JPS6024908B2 - absorption chiller absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an absorber for an absorption refrigerator.

Conventionally, absorbers used in absorption refrigerating machines using ammonia have been air-cooled or water-cooled absorbers with a serpentine shape with many straight sections as shown in FIG.

This type of absorber is provided with a meandering section 2 whose required length is determined based on the process of absorption and removal of absorbed heat carried out in a horizontal pipe 1, and which has to be made into a desired dimension. be. However, in the absorber of an absorption refrigerator, it is important to ensure a gas-liquid contact area between the refrigerant gas and the absorption liquid, which is equal to or more important than the cooling heat exchange area. Therefore, in the conventional meandering shape, the flow of gas and liquid into the absorber is devised so that bubbles are included in the liquid, but due to the amount of gas throughput in the absorber, in reality it is a ubiquitous flow in which gas and liquid are separated. In the horizontal pipe, it was divided into upper and lower parts, and the liquid surface was undulating. Generally, in gas-liquid two-phase flow, bubble flow (gas flows in the form of many fine bubbles in the liquid) occurs when the amount of liquid is large compared to the amount of gas, and wavy flow occurs when the amount of gas is large compared to the liquid. occurs in In an absorber, it is desirable to absorb a large amount of cold soot gas with a small amount of absorption liquid due to its characteristics, but bubble flow is good in terms of gas-liquid contact, but there is a problem in the amount of gas throughput, and wavi flow has a problem with gas throughput. There is a problem with liquid contact. However, either increase the cold soot gas velocity to create an annular flow (a state where the gas flow rate is high and there is a liquid film on the tube wall, and the gas flows in the center), or insert fins that cause turbulent flow inside the tube. Although this is possible, in that case, the inflow gas pressure must be increased. In this case, a pressure difference will occur between the absorber pressure and the evaporation pressure, and if the absorber pressure is held constant due to the cooling temperature, the evaporation pressure will inevitably increase. It's an increase in my blood pressure and I feel very unwell. In addition, there are coil-type heat exchangers that do not have 180° bends in the vertical direction, but in that case, the gas passes through the laminar flow state where the gas and liquid are separated, so the meandering shape is created. absorption efficiency is lower than that of

The present invention has conducted research on the function of the meandering portion of a meandering absorber, and has found that gas-liquid mixing in the meandering portion plays a major role in the absorption function.Based on this finding, the above-mentioned problems are improved.

The details of the present invention will be explained below along with examples. As shown in FIG. 2, an embodiment of the double-pipe spiral pipe absorber 3 is shown.
It has a continuous curved part. In this curved part, turbulence of gas and liquid occurs that cannot be obtained with a straight pipe placed horizontally. Therefore, when flowing the absorption liquid and cold soot gas from the inlet part 6, which is one end of the inner pipe of the double-pipe spiral pipe absorber 3, to the outlet part 7, the rising part is a 1800-degree bend in the vertical direction. 4 and the descending section 5, turbulence of gas and liquid always occurs. Moreover, since the double-pipe spiral pipe absorber 3 is continuous, the effective gas-liquid contact area, which cannot be obtained with horizontal straight pipes, is expanded over almost the entire length of the pipe, and is maintained. It is something that can be done. Note that there is almost no difference between the evaporation pressure and absorption pressure. Further, the cooling water is made to flow inside the outer tube facing the absorption liquid to remove absorbed heat. FIG. 3 shows absorption between a water-cooled double-pipe linear absorber placed almost horizontally in a straight line with the same pipe diameter and the same total pipe length, and a double-pipe spiral pipe absorber 3 according to an embodiment of the present invention. This is a comparison of abilities.

The horizontal axis is the flow rate of the absorption liquid, and the vertical axis shows the ratio of how many times the absorption capacity of the absorber of the present invention is compared to the amount of cold soot gas absorbed by the linear absorber of the comparative example. There is. From this characteristic diagram, it is clear that the absorber according to the present invention absorbs several times the amount of medium gas compared to the linear absorber even with the same pipe diameter and the same pipe length. FIG. 4 shows a solar direct heating absorption type air conditioner using an absorber according to the present invention. In the figure, 8 is a heat collection generator that collects solar heat and uses that heat to separate cold soot vapor from the solution, and a gas-liquid separator 9
The cold soot is liquefied in a condenser 11 via a cold soot vapor conduit 10, and the liquid cooled soot is evaporated in an evaporator 13 via an expansion valve 12. Cooling is performed by the latent heat of vaporization. The evaporated refrigerant vapor flows into the absorber 14 according to the present invention, where the solution, which has been made thinner by releasing a part of the cold soot in the gas-liquid separator 9, flows through the conduit 15 and flows into the absorber 14. 14, it absorbs the cooling vapor and becomes a thick solution. This concentrated solution is pumped via conduit 16 to generator 8 by pump 17.
The feed cycle is completed. Direct solar heating type absorption air conditioners are excellent systems with little loss in heat transport and transfer, but such systems require the use of high-pressure fluorocarbons and ammonia. The device is ideal for such a system.
Note that although solar heat was used as the heat source in the above embodiment, it goes without saying that other heat sources may be used.

As described above, the absorption type absorber according to the present invention has a remarkable increase in the gas-liquid contact area effective for gas absorption, so the absorption efficiency is extremely high, and there is an advantage that the absorber can be made small for a given capacity. Further, because of the spiral shape, it has excellent effects such as being able to be easily and inexpensively manufactured as a double pipe.

[Brief explanation of drawings]

Figure 1 shows the main parts of a conventional meandering absorber, where A is a plan view of an air-cooled type and the mouth is a plan view of a water-cooled type, and Figure 2 A and a mouth are a front view of an absorber according to an embodiment of the present invention. Figure 3 is a characteristic diagram showing the ratio of the capacity of the absorber according to an embodiment of the present invention to the cold soot gas absorption capacity of the direct type absorber, and Figure 4 is a side view.
The figure is a configuration diagram of a solar direct heating type absorption refrigerator showing an application example of the present invention. 3... Spiral tube absorber, 4... Rising part, 5... Descending part, 6... Inlet part, 7
...Exit section. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1 The component is a spiral tube wound around a horizontal axis,
An absorber for an absorption refrigerator, characterized in that an absorption liquid and a refrigerant gas flow from one end of the spiral tube to the other end of the spiral tube.