JPH0439589B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention is applicable to stopping the refrigeration operation of an absorption refrigerator using a salt solution such as water-lithium bromide or alcohol-lithium chloride as an absorption liquid. The present invention relates to an apparatus for operating an absorption refrigerating machine to lower the absorbent concentration of an absorption liquid, that is, an improvement of a dilution operating apparatus for an absorption refrigerating machine.

(b) Prior art In absorption refrigerators, the concentration of lithium bromide in an aqueous lithium bromide solution is increased to about 62%, for example, in order to perform efficient refrigeration operation. Therefore,
When the refrigeration operation is stopped, if the outside temperature is low, the absorption liquid (lithium bromide aqueous solution) will crystallize, which will hinder the resumption of the next refrigeration operation. Therefore, in an absorption refrigerator using a salt solution (hereinafter referred to as this type of absorption refrigerator), it is necessary to perform an operation to lower the concentration of the absorption liquid, that is, a dilution operation, when stopping the refrigeration operation. Conventionally, this dilution operation is continued even after the heating of the generator is stopped, until the concentration of the absorption liquid is sufficiently reduced. This is done by keeping the .

Although such conventional dilution operation methods have the advantage of being able to utilize the refrigerating capacity at the beginning of the dilution operation, that is, the advantage of being able to obtain low-temperature cold water for a while, they have the disadvantage that it takes too much time to complete the dilution operation. ing.

(c) Purpose of the Invention The purpose of the present invention is to provide an apparatus that can shorten the dilution operation time in this type of absorption refrigerator.

(d) Structure of the Invention The present invention provides that in this type of absorption refrigerator, when stopping the refrigeration operation, the generator heating, the cooling water pump, and the absorption liquid pump are stopped, and
The absorbent pump is configured to be activated again after a predetermined time has elapsed using a timer to dilute the absorbent for a predetermined period of time.

According to the present invention, most of the refrigerant liquid remaining in the condenser is mixed into the absorption liquid in the absorber in a short time after the refrigeration operation is stopped, so that the refrigerant capacity is gradually reduced and absorbed. Compared to conventional devices for diluting liquid, the dilution operation time can be shortened.

(E) Embodiment The drawing is a schematic configuration explanatory diagram showing an embodiment of the device of the present invention, in which 1 is a high temperature generator, 2 is a low temperature generator,
3 is a condenser, 4 is an evaporator, 5 is an absorber, 6 is a low temperature solution heat exchanger, 7 is a high temperature solution heat exchanger, 8 is a pump for absorption liquid (hereinafter referred to as solution pump), 9 is for refrigerant pump (hereinafter referred to as refrigerant pump),
These devices include pipes 10 and 10' through which the refrigerant flows, a pipe 11 through which the refrigerant liquid flows, a pipe 12 through which the refrigerant liquid flows back,
12', pipes 13, 13', 14, 1 through which absorption liquid flows
4', 15, and 15' to form a circulation path for refrigerant and absorption liquid.

16 is a water cooler built into the evaporator 4, 17, 18
are coolers built into the absorber 5 and condenser 3, 19 is a heat feeder built into the low temperature generator 2, and 20
is a heater built into the high temperature generator 1. 21,
21' is a pipe through which cold water flows, 22, 22', 22'' are pipes through which cooling water flows, 23, 23' are pipes through which heat source steam flows, and 24 is a cold water pump provided in the pipe 21 (hereinafter referred to as cold water pump). ), 25 is a cooling water pump (hereinafter referred to as cooling water pump) provided in the pipe 22'', and 26 is a valve provided in the pipe 23'. 27,2
8 is a refrigerant liquid reservoir for the condenser 3 and evaporator 4, 29,3
0 and 31 are solution reservoirs for the low temperature generator 2, high temperature generator 1, and absorber 5.

32 is a controller for starting and stopping the operation, and this controller has a built-in timer and a start/stop switch.
The stop switch stops the operation of the solution pump 8, refrigerant pump 9, cold water pump 24, and cooling water pump 25, and closes the valve 26. The timer of the controller 32 causes the solution pump 8 to operate again for a predetermined period of time (approximately 5 minutes) after a predetermined period of time (approximately 20 minutes) has elapsed since the solution pump 8 was stopped.

In addition, 33 is a thermostat provided in the vicinity of the low-temperature solution heat exchanger 6 in the pipe 15', and this thermostat has a function of operating the solution pump 8 which has been stopped when the detected temperature falls below the set temperature. ing. In other words, by the time a predetermined period of time (approximately 20 minutes) has elapsed after the refrigeration operation was stopped, the pipe 1
5' and the high-concentration absorption liquid (concentrated liquid) in the low-temperature solution heat exchanger 6 approaches the crystallization temperature due to the influence of outside air, this concentrated liquid is transferred to the absorption liquid (diluted) sent by the solution pump 8. This is to prevent the concentrated liquid from crystallizing by raising the temperature and diluting it.

Next, we will compare an example of the operation of the absorption chiller dilution operation device (hereinafter referred to as this device) configured in this way with the operation of a conventional device that dilutes the absorption liquid while gradually decreasing the refrigerating capacity. ,explain.

In this device, when the refrigeration operation is stopped, the controller 3
The stop switch No. 2 completely closes the valve 26 and stops the operation of the pumps 8, 9, 24, and 25. When the valve 26 is fully closed and the heating of the high temperature generator 1 is stopped, the function of separating the refrigerant of this generator is stopped, and the function of separating the refrigerant of the low temperature generator 2 is also almost completely stopped. . When the cooling water pump 8 is stopped and cooling water is no longer passed through the coolers 17 and 18, the temperature of the concentrated liquid sprayed in the cooler 17 no longer decreases, and the function of the absorber 5 to absorb refrigerant stops. , and the function of condensing the refrigerant of the condenser 3 also stops. Moreover, when the refrigerant pump 9 and the cold water pump 24 stop, the function of evaporating the refrigerant of the evaporator 4 also stops. As a result, an absorption refrigeration cycle due to the circulation of the refrigerant and absorption liquid is no longer formed in a short time, and the residual heat of the remaining refrigerant and absorption liquid causes the condenser 3
Since the pressure on the side of the evaporator 4 is maintained higher than the pressure on the side of the evaporator 4 for a while (approximately 60 minutes), most of the refrigerant liquid remaining in the refrigerant reservoir 27 of the condenser 3 is absorbed by the pressure difference. The refrigerant liquid flows down to the solution reservoir 31 of the absorber 5 through the pipe 11 and the refrigerant reservoir 28 of the evaporator 4 due to the head difference, and the absorbed liquid in this solution reservoir is diluted. Then, after a predetermined time (approximately 20 minutes) has elapsed since the solution pump 8 was stopped by a timer built in the controller 32, it is restarted for a certain period of time (approximately 5 minutes), and the diluted absorption liquid in the solution reservoir 31 is While circulating through the absorption liquid circulation path, the concentration of the absorption liquid remaining in this circulation path is reduced. In this way, the dilution operation of this device is completed.

On the other hand, in the conventional device, when the refrigeration operation is stopped, only the valve 26 is fully closed and the pumps 8, 9, 24, and 25 are operated, so the function of the high temperature generator 1 is stopped. However, the functions of the absorber 5, condenser 3, evaporator 4, and low temperature generator 2 do not completely stop. As a result, the refrigeration operation continues for a considerable period of time, and the dilution operation time (approximately 30 minutes) increases accordingly.

In this way, the dilution operation time for the conventional device is approximately 30 minutes, whereas for this device it is approximately 5 minutes, and this device reduces the dilution operation time to approximately 1/6 of that of the conventional device. can.

In the embodiment, the refrigerant pump 9 and the cold water pump 24 are stopped at the same time as the valve 26 is fully closed, but even if these pumps 9 and 24 are operated, the dilution operation time of the present invention apparatus is limited to the time when these pumps are operated. It's not much different than if it stopped. This is because the refrigerant absorption function of the absorber 5 is stopped due to the stoppage of the cooling water pump 25, and as a result, the refrigerant cannot be evaporated in the evaporator 4, and an absorption refrigeration cycle is not formed immediately. Of course, it is preferable to stop these pumps 9 and 24 because the power costs for these pumps can be saved.

Furthermore, in the embodiment, the time from stopping the solution pump 8 to starting it again is about 20 minutes.
The timer was set so that the reactivation time of the solution pump 8 would be approximately 5 minutes, but the settings of this timer depend on the type of absorption refrigerator (single effect type, multiple effect type), type of saline solution, absorption It is selected as appropriate depending on the specifications such as the capacity of the refrigerator.

In addition, by flowing low-temperature heat source water into the pipe 21, the pipe 22''
It goes without saying that the device of the present invention can also be applied when hot water is extracted from a refrigerator, that is, when an absorption refrigerator is used as a heat pump.

(f) Effects of the Invention As described above, the device of the present invention, in this type of absorption refrigerator, can quickly remove most of the refrigerant liquid remaining in the condenser after stopping the refrigeration operation. The flow of cooling water and the circulation of the absorption liquid are stopped so that the cooling water flows into the absorption liquid, and the absorption liquid whose concentration has become low due to the flow of refrigerant liquid is recirculated, so this system is more effective than conventional equipment. Dilution operation can be greatly shortened.

[Brief explanation of drawings]

The drawing is a schematic structural explanatory diagram showing an embodiment of the device of the present invention. 1... High temperature generator, 2... Low temperature generator, 3...
Condenser, 4... Evaporator, 5... Absorber, 8... Solution pump, 9... Refrigerant pump, 24... Chilled water pump, 25... Cooling water pump, 26... Valve, 32...
...Controller.

Claims (1)

[Claims] 1. In an absorption refrigerator that uses an aqueous lithium bromide solution or other salt solution as the absorption liquid, when stopping operation, stop the generator heating, the cooling water pump, and the absorption liquid pump, A dilution operation device for an absorption refrigerator, characterized in that the absorption liquid pump is operated again after a predetermined time has elapsed using a timer to dilute the absorption liquid for a certain period of time.