JPH0694964B2 - Multi-effect absorption refrigerator - Google Patents

Description

The present invention relates to a multi-effect absorption refrigerator that concentrates a dilute solution from an absorber in the order of a low temperature generator and a high temperature generator and returns the concentrated solution to the absorber. In particular, the present invention relates to an improvement of a multi-effect absorption refrigerating machine equipped with an auxiliary generator for concentrating a solution in a high-temperature generator with waste heat (hereinafter referred to as "multi-effect absorption refrigerating machine of this kind").

(B) Conventional technology As a conventional technology of this type of multi-effect absorption refrigerator, an auxiliary generator is provided in the middle of the solution flow path from the absorber to the low temperature generator, and this generator and the low temperature generator There is one provided with a condenser for a high temperature generator (see Japanese Patent Laid-Open No. 56-108066). In addition, as another conventional technique, an auxiliary generator is provided in the solution flow path from the absorber to the low temperature generator, and the auxiliary water supplied with cooling water at a temperature lower than that of the condenser for the high temperature generator and the low temperature generator is supplied. There is one equipped with a condenser for an auxiliary generator (see Japanese Patent Laid-Open No. 54-28051).

(C) Problems to be Solved by the Invention The above-mentioned conventional ones have an advantage that the waste heat of the high temperature generator can be recovered to a low temperature level in the auxiliary generator, resulting in a high heat recovery rate. However, since it has a structure in which a solution having a higher concentration than the dilute solution is concentrated by a low temperature generator having the same pressure as or higher than that of the auxiliary generator, the saturation temperature becomes higher than that of the solution in the auxiliary generator. It has the drawback that the solution must be boiled by the heat of a refrigerant with a low temperature level (refrigerant vapor up to about 100 ° C at most). Therefore, the conventional one can increase the heat recovery rate of the auxiliary generator, but on the other hand, it tends to cause a decrease or loss of the solution concentration function in the low-temperature generator, and sufficiently improves the thermal efficiency (operating efficiency) of the entire refrigerator. I had a problem that I could not expect.

In view of this problem, the present invention has an object to provide a multi-effect absorption refrigerating machine of this kind capable of highly efficient operation of the entire refrigerating machine.

(D) Means for Solving Problems As a means for solving the above problems, the present invention bypasses a high temperature generator in a solution flow path downstream of a low temperature generator of a multi-effect absorption refrigerator of this type. Another parallel solution flow path is formed, and an auxiliary generator is provided in this flow path.

(E) Action In this type of multi-effect absorption refrigerator according to the present invention, a dilute solution having a low boiling temperature is sent to a low temperature generator to which a refrigerant having a low temperature level is supplied as a heat source to concentrate the concentrated solution to increase its concentration. Since the solution whose boiling temperature has increased is concentrated in each of the auxiliary generator and the high temperature generator, which are supplied with heat at a higher temperature than that of the above refrigerant, and flows to the absorber, either of these generators is used. Also in this, the concentration function of the solution can be sufficiently exerted. As a result, the thermal efficiency of the refrigerator as a whole is improved, and it is possible to operate with higher efficiency than the conventional one.

(H) Embodiment FIG. 1 is a schematic configuration explanatory view showing an embodiment of a multi-effect absorption refrigerator of this kind according to the present invention. In FIG. 1, (1) is a high-temperature generator, (2) is a low-temperature generator (3), an auxiliary generator (4) and a generating condenser consisting of a condenser (5), and (6) is an evaporator (7). And an absorber (8), (9) is a low temperature solution heat exchanger, (10)
Is a high temperature solution heat exchanger, (P _LA ) is a dilute solution pump, (P _A ) is a solution pump, and (P _R ) is a refrigerant liquid pump. ), (12), (13), pipelines through which the solution is sent (14), (15), (16), pipelines (17), (18) through which the concentrated solution flows, and pipelines (19) through which the solution flows. ),
A pipe (2) through which the mixed solution of the flowing solution and the concentrated solution flows.
0), (21), pipelines (22), (23) through which the refrigerant flows, pipelines (24) through which the refrigerant liquid flows, and pipelines (2) through which the refrigerant liquid flows.
5) and (26) are connected to form a flow path [circulation path] for a refrigerant [water] and a solution [lithium bromide aqueous solution] to form a multi-effect absorption refrigerator or a multi-effect absorption heat pump. .

(27) is a combustion heating chamber of the high temperature generator (1), (28) is a heat source of the low temperature generator (2), (29) is a condenser of the condenser (5), and (30) is an auxiliary generator. The heater of (4), (31) is a heat exchanger of the evaporator (7), (32) is a cooler of the absorber (8), and (33), (33) ... Are high temperature generators (1). ) Is the passage for the combustion gas. Further, (34) and (35) are pipes for cold water connected to the heat exchanger (31), (36), (37) and (38).
Is a cooling water pipe line in which the coolers (32) and (29) are connected in series, and (D ₁ ) is a combustion exhaust gas duct connecting the outlet of the passage (33) and the inlet of the heater (30), (D ₂ ) is a combustion exhaust gas discharge duct connected to the outlet of the heater (30).

Next, an example of the operation of the multi-effect absorption refrigerating machine [hereinafter referred to as the present machine] configured as described above will be described with reference to FIG. Note that FIG. 2 is a Dühring diagram showing an example of the solution cycle during the operation of this machine.

The diluted solution which has passed through the low temperature solution heat exchanger (9) from the absorber (8) by the discharge force of the diluted solution pump (P _LA ) is sent to the low temperature generator (3), where the high temperature generator (1) ) From about 90 ℃
While being heated by the refrigerant of No. 1 through the heat supply unit (28) and boiling at a saturation temperature [about 78 to 82 ° C] corresponding to the internal pressure of the condenser (5), that is, the saturated vapor pressure in the generated condenser (2). Refrigerant vapor is generated and concentrated (see line b → c in FIG. 2). Then, a part of the solution concentrated in the low temperature generator (3) flows down to the auxiliary generator (4), and a part of the solution pump (P _A ).
High temperature generator (1) via high temperature solution heat exchanger (10)
Sent to. The solution flowing into the high temperature generator (1) is 1000 ℃
It is heated by some combustion gas and boils at 142 ° C to 156 ° C to form a concentrated solution. On the other hand, the solution flowing into the auxiliary generator (4) is heated by the combustion exhaust gas of about 250 ° C from the high temperature generator (1), boils at about 82 ° C to 84 ° C, and is concentrated (c in Fig. 2). → See i). Then, the concentrated solution and the solution concentrated in the auxiliary generator (4) merge in the pipe line (20) and return to the absorber (8).

In this way, in this machine, a solution with a low boiling temperature is circulated to a generator to which a heat source with a low temperature level is supplied, while a heat source with a sufficiently high temperature level is supplied to a generator that circulates a solution with a high boiling temperature. Therefore, the waste heat is recovered by the auxiliary generator while exerting an active solution concentrating action on all of these generators, and the thermal efficiency (operating efficiency) of the entire refrigerator is improved.

In addition, in this machine, the solution is circulated separately in the auxiliary generator (4) and the high temperature generator (1), so that the total amount of the solution is circulated through these generators in series. Since the amount of solution circulation in the vessel (1) is reduced, there is an advantage that this high temperature generator can be downsized and the heat for raising the temperature of the solution in the high temperature generator (1) can be saved. Moreover, there is an advantage that the high temperature solution heat exchanger (10) can be downsized.

Of course, even when this machine is used as a heat pump, the operation efficiency can be increased as in the case of using it as a refrigerator.

FIG. 3 is a schematic structural explanatory view showing another embodiment of this type of multiple-effect absorption refrigerator according to the present invention. In FIG. 3, the same constituent equipment as that of the embodiment shown in FIG. Are given the same reference numerals. The embodiment shown in this figure is provided with an auxiliary condenser (50) for liquefying the refrigerant vapor generated in the auxiliary generator (40), and this auxiliary condenser has a cooling flow to the condenser (5). It is configured to supply it at a lower temperature than water. In addition, (290) is an auxiliary condenser (5
0) for the cooling water, and the cooling water pipe (3
9) and (41) are connected. Further, (42) is a pipe line for the refrigerant liquid flow from the condenser (5) to the auxiliary condenser (50),
Reference numeral (43) is a pipeline for flowing the refrigerant liquid from the auxiliary condenser (50) to the evaporator (7).

In the embodiment shown in FIG. 3, the saturated vapor pressure and the saturation temperature in the auxiliary generator are lower than those in the embodiment shown in FIG. 1, so the waste heat is recovered to a much lower temperature level. Therefore, there is an advantage that the heat recovery rate can be improved.

Further, FIG. 4 shows an example of the solution cycle in the case where the embodiment of FIG. 3 is operated.

(G) Effect of the Invention As described above, the multi-effect absorption refrigerator according to the present invention brings about an effect that waste heat can be recovered while sufficiently exhibiting the solution concentrating function in all of the generators thereof, and thus the entire refrigerator has the effect. The effect of improving thermal efficiency (operating efficiency) is brought about.

[Brief description of drawings]

FIG. 1 is a schematic structural explanatory view showing an embodiment of a multi-effect absorption refrigerator of this kind according to the present invention, and FIG. 2 is a Duhring line showing an example of a solution cycle in the embodiment of FIG. 3 and 4 are schematic explanatory views showing another embodiment of the multiple-effect absorption refrigerator according to the present invention, and FIG. 4 is a Duhring line showing an example of the solution cycle in the embodiment of FIG. It is a figure. (1) ... High temperature generator, (2) ... Generating condenser, (3) ... Low temperature generator, (4) ... Auxiliary generator, (5) ... Condenser,
(6) ... Evaporative absorber, (7) ... Evaporator, (8) ... Absorber, (9), (10) ... Low temperature, high temperature solution heat exchanger, (P _LA ).
... dilute solution pump, (P _A ) ... solution pump, (P _R ) ... refrigerant liquid pump, (11), (12), (13), (14), (15),
(16), (17), (18), (19), (20), (21) ... pipe, (27) ... combustion heating chamber, (28) ... heater, (29) ... cooler, (30) ... Heater, (31) ... Heat exchanger, (32) ... Cooler, (33) ... Passage, (D ₁ ), (D ₂ ) ... Duct, (40) ... Auxiliary generator, (50 ) ... Auxiliary condenser.

Claims (1)

[Claims] 1. A dilute solution from an absorber is concentrated in a low temperature generator by heat of a refrigerant generated in a high temperature generator, and then this solution is further concentrated and absorbed in a high temperature generator by a combustion gas or other high temperature heat source. In a multi-effect absorption refrigerator with a solution flow path that returns to the reactor, another solution flow path in parallel with the solution flow path from the low temperature generator to the absorber via the high temperature generator bypasses the high temperature generator. And the auxiliary solution generator is formed in the above-mentioned parallel parallel solution passage, and further comprises an auxiliary generator for further concentrating the concentrated solution in the low temperature generator by the waste heat of the high temperature generator. Multi-effect absorption refrigerator.