JPH03105169A - Absorption freezer - Google Patents

Abstract

PURPOSE:To decrease an absorbing temperature, provide a low concentration of solution and improve a cycle efficiency by a method wherein a heat exchanger is arranged in the midway part of a concentrated solution flow passage from a regenerator to an absorbing device, the concentrated solution is cooled with air in the heat exchanger and then the concen trated solution is dispersed into the absorbing device. CONSTITUTION:Diluted solution that passes through an absorbing device 2 is increased at its pressure by a circulating pump 7 and fed into a regenerator 9. At the regenerator 9, the diluted liquid is heated, condensed at an external heat application 10 and then the solution returns as a concentrated solution. In this case, since a temperature of the concentrated solution at an outlet port of a heat exchanger 8 is not completely decreased down to a satura tion temperature of the solution within the absorbing device 2, so that the concentrated solution evaporates at a moment when the concentrated solution is dispersed into the absorbing device 2 and a heat loss may occur. However, the concentrated solution of which temperature level is decreased by a certain degree with the heat exchanger 8 shows a further decreased temperature through a heat exchanger 6 arranged at a second stage of a dispersion pump 11. As this temperature is decreased down to a saturation temperature of solution within the absorbing device 2, no evaporation just after its dispersion may occur,resulting in that no heat loss occurs. As the temperature is further decreased to make an subcooled state, in turn absorbing capability will be increased.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an absorption refrigerator.

[Conventional technology]

In conventional absorption refrigerators, a heat exchanger exchanges heat between a high-temperature concentrated solution from a regenerator and a low-temperature dilute solution from an absorber, so that the high-temperature concentrated solution is absorbed as a concentrated solution whose temperature has been lowered to a certain degree. It was sprayed on the vessel. On the other hand, the low-temperature dilute solution was sent to the regenerator as a dilute solution whose temperature had been raised to a certain degree. This method is a widely known technology, for example, in Refrigeration and Air Conditioning Technology Vol.
31 &365 (July 1980 issue), and Refrigeration and Air Conditioning Technology VOL. 31Nα367 (September 1980 issue), etc.

[Problem to be solved by the invention]

In the above conventional technology, the concentrated solution from the regenerator is heat exchanged with the dilute solution from the absorber, cooled, and then sent to the absorber. The temperature cannot be lowered to the saturation temperature corresponding to the vessel pressure and concentration. In this case, the solution undergoes rapid evaporation the moment it is sprayed into the absorber, resulting in heat loss.

However, in the conventional technology, if an attempt is made to bring the solution temperature during absorption in the absorber as close as possible to the saturation temperature, the heat exchanger becomes extremely large. Furthermore, as the heat exchanger becomes larger, the pressure loss in the solution circulation system between the regenerator and the absorber increases, which causes problems such as clogging of the circulation system and enlargement of the solution circulation pump. It was. The purpose of the present invention is to lower the temperature of the absorber spray solution to the saturation temperature within the absorber or below the saturation temperature and eliminate heat loss during absorber spraying, thereby reducing the amount of heat dissipated in the absorber and lowering the absorption temperature.・An object of the present invention is to provide an absorption refrigerator that lowers the temperature of the solution, lowers the concentration of the solution, and improves the cycle efficiency.

Another object of the present invention is to provide an air-cooled absorption refrigerator in which an air-cooled heat exchanger for cooling the absorber spray solution with air is arranged compactly and efficiently.

[Means to solve the problem]

In order to achieve the above purpose, the spray solution is cooled down to below the saturation temperature in the absorber before spraying on the absorber using air or cooling water passing through the condenser and absorber, and then sprayed on the absorber. This is what I did.

Furthermore, in the air-cooled absorption refrigerator, the heat transfer fins on the outside air side of the air-cooled heat exchanger for solution cooling are integrated with the heat transfer fins on the outside air side of the air-cooled condenser, and the air-cooled heat exchanger and the air-cooled The condenser is installed adjacent to the condenser.

[Effect]

Generally, the saturation temperature of the solution in the absorber of an absorption refrigerator is. 40
~45°C. On the other hand, the air, cold water, and cooling water used for cooling the solution in the present invention generally have an air temperature of 35°C or less and a cooling water of 35°C or less, respectively, and are at a level below the saturation temperature. is sufficient to pre-cool the absorber sparge solution below the saturation temperature.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5.

In FIG. 1, the refrigerant evaporated in the evaporator 1, through which the cold water pipes 12, 13 pass, flows into the absorber 2 and is absorbed by the spray solution. Here, the air-cooled absorber of the absorption refrigerator includes a group of heat transfer tubes 3 and a large number of heat transfer fins 4 attached to the outside of the tubes. The heat generated by absorption in the tubes of the heat transfer tube group 3 of the absorber is released to the outside via the heat transfer fins 4 by the cooling air 14 generated by the cooling fan 5. Absorption g712. The dilute solution that has passed through is pressurized by the circulation pump 7 and sent to the regenerator 9. In the regenerator 9, the dilute solution is heated and concentrated by external heat 10 and returns as a concentrated solution. Here, in the prior art, a heat exchanger 8 exchanges heat between a low-temperature dilute solution and a high-temperature concentrated solution, and the concentrated solution whose temperature level has been lowered to a certain degree is pressurized by a spray pump 11 and sprayed into the absorber 2. However, with this technology, the temperature of the concentrated solution at the outlet of the heat exchanger 8 cannot be lowered to the saturation temperature of the solution in the absorber 2, so that the solution a evaporates the moment it is sprayed into the absorber 2. , generating heat loss. However, according to this embodiment, the temperature of the concentrated solution whose temperature level has been lowered to some extent by the heat exchanger 8 is further lowered by the heat exchanger 6 provided at the next stage of the sparge pump 11. When this temperature is lowered to the saturation temperature of the solution in the absorber 2, no heat loss occurs because evaporation at the moment of dispersion, which occurs in the prior art, does not occur. If the temperature is further lowered to create a supercooled state, there is the advantage that the absorption capacity increases. Here, the heat exchanger 6 shown in FIG.
This is an example of an air-cooled type.

This air-cooled heat exchanger consists of a heat transfer tube in which a concentrated solution flows and a large number of heat transfer fins are attached to the outside of the tube. As a cooling medium, the cooling upwind 4 that cools the absorber 2 is used.

Further, a separate cooling fan for the heat exchanger 6 may be installed to distinguish it from the cooling fan 4.

Next, another embodiment will be explained with reference to FIG.

FIG. 2 shows heat transfer fins used in the air-cooled heat exchanger 6 shown in FIG. 1 for cooling the concentrated solution. A heat transfer tube 17 for an air-cooled condenser passes through a portion of the heat transfer fin 6, and a heat transfer tube 18 for an air-cooled heat exchanger passes through the remaining portion. As shown in FIG. 3, the air-cooled condenser 9 and the air-cooled heat exchanger 6 are installed adjacent to each other while being completely separated by an upper header and a lower header, and the heat transfer fins 16 are connected to the air-cooled condenser. 19 and the air-cooled heat exchanger 6. Furthermore, as shown in FIG. 4, the flow of cooling air 14 is from the air-cooled condenser 19 to the air-cooled heat exchanger 6. This is because the amount of heat released by the air-cooled condenser 19 is larger than that of the air-cooled heat exchanger 6, so low-temperature air is transferred to the air-cooled condenser 19.
This is to allocate it to On the other hand, inside the air-cooled heat exchanger 6, as shown in Fig. 4, the flow of the solution is reversed at the upper and lower header sections to form a multi-pass cross flow with respect to the cooling air 14, thereby improving heat transfer. We are trying to

The above is an example of an air-cooled absorption refrigerator, but FIG. 5 shows an example of application to a water-cooled absorption refrigerator.

The cooling water branched from the cooling water population 20 passing through the absorber 2 passes through the water-cooled heat exchanger 15, cools the concentrated solution, and then joins the cooling water outlet 21.

Although the above-mentioned embodiments are all single-effect cycles, they can also be applied to double-effect cycles, and are effective.

〔Effect of the invention〕

According to the present invention, the temperature of the solution sprayed in the absorber can be lowered to the solution saturation temperature in the absorber or a supercooling temperature lower than that, thereby eliminating heat loss due to evaporation during solution spraying to the absorber. , and effective absorption takes place.

In other words, by reducing the amount of heat dissipated in the absorber, the absorption temperature is lowered and the solution concentration is reduced.
can improve cycle efficiency,

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention in an air-cooled absorption refrigerator, and FIGS. 2 to 4 show structural examples of an air-cooled heat exchanger for solution cooling in an air-cooled absorption refrigerator. FIG. 5 is an explanatory diagram showing an embodiment of the present invention in a water-cooled absorption refrigerator. 1... Evaporator, 2... Absorber, 5... Cooling fan, 6... Air-cooled heat exchanger. 9... Regenerator, 14...
Cooling air, 15... water-cooled heat exchanger, 16... heat transfer fins.

Claims (1)

[Claims] 1. An absorption refrigerator comprising an evaporator, a regenerator, an absorber, a condenser, a heat exchanger, a pump, and piping connecting these,
An absorption refrigerator characterized in that a heat exchanger is provided in the middle of a concentrated solution flow path flowing from a regenerator to an absorber, and the concentrated solution is cooled by air in the heat exchanger and then sprayed onto the absorber. 2. The heat transfer fins on the outside air side of the heat exchanger and the air side heat transfer fins outside the tube of the air-cooled condenser are integrally molded, and the heat exchanger and the air-cooled condenser are installed adjacent to each other. The absorption refrigerator according to claim 1. 3. The absorption refrigerator according to claim 2, wherein the heat exchanger is installed adjacent to the air outlet side of the air-cooled condenser. 4. In an absorption refrigerator consisting of an evaporator, regenerator, absorber, condenser, heat exchanger, pump, and piping connecting these, a heat exchanger is installed in the middle of the concentrated solution flow path flowing from the regenerator to the absorber. . An absorption refrigerator, characterized in that in the heat exchanger, a concentrated solution is cooled by cooling water passing through a condenser and an absorber.