JPS5844307B2 - Absorption chiller bleed device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air extraction device for extracting non-condensable gas accumulated in an absorption refrigerator.

Non-condensable gas that accumulates during operation of an absorption chiller causes problems such as a decrease in refrigeration capacity, so it must be extracted. However, if outside air enters the absorption chiller during air extraction, the refrigeration Not only will the capacity be almost lost, but there is also a risk that the crystals will cause the system to become inoperable, so a high degree of reliability is required.

FIG. 1 shows a conventional example, in which 1 is an absorption refrigerator, 2.3.4 is a pipe line, which is equipped with a solenoid valve 5 and an oil trap 6, and is connected to a vacuum pump 7.

8 is a timer and 9 is a leak port.

In this system, a timer 8 opens the solenoid valve 5 when a certain period of time has elapsed after the vacuum pump 7 was operated and the leak port 9 was closed.

However, in this method, the pressure in the bleed path is not detected, so the vacuum pump 7 may not rotate due to a lock, or the water in the oil in the vacuum pump 7 may increase, causing the vacuum pump 7 to lose its ability to bleed. If this is not possible, outside air may enter, which is very dangerous.

FIG. 2 shows another conventional example in which the pressure in the bleed path is detected by a pressure switch 10 and the solenoid valve 5 for the main piping is opened after confirming the capacity of the vacuum pump 7.
A high degree of vacuum requires a highly accurate pressure switch, and conventional tongue and diaphragm types have problems with repeatability and longevity, and other types of pressure switches with high precision are expensive.

Further, the solenoid valve 5 is extremely susceptible to dirt and rust, and cannot maintain airtightness.

The present invention is equipped with a vacuum level detector that optically or electromagnetically detects the mercury surface of a mercury manometer as a pressure switch, and uses two or more valves of different types as opening/closing valves for the bleed air path. By bleeding air after confirming the operation of the pump, the above-mentioned drawbacks of conventional pumps are eliminated, and the system prevents outside air from entering during bleeding, has a highly accurate pressure switch, has high reproducibility, has a long service life, and is inexpensive. It is an object of the present invention to provide a safe and reliable air extraction device for an absorption refrigerator, which has a high reliability and reduces the influence of dust getting caught in the on-off valve.

The present invention provides an air bleed device for an absorption refrigerator that extracts non-condensable gas in the absorption chiller via a bleed path using a vacuum pump, and the bleed path is provided with a plurality of on-off valves of different types. A detection mechanism is provided that optically or electromagnetically detects the mercury column of a mercury manometer that detects the degree of vacuum in the extraction path, and detects that a predetermined amount of non-condensable gas is accumulated in the absorption refrigerator and issues an accumulation signal. an accumulation detection mechanism;
an air bleed control mechanism configured to receive the accumulation signal, start the vacuum pump, and open the on-off valve after the degree of vacuum in the air bleed path reaches a predetermined starting vacuum degree;
This is an air bleed device for an absorption refrigerator, characterized in that it includes a stop mechanism configured to issue a stop signal to stop the bleed operation.

To explain the present invention with reference to the drawings, an embodiment of the present invention will be described. As shown in FIG. 3, two on-off valves □ and v2 are provided in the bleed air path.

Different models are selected for the on-off valves ■1 and v2.

For example, one of the on-off valves V2 is a fast-acting valve, such as a solenoid valve, for emergency shutoff in the event of an abnormality such as a power outage.

For the other on-off valve v1, a valve such as an electric diaphragm valve was selected, which easily maintains airtightness even if there is dirt or rust, and is resistant to leakage through the valve. Reliability can be improved by combining different types of on-off valves. It's increasing.

The oil trap 6 is equipped with a mercury manometer 11 and mercury level detectors 12 and 13 as pressure switches.

The mercury manometer 11 is an absolute vacuum mercury manometer having a U-shaped tube with one end closed, and has an absolute pressure of O to 100 mr.
It has high accuracy of ±0.5 mmHg or less even in the ILHg range.

A photoelectric switch may be used as the mercury surface detector 12,13.

Alternatively, a magnet may be floated on the mercury surface and detected using a reed switch.

The use of these detectors does not compromise the above-mentioned degree of accuracy.

Moreover, it has extremely good reproducibility, is inexpensive, and has high reliability.

The mercury surface detectors 12, 13 may detect the mercury surface on either side of the mercury manometer 11, but the mercury surface on the closed end side is preferable because it is clean and free from contamination by noncondensable gases.

The mercury level detector 12 is a confirmation switch that confirms whether the vacuum pump 7 is operating reliably before performing air extraction.
The starting vacuum degree, which indicates that it is OK to start the bleed operation (opening the on-off valves ■1 and ■2), is a set value, and when this set value is reached, the on-off valves ■1 and ■2 are opened via the control mechanism 14. Open and activate the bleed operation.

The starting vacuum degree is set to about 3 mmHgAbs.

The mercury level detector 13 is a monitoring switch for monitoring abnormalities in the pressure of the bleed path and stopping the bleed during the bleed operation.

If the mercury level detector 12 detects an abnormal rise in pressure and stops the bleed, the bleed must be stopped frequently even if there is a slight rise. Set to abnormal vacuum level.

The actions of these mercury level detectors 12 and 13 are shown in Figure 3a.The vacuum pump 7 is activated at point A by an accumulation signal, which will be described later, and when the pressure decreases and reaches the starting vacuum level PB, the mercury level detector is activated. 12 operates and opens the on-off valves ■1 and ■2.

In this case, since the pressure inside the absorption refrigerator is about 6 to 15 iiHg, the pressure increases and reaches PC, and steady air extraction operation is performed.

When the internal pressure abnormally increases due to some reason during operation and reaches the abnormal vacuum degree PD, the mercury level detector 13 is activated, closes the on-off valves V□ and v2, stops the vacuum pump 7, and removes air. Stop operation.

By providing a monitoring switch, it is possible to check whether the vacuum pump 7 is locked or the capacity is reduced due to water being contained in the oil, thereby ensuring safe operation.

During the heating cycle, the internal pressure is 30 to 40 mzHg, so it is necessary to change the set value of the abnormal degree of vacuum PB.

15 is a strainer, 16 is a drain, and 27 is a separator.

The leak port 9 may not be provided.

FIG. 4 shows another embodiment in which a storage chamber 17 is provided in which non-condensable gas is guided and stored by an ejector or the like.

The operating process of the extraction operation is shown in the flow sheet of FIG.

To give a supplementary explanation, the extraction circuit is turned on at the same time as the absorption refrigerator is started.

In determination 18, the accumulation detection mechanism determines whether a predetermined amount of non-condensable gas is accumulated in the absorption refrigerator, and the signal in the case of YES becomes the accumulation signal.

The accumulation detection mechanism includes a timer that estimates that a predetermined amount of accumulation has been accumulated and issues an accumulation signal when a predetermined period of time has elapsed from the start of the absorption chiller, and a timer that issues an accumulation signal when a predetermined amount of accumulation has been accumulated. Related physical quantities, e.g. storage chamber 17
A detector that detects the liquid level in the storage chamber 17, the gas pressure in the storage chamber 17, etc., or a physical quantity related to the amount of non-condensable gas in the absorber of an absorption refrigerator, such as supercooling of the solution in the absorber. Every time,
Condensed! A detector that detects the temperature difference between the internal refrigerant temperature and the absorber outlet solution temperature (when non-condensable gas is stored in the absorber, the absorber outlet temperature decreases and the temperature difference becomes large), etc. etc. are used, and when those set values are reached, YE
S, and an accumulation signal is generated.

Processing 19 is for causing the vacuum pump 7 to operate idly and sucking atmospheric air from the leak port 9 to raise the oil temperature.

An oil temperature thermostat may be used instead of a timer.

Processing 20 and judgment = 21 are parallel, and the pressure is Pl(
If the startup vacuum level is below PB) in Figure 3a, the process 22 can be performed even before 5 minutes, and if it is 41 or higher even after 5 minutes, it may be considered abnormal.

If you are only testing the vacuum pump 7, select step 22) YES.
All you have to do is continue until you get the signal.

P2 of judgment 23 is the abnormal degree of vacuum (PD in FIG. 3a).

The manual operation in process 24 is an operation without monitoring the pressure P2 and is used for initial air extraction.

In the case of initial air extraction, the pressure inside the cylinder is near atmospheric, so the on-off valve ■1,
i ■Opening 2 shows the pressure near the atmosphere.

Decisions 25 and 26 are made by the stop mechanism, and a YES result serves as a stop signal to stop the bleed operation.

The above-mentioned accumulation detection mechanism is used as the stop mechanism, and when the detected value does not reach the set value) or another predetermined set value (the amount of non-condensable gas remaining in the absorption refrigerator falls below a predetermined amount) When the setting value that can be estimated as YES is reached, a stop signal is issued.

A stop signal is also issued in case of decision 23 ONO.

Since non-condensable gas tends to accumulate in specific locations during operation of the refrigerant machine, it is better to carry out the extraction operation while the refrigerating machine is operating.

The accumulation signal or stop signal may be generated by detecting another physical quantity that indicates the operating state of the refrigerator.

The present invention relates to an air bleed device for an absorption refrigerator that extracts non-condensable gas in the absorption chiller via a bleed path using a vacuum pump, and the bleed path includes a plurality of on-off valves of different types, A detection mechanism is provided that optically or electromagnetically detects the mercury column of a mercury manometer that detects the degree of vacuum in the extraction path, and detects that a predetermined amount of non-condensable gas is accumulated in the absorption refrigerator and issues an accumulation signal. an accumulation detection mechanism;
an air bleed control mechanism configured to receive the accumulation signal, start the vacuum pump, and open the on-off valve after the degree of vacuum in the air bleed path reaches a predetermined starting vacuum degree;
Equipped with a stop mechanism configured to issue a stop signal and stop the air bleed operation, it is safe and prevents outside air from entering during the air bleed operation, and the pressure switch is highly accurate and reproducible. It has a long life, is inexpensive, has an on-off valve that is less susceptible to the effects of dirt getting stuck in it, can provide a highly reliable extraction device for absorption refrigerators, and has extremely great practical effects.

[Brief explanation of the drawing]

Figures 1 and 2 are flow diagrams of the conventional example, Figures 3 and 4
The figure is a flow chart of an embodiment of the present invention, Figure 3a is a diagram showing the action of the mercury level detector, and Figure 5 is a flow sheet showing its operating status. 1... Absorption refrigerator, 2.3.4... Pipe line, 5...
Solenoid valve, 6...Oil trap, 7...Vacuum pump, 8...Timer 9...Leak port, 10...
・Pressure switch, 11...Mercury manometer, 12.1
3...Mercury surface detector, 14...Control mechanism, 15...
・Strainer, 16...Drain removal, 17...Storage chamber, 18...Judgment, 19.20...Processing, 21...
・Judgment, 22... Processing, 23... Judgment, 24...
Processing, 25. 26... Judgment, 27... Separator.

Claims (1)

[Claims] 1. For an extraction device of an absorption refrigerator that extracts non-condensable gas in the absorption refrigerator using a vacuum pump via an extraction route,
The bleed path is provided with a plurality of on-off valves of different types,
and a detection mechanism for optically or electromagnetically detecting the mercury column of a mercury manometer as a vacuum degree detection mechanism in the extraction path, and detects that a predetermined amount of non-condensable gas is accumulated in the absorption refrigerator and generates an accumulation signal. an air bleed control mechanism configured to receive the accumulation signal, start the vacuum pump, and open the on-off valve after the degree of vacuum in the bleed path reaches a predetermined starting vacuum degree. An air bleed device for an absorption refrigerator, comprising: a stop mechanism configured to issue a stop signal and stop the air bleed operation. 2. Claim 1, wherein the accumulation signal is issued after a predetermined time has elapsed after the start of the absorption refrigerator.
Apparatus described in section. 3. The device according to claim 1, wherein the accumulation signal detects a physical quantity related to the amount of non-condensable gas in the absorber of the absorption refrigerator and is issued when a set value is reached. 4 The physical quantity related to the amount of non-condensable gas in the absorber is
Claim 3, which is the degree of supercooling of the solution in the absorber.
Apparatus described in section. 5 The physical quantity related to the amount of non-condensable gas in the absorber is
4. The apparatus according to claim 3, wherein the temperature difference is between the refrigerant temperature in the condenser of the absorption refrigerator and the temperature of the solution at the outlet of the absorber. 6 the stop signal is emitted after the accumulation signal is issued;
2. The device according to claim 1, which is activated when a predetermined time has elapsed. 7. The device according to claim 3, wherein the stop signal detects a physical quantity related to the amount of non-condensable gas in the absorber and is issued when a set value for stopping is reached. 8. The apparatus of claim 1, wherein the stop signal is issued when the degree of vacuum in the extraction path reaches a predetermined abnormal degree of vacuum lower than the starting vacuum degree during the bleed operation. 9. The non-condensable gas inside the absorption refrigerator is extracted by the vacuum pump through the extraction route,
The bleed path is provided with a plurality of on-off valves of different types,
and a detection mechanism for optically or electromagnetically detecting the mercury column of a mercury manometer as a vacuum degree detection mechanism in the extraction path, and detects that a predetermined amount of non-condensable gas is accumulated in the absorption refrigerator and generates an accumulation signal. an air bleed control mechanism configured to receive the accumulation signal, start the vacuum pump, and open the on-off valve after the degree of vacuum in the bleed path reaches a predetermined starting vacuum degree. and a stop mechanism configured to issue a stop signal to stop the bleed operation, a storage chamber for storing the non-condensable gas, and the accumulation signal indicates a physical quantity related to the amount stored in the storage chamber. An air bleed device for an absorption refrigerator, characterized in that the signal is detected and issued when a set value is reached. 10. The device according to claim 9, wherein the physical quantity related to the storage amount is a liquid head height in the storage chamber. 11. The device according to claim 9, wherein the physical quantity related to the storage amount is gas pressure within the storage chamber. 12. The device according to claim 9, wherein the stop signal detects a physical quantity related to the storage amount in the storage chamber and is issued when a set value for stopping is reached.