JPS5878063A - Multiple-effect 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 The present invention relates to a multi-effect absorption refrigerator having multiple stages of regenerators.

Absorption refrigerators generally use a lithium salt aqueous solution as the absorption solution and water as the refrigerant.In order to obtain cold water, the evaporated refrigerant evaporated in the evaporator is absorbed into the absorption solution in the absorber, and the refrigerant is absorbed. The absorbent solution and refrigerant are regenerated by heating and concentrating the solution in a regenerator, and are then used again in the evaporator and absorber to obtain cold water.

By the way, this kind of absorption chiller is equipped with two stages of regenerators, and the first stage regenerator heats the dilute solution from the absorber using an external heat source such as a gas burner, and the high temperature refrigerant vapor generated here is sent to the next stage regenerator. A dual-effect absorption refrigerator that supplies heat as a heating source to a refrigerator is well known. However, in a dual-effect absorption refrigerator having such a structure, the theoretical limit of the coefficient of performance, which indicates the ratio of the refrigerating capacity to the heat input of the first stage regenerator, is 1.2 to 1.3.

However, attempts were made to improve the coefficient of performance, and a triple-effect absorption refrigerating machine with three stages of regenerators as shown in Figure 1 was proposed. First, FIG. 1 will be explained.

(1) is a first high-temperature regenerator that heats the dilute solution to form the first intermediate #solution; (2) is the first high-temperature regenerator that converts the first intermediate concentrated bath solution into a high-temperature refrigerant vapor from the regenerator (1); (3) heats the second intermediate concentrated solution to produce a second intermediate concentrated solution;
A low-temperature regenerator heats the refrigerant vapor from the high-temperature regenerator (2) to form an fIk solution, (4) a condenser that condenses the refrigerant vapor to form a liquid refrigerant, and (5) a liquid refrigerant from the condenser 14. The evaporator (6) absorbs the refrigerant evaporated in the evaporator (5) into the concentrated solution from the low-temperature regenerator (3) to form a dilute solution. It is.

In addition, (7) is a solution circulation pump for sending the dilute solution from the absorber (6) to the first high temperature regenerator (1), and (8) is for exchanging heat between the dilute solution and the concentrated solution. A low-temperature heat exchanger (9) raises the temperature of the concentrated solution while lowering the temperature of the concentrated solution; The high-temperature heat exchanger a is a first high-temperature heat exchanger that exchanges heat between the dilute solution further heated in the second high-temperature heat exchanger (9) and the first intermediate concentrated solution.

Furthermore, αυ is a heat source such as a gas burner for heating the dilute solution in the first high-temperature regenerator, and (2) is a second high-temperature regenerator into which the high-temperature refrigerant vapor generated in the first high-temperature regenerator (1) is introduced. The heat exchanger a3 is a low temperature regenerator heat exchanger into which refrigerant vapor generated in the second high temperature regenerator (2) and high temperature liquid refrigerant condensed by heat radiation in the second high temperature regenerator heat exchanger (6) are introduced. (b) is the cooling water coil into which the cooling water for condensing the refrigerant is introduced, (to) is the chilled water coil into which the chilled water from the load (not shown) is introduced, (a) is the refrigerant vapor absorbed by the concentrated solution. This is a cooling water coil into which cooling water is introduced to remove the absorbed heat generated when the

Next, the operation of the conventional triple effect absorption refrigerator configured as described above will be explained.

The dilute solution from the absorber (5) is sent to the low-temperature heat exchanger (8) by the solution circulation pump (7), where it exchanges heat with the concentrated solution (described later), is heated, and then sent to the second high-temperature heat exchanger (8). Enter 9).

Here, it exchanges heat with a second intermediate concentrated solution, which will be described later, and is heated and enters the first high-temperature heat exchanger α.
) exchanges heat with the first intermediate concentrated solution () to raise the temperature and enter the first high temperature regenerator (1).

The dilute solution flowing into the first high temperature regenerator (1) is heated and concentrated by the external heat source I to become a first intermediate solution and enters the first high temperature heat exchanger Ql due to the pressure difference. After being cooled here, it enters the second high temperature regenerator (2).

It is heated and concentrated by the high temperature refrigerant vapor in the second high temperature regenerator heat exchanger 4. Then, it becomes a second intermediate concentrated solution and enters the second high temperature heat exchanger (9) due to the pressure difference.

Here, the solution is cooled by heat exchange with the dilute solution, enters the low-temperature regenerator (3), is heated and concentrated by the high-temperature refrigerant vapor from the second high-temperature regenerator, and becomes a concentrated solution, resulting in a pressure difference. and enters the low temperature heat exchanger (B)K by gravity. After the temperature is lowered here, it enters the absorber (6) and the cooling water coil (
It is cooled by step (b) and becomes a dilute solution by absorbing refrigerant vapor from the evaporator (5).

On the other hand, high-temperature refrigerant vapor generated by the external heat source (b) in the first high-temperature regenerator (1) is sent to the second high-temperature regenerator heat exchanger @. Then, the first intermediate concentrated solution described above is heated, and heat is removed and condensed to become a high-temperature liquid refrigerant.

The high-temperature refrigerant vapor generated in the second high-temperature regenerator (2) flows into the low-temperature regenerator heat exchanger due to the pressure difference together with the liquid medium condensed in the second high-temperature regenerator heat exchanger (2). 2
The intermediate concentrated solution is heated, heat is removed and condensed, and the condenser 14)
sent to. The refrigerant vapor evaporated in the low-temperature regenerator (3) is also sent to the condenser (4), where it is cooled by cooling water and becomes a liquid refrigerant. As mentioned above, this liquid refrigerant is sprayed onto the cold water coil (g) of the evaporator (5), removes the heat of vaporization from the cold water and evaporates, and this refrigerant vapor is absorbed into a concentrated solution in the absorber (6). Ru. The same cycle is repeated thereafter.

In such a conventional triple effect absorption refrigerating machine, it is possible to set the chilled water outlet temperature from the chilled water coil to about 7°C and the coefficient of performance to about 1.8.

However, in order to do so, the temperature of the first high temperature regenerator (1) must be increased to 2
The temperature must be approximately 20°C to 230°C, and if the temperature is set to such a high temperature, a new problem arises in that a large amount of hydrogen gas is generated due to the reaction between the constituent materials of the first high-temperature regenerator (1) and the solution. Since this problem has not been solved, it has been impossible to put the triple-effect absorption refrigerator into practical operation.

The present invention was made based on such circumstances, and an object of the present invention is to enable operation of a triple-effect absorption refrigerator without significantly increasing the temperature of the first high-temperature regenerator.

Embodiments of the present invention will be described in detail below with reference to FIGS. 2 to 4.

FIG. 2 is a system diagram showing an embodiment of the multi-effect absorption refrigerator according to the present invention. Note that in FIG. 2, the same parts as in FIG. 1 are indicated by the same reference numerals, so detailed explanations of those parts will be omitted.

The present invention is characterized in that when refrigerant vapor is supplied from the first high temperature regenerator (1) to the second high temperature regenerator heat exchanger (2), the refrigerant vapor is compressed and then supplied. , a compressor αη is provided in the steam line connecting the first high temperature regenerator (1) and the second high temperature regenerator heat exchanger @. Other details are the same as in FIG.

The movement of the absorption refrigerator of the present invention shown in FIG. 2 is shown on a vapor pressure diagram as shown in FIG. 3. In addition, the third
In the figure, point a is the state at the exit of the dilute solution absorber (6), point b is the state at the start of boiling of the solution in the first high temperature regenerator (+1), and point C is the state at the exit of the first high temperature regenerator (1). The state of the solution, point d is the state when the solution starts boiling in the second high temperature regenerator (2), and point e is the state of the solution at the outlet of the second high temperature regenerator (2).

Point f is the state where the solution starts boiling in the low temperature regenerator (3), g
The point is the state of the solution at the outlet of the low temperature regenerator (3), the h point is the state of the solution when absorption starts in the absorber (6), and the i point is the state of the solution at the compressor αη
Point j shows the state of saturated steam (water) compressed at , and point j shows the state when the steam generated in the first high temperature regenerator (1) is saturated.

Here, the amount of steam generated due to boiling of d − + 6 is calculated by designing the first high temperature heat exchanger αα sufficiently.
-+ The amount of refrigerant is generated due to the boiling of C, and is approximately the same amount as the amount of refrigerant compressed by the compressor αη. Also, since the amount of refrigerant generated by the boiling of f −+ H and the amount of refrigerant generated by the boiling of d + e are almost the same, (a − + d
The cycle −+ e −+ f −+ g −+ h is the same as the conventional double effect cycle. ) Conventional 2
If the coefficient of performance of heavy-effect QB= is □ 1.3, then the coefficient of performance of the refrigerator according to the present invention is Q. If we consider Q as constant,
+ 0.5 QB = 1.3 x 1.5 = 1.95.

G Also, the work of the compressor αη is 130”C1, i
Assuming the temperature at the point is 160℃ and calculating as polytropic compression, 1kl of cold medium? It is about 40 kcal per serving,
Moreover, since the specific volume is also small due to the pressure relationship, the energy required for compression is negligibly small compared to the condensation heat generated in the second high temperature heat exchanger 0.

According to the present invention, after the refrigerant vapor generated in the first high-temperature regenerator (1) is compressed by the compressor αη, the second high-temperature regenerator heat of the second high-temperature regenerator (2) in the subsequent stage is compressed. Exchanger (6)
Therefore, the coefficient of performance can be significantly improved without raising the temperature of the first high-temperature regenerator (1) much. Therefore, the problem of hydrogen gas generation is also solved, and the triple effect absorption refrigerator can be operated practically.

FIG. 4 shows another embodiment of the invention.

In this embodiment, the first high temperature regenerator (1) is provided with a first high temperature regenerator heat exchanger (6), and this heat exchanger (1) and the second high temperature regenerator heat exchanger (6) are closed. The circuits are connected to form α circuits, and a compressor αη is provided in this closed circuit aI, and the refrigerant vapor generated in the first high temperature regenerator (1) is transferred to the low temperature regenerator heat exchanger (2). I'll supply it to 5. The kiln is a saucer that stores condensed refrigerant. The rest is the same as the embodiment shown in FIG.

The internal pressure of the system that forms the closed path is filled with refrigerant, and the refrigerant vapor generated in the first high-temperature regenerator (1) heats the heat exchanger (to) and evaporates the refrigerant in the system. . This evaporated refrigerant vapor in the system is compressed by compressor α♂, pressurized and heated, and then supplied to the second high temperature regenerator heat exchanger (2), which heats the solution and condenses the refrigerant. be done. Thereafter, the refrigerant circulates within the closed circuit Qo. The refrigerant vapor generated in the first high-temperature regenerator t1) becomes a high-temperature liquid refrigerant through heat exchange with the first high-temperature regenerator heat exchanger (to) and accumulates in the saucer pan, from where it is transferred to the low-temperature regenerator heat. Introduced to the exchanger (to).

In the embodiment of FIG. 4, a closed circuit CJ including one compressor α is used.
First, the circuit that is supposed to maintain the vacuum of the refrigerator is in a sealed state, and even when the closed circuit Ql containing the compressor αη is removed for repairs etc., the vacuum of the refrigerator body is destroyed. This will further add the effect that there will be no problems.

It goes without saying that the present invention is not limited to the above-described embodiments, but can be implemented with various modifications without departing from the scope of the invention. The regenerator is not limited to three stages, but may have four or more stages (the present invention is also applicable to the case of one or two stages. Also, the compressor is not limited to between the first and second stage of the regenerator, but between the previous stage and the regenerator). It can be installed between the latter stages0

[Brief explanation of drawings]

Figure 1 is a system diagram showing a conventional multi-effect absorption refrigerator;
The figure is a system diagram showing an embodiment of the multiple effect absorption refrigerator according to the present invention, FIG. 3 is a vapor pressure diagram explaining the operating state of the refrigerator shown in FIG. 2, and FIG. FIG. 3 is a system diagram of another embodiment. (1)...First high temperature regenerator, (2)...Second high temperature regenerator, (3)...Low temperature regenerator, (4)...Condenser, (5)...
-Evaporator, (6)...Absorber, (B)...Second high temperature regenerator heat exchanger, αη...Compressor. v11 diagram

Claims (1)

[Claims] In a multi-effect absorption refrigerator equipped with multiple stages of regenerators that heat and condense a solution that has absorbed refrigerant, the refrigerant vapor heated in the first stage regenerator is compressed and sent to the second stage regenerator as a heating heat source. A multi-effect absorption refrigerating machine characterized by being equipped with a compressor for supplying the air.