JPH10205908A - Direct-fired absorption refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise the temperature of weak solution, which flows into a direct- fired high-pressure reproducer through a high-temperature heat exchanger and a waste gas heat exchanger, by providing the waste gas heat exchanges, heating the weak solution discharged out of a low-temperature heat exchanger. SOLUTION: The temperature of weak solution, having the temperature of about 70 deg.C and flowing from a low temperature heat exchanger 5, is raised to about 80 deg.C by heat exchange in the second waste gas heat exchanger 13 between the waste gas, passed through a waste gas heat exchanger 8 and having the temperature of about 180 deg.C, then, the temperature of the same is raised further to about 155 deg.C by a high-temperature heat exchanger 6 and the same is introduced into a direct-fired high-pressure reproducer 7. The temperature of the dilute solution, flowing into the direct-fired high-pressure reproducer 7, can be raised to 155 deg.C in such a manner whereby the temperature rise of only 15deg deg.C is enough to a refrigerant vapor generating temperature 160 deg.C in the direct-fired high-pressure reproducer 7 and, accordingly, fuel consumption is reduced whereby the performance coefficient of a refrigerating machine can be improved remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a direct-fired absorption refrigerator.

[0002]

2. Description of the Related Art A system diagram of a conventional direct-fired absorption refrigerator is shown in FIG.
Is shown in The liquid refrigerant stored at the bottom of the evaporator 1 is extracted by the refrigerant pump 10 and sprayed from the nozzle 15 disposed at the upper part of the evaporator 1 to the tube group 16 to cool the cold water circulating in the tube group 15. Evaporate by doing. The cooled cold water is supplied to a cooling load.

[0003] The refrigerant vapor evaporated in the evaporator 1 enters the absorber 2 through the eliminator 17, where it is converted into a concentrated solution sprayed to the tube group 19 from the nozzle 18 provided in the upper part of the absorber 2. When absorbed, it becomes a dilute solution and is stored at the bottom. The reaction heat at this time is taken out by the cooling water circulating in the tube group 19.

The dilute solution collected at the bottom of the absorber 2 is extracted by the solution pump 9 and is heated by exchanging heat with the concentrated solution outside the tube in the process of flowing through the heat transfer tube 5A of the low-temperature heat exchanger 5. .

[0005] A part of the dilute solution heated by the low-temperature heat exchanger 5 is supplied to the low-pressure regenerator 4, but most of the diluted solution is heated by the high-temperature heat exchanger 6.
Is heated by exchanging heat with a concentrated solution outside the tube in the process of flowing through the heat transfer tube 6A,
In the process of flowing through the exhaust gas heat exchanger 8 disposed in the exhaust gas passage 14 of the direct-fired high-pressure regenerator 7, heat is generated by exchanging heat with the exhaust gas outside the tube.

Next, the dilute solution enters the direct-fired high-pressure regenerator 7 and is heated by the heat generated by burning fuel in the furnace 20 while being stored at the bottom thereof, so that the refrigerant in the dilute solution is decomposed. Evaporate to a thick solution.

[0007] The concentrated solution concentrated in the direct-fired high-pressure regenerator 7 is introduced into the high-temperature heat exchanger 6 and cooled therein, and then merges with the concentrated solution extracted from the low-pressure regenerator 4 to be cooled. After entering and cooling again, it enters the absorber 14 and is sprayed from the nozzle 18 thereof.

On the other hand, the refrigerant vapor separated from the absorbent in the direct-fired high-pressure regenerator 7 is introduced into a tube group 21 provided in the low-pressure regenerator 4, and flows through the tube group 21 in the course of flowing through the tube group 21. The outer dilute solution is cooled by heating to become a liquid refrigerant. As a result, the refrigerant evaporates and is separated from the dilute solution stored in the bottom of the low-pressure regenerator 4, and the separated refrigerant vapor is supplied to the condenser 3.
The concentrated solution concentrated in the low-pressure regenerator 4 is extracted and flows into the low-temperature heat exchanger 5.

The liquid refrigerant cooled in the tube group 21 is sprayed to the tube group 23 from a nozzle 22 provided in the upper part of the condenser 3, and flows along with the refrigerant vapor in the process of descending in the condenser 3. group
In the process of flowing down the outer surface of 23, the refrigerant vapor is condensed by being cooled by the cooling water circulating in the pipe.

The liquid refrigerant accumulated at the bottom of the condenser 3 is supplied to an expansion valve.
After being squeezed in the course of flowing through the evaporator 1, the evaporator 1 enters the evaporator 1, where a part thereof is flash-evaporated, and the remainder is stored in the bottom of the evaporator 1.

[0011]

In the above-mentioned conventional refrigerator, the temperature of the dilute solution flowing from the exhaust gas heat exchanger 8 into the direct-fired high-pressure regenerator 7 is about 130 ° C. Since the refrigerant vapor generation temperature is about 30 ° C. lower than 160 ° C., it is necessary to heat the dilute solution by this temperature difference in the direct-fired high-pressure regenerator 7 to raise the temperature. There was a problem.

In order to increase the temperature of the dilute solution flowing into the direct-fired high-pressure regenerator 7, it is necessary to increase the heat transfer area of the low-temperature heat exchanger 5 and the high-temperature heat exchanger 6 and to improve the heat transfer performance. There are, however, practical limitations. Further, since the exhaust gas generated in the direct-fired high-pressure regenerator 7 is discharged into the atmosphere from the exhaust gas duct 14 at about 180 ° C., there is a problem that a large amount of heat is discarded.

[0013]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its gist is to provide a direct-fired high-pressure regenerator, a low-pressure regenerator, a condenser, and an evaporator. The dilute solution extracted from the absorber is a low-temperature heat exchanger,
The direct-fired absorption refrigerator, which is heated by a high-temperature heat exchanger and an exhaust gas heat exchanger disposed in an exhaust gas passage of the direct-fired high-pressure regenerator and then introduced into the direct-fired high-pressure regenerator, comprises: A second solution for heating the dilute solution flowing out of the low-temperature heat exchanger on the downstream side of the exhaust gas heat exchanger in the exhaust gas passage of the regenerator.
An exhaust gas heat exchanger is provided, and the diluted solution heated by the second exhaust gas heat exchanger is introduced into the direct-fired high-pressure regenerator through the high-temperature heat exchanger and the exhaust gas heat exchanger in this order. In a direct-fired absorption refrigerator.

Another feature is that a part of the dilute solution heated in the second exhaust gas heat exchanger is introduced into the low-pressure regenerator.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIG. A second exhaust gas heat exchanger 13 is disposed in the exhaust gas passage 14 of the direct-fired high-pressure regenerator 7 so as to be located on the downstream side of the exhaust gas heat exchanger 8.

A part of the dilute solution flowing out of the low-temperature heat exchanger 5 is supplied to the low-pressure regenerator 4, and most of the dilute solution flows through the second exhaust gas heat exchanger 13 in the course of passing through the second exhaust gas heat exchanger 13. 8
After being heated by exchanging heat with the exhaust gas flowing through, the heat is introduced into the direct-fired high-pressure regenerator 7 through the heat transfer tube 6A of the high-temperature heat exchanger 6 and the exhaust gas heat exchanger 8.
The other configuration is the same as that of the conventional one shown in FIG. 3, and the corresponding members are denoted by the same reference numerals.

Thus, the flow out of the low-temperature heat exchanger 5
The 70 ° C. dilute solution exchanges heat with the exhaust gas of about 180 ° C. flowing through the exhaust gas heat exchanger 8 in the second exhaust gas heat exchanger 13 to raise the temperature to about 80 ° C., and further increases in the high temperature heat exchanger 6. About 15
At 5 ° C., it is introduced into the direct-fired high-pressure regenerator 7.

On the other hand, the exhaust gas of about 240 ° C. generated in the furnace 20 of the direct-fired high-pressure regenerator 7 is cooled down to about 180 ° C. in the course of flowing through the exhaust gas heat exchanger 8 and flows through the second exhaust gas heat exchanger 13. The temperature drops to about 160 ° C, and is released into the atmosphere.

Thus, since the temperature of the dilute solution flowing into the direct-fired high-pressure regenerator 7 can be raised to 155 ° C., the temperature of the direct-fired high-pressure regenerator 7 can be increased by 15 ° C. to a refrigerant vapor generation temperature of 160 ° C. As a result, the fuel consumption is reduced, and the coefficient of performance of the refrigerator can be greatly improved.

A second embodiment of the present invention is shown in FIG. In the second embodiment, all of the dilute solution flowing out of the heat transfer tube 5A of the low-temperature heat exchanger 5 is supplied to the second exhaust gas heat exchanger 13
Then, after being heated, it branches off and a part thereof is supplied to the low-pressure regenerator 4, and most of the branch flows into the heat transfer tube 6 </ b> A of the high-temperature heat exchanger 6. Another configuration is the first configuration shown in FIG.
The same reference numerals are given to corresponding members.

In the second embodiment, the temperature of the dilute solution flowing into the low-pressure regenerator 4 can be higher than that of the conventional dilute solution. Can be.

[0022]

According to the present invention, the dilute solution flowing out of the low-temperature heat exchanger is led to the second exhaust gas heat exchanger, where it is heated by exchanging heat with the exhaust gas flowing through the exhaust gas heat exchanger. Therefore, the temperature of the dilute solution flowing into the direct-fired high-pressure regenerator through the high-temperature heat exchanger and the exhaust gas heat exchanger can be higher than that of the conventional solution.

Therefore, the heat required to heat the dilute solution to the refrigerant vapor generation temperature in the direct-fired high-pressure regenerator is reduced,
The fuel required for the direct-fired high-pressure regenerator is sufficient, and the coefficient of performance of the refrigerator can be greatly improved because the dilute solution is heated using the heat of the exhaust gas released to the atmosphere.

If a part of the dilute solution heated in the second exhaust gas heat exchanger is introduced into the low pressure regenerator, the performance of the low pressure regenerator can be improved.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a first embodiment of the present invention.

FIG. 2 is a system diagram showing a second embodiment of the present invention.

FIG. 3 is a system diagram of a conventional direct-fired absorption refrigerator.

[Explanation of symbols]

 7 Direct-fired high pressure regenerator 14 Exhaust gas passage 4 Low pressure regenerator 3 Condenser 1 Evaporator 2 Absorber 5 Low temperature heat exchanger 6 High temperature heat exchanger 8 Exhaust gas heat exchanger 13 Second exhaust gas heat exchanger

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Makoto Fujiwara 2-1-1, Shinhama, Arai-machi, Takasago-shi, Hyogo Prefecture Inside the Takasago Works, Mitsubishi Heavy Industries, Ltd. No. 1 Inside the Mitsubishi Heavy Industries, Ltd. Takasago Factory

Claims (2)

[Claims] 1. A direct-fired high-pressure regenerator, a low-pressure regenerator, a condenser,
An evaporator is provided, and the dilute solution extracted from the absorber is heated by a low-temperature heat exchanger, a high-temperature heat exchanger, and an exhaust gas heat exchanger provided in an exhaust gas passage of the direct-fired high-pressure regenerator, and then heated directly In a direct-fired absorption refrigerator introduced into a high-pressure regenerator, a second solution for heating a dilute solution flowing out of the low-temperature heat exchanger to a downstream side of the exhaust gas heat exchanger in an exhaust gas passage of the direct-fired high-pressure regenerator. An exhaust gas heat exchanger is provided, and the diluted solution heated by the second exhaust gas heat exchanger is introduced into the direct-fired high-pressure regenerator through the high-temperature heat exchanger and the exhaust gas heat exchanger in this order. Direct-fired absorption refrigerator. 2. The direct-fired absorption refrigerator according to claim 1, wherein a part of the dilute solution heated in the second exhaust gas heat exchanger is introduced into the low-pressure regenerator.