Refrigerant treatment method

Abstract

To provide a method for cleaning a pipe in a work such as an air-conditioning system for vehicles such as automobiles and a refrigerating equipment system using a 1224yd refrigerant.SOLUTION: A refrigerant treatment method for washing pipes in a workpiece using a refrigerant on a 1224yd as a cleaning solvent, the refrigerant treatment method comprising: heating a built-in vessel containing the cleaning solvent with a heater; feeding the cleaning solvent to the workpiece; and circulating the cleaning solvent in the workpiece SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a refrigerant treatment method for cleaning piping in a workpiece, such as an air conditioning system for a vehicle, with a refrigerant solvent and recovering the refrigerant solvent remaining in the workpiece. [Background technology]

[0002] Recently, in consideration of the environment, a working fluid using 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) (hereinafter referred to as "1224yd refrigerant"), which has a low impact on the ozone layer and a low GWP, has been used as a refrigerant in automotive air conditioning systems, refrigeration systems, and other applications.

[0003] For example, Patent Document 1 discloses that a working medium mixed with a 1224yd refrigerant and another refrigerant is applied to a heat cycle system. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-218508 Summary of the Invention [Problem to be solved by the invention]

[0005] However, although the above patent documents have the effect of being directly applicable to heat cycle systems designed to use HCFC-123 as the working fluid, they do not disclose a method for cleaning the pipes of workpieces such as air conditioning systems and refrigeration equipment systems using 1224yd.

[0006] Therefore, an object of the present invention is to provide a method for cleaning piping in a workpiece such as an air conditioning system for an automobile or the like, or a refrigeration equipment system, using a 1224 yd refrigerant. [Means for solving the problem]

[0007] One embodiment of the present invention is a refrigerant treatment method for cleaning piping inside a workpiece using a 1224 yd refrigerant as a cleaning solvent, which includes the steps of: heating a built-in container containing the cleaning solvent with a heater; delivering the cleaning solvent to the workpiece; and circulating the cleaning solution inside the workpiece. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a method for cleaning piping in a workpiece such as an air conditioning system for an automobile or the like, or a refrigeration equipment system, using a 1224 yd refrigerant. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a configuration diagram of a refrigerant treatment device according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a flowchart illustrating an example of a refrigerant treatment method according to a first embodiment of the present invention. [Figure 3] FIG. 1 is a flowchart illustrating an example of a refrigerant cleaning method according to a first embodiment of the present invention. [Figure 4] FIG. 1 is a flowchart illustrating an example of a refrigerant recovery method according to a first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The details of the embodiments of the present invention will be described below. A freezing treatment device according to an embodiment of the present invention has the following configuration. [Item 1] A refrigerant treatment method for cleaning piping in a workpiece using a 1224yd refrigerant as a cleaning solvent, a step of heating a container containing the cleaning solvent by a heater; a step of delivering the cleaning solvent to the workpiece; and circulating the cleaning solution within the workpiece. [Item 2] 2. The refrigerant treatment method according to claim 1, wherein the heating step heats the cleaning solvent to 55 degrees Celsius or higher. [Item 3] 2. The refrigerant treatment method according to claim 1, wherein the heating step heats the cleaning solution so that the pressure of the cleaning solution becomes 0.4 MPa or more. [Item 4] Item 2. The refrigerant treatment method according to item 1, further comprising the step of recovering the cleaning solvent in the built-in vessel. [Item 5] 2. The refrigerant treatment method according to item 1, further comprising a step of vacuum drying the inside of the workpiece after the recovery step.

[0011] A refrigerant treatment device according to a first embodiment of the present invention will now be described with reference to the drawings. Figure 1 is an overall configuration diagram showing a refrigerant treatment device according to the first embodiment of the present invention.

[0012] In this embodiment, the refrigerant used to clean refrigeration oil and the like remaining in the piping of vehicle air conditioning systems and refrigeration equipment systems for automobiles, etc., is 1224 yd refrigerant. The 1224 yd refrigerant has attracted attention as an environmentally friendly refrigerant with an ozone depletion potential (ODP) close to zero and a global warming potential (GWP) of 1 or less.

[0013] Another feature is that it is a low-boiling fluorine refrigerant with a standard boiling point of 15°C, and it can be heated to temperatures exceeding 40°C, for example, which not only ensures the self-pressure required to send the 1224yd refrigerant as a solution from the built-in container to the workpiece, but also ensures the ability to wash away refrigeration oil remaining in the piping inside the workpiece as a high-temperature solvent.Furthermore, in the solvent recovery process, its low boiling point also makes it easier to recover the solvent from the workpiece to the refrigerant treatment device.

[0014] The refrigerant treatment system 1 shown in Figure 1 includes a built-in container 3 that contains 1224 yd of refrigerant as solution 2, an induction heater 4 that heats the solution 2 in the built-in container 3, and a valve V5 that opens and closes a connection connected to the inlet of the workpiece so that the heated solvent from the built-in container can be sent to the piping in the workpiece via a flow path in the refrigerant treatment system 1.

[0015] The refrigerant treatment system 1 also includes a vacuum pump 6 for drawing a vacuum in the piping within the work, a compressor 7 for circulating and cleaning the piping within the work, a valve V6 for opening and closing the connection connected to the outlet of the work in order to recover residual machine oil from the piping within the work, an oil separator 8 that recovers the oil recovered from the work through a flow path within the refrigerant treatment system 1 and separates the oil, and a band heater 9 for heating the recovered machine oil in the oil separator.

[0016] FIG. 2 is a flowchart illustrating an example of a refrigerant treatment method according to the first embodiment of the present invention.

[0017] As shown in FIG. 2, in the refrigerant treatment method of this embodiment, a 1224 yd refrigerant, which is a low boiling point fluorine solvent, is used as a solvent for washing machine oil remaining in piping within a workpiece.

[0018] The refrigerant treatment method in this embodiment first includes a pipe cleaning step (S101) of heating a cleaning solvent composed of 1224 yd refrigerant and sending the heated cleaning solvent to a pipe in the workpiece to clean the pipe inside the workpiece. This step will be described in detail with reference to FIG. 3.

[0019] Here, by heating the cleaning solvent 2 contained in the built-in container 3 with an electromagnetic induction heating means such as an IH heater 4, the solvent 2 can be heated quickly and evenly throughout, and by ensuring its own pressure, the solvent 2 can be sent from the main body of the built-in container 3 to the workpiece (not shown) using only its own pressure without relying on a compressor or other pressure-feeding device, and the high temperature of the solvent 2 can improve the cleaning performance of oil remaining in the piping inside the workpiece. Furthermore, this own pressure is not only useful for sending the solvent into the workpiece, but can also be used to gas-purge the solvent remaining in the piping after the cleaning process.

[0020] Conventional one-pass cleaning methods, in which solvent is delivered using a liquid delivery pump or nitrogen gas, or co-washing using a refrigerant, require destruction or other methods for waste liquid disposal. However, this device can regenerate cleaning solvent, making it possible to reuse the solvent.

[0021] The refrigerant treatment method of the present embodiment then includes a solvent recovery step (S102) of recovering the solvent from inside the workpiece after the pipe cleaning. This step will be described in detail with reference to FIG.

[0022] Next, the refrigerant treatment method in this embodiment includes a vacuum drying process (S103) in which the piping in the workpiece is vacuum-dried after the solvent recovery process. This process will also be described in detail following the description of the solvent recovery process using Figure 4.

[0023] FIG. 3 is a flowchart illustrating an example of a refrigerant cleaning method according to the first embodiment of the present invention.

[0024] As shown in FIG. 3, in the refrigerant cleaning step, first, the cleaning solvent 2 contained in the built-in container 3 is heated to adjust the temperature of the solvent 2 (S201).

[0025] As a heating method, for example, as shown in Figure 1, the IH heater 4 is heated by turning on the power supplies S1 and S2 of the IH heater 4. When the temperature of the built-in container rises to 55°C or higher, the internal pressure of the solvent 2 rises to 0.4 MPa or higher. This pressure of 0.4 MPa corresponds to the pressure required to push 1224 yd of refrigerant solvent up to a height of 30 meters in four distribution pipes. Here, the temperature and pressure can be changed as needed.

[0026] At the same time, the piping inside the workpiece is evacuated (S202). For example, as shown in Fig. 1, the power supply S3 of the vacuum pump 6 is turned on and the valves V10, V4, V5, V6, and V7 provided in the flow paths inside the refrigerant treatment system 1 are opened, thereby evacuating the piping inside the workpiece.

[0027] In this way, the solvent 2 is sent to the pipe in the work by utilizing the differential pressure between the pressure in the pipe evacuated by evacuation and the pressure of the solvent 2 itself (S203).

[0028] As a method of liquid delivery, the cleaning solvent 2 contained in the built-in container 3 is delivered to the workpiece by opening the valves V1 and V3 provided in the flow path as shown in Figure 1. Once the operator visually confirms the presence of the cleaning solvent 2 through the filter sight glass 5 provided on the workpiece outlet connection side, he or she closes the valve V1.

[0029] At this point, the piping inside the workpiece is filled with the cleaning solvent 2. Then, the compressor 7 is started to circulate the cleaning solvent 2, thereby cleaning the piping.

[0030] FIG. 4 is a flowchart illustrating an example of a refrigerant recovery method according to the first embodiment of the present invention.

[0031] This method relates to a process of recovering the cleaning solvent 2 from the pipes inside the workpiece after cleaning the pipes and returning it to the built-in container.

[0032] In this method, first, during pipe cleaning, the IH heater 4 is started to raise the temperature of the built-in container 3, thereby adjusting the temperature of the built-in container 3 (S301).

[0033] In adjusting the temperature, the operator checks that the temperature is 55 degrees Celsius or higher (pressure 0.4 MPa or higher) when recovering the solvent 2.

[0034] After adjusting the temperature, the solvent is recovered (S302). Here, in conjunction with the pipe cleaning, valves V3, V4, V5, V6, and V7 on the flow path shown in Figure 1 are in an open state, and compressor 7 is in an activated state.

[0035] The operator then closes valve V3 and opens valve V1, creating a flow path for recovering solvent 2 in built-in container 3. The operator then opens valve V2, forcing the heated solvent 2 into the workpiece as a gas. This forces the solvent remaining in the piping inside the workpiece toward the workpiece outlet, further promoting the evaporation of oil and other components remaining in the piping. Thus, the solvent method of this embodiment, unlike conventional pipe cleaning methods using solvents, can achieve highly efficient solvent recovery.

[0036] Next, to explain in detail the process of vacuum drying the workpiece after solvent recovery, for example, when an operator confirms that the pressure gauge of compressor 7 has reached -0.8 MPa during the solvent recovery process, he closes valves V1, V2, and V7 and opens V9. Then, he opens V10, starts vacuum pump 6, and begins vacuuming. Depending on the volume of solvent to be recovered, this process is completed when the compressor pressure gauge reaches -0.1 MPa and 15 minutes have passed.

[0037] The oil-containing waste liquid recovered from the workpiece is heated by a band heater 9 in an oil separator 8, where it is distilled and separated, and the solvent 2 is recovered again in the built-in container 3.

[0038] The above-described embodiment is merely an example for facilitating understanding of the present invention, and is not intended to limit the present invention. The present invention can be modified and improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof. [Explanation of symbols]

[0039] 1 Refrigerant treatment device 2 1224yd refrigerant (cleaning solvent) 3 Built-in container 4. IH heater 5 sight glass 6. Vacuum pump 7. Compressor 8 Oil Separator 9. Band heater

Claims

1. A refrigerant treatment method for cleaning piping in a workpiece using a 1224 yd refrigerant as a cleaning solvent, a step of heating a container containing the cleaning solvent by a heater; a step of delivering the cleaning solvent to the workpiece; and circulating the cleaning solution within the workpiece.

2. 2. The refrigerant treatment method according to claim 1, wherein the heating step heats the cleaning solvent to 55 degrees Celsius or higher.

3. 2. The refrigerant treatment method according to claim 1, wherein the heating step heats the cleaning solution so that an internal pressure of the cleaning solution becomes 0.4 MPa or more.

4. 2. The method of claim 1, further comprising recovering the cleaning solvent in the on-board vessel.

5. The refrigerant treatment method according to claim 1 , further comprising the step of vacuum-drying the inside of the workpiece after the recovering step.

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