JPS6024903B2 - Multiple effect absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Figure 11 shows the system of a conventional absorption refrigerating machine, in which the cylindrical body, which is sufficiently airtight and maintained in a high vacuum, is divided into upper and lower parts. A condenser 3 and a low-temperature regenerator 4 are built in the upper high-pressure chamber of the evaporator 1 and absorber 2, both of which are composed of a group of tubes through which the required fluid flows.

5 is a high temperature regenerator, 6 is a low temperature heat exchanger installed in the dilute absorption liquid system from the absorber 2 to the low temperature regenerator 4, 7 is a high temperature heat exchanger,
8 is a liner medium pump, 9 is a low-temperature absorption liquid circulation pump, 10 is a high-temperature absorption liquid pump, 11 is a cold soot liquid reservoir, and 12 is a dilute absorption liquid reservoir.

In FIG. 11, the refrigerant vapor that has been evaporated by the cooling effect in the evaporator 1 is absorbed by the absorption liquid in the absorber 2, and the absorption liquid decreases in concentration and loses its absorption capacity, and flows into the dilute absorption liquid reservoir 12 at the bottom. It can be accumulated.

This diluted absorption liquid is sent to the low-temperature regenerator 4 via a pipe 15, a low-temperature heat exchanger 6, and a pipe 16 by a low-temperature absorption liquid pump 9, and is heated by refrigerant vapor generated in a high-temperature regenerator 5, which will be described in detail later, to absorb the diluted liquid. Concentrate the liquid. The dilute absorption liquid is heated in the low-temperature regenerator 4 to evaporate and separate the soot, increasing the concentration of the absorption liquid. At this time, the evaporated refrigerant is condensed with cooling water in the condenser 3. On the other hand, the absorption liquid with increased concentration is pumped to the piping 17, the high temperature heat exchanger 7, and the piping 1 by the high temperature absorption liquid pump 10.
The absorbent liquid is sent to the high-temperature regenerator 5 via a filter 8, where it is heated by an external heat source to evaporate the cold soot and concentrate the absorbent liquid. The medium vapor evaporated in the high temperature regenerator 5 is transferred to the low temperature regenerator 4 as described above.
The soot is used for heating, and it condenses to become a cold soot liquid, which is led to the condenser 3, where it is cooled by cooling water, the temperature of which is further lowered, and then returns to the evaporator 1 through the piping 22 along with the refrigerant liquid, where it exerts a cooling effect. do. On the other hand, the concentrated absorption liquid concentrated in the high-temperature regenerator 5 passes through the pipe 19, the high-temperature heat exchanger 7, and the pipe 20, and further passes through the low-temperature heat exchanger 6 and the pipe 21, and then is sprayed from the spraying device, returns to the absorber 2, and is absorbed. perform an action. In addition, the liquid to be cooled is flowing in the evaporator tube of the evaporator 1, and the amount of heating of the high temperature regenerator 5 is adjusted by the signal from the temperature detection end 23 provided at the evaporator opening, and the cooling effect is adjusted to the required amount. Adjust to. Cooling water is flowed through the absorber tube of the absorber 2 as shown by the arrow, and the lower the temperature of the absorption liquid sprayed on the tube surface of the absorber 2, the greater the absorption capacity. It is designed to absorb the cold soot vapor generated by

Cooling water also flows in the condenser tube of the condenser 3 to cool the cold soot vapor and cold soot drain from the low-temperature regenerator 4. The lower part of the absorber 2 of the absorption chiller is extremely low, and as the pressure increases, non-condensable gas tends to accumulate, so it is necessary to discharge non-condensable gas to the outside from the lower part of the absorber 2 using a gas aeration device. 13 is a bleed pump for discharging the air.

Figure 12 shows the temperature, concentration, and pressure of each part in the above operating state when water is used as the cold soot and a lithium bromide aqueous solution is used as the absorption liquid.

In FIG. 12, the vertical axis shows the pressure, the mechanical axis shows the liquid temperature, and the Q curve shows the crystal limit.

■ indicates the state of the dilute absorption liquid at the outlet of the low-temperature heat exchanger 6, and the state of the dilute absorption liquid in ■ is a temperature of 7300 and a concentration of 58.
%. The point at which the cold soot evaporates in the low-temperature regenerator 4 is point (3), and the absorption liquid is concentrated and leaves the low-temperature regenerator 4 at the point (2) and is sent to the high-temperature regenerator from the high-temperature absorption liquid pump 101. The thermal efficiency of an absorption refrigerator increases as the amount of heat applied from the outside (in the refrigerator system of FIG. 11, the amount of heating in the high-temperature regenerator 5) is smaller than the refrigeration effect in the evaporator 1. If the amount of heating in the low-temperature regenerator 4 is reduced, the amount of evaporation of soot in the high-temperature regenerator 5 will be reduced, so increasing the temperature of the dilute absorption liquid in the low-temperature heat exchanger 6 is beneficial in terms of thermal efficiency. This is effective and reduces the temperature of the concentrated absorption liquid flowing into the absorber 2, thereby increasing the absorption capacity of the absorber 2.

(The temperature of the absorption liquid is low and the absorption capacity is large.) Therefore, as shown in FIG. 11, a conventional absorption refrigerator is provided with a low-temperature heat exchanger 6 at the position shown in FIG. Based on the same concept, a high temperature heat exchanger 7 can be provided between the low temperature regenerator 4 and the high temperature regenerator 5 to improve thermal efficiency, and this has been implemented. From the above point of view, the state of the dilute absorption liquid can be determined by the point ■ in Figure 12.
Bringing it closer to the point is very effective in increasing thermal efficiency, but when comparing the flow rates of the dilute absorption liquid and the concentrated absorption liquid, the flow rate of the concentrated absorption liquid is smaller due to the evaporation of the lining medium. It is difficult to make the point () completely coincide with the point (■), and if the point (■) is brought close to the point (■), the temperature of the concentrated absorption liquid at the outlet of the low-temperature heat exchanger 6 will decrease, and the absorption liquid will have an odor. When using a lithium chloride aqueous solution, the absorption liquid may crystallize, so the point (■) is usually lower than the point (2), and the temperature level is often the same.

'From the viewpoint of energy saving, the present invention provides a heat recovery device 1 between the outlet of the low temperature heat exchanger 6 of the dilute absorption liquid system and the low temperature regenerator 4.
4, and by guiding a low-temperature heat source such as hot water obtained from solar heat or hot water obtained from factory scarlet heat to the heat recovery device 14, crystallization of the concentrated absorption liquid near the outlet of the low-temperature heat exchanger is achieved. It is possible to raise the temperature of the diluted absorbent liquid leaving the low-temperature heat exchanger without worrying about the temperature of the diluted absorbent liquid, and the temperature of the diluted absorbent liquid is kept low, so it is effective even with low-temperature heat sources such as the solar heat and factory waste heat. It has been made available.

To explain the embodiment shown in FIG. 13, the high temperature regenerator 5
Steam from a boiler, etc. is used as the heat source for the
As in the conventional example, the temperature of the absorption liquid in the high-temperature regenerator 5 is 1
There is about 64qC, and the drain of heated and condensed steam is 1
The temperature is around 60°C.

If this high-temperature drain is discharged from the high-temperature regenerator 5 to the atmosphere, significant heat loss will occur, so it is led to the heat recovery device 14 of the present invention, where the heat of the drain can be recovered and thermal efficiency can be increased. In FIG. 13, 24 is a trap for discharging only the steam drain, M 25 is a conduit that leads the steam drain to the heat recovery device 14, and 26 is a conduit that leads the refrigerant vapor generated in the heat recovery device 14 to the low temperature regenerator 4. This is a conduit that leads to the condenser 3 through the condenser. - In another embodiment shown in Figure 14, the high temperature regenerator 5
When combustion heat is used as a heat source, the combustion gas that has heated the absorption liquid in the high-temperature regenerator 5 is discharged at a high temperature.

This discharged combustion gas can be directly led to the heat recovery device 14 of the present invention through the conduit 27 to increase thermal efficiency. In the case of another embodiment shown in FIG. 16, as shown in FIG. 14, combustion exhaust gas is guided to a hot water heater 29 through a conduit 28 to heat hot water, and the heated hot water is disposed in an annular conduit 31 for hot water circulation. The pump 30 guides the heat to the heat recovery device 14 of the present invention and recovers the heat to improve thermal efficiency.

In another embodiment shown in FIG. 16, in addition to the low-temperature portion of the heating source discharged from the high-temperature regenerator 5 (FIG. 13), the heat source that is not used and is discarded is transferred to the heat recovery device 14. This system is designed to recover heat and improve thermal efficiency.

32 is a conduit that guides waste heat to the heat recovery device 14.

FIG. 17 shows yet another embodiment in which, if there is another low-temperature heat source, the heat source is not guided from the high-temperature regenerator 5, but is guided to the heat recovery device 14 of the present invention, It is possible to perform a refrigeration action, and the cold soot and absorption liquid circulation system as a refrigerator has the advantage that the operation system of a conventional absorption refrigerator can be used as is.

Therefore, it is possible to supply the heat source to the high-temperature regenerator 5 and operate it as usual.
It is also possible to introduce a heat source to both of 4 and use them together.

33 is a conduit that guides waste heat and the like to the heat recovery device 14.

As shown in each of the above embodiments, according to the present invention, a heat recovery device is provided in the dilute absorption liquid system between the low-temperature heat exchanger and the low-temperature regenerator, and the heat recovery device and the low-temperature regenerator are connected by a refrigerant vapor conduit. Since the wires are tied together, the effect of improving thermal efficiency and saving energy is extremely large.

[Brief explanation of the drawing]

Fig. 11 is a system diagram of a conventional double-effect absorption refrigerator, Fig. 12 is a characteristic curve diagram showing the temperature, concentration, and pressure of each part during operation of the refrigerator of Fig. 11, and Fig. 13 is a diagram of the characteristic curve of the refrigerator of the present invention. A system diagram showing one embodiment, FIGS. 14 and 15 are system diagrams showing different embodiments, FIG. 16 is a system diagram showing another embodiment, and FIG. 7 is a system diagram showing yet another embodiment. It is a system diagram showing another example. 1...Evaporator, 2...Absorber, 4...
...Low temperature regenerator, 5...High temperature regenerator, 6.
...low temperature heat exchanger, 7 ... high temperature heat exchanger, 14 ... heat recovery device. Figure 1A ■ Figure~ ■ Figure~ ■ Figure size■ Diagram・Figure 15

Claims (1)

[Claims] 1 The evaporator, absorber, condenser, low-temperature regenerator, high-temperature regenerator, and heat exchanger are arranged and connected to perform refrigeration, and low-temperature heat exchange is performed in the system that introduces the diluted absorption liquid from the absorber to the low-temperature regenerator. In a multi-effect absorption refrigerator equipped with a heat exchanger, a heat recovery device that is heated by a heat source is placed in the dilute absorption liquid system between the low-temperature heat exchanger and the low-temperature regenerator, and the heat recovery device and the low-temperature regenerator are A multi-effect absorption refrigerator characterized in that the dilute absorption liquid is heated and the refrigerant is evaporated to concentrate it by connecting it with a conduit.