JPH08145509A - Refrigerating equipment and method for measuring and supplementing refrigerant in refrigerating circuit - Google Patents

Abstract

PURPOSE: To measure easily the quantity of refrigerant and the composition thereof even when a nonazeotropic mixture or the like is used, by providing a refrigerating circuit with a refrigerant takeout port and a refrigerant supply port. CONSTITUTION: A refrigerant takeout port 7 equipped with an on-off valve 5 and a pipeline 6 for connection with a refrigerant recovering vessel and an on-off valve 8 are provided in series to a pipeline connecting a condenser 2 with an expansion valve 3. Moreover, a refrigerant supply port 11 equipped with an on-off valve 9 and a pipeline 10 for connection with the refrigerant recovering vessel is provided for a pipeline connecting the expansion valve 3 with an evaporator 4. At the time of an ordinary operation of refrigerating equipment, the on-off valves 5 and 9 are closed, while the on-off valve 8 is opened. At the time when the quantity of refrigerant or the composition thereof is measured, first the refrigerant recovering vessel 17 which is equipped with a cooler-heater 18 and can be cooled and heated is connected between the refrigerant takeout port 7 and the refrigerant supply port 11 by connecting a pipeline 12 to the pipeline 6 and a pipeline 13 to the pipeline 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus and a method for measuring and replenishing a refrigerant, and more particularly to a refrigerating apparatus using an HFC-based non-azeotropic refrigerant mixture or the like which has no danger of depleting the ozone layer. The present invention relates to a method for providing a refrigerant outlet and a refrigerant supply port in a refrigeration circuit in order to measure the amount or composition of the refrigerant, simply measuring the amount or composition of the refrigerant using them, and supplementing the refrigerant. .

[0002]

2. Description of the Related Art Dichlorodifluoromethane (R-12) and azeotrope mixed refrigerants R-12 and 1,1-difluoroethane (R-) have hitherto been used as refrigerants for refrigerators.
152a) and many R-502s. These are suitable for ordinary refrigeration equipment and have reached high quality levels such as reliability and durability.

However, due to the high ozone depletion potential of each of the above-mentioned refrigerants, when they are released into the atmosphere and reach the ozone layer above the earth, they destroy the ozone layer. The destruction of the ozone layer is caused by chlorine groups (Cl) in the refrigerant. Therefore, a refrigerant with a low chlorine group content, such as chlorodifluoromethane (HCFC-22,
R-22), a refrigerant containing no chlorine group, such as difluoromethane (HFC-32, R-32), pentafluoroethane (HFC-125, R-125), 1,1,1,2
-Tetrafluoroethane (HFC-134a, R-13
4a), or mixtures thereof, are considered as alternative refrigerants for these. The boiling point of R-22 is -40.82 at atmospheric pressure, and the boiling point of R-32 is -51.7 ° C.
The boiling point of R-125 is -48.5 ° C, and the boiling point of R-134a is -26.5 ° C.

The HFC-based refrigerant mixture is a mixture of HFC-based refrigerants.
It is a mixture of three or more kinds, and usually, there are many combinations in which the boiling point and the dew point of the mixture are different. In the present invention, these mixtures are referred to as HFC-based non-azeotropic refrigerant mixture. The HFC-based non-azeotropic refrigerant mixture is specifically, for example,
R125 / R143a / 134a (weight ratio 44/52 /
4) (R404A, boiling point -46.78 ° C, dew point -46.
08 ° C, trade name: HP62, manufactured by DuPont), R32 /
R125 / 134a (weight ratio 20/40/40) (R4
07A, boiling point -45.4 ° C, dew point -38.8 ° C, trade name: KLEA60G2, manufactured by ICI).

FIG. 4 shows an example of a refrigeration circuit of a conventional refrigeration system. Reference numeral 1 is a compressor, 2 is a condenser, 3 is a decompressor, 4 is an evaporator, and arrows indicate the flow direction of the refrigerant. Refrigerant may leak in this refrigeration circuit, and if the amount of refrigerant decreases, the refrigerating capacity and EER (refrigerating capacity / power consumption) decrease.
It becomes necessary to replenish the refrigerant. When a single refrigerant such as R-12 or an azeotropic mixed refrigerant R-502 is used, the refrigerant can be replenished relatively easily by a method such as measuring the refrigerant pressure in the refrigeration circuit. However, when an HFC-based non-azeotropic refrigerant mixture is used, the composition changes with leakage, and therefore, to supplement the refrigerant, it is necessary to know the composition at the same time as the leakage amount. When the HFC-based non-azeotropic refrigerant mixture is used, composition changes occur at various points in the refrigeration circuit, so even if the composition of the refrigerant sampled at a certain point in the refrigeration circuit is measured by a known method such as gas chromatography, It is not possible to know the composition change of the entire refrigerant. It is cumbersome and impractical to sample the refrigerant from multiple points in the refrigeration circuit to analyze the composition.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to make it possible to easily measure the amount of refrigerant or the refrigerant composition even when using an HFC-based non-azeotropic refrigerant mixture or the like that does not have a risk of depleting the ozone layer. The refrigeration apparatus described above is provided, and a method of simply measuring the amount and composition of the refrigerant in the refrigeration circuit and replenishing the refrigerant as needed is provided.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive research to solve the above problems, and as a result, have made it possible to measure the amount of refrigerant and the composition of the refrigerant, and a refrigerant outlet and a refrigerant supply port in a refrigeration circuit. When the measurement is carried out, the amount and the refrigerant composition of the refrigerant can be easily measured by extracting and liquefying the entire amount of the refrigerant from the refrigerant outlet into a container outside the system where the refrigerant has been cooled, and a predetermined amount is necessary according to the measurement result. The inventors have found that the problem can be solved by replenishing the refrigeration circuit with a refrigerant having a predetermined composition from the refrigerant supply port, and completed the present invention.

According to a first aspect of the present invention, a condenser for condensing and liquefying a refrigerant, a decompressor for expanding the refrigerant, an evaporator for evaporating the liquefied refrigerant, and a condenser for compressing the evaporated and evaporated refrigerant. In a refrigerating apparatus including a compressor for discharging to a refrigerant, a refrigerating circuit is provided with a refrigerant outlet and a refrigerant supply port.

According to a second aspect of the present invention, in the refrigerating apparatus according to the first aspect, a refrigerant outlet is provided in a pipeline connecting the condenser and the pressure reducer, and a refrigerant is provided in the pipeline connecting the pressure reducer and the evaporator. A feature is that a supply port is provided.

According to a third aspect of the present invention, in the refrigerating apparatus according to the second aspect, a refrigerant outlet having an on-off valve and an on-off valve are provided in series in a pipeline connecting the condenser and the pressure reducer.
In addition, a refrigerant supply port having an opening / closing valve is provided in a pipe line connecting the pressure reducer and the evaporator.

According to a fourth aspect of the present invention, in the refrigerating apparatus according to the second aspect, a refrigerant outlet having a three-way valve is provided in a pipe line connecting the condenser and the decompressor, and the decompressor and the evaporator are provided. A refrigerant supply port provided with an on-off valve is provided in a pipe line connecting the two.

According to a fifth aspect of the present invention, in the refrigerating apparatus according to the first to fourth aspects, the refrigerant is an HFC type refrigerant or a refrigerant mainly composed of an HFC type refrigerant.

According to a sixth aspect of the present invention, in the refrigerating apparatus according to the fifth aspect, the refrigerant is an HFC-based non-azeotropic refrigerant mixture.

The invention of claim 7 of the present invention is the following (1):
By the steps (6) to (6), the refrigerant is taken out of the refrigeration circuit of the refrigeration system according to claim 1, the amount and composition of the refrigerant are measured, and then the refrigerant is replenished if necessary, and the refrigerant is returned to the refrigeration circuit. A method for measuring and replenishing a refrigerant in a refrigeration circuit, which is characterized in that: (1) A coolant recovery container capable of cooling and heating is connected between the coolant outlet and the coolant supply port. (2) Next, the inside of the container is evacuated and cooled to the boiling point of the refrigerant or less. (3) Substantially all of the refrigerant in the refrigeration circuit is introduced into the container and liquefied. (4) Measure the amount and composition of the refrigerant in the container. (5) If necessary, the refrigerant is replenished in the container. (6) The container is heated to vaporize the refrigerant and supply the refrigerant from the refrigerant supply port into the refrigeration circuit.

According to an eighth aspect of the present invention, the refrigerant is HFC.
The method for measuring and replenishing a refrigerant in a refrigeration circuit according to claim 7, wherein the refrigerant is a refrigerant mainly composed of a system refrigerant or an HFC system refrigerant.

According to a ninth aspect of the present invention, the refrigerant is HFC.
The method for measuring and replenishing a refrigerant in a refrigeration circuit according to claim 8, wherein the refrigerant is a non-azeotropic refrigerant mixture.

[0017]

The present invention is characterized in that the refrigerating circuit of the refrigerating apparatus is provided with the refrigerant outlet and the refrigerant supply port in advance so that the amount of the refrigerant and the composition of the refrigerant can be easily measured. When measuring the amount or composition of the refrigerant, between the refrigerant outlet and the refrigerant supply port, a cooling and heating refrigerant recovery container is connected, the inside of the container is evacuated and the temperature is below the boiling point of the refrigerant. After cooling, substantially all the refrigerant in the refrigeration circuit is introduced into the container and liquefied. For example, the refrigerant is HF
Even if it is a C-based non-azeotropic refrigerant mixture, substantially all the refrigerant in the refrigeration circuit is liquefied and put in the container. Therefore, if the amount and composition of the refrigerant are measured by a known method, It is possible to accurately know the amount and composition of the refrigerant.
From the measurement results of the amount and composition of the refrigerant, it is possible to know the leaked amount and composition, so after replenishing the refrigerant in the container accordingly,
The container is heated to vaporize the refrigerant, and the refrigerant is introduced from the refrigerant supply port into the refrigeration circuit. The refrigerating capacity, EER, etc. of the refrigerating apparatus can be restored by replenishing a predetermined amount and a predetermined composition of the refrigerant.

[0018]

EXAMPLES The contents of the present invention will be described more specifically below with reference to FIGS. 1 to 3, but the present invention is not limited to these contents.

FIG. 1 shows an example of the refrigerating circuit of the refrigerating apparatus of the present invention. 1 is a compressor, 2 is a condenser, 3 is a decompressor (expansion valve), 4 is an evaporator, and an opening / closing valve 5 and a refrigerant recovery container (not shown) are provided in a pipe line connecting the condenser 2 and the expansion valve 3. A refrigerant outlet 7 having a pipe line 6 for connecting to and an opening / closing valve 8 are provided in series, and an opening / closing valve 9 and a refrigerant recovery container (not shown) are provided in a pipe line connecting the expansion valve 3 and the evaporator 4. The coolant supply port 11 is provided with a pipe line 10 for connecting to (1). The arrow indicates the flow of the refrigerant. During normal operation of the refrigeration system, the open / close valves 5 and 9 are closed and the open / close valve 8 is opened.

When measuring the amount and composition of the refrigerant, first, as shown in FIG. 3, the refrigerant outlet port 7 and the refrigerant supply port 1 are shown.
1, a cooling / heatable refrigerant recovery container 17 having a cooler / heater 18 is connected by connecting the conduit 12 to the conduit 6 and the conduit 13 to the conduit 10. . PH and PL are pressure gauges, VP is a vacuum pump, 14, 2
3 is a flexible tube, 15, 19 and 24 are opening / closing valves, 16 is a refrigerant inlet pipe line, 22 is a refrigerant outlet pipe line, 21 is a liquefied refrigerant, 20 is a pipe line serving as a refrigerant sampling and refrigerant replenishing port, and 25 is a scale. Indicates

The on-off valves 5, 9, 19 are closed, and the on-off valves 8, 1
5, 24 are opened, and the vacuum pump VP is operated to make the inside of the system a vacuum to sufficiently remove air, moisture and the like. Refrigerant recovery container 1 by cooler / heater 18 while operating the refrigeration system
Cool 7 to below the boiling point of the refrigerant.

After that, the on-off valve 5 is opened to open the on-off valves 8, 15,
24 is closed and the on-off valve 9 is opened. The refrigerant in the refrigeration circuit enters the refrigerant recovery container 17 via the refrigerant outlet 7 and the refrigerant inlet pipe 16, is cooled and becomes the liquefied refrigerant 21, and is collected in the refrigerant recovery container 17. If the pressure gauge PL has a negative pressure, air or water may enter the refrigeration circuit. Therefore, it is preferable to adjust the degree of vacuum so that the negative pressure does not occur. When the pressure gauge PH reaches about 1 atm (absolute pressure), the on-off valve 5,
By closing 9 to stop the operation of the refrigerator, substantially all the refrigerant in the refrigeration circuit can be collected in the refrigerant recovery container 17.

The weight of the refrigerant recovery container 17 containing the liquefied refrigerant is measured by a known method such as using a scale 25 to measure the amount of the refrigerant. The on-off valve 19 is opened, the refrigerant is sampled from the pipe 20, and the composition of the refrigerant is analyzed by gas chromatography or the like.

Since the leaked amount and composition can be known from the measurement result of the amount and composition of the refrigerant, a predetermined composition and a predetermined amount of the refrigerant can be opened from the pipeline 20 into the refrigerant recovery container 17 by opening the on-off valve 19. refill. Then, the refrigerant recovery container 17 is heated by the cooler / heater 18 to vaporize the refrigerant, open the on-off valves 9 and 24, and perform the reverse operation of the step of collecting the refrigerant in the refrigerant recovery container 17 to perform the refrigerant outlet. Pipe line 22, refrigerant supply port 1
The refrigerant is charged into the refrigeration circuit via 1.

FIG. 2 shows another example of the refrigerating circuit of the refrigerating apparatus of the present invention. Reference numeral 1 is a compressor, 2 is a condenser, 3 is a pressure reducer, and 4 is an evaporator, and is connected to a three-way valve 5A and a refrigerant recovery container (not shown) in a pipe line connecting the condenser 2 and the expansion valve 3. A refrigerant outlet 7 ′ having a pipe 6 is provided, and a pipe connecting the expansion valve 3 and the evaporator 4 is provided with an opening / closing valve 9 and a pipe 10 connecting to a refrigerant recovery container (not shown). A coolant supply port 11 is provided. The arrow indicates the flow of the refrigerant. During normal operation of the refrigeration system, the three-way valve 5A allows the refrigerant to flow from the condenser 2 toward the expansion valve 3, and the on-off valve 9 is closed. When measuring the amount and composition of the refrigerant, the cooler / heater 18 is provided between the refrigerant outlet 7 ′ and the refrigerant supply port 11.
In the case of collecting the refrigerant in the refrigerant recovery container 17 by connecting the cooling and heating capable refrigerant recovery container 17 by connecting the conduit 12 to the conduit 6 and the conduit 13 to the conduit 10. The three-way valve 5A is operated so that the refrigerant does not flow from the three-way valve 5A toward the expansion valve 3 through the refrigerant outlet port 7'and the refrigerant inlet conduit 16 into the refrigerant recovery container 17. The refrigerant is measured in the same manner as above, and a predetermined amount of the refrigerant having a predetermined composition is replenished according to the result.

[0026]

Since the refrigerating apparatus of the present invention is provided with the refrigerant outlet and the refrigerant supply port in the refrigerating circuit so that the amount of the refrigerant and the refrigerant composition can be measured, there is no danger of destroying the ozone layer. Even when an azeotropic refrigerant mixture or the like is used, the amount of the refrigerant and the refrigerant composition can be easily measured by taking out the entire amount of the refrigerant from the refrigerant take-out port into a cooled container outside the system, liquefying it, and collecting it. The refrigerating capacity, EER, etc. can be restored by replenishing the refrigeration circuit with a predetermined composition and a predetermined amount of refrigerant from the refrigerant supply port as necessary based on the measurement result. The refrigerating apparatus of the present invention is economical because it has a simple structure, and is highly effective, so that it has high industrial utility value.

[Brief description of drawings]

FIG. 1 is an example of a refrigeration circuit of a refrigeration apparatus of the present invention.

FIG. 2 is an example of another refrigeration circuit of the refrigeration apparatus of the present invention.

FIG. 3 is an explanatory diagram showing a method of measuring and replenishing a refrigerant.

FIG. 4 is an example of a refrigeration circuit of a conventional refrigeration system.

[Explanation of symbols]

 1 Compressor 2 Condenser 3 Decompressor 4 Evaporator 5, 8, 9, 15, 19, 24 On-off valve 6, 10, 12, 13 Pipe line 7 Refrigerant outlet 11 Refrigerant supply port 14, 23 Flexible tube 16 Refrigerant inlet Pipeline 17 Refrigerant recovery container 18 Cooler / heater 20 Pipeline that also serves as a refrigerant sampling and coolant replenishing port 21 Liquefied refrigerant 22 Refrigerant outlet pipe 25 Scale

Claims (9)

[Claims] 1. A condenser for condensing and liquefying a refrigerant, a decompressor for expanding the refrigerant, an evaporator for evaporating the liquefied refrigerant, a compressor for compressing the evaporated and vaporized refrigerant and discharging it to the condenser. In the refrigeration system, a refrigeration circuit is provided with a refrigerant outlet and a refrigerant supply port. 2. The refrigerating apparatus according to claim 1, wherein a refrigerant outlet is provided in a pipe connecting the condenser and the pressure reducer, and a refrigerant supply port is provided in a pipe connecting the pressure reducer and the evaporator. . 3. A refrigerant supply port having a refrigerant outlet and an on-off valve provided in series in a pipeline connecting a condenser and a pressure reducer, and an on-off valve provided in a pipeline connecting a pressure reducer and an evaporator. The refrigerating apparatus according to claim 2, further comprising: 4. A refrigerant outlet provided with a three-way valve is provided in a pipeline connecting the condenser and the pressure reducer, and a refrigerant supply port provided with an opening / closing valve is provided in the pipeline connecting the pressure reducer and the evaporator. Item 2. The refrigeration apparatus according to item 2. 5. The refrigerating apparatus according to claim 1, wherein the refrigerant is an HFC refrigerant or a refrigerant mainly composed of an HFC refrigerant. 6. The refrigerating apparatus according to claim 5, wherein the refrigerant is an HFC-based non-azeotropic refrigerant mixture. 7. The refrigerant is taken out of the refrigeration circuit of the refrigerating apparatus according to claim 1 out of the system by the following steps (1) to (6), the amount and composition of the refrigerant are measured, and then the refrigerant is replenished if necessary. And then returning the refrigerant into the refrigeration circuit, a method for measuring and replenishing the refrigerant in the refrigeration circuit. (1) A coolant recovery container capable of cooling and heating is connected between the coolant outlet and the coolant supply port. (2) Next, the inside of the container is evacuated and cooled to the boiling point of the refrigerant or less. (3) Substantially all of the refrigerant in the refrigeration circuit is introduced into the container and liquefied. (4) Measure the amount and composition of the refrigerant in the container. (5) If necessary, the refrigerant is replenished in the container. (6) The container is heated to vaporize the refrigerant and supply the refrigerant from the refrigerant supply port into the refrigeration circuit. 8. The method for measuring and replenishing a refrigerant in a refrigeration circuit according to claim 7, wherein the refrigerant is an HFC refrigerant or a refrigerant mainly composed of an HFC refrigerant. 9. The method for measuring and replenishing a refrigerant in a refrigeration circuit according to claim 8, wherein the refrigerant is an HFC-based non-azeotropic refrigerant mixture.