JP2003343938A - Absorption refrigerating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorption refrigerating machine which can efficiently recover the remaining heat of the coolant after radiating the heat to heat the absorption liquid and which has the structure reduced in the number of branch and junction of piping to facilitate the flow control during the operation. <P>SOLUTION: This absorption refrigerating machine is provided with a middle- temperature drain heat recovery unit 10 for recovering the remaining heat of the coolant which radiated the heat in a middle-temperature regenerator 2 by exchanging the heat between the refrigerant, which radiated the heat to heat the absorption liquid in the middle-temperature regenerator 2, and the suction liquid discharged from an absorber 6 to a middle-temperature heat exchanger 8, while bypassing a low-temperature heat exchanger 7, and a low- temperature drain heat recovery unit 11 for recovering the remaining heat of the refrigerant which radiated the heat in a low-temperature regenerator 3 by exchanging the heat between the refrigerant, which radiated the heat to heat the absorption liquid in the low-temperature regenerator 3, and the absorption liquid discharged from the absorber 6 to the low-temperature heat exchanger 7. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerator (including an absorption chiller / heater) used for air conditioning or the like, and more particularly to heating an absorption liquid. The present invention relates to a triple effect absorption refrigerator including three high temperature regenerators, medium temperature regenerators and low temperature regenerators as regenerators for evaporating and separating the refrigerant absorbed in the absorbing liquid. In a triple effect absorption refrigerator, a medium temperature regenerator uses a refrigerant vapor evaporated and separated from an absorbent in a high temperature regenerator as a heat source, and a low temperature regenerator evaporates and separates from the absorbent in a medium temperature regenerator. Using the refrigerant vapor as a heat source, the absorption liquid is heated to evaporate and separate the refrigerant. [0003] The refrigerant that has heated the absorbent and radiated heat in the medium-temperature regenerator and the refrigerant that has heated and radiated the absorbent in the low-temperature regenerator are both sent to the condenser, where they are cooled by the cooling water. The residual heat is further discarded in a condenser in cooling water, completely condensed and sent to an evaporator. However, in order to further increase the efficiency of the absorption refrigerator, it is necessary to further recover the residual heat of the refrigerant conventionally discarded in the cooling water in the condenser. [0005] To achieve this, for example,
In -227838, a device has been proposed in which a drain heat recovery device for recovering heat retained by the refrigerant heated to the absorption liquid by the medium temperature regenerator and the refrigerant heated to the absorption liquid by the low temperature regenerator is proposed. Since the specific heat of the absorbing liquid such as an aqueous solution of lithium bromide is considerably smaller than the specific heat of water as the refrigerant, the heat of the refrigerant is recovered into the refrigeration cycle by the heat exchanger (the refrigerant is discharged from the absorber). When the temperature of the absorbing solution is increased by applying heat to the absorbing solution up to the high-temperature regenerator, it is more effective to consider reducing the temperature of the refrigerant as much as possible in improving the efficiency of the apparatus. Further, since the lowest temperature in the cycle is the absorbing liquid at the outlet of the absorber, the place where the residual heat of the refrigerant is recovered is preferably immediately after the discharge of the absorber.
1-227838 also proposes a configuration example of such a device. However, these pipes have many branching and merging portions, and there has been a problem that it is difficult to control the flow rates of the absorbing liquid and the refrigerant in practical use. In addition, a medium-temperature drain heat recovery unit that recovers heat from the refrigerant whose absorption liquid has been heated by the medium-temperature regenerator and a low-temperature drain heat recovery unit that recovers heat from the refrigerant whose absorption liquid has been heated by the low-temperature regenerator are connected in series. When it is arranged in a heat exchanger, it is difficult to design and manufacture the heat exchanger. That is, since the refrigerant drain flowing inside the drain heat recovery unit is actually a mixed flow of two phases of gas and liquid, the actual temperature of the drain junction often differs from the design value (refrigerant). If there is a flash, the temperature drops even if there is no change in calorific value), so the temperature difference with the partner to exchange heat becomes smaller than the calculated value, and there is a problem that the amount of heat exchange after that decreases. There are difficulties in designing and manufacturing heat exchangers. Therefore, it is possible to efficiently recover the residual heat of the refrigerant radiated by heating the absorbing liquid in the medium temperature regenerator and the refrigerant radiated by heating the absorbing liquid in the low temperature regenerator. In addition, it is necessary to provide an absorption refrigerator having a small number of pipe branches and confluences and easy flow rate adjustment during operation, which has been a problem to be solved. According to the present invention, as a specific means for solving the above-mentioned problems of the prior art, the absorption liquid is heated to evaporate and separate the refrigerant contained in the absorption liquid. A high-temperature regenerator that concentrates and regenerates the absorbent so that it can be used, a medium-temperature regenerator that operates in the same manner as the high-temperature regenerator using the refrigerant vapor evaporated and separated from the absorbent by the high-temperature regenerator as a heat source, and is evaporated and separated from the absorbent by the medium-temperature regenerator. High-temperature regenerator using refrigerant vapor as heat source
A triple-effect absorption refrigeration system equipped with a low-temperature regenerator that operates in the same way as a medium-temperature regenerator, and also includes a high-temperature heat exchanger, a medium-temperature heat exchanger, and a low-temperature heat exchanger as heat exchangers for exchanging heat between absorption liquids at different temperatures. In the machine, the refrigerant that has heated and radiated the absorbing liquid in the medium-temperature regenerator and the absorbent that discharged the absorber and bypassed the low-temperature heat exchanger and reached the medium-temperature heat exchanger exchanged heat and radiated heat in the medium-temperature regenerator. A medium-temperature drain heat recovery unit that recovers the residual heat of the refrigerant, and a low-temperature regenerator that exchanges heat between the refrigerant that has heated the absorbing liquid in the low-temperature regenerator and radiated heat and the absorbing liquid that discharges the absorber and reaches the low-temperature heat exchanger The present invention solves the above-mentioned problems of the related art by providing an absorption refrigerator having a low-temperature drain heat recovery device for recovering residual heat of a refrigerant radiated in the above. Embodiments of the present invention will be described below in detail with reference to the drawings. One embodiment of the present invention will be described in detail with reference to FIG. In the figure, 1 is a high temperature regenerator, 2 is a medium temperature regenerator, 3 is a low temperature regenerator, 4 is a condenser, 5 is an evaporator,
6 is an absorber, 7 is a low-temperature heat exchanger, 8 is a medium-temperature heat exchanger, 9
Is a high-temperature heat exchanger, 10 is a medium-temperature drain heat recovery unit, 11 is a low-temperature drain heat recovery unit, 12 and 13 are absorption liquid pumps, and 14 is a refrigerant pump. The refrigerant pipes are connected by refrigerant pipes shown by broken lines, and are configured to be able to circulate the refrigerant and the absorbing liquid that has absorbed the refrigerant. The high-temperature regenerator 1 is provided with an appropriate heating means (not shown) for heating the absorbing liquid in the apparatus and evaporating and separating the refrigerant absorbed in the absorbing liquid. A cooling water pipe 15 is passed through the evaporator 5, and a cooling water pipe 16 is passed through the absorber 6 and the condenser 4 in series. Therefore, in the absorption refrigerator having the above structure, the absorption pumps 12 and 13 and the refrigerant pump 14 are operated while flowing the cooling water through the cooling water pipe 16, and the heating means (not shown) provided in the high temperature regenerator 1 is used. High temperature regenerator 1
When the absorption liquid is heated and boiled, the refrigerant vapor evaporated and separated from the absorption liquid in the high-temperature regenerator 1 and the absorption liquid in which the concentration of the absorption liquid is increased by separating the refrigerant vapor are obtained. The high-temperature refrigerant vapor generated by the high-temperature regenerator 1 enters the intermediate-temperature regenerator 2, evaporates and separates the refrigerant in the high-temperature regenerator 1, concentrates, and passes through the high-temperature heat exchanger 9. The absorption liquid entered in 2 is condensed by radiating heat and enters the medium-temperature drain heat recovery unit 10. The refrigerant vapor generated by being heated by the refrigerant vapor in the intermediate-temperature regenerator 2 enters the low-temperature regenerator 3, evaporates and separates the refrigerant in the intermediate-temperature regenerator 2, and passes through the intermediate-temperature heat exchanger 8. Then, the absorption liquid entering the low-temperature regenerator 3 is heated and condensed by radiation, and enters the low-temperature drain heat recovery unit 11. The refrigerant heated by the low-temperature regenerator 3 and evaporated and separated from the intermediate absorbing liquid enters the condenser 4 and enters the cooling water pipe 1.
It condenses and liquefies by exchanging heat with the cooling water flowing through the inside 6, and enters the evaporator 5 together with the refrigerant flowing through the medium-temperature drain heat recovery unit 10 and the low-temperature drain heat recovery unit 11. The refrigerant liquid accumulated in the refrigerant reservoir of the evaporator 5 is sprayed by a refrigerant pump 14 on a heat transfer pipe 15A connected to the chilled water pipe 15, and exchanges heat with water supplied through the chilled water pipe 15. Evaporates and cools the water flowing inside the heat transfer tube 15A. The refrigerant evaporated by the evaporator 5 enters the absorber 6 and is heated by the low-temperature regenerator 3 to evaporate and separate the refrigerant. It is supplied via the exchanger 7 and is absorbed by the absorbing liquid sprayed from above. The absorption liquid whose absorption liquid concentration has been reduced by absorbing the refrigerant in the absorber 6 is returned to the high-temperature regenerator 1 by operating the absorption liquid pump 12. When the absorption refrigerator is operated as described above,
The cold water flowing inside the cold water pipe 15 and entering the evaporator 5 is cooled by the heat of vaporization of the refrigerant in the heat transfer pipe 15 </ b> A in the evaporator 5, and the cooled cold water passes through the cold water pipe 15 to a cooling load (not shown). The cooling operation such as cooling can be performed. And in the absorption refrigerator of the present invention,
As described above, a part of the absorption liquid whose absorption liquid concentration has been reduced by absorbing the refrigerant in the absorber 6 is supplied to the low-temperature drain heat recovery unit 11, the low-temperature heat exchanger 7, the medium-temperature heat exchanger 8, and the high-temperature heat exchanger 9, The remaining absorbent is returned to the high-temperature regenerator 1 via the intermediate-temperature drain heat recovery unit 10, the medium-temperature heat exchanger 8, and the high-temperature heat exchanger 9 Further, the medium-temperature drain heat recovery unit 10 is supplied with the refrigerant that has heated and radiated the absorption liquid in the medium-temperature regenerator 2 as described above, and the low-temperature drain heat recovery unit 11 has the absorption liquid in the low-temperature regeneration unit 3. Is supplied by the refrigerant that heats and radiates heat.
The absorbing liquid discharged from the absorber 6 and flowing into the high-temperature regenerator 1 is heated in an efficient and excellent operability state. That is, the refrigerant radiated by heating the absorbent in the medium-temperature regenerator 2 and the refrigerant radiated by heating the absorbent in the low-temperature regenerator 3 have the lowest temperature in the refrigeration cycle. Since the heat exchange with the absorbing liquid is performed, even if the temperature of the condensed refrigerant is considerably low, the residual heat of the refrigerant is efficiently recovered by the absorbing liquid, and the fuel cost and the like consumed by the heating means provided in the high-temperature regenerator 1 are effective. Can be reduced. Since the medium-temperature drain heat recovery unit 10 and the low-temperature drain heat recovery unit 11 are arranged in parallel instead of in series, even if the refrigerant flows as a gas-liquid two-phase flow in each heat recovery unit. After that, since it only enters the condenser 4 and radiates and condenses without heat exchange, there is no problem in heat control. The absorption liquid conveyed from the absorber 6 to the high-temperature regenerator 1 has already been heated by the low-temperature drain heat recovery unit 11 before flowing into the low-temperature heat exchanger 7, and its temperature has risen. Heat is exchanged with the absorbent and the low-temperature heat exchanger 7 to radiate heat,
The absorption liquid conveyed from the low-temperature regenerator 3 to the absorber 6 can be kept away from the crystal line to make it difficult to crystallize. Since the present invention is not limited to the above embodiment, various modifications can be made without departing from the spirit of the appended claims. For example, the absorption liquid whose absorption liquid concentration is reduced by absorbing the refrigerant in the absorber 6 is supplied to the medium-temperature regenerator 2 or the low-temperature regenerator 3 and then to the high-temperature regenerator 1. Alternatively, it may be configured to supply the information to a plurality of regenerators in a parallel manner. It is also possible to exchange the installation site of the intermediate-temperature drain heat recovery unit 10 with the installation site of the low-temperature drain heat recovery unit 11. As described above, according to the present invention, the residual heat of the refrigerant radiated by heating the absorbing liquid in the medium temperature regenerator and the refrigerant radiated by heating the absorbing liquid in the low temperature regenerator are reduced. It becomes possible to provide an absorption refrigerator capable of efficiently collecting. Further, it is possible to provide an absorption refrigerator in which branching and merging of pipes are small and flow rate control during operation is easy.

[Brief description of the drawings] FIG. 1 is an explanatory diagram showing an embodiment of the present invention. [Explanation of symbols] 1 High temperature regenerator 2 Medium temperature regenerator 3 Low temperature regenerator 4 Condenser 5 Evaporator 6 absorber 7 Low-temperature heat exchanger 8 Medium temperature heat exchanger 9 High-temperature heat exchanger 10 Medium temperature drain heat recovery unit 11 Low temperature drain heat recovery unit 12-13 Absorbent pump 14 Refrigerant pump 15 Cold water pipe 16 Cooling water pipe

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Masahiro Furukawa             1 Otsukicho, Ashikaga-shi, Tochigi Sanyo Electric Air Conditioning             Inside the company F term (reference) 3L093 BB16 BB29 BB37

Claims (1)

Claims 1. A high-temperature regenerator that heats an absorption liquid to evaporate and separate a refrigerant contained in the absorption liquid, and concentrates and regenerates the absorption liquid so that the refrigerant can be absorbed. Medium-temperature regenerator that operates in the same manner as a high-temperature regenerator using the refrigerant vapor evaporated and separated from the heat source, and low-temperature regeneration that operates in the same manner as the high-temperature and medium-temperature regenerators using the refrigerant vapor evaporated and separated from the absorbent by the medium-temperature regenerator as a heat source A triple-effect absorption refrigerator equipped with a high-temperature heat exchanger, a medium-temperature heat exchanger, and a low-temperature heat exchanger as a heat exchanger for exchanging heat between absorption liquids at different temperatures. Medium-temperature drain heat recovery that recovers the residual heat of the refrigerant that heats and radiates heat and exchanges heat with the absorbent that discharges the absorber and bypasses the low-temperature heat exchanger and reaches the medium-temperature heat exchanger. Liquid in the vessel and low-temperature regenerator A low-temperature drain heat recovery unit that exchanges heat between the refrigerant that has radiated heat and discharged to the low-temperature heat exchanger by discharging the absorber and recovers residual heat of the refrigerant that has radiated by the low-temperature regenerator; Characteristic absorption refrigerator.