JP2785143B2 - Operating method of absorption refrigerator - Google Patents

Description

The present invention relates to an operation method of an absorption refrigerator, and more particularly to a method of operating an absorption refrigerator, which determines the presence or absence of crystals in an absorption solution during operation of the absorption refrigerator. Related to driving method.

[Conventional technology]

Conventionally, in the case of an absorption refrigerator, problems related to crystals have been a major problem. When crystals are generated, first, the circulation of the solution deteriorates, the refrigeration capacity decreases, and when it further develops,
Solution circulation becomes impossible, and refrigeration capacity is lost. And if you continue to add a heat source while crystals are generated, the amount of crystals will increase,
Recrystallization becomes difficult. Furthermore, the generator is also developed for empty cooking (heating in a state where there is no liquid), and in the case of a direct fire type, the can body is deformed due to thermal expansion and may even melt.

Such a state also occurs when there is non-condensable gas in the absorber, and there is a concentration effect due to the heat source of the generator, but the absorption in the absorber is poor and it cannot be diluted. If left untreated, it develops into crystals and loses its refrigeration capacity. As described above, when the non-condensable gas is present and the absorption is poor, the refrigerating capacity is extremely reduced as compared with a normal state (a state without the non-condensable gas). As described above, in the refrigerator, when operating while crystals are generated,
There is no refrigeration capacity, which leads to the major problem described above.

Therefore, in the prior art, the generation of crystals is monitored by monitoring the concentration.

[Problems to be solved by the invention]

However, in the concentration monitoring as described above, there is a case where a problem of accuracy, a crystal generated locally, or the like cannot be caught, and it is necessary to use another method together.

An object of the present invention is to provide an operation method of an absorption refrigeration system that determines an abnormality of a device such as a crystal by monitoring a refrigeration capacity that is reduced by generation of non-condensable gas or crystal.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, in an absorption refrigerator having an absorber, an evaporator, a generator, a condenser, a solution path connecting these devices, and a refrigerant path, a heat source is supplied to the generator. An absorption chiller operating method characterized by stopping the supply of a heat source to the generator when the chiller is operated and the actual capacity is extremely reduced compared to the normal capacity of the chiller. It is.

The comparison with the normal capacity of the refrigerator is performed in a state in which the refrigerator can exhibit the capacity after a predetermined time elapses after the supply of the heat source or when the cycle concentration is equal to or higher than the predetermined concentration. The extreme decrease in the refrigerating capacity refers to, for example, a state where the chilled water outlet temperature is not lower than the inlet temperature when the chilled water temperature is increasing.

(Operation)

In the absorption refrigerator, the refrigerating capacity is extremely reduced compared to the normal state due to the mixing of non-condensable gas or the formation of crystals.Therefore, determine the abnormality by monitoring the refrigerating capacity during the operation of the refrigerator. Can be.

That is, the capacity of the refrigerator is generally obtained by the following formula: refrigeration capacity = (chilled water inlet temperature-chilled water outlet temperature) x chilled water flow rate. Abnormality can be determined by comparing the heat source amount, the cooling water temperature, the cold water temperature, and the like) with the actual refrigeration capacity.

The judgment of abnormalities can be made based on extreme decline, such as half the ability. In this case, the accuracy of the sensor or the fluctuation at the time of unsteady state becomes a problem.
When taken into account, it gets too complicated.

As a simple method that also takes into account load fluctuations, if the chilled water temperature tends to decrease (temporarily), the capacity is at least a certain level, and the chilled water temperature tends to increase (temporally).
In the case of (1), if the chilled water outlet temperature is not lower than the chilled water inlet temperature, it is determined by a method of judging that the capacity is not sufficient.

Generally, when the refrigerator is started, the solution concentration is low,
Since the ability does not come out immediately, it is better to wait for a predetermined time and enter into judgment. Alternatively, it is better to start the ability judgment after the solution concentration reaches a predetermined concentration. If the cycle concentration is very low, there is no need to worry about crystals, so even during operation,
Capability monitoring can be removed.

Also, it is difficult to determine whether or not non-condensable gas is present at the time of starting the refrigerator. (It is difficult to judge even a small amount because it affects the ability). If the apparatus is started as it is and the extraction of the non-condensable gas is insufficient, the refrigeration capacity is not generally obtained, and the concentration and the crystals are continued. Therefore, after a predetermined time elapses after the start, the refrigeration capacity is monitored to determine whether there is an abnormality.

In addition, when starting the refrigerator,
It is also difficult to determine if there is. If the refrigerator is started in a state where crystals are generated in the refrigerator (although it may happen to be accidentally crystallized), generally, the refrigerating capacity is not sufficient, and the crystals further grow, leading to the above-mentioned major problem of crystals. Go. Therefore, after starting, after a predetermined time has elapsed, the refrigeration capacity is monitored,
Judge whether it is abnormal.

Then, when the heat source is supplied to the generator and the capacity of the refrigerator can be obtained, when the actual capacity is extremely reduced compared to the normal capacity of the refrigerator, the power to the generator is Turn off the heat source supply and issue an alarm. At this time, when the solution concentration is expected to be high, the refrigerant liquid of the evaporator is returned to the solution cycle side, and a dilution operation for preventing crystallization is performed.

〔Example〕

Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
The present invention is not limited to this.

FIG. 1 is a process diagram illustrating an operation method of an absorption refrigerator of the present invention.

In FIG. 1, the absorption refrigerator includes an absorber A, an evaporator E, a condenser C, a high-temperature generator GH, a low-temperature generator GL, a high-temperature heat exchanger XH, a low-temperature heat exchanger XL, a solution pump SP, and a refrigerant pump.
It is composed of RP, and each device is connected by piping through a solution path and a refrigerant path.

During normal operation of the device configured as described above, first, the absorption solution is withdrawn from the bottom of the absorber by the absorption pump SP, passes through the low-temperature heat exchanger XL and the high-temperature heat exchanger XH by the pipe 21, and passes through the pipe 23. Then, it enters the high-temperature generator GH. In the high-temperature generator GH, the refrigerant that has been heated and absorbed by the heat source from the heating pipe 7 evaporates, and the concentrated high-temperature solution passes through the heating side of the high-temperature heat exchanger XH from the pipe 26 and the low-temperature generator from the pipe 27. Enter GL.

The low-temperature generator GL pipes the refrigerant evaporated by the high-temperature generator GH.
From 13 heat is applied to the heating tube 4 and the solution is further concentrated, while the evaporated refrigerant is condensed. The further concentrated solution is withdrawn from the bottom of the low-temperature generator GL by the pipe 24, passes through the heating side of the low-temperature heat exchanger, and is sprayed from the pipe 25 onto the cooling pipe 2 from the top of the absorber A to absorb the refrigerant. Then, there is a circulation path that becomes a dilute solution.

On the other hand, the refrigerant liquid is absorbed by the solution in the absorber, enters the high-temperature generator together with the solution, is evaporated by the heat source, is condensed from the pipe 13 as the heating source of the low-temperature generator GL, and enters the condenser C. The refrigerant is evaporated by the low-temperature generator, merges with the refrigerant liquid condensed by the cooling water pipe 3, and is sprayed from the pipe 12 onto the cold water pipe 1 from above the evaporator E, where the refrigerant evaporates to generate cold heat. I do. This cold heat is used for cooling or the like by cold water. The refrigerant liquid that is not evaporated is circulated on the evaporator by the refrigerant pump RP.

By the way, in such an operation, when an abnormality occurs due to mixing of non-condensable gas or generation of crystals, an abnormality occurs in the refrigeration capacity detectors 5 and 5 'which are constantly monitored. This abnormality is judged by the control means 6, and the heat source heat quantity control valve H is controlled so that the heat source is not sent to the generator.

The determination of the refrigerating capacity abnormality is made as shown in the explanatory diagram of FIG. That is, as shown in FIG. 2 (a), when the temperature of the chilled water decreases with time, it is regarded as normal.
If the cold water temperature rises with time as in (b), it is considered normal if the cold water inlet temperature to the evaporator is higher than the outlet temperature. If there is no difference between the chilled water inlet temperature and the outlet temperature, it is determined to be abnormal.

Then, if it is determined that there is an abnormality, first, stop the heat source to the high-temperature generator, guide the refrigerant from the refrigerant path to the solution path, dilute the solution, prevent the generation of crystals, prevent crystallization, etc. Take action.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, in operation | movement of an absorption refrigerator, it can easily judge mixing of an uncondensable gas and the presence or absence of the crystal | crystallization in an absorption solution, and can take appropriate measures before becoming a serious obstacle. In particular, when starting the absorption refrigerator, it is very difficult to determine the presence or absence of crystals. However, according to the operation method of the present invention, the presence or absence of crystals can be easily and reliably determined, and appropriate and prompt measures can be taken. Can be.

[Brief description of the drawings]

FIG. 1 is a process diagram for explaining an operation method of an absorption refrigerator of the present invention, and FIG. 2 is an explanatory diagram for judging a refrigerating capacity based on a relationship between time and temperature. A: Absorber, E: Evaporator, C: Condenser, GH: High temperature generator, GL: Low temperature generator, XH: High temperature heat exchanger, XL
... Low-temperature heat exchanger, SP ... Solution pump, RP ... Refrigerant pump, H ... Heat source calorie control valve, 5, 5 '... Refrigeration capacity detector, 6 ... Control means

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F25B 15/00 306

Claims (4)

(57) [Claims] 1. An absorption refrigerator having an absorber, an evaporator, a generator, a condenser, and a solution path and a refrigerant path connecting these devices, is operated by supplying a heat source to the generator to operate the refrigerator normally. A method for operating an absorption refrigerator, wherein the supply of a heat source to a generator is stopped if the actual capacity is extremely reduced as compared with the capacity at the time. 2. The comparison with the normal capacity of the refrigerator is a comparison in an operation in a state in which the refrigerator can exhibit its capacity after a predetermined time has elapsed after the supply of the heat source. Item 1
The operation method of the absorption refrigerator described above. 3. The comparison with the normal capacity of the refrigerator is a comparison in an operation in which the cycle concentration is equal to or higher than a predetermined concentration after the supply of the heat source and the refrigerator is capable of exhibiting the capacity. The method for operating an absorption refrigerator according to claim 1. 4. An extreme decrease in the refrigerating capacity is determined to be an extreme decrease when the chilled water outlet temperature is not lower than the inlet temperature when the chilled water temperature is increasing. Item 4. The method for operating an absorption refrigerator according to item 1, 2 or 3.