JP3087646B2 - Moisture inspection device in closed space - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting moisture in a closed space such as a refrigerant pipe of an air conditioner.

[0002]

2. Description of the Related Art For example, a so-called separate type air conditioner, in which an indoor unit and an outdoor unit are separated from each other, has an outdoor unit outdoors and an indoor unit indoors at an installation location desired by a user in the field. After installation, the two are connected to each other by a refrigerant pipe (gas pipe, liquid pipe) and electric wiring.

[0003] For this reason, there is a possibility that water may enter the connection pipe and the refrigerant pipe of the indoor unit due to, for example, rainfall during the pipe connection work. Such a case requires installation of a large number of indoor units, for example, as in a multi-type case, and is particularly frequent when the construction site is large, the piping length is long, and the construction time is long.

Therefore, a vacuum drying method has been practiced in which the refrigerant pipe is evacuated and dewatered using a vacuum pump and a vacuum gauge after the completion of the piping work.

[0005]

However, there has not yet been developed a suitable moisture inspection apparatus for confirming whether or not the moisture in the piping has actually been removed even after the vacuum drying. Under the following circumstances, it is presently difficult to perform truly reliable dehydration and its confirmation.

(1) If water remains in the piping,
Water becomes water vapor and the pressure increases by that amount, but a vacuum gauge cannot confirm that it is due to water. In addition, when the vacuum pump sucks water vapor, the performance of the pump itself deteriorates, and the pressure does not decrease even after the completion of water discharge, so that the completion of vacuum drying cannot be confirmed.

(2) The vacuum pump used in the field is small and portable, and when a refrigerant or moisture is sucked, the performance of the vacuum pump is easily deteriorated, and the pressure does not decrease to a level at which moisture can be inspected by a vacuum gauge ( In order to confirm that there is no water inside the pipe at a degree of vacuum, it is necessary to reduce the pressure in the pipe to a vacuum level higher than a predetermined value.)

(3) In general, the position of a vacuum gauge that can be measured is near a vacuum pump having the lowest pressure in a piping system, and a pressure difference gradient is formed inside the piping. In the above-described air conditioner, since the diameter and length of the pipe are various depending on the type and the condition of the indoor unit, it is possible to set a vacuum degree standard for determining the presence or absence of moisture. Have difficulty.

Of course, in the case of an air conditioner, there is already a moisture inspection device in a product production line in a factory,
It is complex and expensive in both structure and system,
It is not something that can be used easily at the installation site.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a pressure change in a closed space such as a pipe is caused in response to the presence or absence of moisture during bleeding and dewatering by a vacuum drying means. An object of the present invention is to provide a low-cost moisture inspection apparatus in a closed space which is small and lightweight, and which can be easily handled at an installation site by providing a moisture adsorption means.

[0011]

Means for Solving the Problems Each of the inventions of the present application is provided with the following effective problem solving means in order to achieve the above object.

(1) Invention of Claim 1 First, as shown in FIGS. 1 to 5, for example, a moisture inspection apparatus in a closed space according to the invention of claim 1 of the present invention has a predetermined structure such as a refrigerant pipe of an air conditioner. Closed space bodies 3a and 3b, a vacuum pump 5 connected to the closed space bodies 3a and 3b, and evacuating the closed space bodies 3a and 3b, and the vacuum pump 5 and the closed space bodies 3a and 3b. is connected via an on-off valve V ₁ between, the closed space body 3a, the moisture adsorption device 4 with a built-in adsorbent for adsorbing 3b inside the steam, the closed space body 3a, 3
b and the open / close valve V ₁ of the moisture adsorber 4,
And a pressure gauge 6 for measuring the pressure in the closed space body 3a, the 3b, after once evacuated the moisture adsorption device 4 by the vacuum pump 5 by opening the on-off valve V ₁ of the above moisture adsorption device 4 closed-off valve V _1, further said closed space body 3a by the vacuum pump 5, the vacuum state within 3b, the closed space again open the on-off valve V ₁ to the water absorbent of the moisture adsorption device 4 A moisture inspection device for detecting the presence or absence of moisture in the closed space bodies 3a, 3b based on a change in the pressure measurement value of the pressure gauge 6 when the water vapor in the bodies 3a, 3b is adsorbed. In the closed space body 3
a, 3b, the vacuum pump 5, the moisture adsorber 4, and the pressure gauge 6 each have four sets of connection ports 8c, 8 corresponding to each of them.
They are connected to each other via a connection manifold 10 having b, 8a, and 8d.

[0013] As described above, first on-off valve closes the on-off valve V ₁ after vacuuming the water adsorption vessel 4 by the vacuum pump 5 by opening the V _1, further said closed space body 3a, a vacuum pump within 3b 5 by evacuating the, for example, after vacuum dried, re-open the on-off valve V ₁ as needed, the closed space body 3a to moisture adsorption means 4 having a water adsorbent, the adsorption of water vapor in 3b And the closed space body 3
When there is no moisture in the a and 3b, there is no change in the pressure measured by the pressure gauge 6. On the other hand, when there is moisture, it becomes water vapor and is adsorbed by the moisture adsorbent of the moisture adsorber 4. As a result, the pressure decreases, and the decrease in the pressure is measured by the pressure gauge 6.

Therefore, the presence or absence of moisture in the closed spaces 3a and 3b is detected from the decrease in the pressure measured by the single pressure gauge 6.

Moreover, in the above configuration, the closed space 3
a, 3b, the vacuum pump 5, the moisture adsorber 4, and the pressure gauge 6 each have four sets of connection ports 8c, 8 corresponding to each of them.
Since they are connected to each other via the connection manifold 10 having the b, 8a and 8d, the measurement of the pressure difference between the inlet and the outlet of the moisture adsorber 4 becomes unnecessary as described above. The configuration is simple, and the mutual connection work at the time of inspection can be facilitated.

(2) Invention of Claim 2 Next, as shown in FIG. 1 to FIG.
The closed space bodies 3a and 3b in the configuration of the invention of the fifth aspect are characterized by being refrigerant pipes of an air conditioner.

Therefore, the above-mentioned action is effectively exhibited in the refrigerant pipe of the air conditioner.

[0018]

As described above, according to the moisture inspection apparatus in a closed space according to the present invention, the presence or absence of moisture in various closed spaces such as refrigerant pipes of an air conditioner can be easily detected at a local construction site. It is possible to provide a low-cost moisture inspection apparatus that is simple and has a simple structure.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a basic structure of a moisture inspection apparatus in a closed space according to an embodiment of the present invention, which is constituted as, for example, a moisture inspection apparatus for detecting moisture in piping of an air conditioner. FIG. 2 shows a moisture test method using the same apparatus.
Further, FIG. 3 shows the change characteristics of the pressure in the piping of the air conditioner corresponding to the presence or absence of moisture when a moisture test is performed using the same apparatus.

First, in FIG. 1, reference numeral 1A denotes an indoor unit (one or more units) of an air conditioner having connection pipes and refrigerant pipes to be inspected.
A has a predetermined total piping volume. One of the connection pipes 3a, 3b (gas pipe) 3a between the indoor unit 1A and the outdoor unit 1B is connected to a moisture adsorption trap (moisture adsorbing means / moisture means) via a connection manifold 8 having four branch pipes. Moisture adsorber) 4, vacuum pump (vacuum evacuation means) 5,
A moisture testing device 10 having a vacuum drying function, comprising a vacuum gauge (pressure detecting means / pressure gauge) 6, is connected.

The connection manifold 8 has first to fourth four sets of connection ports 8a to 8d provided for each branch pipe, and the first connection port 8a is connected to the first opening / closing valve V _1. To the water inlet 4a of the water adsorption trap 4 through the
Connection port 8b of the second switching valve via the V ₂ to the suction port 5a of the vacuum pump 5, and the third connection port 8c of the third opening and closing the indoor unit via a valve V ₃ units 1A and the outdoor unit By connecting one connection pipe 3a to the unit 1B and a fourth connection port 8d to the vacuum pressure sensor 6a of the vacuum gauge 6, respectively, the moisture adsorption trap 4, the vacuum pump 5, the connection pipe 3a, and the vacuum The total 6 is configured to be able to communicate with each other. The moisture adsorption trap 4 is configured such that, for example, an appropriate amount of a high-performance moisture adsorbent (not shown) such as zeolite is accommodated in a pressure-resistant rigid container that can withstand vacuum pressure.

On the other hand, the connecting pipes 3a and 3b between the indoor unit 1A and the outdoor unit 1B are provided with _fourth and _fifth opening / closing valves V ₄ and V ₅ located on the side of the outdoor unit 1B. Have been.

Next, a moisture test method performed using the moisture test apparatus 10 configured as described above will be described in detail with reference to the flowchart of FIG.

That is, when the installation of each of the indoor unit 1A and the outdoor unit 1B and the connection work by the connection pipes 3a and 3b are completed, first, the outdoor unit 1B
With the fourth and fifth on-off valves V ₄ and V ₅ on the side closed, the moisture test device 10 is connected to one side 3a of the connection pipes 3a and 3b as shown in FIG. 1 (step S). ₁ ). Then, then in the closed state of the on-off valve V ₃ of the connection pipe 3a side third, open the water adsorption trap 4 side first, the vacuum pump 5 side second on-off valve V _1, V ₂ respectively.

Then, in this state, the vacuum pump 5 is driven for a predetermined time to evacuate the moisture adsorption trap 4 to discharge the air in the moisture adsorption trap 4 (step S ₂ ). At this time, the pressure inside the adsorption trap after evacuation must be lower than the pressure inside the refrigerant pipe at the end of vacuum drying. The time required for this is usually a few minutes. Of course, in this state, the moisture adsorbent in the moisture adsorption trap 4 is maintained in a state capable of exhibiting sufficient water absorption performance.

Next, from the state, while closing only off valve V ₁ of the above moisture adsorption trap 4 side first turn, connected while the on-off valve V ₂ of the vacuum pump 5 side second in an open pipe 3a open side third on-off valve V _3, by driving the vacuum pump 5 in turn vacuum drying the refrigerant in the pipe by performing evacuation of the indoor unit 1A side refrigerant pipe through the connection pipe 3a (bleed dehydrated) is executed (step S _3). The vacuum drying is continued for a predetermined time according to the total refrigerant pipe volume while watching the pointer of the vacuum gauge 6. As a result, the pressure in the refrigerant pipe gradually decreases, for example, as shown by the characteristics in FIG.

Next, it is determined that the vacuum drying has been completed for the predetermined time, and if it is determined that the vacuum drying has been completed (YES), it is determined that the vacuum drying has been completed. continue the above vacuum drying time in (step S _4). Then, when it is determined that the vacuum drying is completed, then, subsequently in a state of being continued evacuation by the vacuum pump 5, to open and close multiple times off valve V ₁ of the above moisture adsorption trap 4 side first (step S _5).

Then, for example, when moisture is not mixed in the connection pipe 3a and the refrigerant pipe on the indoor unit 1A side, the pressure in the adsorption trap and the pressure in the refrigerant pipe are equalized and measured (detected) by the vacuum gauge 6. that although the pressure no longer changes, when the other water is mixed, when the first on-off valve V ₁ is opened, the moisture adsorption trap 4 acts as a second vacuum pump for the water vapor and, the water for the water vapor is adsorbed by the moisture adsorbent of the adsorption trap 4, the first open time, for example, Figure 3 of the opening and closing valve V ₁
As described above, the pressure in the refrigerant pipe decreases, and the decrease in the pressure is measured by the vacuum gauge 6. Therefore, it can be seen that moisture was mixed thereby. Then, the pressure in the refrigerant pipe, when the first on-off valve V ₁ is closed,
It almost returns to the original pressure. Return several times repeated the first opening and closing of the valve V ₁ was, for the adsorption trap pressure before the normal step S ₅ is lower than the refrigerant pipe pressure, water pressure decreases when opened V ₁ first This is because there is a case where it is difficult to discriminate the mixture.

That is, in the above apparatus, the vacuum gauge 6
In the relationship between the pressure P ₂ when closed and the pressure P ₁ when the opened first on-off valve V ₁ to be measured, it is possible to determine the contamination condition of the water in the next or the like .

In this case, if the relationship between the pressures P ₁ and P ₂ is as shown, for example, it is considered that the air in the moisture adsorption trap 4 in step S ₂ was insufficiently discharged, Back to S _2. Nevertheless, the state is not or the state is not, and in the case of the state, a possibility of a device failure such as a leak is assumed.

V1 opening pressure P ₁ <V1 closing pressure P ₂ →
It is determined that there is water vapor (in this case, for example, step S ₆
From performing vacuum dried again returns to step S ₃₎ V1 certified open when the pressure P ₁ ≒ V1 closing pressure P ₂ → No steam (step S ₇₎ V1 open during the pressure P _1> V1 closing pressure P ₂ → Step S ₂
Return to

[0032] (Modification) In the above configuration, the moisture inspection by the first opening and closing of the valves V _1, for example, FIG reduced degree becomes considerably smaller pressure in the refrigerant pipe by the end of the vacuum drying Although 3 were described as performed in the region of a, water testing by opening and closing of the valve V ₁ of the first, for example, as a region B in FIG. 3, the degree of reduced pressure in the refrigerant pipe by vacuum drying Can be performed in substantially the same manner as long as the area is smaller than a predetermined value.

Further, in the above-described moisture inspection apparatus 10 in a closed space, for example, steam is applied to the fourth connection port 8d of the connection manifold 8 under a vacuum state as shown in FIG. Inspection device 20 for obtaining
Is arbitrarily connected as a substitute for the test object (closed space) containing moisture, and the change in the pressure measurement value of the vacuum gauge 6 at that time is observed, so that the zeolite in the moisture adsorption trap 4 in the moisture test apparatus 10 is checked. It is also possible to check the activity of the moisture adsorbent such as.

The performance checking device 20 is constituted by storing an appropriate amount of a moisture adsorbent 42 such as silica gel in a transparent pressure-resistant rigid container 41 in which the internal state can be visually recognized from the outside. The change in color corresponding to the amount of water absorption can be recognized. Then, by adjusting the initial amount of water absorbed by the moisture adsorbent 42, the amount of water vapor generated at the time of inspection can be changed.

The performance checking device 20 is effective, for example, when checking the normality of the testing performance of the device 10 when the device 10 has not been used for a long time. The performance check device 20 can be easily manufactured or obtained, for example, as a disposable device that can be freely attached and detached. In addition, it can also be incorporated as a part of a moisture testing device.

(Embodiment) Each part of the moisture inspection apparatus 10 in the refrigerant pipe of the air conditioner shown in FIG. 1 is configured as an actual product as a compact unit as shown in FIG. 5, for example. You. In FIG. 5, the same reference numerals are given to the corresponding parts corresponding to the configuration of FIG.

According to the moisture inspection apparatus 10 having the above configuration, the following advantageous effects can be obtained.

(1) The evacuation time in the closed space can be reduced to the minimum necessary time.

(2) Since the presence of moisture can be reliably checked, the quality as an air conditioner can be ensured.

(3) The configuration of the apparatus itself is simple, and the operation and handling are also simple.

(4) The amount of adsorbed water in the water test is small, and the adsorbent can be used for a relatively long time.

(5) Since the water adsorbent is inexpensive and easily available, it can be formed into a disposable type.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a basic configuration of a moisture inspection device in a refrigerant pipe of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a moisture inspection method by the apparatus.

FIG. 3 is a graph showing a change in pressure during a moisture test of the same device.

FIG. 4 is a schematic sectional view showing a configuration of a performance checking device used in the device.

FIG. 5 is a perspective view showing a specific configuration of a moisture inspection device in a refrigerant pipe of the air conditioner according to the embodiment of the present invention.

[Explanation of symbols]

1A is an indoor unit, 1B is an outdoor unit, 3a,
3b is connected piping, 4 is moisture adsorption trap, a vacuum pump 5, 8 connected manifold, V ₁ ~V ₅ is a first to fifth on-off valve.

Claims (2)

(57) [Claims] And 1. A predetermined closed space body, is connected to the closed space body, via a vacuum pump for evacuating the said closed space inside, the on-off valve between the vacuum pump and the closed space body A moisture adsorber that is connected and contains an adsorbent that adsorbs water vapor inside the closed space body ;
A pressure gauge connected between the valve and the closed valve, for measuring the pressure in the closed space, and opening / closing the moisture adsorber, opening and closing the moisture adsorber after evacuating the moisture adsorber by the vacuum pump, and then opening / closing the moisture adsorber once When the valve is closed and the inside of the closed space is further evacuated by the vacuum pump, the open / close valve is opened again to cause the water adsorbent of the water adsorber to adsorb the water vapor in the closed space. a moisture test apparatus closed space body composed so as to detect the presence or absence of the closed space body water from a change in pressure measurement values in total, the closed space
Each of the body, vacuum pump, moisture adsorber, and pressure gauge
Connection manifold with four sets of connection ports corresponding to each of them
Are connected to each other
A moisture inspection device for a closed space. 2. The moisture analyzer in a closed space according to claim 1, wherein the closed space is a refrigerant pipe of an air conditioner.