JPH0743182B2 - Absorption refrigerator - Google Patents

Description

The present invention relates to an improvement of an absorption refrigerating machine of a type in which an unvaporized refrigerant of an evaporator is recirculated to the evaporator by a refrigerant liquid pump.

(B) Conventional technology As a conventional technology of the absorption refrigerating machine of the above-mentioned type, as seen in, for example, Japanese Utility Model Publication No. 50-43416 and Japanese Utility Model Publication No. 51-16051, the lower end of the condensed refrigerant flowing pipe is One that is connected to a refrigerant reservoir of an evaporator (hereinafter referred to as a first conventional example) is known. Further, as another conventional technique, for example, Japanese Patent Laid-Open No.
As shown in Japanese Patent Application Laid-Open No. 59-109753 and Japanese Patent Application Laid-Open No. 59-173666, one in which the lower end of the condensed refrigerant flow-down conduit is connected to the refrigerant liquid return path on the discharge side of the refrigerant liquid pump (hereinafter referred to as the second A known example) is known.

(C) Problems to be Solved by the Invention In the first conventional example, the condensed refrigerant flows down to the evaporator on the low pressure side while keeping the temperature close to the condensing temperature and self-evaporates while vigorously flushing. The amount of heat exchanged with the refrigerant in the heat exchanger of the evaporator is reduced by that much, and in addition to the flash, the liquid surface of the refrigerant liquid reservoir of the evaporator is severely undulated and a large amount of refrigerant liquid overflows into the solution reservoir of the absorber. There is a problem that it is not used for absorption and refrigeration.

In the second conventional example, the condensed refrigerant merges with the low-temperature unvaporized refrigerant sent by the refrigerant liquid pump and flows to the evaporator while lowering the temperature, so that the flash of the refrigerant is as severe as in the first conventional example. However, on the other hand, on the other hand, one of the non-evaporated refrigerant discharged by the refrigerant liquid pump when the pressure difference between the condenser and the evaporator becomes small, such as when the load is low, when the cooling water temperature drops, or when starting up. There is also a case where the part flows back to the condenser side, or the condensed refrigerant hardly flows down, and it is easy to cause harmful effects such as a decrease in the heat exchange area between the condenser cooler and the refrigerant vapor and cavitation of the refrigerant liquid pump, There is a problem that the operation of the absorption refrigerator may be affected depending on the pressure condition.

In view of these problems, the present invention can easily achieve reduction of flash evaporation of the refrigerant flowing into the evaporator and alleviation of stagnation of the condensed refrigerant in the condenser at the time of low load or cooling water temperature decrease. The purpose is to provide a possible absorption refrigerator.

(D) Means for Solving the Problems The present invention provides, as means for solving the above problems,
A liquid level detector is provided in the refrigerant reservoir of the condenser of the absorption refrigerating machine of the type described above, on the way from the discharge side of the refrigerant liquid pump of the refrigerant liquid recirculation path to the connection portion with the condensed refrigerant flow conduit. An absorption refrigerating machine provided with a flow control valve and a controller for inputting a signal from a liquid level detector to narrow the opening of the flow control valve as the detected liquid level increases.

(E) Operation According to the present invention, when the liquid level of the refrigerant liquid pool portion of the condenser starts to rise, the opening of the flow control valve is reduced by the signal from the liquid level detector and the refrigerant liquid pump is used. Since the absorption refrigerating machine can be provided with the effect of suppressing the flow of the non-evaporated refrigerant, the resistance to the condensed refrigerant flow of the non-evaporated refrigerant at the confluence point of the non-evaporated refrigerant and the condensed refrigerant is weakened to promote the flow of the condensed refrigerant. You can As a result, even when the pressure difference between the condenser and the evaporator becomes small, such as when the cooling water temperature drops or at the time of start-up, congestion of the condensed refrigerant flow, that is, stagnation of the condensed refrigerant in the condenser Can be easily alleviated.

Further, since the condensed refrigerant merges with the non-evaporated refrigerant and flows to the evaporator while lowering the temperature, flash evaporation of the refrigerant in the evaporator is also reduced.

(F) Embodiments The drawings are schematic structural explanatory views showing an embodiment of an absorption refrigerator according to the present invention. (1) is a high temperature generator, (2) is a low temperature generator (3) and a condenser (4). A generating condenser consisting of
(5) is an evaporative absorber comprising an evaporator (6) and an absorber (7), (8) is a low temperature solution heat exchanger, (9) is a high temperature solution heat exchanger, and (P _R ) is a refrigerant liquid pump. , (P _A ) are absorption liquid pumps, and a pipe for connecting these devices forms a circulation path for the refrigerant [water] and the absorption liquid [lithium bromide aqueous solution] to form an absorption refrigerator.

(10) is a combustion heating chamber of the high temperature generator (1), (11) is a heater of the low temperature generator (3), (12) is a cooler of the condenser (4), and (13) is an evaporator (6). ) Is a heat exchanger, (14) is a cooler of the absorber (7), (15), (15) ... Are combustion gas passages, (16) are combustion gas exhaust passages, (17), ( 18) is a cold water pipe connected to the heat exchanger (13), (19), (20),
Reference numeral (21) is a cooling water pipe line in which coolers (14) and (12) are connected in series.

(22), (23), (24), (25), (26), and (27) are absorption liquid pipes, respectively, and (28) is a vapor phase part of the high temperature generator (1) and a heater (11). ) Is a refrigerant vapor line, and (29) is a refrigerant drain line that connects the heater (11) and the condenser (3). Further, (31) is a refrigerant liquid reservoir of the evaporator (6),
(32) is a refrigerant liquid sprinkler arranged in the evaporator (6) above the heat exchanger (13), and (33) is a refrigerant liquid reservoir (31) and a suction port of the refrigerant liquid pump (P _R ). Refrigerant liquid pipe, (3
4) Refrigerant liquid pump (P _R ) outlet and refrigerant liquid sprinkler (3
In the refrigerant liquid pipeline connecting with 2), the refrigerant liquid return passage is formed in the evaporator (6) by the refrigerant liquid pipeline and the refrigerant liquid pump (P _R ). Moreover, (S ₁ ) and (S ₂ ) are the first and second refrigerant liquid reservoirs of the condenser (4), and (35) has its upstream end at the bottom of the second refrigerant liquid reservoir (S ₂ ). Is a U-shaped refrigerant liquid flow-down conduit whose downstream end is connected to the refrigerant liquid conduit (34).

And, (V) is a refrigerant liquid conduit (34) upstream of the connection between the refrigerant liquid conduit (34) and the refrigerant liquid flow-down conduit (35).
To a flow control valve having the degree of opening of the valve controller by the signal in response to an increase in sensing liquid level of the second refrigerant liquid reservoir (S ₂₎ to comprise the liquid level detector (LS) ( The decrease control is performed via C) while the increase control is performed according to the drop of the sensing liquid level. The liquid level detector (LS) uses an electrode type liquid level sensor or an optical liquid level sensor.

In addition, when the condenser (4) does not have the second refrigerant liquid pool (S ₂ ), the liquid level detector (LS) is provided in the first refrigerant liquid pool (S ₁ ).

Next, an operation example of the absorption refrigerating machine (hereinafter referred to as this machine) configured as described above will be described.

During rated operation of this machine [For example, during operation in midsummer, when the temperature of inflow of cooling water to this machine is about 32 ° C, and the internal pressure of the condenser (4) is kept at about 56 mmHg When the difference from the internal pressure of the container (6) is maintained at about 50 mmHg and the liquid surface in the second refrigerant liquid pool (S ₂ ) is at a substantially predetermined height], the flow control valve (V) is opened at a predetermined level. It is opened in degrees.

By the way, when the cooling water inflow temperature to this machine is, for example, about 19 ° C, the internal pressure of the condenser (4) is about 28 mmHg, and the difference between this and the internal pressure of the evaporator (6) is about 22 mmHg. When the machine is operated, the force that the condensed refrigerant tries to flow down the refrigerant liquid flow-down conduit (35) is reduced to about half of the rated operation, while the discharge force of the refrigerant liquid pump (P _R ) is increased. That is, at the confluence of the condensed refrigerant and the non-evaporated refrigerant, the force of the non-evaporated refrigerant to prevent the flow of the condensed refrigerant becomes strong, so that the liquid level in the second refrigerant liquid pool (S ₂ ) rises. start. In this case, if the rise of the liquid level is left as it is,
Since the supply of the condensed refrigerant to the evaporator (6) is significantly reduced, the refrigerant liquid in the refrigerant liquid reservoir (31) eventually disappears, causing cavitation of the refrigerant liquid pump (P _R ), or the condensed refrigerant is the first refrigerant. , The second refrigerant liquid pool (S ₁ ) and (S ₂ ) are filled and overflow to the low temperature generator (3) side, and the heat exchange area between the refrigerant vapor from this generator and the cooler (12) It will cause an adverse effect such as a drastic decrease in the number of vehicles and cause a driving failure.

In this case, in this machine, the flow control valve (V) is throttled by the signal of the liquid level detector (LS) according to the liquid level rise in the second refrigerant liquid pool (S ₂ ) and The flow resistance of the non-evaporated refrigerant increases and the blocking force against the flow of the condensed refrigerant by the non-evaporated refrigerant at the confluence point is weakened, so that the flow of the condensed refrigerant is promoted. Then, the endless rise in the level of the condensed refrigerant stops, the level is maintained at a certain level, and the opening of the flow control valve (V) also reaches a certain value (in this case, an opening close to a fully closed state). ] Will be fixed. As a result, overflow of condensed refrigerant to the low temperature generator (3) side and cavitation of the refrigerant liquid pump (P _R ) are prevented, and good operation is continued. When the cooling water inflow temperature becomes higher than 19 ° C and the internal pressure of the condenser (4) rises and the liquid level in the second refrigerant liquid pool (S ₂ ) drops, the opening degree of the flow control valve (V) Will increase.

As described above, in the present device, by adjusting the reflux resistance of the non-evaporated refrigerant in accordance with the change in the pressure difference between the condenser (4) and the evaporator (6), the liquid level of the condensed refrigerant can be simply and easily adjusted. Can be maintained within a predetermined range and the amount of condensed refrigerant flowing into the evaporator (6) can be maintained within a predetermined range, so that the operation at low cooling water temperature and the operation at startup can be favorably performed. it can. This is the same when this machine is used as a heat pump.

Further, in the present apparatus, the condensed refrigerant merges with the low-temperature (for example, about 6 ° C.) unvaporized refrigerant to lower the temperature, and then flows into the evaporator (6), so that flash evaporation thereof is significantly reduced.

In addition, in this machine, the refrigerant liquid reservoir (31) of the evaporator (6)
Although a liquid level detector (LS) may be installed in the air flow control means (not shown) to increase / decrease the opening of the flow control valve (V) depending on the liquid level of the unvaporized refrigerant, Since the change and that of the non-evaporated refrigerant do not necessarily have a fixed correlation, the above-mentioned means may cause an excessive liquid level of the condensed refrigerant, which is not a preferable means.

(G) Effect of the Invention As described above, the present invention alleviates the stagnation of the refrigerant liquid in the condenser when the pressure difference between the condenser and the evaporator is small, that is, the congestion of the flow of the condensed refrigerant at the time of start-up. The effect of improving the operation of the above, and the effect of reducing the flash evaporation of the condensed refrigerant to keep the operation efficiency high, and the effect that it is possible to easily achieve stable operation with excellent start-up performance. It has high practical value.

It goes without saying that the present invention can also be applied to a single-effect absorption refrigerator.

[Brief description of drawings]

The drawings are schematic illustrations of an embodiment of an absorption refrigerator according to the present invention. (1) …… High temperature generator, (3) …… Low temperature generator, (4)
… Condenser, (6) …… Evaporator, (7) …… Absorber,
(8), (9) …… Low temperature and high temperature solution heat exchanger, (P _R ) ……
Refrigerant liquid pump, (31) …… Refrigerant liquid reservoir, (32) …… Refrigerant liquid sprinkler, (33), (34) …… Refrigerant liquid conduit, (35)
...... Refrigerant liquid flow-down conduit, (S ₁ ), (S ₂ ) …… Refrigerant liquid reservoir,
(LS) ... Liquid level detector, (C) ... Controller, (V) ...
Flow control valve.

Claims (1)

[Claims] 1. A device such as a generator, a condenser, an evaporator, and an absorber is connected by piping to form a circulation path between a refrigerant and an absorbing liquid, and an unvaporized refrigerant of the evaporator is evaporated by a refrigerant liquid pump. In the absorption refrigerating machine, which forms a refrigerant liquid return path for returning to the refrigerant liquid, and which connects the refrigerant liquid pump discharge side of this return path and the downstream end of the condensed refrigerant circulation pipe line connected to the condenser, Level detector provided in the refrigerant reservoir of the container, and a flow control valve provided on the way from the discharge side of the refrigerant liquid pump in the refrigerant liquid recirculation path to the connection part with the condensed refrigerant flow conduit An absorption refrigerating machine comprising: a liquid level detector; and a controller that narrows the opening of the flow control valve as the detected liquid level rises.