JPH0752039B2 - Air-cooled absorption chiller / heater - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an air-cooled absorption chiller-heater, and more particularly to an air-cooling absorption chiller-heater capable of maintaining a low pressure in the chilled-water circulation pipe.

[Prior Art] As a conventionally known art, for example, as shown in FIG.
There is one disclosed in Japanese Patent Application No. 60-179954 (Japanese Patent Laid-Open No. 62-66068). In this air-cooled absorption chiller-heater, a three-way valve 12 is provided on the outlet side of the circulating water pump 15, and the three-way valve 12
One outlet is connected to the evaporator 7, the other outlet is connected to the water heater 24 provided in the separator 2, and the circulation water pipes connected to the outlets of the evaporator 7 and the water heater 24 are one. After merging, it is connected to the destination of cold and hot water.

During the cooling operation, the opening / closing valves 14 and 15 provided in the pipelines 26 and 27 are opened, the three-way valve 12 is operated to connect the circulating water pump 15 and the evaporator 7, and the circulating water pump 15 sends The circulated water that has passed through the three-way valve 12 passes through the evaporator 7, is cooled by the refrigerant that evaporates on the outer surface of the evaporator 7, and then flows into the use destination of the cold water.

During heating operation, the on-off valves 14 and 15 are closed and the three-way valve
12 is operated to connect the circulating water pump 12 and the water heater 24. The circulating water sent from the circulating water pump 15 is heated by the water heater 24 and then flows to the hot water use destination.

[Problems to be Solved by the Invention]

In the conventional steam technology, a water heater that exchanges heat with the refrigerant vapor to generate hot water is provided in the separator where hot refrigerant vapor is generated even during the cooling operation, and the inside of the water heater is Since the structure is such that the circulating water is constantly filled and the generation of cold / hot water is switched by the three-way valve provided in the cold / hot water circulation pipe, the following state occurs.

(1) The circulating water in the water heater is heated by the refrigerant vapor even during the cooling operation, and is heated to a temperature determined by the temperature of the refrigerant vapor and the pressure of the circulating water. The refrigerant vapor temperature in the separator of the air-cooled double-effect absorption chiller / heater is 150 to 200 ° C higher than that of the water-cooled absorption chiller / heater, which is higher than the saturated boiling temperature of the circulating water, so the circulating water is warm water. It boils in the vessel and causes heat loss.

(2) The saturated boiling pressure of water when the refrigerant vapor temperature is 150 ° C to 200 ° C is 4.8 to 15.85 kg / cm ² , and when trying to prevent boiling in the circulating water system, the pressure in the circulating water system becomes high. It is necessary to keep it at a certain level, and the safety is also secured when the pressure vessel is used, which causes an increase in equipment cost.

(3) A large three-way valve is required to switch the flow of circulating water having a large flow rate in order to switch the generation of cold / hot water.
This leads to an increase in equipment costs.

An object of the present invention is to reduce heat loss due to boiling of circulating water during cooling operation without inducing high pressure of the circulating water system.

[Means for Solving the Problems]

The above-mentioned problems include a high temperature regenerator that heats a dilute solution that has absorbed a refrigerant, a separator that separates the refrigerant vapor and the solution obtained by the high temperature regenerator, and condenses the refrigerant vapor into a liquid refrigerant. A condenser, an evaporator that evaporates the liquid refrigerant to exchange heat with the circulating water to cool the circulating water, and heat generated by absorbing the refrigerant vapor evaporated in the evaporator into the solution separated in the separator. In the air-cooled absorption chiller-heater equipped with an absorber that removes air by cooling, a water heater that heats circulating water using the refrigerant vapor obtained in the separator as a heating source, and a circulating water pump that circulates the circulating water, The water heater is installed separately from the separator,
And the water heater and the separator are connected by at least two refrigerant flow paths, and at least a refrigerant in the refrigerant flow path is provided with a valve in the flow path from the water heater to the separator. And the circulating water pump, the evaporator, and the water heater are connected in series.

Further, the water heater may be a double-pipe heat exchanger, and the air-cooled absorption cold water heater may be the air-cooled absorption cold water heater, wherein the double-pipe heat exchanger is formed in a horizontal coil shape. May be

Further, the air-cooled absorption chiller-heater according to claim 1 may be a water heater which is a plate heat exchanger.

[Action]

During the heating operation, the refrigerant vapor guided from the separator exchanges heat with the hot water circulating in the water heater, condenses into refrigerant liquid and returns to the separator through the on-off valve 29. The refrigerant liquid returned to the separator is mixed with the solution accumulated in the lower part of the separator, is guided to the high temperature regenerator through the conduit 19, is heated and separated by the separator, and is again heated by hot water to form this cycle. To do. Next, since the on-off valve 29 is closed during the cooling operation, the conduit for guiding the refrigerant vapor from the separator and exchanging heat with the hot water and the inside of the heat exchanger section are filled with the condensed refrigerant liquid, and after the inside is full, the refrigerant is filled. Inflow of steam, that is, heat, disappears, and since the circulating water pump, the evaporator, and the water heater are connected in series, the circulating water flows through the water heater even during the cooling operation, and there is no stagnant portion of the circulating water. The circulating water does not get hot.

If the double-tube heat exchanger is a water heater, the heat exchange area is large with respect to the volume of the refrigerant portion, so the volume of the refrigerant portion is small with respect to the same heat exchange area.

The thickness (height) of the water heater in the vertical direction can be reduced by forming the double-tube heat exchanger in the shape of a horizontal coil, or by using the plate heat exchanger as a water heater with its plate almost horizontal. can do.

〔Example〕

A first embodiment of the present invention will be described with reference to FIG. The air-cooled double-effect absorption chiller-heater shown in the figure has a high temperature regenerator 1 for heating a dilute solution, a separator 2 for separating a refrigerant vapor and an intermediate concentrated solution from the dilute solution heated by the high temperature regenerator 1, The high temperature heat exchanger 3 for exchanging heat between the intermediate concentrated solution and the dilute solution before flowing into the high temperature regenerator 1, is connected to the intermediate concentrated solution outlet of the high temperature heat exchanger 3 by the intermediate concentrated solution circuit 26, and Separator 2
The low-temperature regenerator 4 that generates heat by exchanging heat between the refrigerant vapor separated in step 3 and the intermediate concentrated solution that has passed through the high-temperature heat exchanger 3 and that generates a concentrated solution, and the intermediate concentrated solution circuit. Valve 14 installed in 26 and the low temperature regenerator 4
In the low-temperature heat exchanger 5 for exchanging heat between the concentrated solution generated in 1) and the dilute solution before flowing into the high-temperature heat exchanger 3, the refrigerant vapor outlet which is a heating medium of the low-temperature regenerator 4, and the refrigerant circuit 27. A condenser 6 which is connected and condenses the inflowing refrigerant vapor into a liquid refrigerant, a valve 15 provided in the refrigerant circuit 27, and a condenser 6 are connected by a liquid refrigerant flow path to evaporate the liquid refrigerant. An evaporation chamber 40 having the evaporator 7 installed therein is provided, which is provided so as to communicate with the evaporation chamber 40, and the refrigerant vapor evaporated in the evaporator 7 is absorbed by the concentrated solution that has passed through the low temperature heat exchanger 5 to generate a dilute solution. An absorber 8 for making it cool, an air cooling fan 16 for removing the condensation heat of the condenser 6 and the absorption heat of the absorber 8 by air cooling, a diluted solution produced in the absorber 8 by a check valve 18, a low temperature heat exchanger. 5 through the high temperature heat exchanger 3 and the solution pump 9 that feeds the high temperature regenerator 1 to the high temperature regenerator 1. Heater 10, solution bypass pipe 19 that communicates the lower part of the liquid level of separator 2 with the lower part of high-temperature regenerator 1, and water heater connected to separator 2 via refrigerant lines 28a and 28b. 11 and a valve 29 installed in the refrigerant line 28b
A hot water coil 41 that is installed in the water heater 11 to circulate circulating water; a circulating water pump 13; and a circulating water pipe 42 that connects the circulating water pump 13, the evaporator 7 and the warm water coil 41 in series.
And are equipped with.

During the heating operation, the valves 14 and 15 are closed, the valve 29 is opened, and the high temperature regenerator 1 is heated by the heater 10. The refrigerant evaporates in the separator 2 from the heated dilute solution, and the refrigerant line 28
It flows into the water heater 11 via a, exchanges heat with the circulating water in the hot water coil 41, and then returns to the separator 2 via the valve 29 and the refrigerant pipe line 28b. The refrigerant that has recirculated to the separator 2 is mixed with the solution at the bottom of the separator 2 to form a dilute solution, which then recirculates to the high temperature regenerator 1 via the solution bypass pipe 19. The refluxed dilute solution repeats the above cycle. The circulating water is driven by the circulating water pump 13,
After flowing through the evaporator 7, the hot water 11 flows into the hot water coil 41 where it is heated by heat exchange with the refrigerant vapor in the hot water coil 41 and flows into the hot water use destination. valve
Since 14 and 15 are closed, the liquid refrigerant does not flow into the evaporation chamber 40 and the liquid refrigerant does not evaporate, so that heat exchange with the circulating water flowing through the evaporator 7 is not performed.

During the cooling operation, the valve 29 is closed and the valves 14 and 15 are opened.
The heater 10 heats the dilute solution in the high temperature regenerator 1,
The refrigerant vapor and the intermediate concentrated solution are separated by the separator 2, and the refrigerant vapor heats the intermediate concentrated solution in the low temperature regenerator 4 to generate a new refrigerant vapor, and then passes through the refrigerant circuit 27 and the valve 15 to the condenser 6 Flows in, is condensed, and becomes a liquid refrigerant. The refrigerant vapor generated in the low temperature regenerator 4 also flows into the condenser 6 and is condensed to become a liquid refrigerant. The liquid refrigerant generated in the condenser 6 is supplied to the evaporation chamber 40 and takes heat of evaporation from the circulating water flowing in the evaporator 7 to be evaporated. The intermediate concentrated solution exchanges heat with the dilute solution in the high temperature heat exchanger 3, then flows into the low temperature regenerator 4 through the valve 14, and is heated by the refrigerant vapor to evaporate the refrigerant to become a concentrated solution. This concentrated solution is heat-exchanged with the dilute solution in the low temperature heat exchanger 5, and then is sprayed to the absorber 8 to absorb the refrigerant vapor evaporated in the evaporation chamber 40 and maintain the evaporation chamber 40 at a predetermined low pressure. The condensation heat generated in the condenser 6 and the absorption heat generated in the absorber 8 are air-cooled by the air cooling fan 16. The concentrated solution that has absorbed the refrigerant vapor becomes a dilute solution, and the solution pump 9 causes the check valve 18, the low temperature heat exchanger 5,
It is sent to the high temperature regenerator 1 via the high temperature heat exchanger 3. As described above, the circulating water sent from the circulating water pump 13 is cooled by the evaporator 7 and then flows through the hot water coil 41 of the water heater 11 to the cold water use destination. Since the valve 29 interposed in the refrigerant pipe 28b connecting the water heater 11 and the separator 2 is closed, the refrigerant that has exchanged heat with the circulating water flowing in the hot water coil 41 and condensed is accumulated in the water heater. Since there is no new inflow of refrigerant vapor into the water heater after the refrigerant is full in the water heater, the circulating water is not heated by the refrigerant steam and the amount of heat loss is eliminated.

As described above, according to the present embodiment, during cooling operation, there is no fear of circulating water boiling in the water heater, and there is no need to keep the pressure in the circulating water pipe at a high pressure, so the device cost can be reduced and at the same time safety is ensured. It is easy to secure the sex. In addition, since switching between the hot and cold water operation is performed by opening and closing a valve provided in the pipeline through which the refrigerant and the absorbing liquid flow, it is not necessary to provide a large diameter three-way valve of the circulating water pipe.

FIG. 2 shows a second embodiment of the present invention. This embodiment is the first
The water heater in the embodiment shown in the figure is a double-tube heat exchanger 30, the amount of the condensed refrigerant liquid is very small, and the condensed refrigerant has little effect on others, and the crystallization of the absorbing liquid. It is economical, because the amount of solution held in the entire system is small, and the start-up of heating / cooling operation is quick.

FIG. 3 shows a third embodiment of the present invention. In this embodiment, the double-tube heat exchanger of the embodiment shown in FIG. 2 is used as a horizontal coil heat exchanger 31. The driving force for returning the refrigerant liquid condensed during the heating operation to the separator 2 through the valve 29 is
Only the liquid column height of the refrigerant liquid, and as shown in the figure, the heat exchanger height is set so that the liquid column height H serving as the driving force becomes high.
It is effective to lower H ₀ .

FIG. 4 shows a fourth embodiment of the present invention. In this embodiment, the water heater is a plate-type heat exchanger 32, and the plates constituting the heat exchanger are installed so as to be substantially horizontal, so that the heat exchanger height H ₀ can be reduced.

Although the above-mentioned embodiment provides the present invention to an air-cooled double-effect absorption chiller-heater, it can be applied to an air-cooled single-effect absorption chiller-heater similarly.

〔The invention's effect〕

According to the present invention, the water heater is provided as a separate body from the separator, and of the refrigerant flow paths connecting the water heater and the separator, at least a refrigerant is provided in the refrigerant flow path from the water heater to the separator. Since the evaporator, the water heater and the circulating water pump are connected in series, it is possible to prevent the circulating water in the water heater from boiling during the cooling operation without increasing the pressure of the circulating water.
There is an effect that the device cost can be reduced.

According to the second aspect of the present invention, since the amount of condensed refrigerant stored in the water heater during the cooling operation can be reduced, there is no fear of crystallization of the absorbing liquid, and the amount of solution held in the entire system is reduced. Since it is small, it has the effect of speeding up the start-up of cooling and heating operation.

According to the present invention as set forth in claims 3 and 4, since the height of the water heater can be reduced, it is possible to increase the driving force for returning the liquid refrigerant stored in the hot water to the separator.
This has the effect of facilitating the return of the liquid refrigerant to the separator.

[Brief description of drawings]

FIG. 1 is a system diagram showing a first embodiment of the present invention, FIG.
3 and 4 are system diagrams showing parts of the second, third and fourth embodiments of the present invention, and FIG. 5 is a system diagram showing an example of the prior art. 1 ... High temperature regenerator, 2 ... Separator, 6 ... Condenser, 7 ...
… Evaporator, 8 …… Absorber, 11 …… Water heater, 13 …… Circulating water pump, 28a, 28b …… Refrigerant passage, 29 …… Valve provided in the refrigerant passage, 30 …… Water heater (two Heavy type heat exchanger), 31 ... water heater (horizontal coil shape heat exchanger), 32 ... water heater (plate type heat exchanger).

Claims (4)

[Claims] 1. A high temperature regenerator that heats a dilute solution that has absorbed a refrigerant, a separator that separates the refrigerant vapor and the solution obtained by the high temperature regenerator, and condenses the refrigerant vapor into a liquid refrigerant. A condenser, an evaporator that evaporates the liquid refrigerant to exchange heat with the circulating water to cool the circulating water, and heat generated by absorbing the refrigerant vapor evaporated in the evaporator into the solution separated in the separator. In the air-cooled absorption chiller-heater equipped with an absorber that removes air by cooling, a water heater that heats circulating water using the refrigerant vapor obtained in the separator as a heating source, and a circulating water pump that circulates the circulating water, The water heater is installed separately from the separator, and the water heater and the separator are connected by at least two refrigerant passages, and at least the refrigerant in the refrigerant passage is separated from the water heater. That a valve is installed in the flow path to the vessel Cooled absorption chiller that the circulating water pump and the evaporator and the water heater and in that connected in series. 2. The air-cooled absorption chiller-heater according to claim 1, wherein the water heater is a double pipe heat exchanger. 3. The air-cooled absorption chiller-heater according to claim 2, wherein the double-tube heat exchanger is formed in a horizontal coil shape. 4. The air-cooled absorption chiller-heater according to claim 1, wherein the water heater is a plate heat exchanger.