JPS5944558A - Controller for absorption refrigerator - 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 (a) Technical Field of the Invention The present invention relates to a control device for adjusting the amount of heat exchange between cooling water and absorption liquid of an absorption refrigerator, as well as between cold water and refrigerant liquid.

(B) Prior art and its problems In absorption refrigerators, when the outside air temperature falls, the cooling water temperature also falls under the influence of it, so the temperature of the absorption liquid sprayed into the cooling water pipes of the absorber becomes low. As a result, the saturated vapor pressure of the absorption liquid decreases, the absorption action of the absorption liquid is promoted, and the refrigerating capacity, in other words, the output of the absorption refrigerator is improved. However, (1) When the outside air temperature decreases, the cooling load also decreases, so the output of the absorption refrigerator becomes excessive, resulting in the problem of so-called overcooling. On the other hand, when the outside air temperature becomes high and the cooling water temperature rises, the absorption effect is suppressed, resulting in a problem of insufficient output.

In addition, if the cooling water temperature continues to decrease for a long time and the degree of decrease in the cooling water temperature is extremely large, the amount of refrigerant absorbed by the absorber will be greater than the amount of refrigerant produced by the condenser. Since the amount of refrigerant vaporized liquid increases, the amount of refrigerant in the refrigerant reservoir of the evaporator decreases significantly, which also causes the problem of capacity loss of the refrigerant pump.

Therefore, it has been conventional practice to reduce the refrigerating capacity, or output, of an absorption refrigerator by mixing an absorption liquid into the refrigerant to suppress the vaporization of the refrigerant in the evaporator.
With such conventional means, it is difficult to return the refrigerant to its original state when the cooling water temperature rises once again.Since the IC is used, it is difficult to accurately control the output of the absorption chiller in response to changes in the cooling water temperature. There are some drawbacks that cannot be avoided.

(c) Means for Solving the Problems In view of the problem described in item 1, the present invention provides an object η1! that changes in response to an increase or decrease in cooling water temperature. The absorption liquid, cooling water, and The amount of heat exchange between the refrigerant and the cold water is adjusted to adjust the absorption action of the absorption liquid in the absorber and the evaporation action in the evaporator, thereby accurately controlling the output of the absorption refrigerator.

2) Embodiment The drawing shows an absorption refrigerator that is an embodiment of the present invention, (1) is a generator, (2) is a condenser, (3) is an evaporator, and (4) is an absorption refrigerator. The container and (5) are solution heat exchangers, which include a liquid replacement pipe (7) with a solution pump (6), a concentrated liquid pipe (
8), a refrigerant vapor pipe (9), a refrigerant liquid flow down pipe θ0), and a refrigerant return pipe 02) having a refrigerant pump (11).

03) is a cold water pipe stored in the evaporator (3), θ4) is a cooling water pipe stored in the condenser (2) and absorber (4), (15)
) is a refrigerant reservoir located at the bottom of the evaporator (3).

(A) is the cooling water condenser (2) in the cooling water pipe 04)
Cooling water humidity detector installed on the outlet or inlet side, (
IJ1 is the refrigerant level detector in the refrigerant reservoir 05), (q is the refrigerant vapor temperature detector installed in the generator (1), (IJ is the concentrated liquid temperature detector installed in the concentrated liquid pipe (8)) , (E) and (F
') is a concentration detector for replacement fluid and concentrated solution.

Socite, 06), a7) C, refrigerant distributor, θ8)
, ogI are solution dispersers, and each of the solution dispersers and the concentrated liquid pipe (8) are connected via a solution distribution pipe (2O), 01), and the refrigerant disperser ( 16), α
The power and refrigerant return pipe θ water are the refrigerant distribution pipe (22),
(23). Furthermore, a solution distribution pipe (2
1) and the refrigerant distribution pipe (23) are equipped with control valves (1) and (23), respectively.

(24) is a refrigerant bypass pipe with a refrigerant control valve (3) that connects the refrigerant pump θ1) discharge side of the refrigerant return pipe 02) and the refrigerant reservoir θ5),
6) A solution bypass pipe with a solution control valve connecting the discharge side and the solution reservoir (26) of the absorber (4).

When the outside air temperature drops and the temperature of the cooling water supplied to the absorption chiller begins to drop, a signal from the cooling water humidity detector reduces the opening of the control valve (■ and If the water temperature continues to drop, close it completely.By doing this, the amount of refrigerant guided from the refrigerant distribution pipe (23) to the refrigerant distributor α force and the amount of refrigerant introduced from the solution distribution pipe (21) to the solution distributor a The amount of concentrated liquid distributed decreases, and the area of heat exchange between the refrigerant liquid sprayed and the cold water flowing in the cold water pipe (I3+ and the heat exchange area between the concentrated liquid sprayed and the cooling water flowing in the cooling water pipe 04) increases. As a result, the absorption function of the absorber (4) decreases, and at the same time, the refrigerant vaporization effect of the evaporator (3) is also suppressed, and the refrigeration capacity decreases in response to the decrease in cooling load due to the decrease in outside temperature. This makes it possible to control the output according to the load.
The solution control valve (to) according to the decrease or increase in the opening degree of the control valve (g)
At the same time, the opening degree of the refrigerant control valve (3) is also increased or decreased in accordance with the decrease or increase in the opening degree of the control valve W, and the refrigerant is sent from the refrigerant reservoir 0 to the refrigerant distributors (16) and (17). A balance is maintained between the amount of refrigerant flowing down from these distributors Q61.07) to the refrigerant reservoir a. In order to maintain this balance, a pump whose discharge amount can be controlled may be used, such as by controlling the rotational speed of the solution pump (6) and the refrigerant pump 01).

Although the figure shows an example in which two solution distributors and two solution distribution pipes, two refrigerant distributors and two refrigerant distribution pipes are provided, it is possible to install a large number of these and to connect a large number of solution distribution pipes. Each refrigerant distribution pipe may be provided with a control valve, and each control valve may be closed in stages depending on the degree of decrease in the cooling water temperature.In this way, the heat between the concentrated liquid and the cooling water, as well as between the refrigerant liquid and the cold water, can be closed. The exchange area can be adjusted with higher precision, improving the accuracy of output control.

When the cooling water temperature decreases, the pressure inside the condenser (2) decreases and the pressure inside the generator (1) decreases, and the absorption action of the absorber (/J) is promoted, causing the concentration of replacement fluid to drop. Therefore, the boiling temperature of the absorption liquid in the generator (1), that is, the refrigerant vapor temperature becomes lower, the concentrated liquid temperature also decreases, and the concentrated liquid concentration also decreases. Alternatively, when the cooling water temperature decreases, the absorption action is promoted and the refrigerant level in the refrigerant reservoir (15) also decreases.

In this way, the physics that change as the cooling water temperature decreases
The opening degree of the control valve (■) may also be controlled while detecting the above.In other words, instead of the cooling water temperature detector (5), a refrigerant level detector (B), a refrigerant vapor temperature detector fc),
Any of the concentrated liquid temperature detector Q-)), the replacement liquid concentration detector (E), and the concentrated liquid concentration detector W) may be used.

In order to reduce the output of an absorption chiller in response to a decrease in cooling load due to a drop in outside temperature, directly detecting the cooling water temperature is superior to detecting other physical quantities in terms of control followability. However, another advantage is that cavitation of the refrigerant pump (II) can be reliably prevented by directly detecting the refrigerant liquid level.

Next, when the outside temperature starts to rise again and the cooling water temperature becomes high, the opening degree of the control valve (G) and W are increased to increase the amount of concentrated liquid sprayed and the concentration in the cooling water pipe ( ). The refrigerating capacity, ie, the output, is adjusted to match the increase in load by expanding the area where the liquid is sprayed and at the same time expanding the area where the refrigerant liquid is sprayed to the refrigerant pump and cold water pipe 03).

It should be noted that the present invention is of course applicable not only to single-effect absorption chillers but also to double-effect absorption chillers, and is also applicable to changes in the temperature of cooling water supplied to the double-effect absorption chillers. It is also possible to adjust the output by detecting the temperature and concentration of the absorbent flowing from the high-temperature generator to the low-temperature hanger as a correspondingly changing physical quantity. (E) Effects of the Invention As described above, the present invention The control device detects changes in physical quantities due to changes in cooling water temperature and adjusts the area of refrigerant sprayed onto the cooling water pipes, and at the same time adjusts the area of absorption liquid sprayed onto the cooling water pipes. The refrigerant absorption effect of the absorbing liquid in the evaporator and the refrigerant vaporization effect in the evaporator can be adjusted in a well-balanced manner, resulting in a stable output commensurate with the load, as well as practical benefits such as preventing cavitation in the refrigerant pump. It is something to play.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention. (1) Generator, (2) Condenser, (3)
... Evaporator, (4) ... Absorber, (5) ... Solution heat exchanger, 03) ... Water removal pipe, (14) ... Cooling water pipe, (I5) ... Refrigerant Liquid reservoir, (old, (17)
...refrigerant disperser, (ILθ9...solution disperser,
(Add), (2+1...Solution distribution arm, (2, Ri, (2
Eaves... Refrigerant distribution piping, c! 4)...refrigerant bypass pipe,
(25)...Solution bypass pipe, (5)...Cooling water temperature detector, (I3)...Refrigerant level detector, (
Q...Refrigerant vapor temperature detector, (To)...Concentrated liquid temperature detector, (I→...Dilute acid concentration detector, (G)...
・Concentrated liquid concentration detector, (V), W...control valve, (X
)...refrigerant control valve, 0')...melt, 1 control valve.

Claims (1)

[Claims] (1) In an absorption chiller that consists of a generator, condenser, evaporator, absorber, and solution heat exchanger connected via piping, the solution disperser and evaporator that spray the absorption liquid to the cooling water pipes housed in the absorber A plurality of refrigerant distributors for dispersing refrigerant liquid to the stored cold water pipes are provided, and a solution distribution pipe for guiding the absorption liquid to each of the solution distributors and a refrigerant distribution pipe for guiding the refrigerant liquid to each of the refrigerant distributors are provided, Equipped with a mechanism that controls the number of solution distributors to which the absorption liquid is guided and the number of refrigerant distributors to which the refrigerant liquid is guided, based on signals from a detector that senses physical quantities that change in response to changes in the cooling water temperature, and is connected to the cooling water pipes. A control device for an absorption refrigerating machine, characterized in that the absorption liquid distribution area and the refrigerant liquid distribution area in the cold water pipes are adjusted.