JP2911107B2 - Regenerator for absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerator for an absorption refrigerator, and more particularly to a regenerator using a highly hygroscopic substance such as an aqueous solution of lithium bromide as an absorption solution for a refrigerant such as water. The present invention relates to an improved regenerator used in an absorption refrigerator in which circulation is performed between a regenerator and an absorber.

[0002]

2. Description of the Related Art An absorption refrigerator of the above-mentioned type mainly comprises an absorber, a solution pump, a regenerator, a condenser and an evaporator. FIG. 4 is a system flow chart for explaining the operation principle of the double effect absorption refrigerator. The refrigerant vapor generated in the evaporator E is absorbed by the absorption solution (for example, lithium bromide aqueous solution) in the absorber A, The absorption solution having a low concentration due to absorption is sent to the high-temperature regenerator HG by the solution pump SP. The high-temperature regenerator HG has a burner B, and the low concentration absorbing solution evaporates the refrigerant by the heat from the burner B and is concentrated. The concentrated absorption solution flows from the high-temperature regenerator HG to the low-temperature regenerator LG, where it exchanges heat with the refrigerant vapor from the high-temperature regenerator HG and is concentrated again.
Flows into The evaporated refrigerant is condensed in the condenser C and sent to the evaporator E. In the figure, RP is a refrigerant circulation pump,
The refrigerant in the evaporator E is circulated. There is also known a single-effect absorption refrigerator in which only one regenerator is used and the absorption solution from the regenerator is directly sent out to the absorber A.

FIG. 5 is a cross-sectional view showing an example of a regenerator (high-temperature regenerator HG) used in the above absorption refrigerator. The main body casing 1 has a heat transfer chamber 2 inside, A burner B as a heating source is attached to one side end of the heat chamber 2 so as to inject a flame into the heat transfer chamber 2 in a substantially horizontal direction. A chimney 4 for exhausting combustion gas is arranged. The four circumferences of the heat transfer chamber 2 include a lower absorption solution reservoir 5 located at a lower portion of the heat transfer chamber, an upper absorption solution reservoir 6 located at an upper portion, and an upper absorption solution reservoir 6 and a lower absorption solution at a side portion of the heat transfer chamber. An absorption solution chamber 10 is formed by a communication part (not shown in FIG. 5) communicating with the reservoir 5. And the upper and lower absorbent solution pools 5,
Numeral 6 communicates with a plurality of heat transfer tubes 7 arranged in a substantially vertical direction in the heat transfer chamber 2 at a position not in contact with the flame of the burner B in addition to the above-described communication portion. The lower absorbing solution reservoir 5 is connected to the absorber A via the pipe 8 and the solution pump SP, and the absorbing solution which has absorbed the refrigerant and has a low concentration is transferred from the absorber A to the lower absorbing solution reservoir 5.
(See JP-A-5-187740).

The absorbing solution sent by the solution pump SP rises from the lower absorbing solution reservoir 5 to the inside of the plurality of heat transfer tubes 7 by the feeding pressure and the convection (natural convection) caused by the flame of the burner B and the heating by the combustion gas. The upper absorbent solution reservoir 6 reaches the upper absorbent solution reservoir 6, and the absorbent solution retained in the upper absorbent solution reservoir 6 flows down to the lower absorbent solution reservoir 5 through the communicating portion, and rises again through the heat transfer tube 7. The refrigerant (water) absorbed by the absorbing solution is vaporized by heating the burner B, and the vaporized refrigerant is sent to the low-temperature regenerator LG or the condenser C and liquefied as described above, and then sent to the evaporator E. Further, the absorbing solution concentrated by evaporation of the refrigerant is sent to the absorber A to absorb the refrigerant again.

FIG. 6 is a horizontal sectional view showing another example of a regenerator for an absorption refrigerator. A burner B for injecting a combustion gas containing a flame in a substantially horizontal direction at one end of a heat transfer chamber 2a. Are arranged in the heat transfer chamber 2a, and a number of substantially vertical heat transfer tubes 7a are arranged in the heat transfer chamber 2a at a relatively high density so as to cross the combustion gas of the burner B. And the heat transfer tube 7
The group of heat transfer tubes 7a 'at least on the upstream side of a is arranged in the combustion flame portion, and the heat transfer surface density of the heat transfer tubes is increased as going downstream (see Japanese Utility Model Laid-Open No. 7-22371). With this configuration, the generation of thermal NO _x is effectively suppressed, and the generation of CO is also effectively suppressed since the temperature of the combustion gas gradually decreases.

[0006]

The present inventors have been conducting continuous research and experiments on regenerators for absorption refrigerators. In the process, if the concentration of the absorption solution is low, Although no particular inconvenience occurs, if the concentration of the absorbing solution becomes too high due to excessive evaporation of the coolant, corrosion and crystallization (especially when the solvent such as water (The phenomenon that the solute (absorbing solution) evaporates and the amount of the solute exceeds the solubility in the solvent, and the solute crystallizes and precipitates). The phenomenon is that the heat transfer tube 7 is located directly in contact with the burner flame shown in FIG.
This was particularly noticeable in the case of a regenerator in which a 'was arranged. This is due to the fact that the amount of water (refrigerant) absorbed in the absorbing solution is reduced, so that the absorbing solution cannot sufficiently absorb the high heat flux there in the heat transfer tube group located close to the burner. it is conceivable that. Such crystallization and corrosion must be avoided because the occurrence of corrosion and crystallization shortens the useful life of the heat transfer tube and consequently shortens the useful life of the regenerator itself. An object of the present invention is to solve the above-described disadvantages occurring in the regenerator used in the conventional absorption refrigerator, that is, the disadvantage that crystallization or corrosion occurs in the heat transfer tube by adding a simple configuration. It is to obtain an improved regenerator.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided an absorption solution chamber and a heat transfer chamber, wherein an absorption solution flowing into the absorption solution chamber is disposed in the heat transfer chamber. A regenerator for an absorption type refrigerator for heating and concentrating by passing through a group of heat tubes, wherein the absorption solution chamber has a partition wall for restricting the movement of the contained absorption solution between the upstream side and the downstream side. For the absorption refrigerator, wherein the absorption solution is provided, and the absorption solution having a low concentration by absorbing the refrigerant vapor is made to flow into the absorption solution chamber on the upstream side of the partition wall. A regenerator.

[0008] In a preferred aspect of the present invention, the heat transfer tube group is divided into a first heat transfer tube group close to the burner and a second heat transfer tube group downstream of the first heat transfer tube group. The absorbing solution, which is disposed in the absorbing solution chamber between the first heat transfer tube group and the second heat transfer tube group and has a low concentration by absorbing the refrigerant vapor, is close to the first heat transfer tube group. At the position where the absorption solution flows.

[0009] With this configuration, the absorption solution which has absorbed the refrigerant vapor flowing into the absorption solution chamber in the regenerator and has a low concentration is mixed with the upstream absorption solution chamber partitioned by the partition walls. First circulate through the heat transfer tube group located there. The absorption solution having a low concentration sequentially flows into the absorption solution chamber on the upstream side, so that the concentration of the absorption solution passing through the heat transfer tube group located on the upstream side is always maintained at a low concentration.
The absorption solution concentrated by the evaporation of the refrigerant moves to the downstream absorption solution chamber beyond the partition only at the upper side of the absorption solution chamber, where it is circulated again through the heat transfer tube group, and the refrigerant is further Evaporate and concentrate.

[0010] As described above, in the regenerator according to the present invention,
The absorption solution chamber in which the absorption solution circulates is substantially divided into a side adjacent to the burner by the partition wall, that is, an absorption solution chamber on the upstream side, and an absorption solution chamber on the downstream side thereof. The absorption solution having a low concentration is circulated at all times, and the absorption solution having a high concentration is circulated in the absorption solution chamber on the downstream side. As a result, it is possible to prevent crystallization and corrosion from occurring in the upstream heat transfer tube bank having a high heat flux.
Since the heat flux in the downstream heat transfer tube bank is not so high, crystallization and corrosion do not occur even if a high concentration of the absorbing solution circulates.

In a further preferred embodiment of the present invention,
A plurality of small holes are formed in the vicinity of the lower end of the partition wall, that is, in a portion located in the lower absorbent solution reservoir. In the regenerator of this aspect, when a pressure difference is generated between the upstream side and the downstream side of the partition, the absorbing solution can move from one side to the other through the small holes. Thus, when the absorption refrigerator is started up or at the time of partial load operation, the burner B may stop the solution pump SP in the ignited state for the sake of operation control. The amount of absorbing solution required for natural convection circulation can move from the absorbing solution chamber on the downstream side through the small holes, and the high heat flux of each group of heat transfer close to the burner is considerably absorbed. The generation of crystallization and corrosion is almost suppressed.

When the operation of the absorption refrigerator is stopped, the solution pump is normally operated with the burner stopped to circulate the absorption solution to make the concentration uniform.
Since the absorbing solution can move through the small holes, the homogenizing process can be completed in a shorter time.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view of an embodiment of a regenerator for an absorption refrigerator according to the present invention, FIG. 2 is a sectional view taken along line II-II of FIG.
Is a partially broken perspective view. Hereinafter, a case where this regenerator is used as a high-temperature regenerator HG of a double effect absorption refrigerator will be described as an example. This regenerator HG for absorption refrigerator
Is a conventionally known regenerator described above with reference to FIG.
Other configurations are the same except for a configuration for forced circulation of the absorbing solution and a natural convection circulation described below. Therefore,
In the following description, members having the same function are denoted by the same reference numerals, and detailed description is omitted.

That is, the regenerator HG has a heat transfer chamber 2 penetrating the main body casing 1 inside the main body casing 1, and is located below the heat transfer chamber 2 on four turns of the heat transfer chamber 2. A lower absorbent solution reservoir 5, an upper absorbent solution reservoir 6 located above the heat transfer chamber 2, and a communication portion 5a that communicates the upper absorbent solution reservoir 6 and the lower absorbent solution reservoir 5 on the side of the heat transfer chamber. An absorption solution chamber 10 to be formed is formed. In the heat transfer chamber 2, a first heat transfer tube group 71 is provided at a position close to the burner B, and a second heat transfer tube group 72 is provided on the downstream side thereof. The reservoir 5 is attached vertically with the upper open end communicating with the upper absorbent solution reservoir 6, respectively. A pipe 9 for sending the concentrated absorption solution to the low-temperature regenerator LG is provided at an end opposite to the side where the burner B is located.

A partition 11 is disposed in the absorbing solution chamber 10 between the first and second heat transfer tube groups 71 and 72.
This partition is preferably made of the same material as the regenerator, and its size, as shown, is
And the left and right communication portions 5a are closed, and the upper end thereof is set to a position slightly lower than the level L of the absorbing solution in the upper absorbing solution reservoir 6 in a normal operation state. In addition, a number of small holes 12 are formed near the lower end of the partition wall 11, that is, in a portion that closes the lower absorbent solution reservoir 5.

Further, the partition walls 1 of the absorption solution chambers 5 and 5a are provided.
A line 8 connected to the absorber A is connected to the absorption solution chamber on the upstream side of the first heat transfer tube group 71, that is, on the side where the first heat transfer tube group 71 is located. So that the open end thereof is located below the first heat transfer tube group 71. In addition, the upper absorbent solution pool 6
A shielding plate 36 is fixedly provided above the first heat transfer tube group 71 at a position above the first heat transfer tube group 71, and shields the upward scattering of the absorbing solution spouting from the upper opening of the first heat transfer tube group 71. .

Next, the operation of the regenerator HG for an absorption refrigerator will be described. The regenerator HG is used in the same manner as the conventionally known regenerator described with reference to FIGS. That is, during operation, the absorption solution from the absorber A, which has absorbed the refrigerant vapor and has become low in concentration, is pumped by the pump SP and located upstream of the partition wall 11, preferably immediately below the first heat transfer tube group 71. In, the solution is sent into the lower absorbent solution reservoir 5 from the pipe line 8. The low-concentration absorbing solution sent in passes through the first heat transfer tube group 71 and the upper absorbing solution pool 6
Sent to At this time, the concentrated absorption solution staying downstream (on the side of the second heat transfer tube group 72) does not mix with the downstream side (substantially separated by the partition 11).

The absorption solution that has risen in the first heat transfer tube group 71 descends through the left and right communication portions 5a to reach the lower absorption solution reservoir 5, and then circulates up the first heat transfer tube group 71 again. Alternatively, it passes over the partition 11 to reach the absorption solution chamber on the downstream side, where circulation is performed. Since the low-concentration absorbing solution is always sent under pressure from the pipe 8, the absorbing solution concentrated once by ascending the first heat transfer tube group 71 to evaporate the refrigerant moves to the absorbing solution chamber on the downstream side. In the first heat transfer tube group 71, a low concentration absorbing solution normally circulates.

Therefore, the high heat flux generated in the first heat transfer tube group 71 located close to the burner B is surely absorbed by the low-concentration absorbing solution, and the first heat transfer tube group 71 has corrosion and crystal growth. The occurrence of precipitation is avoided. Although the highly concentrated absorbing solution circulates in the second heat transfer tube group 72, since the heat flux is relatively low, corrosion and crystallization are also avoided there. The concentrated absorbing solution is sent from the pipe 9 to the low-temperature regenerator LG, and further sent to the absorber A to absorb the refrigerant again. On the other hand, the refrigerant vapor is sent to the condenser C.

As described above, at the time of starting the absorption refrigerator or at the time of partial load operation, there may be a case where the solution pump SP is stopped while the burner B is ignited for the sake of operation control. In this case, since the low-concentration absorbing solution is not supplied from the pipe line 8, the amount of the absorbing solution passing through the first heat transfer tube group 71 is insufficient, so that the heat flux cannot be absorbed, and crystallization and corrosion are likely to occur. . A small hole 12 formed near the lower end of the partition 11 is formed to cope with such a situation. In other words, when the amount of the absorbing solution necessary for circulation of natural convection generated by heating is insufficient, the absorbing solution in the downstream absorbing solution chamber easily flows into the upstream absorbing solution chamber through the small holes due to the differential pressure. It can move, and the high heat flux of the heat transfer tube group 71 close to the burner B is absorbed to a considerable extent, and crystallization and corrosion are almost suppressed.

As described above, according to the regenerator for an absorption refrigerator according to the present invention, even if the heat transfer tubes 71 and 72 are arranged in almost the entire area inside the heat transfer chamber 2, the regenerator is the same as the conventional regenerator. Corrosion and crystallization of the heat transfer tube 71 close to the burner are avoided. Therefore, the entire regenerator having the same capacity can be designed to be more compact than before, and there is no tendency to shorten the life. In addition, high temperature regenerator HG
The control between the amount of gas burned by the burner B and the flow rate (circulation amount) of the absorbing solution by the solution pump SP does not require direct control, and the operation of the absorption refrigerator is controlled by a conventional control method. Can be performed without support. Furthermore, the decrease in the residence time in the high temperature field decreases and the combustion gases of the flame temperature enables low NO _x combustion, also, the generation of unburnt also suppressed.

In the drawing, the end of the pipe 8 for feeding the low concentration absorbing solution into the absorbing solution chamber 10 is open to the bottom of the main casing 1. The distal end may be extended into the lower absorbing solution reservoir 5 so as to be located immediately below the lower opening end of the first heat transfer tube group 71. In this case, it becomes more certain that the low-concentration absorbing solution pumped from the solution pump SP efficiently flows to the first heat transfer tube group 71, and the crystallization in the first heat transfer tube group 71 can be prevented. Corrosion can be prevented more effectively. At this time, the end of the pipe 8 may be formed in a nozzle shape. In this case, when the low-concentration absorbing solution is ejected from the nozzle end of the pipe 8, an ejector effect is generated, and in a more stable state. First, use a large amount of absorbing solution
Can be passed through the heat transfer tube group 71, and crystallization and corrosion are more reliably prevented.

The number of the first heat transfer tube group 71, the total flow passage area thereof, and the degree to which the first heat transfer tube group 71 is brought closer to the burner B side are determined. The optimal value should be set according to the design conditions of the actual machine, and the example shown in the figure is merely an example. further,
It will be easily understood that the technical means according to the present invention can be equally applied to the conventional regenerator for an absorption refrigerator described with reference to FIG.

[0024]

According to the present invention, a regenerator having the same capability as a conventional regenerator can be designed to be more compact than the conventional regenerator without shortening the life. Furthermore, it is possible to lower NO _x combustion of the burner, also occurrence of unburned can be suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a regenerator for an absorption refrigerator according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a partially broken perspective view of the regenerator for the absorption refrigerator shown in FIG.

FIG. 4 is a system flow chart for explaining the operation principle of the absorption refrigerator.

FIG. 5 is a sectional view showing an example of a conventional regenerator for an absorption refrigerator.

FIG. 6 is a sectional view showing another example of a conventional regenerator for an absorption refrigerator.

[Description of sign]

DESCRIPTION OF SYMBOLS 1 ... Main body casing, 2 ... Heat transfer chamber, 4 ... Chimney, 5 ... Lower absorption solution pool, 6 ... Upper absorption solution pool, 11 ... Partition wall, 12 ... Small hole provided in partition wall, 71 ... First heat transfer tube group ,
72: second heat transfer tube group, B: burner

Claims (2)

(57) [Claims] An absorption refrigeration system having an absorption solution chamber and a heat transfer chamber, wherein the absorption solution flowing into the absorption solution chamber is heated and concentrated by passing through a group of heat transfer tubes arranged in the heat transfer chamber. A regenerator for the machine, wherein the absorbing solution chamber is provided with a partition wall for restricting the movement of the contained absorbing solution between the upstream side and the downstream side, and absorbs refrigerant vapor to reduce the concentration of the absorbing solution. In the regenerator for an absorption-type refrigerator in which the absorption solution is adapted to flow into the absorption solution chamber on the upstream side of the partition wall, the heat transfer tube group includes a first heat transfer tube group close to a burner. So
It is divided into a second heat transfer tube group on the downstream side of the
The partition wall is located between the first heat transfer tube group and the second heat transfer tube group.
In the absorption solution chamber, and absorbs refrigerant vapor.
The absorbed solution having a low concentration is collected by the first heat transfer tube group.
So as to flow into the absorption solution chamber at a close position
A regenerator for an absorption refrigerator , characterized in that: Wherein an absorption refrigerating machine regenerator according to claim 1, characterized in that it is formed a small hole near the lower end of the partition wall.