JPH0792290B2 - Absorption refrigerator that directly recovers heat - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an absorption refrigerator, and more particularly,
The present invention relates to an absorption refrigerator that directly recovers heat.

[0002]

2. Description of the Related Art FIGS. 1 and 2 show a thermodynamic cycle and a schematic diagram of a conventional absorption refrigerator, respectively.
As shown in FIG. 2, the conventional absorption refrigerator has a generator 3
1, the absorber 32, the condenser 33, the evaporator 34, and the heat exchanger 41 are provided. In such a conventional absorption refrigerator, a solution such as a combination of water and lithium bromide or a combination of water and ammonia is circulated between the generator 31 and the absorber 32.

During operation of the refrigerator, the low temperature solution flowing in the pipe 1 is pumped by the pump 34 via the heat exchanger 41 towards the generator 31 and enters said generator. In the heat exchanger, the cold solution is heated by the hot solution flowing through the pipe 3. In the generator 31, the solution sent from the pipe 2 is reheated to release the refrigerant vapor, which passes through the pipe 5 and enters the condenser 33. In the condenser, the high-temperature and high-pressure refrigerant vapor is condensed to release heat Qc, and the condensed refrigerant flows into the evaporator 34 via the throttling device 21 that reduces the pressure of the condensed refrigerant. In the evaporator 34, the refrigerant absorbs the heat Qe and changes into low-temperature low-pressure steam, which enters the absorber 32. In the absorber 32, the low temperature and low pressure refrigerant is absorbed by the solution stored in the absorber, and heat Qa is released. In this way, the above process is repeated.

In the conventional absorption refrigerator, the heat exchanger 4
1 is used to recover some of the heat contained in the solution leaving the generator 31 and raises the temperature of the solution entering the generator 31. However, the specific heat and moving mass of the solution flowing in the pipe 3 per hour are smaller than the specific heat and moving mass of the solution flowing in the pipe 1. Therefore, the temperature rise of the solution that has absorbed heat in the heat exchanger 41 is less than the temperature drop of the solution that has released heat in the heat exchanger 41.
Furthermore, the temperature of the solution entering the generator 31 is lower than the equilibrium temperature of the generator 31. In other words, as shown in FIG. 1, the solution entering the generator 31 is in state 2 ', but the solution stored in the generator 31 is in state 2'. Pipe 2 (state 2a)
Since the pressure of the solution inside is lower than the pressure inside the generator 31, the solution entering the generator 31 is first heated to a state where the thermodynamic pressure is equal to the pressure inside the generator. Meanwhile, the generator 3
Part of the refrigerant in 1 is absorbed by the solution entering the generator. This absorbed refrigerant vapor can produce a freezing effect if it is not absorbed by the solution entering the generator 31. Therefore, if the temperature of the solution entering the generator 31 is lower than the equilibrium temperature of the generator 31, it has the following three disadvantages.

1. The heat transfer that occurs in the heat exchanger 41 is mainly promoted by convection, and its heat transfer coefficient depends on the phase separation boiling heat transfer (the phases) that generates steam.
separation boiling heat tr
smaller than the heat transfer coefficient of Therefore, promoting heat transfer solely by convection requires more area and more tubes for heat transfer.

2. Since the pressure of the solution entering the generator 31 is less than the pressure inside the generator, the solution entering the generator 31 is
It absorbs some of the refrigerant vapor in the generator 31 in order to reach an equilibrium state. Thus, in order to evaporate the refrigerant vapor absorbed by the fed solution, it is necessary to supply heat, and the heat thus supplied occupies a very large proportion of the heat Qg.

3. The pressure in the generator 31 has to be increased to a pressure to obtain a stable operation, thus the preparation time usually takes longer than the preparation time of a conventional refrigerator using steam pressure. This long preparation time is a common drawback of absorption refrigerators.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an improvement of an absorption refrigerating machine which can eliminate the above-mentioned disadvantages. The object of the present invention is to arrange a solution mixing device between the generator and the heat exchanger for direct heat exchange between the cold solution and the hot solution, whereby It is to improve the efficiency of the generator and reduce the operating cost of the absorption refrigerator.

The absorption refrigerator according to the present invention uses a solution and a refrigerant contained in the solution as a working medium. The absorption refrigerator is in communication with (a) a generator for heating the solution to convert a part of the refrigerant into steam, and (b) for condensing the refrigerant vapor sent from the generator. And (c) a throttling device in communication with the condenser for narrowing the condensed refrigerant sent from the condenser, and (d) water circulating in the inside of the condenser. An evaporator in communication with the throttling device, which is capable of heat transfer between the refrigerant to be sent and the circulating water; and (e) a solution is stored and sent from the evaporator by the stored solution. An absorber communicating with the evaporator for absorbing the refrigerant; and (f) an indirect heat exchange between the solution sent from the generator and the solution sent from the absorber, the absorber and Communication with the generator A heat exchanger, and a solution mixing device arranged between the heat exchanger and the generator for mixing the solution leaving the generator with the solution about to enter the generator. Is characterized by.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 3, an absorption refrigerator according to an embodiment of the present invention includes a generator (131) for generating high temperature and high pressure refrigerant vapor and a generator (1) for condensing the refrigerant vapor.
31) and a condenser (133) arranged between the throttling device (121) and the throttling device (121)
Between the evaporator and the absorber (132) (13)
4) is provided. The liquid refrigerant entering the evaporator (134) absorbs heat from the cooling water circulating inside the evaporator.
The absorber (132) is connected to the evaporator (134) in order to absorb the refrigerant vapor sent from the evaporator (134). A heat exchanger (141) is disposed between the absorber (132) and the generator (131), and includes a hot solution sent from the generator (131) and a cold solution sent from the absorber (132). Performs indirect heat exchange between. Furthermore,
A solution mixing device (151) is arranged between the generator (131) and the heat exchanger (141), and a bypass pipe (16) is provided.
3) is provided for connecting the pipe (164) and the solution mixing device (151). The pipe (164) is
The absorber (132) and the generator (311) are connected. With such an arrangement, the hot solution delivered from the generator (131) is introduced into the solution mixer (151) before entering the heat exchanger (141). Solution Mixer (15
The structure of 1) is shown in FIG. As shown in the figure, the structure of the solution mixer (151) has an inducer structure.
It is similar to the structure of r). According to Bernoulli's theorem, the solution sent from the pump (135) toward the generator (131) is accelerated by the nozzle (162) arranged in the solution mixing device (151), and the outlet of the nozzle (162). The pressure at is reduced. Due to the pressure at the outlet of the nozzle (162), the hot solution delivered from the generator (131)
It is drawn into the solution mixer (151). After being mixed, the mixed solution is passed through the pipe (110) and the generator (13).
Enter 1). The temperature of the solution in the pipe (110) approaches the equilibrium temperature in the generator (131). The optimum flow rate of the hot solution to the cold solution is selected so that the solution temperature in the pipe (110) is close to the equilibrium temperature under pressure in the generator (131).

Furthermore, since the pressure of the mixed solution in the pipe (110) is made equal to the pressure in the generator (131), the mixed solution entering the generator (131) does not absorb the refrigerant vapor. Thus, the only heat transfer that occurs in the generator (131) is boiling heat transfer, and the heat Qg applied to the generator (131) is stored in the solution to be fed and in the generator (131). Effectively used to balance non-equilibrium states with solutions. The boiling heat transfer has a high heat transfer coefficient. Also, the mixing of the hot and cold solutions greatly increases the flow rate of the solution entering the generator (131). Heat transfer is thus enhanced and the thermodynamic cycle approaches the ideal cycle shown in FIG. An apparatus for directly recovering heat, that is, a solution mixing apparatus according to the present invention is a double-effect absorption refrigerator (double-type) shown in FIG.
effect absorptionrefriger
It is important that it can also be applied to the application system. The double-effect absorption refrigerator comprises two heat exchangers (242) and (243), a low pressure generator (236) and a high pressure generator (231). The basic principle and operation of the double-effect absorption refrigerator are the same as the basic principle and operation of the absorption refrigerator shown in FIG. Similarly, the solution mixing device can be applied to a triple effect absorption refrigerator.

Since the temperature of the solution entering the generator is increased by the addition of the solution mixing device and the ineffective heat transfer in the generator is reduced, the temperature rise of the solution in the generator is It is faster than the conventional refrigerator. Therefore, the preparation time for direct heat recovery is also reduced.

In summary, the solution mixing device according to the present invention is capable of increasing heat transfer within the generator. In addition, the high heat transfer performance may reduce the number of heat transfer tubes required in the generator, which may reduce the manufacturing cost of the generator. Also,
The generator has a longer life since the temperature difference between the heat transfer tubes is also reduced and the thermal stress caused by the temperature difference is also reduced. Further, the preparation time of the absorption refrigerating machine which directly recovers heat can be shortened.

[Brief description of drawings]

FIG. 1 is a P-T diagram showing a thermodynamic cycle of a conventional absorption refrigerator.

FIG. 2 is a schematic diagram showing the refrigerator of FIG.

FIG. 3 is a schematic diagram of an absorption refrigerator according to an embodiment of the present invention.

FIG. 4 is a P-T diagram showing a thermodynamic cycle of the absorption refrigerator shown in FIG.

FIG. 5 is a vertical cross-sectional view showing the structure of the absorbent mixing device according to the present invention in a cross section along the longitudinal direction.

FIG. 6 is a schematic diagram showing an improved double-effect absorption refrigerator according to an embodiment of the present invention.

[Explanation of symbols]

 31 Generator 32 Absorber 33 Condenser 34 Evaporator 35 Pump 41 Heat exchanger 21 Throttling device 134 Generator 132 Absorber 133 Condenser 134 Evaporator 151 Solution mixing device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kane Shigenari, No. 195, 4th Section, Zhongxing Road, Zhongxing Town, Hsinchu County, Taiwan (No.) Dan No. 195, 64th Building (No Address) (56) Reference JP-A-61-262566 (JP, A) JP-A-4-203769 (JP, A)

Claims (7)

[Claims] 1. An absorption refrigerator that directly recovers heat using a solution and a refrigerant contained in the solution as a working medium, comprising: (a) heating the solution to vaporize the refrigerant. And (b) a condenser in communication with the generator for condensing the refrigerant vapor sent from the generator, and (c) for condensing the condensed refrigerant sent from the condenser, A throttling device in communication with the condenser; and (d) water that circulates inside, and the heat transfer can be performed between the refrigerant sent from the throttling device and the circulating water. An evaporator in communication with (e) a solution storage, and an absorber in communication with the evaporator for absorbing the refrigerant sent from the evaporator by the stored solution; (f) from the generator The solution to be sent and the Indirect heat exchange with the solution delivered from the collector,
A heat exchanger provided in communication with the absorber and the generator, and a solution mixing device arranged between the heat exchanger and the generator is used to enter the solution coming out of the generator and the generator. An absorption refrigerator that directly recovers heat, characterized in that it is mixed with a solution. 2. The absorption refrigerator according to claim 1, wherein the solution is a combination of water and lithium bromide. 3. The absorption refrigerator according to claim 1, wherein the solution is a combination of water and ammonia. 4. The absorption refrigerator according to claim 1, wherein the solution from the generator is introduced from the inside of the generator. 5. The absorption refrigerator according to claim 1, wherein the solution from the generator is introduced through a pipe in communication with the generator. ． 6. The flow rate of the solution delivered from the generator is
The absorption refrigerator according to claim 1, wherein the temperature of the mixed solution is selected so that the flow rate is close to the temperature in the generator. 7. The mixing device is an inducer.
The absorption refrigerator according to claim 1, wherein the absorption refrigerator is a cer).