KR20050101113A - Absorption refrigerator - Google Patents

Abstract

An object of the present invention is to prevent the inoperability and the crystallization of the absorbent liquid from occurring due to an abnormal lowering of the cold water temperature even when the flow rate control of the discharged thermal fluid becomes impossible and the heat regeneration action to the absorbent liquid is excessively performed.

The heat transfer pipe 3B from which the discharged heat fluid supplied from other facilities flows is installed in the middle end portion of the discharge heat regenerator 3, and the sprayer 3C is disposed above the heat transfer pipe 3B, and the absorbent liquid discharge port is provided below. 3A is provided, and when the state of the flow control valve 13 deteriorates and the supply amount of the thermal fluid discharged from the discharge thermal fluid supply pipe 30 to the heat transfer pipe 3B becomes impossible, the absorption liquid pump 11 A controller 36 capable of stopping the operation or reducing the rotational speed to limit the amount of conveyed liquid from the absorber 7 to the exhaust heat regenerator 3 is provided.

Description

Absorption Chillers {ABSORPTION REFRIGERATOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerator using heat discharged from other equipment as a heat source of a regenerator for heating the absorption liquid and evaporating the refrigerant.

As this type of absorption refrigerator, for example, as shown in Fig. 3, the gas burner 1A is a regenerator that heats and boils the absorbent liquid and evaporates and separates the refrigerant sent to the evaporator 6. From a high temperature regenerator 1 using the combustion heat generated as a heating source of the absorbent liquid, a low temperature regenerator 2 using the refrigerant vapor supplied from the high temperature regenerator 1 as a heating source of the absorbent liquid, and other facilities such as a co-generation system. The absorption chiller 100X comprised with the exhaust heat regenerator 3 which makes the discharged heat fluid supplied as a heating source is well known (for example, refer patent document 1).

In the drawing, reference numeral 4 denotes a condenser provided in the low temperature regenerator 2 so that refrigerant vapor evaporated and separated from the absorbent liquid in the low temperature regenerator 2 is introduced, and 5 is evaporated and separated from the absorbent liquid in the exhaust heat regenerator 3. An exhaust heat condenser provided in the exhaust heat regenerator 3 so that refrigerant vapor can flow in, 7 is an absorber provided in the evaporator 6 so that refrigerant vapor evaporated in the evaporator 6 can be introduced, 8 is a low temperature heat exchanger, 9 is a high temperature heat exchanger, 10 is a refrigerant pump, 11 and 12 are absorbent liquid pumps, 13 is a three-way valve, a flow control valve 14 to 17 is an on-off valve, 18 to 23 is an absorbent liquid tube, 24 to 29 is a refrigerant tube, 30 Silver discharge heat fluid supply pipe, 31 is bypass pipe, 32 is cold and hot water pipe, 33 is cooling water pipe, 34 is equalizing pipe, and as shown in FIG. 3, the pipe wall of the heat transfer pipe 6A installed in the evaporator 6 by pipe connection Cooling / or heating to a predetermined temperature via Water, and is configured so as to be circulated through the heat load (not shown) supplied to the hot water pipe 32.

In the absorption chiller 100X having the above-described configuration, exhaust gas supplied from other equipment such as a co-generation system and the like through combustion heat emitted when burning natural gas or the like with the gas burner 1A and the discharge thermal fluid supply pipe 30 are discharged. Thermal efficiency is high because a heat fluid is heated and boiled as an absorption liquid as a heat source. Therefore, there is an advantage of saving resources and reducing the amount of carbon dioxide emissions.

[Patent Document 1]

Japanese Patent Laid-Open No. 8-54153

However, in the absorption chiller disclosed in Patent Literature 1, when the heat load is small, the flow rate of the discharged heat fluid supplied from other facilities such as a co-generation system and introduced into the exhaust heat regenerator cannot be controlled, thereby reducing the supply amount to the exhaust heat regenerator. In this case, a) the temperature of the cold water cooled and supplied by the evaporator is excessively lowered, and b) the exhaust heat regenerator is not emptied even when the absorption liquid pump is stopped. Therefore, the absorbent liquid remaining in the exhaust heat regenerator is discharged. There was a problem that the heating was continued by the thermal fluid and the concentration of the absorbing liquid proceeded excessively to crystallize.

Therefore, even if the flow rate control of the discharged thermal fluid becomes impossible and the heating and regenerating action for the absorbent liquid is excessively performed, it is necessary to prevent inoperability due to abnormal lowering of the cold water temperature or to prevent the absorbed liquid from crystallizing. It was becoming.

In order to solve the problems of the prior art, the present invention is provided with an exhaust heat regenerator in which discharged heat fluid supplied from another facility is used as a heat source for heating the absorbent liquid absorbing the refrigerant and evaporating and separating the refrigerant to concentrate the regenerated liquid. In one absorption chiller, a heat transfer pipe in which the heat fluid discharged in the middle end of the discharge heat regenerator flows is provided, and an absorber sprayer is installed above the heat transfer pipe and an absorption liquid discharge port is provided below, and discharged into the heat transfer pipe. It is a main feature to provide a control means capable of limiting the amount of conveyed liquid from the absorber to the discharge heat regenerator by stopping the operation of the absorbent liquid pump or reducing the rotation speed when the supply amount of the thermal fluid cannot be reduced.

A heat source for heating an absorbent liquid absorbing a refrigerant, and evaporating and separating the refrigerant to concentrate and regenerate the absorbent liquid, wherein the absorption chiller includes an exhaust heat regenerator in which discharged heat fluid supplied from another facility is used. The heat transfer pipe inside which the discharged heat fluid flows is installed, and the absorption liquid spreader is installed above the heat transfer tube, the absorption liquid discharge port is provided below, and the temperature of the cold water discharged from the evaporator is cooled by the refrigerant evaporated in the evaporator. When it is lower than the temperature, it is possible to stop the operation of the absorbent liquid pump by determining that the amount of discharged heat fluid supplied to the inside of the heat transfer pipe is inoperable or to limit the amount of conveyed liquid from the absorber to the discharge heat regenerator by reducing the rotation speed. Absorption chiller adapted to provide control means.

(First embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of this invention is described in detail based on FIG. The absorption chiller 100 of the present invention illustrated in FIG. 1 is an absorption chiller capable of circulating cold water or hot water to a load (not shown) by using water as a refrigerant and an aqueous lithium bromide (LiBr) solution as an absorption liquid. In addition, in FIG. 1, the same code | symbol is attached | subjected to the part which has the same function as the part demonstrated in FIG.

The main difference between the absorption chiller 100 of the present invention illustrated in FIG. 1 and the absorption chiller 100X shown in FIG. 3 lies in the configuration of the exhaust heat regenerator 3. That is, in the absorption chiller 100X shown in Fig. 3, the discharge port 3A of the absorbent liquid is provided at the middle end portion of the side wall of the discharge heat regenerator 3, and one end of the absorbent liquid tube 19 is provided at the discharge port 3A. The absorption liquid of the discharge heat regenerator 3 located in the position higher than the discharge port 3A is connected to the high temperature regenerator 1 by the operation of the absorption liquid pump 12 interposed in the absorption liquid pipe 19. In the absorption chiller 100 of the present invention illustrated in Fig. 1, the discharge port 3A of the absorbent liquid is provided at the bottom of the discharge heat regenerator 3, and one end of the absorbent liquid tube 19 is connected thereto.

In the absorption refrigerator 100X shown in Fig. 3, the heat transfer pipe 3B inside the discharge heat regenerator 3 to which the discharge heat fluid supply pipe 30 is connected to both ends is biased toward the bottom side of the discharge heat regenerator 3, In other words, in the absorption chiller 100 of the present invention illustrated in FIG. 1, the heat transfer pipe 3B is provided at the middle end of the discharge heat regenerator 3 in the portion lower than the discharge port 3A of the absorbent liquid provided at the middle end portion of the side wall. It is provided in a part, ie, the whole is located above 3 A of discharge ports of an absorption liquid.

In addition, in the absorption chiller 100 of the present invention, a spreader 3C is provided above the heat transfer pipe 3B, and one end of the absorbent liquid tube 18 is connected to the spreader 3C, and interposed in the absorbent liquid tube 18. The lean absorbent liquid in the absorber 7 in which the refrigerant is absorbed by the operation of the absorbent liquid pump 11 and the concentration is reduced is sprayed on the heat transfer pipe 3B.

In addition, a temperature sensor 35 is provided at the exit side of the evaporator 6 of the cold / hot water pipe 32 to exchange heat with the refrigerant through the pipe wall of the heat transfer tube 6A inside the evaporator 6, and to provide the latent heat when the refrigerant evaporates. The temperature of the cold / hot water cooled by cooling and discharged from the evaporator 6 is comprised so that measurement is possible. In addition, a controller for controlling the gas burner 1A, the refrigerant pump 10, the absorbent liquid pumps 11 and 12, the flow control valve 13 and the like based on the temperature of the cold / hot water measured by the temperature sensor 35 ( 36) is also installed.

In the absorption chiller 100 having the above-described configuration, the cooling water flows to the cooling water pipe 33 while the on-off valves 14 to 17 are closed, and the natural gas or the like is burned by the gas burner 1A and the discharge heat fluid. The absorbent liquid pump 11 is connected to the heat transfer tube 3B installed in the discharge heat regenerator 3 through the supply pipe 30 while flowing the discharged thermal fluid such as high temperature / high pressure steam or high temperature water supplied from a co-generation system or the like. By operating and spraying the absorbent liquid stored in the absorbent liquid reservoir of the absorber 7 onto the heat transfer pipe 3B from the spreader 3C, the refrigerant vapor separated from the absorbent liquid and the refrigerant vapor separated from the absorbent liquid are separated by a high temperature regenerator ( 1) and exhaust heat regenerator (3).

The high temperature refrigerant vapor generated in the high temperature regenerator 1 enters the low temperature regenerator 2 through the coolant tube 24, is concentrated in the high temperature regenerator 1, and the high temperature heat exchanger 9 by the absorbent liquid tube 20. The heat absorbed liquid entering the low temperature regenerator 2 is heated to condense heat, and enters the condenser 4.

In addition, the refrigerant vapor separated from the absorbing liquid by heating in the low temperature regenerator 2 enters the condenser 4 and heat-exchanges with the cooling water flowing in the cooling water pipe 33 to condense and condense from the refrigerant pipe 24. It enters the evaporator 6 through the refrigerant pipe 26 in one with the refrigerant supplied.

The high temperature refrigerant vapor generated in the discharge heat regenerator 3 also enters the discharge heat condenser 5 and exchanges heat with the cooling water flowing in the cooling water pipe 33 to condense the liquid, and the evaporator 6 through the refrigerant pipes 27 and 26. Enter).

The refrigerant liquid entering the evaporator 6 and stored in the refrigerant liquid reservoir is sprayed by the refrigerant pump 10 on the heat transfer pipe 6A to which the cold / hot water pipe 32 is connected, and circulated and supplied through the cold / hot water pipe 32. The water is evaporated by heat exchange to cool the water flowing inside the heat transfer pipe 6A.

Then, the refrigerant evaporated in the evaporator 6 enters the absorber 7 and is heated in the low temperature regenerator 2 to evaporate and separate the refrigerant, and the concentration of the absorbent liquid is further increased to reduce the low temperature by the regenerated absorbent liquid, that is, the absorbent liquid tube 21. It is supplied via the heat exchanger 8, and is absorbed by the concentrated absorption liquid sprayed from above.

Absorbent liquid whose absorbent refrigerant is absorbed by the absorber 7, and whose concentration is thin, that is, the lean absorbent liquid, is returned to the exhaust heat regenerator 3 via the low temperature heat exchanger 8 by the operation of the absorbent liquid pump 11, and the sprayer 3C. ) Is sprayed onto the heat transfer tube 3B and heated by heat exchange with the discharged heat fluid supplied from the discharge heat fluid supply pipe 30 as described above, and is concentrated by evaporating and separating the refrigerant.

When the operation is performed as described above, since the cold water cooled by the heat of vaporization of the refrigerant in the heat transfer pipe 6A in the evaporator 6 can be circulated and supplied to the heat load (not shown) via the cold / hot water pipe 32, cooling operation such as cooling Can be done.

In addition, the supply of the heat fluid discharged from the discharge heat fluid supply pipe 30 to the heat transfer pipe 3B takes precedence over the combustion of natural gas or the like in the gas burner 1A. That is, the controller 36 first controls the flow rate control valve 13 so that the temperature of the cold / hot water measured by the temperature sensor 35 is lowered to a predetermined set temperature, for example, 7 ° C, and discharged through the heat transfer pipe 3B. Even when the amount of the heated fluid is maximized, the absorber is heated by the gas burner 1A when the temperature of the cold / hot water measured by the temperature sensor 35 does not decrease to 7 ° C, which is the set temperature, and the high temperature regenerator 1 Also, the refrigerant vapor is generated and concentrated regeneration of the absorbent liquid is controlled so that the temperature of the hot and cold water cooled by the evaporator 6 and discharged to the hot and cold water pipe 32 is set to 7 ° C., which is a set temperature, and is heated by the gas burner 1A. If the temperature of the cold / hot water measured by the temperature sensor 35 does not rise to 7 ° C, which is the set temperature even when the amount is throttled to the minimum, the heating by the gas burner 1A is stopped, and the flow rate control valve 13 is again controlled to transfer the heat transfer pipe ( Drained thermal fluid to 3B) To throttle the feed rate, and is cooled by the evaporator (6) it consists of a hot water temperature of the discharged hot and cold water pipe 32 so that the 7 ℃ set temperature.

In the absorption chiller 100 of the present invention, since the discharge port 3A of the absorbent liquid of the exhaust heat regenerator 3 is provided at the bottom as described above, when the operation of the absorbent liquid pump 11 is stopped, the discharge heat regenerator is stopped. (3) The inside is empty. That is, since the operation of the absorbent liquid pump 12 is stopped by the controller 36 while the combustion of the gas burner 1A is stopped, the discharge heat regenerator () is caused by the pressure difference between the discharge heat regenerator 3 and the absorber 7. 3) The absorbent liquid in 3) is returned to the absorber 7 via the absorbent liquid pipes 19, 22, and 21, and the absorbent liquid pump 12 is also operated by the controller 36 during the combustion of the gas burner 1A. The absorbent liquid in (3) is sent to the high temperature and high temperature regenerator 1 through the absorbent liquid pipe 19.

Therefore, when the state of the flow control valve 13 worsens and it becomes impossible to restrict | limit the flow volume of the discharged heat fluid supplied from the discharge heat fluid supply pipe 30 to the heat transfer pipe 3B of the discharge heat regenerator 3, an absorbent liquid pump The operation amount of the absorbent liquid from the absorber 7 to the exhaust heat regenerator 3 is restricted so that the liquid level of the absorbent liquid in the discharge heat regenerator 3 is below the heat transfer pipe 3B by stopping the operation of (11) or reducing the rotation speed. Therefore, even if the discharged thermal fluid such as high temperature / high pressure steam or high temperature water supplied from the co-generation system or the like is continuously supplied from the discharge thermal fluid supply pipe 30 to the heat transfer pipe 3B, the absorbent liquid is heated in the discharge heat regenerator 3. Since the amount of heat is suppressed or the amount of heating is suppressed, it is possible to eliminate the generation of refrigerant vapor in the exhaust heat regenerator 3 so that the absorbing liquid supplied to the absorber 7 does not crystallize.

Therefore, the operation of the absorbent liquid pump 1 is configured to be controlled by the controller 36 as shown in FIG. 2A based on the temperature of the cold / hot water measured by the temperature sensor 35.

That is, the controller 36 stops the absorbent liquid pump 11 while the temperature of the cold / hot water measured by the temperature sensor 35 rises to 5.5 ° C, for example, when it is 4.5 ° C or lower and 4.5 ° C or lower, and 5.5 It is comprised so that the control signal required for operating the absorbent liquid pump 11 may be output when it is in more than degreeC, and while it falls to 4.5 degreeC from the state of 5.5 degreeC or more.

Therefore, in the absorption chiller 100 of the present invention, the state of the flow control valve 13 worsens, and the discharged heat fluid supplied from the discharge heat fluid supply pipe 30 to the heat transfer pipe 3B of the discharge heat regenerator 3 is discharged. Even if the flow rate restriction is not possible and the heating by the gas burner 1A is stopped, the temperature of the cold and hot water cooled in the heat transfer pipe 6A of the evaporator 6 and discharged to the cold / hot water pipe 32 is lower than 4.5 ° C. When the sensor 35 measures it, the operation of the absorbent liquid pump 11 is stopped by the controller 36.

Therefore, the inside of the exhaust heat regenerator 3 becomes empty, and the discharged heat fluid such as high temperature / high pressure steam and high temperature water supplied from the nose generation system or the like is transferred from the discharge heat fluid supply pipe 30 to the heat transfer pipe 3B. Since the absorbent liquid is not heated in the exhaust heat regenerator 3 even if it is continuously supplied, there is no generation of refrigerant vapor in the exhaust heat regenerator 3, and the absorbent liquid is not excessively concentrated and crystallized.

The absorbent liquid pump 11 is, for example, as shown in FIG. 2B by the controller 36, that is, when the temperature of the cold / hot water measured by the temperature sensor 35 is, for example, 4.5 ° C. or lower, the absorbent liquid pump When the power frequency supplied to the electric motor for driving 11 is 0 Hz and the temperature of the cold / hot water is 5.5 ° C. or more, the prescribed maximum frequency, for example, 60 Hz, is set to 4.5 ° C. and 5.5 ° C. When it is in between, the electric power frequency given to an electric motor is proportional to the temperature of the said hot and cold water, and an electric power frequency may be selected and rotation may be controlled in this way.

In addition, in the absorption chiller 100 of the present invention having the above-described configuration, when the open / close valves 14 to 17 are opened and natural gas or the like is burned by the gas burner 1A, the absorption liquid in the high temperature regenerator 1 is heated and boiled. The refrigerant vapor is separated from the absorbing liquid and introduced into the absorber 7 via the refrigerant pipes 24 and 25, and the refrigerant vapor entering the evaporator 6 touches the tube wall of the heat transfer pipe 6A to condense. Since water flowing in the heat transfer pipe 6A is mainly heated by the heat of condensation of the refrigerant, heating operation such as heating can be performed by circulating the heated water to the load.

By the way, this invention is not limited to the said embodiment, A various deformation | transformation is possible in the range which does not deviate from the meaning described in the claim.

For example, the lean absorbent liquid which absorbs a refrigerant | coolant with the absorber 7, and the density | concentration fell, is first conveyed to the exhaust heat regenerator 3, and it concentrates, The concentrated absorbent liquid is returned to the low temperature regenerator 2, and it concentrates, Finally, the absorbent liquid pipe may be piped so as to be conveyed to the high temperature regenerator 1 and concentrated, and the lean absorbent liquid which absorbs the refrigerant through the absorber 7 and has a reduced concentration branches to the high temperature regenerator 1 and the discharge heat regenerator 3. And the absorbent liquid pipe may be piped so as to convey and concentrate the absorbed liquid concentrated in the high temperature regenerator 1 and the discharge heat regenerator 3 to the low temperature regenerator 2.

In addition, the refrigerant pipe 29 through which the on-off valve 17 is interposed may be provided like the absorption refrigerator 100X shown in FIG. 3, that is, between the downstream side of the refrigerant pump 10 and the absorber 7.

In addition, the absorption chiller may be provided without the high temperature regenerator 1 and the low temperature regenerator 2 and configured to circulate the absorbent liquid between the discharge heat regenerator 3 and the absorber 7.

In the absorption chiller of the present invention, when it is impossible to reduce the supply amount of the heat fluid discharged to the heat transfer pipe in the discharge heat regenerator, the absorbing liquid pump is stopped or the rotational speed is reduced to reduce the amount of transfer of the absorbent liquid from the absorber to the discharge heat regenerator. It is possible to limit.

Therefore, when the cooling load is small and the temperature of the cold water cooled and circulated and supplied by the evaporator is abnormally lowered, the operation of the absorbent liquid pump is stopped or the rotational speed is lowered so that the liquid level of the absorbent liquid is lower than that of the heat transfer pipe provided in the intermediate step of the exhaust heat regenerator. By limiting the amount of conveyance of the absorbent liquid from the absorber to the exhaust heat regenerator by reducing the temperature, the heating of the absorbent liquid can be eliminated or reduced by the thermal fluid discharged to the exhaust heat regenerator.

Therefore, since the generation of the refrigerant vapor in the discharge heat regenerator and the concentrated regeneration of the absorbent liquid are lost or decreased, the temperature of the cold water cooled and supplied by the evaporator is not abnormally lowered or the absorbent liquid is not crystallized.

1 is an explanatory view of an absorption refrigerator of the present invention.

2 is an explanatory diagram showing a control example of an absorbent liquid pump;

3 is an explanatory diagram of a prior art;

<Description of the symbols for the main parts of the drawings>

1: high temperature regenerator

2: low temperature regenerator

3: exhaust heat regenerator

3A: outlet (of absorbent liquid)

3B: heat pipe

3C: Duster

4: condenser

5: exhaust heat condenser

6: evaporator

6A: heat pipe

7: absorber

8: low temperature heat exchanger

9: high temperature heat exchanger

10: refrigerant pump

11, 12: absorbent pump

13: flow control valve (three-way valve)

14 to 17: on-off valve

18 to 23 absorber tube

24 to 29: refrigerant pipe

30: discharge heat fluid supply pipe

31: Bypass tube

32: cold and hot water pipe

33: cooling water pipe

34: equalization tube

35: temperature sensor

36 controller

100, 100X: Absorption Chiller

Claims (2)

An absorption chiller having an exhaust heat regenerator in which an absorbed heat fluid supplied from another facility is used as a heat source for heating an absorbent liquid absorbing a refrigerant, and evaporating and separating the refrigerant to concentrate the regenerated liquid. When a heat pipe discharged inside the heat pipe is installed, and an absorber sprayer is installed above the heat pipe and an absorber discharge port is provided below, the supply amount of the heat fluid discharged into the heat pipe becomes impossible. An absorption chiller comprising a control means capable of stopping the operation of the absorbent liquid pump or reducing the rotational speed to limit the amount of the absorbed liquid returned from the absorber to the discharge heat regenerator. The absorbing liquid according to claim 1, wherein when the temperature of the cold water cooled by the refrigerant evaporated in the evaporator and the temperature of the cold water discharged from the evaporator is lower than the set temperature, the control means determines that the supply amount of the discharged heat fluid into the heat transfer tube cannot be operated. Absorption freezer, characterized in that to stop the operation of the pump or to reduce the number of revolutions to limit the return of the absorbent liquid from the absorber to the exhaust heat regenerator.