JPH0510636A - Oil absorption type gas extraction device for refrigerator - Google Patents

Abstract

PURPOSE:To accommodate for a gas extracting performance of an oil absorption type gas extracting device of a refrigerator even if a hydraulic pressure to be fed to or discharged from a gas extracting drum is varied. CONSTITUTION:An oil absorption type gas extracting device is comprised of a differential pressure switch 10 for sensing a differential pressure between an inner pressure in a gas extracting chamber 1 of a gas extracting drum 2 and a primary pressure at a feeding or a discharging valve 3 in a hydraulic pipe 4 for feeding oil a refrigerator to a gas extracting drum 2 and of a gas extracting valve control device 11 for opening a gas extracting valve 6 for extracting extracted gas from an extracting chamber 1 when the differential pressure variation at an absorption stroke is less than a predetermined differential pressure. The differential pressure variation corresponding to a reduction in partial pressure of refrigerant during an absorption stroke is detected by a differential pressure switch 10 in reference to a hydraulic pressure at a primary side of a feeding or discharging valve 3 at the hydraulic pipe 4. The gas extracting valve 6 is opened by a gas extracting valve control device 11 only when the differential pressure variation is less than the predetermined differential pressure and the extracted gas with rich non-condensed gas is discharged into surrounding air, thereby even if pressure of oil supplied from the hydraulic pipe 4 is varied, the gas extracting performance of the oil absorption type gas extraction device is accommodated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil absorption type extraction device for a refrigerator which absorbs a refrigerant in oil to extract non-condensed gas in a condenser incorporated in a turbo refrigerator or the like.

[0002]

2. Description of the Related Art Conventionally, as this type of oil absorption type extraction device,
For example, as described in “Instruction Manual for Turbo Refrigerator” (published by Mitsubishi York Corporation, Mitsubishi Heavy Industries, Ltd. in December 1989), and as shown in FIG. 3, a turbo compressor is provided below the extraction drum A. A hydraulic pipe C having a supply / discharge valve B for supplying / discharging oil from the oil pump, a gas injection pipe D for injecting a non-condensable gas containing a refrigerant into the extraction drum A, and an upper part of the extraction air An extraction pipe F having an extraction valve E for discharging extraction gas from the drum A is connected, and a cooling pipe G through which the refrigerant liquid from the condenser flows is provided in the extraction drum A.

Further, upper and lower float switches H and I are provided in the bleeding drum A, and these switches H and I are used to switch the supply / discharge valve B interposed in the hydraulic pipe C so that the oil is bleeded. The drum A is alternately filled or emptied to operate as a liquid piston.

Further, the extraction valve E in the extraction pipe F
The internal pressure of the extraction drum A is, for example, 1.
Opens in 4Kg / cm ² G, is provided a pressure switch J closing at 1.05Kg / cm ² G, and so as to open and close the bleed valve E by the opening and closing of the pressure switch J. Incidentally, K
Is a drain pipe connected to the supply / discharge valve B, and L is a switching device for switching the supply / discharge valve B according to the operation of the float switches H, I.

Thus, by switching the supply / discharge valve B, oil is supplied to and discharged from the extraction drum A, and non-condensed gas containing a refrigerant is injected from the gas injection pipe D into the oil of the extraction drum A. The refrigerant is directly absorbed by the oil, or the refrigerant is condensed by cooling the cooling pipe G so that the condensed liquid refrigerant is absorbed by the oil, and the extracted gas rich in non-condensed gas is discharged to the atmosphere while collecting the refrigerant. When there is a large amount of non-condensed gas, the internal pressure of the extraction drum A rises, and when it reaches a predetermined pressure (1.4 Kg / cm ² G), the pressure switch J operates and the extraction valve E Of the extraction gas is discharged to the atmosphere via the extraction pipe F, and the internal pressure of the extraction drum A is reduced by the extraction of the extraction gas to lower the predetermined pressure (1). .05 Kg / cm ² )), the bleed valve E is closed.

When the amount of non-condensed gas is small, the internal pressure of the extraction drum A is a predetermined pressure (1.4 Kg / cm ² G).
The pressure switch J at this time.
Does not operate, and the extraction valve E is kept closed so that the extraction gas with a small amount of non-condensed gas is not discharged to the atmosphere through the extraction pipe F.

[0007]

However, in this oil absorption type extraction apparatus, the oil pump of the turbo compressor is used to supply the oil to the extraction drum A, but the oil pressure is essentially evaporated. Since the control is performed on the basis of the pressure, the evaporation pressure also fluctuates due to the fluctuation of the steam temperature and the hydraulic pressure also fluctuates. Therefore, the oil level in the extraction drum A is controlled by the float switches H and I. Oil is supplied to and discharged from the bleeding drum A, and the bleeding valve E is opened and closed by opening and closing the pressure switch K that opens and closes on the basis of the internal pressure of the bleeding drum A.
When the hydraulic pressure is low, the internal pressure of the extraction drum A may not rise to a predetermined pressure (1.4 Kg / cm ² G) when the hydraulic pressure is low.
At this time, the extraction valve E is not opened, and even if the non-condensed gas is accumulated in the extraction drum A, the non-condensed gas rich extracted gas cannot be discharged to the atmosphere, and when the hydraulic pressure is high, the non-condensed gas is not discharged. Even when the air is not accumulated in the bleeding drum A, the internal pressure of the bleeding drum A has a predetermined value (1.4
Kg / cm ² G) and the bleed valve E is opened by the operation of the pressure switch J, so that the refrigerant is accidentally discharged to the atmosphere. There was a problem that performance could not be compensated.

In order to solve the above problems, according to the present invention, when the refrigerant is mixed with the non-condensable gas in the extraction drum, the refrigerant is absorbed by the oil over time, and the internal pressure of the extraction drum is increased. It was invented paying attention to the fact that the partial pressure of the refrigerant decreases, and its purpose is to be able to compensate the extraction performance of the oil absorption type extraction device of the refrigerator even when the hydraulic pressure supplied to and discharged from the extraction drum changes. That is the point.

[0009]

In order to achieve the above object, the present invention provides a bleeding drum 2 and a hydraulic pipe 4 having a supply / discharge valve 3 for supplying / discharging oil from a refrigerating device to / from the bleeding drum 2. Oil equipped with a gas injection pipe 5 for injecting a non-condensable gas containing a refrigerant into the oil of the extraction drum 2 and an extraction pipe 7 having an extraction valve 6 for discharging the extraction gas from the extraction chamber 1 of the extraction drum 2 In the absorption type extraction device, the extraction chamber 1 of the extraction drum 2
And a differential pressure switch 10 for detecting the differential pressure between the internal pressure in the hydraulic pipe 4 and the primary pressure of the supply / discharge valve 3 in the hydraulic pipe 4, and the bleed valve 6 when the differential pressure change in the absorption stroke is equal to or less than a predetermined differential pressure. The extraction valve control device 11 for performing the opening operation is provided.

[0010]

The differential pressure change corresponding to the decrease of the partial pressure of the refrigerant in the absorption stroke is detected by the differential pressure switch 10 with reference to the primary side hydraulic pressure of the supply / discharge valve 3 in the hydraulic pipe 4. Only when the change in the differential pressure is less than or equal to a predetermined differential pressure, the extraction valve control device 11 can open the extraction valve 6 to discharge the non-condensed gas-rich extraction gas to the atmosphere.

Therefore, even if the pressure of the oil supplied from the hydraulic pipe 4 may fluctuate such as increase or decrease, the amount of non-condensable gas is large despite the pressure fluctuation of the hydraulic pipe 4. The bleed valve 6 is controlled by the bleed valve control device 11 only when the change in the differential pressure due to
Is opened to discharge the non-condensable gas to the atmosphere, and when the change in the differential pressure due to the small amount of the non-condensable gas is less than or equal to a predetermined differential pressure, the extraction valve 6 is kept closed to erroneously release the refrigerant into the atmosphere. Since the oil is not discharged to the air, the extraction performance of the oil absorption type extraction device can be compensated.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The oil absorption type extraction device shown in FIG.
In the lower part of the extraction drum 2 having the above, the oil supply / exhaust valve 3 for supplying and exhausting the oil of the refrigerating device to the extraction drum 2 and the hydraulic pipe 4 having the dryer 31 interposed, and the oil in the extraction drum 2 contains a refrigerant. A gas injection pipe 5 for injecting the non-condensed gas is connected, and a bleed pipe 6 having a check valve 61 and a bleed valve 6 for discharging the bleed gas from the bleed chamber 1 is connected to the upper part.

Further, a cooling pipe 8 through which a part of the refrigerant liquid in the condenser of the refrigerating apparatus flows is penetrated through the extraction drum 2, and in the extraction chamber 1, from the gas injection pipe 5 to the extraction drum 2. The refrigerant injected together with the non-condensable gas is condensed by cooling the cooling pipe 8, and the condensed liquid refrigerant is absorbed in oil to separate the refrigerant from the non-condensable gas and collect it in the oil, while the extraction pipe By opening the bleeding valve 6 installed in 7, the bleeding gas rich in non-condensing gas is released to the atmosphere.

Reference numeral 32 is an oil discharge pipe for discharging the oil in the bleed chamber 1 from the supply / discharge valve 3 to the oil tank, and 51 is a check valve provided in the gas injection pipe 5.

Therefore, a differential pressure switch 10 for detecting the differential pressure between the internal pressure in the bleeding chamber 1 of the bleeding drum 2 and the primary side pressure of the supply / discharge valve 3 in the hydraulic pipe 4, and the differential pressure change in the absorption stroke. However, a bleed valve control device 11 is provided for opening the bleed valve 6 when the pressure is equal to or lower than a predetermined differential pressure.

That is, as shown in FIG.
A solenoid valve that opens and closes in response to an electric signal is used as the bleeding valve 6 installed in the valve, and the supply / discharge valve 3 is a three-way port having three ports: an oil supply port a, an oil supply / discharge oil port b, and an oil discharge port c. Since a valve is used, a switching device 33 for opening and closing each port a, b, c is connected to this three-way valve, and the operation of the switching device causes the oil supply port a and the supply / discharge port b to open. By supplying oil to the bleeding chamber 1, or by discharging the oil from the bleeding chamber 1 by opening the oil supply / exhaust port b and the oil drain port c,
The oil level in the extraction chamber 1 is moved up and down at regular time intervals so that the oil operates as a liquid piston.

A communication pipe 12a is provided between the primary side of the fuel supply port a and the primary side of the extraction valve 6 of the extraction pipe 7.
12b is connected, and the differential pressure switch 10 is interposed between the communication pipes 12a and 12b.
The internal pressure of the extraction chamber 1 and the hydraulic pressure on the primary side of the supply / discharge valve 3 in the hydraulic pipe 4 are allowed to act on the internal pressure of the extraction chamber 1 and the supply of the hydraulic pipe 4 by the differential pressure switch 10. The differential pressure with respect to the primary side pressure of the exhaust valve 3 can be detected, and the bleed valve control device 11 including a controller having a built-in CPU, for example, is provided, and the differential pressure is provided on the input side of the bleed valve control device 11. The pressure switch 10 is connected, and the bleed valve 6 is connected to the output side, and after a certain time has elapsed after the start of a compression stroke or an absorption stroke described later, the internal pressure and the hydraulic pressure in the bleed chamber 1 of the bleed drum 2 are increased. The pressure difference between the supply / discharge valve 3 and the primary side pressure in the pipe 4 is a predetermined pressure difference (for example, 0.15 Kg / cm ^2).
G) In the following cases, the bleed valve 6 is opened by the output of the bleed valve control device 11 for a predetermined time.

Therefore, the oil absorption type device of the refrigerator constructed as described above repeats the following four strokes.

That is, with the extraction valve 6 and the oil drain port c closed, the oil supply port a and the oil supply / exhaust oil port b are opened for a certain period of time to supply oil to the extraction chamber 1 for a certain period of time. After refueling, the compression process of closing the refueling port a, the absorption process of maintaining a state in which oil is not discharged to the bleed chamber 1 for a predetermined time, and the bleed valve 6 are opened to discharge the non-condensed gas rich bleed gas. The bleeding stroke, and with the bleeding valve 6 closed, the oil supply / drain port b and the oil drain port c of the supply / drain valve 3 are opened to drain the oil in the bleed chamber 1 and The suction stroke of sucking the refrigerant gas containing the non-condensable gas from the condenser of the refrigerating device into the low pressure extraction chamber 1 through the gas injection pipe 5 is repeated.

By the way, the compression process is performed by the switching device 33.
Is controlled by a timer or a float switch is provided to control the oil level in the extraction chamber 1 to a constant height.

After a lapse of a certain period of time or when the height of the oil surface reaches a certain level, the supply / discharge port b of the three-way valve is closed so that neither the supply port a nor the discharge port c is supplied or discharged. To maintain.

In this state, the differential pressure switch 1
The opening / closing control of the bleed valve 6 is controlled based on the detection result of 0. The opening / closing control of the bleed valve 6 is such that when the compression stroke is time-controlled, the time control of the compression stroke is continued to perform compression. This is done after a certain time (T1) has elapsed after the end of the stroke, and when a float switch is used, the timer count is started based on the detection of the end of the compression stroke by the float switch, and after the start of the absorption stroke. This is done after a certain time (T2) has elapsed.

Therefore, after the compression stroke is completed as described above, after a fixed time, that is, after the completion of the absorption stroke by the time control, the bleeding stroke is moved based on the detection result of the differential pressure switch 10. The differential pressure detected by the differential pressure switch 10 is a predetermined differential pressure (for example, 0.15 Kg / cm ²
G) In the following cases, the bleeding valve 6 is opened to bleed air, and the differential pressure is a predetermined differential pressure (for example, 0.15 Kg /
cm ² G), the suction stroke is entered without entering the bleed stroke in which the bleed valve 6 is opened. Further, as described above, as the supply and discharge of oil to and from the extraction chamber 1 is repeated without entering the extraction process, the non-condensed gas accumulates in the extraction chamber 1 and the amount of non-condensed gas increases. At this time, the bleeding valve 6 is opened by the output of the bleeding valve control device 11, and the bleeding stroke for discharging the bleeding gas rich in non-condensing gas is entered.

The case where the bleed valve 6 is opened by the output of the bleed valve control device 11 and the case where the bleed valve 6 is kept closed will be described.

The graph shown in FIG. 2 shows the change over time in the internal pressure of the bleed chamber 1 after the start of the refueling of the bleed chamber 1, that is, after the compression stroke is started. The hydraulic pressure rises as the pressure increases and the pressure becomes the same as the hydraulic pressure in the hydraulic pipe 4. Next, in the absorption stroke, the partial pressure of the refrigerant absorbed by the oil decreases with time, and when the amount of non-condensed gas is small, that is, when there is a large amount of refrigerant, the pressure decreases as shown by the solid line, and the absorption stroke decreases. At the end, that is, after the elapse of T1 time or T2 time, the pressure becomes equal to or lower than the set pressure (oil pressure −0.15 Kg / cm ² G) shown by the chain line. Further, when the amount of non-condensed gas is large, that is, when the amount of refrigerant is small, the pressure decreases as shown by the dotted line, but it does not decrease below the set pressure (oil pressure −0.15 Kg / cm ² G). In this case, the hydraulic pipe 4
The set pressure also fluctuates in the same manner as the fluctuation of the hydraulic pressure.

However, when there is a large amount of non-condensable gas and the internal pressure changes as shown by the dotted line in FIG. 2, the difference in the differential pressure detected by the differential pressure switch 10 after the passage of the time T1 or T2. The predetermined differential pressure (0.
15 Kg / cm ² G) or less, the bleed valve 6 is opened for a predetermined time by the output of the bleed valve control device 11 to release the non-condensed gas rich bleed gas to the atmosphere via the bleed pipe 7. Further, when the internal pressure changes as indicated by the solid line in FIG. 2 due to a small amount of non-condensed gas, the change in the differential pressure becomes higher than the predetermined differential pressure (0.15 Kg / cm ² G). There is no output from the bleed valve controller 11, the bleed valve 6 remains closed, the bleed chamber 1 of the bleed drum 2 is not opened to the atmosphere, and the bleed stroke is not performed.

That is, the differential pressure change in accordance with the decrease of the partial pressure of the refrigerant in the absorption stroke is detected by the differential pressure switch 10 with reference to the hydraulic pressure on the primary side of the supply / discharge valve 3 in the hydraulic pipe 4. The extraction valve 6 can be opened by the extraction valve control device 11 only when the change in the differential pressure is less than or equal to a predetermined differential pressure, and the extraction gas rich in non-condensing gas can be discharged to the atmosphere.

Therefore, even if the pressure of the oil supplied from the hydraulic pipe 4 may fluctuate such as increase or decrease, the amount of non-condensable gas is large despite the pressure fluctuation of the hydraulic pipe 4. Because the extraction valve control device 11 causes the extraction valve 6 to open the extraction valve 6 only when the change in the differential pressure due to is less than or equal to a preset predetermined differential pressure, the non-condensed gas is released to the atmosphere, and the non-condensed gas is small. When the change in the differential pressure is higher than the predetermined differential pressure, the extraction valve 6 is kept closed and the refrigerant is not accidentally discharged to the atmosphere. Therefore, the extraction performance of the oil absorption type extraction device is compensated. You can

[0029]

As described above, in the present invention, the extraction drum 2, the hydraulic pipe 4 having the supply / discharge valve 3 for supplying / discharging the oil of the refrigerating device to / from the extraction drum 2, and the extraction drum 2 are provided. A gas injection pipe 5 for injecting a non-condensable gas containing a refrigerant into oil,
In an oil absorption type extraction device provided with an extraction pipe 7 having an extraction valve 6 for discharging extraction gas from the extraction chamber 1 of the extraction drum 2, an internal pressure in the extraction chamber 1 of the extraction drum 2 and the hydraulic pipe 4 described above. A differential pressure switch 10 for detecting a differential pressure from the primary pressure of the supply / discharge valve 3 and a bleed valve control device 11 for opening the bleed valve 6 when a differential pressure change in an absorption stroke is equal to or less than a predetermined differential pressure. Since it is provided, the differential pressure change according to the decrease of the partial pressure of the refrigerant in the absorption stroke is detected by the differential pressure switch 10 with reference to the primary side hydraulic pressure of the supply / discharge valve 3 in the hydraulic pipe 4. The extraction valve 6 can be opened by the extraction valve control device 11 only when the change in the differential pressure is less than or equal to a predetermined differential pressure, and the extraction gas rich in non-condensing gas can be discharged to the atmosphere.

Therefore, even if the pressure of the oil supplied from the hydraulic pipe 4 may fluctuate such as increase or decrease, the amount of non-condensable gas is large despite the pressure fluctuation of the hydraulic pipe 4. The bleed valve 6 is controlled by the bleed valve control device 11 only when the change in the differential pressure due to
To release the non-condensable gas to the atmosphere, and when the change in the differential pressure due to the small amount of the non-condensable gas is less than or equal to a predetermined differential pressure, the extraction valve 6 is kept closed to erroneously release the refrigerant into the atmosphere. Since the oil is not discharged to the air, the extraction performance of the oil absorption type extraction device can be compensated.

[Brief description of drawings]

FIG. 1 is a piping system diagram of an oil absorption type extraction device of a refrigerator according to the present invention.

FIG. 2 is a graph showing an example of changes over time in the extraction chamber pressure after refueling.

FIG. 3 is a conventional piping system diagram.

[Explanation of symbols]

 1 Bleed Chamber 2 Bleed Drum 3 Supply / Discharge Valve 4 Hydraulic Pipe 5 Gas Injection Pipe 6 Bleed Valve 7 Bleed Pipe 10 Differential Pressure Switch 11 Bleed Valve Control Device

Claims (1)

Claim: What is claimed is: 1. An extraction drum 2, a hydraulic pipe 4 having a supply / discharge valve 3 for supplying / discharging oil from a refrigerating device to / from the extraction drum 2, and a refrigerant in the oil of the extraction drum 2. In the oil absorption type extraction device, the extraction pipe is provided with a gas injection pipe 5 for injecting a non-condensable gas containing a gas, and an extraction pipe 7 having an extraction valve 6 for discharging the extraction gas from the extraction chamber 1 of the extraction drum 2. 2 bleed chamber 1
And a differential pressure switch 10 for detecting the differential pressure between the internal pressure in the hydraulic pipe 4 and the primary pressure of the supply / discharge valve 3 in the hydraulic pipe 4, and the bleed valve 6 when the differential pressure change in the absorption stroke is equal to or less than a predetermined differential pressure. An oil absorption type extraction device for a refrigerator, which is provided with an extraction valve control device 11 for opening operation.