from the refrigerant pipe 70 based on the measurement result of the differential pressure gauge 2. The judgment of whether or not there is leakage of the fluid from the refrigerant pipe 70 is performed as follows. After the supply side valve, the first valve 34, the second valve 12, and the third valve 13 are opened and the refrigerant pipe 70 and the reference container 1 are filled with the fluid, the supply side valve is closed and the pressure of the fluid in the refrigerant pipe 70 and the reference container 1 is equalized. After the pressure is equalized, the second valve 12, the third valve 13, etc. are closed. The processing device 5 judges whether or not there is leakage of the fluid from the refrigerant pipe 70 based on the differential pressure measured by the differential pressure gauge 2 after the test time has elapsed from the time when the pressure of the fluid in the refrigerant pipe 70 and the reference container 1 is equalized. The test time is a time set for the airtight test, and is, for example, within 3 hours. The judgment of whether or not there is leakage of the fluid from the refrigerant pipe 70 may be performed by a test operator based on the measurement result of the differential pressure gauge 2 instead of the processing device 5.

[0048] The processing device 5 may perform a time measurement process to determine whether or not the test time has elapsed. The processing device 5 may control at least one of the first valve 34, the second valve 12, the third valve 13, and the supply-side valve, and control the opening degree of the valve. In this case, the processing device 5 may be connected to the valve to be controlled by a control line (not shown) and control the opening degree of the valve by transmitting a control signal to the valve to be controlled. Alternatively, the processing device 5 may transmit a control signal to the valve to be controlled by wireless communication, and control the opening degree of the valve.

[0049] The processing device 5 can be configured with a processor such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit), a memory such as a ROM (Read Only Memory) or RAM (Random Access Memory), a communication interface circuit, and a bus connecting them. When the processing device 5 is configured to perform a timekeeping process, it may include a timekeeping device such as an RTC (Real Time Clock), or may include a communication interface circuit for receiving information indicating the time from the outside. Alternatively, the processing device 5 may perform the timekeeping process by software processing using a processor and a memory. The processing device 5 may have hardware such as a CPLD (Complex Programmable Logic Device) or an FPGA (Field Programmable Gate Array) instead of or in addition to a processor and a memory.

[0050] A pressure measuring device 17 for measuring the pressure of the fluid in the refrigerant pipe 70 is provided on the inspection pipe 6 connecting the differential pressure gauge 2 to the high pressure joint 71 and the low pressure joint 72. The pressure measuring device 17 is provided at a position after the merging of the fluid from each of the high pressure joint 71 and the low pressure joint 72. The pressure measuring device 17 is, for example, a gauge manifold. The pressure measuring device 17 measures the pressure of the fluid when the refrigerant pipe 70 is filled with the fluid. The pressure measuring device 17 may be removed after measuring the pressure.

[0051] The processing device 5 acquires the measurement results from the pressure measuring device 17 via a signal line (not shown) or by wireless communication. Note that a test operator may acquire the measurement results by the pressure measuring device 17 instead of the processing device 5. The processing device 5 or the test operator may acquire the measurement results by the pressure measuring device 17 via the information collecting device 4. In this case, the information collecting device 4 acquires the measurement results from the pressure measuring device 17 via a signal line (not shown) or by wireless communication.

[0052] The differential pressure gauge 2 is provided with a second mounting fixture 20. The second mounting fixture 20 is, for example, a mounting hook. The material of the second mounting fixture 20 is not limited, but it is preferable that the second mounting fixture 20 is made of a durable material such as steel. The differential pressure gauge 2 is installed, for example, on an installation target inside or outside the outdoor unit 7 by the second mounting fixture 20. In FIG. 3, the differential pressure gauge 2 is shown outside the outdoor unit 7 to prevent the drawing from becoming too complicated, but in the first embodiment, the differential pressure gauge 2 is installed inside the outdoor unit 7 together with the temperature measuring device 3.

[0053] Next, the process of the airtight test using the airtight test device 100 according to the embodiment 1 will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a flow chart illustrating the process flow in the first half of the airtight test according to the embodiment 1. Fig. 5 is a flow chart illustrating the process flow in the second half of the airtight test according to the embodiment 1.

[0054] In step S1, the first valve 34, the second valve 12, and the third valve 13 are opened under the control of the processing device 5 or manually by the test operator. At this time, the supply side valve of the fluid supply device 9 is also opened under the control of the processing device 5 or manually by the test operator. When the first valve 34, the second valve 12, the third valve 13, and the supply side valve are opened, the fluid flows out from the fluid supply device 9, and the flowing out fluid flows into the refrigerant pipe 70, the reference container 1, etc. That is, the refrigerant pipe 70, the reference container 1, etc. are filled with the fluid.

[0055] In step S2, the processing device 5 or the test operator determines whether the amount of fluid filled in the refrigerant pipe 70 has reached a predetermined set filling amount. In the first embodiment, the processing device 5 or the test operator determines whether the amount of fluid filled in the refrigerant pipe 70 has reached the set filling amount by determining whether the pressure measured by the pressure measuring device 17 has reached the first pressure.

[0056] If the amount of fluid filled in the refrigerant pipe 70 is less than the set filling amount (step S2: NO), the process in the airtightness test remains at step S2. If the amount of fluid filled in the refrigerant pipe 70 reaches the set filling amount (step S2: YES), in step S3, the supply side valve is closed under the control of the processing device 5 or manually by a test operator. At this time, the first valve 34 may also be closed under the control of the processing device 5 or manually by a test operator.

[0057] In step S4, the fluids in the refrigerant pipe 70, the temperature measurement container 30, the reference container 1, etc. are equalized for a pressure equalization time. The pressure equalization time is the time until the pressures of the fluids in the refrigerant pipe 70, the temperature measurement container 30, the reference container 1, etc. become uniform, and is determined in advance by experiments, etc. The pressure equalization time is, for example, 10 minutes.

[0058] In step S5, the processing device 5 acquires the measurement result of the pressure of the fluid in the refrigerant pipe 70 after pressure equalization from the pressure measuring device 17. Note that a test worker may acquire the measurement result instead of the processing device 5. Hereinafter, the pressure of the fluid in the refrigerant pipe 70 after pressure equalization acquired in step S5 may be referred to as an initial pressure P1. Note that the processing device 5 or the test worker may acquire the measurement result by the pressure measuring device 17 via the information collecting device 4. In this case, the information collecting device 4 may be powered on in step S5 and start collecting various information.

[0059] In step S6, the processing device 5 or the test operator acquires the temperature measured by the temperature measuring device 3 after pressure equalization from the information collecting device 4. Hereinafter, the temperature acquired in step S6 may be referred to as the initial temperature T1. The processes in steps S5 and S6 may be executed in reverse order or in parallel. The information collecting device 4 may be powered on in step S6 and start collecting various information.

[0060] In step S7, the first valve 34, the second valve 12, and the third valve 13 are closed under the control of the processing device 5 or by manual processing by the test operator. When the first valve 34 is closed together with the supply side valve in step S3, the second valve 12 and the third valve 13 are closed in step S7 under the control of the processing device 5 or by manual processing by the test operator. The flow of fluid between the refrigerant piping 70 and the reference container 1 is blocked by the processing of step S7.

[0061] In step S8, the differential pressure gauge 2 starts measuring the differential pressure between the pressure of the fluid in the refrigerant piping 70 and the pressure of the fluid in the reference container 1. Hereinafter, the differential pressure measured by the differential pressure gauge 2 may be referred to as differential pressure ΔP. Note that, below, the differential pressure ΔP is defined as the difference between the pressure of the fluid in the refrigerant piping 70 and the pressure of the fluid in the reference container 1. The information collecting device 4 acquires the measured differential pressure ΔP from the differential pressure gauge 2.

[0062] In step S9, the processing device 5 or the test operator determines whether or not the test time has elapsed since the processing of step S7. If the test time has not elapsed (step S9: NO), the processing of the airtight test remains in step S9. If the test time has elapsed (step S9: YES), in step S10, the processing device 5 or the test operator acquires the temperature measured by the temperature measuring device 3 at the end of the test time from the information collecting device 4. Hereinafter, the temperature acquired in step S10 may be referred to as the end temperature T2.

[0063] In step S11, the processing device 5 or the test operator acquires the differential pressure ΔP measured by the differential pressure gauge 2 at the end of the test time via the information collecting device 4. The processes in steps S10 and S11 may be executed in the reverse order or in parallel.

[0064] Instead of step S8, the differential pressure gauge 2 may start measuring the differential pressure at the end of the test time, such as step S10 or step S11. In this case, the process of step S8 is omitted. However, by having the differential pressure gauge 2 start measuring the differential pressure in step S8, the test operator can check the differential pressure during the test time.

[0065] In step S12, the processor 5 uses the initial pressure P1, the initial temperature T1 and the final temperature T2 to calculate the final pressure P2, which is the pressure of the fluid in the refrigerant pipe 70 after the test time, based on the following formula (1). P2={(T2+273.15) / (T1+273.15)}×P1 (1)

[0066] When the test operator acquires the initial pressure P1, the initial temperature T1, and the final temperature T2 in each of steps S5, S6, and S10, the test operator inputs the initial pressure P1, the initial temperature T1, and the final temperature T2 into the processing device 5 prior to the processing of step S12. Alternatively, the calculation processing of step S12 may be performed by the test operator.

[0067] The following describes formula (1). The deviation of the final pressure P2 from the initial pressure P1 is the theoretical fluctuation value of the pressure of the fluid due to the temperature change. Here, the initial pressure P1 is equal to the pressure of the fluid in the reference container 1 at the start of the test time. Therefore, the deviation of the final pressure P2 from the initial pressure P1 is the theoretical fluctuation value of the pressure in the refrigerant piping 70 based on the pressure of the fluid in the reference container 1 at the start of the test time. If the fluid in the reference container 1 is not easily affected by changes in the outside air temperature, the pressure of the fluid in the reference container 1 at the end of the test time can be considered to be equal to the initial pressure P1. Then, the deviation of the final pressure P2 from the initial pressure P1 can be considered to be the theoretical value of the differential pressure between the pressure of the fluid in the refrigerant piping 70 at the end of the test time and the pressure of the fluid in the reference container 1 at the end of the test time. In the first embodiment, as described above, the reference container 1 has thermal insulation, so the pressure of the fluid in the reference container 1 at the end of the test time can be considered to be equal to the initial pressure P1. Therefore, the deviation of the final pressure P2 from the initial pressure P1 can be regarded as the theoretical value of the pressure difference between the fluid pressure in the refrigerant piping 70 at the end of the test time and the fluid pressure in the reference container 1 at the end of the test time.

[0068] In step S13, the processing device 5 judges whether or not the magnitude of {ΔP-(P2-P1)} is greater than the first threshold value α. That is, the processing device 5 judges whether or not the following formula (2) is satisfied. Note that |ΔP-(P2-P1)| in formula (2) is the absolute value of {ΔP-(P2-P1)}. Also, ΔP in formula (2) is the differential pressure measured by the differential pressure gauge 2 at the end of the test time. |ΔP-(P2-P1)|>α (2)

[0069] The first threshold value α is determined in advance through experiments or the like as a value greater than 0 to prevent erroneous determination that fluid is leaking within an allowable error range. If the magnitude of {ΔP-(P2-P1)} is greater than the first threshold value α (step S13: YES), in step S14, the processing device 5 or the test operator determines that fluid is leaking from the refrigerant piping 70. After the process of step S14, the process of step S17 is executed.

[0070] If the magnitude of {ΔP-(P2-P1)} is equal to or smaller than the first threshold value α (step S13: NO), in step S15, the processing device 5 or the test operator determines whether or not a total test time has elapsed since the processing of step S7. The total test time is, for example, 3 hours. If the total test time has not elapsed (step S15: NO), the processing returns to step S10. In this case, after a predetermined waiting time has elapsed from the time when the processing of step S15 was performed, the processing returns to step S10. The waiting time is, for example, 1 to 30 minutes. When the processing returns to step S10 after the waiting time has elapsed, the test time is the original test time plus the waiting time.

[0071] If the test time is equal to or longer than the total test time (step S15: YES), in step S16, the processing device 5 or the test operator determines that no fluid is leaking from the refrigerant piping 70. After the process of step S16, the process of step S17 is executed.

[0072] In step S17, the fluid is discharged from the refrigerant pipes 70, etc. Discharging the fluid is performed, for example, by removing the inspection pipe 6 connected to the fluid delivery connection port 33 from the fluid supply device 9 and opening the first valve 34. After the process of step S17, the airtightness test process ends.

[0073] In the above step S5, the case where the processing device 5 or the test operator acquires the initial pressure P1 via the information collecting device 4 has been described, but the processing performed in step S5 may be up to the processing where the information collecting device 4 acquires the initial pressure P1 from the pressure measuring device 17. The processing device 5 or the test operator may acquire the initial pressure P1 from the information collecting device 4 after step S5 and before step S12.

[0074] In the above step S6, the processing device 5 or the test operator acquires the initial temperature T1 from the temperature acquisition unit 31 via the information collecting device 4, but the process performed in step S6 may be a process in which the information collecting device 4 collects the initial temperature T1 from the temperature acquisition unit 31. The processing device 5 or the test operator may acquire the initial temperature T1 from the information collecting device 4 after step S6 and before step S12.

[0075] In the above step S10, the processing device 5 or the test operator acquires the end temperature T2 from the temperature acquisition unit 31 via the information collecting device 4, but the process performed in step S10 may be a process in which the information collecting device 4 collects the end temperature T2 from the temperature acquisition unit 31. The processing device 5 or the test operator may acquire the end temperature T2 from the information collecting device 4 after step S10 and before step S12.

[0076] In the above step S13, the determination as to whether |ΔP-(P2-P1)| is greater than the first threshold value α is performed by the processing device 5, but the determination may be performed by a test operator instead of the processing device 5. In this case, the test operator may obtain the initial pressure P1 and the differential pressure ΔP in each of steps S5 and S11, and calculate the final pressure P2 in step S12. In the case where the test operator obtains the differential pressure ΔP in the above step S11 and the processing device 5 performs the determination in step S13, the test operator inputs the differential pressure ΔP to the processing device 5 prior to step S13.

[0077] The effects of the airtightness test device 100 according to the first embodiment will be described below. The airtightness test device 100 is for testing the airtightness of the refrigerant pipe 70 in an air conditioner. The airtightness test device 100 includes a differential pressure gauge 2 and a temperature measurement device 3. The differential pressure gauge 2 measures a differential pressure, which is a difference between the pressures of the fluids filled in the refrigerant pipe 70 and the reference container 1. The reference container 1 is airtight. The temperature measurement device 3 is connected to the refrigerant pipe 70 and measures the temperature of the fluid in the refrigerant pipe 70. The temperature measurement device 3 includes a temperature measurement container 30 and a temperature acquisition unit 31. The temperature measurement container 30 communicates with the refrigerant pipe 70 and can enclose a fluid therein. The temperature acquisition unit 31 is installed in the temperature measurement container 30 and measures the temperature of the fluid. The temperature measurement container 30 satisfies either or both of the conditions that the thermal diffusivity is equal to or greater than the thermal diffusivity of the refrigerant piping 70 and that the thermal conductivity is equal to or greater than the thermal conductivity of the refrigerant piping 70.

[0078] According to the above configuration, the speed of the temperature change of the temperature measurement container 30 accompanying the temperature change of the outside air is equal to or faster than the temperature change of the refrigerant pipe 70 accompanying the temperature change of the outside air. Therefore, when the temperature of the outside air changes, the temperature of the fluid in the temperature measurement container 30 changes at a speed equal to or faster than the temperature change of the fluid in the refrigerant pipe 70. This suppresses the delay in the change of the temperature of the fluid in the temperature measurement container 30 relative to the change of the temperature of the fluid in the refrigerant pipe 70, and the temperature of the fluid in the refrigerant pipe 70 and the temperature of the fluid in the temperature measurement container 30 become close to each other. Therefore, the temperature measurement device 3 can measure the temperature of the fluid in the refrigerant pipe 70 with high accuracy. The differential pressure ΔP measured by the differential pressure gauge 2 depends on the temperature change of the fluid in the refrigerant pipe 70, but according to the airtightness test using the airtightness test device 100 according to the first embodiment, the temperature of the fluid obtained with high accuracy is used together with the differential pressure ΔP, so that the accuracy of the judgment of the airtightness is improved.

[0079] The temperature measuring device 3 in the first embodiment is installed in the same environment as the installation environment of the outdoor unit 7 of the air conditioner. Since the outdoor temperature often fluctuates greatly compared to the indoor temperature, the temperature of the fluid in the refrigerant piping 70 may fluctuate due to changes in the air temperature in the installation environment of the outdoor unit 7. In the first embodiment, since the temperature measuring device 3 is installed in the same environment as the installation environment of the outdoor unit 7, the temperature of the fluid in the temperature measurement container 30 approaches the temperature of the fluid in the refrigerant piping 70 in the outdoor unit 7. Therefore, the temperature measuring device 3 can measure with high accuracy the temperature of the fluid in the refrigerant piping 70 in the outdoor unit 7, which affects the differential pressure ΔP. Therefore, according to the airtightness test by the airtightness test device 100 in the first embodiment, the temperature of the fluid in the outdoor unit 7 obtained with high accuracy is used together with the differential pressure ΔP, so that the accuracy of the judgment on the airtightness is improved.

[0080] The temperature measuring device 3 in the first embodiment is installed in the outdoor unit 7. Here, since the outdoor temperature often fluctuates greatly compared to the indoor air temperature, the temperature change of the fluid in the refrigerant piping 70 is considered to be due to the temperature change in the outdoor unit 7 rather than the temperature change in the indoor unit. In the first embodiment, since the temperature measuring device 3 is placed in an environment similar to the installation environment of the refrigerant piping 70 in the outdoor unit 7, the temperature of the fluid in the temperature measurement container 30 approaches the temperature of the fluid in the refrigerant piping 70 in the outdoor unit 7. Therefore, the temperature measuring device 3 can measure with high accuracy the temperature of the fluid in the refrigerant piping 70 in the outdoor unit 7, which affects the differential pressure ΔP. Therefore, according to the airtightness test by the airtightness test device 100 according to the first embodiment, the temperature of the fluid in the outdoor unit 7 obtained with high accuracy is used together with the differential pressure ΔP, so that the accuracy of the judgment on the airtightness is improved.

[0081] The temperature measurement container 30 in the first embodiment is provided with a plurality of fins 37 inside. This increases the surface area inside the temperature measurement container 30. This promotes heat exchange between the fluid in the temperature measurement container 30 and the outside air. Therefore, when the temperature of the outside air changes, the delay in the change in temperature of the fluid in the temperature measurement container 30 relative to the change in temperature of the fluid in the refrigerant pipe 70 is suppressed. Therefore, the temperature of the fluid in the refrigerant pipe 70 and the temperature of the fluid in the temperature measurement container 30 become close to each other. This allows the temperature measuring device 3 to measure the temperature of the fluid in the refrigerant pipe 70 with high accuracy, improving the accuracy of the airtightness test.

[0082] The material of the temperature measurement container 30 in the first embodiment is the same as the material of the refrigerant piping 70. This makes the effect of the outside air temperature on the temperature of the fluid in the temperature measurement container 30 equal to the effect of the outside air temperature on the temperature of the fluid in the refrigerant piping 70. Therefore, the temperature of the fluid in the temperature measurement container 30 approaches the temperature of the fluid in the refrigerant piping 70 in the outdoor unit 7. Therefore, the temperature measuring device 3 can measure the temperature of the fluid in the refrigerant piping 70 with high accuracy, improving the accuracy of the airtightness test.

[0083] The temperature measurement container 30 in the first embodiment is obtained by processing the refrigerant piping 70. As a result, the influence of the outside air temperature on the temperature of the fluid in the temperature measurement container 30 and the influence of the outside air temperature on the temperature of the fluid in the refrigerant piping 70 become equal. Therefore, the temperature of the fluid in the temperature measurement container 30 approaches the temperature of the fluid in the refrigerant piping 70 in the outdoor unit 7. Therefore, the temperature measuring device 3 can measure the temperature of the fluid in the refrigerant piping 70 with high accuracy, improving the accuracy of the airtightness test.

[0084] The internal volume of the temperature measurement container 30 in the first embodiment is 50 cm 3] or less. This makes it possible to shorten the time it takes for heat to be transferred from the outside to the fluid in the temperature measurement container 30. This makes it possible to suppress a delay in the change in temperature of the fluid in the temperature measurement container 30 relative to the change in temperature of the fluid in the refrigerant piping 70. Therefore, the temperature measurement device 3 can measure the temperature of the fluid in the refrigerant piping 70 with high accuracy by the temperature acquisition unit 31 measuring the temperature of the fluid in the temperature measurement container 30. This improves the accuracy of the airtightness test.

[0085] The differential pressure gauge 2 in the first embodiment is connected to each of the refrigerant pipe 70 and the reference container 1. This allows the differential pressure gauge 2 to measure the differential pressure ΔP between the pressure of the fluid in the refrigerant pipe 70 and the pressure of the fluid in the reference container 1.

[0086] The temperature measurement container 30 in the first embodiment is provided with an external opening 35 that communicates the space inside the temperature measurement container 30 with the external space, and a seal material 36 that closes the external opening 35. The temperature measurement container 30 and the seal material 36 have a pressure resistance of at least a first pressure corresponding to the set filling amount of the fluid in the refrigerant pipe 70. The temperature acquisition unit 31 is installed in the seal material 36. This reduces the possibility of damage to the temperature measurement container 30 and the seal material 36 when the refrigerant pipe 70 is filled with a set filling amount of fluid while the inside of the refrigerant pipe 70 is in communication with the inside of the temperature measurement container 30. In addition, since the seal material 36 is not damaged, a state of isolation between the outside and the inside of the temperature measurement container 30 is maintained, so that the temperature acquisition unit 31 can measure the temperature of the fluid in the refrigerant pipe 70 with high accuracy by measuring the temperature of the fluid in the temperature measurement container 30. This improves the accuracy of the airtightness test.

[0087] The first pressure in the first embodiment is 2 [MPa]. This ensures the pressure resistance of the refrigerant pipes 70 during the test period, and reduces the amount of fluid used.

[0088] The temperature measurement container 30 in the first embodiment is provided with a fluid transfer connection port 33 for allowing the fluid flowing out of the fluid supply device 9 for supplying the fluid to the refrigerant pipe 70 to flow into the temperature measurement container 30. This allows the temperature measurement container 30 to be filled with fluid as well as the refrigerant pipe 70.

[0089] In the temperature measuring device 3 in the first embodiment, a first valve 34 that allows the fluid to flow in an open state and blocks the flow of the fluid in a closed state is provided at the fluid supply / reception connection port 33. By opening the first valve 34, the fluid can be supplied to the refrigerant pipe 70. In addition, by closing the first valve 34, the inflow of an excessive amount of fluid into the refrigerant pipe 70 that may cause damage to the refrigerant pipe 70 can be suppressed.

[0090] The airtightness test device 100 according to the first embodiment further includes a pressure measuring device 17, a guide device 10, and a processing device 5. The pressure measuring device 17 measures the pressure of the fluid in the refrigerant pipe 70. The guide device 10 allows the fluid to flow between the refrigerant pipe 70 and the reference container 1 before the start of the test time, and blocks the flow of the fluid between the refrigerant pipe 70 and the reference container 1 after the start of the test time. The processing device 5 determines whether or not the fluid is leaking from the refrigerant pipe 70 based on the differential pressure ΔP measured by the differential pressure gauge 2 at the end of the test time, the initial pressure P1 measured by the pressure measuring device 17 at the start of the test time, the initial temperature T1 measured by the temperature measuring device 3 at the start of the test time, and the final temperature T2 measured by the temperature measuring device 3 at the end of the test time. This automates the process of determining whether or not the fluid is leaking from the refrigerant pipe 70, thereby reducing the labor of the test operator. Furthermore, according to the above configuration, at the start of the test time, the initial pressure P1 of the fluid in the refrigerant piping 70 and the pressure of the fluid in the reference container 1 are equal. Then, at the end of the test time, it becomes possible to determine whether or not there is leakage of the fluid from the refrigerant piping 70 from the differential pressure ΔP measured by the differential pressure gauge 2. Also, the temperature measuring device 3 obtains a fluctuation value of the temperature of the fluid in the refrigerant piping 70 before and after the test time, and thereby obtains a fluctuation value of the pressure of the fluid in the refrigerant piping 70. Although the differential pressure ΔP measured by the differential pressure gauge 2 is affected by the fluctuation of the pressure, the processing device 5 determines whether or not there is leakage using the fluctuation value of the pressure together with the differential pressure ΔP measured by the differential pressure gauge 2, thereby improving the accuracy of the airtightness test.

[0091] The processing device 5 in the first embodiment calculates the final pressure P2 of the fluid in the refrigerant pipe 70 at the end time based on the initial pressure P1, the initial temperature T1, and the end temperature T2. The processing device 5 determines whether or not the fluid is leaking from the refrigerant pipe 70 based on the difference between the initial pressure P1 and the final pressure P2 and the differential pressure ΔP measured by the differential pressure gauge 2 at the end time. According to the above configuration, the processing device 5 calculates the final pressure P2 based on the initial pressure P1, the initial temperature T1, and the end temperature T2, and calculates the difference between the initial pressure P1 and the final pressure P2, thereby obtaining a theoretical fluctuation value of the pressure during the test time. Although the differential pressure ΔP measured by the differential pressure gauge 2 is affected by the fluctuation of the pressure, the processing device 5 uses the fluctuation value of the pressure together with the differential pressure ΔP measured by the differential pressure gauge 2, and therefore can determine whether or not the fluid is leaking from the refrigerant pipe 70 with high accuracy.

[0092] The reference container 1 in the first embodiment has thermal insulation properties. The processing device 5 determines that the fluid is leaking when the magnitude of the difference between the differential pressure ΔP, which is the difference between the pressure of the fluid in the refrigerant pipe 70 from the pressure of the fluid in the reference container 1, and the difference between the final pressure P2 from the initial pressure P1 is greater than a first threshold value α that is determined in advance. The differential pressure ΔP is measured at the end of the test time. According to the above configuration, at the start of the test time, the initial pressure P1 of the fluid in the refrigerant pipe 70 and the pressure of the fluid in the reference container 1 are equal. In addition, since the temperature of the fluid in the reference container 1 is constant before and after the test time, the pressure of the fluid in the reference container 1 at the end of the test time is considered to be equal to the initial pressure P1. Therefore, the difference between the initial pressure P1 and the final pressure P2 is equal to the theoretical value of the difference between the pressure of the fluid in the refrigerant pipe 70 from the pressure of the fluid in the reference container 1 at the end of the test time. When the differential pressure ΔP measured at the end of the test time differs from the difference between the initial pressure P1 and the final pressure P2 by more than the first threshold value α, it is considered that the fluid is leaking from the refrigerant pipe 70 and the pressure of the fluid in the refrigerant pipe 70 is decreasing. Therefore, by using the airtightness testing device 100 according to the first embodiment, it is possible to check the airtightness of the refrigerant pipe 70 with high accuracy.

[0093] The temperature measuring device 3 in the first embodiment is provided with a first mounting fixture 38 for detachably mounting the temperature measuring device 3 to an installation target in the outdoor unit 7. This allows the temperature measuring device 3 to be mounted in the outdoor unit 7, in an environment that is the same as the installation environment of the refrigerant piping 70, during an airtightness test. Therefore, the state of the fluid in the temperature measurement container 30 becomes equal to the state of the fluid in the refrigerant piping 70, and the temperature measuring device 3 can measure the temperature of the fluid in the refrigerant piping 70 with high accuracy. This improves the accuracy of the airtightness test.

[0094] The temperature measurement container 30 in the first embodiment is provided with a piping side connection port 32 for communicating with the refrigerant piping 70. This allows communication between the inside of the temperature measurement container 30 and the inside of the refrigerant piping 70. Therefore, the state of the fluid in the temperature measurement container 30 can be made the same as the state of the fluid in the refrigerant piping 70. Therefore, the temperature measurement device 3 can measure the temperature of the fluid in the refrigerant piping 70 by measuring the temperature of the fluid in the temperature measurement container 30.

[0095] A branching tool 8 is provided at the piping side connection port 32 of the temperature measurement container 30 in the first embodiment. The branching tool 8 connects the inspection pipe 6 connected to the differential pressure gauge 2 and the inspection pipe 6 connected to the refrigerant piping 70 to the temperature measurement container 30. This allows the differential pressure gauge 2 and the temperature measurement device 3 to be connected to the refrigerant piping 70 together.

[0096] The differential pressure gauge 2 in the first embodiment is provided with a second mounting fixture 20 for detachably mounting the differential pressure gauge 2 to an installation target within the outdoor unit 7. This allows the differential pressure gauge 2 to be installed together with the temperature measuring device 3 within the outdoor unit 7. Also, the inspection pipe 6 connecting the differential pressure gauge 2 and the refrigerant piping 70 can be shortened.

[0097] Embodiment 2 In the first embodiment, the temperature measuring device 3 and the differential pressure gauge 2 are installed in the outdoor unit 7, but depending on the model of the air conditioner, the outdoor unit 7 may be narrow and may not be able to accommodate them in the outdoor unit 7. In the airtightness test device 100 according to the second embodiment, the temperature measuring device 3 is installed in the outdoor unit 7 and the differential pressure gauge 2 is installed outside the outdoor unit 7. The airtightness test device 100 according to the second embodiment will be described below. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals. In the second embodiment, the same components as those in the first embodiment and the same functions as those in the first embodiment will not be described unless there are special circumstances.

[0098] Fig. 6 is a schematic diagram showing an example of installation of an airtightness test apparatus according to embodiment 2. The configuration included in the airtightness test apparatus 100 according to embodiment 2 is illustrated in Fig. 1, similarly to embodiment 1. As in embodiment 1, the temperature measuring device 3 is installed by a first mounting fixture 38 at a position inside the outdoor unit 7, within a first distance from the refrigerant pipe 70. Meanwhile, the differential pressure gauge 2 is attached to the outside of the outdoor unit 7 via a second mounting fixture 20.

[0099] The differential pressure gauge 2 in the second embodiment is connected to the refrigerant pipe 70 without the temperature measuring device 3. The differential pressure gauge 2 is connected to each of the high pressure joint 71 and the low pressure joint 72 by the inspection pipe 6. The inspection pipe 6 on the refrigerant pipe 70 side is branched into two, one connected to the high pressure joint 71 and the other connected to the low pressure joint 72. The inspection pipe 6 on the differential pressure gauge 2 side is a single pipe, and the fluids from the high pressure joint 71 side and the low pressure joint 72 side join in the inspection pipe 6 on the differential pressure gauge 2 side. The second valve 12 and the above-mentioned pressure measuring device 17 are provided in the inspection pipe 6 on the differential pressure gauge 2 side. The pressure measuring device 17 is provided between the second valve 12 and the refrigerant pipe 70.

[0100] The temperature measuring device 3 is connected to the refrigerant piping 70 by the inspection tube 6. At this time, one end of the inspection tube 6 is connected to the piping side connection port 32 of the temperature measurement container 30, and the other end is connected to the refrigerant piping 70. This allows communication between the inside of the temperature measurement container 30 and the inside of the refrigerant piping 70. In the second embodiment, the end of the inspection tube 6 connecting the temperature measuring device 3 and the refrigerant piping 70 on the refrigerant piping 70 side is installed in an operating valve 73 in the refrigerant piping 70. The operating valve 73 is for controlling the flow rate of the fluid. The operating valve 73 may be a liquid operating valve for controlling the flow rate of a liquid fluid, or may be a gas operating valve for controlling the flow rate of a gaseous fluid.

[0101] The temperature measuring device 3 is connected to the fluid supply device 9 by the inspection pipe 6. The inspection pipe 6, which connects to the fluid supply device 9, is connected to the fluid transfer connection port 33 of the temperature measuring container 30. By opening the first valve 34 and the supply side valve, the fluid flows out from the fluid supply device 9, and the flowing out fluid flows into the temperature measuring container 30 and the refrigerant piping 70. The fluid supplied from the fluid supply device 9 to the refrigerant piping 70 flows to the differential pressure gauge 2 via the inspection pipe 6, which connects the refrigerant piping 70 and the differential pressure gauge 2. At this time, by opening the second valve 12 and the third valve 13, the fluid is also supplied to the reference container 1.

[0102] The process flow in the first half of the airtight test according to the second embodiment is illustrated in Fig. 4, and the process flow in the second half is illustrated in Fig. 5. The process of the airtight test according to the second embodiment is the same as that of the first embodiment, except for the points described below.

[0103] In the second embodiment, in step S1, the first valve 34, the second valve 12, and the third valve 13 are opened, and the supply side valve is opened. In the first embodiment, by opening these valves, the fluid flowing out from the fluid supply device 9 flows into the temperature measurement container 30, and the fluid flowing into the temperature measurement container 30 flows into the refrigerant pipe 70 and the reference container 1. In the second embodiment, by opening these valves, the fluid flowing out from the fluid supply device 9 flows into the refrigerant pipe 70 through the inspection pipe 6 and the temperature measurement container 30, and the fluid flowing into the refrigerant pipe 70 flows into the reference container 1 through the inspection pipe 6 and the branch pipe 11. As a result, the refrigerant pipe 70 and the reference container 1 are filled with the fluid.

[0104] The effects of the airtightness test apparatus 100 according to the second embodiment will be described below. The differential pressure gauge 2 in the second embodiment is installed outside the outdoor unit 7. The differential pressure gauge 2 is provided with a second mounting fixture 20 for detachably installing the differential pressure gauge 2 on an installation target. By installing the differential pressure gauge 2 outside the outdoor unit 7, the differential pressure gauge 2 becomes easier to handle. Also, in cases where the differential pressure ΔP between the pressure of the fluid in the refrigerant piping 70 and the pressure of the fluid in the reference container 1 is so large that it exceeds the measurement range of the differential pressure gauge 2, it becomes possible to take prompt action.

[0105] Embodiment 3 The airtightness test apparatus 100 according to the first and second embodiments includes a temperature measuring device 3 that measures the temperature of the fluid. In the first and second embodiments, the airtightness test is performed based on the temperature measured by the temperature measuring device 3. The airtightness test apparatus 200 according to the third embodiment is for performing an airtightness test without measuring the temperature of the fluid. The airtightness test apparatus 200 according to the third embodiment will be described below. In the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals. In the third embodiment, the same components as those in the first and second embodiments and the same functions as those in the first and second embodiments are not described unless there are special circumstances.

[0106] FIG. 7 is a block diagram showing a configuration example of an airtightness testing apparatus 200 according to a third embodiment. The airtightness testing apparatus 200 includes a differential pressure gauge 2, an information collecting device 4, and a processing device 5, as in the first and second embodiments. The airtightness testing apparatus 200 includes a reference container 1A instead of the reference container 1 in the first and second embodiments. The airtightness testing apparatus 200 does not include the temperature measuring device 3 in the first and second embodiments. In FIG. 7, the reference container 1A and the differential pressure gauge 2 are shown within a dashed frame to facilitate understanding of the components included in the airtightness testing apparatus 200, but these components are not necessarily arranged together in a single housing.

[0107] The reference container 1A does not have thermal insulation properties and is easy to exchange heat with, similar to the temperature measuring device 3. The reference container 1A in the third embodiment satisfies either or both of the conditions that the thermal diffusivity is equal to or greater than the thermal diffusivity of the refrigerant pipe 70 and the thermal conductivity is equal to or greater than the thermal conductivity of the refrigerant pipe 70.

[0108] A plurality of fins may be provided on the outer wall of the reference container 1A. In this case, the reference container 1A may be cylindrical, and the plurality of fins may be provided on the outer periphery of the reference container 1A.

[0109] The material of the reference container 1A may be the same as the material of the refrigerant pipe 70. For example, the material of the reference container 1A may be copper, which is widely used as the material of the refrigerant pipe 70.

[0110] 8 is a schematic diagram showing an example of installation of an airtightness test device according to embodiment 3. The reference container 1A is installed in an environment similar to the installation environment of the outdoor unit 7, such as outdoors. In embodiment 3, the pressure measuring device 17 does not need to be provided. The fluid supply device 9 is connected to the refrigerant piping 70 by an inspection pipe 6. In this case, one end of the inspection pipe 6 is installed in a fluid supply port of the fluid supply device 9, and the other end is installed in an operating valve 73 in the refrigerant piping 70.

[0111] The differential pressure gauge 2 is installed outside or inside the outdoor unit 7 by the second mounting fixture 20. The differential pressure gauge 2 is connected to the high pressure joint 71 and the low pressure joint 72 by the inspection pipe 6, as in the second embodiment. The differential pressure gauge 2 is connected to the reference container 1A via the inspection pipe 6 and a guiding device 10. A third valve 13 is installed in the inspection pipe 6 and the branch pipe 11 that connect the differential pressure gauge 2 and the reference container 1A.

[0112] FIG. 9 is a flow chart illustrating the flow of the process of the airtightness test according to the third embodiment. In step S21, the second valve 12 and the third valve 13 are opened under the control of the processing device 5 or by manual processing by the test operator. At this time, the supply side valve of the fluid supply device 9 is also opened under the control of the processing device 5 or by manual processing by the test operator. As a result, the fluid flows out from the fluid supply device 9, and the flowing out fluid flows into the refrigerant pipe 70 through the inspection pipe 6. Then, the fluid that has flowed into the refrigerant pipe 70 flows into the reference container 1 through the inspection pipe 6 and the branch pipe 11. As a result, the refrigerant pipe 70 and the reference container 1A are filled with the fluid.

[0113] The processes in steps S22 to S24 are the same as those in steps S2 to S4. In step S25, the second valve 12 and the third valve 13 are closed under the control of the processing device 5 or manually by a test operator. The process in step S26 is the same as that in step S8.

[0114] In step S27, the processing device 5 or the test operator determines whether or not the test time has elapsed since the processing of step S25. If the test time has not elapsed (step S27: NO), the processing of the airtight test remains at step S27. If the test time has elapsed (step S27: YES), in step S28, the processing device 5 or the test operator determines whether or not the differential pressure ΔP measured at the end of the test time is greater than a second threshold value β. The second threshold value β is determined in advance through experiments or the like as a value greater than 0 to prevent erroneous determination that fluid is leaking within an acceptable error range.

[0115] When the pressure difference ΔP is greater than the second threshold value β (step S28: YES), in step S29, the processing device 5 or the test operator determines that a fluid is leaking from the refrigerant pipe 70. After the process of step S29, the process of step S32 is executed.

[0116] If the differential pressure ΔP is equal to or less than the second threshold value β (step S28: NO), in step S30, the processing device 5 or the test operator determines whether or not the overall test time has elapsed since the processing of step S25. If the overall test time has not elapsed (step S30: NO), the processing returns to step S28. In this case, after the waiting time has elapsed from the time when the processing of step S30 was performed, the processing returns to step S28. If the processing returns to step S28 after the waiting time has elapsed, the test time is the original test time plus the waiting time.

[0117] If the comprehensive test time has elapsed (step S30: YES), in step S31, the processing device 5 or the test operator determines that no fluid is leaking from the refrigerant piping 70. After the process of step S31, the process of step S32 is executed.

[0118] The process of step S32 is similar to the process of step S 17. After the process of step S32, the airtightness test process ends.

[0119] The effects of the airtightness test apparatus 200 according to the third embodiment will be described below. The airtightness test apparatus 200 is used to test the airtightness of the refrigerant piping 70 in an air conditioner, and includes a reference container 1A and a differential pressure gauge 2. The reference container 1A is an airtight container. The differential pressure gauge 2 measures a differential pressure ΔP, which is the difference between the pressures of the fluids filled in the refrigerant piping 70 and the reference container 1A. The reference container 1A satisfies either or both of the following conditions: the thermal diffusivity is equal to or greater than the thermal diffusivity of the refrigerant piping 70, and the thermal conductivity is equal to or greater than the thermal conductivity of the refrigerant piping 70.

[0120] According to the above configuration, the speed of the temperature change of the reference container 1A accompanying the change in temperature of the outside air is equal to or faster than the speed of the temperature change of the refrigerant pipe 70 accompanying the change in temperature of the outside air. Therefore, when the temperature of the outside air changes, the temperature of the fluid in the reference container 1A changes at a speed equal to or faster than the speed of the temperature change of the fluid in the refrigerant pipe 70. This suppresses the delay in the change in the temperature of the fluid in the reference container 1A relative to the change in the temperature of the fluid in the refrigerant pipe 70. Therefore, the temperature of the fluid in the refrigerant pipe 70 and the temperature of the fluid in the reference container 1A quickly approach each other. Therefore, the pressure difference of the fluid caused only by the difference in temperature between the refrigerant pipe 70 and the reference container 1A can be reduced. Therefore, it is not necessary to consider the fluctuation in the pressure of the fluid in the refrigerant pipe 70 caused by the fluctuation in the temperature of the fluid in the refrigerant pipe 70. Therefore, it is not necessary to measure the temperature of the fluid in the refrigerant pipe 70 or to calculate the final pressure P2 based on the temperature. Therefore, according to the airtightness test device 200, it is possible to perform an airtightness test with high accuracy using only the differential pressure ΔP measured by the differential pressure gauge 2, and to shorten the test process.

[0121] The reference container 1A in the first embodiment is installed in the same environment as the installation environment of the outdoor unit 7. Here, since the outdoor temperature often fluctuates greatly compared to the indoor air temperature, it is considered that the temperature change of the fluid in the refrigerant piping 70 is caused by the temperature change in the outdoor unit 7 rather than the temperature change in the indoor unit. In the third embodiment, since the reference container 1A is installed in the same environment as the installation environment of the outdoor unit 7, the temperature of the fluid in the reference container 1A approaches the temperature of the fluid in the refrigerant piping 70 in the outdoor unit 7. This reduces the pressure difference of the fluid caused only by the difference in temperature between the refrigerant piping 70 and the reference container 1A. Therefore, it is not necessary to consider the fluctuation in the pressure of the fluid in the refrigerant piping 70 caused by the fluctuation in the temperature of the fluid in the refrigerant piping 70. Therefore, it is not necessary to measure the temperature of the fluid in the refrigerant piping 70 or to calculate the end pressure P2 based on the temperature. Therefore, according to the airtightness test device 200, it is possible to perform an airtightness test with high accuracy using only the differential pressure ΔP measured by the differential pressure gauge 2, and to shorten the test process.

[0122] The reference container 1A in the third embodiment has a plurality of fins on its outer wall. This increases the installation area between the reference container 1A and the outside air, facilitating heat exchange between the reference container 1A body and the outside air. This facilitates heat exchange between the fluid in the reference container 1A and the outside air through the wall of the reference container 1A. This makes it possible to suppress the delay in the temperature change of the fluid in the reference container 1A relative to the temperature change of the fluid in the refrigerant pipe 70. This makes it possible to perform an airtightness test quickly and with high accuracy using only the differential pressure ΔP measured by the differential pressure gauge 2.

[0123] The material of the reference container 1A in the third embodiment is the same as the material of the refrigerant pipe 70. As a result, the fluid in the reference container 1A and the fluid in the refrigerant pipe 70 exchange heat with the outside air in a similar manner. Therefore, the temperature of the fluid in the reference container 1A approaches the temperature of the fluid in the refrigerant pipe 70. This makes it possible to reduce the pressure difference of the fluid caused only by the difference in temperature between the refrigerant pipe 70 and the reference container 1A. This makes it unnecessary to measure the temperature of the fluid in the refrigerant pipe 70 and to calculate the final pressure P2 based on the temperature. Therefore, according to the airtightness test device 200, it is possible to perform an airtightness test with high accuracy using only the differential pressure ΔP measured by the differential pressure gauge 2, and to shorten the test process.

[0124] The airtightness test apparatus 200 according to the third embodiment further includes a guiding device 10. The guiding device 10 allows fluid to flow between the refrigerant pipe 70 and the reference container 1 before the start of the test time, and blocks the flow of fluid between the refrigerant pipe 70 and the reference container 1 after the start of the test time. As a result, the fluid pressure in the refrigerant pipe 70 and the fluid pressure in the reference container 1 are equalized before the start of the test time. A test operator can quickly and easily determine whether or not there is a leakage of fluid from the refrigerant pipe 70 by checking the differential pressure ΔP measured by the differential pressure gauge 2 at the end of the test time.

[0125] The airtightness testing apparatus 200 according to the third embodiment further includes a processing device 5. The processing device 5 determines the presence or absence of leakage of fluid from the refrigerant pipe 70 based on the differential pressure ΔP measured by the differential pressure gauge 2 at the end of the test time. This allows the airtightness testing to be automated.

[0126] Although the embodiments have been described above, the contents of the present disclosure are not limited to the embodiments and include the scope of conceivable equivalents. [Explanation of symbols]

[0127] 1, 1A Reference vessel, 2 Differential pressure gauge, 3 Temperature measuring device, 4 Information collecting device, 5 Processing device, 6 Inspection pipe, 7 Outdoor unit, 8 Branching tool, 9 Fluid supply device, 10 Guide device, 11 Branching pipe, 12 Second valve, 13 Third valve, 14 First communication line, 15 Second communication line, 16 Third communication line, 17 Pressure measuring device, 20 Second mounting tool, 30 Temperature measuring vessel, 31 Temperature acquiring unit, 32 Pipe side connection port, 33 Fluid transfer connection port, 34 First valve, 35 External side opening, 36 Sealing material, 37 Fin, 38 First mounting tool, 70 Refrigerant pipe, 71 High pressure joint, 72 Low pressure joint, 73 Operation valve, 100, 200 Air tightness test device, P1 Initial pressure, P2 Final pressure, T1 Initial temperature, T2 Final temperature, α First threshold, β Second threshold, ΔP Differential pressure.

Claims

1. An airtightness testing device for testing the airtightness of refrigerant piping in an air conditioner, a differential pressure gauge that measures a differential pressure between the pressures of the fluids filled in the refrigerant pipe and the airtight reference container; a temperature measuring device connected to the refrigerant pipe and configured to measure a temperature of the fluid in the refrigerant pipe; Equipped with The temperature measuring device is a temperature measuring vessel communicating with the refrigerant pipe and capable of sealing the fluid therein; a temperature acquisition unit that is installed in the temperature measurement container and that measures a temperature of the fluid; having The temperature measurement container comprises: An airtightness testing device that satisfies either or both of the following conditions: a thermal diffusivity is equal to or greater than the thermal diffusivity of the refrigerant piping; and a thermal conductivity is equal to or greater than the thermal conductivity of the refrigerant piping.

2. The temperature measuring device is The airtightness testing device according to claim 1 , which is installed in the same environment as an installation environment of an outdoor unit of the air conditioner.

3. The temperature measuring device is The airtightness testing device according to claim 1 or 2, which is installed in an outdoor unit of the air conditioner.

4. The temperature measurement container comprises: The airtightness testing device according to any one of claims 1 to 3, further comprising a plurality of fins provided therein.

5. The temperature measurement container comprises: The airtightness testing apparatus according to any one of claims 1 to 4, wherein the material is the same as the material of the refrigerant piping.

6. The temperature measurement container comprises: The airtightness testing device according to any one of claims 1 to 5, obtained by processing the refrigerant piping.

7. The internal volume of the temperature measurement container is 50 cm ３ 7. The airtightness testing device according to claim 1, wherein the airtightness testing device is equal to or smaller than the airtightness testing device according to claim 1.

8. The differential pressure gauge is The airtightness testing device according to any one of claims 1 to 7, which is connected to each of the refrigerant piping and the reference container and measures the differential pressure between the pressure of the fluid in the refrigerant piping and the pressure of the fluid in the reference container.

9. The temperature measurement container comprises: an external opening that communicates a space inside the temperature measurement container with an external space; A seal material for closing the exterior opening; is established, The temperature measurement container and the sealing material are The refrigerant pipe has a pressure resistance of equal to or higher than a first pressure corresponding to a set filling amount of the fluid, The temperature acquisition unit is The airtightness testing device according to any one of claims 1 to 8, which is installed in the sealing material.

10. The airtightness testing device according to claim 9 , wherein the first pressure is 2 MPa.

11. The temperature measurement container comprises: The airtightness test apparatus according to any one of claims 1 to 10, further comprising a fluid transfer connection port for allowing the fluid flowing out of a fluid supply device for supplying the fluid to the refrigerant piping to flow into the temperature measurement container.

12. The temperature measuring device is 12. The airtightness testing device according to claim 11, further comprising a first valve provided at the fluid supply / receive connection port, the first valve allowing the fluid to flow in an open state and blocking the flow of the fluid in a closed state.

13. a pressure measuring device that measures the pressure of the fluid in the refrigerant pipe; a processing device that determines whether or not the fluid is leaking from the refrigerant pipe using the differential pressure measured by the differential pressure gauge; and a guide device that allows the fluid to flow between the refrigerant piping and the reference container before a test time set for the test starts, and blocks the flow of the fluid between the refrigerant piping and the reference container after the test time starts; Further comprising: The processing device includes: The airtightness testing device according to any one of claims 1 to 12, wherein the presence or absence of leakage is determined based on the differential pressure measured by the differential pressure gauge at the end of the test time, the initial pressure which is the pressure measured by the pressure measuring device at the start of the test time, the initial temperature which is the temperature measured by the temperature measuring device at the start of the test time, and the final temperature which is the temperature measured by the temperature measuring device at the end of the test time.

14. The processing device includes: Calculating a final pressure, which is the pressure of the fluid in the refrigerant pipe at the end time, based on the initial pressure, the initial temperature, and the final temperature; The airtightness testing device according to claim 13, wherein the presence or absence of the leakage is determined based on a difference between the initial pressure and the final pressure and the differential pressure measured by the differential pressure gauge at the end point.

15. The reference container has thermal insulation properties, The processing device includes:

15. The airtightness testing device according to claim 14, wherein the fluid is determined to be leaking when the magnitude of the difference between the differential pressure, which is the difference between the pressure of the fluid in the refrigerant piping from the pressure of the fluid in the reference container, and the difference between the final pressure from the initial pressure, is greater than a first threshold value.

16. The airtightness testing device according to any one of claims 1 to 15, further comprising a first mounting fixture for detachably mounting the temperature measuring device to an object to be installed.

17. The temperature measurement container includes: The airtightness testing device according to any one of claims 1 to 16, further comprising a piping side connection port for communicating with the refrigerant piping.

18. 18. The airtightness testing device according to claim 17, wherein a branching tool is provided at the piping side connection port for connecting an inspection pipe connected to the differential pressure gauge and an inspection pipe connected to the refrigerant piping to the temperature measurement container.

19. The airtightness testing device according to any one of claims 1 to 18, further comprising a second mounting fixture for detachably mounting the differential pressure gauge to an object to be installed.

20. An airtightness test method performed by an airtightness test device for testing the airtightness of refrigerant piping in an air conditioner, comprising: The airtightness test device is A temperature measuring device is provided which is connected to the refrigerant pipe, The temperature measuring device is A temperature measuring vessel that communicates with the refrigerant pipe and can seal a fluid therein; a temperature acquisition unit that is installed in the temperature measurement container and that measures a temperature of the fluid; having The temperature measurement container comprises: The thermal diffusivity is equal to or greater than the thermal diffusivity of the refrigerant piping, and the thermal conductivity is equal to or greater than the thermal conductivity of the refrigerant piping, or both of these conditions are satisfied; The airtightness test method includes: The temperature measuring device is installed in an outdoor unit of the air conditioner, measuring a differential pressure between the pressures of the fluid filled in the refrigerant pipe and an airtight reference container; measuring a temperature of the fluid in the refrigerant pipe; An airtightness test method, including:

21. An airtightness test method performed by an airtightness test device for testing the airtightness of refrigerant piping in an air conditioner, comprising: The airtightness test device is A temperature measuring device is provided which is connected to the refrigerant pipe, The temperature measuring device is A temperature measuring vessel that is in communication with the refrigerant pipe and capable of sealing a fluid therein; a temperature acquisition unit that is installed in the temperature measurement container and that measures a temperature of the fluid; having The temperature measurement container comprises: The thermal diffusivity is equal to or greater than the thermal diffusivity of the refrigerant piping, and the thermal conductivity is equal to or greater than the thermal conductivity of the refrigerant piping, or both of these conditions are satisfied; The airtightness test method includes: The temperature measuring device is installed in an environment similar to the installation environment of the outdoor unit of the air conditioner, measuring a differential pressure between the pressures of the fluid filled in the refrigerant pipe and an airtight reference container; measuring a temperature of the fluid in the refrigerant pipe; An airtightness test method, including:

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