JPH0760037B2 - Absorption refrigerator - Google Patents

Description

TECHNICAL FIELD The present invention relates to an absorption refrigerator having an extraction device that sucks and discharges noncondensable gas from the inside of an evaporator or an absorber.

(B) Conventional technology For example, as an absorption refrigerator equipped with an extraction device, the non-condensed gas in the evaporative absorber is extracted together with the refrigerant vapor by the ejector action of the absorbing liquid injected from the solution pump to separate them. A non-condensable gas is stored in a tank and discharged to the outside of the machine (see, for example, Japanese Utility Model Publication No. 53-2360).

(C) Problems to be solved by the invention In the cold / heat switching type absorption refrigerator, the pressure in the evaporative absorber during cold water extraction operation is at most about 10 mmHg, but during hot water extraction operation it is about 200 mmHg. It may increase to. Therefore, in the conventional extraction device, the absorbing liquid is pushed out to the tank for non-condensable gas by the internal pressure of the evaporative absorber during the hot water extraction operation and is used as an exhaust device such as a vacuum pump (a pump for non-condensable gas exhaust) or a palladium cell. May flow into the tank and damage them, and when the capacity of the non-condensable gas tank is increased, the absorption liquid circulating in the absorption refrigerator may become insufficient and the cavitation of the solution pump and the empty space of the generator. There are various problems such as burning.

And, as a conventional means for solving these problems, at the time of hot water extraction operation, the non-condensable gas tank is heated by the refrigerant vapor from the generator to pressurize the inside of the tank (for example, Japanese Patent Publication No. 52-49182). [See Japanese Patent Application Publication], or a tank for non-condensable gas is formed in the vapor phase portion of the evaporative absorber, and the temperature inside the tank is raised to the same level as the vapor phase portion [see, for example, Jitsuko Sho]
57-33347] is proposed.

However, in these conventional means, it takes a considerable amount of time for the non-condensable gas tank to rise in temperature and pressure when the absorption refrigerating machine is switched to a cold temperature. In addition, it will invade a bleeding device such as a vacuum pump or a vacuum pump, and in the end, the above problems cannot be reliably solved.

By connecting the vapor phase part of the evaporator / cooler of the cold temperature switching type absorption refrigerator and the tank for non-condensable gas with a pipe with an on-off valve, the on-off valve is opened at the same time as switching the hot water extraction operation to evaporate and absorb the inside of the tank. There is also a method of preventing the absorption liquid from entering the tank, the palladium cell, the vacuum pump, etc. by equalizing the pressure inside the vessel (see, for example, JP-A-60-235975), but in this method the gas in the tank Will return to the side of the evaporative absorber, so there is a problem that the non-condensable gas cannot be collected during the hot water extraction operation.

Further, Japanese Patent Laid-Open No. 60-226681 discloses a non-condensable gas discharge device in which a return pipe for absorbing liquid is connected to a lower portion of a container near a lower end opening of a gas-liquid flow pipe provided in the container. ing. However, in this discharge device, a part of the non-condensable gas discharged from the lower end of the gas-liquid flow-down pipe may enter the return pipe and return to the inside of the vessel (absorber) to reduce the discharge efficiency of the non-condensable gas. there were. In addition, the high temperature absorbent flowing out of the gas-liquid downflow pipe flows to the return pipe, the temperature of the absorbent surface in the container does not rise easily, the temperature of the storage chamber does not rise easily, and the pressure does not rise easily. In some cases, the level of the absorbing liquid rises, which may damage the vacuum pump and the like.

The present invention prevents the non-condensable gas from returning from the extraction device to the absorber or the evaporator, and also prevents the absorption liquid generated by the rise of the absorption liquid level of the separator from entering the palladium cell, the vacuum pump or the like. The purpose is to

(D) Means for Solving the Problems In order to solve the above problems, the present invention provides an ejector (E _J that sucks non-condensable gas in an absorber (6) or an evaporator (5) using an absorbing liquid. ), A separator (30) for separating the noncondensable gas and the absorbing liquid, a storage chamber (T ₁ ) for temporarily storing the noncondensable gas separated by the separator (30), and a storage chamber (T ₁ ), An exhaust device for exhausting the non-condensed gas, and a bottomed separation pipe (31) extending downward from the lower end of the separator (30) and having a horizontal cross-sectional area smaller than that of the separator (30). , The upper end is connected to the ejector (EJ), penetrates the separator (30) and extends downward in the separation pipe (31), and the lower end is a gas-liquid downflow pipe (29) which opens at the lower part of the separation pipe (31). A return pipe (32) provided between the separator (30) and the absorber (6) for returning the absorption liquid near the absorption liquid surface of the separator (30) to the absorber (6). It is intended to provide the example was absorption refrigerator.

Further, an ejector (E _J ) for sucking the non-condensable gas in the absorber (6) or the evaporator (5) using the absorbing liquid, and a separator (37A) for separating the non-condensing gas and the absorbing liquid. An absorption refrigerator having a storage chamber (37B) for temporarily storing the non-condensable gas separated by the separator (37A) and an exhaust device for exhausting the non-condensable gas in the storage chamber (37B). A bottomed separation tube (3A) that is provided below the absorbing liquid surface and has an open top.
8), the gas-liquid flow-down pipe (29) connected to the ejector (E _J ) and inserted into the separation pipe (38), and the absorber (6) below the separator (37A). An absorption refrigerating machine provided with a return pipe (40) for returning the liquid to the absorber (6).

(E) Action During the extraction of cold water from the absorption refrigerator, the extraction of hot water, or the switching of cold temperature, the high-temperature absorption liquid that has flowed out of the gas-liquid downflow pipe (29) is temporarily absorbed on the absorption liquid surface or the absorption liquid surface. And the temperature of the absorbing liquid surface rises. The separator vapor (3
0) and the non-condensable gas in the storage chamber (T ₁ ) are warmed and the temperature rises, the pressure in the separator (30) and the storage chamber (T ₁ ) rises, and the absorber (6) or evaporation It is possible to prevent the pressure from becoming extremely lower than the pressure in the vessel (5), suppress the rise of the absorption liquid surface, and prevent the exhaust device such as the palladium cell (PC) from being damaged by the absorption liquid. In addition, the separator (3
Since the horizontal cross-sectional area of the separation pipe (31), which extends downward from the lower end of (0) and the gas-liquid flow-down pipe (29) extends downward, is smaller than that of the separator (30), the separator (30) and the separation pipe (31)
It is possible to reduce the amount of absorbing liquid that accumulates inside. It is possible to reduce the amount of absorption liquid held by the absorption refrigerator.

In addition, during the operation of the absorption chiller, during cold water extraction, during hot water extraction, or during cold temperature switching, the absorbent that has flowed out from the lower end of the gas-liquid flow down pipe (29) will flow through the separator (38). The temperature rises and once rises to or near the absorption liquid surface, and the temperature of the absorption liquid surface rises. Then, the vaporization of the refrigerant vapor from the absorbing liquid level is promoted, the pressure of the non-condensable gas in the savings (37B) rises, and becomes extremely lower than the pressure in the absorber (6) or the evaporator (5). Is avoided, the rise of the absorbing liquid level is suppressed, and the exhaust device can be prevented from being damaged by the absorbing liquid. Further, the absorption liquid that has risen to the vicinity of the absorption liquid surface flows to the lower part of the separator (37A) and is returned from the lower part to the absorber (6) through the return pipe (40) to separate the noncondensable gas and the absorption liquid. Separation is ensured in the upper part of the separator (37B), and non-condensable gas is prevented from returning to the absorber (6).

(F) Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

The one shown in Fig. 1 is a cold-temperature switching absorption refrigerator, which uses water (H ₂ O) as a refrigerant and lithium bromide (LiB) as an absorbing liquid (solution).
r) It uses an aqueous solution.

In FIG. 1, (1) is a high temperature generator, (2) is a low temperature generator, (3) is a condenser, (4) is an evaporative absorber consisting of an evaporator (5) and an absorber (6), ( (7) and (8) are low and high temperature solution heat exchangers, (P _A ) is a solution pump, (9)
Is a separator, and these are pipes (10), (1
1), a pipe (12) through which a refrigerant liquid flows, pipes (13), (14), (15), (16) through which a dilute solution is fed, a pumping pipe (17), and a pipe through which a solution of an intermediate concentration flows ( 18), (19), pipes (20), (21) through which concentrated solution flows, pipes (22) with cold / hot switching valve (V _CH ).
A conventional cold-temperature switching type absorption refrigerating machine [hereinafter referred to as this machine] is configured by connecting with.

(B) is a burner of the high temperature generator (1), (23) is a heat source of the low temperature generator (2), (24) is a cooler of the condenser (3),
(25) is a heat exchanger of the evaporator (5), and (26) is a cooler of the absorber (6).

Then, during the chilled water extraction operation of this machine, an absorption refrigeration cycle is generated by circulating the refrigerant and the absorbing liquid as in the conventional cold / temperature switching absorption refrigerator, and the refrigerant in the heat exchanger (25) of the evaporator (5) is generated. The water in this heat exchanger with the latent heat of vaporization of 6
The temperature is lowered to about 8 ° C and the product is taken out. In addition, during the hot water extraction operation of this machine, the cooling water supply to the coolers (26) and (24) is stopped as before, while the cold / hot switching valve (V _CH ) is switched from closed to open to a high temperature. The absorption liquid and refrigerant vapor of the refrigerant are led to the evaporation absorber (4) via the pipe (22), and the water is heated by the latent heat of condensation of the refrigerant in the heat exchanger (25) [or this heat and the sensible heat of the absorption liquid]. It is designed to be taken out.

Moreover, (27) and (27) are extraction tubes arranged in the evaporative absorber (4), (E _J ) is an ejector for extraction air, and (28) is an absorption liquid to be ejected to the ejector for extraction (E _J ). A conduit connects its upstream end to the solution pump (P _A ) discharge side pipe (14). Reference numeral (30) is a separator, and the separator (30) contains the absorbing liquid injected into the extraction ejector (E _J ) and the non-condensed gas extracted by the action of the ejector from the ejector. A gas-liquid downflow pipe (2
9) is plugged in. Further, (31) is a separation pipe provided in the lower part of the separator (30), and a gas-liquid flow-down pipe (29) is inserted in the separation pipe (31). Further, (T) is a non-condensable gas tank provided above the separator (30) and connected to the separator (30) through a gas pipe (30A). The tank (T) is a non-condensable gas tank. It has become a storage room (T ₁ ). (PC) is a palladium cell in communication with the non-condensable gas tank (T). This palladium cell (exhaust device)
Non-condensable gas (hydrogen gas) is discharged from (PC). or,
Reference numeral (32) is a return pipe for the absorbing liquid, and the return pipe (32) is formed in a U shape. One end of the return pipe (32) is connected to the bottom wall of the separator (30) separately from the separation pipe (31), and the other end is open to the lower part of the absorber (6). And the opening (3
The 3) and the separator (30) are provided so as to have substantially the same height. Although not shown, it goes without saying that a non-condensable gas may be discharged from the tank (T) by connecting a gas exhaust pipe with an opening / closing valve, and via this exhaust pipe by a vacuum pump.

In this machine equipped with the bleeding device as described above, in any operation during cold water extraction, hot water extraction, or cold / temperature switching, the separation pipe (31) is supplied with the gas-liquid downflow pipe (29). The discharged non-condensable gas moves upward in the separation pipe (31) and is separated from the absorbing liquid in the upper part of the separator (30). Further, the absorbing liquid in the separator (30) flows through the return pipe (32) and is discharged to the absorber (6). At this time, since the return pipe (32) is connected near the absorbing liquid surface of the separator (30) and the flow lower part (32A) is formed, the noncondensable gas discharged from the gas-liquid downflow pipe (29) is Only the absorbing liquid returns from the separator (30) to the evaporative absorber (4) via the return pipe (32) without being sent to the evaporative absorber (4) via the return pipe (32).

Further, the high temperature absorbing liquid flowing out from the gas-liquid flow-down pipe (29) flows into the separator (30) through the separation pipe (31), and the refrigerant vapor is vaporized from the absorbing liquid surface to absorb the temperature-decreasing absorbing liquid. It is returned to the evaporative absorber (4) through a return pipe (32) connected near the absorbing liquid level. Then, the non-condensable gas in the separator (30) is warmed by the refrigerant vapor that is vaporized from the absorbing liquid, and the temperature of the non-condensable gas in the separator (30) and the non-condensable gas tank (T) is the evaporation absorber. It becomes almost equal to the temperature of the absorbing liquid flowing out from (4). As a result, the gas pressure in the non-condensable gas tank (T) is extremely lower than the pressure in the evaporative absorber (4) during any operation during cold water extraction, hot water extraction, or cold / temperature switching. Is prevented from becoming a separator (3
The rise of the absorption liquid level in 0) is avoided. As a result, the absorption liquid in the evaporative absorber (4) flows into the non-condensable gas tank (T) through the separator (30) and the gas pipe (30A) during any operation of the machine. It will not accumulate in the tank (T) and will not damage the palladium cell (PC).

As described above, in this machine, since the return pipe (32) is formed with the downflow portion (32A) extending downward from the connection portion with the separator (30), the gas-liquid downflow pipe (29) The discharged non-condensable gas can be prevented from flowing into the return pipe (32), and all the extracted non-condensable gas can be sent to the tank (T),
As a result, the non-condensable gas discharge efficiency can be improved with a simple configuration. Further, even when the pressure in the separator (30) and the non-condensable gas tank (T) rises and the absorption liquid level decreases, the non-condensable gas is evaporated by the lower flow section (32A) (4). It is possible to prevent returning to the inside.

Further, the separator (30) is provided at substantially the same height as the opening (33) of the return pipe (32), and the return pipe (32) is separated from the separator (30).
The absorption liquid connected to the vicinity of the absorption liquid surface of No. 1 and flowing into the separator (30) once rises to the absorption liquid surface and is then returned to the evaporation absorber (4) via the return pipe (32). Therefore, the temperature of the absorption liquid surface rises, the non-condensable gas in the separator (30) and the non-condensable gas tank (T) is heated by the refrigerant vapor evaporated from the absorption liquid surface, and The temperature is substantially equal to the temperature of the absorbing liquid flowing out from the evaporative absorber (4). As a result, the inside of the separator (30) and the tank for non-condensable gas (T)
In any operation, the internal pressure can be prevented from becoming extremely lower than the internal pressure of the evaporative absorber (4), and the absorption liquid can be prevented from flowing into the non-condensable gas tank (T). Damage to the cell (PC) due to the absorbent can be avoided.

Further, since the horizontal cross-sectional area of the separation pipe (31) extending downward from the lower end of the separator (30) and extending downward in the gas-liquid downflow pipe (29) is smaller than that of the separator (30), the separator ( 30)
Also, the amount of the absorbing liquid accumulated in the separation pipe (31) can be suppressed to a small amount. As a result, it is possible to reduce the amount of the absorption liquid held by the absorption refrigerator, reduce the injection amount of the absorption liquid when the absorption refrigerator is installed and replaces the absorption liquid, and reduce the manufacturing cost and maintenance cost. .

FIG. 2 is a circuit configuration diagram of a double-effect absorption refrigerator showing another embodiment of the present invention. The same components as those in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.

In FIG. 2, (35) and (36) are refrigerant liquid circulation pipes, and (P _B ) is a refrigerant liquid circulation pump. Further, (37) is a tank in which the separator (37A) and the storage chamber (37B) are integrated, and the bottom of the tank (37) has a bottomed separation pipe whose upper end opens below the liquid absorption surface. (38) is provided. The gas-liquid flow-down pipe (29) is inserted in the separation pipe (38). (40) is a return pipe for absorbing liquid, and this return pipe (40)
Has one end connected to the lower portion of the tank (37) and the opening at the other end located in the absorber (6). And tanks (37)
A lower part (41) of the absorbent is formed between the separation pipe (38) and the separation pipe (38), and the lower part (41) of the lower part and the return pipe (40) form a return path of the absorbent. Further, (42) is a vacuum pump for discharging gas, and this vacuum pump (42) is connected to the upper part of the tank (37) via an exhaust pipe (44) equipped with an on-off valve (43). Further, (45) is a first bypass pipe provided between the pipe (10) through which the refrigerant flows and the absorber (6), and (4)
6) is a first cold / hot switching valve, (47) is a second bypass pipe provided between the solution pipe (18) and the absorber (6), and (48) is a second cold / hot switching valve.

During the cold water extraction operation of the absorption refrigeration machine, an absorption refrigeration cycle is generated by circulating the refrigerant and the absorption liquid as in the conventional absorption refrigeration machine, and the refrigerant is vaporized in the heat exchanger (25) of the evaporator (5). The water in the heat exchanger is heated to about 6 to 8 ° C. by latent heat and taken out. Also, during the hot water extraction operation, the first and second cold / hot switching valves (46) and (48) are opened,
Refrigerant vapor and high-temperature absorption liquid are used for the first and second bypass pipes (4
Flows through 5) and (47) to the evaporative absorber (4). Then, the latent heat of condensation of the refrigerant in the heat exchanger (25) (or this heat and the sensible heat of the absorbing liquid) is used to raise the temperature of the water and take it out.

At the time of taking out cold water, taking out hot water, or switching to cold temperature of the absorption refrigerator, the non-condensed gas extracted from the absorber (6) is discharged from the gas-liquid downflow pipe (29),
It moves upward in the separation pipe (38) and is separated from the absorbing liquid flowing out of the separation pipe (38) and flowing into the flow lower part (41). Then, the absorbent separated from the non-condensed gas is returned to the absorber (6) via the flow lower part (41) and the return pipe (40). For this reason, it is possible to prevent the non-condensable gas extracted by the extraction device from being sent to the absorber (6) together with the absorbing liquid, and it is possible to improve the discharge efficiency of the non-condensable gas.

Further, the absorption liquid flowing into the tank (37) flows upward in the separation pipe (38), the temperature of the absorption liquid surface rises, and the non-condensed gas is warmed by the refrigerant vapor vaporized on the absorption liquid surface. The temperature of the non-condensable gas can be made substantially the same as the temperature of the absorbing liquid flowing from the absorber (6). As a result, the storage room (37
The pressure in B) can be prevented from becoming extremely lower than the pressure in the evaporative absorber (4), and the rise of the absorption liquid level in the tank (37) can be prevented during any operation. (PC) and the vacuum pump (42) can be prevented from being damaged by the absorbing liquid.

(G) Effect of the Invention The present invention is an absorption refrigerator configured as described above, and has a bottomed separation pipe extending downward from the lower end of the separator and having a horizontal cross-sectional area smaller than that of the separator, and an upper end connected to the ejector. Is passed through the separator to extend downward in the separation tube and the lower end is opened in the lower part of the separation tube, and the absorption liquid near the absorption surface of the separator is provided between the separator and the absorber. Since it has a return pipe to return to the absorber, the absorption liquid that has flowed into the separator once reaches the absorption liquid surface, the temperature of the absorption liquid surface rises, and the non-condensed gas in the storage chamber evaporates from the absorption liquid surface. The temperature of the non-condensed gas, which is warmed by the vaporized refrigerant, can be made approximately equal to the temperature of the absorbing liquid that has flowed into the separator, and as a result, the pressure in the storage chamber is approximately equal to the pressure in the absorber or evaporator. Becomes
It is possible to prevent the absorption liquid level in the storage chamber from rising, and prevent damage to the exhaust device such as the palladium cell.

Further, since the horizontal cross-sectional area of the separation pipe extending downward from the separator is smaller than the horizontal cross-sectional area of the separator, it is possible to reduce the amount of the absorbing liquid accumulated in the separator and the separation pipe. As a result, it is possible to reduce the amount of absorption liquid held by the absorption refrigerator, reduce the injection amount of absorption liquid when the absorption refrigerator is installed and during replacement of the absorption liquid, and reduce manufacturing costs and maintenance costs. .

Further, a separation pipe was provided below the absorption liquid level in the separator, a gas-liquid flow-down pipe was inserted into the separation pipe, and a return pipe was connected to the lower part of the separator to separate the non-condensed gas in the separation pipe. It is possible to prevent the absorption liquid from flowing between the separation pipe and the separator to the absorber via the return pipe and prevent the non-condensed gas from flowing to the absorber via the return pipe, thereby improving the exhaust efficiency of the non-condensed gas. be able to. Also, the temperature of the absorption liquid rises, the non-condensable gas in the storage chamber is warmed by the refrigerant vapor evaporated from the absorption liquid level, and becomes almost equal to the temperature of the absorption liquid flowing into the separator, and the pressure in the storage chamber is absorbed. The pressure becomes almost equal to the pressure inside the container or the evaporator, the rise of the absorption liquid level can be prevented, and as a result, the exhaust device can be prevented from being damaged.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an absorption chiller showing an embodiment of the present invention, and FIG. 2 is a circuit configuration diagram of an absorption chiller showing another embodiment of the present invention. (5) …… Evaporator, (6) …… Absorber, (E _J ) …… Ejector, (29) …… Gas-liquid flow down pipe, (30), (37A) ……
Separator, (31) …… Separation pipe, (T1), (37B) …… Reservoir, (32), (40) …… Return pipe, (32A), (41) Downstream part, (33) …… Opening, (38) ... Separation tube.

Claims (2)

[Claims] 1. An ejector for sucking non-condensable gas in an absorber or an evaporator using an absorbing liquid, a separator for separating the non-condensing gas and the absorbing liquid, and a non-condensing gas separated by the separator. In an absorption refrigerating machine having a storage chamber for temporarily storing the gas and an exhaust device for exhausting the non-condensable gas in the storage chamber, a bottomed separation pipe extending downward from the lower end of the separator and having a horizontal cross-sectional area smaller than that of the separator. Is installed between the separator and the absorber, and the gas-liquid flow-down pipe whose upper end is connected to the ejector, penetrates the separator, extends downward in the separation pipe, and opens at the lower end inside the separation pipe. An absorption refrigerator comprising: a return pipe for returning the absorbing liquid near the liquid surface to the absorber. 2. An ejector for sucking the non-condensable gas in the absorber or the evaporator with the absorbing liquid, a separator for separating the non-condensing gas and the absorbing liquid, and the non-condensing gas separated by the separator temporarily. In an absorption refrigerating machine having a storage chamber for accumulating gas and an exhaust device for exhausting non-condensed gas in the storage chamber, a bottomed separation pipe provided below the absorption liquid level of the separator and having an open upper end, and an ejector An absorption refrigerator comprising: a gas-liquid flow-down pipe connected to and inserted into a separation pipe; and a return pipe provided between a lower part of the separator and the absorber to return the absorption liquid to the absorber.