JPH079318B2 - Absorption type water heater - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an absorption chiller-heater, and more particularly to an absorption chiller-heater suitable for an absorber using air as a cooling medium.

[Conventional technology]

Conventionally, as described in Japanese Patent Laid-Open No. 62-202972, there is a cold / hot water machine including one evaporator and an air-cooled absorber that sprays solutions having different concentrations in multiple stages. One evaporator was integrally formed through a duct, and the evaporation temperature (evaporation pressure) in each stage of the absorber was constant.

[Problems to be Solved by the Invention]

The above-mentioned prior art has not taken into consideration the absorption capacity and heat dissipation capacity of the absorber and the optimization of the evaporation capacity of the evaporator.

An object of the present invention is to provide an absorption chiller-heater capable of improving the efficiency of the absorber and the evaporator and improving the reliability of the refrigeration cycle.

[Means for Solving the Problems]

The above-mentioned object is an absorption chiller-heater equipped with an evaporator, an air-cooled absorber and a regenerator, in which a combination of an evaporator and an air-cooled absorber is arranged in multiple stages, and the absorption liquid sprayed on the air-cooled absorber is Air-cooled absorbers with different concentrations in each stage, with air-cooled absorbers spraying the most concentrated absorber liquid to air-cooled absorbers spraying the rarest absorbent liquid are connected in series and arranged in series. In contrast, the evaporator that contains the coldest hot water is combined with the air-cooled absorber that sprays the rarest absorbing liquid, and the evaporator that contains the coldest cold water is the air-cooling absorber that sprays the thickest absorbing liquid. These multi-stage evaporators are connected in series in combination with, and the air-cooled absorber is composed of a plurality of vertical pipes in each stage and an absorption liquid tank for storing the absorption liquid located under each of these vertical pipes, Separate multiple vertical tubes The cold absorber divided, this divided portion of the air-cooled absorber the absorption liquid is circulated again to be improved absorbency can be achieved by.

[Action]

The evaporating temperature (evaporating pressure) of the refrigerant gradually decreases as the temperature of the cold water, which has the highest temperature, changes from the evaporator, which has the lowest temperature. Therefore, the difference between the cold water temperature and the refrigerant temperature can be made substantially uniform and large, and as a result, the evaporation efficiency of the evaporator is improved.

〔Example〕

FIG. 1 is a system diagram of an absorption chiller-heater according to the present invention, which is an embodiment in which an evaporator and an air-cooled absorber are composed of two stages. In the figure, a heat transfer tube for introducing the first evaporator 1
The refrigerant spray pipe 3 is composed of two refrigerant spray pipes 3, and a refrigerant spray pump 5 for circulating the refrigerant 4 is connected to the refrigerant spray pipe 3. A first air-cooling absorber 6 using the atmosphere as a cooling medium, a vertical heat transfer tube 7, an air-cooling fin 8 fitted in the vertical heat transfer tube 7,
Absorption liquid spray pipe 9, Absorption liquid tank 11 for temporarily retaining the absorption liquid 10
An absorption liquid spray pump 12 for circulating an absorption liquid 10 is connected to the absorption liquid spray pipe 9. The evaporator 1 and the air-cooled absorber 6 are connected by a duct 13. The second evaporator 14 is also composed of a heat transfer pipe 15 for introducing cold water and a refrigerant spray pipe 16 similarly to the above-mentioned first evaporator 1, and a refrigerant spray pump for circulating the refrigerant 4 in the refrigerant spray pipe 16. 17 connected. The second air-cooled absorber 18, which uses the atmosphere as a cooling medium, is a vertical heat transfer device 19 and a vertical heat transfer tube.
Air-cooled fin 20 inserted into 19, absorption liquid spray tube 21, absorption liquid 10
An absorption liquid spray pump that circulates the absorption liquid in the absorption liquid spray pipe 21.
23 is connected. The evaporator 14 and the air-cooled absorber 18 are connected by a duct 24. The pipe 25 connects the heat transfer pipe 2 in the first evaporator 1 and the heat transfer pipe 15 in the second evaporator 14, and the pipe 26 connects the refrigerant spray pipe 3 in the first evaporator 1 and the second pipe. The refrigerant spray pipe 16 of the evaporator 14 is connected, and the pipe 27 is connected to the absorption liquid tank 11 of the first air-cooled absorber 6 and the absorption liquid tank 23 of the second air-cooled absorber 18.

Next, the operation of the air-cooled absorption type chiller-heater having the above structure will be described.

In the first evaporator 1, the refrigerant spray pump 5 sprays the liquid refrigerant 4 from the refrigerant spray pipe 3 onto the surface of the heat transfer pipe 2. Here, the cold water and the liquid refrigerant passing through the heat transfer tube 2 exchange heat. By utilizing this cold water, the cooling effect can be obtained. The refrigerant vapor that has exchanged heat with cold water and evaporated on the surface of the heat transfer tube 2 flows into the air-cooled absorber 6 through the duct 13. Here, the absorption liquid 10 is sprayed from the absorption liquid spray pipe 9 to the vertical heat transfer pipe 7 by the absorption liquid spray pump 12. The absorbing liquid 10 flows down on the inner surface of the vertical heat transfer tube 7 while absorbing the refrigerant vapor and being cooled by the cooling air Air flowing in the arrow direction at the same time. A part of the flowing down absorption liquid 10 is again circulated by the absorption liquid spray pump 12 and sprayed from the absorption liquid spray pipe 9, but a part is sent to a regenerator (not shown), and the cycle of the water cooler Circulate through the system. On the other hand, the cold water that has exchanged heat with the refrigerant 4 in the heat transfer tube 22 is further sent to the second evaporator 14 and exchanges heat with the liquid refrigerant as described above. Also, the second
Part of the absorption liquid 10 that has absorbed the refrigerant vapor in the air-cooled absorber 18 is circulated by the absorption liquid spray pump 23 and sprayed from the absorption liquid spray pipe 12, but part of the absorption liquid 10 is absorbed in the first air-cooled absorber 6. It is sent and absorbs.

FIG. 2 is a schematic diagram of an embodiment in which the evaporator and the air-cooled absorber are configured in three stages. The evaporator has 3 stages (first stage evaporator 28, second stage
The stage evaporator 29, the third stage evaporator 30), and similarly, the absorber also has three stages (first stage absorber 31, second stage absorber 32, third stage absorber 33). Furthermore, the third stage evaporator 30 and the first stage absorber 31, the second stage evaporator 29 and the second stage absorber 32, the first stage evaporator
28 and the third stage absorber 33 are arranged so as to be paired with each other. Cold water is the first-stage evaporator 28 → the second-stage evaporator as shown by the arrow.
Flows in the order of 29 → third stage evaporator 30. Further, the absorbing liquid flows in the order of the first-stage absorber 31, the second-stage absorber 32, and the third-stage absorber 33. FIG. 3 is a diagram showing the temperature difference and the absorption capacity in each stage of the evaporator and the absorber in the case of the above configuration. As is clear from the figure, the temperature difference between the cold water temperature t and the refrigerant vapor temperature Ts is large even in the third stage (about 1.5 ° C.), the effect of heat exchange is improved, and the evaporation amount can be made uniform. Moreover, since the concentration ξ of the absorbing liquid is determined from ξ = f (Tl, Ts), it can be made rare.

As shown in Fig. 4, one evaporator and one
When a pair of individual absorbers is configured, the difference between the cold water temperature t and the refrigerant evaporation temperature Ts can be made large at the cold water inlet side, but the difference between the cold water outlet side is small (about 1.0
C.), which reduces the efficiency of heat exchange on the outlet side and generally reduces the effect of heat exchange. Therefore, the absorption liquid concentration ξ does not decrease as is clear from the above equation.

As described above, according to this embodiment, the heat exchange efficiency in the evaporator is improved, so that the size of the evaporator can be reduced, and the concentration of the absorbing liquid can be reduced. Can be prevented and the reliability of the refrigeration cycle is improved.

FIG. 5 is a schematic view of still another embodiment of the present invention, in which the air-cooled absorber is further subdivided. That is, the first-stage absorber 34, the second-stage absorber 35, and the third-stage absorber 36 are divided into two parts, and a part of the absorbing liquid discharged from the first-stage absorber 34a is absorbed again into the first-stage absorber. Circulating another part of the absorbing liquid to the second-stage absorber 35a, circulating the absorbing liquid leaving the first-stage absorber 34b to the second-stage absorber 35b, and 2nd stage absorber 3
The absorbents discharged from 5a and 35b are circulated to the third stage absorbers 36a and 36b, respectively, and the absorbents discharged from the third stage absorber 36a are transferred to the third stage absorber 36b.
To recycle. 2 each absorber like this
By dividing it, it is possible to further improve the absorption performance in each absorber and reduce the concentration of the absorption liquid,
The absorption liquid can be prevented from crystallizing, and the reliability of the chiller / heater can be improved.

The heat exchange efficiency and the reliability are further improved not only by the above-described embodiments but also by further increasing the number of stages of the evaporator and the absorber and subdividing the absorber.

〔The invention's effect〕

According to the present invention, it is possible to improve the heat exchange efficiency of the evaporator by arranging the evaporator and the absorber in multiple stages and arranging the multistage evaporator and absorber in pairs. Since it is possible to reduce the concentration of the absorbing liquid, it is possible to reduce the size of the absorption chiller-heater and improve its reliability.

[Brief description of drawings]

FIG. 1 is a system diagram of an embodiment of an absorption chiller-heater according to the present invention, FIG. 2 is a schematic view of another embodiment, FIG. 3 is an illustration of temperature distribution and absorption capacity, and FIG. 4 is conventional. FIG. 5 is an explanatory view of the temperature distribution and absorption capacity of the product, and FIG. 5 is an explanatory view of still another embodiment. 1,14,28,29,30 …… Evaporator, 2,15 …… Heat transfer tube, 3,16 ……
Refrigerant spray pipe, 5,17 ... Refrigerant spray pump, 6,18,31,3
2,33,34a, 34b, 35a, 35b, 36a, 36b …… Air-cooled absorber, 7,19…
… Vertical heat transfer tubes, 8,20 …… Heat transfer fins, 9,21 …… Absorption liquid spray tubes, 11,22 …… Absorption liquid tanks, 12,23 …… Absorption liquid spray pumps.

Front page continued (72) Inventor Kyoji Kono 603 Jinritsu-cho, Tsuchiura-shi, Ibaraki Hitate Works Co., Ltd. Tsuchiura Plant (72) Inventor Hiroyasu Anan 603 Kintachi-cho, Tsuchiura-shi Ibaraki Co., Ltd. (72) Inventor ▲ Yoshi ▼ Toshiro I, 603 Kitsudachi, Tsuchiura, Ibaraki Prefecture, inside the Hirate Factory Tsuchiura Plant (72) Inventor, Tomihisa Ouchi, 502, Jinmachi, Tsuchiura, Ibaraki Machinery Research Institute, Hitachi Ltd. Examiner Toru Uehara (56) References JP-A-60-245973 (JP, A) JP-A-62-202972 (JP, A)

Claims (1)

[Claims] 1. An absorption chiller-heater equipped with an evaporator, an air-cooled absorber and a regenerator, in which a combination of an evaporator and an air-cooled absorber is arranged in multiple stages and the absorbent is sprayed on the air-cooled absorber. The concentration is different in each stage, and the air-cooled absorber that sprays the most concentrated absorbent is sprayed from the air-cooled absorber that sprays the most concentrated absorbent. For the vessel, combine the evaporator that contains the hottest cold water with the air-cooled absorber that sprays the rarest absorption liquid, and the evaporator that contains the coldest cold water the air-cooled absorption that sprays the thickest absorption liquid. These multi-stage evaporators are connected in series in combination with a vessel, and the air-cooled absorber is composed of a plurality of vertical pipes in each stage and an absorption liquid tank located under each of these vertical pipes to store the absorption liquid. , Separate multiple vertical tubes The cold absorber divided, absorption chiller being characterized in that so as to increase the absorbability of the absorbent solution is circulated again to the air-cooled absorber part that this division.