JPH10153363A - Air removal device of refrigerating cycle and carbon dioxide generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the air remaining in a refrigeration cycle which lowers a refrigeration power as a non-condensable gas and further remove the remaining gas whose oxygen or water content promotes the deterioration of a substance in the refrigeration cycle where an exhaust air method based on a prior art vacuum pump demands for a power source available on a construction site to drive the vacuum pump in the case when the refrigeration cycle calls for a separation type air conditioner or a refrigeration replacement method involves the air emission of fleon which is refrigerant and caused unfavorable problems about the destruction of the earth environment or earth warming up and therefore, solve out these unfavorable problems according to this device. SOLUTION: A carbon dioxide generation device which holds ethylene carbonate or propylene carbonate as a carbon dioxide generator and a carbon dioxide absorption device 14 are connected with valves 16 and 17 and a pipeline 15, thereby removing the air existing partially or wholly in a refrigeration cycle before circulating the refrigerant to the refrigeration cycle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a refrigeration cycle, and more particularly, to refrigeration before circulating refrigerant to the refrigeration cycle when constructing a refrigeration cycle having a refrigerating compressor such as an electric refrigerator or an air conditioner. The present invention relates to a device for removing air present in a part or the whole of a cycle.

[0002]

2. Description of the Related Art A refrigeration cycle used for a refrigerator, a vending machine, an air conditioner, or the like is provided with a refrigerant flow control unit having an expansion mechanism such as a refrigeration compressor, a heat exchanger, a capillary tube or an expansion valve, and a piping such as a copper pipe. And a fluid filled in the refrigeration cycle such as a refrigerant and a lubricating oil composition.

[0003] In the construction, a vacuum pump is used to exhaust the refrigeration cycle before a refrigerant charging step in order to remove air components existing in the refrigeration cycle.

[0004] That is, an outdoor unit having a refrigerating compressor and a heat exchanger and an indoor unit having a heat exchanger installed at a site where refrigerating and air conditioning are performed are connected by a pipe such as a copper pipe. In a refrigerating cycle used for a separation type air conditioner, the outdoor unit is filled with a part or all of the refrigerant and a lubricating oil composition in advance, and the service valve is closed. It is common to form a refrigeration cycle by connecting with a vessel.

[0005] By simply connecting the pipes, air remains in the indoor heat exchanger and the connection pipes. In order to remove this air, a vacuum pump was connected to the port of the service valve to remove the air, and then the service valve was opened to connect the indoor unit and the outdoor unit to form a refrigeration cycle.

[0006] In addition, simply, at the time of construction, the service valve is opened, the refrigerant in the outdoor unit flows into the pipe and the indoor unit, and the refrigerant containing air is discharged from the port of the other service valve, so that the inside of the pipe is released. An operation to replace gas was being performed.

[0007] These methods are disclosed in Japanese Patent Laid-Open No. 3-709.
No. 53 discloses a method for manufacturing a refrigeration cycle without using a vacuum pump by replacing the inside of the refrigeration cycle with oxygen, filling the refrigerant, and fixing oxygen with an oxygen fixing agent provided in the refrigeration cycle. doing.

In Japanese Patent Application Laid-Open No. Hei 7-159004, one of a condenser or an evaporator, one of a condenser and an evaporator, of a refrigerating compressor, a condenser, a capillary tube or an expansion valve, and an evaporator. In a separate type refrigeration cycle in which one of the vessels and the expansion mechanism are separated and connected by piping, a substance that can absorb two or more types of moisture, oxygen, nitrogen, carbon dioxide, etc. in the air is used in a part of the refrigeration cycle. A method of encapsulation is disclosed.

Japanese Patent Laid-Open Publication No. Hei 7-269994 discloses a refrigeration cycle in which an oxygen absorbent is provided in a refrigerant circulation system.

[0010]

The air remaining in the refrigeration cycle reduces the refrigeration capacity as non-condensable gas,
Oxygen and moisture must be removed because they promote the deterioration of the substances in the refrigeration cycle.

In consideration of various conventional methods for removing air, the first method of evacuating the refrigeration cycle using a vacuum pump is that when the refrigeration cycle is a separate type air conditioner or the like, a vacuum pump is used at the construction site. A power supply had to be available in order to operate, and it could not be called a convenient method that could always be used.

In the second method of replacing the air in the indoor unit and the flow path piping of the working medium with the refrigerant, the discharge of Freon as the refrigerant accompanies the air. Was not preferred.

In the third method, the inside of the third refrigeration cycle is replaced with oxygen, the refrigerant is charged, and the oxygen is fixed with an oxygen fixing agent provided in the refrigeration cycle. For this reason, the effect was not sufficiently exhibited, and the oxygen absorbent could adversely affect the refrigerant and the refrigerating machine oil.

In the fourth refrigeration cycle, a substance that can absorb two or more substances such as moisture, oxygen, nitrogen, and carbon dioxide in a part of the refrigeration cycle is included in the refrigeration cycle. There is a possibility that the volatile substance may adversely affect the refrigerant, the refrigerating machine oil, and the like.

[0015] Regarding the fifth refrigerant circulation system in which an oxygen absorbent is provided, the oxygen absorbent may adversely affect the refrigerant and the refrigerating machine oil.

An object of the present invention is to provide a simple and environmentally-friendly method in consideration of such problems of the conventional construction method. In the construction of the refrigeration cycle, the air in the refrigeration cycle is circulated before the circulation of the refrigerant to the refrigeration cycle. It is an object of the present invention to provide an apparatus for removing carbon dioxide and an apparatus for generating carbon dioxide therefor.

[0017]

According to the present invention, there is provided a refrigeration system wherein a carbon dioxide generator holding ethylene carbonate or propylene carbonate as a carbon dioxide source and a carbon dioxide absorber are connected by a valve and a pipe. This is an apparatus that removes air existing in a part or all of the refrigeration cycle before circulating the refrigerant to the cycle.

The present invention also provides a carbon dioxide absorption device, wherein zeolite, an epoxy compound, or calcium hydroxide is retained, and air existing in a part or all of the refrigeration cycle is circulated before the refrigerant circulates to the refrigeration cycle. It is a device to remove.

Further, the present invention is characterized in that ethylene carbonate or propylene carbonate is retained as a carbon dioxide source, and air present in a part or the whole of the refrigeration cycle is converted into carbon dioxide before the refrigerant circulates to the refrigeration cycle. It is a carbon dioxide generator for replacement.

The present invention also relates to an ethylene carbonate or propylene carbonate as a carbon dioxide generating source,
A carbon dioxide generator characterized in that the active substance reacting with these is partitioned and held, and the partition is removable.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

First, a refrigeration cycle to which an embodiment of the present invention is applied will be described with reference to the drawings. FIG. 1 is a configuration diagram of a refrigeration cycle applied in an embodiment of the present invention,
An outdoor unit 5 having a refrigeration compressor 1, a heat exchanger 2a, a refrigerant flow control unit 3 such as a capillary tube or an expansion valve, and a pipe 4 connecting these, and a heat exchanger 2b installed at a site where refrigeration and air conditioning is performed Indoor unit 6 having
Are connected by a connection pipe 7, valves 8a and 8b, and flare nuts 9a and 9b. In this case, since the outdoor unit 5 has the four-way valve 10, the function of condensation or evaporation of the heat exchangers 2a and 2b can be exchanged. Further, the outdoor unit 5 may be provided with an accumulator 11.

When the cooling operation is performed, the refrigerant compressed by the refrigerating compressor 1 flows through the heat exchanger 2.
a, the refrigerant is liquefied, passes through the refrigerant flow control unit 3, becomes a low-temperature gas-liquid mixed refrigerant, is absorbed and vaporized in the heat exchanger 2b in the indoor unit 5, and is sucked into the refrigerating compressor again. . When the flow path is switched by the rotation of the four-way valve 10, the heat is condensed in the heat exchanger 2b and evaporated in the heat exchanger 2a, and a heating operation is performed.

Next, an apparatus for removing air present in a part or the whole of a refrigeration cycle according to an embodiment of the present invention will be described.

As shown in FIG. 2, the apparatus 12 for removing air present in a part or all of the refrigeration cycle of the present invention is a carbon dioxide generator 13 for holding ethylene carbonate or propylene carbonate as a carbon dioxide source.
And a carbon dioxide absorbing device 14 via a pipe 15.

The carbon dioxide generator 13 and the carbon dioxide absorber 14 have valves 16 and 17 for non-use, and are connected to the pipe 15 via these.

A connection portion 18 such as a flare may be provided to facilitate connection to the refrigeration cycle side or a manifold used for construction.

Next, the carbon dioxide generator 13 according to the embodiment of the present invention for replacing air present in a part or the whole of the refrigeration cycle with carbon dioxide before the circulation of the refrigerant to the refrigeration cycle will be described in more detail.

The carbon dioxide generator 13 comprises a container 19 for holding a carbon dioxide source, an internal carbon dioxide source, and a valve 16.

The carbon dioxide source is ethylene carbonate or propylene carbonate. These compounds generate ethylene oxide or propylene oxide and carbon dioxide by heating, and coexist with a compound having active hydrogen such as an organic acid, a primary or secondary amine, or a phenol.
Thus, an alcohol compound and carbon dioxide can be generated.

[0031]

Embedded image

(Wherein R1 is hydrogen or a methyl group, R2, R4, and R5 are not necessarily the same hydrogen;
Such as an alkyl group or an aryl group, and R3 is an alkyl group or an aryl group.) These active substances that react with ethylene carbonate or propylene carbonate may coexist inside the vessel of the carbon dioxide generator before use. good. Since the reaction of the chemical formula (1) is a reversible reaction, equilibrium inclines to some extent to the right side of the reaction equation from the start of coexistence. As the carbon concentration decreases, the reaction proceeds further to the right side.

Further, as shown in FIG. 3, ethylene carbonate or propylene carbonate, which is a carbon dioxide generating source, and an active substance which reacts with them are partitioned and held by a partition 21. A configuration in which carbon dioxide is destroyed and carbon dioxide is generated in the coexistence of both is a more preferable configuration because the storage stability of the carbon dioxide generator can be improved.

Further, a catalyst for causing this reaction to proceed at a higher speed may be used in combination. In this case, the catalyst may be in either compartment of ethylene carbonate or propylene carbonate and the active substance reacting therewith.

Ethylene carbonate or propylene carbonate and the active substance which reacts with them,
Alternatively, it is preferable to keep the solution in a liquid phase, but in order to prevent the liquid inside the container holding these carbon dioxide generating sources from scattering to the refrigeration cycle side during use,
The carbon dioxide generating source may be impregnated with a liquid-absorbing medium such as cotton or glass wool, or a filter may be provided near the outlet of the container holding the carbon dioxide generating source up to the valve 16.

Next, the carbon dioxide absorbing device 14 according to the embodiment of the present invention will be described in more detail.

As a substance that absorbs carbon dioxide held in the carbon dioxide absorption device 14, zeolite can be exemplified. Zeolite is widely known for absorbing moisture, and is used in refrigerators and air conditioners to remove moisture from the refrigeration cycle.We have found that zeolite efficiently absorbs carbon dioxide at room temperature, In addition, they found that they could be used repeatedly, and found that using this zeolite for construction of a refrigeration cycle could simplify construction.

The carbon dioxide absorbing device 14 has a container 20 for holding a substance absorbing carbon dioxide and a valve 17. Although zeolite is held as an adsorbent in the container 20, it is necessary to sufficiently exhaust a gas present in at least the container portion of the carbon dioxide absorbing device with a vacuum pump before use.

In order to desorb the substance adsorbed on the zeolite, generally, the partial pressure of the substance to be adsorbed in the atmosphere is reduced, that is, the substance is placed in a reduced pressure atmosphere, and the substance is placed in a temperature atmosphere in which the amount of adsorbed zeolite is reduced. That is, there is a method of placing in a high-temperature atmosphere. When these are used in combination, desorption can be carried out efficiently.

The smaller the amount of adsorption on the zeolite before use, the higher the carbon dioxide adsorption capacity. Therefore, the operation of desorbing the substance to be adsorbed should be performed sufficiently.

The above evacuation and desorption operations need not be performed immediately before construction, and it is convenient and preferable to carry the carbon dioxide absorption device 14 that has been previously evacuation and desorption operations with the valve 17 closed.

The amount of zeolite retained in the carbon dioxide absorption device 14 can be determined by the amount of carbon dioxide in the portion to be degassed.

As the zeolite, it is preferable to use an X-type zeolite having an average pore diameter of about 1.0 nm because carbon dioxide can be rapidly removed.

Although the shape of the zeolite is not particularly limited, it is preferable that the zeolite be spherical because the bulk specific gravity is large and the volume can be reduced in holding the same weight of zeolite in the carbon dioxide absorbing device.

As another substance that absorbs carbon dioxide held in the carbon dioxide absorption device, an epoxy compound is preferable. Specifically, epoxy ethane, 1,2-epoxypropane, 1,2-epoxybutane, 2,3-epoxybutane, 1,2-epoxyhexane, 1,2-epoxyoctane, 3,
Monofunctional and polyfunctional epoxy compounds such as 4-epoxy-1-propene, styrene oxide, cyclohexene oxide, glycidylphenyl, and perfluoropropylene oxide; glycidyl such as glycidyl acetate, glycidyl propionate, and diglycidyl adipate Epoxy compounds such as ester compounds, glycidyl ether compounds such as phenyl glycidyl ether, trimethylsilyl glycidyl ether, resorcin diglycidyl ether, and aryl glycidyl ether can be exemplified.

In the absorption of carbon dioxide by the epoxy compound, an organic zinc compound or
It is preferable to use a magnesium-based catalyst in combination.

Specific examples of the reaction catalyst include dialkyl zinc and dialkyl magnesium and a divalent active hydrogen compound,
For example, the molar ratio with water, primary amine, dihydric phenol, aromatic dicarboxylic acid and aromatic hydroxycarboxylic acid is 1:
Substances reacted in 1, organic zinc-based catalysts such as diethyl zinc / γ-alumina, zinc carbonate, zinc acetate, cobalt acetate, zinc chloride / tetrabutyl ammonium bromide and inorganic catalysts, triethyl aluminum / Lewis base, diethyl aluminum Aluminum compound-based catalysts such as diethylamide, α, β, γ, δ-tetraphenylporphinato aluminum methoxide can be mentioned.

Even at room temperature, carbon dioxide is easily absorbed by the epoxy compound. However, if the carbon dioxide absorbing device 14 has a heater or the like to heat the container holding the substance absorbing carbon dioxide, it reacts more quickly. Can be done.

Further, as another substance that absorbs carbon dioxide held in the carbon dioxide absorbing device 14, calcium hydroxide can be exemplified. This utilizes the reaction of reacting with carbon dioxide to form calcium carbonate and water. If a small amount of water is present at the beginning of the reaction, carbon dioxide can be absorbed more efficiently.

Next, an example of the construction of a refrigeration cycle to which the embodiment of the present invention is applied will be described.

In the construction of a refrigeration cycle in which an outdoor unit having a refrigerating compressor and a heat exchanger and an indoor unit having a heat exchanger installed at a site where refrigerating and air conditioning are performed are connected by flow pipes, 1) The outdoor unit and the indoor unit are connected by a flow pipe. 2) After replacing the indoor unit or the flow pipe with carbon dioxide. 3) The carbon dioxide is absorbed by a carbon dioxide absorbing device arranged in the middle of the outdoor unit or the flow pipe. Removal of carbon 4) After that, disconnecting the carbon dioxide absorber from the refrigeration cycle 5) By circulating the refrigerant during the refrigeration cycle, it is possible to construct a refrigeration cycle in which the air in the indoor unit or the flow path piping is removed. become.

The procedure will be described in detail with reference to the drawings.

FIG. 4 shows an example of construction of a refrigeration / air-conditioning apparatus in which the outdoor unit 5 and the indoor unit 6 are connected by a working medium flow path pipe 7.

The outdoor unit 5 and the indoor unit 6 are connected to a connecting pipe 7, valves 8a and 8b, and flare nuts 9a and 9
Connect with b. The valves 8a and 8b, which control the connection between the outdoor unit-side working medium flow path and the working medium flow path pipe side, are evacuated by a vacuum pump, filled with carbon dioxide, or added with a refrigerant in addition to the connection port with the working medium flow path pipe. It has ports 23a and 23b for performing filling. A device 13 for generating carbon dioxide is connected to one 23a of the port 23, the other 23b is opened, and carbon dioxide is supplied from the device 13 for generating carbon dioxide. Can be replaced with carbon dioxide.

Thereafter, the supply of carbon dioxide from the carbon dioxide generator 13 is terminated, and the port 23b to which the carbon dioxide generator 13 is not connected is closed.
The carbon dioxide absorbing device 14 is connected to one of the ports 23a as shown in FIG. The carbon dioxide absorbing device 14 becomes unnecessary if carbon dioxide is removed from the cycle before the operation, and the carbon dioxide absorbing material retained in the carbon dioxide absorbing device interacts with the refrigerant or the refrigerating machine oil. After removing carbon dioxide, cut off the refrigeration cycle. Of course, since it can be reused, it may be physically removed.

The valve 17 of the carbon dioxide absorption device 14 is connected to the port 23a with the valve closed. At this time, the valve 8 is closed and the outdoor unit 5 and the indoor unit 6 are isolated. Continue the valve 1 of the carbon dioxide absorber 14
7, the indoor unit 6 and the carbon dioxide in the pipe and the container 20 are allowed to flow to absorb carbon dioxide, and after leaving for a certain period of time, the valve 17 of the carbon dioxide absorbing device 14 is closed, and the valve 8 is opened to open the outdoor unit. After the refrigerant of No. 5 is passed through the indoor unit 6 and the connection pipe 7, the construction can be performed by removing the carbon dioxide absorbing device 14 from the port 23a.

Although the carbon dioxide absorbing device 14 is connected to the valve 8a in FIG. 5, it may be connected to the valve 8b, or a valve having the same function may be provided on the indoor unit side. good. Also, the valves 8a, 8b
The refrigerant may be additionally charged inside the refrigeration cycle before opening the refrigeration cycle.

Also, as shown in FIG. 6, valves 8a, 8b, 8c, 8c, 8c, 8c, 8c, 9c, 9c, 9c, 9c, 10c, 10c, 10c, 10c connect the outdoor unit-side working medium flow path to the working medium flow path pipe side.
8b, even if there is only one port 23 for exhausting by a vacuum pump, filling with carbon dioxide, or additionally filling with a refrigerant other than a port connected to the flow path piping of the working medium, the carbon dioxide generating vessel 19 By using the air removing device 12 in which the carbon absorbing container 20 is connected by a valve and a pipe, the carbon dioxide can be absorbed after the indoor unit 6 and the flow pipe section are replaced with carbon dioxide.

That is, the port 23 is connected to the device 12 for removing air present in a part or the whole of the refrigeration cycle, and the flare connection with the flow path piping at the valve 8b having no port 13 is provided. With the valve loosened, the valve 16 is opened to supply carbon dioxide, and after the replacement, the valve 16 is closed to terminate the supply of carbon dioxide, and the flare connection with the flow path piping at the valve 8b is completely performed. Subsequently, by opening the valve 17, carbon dioxide can be absorbed. When the absorption of carbon dioxide is completed, the valve 17 is closed, the valve 8 is opened, and the refrigerant of the outdoor unit 5 flows through the indoor unit 6 and the connection pipe. Construction can be carried out by removing the air removing device 12.

[0060]

As described above, according to the present invention, an apparatus for removing air in a refrigeration cycle before circulating the refrigerant to the refrigeration cycle during construction of the refrigeration cycle, and a method for simplifying the refrigeration cycle. A carbon dioxide generator can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view of a refrigeration cycle used in an embodiment of the present invention.

FIG. 2 is a schematic view of an air removing device according to an embodiment of the present invention.

FIG. 3 is a schematic sectional view of a carbon dioxide generator according to one embodiment of the present invention.

FIG. 4 is a schematic diagram showing a connection state of the carbon dioxide generator according to one embodiment of the present invention.

FIG. 5 is a schematic diagram showing a connection state of the carbon dioxide absorption device according to one embodiment of the present invention.

FIG. 6 is a schematic diagram showing a connection state of the air removing device according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration compressor 2 Heat exchanger 3 Refrigerant flow control part 4 Piping 5 Outdoor unit 6 Indoor unit 7 Connection pipe 8 Three-way valve 9 Flare nut 10 Four-way valve 11 Accumulator 12 Device for removing air of refrigeration cycle 13 Carbon dioxide generator 14 Carbon dioxide absorbing device 15 Piping 16 Valve 17 Valve 18 Connecting portion 19 Container holding a carbon dioxide generating source 20 Container holding a substance absorbing carbon dioxide 21 Partition 22 Partition breaker 23 Port

Continued on the front page (72) Keizo Nakajima Inventor 1006 Odakadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A carbon dioxide generator that holds ethylene carbonate or propylene carbonate as a carbon dioxide source, a carbon dioxide absorber that absorbs carbon dioxide, and a pipe that connects the carbon dioxide generator and the carbon dioxide absorber. And a valve for opening and closing the carbon dioxide generating device and the carbon dioxide absorbing device to remove air present in a part or all of the refrigeration cycle before circulating the refrigerant to the refrigeration cycle. Characteristic air removal device for refrigeration cycle. 2. The air removal device for a refrigeration cycle according to claim 1, wherein the carbon dioxide absorption device holds zeolite, an epoxy compound, or calcium hydroxide. 3. The method according to claim 1, wherein ethylene carbonate or propylene carbonate is retained as a carbon dioxide source, and air present in a part or all of the refrigeration cycle can be replaced with carbon dioxide before the refrigerant is circulated to the refrigeration cycle. Characteristic carbon dioxide generator. 4. The method according to claim 3, wherein ethylene carbonate or propylene carbonate, which is a carbon dioxide generating source, and an active substance reacting therewith are partitioned and retained by a partition, and the partition can be removed. CO2 generator.