JPH02230069A - Absorption freezer and its operating method - Google Patents

Abstract

PURPOSE:To always enable a preheating just before adsorbing or desorbing to be performed by a method wherein a tank having a valve therein is arranged at a pipe for a cooling water or a heating thermal medium, thereby remaining hot water is temporarily stored as the adsorbing stage in one adsorbing tower is completed even if both adsorbing and desorbing stages are not simultaneously completed and the medium is supplied to the adsorbing tower just before the other adsorbing tower proceeds to an adsorbing step. CONSTITUTION:A refrigerant machine is constructed such that a tank 27 is arranged in a pipe for connecting between adsorbing towers 11 and 11' through valves V14, V15 and V16. Upon completion of the desorbing in one adsorbing tower 11, heating thermal medium is left as hot water in the adsorbing tower or a piping thereacross. However, the left water is pushed by a cooling water flowing as the adsorbing stage is started, the water is fed into a tank 27 under a proper valve operation and at once the water is stored there. When the adsorbing stage is completed in the other adsorbing tower 11', a proper valve operation is carried out to cause the aforesaid hot water to be guided from the tank 27 to the adsorbing tower 11' and then a preheating of the solid adsorptive agent is carried out.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an adsorption chiller and its operating method. Specifically, in order to improve the refrigeration efficiency, it is possible to preheat the inside of the adsorption tower immediately before entering the desorption process. This paper relates to an adsorption refrigerator and its efficient operating method.

(Prior art) Adsorption refrigerators that utilize the refrigerant adsorption/desorption effect of solid adsorbents generally have two adsorption towers installed in parallel containing fixed adsorbents such as silica gel, zeolite, activated carbon, and activated alumina. A system is constructed in which a heating medium for heating the adsorbent and cooling water are alternately supplied to both adsorption towers, and the adsorption/desorption process is repeated to continuously obtain refrigeration output.

Recently, various improvements have been made to improve refrigeration efficiency. One of these improvements is to supply the hot water remaining in the adsorption tower immediately after the desorption process to the other adsorption tower immediately after the adsorption process, thereby starting the new desorption process. The present inventor has previously disclosed a method for preheating a solid adsorbent prior to cooling to improve desorption efficiency, thereby improving overall refrigeration efficiency (Japanese Patent Application No. 62-21).
(See Publication No. 6140).

When the desorption efficiency improves with such a method, the adsorption efficiency also increases correspondingly, resulting in an improvement in the overall refrigeration efficiency.
During this time, the improvement in desorption efficiency and the improvement in adsorption efficiency are not necessarily in direct proportion.

In other words, even if desorption efficiency is improved, if it is too effective, it may not be possible to completely adsorb within a predetermined time, or if desorption efficiency is improved, desorption may be shorter than adsorption. In some cases, it may take a while to complete the process, and in any case, improvements in desorption efficiency did not always directly translate into improvements in refrigeration efficiency.

(Problem to be solved by the invention) Therefore, an operation method can be considered in which the desorption efficiency is improved by reducing the operation time of the desorption process and increasing the time of the adsorption process per unit time. According to this method, as is clear from the time chart of FIG. 7, even if the desorption process is completed in one adsorption tower, the adsorption process continues in the other adsorption tower. For this reason, in order to improve the desorption efficiency by preheating the adsorption tower immediately before the desorption step, it is impossible to improve the desorption efficiency using the conventional means of directly supplying residual hot water from one adsorption tower to the other.

In view of such actual circumstances, the present invention has been developed, even if adsorption. Even if both desorption processes do not finish at the same time, the hot water remaining after the desorption process in one adsorption tower is completed can be temporarily stored and supplied to the other adsorption tower just before it starts the desorption process. This makes it possible to always preheat just before the desorption process, and
The purpose of this invention is to operate such an adsorption refrigerator while shortening the time for the desorption process as described above, thereby further improving the refrigeration efficiency.

(Means for Solving the Problems) That is, the feature of the adsorption refrigerator according to the present invention that satisfies the above purpose is that two adsorption towers each having a built-in solid adsorbent and a heat transfer tube are used.
In an adsorption refrigerator, in which the adsorption tower is operated by switching between adsorption and desorption processes, the body of each adsorption tower is connected to a condenser and an evaporator so that refrigerant can circulate, and the adsorption tower is operated by switching between adsorption and desorption processes. A tank is placed in the pipe for the cooling water or heating medium of the refrigerator, and a valve is attached to the pipe close to the place where the tank is placed.

Here, the tank used has a capacity that is approximately equal to the amount of hot water remaining inside the adsorption tower immediately after the desorption process and in the piping located before and after it, and the tank is used to connect the adsorption towers. Connected to piping.

In addition, the characteristics when operating the above adsorption refrigerator are as follows.
The operation time of the desorption process is shortened by a predetermined period from the operation time of the adsorption process, and as a result, the operation time of the adsorption process per unit time is increased, and furthermore, the hot water held in the adsorption tower at the end of desorption is The purpose is to store hot water in a tank and then use the stored hot water in the tank to preheat the adsorption tower that switches from adsorption to desorption.

(Function) When an adsorption refrigerator as described above is operated according to the method of the present invention, first of all, as described above, even if the desorption process is completed in one adsorption tower, the adsorption process continues in the other adsorption tower. occurs.

Therefore, in one adsorption tower, when the desorption process is completed, the heating medium remains as hot water inside the adsorption tower and in the piping before and after it. It is pushed out with water and introduced into a tank, which is a feature of the present invention, by operating a suitable valve, where it is temporarily stored.

When the adsorption step is completed in the other adsorption tower, by appropriately operating a valve, the hot water is guided from the tank to this adsorption tower, and the solid adsorbent is preheated.

After this, the adsorption tower moves to the desorption step, and the refrigerant desorption at this time becomes efficient due to the preheating described above.

Therefore, the desorption process functions satisfactorily even if the operating time is shortened by the operating method according to the present invention, while in the adsorption process, even if the operating time remains the same, the operating interval is shortened, so the refrigeration efficiency of the entire refrigerator is improved. It turns out.

(Embodiment) An embodiment of the adsorption refrigerator according to the present invention will be described below along with a method of operating the adsorption refrigerator of the present invention.

1 to 6 are schematic diagrams showing an example of an adsorption refrigerator according to the present invention.

Note that the flow path through which the heat medium or refrigerant is flowing is shown as a solid line, and
Residual hot water is shown as a dashed line.

In these figures, 0υ and (11)' are hot water supplied into the vacuum vessels a21 and (12)' from a low-grade heat source such as a solar collector or factory waste heat, with or without a heat exchanger. and a fin tube (13) through which cooling water generated by a cooling water generator such as a cooling tower passes alternately. (13)', and the fin tube (13). (13) Solid adsorbent such as silica gel, zeolite activated carbon 1 activated alumina (
There are two adsorption towers packed with S), α0 is both adsorption towers (1
1), (11)' body (12), (12)' with valves (V?1), (Vl14)} (
16), condenser connected via (16)', αη
is an evaporator connected to the bottom of the body (Ma) of the condenser (+4) via a trap-shaped pipe 00), and the casing (17a) of the evaporator 0η and the first . Vacuum vessel (12) of second adsorption tower (11), (11)'.
(12)' means that there are valves (v, It), (v
i2) are connected to each other by ducts (20), (20)', and a predetermined amount of refrigerant such as water sealed in the vacuum containers (12), (12)' is supplied to the valves (νe+), (V*■). As (vR3) and (VR4) are opened and closed, it is possible to circulate between them.

The condenser is one in which a finned heat exchanger tube (21) such as a cross fin tube or an erotic fin tube is housed inside the body (14a), and the condenser is constantly supplied into the heat exchanger tube (21). The adsorption tower (11) is cooled by cooling water.
The refrigerant vapor discharged from the solid adsorbent (S) in (11)' is condensed and liquefied, stored at the bottom of the body (14a), and supplied to the evaporator through the pipe 0. .

On the other hand, the evaporator Q71 has a horizontally long casing (17a
) into which a heat exchanger tube (22) through which the user-side heat medium passes is inserted, and an evaporation plate (not shown) provided at the lower part of the heat exchanger tube (22).
The refrigerant liquid introduced from the condenser αa is stored and evaporated on the surface of the heat transfer tube (22), and the latent heat of evaporation is taken from the user-side heating medium to cool it.

Further, (27) is a tank that is a feature of the present invention, and has a necessary and sufficient capacity to store residual hot water, which will be described later, and has valves (VI4), (VI5), (V
, 6).

In the figure, (Vl), (V2), (Vl)...(VI3
) is the heat exchanger tube (1) of the adsorption tower (11), (11)'.
3), (13)', heat transfer tube (21) of condenser αa,
This is a valve provided in a pipe line that connects a cooling water inlet (23), a cooling water outlet (24), a heat source side heat medium inlet (25), and a heat source side heat medium outlet (26).

Koreranohalbu (Vl), (V2), (V3)
-(V.3) and valve (v,4). (ν+s), (L
a), and further the above-mentioned hulls (VRI), (VR2), (VIl!), (VR4) provided in the refrigerant circulation path.
) are all configured to open and close in sequence based on commands from a control means (not shown).

Next, the method of the present invention will be explained based on the adsorption refrigerator having the above structure.

First, in FIG. 7, a time chart 1 of the adsorption refrigerator shown in FIGS. 1 to 6 is shown. In the figure, the numbers representing the states correspond to the states in FIGS. 1 to 6, respectively. Also, quasi represents preparation for switching the process, desorption represents the desorption process, and suction represents the adsorption process.

Each state ■ to ■ is operated for a predetermined time, for example, in the example in the same figure, ■ is operated for 0.5 minutes, ■ is operated for 3 minutes, and ■
is 0.5 minutes, ■ is 1.5 minutes, and ■ is 0.5 minutes. ■ is 3 minutes.

Therefore, FIG. 1 shows the first suction. This is a preparatory stage when the adsorption tower switches from the adsorption process to the desorption process, while the second adsorption tower switches from the adsorption process to the adsorption tower.

In the same figure, the heat source side heating medium flowing in from the inlet (25) is
It is returned to the outlet (26) by the valve (v3) and the supply to the second adsorption column (11)' is stopped. As a result, the heat source-side heating medium that has been supplied until now remains as hot water in the heat exchanger tube (13)' of the second adsorption tower (11)' and the piping located before and after it, but on the other hand, the inlet ( 23)? Since the cooling water flows into the heat transfer tube (13)' to cool the solid adsorbent (S), the residual hot water is pushed out and the valve (V+
) and enters the heat exchanger tube side of the first adsorption tower αυ, where the solid adsorbent (S) is heated and preheated before the desorption process of the first adsorption tower a0.

Next, until the hot water flows out from the heat exchanger tube α of the first adsorption tower aυ, the timing is determined and the halve (Vl), (vz), (V3), (V?) is adjusted as shown in Fig. 2.
, (vs) , (VI +) and (V.■), (ν
When R3) is switched all at once, the heat medium on the heat source side flows through the valve (
v2) to the heat exchanger tube OJ of the first adsorption tower 0υ to thermally desorb the solid adsorbent (S), while the cooling water is
After being supplied to the heat transfer tube (13)' of the second adsorption tower (11)', it is directed to the outlet (24) by the valve (v6), and in another piping route, it is supplied to the evaporator Q41 following FIG.
It is also supplied to the heat exchanger tubes (21).

As a result, the refrigerant vapor thermally desorbed in the first adsorption tower αυ passes through the valve (VR:I) and enters the condenser Q4), where it is cooled and liquefied by the cooling water flowing through the heat transfer tube (21). , is stored at the bottom of the body (14a), and is sent to the evaporator α7 through the pipe (18+) due to the pressure difference.

Also, during this time, in the second adsorption tower (11)', the solid adsorbent (S) is cooled and adsorbs the refrigerant vapor.
The refrigerant liquid in the evaporator Q7) actively evaporates from the surface of the heat exchanger tube (22) and cools the user-side heat medium by removing the latent heat of evaporation from the user-side heat medium flowing inside the heat exchanger tube (22). If supplied to the fan coil UniSoto installed in the air conditioning target area, it will meet the temperature conditions of general air conditioning systems (for example, cooling water inlet temperature 30°C, user side heat medium inlet temperature 12°C, same outlet temperature 7°C)
can be satisfied.

Next, FIG. 3 shows a case where only the adsorption tower in the desorption step, which is a feature of the method of the present invention, that is, in this case, the first adsorption tower at+ is switched from the desorption step to the adsorption step.

First, Harub (V2), (V3), (V5), (V?)
, (VI2), (li+, :l) , (V+ a”)
, (V+6), (Va3), the supply of the heat source side heating medium to the first adsorption tower Ql) is stopped, and the cooling water is supplied to the first adsorption tower Ql by opening the valve (V,). It also flows to the adsorption tower αυ. In the heat transfer tube Q3) of the first adsorption tower (11) and the piping before and after it, the heat medium on the heat source side is present as residual hot water, as in the case of the second adsorption tower (11)' in Fig. 1. However, as mentioned above, it is pushed out by the inflowing cooling water and the valve (
With the opening of Li, ) and valve (Vl4), the tank (
27).

During this time, the adsorption process continues in the second adsorption tower (11)', but the supply of cooling water to the condenser α0 is stopped.

When all the residual hot water flows into the tank (27), the valves (Vl4) and (Vl6) are closed to store the hot water in the tank (27) as shown in FIG.
By opening 1), the cooling water flowing out from the first adsorption tower αυ is directed to the outlet (24).

As a result, the heat exchanger tube (transfer) of the first adsorption tower 0υ also has a second
Cooling water flows in exactly the same way as in the adsorption tower (11)', and when the valves (v, lI) are opened at the same time, the first adsorption tower Ql) and the evaporator α force are communicated, and the first adsorption Adsorption operation by tower αD begins.

In other words, the adsorption process will be operated using the two adsorption towers (11, (11)'), and at this time, of course, the supply of cooling water to the condenser Q41 will be in the state shown in Figure 3. It has been stopped since then.

Next, FIG. 5 shows a preparatory stage when the second adsorption tower (11)' shifts from the adsorption step to the desorption step.

First, close the valve (Vi2) and open the second adsorption tower (11).
’, while preventing the adsorption and movement of refrigerant by the valve (V+
■), (VI3) are opened to supply cooling water to the condenser outlet, and the cooling water that has passed through the first adsorption tower aD is supplied to the valve (VI3).
6) into the tank (27).

In FIG. 3, the hot water stored in the tank (27) is pushed out through the valve (V ls ) by the cooling water flowing into the tank (27), and flows into the second adsorption tower (
The solid adsorbent (S) is driven into the heat exchanger tube (13)' of 11)' and the piping before and after it, and preheats the solid adsorbent (S).

During this time, the adsorption process continues in the first adsorption tower 0υ.

Next, when all the hot water in the tank (27) has been drained, as shown in Fig. 6,
All the tanks (27) are closed, and the cooling water that has passed through the first adsorption tower αυ is discharged from the outlet (24) by opening the valve (V.).

On the other hand, the second adsorption tower (1
1) To ', close valve (v3) and open valve (ν,)
By opening, the heat medium from the heat source side is supplied and desorption operation is performed. As a result, adsorption is carried out in the first adsorption tower αυ, and desorption and desorption are carried out in the second adsorption tower (11)', but a description of this process will be omitted.

It goes without saying that the adsorption refrigerator according to the present invention can be operated according to the method of the present invention even when the situation as shown in FIG. 2 in which the adsorption and desorption processes are switched at the same time does not occur at all. .

Furthermore, in the above embodiment, two adsorption towers were used and they were connected in parallel to the condenser and evaporator so that the refrigerant could be circulated, but three adsorption towers were used.
The method of the present invention can also be applied by arranging tanks in the same manner when arranging two or more tanks in parallel and operating them in adsorption/desorption operation in order to obtain a continuous refrigerating output.

(Effects of the Invention) As described above, the adsorption refrigerator according to the present invention has two or more adsorption towers, and a tank is arranged together with a valve in the piping connecting the adsorption towers. When the desorption process is completed in one adsorption tower, the remaining hot water can be temporarily stored in the tank and then supplied to the other adsorption tower after a certain period of time, so the operating time of the desorption process is Even if there is a difference in the process switching time between adsorption towers due to the shortened operating method of the present invention, it is possible to always supply hot water to the adsorption tower to preheat the adsorbent before moving to the desorption step.

That is, the desorption efficiency is improved in all cases, which makes it possible to shorten the desorption operation and thereby increase the operating time per unit time of the adsorption process, thereby making it possible to greatly improve the refrigeration efficiency.

[Brief explanation of the drawing]

1 to 6 are schematic diagrams showing an example of an adsorption refrigerator according to the present invention to which the method of the present invention can be applied, and FIG. 7 is a time chart showing an example of the method of operating the adsorption refrigerator according to the present invention. It is. (11), (11)'...adsorption tower, (12),
(12)'...Body (vacuum container), (13),
(13)'... Heat exchanger tube, (14)... Condenser, (17)... Evaporator, (27)... Tank, (VI4), (VI5), (Vl6)...- valve,(
S)...Solid adsorbent. Figure 1 Figure 2 Figure 3122 Figure 6 Figure 7 Closed

Claims (1)

[Claims] 1. Two or more adsorption towers each containing a solid adsorbent and a heat transfer tube are used, and the body of each adsorption tower is connected to a condenser and an evaporator so that refrigerant can circulate, and In an adsorption refrigerator where the tower is operated by switching between adsorption and desorption processes,
A tank with approximately the same capacity as the amount of hot water remaining in the heat transfer tubes and piping of the adsorption tower immediately after the desorption process is completed is placed in the piping connecting the adsorption towers, and a valve is attached to the piping close to the placement point. An adsorption refrigerator characterized by being able to store residual hot water in an adsorption tower. 2. When operating the adsorption refrigerator according to claim 1 by switching between adsorption and desorption processes, the desorption process is operated with a predetermined shorter time than the adsorption process in both adsorption towers. A method of operating an adsorption refrigerator characterized by the following. 3. In the adsorption refrigerator according to claim 1, the hot water held by the adsorption tower at the end of desorption is stored in the tank, and then stored in the tank for preheating the adsorption tower when switching from adsorption to desorption. A method of operating an adsorption refrigerator characterized by using hot water.