JPS6033465A - Chemical heat pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to chemical heat pumps for heating, cooling, and heat storage that operate with low energy consumption, and in particular to passive chemical heat pumps that can be easily operated by eliminating the power source to the maximum extent possible. It concerns heat pumps.

Conventional Structures and Problems Concerning conventional chemical heat pumps, cooling equipment in which an aqueous lithium bromide solution is used as an absorbent has been developed. In this case, in order to uniformly absorb the refrigerant (water, etc.) into the absorbent, it is necessary to forcefully circulate the solution with a pump, and to ensure a wide absorption area, it is necessary to spray the solution with a shower. Therefore, these operating mechanisms have significantly increased the cost of chemical heat pumps. Therefore, in order to provide a chemical heat pump with lower cost and higher efficiency, it is necessary to use a method that basically moves refrigerant vapor between two tanks, an evaporator and an absorber, without using a mechanism that requires power. is as expected.

At this time, it is extremely important to ensure that the absorbent has a large absorption area so that the absorbent absorbs the refrigerant uniformly.

On the other hand, calcium chloride is a cheaper absorbent with higher heat storage density, but depending on the water content, calcium chloride
It has been difficult to actually use it as an absorbent because it undergoes a solid-liquid phase change and solidifies into rock candy near the inlet of the refrigerant vapor.

Purpose of the Invention In order to overcome the above-mentioned problems, the present invention ensures a wide absorption area for the absorbent and has an internal structure that prevents the absorbent from caking, thereby maintaining the efficiency for a long time at low cost. The purpose is to easily provide a chemical heat pump that can be used.

Structure of the Invention In the present invention, the chemical heat pump device consists of a closed system that is equipped with at least two tanks, a regenerator/absorber 1 and an evaporator/condenser 2, and these are connected via an on-off valve 3. be.

In FIG. 1, a container 1 is filled with an absorbent A, and a container 2 is filled with a refrigerant B.

At least one of the absorbent A and the total refrigerant (preferably both) is impregnated into the inorganic fiber C.

Examples of inorganic fibers include, for example, the inorganic fiber developed by British Imperial Chemical Industries as a heat insulating material.
Various shapes (for example, plate-like, felt-like, paper-like, cotton-like, and paste-like) are suitable, and are made from fibers with the trade name ``Safil'' whose main components are alumina 95% and silica 5%. Similar products in Japan include Taiyo Chemical Co.'s ``Super Fire Board,'' Ibiyo Denki Kogyo Co., Ltd.'s ``Ibi Wool,'' NICHIAS Co., Ltd.'s ``1 Fine Flex,'' and Inrite Kogyo Co., Ltd.'s ``Kao Wool Lu 1 Class.'' Both are trademarks).

In general, inorganic fibers whose main components are alumina and silica have a mixture ratio of 50 to 95% alumina and 5 to 6% silica, and are used as insulation materials for high temperatures (over 1000°C). As for the high ratio of alumina (~96 section)
is used.

Under the above circumstances, the inventor conducted research on a two-tank chemical heat pump using a calcium chloride-water system, and found that the chemical heat pump in which the above-mentioned inorganic fibers were impregnated with absorbent and refrigerant had a high absorption rate. We have discovered that it is possible to simultaneously increase the number of nanotubes, increase cycle life, homogenize the reaction, and reduce corrosiveness.

DESCRIPTION OF EMBODIMENTS Examples of the present invention will be described together with experimental examples proving that the various properties mentioned above can be improved by using inorganic fibers as an impregnating material.

Below, regarding various inorganic fibers, alumina (~6o%
), among those containing silica (~6o%) (a)
liquid, (b) felt-like, (0) paper-like, (d) cotton-like, (
e) dried paste, and (f)
A plate-shaped material containing aluminum (~95%) and silica (~6%) was used.

6..2 1) Improvement of absorption rate In the heat pump device shown in FIG. Impregnate, then 1
It was vacuum dried at 50°C to form an anhydrous salt. At this time, each is 8
It was 30-835g. However, theoretically 834g
becomes. Container 2 also contains 40 oyf of water: an inorganic fiber board (same material as that filled in container 1) impregnated with water.
was filled.

On the other hand, as a comparison target (g), in another similar device, container 1 contained calcium chloride anhydrous 63 without using an impregnating material.
Container 2 was filled with 40C1 of water.

After a total of seven devices were completely evacuated, the valves were opened at the same time and the devices were left at room temperature, and the amount of water reduction in the containers 2 was measured. Figure 2 shows a plot of the amount of water loss versus time.

11) Improving cycle life After completing the experiment in 1), leave it for a while and confirm that the water in container 2 has been completely absorbed into container 1.
As a result of heating the container 2 to 150°C and cooling it to 5°C, 400ml of water was added to the container 2! was confirmed to have condensed again. After this, each device was completely vented, and at the same time, the pulp 3 was opened and left at room temperature. The above operations are considered as one cycle, and 1
An operation equivalent to 00 cycles was performed. The water loss ik was measured one hour after the valve was opened for each cycle. FIG. 3 shows the amount of water loss plotted against the number of cycles.

111) Reaction equalization When carrying out the experiment in 11), the insides of containers 1 and 2 after completion of %100 cycles were observed and compared with the state before the test.

+V) Corrosion reducing impregnation material (a) Calcium chloride tetrahydrate 50 Ik in 101
The impregnated product and calcium chloride tetrahydrate 601g (without impregnating material) were filled into three types of containers (each weighing 1001i') made of steel and 5US304° iron, and after sealing, the containers were kept at 150°C. Figures 4 to 6 show measurements of weight loss due to corrosion.

To summarize the above experimental results, as is clear from Figure 2, in all cases of (2L) to (0), a remarkable improvement in absorption rate was observed compared to the case (g) in which no impregnating material was used.Especially The absorption rate after 5 hours has been significantly improved compared to the conventional example in which no impregnating material was used.
As shown in the figure, when no impregnating material was used, the absorption rate decreased significantly after about 20 reaction cycles, but when using an impregnating material, the absorption rate decreased even after many cycles, that is, even when used for a long time. was able to suppress it. 100
Observing the internal condition at the end of the cycle, we found that without the impregnation material, the surface became rock sugar-like and the water vapor absorption surface was significantly impaired, whereas with the impregnation material, the surface remained as good as before the reaction started. The same surface condition was maintained. This clearly shows that the reaction was homogenized. In addition, when the results in Figures 2 and 3 are combined, among the impregnated materials, the plate-like and paper-like ones (a, f, and C) are 1.9 times more expensive than the metal ones, and the cotton-like ones are 1.9 It can be seen that the absorbent in these impregnants absorbs water faster than those in (d), in felt form) and in paste form (6). Although this cannot be determined immediately, it is thought that the effective surface area of the absorbent can be increased if the impregnating material is plate-shaped or paper-shaped.

Regarding the corrosiveness of the metal container, as shown in FIGS. 4 to 6, when no impregnation material was used, corrosivity was observed for all three types of metals.

The use of an impregnating material reduces the direct contact between calcium chloride and the metal, resulting in a significant anti-corrosion effect. In particular, corrosion of copper and 5US304 could be suppressed to virtually no corrosion.

In addition to the effects of the invention, by impregnating the above-mentioned impregnating material with an absorbent and a refrigerant, the problems of increasing reaction rate, improving cycle life, making reaction uniform, and preventing corrosion can be greatly improved.
We were able to solve the problem at the same time using a convenient method. That is, the present invention has made it possible to easily provide an efficient chemical heat pump.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view showing the structure of a chemical heat pump device common to the conventional example and the present invention, and Fig. 2 shows the water absorption rate g (cc/hour) ), Figure 3 shows the water absorption rate ff one hour after the pulp is opened.
Figures 4 to 6 plot f-(cc/hour) against the number of reaction cycles. Figures 4 to 6 show the amount of decrease in container weight (integrated value from the start of the experiment) due to corrosion of copper and 5US304° iron as a function of time. (hours). M...absorbent, B...refrigerant, C...
... Impregnation material, 1゜2 ... Container, 3 ...
・Opening/closing valve. Name of agent: Patent attorney Toshio Nakao and 1 other person (0)
and λV76) ゞ,&age

Claims (4)

[Claims] (1) Consisting of at least two tanks, an absorber and an evaporator, and 6
A chemical heat pump characterized in that at least one of an absorbent and a refrigerant, which are contents of a tank, is impregnated with inorganic fibers in the corresponding tank. (2) The main component of the inorganic fiber is at least alumina (
Al2O5) 20-100%, Siliiy (5i02
) The chemical heat pump according to claim 1, wherein the chemical heat pump contains 0 to 80 inches. (3) The main component of the inorganic fiber is alumina 50 to 100.
%, and 0 to 50% of silica. (4) The chemical heat pump according to claim 1, 2, or 3, wherein the absorbent is an aqueous calcium chloride solution and the refrigerant is water.